Merge remote-tracking branch 'origin/dev' into wip/scenegraphng

Change-Id: Ib5662d80d5b2f58cf4634c54c054545ba9df807e

639 files changed, 70486 insertions, 53297 deletions

diff --git a/src/qml/animations/qabstractanimationjob.cpp b/src/qml/animations/qabstractanimationjob.cpp
index 1ac4925ed3..ece2f0d692 100644
--- a/src/qml/animations/qabstractanimationjob.cpp
+++ b/src/qml/animations/qabstractanimationjob.cpp
@@ -70,17 +70,12 @@ QQmlAnimationTimer::QQmlAnimationTimer() :
 QQmlAnimationTimer *QQmlAnimationTimer::instance(bool create)
 {
     QQmlAnimationTimer *inst;
-#ifndef QT_NO_THREAD
     if (create && !animationTimer()->hasLocalData()) {
         inst = new QQmlAnimationTimer;
         animationTimer()->setLocalData(inst);
     } else {
         inst = animationTimer() ? animationTimer()->localData() : 0;
     }
-#else
-    static QAnimationTimer unifiedTimer;
-    inst = &unifiedTimer;
-#endif
     return inst;
 }
 
@@ -91,9 +86,8 @@ QQmlAnimationTimer *QQmlAnimationTimer::instance()
 
 void QQmlAnimationTimer::ensureTimerUpdate()
 {
-    QQmlAnimationTimer *inst = QQmlAnimationTimer::instance(false);
     QUnifiedTimer *instU = QUnifiedTimer::instance(false);
-    if (instU && inst && inst->isPaused)
+    if (instU && isPaused)
         instU->updateAnimationTimers(-1);
 }
 
@@ -128,9 +122,7 @@ void QQmlAnimationTimer::updateAnimationsTime(qint64 delta)
 
 void QQmlAnimationTimer::updateAnimationTimer()
 {
-    QQmlAnimationTimer *inst = QQmlAnimationTimer::instance(false);
-    if (inst)
-        inst->restartAnimationTimer();
+    restartAnimationTimer();
 }
 
 void QQmlAnimationTimer::restartAnimationTimer()
@@ -175,45 +167,38 @@ void QQmlAnimationTimer::registerAnimation(QAbstractAnimationJob *animation, boo
     if (animation->userControlDisabled())
         return;
 
-    QQmlAnimationTimer *inst = instance(true); //we create the instance if needed
-    inst->registerRunningAnimation(animation);
+    registerRunningAnimation(animation);
     if (isTopLevel) {
         Q_ASSERT(!animation->m_hasRegisteredTimer);
         animation->m_hasRegisteredTimer = true;
-        inst->animationsToStart << animation;
-        if (!inst->startAnimationPending) {
-            inst->startAnimationPending = true;
-            QMetaObject::invokeMethod(inst, "startAnimations", Qt::QueuedConnection);
+        animationsToStart << animation;
+        if (!startAnimationPending) {
+            startAnimationPending = true;
+            QMetaObject::invokeMethod(this, "startAnimations", Qt::QueuedConnection);
         }
     }
 }
 
 void QQmlAnimationTimer::unregisterAnimation(QAbstractAnimationJob *animation)
 {
-    QQmlAnimationTimer *inst = QQmlAnimationTimer::instance(false);
-    if (inst) {
-        //at this point the unified timer should have been created
-        //but it might also have been already destroyed in case the application is shutting down
-
-        inst->unregisterRunningAnimation(animation);
+    unregisterRunningAnimation(animation);
 
-        if (!animation->m_hasRegisteredTimer)
-            return;
+    if (!animation->m_hasRegisteredTimer)
+        return;
 
-        int idx = inst->animations.indexOf(animation);
-        if (idx != -1) {
-            inst->animations.removeAt(idx);
-            // this is needed if we unregister an animation while its running
-            if (idx <= inst->currentAnimationIdx)
-                --inst->currentAnimationIdx;
+    int idx = animations.indexOf(animation);
+    if (idx != -1) {
+        animations.removeAt(idx);
+        // this is needed if we unregister an animation while its running
+        if (idx <= currentAnimationIdx)
+            --currentAnimationIdx;
 
-            if (inst->animations.isEmpty() && !inst->stopTimerPending) {
-                inst->stopTimerPending = true;
-                QMetaObject::invokeMethod(inst, "stopTimer", Qt::QueuedConnection);
-            }
-        } else {
-            inst->animationsToStart.removeOne(animation);
+        if (animations.isEmpty() && !stopTimerPending) {
+            stopTimerPending = true;
+            QMetaObject::invokeMethod(this, "stopTimer", Qt::QueuedConnection);
         }
+    } else {
+        animationsToStart.removeOne(animation);
     }
     animation->m_hasRegisteredTimer = false;
 }
@@ -268,7 +253,7 @@ int QQmlAnimationTimer::closestPauseAnimationTimeToFinish()
 
 QAbstractAnimationJob::QAbstractAnimationJob()
     : m_loopCount(1)
-    , m_group(0)
+    , m_group(nullptr)
     , m_direction(QAbstractAnimationJob::Forward)
     , m_state(QAbstractAnimationJob::Stopped)
     , m_totalCurrentTime(0)
@@ -276,9 +261,9 @@ QAbstractAnimationJob::QAbstractAnimationJob()
     , m_currentLoop(0)
     , m_uncontrolledFinishTime(-1)
     , m_currentLoopStartTime(0)
-    , m_nextSibling(0)
-    , m_previousSibling(0)
-    , m_wasDeleted(0)
+    , m_nextSibling(nullptr)
+    , m_previousSibling(nullptr)
+    , m_wasDeleted(nullptr)
     , m_hasRegisteredTimer(false)
     , m_isPause(false)
     , m_isGroup(false)
@@ -302,8 +287,10 @@ QAbstractAnimationJob::~QAbstractAnimationJob()
         stateChanged(oldState, m_state);
 
         Q_ASSERT(m_state == Stopped);
-        if (oldState == Running)
-            QQmlAnimationTimer::unregisterAnimation(this);
+        if (oldState == Running) {
+            Q_ASSERT(QQmlAnimationTimer::instance() == m_timer);
+            m_timer->unregisterAnimation(this);
+        }
         Q_ASSERT(!m_hasRegisteredTimer);
     }
 
@@ -327,6 +314,9 @@ void QAbstractAnimationJob::setState(QAbstractAnimationJob::State newState)
     if (m_loopCount == 0)
         return;
 
+    if (!m_timer)
+        m_timer = QQmlAnimationTimer::instance();
+
     State oldState = m_state;
     int oldCurrentTime = m_currentTime;
     int oldCurrentLoop = m_currentLoop;
@@ -352,11 +342,11 @@ void QAbstractAnimationJob::setState(QAbstractAnimationJob::State newState)
     bool isTopLevel = !m_group || m_group->isStopped();
     if (oldState == Running) {
         if (newState == Paused && m_hasRegisteredTimer)
-            QQmlAnimationTimer::ensureTimerUpdate();
+            m_timer->ensureTimerUpdate();
         //the animation, is not running any more
-        QQmlAnimationTimer::unregisterAnimation(this);
+        m_timer->unregisterAnimation(this);
     } else if (newState == Running) {
-        QQmlAnimationTimer::registerAnimation(this, isTopLevel);
+        m_timer->registerAnimation(this, isTopLevel);
     }
 
     //starting an animation qualifies as a top level loop change
@@ -383,7 +373,7 @@ void QAbstractAnimationJob::setState(QAbstractAnimationJob::State newState)
                 m_currentLoop = 0;
                 if (isTopLevel) {
                     // currentTime needs to be updated if pauseTimer is active
-                    RETURN_IF_DELETED(QQmlAnimationTimer::ensureTimerUpdate());
+                    RETURN_IF_DELETED(m_timer->ensureTimerUpdate());
                     RETURN_IF_DELETED(setCurrentTime(m_totalCurrentTime));
                 }
             }
@@ -420,14 +410,14 @@ void QAbstractAnimationJob::setDirection(Direction direction)
     // the commands order below is important: first we need to setCurrentTime with the old direction,
     // then update the direction on this and all children and finally restart the pauseTimer if needed
     if (m_hasRegisteredTimer)
-        QQmlAnimationTimer::ensureTimerUpdate();
+        m_timer->ensureTimerUpdate();
 
     m_direction = direction;
     updateDirection(direction);
 
     if (m_hasRegisteredTimer)
         // needed to update the timer interval in case of a pause animation
-        QQmlAnimationTimer::updateAnimationTimer();
+        m_timer->updateAnimationTimer();
 }
 
 void QAbstractAnimationJob::setLoopCount(int loopCount)
diff --git a/src/qml/animations/qabstractanimationjob_p.h b/src/qml/animations/qabstractanimationjob_p.h
index 95a39b1301..0be6ca96ea 100644
--- a/src/qml/animations/qabstractanimationjob_p.h
+++ b/src/qml/animations/qabstractanimationjob_p.h
@@ -56,10 +56,14 @@
 #include <QtCore/private/qabstractanimation_p.h>
 #include <vector>
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class QAnimationGroupJob;
 class QAnimationJobChangeListener;
+class QQmlAnimationTimer;
+
 class Q_QML_PRIVATE_EXPORT QAbstractAnimationJob
 {
     Q_DISABLE_COPY(QAbstractAnimationJob)
@@ -168,6 +172,7 @@ protected:
 
     QAbstractAnimationJob *m_nextSibling;
     QAbstractAnimationJob *m_previousSibling;
+    QQmlAnimationTimer *m_timer = nullptr;
 
     bool *m_wasDeleted;
     bool m_hasRegisteredTimer:1;
@@ -203,20 +208,20 @@ public:
     static QQmlAnimationTimer *instance();
     static QQmlAnimationTimer *instance(bool create);
 
-    static void registerAnimation(QAbstractAnimationJob *animation, bool isTopLevel);
-    static void unregisterAnimation(QAbstractAnimationJob *animation);
+    void registerAnimation(QAbstractAnimationJob *animation, bool isTopLevel);
+    void unregisterAnimation(QAbstractAnimationJob *animation);
 
     /*
         this is used for updating the currentTime of all animations in case the pause
         timer is active or, otherwise, only of the animation passed as parameter.
     */
-    static void ensureTimerUpdate();
+    void ensureTimerUpdate();
 
     /*
         this will evaluate the need of restarting the pause timer in case there is still
         some pause animations running.
     */
-    static void updateAnimationTimer();
+    void updateAnimationTimer();
 
     void restartAnimationTimer() override;
     void updateAnimationsTime(qint64 timeStep) override;
diff --git a/src/qml/animations/qanimationgroupjob.cpp b/src/qml/animations/qanimationgroupjob.cpp
index ea6d87952a..66599561fc 100644
--- a/src/qml/animations/qanimationgroupjob.cpp
+++ b/src/qml/animations/qanimationgroupjob.cpp
@@ -42,7 +42,7 @@
 QT_BEGIN_NAMESPACE
 
 QAnimationGroupJob::QAnimationGroupJob()
-    : QAbstractAnimationJob(), m_firstChild(0), m_lastChild(0)
+    : QAbstractAnimationJob(), m_firstChild(nullptr), m_lastChild(nullptr)
 {
     m_isGroup = true;
 }
@@ -111,25 +111,21 @@ void QAnimationGroupJob::removeAnimation(QAbstractAnimationJob *animation)
     else
         m_lastChild = prev;
 
-    animation->m_previousSibling = 0;
-    animation->m_nextSibling = 0;
+    animation->m_previousSibling = nullptr;
+    animation->m_nextSibling = nullptr;
 
-    animation->m_group = 0;
+    animation->m_group = nullptr;
     animationRemoved(animation, prev, next);
 }
 
 void QAnimationGroupJob::clear()
 {
-    QAbstractAnimationJob *child = firstChild();
-    QAbstractAnimationJob *nextSibling = 0;
-    while (child != 0) {
-         child->m_group = 0;
-         nextSibling = child->nextSibling();
-         delete child;
-         child = nextSibling;
+    while (QAbstractAnimationJob *child = firstChild()) {
+        removeAnimation(child);
+        delete child;
     }
-    m_firstChild = 0;
-    m_lastChild = 0;
+    m_firstChild = nullptr;
+    m_lastChild = nullptr;
 }
 
 void QAnimationGroupJob::resetUncontrolledAnimationsFinishTime()
diff --git a/src/qml/animations/qanimationgroupjob_p.h b/src/qml/animations/qanimationgroupjob_p.h
index 26965c0264..a27c9195dd 100644
--- a/src/qml/animations/qanimationgroupjob_p.h
+++ b/src/qml/animations/qanimationgroupjob_p.h
@@ -54,6 +54,8 @@
 #include "private/qabstractanimationjob_p.h"
 #include <QtCore/qdebug.h>
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class Q_QML_PRIVATE_EXPORT QAnimationGroupJob : public QAbstractAnimationJob
@@ -61,7 +63,7 @@ class Q_QML_PRIVATE_EXPORT QAnimationGroupJob : public QAbstractAnimationJob
     Q_DISABLE_COPY(QAnimationGroupJob)
 public:
     QAnimationGroupJob();
-    ~QAnimationGroupJob();
+    ~QAnimationGroupJob() override;
 
     void appendAnimation(QAbstractAnimationJob *animation);
     void prependAnimation(QAbstractAnimationJob *animation);
@@ -70,7 +72,7 @@ public:
     QAbstractAnimationJob *firstChild() const { return m_firstChild; }
     QAbstractAnimationJob *lastChild() const { return m_lastChild; }
 
-    void clear();
+    virtual void clear();
 
     //called by QAbstractAnimationJob
     virtual void uncontrolledAnimationFinished(QAbstractAnimationJob *animation);
@@ -90,8 +92,8 @@ protected:
 
 private:
     //definition
-    QAbstractAnimationJob *m_firstChild;
-    QAbstractAnimationJob *m_lastChild;
+    QAbstractAnimationJob *m_firstChild = nullptr;
+    QAbstractAnimationJob *m_lastChild = nullptr;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/animations/qanimationjobutil_p.h b/src/qml/animations/qanimationjobutil_p.h
index 0bb9e83b2d..e3d6fe9178 100644
--- a/src/qml/animations/qanimationjobutil_p.h
+++ b/src/qml/animations/qanimationjobutil_p.h
@@ -51,6 +51,8 @@
 // We mean it.
 //
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 #define RETURN_IF_DELETED(func) \
 { \
     bool *prevWasDeleted = m_wasDeleted; \
diff --git a/src/qml/animations/qcontinuinganimationgroupjob.cpp b/src/qml/animations/qcontinuinganimationgroupjob.cpp
index 02dcaf1313..10096bf19c 100644
--- a/src/qml/animations/qcontinuinganimationgroupjob.cpp
+++ b/src/qml/animations/qcontinuinganimationgroupjob.cpp
@@ -43,7 +43,6 @@
 QT_BEGIN_NAMESPACE
 
 QContinuingAnimationGroupJob::QContinuingAnimationGroupJob()
-    : QAnimationGroupJob()
 {
 }
 
diff --git a/src/qml/animations/qcontinuinganimationgroupjob_p.h b/src/qml/animations/qcontinuinganimationgroupjob_p.h
index baf4ff1ae5..c67b8d39ad 100644
--- a/src/qml/animations/qcontinuinganimationgroupjob_p.h
+++ b/src/qml/animations/qcontinuinganimationgroupjob_p.h
@@ -53,6 +53,8 @@
 
 #include "private/qanimationgroupjob_p.h"
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class Q_QML_PRIVATE_EXPORT QContinuingAnimationGroupJob : public QAnimationGroupJob
diff --git a/src/qml/animations/qparallelanimationgroupjob_p.h b/src/qml/animations/qparallelanimationgroupjob_p.h
index 358b95ce53..0265fe3274 100644
--- a/src/qml/animations/qparallelanimationgroupjob_p.h
+++ b/src/qml/animations/qparallelanimationgroupjob_p.h
@@ -53,6 +53,8 @@
 
 #include "private/qanimationgroupjob_p.h"
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class Q_QML_PRIVATE_EXPORT QParallelAnimationGroupJob : public QAnimationGroupJob
@@ -76,8 +78,8 @@ private:
     void applyGroupState(QAbstractAnimationJob *animation);
 
     //state
-    int m_previousLoop;
-    int m_previousCurrentTime;
+    int m_previousLoop = 0;
+    int m_previousCurrentTime = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/animations/qpauseanimationjob.cpp b/src/qml/animations/qpauseanimationjob.cpp
index 27175580dc..0652ed578b 100644
--- a/src/qml/animations/qpauseanimationjob.cpp
+++ b/src/qml/animations/qpauseanimationjob.cpp
@@ -42,8 +42,7 @@
 QT_BEGIN_NAMESPACE
 
 QPauseAnimationJob::QPauseAnimationJob(int duration)
-    : QAbstractAnimationJob()
-    , m_duration(duration)
+    : m_duration(duration)
 {
     m_isPause = true;
 }
diff --git a/src/qml/animations/qpauseanimationjob_p.h b/src/qml/animations/qpauseanimationjob_p.h
index e228f46daa..6c9bbf0dab 100644
--- a/src/qml/animations/qpauseanimationjob_p.h
+++ b/src/qml/animations/qpauseanimationjob_p.h
@@ -53,6 +53,8 @@
 
 #include <private/qanimationgroupjob_p.h>
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class Q_QML_PRIVATE_EXPORT QPauseAnimationJob : public QAbstractAnimationJob
@@ -60,7 +62,7 @@ class Q_QML_PRIVATE_EXPORT QPauseAnimationJob : public QAbstractAnimationJob
     Q_DISABLE_COPY(QPauseAnimationJob)
 public:
     explicit QPauseAnimationJob(int duration = 250);
-    ~QPauseAnimationJob();
+    ~QPauseAnimationJob() override;
 
     int duration() const override;
     void setDuration(int msecs);
diff --git a/src/qml/animations/qsequentialanimationgroupjob.cpp b/src/qml/animations/qsequentialanimationgroupjob.cpp
index 25d31e4042..d98546122f 100644
--- a/src/qml/animations/qsequentialanimationgroupjob.cpp
+++ b/src/qml/animations/qsequentialanimationgroupjob.cpp
@@ -45,7 +45,7 @@ QT_BEGIN_NAMESPACE
 
 QSequentialAnimationGroupJob::QSequentialAnimationGroupJob()
     : QAnimationGroupJob()
-    , m_currentAnimation(0)
+    , m_currentAnimation(nullptr)
     , m_previousLoop(0)
 {
 }
@@ -87,7 +87,7 @@ QSequentialAnimationGroupJob::AnimationIndex QSequentialAnimationGroupJob::index
     Q_ASSERT(firstChild());
 
     AnimationIndex ret;
-    QAbstractAnimationJob *anim = 0;
+    QAbstractAnimationJob *anim = nullptr;
     int duration = 0;
 
     for (anim = firstChild(); anim; anim = anim->nextSibling()) {
@@ -204,6 +204,15 @@ int QSequentialAnimationGroupJob::duration() const
     return ret;
 }
 
+void QSequentialAnimationGroupJob::clear()
+{
+    m_previousLoop = 0;
+    QAnimationGroupJob::clear();
+
+    // clear() should call removeAnimation(), which will clear m_currentAnimation, eventually.
+    Q_ASSERT(m_currentAnimation == nullptr);
+}
+
 void QSequentialAnimationGroupJob::updateCurrentTime(int currentTime)
 {
     if (!m_currentAnimation)
@@ -283,7 +292,7 @@ void QSequentialAnimationGroupJob::setCurrentAnimation(QAbstractAnimationJob *an
 {
     if (!anim) {
         Q_ASSERT(!firstChild());
-        m_currentAnimation = 0;
+        m_currentAnimation = nullptr;
         return;
     }
 
@@ -364,7 +373,7 @@ void QSequentialAnimationGroupJob::uncontrolledAnimationFinished(QAbstractAnimat
 
 void QSequentialAnimationGroupJob::animationInserted(QAbstractAnimationJob *anim)
 {
-    if (m_currentAnimation == 0)
+    if (m_currentAnimation == nullptr)
         setCurrentAnimation(firstChild()); // initialize the current animation
 
     if (m_currentAnimation == anim->nextSibling()
@@ -393,7 +402,7 @@ void QSequentialAnimationGroupJob::animationRemoved(QAbstractAnimationJob *anim,
         else if (prev)
             setCurrentAnimation(prev);
         else// case all animations were removed
-            setCurrentAnimation(0);
+            setCurrentAnimation(nullptr);
     }
 
     // duration of the previous animations up to the current animation
diff --git a/src/qml/animations/qsequentialanimationgroupjob_p.h b/src/qml/animations/qsequentialanimationgroupjob_p.h
index 5fbafcb9ac..34e8fe1e08 100644
--- a/src/qml/animations/qsequentialanimationgroupjob_p.h
+++ b/src/qml/animations/qsequentialanimationgroupjob_p.h
@@ -53,6 +53,8 @@
 
 #include <private/qanimationgroupjob_p.h>
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class QPauseAnimationJob;
@@ -66,6 +68,7 @@ public:
     int duration() const override;
 
     QAbstractAnimationJob *currentAnimation() const { return m_currentAnimation; }
+    void clear() override;
 
 protected:
     void updateCurrentTime(int) override;
@@ -77,12 +80,12 @@ protected:
 private:
     struct AnimationIndex
     {
-        AnimationIndex() : afterCurrent(false), timeOffset(0), animation(0) {}
+        AnimationIndex() {}
         // AnimationIndex points to the animation at timeOffset, skipping 0 duration animations.
         // Note that the index semantic is slightly different depending on the direction.
-        bool afterCurrent;  //whether animation is before or after m_currentAnimation   //TODO: make enum Before/After/Same
-        int timeOffset; // time offset when the animation at index starts.
-        QAbstractAnimationJob *animation; //points to the animation at timeOffset
+        bool afterCurrent = false;  //whether animation is before or after m_currentAnimation   //TODO: make enum Before/After/Same
+        int timeOffset = 0; // time offset when the animation at index starts.
+        QAbstractAnimationJob *animation = nullptr; //points to the animation at timeOffset
     };
 
     int animationActualTotalDuration(QAbstractAnimationJob *anim) const;
@@ -103,8 +106,8 @@ private:
     void advanceForwards(const AnimationIndex &newAnimationIndex);
 
     //state
-    QAbstractAnimationJob *m_currentAnimation;
-    int m_previousLoop;
+    QAbstractAnimationJob *m_currentAnimation = nullptr;
+    int m_previousLoop = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/compiler/compiler.pri b/src/qml/compiler/compiler.pri
index 60f548a2b0..da3c173545 100644
--- a/src/qml/compiler/compiler.pri
+++ b/src/qml/compiler/compiler.pri
@@ -2,26 +2,28 @@ INCLUDEPATH += $$PWD
 INCLUDEPATH += $$OUT_PWD
 
 HEADERS += \
+    $$PWD/qv4bytecodegenerator_p.h \
     $$PWD/qv4compileddata_p.h \
     $$PWD/qv4compiler_p.h \
+    $$PWD/qv4compilercontext_p.h \
+    $$PWD/qv4compilercontrolflow_p.h \
+    $$PWD/qv4compilerscanfunctions_p.h \
     $$PWD/qv4codegen_p.h \
-    $$PWD/qv4isel_p.h \
-    $$PWD/qv4jsir_p.h \
-    $$PWD/qv4isel_util_p.h \
-    $$PWD/qv4ssa_p.h \
     $$PWD/qqmlirbuilder_p.h \
     $$PWD/qqmltypecompiler_p.h \
-    $$PWD/qv4jssimplifier_p.h
+    $$PWD/qv4instr_moth_p.h \
+    $$PWD/qv4bytecodehandler_p.h
 
 SOURCES += \
+    $$PWD/qv4bytecodegenerator.cpp \
     $$PWD/qv4compileddata.cpp \
     $$PWD/qv4compiler.cpp \
+    $$PWD/qv4compilercontext.cpp \
+    $$PWD/qv4compilerscanfunctions.cpp \
     $$PWD/qv4codegen.cpp \
-    $$PWD/qv4isel_p.cpp \
-    $$PWD/qv4jsir.cpp \
-    $$PWD/qv4ssa.cpp \
     $$PWD/qqmlirbuilder.cpp \
-    $$PWD/qv4jssimplifier.cpp
+    $$PWD/qv4instr_moth.cpp \
+    $$PWD/qv4bytecodehandler.cpp
 
 !qmldevtools_build {
 
@@ -40,15 +42,8 @@ SOURCES += \
 
 unix: SOURCES += $$PWD/qv4compilationunitmapper_unix.cpp
 else: SOURCES += $$PWD/qv4compilationunitmapper_win.cpp
-
-qtConfig(private_tests):qtConfig(dlopen): QMAKE_USE_PRIVATE += libdl
 }
 
-qmldevtools_build|qtConfig(qml-interpreter) {
-    HEADERS += \
-        $$PWD/qv4instr_moth_p.h \
-        $$PWD/qv4isel_moth_p.h
-    SOURCES += \
-        $$PWD/qv4instr_moth.cpp \
-        $$PWD/qv4isel_moth.cpp
+gcc {
+    equals(QT_GCC_MAJOR_VERSION, 5): QMAKE_CXXFLAGS += -fno-strict-aliasing
 }
diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index f766f0e4c8..ea5efcfc66 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -43,8 +43,10 @@
 #include <private/qv4compileddata_p.h>
 #include <private/qqmljsparser_p.h>
 #include <private/qqmljslexer_p.h>
+#include <private/qv4compilerscanfunctions_p.h>
 #include <QCoreApplication>
 #include <QCryptographicHash>
+#include <cmath>
 
 #ifndef V4_BOOTSTRAP
 #include <private/qqmlglobal_p.h>
@@ -60,7 +62,7 @@ QT_USE_NAMESPACE
 
 static const quint32 emptyStringIndex = 0;
 
-#ifndef V4_BOOTSTRAP
+#if 0 //ndef V4_BOOTSTRAP
 DEFINE_BOOL_CONFIG_OPTION(lookupHints, QML_LOOKUP_HINTS);
 #endif // V4_BOOTSTRAP
 
@@ -86,30 +88,32 @@ void Object::init(QQmlJS::MemoryPool *pool, int typeNameIndex, int idIndex, cons
     flags = QV4::CompiledData::Object::NoFlag;
     properties = pool->New<PoolList<Property> >();
     aliases = pool->New<PoolList<Alias> >();
+    qmlEnums = pool->New<PoolList<Enum>>();
     qmlSignals = pool->New<PoolList<Signal> >();
     bindings = pool->New<PoolList<Binding> >();
     functions = pool->New<PoolList<Function> >();
     functionsAndExpressions = pool->New<PoolList<CompiledFunctionOrExpression> >();
-    declarationsOverride = 0;
+    declarationsOverride = nullptr;
 }
 
-QString Object::sanityCheckFunctionNames(const QSet<QString> &illegalNames, QQmlJS::AST::SourceLocation *errorLocation)
+QString IRBuilder::sanityCheckFunctionNames(Object *obj, const QSet<QString> &illegalNames, QQmlJS::AST::SourceLocation *errorLocation)
 {
     QSet<int> functionNames;
-    for (Function *f = functions->first; f; f = f->next) {
-        QQmlJS::AST::FunctionDeclaration *function = f->functionDeclaration;
-        Q_ASSERT(function);
-        *errorLocation = function->identifierToken;
+    for (auto functionit = obj->functionsBegin(); functionit != obj->functionsEnd(); ++functionit) {
+        Function *f = functionit.ptr;
+        errorLocation->startLine = f->location.line;
+        errorLocation->startColumn = f->location.column;
         if (functionNames.contains(f->nameIndex))
             return tr("Duplicate method name");
         functionNames.insert(f->nameIndex);
 
-        for (QmlIR::Signal *s = qmlSignals->first; s; s = s->next) {
+        for (auto signalit = obj->signalsBegin(); signalit != obj->signalsEnd(); ++signalit) {
+            QmlIR::Signal *s = signalit.ptr;
             if (s->nameIndex == f->nameIndex)
                 return tr("Duplicate method name");
         }
 
-        const QString name = function->name.toString();
+        const QString name = stringAt(f->nameIndex);
         if (name.at(0).isUpper())
             return tr("Method names cannot begin with an upper case letter");
         if (illegalNames.contains(name))
@@ -118,6 +122,21 @@ QString Object::sanityCheckFunctionNames(const QSet<QString> &illegalNames, QQml
     return QString(); // no error
 }
 
+QString Object::appendEnum(Enum *enumeration)
+{
+    Object *target = declarationsOverride;
+    if (!target)
+        target = this;
+
+    for (Enum *e = qmlEnums->first; e; e = e->next) {
+        if (e->nameIndex == enumeration->nameIndex)
+            return tr("Duplicate scoped enum name");
+    }
+
+    target->qmlEnums->append(enumeration);
+    return QString(); // no error
+}
+
 QString Object::appendSignal(Signal *signal)
 {
     Object *target = declarationsOverride;
@@ -215,7 +234,7 @@ Binding *Object::findBinding(quint32 nameIndex) const
     for (Binding *b = bindings->first; b; b = b->next)
         if (b->propertyNameIndex == nameIndex)
             return b;
-    return 0;
+    return nullptr;
 }
 
 void Object::insertSorted(Binding *b)
@@ -257,7 +276,7 @@ void Document::removeScriptPragmas(QString &script)
     const QLatin1String pragma("pragma");
     const QLatin1String library("library");
 
-    QQmlJS::Lexer l(0);
+    QQmlJS::Lexer l(nullptr);
     l.setCode(script, 0);
 
     int token = l.lex();
@@ -299,22 +318,21 @@ void Document::removeScriptPragmas(QString &script)
 
 Document::Document(bool debugMode)
     : jsModule(debugMode)
-    , program(0)
-    , indexOfRootObject(0)
+    , program(nullptr)
     , jsGenerator(&jsModule)
 {
 }
 
-ScriptDirectivesCollector::ScriptDirectivesCollector(QQmlJS::Engine *engine, QV4::Compiler::JSUnitGenerator *unitGenerator)
-    : engine(engine)
-    , jsGenerator(unitGenerator)
-    , hasPragmaLibrary(false)
+ScriptDirectivesCollector::ScriptDirectivesCollector(Document *doc)
+    : document(doc)
+    , engine(&doc->jsParserEngine)
+    , jsGenerator(&doc->jsGenerator)
 {
 }
 
 void ScriptDirectivesCollector::pragmaLibrary()
 {
-    hasPragmaLibrary = true;
+    document->jsModule.unitFlags |= QV4::CompiledData::Unit::IsSharedLibrary;
 }
 
 void ScriptDirectivesCollector::importFile(const QString &jsfile, const QString &module, int lineNumber, int column)
@@ -325,7 +343,7 @@ void ScriptDirectivesCollector::importFile(const QString &jsfile, const QString
     import->qualifierIndex = jsGenerator->registerString(module);
     import->location.line = lineNumber;
     import->location.column = column;
-    imports << import;
+    document->imports << import;
 }
 
 void ScriptDirectivesCollector::importModule(const QString &uri, const QString &version, const QString &module, int lineNumber, int column)
@@ -341,21 +359,21 @@ void ScriptDirectivesCollector::importModule(const QString &uri, const QString &
     import->qualifierIndex = jsGenerator->registerString(module);
     import->location.line = lineNumber;
     import->location.column = column;
-    imports << import;
+    document->imports << import;
 }
 
 IRBuilder::IRBuilder(const QSet<QString> &illegalNames)
     : illegalNames(illegalNames)
-    , _object(0)
-    , _propertyDeclaration(0)
-    , pool(0)
-    , jsGenerator(0)
+    , _object(nullptr)
+    , _propertyDeclaration(nullptr)
+    , pool(nullptr)
+    , jsGenerator(nullptr)
 {
 }
 
 bool IRBuilder::generateFromQml(const QString &code, const QString &url, Document *output)
 {
-    QQmlJS::AST::UiProgram *program = 0;
+    QQmlJS::AST::UiProgram *program = nullptr;
     {
         QQmlJS::Lexer lexer(&output->jsParserEngine);
         lexer.setCode(code, /*line = */ 1);
@@ -404,7 +422,10 @@ bool IRBuilder::generateFromQml(const QString &code, const QString &url, Documen
 
     QQmlJS::AST::UiObjectDefinition *rootObject = QQmlJS::AST::cast<QQmlJS::AST::UiObjectDefinition*>(program->members->member);
     Q_ASSERT(rootObject);
-    defineQMLObject(&output->indexOfRootObject, rootObject);
+    int rootObjectIndex = -1;
+    if (defineQMLObject(&rootObjectIndex, rootObject)) {
+        Q_ASSERT(rootObjectIndex == 0);
+    }
 
     qSwap(_imports, output->imports);
     qSwap(_pragmas, output->pragmas);
@@ -459,7 +480,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiObjectDefinition *node)
         appendBinding(nameLocation, nameLocation, emptyStringIndex, idx);
     } else {
         int idx = 0;
-        if (!defineQMLObject(&idx, /*qualfied type name id*/0, node->qualifiedTypeNameId->firstSourceLocation(), node->initializer, /*declarations should go here*/_object))
+        if (!defineQMLObject(&idx, /*qualfied type name id*/nullptr, node->qualifiedTypeNameId->firstSourceLocation(), node->initializer, /*declarations should go here*/_object))
             return false;
         appendBinding(node->qualifiedTypeNameId, idx);
     }
@@ -477,14 +498,14 @@ bool IRBuilder::visit(QQmlJS::AST::UiObjectBinding *node)
 
 bool IRBuilder::visit(QQmlJS::AST::UiScriptBinding *node)
 {
-    appendBinding(node->qualifiedId, node->statement);
+    appendBinding(node->qualifiedId, node->statement, node);
     return false;
 }
 
 bool IRBuilder::visit(QQmlJS::AST::UiArrayBinding *node)
 {
     const QQmlJS::AST::SourceLocation qualifiedNameLocation = node->qualifiedId->identifierToken;
-    Object *object = 0;
+    Object *object = nullptr;
     QQmlJS::AST::UiQualifiedId *name = node->qualifiedId;
     if (!resolveQualifiedId(&name, &object))
         return false;
@@ -493,7 +514,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiArrayBinding *node)
 
     const int propertyNameIndex = registerString(name->name.toString());
 
-    if (bindingsTarget()->findBinding(propertyNameIndex) != 0) {
+    if (bindingsTarget()->findBinding(propertyNameIndex) != nullptr) {
         recordError(name->identifierToken, tr("Property value set multiple times"));
         return false;
     }
@@ -568,7 +589,7 @@ bool IRBuilder::defineQMLObject(int *objectIndex, QQmlJS::AST::UiQualifiedId *qu
     _object->declarationsOverride = declarationsOverride;
 
     // A new object is also a boundary for property declarations.
-    Property *declaration = 0;
+    Property *declaration = nullptr;
     qSwap(_propertyDeclaration, declaration);
 
     accept(initializer);
@@ -581,7 +602,7 @@ bool IRBuilder::defineQMLObject(int *objectIndex, QQmlJS::AST::UiQualifiedId *qu
         return false;
 
     QQmlJS::AST::SourceLocation loc;
-    QString error = obj->sanityCheckFunctionNames(illegalNames, &loc);
+    QString error = sanityCheckFunctionNames(obj, illegalNames, &loc);
     if (!error.isEmpty()) {
         recordError(loc, error);
         return false;
@@ -598,7 +619,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiImport *node)
     if (!node->fileName.isNull()) {
         uri = node->fileName.toString();
 
-        if (uri.endsWith(QLatin1String(".js"))) {
+        if (uri.endsWith(QLatin1String(".js")) || uri.endsWith(QLatin1String(".mjs"))) {
             import->type = QV4::CompiledData::Import::ImportScript;
         } else {
             import->type = QV4::CompiledData::Import::ImportFile;
@@ -670,9 +691,9 @@ bool IRBuilder::visit(QQmlJS::AST::UiPragma *node)
     Pragma *pragma = New<Pragma>();
 
     // For now the only valid pragma is Singleton, so lets validate the input
-    if (!node->pragmaType->name.isNull())
+    if (!node->name.isNull())
     {
-        if (QLatin1String("Singleton") == node->pragmaType->name)
+        if (QLatin1String("Singleton") == node->name)
         {
             pragma->type = Pragma::PragmaSingleton;
         } else {
@@ -709,6 +730,52 @@ static QStringList astNodeToStringList(QQmlJS::AST::Node *node)
     return QStringList();
 }
 
+bool IRBuilder::visit(QQmlJS::AST::UiEnumDeclaration *node)
+{
+    Enum *enumeration = New<Enum>();
+    QString enumName = node->name.toString();
+    enumeration->nameIndex = registerString(enumName);
+
+    if (enumName.at(0).isLower())
+        COMPILE_EXCEPTION(node->enumToken, tr("Scoped enum names must begin with an upper case letter"));
+
+    enumeration->location.line = node->enumToken.startLine;
+    enumeration->location.column = node->enumToken.startColumn;
+
+    enumeration->enumValues = New<PoolList<EnumValue>>();
+
+    QQmlJS::AST::UiEnumMemberList *e = node->members;
+    while (e) {
+        EnumValue *enumValue = New<EnumValue>();
+        QString member = e->member.toString();
+        enumValue->nameIndex = registerString(member);
+        if (member.at(0).isLower())
+            COMPILE_EXCEPTION(e->memberToken, tr("Enum names must begin with an upper case letter"));
+
+        double part;
+        if (std::modf(e->value, &part) != 0.0)
+            COMPILE_EXCEPTION(e->valueToken, tr("Enum value must be an integer"));
+        if (e->value > std::numeric_limits<qint32>::max() || e->value < std::numeric_limits<qint32>::min())
+            COMPILE_EXCEPTION(e->valueToken, tr("Enum value out of range"));
+        enumValue->value = e->value;
+
+        enumValue->location.line = e->memberToken.startLine;
+        enumValue->location.column = e->memberToken.startColumn;
+        enumeration->enumValues->append(enumValue);
+
+        e = e->next;
+    }
+
+    QString error = _object->appendEnum(enumeration);
+    if (!error.isEmpty()) {
+        recordError(node->enumToken, error);
+        return false;
+    }
+
+    return false;
+}
+
+
 bool IRBuilder::visit(QQmlJS::AST::UiPublicMember *node)
 {
     static const struct TypeNameToType {
@@ -765,7 +832,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiPublicMember *node)
                 return false;
             }
 
-            const TypeNameToType *type = 0;
+            const TypeNameToType *type = nullptr;
             for (int typeIndex = 0; typeIndex < propTypeNameToTypesCount; ++typeIndex) {
                 const TypeNameToType *t = propTypeNameToTypes + typeIndex;
                 if (memberType == QLatin1String(t->name, static_cast<int>(t->nameLength))) {
@@ -891,7 +958,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiPublicMember *node)
                 QQmlJS::AST::Node::accept(node->binding, this);
             } else if (node->statement) {
                 if (!isRedundantNullInitializerForPropertyDeclaration(_propertyDeclaration, node->statement))
-                    appendBinding(node->identifierToken, node->identifierToken, _propertyDeclaration->nameIndex, node->statement);
+                    appendBinding(node->identifierToken, node->identifierToken, _propertyDeclaration->nameIndex, node->statement, node);
             }
             qSwap(_propertyDeclaration, property);
         }
@@ -905,26 +972,27 @@ bool IRBuilder::visit(QQmlJS::AST::UiSourceElement *node)
     if (QQmlJS::AST::FunctionDeclaration *funDecl = QQmlJS::AST::cast<QQmlJS::AST::FunctionDeclaration *>(node->sourceElement)) {
         CompiledFunctionOrExpression *foe = New<CompiledFunctionOrExpression>();
         foe->node = funDecl;
+        foe->parentNode = funDecl;
         foe->nameIndex = registerString(funDecl->name.toString());
         foe->disableAcceleratedLookups = false;
         const int index = _object->functionsAndExpressions->append(foe);
 
         Function *f = New<Function>();
-        f->functionDeclaration = funDecl;
         QQmlJS::AST::SourceLocation loc = funDecl->identifierToken;
         f->location.line = loc.startLine;
         f->location.column = loc.startColumn;
         f->index = index;
         f->nameIndex = registerString(funDecl->name.toString());
 
-        int formalsCount = 0;
-        for (QQmlJS::AST::FormalParameterList *it = funDecl->formals; it; it = it->next)
-            ++formalsCount;
+        const QStringList formals = funDecl->formals ? funDecl->formals->formals() : QStringList();
+        int formalsCount = formals.size();
         f->formals.allocate(pool, formalsCount);
 
         int i = 0;
-        for (QQmlJS::AST::FormalParameterList *it = funDecl->formals; it; it = it->next, ++i)
-            f->formals[i] = registerString(it->name.toString());
+        for (const QString &arg : formals) {
+            f->formals[i] = registerString(arg);
+            ++i;
+        }
 
         _object->appendFunction(f);
     } else {
@@ -978,7 +1046,7 @@ QStringRef IRBuilder::textRefAt(const QQmlJS::AST::SourceLocation &first, const
     return QStringRef(&sourceCode, first.offset, last.offset + last.length - first.offset);
 }
 
-void IRBuilder::setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST::Statement *statement)
+void IRBuilder::setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST::Statement *statement, QQmlJS::AST::Node *parentNode)
 {
     QQmlJS::AST::SourceLocation loc = statement->firstSourceLocation();
     binding->valueLocation.line = loc.startLine;
@@ -1001,15 +1069,23 @@ void IRBuilder::setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST
             binding->value.b = false;
         } else if (QQmlJS::AST::NumericLiteral *lit = QQmlJS::AST::cast<QQmlJS::AST::NumericLiteral *>(expr)) {
             binding->type = QV4::CompiledData::Binding::Type_Number;
-            binding->setNumberValueInternal(lit->value);
-        } else {
-
-            if (QQmlJS::AST::UnaryMinusExpression *unaryMinus = QQmlJS::AST::cast<QQmlJS::AST::UnaryMinusExpression *>(expr)) {
-               if (QQmlJS::AST::NumericLiteral *lit = QQmlJS::AST::cast<QQmlJS::AST::NumericLiteral *>(unaryMinus->expression)) {
-                   binding->type = QV4::CompiledData::Binding::Type_Number;
-                   binding->setNumberValueInternal(-lit->value);
-               }
+            binding->value.constantValueIndex = jsGenerator->registerConstant(QV4::Encode(lit->value));
+        } else if (QQmlJS::AST::CallExpression *call = QQmlJS::AST::cast<QQmlJS::AST::CallExpression *>(expr)) {
+            if (QQmlJS::AST::IdentifierExpression *base = QQmlJS::AST::cast<QQmlJS::AST::IdentifierExpression *>(call->base)) {
+                tryGeneratingTranslationBinding(base->name, call->arguments, binding);
+                // If it wasn't a translation binding, a normal script binding will be generated
+                // below.
             }
+        } else if (QQmlJS::AST::cast<QQmlJS::AST::FunctionExpression *>(expr)) {
+            binding->flags |= QV4::CompiledData::Binding::IsFunctionExpression;
+        } else if (QQmlJS::AST::UnaryMinusExpression *unaryMinus = QQmlJS::AST::cast<QQmlJS::AST::UnaryMinusExpression *>(expr)) {
+            if (QQmlJS::AST::NumericLiteral *lit = QQmlJS::AST::cast<QQmlJS::AST::NumericLiteral *>(unaryMinus->expression)) {
+                binding->type = QV4::CompiledData::Binding::Type_Number;
+                binding->value.constantValueIndex = jsGenerator->registerConstant(QV4::Encode(-lit->value));
+            }
+        } else if (QQmlJS::AST::cast<QQmlJS::AST::NullExpression *>(expr)) {
+            binding->type = QV4::CompiledData::Binding::Type_Null;
+            binding->value.nullMarker = 0;
         }
     }
 
@@ -1019,6 +1095,7 @@ void IRBuilder::setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST
 
         CompiledFunctionOrExpression *expr = New<CompiledFunctionOrExpression>();
         expr->node = statement;
+        expr->parentNode = parentNode;
         expr->nameIndex = registerString(QLatin1String("expression for ")
                                          + stringAt(binding->propertyNameIndex));
         expr->disableAcceleratedLookups = false;
@@ -1030,10 +1107,125 @@ void IRBuilder::setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST
     }
 }
 
-void IRBuilder::appendBinding(QQmlJS::AST::UiQualifiedId *name, QQmlJS::AST::Statement *value)
+void IRBuilder::tryGeneratingTranslationBinding(const QStringRef &base, AST::ArgumentList *args, QV4::CompiledData::Binding *binding)
+{
+    if (base == QLatin1String("qsTr")) {
+        QV4::CompiledData::TranslationData translationData;
+        translationData.number = -1;
+        translationData.commentIndex = 0; // empty string
+
+        if (!args || !args->expression)
+            return; // no arguments, stop
+
+        QStringRef translation;
+        if (QQmlJS::AST::StringLiteral *arg1 = QQmlJS::AST::cast<QQmlJS::AST::StringLiteral *>(args->expression)) {
+            translation = arg1->value;
+        } else {
+            return; // first argument is not a string, stop
+        }
+        translationData.stringIndex = jsGenerator->registerString(translation.toString());
+
+        args = args->next;
+
+        if (args) {
+            QQmlJS::AST::StringLiteral *arg2 = QQmlJS::AST::cast<QQmlJS::AST::StringLiteral *>(args->expression);
+            if (!arg2)
+                return; // second argument is not a string, stop
+            translationData.commentIndex = jsGenerator->registerString(arg2->value.toString());
+
+            args = args->next;
+            if (args) {
+                if (QQmlJS::AST::NumericLiteral *arg3 = QQmlJS::AST::cast<QQmlJS::AST::NumericLiteral *>(args->expression)) {
+                    translationData.number = int(arg3->value);
+                    args = args->next;
+                } else {
+                    return; // third argument is not a translation number, stop
+                }
+            }
+        }
+
+        if (args)
+            return; // too many arguments, stop
+
+        binding->type = QV4::CompiledData::Binding::Type_Translation;
+        binding->value.translationDataIndex = jsGenerator->registerTranslation(translationData);
+    } else if (base == QLatin1String("qsTrId")) {
+        QV4::CompiledData::TranslationData translationData;
+        translationData.number = -1;
+        translationData.commentIndex = 0; // empty string, but unused
+
+        if (!args || !args->expression)
+            return; // no arguments, stop
+
+        QStringRef id;
+        if (QQmlJS::AST::StringLiteral *arg1 = QQmlJS::AST::cast<QQmlJS::AST::StringLiteral *>(args->expression)) {
+            id = arg1->value;
+        } else {
+            return; // first argument is not a string, stop
+        }
+        translationData.stringIndex = jsGenerator->registerString(id.toString());
+
+        args = args->next;
+
+        if (args) {
+            if (QQmlJS::AST::NumericLiteral *arg3 = QQmlJS::AST::cast<QQmlJS::AST::NumericLiteral *>(args->expression)) {
+                translationData.number = int(arg3->value);
+                args = args->next;
+            } else {
+                return; // third argument is not a translation number, stop
+            }
+        }
+
+        if (args)
+            return; // too many arguments, stop
+
+        binding->type = QV4::CompiledData::Binding::Type_TranslationById;
+        binding->value.translationDataIndex = jsGenerator->registerTranslation(translationData);
+    } else if (base == QLatin1String("QT_TR_NOOP") || base == QLatin1String("QT_TRID_NOOP")) {
+        if (!args || !args->expression)
+            return; // no arguments, stop
+
+        QStringRef str;
+        if (QQmlJS::AST::StringLiteral *arg1 = QQmlJS::AST::cast<QQmlJS::AST::StringLiteral *>(args->expression)) {
+            str = arg1->value;
+        } else {
+            return; // first argument is not a string, stop
+        }
+
+        args = args->next;
+        if (args)
+            return; // too many arguments, stop
+
+        binding->type = QV4::CompiledData::Binding::Type_String;
+        binding->stringIndex = jsGenerator->registerString(str.toString());
+    } else if (base == QLatin1String("QT_TRANSLATE_NOOP")) {
+        if (!args || !args->expression)
+            return; // no arguments, stop
+
+        args = args->next;
+        if (!args || !args->expression)
+            return; // no second arguments, stop
+
+        QStringRef str;
+        if (QQmlJS::AST::StringLiteral *arg2 = QQmlJS::AST::cast<QQmlJS::AST::StringLiteral *>(args->expression)) {
+            str = arg2->value;
+        } else {
+            return; // first argument is not a string, stop
+        }
+
+        args = args->next;
+        if (args)
+            return; // too many arguments, stop
+
+        binding->type = QV4::CompiledData::Binding::Type_String;
+        binding->stringIndex = jsGenerator->registerString(str.toString());
+    }
+}
+
+void IRBuilder::appendBinding(QQmlJS::AST::UiQualifiedId *name, QQmlJS::AST::Statement *value, QQmlJS::AST::Node *parentNode)
 {
     const QQmlJS::AST::SourceLocation qualifiedNameLocation = name->identifierToken;
-    Object *object = 0;
+    Object *object = nullptr;
     if (!resolveQualifiedId(&name, &object))
         return;
     if (_object == object && name->name == QLatin1String("id")) {
@@ -1041,14 +1233,14 @@ void IRBuilder::appendBinding(QQmlJS::AST::UiQualifiedId *name, QQmlJS::AST::Sta
         return;
     }
     qSwap(_object, object);
-    appendBinding(qualifiedNameLocation, name->identifierToken, registerString(name->name.toString()), value);
+    appendBinding(qualifiedNameLocation, name->identifierToken, registerString(name->name.toString()), value, parentNode);
     qSwap(_object, object);
 }
 
 void IRBuilder::appendBinding(QQmlJS::AST::UiQualifiedId *name, int objectIndex, bool isOnAssignment)
 {
     const QQmlJS::AST::SourceLocation qualifiedNameLocation = name->identifierToken;
-    Object *object = 0;
+    Object *object = nullptr;
     if (!resolveQualifiedId(&name, &object, isOnAssignment))
         return;
     qSwap(_object, object);
@@ -1056,7 +1248,8 @@ void IRBuilder::appendBinding(QQmlJS::AST::UiQualifiedId *name, int objectIndex,
     qSwap(_object, object);
 }
 
-void IRBuilder::appendBinding(const QQmlJS::AST::SourceLocation &qualifiedNameLocation, const QQmlJS::AST::SourceLocation &nameLocation, quint32 propertyNameIndex, QQmlJS::AST::Statement *value)
+void IRBuilder::appendBinding(const QQmlJS::AST::SourceLocation &qualifiedNameLocation, const QQmlJS::AST::SourceLocation &nameLocation, quint32 propertyNameIndex,
+                              QQmlJS::AST::Statement *value, QQmlJS::AST::Node *parentNode)
 {
     Binding *binding = New<Binding>();
     binding->propertyNameIndex = propertyNameIndex;
@@ -1064,7 +1257,7 @@ void IRBuilder::appendBinding(const QQmlJS::AST::SourceLocation &qualifiedNameLo
     binding->location.line = nameLocation.startLine;
     binding->location.column = nameLocation.startColumn;
     binding->flags = 0;
-    setBindingValue(binding, value);
+    setBindingValue(binding, value, parentNode);
     QString error = bindingsTarget()->appendBinding(binding, /*isListBinding*/false);
     if (!error.isEmpty()) {
         recordError(qualifiedNameLocation, error);
@@ -1199,7 +1392,7 @@ bool IRBuilder::setId(const QQmlJS::AST::SourceLocation &idLocation, QQmlJS::AST
     if (QQmlJS::AST::ExpressionStatement *stmt = QQmlJS::AST::cast<QQmlJS::AST::ExpressionStatement *>(node)) {
         if (QQmlJS::AST::StringLiteral *lit = QQmlJS::AST::cast<QQmlJS::AST::StringLiteral *>(stmt->expression)) {
             str = lit->value;
-            node = 0;
+            node = nullptr;
         } else
             node = stmt->expression;
     }
@@ -1270,9 +1463,9 @@ bool IRBuilder::resolveQualifiedId(QQmlJS::AST::UiQualifiedId **nameToResolve, O
         if (binding) {
             if (isAttachedProperty) {
                 if (!binding->isAttachedProperty())
-                    binding = 0;
+                    binding = nullptr;
             } else if (!binding->isGroupProperty()) {
-                binding = 0;
+                binding = nullptr;
             }
         }
         if (!binding) {
@@ -1294,7 +1487,7 @@ bool IRBuilder::resolveQualifiedId(QQmlJS::AST::UiQualifiedId **nameToResolve, O
                 binding->type = QV4::CompiledData::Binding::Type_GroupProperty;
 
             int objIndex = 0;
-            if (!defineQMLObject(&objIndex, 0, QQmlJS::AST::SourceLocation(), 0, 0))
+            if (!defineQMLObject(&objIndex, nullptr, QQmlJS::AST::SourceLocation(), nullptr, nullptr))
                 return false;
             binding->value.objectIndex = objIndex;
 
@@ -1361,60 +1554,105 @@ bool IRBuilder::isRedundantNullInitializerForPropertyDeclaration(Property *prope
     return QQmlJS::AST::cast<QQmlJS::AST::NullExpression *>(expr);
 }
 
-QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
+void QmlUnitGenerator::generate(Document &output, const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
 {
+    output.jsGenerator.stringTable.registerString(output.jsModule.fileName);
+    output.jsGenerator.stringTable.registerString(output.jsModule.finalUrl);
+
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit = output.javaScriptCompilationUnit;
-    QV4::CompiledData::Unit *jsUnit = compilationUnit->createUnitData(&output);
-    const uint unitSize = jsUnit->unitSize;
 
-    const int importSize = sizeof(QV4::CompiledData::Import) * output.imports.count();
-    const int objectOffsetTableSize = output.objects.count() * sizeof(quint32);
+    const QV4::CompiledData::Unit *jsUnit = nullptr;
+    std::function<QV4::CompiledData::QmlUnit *(QV4::CompiledData::QmlUnit *, uint)> unitFinalizer
+            = [](QV4::CompiledData::QmlUnit *unit, uint) {
+        return unit;
+    };
+
+    // We may already have unit data if we're loading an ahead-of-time generated cache file.
+    if (compilationUnit->data) {
+        jsUnit = compilationUnit->data;
+#ifndef V4_BOOTSTRAP
+        output.javaScriptCompilationUnit->dynamicStrings = output.jsGenerator.stringTable.allStrings();
+#endif
+    } else {
+        QV4::CompiledData::Unit *createdUnit;
+        jsUnit = createdUnit = output.jsGenerator.generateUnit();
+
+        // enable flag if we encountered pragma Singleton
+        for (Pragma *p : qAsConst(output.pragmas)) {
+            if (p->type == Pragma::PragmaSingleton) {
+                createdUnit->flags |= QV4::CompiledData::Unit::IsSingleton;
+                break;
+            }
+        }
+        // This unit's memory was allocated with malloc on the heap, so it's
+        // definitely not suitable for StaticData access.
+        createdUnit->flags &= ~QV4::CompiledData::Unit::StaticData;
+
+#ifndef V4_BOOTSTRAP
+        if (dependencyHasher) {
+            QCryptographicHash hash(QCryptographicHash::Md5);
+            if (dependencyHasher(&hash)) {
+                QByteArray checksum = hash.result();
+                Q_ASSERT(checksum.size() == sizeof(createdUnit->dependencyMD5Checksum));
+                memcpy(createdUnit->dependencyMD5Checksum, checksum.constData(), sizeof(createdUnit->dependencyMD5Checksum));
+            }
+        }
+#else
+        Q_UNUSED(dependencyHasher);
+#endif
+        createdUnit->sourceFileIndex = output.jsGenerator.stringTable.getStringId(output.jsModule.fileName);
+        createdUnit->finalUrlIndex = output.jsGenerator.stringTable.getStringId(output.jsModule.finalUrl);
+
+        // Combine the qml data into the general unit data.
+        unitFinalizer = [&jsUnit](QV4::CompiledData::QmlUnit *qmlUnit, uint qmlDataSize) {
+            void *ptr = const_cast<QV4::CompiledData::Unit*>(jsUnit);
+            QV4::CompiledData::Unit *newUnit = (QV4::CompiledData::Unit *)realloc(ptr, jsUnit->unitSize + qmlDataSize);
+            jsUnit = newUnit;
+            newUnit->offsetToQmlUnit = newUnit->unitSize;
+            newUnit->unitSize += qmlDataSize;
+            memcpy(const_cast<QV4::CompiledData::QmlUnit *>(newUnit->qmlUnit()), qmlUnit, qmlDataSize);
+            free(const_cast<QV4::CompiledData::QmlUnit*>(qmlUnit));
+            qmlUnit = nullptr;
+            newUnit->generateChecksum();
+            return const_cast<QV4::CompiledData::QmlUnit*>(newUnit->qmlUnit());
+        };
+    }
+
+    // No more new strings after this point, we're calculating offsets.
+    output.jsGenerator.stringTable.freeze();
+
+    const uint importSize = sizeof(QV4::CompiledData::Import) * output.imports.count();
+    const uint objectOffsetTableSize = output.objects.count() * sizeof(quint32);
 
     QHash<const Object*, quint32> objectOffsets;
 
-    int objectsSize = 0;
+    const unsigned int objectOffset = sizeof(QV4::CompiledData::QmlUnit) + importSize;
+    uint nextOffset = objectOffset + objectOffsetTableSize;
     for (Object *o : qAsConst(output.objects)) {
-        objectOffsets.insert(o, unitSize + importSize + objectOffsetTableSize + objectsSize);
-        objectsSize += QV4::CompiledData::Object::calculateSizeExcludingSignals(o->functionCount(), o->propertyCount(), o->aliasCount(), o->signalCount(), o->bindingCount(), o->namedObjectsInComponent.count);
+        objectOffsets.insert(o, nextOffset);
+        nextOffset += QV4::CompiledData::Object::calculateSizeExcludingSignalsAndEnums(o->functionCount(), o->propertyCount(), o->aliasCount(), o->enumCount(), o->signalCount(), o->bindingCount(), o->namedObjectsInComponent.size());
 
         int signalTableSize = 0;
         for (const Signal *s = o->firstSignal(); s; s = s->next)
             signalTableSize += QV4::CompiledData::Signal::calculateSize(s->parameters->count);
 
-        objectsSize += signalTableSize;
+        nextOffset += signalTableSize;
+
+        int enumTableSize = 0;
+        for (const Enum *e = o->firstEnum(); e; e = e->next)
+            enumTableSize += QV4::CompiledData::Enum::calculateSize(e->enumValues->count);
+
+        nextOffset += enumTableSize;
     }
 
-    const int totalSize = unitSize + importSize + objectOffsetTableSize + objectsSize + output.jsGenerator.stringTable.sizeOfTableAndData();
+    const uint totalSize = nextOffset;
     char *data = (char*)malloc(totalSize);
-    memcpy(data, jsUnit, unitSize);
-    memset(data + unitSize, 0, totalSize - unitSize);
-    if (jsUnit != compilationUnit->data)
-        free(jsUnit);
-    jsUnit = 0;
-
-    QV4::CompiledData::Unit *qmlUnit = reinterpret_cast<QV4::CompiledData::Unit *>(data);
-    qmlUnit->unitSize = totalSize;
-    qmlUnit->flags |= QV4::CompiledData::Unit::IsQml;
-    qmlUnit->offsetToImports = unitSize;
+    memset(data, 0, totalSize);
+    QV4::CompiledData::QmlUnit *qmlUnit = reinterpret_cast<QV4::CompiledData::QmlUnit *>(data);
+    qmlUnit->offsetToImports = sizeof(*qmlUnit);
     qmlUnit->nImports = output.imports.count();
-    qmlUnit->offsetToObjects = unitSize + importSize;
+    qmlUnit->offsetToObjects = objectOffset;
     qmlUnit->nObjects = output.objects.count();
-    qmlUnit->indexOfRootObject = output.indexOfRootObject;
-    qmlUnit->offsetToStringTable = totalSize - output.jsGenerator.stringTable.sizeOfTableAndData();
-    qmlUnit->stringTableSize = output.jsGenerator.stringTable.stringCount();
-
-#ifndef V4_BOOTSTRAP
-    if (dependencyHasher) {
-        QCryptographicHash hash(QCryptographicHash::Md5);
-        if (dependencyHasher(&hash)) {
-            QByteArray checksum = hash.result();
-            Q_ASSERT(checksum.size() == sizeof(qmlUnit->dependencyMD5Checksum));
-            memcpy(qmlUnit->dependencyMD5Checksum, checksum.constData(), sizeof(qmlUnit->dependencyMD5Checksum));
-        }
-    }
-#else
-    Q_UNUSED(dependencyHasher);
-#endif
 
     // write imports
     char *importPtr = data + qmlUnit->offsetToImports;
@@ -1425,10 +1663,10 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4:
     }
 
     // write objects
-    quint32 *objectTable = reinterpret_cast<quint32*>(data + qmlUnit->offsetToObjects);
-    char *objectPtr = data + qmlUnit->offsetToObjects + objectOffsetTableSize;
+    quint32_le *objectTable = reinterpret_cast<quint32_le*>(data + qmlUnit->offsetToObjects);
     for (int i = 0; i < output.objects.count(); ++i) {
         const Object *o = output.objects.at(i);
+        char * const objectPtr = data + objectOffsets.value(o);
         *objectTable++ = objectOffsets.value(o);
 
         QV4::CompiledData::Object *objectToWrite = reinterpret_cast<QV4::CompiledData::Object*>(objectPtr);
@@ -1455,6 +1693,10 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4:
         objectToWrite->offsetToAliases = nextOffset;
         nextOffset += objectToWrite->nAliases * sizeof(QV4::CompiledData::Alias);
 
+        objectToWrite->nEnums = o->enumCount();
+        objectToWrite->offsetToEnums = nextOffset;
+        nextOffset += objectToWrite->nEnums * sizeof(quint32);
+
         objectToWrite->nSignals = o->signalCount();
         objectToWrite->offsetToSignals = nextOffset;
         nextOffset += objectToWrite->nSignals * sizeof(quint32);
@@ -1463,11 +1705,11 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4:
         objectToWrite->offsetToBindings = nextOffset;
         nextOffset += objectToWrite->nBindings * sizeof(QV4::CompiledData::Binding);
 
-        objectToWrite->nNamedObjectsInComponent = o->namedObjectsInComponent.count;
+        objectToWrite->nNamedObjectsInComponent = o->namedObjectsInComponent.size();
         objectToWrite->offsetToNamedObjectsInComponent = nextOffset;
         nextOffset += objectToWrite->nNamedObjectsInComponent * sizeof(quint32);
 
-        quint32 *functionsTable = reinterpret_cast<quint32*>(objectPtr + objectToWrite->offsetToFunctions);
+        quint32_le *functionsTable = reinterpret_cast<quint32_le *>(objectPtr + objectToWrite->offsetToFunctions);
         for (const Function *f = o->firstFunction(); f; f = f->next)
             *functionsTable++ = o->runtimeFunctionIndices.at(f->index);
 
@@ -1493,7 +1735,7 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4:
         bindingPtr = writeBindings(bindingPtr, o, &QV4::CompiledData::Binding::isValueBindingToAlias);
         Q_ASSERT((bindingPtr - objectToWrite->offsetToBindings - objectPtr) / sizeof(QV4::CompiledData::Binding) == unsigned(o->bindingCount()));
 
-        quint32 *signalOffsetTable = reinterpret_cast<quint32*>(objectPtr + objectToWrite->offsetToSignals);
+        quint32_le *signalOffsetTable = reinterpret_cast<quint32_le *>(objectPtr + objectToWrite->offsetToSignals);
         quint32 signalTableSize = 0;
         char *signalPtr = objectPtr + nextOffset;
         for (const Signal *s = o->firstSignal(); s; s = s->next) {
@@ -1512,29 +1754,59 @@ QV4::CompiledData::Unit *QmlUnitGenerator::generate(Document &output, const QV4:
             signalTableSize += size;
             signalPtr += size;
         }
-
-        quint32 *namedObjectInComponentPtr = reinterpret_cast<quint32*>(objectPtr + objectToWrite->offsetToNamedObjectsInComponent);
-        for (int i = 0; i < o->namedObjectsInComponent.count; ++i) {
-            *namedObjectInComponentPtr++ = o->namedObjectsInComponent.at(i);
+        nextOffset += signalTableSize;
+
+        quint32_le *enumOffsetTable = reinterpret_cast<quint32_le*>(objectPtr + objectToWrite->offsetToEnums);
+        quint32 enumTableSize = 0;
+        char *enumPtr = objectPtr + nextOffset;
+        for (const Enum *e = o->firstEnum(); e; e = e->next) {
+            *enumOffsetTable++ = enumPtr - objectPtr;
+            QV4::CompiledData::Enum *enumToWrite = reinterpret_cast<QV4::CompiledData::Enum*>(enumPtr);
+
+            enumToWrite->nameIndex = e->nameIndex;
+            enumToWrite->location = e->location;
+            enumToWrite->nEnumValues = e->enumValues->count;
+
+            QV4::CompiledData::EnumValue *enumValueToWrite = reinterpret_cast<QV4::CompiledData::EnumValue*>(enumPtr + sizeof(*enumToWrite));
+            for (EnumValue *enumValue = e->enumValues->first; enumValue; enumValue = enumValue->next, ++enumValueToWrite)
+                *enumValueToWrite = *enumValue;
+
+            int size = QV4::CompiledData::Enum::calculateSize(e->enumValues->count);
+            enumTableSize += size;
+            enumPtr += size;
         }
 
-        objectPtr += QV4::CompiledData::Object::calculateSizeExcludingSignals(o->functionCount(), o->propertyCount(), o->aliasCount(), o->signalCount(), o->bindingCount(), o->namedObjectsInComponent.count);
-        objectPtr += signalTableSize;
-    }
-
-    // enable flag if we encountered pragma Singleton
-    for (Pragma *p : qAsConst(output.pragmas)) {
-        if (p->type == Pragma::PragmaSingleton) {
-            qmlUnit->flags |= QV4::CompiledData::Unit::IsSingleton;
-            break;
+        quint32_le *namedObjectInComponentPtr = reinterpret_cast<quint32_le *>(objectPtr + objectToWrite->offsetToNamedObjectsInComponent);
+        for (int i = 0; i < o->namedObjectsInComponent.size(); ++i) {
+            *namedObjectInComponentPtr++ = o->namedObjectsInComponent.at(i);
         }
     }
 
-    output.jsGenerator.stringTable.serialize(qmlUnit);
+    qmlUnit = unitFinalizer(qmlUnit, totalSize);
 
-    qmlUnit->generateChecksum();
+    static const bool showStats = qEnvironmentVariableIsSet("QML_SHOW_UNIT_STATS");
+    if (showStats) {
+        qDebug() << "Generated QML unit that is" << totalSize << "bytes big contains:";
+        qDebug() << "    " << jsUnit->functionTableSize << "functions";
+        qDebug() << "    " << jsUnit->unitSize << "for JS unit";
+        qDebug() << "    " << importSize << "for imports";
+        qDebug() << "    " << nextOffset - objectOffset - objectOffsetTableSize << "for" << qmlUnit->nObjects << "objects";
+        quint32 totalBindingCount = 0;
+        for (quint32 i = 0; i < qmlUnit->nObjects; ++i)
+            totalBindingCount += qmlUnit->objectAt(i)->nBindings;
+        qDebug() << "    " << totalBindingCount << "bindings";
+        quint32 totalCodeSize = 0;
+        for (quint32 i = 0; i < jsUnit->functionTableSize; ++i)
+            totalCodeSize += jsUnit->functionAt(i)->codeSize;
+        qDebug() << "    " << totalCodeSize << "bytes total byte code";
+        qDebug() << "    " << jsUnit->stringTableSize << "strings";
+        quint32 totalStringSize = 0;
+        for (quint32 i = 0; i < jsUnit->stringTableSize; ++i)
+            totalStringSize += QV4::CompiledData::String::calculateSize(jsUnit->stringAtInternal(i));
+        qDebug() << "    " << totalStringSize << "bytes total strings";
+    }
 
-    return qmlUnit;
+    compilationUnit->setUnitData(jsUnit, qmlUnit, output.jsModule.fileName, output.jsModule.finalUrl);
 }
 
 char *QmlUnitGenerator::writeBindings(char *bindingPtr, const Object *o, BindingFilter filter) const
@@ -1551,22 +1823,25 @@ char *QmlUnitGenerator::writeBindings(char *bindingPtr, const Object *o, Binding
     return bindingPtr;
 }
 
-JSCodeGen::JSCodeGen(const QString &fileName, const QString &sourceCode, QV4::IR::Module *jsModule, QQmlJS::Engine *jsEngine,
-                     QQmlJS::AST::UiProgram *qmlRoot, QQmlTypeNameCache *imports, const QV4::Compiler::StringTableGenerator *stringPool)
-    : QQmlJS::Codegen(/*strict mode*/false)
+JSCodeGen::JSCodeGen(const QString &sourceCode, QV4::Compiler::JSUnitGenerator *jsUnitGenerator,
+                     QV4::Compiler::Module *jsModule, QQmlJS::Engine *jsEngine,
+                     QQmlJS::AST::UiProgram *qmlRoot, QQmlTypeNameCache *imports,
+                     const QV4::Compiler::StringTableGenerator *stringPool, const QSet<QString> &globalNames)
+    : QV4::Compiler::Codegen(jsUnitGenerator, /*strict mode*/false)
     , sourceCode(sourceCode)
     , jsEngine(jsEngine)
     , qmlRoot(qmlRoot)
     , imports(imports)
     , stringPool(stringPool)
     , _disableAcceleratedLookups(false)
-    , _contextObject(0)
-    , _scopeObject(0)
-    , _qmlContextTemp(-1)
-    , _importedScriptsTemp(-1)
+    , _contextObject(nullptr)
+    , _scopeObject(nullptr)
+    , _qmlContextSlot(-1)
+    , _importedScriptsSlot(-1)
 {
+    m_globalNames = globalNames;
+
     _module = jsModule;
-    _module->setFileName(fileName);
     _fileNameIsUrl = true;
 }
 
@@ -1574,7 +1849,7 @@ void JSCodeGen::beginContextScope(const JSCodeGen::ObjectIdMapping &objectIds, Q
 {
     _idObjects = objectIds;
     _contextObject = contextObject;
-    _scopeObject = 0;
+    _scopeObject = nullptr;
 }
 
 void JSCodeGen::beginObjectScope(QQmlPropertyCache *scopeObject)
@@ -1584,28 +1859,37 @@ void JSCodeGen::beginObjectScope(QQmlPropertyCache *scopeObject)
 
 QVector<int> JSCodeGen::generateJSCodeForFunctionsAndBindings(const QList<CompiledFunctionOrExpression> &functions)
 {
+    auto qmlName = [&](const CompiledFunctionOrExpression &c) {
+        if (c.nameIndex != 0)
+            return stringPool->stringForIndex(c.nameIndex);
+        else
+            return QStringLiteral("%qml-expression-entry");
+    };
     QVector<int> runtimeFunctionIndices(functions.size());
 
-    ScanFunctions scan(this, sourceCode, GlobalCode);
-    scan.enterEnvironment(0, QmlBinding);
-    scan.enterQmlScope(qmlRoot, QStringLiteral("context scope"));
+    QV4::Compiler::ScanFunctions scan(this, sourceCode, QV4::Compiler::ContextType::Global);
+    scan.enterGlobalEnvironment(QV4::Compiler::ContextType::Binding);
     for (const CompiledFunctionOrExpression &f : functions) {
         Q_ASSERT(f.node != qmlRoot);
+        Q_ASSERT(f.parentNode && f.parentNode != qmlRoot);
         QQmlJS::AST::FunctionDeclaration *function = QQmlJS::AST::cast<QQmlJS::AST::FunctionDeclaration*>(f.node);
 
-        if (function)
+        if (function) {
             scan.enterQmlFunction(function);
-        else
-            scan.enterEnvironment(f.node, QmlBinding);
+        } else {
+            Q_ASSERT(f.node != f.parentNode);
+            scan.enterEnvironment(f.parentNode, QV4::Compiler::ContextType::Binding, qmlName(f));
+        }
 
         scan(function ? function->body : f.node);
         scan.leaveEnvironment();
     }
     scan.leaveEnvironment();
-    scan.leaveEnvironment();
 
-    _variableEnvironment = 0;
-    _function = _module->functions.at(defineFunction(QStringLiteral("context scope"), qmlRoot, 0, 0));
+    if (hasError)
+        return QVector<int>();
+
+    _context = nullptr;
 
     for (int i = 0; i < functions.count(); ++i) {
         const CompiledFunctionOrExpression &qmlFunction = functions.at(i);
@@ -1617,15 +1901,13 @@ QVector<int> JSCodeGen::generateJSCodeForFunctionsAndBindings(const QList<Compil
         QString name;
         if (function)
             name = function->name.toString();
-        else if (qmlFunction.nameIndex != 0)
-            name = stringPool->stringForIndex(qmlFunction.nameIndex);
         else
-            name = QStringLiteral("%qml-expression-entry");
+            name = qmlName(qmlFunction);
 
-        QQmlJS::AST::SourceElements *body;
-        if (function)
-            body = function->body ? function->body->elements : 0;
-        else {
+        QQmlJS::AST::StatementList *body;
+        if (function) {
+            body = function->body;
+        } else {
             // Synthesize source elements.
             QQmlJS::MemoryPool *pool = jsEngine->pool();
 
@@ -1635,47 +1917,43 @@ QVector<int> JSCodeGen::generateJSCodeForFunctionsAndBindings(const QList<Compil
                 QQmlJS::AST::ExpressionNode *expr = node->expressionCast();
                 stmt = new (pool) QQmlJS::AST::ExpressionStatement(expr);
             }
-            QQmlJS::AST::SourceElement *element = new (pool) QQmlJS::AST::StatementSourceElement(stmt);
-            body = new (pool) QQmlJS::AST::SourceElements(element);
+            body = new (pool) QQmlJS::AST::StatementList(stmt);
             body = body->finish();
         }
 
         _disableAcceleratedLookups = qmlFunction.disableAcceleratedLookups;
-        int idx = defineFunction(name, node,
-                                 function ? function->formals : 0,
+        int idx = defineFunction(name, function ? function : qmlFunction.parentNode,
+                                 function ? function->formals : nullptr,
                                  body);
         runtimeFunctionIndices[i] = idx;
     }
 
-    qDeleteAll(_envMap);
-    _envMap.clear();
     return runtimeFunctionIndices;
 }
 
-#ifndef V4_BOOTSTRAP
-QQmlPropertyData *JSCodeGen::lookupQmlCompliantProperty(QQmlPropertyCache *cache, const QString &name, bool *propertyExistsButForceNameLookup)
+int JSCodeGen::defineFunction(const QString &name, AST::Node *ast, AST::FormalParameterList *formals, AST::StatementList *body)
 {
-    if (propertyExistsButForceNameLookup)
-        *propertyExistsButForceNameLookup = false;
-    QQmlPropertyData *pd = cache->property(name, /*object*/0, /*context*/0);
+    int qmlContextTemp = -1;
+    int importedScriptsTemp = -1;
+    qSwap(_qmlContextSlot, qmlContextTemp);
+    qSwap(_importedScriptsSlot, importedScriptsTemp);
 
-    // Q_INVOKABLEs can't be FINAL, so we have to look them up at run-time
-    if (pd && pd->isFunction()) {
-        if (propertyExistsButForceNameLookup)
-            *propertyExistsButForceNameLookup = true;
-        pd = 0;
-    }
+    int result = Codegen::defineFunction(name, ast, formals, body);
+
+    qSwap(_importedScriptsSlot, importedScriptsTemp);
+    qSwap(_qmlContextSlot, qmlContextTemp);
+
+    return result;
+}
+
+#ifndef V4_BOOTSTRAP
+QQmlPropertyData *JSCodeGen::lookupQmlCompliantProperty(QQmlPropertyCache *cache, const QString &name)
+{
+    QQmlPropertyData *pd = cache->property(name, /*object*/nullptr, /*context*/nullptr);
 
     if (pd && !cache->isAllowedInRevision(pd))
-        pd = 0;
+        return nullptr;
 
-    // Return a copy allocated from our memory pool. Property data pointers can change
-    // otherwise when the QQmlPropertyCache changes later in the QML type compilation process.
-    if (pd) {
-        QQmlPropertyData *copy = pd;
-        pd = _function->New<QQmlPropertyData>();
-        *pd = *copy;
-    }
     return pd;
 }
 
@@ -1686,8 +1964,10 @@ enum MetaObjectResolverFlags {
     ResolveTypeInformationOnly = 0x8
 };
 
+#if 0
 static void initMetaObjectResolver(QV4::IR::MemberExpressionResolver *resolver, QQmlPropertyCache *metaObject);
-static void initScopedEnumResolver(QV4::IR::MemberExpressionResolver *resolver, QQmlType *qmlType, int index);
+
+static void initScopedEnumResolver(QV4::IR::MemberExpressionResolver *resolver, const QQmlType &qmlType, int index);
 
 static QV4::IR::DiscoveredType resolveQmlType(QQmlEnginePrivate *qmlEngine,
                                               const QV4::IR::MemberExpressionResolver *resolver,
@@ -1695,16 +1975,16 @@ static QV4::IR::DiscoveredType resolveQmlType(QQmlEnginePrivate *qmlEngine,
 {
     QV4::IR::Type result = QV4::IR::VarType;
 
-    QQmlType *type = static_cast<QQmlType*>(resolver->data);
+    QQmlType type = resolver->qmlType;
 
     if (member->name->constData()->isUpper()) {
         bool ok = false;
-        int value = type->enumValue(qmlEngine, *member->name, &ok);
+        int value = type.enumValue(qmlEngine, *member->name, &ok);
         if (ok) {
             member->setEnumValue(value);
             return QV4::IR::SInt32Type;
         } else {
-            int index = type->scopedEnumIndex(qmlEngine, *member->name, &ok);
+            int index = type.scopedEnumIndex(qmlEngine, *member->name, &ok);
             if (ok) {
                 auto newResolver = resolver->owner->New<QV4::IR::MemberExpressionResolver>();
                 newResolver->owner = resolver->owner;
@@ -1714,8 +1994,8 @@ static QV4::IR::DiscoveredType resolveQmlType(QQmlEnginePrivate *qmlEngine,
         }
     }
 
-    if (type->isCompositeSingleton()) {
-        QQmlRefPointer<QQmlTypeData> tdata = qmlEngine->typeLoader.getType(type->singletonInstanceInfo()->url);
+    if (type.isCompositeSingleton()) {
+        QQmlRefPointer<QQmlTypeData> tdata = qmlEngine->typeLoader.getType(type.singletonInstanceInfo()->url);
         Q_ASSERT(tdata);
         tdata->release(); // Decrease the reference count added from QQmlTypeLoader::getType()
         // When a singleton tries to reference itself, it may not be complete yet.
@@ -1726,8 +2006,8 @@ static QV4::IR::DiscoveredType resolveQmlType(QQmlEnginePrivate *qmlEngine,
             newResolver->flags |= AllPropertiesAreFinal;
             return newResolver->resolveMember(qmlEngine, newResolver, member);
         }
-    }  else if (type->isSingleton()) {
-        const QMetaObject *singletonMeta = type->singletonInstanceInfo()->instanceMetaObject;
+    }  else if (type.isSingleton()) {
+        const QMetaObject *singletonMeta = type.singletonInstanceInfo()->instanceMetaObject;
         if (singletonMeta) { // QJSValue-based singletons cannot be accelerated
             auto newResolver = resolver->owner->New<QV4::IR::MemberExpressionResolver>();
             newResolver->owner = resolver->owner;
@@ -1752,13 +2032,13 @@ static QV4::IR::DiscoveredType resolveQmlType(QQmlEnginePrivate *qmlEngine,
     return result;
 }
 
-static void initQmlTypeResolver(QV4::IR::MemberExpressionResolver *resolver, QQmlType *qmlType)
+static void initQmlTypeResolver(QV4::IR::MemberExpressionResolver *resolver, const QQmlType &qmlType)
 {
     Q_ASSERT(resolver);
 
     resolver->resolveMember = &resolveQmlType;
-    resolver->data = qmlType;
-    resolver->extraData = 0;
+    resolver->qmlType = qmlType;
+    resolver->typenameCache = 0;
     resolver->flags = 0;
 }
 
@@ -1767,8 +2047,8 @@ static QV4::IR::DiscoveredType resolveImportNamespace(
         QV4::IR::Member *member)
 {
     QV4::IR::Type result = QV4::IR::VarType;
-    QQmlTypeNameCache *typeNamespace = static_cast<QQmlTypeNameCache*>(resolver->extraData);
-    void *importNamespace = resolver->data;
+    QQmlTypeNameCache *typeNamespace = resolver->typenameCache;
+    const QQmlImportRef *importNamespace = resolver->import;
 
     QQmlTypeNameCache::Result r = typeNamespace->query(*member->name, importNamespace);
     if (r.isValid()) {
@@ -1776,11 +2056,11 @@ static QV4::IR::DiscoveredType resolveImportNamespace(
         if (r.scriptIndex != -1) {
             // TODO: remember the index and replace with subscript later.
             result = QV4::IR::VarType;
-        } else if (r.type) {
+        } else if (r.type.isValid()) {
             // TODO: Propagate singleton information, so that it is loaded
             // through the singleton getter in the run-time. Until then we
             // can't accelerate access :(
-            if (!r.type->isSingleton()) {
+            if (!r.type.isSingleton()) {
                 auto newResolver = resolver->owner->New<QV4::IR::MemberExpressionResolver>();
                 newResolver->owner = resolver->owner;
                 initQmlTypeResolver(newResolver, r.type);
@@ -1795,11 +2075,11 @@ static QV4::IR::DiscoveredType resolveImportNamespace(
 }
 
 static void initImportNamespaceResolver(QV4::IR::MemberExpressionResolver *resolver,
-                                        QQmlTypeNameCache *imports, const void *importNamespace)
+                                        QQmlTypeNameCache *imports, const QQmlImportRef *importNamespace)
 {
     resolver->resolveMember = &resolveImportNamespace;
-    resolver->data = const_cast<void*>(importNamespace);
-    resolver->extraData = imports;
+    resolver->import = importNamespace;
+    resolver->typenameCache = imports;
     resolver->flags = 0;
 }
 
@@ -1808,7 +2088,7 @@ static QV4::IR::DiscoveredType resolveMetaObjectProperty(
         QV4::IR::Member *member)
 {
     QV4::IR::Type result = QV4::IR::VarType;
-    QQmlPropertyCache *metaObject = static_cast<QQmlPropertyCache*>(resolver->data);
+    QQmlPropertyCache *metaObject = resolver->propertyCache;
 
     if (member->name->constData()->isUpper() && (resolver->flags & LookupsIncludeEnums)) {
         const QMetaObject *mo = metaObject->createMetaObject();
@@ -1890,7 +2170,7 @@ static void initMetaObjectResolver(QV4::IR::MemberExpressionResolver *resolver,
     Q_ASSERT(resolver);
 
     resolver->resolveMember = &resolveMetaObjectProperty;
-    resolver->data = metaObject;
+    resolver->propertyCache = metaObject;
     resolver->flags = 0;
 }
 
@@ -1901,54 +2181,59 @@ static QV4::IR::DiscoveredType resolveScopedEnum(QQmlEnginePrivate *qmlEngine,
     if (!member->name->constData()->isUpper())
         return QV4::IR::VarType;
 
-    QQmlType *type = static_cast<QQmlType*>(resolver->data);
+    QQmlType type = resolver->qmlType;
     int index = resolver->flags;
 
     bool ok = false;
-    int value = type->scopedEnumValue(qmlEngine, index, *member->name, &ok);
+    int value = type.scopedEnumValue(qmlEngine, index, *member->name, &ok);
     if (!ok)
         return QV4::IR::VarType;
     member->setEnumValue(value);
     return QV4::IR::SInt32Type;
 }
 
-static void initScopedEnumResolver(QV4::IR::MemberExpressionResolver *resolver, QQmlType *qmlType, int index)
+static void initScopedEnumResolver(QV4::IR::MemberExpressionResolver *resolver, const QQmlType &qmlType, int index)
 {
     Q_ASSERT(resolver);
 
     resolver->resolveMember = &resolveScopedEnum;
-    resolver->data = qmlType;
-    resolver->extraData = 0;
+    resolver->qmlType = qmlType;
     resolver->flags = index;
 }
+#endif
 
 #endif // V4_BOOTSTRAP
 
 void JSCodeGen::beginFunctionBodyHook()
 {
-    _qmlContextTemp = _block->newTemp();
-    _importedScriptsTemp = _block->newTemp();
+    _qmlContextSlot = bytecodeGenerator->newRegister();
+    _importedScriptsSlot = bytecodeGenerator->newRegister();
 
 #ifndef V4_BOOTSTRAP
-    QV4::IR::Temp *temp = _block->TEMP(_qmlContextTemp);
+    Instruction::LoadQmlContext load;
+    load.result = Reference::fromStackSlot(this, _qmlContextSlot).stackSlot();
+    bytecodeGenerator->addInstruction(load);
+
+#if 0
     temp->type = QV4::IR::QObjectType;
     temp->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
     initMetaObjectResolver(temp->memberResolver, _scopeObject);
     auto name = _block->NAME(QV4::IR::Name::builtin_qml_context, 0, 0);
     name->type = temp->type;
-    move(temp, name);
+#endif
 
-    move(_block->TEMP(_importedScriptsTemp), _block->NAME(QV4::IR::Name::builtin_qml_imported_scripts_object, 0, 0));
+    Instruction::LoadQmlImportedScripts loadScripts;
+    loadScripts.result = Reference::fromStackSlot(this, _importedScriptsSlot).stackSlot();
+    bytecodeGenerator->addInstruction(loadScripts);
 #endif
 }
 
-QV4::IR::Expr *JSCodeGen::fallbackNameLookup(const QString &name, int line, int col)
+QV4::Compiler::Codegen::Reference JSCodeGen::fallbackNameLookup(const QString &name)
 {
-    Q_UNUSED(line)
-    Q_UNUSED(col)
 #ifndef V4_BOOTSTRAP
     if (_disableAcceleratedLookups)
-        return 0;
+        return Reference();
+
     // Implement QML lookup semantics in the current file context.
     //
     // Note: We do not check if properties of the qml scope object or context object
@@ -1963,20 +2248,16 @@ QV4::IR::Expr *JSCodeGen::fallbackNameLookup(const QString &name, int line, int
     // Look for IDs first.
     for (const IdMapping &mapping : qAsConst(_idObjects)) {
         if (name == mapping.name) {
-            if (_function->isQmlBinding)
-                _function->idObjectDependencies.insert(mapping.idIndex);
-
-            QV4::IR::Expr *s = _block->MEMBER(_block->TEMP(_qmlContextTemp), _function->newString(name), 0, QV4::IR::Member::MemberOfIdObjectsArray, mapping.idIndex);
-            QV4::IR::Temp *result = _block->TEMP(_block->newTemp());
-            _block->MOVE(result, s);
-            result = _block->TEMP(result->index);
-            if (mapping.type) {
-                result->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
-                result->memberResolver->owner = _function;
-                initMetaObjectResolver(result->memberResolver, mapping.type);
-                result->memberResolver->flags |= AllPropertiesAreFinal;
-            }
-            result->isReadOnly = true; // don't allow use as lvalue
+            if (_context->contextType == QV4::Compiler::ContextType::Binding)
+                _context->idObjectDependencies.insert(mapping.idIndex);
+
+            Instruction::LoadIdObject load;
+            load.base = Reference::fromStackSlot(this, _qmlContextSlot).stackSlot();
+            load.index = mapping.idIndex;
+
+            Reference result = Reference::fromAccumulator(this);
+            bytecodeGenerator->addInstruction(load);
+            result.isReadonly = true;
             return result;
         }
     }
@@ -1985,68 +2266,54 @@ QV4::IR::Expr *JSCodeGen::fallbackNameLookup(const QString &name, int line, int
         QQmlTypeNameCache::Result r = imports->query(name);
         if (r.isValid()) {
             if (r.scriptIndex != -1) {
-                return subscript(_block->TEMP(_importedScriptsTemp), _block->CONST(QV4::IR::SInt32Type, r.scriptIndex));
-            } else if (r.type) {
-                QV4::IR::Name *typeName = _block->NAME(name, line, col);
-                // Make sure the run-time loads this through the more efficient singleton getter.
-                typeName->qmlSingleton = r.type->isCompositeSingleton();
-                typeName->freeOfSideEffects = true;
-                QV4::IR::Temp *result = _block->TEMP(_block->newTemp());
-                _block->MOVE(result, typeName);
-
-                result = _block->TEMP(result->index);
-                result->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
-                result->memberResolver->owner = _function;
-                initQmlTypeResolver(result->memberResolver, r.type);
-                return result;
+                Reference imports = Reference::fromStackSlot(this, _importedScriptsSlot);
+                return Reference::fromSubscript(imports, Reference::fromConst(this, QV4::Encode(r.scriptIndex)));
+            } else if (r.type.isValid()) {
+                return Reference::fromName(this, name);
             } else {
                 Q_ASSERT(r.importNamespace);
-                QV4::IR::Name *namespaceName = _block->NAME(name, line, col);
-                namespaceName->freeOfSideEffects = true;
-                QV4::IR::Temp *result = _block->TEMP(_block->newTemp());
-                result->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
-                result->memberResolver->owner = _function;
-                initImportNamespaceResolver(result->memberResolver, imports, r.importNamespace);
-
-                _block->MOVE(result, namespaceName);
-                return _block->TEMP(result->index);
+                return Reference::fromName(this, name);
             }
         }
     }
 
     if (_scopeObject) {
-        bool propertyExistsButForceNameLookup = false;
-        QQmlPropertyData *pd = lookupQmlCompliantProperty(_scopeObject, name, &propertyExistsButForceNameLookup);
-        if (propertyExistsButForceNameLookup)
-            return 0;
-        if (pd) {
-            QV4::IR::Temp *base = _block->TEMP(_qmlContextTemp);
-            base->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
-            base->memberResolver->owner = _function;
-            initMetaObjectResolver(base->memberResolver, _scopeObject);
-            return _block->MEMBER(base, _function->newString(name), pd, QV4::IR::Member::MemberOfQmlScopeObject);
+        QQmlPropertyData *data = lookupQmlCompliantProperty(_scopeObject, name);
+        if (data) {
+            // Q_INVOKABLEs can't be FINAL, so we have to look them up at run-time
+            if (data->isFunction())
+                return Reference::fromName(this, name);
+
+            Reference base = Reference::fromStackSlot(this, _qmlContextSlot);
+            Reference::PropertyCapturePolicy capturePolicy;
+            if (!data->isConstant() && !data->isQmlBinding())
+                capturePolicy = Reference::CaptureAtRuntime;
+            else
+                capturePolicy = data->isConstant() ? Reference::DontCapture : Reference::CaptureAheadOfTime;
+            return Reference::fromQmlScopeObject(base, data->coreIndex(), data->notifyIndex(), capturePolicy);
         }
     }
 
     if (_contextObject) {
-        bool propertyExistsButForceNameLookup = false;
-        QQmlPropertyData *pd = lookupQmlCompliantProperty(_contextObject, name, &propertyExistsButForceNameLookup);
-        if (propertyExistsButForceNameLookup)
-            return 0;
-        if (pd) {
-            QV4::IR::Temp *base = _block->TEMP(_qmlContextTemp);
-            base->memberResolver = _function->New<QV4::IR::MemberExpressionResolver>();
-            base->memberResolver->owner = _function;
-            initMetaObjectResolver(base->memberResolver, _contextObject);
-            return _block->MEMBER(base, _function->newString(name), pd, QV4::IR::Member::MemberOfQmlContextObject);
+        QQmlPropertyData *data = lookupQmlCompliantProperty(_contextObject, name);
+        if (data) {
+            // Q_INVOKABLEs can't be FINAL, so we have to look them up at run-time
+            if (data->isFunction())
+                return Reference::fromName(this, name);
+
+            Reference base = Reference::fromStackSlot(this, _qmlContextSlot);
+            Reference::PropertyCapturePolicy capturePolicy;
+            if (!data->isConstant() && !data->isQmlBinding())
+                capturePolicy = Reference::CaptureAtRuntime;
+            else
+                capturePolicy = data->isConstant() ? Reference::DontCapture : Reference::CaptureAheadOfTime;
+            return Reference::fromQmlContextObject(base, data->coreIndex(), data->notifyIndex(), capturePolicy);
         }
     }
-
 #else
     Q_UNUSED(name)
 #endif // V4_BOOTSTRAP
-    // fall back to name lookup at run-time.
-    return 0;
+    return Reference();
 }
 
 #ifndef V4_BOOTSTRAP
@@ -2055,7 +2322,7 @@ QQmlPropertyData *PropertyResolver::property(const QString &name, bool *notInRev
 {
     if (notInRevision) *notInRevision = false;
 
-    QQmlPropertyData *d = cache->property(name, 0, 0);
+    QQmlPropertyData *d = cache->property(name, nullptr, nullptr);
 
     // Find the first property
     while (d && d->isFunction())
@@ -2063,7 +2330,7 @@ QQmlPropertyData *PropertyResolver::property(const QString &name, bool *notInRev
 
     if (check != IgnoreRevision && d && !cache->isAllowedInRevision(d)) {
         if (notInRevision) *notInRevision = true;
-        return 0;
+        return nullptr;
     } else {
         return d;
     }
@@ -2074,7 +2341,7 @@ QQmlPropertyData *PropertyResolver::signal(const QString &name, bool *notInRevis
 {
     if (notInRevision) *notInRevision = false;
 
-    QQmlPropertyData *d = cache->property(name, 0, 0);
+    QQmlPropertyData *d = cache->property(name, nullptr, nullptr);
     if (notInRevision) *notInRevision = false;
 
     while (d && !(d->isFunction()))
@@ -2082,7 +2349,7 @@ QQmlPropertyData *PropertyResolver::signal(const QString &name, bool *notInRevis
 
     if (d && !cache->isAllowedInRevision(d)) {
         if (notInRevision) *notInRevision = true;
-        return 0;
+        return nullptr;
     } else if (d && d->isSignal()) {
         return d;
     }
@@ -2095,7 +2362,7 @@ QQmlPropertyData *PropertyResolver::signal(const QString &name, bool *notInRevis
             return cache->signal(d->notifyIndex());
     }
 
-    return 0;
+    return nullptr;
 }
 
 IRLoader::IRLoader(const QV4::CompiledData::Unit *qmlData, QmlIR::Document *output)
@@ -2107,12 +2374,12 @@ IRLoader::IRLoader(const QV4::CompiledData::Unit *qmlData, QmlIR::Document *outp
 
 void IRLoader::load()
 {
-    output->jsGenerator.stringTable.clear();
-    for (uint i = 0; i < unit->stringTableSize; ++i)
-        output->jsGenerator.stringTable.registerString(unit->stringAt(i));
+    output->jsGenerator.stringTable.initializeFromBackingUnit(unit);
 
-    for (quint32 i = 0; i < unit->nImports; ++i)
-        output->imports << unit->importAt(i);
+    const QV4::CompiledData::QmlUnit *qmlUnit = unit->qmlUnit();
+
+    for (quint32 i = 0; i < qmlUnit->nImports; ++i)
+        output->imports << qmlUnit->importAt(i);
 
     if (unit->flags & QV4::CompiledData::Unit::IsSingleton) {
         QmlIR::Pragma *p = New<QmlIR::Pragma>();
@@ -2121,10 +2388,8 @@ void IRLoader::load()
         output->pragmas << p;
     }
 
-    output->indexOfRootObject = unit->indexOfRootObject;
-
-    for (uint i = 0; i < unit->nObjects; ++i) {
-        const QV4::CompiledData::Object *serializedObject = unit->objectAt(i);
+    for (uint i = 0; i < qmlUnit->nObjects; ++i) {
+        const QV4::CompiledData::Object *serializedObject = qmlUnit->objectAt(i);
         QmlIR::Object *object = loadObject(serializedObject);
         output->objects.append(object);
     }
@@ -2206,6 +2471,22 @@ QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedO
         object->qmlSignals->append(s);
     }
 
+    for (uint i = 0; i < serializedObject->nEnums; ++i) {
+        const QV4::CompiledData::Enum *serializedEnum = serializedObject->enumAt(i);
+        QmlIR::Enum *e = pool->New<QmlIR::Enum>();
+        e->nameIndex = serializedEnum->nameIndex;
+        e->location = serializedEnum->location;
+        e->enumValues = pool->New<QmlIR::PoolList<QmlIR::EnumValue> >();
+
+        for (uint i = 0; i < serializedEnum->nEnumValues; ++i) {
+            QmlIR::EnumValue *v = pool->New<QmlIR::EnumValue>();
+            *static_cast<QV4::CompiledData::EnumValue*>(v) = *serializedEnum->enumValueAt(i);
+            e->enumValues->append(v);
+        }
+
+        object->qmlEnums->append(e);
+    }
+
     const QV4::CompiledData::Property *serializedProperty = serializedObject->propertyTable();
     for (uint i = 0; i < serializedObject->nProperties; ++i, ++serializedProperty) {
         QmlIR::Property *p = pool->New<QmlIR::Property>();
@@ -2222,9 +2503,7 @@ QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedO
         }
     }
 
-    QQmlJS::Engine *jsParserEngine = &output->jsParserEngine;
-
-    const QV4::CompiledData::LEUInt32 *functionIdx = serializedObject->functionOffsetTable();
+    const quint32_le *functionIdx = serializedObject->functionOffsetTable();
     for (uint i = 0; i < serializedObject->nFunctions; ++i, ++functionIdx) {
         QmlIR::Function *f = pool->New<QmlIR::Function>();
         const QV4::CompiledData::Function *compiledFunction = unit->functionAt(*functionIdx);
@@ -2234,26 +2513,8 @@ QmlIR::Object *IRLoader::loadObject(const QV4::CompiledData::Object *serializedO
         f->location = compiledFunction->location;
         f->nameIndex = compiledFunction->nameIndex;
 
-        QQmlJS::AST::FormalParameterList *paramList = 0;
-        const QV4::CompiledData::LEUInt32 *formalNameIdx = compiledFunction->formalsTable();
-        for (uint i = 0; i < compiledFunction->nFormals; ++i, ++formalNameIdx) {
-            const QString formal = unit->stringAt(*formalNameIdx);
-            QStringRef paramNameRef = jsParserEngine->newStringRef(formal);
-
-            if (paramList)
-                paramList = new (pool) QQmlJS::AST::FormalParameterList(paramList, paramNameRef);
-            else
-                paramList = new (pool) QQmlJS::AST::FormalParameterList(paramNameRef);
-        }
-
-        if (paramList)
-            paramList = paramList->finish();
-
-        const QString name = unit->stringAt(compiledFunction->nameIndex);
-        f->functionDeclaration = new(pool) QQmlJS::AST::FunctionDeclaration(jsParserEngine->newStringRef(name), paramList, /*body*/0);
-
         f->formals.allocate(pool, int(compiledFunction->nFormals));
-        formalNameIdx = compiledFunction->formalsTable();
+        const quint32_le *formalNameIdx = compiledFunction->formalsTable();
         for (uint i = 0; i < compiledFunction->nFormals; ++i, ++formalNameIdx)
             f->formals[i] = *formalNameIdx;
 
diff --git a/src/qml/compiler/qqmlirbuilder_p.h b/src/qml/compiler/qqmlirbuilder_p.h
index 64bf111d9a..8512b22fbd 100644
--- a/src/qml/compiler/qqmlirbuilder_p.h
+++ b/src/qml/compiler/qqmlirbuilder_p.h
@@ -57,14 +57,9 @@
 #include <private/qqmljsmemorypool_p.h>
 #include <private/qv4codegen_p.h>
 #include <private/qv4compiler_p.h>
-#include <private/qqmljslexer_p.h>
 #include <QTextStream>
 #include <QCoreApplication>
 
-#ifndef V4_BOOTSTRAP
-#include <private/qqmlpropertycache_p.h>
-#endif
-
 QT_BEGIN_NAMESPACE
 
 class QQmlPropertyCache;
@@ -80,17 +75,16 @@ template <typename T>
 struct PoolList
 {
     PoolList()
-        : first(0)
-        , last(0)
-        , count(0)
+        : first(nullptr)
+        , last(nullptr)
     {}
 
     T *first;
     T *last;
-    int count;
+    int count = 0;
 
     int append(T *item) {
-        item->next = 0;
+        item->next = nullptr;
         if (last)
             last->next = item;
         else
@@ -110,7 +104,7 @@ struct PoolList
     template <typename Sortable, typename Base, Sortable Base::*sortMember>
     T *findSortedInsertionPoint(T *item) const
     {
-        T *insertPos = 0;
+        T *insertPos = nullptr;
 
         for (T *it = first; it; it = it->next) {
             if (!(it->*sortMember <= item->*sortMember))
@@ -200,70 +194,26 @@ struct PoolList
     Iterator end() { return Iterator(nullptr); }
 };
 
-template <typename T>
-class FixedPoolArray
-{
-    T *data;
-public:
-    int count;
-
-    FixedPoolArray()
-        : data(0)
-        , count(0)
-    {}
-
-    void allocate(QQmlJS::MemoryPool *pool, int size)
-    {
-        count = size;
-        data = reinterpret_cast<T*>(pool->allocate(count * sizeof(T)));
-    }
-
-    void allocate(QQmlJS::MemoryPool *pool, const QVector<T> &vector)
-    {
-        count = vector.count();
-        data = reinterpret_cast<T*>(pool->allocate(count * sizeof(T)));
-
-        if (QTypeInfo<T>::isComplex) {
-            for (int i = 0; i < count; ++i)
-                new (data + i) T(vector.at(i));
-        } else {
-            memcpy(data, static_cast<const void*>(vector.constData()), count * sizeof(T));
-        }
-    }
-
-    template <typename Container>
-    void allocate(QQmlJS::MemoryPool *pool, const Container &container)
-    {
-        count = container.count();
-        data = reinterpret_cast<T*>(pool->allocate(count * sizeof(T)));
-        typename Container::ConstIterator it = container.constBegin();
-        for (int i = 0; i < count; ++i)
-            new (data + i) T(*it++);
-    }
-
-    const T &at(int index) const {
-        Q_ASSERT(index >= 0 && index < count);
-        return data[index];
-    }
+struct Object;
 
-    T &operator[](int index) {
-        Q_ASSERT(index >= 0 && index < count);
-        return data[index];
-    }
+struct EnumValue : public QV4::CompiledData::EnumValue
+{
+    EnumValue *next;
+};
 
+struct Enum
+{
+    int nameIndex;
+    QV4::CompiledData::Location location;
+    PoolList<EnumValue> *enumValues;
 
-    int indexOf(const T &value) const {
-        for (int i = 0; i < count; ++i)
-            if (data[i] == value)
-                return i;
-        return -1;
-    }
+    int enumValueCount() const { return enumValues->count; }
+    PoolList<EnumValue>::Iterator enumValuesBegin() const { return enumValues->begin(); }
+    PoolList<EnumValue>::Iterator enumValuesEnd() const { return enumValues->end(); }
 
-    const T *begin() const { return data; }
-    const T *end() const { return data + count; }
+    Enum *next;
 };
 
-struct Object;
 
 struct SignalParameter : public QV4::CompiledData::Parameter
 {
@@ -307,7 +257,6 @@ struct Alias : public QV4::CompiledData::Alias
 
 struct Function
 {
-    QQmlJS::AST::FunctionDeclaration *functionDeclaration;
     QV4::CompiledData::Location location;
     int nameIndex;
     quint32 index; // index in parsedQML::functions
@@ -324,21 +273,13 @@ struct Function
 struct Q_QML_PRIVATE_EXPORT CompiledFunctionOrExpression
 {
     CompiledFunctionOrExpression()
-        : node(0)
-        , nameIndex(0)
-        , disableAcceleratedLookups(false)
-        , next(0)
-    {}
-    CompiledFunctionOrExpression(QQmlJS::AST::Node *n)
-        : node(n)
-        , nameIndex(0)
-        , disableAcceleratedLookups(false)
-        , next(0)
     {}
-    QQmlJS::AST::Node *node; // FunctionDeclaration, Statement or Expression
-    quint32 nameIndex;
-    bool disableAcceleratedLookups;
-    CompiledFunctionOrExpression *next;
+
+    QQmlJS::AST::Node *parentNode = nullptr; // FunctionDeclaration, Statement or Expression
+    QQmlJS::AST::Node *node = nullptr; // FunctionDeclaration, Statement or Expression
+    quint32 nameIndex = 0;
+    bool disableAcceleratedLookups = false;
+    CompiledFunctionOrExpression *next = nullptr;
 };
 
 struct Q_QML_PRIVATE_EXPORT Object
@@ -359,6 +300,8 @@ public:
     int propertyCount() const { return properties->count; }
     Alias *firstAlias() const { return aliases->first; }
     int aliasCount() const { return aliases->count; }
+    const Enum *firstEnum() const { return qmlEnums->first; }
+    int enumCount() const { return qmlEnums->count; }
     const Signal *firstSignal() const { return qmlSignals->first; }
     int signalCount() const { return qmlSignals->count; }
     Binding *firstBinding() const { return bindings->first; }
@@ -372,6 +315,8 @@ public:
     PoolList<Property>::Iterator propertiesEnd() const { return properties->end(); }
     PoolList<Alias>::Iterator aliasesBegin() const { return aliases->begin(); }
     PoolList<Alias>::Iterator aliasesEnd() const { return aliases->end(); }
+    PoolList<Enum>::Iterator enumsBegin() const { return qmlEnums->begin(); }
+    PoolList<Enum>::Iterator enumsEnd() const { return qmlEnums->end(); }
     PoolList<Signal>::Iterator signalsBegin() const { return qmlSignals->begin(); }
     PoolList<Signal>::Iterator signalsEnd() const { return qmlSignals->end(); }
     PoolList<Function>::Iterator functionsBegin() const { return functions->begin(); }
@@ -383,8 +328,7 @@ public:
 
     void init(QQmlJS::MemoryPool *pool, int typeNameIndex, int idIndex, const QQmlJS::AST::SourceLocation &location = QQmlJS::AST::SourceLocation());
 
-    QString sanityCheckFunctionNames(const QSet<QString> &illegalNames, QQmlJS::AST::SourceLocation *errorLocation);
-
+    QString appendEnum(Enum *enumeration);
     QString appendSignal(Signal *signal);
     QString appendProperty(Property *prop, const QString &propertyName, bool isDefaultProperty, const QQmlJS::AST::SourceLocation &defaultToken, QQmlJS::AST::SourceLocation *errorLocation);
     QString appendAlias(Alias *prop, const QString &aliasName, bool isDefaultProperty, const QQmlJS::AST::SourceLocation &defaultToken, QQmlJS::AST::SourceLocation *errorLocation);
@@ -400,7 +344,7 @@ public:
     FixedPoolArray<int> runtimeFunctionIndices;
 
     FixedPoolArray<quint32> namedObjectsInComponent;
-    int namedObjectsInComponentCount() const { return namedObjectsInComponent.count; }
+    int namedObjectsInComponentCount() const { return namedObjectsInComponent.size(); }
     const quint32 *namedObjectsInComponentTable() const { return namedObjectsInComponent.begin(); }
 
 private:
@@ -408,6 +352,7 @@ private:
 
     PoolList<Property> *properties;
     PoolList<Alias> *aliases;
+    PoolList<Enum> *qmlEnums;
     PoolList<Signal> *qmlSignals;
     PoolList<Binding> *bindings;
     PoolList<Function> *functions;
@@ -428,11 +373,10 @@ struct Q_QML_PRIVATE_EXPORT Document
     Document(bool debugMode);
     QString code;
     QQmlJS::Engine jsParserEngine;
-    QV4::IR::Module jsModule;
+    QV4::Compiler::Module jsModule;
     QList<const QV4::CompiledData::Import *> imports;
     QList<Pragma*> pragmas;
     QQmlJS::AST::UiProgram *program;
-    int indexOfRootObject;
     QVector<Object*> objects;
     QV4::Compiler::JSUnitGenerator jsGenerator;
 
@@ -444,14 +388,14 @@ struct Q_QML_PRIVATE_EXPORT Document
     static void removeScriptPragmas(QString &script);
 };
 
-struct Q_QML_PRIVATE_EXPORT ScriptDirectivesCollector : public QQmlJS::Directives
+class Q_QML_PRIVATE_EXPORT ScriptDirectivesCollector : public QQmlJS::Directives
 {
-    ScriptDirectivesCollector(QQmlJS::Engine *engine, QV4::Compiler::JSUnitGenerator *unitGenerator);
-
+    QmlIR::Document *document;
     QQmlJS::Engine *engine;
     QV4::Compiler::JSUnitGenerator *jsGenerator;
-    QList<const QV4::CompiledData::Import *> imports;
-    bool hasPragmaLibrary;
+
+public:
+    ScriptDirectivesCollector(QmlIR::Document *doc);
 
     void pragmaLibrary() override;
     void importFile(const QString &jsfile, const QString &module, int lineNumber, int column) override;
@@ -482,6 +426,7 @@ public:
     bool visit(QQmlJS::AST::UiArrayBinding *ast) override;
     bool visit(QQmlJS::AST::UiObjectBinding *ast) override;
     bool visit(QQmlJS::AST::UiObjectDefinition *ast) override;
+    bool visit(QQmlJS::AST::UiEnumDeclaration *ast) override;
     bool visit(QQmlJS::AST::UiPublicMember *ast) override;
     bool visit(QQmlJS::AST::UiScriptBinding *ast) override;
     bool visit(QQmlJS::AST::UiSourceElement *ast) override;
@@ -489,8 +434,8 @@ public:
     void accept(QQmlJS::AST::Node *node);
 
     // returns index in _objects
-    bool defineQMLObject(int *objectIndex, QQmlJS::AST::UiQualifiedId *qualifiedTypeNameId, const QQmlJS::AST::SourceLocation &location, QQmlJS::AST::UiObjectInitializer *initializer, Object *declarationsOverride = 0);
-    bool defineQMLObject(int *objectIndex, QQmlJS::AST::UiObjectDefinition *node, Object *declarationsOverride = 0)
+    bool defineQMLObject(int *objectIndex, QQmlJS::AST::UiQualifiedId *qualifiedTypeNameId, const QQmlJS::AST::SourceLocation &location, QQmlJS::AST::UiObjectInitializer *initializer, Object *declarationsOverride = nullptr);
+    bool defineQMLObject(int *objectIndex, QQmlJS::AST::UiObjectDefinition *node, Object *declarationsOverride = nullptr)
     { return defineQMLObject(objectIndex, node->qualifiedTypeNameId, node->qualifiedTypeNameId->firstSourceLocation(), node->initializer, declarationsOverride); }
 
     static QString asString(QQmlJS::AST::UiQualifiedId *node);
@@ -501,11 +446,12 @@ public:
     QStringRef textRefAt(const QQmlJS::AST::SourceLocation &first,
                          const QQmlJS::AST::SourceLocation &last) const;
 
-    void setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST::Statement *statement);
+    void setBindingValue(QV4::CompiledData::Binding *binding, QQmlJS::AST::Statement *statement, AST::Node *parentNode);
+    void tryGeneratingTranslationBinding(const QStringRef &base, QQmlJS::AST::ArgumentList *args, QV4::CompiledData::Binding *binding);
 
-    void appendBinding(QQmlJS::AST::UiQualifiedId *name, QQmlJS::AST::Statement *value);
+    void appendBinding(QQmlJS::AST::UiQualifiedId *name, QQmlJS::AST::Statement *value, AST::Node *parentNode);
     void appendBinding(QQmlJS::AST::UiQualifiedId *name, int objectIndex, bool isOnAssignment = false);
-    void appendBinding(const QQmlJS::AST::SourceLocation &qualifiedNameLocation, const QQmlJS::AST::SourceLocation &nameLocation, quint32 propertyNameIndex, QQmlJS::AST::Statement *value);
+    void appendBinding(const QQmlJS::AST::SourceLocation &qualifiedNameLocation, const QQmlJS::AST::SourceLocation &nameLocation, quint32 propertyNameIndex, QQmlJS::AST::Statement *value, AST::Node *parentNode);
     void appendBinding(const QQmlJS::AST::SourceLocation &qualifiedNameLocation, const QQmlJS::AST::SourceLocation &nameLocation, quint32 propertyNameIndex, int objectIndex, bool isListItem = false, bool isOnAssignment = false);
 
     bool appendAlias(QQmlJS::AST::UiPublicMember *node);
@@ -528,6 +474,8 @@ public:
     static bool isStatementNodeScript(QQmlJS::AST::Statement *statement);
     static bool isRedundantNullInitializerForPropertyDeclaration(Property *property, QQmlJS::AST::Statement *statement);
 
+    QString sanityCheckFunctionNames(Object *obj, const QSet<QString> &illegalNames, QQmlJS::AST::SourceLocation *errorLocation);
+
     QList<QQmlJS::DiagnosticMessage> errors;
 
     QSet<QString> illegalNames;
@@ -548,7 +496,7 @@ public:
 
 struct Q_QML_PRIVATE_EXPORT QmlUnitGenerator
 {
-    QV4::CompiledData::Unit *generate(Document &output, const QV4::CompiledData::DependentTypesHasher &dependencyHasher = QV4::CompiledData::DependentTypesHasher());
+    void generate(Document &output, const QV4::CompiledData::DependentTypesHasher &dependencyHasher = QV4::CompiledData::DependentTypesHasher());
 
 private:
     typedef bool (Binding::*BindingFilter)() const;
@@ -558,7 +506,7 @@ private:
 #ifndef V4_BOOTSTRAP
 struct Q_QML_EXPORT PropertyResolver
 {
-    PropertyResolver(const QQmlPropertyCache *cache)
+    PropertyResolver(const QQmlRefPointer<QQmlPropertyCache> &cache)
         : cache(cache)
     {}
 
@@ -572,20 +520,20 @@ struct Q_QML_EXPORT PropertyResolver
         IgnoreRevision
     };
 
-    QQmlPropertyData *property(const QString &name, bool *notInRevision = 0, RevisionCheck check = CheckRevision) const;
+    QQmlPropertyData *property(const QString &name, bool *notInRevision = nullptr, RevisionCheck check = CheckRevision) const;
 
     // This code must match the semantics of QQmlPropertyPrivate::findSignalByName
     QQmlPropertyData *signal(const QString &name, bool *notInRevision) const;
 
-    const QQmlPropertyCache *cache;
+    QQmlRefPointer<QQmlPropertyCache> cache;
 };
 #endif
 
-struct Q_QML_PRIVATE_EXPORT JSCodeGen : public QQmlJS::Codegen
+struct Q_QML_PRIVATE_EXPORT JSCodeGen : public QV4::Compiler::Codegen
 {
-    JSCodeGen(const QString &fileName, const QString &sourceCode, QV4::IR::Module *jsModule,
-              QQmlJS::Engine *jsEngine, QQmlJS::AST::UiProgram *qmlRoot, QQmlTypeNameCache *imports,
-              const QV4::Compiler::StringTableGenerator *stringPool);
+    JSCodeGen(const QString &sourceCode, QV4::Compiler::JSUnitGenerator *jsUnitGenerator, QV4::Compiler::Module *jsModule,
+              QQmlJS::Engine *jsEngine, QQmlJS::AST::UiProgram *qmlRoot,
+              QQmlTypeNameCache *imports, const QV4::Compiler::StringTableGenerator *stringPool, const QSet<QString> &globalNames);
 
     struct IdMapping
     {
@@ -601,12 +549,18 @@ struct Q_QML_PRIVATE_EXPORT JSCodeGen : public QQmlJS::Codegen
     // Returns mapping from input functions to index in IR::Module::functions / compiledData->runtimeFunctions
     QVector<int> generateJSCodeForFunctionsAndBindings(const QList<CompiledFunctionOrExpression> &functions);
 
+    int defineFunction(const QString &name, AST::Node *ast,
+                       AST::FormalParameterList *formals,
+                       AST::StatementList *body) override;
+
 protected:
     void beginFunctionBodyHook() override;
-    QV4::IR::Expr *fallbackNameLookup(const QString &name, int line, int col) override;
+    bool canAccelerateGlobalLookups() const override { return !_disableAcceleratedLookups; }
+    Reference fallbackNameLookup(const QString &name) override;
 
 private:
-    QQmlPropertyData *lookupQmlCompliantProperty(QQmlPropertyCache *cache, const QString &name, bool *propertyExistsButForceNameLookup = 0);
+    // returns nullptr if lookup needs to happen by name
+    QQmlPropertyData *lookupQmlCompliantProperty(QQmlPropertyCache *cache, const QString &name);
 
     QString sourceCode;
     QQmlJS::Engine *jsEngine; // needed for memory pool
@@ -618,8 +572,8 @@ private:
     ObjectIdMapping _idObjects;
     QQmlPropertyCache *_contextObject;
     QQmlPropertyCache *_scopeObject;
-    int _qmlContextTemp;
-    int _importedScriptsTemp;
+    int _qmlContextSlot;
+    int _importedScriptsSlot;
 };
 
 struct Q_QML_PRIVATE_EXPORT IRLoader {
@@ -639,6 +593,17 @@ private:
 
 } // namespace QmlIR
 
+struct QQmlCompileError
+{
+    QQmlCompileError() {}
+    QQmlCompileError(const QV4::CompiledData::Location &location, const QString &description)
+        : location(location), description(description) {}
+    QV4::CompiledData::Location location;
+    QString description;
+
+    bool isSet() const { return !description.isEmpty(); }
+};
+
 QT_END_NAMESPACE
 
 #endif // QQMLIRBUILDER_P_H
diff --git a/src/qml/compiler/qqmlpropertycachecreator.cpp b/src/qml/compiler/qqmlpropertycachecreator.cpp
index f8d63ec634..fb54da5b73 100644
--- a/src/qml/compiler/qqmlpropertycachecreator.cpp
+++ b/src/qml/compiler/qqmlpropertycachecreator.cpp
@@ -45,26 +45,54 @@ QT_BEGIN_NAMESPACE
 
 QAtomicInt QQmlPropertyCacheCreatorBase::classIndexCounter(0);
 
-QQmlBindingInstantiationContext::QQmlBindingInstantiationContext()
-    : referencingObjectIndex(-1)
-    , instantiatingBinding(nullptr)
-    , instantiatingProperty(nullptr)
+QQmlBindingInstantiationContext::QQmlBindingInstantiationContext(int referencingObjectIndex, const QV4::CompiledData::Binding *instantiatingBinding,
+                                                                 const QString &instantiatingPropertyName, QQmlPropertyCache *referencingObjectPropertyCache)
+    : referencingObjectIndex(referencingObjectIndex)
+    , instantiatingBinding(instantiatingBinding)
+    , instantiatingPropertyName(instantiatingPropertyName)
+    , referencingObjectPropertyCache(referencingObjectPropertyCache)
 {
+}
 
+bool QQmlBindingInstantiationContext::resolveInstantiatingProperty()
+{
+    if (!instantiatingBinding || instantiatingBinding->type != QV4::CompiledData::Binding::Type_GroupProperty)
+        return true;
+
+    Q_ASSERT(referencingObjectIndex >= 0);
+    Q_ASSERT(referencingObjectPropertyCache);
+    Q_ASSERT(instantiatingBinding->propertyNameIndex != 0);
+
+    bool notInRevision = false;
+    instantiatingProperty = QmlIR::PropertyResolver(referencingObjectPropertyCache).property(instantiatingPropertyName, &notInRevision, QmlIR::PropertyResolver::IgnoreRevision);
+    return instantiatingProperty != nullptr;
 }
 
-QQmlBindingInstantiationContext::QQmlBindingInstantiationContext(int referencingObjectIndex, const QV4::CompiledData::Binding *instantiatingBinding, const QString &instantiatingPropertyName, const QQmlPropertyCache *referencingObjectPropertyCache)
-    : referencingObjectIndex(referencingObjectIndex)
-    , instantiatingBinding(instantiatingBinding)
-    , instantiatingProperty(nullptr)
+QQmlRefPointer<QQmlPropertyCache> QQmlBindingInstantiationContext::instantiatingPropertyCache(QQmlEnginePrivate *enginePrivate) const
 {
-    if (instantiatingBinding && instantiatingBinding->type == QV4::CompiledData::Binding::Type_GroupProperty) {
-        Q_ASSERT(referencingObjectIndex >= 0);
-        Q_ASSERT(referencingObjectPropertyCache);
-        Q_ASSERT(instantiatingBinding->propertyNameIndex != 0);
+    if (instantiatingProperty) {
+        if (instantiatingProperty->isQObject()) {
+            return enginePrivate->rawPropertyCacheForType(instantiatingProperty->propType(), instantiatingProperty->typeMinorVersion());
+        } else if (const QMetaObject *vtmo = QQmlValueTypeFactory::metaObjectForMetaType(instantiatingProperty->propType())) {
+            return enginePrivate->cache(vtmo, instantiatingProperty->typeMinorVersion());
+        }
+    }
+    return QQmlRefPointer<QQmlPropertyCache>();
+}
+
+void QQmlPendingGroupPropertyBindings::resolveMissingPropertyCaches(QQmlEnginePrivate *enginePrivate, QQmlPropertyCacheVector *propertyCaches) const
+{
+    for (QQmlBindingInstantiationContext pendingBinding: *this) {
+        const int groupPropertyObjectIndex = pendingBinding.instantiatingBinding->value.objectIndex;
+
+        if (propertyCaches->at(groupPropertyObjectIndex))
+            continue;
+
+        if (!pendingBinding.resolveInstantiatingProperty())
+            continue;
 
-        bool notInRevision = false;
-        instantiatingProperty = QmlIR::PropertyResolver(referencingObjectPropertyCache).property(instantiatingPropertyName, &notInRevision);
+        auto cache = pendingBinding.instantiatingPropertyCache(enginePrivate);
+        propertyCaches->set(groupPropertyObjectIndex, cache);
     }
 }
 
diff --git a/src/qml/compiler/qqmlpropertycachecreator_p.h b/src/qml/compiler/qqmlpropertycachecreator_p.h
index 3c14abc019..7d416561bb 100644
--- a/src/qml/compiler/qqmlpropertycachecreator_p.h
+++ b/src/qml/compiler/qqmlpropertycachecreator_p.h
@@ -50,18 +50,32 @@
 // We mean it.
 //
 
-#include "qqmltypecompiler_p.h"
 #include <private/qqmlvaluetype_p.h>
 #include <private/qqmlengine_p.h>
+#include <private/qqmlmetaobject_p.h>
 
 QT_BEGIN_NAMESPACE
 
 struct QQmlBindingInstantiationContext {
-    QQmlBindingInstantiationContext();
-    QQmlBindingInstantiationContext(int referencingObjectIndex, const QV4::CompiledData::Binding *instantiatingBinding, const QString &instantiatingPropertyName, const QQmlPropertyCache *referencingObjectPropertyCache);
-    int referencingObjectIndex;
-    const QV4::CompiledData::Binding *instantiatingBinding;
-    QQmlPropertyData *instantiatingProperty;
+    QQmlBindingInstantiationContext() {}
+    QQmlBindingInstantiationContext(int referencingObjectIndex,
+                                    const QV4::CompiledData::Binding *instantiatingBinding,
+                                    const QString &instantiatingPropertyName,
+                                    QQmlPropertyCache *referencingObjectPropertyCache);
+
+    bool resolveInstantiatingProperty();
+    QQmlRefPointer<QQmlPropertyCache> instantiatingPropertyCache(QQmlEnginePrivate *enginePrivate) const;
+
+    int referencingObjectIndex = -1;
+    const QV4::CompiledData::Binding *instantiatingBinding = nullptr;
+    QString instantiatingPropertyName;
+    QQmlRefPointer<QQmlPropertyCache> referencingObjectPropertyCache;
+    QQmlPropertyData *instantiatingProperty = nullptr;
+};
+
+struct QQmlPendingGroupPropertyBindings : public QVector<QQmlBindingInstantiationContext>
+{
+    void resolveMissingPropertyCaches(QQmlEnginePrivate *enginePrivate, QQmlPropertyCacheVector *propertyCaches) const;
 };
 
 struct QQmlPropertyCacheCreatorBase
@@ -77,14 +91,17 @@ class QQmlPropertyCacheCreator : public QQmlPropertyCacheCreatorBase
 public:
     typedef typename ObjectContainer::CompiledObject CompiledObject;
 
-    QQmlPropertyCacheCreator(QQmlPropertyCacheVector *propertyCaches, QQmlEnginePrivate *enginePrivate, const ObjectContainer *objectContainer, const QQmlImports *imports);
+    QQmlPropertyCacheCreator(QQmlPropertyCacheVector *propertyCaches,
+                             QQmlPendingGroupPropertyBindings *pendingGroupPropertyBindings,
+                             QQmlEnginePrivate *enginePrivate,
+                             const ObjectContainer *objectContainer, const QQmlImports *imports);
 
     QQmlCompileError buildMetaObjects();
 
 protected:
     QQmlCompileError buildMetaObjectRecursively(int objectIndex, const QQmlBindingInstantiationContext &context);
-    QQmlPropertyCache *propertyCacheForObject(const CompiledObject *obj, const QQmlBindingInstantiationContext &context, QQmlCompileError *error) const;
-    QQmlCompileError createMetaObject(int objectIndex, const CompiledObject *obj, QQmlPropertyCache *baseTypeCache);
+    QQmlRefPointer<QQmlPropertyCache> propertyCacheForObject(const CompiledObject *obj, const QQmlBindingInstantiationContext &context, QQmlCompileError *error) const;
+    QQmlCompileError createMetaObject(int objectIndex, const CompiledObject *obj, const QQmlRefPointer<QQmlPropertyCache> &baseTypeCache);
 
     QString stringAt(int index) const { return objectContainer->stringAt(index); }
 
@@ -92,14 +109,19 @@ protected:
     const ObjectContainer * const objectContainer;
     const QQmlImports * const imports;
     QQmlPropertyCacheVector *propertyCaches;
+    QQmlPendingGroupPropertyBindings *pendingGroupPropertyBindings;
 };
 
 template <typename ObjectContainer>
-inline QQmlPropertyCacheCreator<ObjectContainer>::QQmlPropertyCacheCreator(QQmlPropertyCacheVector *propertyCaches, QQmlEnginePrivate *enginePrivate, const ObjectContainer *objectContainer, const QQmlImports *imports)
+inline QQmlPropertyCacheCreator<ObjectContainer>::QQmlPropertyCacheCreator(QQmlPropertyCacheVector *propertyCaches,
+                                                                           QQmlPendingGroupPropertyBindings *pendingGroupPropertyBindings,
+                                                                           QQmlEnginePrivate *enginePrivate,
+                                                                           const ObjectContainer *objectContainer, const QQmlImports *imports)
     : enginePrivate(enginePrivate)
     , objectContainer(objectContainer)
     , imports(imports)
     , propertyCaches(propertyCaches)
+    , pendingGroupPropertyBindings(pendingGroupPropertyBindings)
 {
     propertyCaches->resize(objectContainer->objectCount());
 }
@@ -108,7 +130,7 @@ template <typename ObjectContainer>
 inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObjects()
 {
     QQmlBindingInstantiationContext context;
-    return buildMetaObjectRecursively(objectContainer->rootObjectIndex(), context);
+    return buildMetaObjectRecursively(/*root object*/0, context);
 }
 
 template <typename ObjectContainer>
@@ -116,7 +138,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObje
 {
     const CompiledObject *obj = objectContainer->objectAt(objectIndex);
 
-    bool needVMEMetaObject = obj->propertyCount() != 0 || obj->aliasCount() != 0 || obj->signalCount() != 0 || obj->functionCount() != 0;
+    bool needVMEMetaObject = obj->propertyCount() != 0 || obj->aliasCount() != 0 || obj->signalCount() != 0 || obj->functionCount() != 0 || obj->enumCount() != 0;
     if (!needVMEMetaObject) {
         auto binding = obj->bindingsBegin();
         auto end = obj->bindingsEnd();
@@ -129,9 +151,9 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObje
                 if (context.instantiatingProperty && QQmlValueTypeFactory::isValueType(context.instantiatingProperty->propType())) {
                     if (!propertyCaches->needsVMEMetaObject(context.referencingObjectIndex)) {
                         const CompiledObject *obj = objectContainer->objectAt(context.referencingObjectIndex);
-                        auto *typeRef = objectContainer->resolvedTypes.value(obj->inheritedTypeNameIndex);
+                        auto *typeRef = objectContainer->resolvedType(obj->inheritedTypeNameIndex);
                         Q_ASSERT(typeRef);
-                        QQmlPropertyCache *baseTypeCache = typeRef->createPropertyCache(QQmlEnginePrivate::get(enginePrivate));
+                        QQmlRefPointer<QQmlPropertyCache> baseTypeCache = typeRef->createPropertyCache(QQmlEnginePrivate::get(enginePrivate));
                         QQmlCompileError error = createMetaObject(context.referencingObjectIndex, obj, baseTypeCache);
                         if (error.isSet())
                             return error;
@@ -145,7 +167,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObje
         }
     }
 
-    QQmlPropertyCache *baseTypeCache;
+    QQmlRefPointer<QQmlPropertyCache> baseTypeCache;
     {
         QQmlCompileError error;
         baseTypeCache = propertyCacheForObject(obj, context, &error);
@@ -169,6 +191,14 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObje
         for ( ; binding != end; ++binding)
             if (binding->type >= QV4::CompiledData::Binding::Type_Object) {
                 QQmlBindingInstantiationContext context(objectIndex, &(*binding), stringAt(binding->propertyNameIndex), thisCache);
+
+                // Binding to group property where we failed to look up the type of the
+                // property? Possibly a group property that is an alias that's not resolved yet.
+                // Let's attempt to resolve it after we're done with the aliases and fill in the
+                // propertyCaches entry then.
+                if (!context.resolveInstantiatingProperty())
+                    pendingGroupPropertyBindings->append(context);
+
                 QQmlCompileError error = buildMetaObjectRecursively(binding->value.objectIndex, context);
                 if (error.isSet())
                     return error;
@@ -180,16 +210,12 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::buildMetaObje
 }
 
 template <typename ObjectContainer>
-inline QQmlPropertyCache *QQmlPropertyCacheCreator<ObjectContainer>::propertyCacheForObject(const CompiledObject *obj, const QQmlBindingInstantiationContext &context, QQmlCompileError *error) const
+inline QQmlRefPointer<QQmlPropertyCache> QQmlPropertyCacheCreator<ObjectContainer>::propertyCacheForObject(const CompiledObject *obj, const QQmlBindingInstantiationContext &context, QQmlCompileError *error) const
 {
     if (context.instantiatingProperty) {
-        if (context.instantiatingProperty->isQObject()) {
-            return enginePrivate->rawPropertyCacheForType(context.instantiatingProperty->propType());
-        } else if (const QMetaObject *vtmo = QQmlValueTypeFactory::metaObjectForMetaType(context.instantiatingProperty->propType())) {
-            return enginePrivate->cache(vtmo);
-        }
+        return context.instantiatingPropertyCache(enginePrivate);
     } else if (obj->inheritedTypeNameIndex != 0) {
-        auto *typeRef = objectContainer->resolvedTypes.value(obj->inheritedTypeNameIndex);
+        auto *typeRef = objectContainer->resolvedType(obj->inheritedTypeNameIndex);
         Q_ASSERT(typeRef);
 
         if (typeRef->isFullyDynamicType) {
@@ -209,26 +235,25 @@ inline QQmlPropertyCache *QQmlPropertyCacheCreator<ObjectContainer>::propertyCac
 
         return typeRef->createPropertyCache(QQmlEnginePrivate::get(enginePrivate));
     } else if (context.instantiatingBinding && context.instantiatingBinding->isAttachedProperty()) {
-        auto *typeRef = objectContainer->resolvedTypes.value(context.instantiatingBinding->propertyNameIndex);
+        auto *typeRef = objectContainer->resolvedType(
+                context.instantiatingBinding->propertyNameIndex);
         Q_ASSERT(typeRef);
-        QQmlType *qmltype = typeRef->type;
-        if (!qmltype) {
+        QQmlType qmltype = typeRef->type;
+        if (!qmltype.isValid()) {
             QString propertyName = stringAt(context.instantiatingBinding->propertyNameIndex);
-            if (imports->resolveType(propertyName, &qmltype, 0, 0, 0)) {
-                if (qmltype->isComposite()) {
-                    QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype->sourceUrl());
+            if (imports->resolveType(propertyName, &qmltype, nullptr, nullptr, nullptr)) {
+                if (qmltype.isComposite()) {
+                    QQmlRefPointer<QQmlTypeData> tdata = enginePrivate->typeLoader.getType(qmltype.sourceUrl());
                     Q_ASSERT(tdata);
                     Q_ASSERT(tdata->isComplete());
 
                     auto compilationUnit = tdata->compilationUnit();
                     qmltype = QQmlMetaType::qmlType(compilationUnit->metaTypeId);
-
-                    tdata->release();
                 }
             }
         }
 
-        const QMetaObject *attachedMo = qmltype ? qmltype->attachedPropertiesType(enginePrivate) : 0;
+        const QMetaObject *attachedMo = qmltype.attachedPropertiesType(enginePrivate);
         if (!attachedMo) {
             *error = QQmlCompileError(context.instantiatingBinding->location, QQmlPropertyCacheCreatorBase::tr("Non-existent attached object"));
             return nullptr;
@@ -239,12 +264,12 @@ inline QQmlPropertyCache *QQmlPropertyCacheCreator<ObjectContainer>::propertyCac
 }
 
 template <typename ObjectContainer>
-inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObject(int objectIndex, const CompiledObject *obj, QQmlPropertyCache *baseTypeCache)
+inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObject(int objectIndex, const CompiledObject *obj, const QQmlRefPointer<QQmlPropertyCache> &baseTypeCache)
 {
     QQmlRefPointer<QQmlPropertyCache> cache;
     cache.adopt(baseTypeCache->copyAndReserve(obj->propertyCount() + obj->aliasCount(),
                                               obj->functionCount() + obj->propertyCount() + obj->aliasCount() + obj->signalCount(),
-                                              obj->signalCount() + obj->propertyCount() + obj->aliasCount()));
+                                              obj->signalCount() + obj->propertyCount() + obj->aliasCount(), obj->enumCount()));
 
     propertyCaches->set(objectIndex, cache);
     propertyCaches->setNeedsVMEMetaObject(objectIndex);
@@ -278,7 +303,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
 
     QByteArray newClassName;
 
-    if (objectIndex == objectContainer->rootObjectIndex()) {
+    if (objectIndex == /*root object*/0) {
         const QString path = objectContainer->url().path();
         int lastSlash = path.lastIndexOf(QLatin1Char('/'));
         if (lastSlash > -1) {
@@ -289,7 +314,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
         }
     }
     if (newClassName.isEmpty()) {
-        newClassName = QQmlMetaObject(baseTypeCache).className();
+        newClassName = QQmlMetaObject(baseTypeCache.data()).className();
         newClassName.append("_QML_");
         newClassName.append(QByteArray::number(classIndexCounter.fetchAndAddRelaxed(1)));
     }
@@ -329,7 +354,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
     // and throw an error if there is a signal/method defined as an override.
     QSet<QString> seenSignals;
     seenSignals << QStringLiteral("destroyed") << QStringLiteral("parentChanged") << QStringLiteral("objectNameChanged");
-    QQmlPropertyCache *parentCache = cache;
+    QQmlPropertyCache *parentCache = cache.data();
     while ((parentCache = parentCache->parent())) {
         if (int pSigCount = parentCache->signalCount()) {
             int pSigOffset = parentCache->signalOffset();
@@ -370,6 +395,21 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
         cache->appendSignal(changedSigName, flags, effectiveMethodIndex++);
     }
 
+    auto e = obj->enumsBegin();
+    auto eend = obj->enumsEnd();
+    for ( ; e != eend; ++e) {
+        const int enumValueCount = e->enumValueCount();
+        QVector<QQmlEnumValue> values;
+        values.reserve(enumValueCount);
+
+        auto enumValue = e->enumValuesBegin();
+        auto end = e->enumValuesEnd();
+        for ( ; enumValue != end; ++enumValue)
+            values.append(QQmlEnumValue(stringAt(enumValue->nameIndex), enumValue->value));
+
+        cache->appendEnum(stringAt(e->nameIndex), values);
+    }
+
     // Dynamic signals
     auto s = obj->signalsBegin();
     auto send = obj->signalsEnd();
@@ -395,22 +435,20 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
                     // lazily resolved type
                     Q_ASSERT(param->type == QV4::CompiledData::Property::Custom);
                     const QString customTypeName = stringAt(param->customTypeNameIndex);
-                    QQmlType *qmltype = 0;
-                    if (!imports->resolveType(customTypeName, &qmltype, 0, 0, 0))
+                    QQmlType qmltype;
+                    if (!imports->resolveType(customTypeName, &qmltype, nullptr, nullptr, nullptr))
                         return QQmlCompileError(s->location, QQmlPropertyCacheCreatorBase::tr("Invalid signal parameter type: %1").arg(customTypeName));
 
-                    if (qmltype->isComposite()) {
-                        QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype->sourceUrl());
+                    if (qmltype.isComposite()) {
+                        QQmlRefPointer<QQmlTypeData> tdata = enginePrivate->typeLoader.getType(qmltype.sourceUrl());
                         Q_ASSERT(tdata);
                         Q_ASSERT(tdata->isComplete());
 
                         auto compilationUnit = tdata->compilationUnit();
 
                         paramTypes[i + 1] = compilationUnit->metaTypeId;
-
-                        tdata->release();
                     } else {
-                        paramTypes[i + 1] = qmltype->typeId();
+                        paramTypes[i + 1] = qmltype.typeId();
                     }
                 }
             }
@@ -426,7 +464,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
         seenSignals.insert(signalName);
 
         cache->appendSignal(signalName, flags, effectiveMethodIndex++,
-                            paramCount?paramTypes.constData():0, names);
+                            paramCount?paramTypes.constData():nullptr, names);
     }
 
 
@@ -461,6 +499,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
     pend = obj->propertiesEnd();
     for ( ; p != pend; ++p, ++propertyIdx) {
         int propertyType = 0;
+        int propertTypeMinorVersion = 0;
         QQmlPropertyData::Flags propertyFlags;
 
         if (p->type == QV4::CompiledData::Property::Var) {
@@ -475,14 +514,14 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
             Q_ASSERT(p->type == QV4::CompiledData::Property::CustomList ||
                      p->type == QV4::CompiledData::Property::Custom);
 
-            QQmlType *qmltype = 0;
-            if (!imports->resolveType(stringAt(p->customTypeNameIndex), &qmltype, 0, 0, 0)) {
+            QQmlType qmltype;
+            if (!imports->resolveType(stringAt(p->customTypeNameIndex), &qmltype, nullptr, nullptr, nullptr)) {
                 return QQmlCompileError(p->location, QQmlPropertyCacheCreatorBase::tr("Invalid property type"));
             }
 
-            Q_ASSERT(qmltype);
-            if (qmltype->isComposite()) {
-                QQmlTypeData *tdata = enginePrivate->typeLoader.getType(qmltype->sourceUrl());
+            Q_ASSERT(qmltype.isValid());
+            if (qmltype.isComposite()) {
+                QQmlRefPointer<QQmlTypeData> tdata = enginePrivate->typeLoader.getType(qmltype.sourceUrl());
                 Q_ASSERT(tdata);
                 Q_ASSERT(tdata->isComplete());
 
@@ -493,13 +532,12 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
                 } else {
                     propertyType = compilationUnit->listMetaTypeId;
                 }
-
-                tdata->release();
             } else {
                 if (p->type == QV4::CompiledData::Property::Custom) {
-                    propertyType = qmltype->typeId();
+                    propertyType = qmltype.typeId();
+                    propertTypeMinorVersion = qmltype.minorVersion();
                 } else {
-                    propertyType = qmltype->qListTypeId();
+                    propertyType = qmltype.qListTypeId();
                 }
             }
 
@@ -517,7 +555,7 @@ inline QQmlCompileError QQmlPropertyCacheCreator<ObjectContainer>::createMetaObj
         if (!obj->defaultPropertyIsAlias && propertyIdx == obj->indexOfDefaultPropertyOrAlias)
             cache->_defaultPropertyName = propertyName;
         cache->appendProperty(propertyName, propertyFlags, effectivePropertyIndex++,
-                              propertyType, effectiveSignalIndex);
+                              propertyType, propertTypeMinorVersion, effectiveSignalIndex);
 
         effectiveSignalIndex++;
     }
@@ -536,11 +574,11 @@ public:
 
     void appendAliasPropertiesToMetaObjects();
 
-    void appendAliasesToPropertyCache(const CompiledObject &component, int objectIndex);
+    QQmlCompileError appendAliasesToPropertyCache(const CompiledObject &component, int objectIndex);
 
 private:
     void appendAliasPropertiesInMetaObjectsWithinComponent(const CompiledObject &component, int firstObjectIndex);
-    void propertyDataForAlias(const CompiledObject &component, const QV4::CompiledData::Alias &alias, int *type, QQmlPropertyRawData::Flags *propertyFlags);
+    QQmlCompileError propertyDataForAlias(const CompiledObject &component, const QV4::CompiledData::Alias &alias, int *type, int *rev, QQmlPropertyRawData::Flags *propertyFlags);
 
     void collectObjectsWithAliasesRecursively(int objectIndex, QVector<int> *objectsWithAliases) const;
 
@@ -561,7 +599,9 @@ inline QQmlPropertyCacheAliasCreator<ObjectContainer>::QQmlPropertyCacheAliasCre
 template <typename ObjectContainer>
 inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasPropertiesToMetaObjects()
 {
-    for (int i = 0; i < objectContainer->objectCount(); ++i) {
+    // skip the root object (index 0) as that one does not have a first object index originating
+    // from a binding.
+    for (int i = 1; i < objectContainer->objectCount(); ++i) {
         const CompiledObject &component = *objectContainer->objectAt(i);
         if (!(component.flags & QV4::CompiledData::Object::IsComponent))
             continue;
@@ -570,7 +610,7 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasPropertie
         appendAliasPropertiesInMetaObjectsWithinComponent(component, rootBinding->value.objectIndex);
     }
 
-    const int rootObjectIndex = objectContainer->rootObjectIndex();
+    const int rootObjectIndex = 0;
     appendAliasPropertiesInMetaObjectsWithinComponent(*objectContainer->objectAt(rootObjectIndex), rootObjectIndex);
 }
 
@@ -633,7 +673,7 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::collectObjectsWithAl
         objectsWithAliases->append(objectIndex);
 
     // Stop at Component boundary
-    if (object.flags & QV4::CompiledData::Object::IsComponent && objectIndex != objectContainer->rootObjectIndex())
+    if (object.flags & QV4::CompiledData::Object::IsComponent && objectIndex != /*root object*/0)
         return;
 
     auto binding = object.bindingsBegin();
@@ -649,8 +689,8 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::collectObjectsWithAl
 }
 
 template <typename ObjectContainer>
-inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataForAlias(
-        const CompiledObject &component, const QV4::CompiledData::Alias &alias, int *type,
+inline QQmlCompileError QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataForAlias(
+        const CompiledObject &component, const QV4::CompiledData::Alias &alias, int *type, int *minorVersion,
         QQmlPropertyData::Flags *propertyFlags)
 {
     const int targetObjectIndex = objectForId(component, alias.targetObjectId);
@@ -668,18 +708,24 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataForAlias
         auto targetAlias = targetObject.aliasesBegin();
         for (uint i = 0; i < alias.localAliasIndex; ++i)
             ++targetAlias;
-        propertyDataForAlias(component, *targetAlias, type, propertyFlags);
-        return;
+        return propertyDataForAlias(component, *targetAlias, type, minorVersion, propertyFlags);
     } else if (alias.encodedMetaPropertyIndex == -1) {
         Q_ASSERT(alias.flags & QV4::CompiledData::Alias::AliasPointsToPointerObject);
-        auto *typeRef = objectContainer->resolvedTypes.value(targetObject.inheritedTypeNameIndex);
-        Q_ASSERT(typeRef);
+        auto *typeRef = objectContainer->resolvedType(targetObject.inheritedTypeNameIndex);
+        if (!typeRef) {
+            // Can be caused by the alias target not being a valid id or property. E.g.:
+            // property alias dataValue: dataVal
+            // invalidAliasComponent { id: dataVal }
+            return QQmlCompileError(targetObject.location, QQmlPropertyCacheCreatorBase::tr("Invalid alias target"));
+        }
 
-        if (typeRef->type)
-            *type = typeRef->type->typeId();
+        if (typeRef->type.isValid())
+            *type = typeRef->type.typeId();
         else
             *type = typeRef->compilationUnit->metaTypeId;
 
+        *minorVersion = typeRef->minorVersion;
+
         propertyFlags->type = QQmlPropertyData::Flags::QObjectDerivedType;
     } else {
         int coreIndex = QQmlPropertyIndex::fromEncoded(alias.encodedMetaPropertyIndex).coreIndex();
@@ -716,15 +762,16 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::propertyDataForAlias
 
     propertyFlags->isWritable = !(alias.flags & QV4::CompiledData::Property::IsReadOnly) && writable;
     propertyFlags->isResettable = resettable;
+    return QQmlCompileError();
 }
 
 template <typename ObjectContainer>
-inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasesToPropertyCache(
+inline QQmlCompileError QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasesToPropertyCache(
         const CompiledObject &component, int objectIndex)
 {
     const CompiledObject &object = *objectContainer->objectAt(objectIndex);
     if (!object.aliasCount())
-        return;
+        return QQmlCompileError();
 
     QQmlPropertyCache *propertyCache = propertyCaches->at(objectIndex);
     Q_ASSERT(propertyCache);
@@ -739,8 +786,11 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasesToPrope
         Q_ASSERT(alias->flags & QV4::CompiledData::Alias::Resolved);
 
         int type = 0;
+        int minorVersion = 0;
         QQmlPropertyData::Flags propertyFlags;
-        propertyDataForAlias(component, *alias, &type, &propertyFlags);
+        QQmlCompileError error = propertyDataForAlias(component, *alias, &type, &minorVersion, &propertyFlags);
+        if (error.isSet())
+            return error;
 
         const QString propertyName = objectContainer->stringAt(alias->nameIndex);
 
@@ -748,8 +798,10 @@ inline void QQmlPropertyCacheAliasCreator<ObjectContainer>::appendAliasesToPrope
             propertyCache->_defaultPropertyName = propertyName;
 
         propertyCache->appendProperty(propertyName, propertyFlags, effectivePropertyIndex++,
-                                      type, effectiveSignalIndex++);
+                                      type, minorVersion, effectiveSignalIndex++);
     }
+
+    return QQmlCompileError();
 }
 
 template <typename ObjectContainer>
diff --git a/src/qml/compiler/qqmlpropertyvalidator.cpp b/src/qml/compiler/qqmlpropertyvalidator.cpp
index 383c20239f..4714f505a7 100644
--- a/src/qml/compiler/qqmlpropertyvalidator.cpp
+++ b/src/qml/compiler/qqmlpropertyvalidator.cpp
@@ -45,20 +45,20 @@
 
 QT_BEGIN_NAMESPACE
 
-QQmlPropertyValidator::QQmlPropertyValidator(QQmlEnginePrivate *enginePrivate, const QQmlImports &imports, QV4::CompiledData::CompilationUnit *compilationUnit)
+QQmlPropertyValidator::QQmlPropertyValidator(QQmlEnginePrivate *enginePrivate, const QQmlImports &imports, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit)
     : enginePrivate(enginePrivate)
+    , compilationUnit(compilationUnit)
     , imports(imports)
-    , qmlUnit(compilationUnit->data)
-    , resolvedTypes(compilationUnit->resolvedTypes)
+    , qmlUnit(compilationUnit->unitData())
     , propertyCaches(compilationUnit->propertyCaches)
     , bindingPropertyDataPerObject(&compilationUnit->bindingPropertyDataPerObject)
 {
-    bindingPropertyDataPerObject->resize(qmlUnit->nObjects);
+    bindingPropertyDataPerObject->resize(compilationUnit->objectCount());
 }
 
 QVector<QQmlCompileError> QQmlPropertyValidator::validate()
 {
-    return validateObject(qmlUnit->indexOfRootObject, /*instantiatingBinding*/0);
+    return validateObject(/*root object*/0, /*instantiatingBinding*/nullptr);
 }
 
 typedef QVarLengthArray<const QV4::CompiledData::Binding *, 8> GroupPropertyVector;
@@ -81,7 +81,7 @@ struct BindingFinder
 
 QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex, const QV4::CompiledData::Binding *instantiatingBinding, bool populatingValueTypeGroupProperty) const
 {
-    const QV4::CompiledData::Object *obj = qmlUnit->objectAt(objectIndex);
+    const QV4::CompiledData::Object *obj = compilationUnit->objectAt(objectIndex);
 
     if (obj->flags & QV4::CompiledData::Object::IsComponent) {
         Q_ASSERT(obj->nBindings == 1);
@@ -94,20 +94,10 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
     if (!propertyCache)
         return QVector<QQmlCompileError>();
 
-    QStringList deferredPropertyNames;
-    {
-        const QMetaObject *mo = propertyCache->firstCppMetaObject();
-        const int namesIndex = mo->indexOfClassInfo("DeferredPropertyNames");
-        if (namesIndex != -1) {
-            QMetaClassInfo classInfo = mo->classInfo(namesIndex);
-            deferredPropertyNames = QString::fromUtf8(classInfo.value()).split(QLatin1Char(','));
-        }
-    }
-
-    QQmlCustomParser *customParser = 0;
-    if (auto typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex)) {
-        if (typeRef->type)
-            customParser = typeRef->type->customParser();
+    QQmlCustomParser *customParser = nullptr;
+    if (auto typeRef = resolvedType(obj->inheritedTypeNameIndex)) {
+        if (typeRef->type.isValid())
+            customParser = typeRef->type.customParser();
     }
 
     QList<const QV4::CompiledData::Binding*> customBindings;
@@ -134,7 +124,7 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
     QmlIR::PropertyResolver propertyResolver(propertyCache);
 
     QString defaultPropertyName;
-    QQmlPropertyData *defaultProperty = 0;
+    QQmlPropertyData *defaultProperty = nullptr;
     if (obj->indexOfDefaultPropertyOrAlias != -1) {
         QQmlPropertyCache *cache = propertyCache->parent();
         defaultPropertyName = cache->defaultPropertyName();
@@ -167,19 +157,21 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
         bool isGroupProperty = instantiatingBinding && instantiatingBinding->type == QV4::CompiledData::Binding::Type_GroupProperty;
 
         bool notInRevision = false;
-        QQmlPropertyData *pd = 0;
+        QQmlPropertyData *pd = nullptr;
         if (!name.isEmpty()) {
             if (binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression
-                || binding->flags & QV4::CompiledData::Binding::IsSignalHandlerObject)
+                || binding->flags & QV4::CompiledData::Binding::IsSignalHandlerObject) {
                 pd = propertyResolver.signal(name, &notInRevision);
-            else
-                pd = propertyResolver.property(name, &notInRevision, isGroupProperty ? QmlIR::PropertyResolver::IgnoreRevision : QmlIR::PropertyResolver::CheckRevision);
+            } else {
+                pd = propertyResolver.property(name, &notInRevision,
+                                               QmlIR::PropertyResolver::CheckRevision);
+            }
 
             if (notInRevision) {
                 QString typeName = stringAt(obj->inheritedTypeNameIndex);
-                auto *objectType = resolvedTypes.value(obj->inheritedTypeNameIndex);
-                if (objectType && objectType->type) {
-                    return recordError(binding->location, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(name).arg(objectType->type->module()).arg(objectType->majorVersion).arg(objectType->minorVersion));
+                auto *objectType = resolvedType(obj->inheritedTypeNameIndex);
+                if (objectType && objectType->type.isValid()) {
+                    return recordError(binding->location, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(name).arg(objectType->type.module()).arg(objectType->majorVersion).arg(objectType->minorVersion));
                 } else {
                     return recordError(binding->location, tr("\"%1.%2\" is not available due to component versioning.").arg(typeName).arg(name));
                 }
@@ -197,16 +189,22 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
             collectedBindingPropertyData[i] = pd;
 
         if (name.constData()->isUpper() && !binding->isAttachedProperty()) {
-            QQmlType *type = 0;
-            QQmlImportNamespace *typeNamespace = 0;
-            imports.resolveType(stringAt(binding->propertyNameIndex), &type, 0, 0, &typeNamespace);
+            QQmlType type;
+            QQmlImportNamespace *typeNamespace = nullptr;
+            imports.resolveType(stringAt(binding->propertyNameIndex), &type, nullptr, nullptr, &typeNamespace);
             if (typeNamespace)
                 return recordError(binding->location, tr("Invalid use of namespace"));
             return recordError(binding->location, tr("Invalid attached object assignment"));
         }
 
         if (binding->type >= QV4::CompiledData::Binding::Type_Object && (pd || binding->isAttachedProperty())) {
-            const QVector<QQmlCompileError> subObjectValidatorErrors = validateObject(binding->value.objectIndex, binding, pd && QQmlValueTypeFactory::metaObjectForMetaType(pd->propType()));
+            const bool populatingValueTypeGroupProperty
+                    = pd
+                      && QQmlValueTypeFactory::metaObjectForMetaType(pd->propType())
+                      && !(binding->flags & QV4::CompiledData::Binding::IsOnAssignment);
+            const QVector<QQmlCompileError> subObjectValidatorErrors
+                    = validateObject(binding->value.objectIndex, binding,
+                                     populatingValueTypeGroupProperty);
             if (!subObjectValidatorErrors.isEmpty())
                 return subObjectValidatorErrors;
         }
@@ -279,7 +277,11 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
                     }
                 } else {
                     if (!enginePrivate->propertyCacheForType(pd->propType())) {
-                        return recordError(binding->location, tr("Invalid grouped property access"));
+                        return recordError(binding->location,
+                                           tr("Invalid grouped property access: Property \"%1\" with type \"%2\", which is not a value type")
+                                           .arg(name)
+                                           .arg(QString::fromLatin1(QMetaType::typeName(pd->propType())))
+                                          );
                     }
                 }
             }
@@ -297,6 +299,9 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
     }
 
     if (obj->idNameIndex) {
+        if (populatingValueTypeGroupProperty)
+            return recordError(obj->locationOfIdProperty, tr("Invalid use of id property with a value type"));
+
         bool notInRevision = false;
         collectedBindingPropertyData << propertyResolver.property(QStringLiteral("id"), &notInRevision);
     }
@@ -306,10 +311,10 @@ QVector<QQmlCompileError> QQmlPropertyValidator::validateObject(int objectIndex,
         customParser->validator = this;
         customParser->engine = enginePrivate;
         customParser->imports = &imports;
-        customParser->verifyBindings(qmlUnit, customBindings);
-        customParser->validator = 0;
-        customParser->engine = 0;
-        customParser->imports = (QQmlImports*)0;
+        customParser->verifyBindings(compilationUnit, customBindings);
+        customParser->validator = nullptr;
+        customParser->engine = nullptr;
+        customParser->imports = (QQmlImports*)nullptr;
         QVector<QQmlCompileError> parserErrors = customParser->errors();
         if (!parserErrors.isEmpty())
             return parserErrors;
@@ -333,7 +338,7 @@ QQmlCompileError QQmlPropertyValidator::validateLiteralBinding(QQmlPropertyCache
         if (binding->flags & QV4::CompiledData::Binding::IsResolvedEnum)
             return noError;
 
-        QString value = binding->valueAsString(qmlUnit);
+        QString value = binding->valueAsString(compilationUnit.data());
         QMetaProperty p = propertyCache->firstCppMetaObject()->property(property->coreIndex());
         bool ok;
         if (p.isFlagType()) {
@@ -347,148 +352,163 @@ QQmlCompileError QQmlPropertyValidator::validateLiteralBinding(QQmlPropertyCache
         return noError;
     }
 
+    auto warnOrError = [&](const QString &error) {
+        if (binding->type == QV4::CompiledData::Binding::Type_Null) {
+            QQmlError warning;
+            warning.setUrl(compilationUnit->url());
+            warning.setLine(binding->valueLocation.line);
+            warning.setColumn(binding->valueLocation.column);
+            warning.setDescription(error + tr(" - Assigning null to incompatible properties in QML "
+                                              "is deprecated. This will become a compile error in "
+                                              "future versions of Qt."));
+            enginePrivate->warning(warning);
+            return noError;
+        }
+        return QQmlCompileError(binding->valueLocation, error);
+    };
+
     switch (property->propType()) {
     case QMetaType::QVariant:
     break;
     case QVariant::String: {
         if (!binding->evaluatesToString()) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: string expected"));
+            return warnOrError(tr("Invalid property assignment: string expected"));
         }
     }
     break;
     case QVariant::StringList: {
         if (!binding->evaluatesToString()) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: string or string list expected"));
+            return warnOrError(tr("Invalid property assignment: string or string list expected"));
         }
     }
     break;
     case QVariant::ByteArray: {
         if (binding->type != QV4::CompiledData::Binding::Type_String) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: byte array expected"));
+            return warnOrError(tr("Invalid property assignment: byte array expected"));
         }
     }
     break;
     case QVariant::Url: {
         if (binding->type != QV4::CompiledData::Binding::Type_String) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: url expected"));
+            return warnOrError(tr("Invalid property assignment: url expected"));
         }
     }
     break;
     case QVariant::UInt: {
         if (binding->type == QV4::CompiledData::Binding::Type_Number) {
-            double d = binding->valueAsNumber();
+            double d = binding->valueAsNumber(compilationUnit->constants);
             if (double(uint(d)) == d)
                 return noError;
         }
-        return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: unsigned int expected"));
+        return warnOrError(tr("Invalid property assignment: unsigned int expected"));
     }
     break;
     case QVariant::Int: {
         if (binding->type == QV4::CompiledData::Binding::Type_Number) {
-            double d = binding->valueAsNumber();
+            double d = binding->valueAsNumber(compilationUnit->constants);
             if (double(int(d)) == d)
                 return noError;
         }
-        return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: int expected"));
+        return warnOrError(tr("Invalid property assignment: int expected"));
     }
     break;
     case QMetaType::Float: {
         if (binding->type != QV4::CompiledData::Binding::Type_Number) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: number expected"));
+            return warnOrError(tr("Invalid property assignment: number expected"));
         }
     }
     break;
     case QVariant::Double: {
         if (binding->type != QV4::CompiledData::Binding::Type_Number) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: number expected"));
+            return warnOrError(tr("Invalid property assignment: number expected"));
         }
     }
     break;
     case QVariant::Color: {
         bool ok = false;
-        QQmlStringConverters::rgbaFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::rgbaFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: color expected"));
+            return warnOrError(tr("Invalid property assignment: color expected"));
         }
     }
     break;
 #if QT_CONFIG(datestring)
     case QVariant::Date: {
         bool ok = false;
-        QQmlStringConverters::dateFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::dateFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: date expected"));
+            return warnOrError(tr("Invalid property assignment: date expected"));
         }
     }
     break;
     case QVariant::Time: {
         bool ok = false;
-        QQmlStringConverters::timeFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::timeFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: time expected"));
+            return warnOrError(tr("Invalid property assignment: time expected"));
         }
     }
     break;
     case QVariant::DateTime: {
         bool ok = false;
-        QQmlStringConverters::dateTimeFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::dateTimeFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: datetime expected"));
+            return warnOrError(tr("Invalid property assignment: datetime expected"));
         }
     }
     break;
 #endif // datestring
     case QVariant::Point: {
         bool ok = false;
-        QQmlStringConverters::pointFFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::pointFFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: point expected"));
+            return warnOrError(tr("Invalid property assignment: point expected"));
         }
     }
     break;
     case QVariant::PointF: {
         bool ok = false;
-        QQmlStringConverters::pointFFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::pointFFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: point expected"));
+            return warnOrError(tr("Invalid property assignment: point expected"));
         }
     }
     break;
     case QVariant::Size: {
         bool ok = false;
-        QQmlStringConverters::sizeFFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::sizeFFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: size expected"));
+            return warnOrError(tr("Invalid property assignment: size expected"));
         }
     }
     break;
     case QVariant::SizeF: {
         bool ok = false;
-        QQmlStringConverters::sizeFFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::sizeFFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: size expected"));
+            return warnOrError(tr("Invalid property assignment: size expected"));
         }
     }
     break;
     case QVariant::Rect: {
         bool ok = false;
-        QQmlStringConverters::rectFFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::rectFFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: rect expected"));
+            return warnOrError(tr("Invalid property assignment: rect expected"));
         }
     }
     break;
     case QVariant::RectF: {
         bool ok = false;
-        QQmlStringConverters::rectFFromString(binding->valueAsString(qmlUnit), &ok);
+        QQmlStringConverters::rectFFromString(binding->valueAsString(compilationUnit.data()), &ok);
         if (!ok) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: point expected"));
+            return warnOrError(tr("Invalid property assignment: point expected"));
         }
     }
     break;
     case QVariant::Bool: {
         if (binding->type != QV4::CompiledData::Binding::Type_Boolean) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: boolean expected"));
+            return warnOrError(tr("Invalid property assignment: boolean expected"));
         }
     }
     break;
@@ -497,8 +517,8 @@ QQmlCompileError QQmlPropertyValidator::validateLiteralBinding(QQmlPropertyCache
             float xp;
             float yp;
         } vec;
-        if (!QQmlStringConverters::createFromString(QMetaType::QVector2D, binding->valueAsString(qmlUnit), &vec, sizeof(vec))) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: 2D vector expected"));
+        if (!QQmlStringConverters::createFromString(QMetaType::QVector2D, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec))) {
+            return warnOrError(tr("Invalid property assignment: 2D vector expected"));
         }
     }
     break;
@@ -508,8 +528,8 @@ QQmlCompileError QQmlPropertyValidator::validateLiteralBinding(QQmlPropertyCache
             float yp;
             float zy;
         } vec;
-        if (!QQmlStringConverters::createFromString(QMetaType::QVector3D, binding->valueAsString(qmlUnit), &vec, sizeof(vec))) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: 3D vector expected"));
+        if (!QQmlStringConverters::createFromString(QMetaType::QVector3D, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec))) {
+            return warnOrError(tr("Invalid property assignment: 3D vector expected"));
         }
     }
     break;
@@ -520,8 +540,8 @@ QQmlCompileError QQmlPropertyValidator::validateLiteralBinding(QQmlPropertyCache
             float zy;
             float wp;
         } vec;
-        if (!QQmlStringConverters::createFromString(QMetaType::QVector4D, binding->valueAsString(qmlUnit), &vec, sizeof(vec))) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: 4D vector expected"));
+        if (!QQmlStringConverters::createFromString(QMetaType::QVector4D, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec))) {
+            return warnOrError(tr("Invalid property assignment: 4D vector expected"));
         }
     }
     break;
@@ -532,55 +552,59 @@ QQmlCompileError QQmlPropertyValidator::validateLiteralBinding(QQmlPropertyCache
             float yp;
             float zp;
         } vec;
-        if (!QQmlStringConverters::createFromString(QMetaType::QQuaternion, binding->valueAsString(qmlUnit), &vec, sizeof(vec))) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: quaternion expected"));
+        if (!QQmlStringConverters::createFromString(QMetaType::QQuaternion, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec))) {
+            return warnOrError(tr("Invalid property assignment: quaternion expected"));
         }
     }
     break;
     case QVariant::RegExp:
-        return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: regular expression expected; use /pattern/ syntax"));
+    case QVariant::RegularExpression:
+        return warnOrError(tr("Invalid property assignment: regular expression expected; use /pattern/ syntax"));
     default: {
         // generate single literal value assignment to a list property if required
         if (property->propType() == qMetaTypeId<QList<qreal> >()) {
             if (binding->type != QV4::CompiledData::Binding::Type_Number) {
-                return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: number or array of numbers expected"));
+                return warnOrError(tr("Invalid property assignment: number or array of numbers expected"));
             }
             break;
         } else if (property->propType() == qMetaTypeId<QList<int> >()) {
             bool ok = (binding->type == QV4::CompiledData::Binding::Type_Number);
             if (ok) {
-                double n = binding->valueAsNumber();
+                double n = binding->valueAsNumber(compilationUnit->constants);
                 if (double(int(n)) != n)
                     ok = false;
             }
             if (!ok)
-                return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: int or array of ints expected"));
+                return warnOrError(tr("Invalid property assignment: int or array of ints expected"));
             break;
         } else if (property->propType() == qMetaTypeId<QList<bool> >()) {
             if (binding->type != QV4::CompiledData::Binding::Type_Boolean) {
-                return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: bool or array of bools expected"));
+                return warnOrError(tr("Invalid property assignment: bool or array of bools expected"));
             }
             break;
         } else if (property->propType() == qMetaTypeId<QList<QUrl> >()) {
             if (binding->type != QV4::CompiledData::Binding::Type_String) {
-                return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: url or array of urls expected"));
+                return warnOrError(tr("Invalid property assignment: url or array of urls expected"));
             }
             break;
         } else if (property->propType() == qMetaTypeId<QList<QString> >()) {
             if (!binding->evaluatesToString()) {
-                return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: string or array of strings expected"));
+                return warnOrError(tr("Invalid property assignment: string or array of strings expected"));
             }
             break;
         } else if (property->propType() == qMetaTypeId<QJSValue>()) {
             break;
         } else if (property->propType() == qMetaTypeId<QQmlScriptString>()) {
             break;
+        } else if (property->isQObject()
+                   && binding->type == QV4::CompiledData::Binding::Type_Null) {
+            break;
         }
 
         // otherwise, try a custom type assignment
         QQmlMetaType::StringConverter converter = QQmlMetaType::customStringConverter(property->propType());
         if (!converter) {
-            return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: unsupported type \"%1\"").arg(QString::fromLatin1(QMetaType::typeName(property->propType()))));
+            return warnOrError(tr("Invalid property assignment: unsupported type \"%1\"").arg(QString::fromLatin1(QMetaType::typeName(property->propType()))));
         }
     }
     break;
@@ -628,21 +652,19 @@ QQmlCompileError QQmlPropertyValidator::validateObjectBinding(QQmlPropertyData *
         bool isValueSource = false;
         bool isPropertyInterceptor = false;
 
-        QQmlType *qmlType = 0;
-        const QV4::CompiledData::Object *targetObject = qmlUnit->objectAt(binding->value.objectIndex);
-        if (auto *typeRef = resolvedTypes.value(targetObject->inheritedTypeNameIndex)) {
-            QQmlPropertyCache *cache = typeRef->createPropertyCache(QQmlEnginePrivate::get(enginePrivate));
+        const QV4::CompiledData::Object *targetObject = compilationUnit->objectAt(binding->value.objectIndex);
+        if (auto *typeRef = resolvedType(targetObject->inheritedTypeNameIndex)) {
+            QQmlRefPointer<QQmlPropertyCache> cache = typeRef->createPropertyCache(QQmlEnginePrivate::get(enginePrivate));
             const QMetaObject *mo = cache->firstCppMetaObject();
-            while (mo && !qmlType) {
+            QQmlType qmlType;
+            while (mo && !qmlType.isValid()) {
                 qmlType = QQmlMetaType::qmlType(mo);
                 mo = mo->superClass();
             }
-            Q_ASSERT(qmlType);
-        }
+            Q_ASSERT(qmlType.isValid());
 
-        if (qmlType) {
-            isValueSource = qmlType->propertyValueSourceCast() != -1;
-            isPropertyInterceptor = qmlType->propertyValueInterceptorCast() != -1;
+            isValueSource = qmlType.propertyValueSourceCast() != -1;
+            isPropertyInterceptor = qmlType.propertyValueInterceptorCast() != -1;
         }
 
         if (!isValueSource && !isPropertyInterceptor) {
@@ -656,7 +678,7 @@ QQmlCompileError QQmlPropertyValidator::validateObjectBinding(QQmlPropertyData *
         // Can only check at instantiation time if the created sub-object successfully casts to the
         // target interface.
         return noError;
-    } else if (property->propType() == QMetaType::QVariant) {
+    } else if (property->propType() == QMetaType::QVariant || property->propType() == qMetaTypeId<QJSValue>()) {
         // We can convert everything to QVariant :)
         return noError;
     } else if (property->isQList()) {
@@ -668,21 +690,20 @@ QQmlCompileError QQmlPropertyValidator::validateObjectBinding(QQmlPropertyData *
             }
         }
         return noError;
-    } else if (qmlUnit->objectAt(binding->value.objectIndex)->flags & QV4::CompiledData::Object::IsComponent) {
-        return noError;
     } else if (binding->flags & QV4::CompiledData::Binding::IsSignalHandlerObject && property->isFunction()) {
         return noError;
     } else if (QQmlValueTypeFactory::isValueType(property->propType())) {
-        return QQmlCompileError(binding->location, tr("Unexpected object assignment"));
+        return QQmlCompileError(binding->location, tr("Unexpected object assignment for property \"%1\"").arg(propertyName));
     } else if (property->propType() == qMetaTypeId<QQmlScriptString>()) {
         return QQmlCompileError(binding->valueLocation, tr("Invalid property assignment: script expected"));
     } else {
-        // We want to raw metaObject here as the raw metaobject is the
+        // We want to use the raw metaObject here as the raw metaobject is the
         // actual property type before we applied any extensions that might
         // effect the properties on the type, but don't effect assignability
-        QQmlPropertyCache *propertyMetaObject = enginePrivate->rawPropertyCacheForType(property->propType());
+        // Using -1 for the minor version ensures that we get the raw metaObject.
+        QQmlPropertyCache *propertyMetaObject = enginePrivate->rawPropertyCacheForType(property->propType(), -1);
 
-        // Will be true if the assgned type inherits propertyMetaObject
+        // Will be true if the assigned type inherits propertyMetaObject
         bool isAssignable = false;
         // Determine isAssignable value
         if (propertyMetaObject) {
@@ -694,7 +715,8 @@ QQmlCompileError QQmlPropertyValidator::validateObjectBinding(QQmlPropertyData *
         }
 
         if (!isAssignable) {
-            return QQmlCompileError(binding->valueLocation, tr("Cannot assign object to property"));
+            return QQmlCompileError(binding->valueLocation, tr("Cannot assign object of type \"%1\" to property of type \"%2\" as the former is neither the same as the latter nor a sub-class of it.")
+                    .arg(stringAt(compilationUnit->objectAt(binding->value.objectIndex)->inheritedTypeNameIndex)).arg(QLatin1String(QMetaType::typeName(property->propType()))));
         }
     }
     return noError;
diff --git a/src/qml/compiler/qqmlpropertyvalidator_p.h b/src/qml/compiler/qqmlpropertyvalidator_p.h
index e37b8141f4..e9ae844ccb 100644
--- a/src/qml/compiler/qqmlpropertyvalidator_p.h
+++ b/src/qml/compiler/qqmlpropertyvalidator_p.h
@@ -58,7 +58,7 @@ class QQmlPropertyValidator
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlPropertyValidator)
 public:
-    QQmlPropertyValidator(QQmlEnginePrivate *enginePrivate, const QQmlImports &imports, QV4::CompiledData::CompilationUnit *compilationUnit);
+    QQmlPropertyValidator(QQmlEnginePrivate *enginePrivate, const QQmlImports &imports, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit);
 
     QVector<QQmlCompileError> validate();
 
@@ -71,12 +71,16 @@ private:
 
     Q_REQUIRED_RESULT QVector<QQmlCompileError> recordError(const QV4::CompiledData::Location &location, const QString &description) const;
     Q_REQUIRED_RESULT QVector<QQmlCompileError> recordError(const QQmlCompileError &error) const;
-    QString stringAt(int index) const { return qmlUnit->stringAt(index); }
+    QString stringAt(int index) const { return compilationUnit->stringAt(index); }
+    QV4::CompiledData::ResolvedTypeReference *resolvedType(int id) const
+    {
+        return compilationUnit->resolvedType(id);
+    }
 
     QQmlEnginePrivate *enginePrivate;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
     const QQmlImports &imports;
     const QV4::CompiledData::Unit *qmlUnit;
-    const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypes;
     const QQmlPropertyCacheVector &propertyCaches;
 
     QVector<QV4::CompiledData::BindingPropertyData> * const bindingPropertyDataPerObject;
diff --git a/src/qml/compiler/qqmltypecompiler.cpp b/src/qml/compiler/qqmltypecompiler.cpp
index c09fde86f1..70b048d737 100644
--- a/src/qml/compiler/qqmltypecompiler.cpp
+++ b/src/qml/compiler/qqmltypecompiler.cpp
@@ -44,10 +44,7 @@
 #include <private/qqmlcustomparser_p.h>
 #include <private/qqmlvmemetaobject_p.h>
 #include <private/qqmlcomponent_p.h>
-#include <private/qv4ssa_p.h>
-
-#include "qqmlpropertycachecreator_p.h"
-#include "qv4jssimplifier_p.h"
+#include <private/qqmldelegatecomponent_p.h>
 
 #define COMPILE_EXCEPTION(token, desc) \
     { \
@@ -59,7 +56,7 @@ QT_BEGIN_NAMESPACE
 
 QQmlTypeCompiler::QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *typeData,
                                    QmlIR::Document *parsedQML, const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
-                                   const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache, const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
+                                   QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache, const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
     : resolvedTypes(resolvedTypeCache)
     , engine(engine)
     , typeData(typeData)
@@ -69,19 +66,23 @@ QQmlTypeCompiler::QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *type
 {
 }
 
-QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
+QQmlRefPointer<QV4::CompiledData::CompilationUnit> QQmlTypeCompiler::compile()
 {
     // Build property caches and VME meta object data
 
-    for (auto it = resolvedTypes.constBegin(), end = resolvedTypes.constEnd();
+    for (auto it = resolvedTypes->constBegin(), end = resolvedTypes->constEnd();
          it != end; ++it) {
-        QQmlCustomParser *customParser = (*it)->type ? (*it)->type->customParser() : 0;
+        QQmlCustomParser *customParser = (*it)->type.customParser();
         if (customParser)
             customParsers.insert(it.key(), customParser);
     }
 
+    QQmlPendingGroupPropertyBindings pendingGroupPropertyBindings;
+
+
     {
-        QQmlPropertyCacheCreator<QQmlTypeCompiler> propertyCacheBuilder(&m_propertyCaches, engine, this, imports());
+        QQmlPropertyCacheCreator<QQmlTypeCompiler> propertyCacheBuilder(&m_propertyCaches, &pendingGroupPropertyBindings,
+                                                                        engine, this, imports());
         QQmlCompileError error = propertyCacheBuilder.buildMetaObjects();
         if (error.isSet()) {
             recordError(error);
@@ -123,6 +124,8 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
         QQmlComponentAndAliasResolver resolver(this);
         if (!resolver.resolve())
             return nullptr;
+
+        pendingGroupPropertyBindings.resolveMissingPropertyCaches(engine, &m_propertyCaches);
     }
 
     {
@@ -131,8 +134,8 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
             return nullptr;
     }
 
-    // Compile JS binding expressions and signal handlers
     if (!document->javaScriptCompilationUnit) {
+        // Compile JS binding expressions and signal handlers if necessary
         {
             // We can compile script strings ahead of time, but they must be compiled
             // without type optimizations as their scope is always entirely dynamic.
@@ -140,37 +143,28 @@ QV4::CompiledData::CompilationUnit *QQmlTypeCompiler::compile()
             sss.scan();
         }
 
-        QmlIR::JSCodeGen v4CodeGenerator(typeData->finalUrlString(), document->code, &document->jsModule, &document->jsParserEngine, document->program, typeNameCache, &document->jsGenerator.stringTable);
+        document->jsModule.fileName = typeData->urlString();
+        document->jsModule.finalUrl = typeData->finalUrlString();
+        QmlIR::JSCodeGen v4CodeGenerator(document->code, &document->jsGenerator, &document->jsModule, &document->jsParserEngine,
+                                         document->program, typeNameCache.data(), &document->jsGenerator.stringTable, engine->v8engine()->illegalNames());
+        v4CodeGenerator.setUseFastLookups(false);
         QQmlJSCodeGenerator jsCodeGen(this, &v4CodeGenerator);
         if (!jsCodeGen.generateCodeForComponents())
             return nullptr;
 
-        QQmlJavaScriptBindingExpressionSimplificationPass pass(document->objects, &document->jsModule, &document->jsGenerator);
-        pass.reduceTranslationBindings();
-
-        QV4::ExecutionEngine *v4 = engine->v4engine();
-        QScopedPointer<QV4::EvalInstructionSelection> isel(v4->iselFactory->create(engine, v4->executableAllocator, &document->jsModule, &document->jsGenerator));
-        isel->setUseFastLookups(false);
-        isel->setUseTypeInference(true);
-        document->javaScriptCompilationUnit = isel->compile(/*generated unit data*/false);
+        document->javaScriptCompilationUnit = v4CodeGenerator.generateCompilationUnit(/*generated unit data*/false);
     }
 
     // Generate QML compiled type data structures
 
     QmlIR::QmlUnitGenerator qmlGenerator;
-    QV4::CompiledData::Unit *qmlUnit = qmlGenerator.generate(*document, dependencyHasher);
-
-    Q_ASSERT(document->javaScriptCompilationUnit);
-    // The js unit owns the data and will free the qml unit.
-    document->javaScriptCompilationUnit->data = qmlUnit;
+    qmlGenerator.generate(*document, dependencyHasher);
 
-    QV4::CompiledData::CompilationUnit *compilationUnit = document->javaScriptCompilationUnit;
-    compilationUnit = document->javaScriptCompilationUnit;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit = document->javaScriptCompilationUnit;
     compilationUnit->typeNameCache = typeNameCache;
-    compilationUnit->resolvedTypes = resolvedTypes;
+    compilationUnit->resolvedTypes = *resolvedTypes;
     compilationUnit->propertyCaches = std::move(m_propertyCaches);
-    Q_ASSERT(compilationUnit->propertyCaches.count() == static_cast<int>(compilationUnit->data->nObjects));
-
+    Q_ASSERT(compilationUnit->propertyCaches.count() == static_cast<int>(compilationUnit->objectCount()));
 
     if (errors.isEmpty())
         return compilationUnit;
@@ -209,14 +203,14 @@ int QQmlTypeCompiler::registerString(const QString &str)
     return document->jsGenerator.registerString(str);
 }
 
-QV4::IR::Module *QQmlTypeCompiler::jsIRModule() const
+int QQmlTypeCompiler::registerConstant(QV4::ReturnedValue v)
 {
-    return &document->jsModule;
+    return document->jsGenerator.registerConstant(v);
 }
 
 const QV4::CompiledData::Unit *QQmlTypeCompiler::qmlUnit() const
 {
-    return document->javaScriptCompilationUnit->data;
+    return document->javaScriptCompilationUnit->unitData();
 }
 
 const QQmlImports *QQmlTypeCompiler::imports() const
@@ -229,15 +223,10 @@ QVector<QmlIR::Object *> *QQmlTypeCompiler::qmlObjects() const
     return &document->objects;
 }
 
-int QQmlTypeCompiler::rootObjectIndex() const
-{
-    return document->indexOfRootObject;
-}
-
 void QQmlTypeCompiler::setPropertyCaches(QQmlPropertyCacheVector &&caches)
 {
     m_propertyCaches = std::move(caches);
-    Q_ASSERT(m_propertyCaches.count() >= document->indexOfRootObject);
+    Q_ASSERT(m_propertyCaches.count() > 0);
 }
 
 const QQmlPropertyCacheVector *QQmlTypeCompiler::propertyCaches() const
@@ -310,8 +299,7 @@ SignalHandlerConverter::SignalHandlerConverter(QQmlTypeCompiler *typeCompiler)
     , qmlObjects(*typeCompiler->qmlObjects())
     , imports(typeCompiler->imports())
     , customParsers(typeCompiler->customParserCache())
-    , resolvedTypes(typeCompiler->resolvedTypes)
-    , illegalNames(QV8Engine::get(QQmlEnginePrivate::get(typeCompiler->enginePrivate()))->illegalNames())
+    , illegalNames(typeCompiler->enginePrivate()->v8engine()->illegalNames())
     , propertyCaches(typeCompiler->propertyCaches())
 {
 }
@@ -344,24 +332,22 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
         // Attached property?
         if (binding->type == QV4::CompiledData::Binding::Type_AttachedProperty) {
             const QmlIR::Object *attachedObj = qmlObjects.at(binding->value.objectIndex);
-            auto *typeRef = resolvedTypes.value(binding->propertyNameIndex);
-            QQmlType *type = typeRef ? typeRef->type : 0;
-            if (!type) {
-                if (imports->resolveType(propertyName, &type, 0, 0, 0)) {
-                    if (type->isComposite()) {
-                        QQmlTypeData *tdata = enginePrivate->typeLoader.getType(type->sourceUrl());
+            auto *typeRef = resolvedType(binding->propertyNameIndex);
+            QQmlType type = typeRef ? typeRef->type : QQmlType();
+            if (!type.isValid()) {
+                if (imports->resolveType(propertyName, &type, nullptr, nullptr, nullptr)) {
+                    if (type.isComposite()) {
+                        QQmlRefPointer<QQmlTypeData> tdata = enginePrivate->typeLoader.getType(type.sourceUrl());
                         Q_ASSERT(tdata);
                         Q_ASSERT(tdata->isComplete());
 
                         auto compilationUnit = tdata->compilationUnit();
                         type = QQmlMetaType::qmlType(compilationUnit->metaTypeId);
-
-                        tdata->release();
                     }
                 }
             }
 
-            const QMetaObject *attachedType = type ? type->attachedPropertiesType(enginePrivate) : 0;
+            const QMetaObject *attachedType = type.attachedPropertiesType(enginePrivate);
             if (!attachedType)
                 COMPILE_EXCEPTION(binding, tr("Non-existent attached object"));
             QQmlPropertyCache *cache = compiler->enginePrivate()->cache(attachedType);
@@ -412,15 +398,15 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
         } else {
             if (notInRevision) {
                 // Try assinging it as a property later
-                if (resolver.property(propertyName, /*notInRevision ptr*/0))
+                if (resolver.property(propertyName, /*notInRevision ptr*/nullptr))
                     continue;
 
                 const QString &originalPropertyName = stringAt(binding->propertyNameIndex);
 
-                auto *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex);
-                const QQmlType *type = typeRef ? typeRef->type : 0;
-                if (type) {
-                    COMPILE_EXCEPTION(binding, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(originalPropertyName).arg(type->module()).arg(type->majorVersion()).arg(type->minorVersion()));
+                auto *typeRef = resolvedType(obj->inheritedTypeNameIndex);
+                const QQmlType type = typeRef ? typeRef->type : QQmlType();
+                if (type.isValid()) {
+                    COMPILE_EXCEPTION(binding, tr("\"%1.%2\" is not available in %3 %4.%5.").arg(typeName).arg(originalPropertyName).arg(type.module()).arg(type.majorVersion()).arg(type.minorVersion()));
                 } else {
                     COMPILE_EXCEPTION(binding, tr("\"%1.%2\" is not available due to component versioning.").arg(typeName).arg(originalPropertyName));
                 }
@@ -472,21 +458,19 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
 
         QQmlJS::MemoryPool *pool = compiler->memoryPool();
 
-        QQmlJS::AST::FormalParameterList *paramList = 0;
+        QQmlJS::AST::FormalParameterList *paramList = nullptr;
         for (const QString &param : qAsConst(parameters)) {
             QStringRef paramNameRef = compiler->newStringRef(param);
 
-            if (paramList)
-                paramList = new (pool) QQmlJS::AST::FormalParameterList(paramList, paramNameRef);
-            else
-                paramList = new (pool) QQmlJS::AST::FormalParameterList(paramNameRef);
+            QQmlJS::AST::PatternElement *b = new (pool) QQmlJS::AST::PatternElement(paramNameRef, nullptr);
+            paramList = new (pool) QQmlJS::AST::FormalParameterList(paramList, b);
         }
 
         if (paramList)
-            paramList = paramList->finish();
+            paramList = paramList->finish(pool);
 
         QmlIR::CompiledFunctionOrExpression *foe = obj->functionsAndExpressions->slowAt(binding->value.compiledScriptIndex);
-        QQmlJS::AST::FunctionDeclaration *functionDeclaration = 0;
+        QQmlJS::AST::FunctionDeclaration *functionDeclaration = nullptr;
         if (QQmlJS::AST::ExpressionStatement *es = QQmlJS::AST::cast<QQmlJS::AST::ExpressionStatement*>(foe->node)) {
             if (QQmlJS::AST::FunctionExpression *fe = QQmlJS::AST::cast<QQmlJS::AST::FunctionExpression*>(es->expression)) {
                 functionDeclaration = new (pool) QQmlJS::AST::FunctionDeclaration(fe->name, fe->formals, fe->body);
@@ -500,14 +484,13 @@ bool SignalHandlerConverter::convertSignalHandlerExpressionsToFunctionDeclaratio
         }
         if (!functionDeclaration) {
             QQmlJS::AST::Statement *statement = static_cast<QQmlJS::AST::Statement*>(foe->node);
-            QQmlJS::AST::SourceElement *sourceElement = new (pool) QQmlJS::AST::StatementSourceElement(statement);
-            QQmlJS::AST::SourceElements *elements = new (pool) QQmlJS::AST::SourceElements(sourceElement);
-            elements = elements->finish();
-
-            QQmlJS::AST::FunctionBody *body = new (pool) QQmlJS::AST::FunctionBody(elements);
+            QQmlJS::AST::StatementList *body = new (pool) QQmlJS::AST::StatementList(statement);
+            body = body->finish();
 
             functionDeclaration = new (pool) QQmlJS::AST::FunctionDeclaration(compiler->newStringRef(stringAt(binding->propertyNameIndex)), paramList, body);
-            functionDeclaration->functionToken = foe->node->firstSourceLocation();
+            functionDeclaration->lbraceToken = functionDeclaration->functionToken
+                    = foe->node->firstSourceLocation();
+            functionDeclaration->rbraceToken = foe->node->lastSourceLocation();
         }
         foe->node = functionDeclaration;
         binding->propertyNameIndex = compiler->registerString(propertyName);
@@ -521,7 +504,6 @@ QQmlEnumTypeResolver::QQmlEnumTypeResolver(QQmlTypeCompiler *typeCompiler)
     , qmlObjects(*typeCompiler->qmlObjects())
     , propertyCaches(typeCompiler->propertyCaches())
     , imports(typeCompiler->imports())
-    , resolvedTypes(&typeCompiler->resolvedTypes)
 {
 }
 
@@ -572,7 +554,8 @@ bool QQmlEnumTypeResolver::assignEnumToBinding(QmlIR::Binding *binding, const QS
         COMPILE_EXCEPTION(binding, tr("Invalid property assignment: Enum value \"%1\" cannot start with a lowercase letter").arg(enumName.toString()));
     }
     binding->type = QV4::CompiledData::Binding::Type_Number;
-    binding->setNumberValueInternal((double)enumValue);
+    binding->value.constantValueIndex = compiler->registerConstant(QV4::Encode((double)enumValue));
+//    binding->setNumberValueInternal((double)enumValue);
     binding->flags |= QV4::CompiledData::Binding::IsResolvedEnum;
     return true;
 }
@@ -623,17 +606,17 @@ bool QQmlEnumTypeResolver::tryQualifiedEnumAssignment(const QmlIR::Object *obj,
         }
         return true;
     }
-    QQmlType *type = 0;
-    imports->resolveType(typeName, &type, 0, 0, 0);
+    QQmlType type;
+    imports->resolveType(typeName, &type, nullptr, nullptr, nullptr);
 
-    if (!type && !isQtObject)
+    if (!type.isValid() && !isQtObject)
         return true;
 
     int value = 0;
     bool ok = false;
 
-    auto *tr = resolvedTypes->value(obj->inheritedTypeNameIndex);
-    if (type && tr && tr->type == type) {
+    auto *tr = resolvedType(obj->inheritedTypeNameIndex);
+    if (type.isValid() && tr && tr->type == type) {
         // When these two match, we can short cut the search
         QMetaProperty mprop = propertyCache->firstCppMetaObject()->property(prop->coreIndex());
         QMetaEnum menum = mprop.enumerator();
@@ -648,11 +631,11 @@ bool QQmlEnumTypeResolver::tryQualifiedEnumAssignment(const QmlIR::Object *obj,
         }
     } else {
         // Otherwise we have to search the whole type
-        if (type) {
+        if (type.isValid()) {
             if (!scopedEnumName.isEmpty())
-                value = type->scopedEnumValue(compiler->enginePrivate(), scopedEnumName, enumValue, &ok);
+                value = type.scopedEnumValue(compiler->enginePrivate(), scopedEnumName, enumValue, &ok);
             else
-                value = type->enumValue(compiler->enginePrivate(), QHashedStringRef(enumValue), &ok);
+                value = type.enumValue(compiler->enginePrivate(), QHashedStringRef(enumValue), &ok);
         } else {
             QByteArray enumName = enumValue.toUtf8();
             const QMetaObject *metaObject = StaticQtMetaObject::get();
@@ -675,13 +658,13 @@ int QQmlEnumTypeResolver::evaluateEnum(const QString &scope, const QStringRef &e
     *ok = false;
 
     if (scope != QLatin1String("Qt")) {
-        QQmlType *type = 0;
-        imports->resolveType(scope, &type, 0, 0, 0);
-        if (!type)
+        QQmlType type;
+        imports->resolveType(scope, &type, nullptr, nullptr, nullptr);
+        if (!type.isValid())
             return -1;
         if (!enumName.isEmpty())
-            return type->scopedEnumValue(compiler->enginePrivate(), enumName, enumValue, ok);
-        return type->enumValue(compiler->enginePrivate(), QHashedStringRef(enumValue.constData(), enumValue.length()), ok);
+            return type.scopedEnumValue(compiler->enginePrivate(), enumName, enumValue, ok);
+        return type.enumValue(compiler->enginePrivate(), QHashedStringRef(enumValue.constData(), enumValue.length()), ok);
     }
 
     const QMetaObject *mo = StaticQtMetaObject::get();
@@ -704,7 +687,7 @@ QQmlCustomParserScriptIndexer::QQmlCustomParserScriptIndexer(QQmlTypeCompiler *t
 
 void QQmlCustomParserScriptIndexer::annotateBindingsWithScriptStrings()
 {
-    scanObjectRecursively(compiler->rootObjectIndex());
+    scanObjectRecursively(/*root object*/0);
 }
 
 void QQmlCustomParserScriptIndexer::scanObjectRecursively(int objectIndex, bool annotateScriptBindings)
@@ -799,8 +782,6 @@ QQmlComponentAndAliasResolver::QQmlComponentAndAliasResolver(QQmlTypeCompiler *t
     , enginePrivate(typeCompiler->enginePrivate())
     , pool(typeCompiler->memoryPool())
     , qmlObjects(typeCompiler->qmlObjects())
-    , indexOfRootObject(typeCompiler->rootObjectIndex())
-    , resolvedTypes(&typeCompiler->resolvedTypes)
     , propertyCaches(std::move(typeCompiler->takePropertyCaches()))
 {
 }
@@ -818,17 +799,25 @@ void QQmlComponentAndAliasResolver::findAndRegisterImplicitComponents(const QmlI
             continue;
 
         const QmlIR::Object *targetObject = qmlObjects->at(binding->value.objectIndex);
-        auto *tr = resolvedTypes->value(targetObject->inheritedTypeNameIndex);
+        auto *tr = resolvedType(targetObject->inheritedTypeNameIndex);
         Q_ASSERT(tr);
-        if (QQmlType *targetType = tr->type) {
-            if (targetType->metaObject() == &QQmlComponent::staticMetaObject)
-                continue;
-        } else if (tr->compilationUnit) {
-            if (tr->compilationUnit->rootPropertyCache()->firstCppMetaObject() == &QQmlComponent::staticMetaObject)
-                continue;
-        }
 
-        QQmlPropertyData *pd = 0;
+        const QMetaObject *firstMetaObject = nullptr;
+        if (tr->type.isValid())
+            firstMetaObject = tr->type.metaObject();
+        else if (tr->compilationUnit)
+            firstMetaObject = tr->compilationUnit->rootPropertyCache()->firstCppMetaObject();
+        // 1: test for QQmlComponent
+        if (firstMetaObject && firstMetaObject == &QQmlComponent::staticMetaObject)
+            continue;
+        // 2: test for QQmlAbstractDelegateComponent
+        while (firstMetaObject && firstMetaObject != &QQmlAbstractDelegateComponent::staticMetaObject)
+            firstMetaObject = firstMetaObject->superClass();
+        if (firstMetaObject)
+            continue;
+        // if here, not a QQmlComponent or a QQmlAbstractDelegateComponent, so needs wrapping
+
+        QQmlPropertyData *pd = nullptr;
         if (binding->propertyNameIndex != quint32(0)) {
             bool notInRevision = false;
             pd = propertyResolver.property(stringAt(binding->propertyNameIndex), &notInRevision);
@@ -838,8 +827,8 @@ void QQmlComponentAndAliasResolver::findAndRegisterImplicitComponents(const QmlI
         if (!pd || !pd->isQObject())
             continue;
 
-        QQmlPropertyCache *pc = enginePrivate->rawPropertyCacheForType(pd->propType());
-        const QMetaObject *mo = pc ? pc->firstCppMetaObject() : 0;
+        QQmlPropertyCache *pc = enginePrivate->rawPropertyCacheForType(pd->propType(), pd->typeMinorVersion());
+        const QMetaObject *mo = pc ? pc->firstCppMetaObject() : nullptr;
         while (mo) {
             if (mo == &QQmlComponent::staticMetaObject)
                 break;
@@ -850,23 +839,23 @@ void QQmlComponentAndAliasResolver::findAndRegisterImplicitComponents(const QmlI
             continue;
 
         // emulate "import Qml 2.0 as QmlInternals" and then wrap the component in "QmlInternals.Component {}"
-        QQmlType *componentType = QQmlMetaType::qmlType(&QQmlComponent::staticMetaObject);
-        Q_ASSERT(componentType);
+        QQmlType componentType = QQmlMetaType::qmlType(&QQmlComponent::staticMetaObject);
+        Q_ASSERT(componentType.isValid());
         const QString qualifier = QStringLiteral("QmlInternals");
 
-        compiler->addImport(componentType->module(), qualifier, componentType->majorVersion(), componentType->minorVersion());
+        compiler->addImport(componentType.module(), qualifier, componentType.majorVersion(), componentType.minorVersion());
 
         QmlIR::Object *syntheticComponent = pool->New<QmlIR::Object>();
-        syntheticComponent->init(pool, compiler->registerString(qualifier + QLatin1Char('.') + componentType->elementName()), compiler->registerString(QString()));
+        syntheticComponent->init(pool, compiler->registerString(qualifier + QLatin1Char('.') + componentType.elementName()), compiler->registerString(QString()));
         syntheticComponent->location = binding->valueLocation;
         syntheticComponent->flags |= QV4::CompiledData::Object::IsComponent;
 
-        if (!resolvedTypes->contains(syntheticComponent->inheritedTypeNameIndex)) {
+        if (!containsResolvedType(syntheticComponent->inheritedTypeNameIndex)) {
             auto typeRef = new QV4::CompiledData::ResolvedTypeReference;
             typeRef->type = componentType;
-            typeRef->majorVersion = componentType->majorVersion();
-            typeRef->minorVersion = componentType->minorVersion();
-            resolvedTypes->insert(syntheticComponent->inheritedTypeNameIndex, typeRef);
+            typeRef->majorVersion = componentType.majorVersion();
+            typeRef->minorVersion = componentType.minorVersion();
+            insertResolvedType(syntheticComponent->inheritedTypeNameIndex, typeRef);
         }
 
         qmlObjects->append(syntheticComponent);
@@ -904,9 +893,9 @@ bool QQmlComponentAndAliasResolver::resolve()
         bool isExplicitComponent = false;
 
         if (obj->inheritedTypeNameIndex) {
-            auto *tref = resolvedTypes->value(obj->inheritedTypeNameIndex);
+            auto *tref = resolvedType(obj->inheritedTypeNameIndex);
             Q_ASSERT(tref);
-            if (tref->type && tref->type->metaObject() == &QQmlComponent::staticMetaObject)
+            if (tref->type.metaObject() == &QQmlComponent::staticMetaObject)
                 isExplicitComponent = true;
         }
         if (!isExplicitComponent) {
@@ -937,9 +926,9 @@ bool QQmlComponentAndAliasResolver::resolve()
         if (rootBinding->next || rootBinding->type != QV4::CompiledData::Binding::Type_Object)
             COMPILE_EXCEPTION(obj, tr("Invalid component body specification"));
 
-        // We are going to collect ids/aliases and resolve them for the root object as a separate
+        // For the root object, we are going to collect ids/aliases and resolve them for as a separate
         // last pass.
-        if (i != indexOfRootObject)
+        if (i != 0)
             componentRoots.append(i);
 
     }
@@ -965,12 +954,12 @@ bool QQmlComponentAndAliasResolver::resolve()
     _idToObjectIndex.clear();
     _objectsWithAliases.clear();
 
-    collectIdsAndAliases(indexOfRootObject);
+    collectIdsAndAliases(/*root object*/0);
 
-    QmlIR::Object *rootComponent = qmlObjects->at(indexOfRootObject);
+    QmlIR::Object *rootComponent = qmlObjects->at(/*root object*/0);
     rootComponent->namedObjectsInComponent.allocate(pool, _idToObjectIndex);
 
-    if (!resolveAliases(indexOfRootObject))
+    if (!resolveAliases(/*root object*/0))
         return false;
 
     // Implicit component insertion may have added objects and thus we also need
@@ -998,7 +987,7 @@ bool QQmlComponentAndAliasResolver::collectIdsAndAliases(int objectIndex)
         _objectsWithAliases.append(objectIndex);
 
     // Stop at Component boundary
-    if (obj->flags & QV4::CompiledData::Object::IsComponent && objectIndex != compiler->rootObjectIndex())
+    if (obj->flags & QV4::CompiledData::Object::IsComponent && objectIndex != /*root object*/0)
         return true;
 
     for (const QmlIR::Binding *binding = obj->firstBinding(); binding; binding = binding->next) {
@@ -1037,7 +1026,11 @@ bool QQmlComponentAndAliasResolver::resolveAliases(int componentIndex)
             }
 
             if (result == AllAliasesResolved) {
-                aliasCacheCreator.appendAliasesToPropertyCache(*qmlObjects->at(componentIndex), objectIndex);
+                QQmlCompileError error = aliasCacheCreator.appendAliasesToPropertyCache(*qmlObjects->at(componentIndex), objectIndex);
+                if (error.isSet()) {
+                    recordError(error);
+                    return false;
+                }
                 atLeastOneAliasResolved = true;
             } else if (result == SomeAliasesResolved) {
                 atLeastOneAliasResolved = true;
@@ -1107,7 +1100,11 @@ QQmlComponentAndAliasResolver::AliasResolutionResult QQmlComponentAndAliasResolv
             alias->flags |= QV4::CompiledData::Alias::AliasPointsToPointerObject;
         } else {
             QQmlPropertyCache *targetCache = propertyCaches.at(targetObjectIndex);
-            Q_ASSERT(targetCache);
+            if (!targetCache) {
+                *error = QQmlCompileError(alias->referenceLocation, tr("Invalid alias target location: %1").arg(property.toString()));
+                break;
+            }
+
             QmlIR::PropertyResolver resolver(targetCache);
 
             QQmlPropertyData *targetProperty = resolver.property(property.toString());
@@ -1189,7 +1186,7 @@ QQmlDeferredAndCustomParserBindingScanner::QQmlDeferredAndCustomParserBindingSca
 
 bool QQmlDeferredAndCustomParserBindingScanner::scanObject()
 {
-    return scanObject(compiler->rootObjectIndex());
+    return scanObject(/*root object*/0);
 }
 
 bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
@@ -1210,7 +1207,7 @@ bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
         return true;
 
     QString defaultPropertyName;
-    QQmlPropertyData *defaultProperty = 0;
+    QQmlPropertyData *defaultProperty = nullptr;
     if (obj->indexOfDefaultPropertyOrAlias != -1) {
         QQmlPropertyCache *cache = propertyCache->parent();
         defaultPropertyName = cache->defaultPropertyName();
@@ -1235,7 +1232,7 @@ bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
     }
 
     for (QmlIR::Binding *binding = obj->firstBinding(); binding; binding = binding->next) {
-        QQmlPropertyData *pd = 0;
+        QQmlPropertyData *pd = nullptr;
         QString name = stringAt(binding->propertyNameIndex);
 
         if (customParser) {
@@ -1275,7 +1272,7 @@ bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
             _seenObjectWithId |= seenSubObjectWithId;
         }
 
-        if (!seenSubObjectWithId
+        if (!seenSubObjectWithId && binding->type != QV4::CompiledData::Binding::Type_GroupProperty
             && !deferredPropertyNames.isEmpty() && deferredPropertyNames.contains(name)) {
 
             binding->flags |= QV4::CompiledData::Binding::IsDeferredBinding;
@@ -1299,7 +1296,6 @@ bool QQmlDeferredAndCustomParserBindingScanner::scanObject(int objectIndex)
 
 QQmlJSCodeGenerator::QQmlJSCodeGenerator(QQmlTypeCompiler *typeCompiler, QmlIR::JSCodeGen *v4CodeGen)
     : QQmlCompilePass(typeCompiler)
-    , resolvedTypes(typeCompiler->resolvedTypes)
     , customParsers(typeCompiler->customParserCache())
     , qmlObjects(*typeCompiler->qmlObjects())
     , propertyCaches(typeCompiler->propertyCaches())
@@ -1315,7 +1311,7 @@ bool QQmlJSCodeGenerator::generateCodeForComponents()
             return false;
     }
 
-    return compileComponent(compiler->rootObjectIndex());
+    return compileComponent(/*root object*/0);
 }
 
 bool QQmlJSCodeGenerator::compileComponent(int contextObject)
@@ -1329,8 +1325,8 @@ bool QQmlJSCodeGenerator::compileComponent(int contextObject)
     }
 
     QmlIR::JSCodeGen::ObjectIdMapping idMapping;
-    idMapping.reserve(obj->namedObjectsInComponent.count);
-    for (int i = 0; i < obj->namedObjectsInComponent.count; ++i) {
+    idMapping.reserve(obj->namedObjectsInComponent.size());
+    for (int i = 0; i < obj->namedObjectsInComponent.size(); ++i) {
         const int objectIndex = obj->namedObjectsInComponent.at(i);
         QmlIR::JSCodeGen::IdMapping m;
         const QmlIR::Object *obj = qmlObjects.at(objectIndex);
@@ -1338,9 +1334,9 @@ bool QQmlJSCodeGenerator::compileComponent(int contextObject)
         m.idIndex = obj->id;
         m.type = propertyCaches->at(objectIndex);
 
-        auto *tref = resolvedTypes.value(obj->inheritedTypeNameIndex);
+        auto *tref = resolvedType(obj->inheritedTypeNameIndex);
         if (tref && tref->isFullyDynamicType)
-            m.type = 0;
+            m.type = nullptr;
 
         idMapping << m;
     }
@@ -1418,10 +1414,10 @@ void QQmlDefaultPropertyMerger::mergeDefaultProperties(int objectIndex)
     QmlIR::Object *object = qmlObjects.at(objectIndex);
 
     QString defaultProperty = object->indexOfDefaultPropertyOrAlias != -1 ? propertyCache->parent()->defaultPropertyName() : propertyCache->defaultPropertyName();
-    QmlIR::Binding *bindingsToReinsert = 0;
-    QmlIR::Binding *tail = 0;
+    QmlIR::Binding *bindingsToReinsert = nullptr;
+    QmlIR::Binding *tail = nullptr;
 
-    QmlIR::Binding *previousBinding = 0;
+    QmlIR::Binding *previousBinding = nullptr;
     QmlIR::Binding *binding = object->firstBinding();
     while (binding) {
         if (binding->propertyNameIndex == quint32(0) || stringAt(binding->propertyNameIndex) != defaultProperty) {
@@ -1440,7 +1436,7 @@ void QQmlDefaultPropertyMerger::mergeDefaultProperties(int objectIndex)
             tail->next = toReinsert;
             tail = tail->next;
         }
-        tail->next = 0;
+        tail->next = nullptr;
     }
 
     binding = bindingsToReinsert;
diff --git a/src/qml/compiler/qqmltypecompiler_p.h b/src/qml/compiler/qqmltypecompiler_p.h
index 76aa422fc5..a49b97453f 100644
--- a/src/qml/compiler/qqmltypecompiler_p.h
+++ b/src/qml/compiler/qqmltypecompiler_p.h
@@ -55,6 +55,7 @@
 #include <qhash.h>
 #include <private/qqmltypeloader_p.h>
 #include <private/qqmlirbuilder_p.h>
+#include <private/qqmlpropertycachecreator_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -74,22 +75,13 @@ struct Location;
 }
 }
 
-struct QQmlCompileError
-{
-    QQmlCompileError() {}
-    QQmlCompileError(const QV4::CompiledData::Location &location, const QString &description)
-        : location(location), description(description) {}
-    QV4::CompiledData::Location location;
-    QString description;
-
-    bool isSet() const { return !description.isEmpty(); }
-};
-
 struct QQmlTypeCompiler
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlTypeCompiler)
 public:
-    QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *typeData, QmlIR::Document *document, const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache,
+    QQmlTypeCompiler(QQmlEnginePrivate *engine, QQmlTypeData *typeData, QmlIR::Document *document,
+                     const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
+                     QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache,
                      const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
 
     // --- interface used by QQmlPropertyCacheCreator
@@ -99,10 +91,10 @@ public:
     QString stringAt(int idx) const;
     QmlIR::PoolList<QmlIR::Function>::Iterator objectFunctionsBegin(const QmlIR::Object *object) const { return object->functionsBegin(); }
     QmlIR::PoolList<QmlIR::Function>::Iterator objectFunctionsEnd(const QmlIR::Object *object) const { return object->functionsEnd(); }
-    QV4::CompiledData::ResolvedTypeReferenceMap resolvedTypes;
+    QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypes = nullptr;
     // ---
 
-    QV4::CompiledData::CompilationUnit *compile();
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compile();
 
     QList<QQmlError> compilationErrors() const { return errors; }
     void recordError(QQmlError error);
@@ -110,8 +102,7 @@ public:
     void recordError(const QQmlCompileError &error);
 
     int registerString(const QString &str);
-
-    QV4::IR::Module *jsIRModule() const;
+    int registerConstant(QV4::ReturnedValue v);
 
     const QV4::CompiledData::Unit *qmlUnit() const;
 
@@ -119,7 +110,6 @@ public:
     QQmlEnginePrivate *enginePrivate() const { return engine; }
     const QQmlImports *imports() const;
     QVector<QmlIR::Object *> *qmlObjects() const;
-    int rootObjectIndex() const;
     void setPropertyCaches(QQmlPropertyCacheVector &&caches);
     const QQmlPropertyCacheVector *propertyCaches() const;
     QQmlPropertyCacheVector &&takePropertyCaches();
@@ -136,6 +126,11 @@ public:
 
     void addImport(const QString &module, const QString &qualifier, int majorVersion, int minorVersion);
 
+    QV4::CompiledData::ResolvedTypeReference *resolvedType(int id) const
+    {
+        return resolvedTypes->value(id);
+    }
+
 private:
     QList<QQmlError> errors;
     QQmlEnginePrivate *engine;
@@ -162,6 +157,14 @@ protected:
     void recordError(const QQmlCompileError &error)
     { compiler->recordError(error); }
 
+    QV4::CompiledData::ResolvedTypeReference *resolvedType(int id) const
+    { return compiler->resolvedType(id); }
+    bool containsResolvedType(int id) const
+    { return compiler->resolvedTypes->contains(id); }
+    QV4::CompiledData::ResolvedTypeReferenceMap::iterator insertResolvedType(
+            int id, QV4::CompiledData::ResolvedTypeReference *value)
+    { return compiler->resolvedTypes->insert(id, value); }
+
     QQmlTypeCompiler *compiler;
 };
 
@@ -184,7 +187,6 @@ private:
     const QVector<QmlIR::Object*> &qmlObjects;
     const QQmlImports *imports;
     const QHash<int, QQmlCustomParser*> &customParsers;
-    const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypes;
     const QSet<QString> &illegalNames;
     const QQmlPropertyCacheVector * const propertyCaches;
 };
@@ -215,7 +217,6 @@ private:
     const QVector<QmlIR::Object*> &qmlObjects;
     const QQmlPropertyCacheVector * const propertyCaches;
     const QQmlImports *imports;
-    QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypes;
 };
 
 class QQmlCustomParserScriptIndexer: public QQmlCompilePass
@@ -282,7 +283,6 @@ protected:
     QQmlJS::MemoryPool *pool;
 
     QVector<QmlIR::Object*> *qmlObjects;
-    const int indexOfRootObject;
 
     // indices of the objects that are actually Component {}
     QVector<quint32> componentRoots;
@@ -291,7 +291,6 @@ protected:
     QMap<int, int> _idToObjectIndex;
     QVector<int> _objectsWithAliases;
 
-    QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypes;
     QQmlPropertyCacheVector propertyCaches;
 };
 
@@ -324,7 +323,6 @@ private:
     bool compileComponent(int componentRoot);
     bool compileJavaScriptCodeInObjectsRecursively(int objectIndex, int scopeObjectIndex);
 
-    const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypes;
     const QHash<int, QQmlCustomParser*> &customParsers;
     const QVector<QmlIR::Object*> &qmlObjects;
     const QQmlPropertyCacheVector * const propertyCaches;
diff --git a/src/qml/compiler/qv4bytecodegenerator.cpp b/src/qml/compiler/qv4bytecodegenerator.cpp
new file mode 100644
index 0000000000..ea252a6013
--- /dev/null
+++ b/src/qml/compiler/qv4bytecodegenerator.cpp
@@ -0,0 +1,244 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4bytecodegenerator_p.h>
+#include <private/qv4compilercontext_p.h>
+#include <private/qqmljsastfwd_p.h>
+
+QT_USE_NAMESPACE
+using namespace QV4;
+using namespace Moth;
+
+void BytecodeGenerator::setLocation(const QQmlJS::AST::SourceLocation &loc)
+{
+    currentLine = static_cast<int>(loc.startLine);
+}
+
+int BytecodeGenerator::newRegister()
+{
+    int t = currentReg++;
+    if (regCount < currentReg)
+        regCount = currentReg;
+    return t;
+}
+
+int BytecodeGenerator::newRegisterArray(int n)
+{
+    int t = currentReg;
+    currentReg += n;
+    if (regCount < currentReg)
+        regCount = currentReg;
+    return t;
+}
+
+void BytecodeGenerator::packInstruction(I &i)
+{
+    Instr::Type type = Instr::unpack(i.packed);
+    Q_ASSERT(int(type) < MOTH_NUM_INSTRUCTIONS());
+    type = Instr::narrowInstructionType(type);
+    int instructionsAsInts[sizeof(Instr)/sizeof(int)] = {};
+    int nMembers = Moth::InstrInfo::argumentCount[static_cast<int>(i.type)];
+    uchar *code = i.packed + Instr::encodedLength(type);
+    for (int j = 0; j < nMembers; ++j) {
+        instructionsAsInts[j] = qFromLittleEndian<qint32>(code + j * sizeof(int));
+    }
+    enum {
+        Normal,
+        Wide
+    } width = Normal;
+    for (int n = 0; n < nMembers; ++n) {
+        if (width == Normal && (static_cast<qint8>(instructionsAsInts[n]) != instructionsAsInts[n])) {
+            width = Wide;
+            break;
+        }
+    }
+    code = i.packed;
+    switch (width) {
+    case Normal:
+        code = Instr::pack(code, type);
+        for (int n = 0; n < nMembers; ++n) {
+            qint8 v = static_cast<qint8>(instructionsAsInts[n]);
+            memcpy(code, &v, 1);
+            code += 1;
+        }
+        i.size = code - i.packed;
+        if (i.offsetForJump != -1)
+            i.offsetForJump = i.size - 1;
+        break;
+    case Wide:
+        // nothing to do
+        break;
+    }
+}
+
+void BytecodeGenerator::adjustJumpOffsets()
+{
+    for (int index = 0; index < instructions.size(); ++index) {
+        auto &i = instructions[index];
+        if (i.offsetForJump == -1) // no jump
+            continue;
+        Q_ASSERT(i.linkedLabel != -1 && labels.at(i.linkedLabel) != -1);
+        const auto &linkedInstruction = instructions.at(labels.at(i.linkedLabel));
+        qint8 *c = reinterpret_cast<qint8*>(i.packed + i.offsetForJump);
+        int jumpOffset = linkedInstruction.position - (i.position + i.size);
+//        qDebug() << "adjusting jump offset for instruction" << index << i.position << i.size << "offsetForJump" << i.offsetForJump << "target"
+//                 << labels.at(i.linkedLabel) << linkedInstruction.position << "jumpOffset" << jumpOffset;
+        Instr::Type type = Instr::unpack(i.packed);
+        if (Instr::isWide(type)) {
+            Q_ASSERT(i.offsetForJump == i.size - 4);
+            qToLittleEndian<qint32>(jumpOffset, c);
+        } else {
+            Q_ASSERT(i.offsetForJump == i.size - 1);
+            qint8 o = jumpOffset;
+            Q_ASSERT(o == jumpOffset);
+            *c = o;
+        }
+    }
+}
+
+void BytecodeGenerator::compressInstructions()
+{
+    // first round: compress all non jump instructions
+    int position = 0;
+    for (auto &i : instructions) {
+        i.position = position;
+        if (i.offsetForJump == -1)
+            packInstruction(i);
+        position += i.size;
+    }
+
+    adjustJumpOffsets();
+
+    // compress all jumps
+    position = 0;
+    for (auto &i : instructions) {
+        i.position = position;
+        if (i.offsetForJump != -1)
+            packInstruction(i);
+        position += i.size;
+    }
+
+    // adjust once again, as the packing above could have changed offsets
+    adjustJumpOffsets();
+}
+
+void BytecodeGenerator::finalize(Compiler::Context *context)
+{
+    compressInstructions();
+
+    // collect content and line numbers
+    QByteArray code;
+    QVector<CompiledData::CodeOffsetToLine> lineNumbers;
+    currentLine = -1;
+    Q_UNUSED(startLine);
+    for (const auto &i : qAsConst(instructions)) {
+        if (i.line != currentLine) {
+            currentLine = i.line;
+            CompiledData::CodeOffsetToLine entry;
+            entry.codeOffset = code.size();
+            entry.line = currentLine;
+            lineNumbers.append(entry);
+        }
+        code.append(reinterpret_cast<const char *>(i.packed), i.size);
+    }
+
+    context->code = code;
+    context->lineNumberMapping = lineNumbers;
+
+    for (const auto &li : _labelInfos) {
+        context->labelInfo.push_back(instructions.at(labels.at(li.labelIndex)).position);
+    }
+}
+
+int BytecodeGenerator::addInstructionHelper(Instr::Type type, const Instr &i, int offsetOfOffset) {
+    if (lastInstrType == int(Instr::Type::StoreReg)) {
+        if (type == Instr::Type::LoadReg) {
+            if (i.LoadReg.reg == lastInstr.StoreReg.reg) {
+                // value is already in the accumulator
+                return -1;
+            }
+        }
+        if (type == Instr::Type::MoveReg) {
+            if (i.MoveReg.srcReg == lastInstr.StoreReg.reg) {
+                Instruction::StoreReg store;
+                store.reg = i.MoveReg.destReg;
+                addInstruction(store);
+                return -1;
+            }
+        }
+    }
+    lastInstrType = int(type);
+    lastInstr = i;
+
+#if QT_CONFIG(qml_debug)
+    if (debugMode && type != Instr::Type::Debug) {
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_GCC("-Wmaybe-uninitialized") // broken gcc warns about Instruction::Debug()
+        if (instructions.isEmpty() || currentLine != instructions.constLast().line) {
+            addInstruction(Instruction::Debug());
+        } else if (type == Instr::Type::Ret) {
+            currentLine = -currentLine;
+            addInstruction(Instruction::Debug());
+            currentLine = -currentLine;
+        }
+QT_WARNING_POP
+    }
+#else
+    Q_UNUSED(debugMode);
+#endif
+
+    const int pos = instructions.size();
+
+    const int argCount = Moth::InstrInfo::argumentCount[static_cast<int>(type)];
+    int s = argCount*sizeof(int);
+    if (offsetOfOffset != -1)
+        offsetOfOffset += Instr::encodedLength(type);
+    I instr{type, static_cast<short>(s + Instr::encodedLength(type)), 0, currentLine, offsetOfOffset, -1, "\0\0" };
+    uchar *code = instr.packed;
+    code = Instr::pack(code, Instr::wideInstructionType(type));
+
+    for (int j = 0; j < argCount; ++j) {
+        qToLittleEndian<qint32>(i.argumentsAsInts[j], code);
+        code += sizeof(int);
+    }
+
+    instructions.append(instr);
+
+    return pos;
+}
diff --git a/src/qml/compiler/qv4bytecodegenerator_p.h b/src/qml/compiler/qv4bytecodegenerator_p.h
new file mode 100644
index 0000000000..1d0a57c536
--- /dev/null
+++ b/src/qml/compiler/qv4bytecodegenerator_p.h
@@ -0,0 +1,362 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4BYTECODEGENERATOR_P_H
+#define QV4BYTECODEGENERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+#include <private/qv4instr_moth_p.h>
+#include <private/qv4compileddata_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QQmlJS {
+namespace AST {
+class SourceLocation;
+}
+}
+
+namespace QV4 {
+namespace Moth {
+
+class BytecodeGenerator {
+public:
+    typedef CompiledData::Function::TraceInfoCount TraceInfoCount;
+
+    BytecodeGenerator(int line, bool debug)
+        : startLine(line), debugMode(debug) {}
+
+    struct Label {
+        enum LinkMode {
+            LinkNow,
+            LinkLater
+        };
+        Label() = default;
+        Label(BytecodeGenerator *generator, LinkMode mode = LinkNow)
+            : generator(generator),
+              index(generator->labels.size()) {
+            generator->labels.append(-1);
+            if (mode == LinkNow)
+                link();
+        }
+
+        void link() {
+            Q_ASSERT(index >= 0);
+            Q_ASSERT(generator->labels[index] == -1);
+            generator->labels[index] = generator->instructions.size();
+            generator->clearLastInstruction();
+        }
+        bool isValid() const { return generator != nullptr; }
+
+        BytecodeGenerator *generator = nullptr;
+        int index = -1;
+    };
+
+    struct Jump {
+        Jump(BytecodeGenerator *generator, int instruction)
+            : generator(generator),
+              index(instruction)
+        { Q_ASSERT(generator && index != -1); }
+
+        ~Jump() {
+            Q_ASSERT(index == -1 || generator->instructions[index].linkedLabel != -1); // make sure link() got called
+        }
+
+        Jump(Jump &&j) {
+            std::swap(generator, j.generator);
+            std::swap(index, j.index);
+        }
+
+        BytecodeGenerator *generator = nullptr;
+        int index = -1;
+
+        void link() {
+            link(generator->label());
+        }
+        void link(Label l) {
+            Q_ASSERT(l.index >= 0);
+            Q_ASSERT(generator->instructions[index].linkedLabel == -1);
+            generator->instructions[index].linkedLabel = l.index;
+        }
+
+    private:
+        // make this type move-only:
+        Q_DISABLE_COPY(Jump)
+        // we never move-assign this type anywhere, so disable it:
+        Jump &operator=(Jump &&) = delete;
+    };
+
+    struct ExceptionHandler : public Label {
+        ExceptionHandler() = default;
+        ExceptionHandler(BytecodeGenerator *generator)
+            : Label(generator, LinkLater)
+        {
+        }
+        ~ExceptionHandler()
+        {
+            Q_ASSERT(!generator || generator->currentExceptionHandler != this);
+        }
+        bool isValid() const { return generator != nullptr; }
+    };
+
+    Label label() {
+        return Label(this, Label::LinkNow);
+    }
+
+    Label newLabel() {
+        return Label(this, Label::LinkLater);
+    }
+
+    ExceptionHandler newExceptionHandler() {
+        return ExceptionHandler(this);
+    }
+
+    template<int InstrT>
+    void addInstruction(const InstrData<InstrT> &data)
+    {
+        Instr genericInstr;
+        InstrMeta<InstrT>::setData(genericInstr, data);
+        addInstructionHelper(Moth::Instr::Type(InstrT), genericInstr);
+    }
+
+    // Same as addInstruction, but also add a trace slot. Move only, because the instruction cannot
+    // be reused afterwards.
+    template<int InstrT>
+    void addTracingInstruction(InstrData<InstrT> data)
+    {
+        data.traceSlot = nextTraceInfo();
+        addInstruction(data);
+    }
+
+    Q_REQUIRED_RESULT Jump jump()
+    {
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_GCC("-Wmaybe-uninitialized") // broken gcc warns about Instruction::Debug()
+        Instruction::Jump data;
+        return addJumpInstruction(data);
+QT_WARNING_POP
+    }
+
+    Q_REQUIRED_RESULT Jump jumpTrue()
+    {
+        return addTracingJumpInstruction(Instruction::JumpTrue());
+    }
+
+    Q_REQUIRED_RESULT Jump jumpFalse()
+    {
+        return addTracingJumpInstruction(Instruction::JumpFalse());
+    }
+
+    Q_REQUIRED_RESULT Jump jumpNotUndefined()
+    {
+        Instruction::JumpNotUndefined data;
+        return addJumpInstruction(data);
+    }
+
+    Q_REQUIRED_RESULT Jump jumpNoException()
+    {
+        Instruction::JumpNoException data;
+        return addJumpInstruction(data);
+    }
+
+    void jumpStrictEqual(const StackSlot &lhs, const Label &target)
+    {
+        Instruction::CmpStrictEqual cmp;
+        cmp.lhs = lhs;
+        addInstruction(std::move(cmp));
+        addTracingJumpInstruction(Instruction::JumpTrue()).link(target);
+    }
+
+    void jumpStrictNotEqual(const StackSlot &lhs, const Label &target)
+    {
+        Instruction::CmpStrictNotEqual cmp;
+        cmp.lhs = lhs;
+        addInstruction(std::move(cmp));
+        addTracingJumpInstruction(Instruction::JumpTrue()).link(target);
+    }
+
+    void setUnwindHandler(ExceptionHandler *handler)
+    {
+        currentExceptionHandler = handler;
+        Instruction::SetUnwindHandler data;
+        data.offset = 0;
+        if (!handler)
+            addInstruction(data);
+        else
+            addJumpInstruction(data).link(*handler);
+    }
+
+    void unwindToLabel(int level, const Label &target)
+    {
+        if (level) {
+            Instruction::UnwindToLabel unwind;
+            unwind.level = level;
+            addJumpInstruction(unwind).link(target);
+        } else {
+            jump().link(target);
+        }
+    }
+
+
+
+    void setLocation(const QQmlJS::AST::SourceLocation &loc);
+
+    ExceptionHandler *exceptionHandler() const {
+        return currentExceptionHandler;
+    }
+
+    int newRegister();
+    int newRegisterArray(int n);
+    int registerCount() const { return regCount; }
+    int currentRegister() const { return currentReg; }
+
+    void finalize(Compiler::Context *context);
+
+    template<int InstrT>
+    Jump addTracingJumpInstruction(InstrData<InstrT> &&data)
+    {
+        data.traceSlot = nextTraceInfo();
+        return addJumpInstruction(data);
+    }
+
+    template<int InstrT>
+    Jump addJumpInstruction(const InstrData<InstrT> &data)
+    {
+        Instr genericInstr;
+        InstrMeta<InstrT>::setData(genericInstr, data);
+        return Jump(this, addInstructionHelper(Moth::Instr::Type(InstrT), genericInstr, offsetof(InstrData<InstrT>, offset)));
+    }
+
+    void addCJumpInstruction(bool jumpOnFalse, const Label *trueLabel, const Label *falseLabel)
+    {
+        if (jumpOnFalse)
+            addTracingJumpInstruction(Instruction::JumpFalse()).link(*falseLabel);
+        else
+            addTracingJumpInstruction(Instruction::JumpTrue()).link(*trueLabel);
+    }
+
+    void clearLastInstruction()
+    {
+        lastInstrType = -1;
+    }
+
+    TraceInfoCount nextTraceInfo()
+    {
+        // If tracing is disabled, use slot 0 to unconditionally store all trace info
+        if (nTraceInfos == CompiledData::Function::NoTracing())
+            return TraceInfoCount(0);
+        return nTraceInfos++;
+    }
+
+    void setTracing(bool onoff, int argumentCount)
+    {
+        if (onoff)
+            nTraceInfos = argumentCount;
+        else
+            nTraceInfos = CompiledData::Function::NoTracing();
+    }
+
+    TraceInfoCount traceInfoCount() const
+    {
+        return nTraceInfos;
+    }
+
+    void addLoopStart(const Label &start)
+    {
+        _labelInfos.push_back({ start.index });
+    }
+
+private:
+    friend struct Jump;
+    friend struct Label;
+    friend struct ExceptionHandler;
+
+    int addInstructionHelper(Moth::Instr::Type type, const Instr &i, int offsetOfOffset = -1);
+
+    struct I {
+        Moth::Instr::Type type;
+        short size;
+        uint position;
+        int line;
+        int offsetForJump;
+        int linkedLabel;
+        unsigned char packed[sizeof(Instr) + 2]; // 2 for instruction type
+    };
+
+    void compressInstructions();
+    void packInstruction(I &i);
+    void adjustJumpOffsets();
+
+    QVector<I> instructions;
+    QVector<int> labels;
+    ExceptionHandler *currentExceptionHandler = nullptr;
+    int regCount = 0;
+public:
+    int currentReg = 0;
+private:
+    int startLine = 0;
+    int currentLine = 0;
+    bool debugMode = false;
+
+    int lastInstrType = -1;
+    Moth::Instr lastInstr;
+
+    TraceInfoCount nTraceInfos = TraceInfoCount(0);
+
+    struct LabelInfo {
+        int labelIndex;
+    };
+    std::vector<LabelInfo> _labelInfos;
+};
+
+}
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/compiler/qv4bytecodehandler.cpp b/src/qml/compiler/qv4bytecodehandler.cpp
new file mode 100644
index 0000000000..f9f755b8c0
--- /dev/null
+++ b/src/qml/compiler/qv4bytecodehandler.cpp
@@ -0,0 +1,82 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4bytecodehandler_p.h>
+
+QT_USE_NAMESPACE
+using namespace QV4;
+using namespace Moth;
+
+ByteCodeHandler::~ByteCodeHandler()
+{
+}
+
+#define DISPATCH_INSTRUCTION(name, nargs, ...) \
+    generate_##name( \
+        __VA_ARGS__ \
+    );
+
+#define DECODE_AND_DISPATCH(instr) \
+    { \
+        INSTR_##instr(MOTH_DECODE_WITH_BASE) \
+        Q_UNUSED(base_ptr); \
+        _currentOffset = _nextOffset; \
+        _nextOffset = code - start; \
+        if (startInstruction(Instr::Type::instr) == ProcessInstruction) { \
+            INSTR_##instr(DISPATCH) \
+            endInstruction(Instr::Type::instr); \
+        } \
+        continue; \
+    }
+
+void ByteCodeHandler::decode(const char *code, uint len)
+{
+    MOTH_JUMP_TABLE;
+
+    const char *start = code;
+    const char *end = code + len;
+    while (code < end) {
+        MOTH_DISPATCH()
+
+        FOR_EACH_MOTH_INSTR(DECODE_AND_DISPATCH)
+    }
+}
+
+#undef DECODE_AND_DISPATCH
+#undef DISPATCH_INSTRUCTION
diff --git a/src/qml/compiler/qv4bytecodehandler_p.h b/src/qml/compiler/qv4bytecodehandler_p.h
new file mode 100644
index 0000000000..f1e7c99447
--- /dev/null
+++ b/src/qml/compiler/qv4bytecodehandler_p.h
@@ -0,0 +1,122 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4BYTECODEHANDLER_P_H
+#define QV4BYTECODEHANDLER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+#include <private/qv4instr_moth_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace Moth {
+
+#define BYTECODE_HANDLER_DEFINE_ARGS(nargs, ...) \
+    MOTH_EXPAND_FOR_MSVC(BYTECODE_HANDLER_DEFINE_ARGS##nargs(__VA_ARGS__))
+
+#define BYTECODE_HANDLER_DEFINE_ARGS0()
+#define BYTECODE_HANDLER_DEFINE_ARGS1(arg) \
+    int arg
+#define BYTECODE_HANDLER_DEFINE_ARGS2(arg1, arg2) \
+    int arg1, \
+    int arg2
+#define BYTECODE_HANDLER_DEFINE_ARGS3(arg1, arg2, arg3) \
+    int arg1, \
+    int arg2, \
+    int arg3
+#define BYTECODE_HANDLER_DEFINE_ARGS4(arg1, arg2, arg3, arg4) \
+    int arg1, \
+    int arg2, \
+    int arg3, \
+    int arg4
+#define BYTECODE_HANDLER_DEFINE_ARGS5(arg1, arg2, arg3, arg4, arg5) \
+    int arg1, \
+    int arg2, \
+    int arg3, \
+    int arg4, \
+    int arg5
+
+#define BYTECODE_HANDLER_DEFINE_VIRTUAL_BYTECODE_HANDLER_INSTRUCTION(name, nargs, ...) \
+    virtual void generate_##name( \
+    BYTECODE_HANDLER_DEFINE_ARGS(nargs, __VA_ARGS__) \
+    ) = 0;
+
+#define BYTECODE_HANDLER_DEFINE_VIRTUAL_BYTECODE_HANDLER(instr) \
+    INSTR_##instr(BYTECODE_HANDLER_DEFINE_VIRTUAL_BYTECODE_HANDLER)
+
+class ByteCodeHandler
+{
+public:
+    virtual ~ByteCodeHandler();
+
+    void decode(const char *code, uint len);
+
+    int currentInstructionOffset() const { return _currentOffset; }
+    int nextInstructionOffset() const { return _nextOffset; }
+    int absoluteOffset(int relativeOffset) const
+    { return nextInstructionOffset() + relativeOffset; }
+
+protected:
+    FOR_EACH_MOTH_INSTR(BYTECODE_HANDLER_DEFINE_VIRTUAL_BYTECODE_HANDLER)
+
+    enum Verdict { ProcessInstruction, SkipInstruction };
+    virtual Verdict startInstruction(Moth::Instr::Type instr) = 0;
+    virtual void endInstruction(Moth::Instr::Type instr) = 0;
+
+private:
+    int _currentOffset = 0;
+    int _nextOffset = 0;
+};
+
+} // Moth namespace
+} // QV4 namespace
+
+QT_END_NAMESPACE
+
+#endif // QV4BYTECODEHANDLER_P_H
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 693a4230ba..448fbff27b 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -39,61 +39,39 @@
 
 #include "qv4codegen_p.h"
 #include "qv4util_p.h"
-#include "qv4engine_p.h"
 
 #include <QtCore/QCoreApplication>
 #include <QtCore/QStringList>
-#include <QtCore/QSet>
-#include <QtCore/QBuffer>
-#include <QtCore/QBitArray>
-#include <QtCore/QLinkedList>
 #include <QtCore/QStack>
+#include <QScopeGuard>
 #include <private/qqmljsast_p.h>
 #include <private/qv4string_p.h>
 #include <private/qv4value_p.h>
+#include <private/qv4compilercontext_p.h>
+#include <private/qv4compilercontrolflow_p.h>
+#include <private/qv4bytecodegenerator_p.h>
+#include <private/qv4compilerscanfunctions_p.h>
 
 #ifndef V4_BOOTSTRAP
-#include <qv4context_p.h>
+#  include <qqmlerror.h>
 #endif
 
 #include <cmath>
 #include <iostream>
 
+static const bool disable_lookups = false;
+
 #ifdef CONST
 #undef CONST
 #endif
 
+QT_USE_NAMESPACE
 using namespace QV4;
-using namespace QQmlJS;
-using namespace AST;
-
-static inline void setLocation(IR::Stmt *s, const SourceLocation &loc)
-{
-    if (s && loc.isValid())
-        s->location = loc;
-}
-
-static bool cjumpCanHandle(IR::AluOp op)
-{
-    switch (op) {
-    case IR::OpIn:
-    case IR::OpInstanceof:
-    case IR::OpEqual:
-    case IR::OpNotEqual:
-    case IR::OpGe:
-    case IR::OpGt:
-    case IR::OpLe:
-    case IR::OpLt:
-    case IR::OpStrictEqual:
-    case IR::OpStrictNotEqual:
-        return true;
-    default:
-        return false;
-    }
-}
+using namespace QV4::Compiler;
+using namespace QQmlJS::AST;
 
-static inline void setJumpOutLocation(IR::Stmt *s, const Statement *body,
-                                      const SourceLocation &fallback)
+static inline void setJumpOutLocation(QV4::Moth::BytecodeGenerator *bytecodeGenerator,
+                                      const Statement *body, const SourceLocation &fallback)
 {
     switch (body->kind) {
     // Statements where we might never execute the last line.
@@ -102,677 +80,296 @@ static inline void setJumpOutLocation(IR::Stmt *s, const Statement *body,
     case Statement::Kind_ForEachStatement:
     case Statement::Kind_ForStatement:
     case Statement::Kind_IfStatement:
-    case Statement::Kind_LocalForEachStatement:
-    case Statement::Kind_LocalForStatement:
     case Statement::Kind_WhileStatement:
-        setLocation(s, fallback);
+        bytecodeGenerator->setLocation(fallback);
         break;
     default:
-        setLocation(s, body->lastSourceLocation());
+        bytecodeGenerator->setLocation(body->lastSourceLocation());
         break;
     }
 }
 
-Codegen::ScanFunctions::ScanFunctions(Codegen *cg, const QString &sourceCode, CompilationMode defaultProgramMode)
-    : _cg(cg)
-    , _sourceCode(sourceCode)
-    , _variableEnvironment(0)
-    , _allowFuncDecls(true)
-    , defaultProgramMode(defaultProgramMode)
-{
-}
-
-void Codegen::ScanFunctions::operator()(Node *node)
-{
-    if (node)
-        node->accept(this);
-}
-
-void Codegen::ScanFunctions::enterEnvironment(Node *node, CompilationMode compilationMode)
-{
-    Environment *e = _cg->newEnvironment(node, _variableEnvironment, compilationMode);
-    if (!e->isStrict)
-        e->isStrict = _cg->_strictMode;
-    _envStack.append(e);
-    _variableEnvironment = e;
-}
-
-void Codegen::ScanFunctions::leaveEnvironment()
-{
-    _envStack.pop();
-    _variableEnvironment = _envStack.isEmpty() ? 0 : _envStack.top();
-}
-
-void Codegen::ScanFunctions::checkDirectivePrologue(SourceElements *ast)
-{
-    for (SourceElements *it = ast; it; it = it->next) {
-        if (StatementSourceElement *stmt = cast<StatementSourceElement *>(it->element)) {
-            if (ExpressionStatement *expr = cast<ExpressionStatement *>(stmt->statement)) {
-                if (StringLiteral *strLit = cast<StringLiteral *>(expr->expression)) {
-                    // Use the source code, because the StringLiteral's
-                    // value might have escape sequences in it, which is not
-                    // allowed.
-                    if (strLit->literalToken.length < 2)
-                        continue;
-                    QStringRef str = _sourceCode.midRef(strLit->literalToken.offset + 1, strLit->literalToken.length - 2);
-                    if (str == QLatin1String("use strict")) {
-                        _variableEnvironment->isStrict = true;
-                    } else {
-                        // TODO: give a warning.
-                    }
-                    continue;
-                }
-            }
-        }
-
-        break;
-    }
-}
-
-void Codegen::ScanFunctions::checkName(const QStringRef &name, const SourceLocation &loc)
-{
-    if (_variableEnvironment->isStrict) {
-        if (name == QLatin1String("implements")
-                || name == QLatin1String("interface")
-                || name == QLatin1String("let")
-                || name == QLatin1String("package")
-                || name == QLatin1String("private")
-                || name == QLatin1String("protected")
-                || name == QLatin1String("public")
-                || name == QLatin1String("static")
-                || name == QLatin1String("yield")) {
-            _cg->throwSyntaxError(loc, QStringLiteral("Unexpected strict mode reserved word"));
-        }
-    }
-}
-void Codegen::ScanFunctions::checkForArguments(AST::FormalParameterList *parameters)
-{
-    while (parameters) {
-        if (parameters->name == QLatin1String("arguments"))
-            _variableEnvironment->usesArgumentsObject = Environment::ArgumentsObjectNotUsed;
-        parameters = parameters->next;
-    }
-}
-
-bool Codegen::ScanFunctions::visit(Program *ast)
-{
-    enterEnvironment(ast, defaultProgramMode);
-    checkDirectivePrologue(ast->elements);
-    return true;
-}
-
-void Codegen::ScanFunctions::endVisit(Program *)
-{
-    leaveEnvironment();
-}
-
-bool Codegen::ScanFunctions::visit(CallExpression *ast)
-{
-    if (! _variableEnvironment->hasDirectEval) {
-        if (IdentifierExpression *id = cast<IdentifierExpression *>(ast->base)) {
-            if (id->name == QLatin1String("eval")) {
-                if (_variableEnvironment->usesArgumentsObject == Environment::ArgumentsObjectUnknown)
-                    _variableEnvironment->usesArgumentsObject = Environment::ArgumentsObjectUsed;
-                _variableEnvironment->hasDirectEval = true;
-            }
-        }
-    }
-    int argc = 0;
-    for (ArgumentList *it = ast->arguments; it; it = it->next)
-        ++argc;
-    _variableEnvironment->maxNumberOfArguments = qMax(_variableEnvironment->maxNumberOfArguments, argc);
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(NewMemberExpression *ast)
-{
-    int argc = 0;
-    for (ArgumentList *it = ast->arguments; it; it = it->next)
-        ++argc;
-    _variableEnvironment->maxNumberOfArguments = qMax(_variableEnvironment->maxNumberOfArguments, argc);
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(ArrayLiteral *ast)
-{
-    int index = 0;
-    for (ElementList *it = ast->elements; it; it = it->next) {
-        for (Elision *elision = it->elision; elision; elision = elision->next)
-            ++index;
-        ++index;
-    }
-    if (ast->elision) {
-        for (Elision *elision = ast->elision->next; elision; elision = elision->next)
-            ++index;
-    }
-    _variableEnvironment->maxNumberOfArguments = qMax(_variableEnvironment->maxNumberOfArguments, index);
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(VariableDeclaration *ast)
-{
-    if (_variableEnvironment->isStrict && (ast->name == QLatin1String("eval") || ast->name == QLatin1String("arguments")))
-        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Variable name may not be eval or arguments in strict mode"));
-    checkName(ast->name, ast->identifierToken);
-    if (ast->name == QLatin1String("arguments"))
-        _variableEnvironment->usesArgumentsObject = Environment::ArgumentsObjectNotUsed;
-    if (ast->scope == AST::VariableDeclaration::VariableScope::ReadOnlyBlockScope && !ast->expression) {
-        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Missing initializer in const declaration"));
-        return false;
-    }
-    QString name = ast->name.toString();
-    const Environment::Member *m = 0;
-    if (_variableEnvironment->memberInfo(name, &m)) {
-        if (m->isLexicallyScoped() || ast->isLexicallyScoped()) {
-            _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Identifier %1 has already been declared").arg(name));
-            return false;
-        }
-    }
-    _variableEnvironment->enter(ast->name.toString(), ast->expression ? Environment::VariableDefinition : Environment::VariableDeclaration, ast->scope);
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(IdentifierExpression *ast)
-{
-    checkName(ast->name, ast->identifierToken);
-    if (_variableEnvironment->usesArgumentsObject == Environment::ArgumentsObjectUnknown && ast->name == QLatin1String("arguments"))
-        _variableEnvironment->usesArgumentsObject = Environment::ArgumentsObjectUsed;
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(ExpressionStatement *ast)
-{
-    if (FunctionExpression* expr = AST::cast<AST::FunctionExpression*>(ast->expression)) {
-        if (!_allowFuncDecls)
-            _cg->throwSyntaxError(expr->functionToken, QStringLiteral("conditional function or closure declaration"));
-
-        enterFunction(expr, /*enterName*/ true);
-        Node::accept(expr->formals, this);
-        Node::accept(expr->body, this);
-        leaveEnvironment();
-        return false;
-    } else {
-        SourceLocation firstToken = ast->firstSourceLocation();
-        if (_sourceCode.midRef(firstToken.offset, firstToken.length) == QLatin1String("function")) {
-            _cg->throwSyntaxError(firstToken, QStringLiteral("unexpected token"));
-        }
-    }
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(FunctionExpression *ast)
-{
-    enterFunction(ast, /*enterName*/ false);
-    return true;
-}
-
-void Codegen::ScanFunctions::enterFunction(FunctionExpression *ast, bool enterName, bool isExpression)
-{
-    if (_variableEnvironment->isStrict && (ast->name == QLatin1String("eval") || ast->name == QLatin1String("arguments")))
-        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Function name may not be eval or arguments in strict mode"));
-    enterFunction(ast, ast->name.toString(), ast->formals, ast->body, enterName ? ast : 0, isExpression);
-}
-
-void Codegen::ScanFunctions::endVisit(FunctionExpression *)
-{
-    leaveEnvironment();
-}
-
-bool Codegen::ScanFunctions::visit(ObjectLiteral *ast)
-{
-    int argc = 0;
-    for (PropertyAssignmentList *it = ast->properties; it; it = it->next) {
-        QString key = it->assignment->name->asString();
-        if (QV4::String::toArrayIndex(key) != UINT_MAX)
-            ++argc;
-        ++argc;
-        if (AST::cast<AST::PropertyGetterSetter *>(it->assignment))
-            ++argc;
-    }
-    _variableEnvironment->maxNumberOfArguments = qMax(_variableEnvironment->maxNumberOfArguments, argc);
-
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, true);
-    Node::accept(ast->properties, this);
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(PropertyGetterSetter *ast)
-{
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, true);
-    enterFunction(ast, QString(), ast->formals, ast->functionBody, /*FunctionExpression*/0, /*isExpression*/false);
-    return true;
-}
-
-void Codegen::ScanFunctions::endVisit(PropertyGetterSetter *)
-{
-    leaveEnvironment();
-}
-
-bool Codegen::ScanFunctions::visit(FunctionDeclaration *ast)
-{
-    enterFunction(ast, /*enterName*/ true, /*isExpression */false);
-    return true;
-}
-
-void Codegen::ScanFunctions::endVisit(FunctionDeclaration *)
-{
-    leaveEnvironment();
-}
-
-bool Codegen::ScanFunctions::visit(WithStatement *ast)
-{
-    if (_variableEnvironment->isStrict) {
-        _cg->throwSyntaxError(ast->withToken, QStringLiteral("'with' statement is not allowed in strict mode"));
-        return false;
-    }
-
-    return true;
-}
-
-bool Codegen::ScanFunctions::visit(DoWhileStatement *ast) {
-    {
-        TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_variableEnvironment->isStrict);
-        Node::accept(ast->statement, this);
-    }
-    Node::accept(ast->expression, this);
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(ForStatement *ast) {
-    Node::accept(ast->initialiser, this);
-    Node::accept(ast->condition, this);
-    Node::accept(ast->expression, this);
-
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_variableEnvironment->isStrict);
-    Node::accept(ast->statement, this);
-
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(LocalForStatement *ast) {
-    Node::accept(ast->declarations, this);
-    Node::accept(ast->condition, this);
-    Node::accept(ast->expression, this);
-
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_variableEnvironment->isStrict);
-    Node::accept(ast->statement, this);
-
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(ForEachStatement *ast) {
-    Node::accept(ast->initialiser, this);
-    Node::accept(ast->expression, this);
-
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_variableEnvironment->isStrict);
-    Node::accept(ast->statement, this);
-
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(LocalForEachStatement *ast) {
-    Node::accept(ast->declaration, this);
-    Node::accept(ast->expression, this);
-
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_variableEnvironment->isStrict);
-    Node::accept(ast->statement, this);
-
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(ThisExpression *)
-{
-    _variableEnvironment->usesThis = true;
-    return false;
-}
-
-bool Codegen::ScanFunctions::visit(Block *ast) {
-    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, _variableEnvironment->isStrict ? false : _allowFuncDecls);
-    Node::accept(ast->statements, this);
-    return false;
-}
-
-void Codegen::ScanFunctions::enterFunction(Node *ast, const QString &name, FormalParameterList *formals, FunctionBody *body, FunctionExpression *expr, bool isExpression)
-{
-    bool wasStrict = false;
-    if (_variableEnvironment) {
-        _variableEnvironment->hasNestedFunctions = true;
-        // The identifier of a function expression cannot be referenced from the enclosing environment.
-        if (expr)
-            _variableEnvironment->enter(name, Environment::FunctionDefinition, AST::VariableDeclaration::FunctionScope, expr);
-        if (name == QLatin1String("arguments"))
-            _variableEnvironment->usesArgumentsObject = Environment::ArgumentsObjectNotUsed;
-        wasStrict = _variableEnvironment->isStrict;
-    }
-
-    enterEnvironment(ast, FunctionCode);
-    checkForArguments(formals);
-
-    _variableEnvironment->isNamedFunctionExpression = isExpression && !name.isEmpty();
-    _variableEnvironment->formals = formals;
-
-    if (body)
-        checkDirectivePrologue(body->elements);
-
-    if (wasStrict || _variableEnvironment->isStrict) {
-        QStringList args;
-        for (FormalParameterList *it = formals; it; it = it->next) {
-            QString arg = it->name.toString();
-            if (args.contains(arg)) {
-                _cg->throwSyntaxError(it->identifierToken, QStringLiteral("Duplicate parameter name '%1' is not allowed in strict mode").arg(arg));
-                return;
-            }
-            if (arg == QLatin1String("eval") || arg == QLatin1String("arguments")) {
-                _cg->throwSyntaxError(it->identifierToken, QStringLiteral("'%1' cannot be used as parameter name in strict mode").arg(arg));
-                return;
-            }
-            args += arg;
-        }
-    }
-}
-
-
-Codegen::Codegen(bool strict)
-    : _module(0)
-    , _function(0)
-    , _block(0)
-    , _exitBlock(0)
-    , _returnAddress(0)
-    , _variableEnvironment(0)
-    , _loop(0)
-    , _labelledStatement(0)
-    , _scopeAndFinally(0)
+Codegen::Codegen(QV4::Compiler::JSUnitGenerator *jsUnitGenerator, bool strict)
+    : _module(nullptr)
+    , _returnAddress(-1)
+    , _context(nullptr)
+    , _labelledStatement(nullptr)
+    , jsUnitGenerator(jsUnitGenerator)
     , _strictMode(strict)
     , _fileNameIsUrl(false)
     , hasError(false)
 {
-}
+    jsUnitGenerator->codeGeneratorName = QStringLiteral("moth");
+}
+
+const char *globalNames[] = {
+    "isNaN",
+    "parseFloat",
+    "String",
+    "EvalError",
+    "URIError",
+    "Math",
+    "encodeURIComponent",
+    "RangeError",
+    "eval",
+    "isFinite",
+    "ReferenceError",
+    "Infinity",
+    "Function",
+    "RegExp",
+    "Number",
+    "parseInt",
+    "Object",
+    "decodeURI",
+    "TypeError",
+    "Boolean",
+    "encodeURI",
+    "NaN",
+    "Error",
+    "decodeURIComponent",
+    "Date",
+    "Array",
+    "Symbol",
+    "escape",
+    "unescape",
+    "SyntaxError",
+    "undefined",
+    "JSON",
+    "ArrayBuffer",
+    "SharedArrayBuffer",
+    "DataView",
+    "Int8Array",
+    "Uint8Array",
+    "Uint8ClampedArray",
+    "Int16Array",
+    "Uint16Array",
+    "Int32Array",
+    "Uint32Array",
+    "Float32Array",
+    "Float64Array",
+    "WeakSet",
+    "Set",
+    "WeakMap",
+    "Map",
+    "Reflect",
+    "Proxy",
+    "Atomics",
+    "Promise",
+    nullptr
+};
 
 void Codegen::generateFromProgram(const QString &fileName,
+                                  const QString &finalUrl,
                                   const QString &sourceCode,
                                   Program *node,
-                                  QV4::IR::Module *module,
-                                  CompilationMode mode,
-                                  const QStringList &inheritedLocals)
+                                  Module *module,
+                                  ContextType contextType)
 {
     Q_ASSERT(node);
 
     _module = module;
-    _variableEnvironment = 0;
-
-    _module->setFileName(fileName);
+    _context = nullptr;
+
+    // ### should be set on the module outside of this method
+    _module->fileName = fileName;
+    _module->finalUrl = finalUrl;
+
+    if (contextType == ContextType::ScriptImportedByQML) {
+        // the global object is frozen, so we know that members of it are
+        // pointing to the global object. This is important so that references
+        // to Math etc. do not go through the expensive path in the context wrapper
+        // that tries to see whether we have a matching type
+        //
+        // Since this can be called from the loader thread we can't get the list
+        // directly from the engine, so let's hardcode the most important ones here
+        for (const char **g = globalNames; *g != nullptr; ++g)
+            m_globalNames << QString::fromLatin1(*g);
+    }
 
-    ScanFunctions scan(this, sourceCode, mode);
+    ScanFunctions scan(this, sourceCode, contextType);
     scan(node);
 
-    defineFunction(QStringLiteral("%entry"), node, 0, node->elements, inheritedLocals);
-    qDeleteAll(_envMap);
-    _envMap.clear();
-}
-
-void Codegen::generateFromFunctionExpression(const QString &fileName,
-                                             const QString &sourceCode,
-                                             AST::FunctionExpression *ast,
-                                             QV4::IR::Module *module)
-{
-    _module = module;
-    _module->setFileName(fileName);
-    _variableEnvironment = 0;
-
-    ScanFunctions scan(this, sourceCode, GlobalCode);
-    // fake a global environment
-    scan.enterEnvironment(0, FunctionCode);
-    scan(ast);
-    scan.leaveEnvironment();
-
-    defineFunction(ast->name.toString(), ast, ast->formals, ast->body ? ast->body->elements : 0);
+    if (hasError)
+        return;
 
-    qDeleteAll(_envMap);
-    _envMap.clear();
+    defineFunction(QStringLiteral("%entry"), node, nullptr, node->statements);
 }
 
-
-void Codegen::enterEnvironment(Node *node)
+void Codegen::generateFromModule(const QString &fileName,
+                                 const QString &finalUrl,
+                                 const QString &sourceCode,
+                                 ESModule *node,
+                                 Module *module)
 {
-    _variableEnvironment = _envMap.value(node);
-    Q_ASSERT(_variableEnvironment);
-}
+    Q_ASSERT(node);
 
-void Codegen::leaveEnvironment()
-{
-    Q_ASSERT(_variableEnvironment);
-    _variableEnvironment = _variableEnvironment->parent;
-}
+    _module = module;
+    _context = nullptr;
 
-void Codegen::enterLoop(Statement *node, IR::BasicBlock *breakBlock, IR::BasicBlock *continueBlock)
-{
-    _loop = new Loop(node, breakBlock, continueBlock, _loop);
-    _loop->labelledStatement = _labelledStatement; // consume the enclosing labelled statement
-    _loop->scopeAndFinally = _scopeAndFinally;
-    _labelledStatement = 0;
-}
+    // ### should be set on the module outside of this method
+    _module->fileName = fileName;
+    _module->finalUrl = finalUrl;
 
-void Codegen::leaveLoop()
-{
-    Loop *current = _loop;
-    _loop = _loop->parent;
-    delete current;
-}
+    ScanFunctions scan(this, sourceCode, ContextType::ESModule);
+    scan(node);
 
-IR::Expr *Codegen::member(IR::Expr *base, const QString *name)
-{
     if (hasError)
-        return 0;
-
-    if (base->asTemp() || base->asArgLocal())
-        return _block->MEMBER(base, name);
-    else {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), base);
-        return _block->MEMBER(_block->TEMP(t), name);
-    }
-}
+        return;
 
-IR::Expr *Codegen::subscript(IR::Expr *base, IR::Expr *index)
-{
-    if (hasError)
-        return 0;
+    {
+        Compiler::Context *moduleContext = _module->contextMap.value(node);
+        for (const auto &entry: moduleContext->exportEntries) {
+            if (entry.moduleRequest.isEmpty()) {
+                // ### check against imported bound names
+                _module->localExportEntries << entry;
+            } else if (entry.importName == QLatin1Char('*')) {
+                _module->starExportEntries << entry;
+            } else {
+                _module->indirectExportEntries << entry;
+            }
+        }
+        _module->importEntries = moduleContext->importEntries;
 
-    if (! base->asTemp() && !base->asArgLocal()) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), base);
-        base = _block->TEMP(t);
+        _module->moduleRequests = std::move(moduleContext->moduleRequests);
+        _module->moduleRequests.removeDuplicates();
     }
 
-    if (! index->asTemp() && !index->asArgLocal() && !index->asConst()) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), index);
-        index = _block->TEMP(t);
-    }
+    std::sort(_module->localExportEntries.begin(), _module->localExportEntries.end(), ExportEntry::lessThan);
+    std::sort(_module->starExportEntries.begin(), _module->starExportEntries.end(), ExportEntry::lessThan);
+    std::sort(_module->indirectExportEntries.begin(), _module->indirectExportEntries.end(), ExportEntry::lessThan);
 
-    Q_ASSERT(base->asTemp() || base->asArgLocal());
-    Q_ASSERT(index->asTemp() || index->asArgLocal() || index->asConst());
-    return _block->SUBSCRIPT(base, index);
+    defineFunction(QStringLiteral("%entry"), node, nullptr, node->body);
 }
 
-IR::Expr *Codegen::argument(IR::Expr *expr)
+void Codegen::enterContext(Node *node)
 {
-    if (expr && !expr->asTemp()) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), expr);
-        expr = _block->TEMP(t);
-    }
-    return expr;
+    _context = _module->contextMap.value(node);
+    Q_ASSERT(_context);
 }
 
-// keeps references alive, converts other expressions to temps
-IR::Expr *Codegen::reference(IR::Expr *expr)
+int Codegen::leaveContext()
 {
-    if (hasError)
-        return 0;
+    Q_ASSERT(_context);
+    int functionIndex = _context->functionIndex;
+    _context = _context->parent;
+    return functionIndex;
+}
 
-    if (expr && !expr->asTemp() && !expr->asArgLocal() && !expr->asName() && !expr->asMember() && !expr->asSubscript()) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), expr);
-        expr = _block->TEMP(t);
-    }
-    return expr;
+Context *Codegen::enterBlock(Node *node)
+{
+    enterContext(node);
+    return _context;
 }
 
-IR::Expr *Codegen::unop(IR::AluOp op, IR::Expr *expr, const SourceLocation &loc)
+Codegen::Reference Codegen::unop(UnaryOperation op, const Reference &expr)
 {
     if (hasError)
-        return 0;
-
-    Q_ASSERT(op != IR::OpIncrement);
-    Q_ASSERT(op != IR::OpDecrement);
+        return _expr.result();
 
-    if (IR::Const *c = expr->asConst()) {
-        if (c->type == IR::NumberType) {
+    if (expr.isConstant()) {
+        auto v = Value::fromReturnedValue(expr.constant);
+        if (v.isNumber()) {
             switch (op) {
-            case IR::OpNot:
-                return _block->CONST(IR::BoolType, !c->value);
-            case IR::OpUMinus:
-                return _block->CONST(IR::NumberType, -c->value);
-            case IR::OpUPlus:
+            case Not:
+                return Reference::fromConst(this, Encode(!v.toBoolean()));
+            case UMinus:
+                return Reference::fromConst(this, Runtime::UMinus::call(v));
+            case UPlus:
                 return expr;
-            case IR::OpCompl:
-                return _block->CONST(IR::NumberType, ~QV4::Primitive::toInt32(c->value));
-            case IR::OpIncrement:
-                return _block->CONST(IR::NumberType, c->value + 1);
-            case IR::OpDecrement:
-                return _block->CONST(IR::NumberType, c->value - 1);
+            case Compl:
+                return Reference::fromConst(this, Encode((int)~v.toInt32()));
             default:
                 break;
             }
         }
     }
-    if (!expr->asTemp() && !expr->asArgLocal()) {
-        const unsigned t = _block->newTemp();
-        setLocation(move(_block->TEMP(t), expr), loc);
-        expr = _block->TEMP(t);
-    }
-    Q_ASSERT(expr->asTemp() || expr->asArgLocal());
-    return _block->UNOP(op, expr);
-}
-
-IR::Expr *Codegen::binop(IR::AluOp op, IR::Expr *left, IR::Expr *right, const AST::SourceLocation &loc)
-{
-    if (hasError)
-        return 0;
-
-    if (IR::Const *c1 = left->asConst()) {
-        if (IR::Const *c2 = right->asConst()) {
-            if ((c1->type & IR::NumberType) && (c2->type & IR::NumberType)) {
-                switch (op) {
-                case IR::OpAdd: return _block->CONST(IR::NumberType, c1->value + c2->value);
-                case IR::OpAnd: return _block->CONST(IR::BoolType, c1->value ? c2->value : 0);
-                case IR::OpBitAnd: return _block->CONST(IR::NumberType, int(c1->value) & int(c2->value));
-                case IR::OpBitOr: return _block->CONST(IR::NumberType, int(c1->value) | int(c2->value));
-                case IR::OpBitXor: return _block->CONST(IR::NumberType, int(c1->value) ^ int(c2->value));
-                case IR::OpDiv: return _block->CONST(IR::NumberType, c1->value / c2->value);
-                case IR::OpEqual: return _block->CONST(IR::BoolType, c1->value == c2->value);
-                case IR::OpNotEqual: return _block->CONST(IR::BoolType, c1->value != c2->value);
-                case IR::OpStrictEqual: return _block->CONST(IR::BoolType, c1->value == c2->value);
-                case IR::OpStrictNotEqual: return _block->CONST(IR::BoolType, c1->value != c2->value);
-                case IR::OpGe: return _block->CONST(IR::BoolType, c1->value >= c2->value);
-                case IR::OpGt: return _block->CONST(IR::BoolType, c1->value > c2->value);
-                case IR::OpLe: return _block->CONST(IR::BoolType, c1->value <= c2->value);
-                case IR::OpLt: return _block->CONST(IR::BoolType, c1->value < c2->value);
-                case IR::OpLShift: return _block->CONST(IR::NumberType, QV4::Primitive::toInt32(c1->value) << (QV4::Primitive::toUInt32(c2->value) & 0x1f));
-                case IR::OpMod: return _block->CONST(IR::NumberType, std::fmod(c1->value, c2->value));
-                case IR::OpMul: return _block->CONST(IR::NumberType, c1->value * c2->value);
-                case IR::OpOr: return _block->CONST(IR::NumberType, c1->value ? c1->value : c2->value);
-                case IR::OpRShift: return _block->CONST(IR::NumberType, QV4::Primitive::toInt32(c1->value) >> (QV4::Primitive::toUInt32(c2->value) & 0x1f));
-                case IR::OpSub: return _block->CONST(IR::NumberType, c1->value - c2->value);
-                case IR::OpURShift: return _block->CONST(IR::NumberType,QV4::Primitive::toUInt32(c1->value) >> (QV4::Primitive::toUInt32(c2->value) & 0x1f));
-
-                case IR::OpInstanceof:
-                case IR::OpIn:
-                    break;
 
-                case IR::OpIfTrue: // unary ops
-                case IR::OpNot:
-                case IR::OpUMinus:
-                case IR::OpUPlus:
-                case IR::OpCompl:
-                case IR::OpIncrement:
-                case IR::OpDecrement:
-                case IR::OpInvalid:
-                    break;
-                }
-            }
-        }
-    } else if (op == IR::OpAdd) {
-        if (IR::String *s1 = left->asString()) {
-            if (IR::String *s2 = right->asString()) {
-                return _block->STRING(_function->newString(*s1->value + *s2->value));
-            }
-        }
+    switch (op) {
+    case UMinus: {
+        expr.loadInAccumulator();
+        Instruction::UMinus uminus = {};
+        bytecodeGenerator->addTracingInstruction(uminus);
+        return Reference::fromAccumulator(this);
     }
-
-    if (!left->asTemp() && !left->asArgLocal() && !left->asConst()) {
-        const unsigned t = _block->newTemp();
-        setLocation(move(_block->TEMP(t), left), loc);
-        left = _block->TEMP(t);
+    case UPlus: {
+        expr.loadInAccumulator();
+        Instruction::UPlus uplus;
+        bytecodeGenerator->addInstruction(uplus);
+        return Reference::fromAccumulator(this);
     }
-
-    if (!right->asTemp() && !right->asArgLocal() && !right->asConst()) {
-        const unsigned t = _block->newTemp();
-        setLocation(move(_block->TEMP(t), right), loc);
-        right = _block->TEMP(t);
+    case Not: {
+        expr.loadInAccumulator();
+        Instruction::UNot unot;
+        bytecodeGenerator->addInstruction(unot);
+        return Reference::fromAccumulator(this);
     }
-
-    Q_ASSERT(left->asTemp() || left->asArgLocal() || left->asConst());
-    Q_ASSERT(right->asTemp() || right->asArgLocal() || right->asConst());
-
-    return _block->BINOP(op, left, right);
-}
-
-IR::Expr *Codegen::call(IR::Expr *base, IR::ExprList *args)
-{
-    if (hasError)
-        return 0;
-    base = reference(base);
-    return _block->CALL(base, args);
-}
-
-IR::Stmt *Codegen::move(IR::Expr *target, IR::Expr *source, IR::AluOp op)
-{
-    if (hasError)
-        return 0;
-
-    Q_ASSERT(target->isLValue());
-
-    if (op != IR::OpInvalid) {
-        return move(target, binop(op, target, source));
+    case Compl: {
+        expr.loadInAccumulator();
+        Instruction::UCompl ucompl;
+        bytecodeGenerator->addInstruction(ucompl);
+        return Reference::fromAccumulator(this);
     }
-
-    if (!source->asTemp() && !source->asConst() && !target->asTemp() && !source->asArgLocal() && !target->asArgLocal()) {
-        unsigned t = _block->newTemp();
-        _block->MOVE(_block->TEMP(t), source);
-        source = _block->TEMP(t);
+    case PostIncrement:
+        if (!_expr.accept(nx) || requiresReturnValue) {
+            Reference e = expr.asLValue();
+            e.loadInAccumulator();
+            Instruction::UPlus uplus;
+            bytecodeGenerator->addInstruction(uplus);
+            Reference originalValue = Reference::fromStackSlot(this).storeRetainAccumulator();
+            Instruction::Increment inc = {};
+            bytecodeGenerator->addTracingInstruction(inc);
+            e.storeConsumeAccumulator();
+            return originalValue;
+        } else {
+            // intentionally fall-through: the result is never used, so it's equivalent to
+            // "expr += 1", which is what a pre-increment does as well.
+            Q_FALLTHROUGH();
+        }
+    case PreIncrement: {
+        Reference e = expr.asLValue();
+        e.loadInAccumulator();
+        Instruction::Increment inc = {};
+        bytecodeGenerator->addTracingInstruction(inc);
+        if (_expr.accept(nx))
+            return e.storeConsumeAccumulator();
+        else
+            return e.storeRetainAccumulator();
+    }
+    case PostDecrement:
+        if (!_expr.accept(nx) || requiresReturnValue) {
+            Reference e = expr.asLValue();
+            e.loadInAccumulator();
+            Instruction::UPlus uplus;
+            bytecodeGenerator->addInstruction(uplus);
+            Reference originalValue = Reference::fromStackSlot(this).storeRetainAccumulator();
+            Instruction::Decrement dec = {};
+            bytecodeGenerator->addTracingInstruction(dec);
+            e.storeConsumeAccumulator();
+            return originalValue;
+        } else {
+            // intentionally fall-through: the result is never used, so it's equivalent to
+            // "expr -= 1", which is what a pre-decrement does as well.
+            Q_FALLTHROUGH();
+        }
+    case PreDecrement: {
+        Reference e = expr.asLValue();
+        e.loadInAccumulator();
+        Instruction::Decrement dec = {};
+        bytecodeGenerator->addTracingInstruction(dec);
+        if (_expr.accept(nx))
+            return e.storeConsumeAccumulator();
+        else
+            return e.storeRetainAccumulator();
     }
-    if (source->asConst() && !target->asTemp() && !target->asArgLocal()) {
-        unsigned t = _block->newTemp();
-        _block->MOVE(_block->TEMP(t), source);
-        source = _block->TEMP(t);
     }
 
-    return _block->MOVE(target, source);
+    Q_UNREACHABLE();
 }
 
-IR::Stmt *Codegen::cjump(IR::Expr *cond, IR::BasicBlock *iftrue, IR::BasicBlock *iffalse)
+void Codegen::addCJump()
 {
-    if (hasError)
-        return 0;
-
-    if (! (cond->asTemp() || (cond->asBinop() && cjumpCanHandle(cond->asBinop()->op)) )) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), cond);
-        cond = _block->TEMP(t);
-    }
-    return _block->CJUMP(cond, iftrue, iffalse);
+    bytecodeGenerator->addCJumpInstruction(_expr.trueBlockFollowsCondition(),
+                                           _expr.iftrue(), _expr.iffalse());
 }
 
 void Codegen::accept(Node *node)
@@ -786,8 +383,15 @@ void Codegen::accept(Node *node)
 
 void Codegen::statement(Statement *ast)
 {
-    _block->nextLocation = ast->firstSourceLocation();
+    RecursionDepthCheck depthCheck(this, ast->lastSourceLocation());
+    RegisterScope scope(this);
+
+    bytecodeGenerator->setLocation(ast->firstSourceLocation());
+
+    VolatileMemoryLocations vLocs = scanVolatileMemoryLocations(ast);
+    qSwap(_volatileMemoryLocations, vLocs);
     accept(ast);
+    qSwap(_volatileMemoryLocations, vLocs);
 }
 
 void Codegen::statement(ExpressionNode *ast)
@@ -795,296 +399,685 @@ void Codegen::statement(ExpressionNode *ast)
     if (! ast) {
         return;
     } else {
+        RecursionDepthCheck depthCheck(this, ast->lastSourceLocation());
+        RegisterScope scope(this);
+
         Result r(nx);
         qSwap(_expr, r);
+        VolatileMemoryLocations vLocs = scanVolatileMemoryLocations(ast);
+        qSwap(_volatileMemoryLocations, vLocs);
+
         accept(ast);
+
+        qSwap(_volatileMemoryLocations, vLocs);
+        qSwap(_expr, r);
+
         if (hasError)
             return;
-        qSwap(_expr, r);
-        if (r.format == ex) {
-            if (r->asCall()) {
-                _block->EXP(*r); // the nest nx representation for calls is EXP(CALL(c..))
-            } else if (r->asTemp() || r->asArgLocal()) {
-                // there is nothing to do
-            } else {
-                unsigned t = _block->newTemp();
-                move(_block->TEMP(t), *r);
-            }
-        }
+        if (r.result().loadTriggersSideEffect())
+            r.result().loadInAccumulator(); // triggers side effects
     }
 }
 
-void Codegen::condition(ExpressionNode *ast, IR::BasicBlock *iftrue, IR::BasicBlock *iffalse)
+void Codegen::condition(ExpressionNode *ast, const BytecodeGenerator::Label *iftrue,
+                        const BytecodeGenerator::Label *iffalse, bool trueBlockFollowsCondition)
 {
-    if (ast) {
-        Result r(iftrue, iffalse);
-        qSwap(_expr, r);
-        accept(ast);
-        qSwap(_expr, r);
-        if (r.format == ex) {
-            setLocation(cjump(*r, r.iftrue, r.iffalse), ast->firstSourceLocation());
-        }
+    if (hasError)
+        return;
+
+    if (!ast)
+        return;
+
+    RecursionDepthCheck depthCheck(this, ast->lastSourceLocation());
+    Result r(iftrue, iffalse, trueBlockFollowsCondition);
+    qSwap(_expr, r);
+    accept(ast);
+    qSwap(_expr, r);
+
+    if (hasError)
+        return;
+
+    if (r.format() == ex) {
+        Q_ASSERT(iftrue == r.iftrue());
+        Q_ASSERT(iffalse == r.iffalse());
+        Q_ASSERT(r.result().isValid());
+        bytecodeGenerator->setLocation(ast->firstSourceLocation());
+        r.result().loadInAccumulator();
+        if (r.trueBlockFollowsCondition())
+            bytecodeGenerator->jumpFalse().link(*r.iffalse());
+        else
+            bytecodeGenerator->jumpTrue().link(*r.iftrue());
     }
 }
 
-Codegen::Result Codegen::expression(ExpressionNode *ast)
+Codegen::Reference Codegen::expression(ExpressionNode *ast)
 {
+    RecursionDepthCheck depthCheck(this, ast->lastSourceLocation());
     Result r;
     if (ast) {
         qSwap(_expr, r);
         accept(ast);
         qSwap(_expr, r);
     }
-    return r;
+    return r.result();
 }
 
-Codegen::Result Codegen::sourceElement(SourceElement *ast)
+void Codegen::program(Program *ast)
 {
-    Result r(nx);
     if (ast) {
-        qSwap(_expr, r);
-        accept(ast);
-        qSwap(_expr, r);
+        statementList(ast->statements);
     }
-    return r;
 }
 
-Codegen::UiMember Codegen::uiObjectMember(UiObjectMember *ast)
+enum class CompletionState {
+    Empty,
+    EmptyAbrupt,
+    NonEmpty
+};
+
+static CompletionState completionState(StatementList *list)
+{
+    for (StatementList *it = list; it; it = it->next) {
+        if (it->statement->kind == Statement::Kind_BreakStatement ||
+            it->statement->kind == Statement::Kind_ContinueStatement)
+            return CompletionState::EmptyAbrupt;
+        if (it->statement->kind == Statement::Kind_EmptyStatement ||
+            it->statement->kind == Statement::Kind_VariableDeclaration ||
+            it->statement->kind == Statement::Kind_FunctionDeclaration)
+            continue;
+        if (it->statement->kind == Statement::Kind_Block) {
+            CompletionState subState = completionState(static_cast<Block *>(it->statement)->statements);
+            if (subState != CompletionState::Empty)
+                return subState;
+            continue;
+        }
+        return CompletionState::NonEmpty;
+    }
+    return CompletionState::Empty;
+}
+
+static Node *completionStatement(StatementList *list)
+{
+    Node *completionStatement = nullptr;
+    for (StatementList *it = list; it; it = it->next) {
+        if (it->statement->kind == Statement::Kind_BreakStatement ||
+            it->statement->kind == Statement::Kind_ContinueStatement)
+            return completionStatement;
+        if (it->statement->kind == Statement::Kind_ThrowStatement ||
+            it->statement->kind == Statement::Kind_ReturnStatement)
+            return it->statement;
+        if (it->statement->kind == Statement::Kind_EmptyStatement ||
+            it->statement->kind == Statement::Kind_VariableStatement ||
+            it->statement->kind == Statement::Kind_FunctionDeclaration)
+            continue;
+        if (it->statement->kind == Statement::Kind_Block) {
+            CompletionState state = completionState(static_cast<Block *>(it->statement)->statements);
+            switch (state) {
+            case CompletionState::Empty:
+                continue;
+            case CompletionState::EmptyAbrupt:
+                return it->statement;
+            case CompletionState::NonEmpty:
+                break;
+            }
+        }
+        completionStatement = it->statement;
+    }
+    return completionStatement;
+}
+
+void Codegen::statementList(StatementList *ast)
 {
-    UiMember m;
-    if (ast) {
-        qSwap(_uiMember, m);
-        accept(ast);
-        qSwap(_uiMember, m);
+    if (!ast)
+        return;
+
+    bool _requiresReturnValue = requiresReturnValue;
+    // ### the next line is pessimizing a bit too much, as there are many cases, where the complietion from the break
+    // statement will not be used, but it's at least spec compliant
+    if (!controlFlow || !controlFlow->hasLoop())
+        requiresReturnValue = false;
+
+    Node *needsCompletion = nullptr;
+
+    if (_requiresReturnValue && !requiresReturnValue)
+        needsCompletion = completionStatement(ast);
+
+    if (requiresReturnValue && !needsCompletion && !insideSwitch) {
+        // break or continue is the first real statement, set the return value to undefined
+        Reference::fromConst(this, Encode::undefined()).storeOnStack(_returnAddress);
+    }
+
+    bool _insideSwitch = insideSwitch;
+    insideSwitch = false;
+
+    for (StatementList *it = ast; it; it = it->next) {
+        if (it->statement == needsCompletion)
+            requiresReturnValue = true;
+        if (Statement *s = it->statement->statementCast())
+            statement(s);
+        else
+            statement(static_cast<ExpressionNode *>(it->statement));
+        if (it->statement == needsCompletion)
+            requiresReturnValue = false;
+        if (it->statement->kind == Statement::Kind_ThrowStatement ||
+            it->statement->kind == Statement::Kind_BreakStatement ||
+            it->statement->kind == Statement::Kind_ContinueStatement ||
+            it->statement->kind == Statement::Kind_ReturnStatement)
+            // any code after those statements is unreachable
+            break;
     }
-    return m;
+    requiresReturnValue = _requiresReturnValue;
+    insideSwitch = _insideSwitch;
 }
 
-void Codegen::functionBody(FunctionBody *ast)
+void Codegen::variableDeclaration(PatternElement *ast)
 {
-    if (ast)
-        sourceElements(ast->elements);
+    TailCallBlocker blockTailCalls(this);
+    RegisterScope scope(this);
+
+    if (!ast->initializer) {
+        if (ast->isLexicallyScoped()) {
+            Reference::fromConst(this, Encode::undefined()).loadInAccumulator();
+            Reference varToStore = targetForPatternElement(ast);
+            varToStore.storeConsumeAccumulator();
+        }
+        return;
+    }
+    initializeAndDestructureBindingElement(ast, Reference(), /*isDefinition*/ true);
 }
 
-void Codegen::program(Program *ast)
+void Codegen::variableDeclarationList(VariableDeclarationList *ast)
 {
-    if (ast) {
-        sourceElements(ast->elements);
+    for (VariableDeclarationList *it = ast; it; it = it->next) {
+        variableDeclaration(it->declaration);
     }
 }
 
-void Codegen::sourceElements(SourceElements *ast)
+Codegen::Reference Codegen::targetForPatternElement(AST::PatternElement *p)
 {
-    for (SourceElements *it = ast; it; it = it->next) {
-        sourceElement(it->element);
-        if (hasError)
-            return;
+    if (!p->bindingIdentifier.isNull())
+        return referenceForName(p->bindingIdentifier.toString(), true, p->firstSourceLocation());
+    if (!p->bindingTarget || p->destructuringPattern())
+        return Codegen::Reference::fromStackSlot(this);
+    Reference lhs = expression(p->bindingTarget);
+    if (hasError)
+        return lhs;
+    if (!lhs.isLValue()) {
+        throwReferenceError(p->bindingTarget->firstSourceLocation(), QStringLiteral("Binding target is not a reference."));
+        return lhs;
     }
+    lhs = lhs.asLValue();
+    return lhs;
 }
 
-void Codegen::variableDeclaration(VariableDeclaration *ast)
+void Codegen::initializeAndDestructureBindingElement(AST::PatternElement *e, const Reference &base, bool isDefinition)
 {
-    IR::Expr *initializer = 0;
-    if (!ast->expression)
-        return;
-    Result expr = expression(ast->expression);
+    Q_ASSERT(e->type == AST::PatternElement::Binding || e->type == AST::PatternElement::RestElement);
+    RegisterScope scope(this);
+    Reference baseRef = (base.isAccumulator()) ? base.storeOnStack() : base;
+    Reference varToStore = targetForPatternElement(e);
+    if (isDefinition)
+        varToStore.isReferenceToConst = false;
     if (hasError)
         return;
 
-    Q_ASSERT(expr.code);
-    initializer = *expr;
+    if (e->initializer) {
+        if (!baseRef.isValid()) {
+            // assignment
+            Reference expr = expression(e->initializer);
+            if (hasError)
+                return;
+            expr.loadInAccumulator();
+            varToStore.storeConsumeAccumulator();
+        } else if (baseRef == varToStore) {
+            baseRef.loadInAccumulator();
+            BytecodeGenerator::Jump jump = bytecodeGenerator->jumpNotUndefined();
+            Reference expr = expression(e->initializer);
+            if (hasError) {
+                jump.link();
+                return;
+            }
+            expr.loadInAccumulator();
+            varToStore.storeConsumeAccumulator();
+            jump.link();
+        } else {
+            baseRef.loadInAccumulator();
+            BytecodeGenerator::Jump jump = bytecodeGenerator->jumpNotUndefined();
+            Reference expr = expression(e->initializer);
+            if (hasError) {
+                jump.link();
+                return;
+            }
+            expr.loadInAccumulator();
+            jump.link();
+            varToStore.storeConsumeAccumulator();
+        }
+    } else if (baseRef != varToStore && baseRef.isValid()) {
+        baseRef.loadInAccumulator();
+        varToStore.storeConsumeAccumulator();
+    }
+    Pattern *p = e->destructuringPattern();
+    if (!p)
+        return;
 
-    IR::Expr *lhs = identifier(ast->name.toString(), ast->identifierToken.startLine,
-                               ast->identifierToken.startColumn);
+    if (!varToStore.isStackSlot())
+        varToStore = varToStore.storeOnStack();
+    if (PatternElementList *l = e->elementList()) {
+        destructureElementList(varToStore, l, isDefinition);
+    } else if (PatternPropertyList *p = e->propertyList()) {
+        destructurePropertyList(varToStore, p, isDefinition);
+    } else if (e->bindingTarget) {
+        // empty binding pattern. For spec compatibility, try to coerce the argument to an object
+        varToStore.loadInAccumulator();
+        Instruction::ToObject toObject;
+        bytecodeGenerator->addInstruction(toObject);
+        return;
+    }
+}
 
-    if (lhs->asArgLocal()) {
-        move(lhs, initializer);
+Codegen::Reference Codegen::referenceForPropertyName(const Codegen::Reference &object, AST::PropertyName *name)
+{
+    AST::ComputedPropertyName *cname = AST::cast<AST::ComputedPropertyName *>(name);
+    Reference property;
+    if (cname) {
+        Reference computedName = expression(cname->expression);
+        if (hasError)
+            return Reference();
+        computedName = computedName.storeOnStack();
+        property = Reference::fromSubscript(object, computedName).asLValue();
     } else {
-        int initialized = _block->newTemp();
-        move(_block->TEMP(initialized), initializer);
-        move(lhs, _block->TEMP(initialized));
+        QString propertyName = name->asString();
+        property = Reference::fromMember(object, propertyName);
     }
+    return property;
 }
 
-void Codegen::variableDeclarationList(VariableDeclarationList *ast)
+void Codegen::destructurePropertyList(const Codegen::Reference &object, PatternPropertyList *bindingList, bool isDefinition)
 {
-    for (VariableDeclarationList *it = ast; it; it = it->next) {
-        variableDeclaration(it->declaration);
+    RegisterScope scope(this);
+
+    object.loadInAccumulator();
+    Instruction::ThrowOnNullOrUndefined t;
+    bytecodeGenerator->addInstruction(t);
+
+    for (PatternPropertyList *it = bindingList; it; it = it->next) {
+        PatternProperty *p = it->property;
+        RegisterScope scope(this);
+        Reference property = referenceForPropertyName(object, p->name);
+        if (hasError)
+            return;
+        initializeAndDestructureBindingElement(p, property, isDefinition);
+        if (hasError)
+            return;
     }
 }
 
+void Codegen::destructureElementList(const Codegen::Reference &array, PatternElementList *bindingList, bool isDefinition)
+{
+    RegisterScope scope(this);
+
+    Reference iterator = Reference::fromStackSlot(this);
+    Reference iteratorValue = Reference::fromStackSlot(this);
+    Reference iteratorDone = Reference::fromStackSlot(this);
+    Reference::storeConstOnStack(this, Encode(false), iteratorDone.stackSlot());
+
+    array.loadInAccumulator();
+    Instruction::GetIterator iteratorObjInstr;
+    iteratorObjInstr.iterator = static_cast<int>(AST::ForEachType::Of);
+    bytecodeGenerator->addInstruction(iteratorObjInstr);
+    iterator.storeConsumeAccumulator();
+
+    {
+        auto cleanup = [this, iterator, iteratorDone]() {
+            iterator.loadInAccumulator();
+            Instruction::IteratorClose close;
+            close.done = iteratorDone.stackSlot();
+            bytecodeGenerator->addInstruction(close);
+        };
+
+        ControlFlowUnwindCleanup flow(this, cleanup);
+
+        for (PatternElementList *p = bindingList; p; p = p->next) {
+            PatternElement *e = p->element;
+            for (Elision *elision = p->elision; elision; elision = elision->next) {
+                iterator.loadInAccumulator();
+                Instruction::IteratorNext next;
+                next.value = iteratorValue.stackSlot();
+                next.done = iteratorDone.stackSlot();
+                bytecodeGenerator->addInstruction(next);
+            }
+
+            if (!e)
+                continue;
+
+            RegisterScope scope(this);
+            iterator.loadInAccumulator();
+
+            if (e->type == PatternElement::RestElement) {
+                Reference::fromConst(this, Encode(true)).storeOnStack(iteratorDone.stackSlot());
+                bytecodeGenerator->addInstruction(Instruction::DestructureRestElement());
+                initializeAndDestructureBindingElement(e, Reference::fromAccumulator(this), isDefinition);
+            } else {
+                Instruction::IteratorNext next;
+                next.value = iteratorValue.stackSlot();
+                next.done = iteratorDone.stackSlot();
+                bytecodeGenerator->addInstruction(next);
+                initializeAndDestructureBindingElement(e, iteratorValue, isDefinition);
+                if (hasError)
+                    return;
+            }
+        }
+    }
+}
+
+void Codegen::destructurePattern(Pattern *p, const Reference &rhs)
+{
+    RegisterScope scope(this);
+    if (auto *o = AST::cast<ObjectPattern *>(p))
+        destructurePropertyList(rhs, o->properties);
+    else if (auto *a = AST::cast<ArrayPattern *>(p))
+        destructureElementList(rhs, a->elements);
+    else
+        Q_UNREACHABLE();
+}
+
 
 bool Codegen::visit(ArgumentList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(CaseBlock *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(CaseClause *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(CaseClauses *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(Catch *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(DefaultClause *)
 {
-    Q_ASSERT(!"unreachable");
-    return false;
-}
-
-bool Codegen::visit(ElementList *)
-{
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(Elision *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(Finally *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(FormalParameterList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(FunctionBody *)
+bool Codegen::visit(Program *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(Program *)
+bool Codegen::visit(PatternElement *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(PropertyAssignmentList *)
+bool Codegen::visit(PatternElementList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(PropertyNameAndValue *)
+bool Codegen::visit(PatternProperty *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(PropertyGetterSetter *)
+bool Codegen::visit(PatternPropertyList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(SourceElements *)
+bool Codegen::visit(ExportDeclaration *ast)
 {
-    Q_ASSERT(!"unreachable");
+    if (!ast->exportDefault)
+        return true;
+
+    TailCallBlocker blockTailCalls(this);
+    Reference exportedValue;
+
+    if (auto *fdecl = AST::cast<FunctionDeclaration*>(ast->variableStatementOrDeclaration)) {
+        Result r;
+        qSwap(_expr, r);
+        visit(static_cast<FunctionExpression*>(fdecl));
+        qSwap(_expr, r);
+        exportedValue = r.result();
+    } else if (auto *classDecl = AST::cast<ClassDeclaration*>(ast->variableStatementOrDeclaration)) {
+        Result r;
+        qSwap(_expr, r);
+        visit(static_cast<ClassExpression*>(classDecl));
+        qSwap(_expr, r);
+        exportedValue = r.result();
+    } else if (ExpressionNode *expr = ast->variableStatementOrDeclaration->expressionCast()) {
+        exportedValue = expression(expr);
+    }
+
+    exportedValue.loadInAccumulator();
+
+    const int defaultExportIndex = _context->locals.indexOf(_context->localNameForDefaultExport);
+    Q_ASSERT(defaultExportIndex != -1);
+    Reference defaultExportSlot = Reference::fromScopedLocal(this, defaultExportIndex, /*scope*/0);
+    defaultExportSlot.storeConsumeAccumulator();
+
     return false;
 }
 
 bool Codegen::visit(StatementList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiArrayMemberList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiImport *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiHeaderItemList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiPragma *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiObjectInitializer *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiObjectMemberList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiParameterList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiProgram *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
 bool Codegen::visit(UiQualifiedId *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(UiQualifiedPragmaId *)
+bool Codegen::visit(VariableDeclarationList *)
 {
-    Q_ASSERT(!"unreachable");
+    Q_UNREACHABLE();
     return false;
 }
 
-bool Codegen::visit(VariableDeclaration *)
+bool Codegen::visit(ClassExpression *ast)
 {
-    Q_ASSERT(!"unreachable");
+    TailCallBlocker blockTailCalls(this);
+
+    Compiler::Class jsClass;
+    jsClass.nameIndex = registerString(ast->name.toString());
+
+    ClassElementList *constructor = nullptr;
+    int nComputedNames = 0;
+    int nStaticComputedNames = 0;
+
+    RegisterScope scope(this);
+    ControlFlowBlock controlFlow(this, ast);
+
+    for (auto *member = ast->elements; member; member = member->next) {
+        PatternProperty *p = member->property;
+        FunctionExpression *f = p->initializer->asFunctionDefinition();
+        Q_ASSERT(f);
+        AST::ComputedPropertyName *cname = AST::cast<ComputedPropertyName *>(p->name);
+        if (cname) {
+            ++nComputedNames;
+            if (member->isStatic)
+                ++nStaticComputedNames;
+        }
+        QString name = p->name->asString();
+        uint nameIndex = cname ? UINT_MAX : registerString(name);
+        Compiler::Class::Method::Type type = Compiler::Class::Method::Regular;
+        if (p->type == PatternProperty::Getter)
+            type = Compiler::Class::Method::Getter;
+        else if (p->type == PatternProperty::Setter)
+            type = Compiler::Class::Method::Setter;
+        Compiler::Class::Method m{ nameIndex, type, static_cast<uint>(defineFunction(name, f, f->formals, f->body)) };
+
+        if (member->isStatic) {
+            if (name == QStringLiteral("prototype")) {
+                throwSyntaxError(ast->firstSourceLocation(), QLatin1String("Cannot declare a static method named 'prototype'."));
+                return false;
+            }
+            jsClass.staticMethods << m;
+        } else {
+            if (name == QStringLiteral("constructor")) {
+                if (constructor) {
+                    throwSyntaxError(ast->firstSourceLocation(), QLatin1String("Cannot declare a multiple constructors in a class."));
+                    return false;
+                }
+                if (m.type != Compiler::Class::Method::Regular) {
+                    throwSyntaxError(ast->firstSourceLocation(), QLatin1String("Cannot declare a getter or setter named 'constructor'."));
+                    return false;
+                }
+                constructor = member;
+                jsClass.constructorIndex = m.functionIndex;
+                continue;
+            }
+
+            jsClass.methods << m;
+        }
+    }
+
+    int classIndex = _module->classes.size();
+    _module->classes.append(jsClass);
+
+    Reference heritage = Reference::fromStackSlot(this);
+    if (ast->heritage) {
+        bytecodeGenerator->setLocation(ast->heritage->firstSourceLocation());
+        Reference r = expression(ast->heritage);
+        if (hasError)
+            return false;
+        r.storeOnStack(heritage.stackSlot());
+    } else {
+        Reference::fromConst(this, Value::emptyValue().asReturnedValue()).loadInAccumulator();
+        heritage.storeConsumeAccumulator();
+    }
+
+    int computedNames = nComputedNames ? bytecodeGenerator->newRegisterArray(nComputedNames) : 0;
+    int currentStaticName = computedNames;
+    int currentNonStaticName = computedNames + nStaticComputedNames;
+
+    for (auto *member = ast->elements; member; member = member->next) {
+        AST::ComputedPropertyName *cname = AST::cast<AST::ComputedPropertyName *>(member->property->name);
+        if (!cname)
+            continue;
+        RegisterScope scope(this);
+        bytecodeGenerator->setLocation(cname->firstSourceLocation());
+        Reference computedName = expression(cname->expression);
+        if (hasError)
+            return false;
+        computedName.storeOnStack(member->isStatic ? currentStaticName++ : currentNonStaticName++);
+    }
+
+    Instruction::CreateClass createClass;
+    createClass.classIndex = classIndex;
+    createClass.heritage = heritage.stackSlot();
+    createClass.computedNames = computedNames;
+
+    bytecodeGenerator->addInstruction(createClass);
+
+    if (!ast->name.isEmpty()) {
+        Reference ctor = referenceForName(ast->name.toString(), true);
+        ctor.isReferenceToConst = false; // this is the definition
+        (void) ctor.storeRetainAccumulator();
+    }
+
+    _expr.setResult(Reference::fromAccumulator(this));
     return false;
 }
 
-bool Codegen::visit(VariableDeclarationList *)
+bool Codegen::visit(ClassDeclaration *ast)
 {
-    Q_ASSERT(!"unreachable");
+    TailCallBlocker blockTailCalls(this);
+    Reference outerVar = referenceForName(ast->name.toString(), true);
+    visit(static_cast<ClassExpression *>(ast));
+    (void) outerVar.storeRetainAccumulator();
     return false;
 }
 
@@ -1093,64 +1086,168 @@ bool Codegen::visit(Expression *ast)
     if (hasError)
         return false;
 
+    TailCallBlocker blockTailCalls(this);
     statement(ast->left);
+    blockTailCalls.unblock();
     accept(ast->right);
     return false;
 }
 
-bool Codegen::visit(ArrayLiteral *ast)
+bool Codegen::visit(ArrayPattern *ast)
 {
     if (hasError)
         return false;
 
-    IR::ExprList *args = 0;
-    IR::ExprList *current = 0;
-    for (ElementList *it = ast->elements; it; it = it->next) {
-        for (Elision *elision = it->elision; elision; elision = elision->next) {
-            IR::ExprList *arg = _function->New<IR::ExprList>();
-            if (!current) {
-                args = arg;
+    TailCallBlocker blockTailCalls(this);
+
+    PatternElementList *it = ast->elements;
+
+    int argc = 0;
+    {
+        RegisterScope scope(this);
+
+        int args = -1;
+        auto push = [this, &argc, &args](AST::ExpressionNode *arg) {
+            int temp = bytecodeGenerator->newRegister();
+            if (args == -1)
+                args = temp;
+            if (!arg) {
+                auto c = Reference::fromConst(this, Value::emptyValue().asReturnedValue());
+                (void) c.storeOnStack(temp);
             } else {
-                current->next = arg;
+                RegisterScope scope(this);
+                Reference r = expression(arg);
+                if (hasError)
+                    return;
+                (void) r.storeOnStack(temp);
             }
-            current = arg;
-            current->expr = _block->CONST(IR::MissingType, 0);
-        }
-        Result expr = expression(it->expression);
-        if (hasError)
-            return false;
+            ++argc;
+        };
 
-        IR::ExprList *arg = _function->New<IR::ExprList>();
-        if (!current) {
-            args = arg;
-        } else {
-            current->next = arg;
+        for (; it; it = it->next) {
+            PatternElement *e = it->element;
+            if (e && e->type == PatternElement::SpreadElement)
+                break;
+            for (Elision *elision = it->elision; elision; elision = elision->next)
+                push(nullptr);
+
+            if (!e)
+                continue;
+
+            push(e->initializer);
+            if (hasError)
+                return false;
         }
-        current = arg;
 
-        IR::Expr *exp = *expr;
-        if (exp->asTemp() || expr->asArgLocal() || exp->asConst()) {
-            current->expr = exp;
-        } else {
-            unsigned value = _block->newTemp();
-            move(_block->TEMP(value), exp);
-            current->expr = _block->TEMP(value);
+        if (args == -1) {
+            Q_ASSERT(argc == 0);
+            args = 0;
         }
+
+        Instruction::DefineArray call;
+        call.argc = argc;
+        call.args = Moth::StackSlot::createRegister(args);
+        bytecodeGenerator->addInstruction(call);
+    }
+
+    if (!it) {
+        _expr.setResult(Reference::fromAccumulator(this));
+        return false;
     }
-    for (Elision *elision = ast->elision; elision; elision = elision->next) {
-        IR::ExprList *arg = _function->New<IR::ExprList>();
-        if (!current) {
-            args = arg;
+    Q_ASSERT(it->element && it->element->type == PatternElement::SpreadElement);
+
+    RegisterScope scope(this);
+    Reference array = Reference::fromStackSlot(this);
+    array.storeConsumeAccumulator();
+    Reference index = Reference::storeConstOnStack(this, Encode(argc));
+
+    auto pushAccumulator = [&]() {
+        Reference slot = Reference::fromSubscript(array, index);
+        slot.storeConsumeAccumulator();
+
+        index.loadInAccumulator();
+        Instruction::Increment inc = {};
+        bytecodeGenerator->addTracingInstruction(inc);
+        index.storeConsumeAccumulator();
+    };
+
+    while (it) {
+        for (Elision *elision = it->elision; elision; elision = elision->next) {
+            Reference::fromConst(this, Value::emptyValue().asReturnedValue()).loadInAccumulator();
+            pushAccumulator();
+        }
+
+        if (!it->element) {
+            it = it->next;
+            continue;
+        }
+
+        // handle spread element
+        if (it->element->type == PatternElement::SpreadElement) {
+            RegisterScope scope(this);
+
+            Reference iterator = Reference::fromStackSlot(this);
+            Reference iteratorDone = Reference::fromConst(this, Encode(false)).storeOnStack();
+            Reference lhsValue = Reference::fromStackSlot(this);
+
+            // There should be a temporal block, so that variables declared in lhs shadow outside vars.
+            // This block should define a temporal dead zone for those variables, which is not yet implemented.
+            {
+                RegisterScope innerScope(this);
+                Reference expr = expression(it->element->initializer);
+                if (hasError)
+                    return false;
+
+                expr.loadInAccumulator();
+                Instruction::GetIterator iteratorObjInstr;
+                iteratorObjInstr.iterator = static_cast<int>(AST::ForEachType::Of);
+                bytecodeGenerator->addInstruction(iteratorObjInstr);
+                iterator.storeConsumeAccumulator();
+            }
+
+            BytecodeGenerator::Label in = bytecodeGenerator->newLabel();
+            BytecodeGenerator::Label end = bytecodeGenerator->newLabel();
+
+            {
+                auto cleanup = [this, iterator, iteratorDone]() {
+                    iterator.loadInAccumulator();
+                    Instruction::IteratorClose close;
+                    close.done = iteratorDone.stackSlot();
+                    bytecodeGenerator->addInstruction(close);
+                };
+                ControlFlowLoop flow(this, &end, &in, cleanup);
+
+                in.link();
+                bytecodeGenerator->addLoopStart(in);
+                iterator.loadInAccumulator();
+                Instruction::IteratorNext next;
+                next.value = lhsValue.stackSlot();
+                next.done = iteratorDone.stackSlot();
+                bytecodeGenerator->addInstruction(next);
+                bytecodeGenerator->addTracingJumpInstruction(Instruction::JumpTrue()).link(end);
+
+                lhsValue.loadInAccumulator();
+                pushAccumulator();
+
+                bytecodeGenerator->jump().link(in);
+                end.link();
+            }
         } else {
-            current->next = arg;
+            RegisterScope innerScope(this);
+            Reference expr = expression(it->element->initializer);
+            if (hasError)
+                return false;
+
+            expr.loadInAccumulator();
+            pushAccumulator();
         }
-        current = arg;
-        current->expr = _block->CONST(IR::MissingType, 0);
+
+        it = it->next;
     }
 
-    const unsigned t = _block->newTemp();
-    move(_block->TEMP(t), _block->CALL(_block->NAME(IR::Name::builtin_define_array, 0, 0), args));
-    _expr.code = _block->TEMP(t);
+    array.loadInAccumulator();
+    _expr.setResult(Reference::fromAccumulator(this));
+
     return false;
 }
 
@@ -1159,29 +1256,52 @@ bool Codegen::visit(ArrayMemberExpression *ast)
     if (hasError)
         return false;
 
-    Result base = expression(ast->base);
-    Result index = expression(ast->expression);
+    TailCallBlocker blockTailCalls(this);
+    Reference base = expression(ast->base);
+    if (hasError)
+        return false;
+    if (base.isSuper()) {
+        Reference index = expression(ast->expression).storeOnStack();
+        _expr.setResult(Reference::fromSuperProperty(index));
+        return false;
+    }
+    base = base.storeOnStack();
+    if (hasError)
+        return false;
+    if (AST::StringLiteral *str = AST::cast<AST::StringLiteral *>(ast->expression)) {
+        QString s = str->value.toString();
+        uint arrayIndex = QV4::String::toArrayIndex(s);
+        if (arrayIndex == UINT_MAX) {
+            _expr.setResult(Reference::fromMember(base, str->value.toString()));
+            return false;
+        }
+        Reference index = Reference::fromConst(this, QV4::Encode(arrayIndex));
+        _expr.setResult(Reference::fromSubscript(base, index));
+        return false;
+    }
+    Reference index = expression(ast->expression);
     if (hasError)
         return false;
-    _expr.code = subscript(*base, *index);
+    _expr.setResult(Reference::fromSubscript(base, index));
     return false;
 }
 
-static IR::AluOp baseOp(int op)
+static QSOperator::Op baseOp(int op)
 {
     switch ((QSOperator::Op) op) {
-    case QSOperator::InplaceAnd: return IR::OpBitAnd;
-    case QSOperator::InplaceSub: return IR::OpSub;
-    case QSOperator::InplaceDiv: return IR::OpDiv;
-    case QSOperator::InplaceAdd: return IR::OpAdd;
-    case QSOperator::InplaceLeftShift: return IR::OpLShift;
-    case QSOperator::InplaceMod: return IR::OpMod;
-    case QSOperator::InplaceMul: return IR::OpMul;
-    case QSOperator::InplaceOr: return IR::OpBitOr;
-    case QSOperator::InplaceRightShift: return IR::OpRShift;
-    case QSOperator::InplaceURightShift: return IR::OpURShift;
-    case QSOperator::InplaceXor: return IR::OpBitXor;
-    default: return IR::OpInvalid;
+    case QSOperator::InplaceAnd: return QSOperator::BitAnd;
+    case QSOperator::InplaceSub: return QSOperator::Sub;
+    case QSOperator::InplaceDiv: return QSOperator::Div;
+    case QSOperator::InplaceAdd: return QSOperator::Add;
+    case QSOperator::InplaceLeftShift: return QSOperator::LShift;
+    case QSOperator::InplaceMod: return QSOperator::Mod;
+    case QSOperator::InplaceExp: return QSOperator::Exp;
+    case QSOperator::InplaceMul: return QSOperator::Mul;
+    case QSOperator::InplaceOr: return QSOperator::BitOr;
+    case QSOperator::InplaceRightShift: return QSOperator::RShift;
+    case QSOperator::InplaceURightShift: return QSOperator::URShift;
+    case QSOperator::InplaceXor: return QSOperator::BitXor;
+    default: return QSOperator::Invalid;
     }
 }
 
@@ -1190,100 +1310,124 @@ bool Codegen::visit(BinaryExpression *ast)
     if (hasError)
         return false;
 
+    TailCallBlocker blockTailCalls(this);
+
     if (ast->op == QSOperator::And) {
         if (_expr.accept(cx)) {
-            IR::BasicBlock *iftrue = _function->newBasicBlock(exceptionHandler());
-            condition(ast->left, iftrue, _expr.iffalse);
-            _block = iftrue;
-            condition(ast->right, _expr.iftrue, _expr.iffalse);
+            auto iftrue = bytecodeGenerator->newLabel();
+            condition(ast->left, &iftrue, _expr.iffalse(), true);
+            iftrue.link();
+            blockTailCalls.unblock();
+            condition(ast->right, _expr.iftrue(), _expr.iffalse(), _expr.trueBlockFollowsCondition());
         } else {
-            IR::BasicBlock *iftrue = _function->newBasicBlock(exceptionHandler());
-            IR::BasicBlock *endif = _function->newBasicBlock(exceptionHandler());
-
-            const unsigned r = _block->newTemp();
+            auto iftrue = bytecodeGenerator->newLabel();
+            auto endif = bytecodeGenerator->newLabel();
 
-            Result lhs = expression(ast->left);
+            Reference left = expression(ast->left);
             if (hasError)
                 return false;
-            move(_block->TEMP(r), *lhs);
-            setLocation(cjump(_block->TEMP(r), iftrue, endif), ast->operatorToken);
-            _block = iftrue;
-            Result rhs = expression(ast->right);
+            left.loadInAccumulator();
+
+            bytecodeGenerator->setLocation(ast->operatorToken);
+            bytecodeGenerator->jumpFalse().link(endif);
+            iftrue.link();
+
+            blockTailCalls.unblock();
+            Reference right = expression(ast->right);
             if (hasError)
                 return false;
-            move(_block->TEMP(r), *rhs);
-            _block->JUMP(endif);
+            right.loadInAccumulator();
+
+            endif.link();
 
-            _expr.code = _block->TEMP(r);
-            _block = endif;
+            _expr.setResult(Reference::fromAccumulator(this));
         }
         return false;
     } else if (ast->op == QSOperator::Or) {
         if (_expr.accept(cx)) {
-            IR::BasicBlock *iffalse = _function->newBasicBlock(exceptionHandler());
-            condition(ast->left, _expr.iftrue, iffalse);
-            _block = iffalse;
-            condition(ast->right, _expr.iftrue, _expr.iffalse);
+            auto iffalse = bytecodeGenerator->newLabel();
+            condition(ast->left, _expr.iftrue(), &iffalse, false);
+            iffalse.link();
+            condition(ast->right, _expr.iftrue(), _expr.iffalse(), _expr.trueBlockFollowsCondition());
         } else {
-            IR::BasicBlock *iffalse = _function->newBasicBlock(exceptionHandler());
-            IR::BasicBlock *endif = _function->newBasicBlock(exceptionHandler());
+            auto iffalse = bytecodeGenerator->newLabel();
+            auto endif = bytecodeGenerator->newLabel();
 
-            const unsigned r = _block->newTemp();
-            Result lhs = expression(ast->left);
+            Reference left = expression(ast->left);
             if (hasError)
                 return false;
-            move(_block->TEMP(r), *lhs);
-            setLocation(cjump(_block->TEMP(r), endif, iffalse), ast->operatorToken);
-            _block = iffalse;
-            Result rhs = expression(ast->right);
+            left.loadInAccumulator();
+
+            bytecodeGenerator->setLocation(ast->operatorToken);
+            bytecodeGenerator->jumpTrue().link(endif);
+            iffalse.link();
+
+            blockTailCalls.unblock();
+            Reference right = expression(ast->right);
+            if (hasError)
+                return false;
+            right.loadInAccumulator();
+
+            endif.link();
+
+            _expr.setResult(Reference::fromAccumulator(this));
+        }
+        return false;
+    } else if (ast->op == QSOperator::Assign) {
+        if (AST::Pattern *p = ast->left->patternCast()) {
+            RegisterScope scope(this);
+            Reference right = expression(ast->right);
             if (hasError)
                 return false;
-            move(_block->TEMP(r), *rhs);
-            _block->JUMP(endif);
+            right = right.storeOnStack();
+            destructurePattern(p, right);
+            if (!_expr.accept(nx)) {
+                right.loadInAccumulator();
+                _expr.setResult(Reference::fromAccumulator(this));
+            }
+            return false;
+        }
+        Reference left = expression(ast->left);
+        if (hasError)
+            return false;
 
-            _block = endif;
-            _expr.code = _block->TEMP(r);
+        if (!left.isLValue()) {
+            throwReferenceError(ast->operatorToken, QStringLiteral("left-hand side of assignment operator is not an lvalue"));
+            return false;
         }
+        left = left.asLValue();
+        if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(left, ast->left->lastSourceLocation()))
+            return false;
+        blockTailCalls.unblock();
+        Reference r = expression(ast->right);
+        if (hasError)
+            return false;
+        r.loadInAccumulator();
+        if (_expr.accept(nx))
+            _expr.setResult(left.storeConsumeAccumulator());
+        else
+            _expr.setResult(left.storeRetainAccumulator());
         return false;
     }
 
-    IR::Expr* left = *expression(ast->left);
+    Reference left = expression(ast->left);
     if (hasError)
         return false;
 
     switch (ast->op) {
     case QSOperator::Or:
     case QSOperator::And:
+    case QSOperator::Assign:
+        Q_UNREACHABLE(); // handled separately above
         break;
 
-    case QSOperator::Assign: {
-        if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(left, ast->left->lastSourceLocation()))
-            return false;
-        Result right = expression(ast->right);
-        if (hasError)
-            return false;
-        if (!left->isLValue()) {
-            throwReferenceError(ast->operatorToken, QStringLiteral("left-hand side of assignment operator is not an lvalue"));
-            return false;
-        }
-
-        if (_expr.accept(nx)) {
-            move(left, *right);
-        } else {
-            const unsigned t = _block->newTemp();
-            move(_block->TEMP(t), *right);
-            move(left, _block->TEMP(t));
-            _expr.code = _block->TEMP(t);
-        }
-        break;
-    }
-
     case QSOperator::InplaceAnd:
     case QSOperator::InplaceSub:
     case QSOperator::InplaceDiv:
     case QSOperator::InplaceAdd:
     case QSOperator::InplaceLeftShift:
     case QSOperator::InplaceMod:
+    case QSOperator::InplaceExp:
     case QSOperator::InplaceMul:
     case QSOperator::InplaceOr:
     case QSOperator::InplaceRightShift:
@@ -1291,25 +1435,36 @@ bool Codegen::visit(BinaryExpression *ast)
     case QSOperator::InplaceXor: {
         if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(left, ast->left->lastSourceLocation()))
             return false;
-        Result right = expression(ast->right);
-        if (hasError)
-            return false;
-        if (!left->isLValue()) {
+
+        if (!left.isLValue()) {
             throwSyntaxError(ast->operatorToken, QStringLiteral("left-hand side of inplace operator is not an lvalue"));
             return false;
         }
+        left = left.asLValue();
+
+        Reference tempLeft = left.storeOnStack();
+        Reference right = expression(ast->right);
+
+        if (hasError)
+            return false;
+
+        binopHelper(baseOp(ast->op), tempLeft, right).loadInAccumulator();
+        _expr.setResult(left.storeRetainAccumulator());
 
-        if (_expr.accept(nx)) {
-            move(left, *right, baseOp(ast->op));
-        } else {
-            const unsigned t = _block->newTemp();
-            move(_block->TEMP(t), *right);
-            move(left, _block->TEMP(t), baseOp(ast->op));
-            _expr.code = left;
-        }
         break;
     }
 
+    case QSOperator::BitAnd:
+    case QSOperator::BitOr:
+    case QSOperator::BitXor:
+        if (left.isConstant()) {
+            Reference right = expression(ast->right);
+            if (hasError)
+                return false;
+            _expr.setResult(binopHelper(static_cast<QSOperator::Op>(ast->op), right, left));
+            break;
+        }
+        // intentional fall-through!
     case QSOperator::In:
     case QSOperator::InstanceOf:
     case QSOperator::Equal:
@@ -1319,53 +1474,417 @@ bool Codegen::visit(BinaryExpression *ast)
     case QSOperator::Le:
     case QSOperator::Lt:
     case QSOperator::StrictEqual:
-    case QSOperator::StrictNotEqual: {
-        if (!left->asTemp() && !left->asArgLocal() && !left->asConst()) {
-            const unsigned t = _block->newTemp();
-            setLocation(move(_block->TEMP(t), left), ast->operatorToken);
-            left = _block->TEMP(t);
+    case QSOperator::StrictNotEqual:
+    case QSOperator::Add:
+    case QSOperator::Div:
+    case QSOperator::Exp:
+    case QSOperator::Mod:
+    case QSOperator::Mul:
+    case QSOperator::Sub:
+    case QSOperator::LShift:
+    case QSOperator::RShift:
+    case QSOperator::URShift: {
+        Reference right;
+        if (AST::NumericLiteral *rhs = AST::cast<AST::NumericLiteral *>(ast->right)) {
+            visit(rhs);
+            right = _expr.result();
+        } else {
+            left = left.storeOnStack(); // force any loads of the lhs, so the rhs won't clobber it
+            right = expression(ast->right);
         }
-
-        Result right = expression(ast->right);
         if (hasError)
             return false;
 
-        if (_expr.accept(cx)) {
-            setLocation(cjump(binop(IR::binaryOperator(ast->op), left, *right, ast->operatorToken), _expr.iftrue, _expr.iffalse), ast->operatorToken);
+        _expr.setResult(binopHelper(static_cast<QSOperator::Op>(ast->op), left, right));
+
+        break;
+    }
+
+    } // switch
+
+    return false;
+}
+
+Codegen::Reference Codegen::binopHelper(QSOperator::Op oper, Reference &left, Reference &right)
+{
+    switch (oper) {
+    case QSOperator::Add: {
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        Instruction::Add add;
+        add.lhs = left.stackSlot();
+        bytecodeGenerator->addTracingInstruction(add);
+        break;
+    }
+    case QSOperator::Sub: {
+        if (right.isConstant() && right.constant == Encode(int(1))) {
+            left.loadInAccumulator();
+            Instruction::Decrement dec = {};
+            bytecodeGenerator->addTracingInstruction(dec);
         } else {
-            _expr.code = binop(IR::binaryOperator(ast->op), left, *right, ast->operatorToken);
+            left = left.storeOnStack();
+            right.loadInAccumulator();
+            Instruction::Sub sub;
+            sub.lhs = left.stackSlot();
+            bytecodeGenerator->addTracingInstruction(sub);
         }
         break;
     }
-
-    case QSOperator::Add:
+    case QSOperator::Exp: {
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        Instruction::Exp exp;
+        exp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(exp);
+        break;
+    }
+    case QSOperator::Mul: {
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        Instruction::Mul mul;
+        mul.lhs = left.stackSlot();
+        bytecodeGenerator->addTracingInstruction(mul);
+        break;
+    }
+    case QSOperator::Div: {
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        Instruction::Div div;
+        div.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(div);
+        break;
+    }
+    case QSOperator::Mod: {
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        Instruction::Mod mod;
+        mod.lhs = left.stackSlot();
+        bytecodeGenerator->addTracingInstruction(mod);
+        break;
+    }
     case QSOperator::BitAnd:
+        if (right.isConstant()) {
+            int rightAsInt = Value::fromReturnedValue(right.constant).toInt32();
+            if (left.isConstant()) {
+                int result = Value::fromReturnedValue(left.constant).toInt32() & rightAsInt;
+                return Reference::fromConst(this, Encode(result));
+            }
+            left.loadInAccumulator();
+            Instruction::BitAndConst bitAnd;
+            bitAnd.rhs = rightAsInt;
+            bytecodeGenerator->addInstruction(bitAnd);
+        } else {
+            right.loadInAccumulator();
+            Instruction::BitAnd bitAnd;
+            bitAnd.lhs = left.stackSlot();
+            bytecodeGenerator->addInstruction(bitAnd);
+        }
+        break;
     case QSOperator::BitOr:
+        if (right.isConstant()) {
+            int rightAsInt = Value::fromReturnedValue(right.constant).toInt32();
+            if (left.isConstant()) {
+                int result = Value::fromReturnedValue(left.constant).toInt32() | rightAsInt;
+                return Reference::fromConst(this, Encode(result));
+            }
+            left.loadInAccumulator();
+            Instruction::BitOrConst bitOr;
+            bitOr.rhs = rightAsInt;
+            bytecodeGenerator->addInstruction(bitOr);
+        } else {
+            right.loadInAccumulator();
+            Instruction::BitOr bitOr;
+            bitOr.lhs = left.stackSlot();
+            bytecodeGenerator->addInstruction(bitOr);
+        }
+        break;
     case QSOperator::BitXor:
-    case QSOperator::Div:
-    case QSOperator::LShift:
-    case QSOperator::Mod:
-    case QSOperator::Mul:
+        if (right.isConstant()) {
+            int rightAsInt = Value::fromReturnedValue(right.constant).toInt32();
+            if (left.isConstant()) {
+                int result = Value::fromReturnedValue(left.constant).toInt32() ^ rightAsInt;
+                return Reference::fromConst(this, Encode(result));
+            }
+            left.loadInAccumulator();
+            Instruction::BitXorConst bitXor;
+            bitXor.rhs = rightAsInt;
+            bytecodeGenerator->addInstruction(bitXor);
+        } else {
+            right.loadInAccumulator();
+            Instruction::BitXor bitXor;
+            bitXor.lhs = left.stackSlot();
+            bytecodeGenerator->addInstruction(bitXor);
+        }
+        break;
+    case QSOperator::URShift:
+        if (right.isConstant()) {
+            left.loadInAccumulator();
+            Instruction::UShrConst ushr;
+            ushr.rhs = Value::fromReturnedValue(right.constant).toInt32() & 0x1f;
+            bytecodeGenerator->addInstruction(ushr);
+        } else {
+            right.loadInAccumulator();
+            Instruction::UShr ushr;
+            ushr.lhs = left.stackSlot();
+            bytecodeGenerator->addInstruction(ushr);
+        }
+        break;
     case QSOperator::RShift:
-    case QSOperator::Sub:
-    case QSOperator::URShift: {
-        if (!left->asTemp() && !left->asArgLocal() && !left->asConst()) {
-            const unsigned t = _block->newTemp();
-            setLocation(move(_block->TEMP(t), left), ast->operatorToken);
-            left = _block->TEMP(t);
+        if (right.isConstant()) {
+            left.loadInAccumulator();
+            Instruction::ShrConst shr;
+            shr.rhs = Value::fromReturnedValue(right.constant).toInt32() & 0x1f;
+            bytecodeGenerator->addInstruction(shr);
+        } else {
+            right.loadInAccumulator();
+            Instruction::Shr shr;
+            shr.lhs = left.stackSlot();
+            bytecodeGenerator->addInstruction(shr);
         }
+        break;
+    case QSOperator::LShift:
+        if (right.isConstant()) {
+            left.loadInAccumulator();
+            Instruction::ShlConst shl;
+            shl.rhs = Value::fromReturnedValue(right.constant).toInt32() & 0x1f;
+            bytecodeGenerator->addInstruction(shl);
+        } else {
+            right.loadInAccumulator();
+            Instruction::Shl shl;
+            shl.lhs = left.stackSlot();
+            bytecodeGenerator->addInstruction(shl);
+        }
+        break;
+    case QSOperator::InstanceOf: {
+        Instruction::CmpInstanceOf binop;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        binop.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(binop);
+        break;
+    }
+    case QSOperator::In: {
+        Instruction::CmpIn binop;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        binop.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(binop);
+        break;
+    }
+    case QSOperator::StrictEqual: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpStrictEqual cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::StrictNotEqual: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpStrictNotEqual cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::Equal: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpEq cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::NotEqual: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpNe cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::Gt: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpGt cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::Ge: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpGe cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::Lt: {
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpLt cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    }
+    case QSOperator::Le:
+        if (_expr.accept(cx))
+            return jumpBinop(oper, left, right);
+
+        Instruction::CmpLe cmp;
+        left = left.storeOnStack();
+        right.loadInAccumulator();
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        break;
+    default:
+        Q_UNREACHABLE();
+    }
 
-        Result right = expression(ast->right);
-        if (hasError)
-            return false;
+    return Reference::fromAccumulator(this);
+}
 
-        _expr.code = binop(IR::binaryOperator(ast->op), left, *right, ast->operatorToken);
-        break;
+static QSOperator::Op operatorForSwappedOperands(QSOperator::Op oper)
+{
+    switch (oper) {
+    case QSOperator::StrictEqual: return QSOperator::StrictEqual;
+    case QSOperator::StrictNotEqual: return QSOperator::StrictNotEqual;
+    case QSOperator::Equal: return QSOperator::Equal;
+    case QSOperator::NotEqual: return QSOperator::NotEqual;
+    case QSOperator::Gt: return QSOperator::Le;
+    case QSOperator::Ge: return QSOperator::Lt;
+    case QSOperator::Lt: return QSOperator::Ge;
+    case QSOperator::Le: return QSOperator::Gt;
+    default: Q_UNIMPLEMENTED(); return QSOperator::Invalid;
     }
+}
 
-    } // switch
+Codegen::Reference Codegen::jumpBinop(QSOperator::Op oper, Reference &left, Reference &right)
+{
+    if (left.isConstant()) {
+        oper = operatorForSwappedOperands(oper);
+        qSwap(left, right);
+    }
 
-    return false;
+    if (right.isConstant() && (oper == QSOperator::Equal || oper == QSOperator::NotEqual)) {
+        Value c = Value::fromReturnedValue(right.constant);
+        if (c.isNull() || c.isUndefined()) {
+            left.loadInAccumulator();
+            if (oper == QSOperator::Equal) {
+                Instruction::CmpEqNull cmp;
+                bytecodeGenerator->addInstruction(cmp);
+                addCJump();
+                return Reference();
+            } else if (oper == QSOperator::NotEqual) {
+                Instruction::CmpNeNull cmp;
+                bytecodeGenerator->addInstruction(cmp);
+                addCJump();
+                return Reference();
+            }
+        } else if (c.isInt32()) {
+            left.loadInAccumulator();
+            if (oper == QSOperator::Equal) {
+                Instruction::CmpEqInt cmp;
+                cmp.lhs = c.int_32();
+                bytecodeGenerator->addInstruction(cmp);
+                addCJump();
+                return Reference();
+            } else if (oper == QSOperator::NotEqual) {
+                Instruction::CmpNeInt cmp;
+                cmp.lhs = c.int_32();
+                bytecodeGenerator->addInstruction(cmp);
+                addCJump();
+                return Reference();
+            }
+
+        }
+    }
+
+    left = left.storeOnStack();
+    right.loadInAccumulator();
+
+    switch (oper) {
+    case QSOperator::StrictEqual: {
+        Instruction::CmpStrictEqual cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::StrictNotEqual: {
+        Instruction::CmpStrictNotEqual cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::Equal: {
+        Instruction::CmpEq cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::NotEqual: {
+        Instruction::CmpNe cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::Gt: {
+        Instruction::CmpGt cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::Ge: {
+        Instruction::CmpGe cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::Lt: {
+        Instruction::CmpLt cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    case QSOperator::Le: {
+        Instruction::CmpLe cmp;
+        cmp.lhs = left.stackSlot();
+        bytecodeGenerator->addInstruction(cmp);
+        addCJump();
+        break;
+    }
+    default:
+        Q_UNREACHABLE();
+    }
+    return Reference();
 }
 
 bool Codegen::visit(CallExpression *ast)
@@ -1373,53 +1892,257 @@ bool Codegen::visit(CallExpression *ast)
     if (hasError)
         return false;
 
-    Result base = expression(ast->base);
-    IR::ExprList *args = 0, **args_it = &args;
-    for (ArgumentList *it = ast->arguments; it; it = it->next) {
-        Result arg = expression(it->expression);
-        if (hasError)
-            return false;
-        IR::Expr *actual = argument(*arg);
-        *args_it = _function->New<IR::ExprList>();
-        (*args_it)->init(actual);
-        args_it = &(*args_it)->next;
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
+    Reference base = expression(ast->base);
+
+    if (hasError)
+        return false;
+    switch (base.type) {
+    case Reference::Member:
+    case Reference::Subscript:
+    case Reference::QmlScopeObject:
+    case Reference::QmlContextObject:
+        base = base.asLValue();
+        break;
+    case Reference::Name:
+        break;
+    case Reference::Super:
+        handleConstruct(base, ast->arguments);
+        return false;
+    case Reference::SuperProperty:
+        break;
+    default:
+        base = base.storeOnStack();
+        break;
     }
+
+    int thisObject = bytecodeGenerator->newRegister();
+    int functionObject = bytecodeGenerator->newRegister();
+
+    auto calldata = pushArgs(ast->arguments);
     if (hasError)
         return false;
-    _expr.code = call(*base, args);
+
+    blockTailCalls.unblock();
+    if (calldata.hasSpread || _tailCallsAreAllowed) {
+        Reference baseObject = base.baseObject();
+        if (!baseObject.isStackSlot()) {
+            baseObject.storeOnStack(thisObject);
+            baseObject = Reference::fromStackSlot(this, thisObject);
+        }
+        if (!base.isStackSlot()) {
+            base.storeOnStack(functionObject);
+            base = Reference::fromStackSlot(this, functionObject);
+        }
+
+        if (calldata.hasSpread) {
+            Instruction::CallWithSpread call;
+            call.func = base.stackSlot();
+            call.thisObject = baseObject.stackSlot();
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addTracingInstruction(call);
+        } else {
+            Instruction::TailCall call;
+            call.func = base.stackSlot();
+            call.thisObject = baseObject.stackSlot();
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addInstruction(call);
+        }
+
+        _expr.setResult(Reference::fromAccumulator(this));
+        return false;
+
+    }
+
+    handleCall(base, calldata, functionObject, thisObject);
     return false;
 }
 
-bool Codegen::visit(ConditionalExpression *ast)
+void Codegen::handleCall(Reference &base, Arguments calldata, int slotForFunction, int slotForThisObject)
+{
+    //### Do we really need all these call instructions? can's we load the callee in a temp?
+    if (base.type == Reference::QmlScopeObject) {
+        Instruction::CallScopeObjectProperty call;
+        call.base = base.qmlBase.stackSlot();
+        call.name = base.qmlCoreIndex;
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addTracingInstruction(call);
+    } else if (base.type == Reference::QmlContextObject) {
+        Instruction::CallContextObjectProperty call;
+        call.base = base.qmlBase.stackSlot();
+        call.name = base.qmlCoreIndex;
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addTracingInstruction(call);
+    } else if (base.type == Reference::Member) {
+        if (!disable_lookups && useFastLookups) {
+            Instruction::CallPropertyLookup call;
+            call.base = base.propertyBase.stackSlot();
+            call.lookupIndex = registerGetterLookup(base.propertyNameIndex);
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addTracingInstruction(call);
+        } else {
+            Instruction::CallProperty call;
+            call.base = base.propertyBase.stackSlot();
+            call.name = base.propertyNameIndex;
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addTracingInstruction(call);
+        }
+    } else if (base.type == Reference::Subscript) {
+        Instruction::CallElement call;
+        call.base = base.elementBase;
+        call.index = base.elementSubscript.stackSlot();
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addTracingInstruction(call);
+    } else if (base.type == Reference::Name) {
+        if (base.name == QStringLiteral("eval")) {
+            Instruction::CallPossiblyDirectEval call;
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addTracingInstruction(call);
+        } else if (!disable_lookups && useFastLookups && base.global) {
+            Instruction::CallGlobalLookup call;
+            call.index = registerGlobalGetterLookup(base.nameAsIndex());
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addTracingInstruction(call);
+        } else {
+            Instruction::CallName call;
+            call.name = base.nameAsIndex();
+            call.argc = calldata.argc;
+            call.argv = calldata.argv;
+            bytecodeGenerator->addTracingInstruction(call);
+        }
+    } else if (base.type == Reference::SuperProperty) {
+        Reference receiver = base.baseObject();
+        if (!base.isStackSlot()) {
+            base.storeOnStack(slotForFunction);
+            base = Reference::fromStackSlot(this, slotForFunction);
+        }
+        if (!receiver.isStackSlot()) {
+            receiver.storeOnStack(slotForThisObject);
+            receiver = Reference::fromStackSlot(this, slotForThisObject);
+        }
+        Instruction::CallWithReceiver call;
+        call.name = base.stackSlot();
+        call.thisObject = receiver.stackSlot();
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addTracingInstruction(call);
+    } else {
+        Q_ASSERT(base.isStackSlot());
+        Instruction::CallValue call;
+        call.name = base.stackSlot();
+        call.argc = calldata.argc;
+        call.argv = calldata.argv;
+        bytecodeGenerator->addTracingInstruction(call);
+    }
+
+    _expr.setResult(Reference::fromAccumulator(this));
+}
+
+Codegen::Arguments Codegen::pushArgs(ArgumentList *args)
 {
-    if (hasError)
-        return true;
+    bool hasSpread = false;
+    int argc = 0;
+    for (ArgumentList *it = args; it; it = it->next) {
+        if (it->isSpreadElement) {
+            hasSpread = true;
+            ++argc;
+        }
+        ++argc;
+    }
+
+    if (!argc)
+        return { 0, 0, false };
+
+    int calldata = bytecodeGenerator->newRegisterArray(argc);
+
+    argc = 0;
+    for (ArgumentList *it = args; it; it = it->next) {
+        if (it->isSpreadElement) {
+            Reference::fromConst(this, Value::emptyValue().asReturnedValue()).storeOnStack(calldata + argc);
+            ++argc;
+        }
+        RegisterScope scope(this);
+        Reference e = expression(it->expression);
+        if (hasError)
+            break;
+        if (!argc && !it->next && !hasSpread) {
+            // avoid copy for functions taking a single argument
+            if (e.isStackSlot())
+                return { 1, e.stackSlot(), hasSpread };
+        }
+        (void) e.storeOnStack(calldata + argc);
+        ++argc;
+    }
+
+    return { argc, calldata, hasSpread };
+}
+
+Codegen::Arguments Codegen::pushTemplateArgs(TemplateLiteral *args)
+{
+    int argc = 0;
+    for (TemplateLiteral *it = args; it; it = it->next)
+        ++argc;
 
-    IR::BasicBlock *iftrue = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *iffalse = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *endif = _function->newBasicBlock(exceptionHandler());
+    if (!argc)
+        return { 0, 0, false };
 
-    const unsigned t = _block->newTemp();
+    int calldata = bytecodeGenerator->newRegisterArray(argc);
 
-    condition(ast->expression, iftrue, iffalse);
+    argc = 0;
+    for (TemplateLiteral *it = args; it && it->expression; it = it->next) {
+        RegisterScope scope(this);
+        Reference e = expression(it->expression);
+        if (hasError)
+            break;
+        (void) e.storeOnStack(calldata + argc);
+        ++argc;
+    }
+
+    return { argc, calldata, false };
+}
 
-    _block = iftrue;
-    Result ok = expression(ast->ok);
+bool Codegen::visit(ConditionalExpression *ast)
+{
     if (hasError)
         return false;
-    move(_block->TEMP(t), *ok);
-    _block->JUMP(endif);
 
-    _block = iffalse;
-    Result ko = expression(ast->ko);
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
+    BytecodeGenerator::Label iftrue = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label iffalse = bytecodeGenerator->newLabel();
+    condition(ast->expression, &iftrue, &iffalse, true);
+
+    blockTailCalls.unblock();
+
+    iftrue.link();
+    Reference ok = expression(ast->ok);
     if (hasError)
         return false;
-    move(_block->TEMP(t), *ko);
-    _block->JUMP(endif);
+    ok.loadInAccumulator();
+    BytecodeGenerator::Jump jump_endif = bytecodeGenerator->jump();
 
-    _block = endif;
+    iffalse.link();
+    Reference ko = expression(ast->ko);
+    if (hasError) {
+        jump_endif.link(); // dummy link, to prevent assert in Jump destructor from triggering
+        return false;
+    }
+    ko.loadInAccumulator();
 
-    _expr.code = _block->TEMP(t);
+    jump_endif.link();
+    _expr.setResult(Reference::fromAccumulator(this));
 
     return false;
 }
@@ -1429,48 +2152,69 @@ bool Codegen::visit(DeleteExpression *ast)
     if (hasError)
         return false;
 
-    IR::Expr* expr = *expression(ast->expression);
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+    Reference expr = expression(ast->expression);
     if (hasError)
         return false;
-    // Temporaries cannot be deleted
-    IR::ArgLocal *al = expr->asArgLocal();
-    if (al && al->index < static_cast<unsigned>(_variableEnvironment->members.size())) {
+
+    switch (expr.type) {
+    case Reference::SuperProperty:
+        // ### this should throw a reference error at runtime.
+        return false;
+    case Reference::StackSlot:
+        if (!expr.stackSlotIsLocalOrArgument)
+            break;
+        // fall through
+    case Reference::ScopedLocal:
         // Trying to delete a function argument might throw.
-        if (_function->isStrict) {
+        if (_context->isStrict) {
             throwSyntaxError(ast->deleteToken, QStringLiteral("Delete of an unqualified identifier in strict mode."));
             return false;
         }
-        _expr.code = _block->CONST(IR::BoolType, 0);
+        _expr.setResult(Reference::fromConst(this, QV4::Encode(false)));
         return false;
-    }
-    if (_function->isStrict && expr->asName()) {
-        throwSyntaxError(ast->deleteToken, QStringLiteral("Delete of an unqualified identifier in strict mode."));
+    case Reference::Name: {
+        if (_context->isStrict) {
+            throwSyntaxError(ast->deleteToken, QStringLiteral("Delete of an unqualified identifier in strict mode."));
+            return false;
+        }
+        Instruction::DeleteName del;
+        del.name = expr.nameAsIndex();
+        bytecodeGenerator->addInstruction(del);
+        _expr.setResult(Reference::fromAccumulator(this));
         return false;
     }
-
-    // [[11.4.1]] Return true if it's not a reference
-    if (expr->asConst() || expr->asString()) {
-        _expr.code = _block->CONST(IR::BoolType, 1);
+    case Reference::Member: {
+        //### maybe add a variant where the base can be in the accumulator?
+        expr = expr.asLValue();
+        Instruction::LoadRuntimeString instr;
+        instr.stringId = expr.propertyNameIndex;
+        bytecodeGenerator->addInstruction(instr);
+        Reference index = Reference::fromStackSlot(this);
+        index.storeConsumeAccumulator();
+        Instruction::DeleteProperty del;
+        del.base = expr.propertyBase.stackSlot();
+        del.index = index.stackSlot();
+        bytecodeGenerator->addInstruction(del);
+        _expr.setResult(Reference::fromAccumulator(this));
         return false;
     }
-
-    // Return values from calls are also not a reference, but we have to
-    // perform the call to allow for side effects.
-    if (expr->asCall()) {
-        _block->EXP(expr);
-        _expr.code = _block->CONST(IR::BoolType, 1);
+    case Reference::Subscript: {
+        //### maybe add a variant where the index can be in the accumulator?
+        expr = expr.asLValue();
+        Instruction::DeleteProperty del;
+        del.base = expr.elementBase;
+        del.index = expr.elementSubscript.stackSlot();
+        bytecodeGenerator->addInstruction(del);
+        _expr.setResult(Reference::fromAccumulator(this));
         return false;
     }
-    if (expr->asTemp() ||
-            (expr->asArgLocal() &&
-             expr->asArgLocal()->index >= static_cast<unsigned>(_variableEnvironment->members.size()))) {
-        _expr.code = _block->CONST(IR::BoolType, 1);
-        return false;
+    default:
+        break;
     }
-
-    IR::ExprList *args = _function->New<IR::ExprList>();
-    args->init(reference(expr));
-    _expr.code = call(_block->NAME(IR::Name::builtin_delete, ast->deleteToken.startLine, ast->deleteToken.startColumn), args);
+    // [[11.4.1]] Return true if it's not a reference
+    _expr.setResult(Reference::fromConst(this, QV4::Encode(true)));
     return false;
 }
 
@@ -1479,86 +2223,189 @@ bool Codegen::visit(FalseLiteral *)
     if (hasError)
         return false;
 
-    if (_expr.accept(cx)) {
-        _block->JUMP(_expr.iffalse);
-    } else {
-        _expr.code = _block->CONST(IR::BoolType, 0);
-    }
+    _expr.setResult(Reference::fromConst(this, QV4::Encode(false)));
     return false;
 }
 
-bool Codegen::visit(FieldMemberExpression *ast)
+bool Codegen::visit(SuperLiteral *)
 {
     if (hasError)
         return false;
 
-    Result base = expression(ast->base);
-    if (!hasError)
-        _expr.code = member(*base, _function->newString(ast->name.toString()));
+    _expr.setResult(Reference::fromSuper(this));
     return false;
 }
 
-bool Codegen::visit(FunctionExpression *ast)
+bool Codegen::visit(FieldMemberExpression *ast)
 {
     if (hasError)
         return false;
 
-    int function = defineFunction(ast->name.toString(), ast, ast->formals, ast->body ? ast->body->elements : 0);
-    _expr.code = _block->CLOSURE(function);
+    TailCallBlocker blockTailCalls(this);
+    if (AST::IdentifierExpression *id = AST::cast<AST::IdentifierExpression *>(ast->base)) {
+        if (id->name == QLatin1String("new")) {
+            // new.target
+            Q_ASSERT(ast->name == QLatin1String("target"));
+
+            if (_context->isArrowFunction || _context->contextType == ContextType::Eval) {
+                Reference r = referenceForName(QStringLiteral("new.target"), false);
+                r.isReadonly = true;
+                _expr.setResult(r);
+                return false;
+            }
+
+            Reference r = Reference::fromStackSlot(this, CallData::NewTarget);
+            _expr.setResult(r);
+            return false;
+        }
+    }
+
+    Reference base = expression(ast->base);
+    if (hasError)
+        return false;
+    if (base.isSuper()) {
+        Instruction::LoadRuntimeString load;
+        load.stringId = registerString(ast->name.toString());
+        bytecodeGenerator->addInstruction(load);
+        Reference property = Reference::fromAccumulator(this).storeOnStack();
+        _expr.setResult(Reference::fromSuperProperty(property));
+        return false;
+    }
+    _expr.setResult(Reference::fromMember(base, ast->name.toString()));
     return false;
 }
 
-IR::Expr *Codegen::identifier(const QString &name, int line, int col)
+bool Codegen::visit(TaggedTemplate *ast)
 {
     if (hasError)
-        return 0;
+        return false;
 
-    uint scope = 0;
-    Environment *e = _variableEnvironment;
-    IR::Function *f = _function;
+    RegisterScope scope(this);
 
-    while (f && e->parent) {
-        if (f->insideWithOrCatch || (f->isNamedExpression && QStringRef(f->name) == name))
-            return _block->NAME(name, line, col);
+    int functionObject = -1, thisObject = -1;
 
-        int index = e->findMember(name);
-        Q_ASSERT (index < e->members.size());
-        if (index != -1) {
-            IR::ArgLocal *al = _block->LOCAL(index, scope);
-            if (name == QLatin1String("arguments") || name == QLatin1String("eval"))
-                al->isArgumentsOrEval = true;
-            return al;
-        }
-        const int argIdx = f->indexOfArgument(QStringRef(&name));
-        if (argIdx != -1)
-            return _block->ARG(argIdx, scope);
+    Reference base = expression(ast->base);
+    if (hasError)
+        return false;
+    switch (base.type) {
+    case Reference::Member:
+    case Reference::Subscript:
+        base = base.asLValue();
+        break;
+    case Reference::Name:
+        break;
+    case Reference::SuperProperty:
+        thisObject = bytecodeGenerator->newRegister();
+        functionObject = bytecodeGenerator->newRegister();
+        break;
+    default:
+        base = base.storeOnStack();
+        break;
+    }
+
+    createTemplateObject(ast->templateLiteral);
+    int templateObjectTemp = Reference::fromAccumulator(this).storeOnStack().stackSlot();
+    Q_UNUSED(templateObjectTemp);
+    auto calldata = pushTemplateArgs(ast->templateLiteral);
+    if (hasError)
+        return false;
+    ++calldata.argc;
+    Q_ASSERT(calldata.argv == templateObjectTemp + 1);
+    --calldata.argv;
+
+    handleCall(base, calldata, functionObject, thisObject);
+    return false;
+}
+
+void Codegen::createTemplateObject(TemplateLiteral *t)
+{
+    TemplateObject obj;
+
+    for (TemplateLiteral *it = t; it; it = it->next) {
+        obj.strings.append(registerString(it->value.toString()));
+        obj.rawStrings.append(registerString(it->rawValue.toString()));
+    }
+
+    int index = _module->templateObjects.size();
+    _module->templateObjects.append(obj);
+
+    Instruction::GetTemplateObject getTemplateObject;
+    getTemplateObject.index = index;
+    bytecodeGenerator->addInstruction(getTemplateObject);
+}
+
+bool Codegen::visit(FunctionExpression *ast)
+{
+    if (hasError)
+        return false;
+
+    TailCallBlocker blockTailCalls(this);
+
+    RegisterScope scope(this);
 
-        if (!f->isStrict && f->hasDirectEval)
-            return _block->NAME(name, line, col);
+    int function = defineFunction(ast->name.toString(), ast, ast->formals, ast->body);
+    if (hasError)
+        return false;
+    loadClosure(function);
+    _expr.setResult(Reference::fromAccumulator(this));
+    return false;
+}
 
-        ++scope;
-        e = e->parent;
-        f = f->outer;
+Codegen::Reference Codegen::referenceForName(const QString &name, bool isLhs, const SourceLocation &accessLocation)
+{
+    Context::ResolvedName resolved = _context->resolveName(name, accessLocation);
+
+    if (resolved.type == Context::ResolvedName::Local || resolved.type == Context::ResolvedName::Stack
+        || resolved.type == Context::ResolvedName::Import) {
+        if (resolved.isArgOrEval && isLhs)
+            // ### add correct source location
+            throwSyntaxError(SourceLocation(), QStringLiteral("Variable name may not be eval or arguments in strict mode"));
+        Reference r;
+        switch (resolved.type) {
+        case Context::ResolvedName::Local:
+            r = Reference::fromScopedLocal(this, resolved.index, resolved.scope); break;
+        case Context::ResolvedName::Stack:
+            r = Reference::fromStackSlot(this, resolved.index, true /*isLocal*/); break;
+        case Context::ResolvedName::Import:
+            r = Reference::fromImport(this, resolved.index); break;
+        default: Q_UNREACHABLE();
+        }
+        if (r.isStackSlot() && _volatileMemoryLocations.isVolatile(name))
+            r.isVolatile = true;
+        r.isArgOrEval = resolved.isArgOrEval;
+        r.isReferenceToConst = resolved.isConst;
+        r.requiresTDZCheck = resolved.requiresTDZCheck;
+        r.name = name; // used to show correct name at run-time when TDZ check fails.
+        return r;
     }
 
     // This hook allows implementing QML lookup semantics
-    if (IR::Expr *fallback = fallbackNameLookup(name, line, col))
+    Reference fallback = fallbackNameLookup(name);
+    if (fallback.type != Reference::Invalid)
         return fallback;
 
-    if (!e->parent && (!f || !f->insideWithOrCatch) && _variableEnvironment->compilationMode != EvalCode && e->compilationMode != QmlBinding)
-        return _block->GLOBALNAME(name, line, col);
-
-    // global context or with. Lookup by name
-    return _block->NAME(name, line, col);
+    Reference r = Reference::fromName(this, name);
+    r.global = useFastLookups && (resolved.type == Context::ResolvedName::Global);
+    if (!r.global && canAccelerateGlobalLookups() && m_globalNames.contains(name))
+        r.global = true;
+    return r;
+}
 
+void Codegen::loadClosure(int closureId)
+{
+    if (closureId >= 0) {
+        Instruction::LoadClosure load;
+        load.value = closureId;
+        bytecodeGenerator->addInstruction(load);
+    } else {
+        Reference::fromConst(this, Encode::undefined()).loadInAccumulator();
+    }
 }
 
-IR::Expr *Codegen::fallbackNameLookup(const QString &name, int line, int col)
+Codegen::Reference Codegen::fallbackNameLookup(const QString &name)
 {
     Q_UNUSED(name)
-    Q_UNUSED(line)
-    Q_UNUSED(col)
-    return 0;
+    return Reference();
 }
 
 bool Codegen::visit(IdentifierExpression *ast)
@@ -1566,7 +2413,7 @@ bool Codegen::visit(IdentifierExpression *ast)
     if (hasError)
         return false;
 
-    _expr.code = identifier(ast->name.toString(), ast->identifierToken.startLine, ast->identifierToken.startColumn);
+    _expr.setResult(referenceForName(ast->name.toString(), false, ast->firstSourceLocation()));
     return false;
 }
 
@@ -1579,21 +2426,63 @@ bool Codegen::visit(NestedExpression *ast)
     return false;
 }
 
+void Codegen::handleConstruct(const Reference &base, ArgumentList *arguments)
+{
+    Reference constructor;
+    if (base.isSuper()) {
+        Instruction::LoadSuperConstructor super;
+        bytecodeGenerator->addInstruction(super);
+        constructor = Reference::fromAccumulator(this).storeOnStack();
+    } else {
+        constructor = base.storeOnStack();
+    }
+
+    auto calldata = pushArgs(arguments);
+    if (hasError)
+        return;
+
+    if (base.isSuper())
+        Reference::fromStackSlot(this, CallData::NewTarget).loadInAccumulator();
+    else
+        constructor.loadInAccumulator();
+
+    if (calldata.hasSpread) {
+        Instruction::ConstructWithSpread create;
+        create.func = constructor.stackSlot();
+        create.argc = calldata.argc;
+        create.argv = calldata.argv;
+        bytecodeGenerator->addInstruction(create);
+    } else {
+        Instruction::Construct create;
+        create.func = constructor.stackSlot();
+        create.argc = calldata.argc;
+        create.argv = calldata.argv;
+        bytecodeGenerator->addInstruction(create);
+    }
+    if (base.isSuper())
+        // set the result up as the thisObject
+        Reference::fromAccumulator(this).storeOnStack(CallData::This);
+
+    _expr.setResult(Reference::fromAccumulator(this));
+}
+
 bool Codegen::visit(NewExpression *ast)
 {
     if (hasError)
         return false;
 
-    Result base = expression(ast->expression);
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
+    Reference base = expression(ast->expression);
     if (hasError)
         return false;
-    IR::Expr *expr = *base;
-    if (expr && !expr->asTemp() && !expr->asArgLocal() && !expr->asName() && !expr->asMember()) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), expr);
-        expr = _block->TEMP(t);
+    if (base.isSuper()) {
+        throwSyntaxError(ast->expression->firstSourceLocation(), QStringLiteral("Cannot use new with super."));
+        return false;
     }
-    _expr.code = _block->NEW(expr, 0);
+
+    handleConstruct(base, nullptr);
     return false;
 }
 
@@ -1602,29 +2491,18 @@ bool Codegen::visit(NewMemberExpression *ast)
     if (hasError)
         return false;
 
-    Result base = expression(ast->base);
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
+    Reference base = expression(ast->base);
     if (hasError)
         return false;
-    IR::Expr *expr = *base;
-    if (expr && !expr->asTemp() && !expr->asArgLocal() && !expr->asName() && !expr->asMember()) {
-        const unsigned t = _block->newTemp();
-        move(_block->TEMP(t), expr);
-        expr = _block->TEMP(t);
+    if (base.isSuper()) {
+        throwSyntaxError(ast->base->firstSourceLocation(), QStringLiteral("Cannot use new with super."));
+        return false;
     }
 
-    IR::ExprList *args = 0, **args_it = &args;
-    for (ArgumentList *it = ast->arguments; it; it = it->next) {
-        Result arg = expression(it->expression);
-        if (hasError)
-            return false;
-        IR::Expr *actual = argument(*arg);
-        *args_it = _function->New<IR::ExprList>();
-        (*args_it)->init(actual);
-        args_it = &(*args_it)->next;
-    }
-    const unsigned t = _block->newTemp();
-    move(_block->TEMP(t), _block->NEW(expr, args));
-    _expr.code = _block->TEMP(t);
+    handleConstruct(base, ast->arguments);
     return false;
 }
 
@@ -1633,12 +2511,8 @@ bool Codegen::visit(NotExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
-    if (hasError)
-        return false;
-    const unsigned r = _block->newTemp();
-    setLocation(move(_block->TEMP(r), unop(IR::OpNot, *expr, ast->notToken)), ast->notToken);
-    _expr.code = _block->TEMP(r);
+    TailCallBlocker blockTailCalls(this);
+    _expr.setResult(unop(Not, expression(ast->expression)));
     return false;
 }
 
@@ -1647,8 +2521,10 @@ bool Codegen::visit(NullExpression *)
     if (hasError)
         return false;
 
-    if (_expr.accept(cx)) _block->JUMP(_expr.iffalse);
-    else _expr.code = _block->CONST(IR::NullType, 0);
+    if (_expr.accept(cx))
+        bytecodeGenerator->jump().link(*_expr.iffalse());
+    else
+        _expr.setResult(Reference::fromConst(this, Encode::null()));
 
     return false;
 }
@@ -1658,164 +2534,120 @@ bool Codegen::visit(NumericLiteral *ast)
     if (hasError)
         return false;
 
-    if (_expr.accept(cx)) {
-        if (ast->value) _block->JUMP(_expr.iftrue);
-        else _block->JUMP(_expr.iffalse);
-    } else {
-        _expr.code = _block->CONST(IR::NumberType, ast->value);
-    }
+    _expr.setResult(Reference::fromConst(this, QV4::Encode::smallestNumber(ast->value)));
     return false;
 }
 
-struct ObjectPropertyValue {
-    ObjectPropertyValue()
-        : value(0)
-        , getter(-1)
-        , setter(-1)
-    {}
-
-    IR::Expr *value;
-    int getter; // index in _module->functions or -1 if not set
-    int setter;
-
-    bool hasGetter() const { return getter >= 0; }
-    bool hasSetter() const { return setter >= 0; }
-};
-
-bool Codegen::visit(ObjectLiteral *ast)
+bool Codegen::visit(ObjectPattern *ast)
 {
     if (hasError)
         return false;
 
-    QMap<QString, ObjectPropertyValue> valueMap;
-
-    for (PropertyAssignmentList *it = ast->properties; it; it = it->next) {
-        QString name = it->assignment->name->asString();
-        if (PropertyNameAndValue *nv = AST::cast<AST::PropertyNameAndValue *>(it->assignment)) {
-            Result value = expression(nv->value);
-            if (hasError)
-                return false;
-            ObjectPropertyValue &v = valueMap[name];
-            if (v.hasGetter() || v.hasSetter() || (_function->isStrict && v.value)) {
-                throwSyntaxError(nv->lastSourceLocation(),
-                                 QStringLiteral("Illegal duplicate key '%1' in object literal").arg(name));
-                return false;
-            }
+    TailCallBlocker blockTailCalls(this);
 
-            valueMap[name].value = *value;
-        } else if (PropertyGetterSetter *gs = AST::cast<AST::PropertyGetterSetter *>(it->assignment)) {
-            const int function = defineFunction(name, gs, gs->formals, gs->functionBody ? gs->functionBody->elements : 0);
-            ObjectPropertyValue &v = valueMap[name];
-            if (v.value ||
-                (gs->type == PropertyGetterSetter::Getter && v.hasGetter()) ||
-                (gs->type == PropertyGetterSetter::Setter && v.hasSetter())) {
-                throwSyntaxError(gs->lastSourceLocation(),
-                                 QStringLiteral("Illegal duplicate key '%1' in object literal").arg(name));
-                return false;
-            }
-            if (gs->type == PropertyGetterSetter::Getter)
-                v.getter = function;
-            else
-                v.setter = function;
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
+    RegisterScope scope(this);
 
-    // The linked-list arguments to builtin_define_object_literal
-    // begin with a CONST counting the number of key/value pairs, followed by the
-    // key value pairs, followed by the array entries.
-    IR::ExprList *args = _function->New<IR::ExprList>();
+    QStringList members;
 
-    IR::Const *entryCountParam = _function->New<IR::Const>();
-    entryCountParam->init(IR::SInt32Type, 0);
-    args->expr = entryCountParam;
-    args->next = 0;
+    int argc = 0;
+    int args = 0;
+    auto push = [this, &args, &argc](const Reference &arg) {
+        int temp = bytecodeGenerator->newRegister();
+        if (argc == 0)
+            args = temp;
+        (void) arg.storeOnStack(temp);
+        ++argc;
+    };
 
-    IR::ExprList *keyValueEntries = 0;
-    IR::ExprList *currentKeyValueEntry = 0;
-    int keyValueEntryCount = 0;
-    IR::ExprList *arrayEntries = 0;
+    PatternPropertyList *it = ast->properties;
+    for (; it; it = it->next) {
+        PatternProperty *p = it->property;
+        AST::ComputedPropertyName *cname = AST::cast<AST::ComputedPropertyName *>(p->name);
+        if (cname || p->type != PatternProperty::Literal)
+            break;
+        QString name = p->name->asString();
+        uint arrayIndex = QV4::String::toArrayIndex(name);
+        if (arrayIndex != UINT_MAX)
+            break;
+        if (members.contains(name))
+            break;
+        members.append(name);
 
-    IR::ExprList *currentArrayEntry = 0;
+        {
+            RegisterScope innerScope(this);
+            Reference value = expression(p->initializer);
+            if (hasError)
+                return false;
+            value.loadInAccumulator();
+        }
+        push(Reference::fromAccumulator(this));
+    }
 
-    for (QMap<QString, ObjectPropertyValue>::iterator it = valueMap.begin(); it != valueMap.end(); ) {
-        IR::ExprList **currentPtr = 0;
-        uint keyAsIndex = QV4::String::toArrayIndex(it.key());
-        if (keyAsIndex != UINT_MAX) {
-            if (!arrayEntries) {
-                arrayEntries = _function->New<IR::ExprList>();
-                currentArrayEntry = arrayEntries;
-            } else {
-                currentArrayEntry->next = _function->New<IR::ExprList>();
-                currentArrayEntry = currentArrayEntry->next;
-            }
-            currentPtr = &currentArrayEntry;
-            IR::Const *idx = _function->New<IR::Const>();
-            idx->init(IR::UInt32Type, keyAsIndex);
-            (*currentPtr)->expr = idx;
+    int classId = jsUnitGenerator->registerJSClass(members);
+
+    // handle complex property setters
+    for (; it; it = it->next) {
+        PatternProperty *p = it->property;
+        AST::ComputedPropertyName *cname = AST::cast<AST::ComputedPropertyName *>(p->name);
+        ObjectLiteralArgument argType = ObjectLiteralArgument::Value;
+        if (p->type == PatternProperty::Method)
+            argType = ObjectLiteralArgument::Method;
+        else if (p->type == PatternProperty::Getter)
+            argType = ObjectLiteralArgument::Getter;
+        else if (p->type == PatternProperty::Setter)
+            argType = ObjectLiteralArgument::Setter;
+
+        Reference::fromConst(this, Encode(int(argType))).loadInAccumulator();
+        push(Reference::fromAccumulator(this));
+
+        if (cname) {
+            RegisterScope innerScope(this);
+            Reference name = expression(cname->expression);
+            if (hasError)
+                return false;
+            name.loadInAccumulator();
         } else {
-            if (!keyValueEntries) {
-                keyValueEntries = _function->New<IR::ExprList>();
-                currentKeyValueEntry = keyValueEntries;
-            } else {
-                currentKeyValueEntry->next = _function->New<IR::ExprList>();
-                currentKeyValueEntry = currentKeyValueEntry->next;
+            QString name = p->name->asString();
+#if 0
+            uint arrayIndex = QV4::String::toArrayIndex(name);
+            if (arrayIndex != UINT_MAX) {
+                Reference::fromConst(this, Encode(arrayIndex)).loadInAccumulator();
+            } else
+#endif
+            {
+                Instruction::LoadRuntimeString instr;
+                instr.stringId = registerString(name);
+                bytecodeGenerator->addInstruction(instr);
             }
-            currentPtr = &currentKeyValueEntry;
-            (*currentPtr)->expr = _block->NAME(it.key(), 0, 0);
-            keyValueEntryCount++;
         }
-
-        IR::ExprList *&current = *currentPtr;
-        if (it->value) {
-            current->next = _function->New<IR::ExprList>();
-            current = current->next;
-            current->expr = _block->CONST(IR::BoolType, true);
-
-            unsigned value = _block->newTemp();
-            move(_block->TEMP(value), it->value);
-
-            current->next = _function->New<IR::ExprList>();
-            current = current->next;
-            current->expr = _block->TEMP(value);
-        } else {
-            current->next = _function->New<IR::ExprList>();
-            current = current->next;
-            current->expr = _block->CONST(IR::BoolType, false);
-
-            unsigned getter = _block->newTemp();
-            unsigned setter = _block->newTemp();
-            move(_block->TEMP(getter), it->hasGetter() ? _block->CLOSURE(it->getter) : _block->CONST(IR::UndefinedType, 0));
-            move(_block->TEMP(setter), it->hasSetter() ? _block->CLOSURE(it->setter) : _block->CONST(IR::UndefinedType, 0));
-
-            current->next = _function->New<IR::ExprList>();
-            current = current->next;
-            current->expr = _block->TEMP(getter);
-            current->next = _function->New<IR::ExprList>();
-            current = current->next;
-            current->expr = _block->TEMP(setter);
+        push(Reference::fromAccumulator(this));
+        {
+            RegisterScope innerScope(this);
+            if (p->type != PatternProperty::Literal) {
+                // need to get the closure id for the method
+                FunctionExpression *f = p->initializer->asFunctionDefinition();
+                Q_ASSERT(f);
+                int function = defineFunction(f->name.toString(), f, f->formals, f->body);
+                if (hasError)
+                    return false;
+                Reference::fromConst(this, Encode(function)).loadInAccumulator();
+            } else {
+                Reference value = expression(p->initializer);
+                if (hasError)
+                    return false;
+                value.loadInAccumulator();
+            }
         }
-
-        it = valueMap.erase(it);
-    }
-
-    entryCountParam->value = keyValueEntryCount;
-
-    if (keyValueEntries)
-        args->next = keyValueEntries;
-    if (arrayEntries) {
-        if (currentKeyValueEntry)
-            currentKeyValueEntry->next = arrayEntries;
-        else
-            args->next = arrayEntries;
+        push(Reference::fromAccumulator(this));
     }
 
-    const unsigned t = _block->newTemp();
-    move(_block->TEMP(t), _block->CALL(_block->NAME(IR::Name::builtin_define_object_literal,
-         ast->firstSourceLocation().startLine, ast->firstSourceLocation().startColumn), args));
-
-    _expr.code = _block->TEMP(t);
+    Instruction::DefineObjectLiteral call;
+    call.internalClassId = classId;
+    call.argc = argc;
+    call.args = Moth::StackSlot::createRegister(args);
+    bytecodeGenerator->addInstruction(call);
+    Reference result = Reference::fromAccumulator(this);
+    _expr.setResult(result);
     return false;
 }
 
@@ -1824,25 +2656,17 @@ bool Codegen::visit(PostDecrementExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->base);
+    Reference expr = expression(ast->base);
     if (hasError)
         return false;
-    if (!expr->isLValue()) {
+    if (!expr.isLValue()) {
         throwReferenceError(ast->base->lastSourceLocation(), QStringLiteral("Invalid left-hand side expression in postfix operation"));
         return false;
     }
-    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(*expr, ast->decrementToken))
+    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(expr, ast->decrementToken))
         return false;
 
-    const unsigned oldValue = _block->newTemp();
-    setLocation(move(_block->TEMP(oldValue), unop(IR::OpUPlus, *expr, ast->decrementToken)), ast->decrementToken);
-
-    const unsigned  newValue = _block->newTemp();
-    setLocation(move(_block->TEMP(newValue), binop(IR::OpSub, _block->TEMP(oldValue), _block->CONST(IR::NumberType, 1), ast->decrementToken)), ast->decrementToken);
-    setLocation(move(*expr, _block->TEMP(newValue)), ast->decrementToken);
-
-    if (!_expr.accept(nx))
-        _expr.code = _block->TEMP(oldValue);
+    _expr.setResult(unop(PostDecrement, expr));
 
     return false;
 }
@@ -1852,53 +2676,35 @@ bool Codegen::visit(PostIncrementExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->base);
+    Reference expr = expression(ast->base);
     if (hasError)
         return false;
-    if (!expr->isLValue()) {
+    if (!expr.isLValue()) {
         throwReferenceError(ast->base->lastSourceLocation(), QStringLiteral("Invalid left-hand side expression in postfix operation"));
         return false;
     }
-    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(*expr, ast->incrementToken))
+    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(expr, ast->incrementToken))
         return false;
 
-    const unsigned oldValue = _block->newTemp();
-    setLocation(move(_block->TEMP(oldValue), unop(IR::OpUPlus, *expr, ast->incrementToken)), ast->incrementToken);
-
-    const unsigned  newValue = _block->newTemp();
-    setLocation(move(_block->TEMP(newValue), binop(IR::OpAdd, _block->TEMP(oldValue), _block->CONST(IR::NumberType, 1), ast->incrementToken)), ast->incrementToken);
-    setLocation(move(*expr, _block->TEMP(newValue)), ast->incrementToken);
-
-    if (!_expr.accept(nx))
-        _expr.code = _block->TEMP(oldValue);
-
+    _expr.setResult(unop(PostIncrement, expr));
     return false;
 }
 
 bool Codegen::visit(PreDecrementExpression *ast)
-{
-    if (hasError)
+{    if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
+    Reference expr = expression(ast->expression);
     if (hasError)
         return false;
-    if (!expr->isLValue()) {
+    if (!expr.isLValue()) {
         throwReferenceError(ast->expression->lastSourceLocation(), QStringLiteral("Prefix ++ operator applied to value that is not a reference."));
         return false;
     }
 
-    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(*expr, ast->decrementToken))
+    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(expr, ast->decrementToken))
         return false;
-    IR::Expr *op = binop(IR::OpSub, *expr, _block->CONST(IR::NumberType, 1), ast->decrementToken);
-    if (_expr.accept(nx)) {
-        setLocation(move(*expr, op), ast->decrementToken);
-    } else {
-        const unsigned t = _block->newTemp();
-        setLocation(move(_block->TEMP(t), op), ast->decrementToken);
-        setLocation(move(*expr, _block->TEMP(t)), ast->decrementToken);
-        _expr.code = _block->TEMP(t);
-    }
+    _expr.setResult(unop(PreDecrement, expr));
     return false;
 }
 
@@ -1907,25 +2713,17 @@ bool Codegen::visit(PreIncrementExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
+    Reference expr = expression(ast->expression);
     if (hasError)
         return false;
-    if (!expr->isLValue()) {
+    if (!expr.isLValue()) {
         throwReferenceError(ast->expression->lastSourceLocation(), QStringLiteral("Prefix ++ operator applied to value that is not a reference."));
         return false;
     }
 
-    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(*expr, ast->incrementToken))
+    if (throwSyntaxErrorOnEvalOrArgumentsInStrictMode(expr, ast->incrementToken))
         return false;
-    IR::Expr *op = binop(IR::OpAdd, unop(IR::OpUPlus, *expr, ast->incrementToken), _block->CONST(IR::NumberType, 1), ast->incrementToken);
-    if (_expr.accept(nx)) {
-        setLocation(move(*expr, op), ast->incrementToken);
-    } else {
-        const unsigned t = _block->newTemp();
-        setLocation(move(_block->TEMP(t), op), ast->incrementToken);
-        setLocation(move(*expr, _block->TEMP(t)), ast->incrementToken);
-        _expr.code = _block->TEMP(t);
-    }
+    _expr.setResult(unop(PreIncrement, expr));
     return false;
 }
 
@@ -1934,7 +2732,14 @@ bool Codegen::visit(RegExpLiteral *ast)
     if (hasError)
         return false;
 
-    _expr.code = _block->REGEXP(_function->newString(ast->pattern.toString()), ast->flags);
+    auto r = Reference::fromStackSlot(this);
+    r.isReadonly = true;
+    _expr.setResult(r);
+
+    Instruction::MoveRegExp instr;
+    instr.regExpId = jsUnitGenerator->registerRegExp(ast);
+    instr.destReg = r.stackSlot();
+    bytecodeGenerator->addInstruction(instr);
     return false;
 }
 
@@ -1943,30 +2748,85 @@ bool Codegen::visit(StringLiteral *ast)
     if (hasError)
         return false;
 
-    _expr.code = _block->STRING(_function->newString(ast->value.toString()));
+    auto r = Reference::fromAccumulator(this);
+    r.isReadonly = true;
+    _expr.setResult(r);
+
+    Instruction::LoadRuntimeString instr;
+    instr.stringId = registerString(ast->value.toString());
+    bytecodeGenerator->addInstruction(instr);
     return false;
 }
 
-bool Codegen::visit(ThisExpression *ast)
+bool Codegen::visit(TemplateLiteral *ast)
 {
     if (hasError)
         return false;
 
-    _expr.code = _block->NAME(QStringLiteral("this"), ast->thisToken.startLine, ast->thisToken.startColumn);
+    TailCallBlocker blockTailCalls(this);
+
+    Instruction::LoadRuntimeString instr;
+    instr.stringId = registerString(ast->value.toString());
+    bytecodeGenerator->addInstruction(instr);
+
+    if (ast->expression) {
+        RegisterScope scope(this);
+        int temp = bytecodeGenerator->newRegister();
+        Instruction::StoreReg store;
+        store.reg = temp;
+        bytecodeGenerator->addInstruction(store);
+
+        Reference expr = expression(ast->expression);
+        if (hasError)
+            return false;
+
+        if (ast->next) {
+            int temp2 = bytecodeGenerator->newRegister();
+            expr.storeOnStack(temp2);
+            visit(ast->next);
+
+            Instruction::Add instr;
+            instr.lhs = temp2;
+            bytecodeGenerator->addTracingInstruction(instr);
+        } else {
+            expr.loadInAccumulator();
+        }
+
+        Instruction::Add instr;
+        instr.lhs = temp;
+        bytecodeGenerator->addTracingInstruction(instr);
+    }
+
+    auto r = Reference::fromAccumulator(this);
+    r.isReadonly = true;
+
+    _expr.setResult(r);
     return false;
+
 }
 
-bool Codegen::visit(TildeExpression *ast)
+bool Codegen::visit(ThisExpression *)
 {
     if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
+    if (_context->isArrowFunction) {
+        Reference r = referenceForName(QStringLiteral("this"), false);
+        r.isReadonly = true;
+        _expr.setResult(r);
+        return false;
+    }
+    _expr.setResult(Reference::fromThis(this));
+    return false;
+}
+
+bool Codegen::visit(TildeExpression *ast)
+{
     if (hasError)
         return false;
-    const unsigned t = _block->newTemp();
-    setLocation(move(_block->TEMP(t), unop(IR::OpCompl, *expr, ast->tildeToken)), ast->tildeToken);
-    _expr.code = _block->TEMP(t);
+
+    TailCallBlocker blockTailCalls(this);
+    _expr.setResult(unop(Compl, expression(ast->expression)));
     return false;
 }
 
@@ -1975,11 +2835,7 @@ bool Codegen::visit(TrueLiteral *)
     if (hasError)
         return false;
 
-    if (_expr.accept(cx)) {
-        _block->JUMP(_expr.iftrue);
-    } else {
-        _expr.code = _block->CONST(IR::BoolType, 1);
-    }
+    _expr.setResult(Reference::fromConst(this, QV4::Encode(true)));
     return false;
 }
 
@@ -1988,12 +2844,25 @@ bool Codegen::visit(TypeOfExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
+    Reference expr = expression(ast->expression);
     if (hasError)
         return false;
-    IR::ExprList *args = _function->New<IR::ExprList>();
-    args->init(reference(*expr));
-    _expr.code = call(_block->NAME(IR::Name::builtin_typeof, ast->typeofToken.startLine, ast->typeofToken.startColumn), args);
+
+    if (expr.type == Reference::Name) {
+        // special handling as typeof doesn't throw here
+        Instruction::TypeofName instr;
+        instr.name = expr.nameAsIndex();
+        bytecodeGenerator->addInstruction(instr);
+    } else {
+        expr.loadInAccumulator();
+        Instruction::TypeofValue instr;
+        bytecodeGenerator->addInstruction(instr);
+    }
+    _expr.setResult(Reference::fromAccumulator(this));
+
     return false;
 }
 
@@ -2002,12 +2871,8 @@ bool Codegen::visit(UnaryMinusExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
-    if (hasError)
-        return false;
-    const unsigned t = _block->newTemp();
-    setLocation(move(_block->TEMP(t), unop(IR::OpUMinus, *expr, ast->minusToken)), ast->minusToken);
-    _expr.code = _block->TEMP(t);
+    TailCallBlocker blockTailCalls(this);
+    _expr.setResult(unop(UMinus, expression(ast->expression)));
     return false;
 }
 
@@ -2016,12 +2881,8 @@ bool Codegen::visit(UnaryPlusExpression *ast)
     if (hasError)
         return false;
 
-    Result expr = expression(ast->expression);
-    if (hasError)
-        return false;
-    const unsigned t = _block->newTemp();
-    setLocation(move(_block->TEMP(t), unop(IR::OpUPlus, *expr, ast->plusToken)), ast->plusToken);
-    _expr.code = _block->TEMP(t);
+    TailCallBlocker blockTailCalls(this);
+    _expr.setResult(unop(UPlus, expression(ast->expression)));
     return false;
 }
 
@@ -2030,8 +2891,11 @@ bool Codegen::visit(VoidExpression *ast)
     if (hasError)
         return false;
 
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
     statement(ast->expression);
-    _expr.code = _block->CONST(IR::UndefinedType, 0);
+    _expr.setResult(Reference::fromConst(this, Encode::undefined()));
     return false;
 }
 
@@ -2040,162 +2904,265 @@ bool Codegen::visit(FunctionDeclaration * ast)
     if (hasError)
         return false;
 
-    if (_variableEnvironment->compilationMode == QmlBinding)
-        move(_block->TEMP(_returnAddress), _block->NAME(ast->name.toString(), 0, 0));
+    // no need to block tail calls: the function body isn't visited here.
+    RegisterScope scope(this);
+
+    if (_functionContext->contextType == ContextType::Binding)
+        referenceForName(ast->name.toString(), true).loadInAccumulator();
     _expr.accept(nx);
     return false;
 }
 
-int Codegen::defineFunction(const QString &name, AST::Node *ast,
-                            AST::FormalParameterList *formals,
-                            AST::SourceElements *body,
-                            const QStringList &inheritedLocals)
-{
-    Loop *loop = 0;
-    qSwap(_loop, loop);
-    QStack<IR::BasicBlock *> exceptionHandlers;
-    qSwap(_exceptionHandlers, exceptionHandlers);
-
-    ScopeAndFinally *scopeAndFinally = 0;
-
-    enterEnvironment(ast);
-    IR::Function *function = _module->newFunction(name, _function);
-    int functionIndex = _module->functions.count() - 1;
-
-    IR::BasicBlock *entryBlock = function->newBasicBlock(0);
-    IR::BasicBlock *exitBlock = function->newBasicBlock(0, IR::Function::DontInsertBlock);
-    function->hasDirectEval = _variableEnvironment->hasDirectEval || _variableEnvironment->compilationMode == EvalCode
-            || _module->debugMode; // Conditional breakpoints are like eval in the function
-    function->usesArgumentsObject = _variableEnvironment->parent && (_variableEnvironment->usesArgumentsObject == Environment::ArgumentsObjectUsed);
-    function->usesThis = _variableEnvironment->usesThis;
-    function->maxNumberOfArguments = qMax(_variableEnvironment->maxNumberOfArguments, (int)QV4::Global::ReservedArgumentCount);
-    function->isStrict = _variableEnvironment->isStrict;
-    function->isNamedExpression = _variableEnvironment->isNamedFunctionExpression;
-    function->isQmlBinding = _variableEnvironment->compilationMode == QmlBinding;
-
-    AST::SourceLocation loc = ast->firstSourceLocation();
-    function->line = loc.startLine;
-    function->column = loc.startColumn;
-
-    if (function->usesArgumentsObject)
-        _variableEnvironment->enter(QStringLiteral("arguments"), Environment::VariableDeclaration, AST::VariableDeclaration::FunctionScope);
-
-    // variables in global code are properties of the global context object, not locals as with other functions.
-    if (_variableEnvironment->compilationMode == FunctionCode || _variableEnvironment->compilationMode == QmlBinding) {
-        unsigned t = 0;
-        for (Environment::MemberMap::iterator it = _variableEnvironment->members.begin(), end = _variableEnvironment->members.end(); it != end; ++it) {
-            const QString &local = it.key();
-            function->LOCAL(local);
-            (*it).index = t;
-            entryBlock->MOVE(entryBlock->LOCAL(t, 0), entryBlock->CONST(IR::UndefinedType, 0));
-            ++t;
-        }
-    } else {
-        if (!_variableEnvironment->isStrict) {
-            for (const QString &inheritedLocal : qAsConst(inheritedLocals)) {
-                function->LOCAL(inheritedLocal);
-                unsigned tempIndex = entryBlock->newTemp();
-                Environment::Member member = { Environment::UndefinedMember,
-                                               static_cast<int>(tempIndex), 0,
-                                               AST::VariableDeclaration::VariableScope::FunctionScope };
-                _variableEnvironment->members.insert(inheritedLocal, member);
-            }
-        }
+bool Codegen::visit(YieldExpression *ast)
+{
+    if (inFormalParameterList) {
+        throwSyntaxError(ast->firstSourceLocation(), QLatin1String("yield is not allowed inside parameter lists"));
+        return false;
+    }
 
-        IR::ExprList *args = 0;
-        for (Environment::MemberMap::const_iterator it = _variableEnvironment->members.constBegin(), cend = _variableEnvironment->members.constEnd(); it != cend; ++it) {
-            const QString &local = it.key();
-            IR::ExprList *next = function->New<IR::ExprList>();
-            next->expr = entryBlock->NAME(local, 0, 0);
-            next->next = args;
-            args = next;
-        }
-        if (args) {
-            IR::ExprList *next = function->New<IR::ExprList>();
-            next->expr = entryBlock->CONST(IR::BoolType, false); // ### Investigate removal of bool deletable
-            next->next = args;
-            args = next;
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+    Reference expr = ast->expression ? expression(ast->expression) : Reference::fromConst(this, Encode::undefined());
+    if (hasError)
+        return false;
 
-            entryBlock->EXP(entryBlock->CALL(entryBlock->NAME(IR::Name::builtin_declare_vars, 0, 0), args));
-        }
+    Reference acc = Reference::fromAccumulator(this);
+
+    if (ast->isYieldStar) {
+        Reference iterator = Reference::fromStackSlot(this);
+        Reference lhsValue = Reference::fromConst(this, Encode::undefined()).storeOnStack();
+
+        expr.loadInAccumulator();
+        Instruction::GetIterator getIterator;
+        getIterator.iterator = static_cast<int>(AST::ForEachType::Of);
+        bytecodeGenerator->addInstruction(getIterator);
+        iterator.storeConsumeAccumulator();
+        Instruction::LoadUndefined load;
+        bytecodeGenerator->addInstruction(load);
+
+        BytecodeGenerator::Label in = bytecodeGenerator->newLabel();
+        bytecodeGenerator->jump().link(in);
+
+        BytecodeGenerator::Label loop = bytecodeGenerator->label();
+
+        lhsValue.loadInAccumulator();
+        Instruction::YieldStar yield;
+        bytecodeGenerator->addInstruction(yield);
+
+        in.link();
+
+        Instruction::IteratorNextForYieldStar next;
+        next.object = lhsValue.stackSlot();
+        next.iterator = iterator.stackSlot();
+        bytecodeGenerator->addInstruction(next);
+
+        BytecodeGenerator::Jump done = bytecodeGenerator->jumpTrue();
+        bytecodeGenerator->jumpNotUndefined().link(loop);
+        lhsValue.loadInAccumulator();
+        emitReturn(acc);
+
+
+        done.link();
+
+        lhsValue.loadInAccumulator();
+        _expr.setResult(acc);
+        return false;
     }
 
-    unsigned returnAddress = entryBlock->newTemp();
+    expr.loadInAccumulator();
+    Instruction::Yield yield;
+    bytecodeGenerator->addInstruction(yield);
+    Instruction::Resume resume;
+    BytecodeGenerator::Jump jump = bytecodeGenerator->addJumpInstruction(resume);
+    emitReturn(acc);
+    jump.link();
+    _expr.setResult(acc);
+    return false;
+}
+
+static bool endsWithReturn(Module *module, Node *node)
+{
+    if (!node)
+        return false;
+    if (AST::cast<ReturnStatement *>(node))
+        return true;
+    if (AST::cast<ThrowStatement *>(node))
+        return true;
+    if (Program *p = AST::cast<Program *>(node))
+        return endsWithReturn(module, p->statements);
+    if (StatementList *sl = AST::cast<StatementList *>(node)) {
+        while (sl->next)
+            sl = sl->next;
+        return endsWithReturn(module, sl->statement);
+    }
+    if (Block *b = AST::cast<Block *>(node)) {
+        Context *blockContext = module->contextMap.value(node);
+        if (blockContext->requiresExecutionContext)
+            // we need to emit a return statement here, because of the
+            // unwind handler
+            return false;
+        return endsWithReturn(module, b->statements);
+    }
+    if (IfStatement *is = AST::cast<IfStatement *>(node))
+        return is->ko && endsWithReturn(module, is->ok) && endsWithReturn(module, is->ko);
+    return false;
+}
+
+int Codegen::defineFunction(const QString &name, AST::Node *ast,
+                            AST::FormalParameterList *formals,
+                            AST::StatementList *body)
+{
+    enterContext(ast);
+
+    if (_context->functionIndex >= 0)
+        // already defined
+        return leaveContext();
+
+    _context->name = name;
+    _module->functions.append(_context);
+    _context->functionIndex = _module->functions.count() - 1;
 
-    entryBlock->MOVE(entryBlock->TEMP(returnAddress), entryBlock->CONST(IR::UndefinedType, 0));
-    setLocation(exitBlock->RET(exitBlock->TEMP(returnAddress)), ast->lastSourceLocation());
+    Context *savedFunctionContext = _functionContext;
+    _functionContext = _context;
+    ControlFlow *savedControlFlow = controlFlow;
+    controlFlow = nullptr;
 
-    qSwap(_function, function);
-    qSwap(_block, entryBlock);
-    qSwap(_exitBlock, exitBlock);
+    if (_context->contextType == ContextType::Global || _context->contextType == ContextType::ScriptImportedByQML) {
+        _module->blocks.append(_context);
+        _context->blockIndex = _module->blocks.count() - 1;
+    }
+    if (_module->debugMode) // allow the debugger to see overwritten arguments
+        _context->argumentsCanEscape = true;
+
+    // When a user writes the following QML signal binding:
+    //    onSignal: function() { doSomethingUsefull }
+    // we will generate a binding function that just returns the closure. However, that's not useful
+    // at all, because if the onSignal is a signal handler, the user is actually making it explicit
+    // that the binding is a function, so we should execute that. However, we don't know that during
+    // AOT compilation, so mark the surrounding function as only-returning-a-closure.
+    _context->returnsClosure = body && body->statement && cast<ExpressionStatement *>(body->statement) && cast<FunctionExpression *>(cast<ExpressionStatement *>(body->statement)->expression);
+
+    BytecodeGenerator bytecode(_context->line, _module->debugMode);
+    BytecodeGenerator *savedBytecodeGenerator;
+    savedBytecodeGenerator = bytecodeGenerator;
+    bytecodeGenerator = &bytecode;
+    bytecodeGenerator->setLocation(ast->firstSourceLocation());
+    BytecodeGenerator::Label *savedReturnLabel = _returnLabel;
+    _returnLabel = nullptr;
+
+    bool savedFunctionEndsWithReturn = functionEndsWithReturn;
+    functionEndsWithReturn = endsWithReturn(_module, body);
+    bytecodeGenerator->setTracing(_functionContext->canUseTracingJit(), _context->arguments.size());
+
+    // reserve the js stack frame (Context & js Function & accumulator)
+    bytecodeGenerator->newRegisterArray(sizeof(CallData)/sizeof(Value) - 1 + _context->arguments.size());
+
+    bool _inFormalParameterList = false;
+    qSwap(_inFormalParameterList, inFormalParameterList);
+
+    int returnAddress = -1;
+    bool _requiresReturnValue = _context->requiresImplicitReturnValue();
+    qSwap(requiresReturnValue, _requiresReturnValue);
+    returnAddress = bytecodeGenerator->newRegister();
     qSwap(_returnAddress, returnAddress);
-    qSwap(_scopeAndFinally, scopeAndFinally);
 
-    for (FormalParameterList *it = formals; it; it = it->next) {
-        _function->RECEIVE(it->name.toString());
+    // register the lexical scope for global code
+    if (!_context->parent && _context->requiresExecutionContext) {
+        _module->blocks.append(_context);
+        _context->blockIndex = _module->blocks.count() - 1;
     }
 
-    for (const Environment::Member &member : qAsConst(_variableEnvironment->members)) {
-        if (member.function) {
-            const int function = defineFunction(member.function->name.toString(), member.function, member.function->formals,
-                                                member.function->body ? member.function->body->elements : 0);
-            if (! _variableEnvironment->parent) {
-                move(_block->NAME(member.function->name.toString(), member.function->identifierToken.startLine, member.function->identifierToken.startColumn),
-                     _block->CLOSURE(function));
+    TailCallBlocker maybeBlockTailCalls(this, _context->canHaveTailCalls());
+
+    RegisterScope registerScope(this);
+    _context->emitBlockHeader(this);
+
+    {
+        QScopedValueRollback<bool> inFormals(inFormalParameterList, true);
+        TailCallBlocker blockTailCalls(this); // we're not in the FunctionBody or ConciseBody yet
+
+        int argc = 0;
+        while (formals) {
+            PatternElement *e = formals->element;
+            if (!e) {
+                if (!formals->next)
+                    // trailing comma
+                    break;
+                Q_UNREACHABLE();
+            }
+
+            Reference arg = referenceForName(e->bindingIdentifier.toString(), true);
+            if (e->type == PatternElement::RestElement) {
+                Q_ASSERT(!formals->next);
+                Instruction::CreateRestParameter rest;
+                rest.argIndex = argc;
+                bytecodeGenerator->addInstruction(rest);
+                arg.storeConsumeAccumulator();
             } else {
-                Q_ASSERT(member.index >= 0);
-                move(_block->LOCAL(member.index, 0), _block->CLOSURE(function));
+                if (e->bindingTarget || e->initializer) {
+                    initializeAndDestructureBindingElement(e, arg);
+                    if (hasError)
+                        break;
+                }
             }
+            formals = formals->next;
+            ++argc;
         }
     }
-    if (_function->usesArgumentsObject) {
-        move(identifier(QStringLiteral("arguments"), ast->firstSourceLocation().startLine, ast->firstSourceLocation().startColumn),
-             _block->CALL(_block->NAME(IR::Name::builtin_setup_argument_object,
-                     ast->firstSourceLocation().startLine, ast->firstSourceLocation().startColumn), 0));
-    }
-    if (_function->usesThis && !_function->isStrict) {
-        // make sure we convert this to an object
-        _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_convert_this_to_object,
-                ast->firstSourceLocation().startLine, ast->firstSourceLocation().startColumn), 0));
+
+    if (_context->isGenerator) {
+        Instruction::Yield yield;
+        bytecodeGenerator->addInstruction(yield);
     }
 
     beginFunctionBodyHook();
 
-    sourceElements(body);
+    statementList(body);
 
-    _function->addBasicBlock(_exitBlock);
-
-    _block->JUMP(_exitBlock);
-
-    qSwap(_function, function);
-    qSwap(_block, entryBlock);
-    qSwap(_exitBlock, exitBlock);
-    qSwap(_returnAddress, returnAddress);
-    qSwap(_scopeAndFinally, scopeAndFinally);
-    qSwap(_exceptionHandlers, exceptionHandlers);
-    qSwap(_loop, loop);
+    if (!hasError) {
+        bytecodeGenerator->setLocation(ast->lastSourceLocation());
+        _context->emitBlockFooter(this);
 
-    leaveEnvironment();
+        if (_returnLabel || !functionEndsWithReturn) {
+            if (_returnLabel)
+                _returnLabel->link();
 
-    return functionIndex;
-}
+            if (_returnLabel || requiresReturnValue) {
+                Instruction::LoadReg load;
+                load.reg = Moth::StackSlot::createRegister(_returnAddress);
+                bytecodeGenerator->addInstruction(load);
+            } else {
+                Reference::fromConst(this, Encode::undefined()).loadInAccumulator();
+            }
 
-bool Codegen::visit(FunctionSourceElement *ast)
-{
-    if (hasError)
-        return false;
+            bytecodeGenerator->addInstruction(Instruction::Ret());
+        }
 
-    statement(ast->declaration);
-    return false;
-}
+        Q_ASSERT(_context == _functionContext);
+        bytecodeGenerator->finalize(_context);
+        _context->registerCountInFunction = bytecodeGenerator->registerCount();
+        _context->nTraceInfos = bytecodeGenerator->traceInfoCount();
+        static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_BYTECODE");
+        if (showCode) {
+            qDebug() << "=== Bytecode for" << _context->name << "strict mode" << _context->isStrict
+                     << "register count" << _context->registerCountInFunction << "implicit return" << requiresReturnValue;
+            QV4::Moth::dumpBytecode(_context->code, _context->locals.size(), _context->arguments.size(),
+                                    _context->line, _context->lineNumberMapping);
+            qDebug();
+        }
+    }
 
-bool Codegen::visit(StatementSourceElement *ast)
-{
-    if (hasError)
-        return false;
+    qSwap(_returnAddress, returnAddress);
+    qSwap(requiresReturnValue, _requiresReturnValue);
+    qSwap(_inFormalParameterList, inFormalParameterList);
+    bytecodeGenerator = savedBytecodeGenerator;
+    delete _returnLabel;
+    _returnLabel = savedReturnLabel;
+    controlFlow = savedControlFlow;
+    functionEndsWithReturn = savedFunctionEndsWithReturn;
+    _functionContext = savedFunctionContext;
 
-    statement(ast->statement);
-    return false;
+    return leaveContext();
 }
 
 bool Codegen::visit(Block *ast)
@@ -2203,9 +3170,10 @@ bool Codegen::visit(Block *ast)
     if (hasError)
         return false;
 
-    for (StatementList *it = ast->statements; it; it = it->next) {
-        statement(it->statement);
-    }
+    RegisterScope scope(this);
+
+    ControlFlowBlock controlFlow(this, ast);
+    statementList(ast->statements);
     return false;
 }
 
@@ -2214,25 +3182,23 @@ bool Codegen::visit(BreakStatement *ast)
     if (hasError)
         return false;
 
-    if (!_loop) {
+    // no need to block tail calls here: children aren't visited
+    if (!controlFlow) {
         throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Break outside of loop"));
         return false;
     }
-    Loop *loop = 0;
-    if (ast->label.isEmpty())
-        loop = _loop;
-    else {
-        for (loop = _loop; loop; loop = loop->parent) {
-            if (loop->labelledStatement && loop->labelledStatement->label == ast->label)
-                break;
-        }
-        if (!loop) {
+
+    ControlFlow::UnwindTarget target = controlFlow->unwindTarget(ControlFlow::Break, ast->label.toString());
+    if (!target.linkLabel.isValid()) {
+        if (ast->label.isEmpty())
+            throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Break outside of loop"));
+        else
             throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Undefined label '%1'").arg(ast->label.toString()));
-            return false;
-        }
+        return false;
     }
-    unwindException(loop->scopeAndFinally);
-    _block->JUMP(loop->breakBlock);
+
+    bytecodeGenerator->unwindToLabel(target.unwindLevel, target.linkLabel);
+
     return false;
 }
 
@@ -2241,31 +3207,25 @@ bool Codegen::visit(ContinueStatement *ast)
     if (hasError)
         return false;
 
-    Loop *loop = 0;
-    if (ast->label.isEmpty()) {
-        for (loop = _loop; loop; loop = loop->parent) {
-            if (loop->continueBlock)
-                break;
-        }
-    } else {
-        for (loop = _loop; loop; loop = loop->parent) {
-            if (loop->labelledStatement && loop->labelledStatement->label == ast->label) {
-                if (!loop->continueBlock)
-                    loop = 0;
-                break;
-            }
-        }
-        if (!loop) {
-            throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Undefined label '%1'").arg(ast->label.toString()));
-            return false;
-        }
+    // no need to block tail calls here: children aren't visited
+    RegisterScope scope(this);
+
+    if (!controlFlow) {
+        throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Continue outside of loop"));
+        return false;
     }
-    if (!loop) {
-        throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("continue outside of loop"));
+
+    ControlFlow::UnwindTarget target = controlFlow->unwindTarget(ControlFlow::Continue, ast->label.toString());
+    if (!target.linkLabel.isValid()) {
+        if (ast->label.isEmpty())
+            throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Undefined label '%1'").arg(ast->label.toString()));
+        else
+            throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("continue outside of loop"));
         return false;
     }
-    unwindException(loop->scopeAndFinally);
-    _block->JUMP(loop->continueBlock);
+
+    bytecodeGenerator->unwindToLabel(target.unwindLevel, target.linkLabel);
+
     return false;
 }
 
@@ -2278,47 +3238,59 @@ bool Codegen::visit(DebuggerStatement *)
 bool Codegen::visit(DoWhileStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    IR::BasicBlock *loopbody = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *loopcond = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *loopend = _function->newBasicBlock(exceptionHandler());
+    RegisterScope scope(this);
 
-    enterLoop(ast, loopend, loopcond);
+    BytecodeGenerator::Label body = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label cond = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label end = bytecodeGenerator->newLabel();
 
-    _block->JUMP(loopbody);
+    ControlFlowLoop flow(this, &end, &cond);
 
-    _block = loopbody;
-    statement(ast->statement);
-    setJumpOutLocation(_block->JUMP(loopcond), ast->statement, ast->semicolonToken);
+    // special case that is not a loop:
+    //   do {...} while (false)
+    if (!AST::cast<FalseLiteral *>(ast->expression))
+        bytecodeGenerator->addLoopStart(body);
 
-    _block = loopcond;
-    condition(ast->expression, loopbody, loopend);
-
-    _block = loopend;
+    body.link();
+    statement(ast->statement);
+    setJumpOutLocation(bytecodeGenerator, ast->statement, ast->semicolonToken);
+
+    cond.link();
+    if (AST::cast<TrueLiteral *>(ast->expression)) {
+        // do {} while (true) -> just jump back to the loop body, no need to generate a condition
+        bytecodeGenerator->jump().link(body);
+    } else if (AST::cast<FalseLiteral *>(ast->expression)) {
+        // do {} while (false) -> fall through, no need to generate a condition
+    } else {
+        TailCallBlocker blockTailCalls(this);
+        condition(ast->expression, &body, &end, false);
+    }
 
-    leaveLoop();
+    end.link();
 
     return false;
 }
 
 bool Codegen::visit(EmptyStatement *)
 {
-    if (hasError)
-        return true;
-
     return false;
 }
 
 bool Codegen::visit(ExpressionStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    if (_variableEnvironment->compilationMode == EvalCode || _variableEnvironment->compilationMode == QmlBinding) {
-        Result e = expression(ast->expression);
-        if (*e)
-            move(_block->TEMP(_returnAddress), *e);
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
+
+    if (requiresReturnValue) {
+        Reference e = expression(ast->expression);
+        if (hasError)
+            return false;
+        (void) e.storeOnStack(_returnAddress);
     } else {
         statement(ast->expression);
     }
@@ -2328,81 +3300,138 @@ bool Codegen::visit(ExpressionStatement *ast)
 bool Codegen::visit(ForEachStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    IR::BasicBlock *foreachin = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *foreachbody = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *foreachend = _function->newBasicBlock(exceptionHandler());
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
 
-    int objectToIterateOn = _block->newTemp();
-    Result expr = expression(ast->expression);
-    if (hasError)
-        return false;
-    move(_block->TEMP(objectToIterateOn), *expr);
-    IR::ExprList *args = _function->New<IR::ExprList>();
-    args->init(_block->TEMP(objectToIterateOn));
+    Reference iterator = Reference::fromStackSlot(this);
+    Reference iteratorDone = Reference::fromConst(this, Encode(false)).storeOnStack();
+    Reference lhsValue = Reference::fromStackSlot(this);
 
-    int iterator = _block->newTemp();
-    move(_block->TEMP(iterator), _block->CALL(_block->NAME(IR::Name::builtin_foreach_iterator_object, 0, 0), args));
+    // There should be a temporal block, so that variables declared in lhs shadow outside vars.
+    // This block should define a temporal dead zone for those variables.
+    {
+        RegisterScope innerScope(this);
+        ControlFlowBlock controlFlow(this, ast);
+        Reference expr = expression(ast->expression);
+        if (hasError)
+            return false;
 
-    enterLoop(ast, foreachend, foreachin);
-    _block->JUMP(foreachin);
+        expr.loadInAccumulator();
+        Instruction::GetIterator iteratorObjInstr;
+        iteratorObjInstr.iterator = static_cast<int>(ast->type);
+        bytecodeGenerator->addInstruction(iteratorObjInstr);
+        iterator.storeConsumeAccumulator();
+    }
 
-    _block = foreachbody;
-    int temp = _block->newTemp();
-    Result init = expression(ast->initialiser);
-    if (hasError)
-        return false;
-    move(*init, _block->TEMP(temp));
-    statement(ast->statement);
-    setJumpOutLocation(_block->JUMP(foreachin), ast->statement, ast->forToken);
+    BytecodeGenerator::Label in = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label end = bytecodeGenerator->newLabel();
+
+    {
+        auto cleanup = [ast, iterator, iteratorDone, this]() {
+            if (ast->type == ForEachType::Of) {
+                iterator.loadInAccumulator();
+                Instruction::IteratorClose close;
+                close.done = iteratorDone.stackSlot();
+                bytecodeGenerator->addInstruction(close);
+            }
+        };
+        ControlFlowLoop flow(this, &end, &in, cleanup);
+        bytecodeGenerator->addLoopStart(in);
+        in.link();
+        iterator.loadInAccumulator();
+        Instruction::IteratorNext next;
+        next.value = lhsValue.stackSlot();
+        next.done = iteratorDone.stackSlot();
+        bytecodeGenerator->addInstruction(next);
+        bytecodeGenerator->addTracingJumpInstruction(Instruction::JumpTrue()).link(end);
+
+        // each iteration gets it's own context, as per spec
+        {
+            RegisterScope innerScope(this);
+            ControlFlowBlock controlFlow(this, ast);
+
+            if (ExpressionNode *e = ast->lhs->expressionCast()) {
+                if (AST::Pattern *p = e->patternCast()) {
+                    RegisterScope scope(this);
+                    destructurePattern(p, lhsValue);
+                } else {
+                    Reference lhs = expression(e);
+                    if (hasError)
+                        goto error;
+                    if (!lhs.isLValue()) {
+                        throwReferenceError(e->firstSourceLocation(), QStringLiteral("Invalid left-hand side expression for 'in' expression"));
+                        goto error;
+                    }
+                    lhs = lhs.asLValue();
+                    lhsValue.loadInAccumulator();
+                    lhs.storeConsumeAccumulator();
+                }
+            } else if (PatternElement *p = AST::cast<PatternElement *>(ast->lhs)) {
+                initializeAndDestructureBindingElement(p, lhsValue, /*isDefinition =*/ true);
+                if (hasError)
+                    goto error;
+            } else {
+                Q_UNREACHABLE();
+            }
+
+            blockTailCalls.unblock();
+            statement(ast->statement);
+            setJumpOutLocation(bytecodeGenerator, ast->statement, ast->forToken);
+        }
+
+        bytecodeGenerator->jump().link(in);
 
-    _block = foreachin;
+      error:
+        end.link();
 
-    args = _function->New<IR::ExprList>();
-    args->init(_block->TEMP(iterator));
-    move(_block->TEMP(temp), _block->CALL(_block->NAME(IR::Name::builtin_foreach_next_property_name, 0, 0), args));
-    int null = _block->newTemp();
-    move(_block->TEMP(null), _block->CONST(IR::NullType, 0));
-    setLocation(cjump(_block->BINOP(IR::OpStrictNotEqual, _block->TEMP(temp), _block->TEMP(null)), foreachbody, foreachend), ast->forToken);
-    _block = foreachend;
+        // all execution paths need to end up here (normal loop exit, break, and exceptions) in
+        // order to reset the unwind handler, and to close the iterator in calse of an for-of loop.
+    }
 
-    leaveLoop();
     return false;
 }
 
 bool Codegen::visit(ForStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    IR::BasicBlock *forcond = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *forbody = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *forstep = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *forend = _function->newBasicBlock(exceptionHandler());
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
 
-    statement(ast->initialiser);
-    _block->JUMP(forcond);
+    ControlFlowBlock controlFlow(this, ast);
 
-    enterLoop(ast, forend, forstep);
+    if (ast->initialiser)
+        statement(ast->initialiser);
+    else if (ast->declarations)
+        variableDeclarationList(ast->declarations);
 
-    _block = forcond;
-    if (ast->condition)
-        condition(ast->condition, forbody, forend);
-    else
-        _block->JUMP(forbody);
+    BytecodeGenerator::Label cond = bytecodeGenerator->label();
+    BytecodeGenerator::Label body = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label step = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label end = bytecodeGenerator->newLabel();
 
-    _block = forbody;
+    ControlFlowLoop flow(this, &end, &step);
+    bytecodeGenerator->addLoopStart(cond);
+    condition(ast->condition, &body, &end, true);
+
+    body.link();
+    blockTailCalls.unblock();
     statement(ast->statement);
-    setJumpOutLocation(_block->JUMP(forstep), ast->statement, ast->forToken);
+    blockTailCalls.reblock();
+    setJumpOutLocation(bytecodeGenerator, ast->statement, ast->forToken);
 
-    _block = forstep;
+    step.link();
+    if (_context->requiresExecutionContext) {
+        Instruction::CloneBlockContext clone;
+        bytecodeGenerator->addInstruction(clone);
+    }
     statement(ast->expression);
-    _block->JUMP(forcond);
-
-    _block = forend;
+    bytecodeGenerator->jump().link(cond);
 
-    leaveLoop();
+    end.link();
 
     return false;
 }
@@ -2410,38 +3439,46 @@ bool Codegen::visit(ForStatement *ast)
 bool Codegen::visit(IfStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    IR::BasicBlock *iftrue = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *iffalse = ast->ko ? _function->newBasicBlock(exceptionHandler()) : 0;
-    IR::BasicBlock *endif = _function->newBasicBlock(exceptionHandler());
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
 
-    condition(ast->expression, iftrue, ast->ko ? iffalse : endif);
+    BytecodeGenerator::Label trueLabel = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label falseLabel = bytecodeGenerator->newLabel();
+    condition(ast->expression, &trueLabel, &falseLabel, true);
+    blockTailCalls.unblock();
 
-    _block = iftrue;
+    trueLabel.link();
     statement(ast->ok);
-    setJumpOutLocation(_block->JUMP(endif), ast->ok, ast->ifToken);
-
     if (ast->ko) {
-        _block = iffalse;
-        statement(ast->ko);
-        setJumpOutLocation(_block->JUMP(endif), ast->ko, ast->elseToken);
+        if (endsWithReturn(_module, ast)) {
+            falseLabel.link();
+            statement(ast->ko);
+        } else {
+            BytecodeGenerator::Jump jump_endif = bytecodeGenerator->jump();
+            falseLabel.link();
+            statement(ast->ko);
+            jump_endif.link();
+        }
+    } else {
+        falseLabel.link();
     }
 
-    _block = endif;
-
     return false;
 }
 
 bool Codegen::visit(LabelledStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
+
+    RegisterScope scope(this);
 
     // check that no outer loop contains the label
-    Loop *l = _loop;
+    ControlFlow *l = controlFlow;
     while (l) {
-        if (l->labelledStatement && l->labelledStatement->label == ast->label) {
+        if (l->label() == ast->label) {
             QString error = QString(QStringLiteral("Label '%1' has already been declared")).arg(ast->label.toString());
             throwSyntaxError(ast->firstSourceLocation(), error);
             return false;
@@ -2454,364 +3491,205 @@ bool Codegen::visit(LabelledStatement *ast)
             AST::cast<AST::WhileStatement *>(ast->statement) ||
             AST::cast<AST::DoWhileStatement *>(ast->statement) ||
             AST::cast<AST::ForStatement *>(ast->statement) ||
-            AST::cast<AST::ForEachStatement *>(ast->statement) ||
-            AST::cast<AST::LocalForStatement *>(ast->statement) ||
-            AST::cast<AST::LocalForEachStatement *>(ast->statement)) {
+            AST::cast<AST::ForEachStatement *>(ast->statement)) {
         statement(ast->statement); // labelledStatement will be associated with the ast->statement's loop.
     } else {
-        IR::BasicBlock *breakBlock = _function->newBasicBlock(exceptionHandler());
-        enterLoop(ast->statement, breakBlock, /*continueBlock*/ 0);
+        BytecodeGenerator::Label breakLabel = bytecodeGenerator->newLabel();
+        ControlFlowLoop flow(this, &breakLabel);
         statement(ast->statement);
-        _block->JUMP(breakBlock);
-        _block = breakBlock;
-        leaveLoop();
+        breakLabel.link();
     }
 
     return false;
 }
 
-bool Codegen::visit(LocalForEachStatement *ast)
-{
-    if (hasError)
-        return true;
-
-    IR::BasicBlock *foreachin = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *foreachbody = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *foreachend = _function->newBasicBlock(exceptionHandler());
-
-    variableDeclaration(ast->declaration);
-
-    int iterator = _block->newTemp();
-    move(_block->TEMP(iterator), *expression(ast->expression));
-    IR::ExprList *args = _function->New<IR::ExprList>();
-    args->init(_block->TEMP(iterator));
-    move(_block->TEMP(iterator), _block->CALL(_block->NAME(IR::Name::builtin_foreach_iterator_object, 0, 0), args));
-
-    _block->JUMP(foreachin);
-    enterLoop(ast, foreachend, foreachin);
-
-    _block = foreachbody;
-    int temp = _block->newTemp();
-    move(identifier(ast->declaration->name.toString()), _block->TEMP(temp));
-    statement(ast->statement);
-    setJumpOutLocation(_block->JUMP(foreachin), ast->statement, ast->forToken);
-
-    _block = foreachin;
-
-    args = _function->New<IR::ExprList>();
-    args->init(_block->TEMP(iterator));
-    move(_block->TEMP(temp), _block->CALL(_block->NAME(IR::Name::builtin_foreach_next_property_name, 0, 0), args));
-    int null = _block->newTemp();
-    move(_block->TEMP(null), _block->CONST(IR::NullType, 0));
-    setLocation(cjump(_block->BINOP(IR::OpStrictNotEqual, _block->TEMP(temp), _block->TEMP(null)), foreachbody, foreachend), ast->forToken);
-    _block = foreachend;
-
-    leaveLoop();
-    return false;
-}
-
-bool Codegen::visit(LocalForStatement *ast)
+void Codegen::emitReturn(const Reference &expr)
 {
-    if (hasError)
-        return true;
-
-    IR::BasicBlock *forcond = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *forbody = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *forstep = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *forend = _function->newBasicBlock(exceptionHandler());
-
-    variableDeclarationList(ast->declarations);
-    _block->JUMP(forcond);
-
-    enterLoop(ast, forend, forstep);
-
-    _block = forcond;
-    if (ast->condition)
-        condition(ast->condition, forbody, forend);
-    else
-        _block->JUMP(forbody);
-
-    _block = forbody;
-    statement(ast->statement);
-    setJumpOutLocation(_block->JUMP(forstep), ast->statement, ast->forToken);
-
-    _block = forstep;
-    statement(ast->expression);
-    _block->JUMP(forcond);
-
-    _block = forend;
-
-    leaveLoop();
-
-    return false;
+    ControlFlow::UnwindTarget target = controlFlow ? controlFlow->unwindTarget(ControlFlow::Return) : ControlFlow::UnwindTarget();
+    if (target.linkLabel.isValid() && target.unwindLevel) {
+        Q_ASSERT(_returnAddress >= 0);
+        (void) expr.storeOnStack(_returnAddress);
+        bytecodeGenerator->unwindToLabel(target.unwindLevel, target.linkLabel);
+    } else {
+        expr.loadInAccumulator();
+        bytecodeGenerator->addInstruction(Instruction::Ret());
+    }
 }
 
 bool Codegen::visit(ReturnStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    if (_variableEnvironment->compilationMode != FunctionCode && _variableEnvironment->compilationMode != QmlBinding) {
+    if (_functionContext->contextType != ContextType::Function && _functionContext->contextType != ContextType::Binding) {
         throwSyntaxError(ast->returnToken, QStringLiteral("Return statement outside of function"));
         return false;
     }
+    Reference expr;
     if (ast->expression) {
-        Result expr = expression(ast->expression);
-        move(_block->TEMP(_returnAddress), *expr);
+         expr = expression(ast->expression);
+        if (hasError)
+            return false;
+    } else {
+        expr = Reference::fromConst(this, Encode::undefined());
     }
 
-    // Since we're leaving, don't let any finally statements we emit as part of the unwinding
-    // jump to exception handlers at run-time if they throw.
-    IR::BasicBlock *unwindBlock = _function->newBasicBlock(/*no exception handler*/Q_NULLPTR);
-    _block->JUMP(unwindBlock);
-    _block = unwindBlock;
+    emitReturn(expr);
 
-    unwindException(0);
-
-    _block->JUMP(_exitBlock);
     return false;
 }
 
 bool Codegen::visit(SwitchStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    IR::BasicBlock *switchend = _function->newBasicBlock(exceptionHandler());
+    if (requiresReturnValue)
+        Reference::fromConst(this, Encode::undefined()).storeOnStack(_returnAddress);
+
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
 
     if (ast->block) {
-        int lhs = _block->newTemp();
-        move(_block->TEMP(lhs), *expression(ast->expression));
-        IR::BasicBlock *switchcond = _function->newBasicBlock(exceptionHandler());
-        _block->JUMP(switchcond);
-        IR::BasicBlock *previousBlock = 0;
+        BytecodeGenerator::Label switchEnd = bytecodeGenerator->newLabel();
 
-        QHash<Node *, IR::BasicBlock *> blockMap;
+        Reference lhs = expression(ast->expression);
+        if (hasError)
+            return false;
+        lhs = lhs.storeOnStack();
 
-        enterLoop(ast, switchend, 0);
+        ControlFlowBlock controlFlow(this, ast->block);
 
+        // set up labels for all clauses
+        QHash<Node *, BytecodeGenerator::Label> blockMap;
+        for (CaseClauses *it = ast->block->clauses; it; it = it->next)
+            blockMap[it->clause] = bytecodeGenerator->newLabel();
+        if (ast->block->defaultClause)
+            blockMap[ast->block->defaultClause] = bytecodeGenerator->newLabel();
+        for (CaseClauses *it = ast->block->moreClauses; it; it = it->next)
+            blockMap[it->clause] = bytecodeGenerator->newLabel();
+
+        // do the switch conditions
         for (CaseClauses *it = ast->block->clauses; it; it = it->next) {
             CaseClause *clause = it->clause;
-
-            _block = _function->newBasicBlock(exceptionHandler());
-            blockMap[clause] = _block;
-
-            if (previousBlock && !previousBlock->isTerminated())
-                previousBlock->JUMP(_block);
-
-            for (StatementList *it2 = clause->statements; it2; it2 = it2->next)
-                statement(it2->statement);
-
-            previousBlock = _block;
-        }
-
-        if (ast->block->defaultClause) {
-            _block = _function->newBasicBlock(exceptionHandler());
-            blockMap[ast->block->defaultClause] = _block;
-
-            if (previousBlock && !previousBlock->isTerminated())
-                previousBlock->JUMP(_block);
-
-            for (StatementList *it2 = ast->block->defaultClause->statements; it2; it2 = it2->next)
-                statement(it2->statement);
-
-            previousBlock = _block;
+            Reference rhs = expression(clause->expression);
+            if (hasError)
+                return false;
+            rhs.loadInAccumulator();
+            bytecodeGenerator->jumpStrictEqual(lhs.stackSlot(), blockMap.value(clause));
         }
 
         for (CaseClauses *it = ast->block->moreClauses; it; it = it->next) {
             CaseClause *clause = it->clause;
+            Reference rhs = expression(clause->expression);
+            if (hasError)
+                return false;
+            rhs.loadInAccumulator();
+            bytecodeGenerator->jumpStrictEqual(lhs.stackSlot(), blockMap.value(clause));
+        }
 
-            _block = _function->newBasicBlock(exceptionHandler());
-            blockMap[clause] = _block;
+        if (DefaultClause *defaultClause = ast->block->defaultClause)
+            bytecodeGenerator->jump().link(blockMap.value(defaultClause));
+        else
+            bytecodeGenerator->jump().link(switchEnd);
 
-            if (previousBlock && !previousBlock->isTerminated())
-                previousBlock->JUMP(_block);
+        ControlFlowLoop flow(this, &switchEnd);
 
-            for (StatementList *it2 = clause->statements; it2; it2 = it2->next)
-                statement(it2->statement);
+        insideSwitch = true;
+        blockTailCalls.unblock();
+        for (CaseClauses *it = ast->block->clauses; it; it = it->next) {
+            CaseClause *clause = it->clause;
+            blockMap[clause].link();
 
-            previousBlock = _block;
+            statementList(clause->statements);
         }
 
-        leaveLoop();
-
-        _block->JUMP(switchend);
+        if (ast->block->defaultClause) {
+            DefaultClause *clause = ast->block->defaultClause;
+            blockMap[clause].link();
 
-        _block = switchcond;
-        for (CaseClauses *it = ast->block->clauses; it; it = it->next) {
-            CaseClause *clause = it->clause;
-            Result rhs = expression(clause->expression);
-            IR::BasicBlock *iftrue = blockMap[clause];
-            IR::BasicBlock *iffalse = _function->newBasicBlock(exceptionHandler());
-            setLocation(cjump(binop(IR::OpStrictEqual, _block->TEMP(lhs), *rhs), iftrue, iffalse), clause->caseToken);
-            _block = iffalse;
+            statementList(clause->statements);
         }
 
         for (CaseClauses *it = ast->block->moreClauses; it; it = it->next) {
             CaseClause *clause = it->clause;
-            Result rhs = expression(clause->expression);
-            IR::BasicBlock *iftrue = blockMap[clause];
-            IR::BasicBlock *iffalse = _function->newBasicBlock(exceptionHandler());
-            setLocation(cjump(binop(IR::OpStrictEqual, _block->TEMP(lhs), *rhs), iftrue, iffalse), clause->caseToken);
-            _block = iffalse;
-        }
+            blockMap[clause].link();
 
-        if (DefaultClause *defaultClause = ast->block->defaultClause) {
-            setLocation(_block->JUMP(blockMap[ast->block->defaultClause]), defaultClause->defaultToken);
+            statementList(clause->statements);
         }
-    }
+        insideSwitch = false;
+
+        switchEnd.link();
 
-    _block->JUMP(switchend);
+    }
 
-    _block = switchend;
     return false;
 }
 
 bool Codegen::visit(ThrowStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    Result expr = expression(ast->expression);
-    move(_block->TEMP(_returnAddress), *expr);
-    IR::ExprList *throwArgs = _function->New<IR::ExprList>();
-    throwArgs->expr = _block->TEMP(_returnAddress);
-    _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_throw, /*line*/0, /*column*/0), throwArgs));
-    return false;
-}
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
 
-bool Codegen::visit(TryStatement *ast)
-{
+    Reference expr = expression(ast->expression);
     if (hasError)
-        return true;
-
-    _function->hasTry = true;
-
-    if (_function->isStrict && ast->catchExpression &&
-            (ast->catchExpression->name == QLatin1String("eval") || ast->catchExpression->name == QLatin1String("arguments"))) {
-        throwSyntaxError(ast->catchExpression->identifierToken, QStringLiteral("Catch variable name may not be eval or arguments in strict mode"));
         return false;
-    }
 
-    IR::BasicBlock *surroundingExceptionHandler = exceptionHandler();
-
-    // We always need a finally body to clean up the exception handler
-    // exceptions thrown in finally get caught by the surrounding catch block
-    IR::BasicBlock *finallyBody = 0;
-    IR::BasicBlock *catchBody = 0;
-    IR::BasicBlock *catchExceptionHandler = 0;
-    IR::BasicBlock *end = _function->newBasicBlock(surroundingExceptionHandler, IR::Function::DontInsertBlock);
-
-    if (ast->finallyExpression)
-        finallyBody = _function->newBasicBlock(surroundingExceptionHandler, IR::Function::DontInsertBlock);
+    expr.loadInAccumulator();
+    Instruction::ThrowException instr;
+    bytecodeGenerator->addInstruction(instr);
+    return false;
+}
 
-    if (ast->catchExpression) {
-        // exception handler for the catch body
-        catchExceptionHandler = _function->newBasicBlock(0, IR::Function::DontInsertBlock);
-        pushExceptionHandler(catchExceptionHandler);
-        catchBody =  _function->newBasicBlock(catchExceptionHandler, IR::Function::DontInsertBlock);
-        popExceptionHandler();
-        pushExceptionHandler(catchBody);
-    } else {
-        Q_ASSERT(finallyBody);
-        pushExceptionHandler(finallyBody);
+void Codegen::handleTryCatch(TryStatement *ast)
+{
+    Q_ASSERT(ast);
+    RegisterScope scope(this);
+    {
+        ControlFlowCatch catchFlow(this, ast->catchExpression);
+        RegisterScope scope(this);
+        TailCallBlocker blockTailCalls(this); // IMPORTANT: destruction will unblock tail calls before catch is generated
+        statement(ast->statement);
     }
+}
 
-    IR::BasicBlock *tryBody = _function->newBasicBlock(exceptionHandler());
-    _block->JUMP(tryBody);
-
-    ScopeAndFinally tcf(_scopeAndFinally, ast->finallyExpression);
-    _scopeAndFinally = &tcf;
-
-    _block = tryBody;
-    statement(ast->statement);
-    _block->JUMP(finallyBody ? finallyBody : end);
-
-    popExceptionHandler();
+void Codegen::handleTryFinally(TryStatement *ast)
+{
+    RegisterScope scope(this);
+    ControlFlowFinally finally(this, ast->finallyExpression);
+    TailCallBlocker blockTailCalls(this); // IMPORTANT: destruction will unblock tail calls before finally is generated
 
     if (ast->catchExpression) {
-        pushExceptionHandler(catchExceptionHandler);
-        _function->addBasicBlock(catchBody);
-        _block = catchBody;
-
-        ++_function->insideWithOrCatch;
-        IR::ExprList *catchArgs = _function->New<IR::ExprList>();
-        catchArgs->init(_block->STRING(_function->newString(ast->catchExpression->name.toString())));
-        _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_push_catch_scope, 0, 0), catchArgs));
-        {
-            ScopeAndFinally scope(_scopeAndFinally, ScopeAndFinally::CatchScope);
-            _scopeAndFinally = &scope;
-            statement(ast->catchExpression->statement);
-            _scopeAndFinally = scope.parent;
-        }
-        _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_pop_scope, 0, 0), 0));
-        --_function->insideWithOrCatch;
-        _block->JUMP(finallyBody ? finallyBody : end);
-        popExceptionHandler();
-
-        _function->addBasicBlock(catchExceptionHandler);
-        catchExceptionHandler->EXP(catchExceptionHandler->CALL(catchExceptionHandler->NAME(IR::Name::builtin_pop_scope, 0, 0), 0));
-        if (finallyBody || surroundingExceptionHandler)
-            catchExceptionHandler->JUMP(finallyBody ? finallyBody : surroundingExceptionHandler);
-        else
-            catchExceptionHandler->EXP(catchExceptionHandler->CALL(catchExceptionHandler->NAME(IR::Name::builtin_rethrow, 0, 0), 0));
+        handleTryCatch(ast);
+    } else {
+        RegisterScope scope(this);
+        statement(ast->statement);
     }
+}
 
-    _scopeAndFinally = tcf.parent;
-
-    if (finallyBody) {
-        _function->addBasicBlock(finallyBody);
-        _block = finallyBody;
-
-        int hasException = _block->newTemp();
-        move(_block->TEMP(hasException), _block->CALL(_block->NAME(IR::Name::builtin_unwind_exception, /*line*/0, /*column*/0), 0));
+bool Codegen::visit(TryStatement *ast)
+{
+    if (hasError)
+        return false;
 
-        if (ast->finallyExpression && ast->finallyExpression->statement)
-            statement(ast->finallyExpression->statement);
+    RegisterScope scope(this);
 
-        IR::ExprList *arg = _function->New<IR::ExprList>();
-        arg->expr = _block->TEMP(hasException);
-        _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_throw, /*line*/0, /*column*/0), arg));
-        _block->JUMP(end);
+    if (ast->finallyExpression && ast->finallyExpression->statement) {
+        handleTryFinally(ast);
+    } else {
+        handleTryCatch(ast);
     }
 
-    _function->addBasicBlock(end);
-    _block = end;
-
     return false;
 }
 
-void Codegen::unwindException(Codegen::ScopeAndFinally *outest)
-{
-    int savedDepthForWidthOrCatch = _function->insideWithOrCatch;
-    ScopeAndFinally *scopeAndFinally = _scopeAndFinally;
-    qSwap(_scopeAndFinally, scopeAndFinally);
-    while (_scopeAndFinally != outest) {
-        switch (_scopeAndFinally->type) {
-        case ScopeAndFinally::WithScope:
-            // fall through
-        case ScopeAndFinally::CatchScope:
-            _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_pop_scope, 0, 0)));
-            _scopeAndFinally = _scopeAndFinally->parent;
-            --_function->insideWithOrCatch;
-            break;
-        case ScopeAndFinally::TryScope: {
-            ScopeAndFinally *tc = _scopeAndFinally;
-            _scopeAndFinally = tc->parent;
-            if (tc->finally && tc->finally->statement)
-                statement(tc->finally->statement);
-            break;
-        }
-        }
-    }
-    qSwap(_scopeAndFinally, scopeAndFinally);
-    _function->insideWithOrCatch = savedDepthForWidthOrCatch;
-}
-
 bool Codegen::visit(VariableStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
     variableDeclarationList(ast->declarations);
     return false;
@@ -2820,128 +3698,110 @@ bool Codegen::visit(VariableStatement *ast)
 bool Codegen::visit(WhileStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    IR::BasicBlock *whilecond = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *whilebody = _function->newBasicBlock(exceptionHandler());
-    IR::BasicBlock *whileend = _function->newBasicBlock(exceptionHandler());
+    if (AST::cast<FalseLiteral *>(ast->expression))
+        return false;
 
-    enterLoop(ast, whileend, whilecond);
+    RegisterScope scope(this);
 
-    _block->JUMP(whilecond);
-    _block = whilecond;
-    condition(ast->expression, whilebody, whileend);
+    BytecodeGenerator::Label start = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label end = bytecodeGenerator->newLabel();
+    BytecodeGenerator::Label cond = bytecodeGenerator->label();
+    ControlFlowLoop flow(this, &end, &cond);
+    bytecodeGenerator->addLoopStart(cond);
 
-    _block = whilebody;
-    statement(ast->statement);
-    setJumpOutLocation(_block->JUMP(whilecond), ast->statement, ast->whileToken);
+    if (!AST::cast<TrueLiteral *>(ast->expression)) {
+        TailCallBlocker blockTailCalls(this);
+        condition(ast->expression, &start, &end, true);
+    }
 
-    _block = whileend;
-    leaveLoop();
+    start.link();
+    statement(ast->statement);
+    setJumpOutLocation(bytecodeGenerator, ast->statement, ast->whileToken);
+    bytecodeGenerator->jump().link(cond);
 
+    end.link();
     return false;
 }
 
 bool Codegen::visit(WithStatement *ast)
 {
     if (hasError)
-        return true;
+        return false;
 
-    _function->hasWith = true;
+    RegisterScope scope(this);
+    TailCallBlocker blockTailCalls(this);
 
-    const int withObject = _block->newTemp();
-    Result src = expression(ast->expression);
+    Reference src = expression(ast->expression);
     if (hasError)
         return false;
-    _block->MOVE(_block->TEMP(withObject), *src);
-
-    // need an exception handler for with to cleanup the with scope
-    IR::BasicBlock *withExceptionHandler = _function->newBasicBlock(exceptionHandler());
-    withExceptionHandler->EXP(withExceptionHandler->CALL(withExceptionHandler->NAME(IR::Name::builtin_pop_scope, 0, 0), 0));
-    if (!exceptionHandler())
-        withExceptionHandler->EXP(withExceptionHandler->CALL(withExceptionHandler->NAME(IR::Name::builtin_rethrow, 0, 0), 0));
-    else
-        withExceptionHandler->JUMP(exceptionHandler());
-
-    pushExceptionHandler(withExceptionHandler);
-
-    IR::BasicBlock *withBlock = _function->newBasicBlock(exceptionHandler());
-
-    _block->JUMP(withBlock);
-    _block = withBlock;
-    IR::ExprList *args = _function->New<IR::ExprList>();
-    args->init(_block->TEMP(withObject));
-    _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_push_with_scope, 0, 0), args));
+    src = src.storeOnStack(); // trigger load before we setup the exception handler, so exceptions here go to the right place
+    src.loadInAccumulator();
 
-    ++_function->insideWithOrCatch;
+    enterContext(ast);
     {
-        ScopeAndFinally scope(_scopeAndFinally);
-        _scopeAndFinally = &scope;
+        blockTailCalls.unblock();
+        ControlFlowWith flow(this);
         statement(ast->statement);
-        _scopeAndFinally = scope.parent;
     }
-    --_function->insideWithOrCatch;
-    _block->EXP(_block->CALL(_block->NAME(IR::Name::builtin_pop_scope, 0, 0), 0));
-    popExceptionHandler();
-
-    IR::BasicBlock *next = _function->newBasicBlock(exceptionHandler());
-    _block->JUMP(next);
-    _block = next;
+    leaveContext();
 
     return false;
 }
 
 bool Codegen::visit(UiArrayBinding *)
 {
-    Q_ASSERT(!"not implemented");
+    Q_UNIMPLEMENTED();
     return false;
 }
 
 bool Codegen::visit(UiObjectBinding *)
 {
-    Q_ASSERT(!"not implemented");
+    Q_UNIMPLEMENTED();
     return false;
 }
 
 bool Codegen::visit(UiObjectDefinition *)
 {
-    Q_ASSERT(!"not implemented");
+    Q_UNIMPLEMENTED();
     return false;
 }
 
 bool Codegen::visit(UiPublicMember *)
 {
-    Q_ASSERT(!"not implemented");
+    Q_UNIMPLEMENTED();
     return false;
 }
 
 bool Codegen::visit(UiScriptBinding *)
 {
-    Q_ASSERT(!"not implemented");
+    Q_UNIMPLEMENTED();
     return false;
 }
 
 bool Codegen::visit(UiSourceElement *)
 {
-    Q_ASSERT(!"not implemented");
+    Q_UNIMPLEMENTED();
     return false;
 }
 
-bool Codegen::throwSyntaxErrorOnEvalOrArgumentsInStrictMode(IR::Expr *expr, const SourceLocation& loc)
+bool Codegen::throwSyntaxErrorOnEvalOrArgumentsInStrictMode(const Reference &r, const SourceLocation& loc)
 {
-    if (!_variableEnvironment->isStrict)
-        return false;
-    if (IR::Name *n = expr->asName()) {
-        if (*n->id != QLatin1String("eval") && *n->id != QLatin1String("arguments"))
-            return false;
-    } else if (IR::ArgLocal *al = expr->asArgLocal()) {
-        if (!al->isArgumentsOrEval)
-            return false;
-    } else {
+    if (!_context->isStrict)
         return false;
+    bool isArgOrEval = false;
+    if (r.type == Reference::Name) {
+        QString str = jsUnitGenerator->stringForIndex(r.nameAsIndex());
+        if (str == QLatin1String("eval") || str == QLatin1String("arguments")) {
+            isArgOrEval = true;
+        }
+    } else if (r.type == Reference::ScopedLocal || r.isRegister()) {
+        isArgOrEval = r.isArgOrEval;
     }
-    throwSyntaxError(loc, QStringLiteral("Variable name may not be eval or arguments in strict mode"));
-    return true;
+    if (isArgOrEval)
+        throwSyntaxError(loc, QStringLiteral("Variable name may not be eval or arguments in strict mode"));
+    return isArgOrEval;
 }
 
 void Codegen::throwSyntaxError(const SourceLocation &loc, const QString &detail)
@@ -2973,6 +3833,117 @@ QList<QQmlJS::DiagnosticMessage> Codegen::errors() const
     return _errors;
 }
 
+QQmlRefPointer<CompiledData::CompilationUnit> Codegen::generateCompilationUnit(bool generateUnitData)
+{
+    CompiledData::Unit *unitData = nullptr;
+    if (generateUnitData)
+        unitData = jsUnitGenerator->generateUnit();
+    CompiledData::CompilationUnit *compilationUnit = new CompiledData::CompilationUnit(unitData);
+
+    QQmlRefPointer<CompiledData::CompilationUnit> unit;
+    unit.adopt(compilationUnit);
+    return unit;
+}
+
+QQmlRefPointer<CompiledData::CompilationUnit> Codegen::createUnitForLoading()
+{
+    QQmlRefPointer<CompiledData::CompilationUnit> result;
+    result.adopt(new CompiledData::CompilationUnit);
+    return result;
+}
+
+class Codegen::VolatileMemoryLocationScanner: protected QQmlJS::AST::Visitor
+{
+    VolatileMemoryLocations locs;
+
+public:
+    Codegen::VolatileMemoryLocations scan(AST::Node *s)
+    {
+        s->accept(this);
+        return locs;
+    }
+
+    bool visit(ArrayMemberExpression *) override
+    {
+        locs.setAllVolatile();
+        return false;
+    }
+
+    bool visit(FieldMemberExpression *) override
+    {
+        locs.setAllVolatile();
+        return false;
+    }
+
+    bool visit(PostIncrementExpression *e) override
+    {
+        collectIdentifiers(locs.specificLocations, e->base);
+        return false;
+    }
+
+    bool visit(PostDecrementExpression *e) override
+    {
+        collectIdentifiers(locs.specificLocations, e->base);
+        return false;
+    }
+
+    bool visit(PreIncrementExpression *e) override
+    {
+        collectIdentifiers(locs.specificLocations, e->expression);
+        return false;
+    }
+
+    bool visit(PreDecrementExpression *e) override
+    {
+        collectIdentifiers(locs.specificLocations, e->expression);
+        return false;
+    }
+
+    bool visit(BinaryExpression *e) override
+    {
+        switch (e->op) {
+        case QSOperator::InplaceAnd:
+        case QSOperator::InplaceSub:
+        case QSOperator::InplaceDiv:
+        case QSOperator::InplaceAdd:
+        case QSOperator::InplaceLeftShift:
+        case QSOperator::InplaceMod:
+        case QSOperator::InplaceMul:
+        case QSOperator::InplaceOr:
+        case QSOperator::InplaceRightShift:
+        case QSOperator::InplaceURightShift:
+        case QSOperator::InplaceXor:
+            collectIdentifiers(locs.specificLocations, e);
+            return false;
+
+        default:
+            return true;
+        }
+    }
+
+private:
+    void collectIdentifiers(QVector<QStringView> &ids, AST::Node *node) const {
+        class Collector: public QQmlJS::AST::Visitor {
+            QVector<QStringView> &ids;
+        public:
+            Collector(QVector<QStringView> &ids): ids(ids) {}
+            virtual bool visit(IdentifierExpression *ie) {
+                ids.append(ie->name);
+                return false;
+            }
+        };
+        Collector collector(ids);
+        node->accept(&collector);
+    }
+};
+
+Codegen::VolatileMemoryLocations Codegen::scanVolatileMemoryLocations(AST::Node *ast) const
+{
+    VolatileMemoryLocationScanner scanner;
+    return scanner.scan(ast);
+}
+
+
 #ifndef V4_BOOTSTRAP
 
 QList<QQmlError> Codegen::qmlErrors() const
@@ -2998,20 +3969,489 @@ QList<QQmlError> Codegen::qmlErrors() const
     return qmlErrors;
 }
 
-void RuntimeCodegen::throwSyntaxError(const AST::SourceLocation &loc, const QString &detail)
+#endif // V4_BOOTSTRAP
+
+bool Codegen::RValue::operator==(const RValue &other) const
 {
-    if (hasError)
+    switch (type) {
+    case Accumulator:
+        return other.isAccumulator();
+    case StackSlot:
+        return other.isStackSlot() && theStackSlot == other.theStackSlot;
+    case Const:
+        return other.isConst() && constant == other.constant;
+    default:
+        return false;
+    }
+}
+
+Codegen::RValue Codegen::RValue::storeOnStack() const
+{
+    switch (type) {
+    case Accumulator:
+        return RValue::fromStackSlot(codegen, Reference::fromAccumulator(codegen).storeOnStack().stackSlot());
+    case StackSlot:
+        return *this;
+    case Const:
+        return RValue::fromStackSlot(codegen, Reference::storeConstOnStack(codegen, constant).stackSlot());
+    default:
+        Q_UNREACHABLE();
+    }
+}
+
+void Codegen::RValue::loadInAccumulator() const
+{
+    switch (type) {
+    case Accumulator:
+        // nothing to do
         return;
-    hasError = true;
-    engine->throwSyntaxError(detail, _module->fileName, loc.startLine, loc.startColumn);
+    case StackSlot:
+        return Reference::fromStackSlot(codegen, theStackSlot).loadInAccumulator();
+    case Const:
+        return Reference::fromConst(codegen, constant).loadInAccumulator();
+    default:
+        Q_UNREACHABLE();
+    }
+
 }
 
-void RuntimeCodegen::throwReferenceError(const AST::SourceLocation &loc, const QString &detail)
+bool Codegen::Reference::operator==(const Codegen::Reference &other) const
 {
-    if (hasError)
+    if (type != other.type)
+        return false;
+    switch (type) {
+    case Invalid:
+    case Accumulator:
+        break;
+    case Super:
+        return true;
+    case SuperProperty:
+        return property == other.property;
+    case StackSlot:
+        return theStackSlot == other.theStackSlot;
+    case ScopedLocal:
+        return index == other.index && scope == other.scope;
+    case Name:
+        return nameAsIndex() == other.nameAsIndex();
+    case Member:
+        return propertyBase == other.propertyBase && propertyNameIndex == other.propertyNameIndex;
+    case Subscript:
+        return elementBase == other.elementBase && elementSubscript == other.elementSubscript;
+    case Import:
+        return index == other.index;
+    case Const:
+        return constant == other.constant;
+    case QmlScopeObject:
+    case QmlContextObject:
+        return qmlCoreIndex == other.qmlCoreIndex && qmlNotifyIndex == other.qmlNotifyIndex
+                && capturePolicy == other.capturePolicy;
+    }
+    return true;
+}
+
+Codegen::RValue Codegen::Reference::asRValue() const
+{
+    switch (type) {
+    case Invalid:
+        Q_UNREACHABLE();
+    case Accumulator:
+        return RValue::fromAccumulator(codegen);
+    case StackSlot:
+        return RValue::fromStackSlot(codegen, stackSlot());
+    case Const:
+        return RValue::fromConst(codegen, constant);
+    default:
+        loadInAccumulator();
+        return RValue::fromAccumulator(codegen);
+    }
+}
+
+Codegen::Reference Codegen::Reference::asLValue() const
+{
+    switch (type) {
+    case Invalid:
+    case Accumulator:
+        Q_UNREACHABLE();
+    case Super:
+        codegen->throwSyntaxError(AST::SourceLocation(), QStringLiteral("Super lvalues not implemented."));
+        return *this;
+    case Member:
+        if (!propertyBase.isStackSlot()) {
+            Reference r = *this;
+            r.propertyBase = propertyBase.storeOnStack();
+            return r;
+        }
+        return *this;
+    case Subscript:
+        if (!elementSubscript.isStackSlot()) {
+            Reference r = *this;
+            r.elementSubscript = elementSubscript.storeOnStack();
+            return r;
+        }
+        return *this;
+    default:
+        return *this;
+    }
+}
+
+Codegen::Reference Codegen::Reference::storeConsumeAccumulator() const
+{
+    storeAccumulator(); // it doesn't matter what happens here, just do it.
+    return Reference();
+}
+
+Codegen::Reference Codegen::Reference::baseObject() const
+{
+    if (type == Reference::QmlScopeObject || type == Reference::QmlContextObject) {
+        return Reference::fromStackSlot(codegen, qmlBase.stackSlot());
+    } else if (type == Reference::Member) {
+        RValue rval = propertyBase;
+        if (!rval.isValid())
+            return Reference::fromConst(codegen, Encode::undefined());
+        if (rval.isAccumulator())
+            return Reference::fromAccumulator(codegen);
+        if (rval.isStackSlot())
+            return Reference::fromStackSlot(codegen, rval.stackSlot());
+        if (rval.isConst())
+            return Reference::fromConst(codegen, rval.constantValue());
+        Q_UNREACHABLE();
+    } else if (type == Reference::Subscript) {
+        return Reference::fromStackSlot(codegen, elementBase.stackSlot());
+    } else if (type == Reference::SuperProperty) {
+        return Reference::fromStackSlot(codegen, CallData::This);
+    } else {
+        return Reference::fromConst(codegen, Encode::undefined());
+    }
+}
+
+Codegen::Reference Codegen::Reference::storeOnStack() const
+{ return doStoreOnStack(-1); }
+
+void Codegen::Reference::storeOnStack(int slotIndex) const
+{ doStoreOnStack(slotIndex); }
+
+Codegen::Reference Codegen::Reference::doStoreOnStack(int slotIndex) const
+{
+    Q_ASSERT(isValid());
+
+    if (isStackSlot() && slotIndex == -1 && !(stackSlotIsLocalOrArgument && isVolatile) && !requiresTDZCheck)
+        return *this;
+
+    if (isStackSlot() && !requiresTDZCheck) { // temp-to-temp move
+        Reference dest = Reference::fromStackSlot(codegen, slotIndex);
+        Instruction::MoveReg move;
+        move.srcReg = stackSlot();
+        move.destReg = dest.stackSlot();
+        codegen->bytecodeGenerator->addInstruction(move);
+        return dest;
+    }
+
+    Reference slot = Reference::fromStackSlot(codegen, slotIndex);
+    if (isConstant()) {
+        Instruction::MoveConst move;
+        move.constIndex = codegen->registerConstant(constant);
+        move.destTemp = slot.stackSlot();
+        codegen->bytecodeGenerator->addInstruction(move);
+    } else {
+        loadInAccumulator();
+        slot.storeConsumeAccumulator();
+    }
+    return slot;
+}
+
+Codegen::Reference Codegen::Reference::storeRetainAccumulator() const
+{
+    if (storeWipesAccumulator()) {
+        // a store will
+        auto tmp = Reference::fromStackSlot(codegen);
+        tmp.storeAccumulator(); // this is safe, and won't destory the accumulator
+        storeAccumulator();
+        return tmp;
+    } else {
+        // ok, this is safe, just do the store.
+        storeAccumulator();
+        return *this;
+    }
+}
+
+bool Codegen::Reference::storeWipesAccumulator() const
+{
+    switch (type) {
+    default:
+    case Invalid:
+    case Const:
+    case Accumulator:
+        Q_UNREACHABLE();
+        return false;
+    case StackSlot:
+    case ScopedLocal:
+        return false;
+    case Name:
+    case Member:
+    case Subscript:
+    case QmlScopeObject:
+    case QmlContextObject:
+        return true;
+    }
+}
+
+void Codegen::Reference::storeAccumulator() const
+{
+    if (isReferenceToConst) {
+        // throw a type error
+        RegisterScope scope(codegen);
+        Reference r = codegen->referenceForName(QStringLiteral("TypeError"), false);
+        r = r.storeOnStack();
+        Instruction::Construct construct;
+        construct.func = r.stackSlot();
+        construct.argc = 0;
+        construct.argv = 0;
+        codegen->bytecodeGenerator->addInstruction(construct);
+        Instruction::ThrowException throwException;
+        codegen->bytecodeGenerator->addInstruction(throwException);
         return;
-    hasError = true;
-    engine->throwReferenceError(detail, _module->fileName, loc.startLine, loc.startColumn);
+    }
+    switch (type) {
+    case Super:
+        Q_UNREACHABLE();
+        return;
+    case SuperProperty:
+        Instruction::StoreSuperProperty store;
+        store.property = property.stackSlot();
+        codegen->bytecodeGenerator->addInstruction(store);
+        return;
+    case StackSlot: {
+        Instruction::StoreReg store;
+        store.reg = theStackSlot;
+        codegen->bytecodeGenerator->addInstruction(store);
+        return;
+    }
+    case ScopedLocal: {
+        if (scope == 0) {
+            Instruction::StoreLocal store;
+            store.index = index;
+            codegen->bytecodeGenerator->addInstruction(store);
+        } else {
+            Instruction::StoreScopedLocal store;
+            store.index = index;
+            store.scope = scope;
+            codegen->bytecodeGenerator->addInstruction(store);
+        }
+        return;
+    }
+    case Name: {
+        Context *c = codegen->currentContext();
+        if (c->isStrict) {
+            Instruction::StoreNameStrict store;
+            store.name = nameAsIndex();
+            codegen->bytecodeGenerator->addInstruction(store);
+        } else {
+            Instruction::StoreNameSloppy store;
+            store.name = nameAsIndex();
+            codegen->bytecodeGenerator->addInstruction(store);
+        }
+    } return;
+    case Member:
+        if (!disable_lookups && codegen->useFastLookups) {
+            Instruction::SetLookup store;
+            store.base = propertyBase.stackSlot();
+            store.index = codegen->registerSetterLookup(propertyNameIndex);
+            codegen->bytecodeGenerator->addInstruction(store);
+        } else {
+            Instruction::StoreProperty store;
+            store.base = propertyBase.stackSlot();
+            store.name = propertyNameIndex;
+            codegen->bytecodeGenerator->addInstruction(store);
+        }
+        return;
+    case Subscript: {
+        Instruction::StoreElement store;
+        store.base = elementBase;
+        store.index = elementSubscript.stackSlot();
+        codegen->bytecodeGenerator->addTracingInstruction(store);
+    } return;
+    case QmlScopeObject: {
+        Instruction::StoreScopeObjectProperty store;
+        store.base = qmlBase;
+        store.propertyIndex = qmlCoreIndex;
+        codegen->bytecodeGenerator->addInstruction(store);
+    } return;
+    case QmlContextObject: {
+        Instruction::StoreContextObjectProperty store;
+        store.base = qmlBase;
+        store.propertyIndex = qmlCoreIndex;
+        codegen->bytecodeGenerator->addInstruction(store);
+    } return;
+    case Invalid:
+    case Accumulator:
+    case Const:
+    case Import:
+        break;
+    }
+
+    Q_UNREACHABLE();
 }
 
-#endif // V4_BOOTSTRAP
+void Codegen::Reference::loadInAccumulator() const
+{
+    auto tdzCheck = [this](bool requiresCheck){
+        if (!requiresCheck)
+            return;
+        Instruction::DeadTemporalZoneCheck check;
+        check.name = codegen->registerString(name);
+        codegen->bytecodeGenerator->addInstruction(check);
+    };
+    auto tdzCheckStackSlot = [this, tdzCheck](Moth::StackSlot slot, bool requiresCheck){
+        if (!requiresCheck)
+            return;
+        Instruction::LoadReg load;
+        load.reg = slot;
+        codegen->bytecodeGenerator->addInstruction(load);
+        tdzCheck(true);
+    };
+
+    switch (type) {
+    case Accumulator:
+        return;
+    case Super:
+        Q_UNREACHABLE();
+        return;
+    case SuperProperty:
+        tdzCheckStackSlot(property, subscriptRequiresTDZCheck);
+        Instruction::LoadSuperProperty load;
+        load.property = property.stackSlot();
+        codegen->bytecodeGenerator->addInstruction(load);
+        return;
+    case Const: {
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_GCC("-Wmaybe-uninitialized") // the loads below are empty structs.
+        if (constant == Encode::null()) {
+            Instruction::LoadNull load;
+            codegen->bytecodeGenerator->addInstruction(load);
+        } else if (constant == Encode(true)) {
+            Instruction::LoadTrue load;
+            codegen->bytecodeGenerator->addInstruction(load);
+        } else if (constant == Encode(false)) {
+            Instruction::LoadFalse load;
+            codegen->bytecodeGenerator->addInstruction(load);
+        } else if (constant == Encode::undefined()) {
+            Instruction::LoadUndefined load;
+            codegen->bytecodeGenerator->addInstruction(load);
+        } else {
+            Value p = Value::fromReturnedValue(constant);
+            if (p.isNumber()) {
+                double d = p.asDouble();
+                int i = static_cast<int>(d);
+                if (d == i && (d != 0 || !std::signbit(d))) {
+                    if (!i) {
+                        Instruction::LoadZero load;
+                        codegen->bytecodeGenerator->addInstruction(load);
+                        return;
+                    }
+                    Instruction::LoadInt load;
+                    load.value = Value::fromReturnedValue(constant).toInt32();
+                    codegen->bytecodeGenerator->addInstruction(load);
+                    return;
+                }
+            }
+            Instruction::LoadConst load;
+            load.index = codegen->registerConstant(constant);
+            codegen->bytecodeGenerator->addInstruction(load);
+        }
+QT_WARNING_POP
+    } return;
+    case StackSlot: {
+        Instruction::LoadReg load;
+        load.reg = stackSlot();
+        codegen->bytecodeGenerator->addInstruction(load);
+        tdzCheck(requiresTDZCheck);
+    } return;
+    case ScopedLocal: {
+        if (!scope) {
+            Instruction::LoadLocal load;
+            load.index = index;
+            codegen->bytecodeGenerator->addTracingInstruction(load);
+        } else {
+            Instruction::LoadScopedLocal load;
+            load.index = index;
+            load.scope = scope;
+            codegen->bytecodeGenerator->addTracingInstruction(load);
+        }
+        tdzCheck(requiresTDZCheck);
+        return;
+    }
+    case Name:
+        if (global) {
+            // these value properties of the global object are immutable, we we can directly convert them
+            // to their numeric value here
+            if (name == QStringLiteral("undefined")) {
+                Reference::fromConst(codegen, Encode::undefined()).loadInAccumulator();
+                return;
+            } else if (name == QStringLiteral("Infinity")) {
+                Reference::fromConst(codegen, Encode(qInf())).loadInAccumulator();
+                return;
+            } else if (name == QStringLiteral("Nan")) {
+                Reference::fromConst(codegen, Encode(qQNaN())).loadInAccumulator();
+                return;
+            }
+        }
+        if (!disable_lookups && global) {
+            Instruction::LoadGlobalLookup load;
+            load.index = codegen->registerGlobalGetterLookup(nameAsIndex());
+            codegen->bytecodeGenerator->addTracingInstruction(load);
+        } else {
+            Instruction::LoadName load;
+            load.name = nameAsIndex();
+            codegen->bytecodeGenerator->addTracingInstruction(load);
+        }
+        return;
+    case Member:
+        propertyBase.loadInAccumulator();
+        tdzCheck(requiresTDZCheck);
+        if (!disable_lookups && codegen->useFastLookups) {
+            Instruction::GetLookup load;
+            load.index = codegen->registerGetterLookup(propertyNameIndex);
+            codegen->bytecodeGenerator->addTracingInstruction(load);
+        } else {
+            Instruction::LoadProperty load;
+            load.name = propertyNameIndex;
+            codegen->bytecodeGenerator->addTracingInstruction(load);
+        }
+        return;
+    case Import: {
+        Instruction::LoadImport load;
+        load.index = index;
+        codegen->bytecodeGenerator->addInstruction(load);
+        tdzCheck(requiresTDZCheck);
+    } return;
+    case Subscript: {
+        tdzCheckStackSlot(elementBase, requiresTDZCheck);
+        elementSubscript.loadInAccumulator();
+        tdzCheck(subscriptRequiresTDZCheck);
+        Instruction::LoadElement load;
+        load.base = elementBase;
+        codegen->bytecodeGenerator->addTracingInstruction(load);
+    } return;
+    case QmlScopeObject: {
+        Instruction::LoadScopeObjectProperty load;
+        load.base = qmlBase;
+        load.propertyIndex = qmlCoreIndex;
+        load.captureRequired = capturePolicy == CaptureAtRuntime;
+        codegen->bytecodeGenerator->addInstruction(load);
+        if (capturePolicy == CaptureAheadOfTime)
+            codegen->_context->scopeObjectPropertyDependencies.insert(qmlCoreIndex, qmlNotifyIndex);
+    } return;
+    case QmlContextObject: {
+        Instruction::LoadContextObjectProperty load;
+        load.base = qmlBase;
+        load.propertyIndex = qmlCoreIndex;
+        load.captureRequired = capturePolicy == CaptureAtRuntime;
+        codegen->bytecodeGenerator->addInstruction(load);
+        if (capturePolicy == CaptureAheadOfTime)
+            codegen->_context->contextObjectPropertyDependencies.insert(qmlCoreIndex, qmlNotifyIndex);
+    } return;
+    case Invalid:
+        break;
+    }
+    Q_UNREACHABLE();
+}
diff --git a/src/qml/compiler/qv4codegen_p.h b/src/qml/compiler/qv4codegen_p.h
index 239ed5c4b9..4d7001fe64 100644
--- a/src/qml/compiler/qv4codegen_p.h
+++ b/src/qml/compiler/qv4codegen_p.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -51,303 +51,524 @@
 //
 
 #include "private/qv4global_p.h"
-#include "qv4jsir_p.h"
 #include <private/qqmljsastvisitor_p.h>
 #include <private/qqmljsast_p.h>
-#include <private/qqmljsengine_p.h>
-#include <QtCore/QStringList>
-#include <QStack>
-#ifndef V4_BOOTSTRAP
-#include <qqmlerror.h>
-#endif
+#include <private/qv4compiler_p.h>
+#include <private/qv4compilercontext_p.h>
 #include <private/qv4util_p.h>
+#include <private/qv4bytecodegenerator_p.h>
+#include <private/qv4stackframe_p.h>
 
 QT_BEGIN_NAMESPACE
 
-namespace QQmlJS {
-namespace AST {
-class UiParameterList;
+using namespace QQmlJS;
+
+namespace QV4 {
+
+namespace Moth {
+struct Instruction;
+}
+
+namespace CompiledData {
+struct CompilationUnit;
 }
 
+namespace Compiler {
+
+struct ControlFlow;
+struct ControlFlowCatch;
+struct ControlFlowFinally;
 
-class Q_QML_PRIVATE_EXPORT Codegen: protected AST::Visitor
+class Q_QML_PRIVATE_EXPORT Codegen: protected QQmlJS::AST::Visitor
 {
+protected:
+    using BytecodeGenerator = QV4::Moth::BytecodeGenerator;
+    using Instruction = QV4::Moth::Instruction;
 public:
-    Codegen(bool strict);
-
-    enum CompilationMode {
-        GlobalCode,
-        EvalCode,
-        FunctionCode,
-        QmlBinding // This is almost the same as EvalCode, except:
-                   //  * function declarations are moved to the return address when encountered
-                   //  * return statements are allowed everywhere (like in FunctionCode)
-                   //  * variable declarations are treated as true locals (like in FunctionCode)
-    };
+    Codegen(QV4::Compiler::JSUnitGenerator *jsUnitGenerator, bool strict);
+
 
     void generateFromProgram(const QString &fileName,
+                             const QString &finalUrl,
                              const QString &sourceCode,
                              AST::Program *ast,
-                             QV4::IR::Module *module,
-                             CompilationMode mode = GlobalCode,
-                             const QStringList &inheritedLocals = QStringList());
-    void generateFromFunctionExpression(const QString &fileName,
-                             const QString &sourceCode,
-                             AST::FunctionExpression *ast,
-                             QV4::IR::Module *module);
+                             Module *module,
+                             ContextType contextType = ContextType::Global);
 
-protected:
-    enum Format { ex, cx, nx };
-    struct Result {
-        QV4::IR::Expr *code;
-        QV4::IR::BasicBlock *iftrue;
-        QV4::IR::BasicBlock *iffalse;
-        Format format;
-        Format requested;
-
-        explicit Result(Format requested = ex)
-            : code(0)
-            , iftrue(0)
-            , iffalse(0)
-            , format(ex)
-            , requested(requested) {}
-
-        explicit Result(QV4::IR::BasicBlock *iftrue, QV4::IR::BasicBlock *iffalse)
-            : code(0)
-            , iftrue(iftrue)
-            , iffalse(iffalse)
-            , format(ex)
-            , requested(cx) {}
-
-        inline QV4::IR::Expr *operator*() const { Q_ASSERT(format == ex); return code; }
-        inline QV4::IR::Expr *operator->() const { Q_ASSERT(format == ex); return code; }
+    void generateFromModule(const QString &fileName,
+                            const QString &finalUrl,
+                            const QString &sourceCode,
+                            AST::ESModule *ast,
+                            Module *module);
 
-        bool accept(Format f)
-        {
-            if (requested == f) {
-                format = f;
+public:
+    class VolatileMemoryLocationScanner;
+    class VolatileMemoryLocations {
+        friend VolatileMemoryLocationScanner;
+        bool allVolatile = false;
+        QVector<QStringView> specificLocations;
+    public:
+        bool isVolatile(const QStringView &name) {
+            if (allVolatile)
                 return true;
-            }
-            return false;
+            return specificLocations.contains(name);
         }
+
+        void add(const QStringRef &name) { if (!allVolatile) specificLocations.append(name); }
+        void setAllVolatile() { allVolatile = true; }
     };
+    class RValue {
+        Codegen *codegen;
+        enum Type {
+            Invalid,
+            Accumulator,
+            StackSlot,
+            Const
+        } type;
+        union {
+            Moth::StackSlot theStackSlot;
+            QV4::ReturnedValue constant;
+        };
+
+    public:
+        static RValue fromStackSlot(Codegen *codegen, Moth::StackSlot stackSlot) {
+            RValue r;
+            r.codegen = codegen;
+            r.type = StackSlot;
+            r.theStackSlot = stackSlot;
+            return r;
+        }
+        static RValue fromAccumulator(Codegen *codegen) {
+            RValue r;
+            r.codegen = codegen;
+            r.type = Accumulator;
+            return r;
+        }
+        static RValue fromConst(Codegen *codegen, QV4::ReturnedValue value) {
+            RValue r;
+            r.codegen = codegen;
+            r.type = Const;
+            r.constant = value;
+            return r;
+        }
 
-    struct Environment {
-        Environment *parent;
+        bool operator==(const RValue &other) const;
 
-        enum MemberType {
-            UndefinedMember,
-            VariableDefinition,
-            VariableDeclaration,
-            FunctionDefinition
-        };
+        bool isValid() const { return type != Invalid; }
+        bool isAccumulator() const { return type == Accumulator; }
+        bool isStackSlot() const { return type == StackSlot; }
+        bool isConst() const { return type == Const; }
 
-        struct Member {
-            MemberType type;
-            int index;
-            AST::FunctionExpression *function;
-            AST::VariableDeclaration::VariableScope scope;
+        Moth::StackSlot stackSlot() const {
+            Q_ASSERT(isStackSlot());
+            return theStackSlot;
+        }
+
+        QV4::ReturnedValue constantValue() const {
+            Q_ASSERT(isConst());
+            return constant;
+        }
+
+        Q_REQUIRED_RESULT RValue storeOnStack() const;
+        void loadInAccumulator() const;
+    };
+    struct Reference {
+        enum Type {
+            Invalid,
+            Accumulator,
+            Super,
+            SuperProperty,
+            StackSlot,
+            ScopedLocal,
+            Name,
+            Member,
+            Subscript,
+            Import,
+            QmlScopeObject,
+            QmlContextObject,
+            LastLValue = QmlContextObject,
+            Const
+        } type = Invalid;
+
+        bool isLValue() const { return !isReadonly && type > Accumulator; }
+
+        Reference(Codegen *cg, Type type = Invalid) : type(type), constant(0), codegen(cg) {}
+        Reference(): constant(0) {}
+        Reference(const Reference &) = default;
+        Reference(Reference &&) = default;
+        Reference &operator =(const Reference &) = default;
+        Reference &operator =(Reference &&) = default;
+
+        bool operator==(const Reference &other) const;
+        bool operator!=(const Reference &other) const
+        { return !(*this == other); }
+
+        bool isValid() const { return type != Invalid; }
+        bool loadTriggersSideEffect() const {
+            switch (type) {
+            case QmlScopeObject:
+                return capturePolicy != DontCapture;
+            case QmlContextObject:
+                return capturePolicy != DontCapture;
+            case Name:
+            case Member:
+            case Subscript:
+            case SuperProperty:
+                return true;
+            default:
+                return requiresTDZCheck;
+            }
+        }
+        bool isConstant() const { return type == Const; }
+        bool isAccumulator() const { return type == Accumulator; }
+        bool isSuper() const { return type == Super; }
+        bool isSuperProperty() const { return type == SuperProperty; }
+        bool isStackSlot() const { return type == StackSlot; }
+        bool isRegister() const {
+            return isStackSlot();
+        }
 
-            bool isLexicallyScoped() const { return this->scope != AST::VariableDeclaration::FunctionScope; }
+        enum PropertyCapturePolicy {
+            /*
+                We're reading a property from the scope or context object, but it's a CONSTANT property,
+                so we don't need to register a dependency at all.
+            */
+            DontCapture,
+            /*
+                We're reading the property of a QObject, and we know that it's the
+                scope object or context object, which we know very well. Instead of registering a
+                property capture every time, we can do that ahead of time and then register all those
+                captures in one shot in registerQmlDependencies().
+            */
+            CaptureAheadOfTime,
+            /*
+                We're reading the property of a QObject, and we're not quite sure where
+                the QObject comes from or what it is. So, when reading that property at run-time,
+                make sure that we capture where we read that property so that if it changes we can
+                re-evaluate the entire expression.
+            */
+            CaptureAtRuntime
         };
-        typedef QMap<QString, Member> MemberMap;
-
-        MemberMap members;
-        AST::FormalParameterList *formals;
-        int maxNumberOfArguments;
-        bool hasDirectEval;
-        bool hasNestedFunctions;
-        bool isStrict;
-        bool isNamedFunctionExpression;
-        bool usesThis;
-        enum UsesArgumentsObject {
-            ArgumentsObjectUnknown,
-            ArgumentsObjectNotUsed,
-            ArgumentsObjectUsed
+
+        static Reference fromAccumulator(Codegen *cg) {
+            return Reference(cg, Accumulator);
+        }
+        static Reference fromSuper(Codegen *cg) {
+            return Reference(cg, Super);
+        }
+        static Reference fromStackSlot(Codegen *cg, int tempIndex = -1, bool isLocal = false) {
+            Reference r(cg, StackSlot);
+            if (tempIndex == -1)
+                tempIndex = cg->bytecodeGenerator->newRegister();
+            r.theStackSlot = Moth::StackSlot::createRegister(tempIndex);
+            r.stackSlotIsLocalOrArgument = isLocal;
+            return r;
+        }
+        static Reference fromArgument(Codegen *cg, int index, bool isVolatile) {
+            Reference r(cg, StackSlot);
+            r.theStackSlot = Moth::StackSlot::createRegister(index + sizeof(CallData)/sizeof(Value) - 1);
+            r.stackSlotIsLocalOrArgument = true;
+            r.isVolatile = isVolatile;
+            return r;
+        }
+        static Reference fromScopedLocal(Codegen *cg, int index, int scope) {
+            Reference r(cg, ScopedLocal);
+            r.index = index;
+            r.scope = scope;
+            return r;
+        }
+        static Reference fromImport(Codegen *cg, int index) {
+            Reference r(cg, Import);
+            r.index = index;
+            return r;
+        }
+        static Reference fromName(Codegen *cg, const QString &name) {
+            Reference r(cg, Name);
+            r.name = name;
+            return r;
+        }
+        static Reference fromMember(const Reference &baseRef, const QString &name) {
+            Reference r(baseRef.codegen, Member);
+            r.propertyBase = baseRef.asRValue();
+            r.propertyNameIndex = r.codegen->registerString(name);
+            r.requiresTDZCheck = baseRef.requiresTDZCheck;
+            return r;
+        }
+        static Reference fromSuperProperty(const Reference &property) {
+            Q_ASSERT(property.isStackSlot());
+            Reference r(property.codegen, SuperProperty);
+            r.property = property.stackSlot();
+            r.subscriptRequiresTDZCheck = property.requiresTDZCheck;
+            return r;
+        }
+        static Reference fromSubscript(const Reference &baseRef, const Reference &subscript) {
+            Q_ASSERT(baseRef.isStackSlot());
+            Reference r(baseRef.codegen, Subscript);
+            r.elementBase = baseRef.stackSlot();
+            r.elementSubscript = subscript.asRValue();
+            r.requiresTDZCheck = baseRef.requiresTDZCheck;
+            r.subscriptRequiresTDZCheck = subscript.requiresTDZCheck;
+            return r;
+        }
+        static Reference fromConst(Codegen *cg, QV4::ReturnedValue constant) {
+            Reference r(cg, Const);
+            r.constant = constant;
+            r.isReadonly = true;
+            return r;
+        }
+        static Reference fromQmlScopeObject(const Reference &base, qint16 coreIndex, qint16 notifyIndex, PropertyCapturePolicy capturePolicy) {
+            Reference r(base.codegen, QmlScopeObject);
+            r.qmlBase = base.storeOnStack().stackSlot();
+            r.qmlCoreIndex = coreIndex;
+            r.qmlNotifyIndex = notifyIndex;
+            r.capturePolicy = capturePolicy;
+            return r;
+        }
+        static Reference fromQmlContextObject(const Reference &base, qint16 coreIndex, qint16 notifyIndex, PropertyCapturePolicy capturePolicy) {
+            Reference r(base.codegen, QmlContextObject);
+            r.qmlBase = base.storeOnStack().stackSlot();
+            r.qmlCoreIndex = coreIndex;
+            r.qmlNotifyIndex = notifyIndex;
+            r.capturePolicy = capturePolicy;
+            return r;
+        }
+        static Reference fromThis(Codegen *cg) {
+            Reference r = fromStackSlot(cg, CallData::This);
+            r.isReadonly = true;
+            // ### Optimize this. Functions that are not derived constructors or arrow functions can't have an
+            // empty this object
+            r.requiresTDZCheck = true;
+            return r;
+        }
+
+        RValue asRValue() const;
+        Reference asLValue() const;
+
+        Q_REQUIRED_RESULT static Reference storeConstOnStack(Codegen *cg, QV4::ReturnedValue constant)
+        { return Reference::fromConst(cg, constant).storeOnStack(); }
+
+        static void storeConstOnStack(Codegen *cg, QV4::ReturnedValue constant, int stackSlot)
+        { Reference::fromConst(cg, constant).storeOnStack(stackSlot); }
+
+        Q_REQUIRED_RESULT Reference storeOnStack() const;
+        void storeOnStack(int tempIndex) const;
+        Q_REQUIRED_RESULT Reference storeRetainAccumulator() const;
+        Reference storeConsumeAccumulator() const;
+
+        Q_REQUIRED_RESULT Reference baseObject() const;
+
+        bool storeWipesAccumulator() const;
+        void loadInAccumulator() const;
+
+        int nameAsIndex() const {
+            Q_ASSERT(type == Name);
+            return codegen->registerString(name);
+        }
+
+        Moth::StackSlot stackSlot() const {
+            if (Q_UNLIKELY(!isStackSlot()))
+                Q_UNREACHABLE();
+            return theStackSlot;
+        }
+
+        union {
+            Moth::StackSlot theStackSlot;
+            QV4::ReturnedValue constant;
+            struct { // Scoped arguments/Local
+                int index;
+                int scope;
+            };
+            struct {
+                RValue propertyBase;
+                int propertyNameIndex;
+            };
+            struct {
+                Moth::StackSlot elementBase;
+                RValue elementSubscript;
+            };
+            struct { // QML scope/context object case
+                Moth::StackSlot qmlBase;
+                qint16 qmlCoreIndex;
+                qint16 qmlNotifyIndex;
+                PropertyCapturePolicy capturePolicy;
+            };
+            Moth::StackSlot property; // super property
         };
+        QString name;
+        mutable bool isArgOrEval = false;
+        bool isReadonly = false;
+        bool isReferenceToConst = false;
+        bool requiresTDZCheck = false;
+        bool subscriptRequiresTDZCheck = false;
+        bool stackSlotIsLocalOrArgument = false;
+        bool isVolatile = false;
+        bool global = false;
+        Codegen *codegen = nullptr;
+
+    private:
+        void storeAccumulator() const;
+        Reference doStoreOnStack(int tempIndex) const;
+    };
 
-        UsesArgumentsObject usesArgumentsObject;
-
-        CompilationMode compilationMode;
-
-        Environment(Environment *parent, CompilationMode mode)
-            : parent(parent)
-            , formals(0)
-            , maxNumberOfArguments(0)
-            , hasDirectEval(false)
-            , hasNestedFunctions(false)
-            , isStrict(false)
-            , isNamedFunctionExpression(false)
-            , usesThis(false)
-            , usesArgumentsObject(ArgumentsObjectUnknown)
-            , compilationMode(mode)
-        {
-            if (parent && parent->isStrict)
-                isStrict = true;
+    struct RegisterScope {
+        RegisterScope(Codegen *cg)
+            : generator(cg->bytecodeGenerator),
+              regCountForScope(generator->currentReg) {}
+        ~RegisterScope() {
+            generator->currentReg = regCountForScope;
         }
+        BytecodeGenerator *generator;
+        int regCountForScope;
+    };
+
+    struct ObjectPropertyValue {
+        ObjectPropertyValue() {}
+
+        Reference rvalue;
+        int getter = -1; // index in _module->functions or -1 if not set
+        int setter = -1;
+        uint keyAsIndex = UINT_MAX;
+
+        bool hasGetter() const { return getter >= 0; }
+        bool hasSetter() const { return setter >= 0; }
+    };
+protected:
+
+    enum Format { ex, cx, nx };
+    class Result {
+        Reference _result;
+
+        const BytecodeGenerator::Label *_iftrue = nullptr;
+        const BytecodeGenerator::Label *_iffalse = nullptr;
+        Format _format = ex;
+        Format _requested;
+        bool _trueBlockFollowsCondition = false;
+
+    public:
+        explicit Result(const Reference &lrvalue)
+            : _result(lrvalue)
+            , _requested(ex)
+        {}
 
-        int findMember(const QString &name) const
+        explicit Result(Format requested = ex)
+            : _requested(requested) {}
+
+        explicit Result(const BytecodeGenerator::Label *iftrue,
+                        const BytecodeGenerator::Label *iffalse,
+                        bool trueBlockFollowsCondition)
+            : _iftrue(iftrue)
+            , _iffalse(iffalse)
+            , _requested(cx)
+            , _trueBlockFollowsCondition(trueBlockFollowsCondition)
         {
-            MemberMap::const_iterator it = members.find(name);
-            if (it == members.end())
-                return -1;
-            Q_ASSERT((*it).index != -1 || !parent);
-            return (*it).index;
+            Q_ASSERT(iftrue);
+            Q_ASSERT(iffalse);
         }
 
-        bool memberInfo(const QString &name, const Member **m) const
-        {
-            Q_ASSERT(m);
-            MemberMap::const_iterator it = members.find(name);
-            if (it == members.end()) {
-                *m = 0;
-                return false;
-            }
-            *m = &(*it);
-            return true;
+        const BytecodeGenerator::Label *iftrue() const {
+            Q_ASSERT(_requested == cx);
+            return _iftrue;
         }
 
-        bool lookupMember(const QString &name, Environment **scope, int *index, int *distance)
+        const BytecodeGenerator::Label *iffalse() const {
+            Q_ASSERT(_requested == cx);
+            return _iffalse;
+        }
+
+        Format format() const {
+            return _format;
+        }
+
+        bool accept(Format f)
         {
-            Environment *it = this;
-            *distance = 0;
-            for (; it; it = it->parent, ++(*distance)) {
-                int idx = it->findMember(name);
-                if (idx != -1) {
-                    *scope = it;
-                    *index = idx;
-                    return true;
-                }
+            if (_requested == f) {
+                _format = f;
+                return true;
             }
             return false;
         }
 
-        void enter(const QString &name, MemberType type, AST::VariableDeclaration::VariableScope scope, AST::FunctionExpression *function = 0)
-        {
-            if (! name.isEmpty()) {
-                if (type != FunctionDefinition) {
-                    for (AST::FormalParameterList *it = formals; it; it = it->next)
-                        if (it->name == name)
-                            return;
-                }
-                MemberMap::iterator it = members.find(name);
-                if (it == members.end()) {
-                    Member m;
-                    m.index = -1;
-                    m.type = type;
-                    m.function = function;
-                    m.scope = scope;
-                    members.insert(name, m);
-                } else {
-                    Q_ASSERT(scope == (*it).scope);
-                    if ((*it).type <= type) {
-                        (*it).type = type;
-                        (*it).function = function;
-                    }
-                }
-            }
+        bool trueBlockFollowsCondition() const {
+            return _trueBlockFollowsCondition;
         }
-    };
 
-    Environment *newEnvironment(AST::Node *node, Environment *parent, CompilationMode compilationMode)
-    {
-        Environment *env = new Environment(parent, compilationMode);
-        _envMap.insert(node, env);
-        return env;
-    }
+        const Reference &result() const {
+            return _result;
+        }
 
-    struct UiMember {
+        void setResult(const Reference &result) {
+            _result = result;
+        }
     };
 
-    struct ScopeAndFinally {
-        enum ScopeType {
-            WithScope,
-            TryScope,
-            CatchScope
-        };
-
-        ScopeAndFinally *parent;
-        AST::Finally *finally;
-        ScopeType type;
+    void enterContext(AST::Node *node);
+    int leaveContext();
+public:
+    Context *enterBlock(AST::Node *node);
+    int leaveBlock() { return leaveContext(); }
+protected:
+    void leaveLoop();
 
-        ScopeAndFinally(ScopeAndFinally *parent, ScopeType t = WithScope) : parent(parent), finally(0), type(t) {}
-        ScopeAndFinally(ScopeAndFinally *parent, AST::Finally *finally)
-        : parent(parent), finally(finally), type(TryScope)
-        {}
+    enum UnaryOperation {
+        UPlus,
+        UMinus,
+        PreIncrement,
+        PreDecrement,
+        PostIncrement,
+        PostDecrement,
+        Not,
+        Compl
     };
 
-    struct Loop {
-        AST::LabelledStatement *labelledStatement;
-        AST::Statement *node;
-        QV4::IR::BasicBlock *breakBlock;
-        QV4::IR::BasicBlock *continueBlock;
-        Loop *parent;
-        ScopeAndFinally *scopeAndFinally;
+    Reference unop(UnaryOperation op, const Reference &expr);
 
-        Loop(AST::Statement *node, QV4::IR::BasicBlock *breakBlock, QV4::IR::BasicBlock *continueBlock, Loop *parent)
-            : labelledStatement(0), node(node), breakBlock(breakBlock), continueBlock(continueBlock), parent(parent) {}
-    };
-
-    void enterEnvironment(AST::Node *node);
-    void leaveEnvironment();
+    void addCJump();
 
-    void enterLoop(AST::Statement *node, QV4::IR::BasicBlock *breakBlock, QV4::IR::BasicBlock *continueBlock);
-    void leaveLoop();
-    QV4::IR::BasicBlock *exceptionHandler() const
-    {
-        if (_exceptionHandlers.isEmpty())
-            return 0;
-        return _exceptionHandlers.top();
-    }
-    void pushExceptionHandler(QV4::IR::BasicBlock *handler)
-    {
-        handler->setExceptionHandler(true);
-        _exceptionHandlers.push(handler);
-    }
-    void popExceptionHandler()
-    {
-        Q_ASSERT(!_exceptionHandlers.isEmpty());
-        _exceptionHandlers.pop();
+public:
+    int registerString(const QString &name) {
+        return jsUnitGenerator->registerString(name);
     }
-
-    QV4::IR::Expr *member(QV4::IR::Expr *base, const QString *name);
-    QV4::IR::Expr *subscript(QV4::IR::Expr *base, QV4::IR::Expr *index);
-    QV4::IR::Expr *argument(QV4::IR::Expr *expr);
-    QV4::IR::Expr *reference(QV4::IR::Expr *expr);
-    QV4::IR::Expr *unop(QV4::IR::AluOp op, QV4::IR::Expr *expr, const AST::SourceLocation &loc = AST::SourceLocation());
-    QV4::IR::Expr *binop(QV4::IR::AluOp op, QV4::IR::Expr *left, QV4::IR::Expr *right, const AST::SourceLocation &loc = AST::SourceLocation());
-    QV4::IR::Expr *call(QV4::IR::Expr *base, QV4::IR::ExprList *args);
-    QV4::IR::Stmt *move(QV4::IR::Expr *target, QV4::IR::Expr *source, QV4::IR::AluOp op = QV4::IR::OpInvalid);
-    QV4::IR::Stmt *cjump(QV4::IR::Expr *cond, QV4::IR::BasicBlock *iftrue, QV4::IR::BasicBlock *iffalse);
+    int registerConstant(QV4::ReturnedValue v) { return jsUnitGenerator->registerConstant(v); }
+    int registerGetterLookup(int nameIndex) { return jsUnitGenerator->registerGetterLookup(nameIndex); }
+    int registerSetterLookup(int nameIndex) { return jsUnitGenerator->registerSetterLookup(nameIndex); }
+    int registerGlobalGetterLookup(int nameIndex) { return jsUnitGenerator->registerGlobalGetterLookup(nameIndex); }
 
     // Returns index in _module->functions
-    int defineFunction(const QString &name, AST::Node *ast,
-                       AST::FormalParameterList *formals,
-                       AST::SourceElements *body,
-                       const QStringList &inheritedLocals = QStringList());
-
-    void unwindException(ScopeAndFinally *outest);
+    virtual int defineFunction(const QString &name, AST::Node *ast,
+                               AST::FormalParameterList *formals,
+                               AST::StatementList *body);
 
+protected:
     void statement(AST::Statement *ast);
     void statement(AST::ExpressionNode *ast);
-    void condition(AST::ExpressionNode *ast, QV4::IR::BasicBlock *iftrue, QV4::IR::BasicBlock *iffalse);
-    Result expression(AST::ExpressionNode *ast);
-    Result sourceElement(AST::SourceElement *ast);
-    UiMember uiObjectMember(AST::UiObjectMember *ast);
+    void condition(AST::ExpressionNode *ast, const BytecodeGenerator::Label *iftrue,
+                   const BytecodeGenerator::Label *iffalse,
+                   bool trueBlockFollowsCondition);
+    Reference expression(AST::ExpressionNode *ast);
 
     void accept(AST::Node *node);
 
-    void functionBody(AST::FunctionBody *ast);
     void program(AST::Program *ast);
-    void sourceElements(AST::SourceElements *ast);
-    void variableDeclaration(AST::VariableDeclaration *ast);
+    void statementList(AST::StatementList *ast);
+    void variableDeclaration(AST::PatternElement *ast);
     void variableDeclarationList(AST::VariableDeclarationList *ast);
 
-    QV4::IR::Expr *identifier(const QString &name, int line = 0, int col = 0);
-    // Hook provided to implement QML lookup semantics
-    virtual QV4::IR::Expr *fallbackNameLookup(const QString &name, int line, int col);
+    Reference targetForPatternElement(AST::PatternElement *p);
+    void initializeAndDestructureBindingElement(AST::PatternElement *e, const Reference &baseRef = Reference(), bool isDefinition = false);
+    void destructurePropertyList(const Reference &object, AST::PatternPropertyList *bindingList, bool isDefinition = false);
+    void destructureElementList(const Reference &array, AST::PatternElementList *bindingList, bool isDefinition = false);
+    void destructurePattern(AST::Pattern *p, const Reference &rhs);
+
+    Reference referenceForPropertyName(const Codegen::Reference &object, AST::PropertyName *name);
+
+    // Hooks provided to implement QML lookup semantics
+    virtual bool canAccelerateGlobalLookups() const { return true; }
+    virtual Reference fallbackNameLookup(const QString &name);
+
     virtual void beginFunctionBodyHook() {}
 
+    void emitReturn(const Reference &expr);
+
     // nodes
     bool visit(AST::ArgumentList *ast) override;
     bool visit(AST::CaseBlock *ast) override;
@@ -355,16 +576,10 @@ protected:
     bool visit(AST::CaseClauses *ast) override;
     bool visit(AST::Catch *ast) override;
     bool visit(AST::DefaultClause *ast) override;
-    bool visit(AST::ElementList *ast) override;
     bool visit(AST::Elision *ast) override;
     bool visit(AST::Finally *ast) override;
     bool visit(AST::FormalParameterList *ast) override;
-    bool visit(AST::FunctionBody *ast) override;
     bool visit(AST::Program *ast) override;
-    bool visit(AST::PropertyNameAndValue *ast) override;
-    bool visit(AST::PropertyAssignmentList *ast) override;
-    bool visit(AST::PropertyGetterSetter *ast) override;
-    bool visit(AST::SourceElements *ast) override;
     bool visit(AST::StatementList *ast) override;
     bool visit(AST::UiArrayMemberList *ast) override;
     bool visit(AST::UiImport *ast) override;
@@ -375,20 +590,27 @@ protected:
     bool visit(AST::UiParameterList *ast) override;
     bool visit(AST::UiProgram *ast) override;
     bool visit(AST::UiQualifiedId *ast) override;
-    bool visit(AST::UiQualifiedPragmaId *ast) override;
-    bool visit(AST::VariableDeclaration *ast) override;
     bool visit(AST::VariableDeclarationList *ast) override;
 
+    bool visit(AST::PatternElement *ast) override;
+    bool visit(AST::PatternElementList *ast) override;
+    bool visit(AST::PatternProperty *ast) override;
+    bool visit(AST::PatternPropertyList *ast) override;
+
+    bool visit(AST::ExportDeclaration *ast) override;
+
     // expressions
     bool visit(AST::Expression *ast) override;
-    bool visit(AST::ArrayLiteral *ast) override;
+    bool visit(AST::ArrayPattern *ast) override;
     bool visit(AST::ArrayMemberExpression *ast) override;
     bool visit(AST::BinaryExpression *ast) override;
     bool visit(AST::CallExpression *ast) override;
     bool visit(AST::ConditionalExpression *ast) override;
     bool visit(AST::DeleteExpression *ast) override;
     bool visit(AST::FalseLiteral *ast) override;
+    bool visit(AST::SuperLiteral *ast) override;
     bool visit(AST::FieldMemberExpression *ast) override;
+    bool visit(AST::TaggedTemplate *ast) override;
     bool visit(AST::FunctionExpression *ast) override;
     bool visit(AST::IdentifierExpression *ast) override;
     bool visit(AST::NestedExpression *ast) override;
@@ -397,13 +619,14 @@ protected:
     bool visit(AST::NotExpression *ast) override;
     bool visit(AST::NullExpression *ast) override;
     bool visit(AST::NumericLiteral *ast) override;
-    bool visit(AST::ObjectLiteral *ast) override;
+    bool visit(AST::ObjectPattern *ast) override;
     bool visit(AST::PostDecrementExpression *ast) override;
     bool visit(AST::PostIncrementExpression *ast) override;
     bool visit(AST::PreDecrementExpression *ast) override;
     bool visit(AST::PreIncrementExpression *ast) override;
     bool visit(AST::RegExpLiteral *ast) override;
     bool visit(AST::StringLiteral *ast) override;
+    bool visit(AST::TemplateLiteral *ast) override;
     bool visit(AST::ThisExpression *ast) override;
     bool visit(AST::TildeExpression *ast) override;
     bool visit(AST::TrueLiteral *ast) override;
@@ -412,10 +635,9 @@ protected:
     bool visit(AST::UnaryPlusExpression *ast) override;
     bool visit(AST::VoidExpression *ast) override;
     bool visit(AST::FunctionDeclaration *ast) override;
-
-    // source elements
-    bool visit(AST::FunctionSourceElement *ast) override;
-    bool visit(AST::StatementSourceElement *ast) override;
+    bool visit(AST::YieldExpression *ast) override;
+    bool visit(AST::ClassExpression *ast) override;
+    bool visit(AST::ClassDeclaration *ast) override;
 
     // statements
     bool visit(AST::Block *ast) override;
@@ -429,8 +651,6 @@ protected:
     bool visit(AST::ForStatement *ast) override;
     bool visit(AST::IfStatement *ast) override;
     bool visit(AST::LabelledStatement *ast) override;
-    bool visit(AST::LocalForEachStatement *ast) override;
-    bool visit(AST::LocalForStatement *ast) override;
     bool visit(AST::ReturnStatement *ast) override;
     bool visit(AST::SwitchStatement *ast) override;
     bool visit(AST::ThrowStatement *ast) override;
@@ -447,7 +667,7 @@ protected:
     bool visit(AST::UiScriptBinding *ast) override;
     bool visit(AST::UiSourceElement *ast) override;
 
-    bool throwSyntaxErrorOnEvalOrArgumentsInStrictMode(QV4::IR::Expr* expr, const AST::SourceLocation &loc);
+    bool throwSyntaxErrorOnEvalOrArgumentsInStrictMode(const Reference &r, const AST::SourceLocation &loc);
     virtual void throwSyntaxError(const AST::SourceLocation &loc, const QString &detail);
     virtual void throwReferenceError(const AST::SourceLocation &loc, const QString &detail);
 
@@ -457,117 +677,129 @@ public:
     QList<QQmlError> qmlErrors() const;
 #endif
 
-protected:
-    Result _expr;
-    QString _property;
-    UiMember _uiMember;
-    QV4::IR::Module *_module;
-    QV4::IR::Function *_function;
-    QV4::IR::BasicBlock *_block;
-    QV4::IR::BasicBlock *_exitBlock;
-    unsigned _returnAddress;
-    Environment *_variableEnvironment;
-    Loop *_loop;
-    AST::LabelledStatement *_labelledStatement;
-    ScopeAndFinally *_scopeAndFinally;
-    QHash<AST::Node *, Environment *> _envMap;
-    QHash<AST::FunctionExpression *, int> _functionMap;
-    QStack<QV4::IR::BasicBlock *> _exceptionHandlers;
-    bool _strictMode;
+    Reference binopHelper(QSOperator::Op oper, Reference &left, Reference &right);
+    Reference jumpBinop(QSOperator::Op oper, Reference &left, Reference &right);
+    struct Arguments { int argc; int argv; bool hasSpread; };
+    Arguments pushArgs(AST::ArgumentList *args);
+    void handleCall(Reference &base, Arguments calldata, int slotForFunction, int slotForThisObject);
 
-    bool _fileNameIsUrl;
-    bool hasError;
-    QList<QQmlJS::DiagnosticMessage> _errors;
+    Arguments pushTemplateArgs(AST::TemplateLiteral *args);
+    void createTemplateObject(AST::TemplateLiteral *t);
 
-    class ScanFunctions: protected Visitor
-    {
-        typedef QV4::TemporaryAssignment<bool> TemporaryBoolAssignment;
-    public:
-        ScanFunctions(Codegen *cg, const QString &sourceCode, CompilationMode defaultProgramMode);
-        void operator()(AST::Node *node);
+    void setUseFastLookups(bool b) { useFastLookups = b; }
 
-        void enterEnvironment(AST::Node *node, CompilationMode compilationMode);
-        void leaveEnvironment();
+    void handleTryCatch(AST::TryStatement *ast);
+    void handleTryFinally(AST::TryStatement *ast);
 
-        void enterQmlScope(AST::Node *ast, const QString &name)
-        { enterFunction(ast, name, /*formals*/0, /*body*/0, /*expr*/0, /*isExpression*/false); }
 
-        void enterQmlFunction(AST::FunctionDeclaration *ast)
-        { enterFunction(ast, false, false); }
+    Reference referenceForName(const QString &name, bool lhs, const QQmlJS::AST::SourceLocation &accessLocation = QQmlJS::AST::SourceLocation());
 
-    protected:
-        using Visitor::visit;
-        using Visitor::endVisit;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> generateCompilationUnit(bool generateUnitData = true);
+    static QQmlRefPointer<QV4::CompiledData::CompilationUnit> createUnitForLoading();
 
-        void checkDirectivePrologue(AST::SourceElements *ast);
+    Context *currentContext() const { return _context; }
+    BytecodeGenerator *generator() const { return bytecodeGenerator; }
 
-        void checkName(const QStringRef &name, const AST::SourceLocation &loc);
-        void checkForArguments(AST::FormalParameterList *parameters);
+    void loadClosure(int index);
 
-        bool visit(AST::Program *ast) override;
-        void endVisit(AST::Program *) override;
+    Module *module() const { return _module; }
 
-        bool visit(AST::CallExpression *ast) override;
-        bool visit(AST::NewMemberExpression *ast) override;
-        bool visit(AST::ArrayLiteral *ast) override;
-        bool visit(AST::VariableDeclaration *ast) override;
-        bool visit(AST::IdentifierExpression *ast) override;
-        bool visit(AST::ExpressionStatement *ast) override;
-        bool visit(AST::FunctionExpression *ast) override;
+    BytecodeGenerator::Label returnLabel() {
+        if (!_returnLabel)
+            _returnLabel = new BytecodeGenerator::Label(bytecodeGenerator->newLabel());
+        return *_returnLabel;
+    }
 
-        void enterFunction(AST::FunctionExpression *ast, bool enterName, bool isExpression = true);
+    void setGlobalNames(const QSet<QString>& globalNames) {
+        m_globalNames = globalNames;
+    }
 
-        void endVisit(AST::FunctionExpression *) override;
 
-        bool visit(AST::ObjectLiteral *ast) override;
+protected:
+    friend class ScanFunctions;
+    friend struct ControlFlow;
+    friend struct ControlFlowCatch;
+    friend struct ControlFlowFinally;
+    Result _expr;
+    VolatileMemoryLocations _volatileMemoryLocations;
+    Module *_module;
+    int _returnAddress;
+    Context *_context;
+    Context *_functionContext = nullptr;
+    AST::LabelledStatement *_labelledStatement;
+    QV4::Compiler::JSUnitGenerator *jsUnitGenerator;
+    BytecodeGenerator *bytecodeGenerator = nullptr;
+    Moth::BytecodeGenerator::Label *_returnLabel = nullptr;
+    bool _strictMode;
+    bool useFastLookups = true;
+    bool requiresReturnValue = false;
+    bool insideSwitch = false;
+    bool inFormalParameterList = false;
+    bool functionEndsWithReturn = false;
+    bool _tailCallsAreAllowed = true;
+    QSet<QString> m_globalNames;
 
-        bool visit(AST::PropertyGetterSetter *ast) override;
-        void endVisit(AST::PropertyGetterSetter *) override;
+    ControlFlow *controlFlow = nullptr;
 
-        bool visit(AST::FunctionDeclaration *ast) override;
-        void endVisit(AST::FunctionDeclaration *) override;
+    bool _fileNameIsUrl;
+    bool hasError;
+    QList<QQmlJS::DiagnosticMessage> _errors;
 
-        bool visit(AST::WithStatement *ast) override;
+    class TailCallBlocker
+    {
+    public:
+        TailCallBlocker(Codegen *cg, bool onoff = false)
+            : _cg(cg)
+            , _saved(_cg->_tailCallsAreAllowed)
+            , _onoff(onoff)
+        { _cg->_tailCallsAreAllowed = onoff; }
 
-        bool visit(AST::DoWhileStatement *ast) override;
-        bool visit(AST::ForStatement *ast) override;
-        bool visit(AST::LocalForStatement *ast) override;
-        bool visit(AST::ForEachStatement *ast) override;
-        bool visit(AST::LocalForEachStatement *ast) override;
-        bool visit(AST::ThisExpression *ast) override;
+        ~TailCallBlocker()
+        { _cg->_tailCallsAreAllowed = _saved; }
 
-        bool visit(AST::Block *ast) override;
+        void unblock() const
+        { _cg->_tailCallsAreAllowed = _saved; }
 
-    protected:
-        void enterFunction(AST::Node *ast, const QString &name, AST::FormalParameterList *formals, AST::FunctionBody *body, AST::FunctionExpression *expr, bool isExpression);
+        void reblock() const
+        { _cg->_tailCallsAreAllowed = _onoff; }
 
-    // fields:
+    private:
         Codegen *_cg;
-        const QString _sourceCode;
-        Environment *_variableEnvironment;
-        QStack<Environment *> _envStack;
-
-        bool _allowFuncDecls;
-        CompilationMode defaultProgramMode;
+        bool _saved;
+        bool _onoff;
     };
 
-};
+    class RecursionDepthCheck {
+    public:
+        RecursionDepthCheck(Codegen *cg, const AST::SourceLocation &loc)
+            : _cg(cg)
+        {
+#ifdef QT_NO_DEBUG
+            const int depthLimit = 4000; // limit to ~1000 deep
+#else
+            const int depthLimit = 1000; // limit to ~250 deep
+#endif // QT_NO_DEBUG
+
+            ++_cg->_recursionDepth;
+            if (_cg->_recursionDepth > depthLimit)
+                _cg->throwSyntaxError(loc, QStringLiteral("Maximum statement or expression depth exceeded"));
+        }
 
-#ifndef V4_BOOTSTRAP
-class RuntimeCodegen : public Codegen
-{
-public:
-    RuntimeCodegen(QV4::ExecutionEngine *engine, bool strict)
-        : Codegen(strict)
-        , engine(engine)
-    {}
+        ~RecursionDepthCheck()
+        { --_cg->_recursionDepth; }
+
+    private:
+        Codegen *_cg;
+    };
+    int _recursionDepth = 0;
+    friend class RecursionDepthCheck;
 
-    void throwSyntaxError(const AST::SourceLocation &loc, const QString &detail) override;
-    void throwReferenceError(const AST::SourceLocation &loc, const QString &detail) override;
 private:
-    QV4::ExecutionEngine *engine;
+    VolatileMemoryLocations scanVolatileMemoryLocations(AST::Node *ast) const;
+    void handleConstruct(const Reference &base, AST::ArgumentList *args);
 };
-#endif // V4_BOOTSTRAP
+
+}
 
 }
 
diff --git a/src/qml/compiler/qv4compilationunitmapper.cpp b/src/qml/compiler/qv4compilationunitmapper.cpp
index d94f7ac238..350f6f9485 100644
--- a/src/qml/compiler/qv4compilationunitmapper.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper.cpp
@@ -59,36 +59,4 @@ CompilationUnitMapper::~CompilationUnitMapper()
     close();
 }
 
-bool CompilationUnitMapper::verifyHeader(const CompiledData::Unit *header, QDateTime sourceTimeStamp, QString *errorString)
-{
-    if (strncmp(header->magic, CompiledData::magic_str, sizeof(header->magic))) {
-        *errorString = QStringLiteral("Magic bytes in the header do not match");
-        return false;
-    }
-
-    if (header->version != quint32(QV4_DATA_STRUCTURE_VERSION)) {
-        *errorString = QString::fromUtf8("V4 data structure version mismatch. Found %1 expected %2").arg(header->version, 0, 16).arg(QV4_DATA_STRUCTURE_VERSION, 0, 16);
-        return false;
-    }
-
-    if (header->qtVersion != quint32(QT_VERSION)) {
-        *errorString = QString::fromUtf8("Qt version mismatch. Found %1 expected %2").arg(header->qtVersion, 0, 16).arg(QT_VERSION, 0, 16);
-        return false;
-    }
-
-    if (header->sourceTimeStamp) {
-        // Files from the resource system do not have any time stamps, so fall back to the application
-        // executable.
-        if (!sourceTimeStamp.isValid())
-            sourceTimeStamp = QFileInfo(QCoreApplication::applicationFilePath()).lastModified();
-
-        if (sourceTimeStamp.isValid() && sourceTimeStamp.toMSecsSinceEpoch() != header->sourceTimeStamp) {
-            *errorString = QStringLiteral("QML source file has a different time stamp than cached file.");
-            return false;
-        }
-    }
-
-    return true;
-}
-
 QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4compilationunitmapper_p.h b/src/qml/compiler/qv4compilationunitmapper_p.h
index b24f98df7c..80f914c141 100644
--- a/src/qml/compiler/qv4compilationunitmapper_p.h
+++ b/src/qml/compiler/qv4compilationunitmapper_p.h
@@ -72,8 +72,6 @@ public:
     void close();
 
 private:
-    static bool verifyHeader(const QV4::CompiledData::Unit *header, QDateTime sourceTimeStamp, QString *errorString);
-
 #if defined(Q_OS_UNIX)
     size_t length;
 #endif
diff --git a/src/qml/compiler/qv4compilationunitmapper_unix.cpp b/src/qml/compiler/qv4compilationunitmapper_unix.cpp
index 38dabc41cf..6768bc9596 100644
--- a/src/qml/compiler/qv4compilationunitmapper_unix.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper_unix.cpp
@@ -42,7 +42,7 @@
 #include <sys/mman.h>
 #include <functional>
 #include <private/qcore_unix_p.h>
-#include <private/qdeferredcleanup_p.h>
+#include <QScopeGuard>
 #include <QDateTime>
 
 #include "qv4compileddata_p.h"
@@ -61,7 +61,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    QDeferredCleanup cleanup([fd]{
+    auto cleanup = qScopeGuard([fd]{
        qt_safe_close(fd) ;
     });
 
@@ -73,7 +73,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    if (!verifyHeader(&header, sourceTimeStamp, errorString))
+    if (!header.verifyHeader(sourceTimeStamp, errorString))
         return nullptr;
 
     // Data structure and qt version matched, so now we can access the rest of the file safely.
@@ -92,8 +92,16 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
 
 void CompilationUnitMapper::close()
 {
-    if (dataPtr != nullptr)
-        munmap(dataPtr, length);
+    // Do not unmap the data here.
+    if (dataPtr != nullptr) {
+        // Do not unmap cache files that are built with the StaticData flag. That's the majority of
+        // them and it's necessary to benefit from the QString literal optimization. There might
+        // still be QString instances around that point into that memory area. The memory is backed
+        // on the disk, so the kernel is free to release the pages and all that remains is the
+        // address space allocation.
+        if (!(reinterpret_cast<CompiledData::Unit*>(dataPtr)->flags & CompiledData::Unit::StaticData))
+            munmap(dataPtr, length);
+    }
     dataPtr = nullptr;
 }
 
diff --git a/src/qml/compiler/qv4compilationunitmapper_win.cpp b/src/qml/compiler/qv4compilationunitmapper_win.cpp
index d7a93ae233..779c1288fe 100644
--- a/src/qml/compiler/qv4compilationunitmapper_win.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper_win.cpp
@@ -40,7 +40,7 @@
 #include "qv4compilationunitmapper_p.h"
 
 #include "qv4compileddata_p.h"
-#include <private/qdeferredcleanup_p.h>
+#include <QScopeGuard>
 #include <QFileInfo>
 #include <QDateTime>
 #include <qt_windows.h>
@@ -71,7 +71,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    QDeferredCleanup fileHandleCleanup([handle]{
+    auto fileHandleCleanup = qScopeGuard([handle]{
         CloseHandle(handle);
     });
 
@@ -87,27 +87,22 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    if (!verifyHeader(&header, sourceTimeStamp, errorString))
+    if (!header.verifyHeader(sourceTimeStamp, errorString))
         return nullptr;
 
-    const uint mappingFlags = header.flags & QV4::CompiledData::Unit::ContainsMachineCode
-                              ? PAGE_EXECUTE_READ : PAGE_READONLY;
-    const uint viewFlags = header.flags & QV4::CompiledData::Unit::ContainsMachineCode
-                           ? (FILE_MAP_READ | FILE_MAP_EXECUTE) : FILE_MAP_READ;
-
     // Data structure and qt version matched, so now we can access the rest of the file safely.
 
-    HANDLE fileMappingHandle = CreateFileMapping(handle, 0, mappingFlags, 0, 0, 0);
+    HANDLE fileMappingHandle = CreateFileMapping(handle, 0, PAGE_READONLY, 0, 0, 0);
     if (!fileMappingHandle) {
         *errorString = qt_error_string(GetLastError());
         return nullptr;
     }
 
-    QDeferredCleanup mappingCleanup([fileMappingHandle]{
+    auto mappingCleanup = qScopeGuard([fileMappingHandle]{
         CloseHandle(fileMappingHandle);
     });
 
-    dataPtr = MapViewOfFile(fileMappingHandle, viewFlags, 0, 0, 0);
+    dataPtr = MapViewOfFile(fileMappingHandle, FILE_MAP_READ, 0, 0, 0);
     if (!dataPtr) {
         *errorString = qt_error_string(GetLastError());
         return nullptr;
@@ -118,8 +113,15 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
 
 void CompilationUnitMapper::close()
 {
-    if (dataPtr != nullptr)
-        UnmapViewOfFile(dataPtr);
+    if (dataPtr != nullptr) {
+        // Do not unmap cache files that are built with the StaticData flag. That's the majority of
+        // them and it's necessary to benefit from the QString literal optimization. There might
+        // still be QString instances around that point into that memory area. The memory is backed
+        // on the disk, so the kernel is free to release the pages and all that remains is the
+        // address space allocation.
+        if (!(reinterpret_cast<CompiledData::Unit*>(dataPtr)->flags & CompiledData::Unit::StaticData))
+            UnmapViewOfFile(dataPtr);
+    }
     dataPtr = nullptr;
 }
 
diff --git a/src/qml/compiler/qv4compileddata.cpp b/src/qml/compiler/qv4compileddata.cpp
index a0dd4c426c..5dd6fca023 100644
--- a/src/qml/compiler/qv4compileddata.cpp
+++ b/src/qml/compiler/qv4compileddata.cpp
@@ -38,7 +38,6 @@
 ****************************************************************************/
 
 #include "qv4compileddata_p.h"
-#include "qv4jsir_p.h"
 #include <private/qv4value_p.h>
 #ifndef V4_BOOTSTRAP
 #include <private/qv4engine_p.h>
@@ -46,9 +45,11 @@
 #include <private/qv4objectproto_p.h>
 #include <private/qv4lookup_p.h>
 #include <private/qv4regexpobject_p.h>
-#include <private/qqmlpropertycache_p.h>
+#include <private/qv4regexp_p.h>
 #include <private/qqmltypeloader_p.h>
 #include <private/qqmlengine_p.h>
+#include <private/qv4vme_moth_p.h>
+#include <private/qv4module_p.h>
 #include "qv4compilationunitmapper_p.h"
 #include <QQmlPropertyMap>
 #include <QDateTime>
@@ -57,19 +58,18 @@
 #include <QScopedValueRollback>
 #include <QStandardPaths>
 #include <QDir>
+#include <private/qv4identifiertable_p.h>
 #endif
 #include <private/qqmlirbuilder_p.h>
 #include <QCoreApplication>
 #include <QCryptographicHash>
 #include <QSaveFile>
+#include <QScopeGuard>
 
-#include <algorithm>
+// generated by qmake:
+#include "qml_compile_hash_p.h"
 
-#if defined(QT_BUILD_INTERNAL)
-#if defined(Q_OS_UNIX) && !defined(QT_NO_DYNAMIC_CAST)
-#include <dlfcn.h>
-#endif
-#endif
+#include <algorithm>
 
 QT_BEGIN_NAMESPACE
 
@@ -77,42 +77,56 @@ namespace QV4 {
 
 namespace CompiledData {
 
-#if !defined(V4_BOOTSTRAP)
-static QString cacheFilePath(const QUrl &url)
+#if defined(QML_COMPILE_HASH)
+#  ifdef Q_OS_LINUX
+// Place on a separate section on Linux so it's easier to check from outside
+// what the hash version is.
+__attribute__((section(".qml_compile_hash")))
+#  endif
+const char qml_compile_hash[48 + 1] = QML_COMPILE_HASH;
+static_assert(sizeof(Unit::libraryVersionHash) >= QML_COMPILE_HASH_LENGTH + 1, "Compile hash length exceeds reserved size in data structure. Please adjust and bump the format version");
+#else
+#  error "QML_COMPILE_HASH must be defined for the build of QtDeclarative to ensure version checking for cache files"
+#endif
+
+
+CompilationUnit::CompilationUnit(const Unit *unitData, const QString &fileName, const QString &finalUrlString)
 {
-    const QString localSourcePath = QQmlFile::urlToLocalFileOrQrc(url);
-    const QString localCachePath = localSourcePath + QLatin1Char('c');
-    if (QFileInfo(QFileInfo(localSourcePath).dir().absolutePath()).isWritable())
-        return localCachePath;
-    QCryptographicHash fileNameHash(QCryptographicHash::Sha1);
-    fileNameHash.addData(localSourcePath.toUtf8());
-    QString directory = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QLatin1String("/qmlcache/");
-    QDir::root().mkpath(directory);
-    return directory + QString::fromUtf8(fileNameHash.result().toHex()) + QLatin1Char('.') + QFileInfo(localCachePath).completeSuffix();
+    setUnitData(unitData, nullptr, fileName, finalUrlString);
 }
-#endif
 
 #ifndef V4_BOOTSTRAP
-CompilationUnit::CompilationUnit()
-    : data(0)
-    , engine(0)
-    , runtimeLookups(0)
-    , runtimeRegularExpressions(0)
-    , runtimeClasses(0)
-    , totalBindingsCount(0)
-    , totalParserStatusCount(0)
-    , totalObjectCount(0)
-    , metaTypeId(-1)
-    , listMetaTypeId(-1)
-    , isRegisteredWithEngine(false)
-{}
-
 CompilationUnit::~CompilationUnit()
 {
     unlink();
-    if (data && !(data->flags & QV4::CompiledData::Unit::StaticData))
-        free(const_cast<Unit *>(data));
-    data = 0;
+
+    if (data) {
+        if (data->qmlUnit() != qmlData)
+            free(const_cast<QmlUnit *>(qmlData));
+        qmlData = nullptr;
+
+        if (!(data->flags & QV4::CompiledData::Unit::StaticData))
+            free(const_cast<Unit *>(data));
+    }
+    data = nullptr;
+#if Q_BYTE_ORDER == Q_BIG_ENDIAN
+    delete [] constants;
+    constants = nullptr;
+#endif
+
+    delete [] imports;
+    imports = nullptr;
+}
+
+QString CompilationUnit::localCacheFilePath(const QUrl &url)
+{
+    const QString localSourcePath = QQmlFile::urlToLocalFileOrQrc(url);
+    const QString cacheFileSuffix = QFileInfo(localSourcePath + QLatin1Char('c')).completeSuffix();
+    QCryptographicHash fileNameHash(QCryptographicHash::Sha1);
+    fileNameHash.addData(localSourcePath.toUtf8());
+    QString directory = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QLatin1String("/qmlcache/");
+    QDir::root().mkpath(directory);
+    return directory + QString::fromUtf8(fileNameHash.result().toHex()) + QLatin1Char('.') + cacheFileSuffix;
 }
 
 QV4::Function *CompilationUnit::linkToEngine(ExecutionEngine *engine)
@@ -122,26 +136,21 @@ QV4::Function *CompilationUnit::linkToEngine(ExecutionEngine *engine)
 
     Q_ASSERT(!runtimeStrings);
     Q_ASSERT(data);
-    runtimeStrings = (QV4::Heap::String **)malloc(data->stringTableSize * sizeof(QV4::Heap::String*));
+    const quint32 stringCount = totalStringCount();
+    runtimeStrings = (QV4::Heap::String **)malloc(stringCount * sizeof(QV4::Heap::String*));
     // memset the strings to 0 in case a GC run happens while we're within the loop below
-    memset(runtimeStrings, 0, data->stringTableSize * sizeof(QV4::Heap::String*));
-    for (uint i = 0; i < data->stringTableSize; ++i)
-        runtimeStrings[i] = engine->newIdentifier(data->stringAt(i));
+    memset(runtimeStrings, 0, stringCount * sizeof(QV4::Heap::String*));
+    for (uint i = 0; i < stringCount; ++i)
+        runtimeStrings[i] = engine->newString(stringAt(i));
 
     runtimeRegularExpressions = new QV4::Value[data->regexpTableSize];
     // memset the regexps to 0 in case a GC run happens while we're within the loop below
     memset(runtimeRegularExpressions, 0, data->regexpTableSize * sizeof(QV4::Value));
     for (uint i = 0; i < data->regexpTableSize; ++i) {
         const CompiledData::RegExp *re = data->regexpAt(i);
-        int flags = 0;
-        if (re->flags & CompiledData::RegExp::RegExp_Global)
-            flags |= IR::RegExp::RegExp_Global;
-        if (re->flags & CompiledData::RegExp::RegExp_IgnoreCase)
-            flags |= IR::RegExp::RegExp_IgnoreCase;
-        if (re->flags & CompiledData::RegExp::RegExp_Multiline)
-            flags |= IR::RegExp::RegExp_Multiline;
-        QV4::Heap::RegExpObject *ro = engine->newRegExpObject(data->stringAt(re->stringIndex), flags);
-        runtimeRegularExpressions[i] = ro;
+        uint f = re->flags;
+        const CompiledData::RegExp::Flags flags = static_cast<CompiledData::RegExp::Flags>(f);
+        runtimeRegularExpressions[i] = QV4::RegExp::create(engine, stringAt(re->stringIndex), flags);
     }
 
     if (data->lookupTableSize) {
@@ -158,66 +167,108 @@ QV4::Function *CompilationUnit::linkToEngine(ExecutionEngine *engine)
                 l->setter = QV4::Lookup::setterGeneric;
             else if (type == CompiledData::Lookup::Type_GlobalGetter)
                 l->globalGetter = QV4::Lookup::globalGetterGeneric;
-            else if (type == CompiledData::Lookup::Type_IndexedGetter)
-                l->indexedGetter = QV4::Lookup::indexedGetterGeneric;
-            else if (type == CompiledData::Lookup::Type_IndexedSetter)
-                l->indexedSetter = QV4::Lookup::indexedSetterGeneric;
-
-            for (int j = 0; j < QV4::Lookup::Size; ++j)
-                l->classList[j] = 0;
-            l->level = -1;
-            l->index = UINT_MAX;
             l->nameIndex = compiledLookups[i].nameIndex;
         }
     }
 
     if (data->jsClassTableSize) {
-        runtimeClasses = (QV4::InternalClass**)malloc(data->jsClassTableSize * sizeof(QV4::InternalClass*));
+        runtimeClasses = (QV4::Heap::InternalClass **)malloc(data->jsClassTableSize * sizeof(QV4::Heap::InternalClass *));
+        // memset the regexps to 0 in case a GC run happens while we're within the loop below
+        memset(runtimeClasses, 0, data->jsClassTableSize * sizeof(QV4::Heap::InternalClass *));
         for (uint i = 0; i < data->jsClassTableSize; ++i) {
             int memberCount = 0;
             const CompiledData::JSClassMember *member = data->jsClassAt(i, &memberCount);
-            QV4::InternalClass *klass = engine->internalClasses[QV4::ExecutionEngine::Class_Object];
+            runtimeClasses[i] = engine->internalClasses(QV4::ExecutionEngine::Class_Object);
             for (int j = 0; j < memberCount; ++j, ++member)
-                klass = klass->addMember(runtimeStrings[member->nameOffset]->identifier, member->isAccessor ? QV4::Attr_Accessor : QV4::Attr_Data);
-
-            runtimeClasses[i] = klass;
+                runtimeClasses[i] = runtimeClasses[i]->addMember(engine->identifierTable->asPropertyKey(runtimeStrings[member->nameOffset]), member->isAccessor ? QV4::Attr_Accessor : QV4::Attr_Data);
         }
     }
 
-#if Q_BYTE_ORDER == Q_BIG_ENDIAN
-    Value *bigEndianConstants = new Value[data->constantTableSize];
-    const LEUInt64 *littleEndianConstants = data->constants();
-    for (uint i = 0; i < data->constantTableSize; ++i)
-        bigEndianConstants[i] = Value::fromReturnedValue(littleEndianConstants[i]);
-    constants = bigEndianConstants;
-#else
-    constants = reinterpret_cast<const Value*>(data->constants());
-#endif
+    runtimeFunctions.resize(data->functionTableSize);
+    for (int i = 0 ;i < runtimeFunctions.size(); ++i) {
+        const QV4::CompiledData::Function *compiledFunction = data->functionAt(i);
+        runtimeFunctions[i] = QV4::Function::create(engine, this, compiledFunction);
+    }
+
+    Scope scope(engine);
+    Scoped<InternalClass> ic(scope);
+
+    runtimeBlocks.resize(data->blockTableSize);
+    for (int i = 0 ;i < runtimeBlocks.size(); ++i) {
+        const QV4::CompiledData::Block *compiledBlock = data->blockAt(i);
+        ic = engine->internalClasses(EngineBase::Class_CallContext);
 
-    linkBackendToEngine(engine);
+        // first locals
+        const quint32_le *localsIndices = compiledBlock->localsTable();
+        for (quint32 j = 0; j < compiledBlock->nLocals; ++j)
+            ic = ic->addMember(engine->identifierTable->asPropertyKey(runtimeStrings[localsIndices[j]]), Attr_NotConfigurable);
+        runtimeBlocks[i] = ic->d();
+    }
+
+    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_BYTECODE");
+    if (showCode) {
+        qDebug() << "=== Constant table";
+        Moth::dumpConstantTable(constants, data->constantTableSize);
+        qDebug() << "=== String table";
+        for (uint i = 0, end = totalStringCount(); i < end; ++i)
+            qDebug() << "    " << i << ":" << runtimeStrings[i]->toQString();
+        qDebug() << "=== Closure table";
+        for (uint i = 0; i < data->functionTableSize; ++i)
+            qDebug() << "    " << i << ":" << runtimeFunctions[i]->name()->toQString();
+        qDebug() << "root function at index " << (data->indexOfRootFunction != -1 ? data->indexOfRootFunction : 0);
+    }
 
     if (data->indexOfRootFunction != -1)
         return runtimeFunctions[data->indexOfRootFunction];
     else
-        return 0;
+        return nullptr;
+}
+
+Heap::Object *CompilationUnit::templateObjectAt(int index) const
+{
+    Q_ASSERT(index < int(data->templateObjectTableSize));
+    if (!templateObjects.size())
+        templateObjects.resize(data->templateObjectTableSize);
+    Heap::Object *o = templateObjects.at(index);
+    if (o)
+        return o;
+
+    // create the template object
+    Scope scope(engine);
+    const CompiledData::TemplateObject *t = data->templateObjectAt(index);
+    Scoped<ArrayObject> a(scope, engine->newArrayObject(t->size));
+    Scoped<ArrayObject> raw(scope, engine->newArrayObject(t->size));
+    ScopedValue s(scope);
+    for (uint i = 0; i < t->size; ++i) {
+        s = runtimeStrings[t->stringIndexAt(i)];
+        a->arraySet(i, s);
+        s = runtimeStrings[t->rawStringIndexAt(i)];
+        raw->arraySet(i, s);
+    }
+
+    ObjectPrototype::method_freeze(engine->functionCtor(), nullptr, raw, 1);
+    a->defineReadonlyProperty(QStringLiteral("raw"), raw);
+    ObjectPrototype::method_freeze(engine->functionCtor(), nullptr, a, 1);
+
+    templateObjects[index] = a->objectValue()->d();
+    return templateObjects.at(index);
 }
 
 void CompilationUnit::unlink()
 {
     if (engine)
-        engine->compilationUnits.erase(engine->compilationUnits.find(this));
+        nextCompilationUnit.remove();
 
     if (isRegisteredWithEngine) {
-        Q_ASSERT(data && quint32(propertyCaches.count()) > data->indexOfRootObject && propertyCaches.at(data->indexOfRootObject));
-        QQmlEnginePrivate *qmlEngine = QQmlEnginePrivate::get(propertyCaches.at(data->indexOfRootObject)->engine);
-        qmlEngine->unregisterInternalCompositeType(this);
+        Q_ASSERT(data && propertyCaches.count() > 0 && propertyCaches.at(/*root object*/0));
+        if (qmlEngine)
+            qmlEngine->unregisterInternalCompositeType(this);
+        QQmlMetaType::unregisterInternalCompositeType(this);
         isRegisteredWithEngine = false;
     }
 
     propertyCaches.clear();
 
-    for (int ii = 0; ii < dependentScripts.count(); ++ii)
-        dependentScripts.at(ii)->release();
     dependentScripts.clear();
 
     typeNameCache = nullptr;
@@ -225,75 +276,87 @@ void CompilationUnit::unlink()
     qDeleteAll(resolvedTypes);
     resolvedTypes.clear();
 
-    engine = 0;
+    engine = nullptr;
+    qmlEngine = nullptr;
     free(runtimeStrings);
-    runtimeStrings = 0;
+    runtimeStrings = nullptr;
     delete [] runtimeLookups;
-    runtimeLookups = 0;
+    runtimeLookups = nullptr;
     delete [] runtimeRegularExpressions;
-    runtimeRegularExpressions = 0;
+    runtimeRegularExpressions = nullptr;
     free(runtimeClasses);
-    runtimeClasses = 0;
-    qDeleteAll(runtimeFunctions);
+    runtimeClasses = nullptr;
+    for (QV4::Function *f : qAsConst(runtimeFunctions))
+        f->destroy();
     runtimeFunctions.clear();
-#if Q_BYTE_ORDER == Q_BIG_ENDIAN
-    delete [] constants;
-#endif
 }
 
 void CompilationUnit::markObjects(QV4::MarkStack *markStack)
 {
-    for (uint i = 0; i < data->stringTableSize; ++i)
-        if (runtimeStrings[i])
-            runtimeStrings[i]->mark(markStack);
+    if (runtimeStrings) {
+        for (uint i = 0, end = totalStringCount(); i < end; ++i)
+            if (runtimeStrings[i])
+                runtimeStrings[i]->mark(markStack);
+    }
     if (runtimeRegularExpressions) {
         for (uint i = 0; i < data->regexpTableSize; ++i)
             runtimeRegularExpressions[i].mark(markStack);
     }
-}
+    if (runtimeClasses) {
+        for (uint i = 0; i < data->jsClassTableSize; ++i)
+            if (runtimeClasses[i])
+                runtimeClasses[i]->mark(markStack);
+    }
+    for (QV4::Function *f : qAsConst(runtimeFunctions))
+        if (f && f->internalClass)
+            f->internalClass->mark(markStack);
+    for (QV4::Heap::InternalClass *c : qAsConst(runtimeBlocks))
+        if (c)
+            c->mark(markStack);
+
+    for (QV4::Heap::Object *o : qAsConst(templateObjects))
+        if (o)
+            o->mark(markStack);
+
+    if (runtimeLookups) {
+        for (uint i = 0; i < data->lookupTableSize; ++i)
+            runtimeLookups[i].markObjects(markStack);
+    }
 
-void CompilationUnit::destroy()
-{
-    QQmlEngine *qmlEngine = 0;
-    if (engine && engine->v8Engine)
-        qmlEngine = engine->v8Engine->engine();
-    if (qmlEngine)
-        QQmlEnginePrivate::deleteInEngineThread(qmlEngine, this);
-    else
-        delete this;
+    if (m_module)
+        m_module->mark(markStack);
 }
 
-IdentifierHash<int> CompilationUnit::namedObjectsPerComponent(int componentObjectIndex)
+IdentifierHash CompilationUnit::createNamedObjectsPerComponent(int componentObjectIndex)
 {
-    auto it = namedObjectsPerComponentCache.find(componentObjectIndex);
-    if (it == namedObjectsPerComponentCache.end()) {
-        IdentifierHash<int> namedObjectCache(engine);
-        const CompiledData::Object *component = data->objectAt(componentObjectIndex);
-        const LEUInt32 *namedObjectIndexPtr = component->namedObjectsInComponentTable();
-        for (quint32 i = 0; i < component->nNamedObjectsInComponent; ++i, ++namedObjectIndexPtr) {
-            const CompiledData::Object *namedObject = data->objectAt(*namedObjectIndexPtr);
-            namedObjectCache.add(runtimeStrings[namedObject->idNameIndex], namedObject->id);
-        }
-        it = namedObjectsPerComponentCache.insert(componentObjectIndex, namedObjectCache);
+    IdentifierHash namedObjectCache(engine);
+    const CompiledData::Object *component = objectAt(componentObjectIndex);
+    const quint32_le *namedObjectIndexPtr = component->namedObjectsInComponentTable();
+    for (quint32 i = 0; i < component->nNamedObjectsInComponent; ++i, ++namedObjectIndexPtr) {
+        const CompiledData::Object *namedObject = objectAt(*namedObjectIndexPtr);
+        namedObjectCache.add(runtimeStrings[namedObject->idNameIndex], namedObject->id);
     }
-    return *it;
+    return *namedObjectsPerComponentCache.insert(componentObjectIndex, namedObjectCache);
 }
 
-void CompilationUnit::finalize(QQmlEnginePrivate *engine)
+void CompilationUnit::finalizeCompositeType(QQmlEnginePrivate *qmlEngine)
 {
+    this->qmlEngine = qmlEngine;
+
     // Add to type registry of composites
-    if (propertyCaches.needsVMEMetaObject(data->indexOfRootObject))
-        engine->registerInternalCompositeType(this);
-    else {
-        const QV4::CompiledData::Object *obj = objectAt(data->indexOfRootObject);
+    if (propertyCaches.needsVMEMetaObject(/*root object*/0)) {
+        QQmlMetaType::registerInternalCompositeType(this);
+        qmlEngine->registerInternalCompositeType(this);
+    } else {
+        const QV4::CompiledData::Object *obj = objectAt(/*root object*/0);
         auto *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex);
         Q_ASSERT(typeRef);
         if (typeRef->compilationUnit) {
             metaTypeId = typeRef->compilationUnit->metaTypeId;
             listMetaTypeId = typeRef->compilationUnit->listMetaTypeId;
         } else {
-            metaTypeId = typeRef->type->typeId();
-            listMetaTypeId = typeRef->type->qListTypeId();
+            metaTypeId = typeRef->type.typeId();
+            listMetaTypeId = typeRef->type.qListTypeId();
         }
     }
 
@@ -301,12 +364,12 @@ void CompilationUnit::finalize(QQmlEnginePrivate *engine)
     int bindingCount = 0;
     int parserStatusCount = 0;
     int objectCount = 0;
-    for (quint32 i = 0; i < data->nObjects; ++i) {
-        const QV4::CompiledData::Object *obj = data->objectAt(i);
+    for (quint32 i = 0, count = this->objectCount(); i < count; ++i) {
+        const QV4::CompiledData::Object *obj = objectAt(i);
         bindingCount += obj->nBindings;
         if (auto *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex)) {
-            if (QQmlType *qmlType = typeRef->type) {
-                if (qmlType->parserStatusCast() != -1)
+            if (typeRef->type.isValid()) {
+                if (typeRef->type.parserStatusCast() != -1)
                     ++parserStatusCount;
             }
             ++objectCount;
@@ -341,58 +404,249 @@ bool CompilationUnit::verifyChecksum(const DependentTypesHasher &dependencyHashe
                   sizeof(data->dependencyMD5Checksum)) == 0;
 }
 
-bool CompilationUnit::loadFromDisk(const QUrl &url, const QDateTime &sourceTimeStamp, EvalISelFactory *iselFactory, QString *errorString)
+QStringList CompilationUnit::moduleRequests() const
 {
-    if (!QQmlFile::isLocalFile(url)) {
-        *errorString = QStringLiteral("File has to be a local file.");
-        return false;
-    }
+    QStringList requests;
+    requests.reserve(data->moduleRequestTableSize);
+    for (uint i = 0; i < data->moduleRequestTableSize; ++i)
+        requests << stringAt(data->moduleRequestTable()[i]);
+    return requests;
+}
 
-    const QString sourcePath = QQmlFile::urlToLocalFileOrQrc(url);
-    QScopedPointer<CompilationUnitMapper> cacheFile(new CompilationUnitMapper());
+Heap::Module *CompilationUnit::instantiate(ExecutionEngine *engine)
+{
+    if (isESModule() && m_module)
+        return m_module;
 
-    CompiledData::Unit *mappedUnit = cacheFile->open(cacheFilePath(url), sourceTimeStamp, errorString);
-    if (!mappedUnit)
-        return false;
+    if (data->indexOfRootFunction < 0)
+        return nullptr;
 
-    const Unit * const oldDataPtr = (data && !(data->flags & QV4::CompiledData::Unit::StaticData)) ? data : nullptr;
-    QScopedValueRollback<const Unit *> dataPtrChange(data, mappedUnit);
+    if (!this->engine)
+        linkToEngine(engine);
 
-    if (data->sourceFileIndex != 0 && sourcePath != QQmlFile::urlToLocalFileOrQrc(stringAt(data->sourceFileIndex))) {
-        *errorString = QStringLiteral("QML source file has moved to a different location.");
-        return false;
+    Scope scope(engine);
+    Scoped<Module> module(scope, engine->memoryManager->allocate<Module>(engine, this));
+
+    if (isESModule())
+        m_module = module->d();
+
+    for (const QString &request: moduleRequests()) {
+        auto dependentModuleUnit = engine->loadModule(QUrl(request), this);
+        if (engine->hasException)
+            return nullptr;
+        dependentModuleUnit->instantiate(engine);
     }
 
-    {
-        const QString foundArchitecture = stringAt(data->architectureIndex);
-        const QString expectedArchitecture = QSysInfo::buildAbi();
-        if (foundArchitecture != expectedArchitecture) {
-            *errorString = QString::fromUtf8("Architecture mismatch. Found %1 expected %2").arg(foundArchitecture).arg(expectedArchitecture);
-            return false;
+    ScopedString importName(scope);
+
+    const uint importCount = data->importEntryTableSize;
+    imports = new const Value *[importCount];
+    memset(imports, 0, importCount * sizeof(Value *));
+    for (uint i = 0; i < importCount; ++i) {
+        const CompiledData::ImportEntry &entry = data->importEntryTable()[i];
+        auto dependentModuleUnit = engine->loadModule(QUrl(stringAt(entry.moduleRequest)), this);
+        importName = runtimeStrings[entry.importName];
+        const Value *valuePtr = dependentModuleUnit->resolveExport(importName);
+        if (!valuePtr) {
+            QString referenceErrorMessage = QStringLiteral("Unable to resolve import reference ");
+            referenceErrorMessage += importName->toQString();
+            engine->throwReferenceError(referenceErrorMessage, fileName(), entry.location.line, entry.location.column);
+            return nullptr;
         }
+        imports[i] = valuePtr;
     }
 
-    {
-        const QString foundCodeGenerator = stringAt(data->codeGeneratorIndex);
-        const QString expectedCodeGenerator = iselFactory->codeGeneratorName;
-        if (foundCodeGenerator != expectedCodeGenerator) {
-            *errorString = QString::fromUtf8("Code generator mismatch. Found code generated by %1 but expected %2").arg(foundCodeGenerator).arg(expectedCodeGenerator);
-            return false;
+    for (uint i = 0; i < data->indirectExportEntryTableSize; ++i) {
+        const CompiledData::ExportEntry &entry = data->indirectExportEntryTable()[i];
+        auto dependentModuleUnit = engine->loadModule(QUrl(stringAt(entry.moduleRequest)), this);
+        if (!dependentModuleUnit)
+            return nullptr;
+
+        ScopedString importName(scope, runtimeStrings[entry.importName]);
+        if (!dependentModuleUnit->resolveExport(importName)) {
+            QString referenceErrorMessage = QStringLiteral("Unable to resolve re-export reference ");
+            referenceErrorMessage += importName->toQString();
+            engine->throwReferenceError(referenceErrorMessage, fileName(), entry.location.line, entry.location.column);
+            return nullptr;
         }
     }
 
-    if (!memoryMapCode(errorString))
-        return false;
+    return module->d();
+}
 
-    dataPtrChange.commit();
-    free(const_cast<Unit*>(oldDataPtr));
-    backingFile.reset(cacheFile.take());
-    return true;
+const Value *CompilationUnit::resolveExport(QV4::String *exportName)
+{
+    QVector<ResolveSetEntry> resolveSet;
+    return resolveExportRecursively(exportName, &resolveSet);
+}
+
+QStringList CompilationUnit::exportedNames() const
+{
+    QStringList names;
+    QVector<const CompiledData::CompilationUnit*> exportNameSet;
+    getExportedNamesRecursively(&names, &exportNameSet);
+    names.sort();
+    auto last = std::unique(names.begin(), names.end());
+    names.erase(last, names.end());
+    return names;
+}
+
+const Value *CompilationUnit::resolveExportRecursively(QV4::String *exportName, QVector<ResolveSetEntry> *resolveSet)
+{
+    if (!m_module)
+        return nullptr;
+
+    for (const auto &entry: *resolveSet)
+        if (entry.module == this && entry.exportName->isEqualTo(exportName))
+            return nullptr;
+
+    (*resolveSet) << ResolveSetEntry(this, exportName);
+
+    if (exportName->toQString() == QLatin1String("*"))
+        return &m_module->self;
+
+    Scope scope(engine);
+
+    if (auto localExport = lookupNameInExportTable(data->localExportEntryTable(), data->localExportEntryTableSize, exportName)) {
+        ScopedString localName(scope, runtimeStrings[localExport->localName]);
+        uint index = m_module->scope->internalClass->indexOfValueOrGetter(localName->toPropertyKey());
+        if (index == UINT_MAX)
+            return nullptr;
+        if (index >= m_module->scope->locals.size)
+            return imports[index - m_module->scope->locals.size];
+        return &m_module->scope->locals[index];
+    }
+
+    if (auto indirectExport = lookupNameInExportTable(data->indirectExportEntryTable(), data->indirectExportEntryTableSize, exportName)) {
+        auto dependentModuleUnit = engine->loadModule(QUrl(stringAt(indirectExport->moduleRequest)), this);
+        if (!dependentModuleUnit)
+            return nullptr;
+        ScopedString importName(scope, runtimeStrings[indirectExport->importName]);
+        return dependentModuleUnit->resolveExportRecursively(importName, resolveSet);
+    }
+
+
+    if (exportName->toQString() == QLatin1String("default"))
+        return nullptr;
+
+    const Value *starResolution = nullptr;
+
+    for (uint i = 0; i < data->starExportEntryTableSize; ++i) {
+        const CompiledData::ExportEntry &entry = data->starExportEntryTable()[i];
+        auto dependentModuleUnit = engine->loadModule(QUrl(stringAt(entry.moduleRequest)), this);
+        if (!dependentModuleUnit)
+            return nullptr;
+
+        const Value *resolution = dependentModuleUnit->resolveExportRecursively(exportName, resolveSet);
+        // ### handle ambiguous
+        if (resolution) {
+            if (!starResolution) {
+                starResolution = resolution;
+                continue;
+            }
+            if (resolution != starResolution)
+                return nullptr;
+        }
+    }
+
+    return starResolution;
+}
+
+const ExportEntry *CompilationUnit::lookupNameInExportTable(const ExportEntry *firstExportEntry, int tableSize, QV4::String *name) const
+{
+    const CompiledData::ExportEntry *lastExportEntry = firstExportEntry + tableSize;
+    auto matchingExport = std::lower_bound(firstExportEntry, lastExportEntry, name, [this](const CompiledData::ExportEntry &lhs, QV4::String *name) {
+        return stringAt(lhs.exportName) < name->toQString();
+    });
+    if (matchingExport == lastExportEntry || stringAt(matchingExport->exportName) != name->toQString())
+        return nullptr;
+    return matchingExport;
+}
+
+void CompilationUnit::getExportedNamesRecursively(QStringList *names, QVector<const CompilationUnit*> *exportNameSet, bool includeDefaultExport) const
+{
+    if (exportNameSet->contains(this))
+        return;
+    exportNameSet->append(this);
+
+    const auto append = [names, includeDefaultExport](const QString &name) {
+        if (!includeDefaultExport && name == QLatin1String("default"))
+            return;
+        names->append(name);
+    };
+
+    for (uint i = 0; i < data->localExportEntryTableSize; ++i) {
+        const CompiledData::ExportEntry &entry = data->localExportEntryTable()[i];
+        append(stringAt(entry.exportName));
+    }
+
+    for (uint i = 0; i < data->indirectExportEntryTableSize; ++i) {
+        const CompiledData::ExportEntry &entry = data->indirectExportEntryTable()[i];
+        append(stringAt(entry.exportName));
+    }
+
+    for (uint i = 0; i < data->starExportEntryTableSize; ++i) {
+        const CompiledData::ExportEntry &entry = data->starExportEntryTable()[i];
+        auto dependentModuleUnit = engine->loadModule(QUrl(stringAt(entry.moduleRequest)), this);
+        if (!dependentModuleUnit)
+            return;
+        dependentModuleUnit->getExportedNamesRecursively(names, exportNameSet, /*includeDefaultExport*/false);
+    }
+}
+
+void CompilationUnit::evaluate()
+{
+    QV4::Scope scope(engine);
+    QV4::Scoped<Module> module(scope, m_module);
+    module->evaluate();
+}
+
+void CompilationUnit::evaluateModuleRequests()
+{
+    for (const QString &request: moduleRequests()) {
+        auto dependentModuleUnit = engine->loadModule(QUrl(request), this);
+        if (engine->hasException)
+            return;
+        dependentModuleUnit->evaluate();
+        if (engine->hasException)
+            return;
+    }
 }
 
-bool CompilationUnit::memoryMapCode(QString *errorString)
+bool CompilationUnit::loadFromDisk(const QUrl &url, const QDateTime &sourceTimeStamp, QString *errorString)
 {
-    *errorString = QStringLiteral("Missing code mapping backend");
+    if (!QQmlFile::isLocalFile(url)) {
+        *errorString = QStringLiteral("File has to be a local file.");
+        return false;
+    }
+
+    const QString sourcePath = QQmlFile::urlToLocalFileOrQrc(url);
+    QScopedPointer<CompilationUnitMapper> cacheFile(new CompilationUnitMapper());
+
+    const QStringList cachePaths = { sourcePath + QLatin1Char('c'), localCacheFilePath(url) };
+    for (const QString &cachePath : cachePaths) {
+        CompiledData::Unit *mappedUnit = cacheFile->open(cachePath, sourceTimeStamp, errorString);
+        if (!mappedUnit)
+            continue;
+
+        const Unit * const oldDataPtr = (data && !(data->flags & QV4::CompiledData::Unit::StaticData)) ? data : nullptr;
+        const Unit *oldData = data;
+        auto dataPtrRevert = qScopeGuard([this, oldData](){
+            setUnitData(oldData);
+        });
+        setUnitData(mappedUnit);
+
+        if (data->sourceFileIndex != 0 && sourcePath != QQmlFile::urlToLocalFileOrQrc(stringAt(data->sourceFileIndex))) {
+            *errorString = QStringLiteral("QML source file has moved to a different location.");
+            continue;
+        }
+
+        dataPtrRevert.dismiss();
+        free(const_cast<Unit*>(oldDataPtr));
+        backingFile.reset(cacheFile.take());
+        return true;
+    }
+
     return false;
 }
 
@@ -416,7 +670,7 @@ bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
         *errorString = QStringLiteral("File has to be a local file.");
         return false;
     }
-    const QString outputFileName = cacheFilePath(unitUrl);
+    const QString outputFileName = localCacheFilePath(unitUrl);
 #endif
 
 #if QT_CONFIG(temporaryfile)
@@ -435,17 +689,12 @@ bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
     memcpy(&unitPtr, &dataPtr, sizeof(unitPtr));
     unitPtr->flags |= Unit::StaticData;
 
-    prepareCodeOffsetsForDiskStorage(unitPtr);
-
     qint64 headerWritten = cacheFile.write(modifiedUnit);
     if (headerWritten != modifiedUnit.size()) {
         *errorString = cacheFile.errorString();
         return false;
     }
 
-    if (!saveCodeToDisk(&cacheFile, unitPtr, errorString))
-        return false;
-
     if (!cacheFile.commit()) {
         *errorString = cacheFile.errorString();
         return false;
@@ -459,152 +708,73 @@ bool CompilationUnit::saveToDisk(const QUrl &unitUrl, QString *errorString)
 #endif // QT_CONFIG(temporaryfile)
 }
 
-void CompilationUnit::prepareCodeOffsetsForDiskStorage(Unit *unit)
+void CompilationUnit::setUnitData(const Unit *unitData, const QmlUnit *qmlUnit,
+                                  const QString &fileName, const QString &finalUrlString)
 {
-    Q_UNUSED(unit);
-}
-
-bool CompilationUnit::saveCodeToDisk(QIODevice *device, const Unit *unit, QString *errorString)
-{
-    Q_UNUSED(device);
-    Q_UNUSED(unit);
-    *errorString = QStringLiteral("Saving code to disk is not supported in this configuration");
-    return false;
-}
-
-Unit *CompilationUnit::createUnitData(QmlIR::Document *irDocument)
-{
-    if (!irDocument->javaScriptCompilationUnit->data)
-        return irDocument->jsGenerator.generateUnit(QV4::Compiler::JSUnitGenerator::GenerateWithoutStringTable);
-
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit = irDocument->javaScriptCompilationUnit;
-    QV4::CompiledData::Unit *jsUnit = const_cast<QV4::CompiledData::Unit*>(compilationUnit->data);
-    auto ensureWritableUnit = [&jsUnit, &compilationUnit]() {
-        if (jsUnit == compilationUnit->data) {
-            char *unitCopy = (char*)malloc(jsUnit->unitSize);
-            memcpy(unitCopy, jsUnit, jsUnit->unitSize);
-            jsUnit = reinterpret_cast<QV4::CompiledData::Unit*>(unitCopy);
-        }
-    };
-
-    QV4::Compiler::StringTableGenerator &stringTable = irDocument->jsGenerator.stringTable;
-
-    if (jsUnit->sourceFileIndex == quint32(0) || jsUnit->stringAt(jsUnit->sourceFileIndex) != irDocument->jsModule.fileName) {
-        ensureWritableUnit();
-        jsUnit->sourceFileIndex = stringTable.registerString(irDocument->jsModule.fileName);
-    }
-
-    // Collect signals that have had a change in signature (from onClicked to onClicked(mouse) for example)
-    // and now need fixing in the QV4::CompiledData. Also register strings at the same time, to finalize
-    // the string table.
-    QVector<quint32> changedSignals;
-    QVector<QQmlJS::AST::FormalParameterList*> changedSignalParameters;
-    for (QmlIR::Object *o: qAsConst(irDocument->objects)) {
-        for (QmlIR::Binding *binding = o->firstBinding(); binding; binding = binding->next) {
-            if (!(binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression))
-                continue;
-
-            quint32 functionIndex = binding->value.compiledScriptIndex;
-            QmlIR::CompiledFunctionOrExpression *foe = o->functionsAndExpressions->slowAt(functionIndex);
-            if (!foe)
-                continue;
-
-            // save absolute index
-            changedSignals << o->runtimeFunctionIndices.at(functionIndex);
-
-            Q_ASSERT(foe->node);
-            Q_ASSERT(QQmlJS::AST::cast<QQmlJS::AST::FunctionDeclaration*>(foe->node));
-
-            QQmlJS::AST::FormalParameterList *parameters = QQmlJS::AST::cast<QQmlJS::AST::FunctionDeclaration*>(foe->node)->formals;
-            changedSignalParameters << parameters;
-
-            for (; parameters; parameters = parameters->next)
-                stringTable.registerString(parameters->name.toString());
-        }
-    }
-
-    QVector<quint32> signalParameterNameTable;
-    quint32 signalParameterNameTableOffset = jsUnit->unitSize;
-
-    // Update signal signatures
-    if (!changedSignals.isEmpty()) {
-        if (jsUnit == compilationUnit->data) {
-            char *unitCopy = (char*)malloc(jsUnit->unitSize);
-            memcpy(unitCopy, jsUnit, jsUnit->unitSize);
-            jsUnit = reinterpret_cast<QV4::CompiledData::Unit*>(unitCopy);
-        }
-
-        for (int i = 0; i < changedSignals.count(); ++i) {
-            const uint functionIndex = changedSignals.at(i);
-            // The data is now read-write due to the copy above, so the const_cast is ok.
-            QV4::CompiledData::Function *function = const_cast<QV4::CompiledData::Function *>(jsUnit->functionAt(functionIndex));
-            Q_ASSERT(function->nFormals == quint32(0));
-
-            function->formalsOffset = signalParameterNameTableOffset - jsUnit->functionOffsetTable()[functionIndex];
-
-            for (QQmlJS::AST::FormalParameterList *parameters = changedSignalParameters.at(i);
-                 parameters; parameters = parameters->next) {
-                signalParameterNameTable.append(stringTable.getStringId(parameters->name.toString()));
-                function->nFormals = function->nFormals + 1;
-            }
-
-            // Hack to ensure an activation is created.
-            function->flags |= QV4::CompiledData::Function::HasCatchOrWith | QV4::CompiledData::Function::HasDirectEval;
-
-            signalParameterNameTableOffset += function->nFormals * sizeof(quint32);
-        }
-    }
+    data = unitData;
+    qmlData = nullptr;
+#if Q_BYTE_ORDER == Q_BIG_ENDIAN
+    delete [] constants;
+#endif
+    constants = nullptr;
+    m_fileName.clear();
+    m_finalUrlString.clear();
+    if (!data)
+        return;
 
-    if (!signalParameterNameTable.isEmpty()) {
-        ensureWritableUnit();
-        Q_ASSERT(jsUnit != compilationUnit->data);
-        const uint signalParameterTableSize = signalParameterNameTable.count() * sizeof(quint32);
-        uint newSize = jsUnit->unitSize + signalParameterTableSize;
-        const uint oldSize = jsUnit->unitSize;
-        char *unitWithSignalParameters = (char*)realloc(jsUnit, newSize);
-        memcpy(unitWithSignalParameters + oldSize, signalParameterNameTable.constData(), signalParameterTableSize);
-        jsUnit = reinterpret_cast<QV4::CompiledData::Unit*>(unitWithSignalParameters);
-        jsUnit->unitSize = newSize;
-    }
+    qmlData = qmlUnit ? qmlUnit : data->qmlUnit();
 
-    if (jsUnit != compilationUnit->data)
-        jsUnit->flags &= ~QV4::CompiledData::Unit::StaticData;
+#if Q_BYTE_ORDER == Q_BIG_ENDIAN
+    Value *bigEndianConstants = new Value[data->constantTableSize];
+    const quint64_le *littleEndianConstants = data->constants();
+    for (uint i = 0; i < data->constantTableSize; ++i)
+        bigEndianConstants[i] = Value::fromReturnedValue(littleEndianConstants[i]);
+    constants = bigEndianConstants;
+#else
+    constants = reinterpret_cast<const Value*>(data->constants());
+#endif
 
-    return jsUnit;
+    m_fileName = !fileName.isEmpty() ? fileName : stringAt(data->sourceFileIndex);
+    m_finalUrlString = !finalUrlString.isEmpty() ? finalUrlString : stringAt(data->finalUrlIndex);
 }
 
-QString Binding::valueAsString(const Unit *unit) const
+#ifndef V4_BOOTSTRAP
+QString Binding::valueAsString(const CompilationUnit *unit) const
 {
     switch (type) {
     case Type_Script:
     case Type_String:
         return unit->stringAt(stringIndex);
+    case Type_Null:
+        return QStringLiteral("null");
     case Type_Boolean:
         return value.b ? QStringLiteral("true") : QStringLiteral("false");
     case Type_Number:
-        return QString::number(valueAsNumber());
+        return QString::number(valueAsNumber(unit->constants));
     case Type_Invalid:
         return QString();
 #if !QT_CONFIG(translation)
     case Type_TranslationById:
     case Type_Translation:
-        return unit->stringAt(stringIndex);
+        return unit->stringAt(unit->unitData()->translations()[value.translationDataIndex].stringIndex);
 #else
     case Type_TranslationById: {
-        QByteArray id = unit->stringAt(stringIndex).toUtf8();
-        return qtTrId(id.constData(), value.translationData.number);
+        const TranslationData &translation = unit->unitData()->translations()[value.translationDataIndex];
+        QByteArray id = unit->stringAt(translation.stringIndex).toUtf8();
+        return qtTrId(id.constData(), translation.number);
     }
     case Type_Translation: {
+        const TranslationData &translation = unit->unitData()->translations()[value.translationDataIndex];
         // This code must match that in the qsTr() implementation
-        const QString &path = unit->stringAt(unit->sourceFileIndex);
+        const QString &path = unit->fileName();
         int lastSlash = path.lastIndexOf(QLatin1Char('/'));
         QStringRef context = (lastSlash > -1) ? path.midRef(lastSlash + 1, path.length() - lastSlash - 5)
                                               : QStringRef();
         QByteArray contextUtf8 = context.toUtf8();
-        QByteArray comment = unit->stringAt(value.translationData.commentIndex).toUtf8();
-        QByteArray text = unit->stringAt(stringIndex).toUtf8();
+        QByteArray comment = unit->stringAt(translation.commentIndex).toUtf8();
+        QByteArray text = unit->stringAt(translation.stringIndex).toUtf8();
         return QCoreApplication::translate(contextUtf8.constData(), text.constData(),
-                                           comment.constData(), value.translationData.number);
+                                           comment.constData(), translation.number);
     }
 #endif
     default:
@@ -656,7 +826,7 @@ QString Binding::escapedString(const QString &string)
     return tmp;
 }
 
-QString Binding::valueAsScriptString(const Unit *unit) const
+QString Binding::valueAsScriptString(const CompilationUnit *unit) const
 {
     if (type == Type_String)
         return escapedString(unit->stringAt(stringIndex));
@@ -664,13 +834,12 @@ QString Binding::valueAsScriptString(const Unit *unit) const
         return valueAsString(unit);
 }
 
-#ifndef V4_BOOTSTRAP
 /*!
 Returns the property cache, if one alread exists.  The cache is not referenced.
 */
-QQmlPropertyCache *ResolvedTypeReference::propertyCache() const
+QQmlRefPointer<QQmlPropertyCache> ResolvedTypeReference::propertyCache() const
 {
-    if (type)
+    if (type.isValid())
         return typePropertyCache;
     else
         return compilationUnit->rootPropertyCache();
@@ -679,12 +848,12 @@ QQmlPropertyCache *ResolvedTypeReference::propertyCache() const
 /*!
 Returns the property cache, creating one if it doesn't already exist.  The cache is not referenced.
 */
-QQmlPropertyCache *ResolvedTypeReference::createPropertyCache(QQmlEngine *engine)
+QQmlRefPointer<QQmlPropertyCache> ResolvedTypeReference::createPropertyCache(QQmlEngine *engine)
 {
     if (typePropertyCache) {
         return typePropertyCache;
-    } else if (type) {
-        typePropertyCache = QQmlEnginePrivate::get(engine)->cache(type->metaObject());
+    } else if (type.isValid()) {
+        typePropertyCache = QQmlEnginePrivate::get(engine)->cache(type.metaObject(), minorVersion);
         return typePropertyCache;
     } else {
         return compilationUnit->rootPropertyCache();
@@ -693,12 +862,12 @@ QQmlPropertyCache *ResolvedTypeReference::createPropertyCache(QQmlEngine *engine
 
 bool ResolvedTypeReference::addToHash(QCryptographicHash *hash, QQmlEngine *engine)
 {
-    if (type) {
+    if (type.isValid()) {
         bool ok = false;
         hash->addData(createPropertyCache(engine)->checksum(&ok));
         return ok;
     }
-    hash->addData(compilationUnit->data->md5Checksum, sizeof(compilationUnit->data->md5Checksum));
+    hash->addData(compilationUnit->unitData()->md5Checksum, sizeof(compilationUnit->unitData()->md5Checksum));
     return true;
 }
 
@@ -714,43 +883,16 @@ bool qtTypeInherits(const QMetaObject *mo) {
 
 void ResolvedTypeReference::doDynamicTypeCheck()
 {
-    const QMetaObject *mo = 0;
+    const QMetaObject *mo = nullptr;
     if (typePropertyCache)
         mo = typePropertyCache->firstCppMetaObject();
-    else if (type)
-        mo = type->metaObject();
+    else if (type.isValid())
+        mo = type.metaObject();
     else if (compilationUnit)
         mo = compilationUnit->rootPropertyCache()->firstCppMetaObject();
     isFullyDynamicType = qtTypeInherits<QQmlPropertyMap>(mo);
 }
 
-#if defined(QT_BUILD_INTERNAL)
-
-static QByteArray ownLibraryChecksum()
-{
-    static QByteArray libraryChecksum;
-    static bool checksumInitialized = false;
-    if (checksumInitialized)
-        return libraryChecksum;
-    checksumInitialized = true;
-#if !defined(QT_NO_DYNAMIC_CAST) && QT_CONFIG(dlopen)
-    Dl_info libInfo;
-    if (dladdr(reinterpret_cast<const void *>(&ownLibraryChecksum), &libInfo) != 0) {
-        QFile library(QFile::decodeName(libInfo.dli_fname));
-        if (library.open(QIODevice::ReadOnly)) {
-            QCryptographicHash hash(QCryptographicHash::Md5);
-            hash.addData(&library);
-            libraryChecksum = hash.result();
-        }
-    }
-#else
-    // Not implemented.
-#endif
-    return libraryChecksum;
-}
-
-#endif
-
 bool ResolvedTypeReferenceMap::addToHash(QCryptographicHash *hash, QQmlEngine *engine) const
 {
     for (auto it = constBegin(), end = constEnd(); it != end; ++it) {
@@ -758,18 +900,22 @@ bool ResolvedTypeReferenceMap::addToHash(QCryptographicHash *hash, QQmlEngine *e
             return false;
     }
 
-    // This is a bit of a hack to make development easier. When hacking on the code generator
-    // the cache files may end up being re-used. To avoid that we also add the checksum of
-    // the QtQml library.
-#if defined(QT_BUILD_INTERNAL)
-    hash->addData(ownLibraryChecksum());
-#endif
-
     return true;
 }
 
 #endif
 
+void CompilationUnit::destroy()
+{
+#if !defined(V4_BOOTSTRAP)
+    if (qmlEngine)
+        QQmlEnginePrivate::deleteInEngineThread(qmlEngine, this);
+    else
+#endif
+        delete this;
+}
+
+
 void Unit::generateChecksum()
 {
 #ifndef V4_BOOTSTRAP
@@ -788,6 +934,60 @@ void Unit::generateChecksum()
 #endif
 }
 
+bool Unit::verifyHeader(QDateTime expectedSourceTimeStamp, QString *errorString) const
+{
+#ifndef V4_BOOTSTRAP
+    if (strncmp(magic, CompiledData::magic_str, sizeof(magic))) {
+        *errorString = QStringLiteral("Magic bytes in the header do not match");
+        return false;
+    }
+
+    if (version != quint32(QV4_DATA_STRUCTURE_VERSION)) {
+        *errorString = QString::fromUtf8("V4 data structure version mismatch. Found %1 expected %2").arg(version, 0, 16).arg(QV4_DATA_STRUCTURE_VERSION, 0, 16);
+        return false;
+    }
+
+    if (qtVersion != quint32(QT_VERSION)) {
+        *errorString = QString::fromUtf8("Qt version mismatch. Found %1 expected %2").arg(qtVersion, 0, 16).arg(QT_VERSION, 0, 16);
+        return false;
+    }
+
+    if (sourceTimeStamp) {
+        // Files from the resource system do not have any time stamps, so fall back to the application
+        // executable.
+        if (!expectedSourceTimeStamp.isValid())
+            expectedSourceTimeStamp = QFileInfo(QCoreApplication::applicationFilePath()).lastModified();
+
+        if (expectedSourceTimeStamp.isValid() && expectedSourceTimeStamp.toMSecsSinceEpoch() != sourceTimeStamp) {
+            *errorString = QStringLiteral("QML source file has a different time stamp than cached file.");
+            return false;
+        }
+    }
+
+#if defined(QML_COMPILE_HASH)
+    if (qstrcmp(CompiledData::qml_compile_hash, libraryVersionHash) != 0) {
+        *errorString = QStringLiteral("QML library version mismatch. Expected compile hash does not match");
+        return false;
+    }
+#else
+#error "QML_COMPILE_HASH must be defined for the build of QtDeclarative to ensure version checking for cache files"
+#endif
+
+    return true;
+#else
+    Q_UNUSED(expectedSourceTimeStamp)
+    Q_UNUSED(errorString)
+    return false;
+#endif
+}
+
+Location &Location::operator=(const QQmlJS::AST::SourceLocation &astLocation)
+{
+    line = astLocation.startLine;
+    column = astLocation.startColumn;
+    return *this;
+}
+
 }
 
 }
diff --git a/src/qml/compiler/qv4compileddata_p.h b/src/qml/compiler/qv4compileddata_p.h
index f4ba257cf5..1aaba13241 100644
--- a/src/qml/compiler/qv4compileddata_p.h
+++ b/src/qml/compiler/qv4compileddata_p.h
@@ -62,19 +62,20 @@
 #include <private/qqmlnullablevalue_p.h>
 #include <private/qv4identifier_p.h>
 #include <private/qflagpointer_p.h>
-#include <private/qjson_p.h>
+#include <private/qendian_p.h>
+#include <private/qqmljsastfwd_p.h>
 #ifndef V4_BOOTSTRAP
 #include <private/qqmltypenamecache_p.h>
-#include <private/qqmlpropertycache_p.h>
+#include <private/qqmlpropertycachevector_p.h>
+#include "private/qintrusivelist_p.h"
 #endif
 
 QT_BEGIN_NAMESPACE
 
 // Bump this whenever the compiler data structures change in an incompatible way.
-#define QV4_DATA_STRUCTURE_VERSION 0x11
+#define QV4_DATA_STRUCTURE_VERSION 0x1b
 
 class QIODevice;
-class QQmlPropertyCache;
 class QQmlPropertyData;
 class QQmlTypeNameCache;
 class QQmlScriptData;
@@ -86,9 +87,10 @@ struct Document;
 }
 
 namespace QV4 {
-namespace IR {
-struct Function;
-}
+
+namespace Heap {
+struct Module;
+};
 
 struct Function;
 class EvalISelFactory;
@@ -96,13 +98,6 @@ class CompilationUnitMapper;
 
 namespace CompiledData {
 
-typedef QJsonPrivate::q_littleendian<qint16> LEInt16;
-typedef QJsonPrivate::q_littleendian<quint16> LEUInt16;
-typedef QJsonPrivate::q_littleendian<quint32> LEUInt32;
-typedef QJsonPrivate::q_littleendian<qint32> LEInt32;
-typedef QJsonPrivate::q_littleendian<quint64> LEUInt64;
-typedef QJsonPrivate::q_littleendian<qint64> LEInt64;
-
 struct String;
 struct Function;
 struct Lookup;
@@ -122,85 +117,145 @@ struct TableIterator
     bool operator!=(const TableIterator &rhs) const { return index != rhs.index; }
 };
 
-#if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
-#pragma pack(push, 1)
-#endif
-
 struct Location
 {
     union {
-        QJsonPrivate::qle_bitfield<0, 20> line;
-        QJsonPrivate::qle_bitfield<20, 12> column;
+        quint32 _dummy;
+        quint32_le_bitfield<0, 20> line;
+        quint32_le_bitfield<20, 12> column;
     };
 
-    Location() { line.val = 0; column.val = 0; }
+    Location() : _dummy(0) { }
+
+    Location &operator=(const QQmlJS::AST::SourceLocation &astLocation);
 
     inline bool operator<(const Location &other) const {
         return line < other.line ||
                (line == other.line && column < other.column);
     }
 };
+static_assert(sizeof(Location) == 4, "Location structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct RegExp
 {
     enum Flags : unsigned int {
+        RegExp_NoFlags    = 0x0,
         RegExp_Global     = 0x01,
         RegExp_IgnoreCase = 0x02,
-        RegExp_Multiline  = 0x04
+        RegExp_Multiline  = 0x04,
+        RegExp_Unicode    = 0x08,
+        RegExp_Sticky     = 0x10
     };
     union {
-        QJsonPrivate::qle_bitfield<0, 4> flags;
-        QJsonPrivate::qle_bitfield<4, 28> stringIndex;
+        quint32 _dummy;
+        quint32_le_bitfield<0, 5> flags;
+        quint32_le_bitfield<5, 27> stringIndex;
     };
 
-    RegExp() { flags.val = 0; stringIndex.val = 0; }
+    RegExp() : _dummy(0) { }
 };
+static_assert(sizeof(RegExp) == 4, "RegExp structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Lookup
 {
     enum Type : unsigned int {
         Type_Getter = 0x0,
         Type_Setter = 0x1,
-        Type_GlobalGetter = 2,
-        Type_IndexedGetter = 3,
-        Type_IndexedSetter = 4
+        Type_GlobalGetter = 2
     };
 
     union {
-        QJsonPrivate::qle_bitfield<0, 4> type_and_flags;
-        QJsonPrivate::qle_bitfield<4, 28> nameIndex;
+        quint32 _dummy;
+        quint32_le_bitfield<0, 4> type_and_flags;
+        quint32_le_bitfield<4, 28> nameIndex;
     };
 
-    Lookup() { type_and_flags.val = 0; nameIndex.val = 0; }
+    Lookup() : _dummy(0) { }
 };
+static_assert(sizeof(Lookup) == 4, "Lookup structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct JSClassMember
 {
     union {
-        QJsonPrivate::qle_bitfield<0, 31> nameOffset;
-        QJsonPrivate::qle_bitfield<31, 1> isAccessor;
+        quint32 _dummy;
+        quint32_le_bitfield<0, 31> nameOffset;
+        quint32_le_bitfield<31, 1> isAccessor;
     };
 
-    JSClassMember() { nameOffset = 0; isAccessor = 0; }
+    JSClassMember() : _dummy(0) { }
 };
+static_assert(sizeof(JSClassMember) == 4, "JSClassMember structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct JSClass
 {
-    LEUInt32 nMembers;
+    quint32_le nMembers;
     // JSClassMember[nMembers]
 
     static int calculateSize(int nMembers) { return (sizeof(JSClass) + nMembers * sizeof(JSClassMember) + 7) & ~7; }
 };
-
+static_assert(sizeof(JSClass) == 4, "JSClass structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+// This data structure is intended to be binary compatible with QStringData/QStaticStringData on
+// 64-bit and 32-bit little-endian architectures, in all directions. So the same structure mapped
+// from a file must be castable to a QStringData regardless of the pointer size. With the first
+// few fields that's easy, they're always 32-bit. However the offset field of QArrayData is a
+// ptrdiff_t and thus variable in size.
+// On 64-bit systems compilers enforce an 8-byte alignment and thus place it at offset 16, while
+// on 32-bit systems offset 12 is sufficient. Therefore the two values don't overlap and contain
+// the same value.
 struct String
 {
-    LEInt32 size;
+    qint32_le refcount; // -1
+    qint32_le size;
+    quint32_le allocAndCapacityReservedFlag; // 0
+    quint32_le offsetOn32Bit;
+    quint64_le offsetOn64Bit;
     // uint16 strdata[]
 
     static int calculateSize(const QString &str) {
-        return (sizeof(String) + str.length() * sizeof(quint16) + 7) & ~0x7;
+        return (sizeof(String) + (str.length() + 1) * sizeof(quint16) + 7) & ~0x7;
+    }
+};
+static_assert(sizeof(String) == 24, "String structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+// Ensure compatibility with QString
+static_assert(offsetof(QArrayData, ref) == offsetof(String, refcount), "refcount must be at the same location");
+static_assert(offsetof(QArrayData, size) == offsetof(String, size), "size must be at the same location");
+static_assert(offsetof(String, offsetOn64Bit) == 16, "offset must be at 8-byte aligned location");
+static_assert(offsetof(String, offsetOn32Bit) == 12, "offset must be at 4-byte aligned location");
+#if QT_POINTER_SIZE == 8
+static_assert(offsetof(QArrayData, offset) == offsetof(String, offsetOn64Bit), "offset must be at the same location");
+#else
+static_assert(offsetof(QArrayData, offset) == offsetof(String, offsetOn32Bit), "offset must be at the same location");
+#endif
+
+struct CodeOffsetToLine {
+    quint32_le codeOffset;
+    quint32_le line;
+};
+static_assert(sizeof(CodeOffsetToLine) == 8, "CodeOffsetToLine structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct Block
+{
+    quint32_le nLocals;
+    quint32_le localsOffset;
+    quint16_le sizeOfLocalTemporalDeadZone;
+    quint16_le padding;
+
+    const quint32_le *localsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + localsOffset); }
+
+    static int calculateSize(int nLocals) {
+        int trailingData = nLocals*sizeof (quint32);
+        size_t size = align(align(sizeof(Block)) + size_t(trailingData));
+        Q_ASSERT(size < INT_MAX);
+        return int(size);
+    }
+
+    static size_t align(size_t a) {
+        return (a + 7) & ~size_t(7);
     }
 };
+static_assert(sizeof(Block) == 12, "Block structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 // Function is aligned on an 8-byte boundary to make sure there are no bus errors or penalties
 // for unaligned access. The ordering of the fields is also from largest to smallest.
@@ -208,77 +263,193 @@ struct Function
 {
     enum Flags : unsigned int {
         IsStrict            = 0x1,
-        HasDirectEval       = 0x2,
-        UsesArgumentsObject = 0x4,
-        IsNamedExpression   = 0x8,
-        HasCatchOrWith      = 0x10,
-        CanUseSimpleCall    = 0x20
+        IsArrowFunction     = 0x2,
+        IsGenerator         = 0x4
     };
 
-    // Absolute offset into file where the code for this function is located. Only used when the function
-    // is serialized.
-    LEUInt64 codeOffset;
-    LEUInt64 codeSize;
-
-    LEUInt32 nameIndex;
-    LEUInt32 nFormals;
-    LEUInt32 formalsOffset;
-    LEUInt32 nLocals;
-    LEUInt32 localsOffset;
-    LEUInt32 nInnerFunctions;
+    // Absolute offset into file where the code for this function is located.
+    quint32_le codeOffset;
+    quint32_le codeSize;
+
+    quint32_le nameIndex;
+    quint16_le length;
+    quint16_le nFormals;
+    quint32_le formalsOffset; // Can't turn this into a calculated offset because of the mutation in CompilationUnit::createUnitData.
+    quint32_le localsOffset;
+    quint16_le nLocals;
+    quint16_le nLineNumbers;
+    size_t lineNumberOffset() const { return localsOffset + nLocals * sizeof(quint32); }
+    quint32_le nestedFunctionIndex; // for functions that only return a single closure, used in signal handlers
+    quint16_le sizeOfLocalTemporalDeadZone;
+    quint16_le firstTemporalDeadZoneRegister;
+    quint16_le sizeOfRegisterTemporalDeadZone;
+    quint16_le nRegisters;
     Location location;
 
     // Qml Extensions Begin
-    LEUInt32 nDependingIdObjects;
-    LEUInt32 dependingIdObjectsOffset; // Array of resolved ID objects
-    LEUInt32 nDependingContextProperties;
-    LEUInt32 dependingContextPropertiesOffset; // Array of int pairs (property index and notify index)
-    LEUInt32 nDependingScopeProperties;
-    LEUInt32 dependingScopePropertiesOffset; // Array of int pairs (property index and notify index)
+    // Array of resolved ID objects
+    size_t dependingIdObjectsOffset() const { return lineNumberOffset() + nLineNumbers * sizeof(CodeOffsetToLine); }
+    quint16_le nDependingIdObjects;
+    quint16_le nDependingContextProperties;
+    // Array of int pairs (property index and notify index)
+    size_t dependingContextPropertiesOffset() const { return dependingIdObjectsOffset() + nDependingIdObjects * sizeof(quint32); }
+    quint16_le nDependingScopeProperties;
+   // Array of int pairs (property index and notify index)
+    size_t dependingScopePropertiesOffset() const { return dependingContextPropertiesOffset() + nDependingContextProperties * sizeof(quint32); }
     // Qml Extensions End
 
-//    quint32 formalsIndex[nFormals]
-//    quint32 localsIndex[nLocals]
-//    quint32 offsetForInnerFunctions[nInnerFunctions]
-//    Function[nInnerFunctions]
+    typedef quint16_le TraceInfoCount;
+    TraceInfoCount nTraceInfos;
+    static constexpr TraceInfoCount NoTracing() { return TraceInfoCount::max(); }
+
+    quint32_le nLabelInfos;
+    size_t labelInfosOffset() const { return dependingScopePropertiesOffset() + nDependingScopeProperties; }
 
     // Keep all unaligned data at the end
     quint8 flags;
+    quint8 padding1;
+    quint16 padding2;
+
+    //    quint32 formalsIndex[nFormals]
+    //    quint32 localsIndex[nLocals]
 
-    const LEUInt32 *formalsTable() const { return reinterpret_cast<const LEUInt32 *>(reinterpret_cast<const char *>(this) + formalsOffset); }
-    const LEUInt32 *localsTable() const { return reinterpret_cast<const LEUInt32 *>(reinterpret_cast<const char *>(this) + localsOffset); }
-    const LEUInt32 *qmlIdObjectDependencyTable() const { return reinterpret_cast<const LEUInt32 *>(reinterpret_cast<const char *>(this) + dependingIdObjectsOffset); }
-    const LEUInt32 *qmlContextPropertiesDependencyTable() const { return reinterpret_cast<const LEUInt32 *>(reinterpret_cast<const char *>(this) + dependingContextPropertiesOffset); }
-    const LEUInt32 *qmlScopePropertiesDependencyTable() const { return reinterpret_cast<const LEUInt32 *>(reinterpret_cast<const char *>(this) + dependingScopePropertiesOffset); }
+    const quint32_le *formalsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + formalsOffset); }
+    const quint32_le *localsTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + localsOffset); }
+    const CodeOffsetToLine *lineNumberTable() const { return reinterpret_cast<const CodeOffsetToLine *>(reinterpret_cast<const char *>(this) + lineNumberOffset()); }
+    const quint32_le *qmlIdObjectDependencyTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + dependingIdObjectsOffset()); }
+    const quint32_le *qmlContextPropertiesDependencyTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + dependingContextPropertiesOffset()); }
+    const quint32_le *qmlScopePropertiesDependencyTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + dependingScopePropertiesOffset()); }
 
     // --- QQmlPropertyCacheCreator interface
-    const LEUInt32 *formalsBegin() const { return formalsTable(); }
-    const LEUInt32 *formalsEnd() const { return formalsTable() + nFormals; }
+    const quint32_le *formalsBegin() const { return formalsTable(); }
+    const quint32_le *formalsEnd() const { return formalsTable() + nFormals; }
     // ---
 
+    const quint32_le *labelInfoTable() const { return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + labelInfosOffset()); }
+
+    const char *code() const { return reinterpret_cast<const char *>(this) + codeOffset; }
+
     inline bool hasQmlDependencies() const { return nDependingIdObjects > 0 || nDependingContextProperties > 0 || nDependingScopeProperties > 0; }
 
-    static int calculateSize(int nFormals, int nLocals, int nInnerfunctions, int nIdObjectDependencies, int nPropertyDependencies) {
-        return (sizeof(Function) + (nFormals + nLocals + nInnerfunctions + nIdObjectDependencies + 2 * nPropertyDependencies) * sizeof(quint32) + 7) & ~0x7;
+    static int calculateSize(int nFormals, int nLocals, int nLines, int nInnerfunctions, int nIdObjectDependencies, int nPropertyDependencies, int labelInfoSize, int codeSize) {
+        int trailingData = (nFormals + nLocals + nInnerfunctions +  nIdObjectDependencies + labelInfoSize +
+                2 * nPropertyDependencies)*sizeof (quint32) + nLines*sizeof(CodeOffsetToLine);
+        size_t size = align(align(sizeof(Function)) + size_t(trailingData)) + align(codeSize);
+        Q_ASSERT(size < INT_MAX);
+        return int(size);
+    }
+
+    static size_t align(size_t a) {
+        return (a + 7) & ~size_t(7);
+    }
+};
+static_assert(sizeof(Function) == 60, "Function structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct Method {
+    enum Type {
+        Regular,
+        Getter,
+        Setter
+    };
+
+    quint32_le name;
+    quint32_le type;
+    quint32_le function;
+};
+static_assert(sizeof(Method) == 12, "Method structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct Class
+{
+    quint32_le nameIndex;
+    quint32_le scopeIndex;
+    quint32_le constructorFunction;
+    quint32_le nStaticMethods;
+    quint32_le nMethods;
+    quint32_le methodTableOffset;
+
+    const Method *methodTable() const { return reinterpret_cast<const Method *>(reinterpret_cast<const char *>(this) + methodTableOffset); }
+
+    static int calculateSize(int nStaticMethods, int nMethods) {
+        int trailingData = (nStaticMethods + nMethods) * sizeof(Method);
+        size_t size = align(sizeof(Class) + trailingData);
+        Q_ASSERT(size < INT_MAX);
+        return int(size);
+    }
+
+    static size_t align(size_t a) {
+        return (a + 7) & ~size_t(7);
     }
 };
+static_assert(sizeof(Class) == 24, "Class structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct TemplateObject
+{
+    quint32_le size;
+
+    static int calculateSize(int size) {
+        int trailingData = 2 * size * sizeof(quint32_le);
+        size_t s = align(sizeof(TemplateObject) + trailingData);
+        Q_ASSERT(s < INT_MAX);
+        return int(s);
+    }
+
+    static size_t align(size_t a) {
+        return (a + 7) & ~size_t(7);
+    }
+
+    const quint32_le *stringTable() const {
+        return reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this + 1));
+    }
+
+    uint stringIndexAt(uint i) const {
+        return stringTable()[i];
+    }
+    uint rawStringIndexAt(uint i) const {
+        return stringTable()[size + i];
+    }
+};
+static_assert(sizeof(TemplateObject) == 4, "Template object structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct ExportEntry
+{
+    quint32_le exportName;
+    quint32_le moduleRequest;
+    quint32_le importName;
+    quint32_le localName;
+    Location location;
+};
+static_assert(sizeof(ExportEntry) == 20, "ExportEntry structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct ImportEntry
+{
+    quint32_le moduleRequest;
+    quint32_le importName;
+    quint32_le localName;
+    Location location;
+};
+static_assert(sizeof(ImportEntry) == 16, "ImportEntry structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 // Qml data structures
 
-struct Q_QML_EXPORT TranslationData {
-    LEUInt32 commentIndex;
-    LEInt32 number;
+struct Q_QML_EXPORT TranslationData
+{
+    quint32_le stringIndex;
+    quint32_le commentIndex;
+    qint32_le number;
+    quint32_le padding;
 };
+static_assert(sizeof(TranslationData) == 16, "TranslationData structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Q_QML_PRIVATE_EXPORT Binding
 {
-    LEUInt32 propertyNameIndex;
+    quint32_le propertyNameIndex;
 
     enum ValueType : unsigned int {
         Type_Invalid,
         Type_Boolean,
         Type_Number,
         Type_String,
+        Type_Null,
         Type_Translation,
         Type_TranslationById,
         Type_Script,
@@ -297,20 +468,22 @@ struct Q_QML_PRIVATE_EXPORT Binding
         IsBindingToAlias = 0x40,
         IsDeferredBinding = 0x80,
         IsCustomParserBinding = 0x100,
+        IsFunctionExpression = 0x200
     };
 
     union {
-        QJsonPrivate::qle_bitfield<0, 16> flags;
-        QJsonPrivate::qle_bitfield<16, 16> type;
+        quint32_le_bitfield<0, 16> flags;
+        quint32_le_bitfield<16, 16> type;
     };
     union {
         bool b;
-        quint64 doubleValue; // do not access directly, needs endian protected access
-        LEUInt32 compiledScriptIndex; // used when Type_Script
-        LEUInt32 objectIndex;
-        TranslationData translationData; // used when Type_Translation
+        quint32_le constantValueIndex;
+        quint32_le compiledScriptIndex; // used when Type_Script
+        quint32_le objectIndex;
+        quint32_le translationDataIndex; // used when Type_Translation
+        quint32 nullMarker;
     } value;
-    LEUInt32 stringIndex; // Set for Type_String, Type_Translation and Type_Script (the latter because of script strings)
+    quint32_le stringIndex; // Set for Type_String and Type_Script (the latter because of script strings)
 
     Location location;
     Location valueLocation;
@@ -362,26 +535,22 @@ struct Q_QML_PRIVATE_EXPORT Binding
         return false;
     }
 
+    bool isFunctionExpression() const { return (flags & IsFunctionExpression); }
+
     static QString escapedString(const QString &string);
 
-    bool evaluatesToString() const { return type == Type_String || type == Type_Translation || type == Type_TranslationById; }
+    bool isTranslationBinding() const { return type == Type_Translation || type == Type_TranslationById; }
+    bool evaluatesToString() const { return type == Type_String || isTranslationBinding(); }
 
-    QString valueAsString(const Unit *unit) const;
-    QString valueAsScriptString(const Unit *unit) const;
-    double valueAsNumber() const
+#ifndef V4_BOOTSTRAP
+    QString valueAsString(const CompilationUnit *unit) const;
+    QString valueAsScriptString(const CompilationUnit *unit) const;
+#endif
+    double valueAsNumber(const Value *constantTable) const
     {
         if (type != Type_Number)
             return 0.0;
-        quint64 intval = qFromLittleEndian<quint64>(value.doubleValue);
-        double d;
-        memcpy(&d, &intval, sizeof(double));
-        return d;
-    }
-    void setNumberValueInternal(double d)
-    {
-        quint64 intval;
-        memcpy(&intval, &d, sizeof(double));
-        value.doubleValue = qToLittleEndian<quint64>(intval);
+        return constantTable[value.constantValueIndex].doubleValue();
     }
 
     bool valueAsBoolean() const
@@ -393,18 +562,53 @@ struct Q_QML_PRIVATE_EXPORT Binding
 
 };
 
+static_assert(sizeof(Binding) == 24, "Binding structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct EnumValue
+{
+    quint32_le nameIndex;
+    qint32_le value;
+    Location location;
+};
+static_assert(sizeof(EnumValue) == 12, "EnumValue structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct Enum
+{
+    quint32_le nameIndex;
+    quint32_le nEnumValues;
+    Location location;
+
+    const EnumValue *enumValueAt(int idx) const {
+        return reinterpret_cast<const EnumValue*>(this + 1) + idx;
+    }
+
+    static int calculateSize(int nEnumValues) {
+        return (sizeof(Enum)
+                + nEnumValues * sizeof(EnumValue)
+                + 7) & ~0x7;
+    }
+
+    // --- QQmlPropertyCacheCreatorInterface
+    const EnumValue *enumValuesBegin() const { return enumValueAt(0); }
+    const EnumValue *enumValuesEnd() const { return enumValueAt(nEnumValues); }
+    int enumValueCount() const { return nEnumValues; }
+    // ---
+};
+static_assert(sizeof(Enum) == 12, "Enum structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
 struct Parameter
 {
-    LEUInt32 nameIndex;
-    LEUInt32 type;
-    LEUInt32 customTypeNameIndex;
+    quint32_le nameIndex;
+    quint32_le type;
+    quint32_le customTypeNameIndex;
     Location location;
 };
+static_assert(sizeof(Parameter) == 16, "Parameter structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Signal
 {
-    LEUInt32 nameIndex;
-    LEUInt32 nParameters;
+    quint32_le nameIndex;
+    quint32_le nParameters;
     Location location;
     // Parameter parameters[1];
 
@@ -424,6 +628,7 @@ struct Signal
     int parameterCount() const { return nParameters; }
     // ---
 };
+static_assert(sizeof(Signal) == 12, "Signal structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Property
 {
@@ -436,14 +641,15 @@ struct Property
         IsReadOnly = 0x1
     };
 
-    LEUInt32 nameIndex;
+    quint32_le nameIndex;
     union {
-        QJsonPrivate::qle_bitfield<0, 31> type;
-        QJsonPrivate::qle_bitfield<31, 1> flags; // readonly
+        quint32_le_bitfield<0, 31> type;
+        quint32_le_bitfield<31, 1> flags; // readonly
     };
-    LEUInt32 customTypeNameIndex; // If type >= Custom
+    quint32_le customTypeNameIndex; // If type >= Custom
     Location location;
 };
+static_assert(sizeof(Property) == 16, "Property structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Alias {
     enum Flags : unsigned int {
@@ -452,18 +658,18 @@ struct Alias {
         AliasPointsToPointerObject = 0x4
     };
     union {
-        QJsonPrivate::qle_bitfield<0, 29> nameIndex;
-        QJsonPrivate::qle_bitfield<29, 3> flags;
+        quint32_le_bitfield<0, 29> nameIndex;
+        quint32_le_bitfield<29, 3> flags;
     };
     union {
-        LEUInt32 idIndex; // string index
-        QJsonPrivate::qle_bitfield<0, 31> targetObjectId; // object id index (in QQmlContextData::idValues)
-        QJsonPrivate::qle_bitfield<31, 1> aliasToLocalAlias;
+        quint32_le idIndex; // string index
+        quint32_le_bitfield<0, 31> targetObjectId; // object id index (in QQmlContextData::idValues)
+        quint32_le_bitfield<31, 1> aliasToLocalAlias;
     };
     union {
-        LEUInt32 propertyNameIndex; // string index
-        LEInt32 encodedMetaPropertyIndex;
-        LEUInt32 localAliasIndex; // index in list of aliases local to the object (if targetObjectId == objectId)
+        quint32_le propertyNameIndex; // string index
+        qint32_le encodedMetaPropertyIndex;
+        quint32_le localAliasIndex; // index in list of aliases local to the object (if targetObjectId == objectId)
     };
     Location location;
     Location referenceLocation;
@@ -473,6 +679,7 @@ struct Alias {
         return encodedMetaPropertyIndex == -1;
     }
 };
+static_assert(sizeof(Alias) == 20, "Alias structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Object
 {
@@ -486,26 +693,28 @@ struct Object
     // Depending on the use, this may be the type name to instantiate before instantiating this
     // object. For grouped properties the type name will be empty and for attached properties
     // it will be the name of the attached type.
-    LEUInt32 inheritedTypeNameIndex;
-    LEUInt32 idNameIndex;
+    quint32_le inheritedTypeNameIndex;
+    quint32_le idNameIndex;
     union {
-        QJsonPrivate::qle_bitfield<0, 15> flags;
-        QJsonPrivate::qle_bitfield<15, 1> defaultPropertyIsAlias;
-        QJsonPrivate::qle_signedbitfield<16, 16> id;
+        quint32_le_bitfield<0, 15> flags;
+        quint32_le_bitfield<15, 1> defaultPropertyIsAlias;
+        qint32_le_bitfield<16, 16> id;
     };
-    LEInt32 indexOfDefaultPropertyOrAlias; // -1 means no default property declared in this object
-    LEUInt32 nFunctions;
-    LEUInt32 offsetToFunctions;
-    LEUInt32 nProperties;
-    LEUInt32 offsetToProperties;
-    LEUInt32 nAliases;
-    LEUInt32 offsetToAliases;
-    LEUInt32 nSignals;
-    LEUInt32 offsetToSignals; // which in turn will be a table with offsets to variable-sized Signal objects
-    LEUInt32 nBindings;
-    LEUInt32 offsetToBindings;
-    LEUInt32 nNamedObjectsInComponent;
-    LEUInt32 offsetToNamedObjectsInComponent;
+    qint32_le indexOfDefaultPropertyOrAlias; // -1 means no default property declared in this object
+    quint16_le nFunctions;
+    quint16_le nProperties;
+    quint32_le offsetToFunctions;
+    quint32_le offsetToProperties;
+    quint32_le offsetToAliases;
+    quint16_le nAliases;
+    quint16_le nEnums;
+    quint32_le offsetToEnums; // which in turn will be a table with offsets to variable-sized Enum objects
+    quint32_le offsetToSignals; // which in turn will be a table with offsets to variable-sized Signal objects
+    quint16_le nSignals;
+    quint16_le nBindings;
+    quint32_le offsetToBindings;
+    quint32_le nNamedObjectsInComponent;
+    quint32_le offsetToNamedObjectsInComponent;
     Location location;
     Location locationOfIdProperty;
 //    Function[]
@@ -513,12 +722,13 @@ struct Object
 //    Signal[]
 //    Binding[]
 
-    static int calculateSizeExcludingSignals(int nFunctions, int nProperties, int nAliases, int nSignals, int nBindings, int nNamedObjectsInComponent)
+    static int calculateSizeExcludingSignalsAndEnums(int nFunctions, int nProperties, int nAliases, int nEnums, int nSignals, int nBindings, int nNamedObjectsInComponent)
     {
         return ( sizeof(Object)
                  + nFunctions * sizeof(quint32)
                  + nProperties * sizeof(Property)
                  + nAliases * sizeof(Alias)
+                 + nEnums * sizeof(quint32)
                  + nSignals * sizeof(quint32)
                  + nBindings * sizeof(Binding)
                  + nNamedObjectsInComponent * sizeof(int)
@@ -526,9 +736,9 @@ struct Object
                ) & ~0x7;
     }
 
-    const LEUInt32 *functionOffsetTable() const
+    const quint32_le *functionOffsetTable() const
     {
-        return reinterpret_cast<const LEUInt32*>(reinterpret_cast<const char *>(this) + offsetToFunctions);
+        return reinterpret_cast<const quint32_le*>(reinterpret_cast<const char *>(this) + offsetToFunctions);
     }
 
     const Property *propertyTable() const
@@ -546,21 +756,29 @@ struct Object
         return reinterpret_cast<const Binding*>(reinterpret_cast<const char *>(this) + offsetToBindings);
     }
 
+    const Enum *enumAt(int idx) const
+    {
+        const quint32_le *offsetTable = reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToEnums);
+        const quint32_le offset = offsetTable[idx];
+        return reinterpret_cast<const Enum*>(reinterpret_cast<const char*>(this) + offset);
+    }
+
     const Signal *signalAt(int idx) const
     {
-        const LEUInt32 *offsetTable = reinterpret_cast<const LEUInt32*>((reinterpret_cast<const char *>(this)) + offsetToSignals);
-        const LEUInt32 offset = offsetTable[idx];
+        const quint32_le *offsetTable = reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToSignals);
+        const quint32_le offset = offsetTable[idx];
         return reinterpret_cast<const Signal*>(reinterpret_cast<const char*>(this) + offset);
     }
 
-    const LEUInt32 *namedObjectsInComponentTable() const
+    const quint32_le *namedObjectsInComponentTable() const
     {
-        return reinterpret_cast<const LEUInt32*>(reinterpret_cast<const char *>(this) + offsetToNamedObjectsInComponent);
+        return reinterpret_cast<const quint32_le*>(reinterpret_cast<const char *>(this) + offsetToNamedObjectsInComponent);
     }
 
     // --- QQmlPropertyCacheCreator interface
     int propertyCount() const { return nProperties; }
     int aliasCount() const { return nAliases; }
+    int enumCount() const { return nEnums; }
     int signalCount() const { return nSignals; }
     int functionCount() const { return nFunctions; }
 
@@ -573,6 +791,10 @@ struct Object
     const Alias *aliasesBegin() const { return aliasTable(); }
     const Alias *aliasesEnd() const { return aliasTable() + nAliases; }
 
+    typedef TableIterator<Enum, Object, &Object::enumAt> EnumIterator;
+    EnumIterator enumsBegin() const { return EnumIterator(this, 0); }
+    EnumIterator enumsEnd() const { return EnumIterator(this, nEnums); }
+
     typedef TableIterator<Signal, Object, &Object::signalAt> SignalIterator;
     SignalIterator signalsBegin() const { return SignalIterator(this, 0); }
     SignalIterator signalsEnd() const { return SignalIterator(this, nSignals); }
@@ -580,6 +802,7 @@ struct Object
     int namedObjectsInComponentCount() const { return nNamedObjectsInComponent; }
     // ---
 };
+static_assert(sizeof(Object) == 68, "Object structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct Import
 {
@@ -588,78 +811,111 @@ struct Import
         ImportFile = 0x2,
         ImportScript = 0x3
     };
-    LEUInt32 type;
+    quint32_le type;
 
-    LEUInt32 uriIndex;
-    LEUInt32 qualifierIndex;
+    quint32_le uriIndex;
+    quint32_le qualifierIndex;
 
-    LEInt32 majorVersion;
-    LEInt32 minorVersion;
+    qint32_le majorVersion;
+    qint32_le minorVersion;
 
     Location location;
 
     Import() { type = 0; uriIndex = 0; qualifierIndex = 0; majorVersion = 0; minorVersion = 0; }
 };
+static_assert(sizeof(Import) == 24, "Import structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
+
+struct QmlUnit
+{
+    quint32_le nImports;
+    quint32_le offsetToImports;
+    quint32_le nObjects;
+    quint32_le offsetToObjects;
+
+    const Import *importAt(int idx) const {
+        return reinterpret_cast<const Import*>((reinterpret_cast<const char *>(this)) + offsetToImports + idx * sizeof(Import));
+    }
+
+    const Object *objectAt(int idx) const {
+        const quint32_le *offsetTable = reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToObjects);
+        const quint32_le offset = offsetTable[idx];
+        return reinterpret_cast<const Object*>(reinterpret_cast<const char*>(this) + offset);
+    }
+};
+static_assert(sizeof(QmlUnit) == 16, "QmlUnit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
+enum { QmlCompileHashSpace = 48 };
 static const char magic_str[] = "qv4cdata";
+extern const char qml_compile_hash[QmlCompileHashSpace + 1];
 
 struct Unit
 {
     // DO NOT CHANGE THESE FIELDS EVER
     char magic[8];
-    LEUInt32 version;
-    LEUInt32 qtVersion;
-    LEInt64 sourceTimeStamp;
-    LEUInt32 unitSize; // Size of the Unit and any depending data.
+    quint32_le version;
+    quint32_le qtVersion;
+    qint64_le sourceTimeStamp;
+    quint32_le unitSize; // Size of the Unit and any depending data.
     // END DO NOT CHANGE THESE FIELDS EVER
 
+    char libraryVersionHash[QmlCompileHashSpace];
+
     char md5Checksum[16]; // checksum of all bytes following this field.
     void generateChecksum();
 
-    LEUInt32 architectureIndex; // string index to QSysInfo::buildAbi()
-    LEUInt32 codeGeneratorIndex;
     char dependencyMD5Checksum[16];
 
     enum : unsigned int {
         IsJavascript = 0x1,
-        IsQml = 0x2,
-        StaticData = 0x4, // Unit data persistent in memory?
-        IsSingleton = 0x8,
-        IsSharedLibrary = 0x10, // .pragma shared?
-        ContainsMachineCode = 0x20, // used to determine if we need to mmap with execute permissions
-        PendingTypeCompilation = 0x40 // the QML data structures present are incomplete and require type compilation
+        StaticData = 0x2, // Unit data persistent in memory?
+        IsSingleton = 0x4,
+        IsSharedLibrary = 0x8, // .pragma shared?
+        IsESModule = 0x10,
+        PendingTypeCompilation = 0x20 // the QML data structures present are incomplete and require type compilation
     };
-    LEUInt32 flags;
-    LEUInt32 stringTableSize;
-    LEUInt32 offsetToStringTable;
-    LEUInt32 functionTableSize;
-    LEUInt32 offsetToFunctionTable;
-    LEUInt32 lookupTableSize;
-    LEUInt32 offsetToLookupTable;
-    LEUInt32 regexpTableSize;
-    LEUInt32 offsetToRegexpTable;
-    LEUInt32 constantTableSize;
-    LEUInt32 offsetToConstantTable;
-    LEUInt32 jsClassTableSize;
-    LEUInt32 offsetToJSClassTable;
-    LEInt32 indexOfRootFunction;
-    LEUInt32 sourceFileIndex;
+    quint32_le flags;
+    quint32_le stringTableSize;
+    quint32_le offsetToStringTable;
+    quint32_le functionTableSize;
+    quint32_le offsetToFunctionTable;
+    quint32_le classTableSize;
+    quint32_le offsetToClassTable;
+    quint32_le templateObjectTableSize;
+    quint32_le offsetToTemplateObjectTable;
+    quint32_le blockTableSize;
+    quint32_le offsetToBlockTable;
+    quint32_le lookupTableSize;
+    quint32_le offsetToLookupTable;
+    quint32_le regexpTableSize;
+    quint32_le offsetToRegexpTable;
+    quint32_le constantTableSize;
+    quint32_le offsetToConstantTable;
+    quint32_le jsClassTableSize;
+    quint32_le offsetToJSClassTable;
+    quint32_le translationTableSize;
+    quint32_le offsetToTranslationTable;
+    quint32_le localExportEntryTableSize;
+    quint32_le offsetToLocalExportEntryTable;
+    quint32_le indirectExportEntryTableSize;
+    quint32_le offsetToIndirectExportEntryTable;
+    quint32_le starExportEntryTableSize;
+    quint32_le offsetToStarExportEntryTable;
+    quint32_le importEntryTableSize;
+    quint32_le offsetToImportEntryTable;
+    quint32_le moduleRequestTableSize;
+    quint32_le offsetToModuleRequestTable;
+    qint32_le indexOfRootFunction;
+    quint32_le sourceFileIndex;
+    quint32_le finalUrlIndex;
+
+    quint32_le offsetToQmlUnit;
+
+    bool verifyHeader(QDateTime expectedSourceTimeStamp, QString *errorString) const;
 
     /* QML specific fields */
-    LEUInt32 nImports;
-    LEUInt32 offsetToImports;
-    LEUInt32 nObjects;
-    LEUInt32 offsetToObjects;
-    LEUInt32 indexOfRootObject;
 
-    const Import *importAt(int idx) const {
-        return reinterpret_cast<const Import*>((reinterpret_cast<const char *>(this)) + offsetToImports + idx * sizeof(Import));
-    }
-
-    const Object *objectAt(int idx) const {
-        const LEUInt32 *offsetTable = reinterpret_cast<const LEUInt32*>((reinterpret_cast<const char *>(this)) + offsetToObjects);
-        const LEUInt32 offset = offsetTable[idx];
-        return reinterpret_cast<const Object*>(reinterpret_cast<const char*>(this) + offset);
+    const QmlUnit *qmlUnit() const {
+        return reinterpret_cast<const QmlUnit *>(reinterpret_cast<const char *>(this) + offsetToQmlUnit);
     }
 
     bool isSingleton() const {
@@ -667,21 +923,22 @@ struct Unit
     }
     /* end QML specific fields*/
 
-    QString stringAt(int idx) const {
-        const LEUInt32 *offsetTable = reinterpret_cast<const LEUInt32*>((reinterpret_cast<const char *>(this)) + offsetToStringTable);
-        const LEUInt32 offset = offsetTable[idx];
+    QString stringAtInternal(int idx) const {
+        Q_ASSERT(idx < int(stringTableSize));
+        const quint32_le *offsetTable = reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToStringTable);
+        const quint32_le offset = offsetTable[idx];
         const String *str = reinterpret_cast<const String*>(reinterpret_cast<const char *>(this) + offset);
         if (str->size == 0)
             return QString();
 #if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
+        if (flags & StaticData) {
+            const QStringDataPtr holder = { const_cast<QStringData *>(reinterpret_cast<const QStringData*>(str)) };
+            return QString(holder);
+        }
         const QChar *characters = reinterpret_cast<const QChar *>(str + 1);
-        // Too risky to do this while we unmap disk backed compilation but keep pointers to string
-        // data in the identifier tables.
-        //        if (flags & StaticData)
-        //            return QString::fromRawData(characters, str->size);
         return QString(characters, str->size);
 #else
-        const LEUInt16 *characters = reinterpret_cast<const LEUInt16 *>(str + 1);
+        const quint16_le *characters = reinterpret_cast<const quint16_le *>(str + 1);
         QString qstr(str->size, Qt::Uninitialized);
         QChar *ch = qstr.data();
         for (int i = 0; i < str->size; ++i)
@@ -690,35 +947,65 @@ struct Unit
 #endif
     }
 
-    const LEUInt32 *functionOffsetTable() const { return reinterpret_cast<const LEUInt32*>((reinterpret_cast<const char *>(this)) + offsetToFunctionTable); }
+    const quint32_le *functionOffsetTable() const { return reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToFunctionTable); }
+    const quint32_le *classOffsetTable() const { return reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToClassTable); }
+    const quint32_le *templateObjectOffsetTable() const { return reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToTemplateObjectTable); }
+    const quint32_le *blockOffsetTable() const { return reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToBlockTable); }
 
     const Function *functionAt(int idx) const {
-        const LEUInt32 *offsetTable = functionOffsetTable();
-        const LEUInt32 offset = offsetTable[idx];
+        const quint32_le *offsetTable = functionOffsetTable();
+        const quint32_le offset = offsetTable[idx];
         return reinterpret_cast<const Function*>(reinterpret_cast<const char *>(this) + offset);
     }
 
+    const Class *classAt(int idx) const {
+        const quint32_le *offsetTable = classOffsetTable();
+        const quint32_le offset = offsetTable[idx];
+        return reinterpret_cast<const Class *>(reinterpret_cast<const char *>(this) + offset);
+    }
+
+    const TemplateObject *templateObjectAt(int idx) const {
+        const quint32_le *offsetTable = templateObjectOffsetTable();
+        const quint32_le offset = offsetTable[idx];
+        return reinterpret_cast<const TemplateObject *>(reinterpret_cast<const char *>(this) + offset);
+    }
+
+    const Block *blockAt(int idx) const {
+        const quint32_le *offsetTable = blockOffsetTable();
+        const quint32_le offset = offsetTable[idx];
+        return reinterpret_cast<const Block *>(reinterpret_cast<const char *>(this) + offset);
+    }
+
     const Lookup *lookupTable() const { return reinterpret_cast<const Lookup*>(reinterpret_cast<const char *>(this) + offsetToLookupTable); }
     const RegExp *regexpAt(int index) const {
         return reinterpret_cast<const RegExp*>(reinterpret_cast<const char *>(this) + offsetToRegexpTable + index * sizeof(RegExp));
     }
-    const LEUInt64 *constants() const {
-        return reinterpret_cast<const LEUInt64*>(reinterpret_cast<const char *>(this) + offsetToConstantTable);
+    const quint64_le *constants() const {
+        return reinterpret_cast<const quint64_le*>(reinterpret_cast<const char *>(this) + offsetToConstantTable);
     }
 
     const JSClassMember *jsClassAt(int idx, int *nMembers) const {
-        const LEUInt32 *offsetTable = reinterpret_cast<const LEUInt32 *>(reinterpret_cast<const char *>(this) + offsetToJSClassTable);
-        const LEUInt32 offset = offsetTable[idx];
+        const quint32_le *offsetTable = reinterpret_cast<const quint32_le *>(reinterpret_cast<const char *>(this) + offsetToJSClassTable);
+        const quint32_le offset = offsetTable[idx];
         const char *ptr = reinterpret_cast<const char *>(this) + offset;
         const JSClass *klass = reinterpret_cast<const JSClass *>(ptr);
         *nMembers = klass->nMembers;
         return reinterpret_cast<const JSClassMember*>(ptr + sizeof(JSClass));
     }
+
+    const TranslationData *translations() const {
+        return reinterpret_cast<const TranslationData *>(reinterpret_cast<const char *>(this) + offsetToTranslationTable);
+    }
+
+    const ImportEntry *importEntryTable() const { return reinterpret_cast<const ImportEntry *>(reinterpret_cast<const char *>(this) + offsetToImportEntryTable); }
+    const ExportEntry *localExportEntryTable() const { return reinterpret_cast<const ExportEntry *>(reinterpret_cast<const char *>(this) + offsetToLocalExportEntryTable); }
+    const ExportEntry *indirectExportEntryTable() const { return reinterpret_cast<const ExportEntry *>(reinterpret_cast<const char *>(this) + offsetToIndirectExportEntryTable); }
+    const ExportEntry *starExportEntryTable() const { return reinterpret_cast<const ExportEntry *>(reinterpret_cast<const char *>(this) + offsetToStarExportEntryTable); }
+
+    const quint32_le *moduleRequestTable() const { return reinterpret_cast<const quint32_le*>((reinterpret_cast<const char *>(this)) + offsetToModuleRequestTable); }
 };
 
-#if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
-#pragma pack(pop)
-#endif
+static_assert(sizeof(Unit) == 248, "Unit structure needs to have the expected size to be binary compatible on disk when generated by host compiler and loaded by target");
 
 struct TypeReference
 {
@@ -755,9 +1042,7 @@ struct TypeReferenceMap : QHash<int, TypeReference>
         auto propEnd = obj->propertiesEnd();
         for ( ; prop != propEnd; ++prop) {
             if (prop->type >= QV4::CompiledData::Property::Custom) {
-                // ### FIXME: We could report the more accurate location here by using prop->location, but the old
-                // compiler can't and the tests expect it to be the object location right now.
-                TypeReference &r = this->add(prop->customTypeNameIndex, obj->location);
+                TypeReference &r = this->add(prop->customTypeNameIndex, prop->location);
                 r.errorWhenNotFound = true;
             }
         }
@@ -800,44 +1085,86 @@ typedef QVector<QQmlPropertyData*> BindingPropertyData;
 
 struct Q_QML_PRIVATE_EXPORT CompilationUnitBase
 {
-    QV4::Heap::String **runtimeStrings = 0; // Array
+    // pointers either to data->constants() or little-endian memory copy.
+    QV4::Heap::String **runtimeStrings = nullptr; // Array
+    const Value* constants = nullptr;
+    QV4::Value *runtimeRegularExpressions = nullptr;
+    QV4::Heap::InternalClass **runtimeClasses = nullptr;
+    const Value** imports = nullptr;
 };
 
 Q_STATIC_ASSERT(std::is_standard_layout<CompilationUnitBase>::value);
 Q_STATIC_ASSERT(offsetof(CompilationUnitBase, runtimeStrings) == 0);
+Q_STATIC_ASSERT(offsetof(CompilationUnitBase, constants) == sizeof(QV4::Heap::String **));
+Q_STATIC_ASSERT(offsetof(CompilationUnitBase, runtimeRegularExpressions) == offsetof(CompilationUnitBase, constants) + sizeof(const Value *));
+Q_STATIC_ASSERT(offsetof(CompilationUnitBase, runtimeClasses) == offsetof(CompilationUnitBase, runtimeRegularExpressions) + sizeof(const Value *));
+Q_STATIC_ASSERT(offsetof(CompilationUnitBase, imports) == offsetof(CompilationUnitBase, runtimeClasses) + sizeof(const Value *));
 
-struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public QQmlRefCount
+struct Q_QML_PRIVATE_EXPORT CompilationUnit final : public CompilationUnitBase
 {
+    const Unit *data = nullptr;
+    const QmlUnit *qmlData = nullptr;
+public:
+    CompilationUnit(const Unit *unitData = nullptr, const QString &fileName = QString(), const QString &finalUrlString = QString());
 #ifdef V4_BOOTSTRAP
-    CompilationUnit()
-        : data(0)
-    {}
-    virtual ~CompilationUnit() {}
+    ~CompilationUnit() {}
 #else
-    CompilationUnit();
-    virtual ~CompilationUnit();
+    ~CompilationUnit();
 #endif
 
-    const Unit *data;
+    void addref()
+    {
+        Q_ASSERT(refCount.load() > 0);
+        refCount.ref();
+    }
+
+    void release()
+    {
+        Q_ASSERT(refCount.load() > 0);
+        if (!refCount.deref())
+            destroy();
+    }
+    int count() const
+    {
+        return refCount.load();
+    }
 
-    // Called only when building QML, when we build the header for JS first and append QML data
-    virtual QV4::CompiledData::Unit *createUnitData(QmlIR::Document *irDocument);
+    const Unit *unitData() const { return data; }
+    void setUnitData(const Unit *unitData, const QmlUnit *qmlUnit = nullptr,
+                     const QString &fileName = QString(), const QString &finalUrlString = QString());
 
 #ifndef V4_BOOTSTRAP
-    ExecutionEngine *engine;
-
-    QString fileName() const { return data->stringAt(data->sourceFileIndex); }
+    QIntrusiveListNode nextCompilationUnit;
+    ExecutionEngine *engine = nullptr;
+    QQmlEnginePrivate *qmlEngine = nullptr; // only used in QML environment for composite types, not in plain QJSEngine case.
+
+    // url() and fileName() shall be used to load the actual QML/JS code or to show errors or
+    // warnings about that code. They include any potential URL interceptions and thus represent the
+    // "physical" location of the code.
+    //
+    // finalUrl() and finalUrlString() shall be used to resolve further URLs referred to in the code
+    // They are _not_ intercepted and thus represent the "logical" name for the code.
+
+    QString fileName() const { return m_fileName; }
+    QString finalUrlString() const { return m_finalUrlString; }
     QUrl url() const { if (m_url.isNull) m_url = QUrl(fileName()); return m_url; }
+    QUrl finalUrl() const
+    {
+        if (m_finalUrl.isNull)
+            m_finalUrl = QUrl(finalUrlString());
+        return m_finalUrl;
+    }
 
-    QV4::Lookup *runtimeLookups;
-    QV4::Value *runtimeRegularExpressions;
-    QV4::InternalClass **runtimeClasses;
+    QV4::Lookup *runtimeLookups = nullptr;
     QVector<QV4::Function *> runtimeFunctions;
+    QVector<QV4::Heap::InternalClass *> runtimeBlocks;
+    mutable QVector<QV4::Heap::Object *> templateObjects;
     mutable QQmlNullableValue<QUrl> m_url;
+    mutable QQmlNullableValue<QUrl> m_finalUrl;
 
     // QML specific fields
     QQmlPropertyCacheVector propertyCaches;
-    QQmlPropertyCache *rootPropertyCache() const { return propertyCaches.at(data->indexOfRootObject); }
+    QQmlRefPointer<QQmlPropertyCache> rootPropertyCache() const { return propertyCaches.at(/*root object*/0); }
 
     QQmlRefPointer<QQmlTypeNameCache> typeNameCache;
 
@@ -848,35 +1175,42 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public
 
     // mapping from component object index (CompiledData::Unit object index that points to component) to identifier hash of named objects
     // this is initialized on-demand by QQmlContextData
-    QHash<int, IdentifierHash<int>> namedObjectsPerComponentCache;
-    IdentifierHash<int> namedObjectsPerComponent(int componentObjectIndex);
+    QHash<int, IdentifierHash> namedObjectsPerComponentCache;
+    inline IdentifierHash namedObjectsPerComponent(int componentObjectIndex);
 
-    // pointers either to data->constants() or little-endian memory copy.
-    const Value* constants;
-
-    void finalize(QQmlEnginePrivate *engine);
+    void finalizeCompositeType(QQmlEnginePrivate *qmlEngine);
 
-    int totalBindingsCount; // Number of bindings used in this type
-    int totalParserStatusCount; // Number of instantiated types that are QQmlParserStatus subclasses
-    int totalObjectCount; // Number of objects explicitly instantiated
+    int totalBindingsCount = 0; // Number of bindings used in this type
+    int totalParserStatusCount = 0; // Number of instantiated types that are QQmlParserStatus subclasses
+    int totalObjectCount = 0; // Number of objects explicitly instantiated
 
-    QVector<QQmlScriptData *> dependentScripts;
+    QVector<QQmlRefPointer<QQmlScriptData>> dependentScripts;
     ResolvedTypeReferenceMap resolvedTypes;
+    ResolvedTypeReference *resolvedType(int id) const { return resolvedTypes.value(id); }
 
     bool verifyChecksum(const DependentTypesHasher &dependencyHasher) const;
 
-    int metaTypeId;
-    int listMetaTypeId;
-    bool isRegisteredWithEngine;
+    int metaTypeId = -1;
+    int listMetaTypeId = -1;
+    bool isRegisteredWithEngine = false;
 
     QScopedPointer<CompilationUnitMapper> backingFile;
+    QStringList dynamicStrings;
 
     // --- interface for QQmlPropertyCacheCreator
     typedef Object CompiledObject;
-    int objectCount() const { return data->nObjects; }
-    int rootObjectIndex() const { return data->indexOfRootObject; }
-    const Object *objectAt(int index) const { return data->objectAt(index); }
-    QString stringAt(int index) const { return data->stringAt(index); }
+    int objectCount() const { return qmlData->nObjects; }
+    const Object *objectAt(int index) const { return qmlData->objectAt(index); }
+    int importCount() const { return qmlData->nImports; }
+    const Import *importAt(int index) const { return qmlData->importAt(index); }
+    QString stringAt(int index) const
+    {
+        if (uint(index) >= data->stringTableSize)
+            return dynamicStrings.at(index - data->stringTableSize);
+        return data->stringAtInternal(index);
+    }
+
+    Heap::Object *templateObjectAt(int index) const;
 
     struct FunctionIterator
     {
@@ -894,43 +1228,75 @@ struct Q_QML_PRIVATE_EXPORT CompilationUnit : public CompilationUnitBase, public
     FunctionIterator objectFunctionsEnd(const Object *object) const { return FunctionIterator(data, object, object->nFunctions); }
     // ---
 
+    bool isESModule() const { return data->flags & Unit::IsESModule; }
+    bool isSharedLibrary() const { return data->flags & Unit::IsSharedLibrary; }
+    QStringList moduleRequests() const;
+    Heap::Module *instantiate(ExecutionEngine *engine);
+    const Value *resolveExport(QV4::String *exportName);
+    QStringList exportedNames() const;
+    void evaluate();
+    void evaluateModuleRequests();
+
     QV4::Function *linkToEngine(QV4::ExecutionEngine *engine);
     void unlink();
 
     void markObjects(MarkStack *markStack);
 
-    void destroy() Q_DECL_OVERRIDE;
+    bool loadFromDisk(const QUrl &url, const QDateTime &sourceTimeStamp, QString *errorString);
 
-    bool loadFromDisk(const QUrl &url, const QDateTime &sourceTimeStamp, EvalISelFactory *iselFactory, QString *errorString);
+    static QString localCacheFilePath(const QUrl &url);
 
 protected:
-    virtual void linkBackendToEngine(QV4::ExecutionEngine *engine) = 0;
-    virtual bool memoryMapCode(QString *errorString);
+    quint32 totalStringCount() const
+    { return data->stringTableSize; }
+
+#else // V4_BOOTSTRAP
+    QString stringAt(int index) const { return data->stringAtInternal(index); }
 #endif // V4_BOOTSTRAP
 
+private:
+    void destroy();
+
+    struct ResolveSetEntry
+    {
+        ResolveSetEntry() {}
+        ResolveSetEntry(CompilationUnit *module, QV4::String *exportName)
+            : module(module), exportName(exportName) {}
+        CompilationUnit *module = nullptr;
+        QV4::String *exportName = nullptr;
+    };
+
+    const Value *resolveExportRecursively(QV4::String *exportName, QVector<ResolveSetEntry> *resolveSet);
+    const ExportEntry *lookupNameInExportTable(const ExportEntry *firstExportEntry, int tableSize, QV4::String *name) const;
+    void getExportedNamesRecursively(QStringList *names, QVector<const CompilationUnit *> *exportNameSet, bool includeDefaultExport = true) const;
+
+    QString m_fileName; // initialized from data->sourceFileIndex
+    QString m_finalUrlString; // initialized from data->finalUrlIndex
+
+    QAtomicInt refCount = 1;
+
+    Q_NEVER_INLINE IdentifierHash createNamedObjectsPerComponent(int componentObjectIndex);
+
+    Heap::Module *m_module = nullptr;
+
 public:
 #if defined(V4_BOOTSTRAP)
     bool saveToDisk(const QString &outputFileName, QString *errorString);
 #else
     bool saveToDisk(const QUrl &unitUrl, QString *errorString);
 #endif
-
-protected:
-    virtual void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit);
-    virtual bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString);
 };
 
 #ifndef V4_BOOTSTRAP
 struct ResolvedTypeReference
 {
     ResolvedTypeReference()
-        : type(0)
-        , majorVersion(0)
+        : majorVersion(0)
         , minorVersion(0)
         , isFullyDynamicType(false)
     {}
 
-    QQmlType *type;
+    QQmlType type;
     QQmlRefPointer<QQmlPropertyCache> typePropertyCache;
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
 
@@ -940,17 +1306,24 @@ struct ResolvedTypeReference
     // therefore cannot have a property cache installed when instantiated.
     bool isFullyDynamicType;
 
-    QQmlPropertyCache *propertyCache() const;
-    QQmlPropertyCache *createPropertyCache(QQmlEngine *);
+    QQmlRefPointer<QQmlPropertyCache> propertyCache() const;
+    QQmlRefPointer<QQmlPropertyCache> createPropertyCache(QQmlEngine *);
     bool addToHash(QCryptographicHash *hash, QQmlEngine *engine);
 
     void doDynamicTypeCheck();
 };
-#endif
 
+IdentifierHash CompilationUnit::namedObjectsPerComponent(int componentObjectIndex)
+{
+    auto it = namedObjectsPerComponentCache.find(componentObjectIndex);
+    if (Q_UNLIKELY(it == namedObjectsPerComponentCache.end()))
+        return createNamedObjectsPerComponent(componentObjectIndex);
+    return *it;
 }
+#endif // V4_BOOTSTRAP
 
-}
+} // CompiledData namespace
+} // QV4 namespace
 
 Q_DECLARE_TYPEINFO(QV4::CompiledData::JSClassMember, Q_PRIMITIVE_TYPE);
 
diff --git a/src/qml/compiler/qv4compiler.cpp b/src/qml/compiler/qv4compiler.cpp
index f7e63437e1..0833f552e6 100644
--- a/src/qml/compiler/qv4compiler.cpp
+++ b/src/qml/compiler/qv4compiler.cpp
@@ -39,10 +39,12 @@
 
 #include <qv4compiler_p.h>
 #include <qv4compileddata_p.h>
-#include <qv4isel_p.h>
+#include <qv4codegen_p.h>
 #include <private/qv4string_p.h>
 #include <private/qv4value_p.h>
 #include <private/qv4alloca_p.h>
+#include <private/qqmljslexer_p.h>
+#include <private/qqmljsast_p.h>
 #include <wtf/MathExtras.h>
 #include <QCryptographicHash>
 
@@ -53,6 +55,7 @@ QV4::Compiler::StringTableGenerator::StringTableGenerator()
 
 int QV4::Compiler::StringTableGenerator::registerString(const QString &str)
 {
+    Q_ASSERT(!frozen);
     QHash<QString, int>::ConstIterator it = stringToId.constFind(str);
     if (it != stringToId.cend())
         return *it;
@@ -73,96 +76,114 @@ void QV4::Compiler::StringTableGenerator::clear()
     strings.clear();
     stringToId.clear();
     stringDataSize = 0;
+    frozen = false;
+}
+
+void QV4::Compiler::StringTableGenerator::initializeFromBackingUnit(const QV4::CompiledData::Unit *unit)
+{
+    clear();
+    for (uint i = 0; i < unit->stringTableSize; ++i)
+        registerString(unit->stringAtInternal(i));
+    backingUnitTableSize = unit->stringTableSize;
+    stringDataSize = 0;
 }
 
 void QV4::Compiler::StringTableGenerator::serialize(CompiledData::Unit *unit)
 {
     char *dataStart = reinterpret_cast<char *>(unit);
-    CompiledData::LEUInt32 *stringTable = reinterpret_cast<CompiledData::LEUInt32 *>(dataStart + unit->offsetToStringTable);
-    char *stringData = dataStart + unit->offsetToStringTable + unit->stringTableSize * sizeof(uint);
-    for (int i = 0; i < strings.size(); ++i) {
-        stringTable[i] = stringData - dataStart;
+    quint32_le *stringTable = reinterpret_cast<quint32_le *>(dataStart + unit->offsetToStringTable);
+    char *stringData = reinterpret_cast<char *>(stringTable) + WTF::roundUpToMultipleOf(8, unit->stringTableSize * sizeof(uint));
+    for (int i = backingUnitTableSize ; i < strings.size(); ++i) {
+        const int index = i - backingUnitTableSize;
+        stringTable[index] = stringData - dataStart;
         const QString &qstr = strings.at(i);
 
         QV4::CompiledData::String *s = reinterpret_cast<QV4::CompiledData::String *>(stringData);
+        Q_ASSERT(reinterpret_cast<uintptr_t>(s) % alignof(QV4::CompiledData::String) == 0);
+        s->refcount = -1;
         s->size = qstr.length();
+        s->allocAndCapacityReservedFlag = 0;
+        s->offsetOn32Bit = sizeof(QV4::CompiledData::String);
+        s->offsetOn64Bit = sizeof(QV4::CompiledData::String);
+
+        ushort *uc = reinterpret_cast<ushort *>(reinterpret_cast<char *>(s) + sizeof(*s));
 #if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
-        memcpy(s + 1, qstr.constData(), qstr.length()*sizeof(ushort));
+        memcpy(uc, qstr.constData(), s->size * sizeof(ushort));
 #else
-        ushort *uc = reinterpret_cast<ushort *>(s + 1);
-        for (int i = 0; i < qstr.length(); ++i)
+        for (int i = 0; i < s->size; ++i)
             uc[i] = qToLittleEndian<ushort>(qstr.at(i).unicode());
 #endif
+        uc[s->size] = 0;
 
         stringData += QV4::CompiledData::String::calculateSize(qstr);
     }
 }
 
-QV4::Compiler::JSUnitGenerator::JSUnitGenerator(QV4::IR::Module *module)
-    : irModule(module)
+QV4::Compiler::JSUnitGenerator::JSUnitGenerator(QV4::Compiler::Module *module)
+    : module(module)
 {
     // Make sure the empty string always gets index 0
     registerString(QString());
 }
 
-uint QV4::Compiler::JSUnitGenerator::registerIndexedGetterLookup()
+int QV4::Compiler::JSUnitGenerator::registerGetterLookup(const QString &name)
 {
-    CompiledData::Lookup l;
-    l.type_and_flags = CompiledData::Lookup::Type_IndexedGetter;
-    l.nameIndex = 0;
-    lookups << l;
-    return lookups.size() - 1;
+    return registerGetterLookup(registerString(name));
 }
 
-uint QV4::Compiler::JSUnitGenerator::registerIndexedSetterLookup()
+int QV4::Compiler::JSUnitGenerator::registerGetterLookup(int nameIndex)
 {
     CompiledData::Lookup l;
-    l.type_and_flags = CompiledData::Lookup::Type_IndexedSetter;
-    l.nameIndex = 0;
+    l.type_and_flags = CompiledData::Lookup::Type_Getter;
+    l.nameIndex = nameIndex;
     lookups << l;
     return lookups.size() - 1;
 }
 
-uint QV4::Compiler::JSUnitGenerator::registerGetterLookup(const QString &name)
+int QV4::Compiler::JSUnitGenerator::registerSetterLookup(const QString &name)
 {
-    CompiledData::Lookup l;
-    l.type_and_flags = CompiledData::Lookup::Type_Getter;
-    l.nameIndex = registerString(name);
-    lookups << l;
-    return lookups.size() - 1;
+    return registerSetterLookup(registerString(name));
 }
 
-
-uint QV4::Compiler::JSUnitGenerator::registerSetterLookup(const QString &name)
+int QV4::Compiler::JSUnitGenerator::registerSetterLookup(int nameIndex)
 {
     CompiledData::Lookup l;
     l.type_and_flags = CompiledData::Lookup::Type_Setter;
-    l.nameIndex = registerString(name);
+    l.nameIndex = nameIndex;
     lookups << l;
     return lookups.size() - 1;
 }
 
-uint QV4::Compiler::JSUnitGenerator::registerGlobalGetterLookup(const QString &name)
+int QV4::Compiler::JSUnitGenerator::registerGlobalGetterLookup(const QString &name)
+{
+    return registerGlobalGetterLookup(registerString(name));
+}
+
+int QV4::Compiler::JSUnitGenerator::registerGlobalGetterLookup(int nameIndex)
 {
     CompiledData::Lookup l;
     l.type_and_flags = CompiledData::Lookup::Type_GlobalGetter;
-    l.nameIndex = registerString(name);
+    l.nameIndex = nameIndex;
     lookups << l;
     return lookups.size() - 1;
 }
 
-int QV4::Compiler::JSUnitGenerator::registerRegExp(QV4::IR::RegExp *regexp)
+int QV4::Compiler::JSUnitGenerator::registerRegExp(QQmlJS::AST::RegExpLiteral *regexp)
 {
     CompiledData::RegExp re;
-    re.stringIndex = registerString(*regexp->value);
+    re.stringIndex = registerString(regexp->pattern.toString());
 
     re.flags = 0;
-    if (regexp->flags & QV4::IR::RegExp::RegExp_Global)
+    if (regexp->flags & QQmlJS::Lexer::RegExp_Global)
         re.flags |= CompiledData::RegExp::RegExp_Global;
-    if (regexp->flags & QV4::IR::RegExp::RegExp_IgnoreCase)
+    if (regexp->flags &  QQmlJS::Lexer::RegExp_IgnoreCase)
         re.flags |= CompiledData::RegExp::RegExp_IgnoreCase;
-    if (regexp->flags & QV4::IR::RegExp::RegExp_Multiline)
+    if (regexp->flags &  QQmlJS::Lexer::RegExp_Multiline)
         re.flags |= CompiledData::RegExp::RegExp_Multiline;
+    if (regexp->flags &  QQmlJS::Lexer::RegExp_Unicode)
+        re.flags |= CompiledData::RegExp::RegExp_Unicode;
+    if (regexp->flags &  QQmlJS::Lexer::RegExp_Sticky)
+        re.flags |= CompiledData::RegExp::RegExp_Sticky;
 
     regexps.append(re);
     return regexps.size() - 1;
@@ -177,70 +198,119 @@ int QV4::Compiler::JSUnitGenerator::registerConstant(QV4::ReturnedValue v)
     return constants.size() - 1;
 }
 
-int QV4::Compiler::JSUnitGenerator::registerJSClass(int count, IR::ExprList *args)
+QV4::ReturnedValue QV4::Compiler::JSUnitGenerator::constant(int idx)
+{
+    return constants.at(idx);
+}
+
+int QV4::Compiler::JSUnitGenerator::registerJSClass(const QStringList &members)
 {
     // ### re-use existing class definitions.
 
-    const int size = CompiledData::JSClass::calculateSize(count);
+    const int size = CompiledData::JSClass::calculateSize(members.size());
     jsClassOffsets.append(jsClassData.size());
     const int oldSize = jsClassData.size();
     jsClassData.resize(jsClassData.size() + size);
     memset(jsClassData.data() + oldSize, 0, size);
 
     CompiledData::JSClass *jsClass = reinterpret_cast<CompiledData::JSClass*>(jsClassData.data() + oldSize);
-    jsClass->nMembers = count;
+    jsClass->nMembers = members.size();
     CompiledData::JSClassMember *member = reinterpret_cast<CompiledData::JSClassMember*>(jsClass + 1);
 
-    IR::ExprList *it = args;
-    for (int i = 0; i < count; ++i, it = it->next, ++member) {
-        QV4::IR::Name *name = it->expr->asName();
-        it = it->next;
-
-        const bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        member->nameOffset = registerString(*name->id);
-        member->isAccessor = !isData;
-
-        if (!isData)
-            it = it->next;
+    for (const auto &name : members) {
+        member->nameOffset = registerString(name);
+        member->isAccessor = false;
+        ++member;
     }
 
     return jsClassOffsets.size() - 1;
 }
 
+int QV4::Compiler::JSUnitGenerator::registerTranslation(const QV4::CompiledData::TranslationData &translation)
+{
+    translations.append(translation);
+    return translations.size() - 1;
+}
+
 QV4::CompiledData::Unit *QV4::Compiler::JSUnitGenerator::generateUnit(GeneratorOption option)
 {
-    registerString(irModule->fileName);
-    for (QV4::IR::Function *f : qAsConst(irModule->functions)) {
-        registerString(*f->name);
-        for (int i = 0; i < f->formals.size(); ++i)
-            registerString(*f->formals.at(i));
+    registerString(module->fileName);
+    registerString(module->finalUrl);
+    for (Context *f : qAsConst(module->functions)) {
+        registerString(f->name);
+        for (int i = 0; i < f->arguments.size(); ++i)
+            registerString(f->arguments.at(i));
         for (int i = 0; i < f->locals.size(); ++i)
-            registerString(*f->locals.at(i));
+            registerString(f->locals.at(i));
+    }
+    for (Context *c : qAsConst(module->blocks)) {
+        for (int i = 0; i < c->locals.size(); ++i)
+            registerString(c->locals.at(i));
+    }
+    {
+        const auto registerExportEntry = [this](const Compiler::ExportEntry &entry) {
+            registerString(entry.exportName);
+            registerString(entry.moduleRequest);
+            registerString(entry.importName);
+            registerString(entry.localName);
+        };
+        std::for_each(module->localExportEntries.constBegin(), module->localExportEntries.constEnd(), registerExportEntry);
+        std::for_each(module->indirectExportEntries.constBegin(), module->indirectExportEntries.constEnd(), registerExportEntry);
+        std::for_each(module->starExportEntries.constBegin(), module->starExportEntries.constEnd(), registerExportEntry);
+    }
+    {
+        for (const auto &entry: module->importEntries) {
+            registerString(entry.moduleRequest);
+            registerString(entry.importName);
+            registerString(entry.localName);
+        }
+
+        for (const QString &request: module->moduleRequests)
+            registerString(request);
     }
 
-    Q_ALLOCA_VAR(CompiledData::LEUInt32, functionOffsets, irModule->functions.size() * sizeof(CompiledData::LEUInt32));
+    Q_ALLOCA_VAR(quint32_le, blockClassAndFunctionOffsets, (module->functions.size() + module->classes.size() + module->templateObjects.size() + module->blocks.size()) * sizeof(quint32_le));
     uint jsClassDataOffset = 0;
 
     char *dataPtr;
     CompiledData::Unit *unit;
     {
-        QV4::CompiledData::Unit tempHeader = generateHeader(option, functionOffsets, &jsClassDataOffset);
+        QV4::CompiledData::Unit tempHeader = generateHeader(option, blockClassAndFunctionOffsets, &jsClassDataOffset);
         dataPtr = reinterpret_cast<char *>(malloc(tempHeader.unitSize));
         memset(dataPtr, 0, tempHeader.unitSize);
         memcpy(&unit, &dataPtr, sizeof(CompiledData::Unit*));
         memcpy(unit, &tempHeader, sizeof(tempHeader));
     }
 
-    memcpy(dataPtr + unit->offsetToFunctionTable, functionOffsets, unit->functionTableSize * sizeof(CompiledData::LEUInt32));
+    memcpy(dataPtr + unit->offsetToFunctionTable, blockClassAndFunctionOffsets, unit->functionTableSize * sizeof(quint32_le));
+    memcpy(dataPtr + unit->offsetToClassTable, blockClassAndFunctionOffsets + unit->functionTableSize, unit->classTableSize * sizeof(quint32_le));
+    memcpy(dataPtr + unit->offsetToTemplateObjectTable, blockClassAndFunctionOffsets + unit->functionTableSize + unit->classTableSize, unit->templateObjectTableSize * sizeof(quint32_le));
+    memcpy(dataPtr + unit->offsetToBlockTable, blockClassAndFunctionOffsets + unit->functionTableSize + unit->classTableSize + unit->templateObjectTableSize, unit->blockTableSize * sizeof(quint32_le));
 
-    for (int i = 0; i < irModule->functions.size(); ++i) {
-        QV4::IR::Function *function = irModule->functions.at(i);
-        if (function == irModule->rootFunction)
+    for (int i = 0; i < module->functions.size(); ++i) {
+        Context *function = module->functions.at(i);
+        if (function == module->rootContext)
             unit->indexOfRootFunction = i;
 
-        writeFunction(dataPtr + functionOffsets[i], function);
+        writeFunction(dataPtr + blockClassAndFunctionOffsets[i], function);
+    }
+
+    for (int i = 0; i < module->classes.size(); ++i) {
+        const Class &c = module->classes.at(i);
+
+        writeClass(dataPtr + blockClassAndFunctionOffsets[i + module->functions.size()], c);
+    }
+
+    for (int i = 0; i < module->templateObjects.size(); ++i) {
+        const TemplateObject &t = module->templateObjects.at(i);
+
+        writeTemplateObject(dataPtr + blockClassAndFunctionOffsets[i + module->functions.size() + module->classes.size()], t);
+    }
+
+    for (int i = 0; i < module->blocks.size(); ++i) {
+        Context *block = module->blocks.at(i);
+
+        writeBlock(dataPtr + blockClassAndFunctionOffsets[i + module->classes.size() + module->templateObjects.size() + module->functions.size()], block);
     }
 
     CompiledData::Lookup *lookupsToWrite = reinterpret_cast<CompiledData::Lookup*>(dataPtr + unit->offsetToLookupTable);
@@ -254,7 +324,7 @@ QV4::CompiledData::Unit *QV4::Compiler::JSUnitGenerator::generateUnit(GeneratorO
     ReturnedValue *constantTable = reinterpret_cast<ReturnedValue *>(dataPtr + unit->offsetToConstantTable);
     memcpy(constantTable, constants.constData(), constants.size() * sizeof(ReturnedValue));
 #else
-    CompiledData::LEUInt64 *constantTable = reinterpret_cast<CompiledData::LEUInt64 *>(dataPtr + unit->offsetToConstantTable);
+    quint64_le *constantTable = reinterpret_cast<quint64_le *>(dataPtr + unit->offsetToConstantTable);
     for (int i = 0; i < constants.count(); ++i)
         constantTable[i] = constants.at(i);
 #endif
@@ -263,11 +333,50 @@ QV4::CompiledData::Unit *QV4::Compiler::JSUnitGenerator::generateUnit(GeneratorO
         memcpy(dataPtr + jsClassDataOffset, jsClassData.constData(), jsClassData.size());
 
         // write js classes and js class lookup table
-        CompiledData::LEUInt32 *jsClassOffsetTable = reinterpret_cast<CompiledData::LEUInt32 *>(dataPtr + unit->offsetToJSClassTable);
+        quint32_le *jsClassOffsetTable = reinterpret_cast<quint32_le *>(dataPtr + unit->offsetToJSClassTable);
         for (int i = 0; i < jsClassOffsets.count(); ++i)
             jsClassOffsetTable[i] = jsClassDataOffset + jsClassOffsets.at(i);
     }
 
+
+    memcpy(dataPtr + unit->offsetToTranslationTable, translations.constData(), translations.count() * sizeof(CompiledData::TranslationData));
+
+    {
+        const auto populateExportEntryTable = [this, dataPtr](const QVector<Compiler::ExportEntry> &table, quint32_le offset) {
+            CompiledData::ExportEntry *entryToWrite = reinterpret_cast<CompiledData::ExportEntry *>(dataPtr + offset);
+            for (const Compiler::ExportEntry &entry: table) {
+                entryToWrite->exportName = getStringId(entry.exportName);
+                entryToWrite->moduleRequest = getStringId(entry.moduleRequest);
+                entryToWrite->importName = getStringId(entry.importName);
+                entryToWrite->localName = getStringId(entry.localName);
+                entryToWrite->location = entry.location;
+                entryToWrite++;
+            }
+        };
+        populateExportEntryTable(module->localExportEntries, unit->offsetToLocalExportEntryTable);
+        populateExportEntryTable(module->indirectExportEntries, unit->offsetToIndirectExportEntryTable);
+        populateExportEntryTable(module->starExportEntries, unit->offsetToStarExportEntryTable);
+    }
+
+    {
+        CompiledData::ImportEntry *entryToWrite = reinterpret_cast<CompiledData::ImportEntry *>(dataPtr + unit->offsetToImportEntryTable);
+        for (const Compiler::ImportEntry &entry: module->importEntries) {
+            entryToWrite->moduleRequest = getStringId(entry.moduleRequest);
+            entryToWrite->importName = getStringId(entry.importName);
+            entryToWrite->localName = getStringId(entry.localName);
+            entryToWrite->location = entry.location;
+            entryToWrite++;
+        }
+    }
+
+    {
+        quint32_le *moduleRequestEntryToWrite = reinterpret_cast<quint32_le *>(dataPtr + unit->offsetToModuleRequestTable);
+        for (const QString &moduleRequest: module->moduleRequests) {
+            *moduleRequestEntryToWrite = getStringId(moduleRequest);
+            moduleRequestEntryToWrite++;
+        }
+    }
+
     // write strings and string table
     if (option == GenerateWithStringTable)
         stringTable.serialize(unit);
@@ -277,36 +386,42 @@ QV4::CompiledData::Unit *QV4::Compiler::JSUnitGenerator::generateUnit(GeneratorO
     return unit;
 }
 
-void QV4::Compiler::JSUnitGenerator::writeFunction(char *f, QV4::IR::Function *irFunction) const
+void QV4::Compiler::JSUnitGenerator::writeFunction(char *f, QV4::Compiler::Context *irFunction) const
 {
     QV4::CompiledData::Function *function = (QV4::CompiledData::Function *)f;
 
-    quint32 currentOffset = sizeof(QV4::CompiledData::Function);
-    currentOffset = (currentOffset + 7) & ~quint32(0x7);
+    quint32 currentOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, sizeof(*function)));
 
-    function->nameIndex = getStringId(*irFunction->name);
+    function->nameIndex = getStringId(irFunction->name);
     function->flags = 0;
-    if (irFunction->hasDirectEval)
-        function->flags |= CompiledData::Function::HasDirectEval;
-    if (irFunction->usesArgumentsObject)
-        function->flags |= CompiledData::Function::UsesArgumentsObject;
     if (irFunction->isStrict)
         function->flags |= CompiledData::Function::IsStrict;
-    if (irFunction->isNamedExpression)
-        function->flags |= CompiledData::Function::IsNamedExpression;
-    if (irFunction->hasTry || irFunction->hasWith)
-        function->flags |= CompiledData::Function::HasCatchOrWith;
-    if (irFunction->canUseSimpleCall())
-        function->flags |= CompiledData::Function::CanUseSimpleCall;
-    function->nFormals = irFunction->formals.size();
+    if (irFunction->isArrowFunction)
+        function->flags |= CompiledData::Function::IsArrowFunction;
+    if (irFunction->isGenerator)
+        function->flags |= CompiledData::Function::IsGenerator;
+    function->nestedFunctionIndex =
+            irFunction->returnsClosure ? quint32(module->functions.indexOf(irFunction->nestedContexts.first()))
+                                       : std::numeric_limits<uint32_t>::max();
+    function->length = irFunction->formals ? irFunction->formals->length() : 0;
+    function->nFormals = irFunction->arguments.size();
     function->formalsOffset = currentOffset;
     currentOffset += function->nFormals * sizeof(quint32);
 
+    function->sizeOfLocalTemporalDeadZone = irFunction->sizeOfLocalTemporalDeadZone;
+    function->sizeOfRegisterTemporalDeadZone = irFunction->sizeOfRegisterTemporalDeadZone;
+    function->firstTemporalDeadZoneRegister = irFunction->firstTemporalDeadZoneRegister;
+
     function->nLocals = irFunction->locals.size();
     function->localsOffset = currentOffset;
     currentOffset += function->nLocals * sizeof(quint32);
 
-    function->nInnerFunctions = irFunction->nestedFunctions.size();
+    function->nLineNumbers = irFunction->lineNumberMapping.size();
+    Q_ASSERT(function->lineNumberOffset() == currentOffset);
+    currentOffset += function->nLineNumbers * sizeof(CompiledData::CodeOffsetToLine);
+
+    function->nTraceInfos = irFunction->nTraceInfos;
+    function->nRegisters = irFunction->registerCountInFunction;
 
     function->nDependingIdObjects = 0;
     function->nDependingContextProperties = 0;
@@ -314,78 +429,211 @@ void QV4::Compiler::JSUnitGenerator::writeFunction(char *f, QV4::IR::Function *i
 
     if (!irFunction->idObjectDependencies.isEmpty()) {
         function->nDependingIdObjects = irFunction->idObjectDependencies.count();
-        function->dependingIdObjectsOffset = currentOffset;
+        Q_ASSERT(function->dependingIdObjectsOffset() == currentOffset);
         currentOffset += function->nDependingIdObjects * sizeof(quint32);
     }
 
     if (!irFunction->contextObjectPropertyDependencies.isEmpty()) {
         function->nDependingContextProperties = irFunction->contextObjectPropertyDependencies.count();
-        function->dependingContextPropertiesOffset = currentOffset;
+        Q_ASSERT(function->dependingContextPropertiesOffset() == currentOffset);
         currentOffset += function->nDependingContextProperties * sizeof(quint32) * 2;
     }
 
     if (!irFunction->scopeObjectPropertyDependencies.isEmpty()) {
         function->nDependingScopeProperties = irFunction->scopeObjectPropertyDependencies.count();
-        function->dependingScopePropertiesOffset = currentOffset;
+        Q_ASSERT(function->dependingScopePropertiesOffset() == currentOffset);
         currentOffset += function->nDependingScopeProperties * sizeof(quint32) * 2;
     }
 
+    if (!irFunction->labelInfo.empty()) {
+        function->nLabelInfos = quint32(irFunction->labelInfo.size());
+        Q_ASSERT(function->labelInfosOffset() == currentOffset);
+        currentOffset += function->nLabelInfos * sizeof(quint32);
+    }
+
     function->location.line = irFunction->line;
     function->location.column = irFunction->column;
 
-    function->codeOffset = 0;
-    function->codeSize = 0;
+    function->codeOffset = currentOffset;
+    function->codeSize = irFunction->code.size();
 
     // write formals
-    quint32 *formals = (quint32 *)(f + function->formalsOffset);
-    for (int i = 0; i < irFunction->formals.size(); ++i)
-        formals[i] = getStringId(*irFunction->formals.at(i));
+    quint32_le *formals = (quint32_le *)(f + function->formalsOffset);
+    for (int i = 0; i < irFunction->arguments.size(); ++i)
+        formals[i] = getStringId(irFunction->arguments.at(i));
 
     // write locals
-    quint32 *locals = (quint32 *)(f + function->localsOffset);
+    quint32_le *locals = (quint32_le *)(f + function->localsOffset);
     for (int i = 0; i < irFunction->locals.size(); ++i)
-        locals[i] = getStringId(*irFunction->locals.at(i));
+        locals[i] = getStringId(irFunction->locals.at(i));
+
+    // write line numbers
+    memcpy(f + function->lineNumberOffset(), irFunction->lineNumberMapping.constData(), irFunction->lineNumberMapping.size()*sizeof(CompiledData::CodeOffsetToLine));
 
     // write QML dependencies
-    quint32 *writtenDeps = (quint32 *)(f + function->dependingIdObjectsOffset);
+    quint32_le *writtenDeps = (quint32_le *)(f + function->dependingIdObjectsOffset());
     for (int id : irFunction->idObjectDependencies) {
         Q_ASSERT(id >= 0);
         *writtenDeps++ = static_cast<quint32>(id);
     }
 
-    writtenDeps = (quint32 *)(f + function->dependingContextPropertiesOffset);
+    writtenDeps = (quint32_le *)(f + function->dependingContextPropertiesOffset());
     for (auto property : irFunction->contextObjectPropertyDependencies) {
         *writtenDeps++ = property.key(); // property index
         *writtenDeps++ = property.value(); // notify index
     }
 
-    writtenDeps = (quint32 *)(f + function->dependingScopePropertiesOffset);
+    writtenDeps = (quint32_le *)(f + function->dependingScopePropertiesOffset());
     for (auto property : irFunction->scopeObjectPropertyDependencies) {
         *writtenDeps++ = property.key(); // property index
         *writtenDeps++ = property.value(); // notify index
     }
+
+    quint32_le *labels = (quint32_le *)(f + function->labelInfosOffset());
+    for (unsigned u : irFunction->labelInfo) {
+        *labels++ = u;
+    }
+
+    // write byte code
+    memcpy(f + function->codeOffset, irFunction->code.constData(), irFunction->code.size());
+}
+
+static_assert(int(QV4::Compiler::Class::Method::Regular) == int(QV4::CompiledData::Method::Regular), "Incompatible layout");
+static_assert(int(QV4::Compiler::Class::Method::Getter) == int(QV4::CompiledData::Method::Getter), "Incompatible layout");
+static_assert(int(QV4::Compiler::Class::Method::Setter) == int(QV4::CompiledData::Method::Setter), "Incompatible layout");
+
+void QV4::Compiler::JSUnitGenerator::writeClass(char *b, const QV4::Compiler::Class &c)
+{
+    QV4::CompiledData::Class *cls = reinterpret_cast<QV4::CompiledData::Class *>(b);
+
+    quint32 currentOffset = sizeof(QV4::CompiledData::Class);
+
+    QVector<Class::Method> allMethods = c.staticMethods;
+    allMethods += c.methods;
+
+    cls->constructorFunction = c.constructorIndex;
+    cls->nameIndex = c.nameIndex;
+    cls->nMethods = c.methods.size();
+    cls->nStaticMethods = c.staticMethods.size();
+    cls->methodTableOffset = currentOffset;
+    CompiledData::Method *method = reinterpret_cast<CompiledData::Method *>(b + currentOffset);
+
+    // write methods
+    for (int i = 0; i < allMethods.size(); ++i) {
+        method->name = allMethods.at(i).nameIndex;
+        method->type = allMethods.at(i).type;
+        method->function = allMethods.at(i).functionIndex;
+        ++method;
+    }
+
+    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_BYTECODE");
+    if (showCode) {
+        qDebug() << "=== Class " << stringForIndex(cls->nameIndex) << "static methods" << cls->nStaticMethods << "methods" << cls->nMethods;
+        qDebug() << "    constructor:" << cls->constructorFunction;
+        const char *staticString = ": static ";
+        for (uint i = 0; i < cls->nStaticMethods + cls->nMethods; ++i) {
+            if (i == cls->nStaticMethods)
+                staticString = ": ";
+            const char *type;
+            switch (cls->methodTable()[i].type) {
+            case CompiledData::Method::Getter:
+                type = "get "; break;
+            case CompiledData::Method::Setter:
+                type = "set "; break;
+            default:
+                type = "";
+
+            }
+            qDebug() << "    " << i << staticString << type << stringForIndex(cls->methodTable()[i].name) << cls->methodTable()[i].function;
+        }
+        qDebug();
+    }
 }
 
-QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Compiler::JSUnitGenerator::GeneratorOption option, QJsonPrivate::q_littleendian<quint32> *functionOffsets, uint *jsClassDataOffset)
+void QV4::Compiler::JSUnitGenerator::writeTemplateObject(char *b, const QV4::Compiler::TemplateObject &t)
+{
+    QV4::CompiledData::TemplateObject *tmpl = reinterpret_cast<QV4::CompiledData::TemplateObject *>(b);
+    tmpl->size = t.strings.size();
+
+    quint32 currentOffset = sizeof(QV4::CompiledData::TemplateObject);
+
+    quint32_le *strings = reinterpret_cast<quint32_le *>(b + currentOffset);
+
+    // write methods
+    for (int i = 0; i < t.strings.size(); ++i)
+        strings[i] = t.strings.at(i);
+    strings += t.strings.size();
+
+    for (int i = 0; i < t.rawStrings.size(); ++i)
+        strings[i] = t.rawStrings.at(i);
+
+    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_BYTECODE");
+    if (showCode) {
+        qDebug() << "=== TemplateObject size" << tmpl->size;
+        for (uint i = 0; i < tmpl->size; ++i) {
+            qDebug() << "    " << i << stringForIndex(tmpl->stringIndexAt(i));
+            qDebug() << "        raw: " << stringForIndex(tmpl->rawStringIndexAt(i));
+        }
+        qDebug();
+    }
+}
+
+void QV4::Compiler::JSUnitGenerator::writeBlock(char *b, QV4::Compiler::Context *irBlock) const
+{
+    QV4::CompiledData::Block *block = reinterpret_cast<QV4::CompiledData::Block *>(b);
+
+    quint32 currentOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, sizeof(*block)));
+
+    block->sizeOfLocalTemporalDeadZone = irBlock->sizeOfLocalTemporalDeadZone;
+    block->nLocals = irBlock->locals.size();
+    block->localsOffset = currentOffset;
+    currentOffset += block->nLocals * sizeof(quint32);
+
+    // write locals
+    quint32_le *locals = (quint32_le *)(b + block->localsOffset);
+    for (int i = 0; i < irBlock->locals.size(); ++i)
+        locals[i] = getStringId(irBlock->locals.at(i));
+
+    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_BYTECODE");
+    if (showCode) {
+        qDebug() << "=== Variables for block" << irBlock->blockIndex;
+        for (int i = 0; i < irBlock->locals.size(); ++i)
+            qDebug() << "    " << i << ":" << locals[i];
+        qDebug();
+    }
+}
+
+QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Compiler::JSUnitGenerator::GeneratorOption option, quint32_le *blockAndFunctionOffsets, uint *jsClassDataOffset)
 {
     CompiledData::Unit unit;
     memset(&unit, 0, sizeof(unit));
     memcpy(unit.magic, CompiledData::magic_str, sizeof(unit.magic));
     unit.flags = QV4::CompiledData::Unit::IsJavascript;
-    unit.flags |= irModule->unitFlags;
+    unit.flags |= module->unitFlags;
     unit.version = QV4_DATA_STRUCTURE_VERSION;
     unit.qtVersion = QT_VERSION;
+    qstrcpy(unit.libraryVersionHash, CompiledData::qml_compile_hash);
     memset(unit.md5Checksum, 0, sizeof(unit.md5Checksum));
-    unit.architectureIndex = registerString(irModule->targetABI.isEmpty() ? QSysInfo::buildAbi() : irModule->targetABI);
-    unit.codeGeneratorIndex = registerString(codeGeneratorName);
     memset(unit.dependencyMD5Checksum, 0, sizeof(unit.dependencyMD5Checksum));
 
     quint32 nextOffset = sizeof(CompiledData::Unit);
 
-    unit.functionTableSize = irModule->functions.size();
+    unit.functionTableSize = module->functions.size();
     unit.offsetToFunctionTable = nextOffset;
     nextOffset += unit.functionTableSize * sizeof(uint);
 
+    unit.classTableSize = module->classes.size();
+    unit.offsetToClassTable = nextOffset;
+    nextOffset += unit.classTableSize * sizeof(uint);
+
+    unit.templateObjectTableSize = module->templateObjects.size();
+    unit.offsetToTemplateObjectTable = nextOffset;
+    nextOffset += unit.templateObjectTableSize * sizeof(uint);
+
+    unit.blockTableSize = module->blocks.size();
+    unit.offsetToBlockTable = nextOffset;
+    nextOffset += unit.blockTableSize * sizeof(uint);
+
     unit.lookupTableSize = lookups.count();
     unit.offsetToLookupTable = nextOffset;
     nextOffset += unit.lookupTableSize * sizeof(CompiledData::Lookup);
@@ -408,17 +656,76 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
     *jsClassDataOffset = nextOffset;
     nextOffset += jsClassData.size();
 
-    for (int i = 0; i < irModule->functions.size(); ++i) {
-        QV4::IR::Function *f = irModule->functions.at(i);
-        functionOffsets[i] = nextOffset;
+    nextOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, nextOffset));
+
+    unit.translationTableSize = translations.count();
+    unit.offsetToTranslationTable = nextOffset;
+    nextOffset += unit.translationTableSize * sizeof(CompiledData::TranslationData);
+
+    nextOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, nextOffset));
+
+    const auto reserveExportTable = [&nextOffset](int count, quint32_le *tableSizePtr, quint32_le *offsetPtr) {
+        *tableSizePtr = count;
+        *offsetPtr = nextOffset;
+        nextOffset += count * sizeof(CompiledData::ExportEntry);
+        nextOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, nextOffset));
+    };
+
+    reserveExportTable(module->localExportEntries.count(), &unit.localExportEntryTableSize, &unit.offsetToLocalExportEntryTable);
+    reserveExportTable(module->indirectExportEntries.count(), &unit.indirectExportEntryTableSize, &unit.offsetToIndirectExportEntryTable);
+    reserveExportTable(module->starExportEntries.count(), &unit.starExportEntryTableSize, &unit.offsetToStarExportEntryTable);
+
+    unit.importEntryTableSize = module->importEntries.count();
+    unit.offsetToImportEntryTable = nextOffset;
+    nextOffset += unit.importEntryTableSize * sizeof(CompiledData::ImportEntry);
+    nextOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, nextOffset));
+
+    unit.moduleRequestTableSize = module->moduleRequests.count();
+    unit.offsetToModuleRequestTable = nextOffset;
+    nextOffset += unit.moduleRequestTableSize * sizeof(uint);
+    nextOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, nextOffset));
+
+    quint32 functionSize = 0;
+    for (int i = 0; i < module->functions.size(); ++i) {
+        Context *f = module->functions.at(i);
+        blockAndFunctionOffsets[i] = nextOffset;
 
         const int qmlIdDepsCount = f->idObjectDependencies.count();
         const int qmlPropertyDepsCount = f->scopeObjectPropertyDependencies.count() + f->contextObjectPropertyDependencies.count();
-        nextOffset += QV4::CompiledData::Function::calculateSize(f->formals.size(), f->locals.size(), f->nestedFunctions.size(), qmlIdDepsCount, qmlPropertyDepsCount);
+        quint32 size = QV4::CompiledData::Function::calculateSize(f->arguments.size(), f->locals.size(), f->lineNumberMapping.size(), f->nestedContexts.size(),
+                                                                 qmlIdDepsCount, qmlPropertyDepsCount, int(f->labelInfo.size()), f->code.size());
+        functionSize += size - f->code.size();
+        nextOffset += size;
+    }
+
+    blockAndFunctionOffsets += module->functions.size();
+
+    for (int i = 0; i < module->classes.size(); ++i) {
+        const Class &c = module->classes.at(i);
+        blockAndFunctionOffsets[i] = nextOffset;
+
+        nextOffset += QV4::CompiledData::Class::calculateSize(c.staticMethods.size(), c.methods.size());
+    }
+    blockAndFunctionOffsets += module->classes.size();
+
+    for (int i = 0; i < module->templateObjects.size(); ++i) {
+        const TemplateObject &t = module->templateObjects.at(i);
+        blockAndFunctionOffsets[i] = nextOffset;
+
+        nextOffset += QV4::CompiledData::TemplateObject::calculateSize(t.strings.size());
+    }
+    blockAndFunctionOffsets += module->templateObjects.size();
+
+    for (int i = 0; i < module->blocks.size(); ++i) {
+        Context *c = module->blocks.at(i);
+        blockAndFunctionOffsets[i] = nextOffset;
+
+        nextOffset += QV4::CompiledData::Block::calculateSize(c->locals.size());
     }
 
     if (option == GenerateWithStringTable) {
         unit.stringTableSize = stringTable.stringCount();
+        nextOffset = static_cast<quint32>(WTF::roundUpToMultipleOf(8, nextOffset));
         unit.offsetToStringTable = nextOffset;
         nextOffset += stringTable.sizeOfTableAndData();
     } else {
@@ -426,15 +733,19 @@ QV4::CompiledData::Unit QV4::Compiler::JSUnitGenerator::generateHeader(QV4::Comp
         unit.offsetToStringTable = 0;
     }
     unit.indexOfRootFunction = -1;
-    unit.sourceFileIndex = getStringId(irModule->fileName);
-    unit.sourceTimeStamp = irModule->sourceTimeStamp.isValid() ? irModule->sourceTimeStamp.toMSecsSinceEpoch() : 0;
-    unit.nImports = 0;
-    unit.offsetToImports = 0;
-    unit.nObjects = 0;
-    unit.offsetToObjects = 0;
-    unit.indexOfRootObject = 0;
+    unit.sourceFileIndex = getStringId(module->fileName);
+    unit.finalUrlIndex = getStringId(module->finalUrl);
+    unit.sourceTimeStamp = module->sourceTimeStamp.isValid() ? module->sourceTimeStamp.toMSecsSinceEpoch() : 0;
+    unit.offsetToQmlUnit = 0;
 
     unit.unitSize = nextOffset;
 
+    static const bool showStats = qEnvironmentVariableIsSet("QML_SHOW_UNIT_STATS");
+    if (showStats) {
+        qDebug() << "Generated JS unit that is" << unit.unitSize << "bytes contains:";
+        qDebug() << "    " << functionSize << "bytes for non-code function data for" << unit.functionTableSize << "functions";
+        qDebug() << "    " << translations.count() * sizeof(CompiledData::TranslationData) << "bytes for" << translations.count() << "translations";
+    }
+
     return unit;
 }
diff --git a/src/qml/compiler/qv4compiler_p.h b/src/qml/compiler/qv4compiler_p.h
index 49b8664513..2f5889ab53 100644
--- a/src/qml/compiler/qv4compiler_p.h
+++ b/src/qml/compiler/qv4compiler_p.h
@@ -51,8 +51,11 @@
 //
 
 #include <QtCore/qstring.h>
-#include "qv4jsir_p.h"
-#include <private/qjson_p.h>
+#include <QtCore/qhash.h>
+#include <QtCore/qstringlist.h>
+#include <private/qv4global_p.h>
+#include <private/qqmljsastfwd_p.h>
+#include <private/qv4compileddata_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -69,44 +72,63 @@ struct JSClassMember;
 
 namespace Compiler {
 
+struct Class;
+struct TemplateObject;
+
 struct Q_QML_PRIVATE_EXPORT StringTableGenerator {
     StringTableGenerator();
 
     int registerString(const QString &str);
     int getStringId(const QString &string) const;
     QString stringForIndex(int index) const { return strings.at(index); }
-    uint stringCount() const { return strings.size(); }
+    uint stringCount() const { return strings.size() - backingUnitTableSize; }
+
+    uint sizeOfTableAndData() const { return stringDataSize + ((stringCount() * sizeof(uint) + 7) & ~7); }
 
-    uint sizeOfTableAndData() const { return stringDataSize + strings.count() * sizeof(uint); }
+    void freeze() { frozen = true; }
 
     void clear();
 
+    void initializeFromBackingUnit(const CompiledData::Unit *unit);
+
     void serialize(CompiledData::Unit *unit);
+    QStringList allStrings() const { return strings.mid(backingUnitTableSize); }
 
 private:
     QHash<QString, int> stringToId;
     QStringList strings;
     uint stringDataSize;
+    uint backingUnitTableSize = 0;
+    bool frozen = false;
 };
 
 struct Q_QML_PRIVATE_EXPORT JSUnitGenerator {
-    JSUnitGenerator(IR::Module *module);
+    struct MemberInfo {
+        QString name;
+        bool isAccessor;
+    };
+
+    JSUnitGenerator(Module *module);
 
     int registerString(const QString &str) { return stringTable.registerString(str); }
     int getStringId(const QString &string) const { return stringTable.getStringId(string); }
     QString stringForIndex(int index) const { return stringTable.stringForIndex(index); }
 
-    uint registerGetterLookup(const QString &name);
-    uint registerSetterLookup(const QString &name);
-    uint registerGlobalGetterLookup(const QString &name);
-    uint registerIndexedGetterLookup();
-    uint registerIndexedSetterLookup();
+    int registerGetterLookup(const QString &name);
+    int registerGetterLookup(int nameIndex);
+    int registerSetterLookup(const QString &name);
+    int registerSetterLookup(int nameIndex);
+    int registerGlobalGetterLookup(const QString &name);
+    int registerGlobalGetterLookup(int nameIndex);
 
-    int registerRegExp(IR::RegExp *regexp);
+    int registerRegExp(QQmlJS::AST::RegExpLiteral *regexp);
 
     int registerConstant(ReturnedValue v);
+    ReturnedValue constant(int idx);
+
+    int registerJSClass(const QStringList &members);
 
-    int registerJSClass(int count, IR::ExprList *args);
+    int registerTranslation(const CompiledData::TranslationData &translation);
 
     enum GeneratorOption {
         GenerateWithStringTable,
@@ -114,21 +136,24 @@ struct Q_QML_PRIVATE_EXPORT JSUnitGenerator {
     };
 
     QV4::CompiledData::Unit *generateUnit(GeneratorOption option = GenerateWithStringTable);
-    // Returns bytes written
-    void writeFunction(char *f, IR::Function *irFunction) const;
+    void writeFunction(char *f, Context *irFunction) const;
+    void writeClass(char *f, const Class &c);
+    void writeTemplateObject(char *f, const TemplateObject &o);
+    void writeBlock(char *f, Context *irBlock) const;
 
     StringTableGenerator stringTable;
     QString codeGeneratorName;
 private:
-    CompiledData::Unit generateHeader(GeneratorOption option, QJsonPrivate::q_littleendian<quint32> *functionOffsets, uint *jsClassDataOffset);
+    CompiledData::Unit generateHeader(GeneratorOption option, quint32_le *functionOffsets, uint *jsClassDataOffset);
 
-    IR::Module *irModule;
+    Module *module;
 
     QList<CompiledData::Lookup> lookups;
     QVector<CompiledData::RegExp> regexps;
     QVector<ReturnedValue> constants;
     QByteArray jsClassData;
     QVector<int> jsClassOffsets;
+    QVector<CompiledData::TranslationData> translations;
 };
 
 }
diff --git a/src/qml/compiler/qv4compilercontext.cpp b/src/qml/compiler/qv4compilercontext.cpp
new file mode 100644
index 0000000000..931759fa72
--- /dev/null
+++ b/src/qml/compiler/qv4compilercontext.cpp
@@ -0,0 +1,432 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4compilercontext_p.h"
+#include "qv4compilercontrolflow_p.h"
+#include "qv4bytecodegenerator_p.h"
+
+QT_USE_NAMESPACE
+using namespace QV4;
+using namespace QV4::Compiler;
+using namespace QQmlJS::AST;
+
+QT_BEGIN_NAMESPACE
+
+Context *Module::newContext(Node *node, Context *parent, ContextType contextType)
+{
+    Q_ASSERT(!contextMap.contains(node));
+
+    Context *c = new Context(parent, contextType);
+    if (node) {
+        SourceLocation loc = node->firstSourceLocation();
+        c->line = loc.startLine;
+        c->column = loc.startColumn;
+    }
+
+    contextMap.insert(node, c);
+
+    if (!parent)
+        rootContext = c;
+    else {
+        parent->nestedContexts.append(c);
+        c->isStrict = parent->isStrict;
+    }
+
+    return c;
+}
+
+bool Context::Member::requiresTDZCheck(const SourceLocation &accessLocation, bool accessAcrossContextBoundaries) const
+{
+    if (!isLexicallyScoped())
+        return false;
+
+    if (accessAcrossContextBoundaries)
+        return true;
+
+    if (!accessLocation.isValid() || !endOfInitializerLocation.isValid())
+        return true;
+
+    return accessLocation.begin() < endOfInitializerLocation.end();
+}
+
+bool Context::addLocalVar(const QString &name, Context::MemberType type, VariableScope scope, FunctionExpression *function,
+                          const QQmlJS::AST::SourceLocation &endOfInitializer)
+{
+    // ### can this happen?
+    if (name.isEmpty())
+        return true;
+
+    if (type != FunctionDefinition) {
+        if (formals && formals->containsName(name))
+            return (scope == VariableScope::Var);
+    }
+    if (!isCatchBlock || name != caughtVariable) {
+        MemberMap::iterator it = members.find(name);
+        if (it != members.end()) {
+            if (scope != VariableScope::Var || (*it).scope != VariableScope::Var)
+                return false;
+            if ((*it).type <= type) {
+                (*it).type = type;
+                (*it).function = function;
+            }
+            return true;
+        }
+    }
+
+    // hoist var declarations to the function level
+    if (contextType == ContextType::Block && (scope == VariableScope::Var && type != MemberType::FunctionDefinition))
+        return parent->addLocalVar(name, type, scope, function, endOfInitializer);
+
+    Member m;
+    m.type = type;
+    m.function = function;
+    m.scope = scope;
+    m.endOfInitializerLocation = endOfInitializer;
+    members.insert(name, m);
+    return true;
+}
+
+Context::ResolvedName Context::resolveName(const QString &name, const QQmlJS::AST::SourceLocation &accessLocation)
+{
+    int scope = 0;
+    Context *c = this;
+
+    ResolvedName result;
+
+    while (c) {
+        if (c->isWithBlock)
+            return result;
+
+        Context::Member m = c->findMember(name);
+        if (!c->parent && m.index < 0)
+            break;
+
+        if (m.type != Context::UndefinedMember) {
+            result.type = m.canEscape ? ResolvedName::Local : ResolvedName::Stack;
+            result.scope = scope;
+            result.index = m.index;
+            result.isConst = (m.scope == VariableScope::Const);
+            result.requiresTDZCheck = m.requiresTDZCheck(accessLocation, c != this);
+            if (c->isStrict && (name == QLatin1String("arguments") || name == QLatin1String("eval")))
+                result.isArgOrEval = true;
+            return result;
+        }
+        const int argIdx = c->findArgument(name);
+        if (argIdx != -1) {
+            if (c->argumentsCanEscape) {
+                result.index = argIdx + c->locals.size();
+                result.scope = scope;
+                result.type = ResolvedName::Local;
+                result.isConst = false;
+                return result;
+            } else {
+                result.index = argIdx + sizeof(CallData)/sizeof(Value) - 1;
+                result.scope = 0;
+                result.type = ResolvedName::Stack;
+                result.isConst = false;
+                return result;
+            }
+        }
+        if (c->hasDirectEval) {
+            Q_ASSERT(!c->isStrict && c->contextType != ContextType::Block);
+            return result;
+        }
+
+        if (c->requiresExecutionContext)
+            ++scope;
+        c = c->parent;
+    }
+
+    if (c && c->contextType == ContextType::ESModule) {
+        for (int i = 0; i < c->importEntries.count(); ++i) {
+            if (c->importEntries.at(i).localName == name) {
+                result.index = i;
+                result.type = ResolvedName::Import;
+                result.isConst = true;
+                // We don't know at compile time whether the imported value is let/const or not.
+                result.requiresTDZCheck = true;
+                return result;
+            }
+        }
+    }
+
+    // ### can we relax the restrictions here?
+    if (c->contextType == ContextType::Eval || c->contextType == ContextType::Binding)
+        return result;
+
+    result.type = ResolvedName::Global;
+    return result;
+}
+
+void Context::emitBlockHeader(Codegen *codegen)
+{
+    using Instruction = Moth::Instruction;
+    Moth::BytecodeGenerator *bytecodeGenerator = codegen->generator();
+
+    setupFunctionIndices(bytecodeGenerator);
+
+    if (requiresExecutionContext) {
+        if (blockIndex < 0) {
+            codegen->module()->blocks.append(this);
+            blockIndex = codegen->module()->blocks.count() - 1;
+        }
+
+        if (contextType == ContextType::Global) {
+            Instruction::PushScriptContext scriptContext;
+            scriptContext.index = blockIndex;
+            bytecodeGenerator->addInstruction(scriptContext);
+        } else if (contextType == ContextType::Block || (contextType == ContextType::Eval && !isStrict)) {
+            if (isCatchBlock) {
+                Instruction::PushCatchContext catchContext;
+                catchContext.index = blockIndex;
+                catchContext.name = codegen->registerString(caughtVariable);
+                bytecodeGenerator->addInstruction(catchContext);
+            } else {
+                Instruction::PushBlockContext blockContext;
+                blockContext.index = blockIndex;
+                bytecodeGenerator->addInstruction(blockContext);
+            }
+        } else if (contextType != ContextType::ESModule && contextType != ContextType::ScriptImportedByQML) {
+            Instruction::CreateCallContext createContext;
+            bytecodeGenerator->addInstruction(createContext);
+        }
+    }
+
+    if (contextType == ContextType::Block && sizeOfRegisterTemporalDeadZone > 0) {
+        Instruction::InitializeBlockDeadTemporalZone tdzInit;
+        tdzInit.firstReg = registerOffset + nRegisters - sizeOfRegisterTemporalDeadZone;
+        tdzInit.count = sizeOfRegisterTemporalDeadZone;
+        bytecodeGenerator->addInstruction(tdzInit);
+    }
+
+    if (usesThis) {
+        Q_ASSERT(!isStrict);
+        // make sure we convert this to an object
+        Instruction::ConvertThisToObject convert;
+        bytecodeGenerator->addInstruction(convert);
+    }
+    if (innerFunctionAccessesThis) {
+        Instruction::LoadReg load;
+        load.reg = CallData::This;
+        bytecodeGenerator->addInstruction(load);
+        Codegen::Reference r = codegen->referenceForName(QStringLiteral("this"), true);
+        r.storeConsumeAccumulator();
+    }
+    if (innerFunctionAccessesNewTarget) {
+        Instruction::LoadReg load;
+        load.reg = CallData::NewTarget;
+        bytecodeGenerator->addInstruction(load);
+        Codegen::Reference r = codegen->referenceForName(QStringLiteral("new.target"), true);
+        r.storeConsumeAccumulator();
+    }
+
+    if (contextType == ContextType::Global || contextType == ContextType::ScriptImportedByQML || (contextType == ContextType::Eval && !isStrict)) {
+        // variables in global code are properties of the global context object, not locals as with other functions.
+        for (Context::MemberMap::const_iterator it = members.constBegin(), cend = members.constEnd(); it != cend; ++it) {
+            if (it->isLexicallyScoped())
+                continue;
+            const QString &local = it.key();
+
+            Instruction::DeclareVar declareVar;
+            declareVar.isDeletable = (contextType == ContextType::Eval);
+            declareVar.varName = codegen->registerString(local);
+            bytecodeGenerator->addInstruction(declareVar);
+        }
+    }
+
+    if (contextType == ContextType::Function || contextType == ContextType::Binding || contextType == ContextType::ESModule) {
+        for (Context::MemberMap::iterator it = members.begin(), end = members.end(); it != end; ++it) {
+            if (it->canEscape && it->type == Context::ThisFunctionName) {
+                // move the function from the stack to the call context
+                Instruction::LoadReg load;
+                load.reg = CallData::Function;
+                bytecodeGenerator->addInstruction(load);
+                Instruction::StoreLocal store;
+                store.index = it->index;
+                bytecodeGenerator->addInstruction(store);
+            }
+        }
+    }
+
+    if (usesArgumentsObject == Context::ArgumentsObjectUsed) {
+        Q_ASSERT(contextType != ContextType::Block);
+        if (isStrict || (formals && !formals->isSimpleParameterList())) {
+            Instruction::CreateUnmappedArgumentsObject setup;
+            bytecodeGenerator->addInstruction(setup);
+        } else {
+            Instruction::CreateMappedArgumentsObject setup;
+            bytecodeGenerator->addInstruction(setup);
+        }
+        codegen->referenceForName(QStringLiteral("arguments"), false).storeConsumeAccumulator();
+    }
+
+    for (const Context::Member &member : qAsConst(members)) {
+        if (member.function) {
+            const int function = codegen->defineFunction(member.function->name.toString(), member.function, member.function->formals, member.function->body);
+            codegen->loadClosure(function);
+            Codegen::Reference r = codegen->referenceForName(member.function->name.toString(), true);
+            r.storeConsumeAccumulator();
+        }
+    }
+}
+
+void Context::emitBlockFooter(Codegen *codegen)
+{
+    using Instruction = Moth::Instruction;
+    Moth::BytecodeGenerator *bytecodeGenerator = codegen->generator();
+
+    if (!requiresExecutionContext)
+        return;
+
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_GCC("-Wmaybe-uninitialized") // the loads below are empty structs.
+    if (contextType == ContextType::Global)
+        bytecodeGenerator->addInstruction(Instruction::PopScriptContext());
+    else if (contextType != ContextType::ESModule && contextType != ContextType::ScriptImportedByQML)
+        bytecodeGenerator->addInstruction(Instruction::PopContext());
+QT_WARNING_POP
+}
+
+void Context::setupFunctionIndices(Moth::BytecodeGenerator *bytecodeGenerator)
+{
+    if (registerOffset != -1) {
+        // already computed, check for consistency
+        Q_ASSERT(registerOffset == bytecodeGenerator->currentRegister());
+        bytecodeGenerator->newRegisterArray(nRegisters);
+        return;
+    }
+    Q_ASSERT(locals.size() == 0);
+    Q_ASSERT(nRegisters == 0);
+    registerOffset = bytecodeGenerator->currentRegister();
+
+    QVector<Context::MemberMap::Iterator> localsInTDZ;
+    const auto registerLocal = [this, &localsInTDZ](Context::MemberMap::iterator member) {
+        if (member->isLexicallyScoped()) {
+            localsInTDZ << member;
+        } else {
+            member->index = locals.size();
+            locals.append(member.key());
+        }
+    };
+
+    QVector<Context::MemberMap::Iterator> registersInTDZ;
+    const auto allocateRegister = [bytecodeGenerator, &registersInTDZ](Context::MemberMap::iterator member) {
+        if (member->isLexicallyScoped())
+            registersInTDZ << member;
+        else
+            member->index = bytecodeGenerator->newRegister();
+    };
+
+    switch (contextType) {
+    case ContextType::ESModule:
+    case ContextType::Block:
+    case ContextType::Function:
+    case ContextType::Binding: {
+        for (Context::MemberMap::iterator it = members.begin(), end = members.end(); it != end; ++it) {
+            if (it->canEscape) {
+                registerLocal(it);
+            } else {
+                if (it->type == Context::ThisFunctionName)
+                    it->index = CallData::Function;
+                else
+                    allocateRegister(it);
+            }
+        }
+        break;
+    }
+    case ContextType::Global:
+    case ContextType::ScriptImportedByQML:
+    case ContextType::Eval:
+        for (Context::MemberMap::iterator it = members.begin(), end = members.end(); it != end; ++it) {
+            if (!it->isLexicallyScoped() && (contextType == ContextType::Global || contextType == ContextType::ScriptImportedByQML || !isStrict))
+                continue;
+            if (it->canEscape)
+                registerLocal(it);
+            else
+                allocateRegister(it);
+        }
+        break;
+    }
+
+    sizeOfLocalTemporalDeadZone = localsInTDZ.count();
+    for (auto &member: qAsConst(localsInTDZ)) {
+        member->index = locals.size();
+        locals.append(member.key());
+    }
+
+    if (contextType == ContextType::ESModule && !localNameForDefaultExport.isEmpty()) {
+        if (!members.contains(localNameForDefaultExport)) {
+            // allocate a local slot for the default export, to be used in
+            // CodeGen::visit(ExportDeclaration*).
+            locals.append(localNameForDefaultExport);
+            ++sizeOfLocalTemporalDeadZone;
+        }
+    }
+
+    sizeOfRegisterTemporalDeadZone = registersInTDZ.count();
+    firstTemporalDeadZoneRegister = bytecodeGenerator->currentRegister();
+    for (auto &member: qAsConst(registersInTDZ))
+        member->index = bytecodeGenerator->newRegister();
+
+    nRegisters = bytecodeGenerator->currentRegister() - registerOffset;
+}
+
+bool Context::canUseTracingJit() const
+{
+#if QT_CONFIG(qml_tracing)
+    static bool forceTracing = !qEnvironmentVariableIsEmpty("QV4_FORCE_TRACING");
+    if (forceTracing) //### we can probably remove this when tracing is turned on by default
+        return true; // to be used by unittests
+
+    static bool disableTracing = !qEnvironmentVariableIsEmpty("QV4_DISABLE_TRACING");
+    if (disableTracing)
+        return false;
+
+    static QStringList onlyTrace =
+            qEnvironmentVariable("QV4_ONLY_TRACE").split(QLatin1Char(','), QString::SkipEmptyParts);
+    if (!onlyTrace.isEmpty())
+        return onlyTrace.contains(name);
+
+    return true;
+#else
+    return false;
+#endif
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4compilercontext_p.h b/src/qml/compiler/qv4compilercontext_p.h
new file mode 100644
index 0000000000..5b91b93346
--- /dev/null
+++ b/src/qml/compiler/qv4compilercontext_p.h
@@ -0,0 +1,380 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4COMPILERCONTEXT_P_H
+#define QV4COMPILERCONTEXT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "private/qv4global_p.h"
+#include <private/qqmljsast_p.h>
+#include <private/qv4compileddata_p.h>
+#include <QtCore/QStringList>
+#include <QtCore/QDateTime>
+#include <QtCore/QStack>
+#include <QtCore/QHash>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Compiler {
+
+struct ControlFlow;
+
+enum class ContextType {
+    Global,
+    Function,
+    Eval,
+    Binding, // This is almost the same as Eval, except:
+               //  * function declarations are moved to the return address when encountered
+               //  * return statements are allowed everywhere (like in FunctionCode)
+               //  * variable declarations are treated as true locals (like in FunctionCode)
+    Block,
+    ESModule,
+    ScriptImportedByQML,
+};
+
+struct Context;
+
+struct Class {
+    struct Method {
+        enum Type {
+            Regular,
+            Getter,
+            Setter
+        };
+        uint nameIndex;
+        Type type;
+        uint functionIndex;
+    };
+
+    uint nameIndex;
+    uint constructorIndex = UINT_MAX;
+    QVector<Method> staticMethods;
+    QVector<Method> methods;
+};
+
+struct TemplateObject {
+    QVector<uint> strings;
+    QVector<uint> rawStrings;
+    bool operator==(const TemplateObject &other) {
+        return strings == other.strings && rawStrings == other.rawStrings;
+    }
+};
+
+struct ExportEntry
+{
+    QString exportName;
+    QString moduleRequest;
+    QString importName;
+    QString localName;
+    CompiledData::Location location;
+
+    static bool lessThan(const ExportEntry &lhs, const ExportEntry &rhs)
+    { return lhs.exportName < rhs.exportName; }
+};
+
+struct ImportEntry
+{
+    QString moduleRequest;
+    QString importName;
+    QString localName;
+    CompiledData::Location location;
+};
+
+struct Module {
+    Module(bool debugMode)
+        : debugMode(debugMode)
+    {}
+    ~Module() {
+        qDeleteAll(contextMap);
+    }
+
+    Context *newContext(QQmlJS::AST::Node *node, Context *parent, ContextType compilationMode);
+
+    QHash<QQmlJS::AST::Node *, Context *> contextMap;
+    QList<Context *> functions;
+    QList<Context *> blocks;
+    QVector<Class> classes;
+    QVector<TemplateObject> templateObjects;
+    Context *rootContext;
+    QString fileName;
+    QString finalUrl;
+    QDateTime sourceTimeStamp;
+    uint unitFlags = 0; // flags merged into CompiledData::Unit::flags
+    bool debugMode = false;
+    QVector<ExportEntry> localExportEntries;
+    QVector<ExportEntry> indirectExportEntries;
+    QVector<ExportEntry> starExportEntries;
+    QVector<ImportEntry> importEntries;
+    QStringList moduleRequests;
+};
+
+
+struct Context {
+    Context *parent;
+    QString name;
+    int line = 0;
+    int column = 0;
+    int registerCountInFunction = 0;
+    uint nTraceInfos = 0;
+    int functionIndex = -1;
+    int blockIndex = -1;
+
+    enum MemberType {
+        UndefinedMember,
+        ThisFunctionName,
+        VariableDefinition,
+        VariableDeclaration,
+        FunctionDefinition
+    };
+
+    struct Member {
+        MemberType type = UndefinedMember;
+        int index = -1;
+        QQmlJS::AST::VariableScope scope = QQmlJS::AST::VariableScope::Var;
+        mutable bool canEscape = false;
+        QQmlJS::AST::FunctionExpression *function = nullptr;
+        QQmlJS::AST::SourceLocation endOfInitializerLocation;
+
+        bool isLexicallyScoped() const { return this->scope != QQmlJS::AST::VariableScope::Var; }
+        bool requiresTDZCheck(const QQmlJS::AST::SourceLocation &accessLocation, bool accessAcrossContextBoundaries) const;
+    };
+    typedef QMap<QString, Member> MemberMap;
+
+    MemberMap members;
+    QSet<QString> usedVariables;
+    QQmlJS::AST::FormalParameterList *formals = nullptr;
+    QStringList arguments;
+    QStringList locals;
+    QStringList moduleRequests;
+    QVector<ImportEntry> importEntries;
+    QVector<ExportEntry> exportEntries;
+    QString localNameForDefaultExport;
+    QVector<Context *> nestedContexts;
+
+    ControlFlow *controlFlow = nullptr;
+    QByteArray code;
+    QVector<CompiledData::CodeOffsetToLine> lineNumberMapping;
+    std::vector<unsigned> labelInfo;
+
+    int nRegisters = 0;
+    int registerOffset = -1;
+    int sizeOfLocalTemporalDeadZone = 0;
+    int firstTemporalDeadZoneRegister = 0;
+    int sizeOfRegisterTemporalDeadZone = 0;
+    bool hasDirectEval = false;
+    bool allVarsEscape = false;
+    bool hasNestedFunctions = false;
+    bool isStrict = false;
+    bool isArrowFunction = false;
+    bool isGenerator = false;
+    bool usesThis = false;
+    bool innerFunctionAccessesThis = false;
+    bool innerFunctionAccessesNewTarget = false;
+    bool hasTry = false;
+    bool returnsClosure = false;
+    mutable bool argumentsCanEscape = false;
+    bool requiresExecutionContext = false;
+    bool isWithBlock = false;
+    bool isCatchBlock = false;
+    QString caughtVariable;
+    QQmlJS::AST::SourceLocation lastBlockInitializerLocation;
+
+    enum UsesArgumentsObject {
+        ArgumentsObjectUnknown,
+        ArgumentsObjectNotUsed,
+        ArgumentsObjectUsed
+    };
+
+    UsesArgumentsObject usesArgumentsObject = ArgumentsObjectUnknown;
+
+    ContextType contextType;
+
+    template <typename T>
+    class SmallSet: public QVarLengthArray<T, 8>
+    {
+    public:
+        void insert(int value)
+        {
+            for (auto it : *this) {
+                if (it == value)
+                    return;
+            }
+            this->append(value);
+        }
+    };
+
+    // Map from meta property index (existence implies dependency) to notify signal index
+    struct KeyValuePair
+    {
+        quint32 _key = 0;
+        quint32 _value = 0;
+
+        KeyValuePair() {}
+        KeyValuePair(quint32 key, quint32 value): _key(key), _value(value) {}
+
+        quint32 key() const { return _key; }
+        quint32 value() const { return _value; }
+    };
+
+    class PropertyDependencyMap: public QVarLengthArray<KeyValuePair, 8>
+    {
+    public:
+        void insert(quint32 key, quint32 value)
+        {
+            for (auto it = begin(), eit = end(); it != eit; ++it) {
+                if (it->_key == key) {
+                    it->_value = value;
+                    return;
+                }
+            }
+            append(KeyValuePair(key, value));
+        }
+    };
+
+    // Qml extension:
+    SmallSet<int> idObjectDependencies;
+    PropertyDependencyMap contextObjectPropertyDependencies;
+    PropertyDependencyMap scopeObjectPropertyDependencies;
+
+    Context(Context *parent, ContextType type)
+        : parent(parent)
+        , contextType(type)
+    {
+        if (parent && parent->isStrict)
+            isStrict = true;
+    }
+
+    int findArgument(const QString &name) const
+    {
+        // search backwards to handle duplicate argument names correctly
+        for (int i = arguments.size() - 1; i >= 0; --i) {
+            if (arguments.at(i) == name)
+                return i;
+        }
+        return -1;
+    }
+
+    Member findMember(const QString &name) const
+    {
+        MemberMap::const_iterator it = members.find(name);
+        if (it == members.end())
+            return Member();
+        Q_ASSERT(it->index != -1 || !parent);
+        return (*it);
+    }
+
+    bool memberInfo(const QString &name, const Member **m) const
+    {
+        Q_ASSERT(m);
+        MemberMap::const_iterator it = members.find(name);
+        if (it == members.end()) {
+            *m = nullptr;
+            return false;
+        }
+        *m = &(*it);
+        return true;
+    }
+
+    bool requiresImplicitReturnValue() const {
+        return contextType == ContextType::Binding ||
+               contextType == ContextType::Eval ||
+               contextType == ContextType::Global || contextType == ContextType::ScriptImportedByQML;
+    }
+
+    void addUsedVariable(const QString &name) {
+        usedVariables.insert(name);
+    }
+
+    bool addLocalVar(const QString &name, MemberType contextType, QQmlJS::AST::VariableScope scope, QQmlJS::AST::FunctionExpression *function = nullptr,
+                     const QQmlJS::AST::SourceLocation &endOfInitializer = QQmlJS::AST::SourceLocation());
+
+    struct ResolvedName {
+        enum Type {
+            Unresolved,
+            Global,
+            Local,
+            Stack,
+            Import
+        };
+        Type type = Unresolved;
+        bool isArgOrEval = false;
+        bool isConst = false;
+        bool requiresTDZCheck = false;
+        int scope = -1;
+        int index = -1;
+        QQmlJS::AST::SourceLocation endOfDeclarationLocation;
+        bool isValid() const { return type != Unresolved; }
+    };
+    ResolvedName resolveName(const QString &name, const QQmlJS::AST::SourceLocation &accessLocation);
+    void emitBlockHeader(Compiler::Codegen *codegen);
+    void emitBlockFooter(Compiler::Codegen *codegen);
+
+    void setupFunctionIndices(Moth::BytecodeGenerator *bytecodeGenerator);
+
+    bool canHaveTailCalls() const
+    {
+        if (!isStrict)
+            return false;
+        if (contextType == ContextType::Function)
+            return !isGenerator;
+        if (contextType == ContextType::Block && parent)
+            return parent->canHaveTailCalls();
+        return false;
+    }
+
+    bool canUseTracingJit() const;
+};
+
+
+} } // namespace QV4::Compiler
+
+QT_END_NAMESPACE
+
+#endif // QV4CODEGEN_P_H
diff --git a/src/qml/compiler/qv4compilercontrolflow_p.h b/src/qml/compiler/qv4compilercontrolflow_p.h
new file mode 100644
index 0000000000..5b622e81d8
--- /dev/null
+++ b/src/qml/compiler/qv4compilercontrolflow_p.h
@@ -0,0 +1,436 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4COMPILERCONTROLFLOW_P_H
+#define QV4COMPILERCONTROLFLOW_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+#include <private/qv4codegen_p.h>
+#include <private/qqmljsast_p.h>
+#include <private/qv4bytecodegenerator_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Compiler {
+
+struct ControlFlow {
+    using Reference = Codegen::Reference;
+    using BytecodeGenerator = Moth::BytecodeGenerator;
+    using Instruction = Moth::Instruction;
+
+    enum Type {
+        Loop,
+        With,
+        Block,
+        Finally,
+        Catch
+    };
+
+    enum UnwindType {
+        Break,
+        Continue,
+        Return
+    };
+
+    struct UnwindTarget {
+        BytecodeGenerator::Label linkLabel;
+        int unwindLevel;
+    };
+
+    Codegen *cg;
+    ControlFlow *parent;
+    Type type;
+
+    ControlFlow(Codegen *cg, Type type)
+        : cg(cg), parent(cg->controlFlow), type(type)
+    {
+        cg->controlFlow = this;
+    }
+
+    virtual ~ControlFlow() {
+        cg->controlFlow = parent;
+    }
+
+    UnwindTarget unwindTarget(UnwindType type, const QString &label = QString())
+    {
+        Q_ASSERT(type == Break || type == Continue || type == Return);
+        ControlFlow *flow = this;
+        int level = 0;
+        while (flow) {
+            BytecodeGenerator::Label l = flow->getUnwindTarget(type, label);
+            if (l.isValid())
+                return UnwindTarget{l, level};
+            if (flow->requiresUnwind())
+                ++level;
+            flow = flow->parent;
+        }
+        if (type == Return)
+            return UnwindTarget{ cg->returnLabel(), level };
+        return UnwindTarget();
+    }
+
+    virtual QString label() const { return QString(); }
+
+    bool hasLoop() const {
+        const ControlFlow *flow = this;
+        while (flow) {
+            if (flow->type == Loop)
+                return true;
+            flow = flow->parent;
+        }
+        return false;
+    }
+
+protected:
+    virtual BytecodeGenerator::Label getUnwindTarget(UnwindType, const QString & = QString()) {
+        return BytecodeGenerator::Label();
+    }
+    virtual bool requiresUnwind() {
+        return false;
+    }
+
+public:
+    BytecodeGenerator::ExceptionHandler *parentUnwindHandler() {
+        return parent ? parent->unwindHandler() : nullptr;
+    }
+
+    virtual BytecodeGenerator::ExceptionHandler *unwindHandler() {
+        return parentUnwindHandler();
+    }
+
+
+protected:
+    QString loopLabel() const {
+        QString label;
+        if (cg->_labelledStatement) {
+            label = cg->_labelledStatement->label.toString();
+            cg->_labelledStatement = nullptr;
+        }
+        return label;
+    }
+    BytecodeGenerator *generator() const {
+        return cg->bytecodeGenerator;
+    }
+};
+
+struct ControlFlowUnwind : public ControlFlow
+{
+    BytecodeGenerator::ExceptionHandler unwindLabel;
+
+    ControlFlowUnwind(Codegen *cg, Type type)
+        : ControlFlow(cg, type)
+    {
+    }
+
+    void setupUnwindHandler()
+    {
+        unwindLabel = generator()->newExceptionHandler();
+    }
+
+    void emitUnwindHandler()
+    {
+        Q_ASSERT(requiresUnwind());
+
+        Instruction::UnwindDispatch dispatch;
+        generator()->addInstruction(dispatch);
+    }
+
+    virtual BytecodeGenerator::ExceptionHandler *unwindHandler() override {
+        return unwindLabel.isValid() ? &unwindLabel : parentUnwindHandler();
+    }
+};
+
+struct ControlFlowUnwindCleanup : public ControlFlowUnwind
+{
+    std::function<void()> cleanup = nullptr;
+
+    ControlFlowUnwindCleanup(Codegen *cg, std::function<void()> cleanup, Type type = Block)
+        : ControlFlowUnwind(cg, type), cleanup(cleanup)
+    {
+        if (cleanup) {
+            setupUnwindHandler();
+            generator()->setUnwindHandler(&unwindLabel);
+        }
+    }
+
+    ~ControlFlowUnwindCleanup() {
+        if (cleanup) {
+            unwindLabel.link();
+            generator()->setUnwindHandler(parentUnwindHandler());
+            cleanup();
+            emitUnwindHandler();
+        }
+    }
+
+    bool requiresUnwind() override {
+        return cleanup != nullptr;
+    }
+};
+
+struct ControlFlowLoop : public ControlFlowUnwindCleanup
+{
+    QString loopLabel;
+    BytecodeGenerator::Label *breakLabel = nullptr;
+    BytecodeGenerator::Label *continueLabel = nullptr;
+
+    ControlFlowLoop(Codegen *cg, BytecodeGenerator::Label *breakLabel, BytecodeGenerator::Label *continueLabel = nullptr, std::function<void()> cleanup = nullptr)
+        : ControlFlowUnwindCleanup(cg, cleanup, Loop), loopLabel(ControlFlow::loopLabel()), breakLabel(breakLabel), continueLabel(continueLabel)
+    {
+    }
+
+    BytecodeGenerator::Label getUnwindTarget(UnwindType type, const QString &label) override {
+        switch (type) {
+        case Break:
+            if (breakLabel && (label.isEmpty() || label == loopLabel))
+                return *breakLabel;
+            break;
+        case Continue:
+            if (continueLabel && (label.isEmpty() || label == loopLabel))
+                return *continueLabel;
+            break;
+        default:
+            break;
+        }
+        return BytecodeGenerator::Label();
+    }
+
+    QString label() const override { return loopLabel; }
+};
+
+
+struct ControlFlowWith : public ControlFlowUnwind
+{
+    ControlFlowWith(Codegen *cg)
+        : ControlFlowUnwind(cg, With)
+    {
+        setupUnwindHandler();
+
+        // assumes the with object is in the accumulator
+        Instruction::PushWithContext pushScope;
+        generator()->addInstruction(pushScope);
+        generator()->setUnwindHandler(&unwindLabel);
+    }
+
+    ~ControlFlowWith() {
+        // emit code for unwinding
+        unwindLabel.link();
+
+        generator()->setUnwindHandler(parentUnwindHandler());
+        Instruction::PopContext pop;
+        generator()->addInstruction(pop);
+
+        emitUnwindHandler();
+    }
+
+    bool requiresUnwind() override {
+        return true;
+    }
+
+
+};
+
+struct ControlFlowBlock : public ControlFlowUnwind
+{
+    ControlFlowBlock(Codegen *cg, AST::Node *ast)
+        : ControlFlowUnwind(cg, Block)
+    {
+        block = cg->enterBlock(ast);
+        block->emitBlockHeader(cg);
+
+        if (block->requiresExecutionContext) {
+            setupUnwindHandler();
+            generator()->setUnwindHandler(&unwindLabel);
+        }
+    }
+
+    virtual ~ControlFlowBlock() {
+        // emit code for unwinding
+        if (block->requiresExecutionContext) {
+            unwindLabel.link();
+            generator()->setUnwindHandler(parentUnwindHandler());
+        }
+
+        block->emitBlockFooter(cg);
+
+        if (block->requiresExecutionContext )
+            emitUnwindHandler();
+        cg->leaveBlock();
+    }
+
+    virtual bool requiresUnwind() override {
+        return block->requiresExecutionContext;
+    }
+
+    Context *block;
+};
+
+struct ControlFlowCatch : public ControlFlowUnwind
+{
+    AST::Catch *catchExpression;
+    bool insideCatch = false;
+    BytecodeGenerator::ExceptionHandler exceptionLabel;
+
+    ControlFlowCatch(Codegen *cg, AST::Catch *catchExpression)
+        : ControlFlowUnwind(cg, Catch), catchExpression(catchExpression),
+          exceptionLabel(generator()->newExceptionHandler())
+    {
+        generator()->setUnwindHandler(&exceptionLabel);
+    }
+
+    virtual bool requiresUnwind() override {
+        return true;
+    }
+
+    BytecodeGenerator::ExceptionHandler *unwindHandler() override {
+        return insideCatch ? &unwindLabel : &exceptionLabel;
+    }
+
+    ~ControlFlowCatch() {
+        // emit code for unwinding
+        insideCatch = true;
+        setupUnwindHandler();
+
+        Codegen::RegisterScope scope(cg);
+
+        // exceptions inside the try block go here
+        exceptionLabel.link();
+        BytecodeGenerator::Jump noException = generator()->jumpNoException();
+
+        Context *block = cg->enterBlock(catchExpression);
+
+        block->emitBlockHeader(cg);
+
+        generator()->setUnwindHandler(&unwindLabel);
+
+        if (catchExpression->patternElement->bindingIdentifier.isEmpty())
+            // destructuring pattern
+            cg->initializeAndDestructureBindingElement(catchExpression->patternElement, Reference::fromName(cg, QStringLiteral("@caught")));
+        // skip the additional block
+        cg->statementList(catchExpression->statement->statements);
+
+        // exceptions inside catch and break/return statements go here
+        unwindLabel.link();
+        block->emitBlockFooter(cg);
+
+        cg->leaveBlock();
+
+        noException.link();
+        generator()->setUnwindHandler(parentUnwindHandler());
+
+        emitUnwindHandler();
+        insideCatch = false;
+    }
+};
+
+struct ControlFlowFinally : public ControlFlowUnwind
+{
+    AST::Finally *finally;
+    bool insideFinally = false;
+
+    ControlFlowFinally(Codegen *cg, AST::Finally *finally)
+        : ControlFlowUnwind(cg, Finally), finally(finally)
+    {
+        Q_ASSERT(finally != nullptr);
+        setupUnwindHandler();
+        generator()->setUnwindHandler(&unwindLabel);
+    }
+
+    virtual bool requiresUnwind() override {
+        return !insideFinally;
+    }
+
+    BytecodeGenerator::ExceptionHandler *unwindHandler() override {
+        return insideFinally ? parentUnwindHandler() : ControlFlowUnwind::unwindHandler();
+    }
+
+    ~ControlFlowFinally() {
+        // emit code for unwinding
+        unwindLabel.link();
+
+        Codegen::RegisterScope scope(cg);
+
+        insideFinally = true;
+        int returnValueTemp = -1;
+        if (cg->requiresReturnValue) {
+            returnValueTemp = generator()->newRegister();
+            Instruction::MoveReg move;
+            move.srcReg = cg->_returnAddress;
+            move.destReg = returnValueTemp;
+            generator()->addInstruction(move);
+        }
+        int exceptionTemp = generator()->newRegister();
+        Instruction::GetException instr;
+        generator()->addInstruction(instr);
+        Reference::fromStackSlot(cg, exceptionTemp).storeConsumeAccumulator();
+
+        generator()->setUnwindHandler(parentUnwindHandler());
+        cg->statement(finally->statement);
+        insideFinally = false;
+
+        if (cg->requiresReturnValue) {
+            Instruction::MoveReg move;
+            move.srcReg = returnValueTemp;
+            move.destReg = cg->_returnAddress;
+            generator()->addInstruction(move);
+        }
+        Reference::fromStackSlot(cg, exceptionTemp).loadInAccumulator();
+        Instruction::SetException setException;
+        generator()->addInstruction(setException);
+
+        emitUnwindHandler();
+    }
+};
+
+} } // QV4::Compiler namespace
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/compiler/qv4compilerscanfunctions.cpp b/src/qml/compiler/qv4compilerscanfunctions.cpp
new file mode 100644
index 0000000000..e0eaa8867b
--- /dev/null
+++ b/src/qml/compiler/qv4compilerscanfunctions.cpp
@@ -0,0 +1,895 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4compilerscanfunctions_p.h"
+
+#include <QtCore/QCoreApplication>
+#include <QtCore/QStringList>
+#include <QtCore/QSet>
+#include <QtCore/QBuffer>
+#include <QtCore/QBitArray>
+#include <QtCore/QLinkedList>
+#include <QtCore/QStack>
+#include <private/qqmljsast_p.h>
+#include <private/qv4compilercontext_p.h>
+#include <private/qv4codegen_p.h>
+#include <private/qv4string_p.h>
+
+QT_USE_NAMESPACE
+using namespace QV4;
+using namespace QV4::Compiler;
+using namespace QQmlJS::AST;
+
+ScanFunctions::ScanFunctions(Codegen *cg, const QString &sourceCode, ContextType defaultProgramType)
+    : _cg(cg)
+    , _sourceCode(sourceCode)
+    , _context(nullptr)
+    , _allowFuncDecls(true)
+    , defaultProgramType(defaultProgramType)
+{
+}
+
+void ScanFunctions::operator()(Node *node)
+{
+    if (node)
+        node->accept(this);
+
+    calcEscapingVariables();
+}
+
+void ScanFunctions::enterGlobalEnvironment(ContextType compilationMode)
+{
+    enterEnvironment(astNodeForGlobalEnvironment, compilationMode, QStringLiteral("%GlobalCode"));
+}
+
+void ScanFunctions::enterEnvironment(Node *node, ContextType compilationMode, const QString &name)
+{
+    Context *c = _cg->_module->contextMap.value(node);
+    if (!c)
+        c = _cg->_module->newContext(node, _context, compilationMode);
+    if (!c->isStrict)
+        c->isStrict = _cg->_strictMode;
+    c->name = name;
+    _contextStack.append(c);
+    _context = c;
+}
+
+void ScanFunctions::leaveEnvironment()
+{
+    _contextStack.pop();
+    _context = _contextStack.isEmpty() ? nullptr : _contextStack.top();
+}
+
+bool ScanFunctions::preVisit(Node *ast)
+{
+    if (_cg->hasError)
+        return false;
+    ++_recursionDepth;
+
+    if (_recursionDepth > 1000) {
+        _cg->throwSyntaxError(ast->lastSourceLocation(), QStringLiteral("Maximum statement or expression depth exceeded"));
+        return false;
+    }
+
+    return true;
+}
+
+void ScanFunctions::postVisit(Node *)
+{
+    --_recursionDepth;
+}
+
+void ScanFunctions::checkDirectivePrologue(StatementList *ast)
+{
+    for (StatementList *it = ast; it; it = it->next) {
+        if (ExpressionStatement *expr = cast<ExpressionStatement *>(it->statement)) {
+            if (StringLiteral *strLit = cast<StringLiteral *>(expr->expression)) {
+                // Use the source code, because the StringLiteral's
+                // value might have escape sequences in it, which is not
+                // allowed.
+                if (strLit->literalToken.length < 2)
+                    continue;
+                QStringRef str = _sourceCode.midRef(strLit->literalToken.offset + 1, strLit->literalToken.length - 2);
+                if (str == QLatin1String("use strict")) {
+                    _context->isStrict = true;
+                } else {
+                    // TODO: give a warning.
+                }
+                continue;
+            }
+        }
+
+        break;
+    }
+}
+
+void ScanFunctions::checkName(const QStringRef &name, const SourceLocation &loc)
+{
+    if (_context->isStrict) {
+        if (name == QLatin1String("implements")
+                || name == QLatin1String("interface")
+                || name == QLatin1String("let")
+                || name == QLatin1String("package")
+                || name == QLatin1String("private")
+                || name == QLatin1String("protected")
+                || name == QLatin1String("public")
+                || name == QLatin1String("static")
+                || name == QLatin1String("yield")) {
+            _cg->throwSyntaxError(loc, QStringLiteral("Unexpected strict mode reserved word"));
+        }
+    }
+}
+
+bool ScanFunctions::visit(Program *ast)
+{
+    enterEnvironment(ast, defaultProgramType, QStringLiteral("%ProgramCode"));
+    checkDirectivePrologue(ast->statements);
+    return true;
+}
+
+void ScanFunctions::endVisit(Program *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ESModule *ast)
+{
+    enterEnvironment(ast, defaultProgramType, QStringLiteral("%ModuleCode"));
+    _context->isStrict = true;
+    return true;
+}
+
+void ScanFunctions::endVisit(ESModule *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ExportDeclaration *declaration)
+{
+    QString module;
+    if (declaration->fromClause) {
+        module = declaration->fromClause->moduleSpecifier.toString();
+        if (!module.isEmpty())
+            _context->moduleRequests << module;
+    }
+
+    QString localNameForDefaultExport = QStringLiteral("*default*");
+
+    if (declaration->exportAll) {
+        Compiler::ExportEntry entry;
+        entry.moduleRequest = declaration->fromClause->moduleSpecifier.toString();
+        entry.importName = QStringLiteral("*");
+        entry.location = declaration->firstSourceLocation();
+        _context->exportEntries << entry;
+    } else if (declaration->exportClause) {
+        for (ExportsList *it = declaration->exportClause->exportsList; it; it = it->next) {
+            ExportSpecifier *spec = it->exportSpecifier;
+            Compiler::ExportEntry entry;
+            if (module.isEmpty())
+                entry.localName = spec->identifier.toString();
+            else
+                entry.importName = spec->identifier.toString();
+
+            entry.moduleRequest = module;
+            entry.exportName = spec->exportedIdentifier.toString();
+            entry.location = it->firstSourceLocation();
+
+            _context->exportEntries << entry;
+        }
+    } else if (auto *vstmt = AST::cast<AST::VariableStatement*>(declaration->variableStatementOrDeclaration)) {
+        QStringList boundNames;
+        for (VariableDeclarationList *it = vstmt->declarations; it; it = it->next) {
+            if (!it->declaration)
+                continue;
+            it->declaration->boundNames(&boundNames);
+        }
+        for (const QString &name: boundNames) {
+            Compiler::ExportEntry entry;
+            entry.localName = name;
+            entry.exportName = name;
+            entry.location = vstmt->firstSourceLocation();
+            _context->exportEntries << entry;
+        }
+    } else if (auto *classDecl = AST::cast<AST::ClassDeclaration*>(declaration->variableStatementOrDeclaration)) {
+        QString name = classDecl->name.toString();
+        if (!name.isEmpty()) {
+            Compiler::ExportEntry entry;
+            entry.localName = name;
+            entry.exportName = name;
+            entry.location = classDecl->firstSourceLocation();
+            _context->exportEntries << entry;
+            if (declaration->exportDefault)
+                localNameForDefaultExport = entry.localName;
+        }
+    } else if (auto *fdef = declaration->variableStatementOrDeclaration->asFunctionDefinition()) {
+        QString functionName;
+
+        // Only function definitions for which we enter their name into the local environment
+        // can result in exports. Nested expressions such as (function foo() {}) are not accessible
+        // as locals and can only be exported as default exports (further down).
+        auto ast = declaration->variableStatementOrDeclaration;
+        if (AST::cast<AST::ExpressionStatement*>(ast) || AST::cast<AST::FunctionDeclaration*>(ast))
+            functionName = fdef->name.toString();
+
+        if (!functionName.isEmpty()) {
+            Compiler::ExportEntry entry;
+            entry.localName = functionName;
+            entry.exportName = functionName;
+            entry.location = fdef->firstSourceLocation();
+            _context->exportEntries << entry;
+            if (declaration->exportDefault)
+                localNameForDefaultExport = entry.localName;
+        }
+    }
+
+    if (declaration->exportDefault) {
+        Compiler::ExportEntry entry;
+        entry.localName = localNameForDefaultExport;
+        _context->localNameForDefaultExport = localNameForDefaultExport;
+        entry.exportName = QStringLiteral("default");
+        entry.location = declaration->firstSourceLocation();
+        _context->exportEntries << entry;
+    }
+
+    return true; // scan through potential assignment expression code, etc.
+}
+
+bool ScanFunctions::visit(ImportDeclaration *declaration)
+{
+    QString module;
+    if (declaration->fromClause) {
+        module = declaration->fromClause->moduleSpecifier.toString();
+        if (!module.isEmpty())
+            _context->moduleRequests << module;
+    }
+
+    if (!declaration->moduleSpecifier.isEmpty())
+        _context->moduleRequests << declaration->moduleSpecifier.toString();
+
+    if (ImportClause *import = declaration->importClause) {
+        if (!import->importedDefaultBinding.isEmpty()) {
+            Compiler::ImportEntry entry;
+            entry.moduleRequest = module;
+            entry.importName = QStringLiteral("default");
+            entry.localName = import->importedDefaultBinding.toString();
+            entry.location = declaration->firstSourceLocation();
+            _context->importEntries << entry;
+        }
+
+        if (import->nameSpaceImport) {
+            Compiler::ImportEntry entry;
+            entry.moduleRequest = module;
+            entry.importName = QStringLiteral("*");
+            entry.localName = import->nameSpaceImport->importedBinding.toString();
+            entry.location = declaration->firstSourceLocation();
+            _context->importEntries << entry;
+        }
+
+        if (import->namedImports) {
+            for (ImportsList *it = import->namedImports->importsList; it; it = it->next) {
+                Compiler::ImportEntry entry;
+                entry.moduleRequest = module;
+                entry.localName = it->importSpecifier->importedBinding.toString();
+                if (!it->importSpecifier->identifier.isEmpty())
+                    entry.importName = it->importSpecifier->identifier.toString();
+                else
+                    entry.importName = entry.localName;
+                entry.location = declaration->firstSourceLocation();
+                _context->importEntries << entry;
+            }
+        }
+    }
+    return false;
+}
+
+bool ScanFunctions::visit(CallExpression *ast)
+{
+    if (!_context->hasDirectEval) {
+        if (IdentifierExpression *id = cast<IdentifierExpression *>(ast->base)) {
+            if (id->name == QLatin1String("eval")) {
+                if (_context->usesArgumentsObject == Context::ArgumentsObjectUnknown)
+                    _context->usesArgumentsObject = Context::ArgumentsObjectUsed;
+                _context->hasDirectEval = true;
+            }
+        }
+    }
+    return true;
+}
+
+bool ScanFunctions::visit(PatternElement *ast)
+{
+    if (!ast->isVariableDeclaration())
+        return true;
+
+    QStringList names;
+    ast->boundNames(&names);
+
+    QQmlJS::AST::SourceLocation lastInitializerLocation = ast->lastSourceLocation();
+    if (_context->lastBlockInitializerLocation.isValid())
+        lastInitializerLocation = _context->lastBlockInitializerLocation;
+
+    for (const QString &name : qAsConst(names)) {
+        if (_context->isStrict && (name == QLatin1String("eval") || name == QLatin1String("arguments")))
+            _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Variable name may not be eval or arguments in strict mode"));
+        checkName(QStringRef(&name), ast->identifierToken);
+        if (name == QLatin1String("arguments"))
+            _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+        if (ast->scope == VariableScope::Const && !ast->initializer && !ast->isForDeclaration && !ast->destructuringPattern()) {
+            _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Missing initializer in const declaration"));
+            return false;
+        }
+        if (!_context->addLocalVar(name, ast->initializer ? Context::VariableDefinition : Context::VariableDeclaration, ast->scope,
+                                   /*function*/nullptr, lastInitializerLocation)) {
+            _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Identifier %1 has already been declared").arg(name));
+            return false;
+        }
+    }
+    return true;
+}
+
+bool ScanFunctions::visit(IdentifierExpression *ast)
+{
+    checkName(ast->name, ast->identifierToken);
+    if (_context->usesArgumentsObject == Context::ArgumentsObjectUnknown && ast->name == QLatin1String("arguments"))
+        _context->usesArgumentsObject = Context::ArgumentsObjectUsed;
+    _context->addUsedVariable(ast->name.toString());
+    return true;
+}
+
+bool ScanFunctions::visit(ExpressionStatement *ast)
+{
+    if (FunctionExpression* expr = AST::cast<AST::FunctionExpression*>(ast->expression)) {
+        if (!_allowFuncDecls)
+            _cg->throwSyntaxError(expr->functionToken, QStringLiteral("conditional function or closure declaration"));
+
+        if (!enterFunction(expr, /*enterName*/ true))
+            return false;
+        Node::accept(expr->formals, this);
+        Node::accept(expr->body, this);
+        leaveEnvironment();
+        return false;
+    } else {
+        SourceLocation firstToken = ast->firstSourceLocation();
+        if (_sourceCode.midRef(firstToken.offset, firstToken.length) == QLatin1String("function")) {
+            _cg->throwSyntaxError(firstToken, QStringLiteral("unexpected token"));
+        }
+    }
+    return true;
+}
+
+bool ScanFunctions::visit(FunctionExpression *ast)
+{
+    return enterFunction(ast, /*enterName*/ false);
+}
+
+bool ScanFunctions::visit(ClassExpression *ast)
+{
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%Class"));
+    _context->isStrict = true;
+    _context->hasNestedFunctions = true;
+    if (!ast->name.isEmpty())
+        _context->addLocalVar(ast->name.toString(), Context::VariableDefinition, AST::VariableScope::Const);
+    return true;
+}
+
+void ScanFunctions::endVisit(ClassExpression *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ClassDeclaration *ast)
+{
+    if (!ast->name.isEmpty())
+        _context->addLocalVar(ast->name.toString(), Context::VariableDeclaration, AST::VariableScope::Let);
+
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%Class"));
+    _context->isStrict = true;
+    _context->hasNestedFunctions = true;
+    if (!ast->name.isEmpty())
+        _context->addLocalVar(ast->name.toString(), Context::VariableDefinition, AST::VariableScope::Const);
+    return true;
+}
+
+void ScanFunctions::endVisit(ClassDeclaration *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(TemplateLiteral *ast)
+{
+    while (ast) {
+        if (ast->expression)
+            Node::accept(ast->expression, this);
+        ast = ast->next;
+    }
+    return true;
+
+}
+
+bool ScanFunctions::visit(SuperLiteral *)
+{
+    Context *c = _context;
+    bool needContext = false;
+    while (c && (c->contextType == ContextType::Block || c->isArrowFunction)) {
+        needContext |= c->isArrowFunction;
+        c = c->parent;
+    }
+
+    c->requiresExecutionContext |= needContext;
+
+    return false;
+}
+
+bool ScanFunctions::visit(FieldMemberExpression *ast)
+{
+    if (AST::IdentifierExpression *id = AST::cast<AST::IdentifierExpression *>(ast->base)) {
+        if (id->name == QLatin1String("new")) {
+            // new.target
+            if (ast->name != QLatin1String("target")) {
+                _cg->throwSyntaxError(ast->identifierToken, QLatin1String("Expected 'target' after 'new.'."));
+                return false;
+            }
+            Context *c = _context;
+            bool needContext = false;
+            while (c->contextType == ContextType::Block || c->isArrowFunction) {
+                needContext |= c->isArrowFunction;
+                c = c->parent;
+            }
+            c->requiresExecutionContext |= needContext;
+            c->innerFunctionAccessesNewTarget |= needContext;
+
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool ScanFunctions::visit(ArrayPattern *ast)
+{
+    for (PatternElementList *it = ast->elements; it; it = it->next)
+        Node::accept(it->element, this);
+
+    return false;
+}
+
+bool ScanFunctions::enterFunction(FunctionExpression *ast, bool enterName)
+{
+    if (_context->isStrict && (ast->name == QLatin1String("eval") || ast->name == QLatin1String("arguments")))
+        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Function name may not be eval or arguments in strict mode"));
+    return enterFunction(ast, ast->name.toString(), ast->formals, ast->body, enterName);
+}
+
+void ScanFunctions::endVisit(FunctionExpression *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ObjectPattern *ast)
+{
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, true);
+    Node::accept(ast->properties, this);
+    return false;
+}
+
+bool ScanFunctions::visit(PatternProperty *ast)
+{
+    Q_UNUSED(ast);
+    // ### Shouldn't be required anymore
+//    if (ast->type == PatternProperty::Getter || ast->type == PatternProperty::Setter) {
+//        TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, true);
+//        return enterFunction(ast, QString(), ast->formals, ast->functionBody, /*enterName */ false);
+//    }
+    return true;
+}
+
+void ScanFunctions::endVisit(PatternProperty *)
+{
+    // ###
+//    if (ast->type == PatternProperty::Getter || ast->type == PatternProperty::Setter)
+//        leaveEnvironment();
+}
+
+bool ScanFunctions::visit(FunctionDeclaration *ast)
+{
+    return enterFunction(ast, /*enterName*/ true);
+}
+
+void ScanFunctions::endVisit(FunctionDeclaration *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(DoWhileStatement *ast) {
+    {
+        TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+        Node::accept(ast->statement, this);
+    }
+    Node::accept(ast->expression, this);
+    return false;
+}
+
+bool ScanFunctions::visit(ForStatement *ast) {
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%For"));
+    Node::accept(ast->initialiser, this);
+    Node::accept(ast->declarations, this);
+    Node::accept(ast->condition, this);
+    Node::accept(ast->expression, this);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+    Node::accept(ast->statement, this);
+
+    return false;
+}
+
+void ScanFunctions::endVisit(ForStatement *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ForEachStatement *ast) {
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%Foreach"));
+    if (ast->expression)
+        _context->lastBlockInitializerLocation = ast->expression->lastSourceLocation();
+    Node::accept(ast->lhs, this);
+    Node::accept(ast->expression, this);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, !_context->isStrict);
+    Node::accept(ast->statement, this);
+
+    return false;
+}
+
+void ScanFunctions::endVisit(ForEachStatement *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(ThisExpression *)
+{
+    _context->usesThis = true;
+    return false;
+}
+
+bool ScanFunctions::visit(Block *ast)
+{
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, _context->isStrict ? false : _allowFuncDecls);
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%Block"));
+    Node::accept(ast->statements, this);
+    return false;
+}
+
+void ScanFunctions::endVisit(Block *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(CaseBlock *ast)
+{
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%CaseBlock"));
+    return true;
+}
+
+void ScanFunctions::endVisit(CaseBlock *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(Catch *ast)
+{
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, _context->isStrict ? false : _allowFuncDecls);
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%CatchBlock"));
+    _context->isCatchBlock = true;
+    QString caughtVar = ast->patternElement->bindingIdentifier.toString();
+    if (caughtVar.isEmpty())
+        caughtVar = QStringLiteral("@caught");
+    _context->addLocalVar(caughtVar, Context::MemberType::VariableDefinition, VariableScope::Let);
+
+    _context->caughtVariable = caughtVar;
+    if (_context->isStrict &&
+        (caughtVar == QLatin1String("eval") || caughtVar == QLatin1String("arguments"))) {
+        _cg->throwSyntaxError(ast->identifierToken, QStringLiteral("Catch variable name may not be eval or arguments in strict mode"));
+        return false;
+    }
+    Node::accept(ast->patternElement, this);
+    // skip the block statement
+    Node::accept(ast->statement->statements, this);
+    return false;
+}
+
+void ScanFunctions::endVisit(Catch *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::visit(WithStatement *ast)
+{
+    Node::accept(ast->expression, this);
+
+    TemporaryBoolAssignment allowFuncDecls(_allowFuncDecls, _context->isStrict ? false : _allowFuncDecls);
+    enterEnvironment(ast, ContextType::Block, QStringLiteral("%WithBlock"));
+    _context->isWithBlock = true;
+
+    if (_context->isStrict) {
+        _cg->throwSyntaxError(ast->withToken, QStringLiteral("'with' statement is not allowed in strict mode"));
+        return false;
+    }
+    Node::accept(ast->statement, this);
+
+    return false;
+}
+
+void ScanFunctions::endVisit(WithStatement *)
+{
+    leaveEnvironment();
+}
+
+bool ScanFunctions::enterFunction(Node *ast, const QString &name, FormalParameterList *formals, StatementList *body, bool enterName)
+{
+    Context *outerContext = _context;
+    enterEnvironment(ast, ContextType::Function, name);
+
+    FunctionExpression *expr = AST::cast<FunctionExpression *>(ast);
+    if (!expr)
+        expr = AST::cast<FunctionDeclaration *>(ast);
+    if (outerContext) {
+        outerContext->hasNestedFunctions = true;
+        // The identifier of a function expression cannot be referenced from the enclosing environment.
+        if (enterName) {
+            if (!outerContext->addLocalVar(name, Context::FunctionDefinition, VariableScope::Var, expr)) {
+                _cg->throwSyntaxError(ast->firstSourceLocation(), QStringLiteral("Identifier %1 has already been declared").arg(name));
+                return false;
+            }
+            outerContext->addLocalVar(name, Context::FunctionDefinition, VariableScope::Var, expr);
+        }
+        if (name == QLatin1String("arguments"))
+            outerContext->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+    }
+
+    _context->name = name;
+    if (formals && formals->containsName(QStringLiteral("arguments")))
+        _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+    if (expr) {
+        if (expr->isArrowFunction)
+            _context->isArrowFunction = true;
+        else if (expr->isGenerator)
+            _context->isGenerator = true;
+    }
+
+
+    if (!enterName && (!name.isEmpty() && (!formals || !formals->containsName(name))))
+        _context->addLocalVar(name, Context::ThisFunctionName, VariableScope::Var);
+    _context->formals = formals;
+
+    if (body && !_context->isStrict)
+        checkDirectivePrologue(body);
+
+    bool isSimpleParameterList = formals && formals->isSimpleParameterList();
+
+    _context->arguments = formals ? formals->formals() : QStringList();
+
+    const QStringList boundNames = formals ? formals->boundNames() : QStringList();
+    for (int i = 0; i < boundNames.size(); ++i) {
+        const QString &arg = boundNames.at(i);
+        if (_context->isStrict || !isSimpleParameterList) {
+            bool duplicate = (boundNames.indexOf(arg, i + 1) != -1);
+            if (duplicate) {
+                _cg->throwSyntaxError(formals->firstSourceLocation(), QStringLiteral("Duplicate parameter name '%1' is not allowed.").arg(arg));
+                return false;
+            }
+        }
+        if (_context->isStrict) {
+            if (arg == QLatin1String("eval") || arg == QLatin1String("arguments")) {
+                _cg->throwSyntaxError(formals->firstSourceLocation(), QStringLiteral("'%1' cannot be used as parameter name in strict mode").arg(arg));
+                return false;
+            }
+        }
+        if (!_context->arguments.contains(arg))
+            _context->addLocalVar(arg, Context::VariableDefinition, VariableScope::Var);
+    }
+    return true;
+}
+
+void ScanFunctions::calcEscapingVariables()
+{
+    Module *m = _cg->_module;
+
+    for (Context *inner : qAsConst(m->contextMap)) {
+        if (inner->usesArgumentsObject != Context::ArgumentsObjectUsed)
+            continue;
+        if (inner->contextType != ContextType::Block && !inner->isArrowFunction)
+            continue;
+        Context *c = inner->parent;
+        while (c && (c->contextType == ContextType::Block || c->isArrowFunction))
+            c = c->parent;
+        if (c)
+            c->usesArgumentsObject = Context::ArgumentsObjectUsed;
+        inner->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+    }
+    for (Context *inner : qAsConst(m->contextMap)) {
+        if (!inner->parent || inner->usesArgumentsObject == Context::ArgumentsObjectUnknown)
+            inner->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
+        if (inner->usesArgumentsObject == Context::ArgumentsObjectUsed) {
+            QString arguments = QStringLiteral("arguments");
+            inner->addLocalVar(arguments, Context::VariableDeclaration, AST::VariableScope::Var);
+            if (!inner->isStrict) {
+                inner->argumentsCanEscape = true;
+                inner->requiresExecutionContext = true;
+            }
+        }
+    }
+
+    for (Context *c : qAsConst(m->contextMap)) {
+        if (c->contextType != ContextType::ESModule)
+            continue;
+        for (const auto &entry: c->exportEntries) {
+            auto m = c->members.find(entry.localName);
+            if (m != c->members.end())
+                m->canEscape = true;
+        }
+        break;
+    }
+
+    for (Context *inner : qAsConst(m->contextMap)) {
+        for (const QString &var : qAsConst(inner->usedVariables)) {
+            Context *c = inner;
+            while (c) {
+                Context *current = c;
+                c = c->parent;
+                if (current->isWithBlock || current->contextType != ContextType::Block)
+                    break;
+            }
+            Q_ASSERT(c != inner);
+            while (c) {
+                Context::MemberMap::const_iterator it = c->members.find(var);
+                if (it != c->members.end()) {
+                    if (c->parent || it->isLexicallyScoped()) {
+                        it->canEscape = true;
+                        c->requiresExecutionContext = true;
+                    } else if (c->contextType == ContextType::ESModule) {
+                        // Module instantiation provides a context, but vars used from inner
+                        // scopes need to be stored in its locals[].
+                        it->canEscape = true;
+                    }
+                    break;
+                }
+                if (c->findArgument(var) != -1) {
+                    c->argumentsCanEscape = true;
+                    c->requiresExecutionContext = true;
+                    break;
+                }
+                c = c->parent;
+            }
+        }
+        if (inner->hasDirectEval) {
+            inner->hasDirectEval = false;
+            inner->innerFunctionAccessesNewTarget = true;
+            if (!inner->isStrict) {
+                Context *c = inner;
+                while (c->contextType == ContextType::Block) {
+                    c = c->parent;
+                }
+                Q_ASSERT(c);
+                c->hasDirectEval = true;
+                c->innerFunctionAccessesThis = true;
+            }
+            Context *c = inner;
+            while (c) {
+                c->allVarsEscape = true;
+                c = c->parent;
+            }
+        }
+        if (inner->usesThis) {
+            inner->usesThis = false;
+            bool innerFunctionAccessesThis = false;
+            Context *c = inner;
+            while (c->contextType == ContextType::Block || c->isArrowFunction) {
+                innerFunctionAccessesThis |= c->isArrowFunction;
+                c = c->parent;
+            }
+            Q_ASSERT(c);
+            if (!inner->isStrict)
+                c->usesThis = true;
+            c->innerFunctionAccessesThis |= innerFunctionAccessesThis;
+        }
+    }
+    for (Context *c : qAsConst(m->contextMap)) {
+        if (c->innerFunctionAccessesThis) {
+            // add an escaping 'this' variable
+            c->addLocalVar(QStringLiteral("this"), Context::VariableDefinition, VariableScope::Let);
+            c->requiresExecutionContext = true;
+            auto m = c->members.find(QStringLiteral("this"));
+            m->canEscape = true;
+        }
+        if (c->innerFunctionAccessesNewTarget) {
+            // add an escaping 'new.target' variable
+            c->addLocalVar(QStringLiteral("new.target"), Context::VariableDefinition, VariableScope::Let);
+            c->requiresExecutionContext = true;
+            auto m = c->members.find(QStringLiteral("new.target"));
+            m->canEscape = true;
+        }
+        if (c->allVarsEscape && c->contextType == ContextType::Block && c->members.isEmpty())
+            c->allVarsEscape = false;
+        if (c->contextType == ContextType::Global || c->contextType == ContextType::ScriptImportedByQML || (!c->isStrict && c->contextType == ContextType::Eval) || m->debugMode)
+            c->allVarsEscape = true;
+        if (c->allVarsEscape) {
+            if (c->parent) {
+                c->requiresExecutionContext = true;
+                c->argumentsCanEscape = true;
+            } else {
+                for (const auto &m : qAsConst(c->members)) {
+                    if (m.isLexicallyScoped()) {
+                        c->requiresExecutionContext = true;
+                        break;
+                    }
+                }
+            }
+        }
+        if (c->contextType == ContextType::Block && c->isCatchBlock) {
+            c->requiresExecutionContext = true;
+            auto m = c->members.find(c->caughtVariable);
+            m->canEscape = true;
+        }
+        const QLatin1String exprForOn("expression for on");
+        if (c->contextType == ContextType::Binding && c->name.length() > exprForOn.size() &&
+            c->name.startsWith(exprForOn) && c->name.at(exprForOn.size()).isUpper())
+            // we don't really need this for bindings, but we do for signal handlers, and in this case,
+            // we don't know if the code is a signal handler or not.
+            c->requiresExecutionContext = true;
+        if (c->allVarsEscape) {
+            for (auto &m : c->members)
+                m.canEscape = true;
+        }
+    }
+
+    static const bool showEscapingVars = qEnvironmentVariableIsSet("QV4_SHOW_ESCAPING_VARS");
+    if (showEscapingVars) {
+        qDebug() << "==== escaping variables ====";
+        for (Context *c : qAsConst(m->contextMap)) {
+            qDebug() << "Context" << c << c->name << "requiresExecutionContext" << c->requiresExecutionContext << "isStrict" << c->isStrict;
+            qDebug() << "    isArrowFunction" << c->isArrowFunction << "innerFunctionAccessesThis" << c->innerFunctionAccessesThis;
+            qDebug() << "    parent:" << c->parent;
+            if (c->argumentsCanEscape)
+                qDebug() << "    Arguments escape";
+            for (auto it = c->members.constBegin(); it != c->members.constEnd(); ++it) {
+                qDebug() << "    " << it.key() << it.value().index << it.value().canEscape << "isLexicallyScoped:" << it.value().isLexicallyScoped();
+            }
+        }
+    }
+}
diff --git a/src/qml/compiler/qv4compilerscanfunctions_p.h b/src/qml/compiler/qv4compilerscanfunctions_p.h
new file mode 100644
index 0000000000..28ad846bcd
--- /dev/null
+++ b/src/qml/compiler/qv4compilerscanfunctions_p.h
@@ -0,0 +1,188 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4COMPILERSCANFUNCTIONS_P_H
+#define QV4COMPILERSCANFUNCTIONS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "private/qv4global_p.h"
+#include <private/qqmljsastvisitor_p.h>
+#include <private/qqmljsast_p.h>
+#include <private/qqmljsengine_p.h>
+#include <private/qv4compilercontext_p.h>
+#include <private/qv4util_p.h>
+#include <QtCore/QStringList>
+#include <QStack>
+#include <QScopedValueRollback>
+
+QT_BEGIN_NAMESPACE
+
+using namespace QQmlJS;
+
+namespace QV4 {
+
+namespace Moth {
+struct Instruction;
+}
+
+namespace CompiledData {
+struct CompilationUnit;
+}
+
+namespace Compiler {
+
+class Codegen;
+
+class ScanFunctions: protected QQmlJS::AST::Visitor
+{
+    typedef QScopedValueRollback<bool> TemporaryBoolAssignment;
+public:
+    ScanFunctions(Codegen *cg, const QString &sourceCode, ContextType defaultProgramType);
+    void operator()(AST::Node *node);
+
+    void enterGlobalEnvironment(ContextType compilationMode);
+    void enterEnvironment(AST::Node *node, ContextType compilationMode, const QString &name);
+    void leaveEnvironment();
+
+    void enterQmlFunction(AST::FunctionDeclaration *ast)
+    { enterFunction(ast, false); }
+
+protected:
+    using Visitor::visit;
+    using Visitor::endVisit;
+
+    bool preVisit(AST::Node *ast) override;
+    void postVisit(AST::Node *) override;
+
+    void checkDirectivePrologue(AST::StatementList *ast);
+
+    void checkName(const QStringRef &name, const AST::SourceLocation &loc);
+
+    bool visit(AST::Program *ast) override;
+    void endVisit(AST::Program *) override;
+
+    bool visit(AST::ESModule *ast) override;
+    void endVisit(AST::ESModule *) override;
+
+    bool visit(AST::ExportDeclaration *declaration) override;
+    bool visit(AST::ImportDeclaration *declaration) override;
+
+    bool visit(AST::CallExpression *ast) override;
+    bool visit(AST::PatternElement *ast) override;
+    bool visit(AST::IdentifierExpression *ast) override;
+    bool visit(AST::ExpressionStatement *ast) override;
+    bool visit(AST::FunctionExpression *ast) override;
+    bool visit(AST::TemplateLiteral *ast) override;
+    bool visit(AST::SuperLiteral *) override;
+    bool visit(AST::FieldMemberExpression *) override;
+    bool visit(AST::ArrayPattern *) override;
+
+    bool enterFunction(AST::FunctionExpression *ast, bool enterName);
+
+    void endVisit(AST::FunctionExpression *) override;
+
+    bool visit(AST::ObjectPattern *ast) override;
+
+    bool visit(AST::PatternProperty *ast) override;
+    void endVisit(AST::PatternProperty *) override;
+
+    bool visit(AST::FunctionDeclaration *ast) override;
+    void endVisit(AST::FunctionDeclaration *) override;
+
+    bool visit(AST::ClassExpression *ast) override;
+    void endVisit(AST::ClassExpression *) override;
+
+    bool visit(AST::ClassDeclaration *ast) override;
+    void endVisit(AST::ClassDeclaration *) override;
+
+    bool visit(AST::DoWhileStatement *ast) override;
+    bool visit(AST::ForStatement *ast) override;
+    void endVisit(AST::ForStatement *) override;
+    bool visit(AST::ForEachStatement *ast) override;
+    void endVisit(AST::ForEachStatement *) override;
+
+    bool visit(AST::ThisExpression *ast) override;
+
+    bool visit(AST::Block *ast) override;
+    void endVisit(AST::Block *ast) override;
+
+    bool visit(AST::CaseBlock *ast) override;
+    void endVisit(AST::CaseBlock *ast) override;
+
+    bool visit(AST::Catch *ast) override;
+    void endVisit(AST::Catch *ast) override;
+
+    bool visit(AST::WithStatement *ast) override;
+    void endVisit(AST::WithStatement *ast) override;
+
+protected:
+    bool enterFunction(AST::Node *ast, const QString &name, AST::FormalParameterList *formals, AST::StatementList *body, bool enterName);
+
+    void calcEscapingVariables();
+// fields:
+    Codegen *_cg;
+    const QString _sourceCode;
+    Context *_context;
+    QStack<Context *> _contextStack;
+
+    bool _allowFuncDecls;
+    ContextType defaultProgramType;
+
+    unsigned _recursionDepth = 0;
+
+private:
+    static constexpr AST::Node *astNodeForGlobalEnvironment = nullptr;
+};
+
+}
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4CODEGEN_P_H
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index cf8cf623bc..c0b1be1492 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -38,17 +38,711 @@
 ****************************************************************************/
 
 #include "qv4instr_moth_p.h"
+#include <private/qv4compileddata_p.h>
+#include <private/qv4stackframe_p.h>
 
 using namespace QV4;
 using namespace QV4::Moth;
 
-int Instr::size(Type type)
+int InstrInfo::size(Instr::Type type)
 {
-#define MOTH_RETURN_INSTR_SIZE(I, FMT) case I: return InstrMeta<(int)I>::Size;
+#define MOTH_RETURN_INSTR_SIZE(I) case Instr::Type::I: case Instr::Type::I##_Wide: return InstrMeta<int(Instr::Type::I)>::Size;
     switch (type) {
-    FOR_EACH_MOTH_INSTR(MOTH_RETURN_INSTR_SIZE)
-    default: return 0;
+    FOR_EACH_MOTH_INSTR_ALL(MOTH_RETURN_INSTR_SIZE)
     }
 #undef MOTH_RETURN_INSTR_SIZE
+    Q_UNREACHABLE();
 }
 
+static QByteArray alignedNumber(int n) {
+    QByteArray number = QByteArray::number(n);
+    while (number.size() < 8)
+        number.prepend(' ');
+    return number;
+}
+
+static QByteArray alignedLineNumber(int line) {
+    if (line > 0)
+        return alignedNumber(static_cast<int>(line));
+    return QByteArray("        ");
+}
+
+static QByteArray rawBytes(const char *data, int n)
+{
+    QByteArray ba;
+    while (n) {
+        uint num = *reinterpret_cast<const uchar *>(data);
+        if (num < 16)
+            ba += '0';
+        ba += QByteArray::number(num, 16) + " ";
+        ++data;
+        --n;
+    }
+    while (ba.size() < 25)
+        ba += ' ';
+    return ba;
+}
+
+static QString toString(QV4::ReturnedValue v)
+{
+#ifdef V4_BOOTSTRAP
+    return QStringLiteral("string-const(%1)").arg(v);
+#else // !V4_BOOTSTRAP
+    Value val = Value::fromReturnedValue(v);
+    QString result;
+    if (val.isInt32())
+        result = QLatin1String("int ");
+    else if (val.isDouble())
+        result = QLatin1String("double ");
+    if (val.isEmpty())
+        result += QLatin1String("empty");
+    else
+        result += val.toQStringNoThrow();
+    return result;
+#endif // V4_BOOTSTRAP
+}
+
+#define ABSOLUTE_OFFSET() \
+    (code - start + offset)
+
+#define MOTH_BEGIN_INSTR(instr) \
+    { \
+        INSTR_##instr(MOTH_DECODE_WITH_BASE) \
+        QDebug d = qDebug(); \
+        d.noquote(); \
+        d.nospace(); \
+        if (static_cast<int>(Instr::Type::instr) >= 0x100) \
+            --base_ptr; \
+        d << alignedLineNumber(line) << alignedNumber(codeOffset).constData() << ": " \
+          << rawBytes(base_ptr, int(code - base_ptr)) << #instr << " ";
+
+#define MOTH_END_INSTR(instr) \
+        continue; \
+    }
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace Moth {
+
+const int InstrInfo::argumentCount[] = {
+    FOR_EACH_MOTH_INSTR_ALL(MOTH_COLLECT_NARGS)
+};
+
+
+void dumpConstantTable(const Value *constants, uint count)
+{
+    QDebug d = qDebug();
+    d.nospace();
+    for (uint i = 0; i < count; ++i)
+        d << alignedNumber(int(i)).constData() << ":    "
+          << toString(constants[i].asReturnedValue()).toUtf8().constData() << "\n";
+}
+
+QString dumpRegister(int reg, int nFormals)
+{
+    Q_STATIC_ASSERT(offsetof(CallData, function) == 0);
+    Q_STATIC_ASSERT(offsetof(CallData, context) == sizeof(Value));
+    Q_STATIC_ASSERT(offsetof(CallData, accumulator) == 2*sizeof(Value));
+    Q_STATIC_ASSERT(offsetof(CallData, thisObject) == 3*sizeof(Value));
+    if (reg == CallData::Function)
+        return QStringLiteral("(function)");
+    else if (reg == CallData::Context)
+        return QStringLiteral("(context)");
+    else if (reg == CallData::Accumulator)
+        return QStringLiteral("(accumulator)");
+    else if (reg == CallData::NewTarget)
+        return QStringLiteral("(new.target)");
+    else if (reg == CallData::This)
+        return QStringLiteral("(this)");
+    else if (reg == CallData::Argc)
+        return QStringLiteral("(argc)");
+    reg -= CallData::HeaderSize();
+    if (reg < nFormals)
+        return QStringLiteral("a%1").arg(reg);
+    reg -= nFormals;
+    return QStringLiteral("r%1").arg(reg);
+
+}
+
+QString dumpArguments(int argc, int argv, int nFormals)
+{
+    if (!argc)
+        return QStringLiteral("()");
+    return QStringLiteral("(") + dumpRegister(argv, nFormals) + QStringLiteral(", ") + QString::number(argc) + QStringLiteral(")");
+}
+
+#define TRACE_SLOT QStringLiteral(" {%1}").arg(traceSlot)
+
+void dumpBytecode(const char *code, int len, int nLocals, int nFormals, int /*startLine*/, const QVector<CompiledData::CodeOffsetToLine> &lineNumberMapping)
+{
+    MOTH_JUMP_TABLE;
+
+    auto findLine = [](const CompiledData::CodeOffsetToLine &entry, uint offset) {
+        return entry.codeOffset < offset;
+    };
+
+    int lastLine = -1;
+    const char *start = code;
+    const char *end = code + len;
+    while (code < end) {
+        const CompiledData::CodeOffsetToLine *codeToLine = std::lower_bound(lineNumberMapping.constBegin(), lineNumberMapping.constEnd(), static_cast<uint>(code - start) + 1, findLine) - 1;
+        int line = int(codeToLine->line);
+        if (line != lastLine)
+            lastLine = line;
+        else
+            line = -1;
+
+        int codeOffset = int(code - start);
+
+        MOTH_DISPATCH()
+
+        MOTH_BEGIN_INSTR(LoadReg)
+            d << dumpRegister(reg, nFormals);
+        MOTH_END_INSTR(LoadReg)
+
+        MOTH_BEGIN_INSTR(StoreReg)
+            d << dumpRegister(reg, nFormals);
+        MOTH_END_INSTR(StoreReg)
+
+        MOTH_BEGIN_INSTR(MoveReg)
+            d << dumpRegister(destReg, nFormals) << ", " << dumpRegister(srcReg, nFormals);
+        MOTH_END_INSTR(MoveReg)
+
+        MOTH_BEGIN_INSTR(LoadImport)
+            d << "i" << index;
+        MOTH_END_INSTR(LoadImport)
+
+        MOTH_BEGIN_INSTR(LoadConst)
+            d << "C" << index;
+        MOTH_END_INSTR(LoadConst)
+
+        MOTH_BEGIN_INSTR(LoadNull)
+        MOTH_END_INSTR(LoadNull)
+
+        MOTH_BEGIN_INSTR(LoadZero)
+        MOTH_END_INSTR(LoadZero)
+
+        MOTH_BEGIN_INSTR(LoadTrue)
+        MOTH_END_INSTR(LoadTrue)
+
+        MOTH_BEGIN_INSTR(LoadFalse)
+        MOTH_END_INSTR(LoadFalse)
+
+        MOTH_BEGIN_INSTR(LoadUndefined)
+        MOTH_END_INSTR(LoadUndefined)
+
+        MOTH_BEGIN_INSTR(LoadInt)
+            d << value;
+        MOTH_END_INSTR(LoadInt)
+
+        MOTH_BEGIN_INSTR(MoveConst)
+            d << dumpRegister(destTemp, nFormals) << ", C" << constIndex;
+        MOTH_END_INSTR(MoveConst)
+
+        MOTH_BEGIN_INSTR(LoadLocal)
+            if (index < nLocals)
+                d << "l" << index << TRACE_SLOT;
+            else
+                d << "a" << (index - nLocals) << TRACE_SLOT;
+        MOTH_END_INSTR(LoadLocal)
+
+        MOTH_BEGIN_INSTR(StoreLocal)
+            if (index < nLocals)
+                d << "l" << index;
+            else
+                d << "a" << (index - nLocals);
+        MOTH_END_INSTR(StoreLocal)
+
+        MOTH_BEGIN_INSTR(LoadScopedLocal)
+            if (index < nLocals)
+                d << "l" << index << "@" << scope << TRACE_SLOT;
+            else
+                d << "a" << (index - nLocals) << "@" << scope << TRACE_SLOT;
+        MOTH_END_INSTR(LoadScopedLocal)
+
+        MOTH_BEGIN_INSTR(StoreScopedLocal)
+            if (index < nLocals)
+                d << ", " << "l" << index << "@" << scope;
+            else
+                d << ", " << "a" << (index - nLocals) << "@" << scope;
+        MOTH_END_INSTR(StoreScopedLocal)
+
+        MOTH_BEGIN_INSTR(LoadRuntimeString)
+            d << stringId;
+        MOTH_END_INSTR(LoadRuntimeString)
+
+        MOTH_BEGIN_INSTR(MoveRegExp)
+            d << dumpRegister(destReg, nFormals) << ", " <<regExpId;
+        MOTH_END_INSTR(MoveRegExp)
+
+        MOTH_BEGIN_INSTR(LoadClosure)
+            d << value;
+        MOTH_END_INSTR(LoadClosure)
+
+        MOTH_BEGIN_INSTR(LoadName)
+            d << name << TRACE_SLOT;
+        MOTH_END_INSTR(LoadName)
+
+        MOTH_BEGIN_INSTR(LoadGlobalLookup)
+            d << index << TRACE_SLOT;
+        MOTH_END_INSTR(LoadGlobalLookup)
+
+        MOTH_BEGIN_INSTR(StoreNameSloppy)
+            d << name;
+        MOTH_END_INSTR(StoreNameSloppy)
+
+        MOTH_BEGIN_INSTR(StoreNameStrict)
+            d << name;
+        MOTH_END_INSTR(StoreNameStrict)
+
+        MOTH_BEGIN_INSTR(LoadElement)
+            d << dumpRegister(base, nFormals) << "[acc]" << TRACE_SLOT;
+        MOTH_END_INSTR(LoadElement)
+
+        MOTH_BEGIN_INSTR(StoreElement)
+            d << dumpRegister(base, nFormals) << "[" << dumpRegister(index, nFormals) << "]"
+              << TRACE_SLOT;
+        MOTH_END_INSTR(StoreElement)
+
+        MOTH_BEGIN_INSTR(LoadProperty)
+            d << "acc[" << name << "]" << TRACE_SLOT;
+        MOTH_END_INSTR(LoadProperty)
+
+        MOTH_BEGIN_INSTR(GetLookup)
+            d << "acc(" << index << ")" << TRACE_SLOT;
+        MOTH_END_INSTR(GetLookup)
+
+        MOTH_BEGIN_INSTR(StoreProperty)
+            d << dumpRegister(base, nFormals) << "[" << name<< "]";
+        MOTH_END_INSTR(StoreProperty)
+
+        MOTH_BEGIN_INSTR(SetLookup)
+            d << dumpRegister(base, nFormals) << "(" << index << ")";
+        MOTH_END_INSTR(SetLookup)
+
+        MOTH_BEGIN_INSTR(LoadSuperProperty)
+            d << dumpRegister(property, nFormals);
+        MOTH_END_INSTR(LoadSuperProperty)
+
+        MOTH_BEGIN_INSTR(StoreSuperProperty)
+            d << dumpRegister(property, nFormals);
+        MOTH_END_INSTR(StoreSuperProperty)
+
+        MOTH_BEGIN_INSTR(StoreScopeObjectProperty)
+            d << dumpRegister(base, nFormals) << "[" << propertyIndex << "]";
+        MOTH_END_INSTR(StoreScopeObjectProperty)
+
+        MOTH_BEGIN_INSTR(LoadScopeObjectProperty)
+            d << dumpRegister(base, nFormals) << "[" << propertyIndex << "]" << (captureRequired ? " (capture)" : " (no capture)");
+        MOTH_END_INSTR(LoadScopeObjectProperty)
+
+        MOTH_BEGIN_INSTR(StoreContextObjectProperty)
+            d << dumpRegister(base, nFormals) << "[" << propertyIndex << "]";
+        MOTH_END_INSTR(StoreContextObjectProperty)
+
+        MOTH_BEGIN_INSTR(LoadContextObjectProperty)
+            d << dumpRegister(base, nFormals) << "[" << propertyIndex << "]" << (captureRequired ? " (capture)" : " (no capture)");
+        MOTH_END_INSTR(LoadContextObjectProperty)
+
+        MOTH_BEGIN_INSTR(LoadIdObject)
+            d << dumpRegister(base, nFormals) << "[" << index << "]";
+        MOTH_END_INSTR(LoadIdObject)
+
+        MOTH_BEGIN_INSTR(Yield)
+        MOTH_END_INSTR(Yield)
+
+        MOTH_BEGIN_INSTR(YieldStar)
+        MOTH_END_INSTR(YieldStar)
+
+        MOTH_BEGIN_INSTR(Resume)
+            d << ABSOLUTE_OFFSET();
+        MOTH_END_INSTR(Resume)
+
+        MOTH_BEGIN_INSTR(CallValue)
+            d << dumpRegister(name, nFormals) << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallValue)
+
+        MOTH_BEGIN_INSTR(CallWithReceiver)
+            d << dumpRegister(name, nFormals) << dumpRegister(thisObject, nFormals)
+              << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallWithReceiver)
+
+        MOTH_BEGIN_INSTR(CallProperty)
+            d << dumpRegister(base, nFormals) << "." << name << dumpArguments(argc, argv, nFormals)
+              << TRACE_SLOT;
+        MOTH_END_INSTR(CallProperty)
+
+        MOTH_BEGIN_INSTR(CallPropertyLookup)
+            d << dumpRegister(base, nFormals) << "." << lookupIndex
+              << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallPropertyLookup)
+
+        MOTH_BEGIN_INSTR(CallElement)
+            d << dumpRegister(base, nFormals) << "[" << dumpRegister(index, nFormals) << "]"
+              << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallElement)
+
+        MOTH_BEGIN_INSTR(CallName)
+            d << name << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallName)
+
+        MOTH_BEGIN_INSTR(CallPossiblyDirectEval)
+            d << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallPossiblyDirectEval)
+
+        MOTH_BEGIN_INSTR(CallGlobalLookup)
+            d << index << dumpArguments(argc, argv, nFormals) << TRACE_SLOT;
+        MOTH_END_INSTR(CallGlobalLookup)
+
+        MOTH_BEGIN_INSTR(CallScopeObjectProperty)
+            d << dumpRegister(base, nFormals) << "." << name << dumpArguments(argc, argv, nFormals)
+              << TRACE_SLOT;
+        MOTH_END_INSTR(CallScopeObjectProperty)
+
+        MOTH_BEGIN_INSTR(CallContextObjectProperty)
+            d << dumpRegister(base, nFormals) << "." << name << dumpArguments(argc, argv, nFormals)
+              << TRACE_SLOT;
+        MOTH_END_INSTR(CallContextObjectProperty)
+
+        MOTH_BEGIN_INSTR(CallWithSpread)
+            d << "new " << dumpRegister(func, nFormals) << dumpRegister(thisObject, nFormals)
+              << dumpArguments(argc, argv, nFormals)
+              << TRACE_SLOT;
+        MOTH_END_INSTR(CallWithSpread)
+
+        MOTH_BEGIN_INSTR(Construct)
+            d << "new " << dumpRegister(func, nFormals) << dumpArguments(argc, argv, nFormals);
+        MOTH_END_INSTR(Construct)
+
+        MOTH_BEGIN_INSTR(ConstructWithSpread)
+            d << "new " << dumpRegister(func, nFormals) << dumpArguments(argc, argv, nFormals);
+        MOTH_END_INSTR(ConstructWithSpread)
+
+        MOTH_BEGIN_INSTR(SetUnwindHandler)
+            if (offset)
+                d << ABSOLUTE_OFFSET();
+            else
+                d << "<null>";
+        MOTH_END_INSTR(SetUnwindHandler)
+
+        MOTH_BEGIN_INSTR(UnwindDispatch)
+        MOTH_END_INSTR(UnwindDispatch)
+
+        MOTH_BEGIN_INSTR(UnwindToLabel)
+                d << "(" << level << ") " << ABSOLUTE_OFFSET();
+        MOTH_END_INSTR(UnwindToLabel)
+
+        MOTH_BEGIN_INSTR(DeadTemporalZoneCheck)
+                d << name;
+        MOTH_END_INSTR(DeadTemporalZoneCheck)
+
+        MOTH_BEGIN_INSTR(ThrowException)
+        MOTH_END_INSTR(ThrowException)
+
+        MOTH_BEGIN_INSTR(GetException)
+        MOTH_END_INSTR(HasException)
+
+        MOTH_BEGIN_INSTR(SetException)
+        MOTH_END_INSTR(SetExceptionFlag)
+
+        MOTH_BEGIN_INSTR(CreateCallContext)
+        MOTH_END_INSTR(CreateCallContext)
+
+        MOTH_BEGIN_INSTR(PushCatchContext)
+            d << index << ", " << name;
+        MOTH_END_INSTR(PushCatchContext)
+
+        MOTH_BEGIN_INSTR(PushWithContext)
+        MOTH_END_INSTR(PushWithContext)
+
+        MOTH_BEGIN_INSTR(PushBlockContext)
+            d << index;
+        MOTH_END_INSTR(PushBlockContext)
+
+        MOTH_BEGIN_INSTR(CloneBlockContext)
+        MOTH_END_INSTR(CloneBlockContext)
+
+        MOTH_BEGIN_INSTR(PushScriptContext)
+            d << index;
+        MOTH_END_INSTR(PushScriptContext)
+
+        MOTH_BEGIN_INSTR(PopScriptContext)
+        MOTH_END_INSTR(PopScriptContext)
+
+        MOTH_BEGIN_INSTR(PopContext)
+        MOTH_END_INSTR(PopContext)
+
+        MOTH_BEGIN_INSTR(GetIterator)
+            d << iterator;
+        MOTH_END_INSTR(GetIterator)
+
+        MOTH_BEGIN_INSTR(IteratorNext)
+            d << dumpRegister(value, nFormals) << ", " << dumpRegister(done, nFormals);
+        MOTH_END_INSTR(IteratorNext)
+
+        MOTH_BEGIN_INSTR(IteratorNextForYieldStar)
+            d << dumpRegister(iterator, nFormals) << ", " << dumpRegister(object, nFormals);
+        MOTH_END_INSTR(IteratorNextForYieldStar)
+
+        MOTH_BEGIN_INSTR(IteratorClose)
+            d << dumpRegister(done, nFormals);
+        MOTH_END_INSTR(IteratorClose)
+
+        MOTH_BEGIN_INSTR(DestructureRestElement)
+        MOTH_END_INSTR(DestructureRestElement)
+
+        MOTH_BEGIN_INSTR(DeleteProperty)
+            d << dumpRegister(base, nFormals) << "[" << dumpRegister(index, nFormals) << "]";
+        MOTH_END_INSTR(DeleteProperty)
+
+        MOTH_BEGIN_INSTR(DeleteName)
+            d << name;
+        MOTH_END_INSTR(DeleteName)
+
+        MOTH_BEGIN_INSTR(TypeofName)
+            d << name;
+        MOTH_END_INSTR(TypeofName)
+
+        MOTH_BEGIN_INSTR(TypeofValue)
+        MOTH_END_INSTR(TypeofValue)
+
+        MOTH_BEGIN_INSTR(DeclareVar)
+            d << isDeletable << ", " << varName;
+        MOTH_END_INSTR(DeclareVar)
+
+        MOTH_BEGIN_INSTR(DefineArray)
+            d << dumpRegister(args, nFormals) << ", " << argc;
+        MOTH_END_INSTR(DefineArray)
+
+        MOTH_BEGIN_INSTR(DefineObjectLiteral)
+            d << internalClassId
+              << ", " << argc
+              << ", " << dumpRegister(args, nFormals);
+        MOTH_END_INSTR(DefineObjectLiteral)
+
+        MOTH_BEGIN_INSTR(CreateClass)
+            d << classIndex
+              << ", " << dumpRegister(heritage, nFormals)
+              << ", " << dumpRegister(computedNames, nFormals);
+        MOTH_END_INSTR(CreateClass)
+
+        MOTH_BEGIN_INSTR(CreateMappedArgumentsObject)
+        MOTH_END_INSTR(CreateMappedArgumentsObject)
+
+        MOTH_BEGIN_INSTR(CreateUnmappedArgumentsObject)
+        MOTH_END_INSTR(CreateUnmappedArgumentsObject)
+
+        MOTH_BEGIN_INSTR(CreateRestParameter)
+            d << argIndex;
+        MOTH_END_INSTR(CreateRestParameter)
+
+        MOTH_BEGIN_INSTR(ConvertThisToObject)
+        MOTH_END_INSTR(ConvertThisToObject)
+
+        MOTH_BEGIN_INSTR(LoadSuperConstructor)
+        MOTH_END_INSTR(LoadSuperConstructor)
+
+        MOTH_BEGIN_INSTR(ToObject)
+        MOTH_END_INSTR(ToObject)
+
+        MOTH_BEGIN_INSTR(Jump)
+            d << ABSOLUTE_OFFSET();
+        MOTH_END_INSTR(Jump)
+
+        MOTH_BEGIN_INSTR(JumpTrue)
+            d << ABSOLUTE_OFFSET() << TRACE_SLOT;
+        MOTH_END_INSTR(JumpTrue)
+
+        MOTH_BEGIN_INSTR(JumpFalse)
+            d << ABSOLUTE_OFFSET() << TRACE_SLOT;
+        MOTH_END_INSTR(JumpFalse)
+
+        MOTH_BEGIN_INSTR(JumpNotUndefined)
+            d << ABSOLUTE_OFFSET();
+        MOTH_END_INSTR(JumpNotUndefined)
+
+        MOTH_BEGIN_INSTR(JumpNoException)
+            d << ABSOLUTE_OFFSET();
+        MOTH_END_INSTR(JumpNoException)
+
+        MOTH_BEGIN_INSTR(CmpEqNull)
+        MOTH_END_INSTR(CmpEqNull)
+
+        MOTH_BEGIN_INSTR(CmpNeNull)
+        MOTH_END_INSTR(CmpNeNull)
+
+        MOTH_BEGIN_INSTR(CmpEqInt)
+            d << lhs;
+        MOTH_END_INSTR(CmpEq)
+
+        MOTH_BEGIN_INSTR(CmpNeInt)
+                d << lhs;
+        MOTH_END_INSTR(CmpNeInt)
+
+        MOTH_BEGIN_INSTR(CmpEq)
+            d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpEq)
+
+        MOTH_BEGIN_INSTR(CmpNe)
+                d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpNe)
+
+        MOTH_BEGIN_INSTR(CmpGt)
+                d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpGt)
+
+        MOTH_BEGIN_INSTR(CmpGe)
+                d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpGe)
+
+        MOTH_BEGIN_INSTR(CmpLt)
+                d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpLt)
+
+        MOTH_BEGIN_INSTR(CmpLe)
+                d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpLe)
+
+        MOTH_BEGIN_INSTR(CmpStrictEqual)
+            d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpStrictEqual)
+
+        MOTH_BEGIN_INSTR(CmpStrictNotEqual)
+            d << dumpRegister(lhs, nFormals);
+        MOTH_END_INSTR(CmpStrictNotEqual)
+
+        MOTH_BEGIN_INSTR(UNot)
+        MOTH_END_INSTR(UNot)
+
+        MOTH_BEGIN_INSTR(UPlus)
+        MOTH_END_INSTR(UPlus)
+
+        MOTH_BEGIN_INSTR(UMinus)
+            d << TRACE_SLOT;
+        MOTH_END_INSTR(UMinus)
+
+        MOTH_BEGIN_INSTR(UCompl)
+        MOTH_END_INSTR(UCompl)
+
+        MOTH_BEGIN_INSTR(Increment)
+            d << TRACE_SLOT;
+        MOTH_END_INSTR(Increment)
+
+        MOTH_BEGIN_INSTR(Decrement)
+            d << TRACE_SLOT;
+        MOTH_END_INSTR(Decrement)
+
+        MOTH_BEGIN_INSTR(Add)
+            d << dumpRegister(lhs, nFormals) << ", acc" << TRACE_SLOT;
+        MOTH_END_INSTR(Add)
+
+        MOTH_BEGIN_INSTR(BitAnd)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(BitAnd)
+
+        MOTH_BEGIN_INSTR(BitOr)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(BitOr)
+
+        MOTH_BEGIN_INSTR(BitXor)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(BitXor)
+
+        MOTH_BEGIN_INSTR(UShr)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(UShr)
+
+        MOTH_BEGIN_INSTR(Shr)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(Shr)
+
+        MOTH_BEGIN_INSTR(Shl)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(Shl)
+
+        MOTH_BEGIN_INSTR(BitAndConst)
+            d << "acc, " << rhs;
+        MOTH_END_INSTR(BitAndConst)
+
+        MOTH_BEGIN_INSTR(BitOrConst)
+            d << "acc, " << rhs;
+        MOTH_END_INSTR(BitOr)
+
+        MOTH_BEGIN_INSTR(BitXorConst)
+            d << "acc, " << rhs;
+        MOTH_END_INSTR(BitXor)
+
+        MOTH_BEGIN_INSTR(UShrConst)
+            d << "acc, " << rhs;
+        MOTH_END_INSTR(UShrConst)
+
+        MOTH_BEGIN_INSTR(ShrConst)
+            d << "acc, " << rhs;
+        MOTH_END_INSTR(ShrConst)
+
+        MOTH_BEGIN_INSTR(ShlConst)
+            d << "acc, " << rhs;
+        MOTH_END_INSTR(ShlConst)
+
+        MOTH_BEGIN_INSTR(Exp)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(Exp)
+
+        MOTH_BEGIN_INSTR(Mul)
+            d << dumpRegister(lhs, nFormals) << ", acc" << TRACE_SLOT;
+        MOTH_END_INSTR(Mul)
+
+        MOTH_BEGIN_INSTR(Div)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(Div)
+
+        MOTH_BEGIN_INSTR(Mod)
+            d << dumpRegister(lhs, nFormals) << ", acc" << TRACE_SLOT;
+        MOTH_END_INSTR(Mod)
+
+        MOTH_BEGIN_INSTR(Sub)
+            d << dumpRegister(lhs, nFormals) << ", acc" << TRACE_SLOT;
+        MOTH_END_INSTR(Sub)
+
+        MOTH_BEGIN_INSTR(CmpIn)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(CmpIn)
+
+        MOTH_BEGIN_INSTR(CmpInstanceOf)
+            d << dumpRegister(lhs, nFormals) << ", acc";
+        MOTH_END_INSTR(CmpInstanceOf)
+
+        MOTH_BEGIN_INSTR(Ret)
+        MOTH_END_INSTR(Ret)
+
+        MOTH_BEGIN_INSTR(Debug)
+        MOTH_END_INSTR(Debug)
+
+        MOTH_BEGIN_INSTR(InitializeBlockDeadTemporalZone)
+            d << dumpRegister(firstReg, nFormals) << ", " << count;
+        MOTH_END_INSTR(InitializeBlockDeadTemporalZone)
+
+        MOTH_BEGIN_INSTR(ThrowOnNullOrUndefined)
+        MOTH_END_INSTR(ThrowOnNullOrUndefined)
+
+        MOTH_BEGIN_INSTR(GetTemplateObject)
+            d << index;
+        MOTH_END_INSTR(GetTemplateObject)
+
+        MOTH_BEGIN_INSTR(LoadQmlContext)
+            d << dumpRegister(result, nFormals);
+        MOTH_END_INSTR(LoadQmlContext)
+
+        MOTH_BEGIN_INSTR(LoadQmlImportedScripts)
+            d << dumpRegister(result, nFormals);
+        MOTH_END_INSTR(LoadQmlImportedScripts)
+
+        MOTH_BEGIN_INSTR(TailCall)
+            d << dumpRegister(func, nFormals) << dumpRegister(thisObject, nFormals) << dumpArguments(argc, argv, nFormals);
+        MOTH_END_INSTR(TailCall)
+    }
+}
+
+}
+}
+QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index dabda7bae8..3996143843 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -53,869 +53,575 @@
 #include <private/qv4global_p.h>
 #include <private/qv4value_p.h>
 #include <private/qv4runtime_p.h>
-
-#if !defined(V4_BOOTSTRAP)
-QT_REQUIRE_CONFIG(qml_interpreter);
-#endif
+#include <private/qv4compileddata_p.h> // for CompiledData::CodeOffsetToLine used by the dumper
+#include <qendian.h>
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_NO_QML_DEBUGGER
-#define MOTH_DEBUG_INSTR(F)
-#else
-#define MOTH_DEBUG_INSTR(F) \
-    F(Line, line) \
-    F(Debug, debug)
-#endif
+#define INSTRUCTION(op, name, nargs, ...) \
+    op##_INSTRUCTION(name, nargs, __VA_ARGS__)
+
+/* for all jump instructions, the offset has to come last, to simplify the job of the bytecode generator */
+#define INSTR_Nop(op) INSTRUCTION(op, Nop, 0)
+#define INSTR_Ret(op) INSTRUCTION(op, Ret, 0)
+#define INSTR_Debug(op) INSTRUCTION(op, Debug, 0)
+#define INSTR_LoadConst(op) INSTRUCTION(op, LoadConst, 1, index)
+#define INSTR_LoadZero(op) INSTRUCTION(op, LoadZero, 0)
+#define INSTR_LoadTrue(op) INSTRUCTION(op, LoadTrue, 0)
+#define INSTR_LoadFalse(op) INSTRUCTION(op, LoadFalse, 0)
+#define INSTR_LoadNull(op) INSTRUCTION(op, LoadNull, 0)
+#define INSTR_LoadUndefined(op) INSTRUCTION(op, LoadUndefined, 0)
+#define INSTR_LoadInt(op) INSTRUCTION(op, LoadInt, 1, value)
+#define INSTR_MoveConst(op) INSTRUCTION(op, MoveConst, 2, constIndex, destTemp)
+#define INSTR_LoadReg(op) INSTRUCTION(op, LoadReg, 1, reg)
+#define INSTR_StoreReg(op) INSTRUCTION(op, StoreReg, 1, reg)
+#define INSTR_MoveReg(op) INSTRUCTION(op, MoveReg, 2, srcReg, destReg)
+#define INSTR_LoadImport(op) INSTRUCTION(op, LoadImport, 1, index)
+#define INSTR_LoadLocal(op) INSTRUCTION(op, LoadLocal, 2, index, traceSlot)
+#define INSTR_StoreLocal(op) INSTRUCTION(op, StoreLocal, 1, index)
+#define INSTR_LoadScopedLocal(op) INSTRUCTION(op, LoadScopedLocal, 3, scope, index, traceSlot)
+#define INSTR_StoreScopedLocal(op) INSTRUCTION(op, StoreScopedLocal, 2, scope, index)
+#define INSTR_LoadRuntimeString(op) INSTRUCTION(op, LoadRuntimeString, 1, stringId)
+#define INSTR_MoveRegExp(op) INSTRUCTION(op, MoveRegExp, 2, regExpId, destReg)
+#define INSTR_LoadClosure(op) INSTRUCTION(op, LoadClosure, 1, value)
+#define INSTR_LoadName(op) INSTRUCTION(op, LoadName, 2, name, traceSlot)
+#define INSTR_LoadGlobalLookup(op) INSTRUCTION(op, LoadGlobalLookup, 2, index, traceSlot)
+#define INSTR_StoreNameSloppy(op) INSTRUCTION(op, StoreNameSloppy, 1, name)
+#define INSTR_StoreNameStrict(op) INSTRUCTION(op, StoreNameStrict, 1, name)
+#define INSTR_LoadProperty(op) INSTRUCTION(op, LoadProperty, 2, name, traceSlot)
+#define INSTR_GetLookup(op) INSTRUCTION(op, GetLookup, 2, index, traceSlot)
+#define INSTR_LoadScopeObjectProperty(op) INSTRUCTION(op, LoadScopeObjectProperty, 3, propertyIndex, base, captureRequired)
+#define INSTR_LoadContextObjectProperty(op) INSTRUCTION(op, LoadContextObjectProperty, 3, propertyIndex, base, captureRequired)
+#define INSTR_LoadIdObject(op) INSTRUCTION(op, LoadIdObject, 2, index, base)
+#define INSTR_Yield(op) INSTRUCTION(op, Yield, 0)
+#define INSTR_YieldStar(op) INSTRUCTION(op, YieldStar, 0)
+#define INSTR_Resume(op) INSTRUCTION(op, Resume, 1, offset)
+#define INSTR_IteratorNextForYieldStar(op) INSTRUCTION(op, IteratorNextForYieldStar, 2, iterator, object)
+#define INSTR_StoreProperty(op) INSTRUCTION(op, StoreProperty, 2, name, base)
+#define INSTR_SetLookup(op) INSTRUCTION(op, SetLookup, 2, index, base)
+#define INSTR_LoadSuperProperty(op) INSTRUCTION(op, LoadSuperProperty, 1, property)
+#define INSTR_StoreSuperProperty(op) INSTRUCTION(op, StoreSuperProperty, 1, property)
+#define INSTR_StoreScopeObjectProperty(op) INSTRUCTION(op, StoreScopeObjectProperty, 2, base, propertyIndex)
+#define INSTR_StoreContextObjectProperty(op) INSTRUCTION(op, StoreContextObjectProperty, 2, base, propertyIndex)
+#define INSTR_LoadElement(op) INSTRUCTION(op, LoadElement, 2, base, traceSlot)
+#define INSTR_StoreElement(op) INSTRUCTION(op, StoreElement, 3, base, index, traceSlot)
+#define INSTR_CallValue(op) INSTRUCTION(op, CallValue, 4, name, argc, argv, traceSlot)
+#define INSTR_CallWithReceiver(op) INSTRUCTION(op, CallWithReceiver, 5, name, thisObject, argc, argv, traceSlot)
+#define INSTR_CallProperty(op) INSTRUCTION(op, CallProperty, 5, name, base, argc, argv, traceSlot)
+#define INSTR_CallPropertyLookup(op) INSTRUCTION(op, CallPropertyLookup, 5, lookupIndex, base, argc, argv, traceSlot)
+#define INSTR_CallElement(op) INSTRUCTION(op, CallElement, 5, base, index, argc, argv, traceSlot)
+#define INSTR_CallName(op) INSTRUCTION(op, CallName, 4, name, argc, argv, traceSlot)
+#define INSTR_CallPossiblyDirectEval(op) INSTRUCTION(op, CallPossiblyDirectEval, 3, argc, argv, traceSlot)
+#define INSTR_CallGlobalLookup(op) INSTRUCTION(op, CallGlobalLookup, 4, index, argc, argv, traceSlot)
+#define INSTR_CallScopeObjectProperty(op) INSTRUCTION(op, CallScopeObjectProperty, 5, name, base, argc, argv, traceSlot)
+#define INSTR_CallContextObjectProperty(op) INSTRUCTION(op, CallContextObjectProperty, 5, name, base, argc, argv, traceSlot)
+#define INSTR_CallWithSpread(op) INSTRUCTION(op, CallWithSpread, 5, func, thisObject, argc, argv, traceSlot)
+#define INSTR_Construct(op) INSTRUCTION(op, Construct, 3, func, argc, argv)
+#define INSTR_ConstructWithSpread(op) INSTRUCTION(op, ConstructWithSpread, 3, func, argc, argv)
+#define INSTR_SetUnwindHandler(op) INSTRUCTION(op, SetUnwindHandler, 1, offset)
+#define INSTR_UnwindDispatch(op) INSTRUCTION(op, UnwindDispatch, 0)
+#define INSTR_UnwindToLabel(op) INSTRUCTION(op, UnwindToLabel, 2, level, offset)
+#define INSTR_DeadTemporalZoneCheck(op) INSTRUCTION(op, DeadTemporalZoneCheck, 1, name)
+#define INSTR_ThrowException(op) INSTRUCTION(op, ThrowException, 0)
+#define INSTR_GetException(op) INSTRUCTION(op, GetException, 0)
+#define INSTR_SetException(op) INSTRUCTION(op, SetException, 0)
+#define INSTR_CreateCallContext(op) INSTRUCTION(op, CreateCallContext, 0)
+#define INSTR_PushCatchContext(op) INSTRUCTION(op, PushCatchContext, 2, index, name)
+#define INSTR_PushWithContext(op) INSTRUCTION(op, PushWithContext, 0)
+#define INSTR_PushBlockContext(op) INSTRUCTION(op, PushBlockContext, 1, index)
+#define INSTR_CloneBlockContext(op) INSTRUCTION(op, CloneBlockContext, 0)
+#define INSTR_PushScriptContext(op) INSTRUCTION(op, PushScriptContext, 1, index)
+#define INSTR_PopScriptContext(op) INSTRUCTION(op, PopScriptContext, 0)
+#define INSTR_PopContext(op) INSTRUCTION(op, PopContext, 0)
+#define INSTR_GetIterator(op) INSTRUCTION(op, GetIterator, 1, iterator)
+#define INSTR_IteratorNext(op) INSTRUCTION(op, IteratorNext, 2, value, done)
+#define INSTR_IteratorClose(op) INSTRUCTION(op, IteratorClose, 1, done)
+#define INSTR_DestructureRestElement(op) INSTRUCTION(op, DestructureRestElement, 0)
+#define INSTR_DeleteProperty(op) INSTRUCTION(op, DeleteProperty, 2, base, index)
+#define INSTR_DeleteName(op) INSTRUCTION(op, DeleteName, 1, name)
+#define INSTR_TypeofName(op) INSTRUCTION(op, TypeofName, 1, name)
+#define INSTR_TypeofValue(op) INSTRUCTION(op, TypeofValue, 0)
+#define INSTR_DeclareVar(op) INSTRUCTION(op, DeclareVar, 2, varName, isDeletable)
+#define INSTR_DefineArray(op) INSTRUCTION(op, DefineArray, 2, argc, args)
+#define INSTR_DefineObjectLiteral(op) INSTRUCTION(op, DefineObjectLiteral, 3, internalClassId, argc, args)
+#define INSTR_CreateClass(op) INSTRUCTION(op, CreateClass, 3, classIndex, heritage, computedNames)
+#define INSTR_CreateMappedArgumentsObject(op) INSTRUCTION(op, CreateMappedArgumentsObject, 0)
+#define INSTR_CreateUnmappedArgumentsObject(op) INSTRUCTION(op, CreateUnmappedArgumentsObject, 0)
+#define INSTR_CreateRestParameter(op) INSTRUCTION(op, CreateRestParameter, 1, argIndex)
+#define INSTR_ConvertThisToObject(op) INSTRUCTION(op, ConvertThisToObject, 0)
+#define INSTR_LoadSuperConstructor(op) INSTRUCTION(op, LoadSuperConstructor, 0)
+#define INSTR_ToObject(op) INSTRUCTION(op, ToObject, 0)
+#define INSTR_Jump(op) INSTRUCTION(op, Jump, 1, offset)
+#define INSTR_JumpTrue(op) INSTRUCTION(op, JumpTrue, 2, traceSlot, offset)
+#define INSTR_JumpFalse(op) INSTRUCTION(op, JumpFalse, 2, traceSlot, offset)
+#define INSTR_JumpNotUndefined(op) INSTRUCTION(op, JumpNotUndefined, 1, offset)
+#define INSTR_JumpNoException(op) INSTRUCTION(op, JumpNoException, 1, offset)
+#define INSTR_CmpEqNull(op) INSTRUCTION(op, CmpEqNull, 0)
+#define INSTR_CmpNeNull(op) INSTRUCTION(op, CmpNeNull, 0)
+#define INSTR_CmpEqInt(op) INSTRUCTION(op, CmpEqInt, 1, lhs)
+#define INSTR_CmpNeInt(op) INSTRUCTION(op, CmpNeInt, 1, lhs)
+#define INSTR_CmpEq(op) INSTRUCTION(op, CmpEq, 1, lhs)
+#define INSTR_CmpNe(op) INSTRUCTION(op, CmpNe, 1, lhs)
+#define INSTR_CmpGt(op) INSTRUCTION(op, CmpGt, 1, lhs)
+#define INSTR_CmpGe(op) INSTRUCTION(op, CmpGe, 1, lhs)
+#define INSTR_CmpLt(op) INSTRUCTION(op, CmpLt, 1, lhs)
+#define INSTR_CmpLe(op) INSTRUCTION(op, CmpLe, 1, lhs)
+#define INSTR_CmpStrictEqual(op) INSTRUCTION(op, CmpStrictEqual, 1, lhs)
+#define INSTR_CmpStrictNotEqual(op) INSTRUCTION(op, CmpStrictNotEqual, 1, lhs)
+#define INSTR_CmpIn(op) INSTRUCTION(op, CmpIn, 1, lhs)
+#define INSTR_CmpInstanceOf(op) INSTRUCTION(op, CmpInstanceOf, 1, lhs)
+#define INSTR_UNot(op) INSTRUCTION(op, UNot, 0)
+#define INSTR_UPlus(op) INSTRUCTION(op, UPlus, 0)
+#define INSTR_UMinus(op) INSTRUCTION(op, UMinus, 1, traceSlot)
+#define INSTR_UCompl(op) INSTRUCTION(op, UCompl, 0)
+#define INSTR_Increment(op) INSTRUCTION(op, Increment, 1, traceSlot)
+#define INSTR_Decrement(op) INSTRUCTION(op, Decrement, 1, traceSlot)
+#define INSTR_Add(op) INSTRUCTION(op, Add, 2, lhs, traceSlot)
+#define INSTR_BitAnd(op) INSTRUCTION(op, BitAnd, 1, lhs)
+#define INSTR_BitOr(op) INSTRUCTION(op, BitOr, 1, lhs)
+#define INSTR_BitXor(op) INSTRUCTION(op, BitXor, 1, lhs)
+#define INSTR_UShr(op) INSTRUCTION(op, UShr, 1, lhs)
+#define INSTR_Shr(op) INSTRUCTION(op, Shr, 1, lhs)
+#define INSTR_Shl(op) INSTRUCTION(op, Shl, 1, lhs)
+#define INSTR_BitAndConst(op) INSTRUCTION(op, BitAndConst, 1, rhs)
+#define INSTR_BitOrConst(op) INSTRUCTION(op, BitOrConst, 1, rhs)
+#define INSTR_BitXorConst(op) INSTRUCTION(op, BitXorConst, 1, rhs)
+#define INSTR_UShrConst(op) INSTRUCTION(op, UShrConst, 1, rhs)
+#define INSTR_ShrConst(op) INSTRUCTION(op, ShrConst, 1, rhs)
+#define INSTR_ShlConst(op) INSTRUCTION(op, ShlConst, 1, rhs)
+#define INSTR_Exp(op) INSTRUCTION(op, Exp, 1, lhs)
+#define INSTR_Mul(op) INSTRUCTION(op, Mul, 2, lhs, traceSlot)
+#define INSTR_Div(op) INSTRUCTION(op, Div, 1, lhs)
+#define INSTR_Mod(op) INSTRUCTION(op, Mod, 2, lhs, traceSlot)
+#define INSTR_Sub(op) INSTRUCTION(op, Sub, 2, lhs, traceSlot)
+#define INSTR_LoadQmlContext(op) INSTRUCTION(op, LoadQmlContext, 1, result)
+#define INSTR_LoadQmlImportedScripts(op) INSTRUCTION(op, LoadQmlImportedScripts, 1, result)
+#define INSTR_InitializeBlockDeadTemporalZone(op) INSTRUCTION(op, InitializeBlockDeadTemporalZone, 2, firstReg, count)
+#define INSTR_ThrowOnNullOrUndefined(op) INSTRUCTION(op, ThrowOnNullOrUndefined, 0)
+#define INSTR_GetTemplateObject(op) INSTRUCTION(op, GetTemplateObject, 1, index)
+#define INSTR_TailCall(op) INSTRUCTION(op, TailCall, 4, func, thisObject, argc, argv)
+
+#define FOR_EACH_MOTH_INSTR_ALL(F) \
+    F(Nop) \
+    FOR_EACH_MOTH_INSTR(F)
 
 #define FOR_EACH_MOTH_INSTR(F) \
-    F(Ret, ret) \
-    MOTH_DEBUG_INSTR(F) \
-    F(LoadRuntimeString, loadRuntimeString) \
-    F(LoadRegExp, loadRegExp) \
-    F(LoadClosure, loadClosure) \
-    F(Move, move) \
-    F(MoveConst, moveConst) \
-    F(SwapTemps, swapTemps) \
-    F(LoadName, loadName) \
-    F(GetGlobalLookup, getGlobalLookup) \
-    F(StoreName, storeName) \
-    F(LoadElement, loadElement) \
-    F(LoadElementLookup, loadElementLookup) \
-    F(StoreElement, storeElement) \
-    F(StoreElementLookup, storeElementLookup) \
-    F(LoadProperty, loadProperty) \
-    F(GetLookup, getLookup) \
-    F(StoreProperty, storeProperty) \
-    F(SetLookup, setLookup) \
-    F(StoreQObjectProperty, storeQObjectProperty) \
-    F(LoadQObjectProperty, loadQObjectProperty) \
-    F(StoreScopeObjectProperty, storeScopeObjectProperty) \
-    F(StoreContextObjectProperty, storeContextObjectProperty) \
-    F(LoadScopeObjectProperty, loadScopeObjectProperty) \
-    F(LoadContextObjectProperty, loadContextObjectProperty) \
-    F(LoadIdObject, loadIdObject) \
-    F(LoadAttachedQObjectProperty, loadAttachedQObjectProperty) \
-    F(LoadSingletonQObjectProperty, loadQObjectProperty) \
-    F(Push, push) \
-    F(CallValue, callValue) \
-    F(CallProperty, callProperty) \
-    F(CallPropertyLookup, callPropertyLookup) \
-    F(CallScopeObjectProperty, callScopeObjectProperty) \
-    F(CallContextObjectProperty, callContextObjectProperty) \
-    F(CallElement, callElement) \
-    F(CallActivationProperty, callActivationProperty) \
-    F(CallGlobalLookup, callGlobalLookup) \
-    F(SetExceptionHandler, setExceptionHandler) \
-    F(CallBuiltinThrow, callBuiltinThrow) \
-    F(CallBuiltinUnwindException, callBuiltinUnwindException) \
-    F(CallBuiltinPushCatchScope, callBuiltinPushCatchScope) \
-    F(CallBuiltinPushScope, callBuiltinPushScope) \
-    F(CallBuiltinPopScope, callBuiltinPopScope) \
-    F(CallBuiltinForeachIteratorObject, callBuiltinForeachIteratorObject) \
-    F(CallBuiltinForeachNextPropertyName, callBuiltinForeachNextPropertyName) \
-    F(CallBuiltinDeleteMember, callBuiltinDeleteMember) \
-    F(CallBuiltinDeleteSubscript, callBuiltinDeleteSubscript) \
-    F(CallBuiltinDeleteName, callBuiltinDeleteName) \
-    F(CallBuiltinTypeofScopeObjectProperty, callBuiltinTypeofScopeObjectProperty) \
-    F(CallBuiltinTypeofContextObjectProperty, callBuiltinTypeofContextObjectProperty) \
-    F(CallBuiltinTypeofMember, callBuiltinTypeofMember) \
-    F(CallBuiltinTypeofSubscript, callBuiltinTypeofSubscript) \
-    F(CallBuiltinTypeofName, callBuiltinTypeofName) \
-    F(CallBuiltinTypeofValue, callBuiltinTypeofValue) \
-    F(CallBuiltinDeclareVar, callBuiltinDeclareVar) \
-    F(CallBuiltinDefineArray, callBuiltinDefineArray) \
-    F(CallBuiltinDefineObjectLiteral, callBuiltinDefineObjectLiteral) \
-    F(CallBuiltinSetupArgumentsObject, callBuiltinSetupArgumentsObject) \
-    F(CallBuiltinConvertThisToObject, callBuiltinConvertThisToObject) \
-    F(CreateValue, createValue) \
-    F(CreateProperty, createProperty) \
-    F(ConstructPropertyLookup, constructPropertyLookup) \
-    F(CreateActivationProperty, createActivationProperty) \
-    F(ConstructGlobalLookup, constructGlobalLookup) \
-    F(Jump, jump) \
-    F(JumpEq, jumpEq) \
-    F(JumpNe, jumpNe) \
-    F(UNot, unot) \
-    F(UNotBool, unotBool) \
-    F(UPlus, uplus) \
-    F(UMinus, uminus) \
-    F(UCompl, ucompl) \
-    F(UComplInt, ucomplInt) \
-    F(Increment, increment) \
-    F(Decrement, decrement) \
-    F(Binop, binop) \
-    F(Add, add) \
-    F(BitAnd, bitAnd) \
-    F(BitOr, bitOr) \
-    F(BitXor, bitXor) \
-    F(Shr, shr) \
-    F(Shl, shl) \
-    F(BitAndConst, bitAndConst) \
-    F(BitOrConst, bitOrConst) \
-    F(BitXorConst, bitXorConst) \
-    F(ShrConst, shrConst) \
-    F(ShlConst, shlConst) \
-    F(Mul, mul) \
-    F(Sub, sub) \
-    F(BinopContext, binopContext) \
-    F(LoadThis, loadThis) \
-    F(LoadQmlContext, loadQmlContext) \
-    F(LoadQmlImportedScripts, loadQmlImportedScripts) \
-    F(LoadQmlSingleton, loadQmlSingleton)
-
-#if defined(Q_CC_GNU) && (!defined(Q_CC_INTEL) || __INTEL_COMPILER >= 1200)
-#  define MOTH_THREADED_INTERPRETER
+    F(Ret) \
+    F(LoadConst) \
+    F(LoadZero) \
+    F(LoadTrue) \
+    F(LoadFalse) \
+    F(LoadNull) \
+    F(LoadUndefined) \
+    F(LoadInt) \
+    F(LoadRuntimeString) \
+    F(MoveConst) \
+    F(LoadReg) \
+    F(StoreReg) \
+    F(MoveReg) \
+    F(LoadImport) \
+    F(LoadLocal) \
+    F(StoreLocal) \
+    F(LoadScopedLocal) \
+    F(StoreScopedLocal) \
+    F(MoveRegExp) \
+    F(LoadClosure) \
+    F(LoadName) \
+    F(LoadGlobalLookup) \
+    F(StoreNameSloppy) \
+    F(StoreNameStrict) \
+    F(LoadElement) \
+    F(StoreElement) \
+    F(LoadProperty) \
+    F(GetLookup) \
+    F(StoreProperty) \
+    F(SetLookup) \
+    F(LoadSuperProperty) \
+    F(StoreSuperProperty) \
+    F(StoreScopeObjectProperty) \
+    F(StoreContextObjectProperty) \
+    F(LoadScopeObjectProperty) \
+    F(LoadContextObjectProperty) \
+    F(LoadIdObject) \
+    F(ConvertThisToObject) \
+    F(ToObject) \
+    F(Jump) \
+    F(JumpTrue) \
+    F(JumpFalse) \
+    F(JumpNoException) \
+    F(JumpNotUndefined) \
+    F(CmpEqNull) \
+    F(CmpNeNull) \
+    F(CmpEqInt) \
+    F(CmpNeInt) \
+    F(CmpEq) \
+    F(CmpNe) \
+    F(CmpGt) \
+    F(CmpGe) \
+    F(CmpLt) \
+    F(CmpLe) \
+    F(CmpStrictEqual) \
+    F(CmpStrictNotEqual) \
+    F(CmpIn) \
+    F(CmpInstanceOf) \
+    F(UNot) \
+    F(UPlus) \
+    F(UMinus) \
+    F(UCompl) \
+    F(Increment) \
+    F(Decrement) \
+    F(Add) \
+    F(BitAnd) \
+    F(BitOr) \
+    F(BitXor) \
+    F(UShr) \
+    F(Shr) \
+    F(Shl) \
+    F(BitAndConst) \
+    F(BitOrConst) \
+    F(BitXorConst) \
+    F(UShrConst) \
+    F(ShrConst) \
+    F(ShlConst) \
+    F(Exp) \
+    F(Mul) \
+    F(Div) \
+    F(Mod) \
+    F(Sub) \
+    F(CallValue) \
+    F(CallWithReceiver) \
+    F(CallProperty) \
+    F(CallPropertyLookup) \
+    F(CallElement) \
+    F(CallName) \
+    F(CallPossiblyDirectEval) \
+    F(CallGlobalLookup) \
+    F(CallScopeObjectProperty) \
+    F(CallContextObjectProperty) \
+    F(CallWithSpread) \
+    F(Construct) \
+    F(ConstructWithSpread) \
+    F(SetUnwindHandler) \
+    F(UnwindDispatch) \
+    F(UnwindToLabel) \
+    F(DeadTemporalZoneCheck) \
+    F(ThrowException) \
+    F(GetException) \
+    F(SetException) \
+    F(CreateCallContext) \
+    F(PushCatchContext) \
+    F(PushWithContext) \
+    F(PushBlockContext) \
+    F(CloneBlockContext) \
+    F(PopContext) \
+    F(GetIterator) \
+    F(IteratorNext) \
+    F(IteratorClose) \
+    F(DestructureRestElement) \
+    F(DeleteProperty) \
+    F(DeleteName) \
+    F(TypeofName) \
+    F(TypeofValue) \
+    F(DeclareVar) \
+    F(DefineArray) \
+    F(DefineObjectLiteral) \
+    F(CreateMappedArgumentsObject) \
+    F(CreateUnmappedArgumentsObject) \
+    F(CreateRestParameter) \
+    F(LoadQmlContext) \
+    F(LoadQmlImportedScripts) \
+    F(Yield) \
+    F(YieldStar) \
+    F(Resume) \
+    F(IteratorNextForYieldStar) \
+    F(CreateClass) \
+    F(LoadSuperConstructor) \
+    F(PushScriptContext) \
+    F(PopScriptContext) \
+    F(InitializeBlockDeadTemporalZone) \
+    F(ThrowOnNullOrUndefined) \
+    F(GetTemplateObject) \
+    F(TailCall) \
+    F(Debug) \
+
+#define MOTH_NUM_INSTRUCTIONS() (static_cast<int>(Moth::Instr::Type::Debug_Wide) + 1)
+
+#if defined(Q_CC_GNU)
+#if defined(Q_CC_INTEL)
+// icc before version 1200 doesn't support computed goto, and at least up to version 18.0.0 the
+// current use results in an internal compiler error. We could enable this if/when it gets fixed
+// in a later version.
+# elif defined(Q_OS_WASM) && !defined(__asmjs)
+// Upstream llvm does not support computed goto for the wasm target, unlike the 'fastcomp' llvm fork
+// shipped with the emscripten SDK. Disable computed goto usage for non-fastcomp llvm on Wasm.
+#else
+#  define MOTH_COMPUTED_GOTO
+#endif
 #endif
 
 #define MOTH_INSTR_ALIGN_MASK (Q_ALIGNOF(QV4::Moth::Instr) - 1)
 
-#define MOTH_INSTR_HEADER quint32 instructionType;
+#define MOTH_INSTR_ENUM(I)  I, I##_Wide,
+#define MOTH_INSTR_SIZE(I) (sizeof(QV4::Moth::Instr::instr_##I))
+
+#define MOTH_EXPAND_FOR_MSVC(x) x
+#define MOTH_DEFINE_ARGS(nargs, ...) \
+    MOTH_EXPAND_FOR_MSVC(MOTH_DEFINE_ARGS##nargs(__VA_ARGS__))
+
+#define MOTH_DEFINE_ARGS0()
+#define MOTH_DEFINE_ARGS1(arg) \
+    int arg;
+#define MOTH_DEFINE_ARGS2(arg1, arg2) \
+    int arg1; \
+    int arg2;
+#define MOTH_DEFINE_ARGS3(arg1, arg2, arg3) \
+    int arg1; \
+    int arg2; \
+    int arg3;
+#define MOTH_DEFINE_ARGS4(arg1, arg2, arg3, arg4) \
+    int arg1; \
+    int arg2; \
+    int arg3; \
+    int arg4;
+#define MOTH_DEFINE_ARGS5(arg1, arg2, arg3, arg4, arg5) \
+    int arg1; \
+    int arg2; \
+    int arg3; \
+    int arg4; \
+    int arg5;
+
+#define MOTH_COLLECT_ENUMS(instr) \
+    INSTR_##instr(MOTH_GET_ENUM)
+#define MOTH_GET_ENUM_INSTRUCTION(name, ...) \
+    name,
+
+#define MOTH_EMIT_STRUCTS(instr) \
+    INSTR_##instr(MOTH_EMIT_STRUCT)
+#define MOTH_EMIT_STRUCT_INSTRUCTION(name, nargs, ...) \
+    struct instr_##name { \
+        MOTH_DEFINE_ARGS(nargs, __VA_ARGS__) \
+    };
+
+#define MOTH_EMIT_INSTR_MEMBERS(instr) \
+    INSTR_##instr(MOTH_EMIT_INSTR_MEMBER)
+#define MOTH_EMIT_INSTR_MEMBER_INSTRUCTION(name, nargs, ...) \
+    instr_##name name;
+
+#define MOTH_COLLECT_NARGS(instr) \
+    INSTR_##instr(MOTH_COLLECT_ARG_COUNT)
+#define MOTH_COLLECT_ARG_COUNT_INSTRUCTION(name, nargs, ...) \
+    nargs, nargs,
+
+#define MOTH_DECODE_ARG(arg, type, nargs, offset) \
+    arg = qFromLittleEndian<type>(qFromUnaligned<type>(reinterpret_cast<const type *>(code) - nargs + offset));
+#define MOTH_ADJUST_CODE(type, nargs) \
+    code += static_cast<quintptr>(nargs*sizeof(type) + 1)
+
+#define MOTH_DECODE_INSTRUCTION(name, nargs, ...) \
+        MOTH_DEFINE_ARGS(nargs, __VA_ARGS__) \
+    op_int_##name: \
+        MOTH_ADJUST_CODE(int, nargs); \
+        MOTH_DECODE_ARGS(name, int, nargs, __VA_ARGS__) \
+        goto op_main_##name; \
+    op_byte_##name: \
+        MOTH_ADJUST_CODE(qint8, nargs); \
+        MOTH_DECODE_ARGS(name, qint8, nargs, __VA_ARGS__) \
+    op_main_##name: \
+        ; \
+
+#define MOTH_DECODE_WITH_BASE_INSTRUCTION(name, nargs, ...) \
+        MOTH_DEFINE_ARGS(nargs, __VA_ARGS__) \
+        const char *base_ptr; \
+    op_int_##name: \
+        base_ptr = code; \
+        MOTH_ADJUST_CODE(int, nargs); \
+        MOTH_DECODE_ARGS(name, int, nargs, __VA_ARGS__) \
+        goto op_main_##name; \
+    op_byte_##name: \
+        base_ptr = code; \
+        MOTH_ADJUST_CODE(qint8, nargs); \
+        MOTH_DECODE_ARGS(name, qint8, nargs, __VA_ARGS__) \
+    op_main_##name: \
+        ; \
+
+#define MOTH_DECODE_ARGS(name, type, nargs, ...) \
+    MOTH_EXPAND_FOR_MSVC(MOTH_DECODE_ARGS##nargs(name, type, nargs, __VA_ARGS__))
+
+#define MOTH_DECODE_ARGS0(name, type, nargs, dummy)
+#define MOTH_DECODE_ARGS1(name, type, nargs, arg) \
+        MOTH_DECODE_ARG(arg, type, nargs, 0);
+#define MOTH_DECODE_ARGS2(name, type, nargs, arg1, arg2) \
+        MOTH_DECODE_ARGS1(name, type, nargs, arg1); \
+        MOTH_DECODE_ARG(arg2, type, nargs, 1);
+#define MOTH_DECODE_ARGS3(name, type, nargs, arg1, arg2, arg3) \
+        MOTH_DECODE_ARGS2(name, type, nargs, arg1, arg2); \
+        MOTH_DECODE_ARG(arg3, type, nargs, 2);
+#define MOTH_DECODE_ARGS4(name, type, nargs, arg1, arg2, arg3, arg4) \
+        MOTH_DECODE_ARGS3(name, type, nargs, arg1, arg2, arg3); \
+        MOTH_DECODE_ARG(arg4, type, nargs, 3);
+#define MOTH_DECODE_ARGS5(name, type, nargs, arg1, arg2, arg3, arg4, arg5) \
+        MOTH_DECODE_ARGS4(name, type, nargs, arg1, arg2, arg3, arg4); \
+        MOTH_DECODE_ARG(arg5, type, nargs, 4);
+
+#ifdef MOTH_COMPUTED_GOTO
+/* collect jump labels */
+#define COLLECT_LABELS(instr) \
+    INSTR_##instr(GET_LABEL) \
+    INSTR_##instr(GET_LABEL_WIDE)
+#define GET_LABEL_INSTRUCTION(name, ...) \
+    &&op_byte_##name,
+#define GET_LABEL_WIDE_INSTRUCTION(name, ...) \
+    &&op_int_##name,
+
+#define MOTH_JUMP_TABLE \
+    static const void *jumpTable[] = { \
+        FOR_EACH_MOTH_INSTR_ALL(COLLECT_LABELS) \
+    };
+
+#define MOTH_DISPATCH_SINGLE() \
+    goto *jumpTable[*reinterpret_cast<const uchar *>(code)];
+
+#define MOTH_DISPATCH() \
+    MOTH_DISPATCH_SINGLE() \
+    op_byte_Nop: \
+        ++code; \
+        MOTH_DISPATCH_SINGLE() \
+    op_int_Nop: /* wide prefix */ \
+        ++code; \
+        goto *jumpTable[0x100 | *reinterpret_cast<const uchar *>(code)];
+#else
+#define MOTH_JUMP_TABLE
+
+#define MOTH_INSTR_CASE_AND_JUMP(instr) \
+    INSTR_##instr(GET_CASE_AND_JUMP) \
+    INSTR_##instr(GET_CASE_AND_JUMP_WIDE)
+#define GET_CASE_AND_JUMP_INSTRUCTION(name, ...) \
+    case Instr::Type::name: goto op_byte_##name;
+#define GET_CASE_AND_JUMP_WIDE_INSTRUCTION(name, ...) \
+    case Instr::Type::name##_Wide: goto op_int_##name;
+
+#define MOTH_DISPATCH() \
+    Instr::Type type = Instr::Type(static_cast<uchar>(*code)); \
+  dispatch: \
+    switch (type) { \
+        case Instr::Type::Nop: \
+            ++code; \
+            type = Instr::Type(static_cast<uchar>(*code)); \
+            goto dispatch; \
+        case Instr::Type::Nop_Wide: /* wide prefix */ \
+            ++code; \
+            type = Instr::Type(0x100 | static_cast<uchar>(*code)); \
+            goto dispatch; \
+        FOR_EACH_MOTH_INSTR(MOTH_INSTR_CASE_AND_JUMP) \
+    }
+#endif
 
-#define MOTH_INSTR_ENUM(I, FMT)  I,
-#define MOTH_INSTR_SIZE(I, FMT) ((sizeof(QV4::Moth::Instr::instr_##FMT) + MOTH_INSTR_ALIGN_MASK) & ~MOTH_INSTR_ALIGN_MASK)
+namespace QV4 {
 
+namespace CompiledData {
+struct CodeOffsetToLine;
+}
 
-namespace QV4 {
 namespace Moth {
 
-    // When making changes to the instructions, make sure to bump QV4_DATA_STRUCTURE_VERSION in qv4compileddata_p.h
-
-struct Param {
-    // Params are looked up as follows:
-    // Constant: 0
-    // Temp: 1
-    // Argument: 2
-    // Local: 3
-    // Arg(outer): 4
-    // Local(outer): 5
-    // ...
-    unsigned scope : 12;
-    unsigned index : 20;
-
-    bool isConstant() const { return !scope; }
-    bool isArgument() const { return scope >= 2 && !(scope &1); }
-    bool isLocal() const { return scope == 3; }
-    bool isTemp() const { return scope == 1; }
-    bool isScopedLocal() const { return scope >= 3 && (scope & 1); }
-
-    static Param createConstant(int index)
-    {
-        Param p;
-        p.scope = 0;
-        p.index = index;
-        return p;
-    }
+class StackSlot {
+    int index;
 
-    static Param createArgument(unsigned idx, uint scope)
-    {
-        Param p;
-        p.scope = 2 + 2*scope;
-        p.index = idx;
-        return p;
+public:
+    static StackSlot createRegister(int index) {
+        Q_ASSERT(index >= 0);
+        StackSlot t;
+        t.index = index;
+        return t;
     }
 
-    static Param createLocal(unsigned idx)
-    {
-        Param p;
-        p.scope = 3;
-        p.index = idx;
-        return p;
-    }
-
-    static Param createTemp(unsigned idx)
-    {
-        Param p;
-        p.scope = 1;
-        p.index = idx;
-        return p;
-    }
+    int stackSlot() const { return index; }
+    operator int() const { return index; }
+};
 
-    static Param createScopedLocal(unsigned idx, uint scope)
-    {
-        Param p;
-        p.scope = 3 + 2*scope;
-        p.index = idx;
-        return p;
-    }
+inline bool operator==(const StackSlot &l, const StackSlot &r) { return l.stackSlot() == r.stackSlot(); }
+inline bool operator!=(const StackSlot &l, const StackSlot &r) { return l.stackSlot() != r.stackSlot(); }
 
-    inline bool operator==(const Param &other) const
-    { return scope == other.scope && index == other.index; }
+// When making changes to the instructions, make sure to bump QV4_DATA_STRUCTURE_VERSION in qv4compileddata_p.h
 
-    inline bool operator!=(const Param &other) const
-    { return !(*this == other); }
-};
+void dumpConstantTable(const Value *constants, uint count);
+void dumpBytecode(const char *bytecode, int len, int nLocals, int nFormals, int startLine = 1,
+                  const QVector<CompiledData::CodeOffsetToLine> &lineNumberMapping = QVector<CompiledData::CodeOffsetToLine>());
+inline void dumpBytecode(const QByteArray &bytecode, int nLocals, int nFormals, int startLine = 1,
+                         const QVector<CompiledData::CodeOffsetToLine> &lineNumberMapping = QVector<CompiledData::CodeOffsetToLine>()) {
+    dumpBytecode(bytecode.constData(), bytecode.length(), nLocals, nFormals, startLine, lineNumberMapping);
+}
 
 union Instr
 {
-    enum Type {
-        FOR_EACH_MOTH_INSTR(MOTH_INSTR_ENUM)
-        LastInstruction
-    };
+    enum class Type {
+        FOR_EACH_MOTH_INSTR_ALL(MOTH_INSTR_ENUM)
+    };
+
+    static Type wideInstructionType(Type t) { return Type(int(t) | 1); }
+    static Type narrowInstructionType(Type t) { return Type(int(t) & ~1); }
+    static bool isWide(Type t) { return int(t) & 1; }
+    static bool isNarrow(Type t) { return !(int(t) & 1); }
+    static int encodedLength(Type t) { return int(t) >= 256 ? 2 : 1; }
+
+    static Type unpack(const uchar *c) { if (c[0] == 0x1) return Type(0x100 + c[1]); return Type(c[0]); }
+    static uchar *pack(uchar *c, Type t) {
+        if (uint(t) >= 256) {
+            c[0] = 0x1;
+            c[1] = uint(t) &0xff;
+            return c + 2;
+        }
+        c[0] = uchar(uint(t));
+        return c + 1;
+    }
 
-    struct instr_common {
-        MOTH_INSTR_HEADER
-    };
-    struct instr_ret {
-        MOTH_INSTR_HEADER
-        Param result;
-    };
+    FOR_EACH_MOTH_INSTR_ALL(MOTH_EMIT_STRUCTS)
 
-#ifndef QT_NO_QML_DEBUGGING
-    struct instr_line {
-        MOTH_INSTR_HEADER
-        qint32 lineNumber;
-    };
-    struct instr_debug {
-        MOTH_INSTR_HEADER
-        qint32 lineNumber;
-    };
-#endif // QT_NO_QML_DEBUGGING
+    FOR_EACH_MOTH_INSTR_ALL(MOTH_EMIT_INSTR_MEMBERS)
 
-    struct instr_loadRuntimeString {
-        MOTH_INSTR_HEADER
-        int stringId;
-        Param result;
-    };
-    struct instr_loadRegExp {
-        MOTH_INSTR_HEADER
-        int regExpId;
-        Param result;
-    };
-    struct instr_move {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_moveConst {
-        MOTH_INSTR_HEADER
-        QV4::ReturnedValue source;
-        Param result;
-    };
-    struct instr_swapTemps {
-        MOTH_INSTR_HEADER
-        Param left;
-        Param right;
-    };
-    struct instr_loadClosure {
-        MOTH_INSTR_HEADER
-        int value;
-        Param result;
-    };
-    struct instr_loadName {
-        MOTH_INSTR_HEADER
-        int name;
-        Param result;
-    };
-    struct instr_getGlobalLookup {
-        MOTH_INSTR_HEADER
-        int index;
-        Param result;
-    };
-    struct instr_storeName {
-        MOTH_INSTR_HEADER
-        int name;
-        Param source;
-    };
-    struct instr_loadProperty {
-        MOTH_INSTR_HEADER
-        int name;
-        Param base;
-        Param result;
-    };
-    struct instr_getLookup {
-        MOTH_INSTR_HEADER
-        int index;
-        Param base;
-        Param result;
-    };
-    struct instr_loadScopeObjectProperty {
-        MOTH_INSTR_HEADER
-        int propertyIndex;
-        Param base;
-        Param result;
-        bool captureRequired;
-    };
-    struct instr_loadContextObjectProperty {
-        MOTH_INSTR_HEADER
-        int propertyIndex;
-        Param base;
-        Param result;
-        bool captureRequired;
-    };
-    struct instr_loadIdObject {
-        MOTH_INSTR_HEADER
-        int index;
-        Param base;
-        Param result;
-    };
-    struct instr_loadQObjectProperty {
-        MOTH_INSTR_HEADER
-        int propertyIndex;
-        Param base;
-        Param result;
-        bool captureRequired;
-    };
-    struct instr_loadAttachedQObjectProperty {
-        MOTH_INSTR_HEADER
-        int propertyIndex;
-        Param result;
-        int attachedPropertiesId;
-    };
-    struct instr_storeProperty {
-        MOTH_INSTR_HEADER
-        int name;
-        Param base;
-        Param source;
-    };
-    struct instr_setLookup {
-        MOTH_INSTR_HEADER
-        int index;
-        Param base;
-        Param source;
-    };
-    struct instr_storeScopeObjectProperty {
-        MOTH_INSTR_HEADER
-        Param base;
-        int propertyIndex;
-        Param source;
-    };
-    struct instr_storeContextObjectProperty {
-        MOTH_INSTR_HEADER
-        Param base;
-        int propertyIndex;
-        Param source;
-    };
-    struct instr_storeQObjectProperty {
-        MOTH_INSTR_HEADER
-        Param base;
-        int propertyIndex;
-        Param source;
-    };
-    struct instr_loadElement {
-        MOTH_INSTR_HEADER
-        Param base;
-        Param index;
-        Param result;
-    };
-    struct instr_loadElementLookup {
-        MOTH_INSTR_HEADER
-        uint lookup;
-        Param base;
-        Param index;
-        Param result;
-    };
-    struct instr_storeElement {
-        MOTH_INSTR_HEADER
-        Param base;
-        Param index;
-        Param source;
-    };
-    struct instr_storeElementLookup {
-        MOTH_INSTR_HEADER
-        uint lookup;
-        Param base;
-        Param index;
-        Param source;
-    };
-    struct instr_push {
-        MOTH_INSTR_HEADER
-        quint32 value;
-    };
-    struct instr_callValue {
-        MOTH_INSTR_HEADER
-        quint32 argc;
-        quint32 callData;
-        Param dest;
-        Param result;
-    };
-    struct instr_callProperty {
-        MOTH_INSTR_HEADER
-        int name;
-        quint32 argc;
-        quint32 callData;
-        Param base;
-        Param result;
-    };
-    struct instr_callPropertyLookup {
-        MOTH_INSTR_HEADER
-        int lookupIndex;
-        quint32 argc;
-        quint32 callData;
-        Param base;
-        Param result;
-    };
-    struct instr_callScopeObjectProperty {
-        MOTH_INSTR_HEADER
-        int index;
-        quint32 argc;
-        quint32 callData;
-        Param base;
-        Param result;
-    };
-    struct instr_callContextObjectProperty {
-        MOTH_INSTR_HEADER
-        int index;
-        quint32 argc;
-        quint32 callData;
-        Param base;
-        Param result;
-    };
-    struct instr_callElement {
-        MOTH_INSTR_HEADER
-        Param base;
-        Param index;
-        quint32 argc;
-        quint32 callData;
-        Param result;
-    };
-    struct instr_callActivationProperty {
-        MOTH_INSTR_HEADER
-        int name;
-        quint32 argc;
-        quint32 callData;
-        Param result;
-    };
-    struct instr_callGlobalLookup {
-        MOTH_INSTR_HEADER
-        int index;
-        quint32 argc;
-        quint32 callData;
-        Param result;
-    };
-    struct instr_setExceptionHandler {
-        MOTH_INSTR_HEADER
-        qptrdiff offset;
-    };
-    struct instr_callBuiltinThrow {
-        MOTH_INSTR_HEADER
-        Param arg;
-    };
-    struct instr_callBuiltinUnwindException {
-        MOTH_INSTR_HEADER
-        Param result;
-    };
-    struct instr_callBuiltinPushCatchScope {
-        MOTH_INSTR_HEADER
-        int name;
-    };
-    struct instr_callBuiltinPushScope {
-        MOTH_INSTR_HEADER
-        Param arg;
-    };
-    struct instr_callBuiltinPopScope {
-        MOTH_INSTR_HEADER
-    };
-    struct instr_callBuiltinForeachIteratorObject {
-        MOTH_INSTR_HEADER
-        Param arg;
-        Param result;
-    };
-    struct instr_callBuiltinForeachNextPropertyName {
-        MOTH_INSTR_HEADER
-        Param arg;
-        Param result;
-    };
-    struct instr_callBuiltinDeleteMember {
-        MOTH_INSTR_HEADER
-        int member;
-        Param base;
-        Param result;
-    };
-    struct instr_callBuiltinDeleteSubscript {
-        MOTH_INSTR_HEADER
-        Param base;
-        Param index;
-        Param result;
-    };
-    struct instr_callBuiltinDeleteName {
-        MOTH_INSTR_HEADER
-        int name;
-        Param result;
-    };
-    struct instr_callBuiltinTypeofScopeObjectProperty {
-        MOTH_INSTR_HEADER
-        int index;
-        Param base;
-        Param result;
-    };
-    struct instr_callBuiltinTypeofContextObjectProperty {
-        MOTH_INSTR_HEADER
-        int index;
-        Param base;
-        Param result;
-    };
-    struct instr_callBuiltinTypeofMember {
-        MOTH_INSTR_HEADER
-        int member;
-        Param base;
-        Param result;
-    };
-    struct instr_callBuiltinTypeofSubscript {
-        MOTH_INSTR_HEADER
-        Param base;
-        Param index;
-        Param result;
-    };
-    struct instr_callBuiltinTypeofName {
-        MOTH_INSTR_HEADER
-        int name;
-        Param result;
-    };
-    struct instr_callBuiltinTypeofValue {
-        MOTH_INSTR_HEADER
-        Param value;
-        Param result;
-    };
-    struct instr_callBuiltinDeclareVar {
-        MOTH_INSTR_HEADER
-        int varName;
-        bool isDeletable;
-    };
-    struct instr_callBuiltinDefineArray {
-        MOTH_INSTR_HEADER
-        quint32 argc;
-        quint32 args;
-        Param result;
-    };
-    struct instr_callBuiltinDefineObjectLiteral {
-        MOTH_INSTR_HEADER
-        int internalClassId;
-        uint arrayValueCount;
-        uint arrayGetterSetterCountAndFlags; // 30 bits for count, 1 bit for needsSparseArray boolean
-        quint32 args;
-        Param result;
-    };
-    struct instr_callBuiltinSetupArgumentsObject {
-        MOTH_INSTR_HEADER
-        Param result;
-    };
-    struct instr_callBuiltinConvertThisToObject {
-        MOTH_INSTR_HEADER
-    };
-    struct instr_createValue {
-        MOTH_INSTR_HEADER
-        quint32 argc;
-        quint32 callData;
-        Param func;
-        Param result;
-    };
-    struct instr_createProperty {
-        MOTH_INSTR_HEADER
-        int name;
-        quint32 argc;
-        quint32 callData;
-        Param base;
-        Param result;
-    };
-    struct instr_constructPropertyLookup {
-        MOTH_INSTR_HEADER
-        int index;
-        quint32 argc;
-        quint32 callData;
-        Param base;
-        Param result;
-    };
-    struct instr_createActivationProperty {
-        MOTH_INSTR_HEADER
-        int name;
-        quint32 argc;
-        quint32 callData;
-        Param result;
-    };
-    struct instr_constructGlobalLookup {
-        MOTH_INSTR_HEADER
-        int index;
-        quint32 argc;
-        quint32 callData;
-        Param result;
-    };
-    struct instr_jump {
-        MOTH_INSTR_HEADER
-        ptrdiff_t offset;
-    };
-    struct instr_jumpEq {
-        MOTH_INSTR_HEADER
-        ptrdiff_t offset;
-        Param condition;
-    };
-    struct instr_jumpNe {
-        MOTH_INSTR_HEADER
-        ptrdiff_t offset;
-        Param condition;
-    };
-    struct instr_unot {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_unotBool {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_uplus {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_uminus {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_ucompl {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_ucomplInt {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_increment {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_decrement {
-        MOTH_INSTR_HEADER
-        Param source;
-        Param result;
-    };
-    struct instr_binop {
-        MOTH_INSTR_HEADER
-        int alu; // QV4::Runtime::RuntimeMethods enum value
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_add {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_bitAnd {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_bitOr {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_bitXor {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_shr {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_shl {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_bitAndConst {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        int rhs;
-        Param result;
-    };
-    struct instr_bitOrConst {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        int rhs;
-        Param result;
-    };
-    struct instr_bitXorConst {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        int rhs;
-        Param result;
-    };
-    struct instr_shrConst {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        int rhs;
-        Param result;
-    };
-    struct instr_shlConst {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        int rhs;
-        Param result;
-    };
-    struct instr_mul {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_sub {
-        MOTH_INSTR_HEADER
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_binopContext {
-        MOTH_INSTR_HEADER
-        uint alu; // offset inside the runtime methods
-        Param lhs;
-        Param rhs;
-        Param result;
-    };
-    struct instr_loadThis {
-        MOTH_INSTR_HEADER
-        Param result;
-    };
-    struct instr_loadQmlContext {
-        MOTH_INSTR_HEADER
-        Param result;
-    };
-    struct instr_loadQmlImportedScripts {
-        MOTH_INSTR_HEADER
-        Param result;
-    };
-    struct instr_loadQmlSingleton {
-        MOTH_INSTR_HEADER
-        Param result;
-        int name;
-    };
+    int argumentsAsInts[4];
+};
 
-    instr_common common;
-    instr_ret ret;
-    instr_line line;
-    instr_debug debug;
-    instr_loadRuntimeString loadRuntimeString;
-    instr_loadRegExp loadRegExp;
-    instr_move move;
-    instr_moveConst moveConst;
-    instr_swapTemps swapTemps;
-    instr_loadClosure loadClosure;
-    instr_loadName loadName;
-    instr_getGlobalLookup getGlobalLookup;
-    instr_storeName storeName;
-    instr_loadElement loadElement;
-    instr_loadElementLookup loadElementLookup;
-    instr_storeElement storeElement;
-    instr_storeElementLookup storeElementLookup;
-    instr_loadProperty loadProperty;
-    instr_getLookup getLookup;
-    instr_loadScopeObjectProperty loadScopeObjectProperty;
-    instr_loadContextObjectProperty loadContextObjectProperty;
-    instr_loadIdObject loadIdObject;
-    instr_loadQObjectProperty loadQObjectProperty;
-    instr_loadAttachedQObjectProperty loadAttachedQObjectProperty;
-    instr_storeProperty storeProperty;
-    instr_setLookup setLookup;
-    instr_storeScopeObjectProperty storeScopeObjectProperty;
-    instr_storeContextObjectProperty storeContextObjectProperty;
-    instr_storeQObjectProperty storeQObjectProperty;
-    instr_push push;
-    instr_callValue callValue;
-    instr_callProperty callProperty;
-    instr_callPropertyLookup callPropertyLookup;
-    instr_callScopeObjectProperty callScopeObjectProperty;
-    instr_callContextObjectProperty callContextObjectProperty;
-    instr_callElement callElement;
-    instr_callActivationProperty callActivationProperty;
-    instr_callGlobalLookup callGlobalLookup;
-    instr_callBuiltinThrow callBuiltinThrow;
-    instr_setExceptionHandler setExceptionHandler;
-    instr_callBuiltinUnwindException callBuiltinUnwindException;
-    instr_callBuiltinPushCatchScope callBuiltinPushCatchScope;
-    instr_callBuiltinPushScope callBuiltinPushScope;
-    instr_callBuiltinPopScope callBuiltinPopScope;
-    instr_callBuiltinForeachIteratorObject callBuiltinForeachIteratorObject;
-    instr_callBuiltinForeachNextPropertyName callBuiltinForeachNextPropertyName;
-    instr_callBuiltinDeleteMember callBuiltinDeleteMember;
-    instr_callBuiltinDeleteSubscript callBuiltinDeleteSubscript;
-    instr_callBuiltinDeleteName callBuiltinDeleteName;
-    instr_callBuiltinTypeofScopeObjectProperty callBuiltinTypeofScopeObjectProperty;
-    instr_callBuiltinTypeofContextObjectProperty callBuiltinTypeofContextObjectProperty;
-    instr_callBuiltinTypeofMember callBuiltinTypeofMember;
-    instr_callBuiltinTypeofSubscript callBuiltinTypeofSubscript;
-    instr_callBuiltinTypeofName callBuiltinTypeofName;
-    instr_callBuiltinTypeofValue callBuiltinTypeofValue;
-    instr_callBuiltinDeclareVar callBuiltinDeclareVar;
-    instr_callBuiltinDefineArray callBuiltinDefineArray;
-    instr_callBuiltinDefineObjectLiteral callBuiltinDefineObjectLiteral;
-    instr_callBuiltinSetupArgumentsObject callBuiltinSetupArgumentsObject;
-    instr_callBuiltinConvertThisToObject callBuiltinConvertThisToObject;
-    instr_createValue createValue;
-    instr_createProperty createProperty;
-    instr_constructPropertyLookup constructPropertyLookup;
-    instr_createActivationProperty createActivationProperty;
-    instr_constructGlobalLookup constructGlobalLookup;
-    instr_jump jump;
-    instr_jumpEq jumpEq;
-    instr_jumpNe jumpNe;
-    instr_unot unot;
-    instr_unotBool unotBool;
-    instr_uplus uplus;
-    instr_uminus uminus;
-    instr_ucompl ucompl;
-    instr_ucomplInt ucomplInt;
-    instr_increment increment;
-    instr_decrement decrement;
-    instr_binop binop;
-    instr_add add;
-    instr_bitAnd bitAnd;
-    instr_bitOr bitOr;
-    instr_bitXor bitXor;
-    instr_shr shr;
-    instr_shl shl;
-    instr_bitAndConst bitAndConst;
-    instr_bitOrConst bitOrConst;
-    instr_bitXorConst bitXorConst;
-    instr_shrConst shrConst;
-    instr_shlConst shlConst;
-    instr_mul mul;
-    instr_sub sub;
-    instr_binopContext binopContext;
-    instr_loadThis loadThis;
-    instr_loadQmlContext loadQmlContext;
-    instr_loadQmlImportedScripts loadQmlImportedScripts;
-    instr_loadQmlSingleton loadQmlSingleton;
-
-    static int size(Type type);
+struct InstrInfo
+{
+    static const int argumentCount[];
+    static int size(Instr::Type type);
 };
 
 template<int N>
 struct InstrMeta {
 };
 
-#define MOTH_INSTR_META_TEMPLATE(I, FMT) \
-    template<> struct InstrMeta<(int)Instr::I> { \
-        enum { Size = MOTH_INSTR_SIZE(I, FMT) }; \
-        typedef Instr::instr_##FMT DataType; \
-        static const DataType &data(const Instr &instr) { return instr.FMT; } \
-        static void setData(Instr &instr, const DataType &v) { instr.FMT = v; } \
-        static void setDataNoCommon(Instr &instr, const DataType &v) \
-        { memcpy(reinterpret_cast<char *>(&instr.FMT) + sizeof(Instr::instr_common), \
-                 reinterpret_cast<const char *>(&v) + sizeof(Instr::instr_common), \
-                 Size - sizeof(Instr::instr_common)); } \
-    };
-FOR_EACH_MOTH_INSTR(MOTH_INSTR_META_TEMPLATE);
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_GCC("-Wuninitialized")
+QT_WARNING_DISABLE_GCC("-Wmaybe-uninitialized")
+#define MOTH_INSTR_META_TEMPLATE(I) \
+    template<> struct InstrMeta<int(Instr::Type::I)> { \
+        enum { Size = MOTH_INSTR_SIZE(I) }; \
+        typedef Instr::instr_##I DataType; \
+        static const DataType &data(const Instr &instr) { return instr.I; } \
+        static void setData(Instr &instr, const DataType &v) \
+        { memcpy(reinterpret_cast<char *>(&instr.I), \
+                 reinterpret_cast<const char *>(&v), \
+                 Size); } \
+    };
+FOR_EACH_MOTH_INSTR_ALL(MOTH_INSTR_META_TEMPLATE);
 #undef MOTH_INSTR_META_TEMPLATE
+QT_WARNING_POP
 
 template<int InstrType>
 class InstrData : public InstrMeta<InstrType>::DataType
 {
 };
 
+struct Instruction {
+#define MOTH_INSTR_DATA_TYPEDEF(I) typedef InstrData<int(Instr::Type::I)> I;
+FOR_EACH_MOTH_INSTR_ALL(MOTH_INSTR_DATA_TYPEDEF)
+#undef MOTH_INSTR_DATA_TYPEDEF
+private:
+    Instruction();
+};
+
 } // namespace Moth
 } // namespace QV4
 
diff --git a/src/qml/compiler/qv4isel_moth.cpp b/src/qml/compiler/qv4isel_moth.cpp
deleted file mode 100644
index fb805dce02..0000000000
--- a/src/qml/compiler/qv4isel_moth.cpp
+++ /dev/null
@@ -1,1528 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qv4isel_util_p.h"
-#include "qv4isel_moth_p.h"
-#include "qv4ssa_p.h"
-#include <private/qv4compileddata_p.h>
-#include <wtf/MathExtras.h>
-
-#if !defined(V4_BOOTSTRAP)
-#include "qv4vme_moth_p.h"
-#include <private/qv4function_p.h>
-#endif
-
-#undef USE_TYPE_INFO
-
-using namespace QV4;
-using namespace QV4::Moth;
-
-namespace {
-
-inline QV4::Runtime::RuntimeMethods aluOpFunction(IR::AluOp op)
-{
-    switch (op) {
-    case IR::OpInvalid:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpIfTrue:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpNot:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpUMinus:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpUPlus:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpCompl:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpBitAnd:
-        return QV4::Runtime::bitAnd;
-    case IR::OpBitOr:
-        return QV4::Runtime::bitOr;
-    case IR::OpBitXor:
-        return QV4::Runtime::bitXor;
-    case IR::OpAdd:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpSub:
-        return QV4::Runtime::sub;
-    case IR::OpMul:
-        return QV4::Runtime::mul;
-    case IR::OpDiv:
-        return QV4::Runtime::div;
-    case IR::OpMod:
-        return QV4::Runtime::mod;
-    case IR::OpLShift:
-        return QV4::Runtime::shl;
-    case IR::OpRShift:
-        return QV4::Runtime::shr;
-    case IR::OpURShift:
-        return QV4::Runtime::ushr;
-    case IR::OpGt:
-        return QV4::Runtime::greaterThan;
-    case IR::OpLt:
-        return QV4::Runtime::lessThan;
-    case IR::OpGe:
-        return QV4::Runtime::greaterEqual;
-    case IR::OpLe:
-        return QV4::Runtime::lessEqual;
-    case IR::OpEqual:
-        return QV4::Runtime::equal;
-    case IR::OpNotEqual:
-        return QV4::Runtime::notEqual;
-    case IR::OpStrictEqual:
-        return QV4::Runtime::strictEqual;
-    case IR::OpStrictNotEqual:
-        return QV4::Runtime::strictNotEqual;
-    case IR::OpInstanceof:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpIn:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpAnd:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    case IR::OpOr:
-        return QV4::Runtime::InvalidRuntimeMethod;
-    default:
-        Q_ASSERT(!"Unknown AluOp");
-        return QV4::Runtime::InvalidRuntimeMethod;
-    }
-};
-
-inline bool isNumberType(IR::Expr *e)
-{
-    switch (e->type) {
-    case IR::SInt32Type:
-    case IR::UInt32Type:
-    case IR::DoubleType:
-        return true;
-    default:
-        return false;
-    }
-}
-
-inline bool isIntegerType(IR::Expr *e)
-{
-    switch (e->type) {
-    case IR::SInt32Type:
-    case IR::UInt32Type:
-        return true;
-    default:
-        return false;
-    }
-}
-
-inline bool isBoolType(IR::Expr *e)
-{
-    return (e->type == IR::BoolType);
-}
-
-} // anonymous namespace
-
-InstructionSelection::InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory)
-    : EvalInstructionSelection(execAllocator, module, jsGenerator, iselFactory)
-    , qmlEngine(qmlEngine)
-    , _block(0)
-    , _codeStart(0)
-    , _codeNext(0)
-    , _codeEnd(0)
-    , _currentStatement(0)
-    , compilationUnit(new CompilationUnit)
-{
-    setUseTypeInference(false);
-}
-
-InstructionSelection::~InstructionSelection()
-{
-}
-
-void InstructionSelection::run(int functionIndex)
-{
-    IR::Function *function = irModule->functions[functionIndex];
-    IR::BasicBlock *block = 0, *nextBlock = 0;
-
-    QHash<IR::BasicBlock *, QVector<ptrdiff_t> > patches;
-    QHash<IR::BasicBlock *, ptrdiff_t> addrs;
-
-    int codeSize = 4096;
-    uchar *codeStart = new uchar[codeSize];
-    memset(codeStart, 0, codeSize);
-    uchar *codeNext = codeStart;
-    uchar *codeEnd = codeStart + codeSize;
-
-    qSwap(_function, function);
-    qSwap(block, _block);
-    qSwap(nextBlock, _nextBlock);
-    qSwap(patches, _patches);
-    qSwap(addrs, _addrs);
-    qSwap(codeStart, _codeStart);
-    qSwap(codeNext, _codeNext);
-    qSwap(codeEnd, _codeEnd);
-
-    IR::Optimizer opt(_function);
-    opt.run(qmlEngine, useTypeInference, /*peelLoops =*/ false);
-    if (opt.isInSSA()) {
-        static const bool doStackSlotAllocation =
-                qEnvironmentVariableIsEmpty("QV4_NO_INTERPRETER_STACK_SLOT_ALLOCATION");
-
-        if (doStackSlotAllocation) {
-            IR::AllocateStackSlots(opt.lifeTimeIntervals()).forFunction(_function);
-        } else {
-            opt.convertOutOfSSA();
-            ConvertTemps().toStackSlots(_function);
-        }
-        opt.showMeTheCode(_function, "After stack slot allocation");
-    } else {
-        ConvertTemps().toStackSlots(_function);
-    }
-
-    BitVector removableJumps = opt.calculateOptionalJumps();
-    qSwap(_removableJumps, removableJumps);
-
-    IR::Stmt *cs = 0;
-    qSwap(_currentStatement, cs);
-
-    int locals = frameSize();
-    Q_ASSERT(locals >= 0);
-
-    IR::BasicBlock *exceptionHandler = 0;
-
-    Instruction::Push push;
-    push.value = quint32(locals);
-    addInstruction(push);
-
-    currentLine = 0;
-    const QVector<IR::BasicBlock *> &basicBlocks = _function->basicBlocks();
-    for (int i = 0, ei = basicBlocks.size(); i != ei; ++i) {
-        blockNeedsDebugInstruction = irModule->debugMode;
-        _block = basicBlocks[i];
-        _nextBlock = (i < ei - 1) ? basicBlocks[i + 1] : 0;
-        _addrs.insert(_block, _codeNext - _codeStart);
-
-        if (_block->catchBlock != exceptionHandler) {
-            Instruction::SetExceptionHandler set;
-            set.offset = 0;
-            if (_block->catchBlock) {
-                ptrdiff_t loc = addInstruction(set) + (((const char *)&set.offset) - ((const char *)&set));
-                _patches[_block->catchBlock].append(loc);
-            } else {
-                addInstruction(set);
-            }
-            exceptionHandler = _block->catchBlock;
-        } else if (_block->catchBlock == nullptr && _block->index() != 0 && _block->in.isEmpty()) {
-            exceptionHandler = nullptr;
-            Instruction::SetExceptionHandler set;
-            set.offset = 0;
-            addInstruction(set);
-        }
-
-        for (IR::Stmt *s : _block->statements()) {
-            _currentStatement = s;
-
-            if (s->location.isValid()) {
-                if (s->location.startLine != currentLine) {
-                    blockNeedsDebugInstruction = false;
-                    currentLine = s->location.startLine;
-#ifndef QT_NO_QML_DEBUGGER
-                    if (irModule->debugMode) {
-                        Instruction::Debug debug;
-                        debug.lineNumber = currentLine;
-                        addInstruction(debug);
-                    } else {
-                        Instruction::Line line;
-                        line.lineNumber = currentLine;
-                        addInstruction(line);
-                    }
-#endif
-                }
-            }
-
-            visit(s);
-        }
-    }
-
-    // TODO: patch stack size (the push instruction)
-    patchJumpAddresses();
-
-    codeRefs.insert(_function, squeezeCode());
-
-    qSwap(_currentStatement, cs);
-    qSwap(_removableJumps, removableJumps);
-    qSwap(_function, function);
-    qSwap(block, _block);
-    qSwap(nextBlock, _nextBlock);
-    qSwap(patches, _patches);
-    qSwap(addrs, _addrs);
-    qSwap(codeStart, _codeStart);
-    qSwap(codeNext, _codeNext);
-    qSwap(codeEnd, _codeEnd);
-
-    delete[] codeStart;
-}
-
-QQmlRefPointer<QV4::CompiledData::CompilationUnit> InstructionSelection::backendCompileStep()
-{
-    compilationUnit->codeRefs.resize(irModule->functions.size());
-    int i = 0;
-    for (IR::Function *irFunction : qAsConst(irModule->functions))
-        compilationUnit->codeRefs[i++] = codeRefs[irFunction];
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> result;
-    result.adopt(compilationUnit.take());
-    return result;
-}
-
-void InstructionSelection::callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
-{
-    Instruction::CallValue call;
-    prepareCallArgs(args, call.argc);
-    call.callData = callDataStart();
-    call.dest = getParam(value);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject) {
-        Instruction::CallScopeObjectProperty call;
-        call.base = getParam(base);
-        call.index = propertyIndex;
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(result);
-        addInstruction(call);
-    } else if (kind == IR::Member::MemberOfQmlContextObject) {
-        Instruction::CallContextObjectProperty call;
-        call.base = getParam(base);
-        call.index = propertyIndex;
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(result);
-        addInstruction(call);
-    } else {
-        Q_ASSERT(false);
-    }
-}
-
-void InstructionSelection::callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
-                                        IR::Expr *result)
-{
-    if (useFastLookups) {
-        Instruction::CallPropertyLookup call;
-        call.base = getParam(base);
-        call.lookupIndex = registerGetterLookup(name);
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(result);
-        addInstruction(call);
-    } else {
-        // call the property on the loaded base
-        Instruction::CallProperty call;
-        call.base = getParam(base);
-        call.name = registerString(name);
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(result);
-        addInstruction(call);
-    }
-}
-
-void InstructionSelection::callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
-                                         IR::Expr *result)
-{
-    // call the property on the loaded base
-    Instruction::CallElement call;
-    call.base = getParam(base);
-    call.index = getParam(index);
-    prepareCallArgs(args, call.argc);
-    call.callData = callDataStart();
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::convertType(IR::Expr *source, IR::Expr *target)
-{
-    // FIXME: do something more useful with this info
-    if (target->type & IR::NumberType && !(source->type & IR::NumberType))
-        unop(IR::OpUPlus, source, target);
-    else
-        copyValue(source, target);
-}
-
-void InstructionSelection::constructActivationProperty(IR::Name *func,
-                                                       IR::ExprList *args,
-                                                       IR::Expr *target)
-{
-    if (useFastLookups && func->global) {
-        Instruction::ConstructGlobalLookup call;
-        call.index = registerGlobalGetterLookup(*func->id);
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(target);
-        addInstruction(call);
-        return;
-    }
-    Instruction::CreateActivationProperty create;
-    create.name = registerString(*func->id);
-    prepareCallArgs(args, create.argc);
-    create.callData = callDataStart();
-    create.result = getResultParam(target);
-    addInstruction(create);
-}
-
-void InstructionSelection::constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *target)
-{
-    if (useFastLookups) {
-        Instruction::ConstructPropertyLookup call;
-        call.base = getParam(base);
-        call.index = registerGetterLookup(name);
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(target);
-        addInstruction(call);
-        return;
-    }
-    Instruction::CreateProperty create;
-    create.base = getParam(base);
-    create.name = registerString(name);
-    prepareCallArgs(args, create.argc);
-    create.callData = callDataStart();
-    create.result = getResultParam(target);
-    addInstruction(create);
-}
-
-void InstructionSelection::constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *target)
-{
-    Instruction::CreateValue create;
-    create.func = getParam(value);
-    prepareCallArgs(args, create.argc);
-    create.callData = callDataStart();
-    create.result = getResultParam(target);
-    addInstruction(create);
-}
-
-void InstructionSelection::loadThisObject(IR::Expr *e)
-{
-    Instruction::LoadThis load;
-    load.result = getResultParam(e);
-    addInstruction(load);
-}
-
-void InstructionSelection::loadQmlContext(IR::Expr *e)
-{
-    Instruction::LoadQmlContext load;
-    load.result = getResultParam(e);
-    addInstruction(load);
-}
-
-void InstructionSelection::loadQmlImportedScripts(IR::Expr *e)
-{
-    Instruction::LoadQmlImportedScripts load;
-    load.result = getResultParam(e);
-    addInstruction(load);
-}
-
-void InstructionSelection::loadQmlSingleton(const QString &name, IR::Expr *e)
-{
-    Instruction::LoadQmlSingleton load;
-    load.result = getResultParam(e);
-    load.name = registerString(name);
-    addInstruction(load);
-}
-
-void InstructionSelection::loadConst(IR::Const *sourceConst, IR::Expr *e)
-{
-    Q_ASSERT(sourceConst);
-
-    Instruction::MoveConst move;
-    move.source = convertToValue(sourceConst).asReturnedValue();
-    move.result = getResultParam(e);
-    addInstruction(move);
-}
-
-void InstructionSelection::loadString(const QString &str, IR::Expr *target)
-{
-    Instruction::LoadRuntimeString load;
-    load.stringId = registerString(str);
-    load.result = getResultParam(target);
-    addInstruction(load);
-}
-
-void InstructionSelection::loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target)
-{
-    Instruction::LoadRegExp load;
-    load.regExpId = registerRegExp(sourceRegexp);
-    load.result = getResultParam(target);
-    addInstruction(load);
-}
-
-void InstructionSelection::getActivationProperty(const IR::Name *name, IR::Expr *target)
-{
-    if (useFastLookups && name->global) {
-        Instruction::GetGlobalLookup load;
-        load.index = registerGlobalGetterLookup(*name->id);
-        load.result = getResultParam(target);
-        addInstruction(load);
-        return;
-    }
-    Instruction::LoadName load;
-    load.name = registerString(*name->id);
-    load.result = getResultParam(target);
-    addInstruction(load);
-}
-
-void InstructionSelection::setActivationProperty(IR::Expr *source, const QString &targetName)
-{
-    Instruction::StoreName store;
-    store.source = getParam(source);
-    store.name = registerString(targetName);
-    addInstruction(store);
-}
-
-void InstructionSelection::initClosure(IR::Closure *closure, IR::Expr *target)
-{
-    int id = closure->value;
-    Instruction::LoadClosure load;
-    load.value = id;
-    load.result = getResultParam(target);
-    addInstruction(load);
-}
-
-void InstructionSelection::getProperty(IR::Expr *base, const QString &name, IR::Expr *target)
-{
-    if (useFastLookups) {
-        Instruction::GetLookup load;
-        load.base = getParam(base);
-        load.index = registerGetterLookup(name);
-        load.result = getResultParam(target);
-        addInstruction(load);
-        return;
-    }
-    Instruction::LoadProperty load;
-    load.base = getParam(base);
-    load.name = registerString(name);
-    load.result = getResultParam(target);
-    addInstruction(load);
-}
-
-void InstructionSelection::setProperty(IR::Expr *source, IR::Expr *targetBase,
-                                       const QString &targetName)
-{
-    if (useFastLookups) {
-        Instruction::SetLookup store;
-        store.base = getParam(targetBase);
-        store.index = registerSetterLookup(targetName);
-        store.source = getParam(source);
-        addInstruction(store);
-        return;
-    }
-    Instruction::StoreProperty store;
-    store.base = getParam(targetBase);
-    store.name = registerString(targetName);
-    store.source = getParam(source);
-    addInstruction(store);
-}
-
-void InstructionSelection::setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject) {
-        Instruction::StoreScopeObjectProperty store;
-        store.base = getParam(targetBase);
-        store.propertyIndex = propertyIndex;
-        store.source = getParam(source);
-        addInstruction(store);
-    } else if (kind == IR::Member::MemberOfQmlContextObject) {
-        Instruction::StoreContextObjectProperty store;
-        store.base = getParam(targetBase);
-        store.propertyIndex = propertyIndex;
-        store.source = getParam(source);
-        addInstruction(store);
-    } else {
-        Q_ASSERT(false);
-    }
-}
-
-void InstructionSelection::setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex)
-{
-    Instruction::StoreQObjectProperty store;
-    store.base = getParam(targetBase);
-    store.propertyIndex = propertyIndex;
-    store.source = getParam(source);
-    addInstruction(store);
-}
-
-void InstructionSelection::getQmlContextProperty(IR::Expr *source, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject) {
-        Instruction::LoadScopeObjectProperty load;
-        load.base = getParam(source);
-        load.propertyIndex = index;
-        load.captureRequired = captureRequired;
-        load.result = getResultParam(target);
-        addInstruction(load);
-    } else if (kind == IR::Member::MemberOfQmlContextObject) {
-        Instruction::LoadContextObjectProperty load;
-        load.base = getParam(source);
-        load.propertyIndex = index;
-        load.captureRequired = captureRequired;
-        load.result = getResultParam(target);
-        addInstruction(load);
-    } else if (kind == IR::Member::MemberOfIdObjectsArray) {
-        Instruction::LoadIdObject load;
-        load.base = getParam(source);
-        load.index = index;
-        load.result = getResultParam(target);
-        addInstruction(load);
-    } else {
-        Q_ASSERT(false);
-    }
-}
-
-void InstructionSelection::getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingletonProperty, int attachedPropertiesId, IR::Expr *target)
-{
-    if (attachedPropertiesId != 0) {
-        Instruction::LoadAttachedQObjectProperty load;
-        load.propertyIndex = propertyIndex;
-        load.result = getResultParam(target);
-        load.attachedPropertiesId = attachedPropertiesId;
-        addInstruction(load);
-    } else if (isSingletonProperty) {
-        Instruction::LoadSingletonQObjectProperty load;
-        load.base = getParam(base);
-        load.propertyIndex = propertyIndex;
-        load.result = getResultParam(target);
-        load.captureRequired = captureRequired;
-        addInstruction(load);
-    } else {
-        Instruction::LoadQObjectProperty load;
-        load.base = getParam(base);
-        load.propertyIndex = propertyIndex;
-        load.result = getResultParam(target);
-        load.captureRequired = captureRequired;
-        addInstruction(load);
-    }
-}
-
-void InstructionSelection::getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target)
-{
-    if (0 && useFastLookups) {
-        Instruction::LoadElementLookup load;
-        load.lookup = registerIndexedGetterLookup();
-        load.base = getParam(base);
-        load.index = getParam(index);
-        load.result = getResultParam(target);
-        addInstruction(load);
-        return;
-    }
-    Instruction::LoadElement load;
-    load.base = getParam(base);
-    load.index = getParam(index);
-    load.result = getResultParam(target);
-    addInstruction(load);
-}
-
-void InstructionSelection::setElement(IR::Expr *source, IR::Expr *targetBase,
-                                      IR::Expr *targetIndex)
-{
-    if (0 && useFastLookups) {
-        Instruction::StoreElementLookup store;
-        store.lookup = registerIndexedSetterLookup();
-        store.base = getParam(targetBase);
-        store.index = getParam(targetIndex);
-        store.source = getParam(source);
-        addInstruction(store);
-        return;
-    }
-    Instruction::StoreElement store;
-    store.base = getParam(targetBase);
-    store.index = getParam(targetIndex);
-    store.source = getParam(source);
-    addInstruction(store);
-}
-
-void InstructionSelection::copyValue(IR::Expr *source, IR::Expr *target)
-{
-    Instruction::Move move;
-    move.source = getParam(source);
-    move.result = getResultParam(target);
-    if (move.source != move.result)
-        addInstruction(move);
-}
-
-void InstructionSelection::swapValues(IR::Expr *source, IR::Expr *target)
-{
-    Instruction::SwapTemps swap;
-    swap.left = getParam(source);
-    swap.right = getParam(target);
-    addInstruction(swap);
-}
-
-void InstructionSelection::unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target)
-{
-    switch (oper) {
-    case IR::OpIfTrue:
-        Q_ASSERT(!"unreachable"); break;
-    case IR::OpNot: {
-        // ### enabling this fails in some cases, where apparently the value is not a bool at runtime
-        if (0 && isBoolType(source)) {
-            Instruction::UNotBool unot;
-            unot.source = getParam(source);
-            unot.result = getResultParam(target);
-            addInstruction(unot);
-            return;
-        }
-        Instruction::UNot unot;
-        unot.source = getParam(source);
-        unot.result = getResultParam(target);
-        addInstruction(unot);
-        return;
-    }
-    case IR::OpUMinus: {
-        Instruction::UMinus uminus;
-        uminus.source = getParam(source);
-        uminus.result = getResultParam(target);
-        addInstruction(uminus);
-        return;
-    }
-    case IR::OpUPlus: {
-        if (isNumberType(source)) {
-            // use a move
-            Instruction::Move move;
-            move.source = getParam(source);
-            move.result = getResultParam(target);
-            if (move.source != move.result)
-                addInstruction(move);
-            return;
-        }
-        Instruction::UPlus uplus;
-        uplus.source = getParam(source);
-        uplus.result = getResultParam(target);
-        addInstruction(uplus);
-        return;
-    }
-    case IR::OpCompl: {
-        // ### enabling this fails in some cases, where apparently the value is not a int at runtime
-        if (0 && isIntegerType(source)) {
-            Instruction::UComplInt unot;
-            unot.source = getParam(source);
-            unot.result = getResultParam(target);
-            addInstruction(unot);
-            return;
-        }
-        Instruction::UCompl ucompl;
-        ucompl.source = getParam(source);
-        ucompl.result = getResultParam(target);
-        addInstruction(ucompl);
-        return;
-    }
-    case IR::OpIncrement: {
-        Instruction::Increment inc;
-        inc.source = getParam(source);
-        inc.result = getResultParam(target);
-        addInstruction(inc);
-        return;
-    }
-    case IR::OpDecrement: {
-        Instruction::Decrement dec;
-        dec.source = getParam(source);
-        dec.result = getResultParam(target);
-        addInstruction(dec);
-        return;
-    }
-    default:  break;
-    } // switch
-
-    Q_ASSERT(!"unreachable");
-}
-
-void InstructionSelection::binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
-{
-    binopHelper(oper, leftSource, rightSource, target);
-}
-
-Param InstructionSelection::binopHelper(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
-{
-    if (oper == IR::OpAdd) {
-        Instruction::Add add;
-        add.lhs = getParam(leftSource);
-        add.rhs = getParam(rightSource);
-        add.result = getResultParam(target);
-        addInstruction(add);
-        return add.result;
-    }
-    if (oper == IR::OpSub) {
-        Instruction::Sub sub;
-        sub.lhs = getParam(leftSource);
-        sub.rhs = getParam(rightSource);
-        sub.result = getResultParam(target);
-        addInstruction(sub);
-        return sub.result;
-    }
-    if (oper == IR::OpMul) {
-        Instruction::Mul mul;
-        mul.lhs = getParam(leftSource);
-        mul.rhs = getParam(rightSource);
-        mul.result = getResultParam(target);
-        addInstruction(mul);
-        return mul.result;
-    }
-    if (oper == IR::OpBitAnd) {
-        if (leftSource->asConst())
-            qSwap(leftSource, rightSource);
-        if (IR::Const *c = rightSource->asConst()) {
-            Instruction::BitAndConst bitAnd;
-            bitAnd.lhs = getParam(leftSource);
-            bitAnd.rhs = convertToValue(c).Value::toInt32();
-            bitAnd.result = getResultParam(target);
-            addInstruction(bitAnd);
-            return bitAnd.result;
-        }
-        Instruction::BitAnd bitAnd;
-        bitAnd.lhs = getParam(leftSource);
-        bitAnd.rhs = getParam(rightSource);
-        bitAnd.result = getResultParam(target);
-        addInstruction(bitAnd);
-        return bitAnd.result;
-    }
-    if (oper == IR::OpBitOr) {
-        if (leftSource->asConst())
-            qSwap(leftSource, rightSource);
-        if (IR::Const *c = rightSource->asConst()) {
-            Instruction::BitOrConst bitOr;
-            bitOr.lhs = getParam(leftSource);
-            bitOr.rhs = convertToValue(c).Value::toInt32();
-            bitOr.result = getResultParam(target);
-            addInstruction(bitOr);
-            return bitOr.result;
-        }
-        Instruction::BitOr bitOr;
-        bitOr.lhs = getParam(leftSource);
-        bitOr.rhs = getParam(rightSource);
-        bitOr.result = getResultParam(target);
-        addInstruction(bitOr);
-        return bitOr.result;
-    }
-    if (oper == IR::OpBitXor) {
-        if (leftSource->asConst())
-            qSwap(leftSource, rightSource);
-        if (IR::Const *c = rightSource->asConst()) {
-            Instruction::BitXorConst bitXor;
-            bitXor.lhs = getParam(leftSource);
-            bitXor.rhs = convertToValue(c).Value::toInt32();
-            bitXor.result = getResultParam(target);
-            addInstruction(bitXor);
-            return bitXor.result;
-        }
-        Instruction::BitXor bitXor;
-        bitXor.lhs = getParam(leftSource);
-        bitXor.rhs = getParam(rightSource);
-        bitXor.result = getResultParam(target);
-        addInstruction(bitXor);
-        return bitXor.result;
-    }
-    if (oper == IR::OpRShift) {
-        if (IR::Const *c = rightSource->asConst()) {
-            Instruction::ShrConst shr;
-            shr.lhs = getParam(leftSource);
-            shr.rhs = convertToValue(c).Value::toInt32() & 0x1f;
-            shr.result = getResultParam(target);
-            addInstruction(shr);
-            return shr.result;
-        }
-        Instruction::Shr shr;
-        shr.lhs = getParam(leftSource);
-        shr.rhs = getParam(rightSource);
-        shr.result = getResultParam(target);
-        addInstruction(shr);
-        return shr.result;
-    }
-    if (oper == IR::OpLShift) {
-        if (IR::Const *c = rightSource->asConst()) {
-            Instruction::ShlConst shl;
-            shl.lhs = getParam(leftSource);
-            shl.rhs = convertToValue(c).Value::toInt32() & 0x1f;
-            shl.result = getResultParam(target);
-            addInstruction(shl);
-            return shl.result;
-        }
-        Instruction::Shl shl;
-        shl.lhs = getParam(leftSource);
-        shl.rhs = getParam(rightSource);
-        shl.result = getResultParam(target);
-        addInstruction(shl);
-        return shl.result;
-    }
-
-    if (oper == IR::OpInstanceof || oper == IR::OpIn || oper == IR::OpAdd) {
-        Instruction::BinopContext binop;
-        if (oper == IR::OpInstanceof)
-            binop.alu = QV4::Runtime::instanceof;
-        else if (oper == IR::OpIn)
-            binop.alu = QV4::Runtime::in;
-        else
-            binop.alu = QV4::Runtime::add;
-        binop.lhs = getParam(leftSource);
-        binop.rhs = getParam(rightSource);
-        binop.result = getResultParam(target);
-        Q_ASSERT(binop.alu != QV4::Runtime::InvalidRuntimeMethod);
-        addInstruction(binop);
-        return binop.result;
-    } else {
-        auto binopFunc = aluOpFunction(oper);
-        Q_ASSERT(binopFunc != QV4::Runtime::InvalidRuntimeMethod);
-        Instruction::Binop binop;
-        binop.alu = binopFunc;
-        binop.lhs = getParam(leftSource);
-        binop.rhs = getParam(rightSource);
-        binop.result = getResultParam(target);
-        addInstruction(binop);
-        return binop.result;
-    }
-}
-
-void InstructionSelection::prepareCallArgs(IR::ExprList *e, quint32 &argc, quint32 *args)
-{
-    int argLocation = outgoingArgumentTempStart();
-    argc = 0;
-    if (args)
-        *args = argLocation;
-    if (e) {
-        // We need to move all the temps into the function arg array
-        Q_ASSERT(argLocation >= 0);
-        while (e) {
-            if (IR::Const *c = e->expr->asConst()) {
-                Instruction::MoveConst move;
-                move.source = convertToValue(c).asReturnedValue();
-                move.result = Param::createTemp(argLocation);
-                addInstruction(move);
-            } else {
-                Instruction::Move move;
-                move.source = getParam(e->expr);
-                move.result = Param::createTemp(argLocation);
-                addInstruction(move);
-            }
-            ++argLocation;
-            ++argc;
-            e = e->next;
-        }
-    }
-}
-
-void InstructionSelection::addDebugInstruction()
-{
-#ifndef QT_NO_QML_DEBUGGER
-    if (blockNeedsDebugInstruction) {
-        Instruction::Debug debug;
-        debug.lineNumber = -int(currentLine);
-        addInstruction(debug);
-    }
-#endif
-}
-
-void InstructionSelection::visitJump(IR::Jump *s)
-{
-    if (s->target == _nextBlock)
-        return;
-    if (_removableJumps.at(_block->index()))
-        return;
-
-    addDebugInstruction();
-
-    Instruction::Jump jump;
-    jump.offset = 0;
-    ptrdiff_t loc = addInstruction(jump) + (((const char *)&jump.offset) - ((const char *)&jump));
-
-    _patches[s->target].append(loc);
-}
-
-void InstructionSelection::visitCJump(IR::CJump *s)
-{
-    addDebugInstruction();
-
-    Param condition;
-    if (IR::Temp *t = s->cond->asTemp()) {
-        condition = getResultParam(t);
-    } else if (IR::Binop *b = s->cond->asBinop()) {
-        condition = binopHelper(b->op, b->left, b->right, /*target*/0);
-    } else {
-        Q_UNIMPLEMENTED();
-    }
-
-    if (s->iftrue == _nextBlock) {
-        Instruction::JumpNe jump;
-        jump.offset = 0;
-        jump.condition = condition;
-        ptrdiff_t falseLoc = addInstruction(jump) + (((const char *)&jump.offset) - ((const char *)&jump));
-        _patches[s->iffalse].append(falseLoc);
-    } else {
-        Instruction::JumpEq jump;
-        jump.offset = 0;
-        jump.condition = condition;
-        ptrdiff_t trueLoc = addInstruction(jump) + (((const char *)&jump.offset) - ((const char *)&jump));
-        _patches[s->iftrue].append(trueLoc);
-
-        if (s->iffalse != _nextBlock) {
-            Instruction::Jump jump;
-            jump.offset = 0;
-            ptrdiff_t falseLoc = addInstruction(jump) + (((const char *)&jump.offset) - ((const char *)&jump));
-            _patches[s->iffalse].append(falseLoc);
-        }
-    }
-}
-
-void InstructionSelection::visitRet(IR::Ret *s)
-{
-    // this is required so stepOut will always be guaranteed to stop in every stack frame
-    addDebugInstruction();
-
-    Instruction::Ret ret;
-    ret.result = getParam(s->expr);
-    addInstruction(ret);
-}
-
-void InstructionSelection::callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result)
-{
-    if (useFastLookups && func->global) {
-        Instruction::CallGlobalLookup call;
-        call.index = registerGlobalGetterLookup(*func->id);
-        prepareCallArgs(args, call.argc);
-        call.callData = callDataStart();
-        call.result = getResultParam(result);
-        addInstruction(call);
-        return;
-    }
-    Instruction::CallActivationProperty call;
-    call.name = registerString(*func->id);
-    prepareCallArgs(args, call.argc);
-    call.callData = callDataStart();
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinTypeofQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::Expr *result)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject) {
-        Instruction::CallBuiltinTypeofScopeObjectProperty call;
-        call.base = getParam(base);
-        call.index = propertyIndex;
-        call.result = getResultParam(result);
-        addInstruction(call);
-    } else if (kind == IR::Member::MemberOfQmlContextObject) {
-        Instruction::CallBuiltinTypeofContextObjectProperty call;
-        call.base = getParam(base);
-        call.index = propertyIndex;
-        call.result = getResultParam(result);
-        addInstruction(call);
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-void InstructionSelection::callBuiltinTypeofMember(IR::Expr *base, const QString &name,
-                                                   IR::Expr *result)
-{
-    Instruction::CallBuiltinTypeofMember call;
-    call.base = getParam(base);
-    call.member = registerString(name);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index,
-                                                      IR::Expr *result)
-{
-    Instruction::CallBuiltinTypeofSubscript call;
-    call.base = getParam(base);
-    call.index = getParam(index);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinTypeofName(const QString &name, IR::Expr *result)
-{
-    Instruction::CallBuiltinTypeofName call;
-    call.name = registerString(name);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result)
-{
-    Instruction::CallBuiltinTypeofValue call;
-    call.value = getParam(value);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result)
-{
-    Instruction::CallBuiltinDeleteMember call;
-    call.base = getParam(base);
-    call.member = registerString(name);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index,
-                                                      IR::Expr *result)
-{
-    Instruction::CallBuiltinDeleteSubscript call;
-    call.base = getParam(base);
-    call.index = getParam(index);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinDeleteName(const QString &name, IR::Expr *result)
-{
-    Instruction::CallBuiltinDeleteName call;
-    call.name = registerString(name);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinDeleteValue(IR::Expr *result)
-{
-    Instruction::MoveConst move;
-    move.source = QV4::Encode(false);
-    move.result = getResultParam(result);
-    addInstruction(move);
-}
-
-void InstructionSelection::callBuiltinThrow(IR::Expr *arg)
-{
-    Instruction::CallBuiltinThrow call;
-    call.arg = getParam(arg);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinReThrow()
-{
-    if (_block->catchBlock) {
-        // jump to exception handler
-        Instruction::Jump jump;
-        jump.offset = 0;
-        ptrdiff_t loc = addInstruction(jump) + (((const char *)&jump.offset) - ((const char *)&jump));
-
-        _patches[_block->catchBlock].append(loc);
-    } else {
-        Instruction::Ret ret;
-        int idx = jsUnitGenerator()->registerConstant(QV4::Encode::undefined());
-        ret.result = Param::createConstant(idx);
-        addInstruction(ret);
-    }
-}
-
-void InstructionSelection::callBuiltinUnwindException(IR::Expr *result)
-{
-    Instruction::CallBuiltinUnwindException call;
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-
-void InstructionSelection::callBuiltinPushCatchScope(const QString &exceptionName)
-{
-    Instruction::CallBuiltinPushCatchScope call;
-    call.name = registerString(exceptionName);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result)
-{
-    Instruction::CallBuiltinForeachIteratorObject call;
-    call.arg = getParam(arg);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result)
-{
-    Instruction::CallBuiltinForeachNextPropertyName call;
-    call.arg = getParam(arg);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinPushWithScope(IR::Expr *arg)
-{
-    Instruction::CallBuiltinPushScope call;
-    call.arg = getParam(arg);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinPopScope()
-{
-    QT_WARNING_PUSH
-    QT_WARNING_DISABLE_GCC("-Wuninitialized")
-    Instruction::CallBuiltinPopScope call;
-    addInstruction(call);
-    QT_WARNING_POP
-}
-
-void InstructionSelection::callBuiltinDeclareVar(bool deletable, const QString &name)
-{
-    Instruction::CallBuiltinDeclareVar call;
-    call.isDeletable = deletable;
-    call.varName = registerString(name);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args)
-{
-    Instruction::CallBuiltinDefineArray call;
-    prepareCallArgs(args, call.argc, &call.args);
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray)
-{
-    int argLocation = outgoingArgumentTempStart();
-
-    const int classId = registerJSClass(keyValuePairCount, keyValuePairs);
-
-    // Process key/value pairs first
-    IR::ExprList *it = keyValuePairs;
-    for (int i = 0; i < keyValuePairCount; ++i, it = it->next) {
-        // Skip name
-        it = it->next;
-
-        bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        if (IR::Const *c = it->expr->asConst()) {
-            Instruction::MoveConst move;
-            move.source = convertToValue(c).asReturnedValue();
-            move.result = Param::createTemp(argLocation);
-            addInstruction(move);
-        } else {
-            Instruction::Move move;
-            move.source = getParam(it->expr);
-            move.result = Param::createTemp(argLocation);
-            addInstruction(move);
-        }
-        ++argLocation;
-
-        if (!isData) {
-            it = it->next;
-
-            Instruction::Move move;
-            move.source = getParam(it->expr);
-            move.result = Param::createTemp(argLocation);
-            addInstruction(move);
-            ++argLocation;
-        }
-    }
-
-    // Process array values
-    uint arrayValueCount = 0;
-    it = arrayEntries;
-    while (it) {
-        IR::Const *index = it->expr->asConst();
-        it = it->next;
-
-        bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        if (!isData) {
-            it = it->next; // getter
-            it = it->next; // setter
-            continue;
-        }
-
-        ++arrayValueCount;
-
-        Instruction::MoveConst indexMove;
-        indexMove.source = convertToValue(index).asReturnedValue();
-        indexMove.result = Param::createTemp(argLocation);
-        addInstruction(indexMove);
-        ++argLocation;
-
-        Instruction::Move move;
-        move.source = getParam(it->expr);
-        move.result = Param::createTemp(argLocation);
-        addInstruction(move);
-        ++argLocation;
-        it = it->next;
-    }
-
-    // Process array getter/setter pairs
-    uint arrayGetterSetterCount = 0;
-    it = arrayEntries;
-    while (it) {
-        IR::Const *index = it->expr->asConst();
-        it = it->next;
-
-        bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        if (isData) {
-            it = it->next; // value
-            continue;
-        }
-
-        ++arrayGetterSetterCount;
-
-        Instruction::MoveConst indexMove;
-        indexMove.source = convertToValue(index).asReturnedValue();
-        indexMove.result = Param::createTemp(argLocation);
-        addInstruction(indexMove);
-        ++argLocation;
-
-        // getter
-        Instruction::Move moveGetter;
-        moveGetter.source = getParam(it->expr);
-        moveGetter.result = Param::createTemp(argLocation);
-        addInstruction(moveGetter);
-        ++argLocation;
-        it = it->next;
-
-        // setter
-        Instruction::Move moveSetter;
-        moveSetter.source = getParam(it->expr);
-        moveSetter.result = Param::createTemp(argLocation);
-        addInstruction(moveSetter);
-        ++argLocation;
-        it = it->next;
-    }
-
-    Instruction::CallBuiltinDefineObjectLiteral call;
-    call.internalClassId = classId;
-    call.arrayValueCount = arrayValueCount;
-    call.arrayGetterSetterCountAndFlags = arrayGetterSetterCount | (needSparseArray << 30);
-    call.args = outgoingArgumentTempStart();
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-void InstructionSelection::callBuiltinSetupArgumentObject(IR::Expr *result)
-{
-    Instruction::CallBuiltinSetupArgumentsObject call;
-    call.result = getResultParam(result);
-    addInstruction(call);
-}
-
-
-void QV4::Moth::InstructionSelection::callBuiltinConvertThisToObject()
-{
-    QT_WARNING_PUSH
-    QT_WARNING_DISABLE_GCC("-Wuninitialized")
-    Instruction::CallBuiltinConvertThisToObject call;
-    addInstruction(call);
-    QT_WARNING_POP
-}
-
-ptrdiff_t InstructionSelection::addInstructionHelper(Instr::Type type, Instr &instr)
-{
-    instr.common.instructionType = type;
-
-    int instructionSize = Instr::size(type);
-    if (_codeEnd - _codeNext < instructionSize) {
-        int currSize = _codeEnd - _codeStart;
-        uchar *newCode = new uchar[currSize * 2];
-        ::memset(newCode + currSize, 0, currSize);
-        ::memcpy(newCode, _codeStart, currSize);
-        _codeNext = _codeNext - _codeStart + newCode;
-        delete[] _codeStart;
-        _codeStart = newCode;
-        _codeEnd = _codeStart + currSize * 2;
-    }
-
-    ::memcpy(_codeNext, reinterpret_cast<const char *>(&instr), instructionSize);
-    ptrdiff_t ptrOffset = _codeNext - _codeStart;
-    _codeNext += instructionSize;
-
-    return ptrOffset;
-}
-
-void InstructionSelection::patchJumpAddresses()
-{
-    typedef QHash<IR::BasicBlock *, QVector<ptrdiff_t> >::ConstIterator PatchIt;
-    for (PatchIt i = _patches.cbegin(), ei = _patches.cend(); i != ei; ++i) {
-        Q_ASSERT(_addrs.contains(i.key()));
-        ptrdiff_t target = _addrs.value(i.key());
-
-        const QVector<ptrdiff_t> &patchList = i.value();
-        for (int ii = 0, eii = patchList.count(); ii < eii; ++ii) {
-            ptrdiff_t patch = patchList.at(ii);
-
-            *((ptrdiff_t *)(_codeStart + patch)) = target - patch;
-        }
-    }
-
-    _patches.clear();
-    _addrs.clear();
-}
-
-QByteArray InstructionSelection::squeezeCode() const
-{
-    int codeSize = _codeNext - _codeStart;
-    QByteArray squeezed;
-    squeezed.resize(codeSize);
-    ::memcpy(squeezed.data(), _codeStart, codeSize);
-    return squeezed;
-}
-
-Param InstructionSelection::getParam(IR::Expr *e) {
-    Q_ASSERT(e);
-
-    if (IR::Const *c = e->asConst()) {
-        int idx = jsUnitGenerator()->registerConstant(convertToValue(c).asReturnedValue());
-        return Param::createConstant(idx);
-    } else if (IR::Temp *t = e->asTemp()) {
-        switch (t->kind) {
-        case IR::Temp::StackSlot:
-            return Param::createTemp(t->index);
-        default:
-            Q_UNREACHABLE();
-            return Param();
-        }
-    } else if (IR::ArgLocal *al = e->asArgLocal()) {
-        switch (al->kind) {
-        case IR::ArgLocal::Formal:
-        case IR::ArgLocal::ScopedFormal: return Param::createArgument(al->index, al->scope);
-        case IR::ArgLocal::Local: return Param::createLocal(al->index);
-        case IR::ArgLocal::ScopedLocal: return Param::createScopedLocal(al->index, al->scope);
-        default:
-            Q_UNREACHABLE();
-            return Param();
-        }
-    } else {
-        Q_UNIMPLEMENTED();
-        return Param();
-    }
-}
-
-
-CompilationUnit::~CompilationUnit()
-{
-}
-
-#if !defined(V4_BOOTSTRAP)
-
-void CompilationUnit::linkBackendToEngine(QV4::ExecutionEngine *engine)
-{
-    runtimeFunctions.resize(data->functionTableSize);
-    runtimeFunctions.fill(0);
-    for (int i = 0 ;i < runtimeFunctions.size(); ++i) {
-        const QV4::CompiledData::Function *compiledFunction = data->functionAt(i);
-
-        QV4::Function *runtimeFunction = new QV4::Function(engine, this, compiledFunction, &VME::exec);
-        runtimeFunction->codeData = reinterpret_cast<const uchar *>(codeRefs.at(i).constData());
-        runtimeFunctions[i] = runtimeFunction;
-    }
-}
-
-bool CompilationUnit::memoryMapCode(QString *errorString)
-{
-    Q_UNUSED(errorString);
-    codeRefs.resize(data->functionTableSize);
-
-    const char *basePtr = reinterpret_cast<const char *>(data);
-
-    for (uint i = 0; i < data->functionTableSize; ++i) {
-        const CompiledData::Function *compiledFunction = data->functionAt(i);
-        const char *codePtr = const_cast<const char *>(reinterpret_cast<const char *>(basePtr + compiledFunction->codeOffset));
-#ifdef MOTH_THREADED_INTERPRETER
-        // for the threaded interpreter we need to make a copy of the data because it needs to be
-        // modified for the instruction handler addresses.
-        QByteArray code(codePtr, compiledFunction->codeSize);
-#else
-        QByteArray code = QByteArray::fromRawData(codePtr, compiledFunction->codeSize);
-#endif
-        codeRefs[i] = code;
-    }
-
-    return true;
-}
-
-#endif // V4_BOOTSTRAP
-
-void CompilationUnit::prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit)
-{
-    const int codeAlignment = 16;
-    quint64 offset = WTF::roundUpToMultipleOf(codeAlignment, unit->unitSize);
-    Q_ASSERT(int(unit->functionTableSize) == codeRefs.size());
-    for (int i = 0; i < codeRefs.size(); ++i) {
-        CompiledData::Function *compiledFunction = const_cast<CompiledData::Function *>(unit->functionAt(i));
-        compiledFunction->codeOffset = offset;
-        compiledFunction->codeSize = codeRefs.at(i).size();
-        offset = WTF::roundUpToMultipleOf(codeAlignment, offset + compiledFunction->codeSize);
-    }
-}
-
-bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString)
-{
-    Q_ASSERT(device->pos() == unit->unitSize);
-    Q_ASSERT(device->atEnd());
-    Q_ASSERT(int(unit->functionTableSize) == codeRefs.size());
-
-    QByteArray padding;
-
-    for (int i = 0; i < codeRefs.size(); ++i) {
-        const CompiledData::Function *compiledFunction = unit->functionAt(i);
-
-        if (device->pos() > qint64(compiledFunction->codeOffset)) {
-            *errorString = QStringLiteral("Invalid state of cache file to write.");
-            return false;
-        }
-
-        const quint64 paddingSize = compiledFunction->codeOffset - device->pos();
-        padding.fill(0, paddingSize);
-        qint64 written = device->write(padding);
-        if (written != padding.size()) {
-            *errorString = device->errorString();
-            return false;
-        }
-
-        QByteArray code = codeRefs.at(i);
-
-        written = device->write(code.constData(), compiledFunction->codeSize);
-        if (written != qint64(compiledFunction->codeSize)) {
-            *errorString = device->errorString();
-            return false;
-        }
-    }
-    return true;
-}
-
-QQmlRefPointer<CompiledData::CompilationUnit> ISelFactory::createUnitForLoading()
-{
-    QQmlRefPointer<CompiledData::CompilationUnit> result;
-    result.adopt(new Moth::CompilationUnit);
-    return result;
-}
diff --git a/src/qml/compiler/qv4isel_moth_p.h b/src/qml/compiler/qv4isel_moth_p.h
deleted file mode 100644
index 4b84bd2831..0000000000
--- a/src/qml/compiler/qv4isel_moth_p.h
+++ /dev/null
@@ -1,240 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QV4ISEL_MOTH_P_H
-#define QV4ISEL_MOTH_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <private/qv4global_p.h>
-#include <private/qv4isel_p.h>
-#include <private/qv4isel_util_p.h>
-#include <private/qv4util_p.h>
-#include <private/qv4jsir_p.h>
-#include <private/qv4value_p.h>
-#include "qv4instr_moth_p.h"
-
-#if !defined(V4_BOOTSTRAP)
-QT_REQUIRE_CONFIG(qml_interpreter);
-#endif
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace Moth {
-
-struct CompilationUnit : public QV4::CompiledData::CompilationUnit
-{
-    virtual ~CompilationUnit();
-#if !defined(V4_BOOTSTRAP)
-    void linkBackendToEngine(QV4::ExecutionEngine *engine) Q_DECL_OVERRIDE;
-    bool memoryMapCode(QString *errorString) Q_DECL_OVERRIDE;
-#endif
-    void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit) Q_DECL_OVERRIDE;
-    bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString) Q_DECL_OVERRIDE;
-
-    QVector<QByteArray> codeRefs;
-
-};
-
-class Q_QML_EXPORT InstructionSelection:
-        public IR::IRDecoder,
-        public EvalInstructionSelection
-{
-public:
-    InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory);
-    ~InstructionSelection();
-
-    void run(int functionIndex) override;
-
-protected:
-    QQmlRefPointer<CompiledData::CompilationUnit> backendCompileStep() override;
-
-    void visitJump(IR::Jump *) override;
-    void visitCJump(IR::CJump *) override;
-    void visitRet(IR::Ret *) override;
-
-    void callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result) override;
-    void callBuiltinTypeofQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::Expr *result) override;
-    void callBuiltinTypeofMember(IR::Expr *base, const QString &name, IR::Expr *result) override;
-    void callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result) override;
-    void callBuiltinTypeofName(const QString &name, IR::Expr *result) override;
-    void callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result) override;
-    void callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result) override;
-    void callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result) override;
-    void callBuiltinDeleteName(const QString &name, IR::Expr *result) override;
-    void callBuiltinDeleteValue(IR::Expr *result) override;
-    void callBuiltinThrow(IR::Expr *arg) override;
-    void callBuiltinReThrow() override;
-    void callBuiltinUnwindException(IR::Expr *) override;
-    void callBuiltinPushCatchScope(const QString &exceptionName) override;
-    void callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result) override;
-    void callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result) override;
-    void callBuiltinPushWithScope(IR::Expr *arg) override;
-    void callBuiltinPopScope() override;
-    void callBuiltinDeclareVar(bool deletable, const QString &name) override;
-    void callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args) override;
-    void callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray) override;
-    void callBuiltinSetupArgumentObject(IR::Expr *result) override;
-    void callBuiltinConvertThisToObject() override;
-    void callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) override;
-    void callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result) override;
-    void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result) override;
-    void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args, IR::Expr *result) override;
-    void convertType(IR::Expr *source, IR::Expr *target) override;
-    void constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result) override;
-    void constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result) override;
-    void constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) override;
-    void loadThisObject(IR::Expr *e) override;
-    void loadQmlContext(IR::Expr *e) override;
-    void loadQmlImportedScripts(IR::Expr *e) override;
-    void loadQmlSingleton(const QString &name, IR::Expr *e) override;
-    void loadConst(IR::Const *sourceConst, IR::Expr *e) override;
-    void loadString(const QString &str, IR::Expr *target) override;
-    void loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target) override;
-    void getActivationProperty(const IR::Name *name, IR::Expr *target) override;
-    void setActivationProperty(IR::Expr *source, const QString &targetName) override;
-    void initClosure(IR::Closure *closure, IR::Expr *target) override;
-    void getProperty(IR::Expr *base, const QString &name, IR::Expr *target) override;
-    void setProperty(IR::Expr *source, IR::Expr *targetBase, const QString &targetName) override;
-    void setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex) override;
-    void setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex) override;
-    void getQmlContextProperty(IR::Expr *source, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target) override;
-    void getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingleton, int attachedPropertiesId, IR::Expr *target) override;
-    void getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target) override;
-    void setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex) override;
-    void copyValue(IR::Expr *source, IR::Expr *target) override;
-    void swapValues(IR::Expr *source, IR::Expr *target) override;
-    void unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target) override;
-    void binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target) override;
-
-private:
-    Param binopHelper(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target);
-
-    struct Instruction {
-#define MOTH_INSTR_DATA_TYPEDEF(I, FMT) typedef InstrData<Instr::I> I;
-    FOR_EACH_MOTH_INSTR(MOTH_INSTR_DATA_TYPEDEF)
-#undef MOTH_INSTR_DATA_TYPEDEF
-    private:
-        Instruction();
-    };
-
-    Param getParam(IR::Expr *e);
-
-    Param getResultParam(IR::Expr *result)
-    {
-        if (result)
-            return getParam(result);
-        else
-            return Param::createTemp(scratchTempIndex());
-    }
-
-    void simpleMove(IR::Move *);
-    void prepareCallArgs(IR::ExprList *, quint32 &, quint32 * = 0);
-
-    int scratchTempIndex() const { return _function->tempCount; }
-    int callDataStart() const { return scratchTempIndex() + 1; }
-    int outgoingArgumentTempStart() const { return callDataStart() + offsetof(QV4::CallData, args)/sizeof(QV4::Value); }
-    int frameSize() const { return outgoingArgumentTempStart() + _function->maxNumberOfArguments; }
-
-    template <int Instr>
-    inline ptrdiff_t addInstruction(const InstrData<Instr> &data);
-    inline void addDebugInstruction();
-
-    ptrdiff_t addInstructionHelper(Instr::Type type, Instr &instr);
-    void patchJumpAddresses();
-    QByteArray squeezeCode() const;
-
-    QQmlEnginePrivate *qmlEngine;
-
-    bool blockNeedsDebugInstruction;
-    uint currentLine;
-    IR::BasicBlock *_block;
-    IR::BasicBlock *_nextBlock;
-
-    QHash<IR::BasicBlock *, QVector<ptrdiff_t> > _patches;
-    QHash<IR::BasicBlock *, ptrdiff_t> _addrs;
-
-    uchar *_codeStart;
-    uchar *_codeNext;
-    uchar *_codeEnd;
-
-    BitVector _removableJumps;
-    IR::Stmt *_currentStatement;
-
-    QScopedPointer<CompilationUnit> compilationUnit;
-    QHash<IR::Function *, QByteArray> codeRefs;
-};
-
-class Q_QML_EXPORT ISelFactory: public EvalISelFactory
-{
-public:
-    ISelFactory() : EvalISelFactory(QStringLiteral("moth")) {}
-    virtual ~ISelFactory() {}
-    EvalInstructionSelection *create(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator) Q_DECL_OVERRIDE Q_DECL_FINAL
-    { return new InstructionSelection(qmlEngine, execAllocator, module, jsGenerator, this); }
-    bool jitCompileRegexps() const Q_DECL_OVERRIDE Q_DECL_FINAL
-    { return false; }
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> createUnitForLoading() Q_DECL_OVERRIDE;
-
-};
-
-template<int InstrT>
-ptrdiff_t InstructionSelection::addInstruction(const InstrData<InstrT> &data)
-{
-    Instr genericInstr;
-    InstrMeta<InstrT>::setDataNoCommon(genericInstr, data);
-    return addInstructionHelper(static_cast<Instr::Type>(InstrT), genericInstr);
-}
-
-} // namespace Moth
-} // namespace QV4
-
-QT_END_NAMESPACE
-
-#endif // QV4ISEL_MOTH_P_H
diff --git a/src/qml/compiler/qv4isel_p.cpp b/src/qml/compiler/qv4isel_p.cpp
deleted file mode 100644
index efcfb9bd77..0000000000
--- a/src/qml/compiler/qv4isel_p.cpp
+++ /dev/null
@@ -1,446 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include <QtCore/QDebug>
-#include <QtCore/QBuffer>
-#include "qv4jsir_p.h"
-#include "qv4isel_p.h"
-#include "qv4isel_util_p.h"
-#include <private/qv4value_p.h>
-#ifndef V4_BOOTSTRAP
-#include <private/qqmlpropertycache_p.h>
-#endif
-
-#include <QString>
-
-using namespace QV4;
-using namespace QV4::IR;
-
-EvalInstructionSelection::EvalInstructionSelection(QV4::ExecutableAllocator *execAllocator, Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory)
-    : useFastLookups(true)
-    , useTypeInference(true)
-    , executableAllocator(execAllocator)
-    , irModule(module)
-{
-    if (!jsGenerator) {
-        jsGenerator = new QV4::Compiler::JSUnitGenerator(module);
-        ownJSGenerator.reset(jsGenerator);
-    }
-    this->jsGenerator = jsGenerator;
-#ifndef V4_BOOTSTRAP
-    Q_ASSERT(execAllocator);
-#endif
-    Q_ASSERT(module);
-    jsGenerator->codeGeneratorName = iselFactory->codeGeneratorName;
-}
-
-EvalInstructionSelection::~EvalInstructionSelection()
-{}
-
-EvalISelFactory::~EvalISelFactory()
-{}
-
-QQmlRefPointer<CompiledData::CompilationUnit> EvalInstructionSelection::compile(bool generateUnitData)
-{
-    for (int i = 0; i < irModule->functions.size(); ++i)
-        run(i);
-
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = backendCompileStep();
-    if (generateUnitData)
-        unit->data = jsGenerator->generateUnit();
-    return unit;
-}
-
-void IRDecoder::visitMove(IR::Move *s)
-{
-    if (IR::Name *n = s->target->asName()) {
-        if (s->source->asTemp() || s->source->asConst() || s->source->asArgLocal()) {
-            setActivationProperty(s->source, *n->id);
-            return;
-        }
-    } else if (s->target->asTemp() || s->target->asArgLocal()) {
-        if (IR::Name *n = s->source->asName()) {
-            if (n->id && *n->id == QLatin1String("this")) // TODO: `this' should be a builtin.
-                loadThisObject(s->target);
-            else if (n->builtin == IR::Name::builtin_qml_context)
-                loadQmlContext(s->target);
-            else if (n->builtin == IR::Name::builtin_qml_imported_scripts_object)
-                loadQmlImportedScripts(s->target);
-            else if (n->qmlSingleton)
-                loadQmlSingleton(*n->id, s->target);
-            else
-                getActivationProperty(n, s->target);
-            return;
-        } else if (IR::Const *c = s->source->asConst()) {
-            loadConst(c, s->target);
-            return;
-        } else if (s->source->asTemp() || s->source->asArgLocal()) {
-            if (s->swap)
-                swapValues(s->source, s->target);
-            else
-                copyValue(s->source, s->target);
-            return;
-        } else if (IR::String *str = s->source->asString()) {
-            loadString(*str->value, s->target);
-            return;
-        } else if (IR::RegExp *re = s->source->asRegExp()) {
-            loadRegexp(re, s->target);
-            return;
-        } else if (IR::Closure *clos = s->source->asClosure()) {
-            initClosure(clos, s->target);
-            return;
-        } else if (IR::New *ctor = s->source->asNew()) {
-            if (Name *func = ctor->base->asName()) {
-                constructActivationProperty(func, ctor->args, s->target);
-                return;
-            } else if (IR::Member *member = ctor->base->asMember()) {
-                constructProperty(member->base, *member->name, ctor->args, s->target);
-                return;
-            } else if (ctor->base->asTemp() || ctor->base->asArgLocal()) {
-                constructValue(ctor->base, ctor->args, s->target);
-                return;
-            }
-        } else if (IR::Member *m = s->source->asMember()) {
-            if (m->property) {
-#ifdef V4_BOOTSTRAP
-                Q_UNIMPLEMENTED();
-#else
-                bool captureRequired = true;
-
-                Q_ASSERT(m->kind != IR::Member::MemberOfEnum && m->kind != IR::Member::MemberOfIdObjectsArray);
-                const int attachedPropertiesId = m->attachedPropertiesId;
-                const bool isSingletonProperty = m->kind == IR::Member::MemberOfSingletonObject;
-
-                if (_function && attachedPropertiesId == 0 && !m->property->isConstant() && _function->isQmlBinding) {
-                    if (m->kind == IR::Member::MemberOfQmlContextObject) {
-                        _function->contextObjectPropertyDependencies.insert(m->property->coreIndex(), m->property->notifyIndex());
-                        captureRequired = false;
-                    } else if (m->kind == IR::Member::MemberOfQmlScopeObject) {
-                        _function->scopeObjectPropertyDependencies.insert(m->property->coreIndex(), m->property->notifyIndex());
-                        captureRequired = false;
-                    }
-                }
-                if (m->kind == IR::Member::MemberOfQmlScopeObject || m->kind == IR::Member::MemberOfQmlContextObject) {
-                    getQmlContextProperty(m->base, (IR::Member::MemberKind)m->kind, m->property->coreIndex(), captureRequired, s->target);
-                    return;
-                }
-                getQObjectProperty(m->base, m->property->coreIndex(), captureRequired, isSingletonProperty, attachedPropertiesId, s->target);
-#endif // V4_BOOTSTRAP
-                return;
-            } else if (m->kind == IR::Member::MemberOfIdObjectsArray) {
-                getQmlContextProperty(m->base, (IR::Member::MemberKind)m->kind, m->idIndex, /*captureRequired*/false, s->target);
-                return;
-            } else if (m->base->asTemp() || m->base->asConst() || m->base->asArgLocal()) {
-                getProperty(m->base, *m->name, s->target);
-                return;
-            }
-        } else if (IR::Subscript *ss = s->source->asSubscript()) {
-            getElement(ss->base, ss->index, s->target);
-            return;
-        } else if (IR::Unop *u = s->source->asUnop()) {
-            unop(u->op, u->expr, s->target);
-            return;
-        } else if (IR::Binop *b = s->source->asBinop()) {
-            binop(b->op, b->left, b->right, s->target);
-            return;
-        } else if (IR::Call *c = s->source->asCall()) {
-            if (c->base->asName()) {
-                callBuiltin(c, s->target);
-                return;
-            } else if (Member *member = c->base->asMember()) {
-#ifndef V4_BOOTSTRAP
-                Q_ASSERT(member->kind != IR::Member::MemberOfIdObjectsArray);
-                if (member->kind == IR::Member::MemberOfQmlScopeObject || member->kind == IR::Member::MemberOfQmlContextObject) {
-                    callQmlContextProperty(member->base, (IR::Member::MemberKind)member->kind, member->property->coreIndex(), c->args, s->target);
-                    return;
-                }
-#endif
-                callProperty(member->base, *member->name, c->args, s->target);
-                return;
-            } else if (Subscript *ss = c->base->asSubscript()) {
-                callSubscript(ss->base, ss->index, c->args, s->target);
-                return;
-            } else if (c->base->asTemp() || c->base->asArgLocal() || c->base->asConst()) {
-                callValue(c->base, c->args, s->target);
-                return;
-            }
-        } else if (IR::Convert *c = s->source->asConvert()) {
-            Q_ASSERT(c->expr->asTemp() || c->expr->asArgLocal());
-            convertType(c->expr, s->target);
-            return;
-        }
-    } else if (IR::Member *m = s->target->asMember()) {
-        if (m->base->asTemp() || m->base->asConst() || m->base->asArgLocal()) {
-            if (s->source->asTemp() || s->source->asConst() || s->source->asArgLocal()) {
-                Q_ASSERT(m->kind != IR::Member::MemberOfEnum);
-                Q_ASSERT(m->kind != IR::Member::MemberOfIdObjectsArray);
-                const int attachedPropertiesId = m->attachedPropertiesId;
-                if (m->property && attachedPropertiesId == 0) {
-#ifdef V4_BOOTSTRAP
-                    Q_UNIMPLEMENTED();
-#else
-                    if (m->kind == IR::Member::MemberOfQmlScopeObject || m->kind == IR::Member::MemberOfQmlContextObject) {
-                        setQmlContextProperty(s->source, m->base, (IR::Member::MemberKind)m->kind, m->property->coreIndex());
-                        return;
-                    }
-                    setQObjectProperty(s->source, m->base, m->property->coreIndex());
-#endif
-                    return;
-                } else {
-                    setProperty(s->source, m->base, *m->name);
-                    return;
-                }
-            }
-        }
-    } else if (IR::Subscript *ss = s->target->asSubscript()) {
-        if (s->source->asTemp() || s->source->asConst() || s->source->asArgLocal()) {
-            setElement(s->source, ss->base, ss->index);
-            return;
-        }
-    }
-
-    // For anything else...:
-    Q_UNIMPLEMENTED();
-    QBuffer buf;
-    buf.open(QIODevice::WriteOnly);
-    QTextStream qout(&buf);
-    IRPrinter(&qout).print(s);
-    qout << endl;
-    qDebug("%s", buf.data().constData());
-    Q_ASSERT(!"TODO");
-}
-
-IRDecoder::~IRDecoder()
-{
-}
-
-void IRDecoder::visitExp(IR::Exp *s)
-{
-    if (IR::Call *c = s->expr->asCall()) {
-        // These are calls where the result is ignored.
-        if (c->base->asName()) {
-            callBuiltin(c, 0);
-        } else if (c->base->asTemp() || c->base->asArgLocal() || c->base->asConst()) {
-            callValue(c->base, c->args, 0);
-        } else if (Member *member = c->base->asMember()) {
-            Q_ASSERT(member->base->asTemp() || member->base->asArgLocal());
-#ifndef V4_BOOTSTRAP
-            Q_ASSERT(member->kind != IR::Member::MemberOfIdObjectsArray);
-            if (member->kind == IR::Member::MemberOfQmlScopeObject || member->kind == IR::Member::MemberOfQmlContextObject) {
-                callQmlContextProperty(member->base, (IR::Member::MemberKind)member->kind, member->property->coreIndex(), c->args, 0);
-                return;
-            }
-#endif
-            callProperty(member->base, *member->name, c->args, 0);
-        } else if (Subscript *s = c->base->asSubscript()) {
-            callSubscript(s->base, s->index, c->args, 0);
-        } else {
-            Q_UNREACHABLE();
-        }
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-void IRDecoder::callBuiltin(IR::Call *call, Expr *result)
-{
-    IR::Name *baseName = call->base->asName();
-    Q_ASSERT(baseName != 0);
-
-    switch (baseName->builtin) {
-    case IR::Name::builtin_invalid:
-        callBuiltinInvalid(baseName, call->args, result);
-        return;
-
-    case IR::Name::builtin_typeof: {
-        if (IR::Member *member = call->args->expr->asMember()) {
-#ifndef V4_BOOTSTRAP
-            Q_ASSERT(member->kind != IR::Member::MemberOfIdObjectsArray);
-            if (member->kind == IR::Member::MemberOfQmlScopeObject || member->kind == IR::Member::MemberOfQmlContextObject) {
-                callBuiltinTypeofQmlContextProperty(member->base,
-                                                    IR::Member::MemberKind(member->kind),
-                                                    member->property->coreIndex(), result);
-                return;
-            }
-#endif
-            callBuiltinTypeofMember(member->base, *member->name, result);
-            return;
-        } else if (IR::Subscript *ss = call->args->expr->asSubscript()) {
-            callBuiltinTypeofSubscript(ss->base, ss->index, result);
-            return;
-        } else if (IR::Name *n = call->args->expr->asName()) {
-            callBuiltinTypeofName(*n->id, result);
-            return;
-        } else if (call->args->expr->asTemp() ||
-                   call->args->expr->asConst() ||
-                   call->args->expr->asArgLocal()) {
-            callBuiltinTypeofValue(call->args->expr, result);
-            return;
-        }
-    } break;
-
-    case IR::Name::builtin_delete: {
-        if (IR::Member *m = call->args->expr->asMember()) {
-            callBuiltinDeleteMember(m->base, *m->name, result);
-            return;
-        } else if (IR::Subscript *ss = call->args->expr->asSubscript()) {
-            callBuiltinDeleteSubscript(ss->base, ss->index, result);
-            return;
-        } else if (IR::Name *n = call->args->expr->asName()) {
-            callBuiltinDeleteName(*n->id, result);
-            return;
-        } else if (call->args->expr->asTemp() ||
-                   call->args->expr->asArgLocal()) {
-            // TODO: should throw in strict mode
-            callBuiltinDeleteValue(result);
-            return;
-        }
-    } break;
-
-    case IR::Name::builtin_throw: {
-        IR::Expr *arg = call->args->expr;
-        Q_ASSERT(arg->asTemp() || arg->asConst() || arg->asArgLocal());
-        callBuiltinThrow(arg);
-    } return;
-
-    case IR::Name::builtin_rethrow: {
-        callBuiltinReThrow();
-    } return;
-
-    case IR::Name::builtin_unwind_exception: {
-        callBuiltinUnwindException(result);
-    } return;
-
-    case IR::Name::builtin_push_catch_scope: {
-        IR::String *s = call->args->expr->asString();
-        Q_ASSERT(s);
-        callBuiltinPushCatchScope(*s->value);
-    } return;
-
-    case IR::Name::builtin_foreach_iterator_object: {
-        IR::Expr *arg = call->args->expr;
-        Q_ASSERT(arg != 0);
-        callBuiltinForeachIteratorObject(arg, result);
-    } return;
-
-    case IR::Name::builtin_foreach_next_property_name: {
-        IR::Expr *arg = call->args->expr;
-        Q_ASSERT(arg != 0);
-        callBuiltinForeachNextPropertyname(arg, result);
-    } return;
-    case IR::Name::builtin_push_with_scope: {
-        if (call->args->expr->asTemp() || call->args->expr->asArgLocal())
-            callBuiltinPushWithScope(call->args->expr);
-        else
-            Q_UNIMPLEMENTED();
-    } return;
-
-    case IR::Name::builtin_pop_scope:
-        callBuiltinPopScope();
-        return;
-
-    case IR::Name::builtin_declare_vars: {
-        if (!call->args)
-            return;
-        IR::Const *deletable = call->args->expr->asConst();
-        Q_ASSERT(deletable->type == IR::BoolType);
-        for (IR::ExprList *it = call->args->next; it; it = it->next) {
-            IR::Name *arg = it->expr->asName();
-            Q_ASSERT(arg != 0);
-            callBuiltinDeclareVar(deletable->value != 0, *arg->id);
-        }
-    } return;
-
-    case IR::Name::builtin_define_array:
-        callBuiltinDefineArray(result, call->args);
-        return;
-
-    case IR::Name::builtin_define_object_literal: {
-        IR::ExprList *args = call->args;
-        const int keyValuePairsCount = args->expr->asConst()->value;
-        args = args->next;
-
-        IR::ExprList *keyValuePairs = args;
-        for (int i = 0; i < keyValuePairsCount; ++i) {
-            args = args->next; // name
-            bool isData = args->expr->asConst()->value;
-            args = args->next; // isData flag
-            args = args->next; // value or getter
-            if (!isData)
-                args = args->next; // setter
-        }
-
-        IR::ExprList *arrayEntries = args;
-        bool needSparseArray = false;
-        for (IR::ExprList *it = arrayEntries; it; it = it->next) {
-            uint index = it->expr->asConst()->value;
-            if (index > 16)  {
-                needSparseArray = true;
-                break;
-            }
-            it = it->next;
-            bool isData = it->expr->asConst()->value;
-            it = it->next;
-            if (!isData)
-                it = it->next;
-        }
-
-        callBuiltinDefineObjectLiteral(result, keyValuePairsCount, keyValuePairs, arrayEntries, needSparseArray);
-    } return;
-
-    case IR::Name::builtin_setup_argument_object:
-        callBuiltinSetupArgumentObject(result);
-        return;
-
-    case IR::Name::builtin_convert_this_to_object:
-        callBuiltinConvertThisToObject();
-        return;
-
-    default:
-        break;
-    }
-
-    Q_UNIMPLEMENTED();
-    QBuffer buf;
-    buf.open(QIODevice::WriteOnly);
-    QTextStream qout(&buf);
-    IRPrinter(&qout).print(call); qout << endl;
-    qDebug("%s", buf.data().constData());
-    Q_UNREACHABLE();
-}
diff --git a/src/qml/compiler/qv4isel_p.h b/src/qml/compiler/qv4isel_p.h
deleted file mode 100644
index 037c02e5ea..0000000000
--- a/src/qml/compiler/qv4isel_p.h
+++ /dev/null
@@ -1,218 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QV4ISEL_P_H
-#define QV4ISEL_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "private/qv4global_p.h"
-#include "qv4jsir_p.h"
-#include <private/qv4compileddata_p.h>
-#include <private/qv4compiler_p.h>
-
-#include <qglobal.h>
-#include <QHash>
-
-QT_BEGIN_NAMESPACE
-
-class QQmlEnginePrivate;
-
-namespace QV4 {
-
-class EvalISelFactory;
-class ExecutableAllocator;
-struct Function;
-
-class Q_QML_PRIVATE_EXPORT EvalInstructionSelection
-{
-public:
-    EvalInstructionSelection(QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory);
-    virtual ~EvalInstructionSelection() = 0;
-
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compile(bool generateUnitData = true);
-
-    void setUseFastLookups(bool b) { useFastLookups = b; }
-    void setUseTypeInference(bool onoff) { useTypeInference = onoff; }
-
-    int registerString(const QString &str) { return jsGenerator->registerString(str); }
-    uint registerIndexedGetterLookup() { return jsGenerator->registerIndexedGetterLookup(); }
-    uint registerIndexedSetterLookup() { return jsGenerator->registerIndexedSetterLookup(); }
-    uint registerGetterLookup(const QString &name) { return jsGenerator->registerGetterLookup(name); }
-    uint registerSetterLookup(const QString &name) { return jsGenerator->registerSetterLookup(name); }
-    uint registerGlobalGetterLookup(const QString &name) { return jsGenerator->registerGlobalGetterLookup(name); }
-    int registerRegExp(IR::RegExp *regexp) { return jsGenerator->registerRegExp(regexp); }
-    int registerJSClass(int count, IR::ExprList *args) { return jsGenerator->registerJSClass(count, args); }
-    QV4::Compiler::JSUnitGenerator *jsUnitGenerator() const { return jsGenerator; }
-
-protected:
-    virtual void run(int functionIndex) = 0;
-    virtual QQmlRefPointer<QV4::CompiledData::CompilationUnit> backendCompileStep() = 0;
-
-    bool useFastLookups;
-    bool useTypeInference;
-    QV4::ExecutableAllocator *executableAllocator;
-    QV4::Compiler::JSUnitGenerator *jsGenerator;
-    QScopedPointer<QV4::Compiler::JSUnitGenerator> ownJSGenerator;
-    IR::Module *irModule;
-};
-
-class Q_QML_PRIVATE_EXPORT EvalISelFactory
-{
-public:
-    EvalISelFactory(const QString &codeGeneratorName) : codeGeneratorName(codeGeneratorName) {}
-    virtual ~EvalISelFactory() = 0;
-    virtual EvalInstructionSelection *create(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator) = 0;
-    virtual bool jitCompileRegexps() const = 0;
-    virtual QQmlRefPointer<QV4::CompiledData::CompilationUnit> createUnitForLoading() = 0;
-
-    const QString codeGeneratorName;
-};
-
-namespace IR {
-class Q_QML_PRIVATE_EXPORT IRDecoder
-{
-public:
-    IRDecoder() : _function(0) {}
-    virtual ~IRDecoder() = 0;
-
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            visitExp(e);
-        } else if (auto m = s->asMove()) {
-            visitMove(m);
-        } else if (auto j = s->asJump()) {
-            visitJump(j);
-        } else if (auto c = s->asCJump()) {
-            visitCJump(c);
-        } else if (auto r = s->asRet()) {
-            visitRet(r);
-        } else if (auto p = s->asPhi()) {
-            visitPhi(p);
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-private: // visitor methods for StmtVisitor:
-    void visitMove(IR::Move *s);
-    void visitExp(IR::Exp *s);
-
-public: // to implement by subclasses:
-    virtual void callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void callBuiltinTypeofQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::Expr *result) = 0;
-    virtual void callBuiltinTypeofMember(IR::Expr *base, const QString &name, IR::Expr *result) = 0;
-    virtual void callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result) = 0;
-    virtual void callBuiltinTypeofName(const QString &name, IR::Expr *result) = 0;
-    virtual void callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result) = 0;
-    virtual void callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result) = 0;
-    virtual void callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result) = 0;
-    virtual void callBuiltinDeleteName(const QString &name, IR::Expr *result) = 0;
-    virtual void callBuiltinDeleteValue(IR::Expr *result) = 0;
-    virtual void callBuiltinThrow(IR::Expr *arg) = 0;
-    virtual void callBuiltinReThrow() = 0;
-    virtual void callBuiltinUnwindException(IR::Expr *) = 0;
-    virtual void callBuiltinPushCatchScope(const QString &exceptionName) = 0;
-    virtual void callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result) = 0;
-    virtual void callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result) = 0;
-    virtual void callBuiltinPushWithScope(IR::Expr *arg) = 0;
-    virtual void callBuiltinPopScope() = 0;
-    virtual void callBuiltinDeclareVar(bool deletable, const QString &name) = 0;
-    virtual void callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args) = 0;
-    virtual void callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray) = 0;
-    virtual void callBuiltinSetupArgumentObject(IR::Expr *result) = 0;
-    virtual void callBuiltinConvertThisToObject() = 0;
-    virtual void callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void convertType(IR::Expr *source, IR::Expr *target) = 0;
-    virtual void constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) = 0;
-    virtual void loadThisObject(IR::Expr *target) = 0;
-    virtual void loadQmlContext(IR::Expr *target) = 0;
-    virtual void loadQmlImportedScripts(IR::Expr *target) = 0;
-    virtual void loadQmlSingleton(const QString &name, IR::Expr *target) = 0;
-    virtual void loadConst(IR::Const *sourceConst, IR::Expr *target) = 0;
-    virtual void loadString(const QString &str, IR::Expr *target) = 0;
-    virtual void loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target) = 0;
-    virtual void getActivationProperty(const IR::Name *name, IR::Expr *target) = 0;
-    virtual void setActivationProperty(IR::Expr *source, const QString &targetName) = 0;
-    virtual void initClosure(IR::Closure *closure, IR::Expr *target) = 0;
-    virtual void getProperty(IR::Expr *base, const QString &name, IR::Expr *target) = 0;
-    virtual void getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingletonProperty, int attachedPropertiesId, IR::Expr *target) = 0;
-    virtual void getQmlContextProperty(IR::Expr *source, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target) = 0;
-    virtual void setProperty(IR::Expr *source, IR::Expr *targetBase, const QString &targetName) = 0;
-    virtual void setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex) = 0;
-    virtual void setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex) = 0;
-    virtual void getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target) = 0;
-    virtual void setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex) = 0;
-    virtual void copyValue(IR::Expr *source, IR::Expr *target) = 0;
-    virtual void swapValues(IR::Expr *source, IR::Expr *target) = 0;
-    virtual void unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target) = 0;
-    virtual void binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target) = 0;
-
-protected:
-    virtual void visitJump(IR::Jump *) = 0;
-    virtual void visitCJump(IR::CJump *) = 0;
-    virtual void visitRet(IR::Ret *) = 0;
-    virtual void visitPhi(IR::Phi *) {}
-
-    virtual void callBuiltin(IR::Call *c, IR::Expr *result);
-
-    IR::Function *_function; // subclass needs to set
-};
-} // namespace IR
-
-} // namespace QV4
-
-QT_END_NAMESPACE
-
-#endif // QV4ISEL_P_H
diff --git a/src/qml/compiler/qv4isel_util_p.h b/src/qml/compiler/qv4isel_util_p.h
deleted file mode 100644
index e949e6f0ad..0000000000
--- a/src/qml/compiler/qv4isel_util_p.h
+++ /dev/null
@@ -1,241 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QV4ISEL_UTIL_P_H
-#define QV4ISEL_UTIL_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "private/qv4value_p.h"
-#include "qv4jsir_p.h"
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-
-struct TargetPrimitive32 {
-    static TargetPrimitive32 emptyValue() { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Empty) << 32; return p; }
-    static TargetPrimitive32 nullValue() { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Null) << 32; return p; }
-    static TargetPrimitive32 undefinedValue() { TargetPrimitive32 p; p._val = quint64(Value::Managed_Type_Internal_32) << 32; return p; }
-    static TargetPrimitive32 fromBoolean(bool b) { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Boolean) << 32 | quint64(b); return p; }
-    static TargetPrimitive32 fromInt32(int v) { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Integer) << 32 | quint32(v); return p; }
-    static TargetPrimitive32 fromDouble(double v) {
-        TargetPrimitive32 p;
-        memcpy(&p._val, &v, 8);
-        return p;
-    }
-    static TargetPrimitive32 fromUInt32(uint v) {
-        if (v < INT_MAX)
-            return fromInt32(qint32(v));
-        return fromDouble(double(v));
-    }
-
-    quint32 value() const { return _val & quint64(~quint32(0)); }
-    quint32 tag() const { return _val >> 32; }
-
-    quint64 rawValue() const { return _val; }
-
-private:
-    quint64 _val;
-};
-
-struct TargetPrimitive64 {
-    static TargetPrimitive64 emptyValue() { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Empty) << 32; return p; }
-    static TargetPrimitive64 nullValue() { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Null) << 32; return p; }
-    static TargetPrimitive64 undefinedValue() { TargetPrimitive64 p; p._val = 0; return p; }
-    static TargetPrimitive64 fromBoolean(bool b) { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Boolean) << 32 | quint64(b); return p; }
-    static TargetPrimitive64 fromInt32(int v) { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Integer) << 32 | quint32(v); return p; }
-    static TargetPrimitive64 fromDouble(double v) {
-        TargetPrimitive64 p;
-        memcpy(&p._val, &v, 8);
-        p._val ^= Value::NaNEncodeMask;
-        return p;
-    }
-    static TargetPrimitive64 fromUInt32(uint v) {
-        if (v < INT_MAX)
-            return fromInt32(qint32(v));
-        return fromDouble(double(v));
-    }
-
-    quint32 value() const { return _val & quint64(~quint32(0)); }
-    quint32 tag() const { return _val >> 32; }
-
-    quint64 rawValue() const { return _val; }
-
-private:
-    quint64 _val;
-};
-
-inline bool canConvertToSignedInteger(double value)
-{
-    int ival = (int) value;
-    // +0 != -0, so we need to convert to double when negating 0
-    return ival == value && !(value == 0 && isNegative(value));
-}
-
-inline bool canConvertToUnsignedInteger(double value)
-{
-    unsigned uval = (unsigned) value;
-    // +0 != -0, so we need to convert to double when negating 0
-    return uval == value && !(value == 0 && isNegative(value));
-}
-
-template <typename PrimitiveType = Primitive>
-inline PrimitiveType convertToValue(IR::Const *c)
-{
-    switch (c->type) {
-    case IR::MissingType:
-        return PrimitiveType::emptyValue();
-    case IR::NullType:
-        return PrimitiveType::nullValue();
-    case IR::UndefinedType:
-        return PrimitiveType::undefinedValue();
-    case IR::BoolType:
-        return PrimitiveType::fromBoolean(c->value != 0);
-    case IR::SInt32Type:
-        return PrimitiveType::fromInt32(int(c->value));
-    case IR::UInt32Type:
-        return PrimitiveType::fromUInt32(unsigned(c->value));
-    case IR::DoubleType:
-        return PrimitiveType::fromDouble(c->value);
-    case IR::NumberType: {
-        int ival = (int)c->value;
-        if (canConvertToSignedInteger(c->value)) {
-            return PrimitiveType::fromInt32(ival);
-        } else {
-            return PrimitiveType::fromDouble(c->value);
-        }
-    }
-    default:
-        Q_UNREACHABLE();
-    }
-    // unreachable, but the function must return something
-    return PrimitiveType::undefinedValue();
-}
-
-class ConvertTemps
-{
-    void renumber(IR::Temp *t)
-    {
-        if (t->kind != IR::Temp::VirtualRegister)
-            return;
-
-        int stackSlot = _stackSlotForTemp.value(t->index, -1);
-        if (stackSlot == -1) {
-            stackSlot = allocateFreeSlot();
-            _stackSlotForTemp[t->index] = stackSlot;
-        }
-
-        t->kind = IR::Temp::StackSlot;
-        t->index = stackSlot;
-    }
-
-protected:
-    int _nextUnusedStackSlot;
-    QHash<int, int> _stackSlotForTemp;
-    IR::BasicBlock *_currentBasicBlock;
-    virtual int allocateFreeSlot()
-    {
-        return _nextUnusedStackSlot++;
-    }
-
-    virtual void process(IR::Stmt *s)
-    {
-        visit(s);
-    }
-
-public:
-    ConvertTemps()
-        : _nextUnusedStackSlot(0)
-        , _currentBasicBlock(0)
-    {}
-
-    void toStackSlots(IR::Function *function)
-    {
-        _stackSlotForTemp.reserve(function->tempCount);
-
-        for (IR::BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-            _currentBasicBlock = bb;
-            for (IR::Stmt *s : bb->statements())
-                process(s);
-        }
-
-        function->tempCount = _nextUnusedStackSlot;
-    }
-
-protected:
-    void visit(IR::Stmt *s) {
-        switch (s->stmtKind) {
-        case IR::Stmt::PhiStmt:
-            visitPhi(s->asPhi());
-            break;
-        default:
-            STMT_VISIT_ALL_KINDS(s);
-            break;
-        }
-    }
-
-    virtual void visitPhi(IR::Phi *)
-    { Q_UNREACHABLE(); }
-
-private:
-    void visit(IR::Expr *e) {
-        if (auto temp = e->asTemp()) {
-            renumber(temp);
-        } else {
-            EXPR_VISIT_ALL_KINDS(e);
-        }
-    }
-};
-} // namespace QV4
-
-QT_END_NAMESPACE
-
-#endif // QV4ISEL_UTIL_P_H
diff --git a/src/qml/compiler/qv4jsir.cpp b/src/qml/compiler/qv4jsir.cpp
deleted file mode 100644
index 5a58380005..0000000000
--- a/src/qml/compiler/qv4jsir.cpp
+++ /dev/null
@@ -1,992 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qv4jsir_p.h"
-#include <private/qqmljsast_p.h>
-
-#ifndef V4_BOOTSTRAP
-#include <private/qqmlpropertycache_p.h>
-#endif
-
-#include <QtCore/QBuffer>
-#include <QtCore/qtextstream.h>
-#include <QtCore/qdebug.h>
-#include <QtCore/qset.h>
-#include <cmath>
-
-#include <vector>
-
-#ifdef CONST
-#undef CONST
-#endif
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace IR {
-
-QString typeName(Type t)
-{
-    switch (t) {
-    case UnknownType: return QStringLiteral("");
-    case MissingType: return QStringLiteral("missing");
-    case UndefinedType: return QStringLiteral("undefined");
-    case NullType: return QStringLiteral("null");
-    case BoolType: return QStringLiteral("bool");
-    case UInt32Type: return QStringLiteral("uint32");
-    case SInt32Type: return QStringLiteral("int32");
-    case DoubleType: return QStringLiteral("double");
-    case NumberType: return QStringLiteral("number");
-    case StringType: return QStringLiteral("string");
-    case VarType: return QStringLiteral("var");
-    case QObjectType: return QStringLiteral("qobject");
-    default: return QStringLiteral("multiple");
-    }
-}
-
-const char *opname(AluOp op)
-{
-    switch (op) {
-    case OpInvalid: return "?";
-
-    case OpIfTrue: return "(bool)";
-    case OpNot: return "not";
-    case OpUMinus: return "neg";
-    case OpUPlus: return "plus";
-    case OpCompl: return "invert";
-    case OpIncrement: return "incr";
-    case OpDecrement: return "decr";
-
-    case OpBitAnd: return "bitand";
-    case OpBitOr: return "bitor";
-    case OpBitXor: return "bitxor";
-
-    case OpAdd: return "add";
-    case OpSub: return "sub";
-    case OpMul: return "mul";
-    case OpDiv: return "div";
-    case OpMod: return "mod";
-
-    case OpLShift: return "shl";
-    case OpRShift: return "shr";
-    case OpURShift: return "asr";
-
-    case OpGt: return "gt";
-    case OpLt: return "lt";
-    case OpGe: return "ge";
-    case OpLe: return "le";
-    case OpEqual: return "eq";
-    case OpNotEqual: return "ne";
-    case OpStrictEqual: return "se";
-    case OpStrictNotEqual: return "sne";
-
-    case OpInstanceof: return "instanceof";
-    case OpIn: return "in";
-
-    case OpAnd: return "and";
-    case OpOr: return "or";
-
-    default: return "?";
-
-    } // switch
-}
-
-AluOp binaryOperator(int op)
-{
-    switch (static_cast<QSOperator::Op>(op)) {
-    case QSOperator::Add: return OpAdd;
-    case QSOperator::And: return OpAnd;
-    case QSOperator::BitAnd: return OpBitAnd;
-    case QSOperator::BitOr: return OpBitOr;
-    case QSOperator::BitXor: return OpBitXor;
-    case QSOperator::Div: return OpDiv;
-    case QSOperator::Equal: return OpEqual;
-    case QSOperator::Ge: return OpGe;
-    case QSOperator::Gt: return OpGt;
-    case QSOperator::Le: return OpLe;
-    case QSOperator::LShift: return OpLShift;
-    case QSOperator::Lt: return OpLt;
-    case QSOperator::Mod: return OpMod;
-    case QSOperator::Mul: return OpMul;
-    case QSOperator::NotEqual: return OpNotEqual;
-    case QSOperator::Or: return OpOr;
-    case QSOperator::RShift: return OpRShift;
-    case QSOperator::StrictEqual: return OpStrictEqual;
-    case QSOperator::StrictNotEqual: return OpStrictNotEqual;
-    case QSOperator::Sub: return OpSub;
-    case QSOperator::URShift: return OpURShift;
-    case QSOperator::InstanceOf: return OpInstanceof;
-    case QSOperator::In: return OpIn;
-    default: return OpInvalid;
-    }
-}
-
-class RemoveSharedExpressions
-{
-    CloneExpr clone;
-    std::vector<Expr *> subexpressions; // contains all the non-cloned subexpressions in the given function. sorted using std::lower_bound.
-    Expr *uniqueExpr;
-
-public:
-    RemoveSharedExpressions(): uniqueExpr(0) {}
-
-    void operator()(IR::Function *function)
-    {
-        subexpressions.clear();
-        subexpressions.reserve(function->basicBlockCount() * 8);
-
-        for (BasicBlock *block : function->basicBlocks()) {
-            if (block->isRemoved())
-                continue;
-            clone.setBasicBlock(block);
-
-            for (Stmt *s : block->statements()) {
-                visit(s);
-            }
-        }
-    }
-
-private:
-    template <typename Expr_>
-    Expr_ *cleanup(Expr_ *expr)
-    {
-        std::vector<Expr *>::iterator it = std::lower_bound(subexpressions.begin(), subexpressions.end(), expr);
-        if (it == subexpressions.end() || *it != expr) {
-            subexpressions.insert(it, expr);
-            IR::Expr *e = expr;
-            qSwap(uniqueExpr, e);
-            visit(expr);
-            qSwap(uniqueExpr, e);
-            return static_cast<Expr_ *>(e);
-        }
-
-        // the cloned expression is unique by definition
-        // so we don't need to add it to `subexpressions'.
-        return clone(expr);
-    }
-
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            e->expr = cleanup(e->expr);
-        } else if (auto m = s->asMove()) {
-            m->target = cleanup(m->target);
-            m->source = cleanup(m->source);
-        } else if (auto c = s->asCJump()) {
-            c->cond = cleanup(c->cond);
-        } else if (auto r = s->asRet()) {
-            r->expr = cleanup(r->expr);
-        }
-    }
-
-    void visit(Expr *e)
-    {
-        if (auto c = e->asConvert()) {
-            c->expr = cleanup(c->expr);
-        } else if (auto u = e->asUnop()) {
-            u->expr = cleanup(u->expr);
-        } else if (auto b = e->asBinop()) {
-            b->left = cleanup(b->left);
-            b->right = cleanup(b->right);
-        } else if (auto c = e->asCall()) {
-            c->base = cleanup(c->base);
-            for (IR::ExprList *it = c->args; it; it = it->next) {
-                it->expr = cleanup(it->expr);
-            }
-        } else if (auto n = e->asNew()) {
-            n->base = cleanup(n->base);
-            for (IR::ExprList *it = n->args; it; it = it->next) {
-                it->expr = cleanup(it->expr);
-            }
-        } else if (auto s = e->asSubscript()) {
-            s->base = cleanup(s->base);
-            s->index = cleanup(s->index);
-        } else if (auto m = e->asMember()) {
-            m->base = cleanup(m->base);
-        }
-    }
-};
-
-void Name::initGlobal(const QString *id, quint32 line, quint32 column)
-{
-    this->id = id;
-    this->builtin = builtin_invalid;
-    this->global = true;
-    this->qmlSingleton = false;
-    this->freeOfSideEffects = false;
-    this->line = line;
-    this->column = column;
-}
-
-void Name::init(const QString *id, quint32 line, quint32 column)
-{
-    this->id = id;
-    this->builtin = builtin_invalid;
-    this->global = false;
-    this->qmlSingleton = false;
-    this->freeOfSideEffects = false;
-    this->line = line;
-    this->column = column;
-}
-
-void Name::init(Builtin builtin, quint32 line, quint32 column)
-{
-    this->id = 0;
-    this->builtin = builtin;
-    this->global = false;
-    this->qmlSingleton = false;
-    this->freeOfSideEffects = false;
-    this->line = line;
-    this->column = column;
-}
-
-const char *builtin_to_string(Name::Builtin b)
-{
-    switch (b) {
-    case Name::builtin_invalid:
-        return "builtin_invalid";
-    case Name::builtin_typeof:
-        return "builtin_typeof";
-    case Name::builtin_delete:
-        return "builtin_delete";
-    case Name::builtin_throw:
-        return "builtin_throw";
-    case Name::builtin_rethrow:
-        return "builtin_rethrow";
-    case Name::builtin_unwind_exception:
-        return "builtin_unwind_exception";
-    case Name::builtin_push_catch_scope:
-        return "builtin_push_catch_scope";
-    case IR::Name::builtin_foreach_iterator_object:
-        return "builtin_foreach_iterator_object";
-    case IR::Name::builtin_foreach_next_property_name:
-        return "builtin_foreach_next_property_name";
-    case IR::Name::builtin_push_with_scope:
-        return "builtin_push_with_scope";
-    case IR::Name::builtin_pop_scope:
-        return "builtin_pop_scope";
-    case IR::Name::builtin_declare_vars:
-        return "builtin_declare_vars";
-    case IR::Name::builtin_define_array:
-        return "builtin_define_array";
-    case IR::Name::builtin_define_object_literal:
-        return "builtin_define_object_literal";
-    case IR::Name::builtin_setup_argument_object:
-        return "builtin_setup_argument_object";
-    case IR::Name::builtin_convert_this_to_object:
-        return "builtin_convert_this_to_object";
-    case IR::Name::builtin_qml_context:
-        return "builtin_qml_context";
-    case IR::Name::builtin_qml_imported_scripts_object:
-        return "builtin_qml_imported_scripts_object";
-    }
-    return "builtin_(###FIXME)";
-};
-
-bool operator<(const Temp &t1, const Temp &t2) Q_DECL_NOTHROW
-{
-    if (t1.kind < t2.kind) return true;
-    if (t1.kind > t2.kind) return false;
-    return t1.index < t2.index;
-}
-
-Function *Module::newFunction(const QString &name, Function *outer)
-{
-    Function *f = new Function(this, outer, name);
-    functions.append(f);
-    if (!outer) {
-        if (!isQmlModule) {
-            Q_ASSERT(!rootFunction);
-            rootFunction = f;
-        }
-    } else {
-        outer->nestedFunctions.append(f);
-    }
-    return f;
-}
-
-Module::~Module()
-{
-    qDeleteAll(functions);
-}
-
-void Module::setFileName(const QString &name)
-{
-    fileName = name;
-}
-
-Function::Function(Module *module, Function *outer, const QString &name)
-    : module(module)
-    , pool(&module->pool)
-    , tempCount(0)
-    , maxNumberOfArguments(0)
-    , outer(outer)
-    , insideWithOrCatch(0)
-    , hasDirectEval(false)
-    , usesArgumentsObject(false)
-    , isStrict(false)
-    , isNamedExpression(false)
-    , hasTry(false)
-    , hasWith(false)
-    , isQmlBinding(false)
-    , unused(0)
-    , line(0)
-    , column(0)
-    , _allBasicBlocks(0)
-    , _statementCount(0)
-{
-    this->name = newString(name);
-    _basicBlocks.reserve(8);
-}
-
-Function::~Function()
-{
-    if (_allBasicBlocks) {
-        qDeleteAll(*_allBasicBlocks);
-        delete _allBasicBlocks;
-    } else {
-        qDeleteAll(_basicBlocks);
-    }
-
-    pool = 0;
-    module = 0;
-}
-
-
-const QString *Function::newString(const QString &text)
-{
-    return &*strings.insert(text);
-}
-
-BasicBlock *Function::newBasicBlock(BasicBlock *catchBlock, BasicBlockInsertMode mode)
-{
-    BasicBlock *block = new BasicBlock(this, catchBlock);
-    return mode == InsertBlock ? addBasicBlock(block) : block;
-}
-
-BasicBlock *Function::addBasicBlock(BasicBlock *block)
-{
-    Q_ASSERT(block->index() < 0);
-    block->setIndex(_basicBlocks.size());
-    _basicBlocks.append(block);
-    return block;
-}
-
-void Function::removeBasicBlock(BasicBlock *block)
-{
-    block->markAsRemoved();
-    block->in.clear();
-    block->out.clear();
-}
-
-int Function::liveBasicBlocksCount() const
-{
-    int count = 0;
-    for (BasicBlock *bb : basicBlocks())
-        if (!bb->isRemoved())
-            ++count;
-    return count;
-}
-
-void Function::removeSharedExpressions()
-{
-    RemoveSharedExpressions removeSharedExpressions;
-    removeSharedExpressions(this);
-}
-
-int Function::indexOfArgument(const QStringRef &string) const
-{
-    for (int i = formals.size() - 1; i >= 0; --i) {
-        if (*formals.at(i) == string)
-            return i;
-    }
-    return -1;
-}
-
-void Function::setScheduledBlocks(const QVector<BasicBlock *> &scheduled)
-{
-    Q_ASSERT(!_allBasicBlocks);
-    _allBasicBlocks = new QVector<BasicBlock *>(basicBlocks());
-    _basicBlocks = scheduled;
-    for (int i = 0, ei = basicBlockCount(); i != ei; ++i)
-        basicBlock(i)->changeIndex(i);
-}
-
-BasicBlock *Function::getOrCreateBasicBlock(int index)
-{
-    if (_basicBlocks.size() <= index) {
-        const int oldSize = _basicBlocks.size();
-        _basicBlocks.resize(index + 1);
-        for (int i = oldSize; i <= index; ++i) {
-            BasicBlock *block = new BasicBlock(this, 0);
-            block->setIndex(i);
-            _basicBlocks[i] = block;
-        }
-    }
-
-    return _basicBlocks.at(index);
-}
-
-void Function::setStatementCount(int cnt)
-{
-    _statementCount = cnt;
-}
-
-void BasicBlock::setStatements(const QVector<Stmt *> &newStatements)
-{
-    Q_ASSERT(!isRemoved());
-    Q_ASSERT(newStatements.size() >= _statements.size());
-    for (Stmt *s : qAsConst(_statements)) {
-        if (Phi *p = s->asPhi()) {
-            if (!newStatements.contains(p)) {
-                // phi-node was not copied over, so:
-                p->destroyData();
-            }
-        } else {
-            break;
-        }
-    }
-    _statements = newStatements;
-}
-
-CloneExpr::CloneExpr(BasicBlock *block)
-    : block(block), cloned(0)
-{
-}
-
-void CloneExpr::setBasicBlock(BasicBlock *block)
-{
-    this->block = block;
-}
-
-ExprList *CloneExpr::clone(ExprList *list)
-{
-    if (! list)
-        return 0;
-
-    ExprList *clonedList = block->function->New<IR::ExprList>();
-    clonedList->init(clone(list->expr), clone(list->next));
-    return clonedList;
-}
-
-void CloneExpr::visit(Expr *e)
-{
-    if (auto c = e->asConst()) {
-        cloned = cloneConst(c, block->function);
-    } else if (auto s = e->asString()) {
-        cloned = block->STRING(s->value);
-    } else if (auto r = e->asRegExp()) {
-        cloned = block->REGEXP(r->value, r->flags);
-    } else if (auto n = e->asName()) {
-        cloned = cloneName(n, block->function);
-    } else if (auto t = e->asTemp()) {
-        cloned = cloneTemp(t, block->function);
-    } else if (auto a = e->asArgLocal()) {
-        cloned = cloneArgLocal(a, block->function);
-    } else if (auto c = e->asClosure()) {
-        cloned = block->CLOSURE(c->value);
-    } else if (auto c = e->asConvert()) {
-        cloned = block->CONVERT(clone(c->expr), c->type);
-    } else if (auto u = e->asUnop()) {
-        cloned = block->UNOP(u->op, clone(u->expr));
-    } else if (auto b = e->asBinop()) {
-        cloned = block->BINOP(b->op, clone(b->left), clone(b->right));
-    } else if (auto c = e->asCall()) {
-        cloned = block->CALL(clone(c->base), clone(c->args));
-    } else if (auto n = e->asNew()) {
-        cloned = block->NEW(clone(n->base), clone(n->args));
-    } else if (auto s = e->asSubscript()) {
-        cloned = block->SUBSCRIPT(clone(s->base), clone(s->index));
-    } else if (auto m = e->asMember()) {
-        cloned = block->MEMBER(clone(m->base), m->name, m->property, m->kind, m->idIndex);
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-IRPrinter::IRPrinter(QTextStream *out)
-    : out(out)
-    , positionSize(Stmt::InvalidId)
-    , currentBB(0)
-{
-}
-
-IRPrinter::~IRPrinter()
-{
-}
-
-void IRPrinter::print(Stmt *s)
-{
-    visit(s);
-}
-
-void IRPrinter::print(const Expr &e)
-{
-    visit(const_cast<Expr *>(&e));
-}
-
-void IRPrinter::print(Expr *e)
-{
-    visit(e);
-}
-
-void IRPrinter::print(Function *f)
-{
-    if (positionSize == Stmt::InvalidId)
-        positionSize = QString::number(f->statementCount()).size();
-
-    QString n = f->name ? *f->name : QString();
-    if (n.isEmpty())
-        n.sprintf("%p", f);
-    *out << "function " << n << '(';
-
-    for (int i = 0; i < f->formals.size(); ++i) {
-        if (i != 0)
-            *out << ", ";
-        *out << *f->formals.at(i);
-    }
-    *out << ')' << endl
-        << '{' << endl;
-
-    for (const QString *local : qAsConst(f->locals))
-        *out << "    local var " << *local << endl;
-
-    bool needsSeperator = !f->locals.isEmpty();
-    for (BasicBlock *bb : f->basicBlocks()) {
-        if (bb->isRemoved())
-            continue;
-
-        if (needsSeperator)
-            *out << endl;
-        else
-            needsSeperator = true;
-        print(bb);
-    }
-    *out << '}' << endl;
-}
-
-void IRPrinter::print(BasicBlock *bb)
-{
-    std::swap(currentBB, bb);
-    printBlockStart();
-
-    for (Stmt *s : currentBB->statements()) {
-        if (!s)
-            continue;
-
-        QByteArray str;
-        QBuffer buf(&str);
-        buf.open(QIODevice::WriteOnly);
-        QTextStream os(&buf);
-        QTextStream *prevOut = &os;
-        std::swap(out, prevOut);
-        addStmtNr(s);
-        visit(s);
-        if (s->location.startLine) {
-            out->flush();
-            for (int i = 58 - str.length(); i > 0; --i)
-                *out << ' ';
-            *out << "    ; line: " << s->location.startLine << ", column: " << s->location.startColumn;
-        }
-
-        out->flush();
-        std::swap(out, prevOut);
-
-        *out << "    " << str << endl;
-    }
-
-    std::swap(currentBB, bb);
-}
-
-void IRPrinter::visit(Stmt *s)
-{
-    if (auto e = s->asExp()) {
-        visitExp(e);
-    } else if (auto m = s->asMove()) {
-        visitMove(m);
-    } else if (auto j = s->asJump()) {
-        visitJump(j);
-    } else if (auto c = s->asCJump()) {
-        visitCJump(c);
-    } else if (auto r = s->asRet()) {
-        visitRet(r);
-    } else if (auto p = s->asPhi()) {
-        visitPhi(p);
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-void IRPrinter::visitExp(Exp *s)
-{
-    *out << "void ";
-    visit(s->expr);
-}
-
-void IRPrinter::visitMove(Move *s)
-{
-    if (Temp *targetTemp = s->target->asTemp())
-        if (!s->swap && targetTemp->type != UnknownType)
-            *out << typeName(targetTemp->type) << ' ';
-
-    visit(s->target);
-    *out << ' ';
-    if (s->swap)
-        *out << "<=> ";
-    else
-        *out << "= ";
-    visit(s->source);
-}
-
-void IRPrinter::visitJump(Jump *s)
-{
-    *out << "goto L" << s->target->index();
-}
-
-void IRPrinter::visitCJump(CJump *s)
-{
-    *out << "if ";
-    visit(s->cond);
-    *out << " goto L" << s->iftrue->index()
-         << " else goto L" << s->iffalse->index();
-}
-
-void IRPrinter::visitRet(Ret *s)
-{
-    *out << "return";
-    if (s->expr) {
-        *out << ' ';
-        visit(s->expr);
-    }
-}
-
-void IRPrinter::visitPhi(Phi *s)
-{
-    if (s->targetTemp->type != UnknownType)
-        *out << typeName(s->targetTemp->type) << ' ';
-
-    visit(s->targetTemp);
-    *out << " = phi ";
-    for (int i = 0, ei = s->incoming.size(); i < ei; ++i) {
-        if (i > 0)
-            *out << ", ";
-        if (currentBB)
-            *out << 'L' << currentBB->in.at(i)->index() << ": ";
-        if (s->incoming[i])
-            visit(s->incoming[i]);
-    }
-}
-
-void IRPrinter::visit(Expr *e)
-{
-    if (auto c = e->asConst()) {
-        visitConst(c);
-    } else if (auto s = e->asString()) {
-        visitString(s);
-    } else if (auto r = e->asRegExp()) {
-        visitRegExp(r);
-    } else if (auto n = e->asName()) {
-        visitName(n);
-    } else if (auto t = e->asTemp()) {
-        visitTemp(t);
-    } else if (auto a = e->asArgLocal()) {
-        visitArgLocal(a);
-    } else if (auto c = e->asClosure()) {
-        visitClosure(c);
-    } else if (auto c = e->asConvert()) {
-        visitConvert(c);
-    } else if (auto u = e->asUnop()) {
-        visitUnop(u);
-    } else if (auto b = e->asBinop()) {
-        visitBinop(b);
-    } else if (auto c = e->asCall()) {
-        visitCall(c);
-    } else if (auto n = e->asNew()) {
-        visitNew(n);
-    } else if (auto s = e->asSubscript()) {
-        visitSubscript(s);
-    } else if (auto m = e->asMember()) {
-        visitMember(m);
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-void IRPrinter::visitConst(Const *e)
-{
-    switch (e->type) {
-    case QV4::IR::UndefinedType:
-        *out << "undefined";
-        break;
-    case QV4::IR::NullType:
-        *out << "null";
-        break;
-    case QV4::IR::BoolType:
-        *out << (e->value ? "true" : "false");
-        break;
-    case QV4::IR::MissingType:
-        *out << "missing";
-        break;
-    default:
-        if (int(e->value) == 0 && int(e->value) == e->value) {
-            if (isNegative(e->value))
-                *out << "-0";
-            else
-                *out << "0";
-        } else {
-            *out << QString::number(e->value, 'g', 16);
-        }
-        break;
-    }
-}
-
-void IRPrinter::visitString(String *e)
-{
-    *out << '"' << escape(*e->value) << '"';
-}
-
-void IRPrinter::visitRegExp(RegExp *e)
-{
-    char f[3];
-    int i = 0;
-    if (e->flags & RegExp::RegExp_Global)
-        f[i++] = 'g';
-    if (e->flags & RegExp::RegExp_IgnoreCase)
-        f[i++] = 'i';
-    if (e->flags & RegExp::RegExp_Multiline)
-        f[i++] = 'm';
-    f[i] = 0;
-
-    *out << '/' << *e->value << '/' << f;
-}
-
-void IRPrinter::visitName(Name *e)
-{
-    if (e->id) {
-        if (*e->id != QLatin1String("this"))
-            *out << '.';
-        *out << *e->id;
-    } else {
-        *out << builtin_to_string(e->builtin);
-    }
-}
-
-void IRPrinter::visitTemp(Temp *e)
-{
-    switch (e->kind) {
-    case Temp::VirtualRegister:  *out << '%' << e->index; break;
-    case Temp::PhysicalRegister: *out << (e->type == DoubleType ? "fp" : "r")
-                                     << e->index; break;
-    case Temp::StackSlot:        *out << '&' << e->index; break;
-    default:                     *out << "INVALID";
-    }
-}
-
-void IRPrinter::visitArgLocal(ArgLocal *e)
-{
-    switch (e->kind) {
-    case ArgLocal::Formal:           *out << '#' << e->index; break;
-    case ArgLocal::ScopedFormal:     *out << '#' << e->index
-                                     << '@' << e->scope; break;
-    case ArgLocal::Local:            *out << '$' << e->index; break;
-    case ArgLocal::ScopedLocal:      *out << '$' << e->index
-                                     << '@' << e->scope; break;
-    default:                     *out << "INVALID";
-    }
-}
-
-void IRPrinter::visitClosure(Closure *e)
-{
-    QString name = e->functionName ? *e->functionName : QString();
-    if (name.isEmpty())
-        name.sprintf("%x", e->value);
-    *out << "closure " << name;
-}
-
-void IRPrinter::visitConvert(Convert *e)
-{
-    *out << "convert " << typeName(e->expr->type) << " to " << typeName(e->type) << ' ';
-    visit(e->expr);
-}
-
-void IRPrinter::visitUnop(Unop *e)
-{
-    *out << opname(e->op) << ' ';
-    visit(e->expr);
-}
-
-void IRPrinter::visitBinop(Binop *e)
-{
-    *out << opname(e->op) << ' ';
-    visit(e->left);
-    *out << ", ";
-    visit(e->right);
-}
-
-void IRPrinter::visitCall(Call *e)
-{
-    *out << "call ";
-    visit(e->base);
-    *out << '(';
-    for (ExprList *it = e->args; it; it = it->next) {
-        if (it != e->args)
-            *out << ", ";
-        visit(it->expr);
-    }
-    *out << ')';
-}
-
-void IRPrinter::visitNew(New *e)
-{
-    *out << "new ";
-    visit(e->base);
-    *out << '(';
-    for (ExprList *it = e->args; it; it = it->next) {
-        if (it != e->args)
-            *out << ", ";
-        visit(it->expr);
-    }
-    *out << ')';
-}
-
-void IRPrinter::visitSubscript(Subscript *e)
-{
-    visit(e->base);
-    *out << '[';
-    visit(e->index);
-    *out << ']';
-}
-
-void IRPrinter::visitMember(Member *e)
-{
-    if (e->kind != Member::MemberOfEnum && e->kind != Member::MemberOfIdObjectsArray
-            && e->attachedPropertiesId != 0 && !e->base->asTemp())
-        *out << "[[attached property from " << e->attachedPropertiesId << "]]";
-    else
-        visit(e->base);
-    *out << '.' << *e->name;
-#ifndef V4_BOOTSTRAP
-    if (e->property)
-        *out << " (meta-property " << e->property->coreIndex()
-            << " <" << QMetaType::typeName(e->property->propType())
-            << ">)";
-    else if (e->kind == Member::MemberOfIdObjectsArray)
-        *out << "(id object " << e->idIndex << ")";
-#endif
-}
-
-QString IRPrinter::escape(const QString &s)
-{
-    QString r;
-    for (int i = 0; i < s.length(); ++i) {
-        const QChar ch = s.at(i);
-        if (ch == QLatin1Char('\n'))
-            r += QLatin1String("\\n");
-        else if (ch == QLatin1Char('\r'))
-            r += QLatin1String("\\r");
-        else if (ch == QLatin1Char('\\'))
-            r += QLatin1String("\\\\");
-        else if (ch == QLatin1Char('"'))
-            r += QLatin1String("\\\"");
-        else if (ch == QLatin1Char('\''))
-            r += QLatin1String("\\'");
-        else
-            r += ch;
-    }
-    return r;
-}
-
-void IRPrinter::addStmtNr(Stmt *s)
-{
-    if (s->id() >= 0)
-        addJustifiedNr(s->id());
-}
-
-void IRPrinter::addJustifiedNr(int pos)
-{
-    if (positionSize == Stmt::InvalidId) {
-        *out << pos << ": ";
-    } else {
-        QString posStr;
-        if (pos != Stmt::InvalidId)
-            posStr = QString::number(pos);
-        *out << posStr.rightJustified(positionSize);
-        if (pos == Stmt::InvalidId)
-            *out << "  ";
-        else
-            *out << ": ";
-    }
-}
-
-void IRPrinter::printBlockStart()
-{
-    if (currentBB->isRemoved()) {
-        *out << "(block has been removed)";
-        return;
-    }
-
-    QByteArray str;
-    str.append('L');
-    str.append(QByteArray::number(currentBB->index()));
-    str.append(':');
-    if (currentBB->catchBlock) {
-        str.append(" (exception handler L");
-        str.append(QByteArray::number(currentBB->catchBlock->index()));
-        str.append(')');
-    }
-    for (int i = 66 - str.length(); i; --i)
-        str.append(' ');
-    *out << str;
-
-    *out << "; predecessors:";
-    for (BasicBlock *in : qAsConst(currentBB->in))
-        *out << " L" << in->index();
-    if (currentBB->in.isEmpty())
-        *out << " none";
-    if (BasicBlock *container = currentBB->containingGroup())
-        *out << ", container: L" << container->index();
-    if (currentBB->isGroupStart())
-        *out << ", loop_header: yes";
-    *out << endl;
-}
-
-} // end of namespace IR
-} // end of namespace QV4
-
-QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4jsir_p.h b/src/qml/compiler/qv4jsir_p.h
deleted file mode 100644
index b534eaa54f..0000000000
--- a/src/qml/compiler/qv4jsir_p.h
+++ /dev/null
@@ -1,1792 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#ifndef QV4JSIR_P_H
-#define QV4JSIR_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "private/qv4global_p.h"
-#include <private/qqmljsmemorypool_p.h>
-#include <private/qqmljsastfwd_p.h>
-#include <private/qflagpointer_p.h>
-
-#include <QtCore/private/qnumeric_p.h>
-#include <QtCore/QVector>
-#include <QtCore/QString>
-#include <QtCore/QBitArray>
-#include <QtCore/qurl.h>
-#include <QtCore/QVarLengthArray>
-#include <QtCore/QDateTime>
-#include <qglobal.h>
-
-#if defined(CONST) && defined(Q_OS_WIN)
-# define QT_POP_CONST
-# pragma push_macro("CONST")
-# undef CONST // CONST conflicts with our own identifier
-#endif
-
-QT_BEGIN_NAMESPACE
-
-class QTextStream;
-class QQmlType;
-class QQmlPropertyData;
-class QQmlPropertyCache;
-class QQmlEnginePrivate;
-
-namespace QV4 {
-
-inline bool isNegative(double d)
-{
-    uchar *dch = (uchar *)&d;
-    if (QSysInfo::ByteOrder == QSysInfo::BigEndian)
-        return (dch[0] & 0x80);
-    else
-        return (dch[7] & 0x80);
-
-}
-
-namespace IR {
-
-struct BasicBlock;
-struct Function;
-struct Module;
-
-struct Stmt;
-struct Expr;
-
-// expressions
-struct Const;
-struct String;
-struct RegExp;
-struct Name;
-struct Temp;
-struct ArgLocal;
-struct Closure;
-struct Convert;
-struct Unop;
-struct Binop;
-struct Call;
-struct New;
-struct Subscript;
-struct Member;
-
-// statements
-struct Exp;
-struct Move;
-struct Jump;
-struct CJump;
-struct Ret;
-struct Phi;
-
-template<class T, int Prealloc>
-class VarLengthArray: public QVarLengthArray<T, Prealloc>
-{
-public:
-    bool removeOne(const T &element)
-    {
-        for (int i = 0; i < this->size(); ++i) {
-            if (this->at(i) == element) {
-                this->remove(i);
-                return true;
-            }
-        }
-
-        return false;
-    }
-};
-
-// Flag pointer:
-// * The first flag indicates whether the meta object is final.
-//   If final, then none of its properties themselves need to
-//   be final when considering for lookups in QML.
-// * The second flag indicates whether enums should be included
-//   in the lookup of properties or not. The default is false.
-typedef QFlagPointer<QQmlPropertyCache> IRMetaObject;
-
-enum AluOp {
-    OpInvalid = 0,
-
-    OpIfTrue,
-    OpNot,
-    OpUMinus,
-    OpUPlus,
-    OpCompl,
-    OpIncrement,
-    OpDecrement,
-
-    OpBitAnd,
-    OpBitOr,
-    OpBitXor,
-
-    OpAdd,
-    OpSub,
-    OpMul,
-    OpDiv,
-    OpMod,
-
-    OpLShift,
-    OpRShift,
-    OpURShift,
-
-    OpGt,
-    OpLt,
-    OpGe,
-    OpLe,
-    OpEqual,
-    OpNotEqual,
-    OpStrictEqual,
-    OpStrictNotEqual,
-
-    OpInstanceof,
-    OpIn,
-
-    OpAnd,
-    OpOr,
-
-    LastAluOp = OpOr
-};
-AluOp binaryOperator(int op);
-const char *opname(IR::AluOp op);
-
-enum Type : quint16 {
-    UnknownType   = 0,
-
-    MissingType   = 1 << 0,
-    UndefinedType = 1 << 1,
-    NullType      = 1 << 2,
-    BoolType      = 1 << 3,
-
-    SInt32Type    = 1 << 4,
-    UInt32Type    = 1 << 5,
-    DoubleType    = 1 << 6,
-    NumberType    = SInt32Type | UInt32Type | DoubleType,
-
-    StringType    = 1 << 7,
-    QObjectType   = 1 << 8,
-    VarType       = 1 << 9
-};
-
-inline bool strictlyEqualTypes(Type t1, Type t2)
-{
-    return t1 == t2 || ((t1 & NumberType) && (t2 & NumberType));
-}
-
-QString typeName(Type t);
-
-struct MemberExpressionResolver;
-
-struct DiscoveredType {
-    int type;
-    MemberExpressionResolver *memberResolver;
-
-    DiscoveredType() : type(UnknownType), memberResolver(0) {}
-    DiscoveredType(Type t) : type(t), memberResolver(0) { Q_ASSERT(type != QObjectType); }
-    explicit DiscoveredType(int t) : type(t), memberResolver(0) { Q_ASSERT(type != QObjectType); }
-    explicit DiscoveredType(MemberExpressionResolver *memberResolver)
-        : type(QObjectType)
-        , memberResolver(memberResolver)
-    { Q_ASSERT(memberResolver); }
-
-    bool test(Type t) const { return type & t; }
-    bool isNumber() const { return (type & NumberType) && !(type & ~NumberType); }
-
-    bool operator!=(Type other) const { return type != other; }
-    bool operator==(Type other) const { return type == other; }
-    bool operator==(const DiscoveredType &other) const { return type == other.type; }
-    bool operator!=(const DiscoveredType &other) const { return type != other.type; }
-};
-
-struct MemberExpressionResolver
-{
-    typedef DiscoveredType (*ResolveFunction)(QQmlEnginePrivate *engine,
-                                              const MemberExpressionResolver *resolver,
-                                              Member *member);
-
-    MemberExpressionResolver()
-        : resolveMember(0), data(0), extraData(0), owner(nullptr), flags(0) {}
-
-    bool isValid() const { return !!resolveMember; }
-    void clear() { *this = MemberExpressionResolver(); }
-
-    ResolveFunction resolveMember;
-    void *data; // Could be pointer to meta object, importNameSpace, etc. - depends on resolveMember implementation
-    void *extraData; // Could be QQmlTypeNameCache
-    Function *owner;
-    unsigned int flags;
-};
-
-struct Q_AUTOTEST_EXPORT Expr {
-    enum ExprKind : quint8 {
-        NameExpr,
-        TempExpr,
-        ArgLocalExpr,
-        SubscriptExpr,
-        MemberExpr,
-
-        LastLValue = MemberExpr,
-
-        ConstExpr,
-        StringExpr,
-        RegExpExpr,
-        ClosureExpr,
-        ConvertExpr,
-        UnopExpr,
-        BinopExpr,
-        CallExpr,
-        NewExpr
-    };
-
-    Type type;
-    const ExprKind exprKind;
-
-    Expr &operator=(const Expr &other) {
-        Q_ASSERT(exprKind == other.exprKind);
-        type = other.type;
-        return *this;
-    }
-
-    template <typename To>
-    inline bool isa() const {
-        return To::classof(this);
-    }
-
-    template <typename To>
-    inline To *as() {
-        if (isa<To>()) {
-            return static_cast<To *>(this);
-        } else {
-            return nullptr;
-        }
-    }
-
-    template <typename To>
-    inline const To *as() const {
-        if (isa<To>()) {
-            return static_cast<const To *>(this);
-        } else {
-            return nullptr;
-        }
-    }
-
-    Expr(ExprKind exprKind): type(UnknownType), exprKind(exprKind) {}
-    bool isLValue() const;
-
-    Const *asConst();
-    String *asString();
-    RegExp *asRegExp();
-    Name *asName();
-    Temp *asTemp();
-    ArgLocal *asArgLocal();
-    Closure *asClosure();
-    Convert *asConvert();
-    Unop *asUnop();
-    Binop *asBinop();
-    Call *asCall();
-    New *asNew();
-    Subscript *asSubscript();
-    Member *asMember();
-};
-
-#define EXPR_VISIT_ALL_KINDS(e) \
-    switch (e->exprKind) { \
-    case QV4::IR::Expr::ConstExpr: \
-        break; \
-    case QV4::IR::Expr::StringExpr: \
-        break; \
-    case QV4::IR::Expr::RegExpExpr: \
-        break; \
-    case QV4::IR::Expr::NameExpr: \
-        break; \
-    case QV4::IR::Expr::TempExpr: \
-        break; \
-    case QV4::IR::Expr::ArgLocalExpr: \
-        break; \
-    case QV4::IR::Expr::ClosureExpr: \
-        break; \
-    case QV4::IR::Expr::ConvertExpr: { \
-        auto casted = e->asConvert(); \
-        visit(casted->expr); \
-    } break; \
-    case QV4::IR::Expr::UnopExpr: { \
-        auto casted = e->asUnop(); \
-        visit(casted->expr); \
-    } break; \
-    case QV4::IR::Expr::BinopExpr: { \
-        auto casted = e->asBinop(); \
-        visit(casted->left); \
-        visit(casted->right); \
-    } break; \
-    case QV4::IR::Expr::CallExpr: { \
-        auto casted = e->asCall(); \
-        visit(casted->base); \
-        for (QV4::IR::ExprList *it = casted->args; it; it = it->next) \
-            visit(it->expr); \
-    } break; \
-    case QV4::IR::Expr::NewExpr: { \
-        auto casted = e->asNew(); \
-        visit(casted->base); \
-        for (QV4::IR::ExprList *it = casted->args; it; it = it->next) \
-            visit(it->expr); \
-    } break; \
-    case QV4::IR::Expr::SubscriptExpr: { \
-        auto casted = e->asSubscript(); \
-        visit(casted->base); \
-        visit(casted->index); \
-    } break; \
-    case QV4::IR::Expr::MemberExpr: { \
-        auto casted = e->asMember(); \
-        visit(casted->base); \
-    } break; \
-    }
-
-struct ExprList {
-    Expr *expr;
-    ExprList *next;
-
-    ExprList(): expr(0), next(0) {}
-
-    void init(Expr *expr, ExprList *next = 0)
-    {
-        this->expr = expr;
-        this->next = next;
-    }
-};
-
-struct Const: Expr {
-    double value;
-
-    Const(): Expr(ConstExpr) {}
-
-    void init(Type type, double value)
-    {
-        this->type = type;
-        this->value = value;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == ConstExpr; }
-};
-
-struct String: Expr {
-    const QString *value;
-
-    String(): Expr(StringExpr) {}
-
-    void init(const QString *value)
-    {
-        this->value = value;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == StringExpr; }
-};
-
-struct RegExp: Expr {
-    // needs to be compatible with the flags in the lexer, and in RegExpObject
-    enum Flags {
-        RegExp_Global     = 0x01,
-        RegExp_IgnoreCase = 0x02,
-        RegExp_Multiline  = 0x04
-    };
-
-    const QString *value;
-    int flags;
-
-    RegExp(): Expr(RegExpExpr) {}
-
-    void init(const QString *value, int flags)
-    {
-        this->value = value;
-        this->flags = flags;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == RegExpExpr; }
-};
-
-struct Name: Expr {
-    enum Builtin {
-        builtin_invalid,
-        builtin_typeof,
-        builtin_delete,
-        builtin_throw,
-        builtin_rethrow,
-        builtin_unwind_exception,
-        builtin_push_catch_scope,
-        builtin_foreach_iterator_object,
-        builtin_foreach_next_property_name,
-        builtin_push_with_scope,
-        builtin_pop_scope,
-        builtin_declare_vars,
-        builtin_define_array,
-        builtin_define_object_literal,
-        builtin_setup_argument_object,
-        builtin_convert_this_to_object,
-        builtin_qml_context,
-        builtin_qml_imported_scripts_object
-    };
-
-    const QString *id;
-    Builtin builtin;
-    bool global : 1;
-    bool qmlSingleton : 1;
-    bool freeOfSideEffects : 1;
-    quint32 line;
-    quint32 column;
-
-    Name(): Expr(NameExpr) {}
-
-    void initGlobal(const QString *id, quint32 line, quint32 column);
-    void init(const QString *id, quint32 line, quint32 column);
-    void init(Builtin builtin, quint32 line, quint32 column);
-
-    static bool classof(const Expr *c) { return c->exprKind == NameExpr; }
-};
-
-struct Q_AUTOTEST_EXPORT Temp: Expr {
-    enum Kind {
-        Invalid = 0,
-        VirtualRegister,
-        PhysicalRegister,
-        StackSlot
-    };
-
-    unsigned index      : 28;
-    unsigned isReadOnly :  1;
-    unsigned kind       :  3;
-
-    // Used when temp is used as base in member expression
-    MemberExpressionResolver *memberResolver;
-
-    Temp()
-        : Expr(TempExpr)
-        , index((1 << 28) - 1)
-        , isReadOnly(0)
-        , kind(Invalid)
-        , memberResolver(0)
-    {}
-
-    Temp(Type type, Kind kind, unsigned index)
-        : Expr(TempExpr)
-        , index(index)
-        , isReadOnly(0)
-        , kind(kind)
-        , memberResolver(0)
-    {
-        this->type = type;
-    }
-
-    void init(unsigned kind, unsigned index)
-    {
-        this->index = index;
-        this->isReadOnly = false;
-        this->kind = kind;
-    }
-
-    bool isInvalid() const { return kind == Invalid; }
-
-    static bool classof(const Expr *c) { return c->exprKind == TempExpr; }
-};
-
-inline bool operator==(const Temp &t1, const Temp &t2) Q_DECL_NOTHROW
-{ return t1.index == t2.index && t1.kind == t2.kind && t1.type == t2.type; }
-
-inline bool operator!=(const Temp &t1, const Temp &t2) Q_DECL_NOTHROW
-{ return !(t1 == t2); }
-
-inline uint qHash(const Temp &t, uint seed = 0) Q_DECL_NOTHROW
-{ return t.index ^ t.kind ^ seed; }
-
-bool operator<(const Temp &t1, const Temp &t2) Q_DECL_NOTHROW;
-
-struct Q_AUTOTEST_EXPORT ArgLocal: Expr {
-    enum Kind {
-        Formal = 0,
-        ScopedFormal,
-        Local,
-        ScopedLocal
-    };
-
-    unsigned index;
-    unsigned scope             : 29; // how many scopes outside the current one?
-    unsigned kind              :  2;
-    unsigned isArgumentsOrEval :  1;
-
-    void init(unsigned kind, unsigned index, unsigned scope)
-    {
-        Q_ASSERT((kind == ScopedLocal && scope != 0) ||
-                 (kind == ScopedFormal && scope != 0) ||
-                 (scope == 0));
-
-        this->kind = kind;
-        this->index = index;
-        this->scope = scope;
-        this->isArgumentsOrEval = false;
-    }
-
-    ArgLocal(): Expr(ArgLocalExpr) {}
-
-    bool operator==(const ArgLocal &other) const
-    { return index == other.index && scope == other.scope && kind == other.kind; }
-
-    static bool classof(const Expr *c) { return c->exprKind == ArgLocalExpr; }
-};
-
-struct Closure: Expr {
-    int value; // index in _module->functions
-    const QString *functionName;
-
-    Closure(): Expr(ClosureExpr) {}
-
-    void init(int functionInModule, const QString *functionName)
-    {
-        this->value = functionInModule;
-        this->functionName = functionName;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == ClosureExpr; }
-};
-
-struct Convert: Expr {
-    Expr *expr;
-
-    Convert(): Expr(ConvertExpr) {}
-
-    void init(Expr *expr, Type type)
-    {
-        this->expr = expr;
-        this->type = type;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == ConvertExpr; }
-};
-
-struct Unop: Expr {
-    Expr *expr;
-    AluOp op;
-
-    Unop(): Expr(UnopExpr) {}
-
-    void init(AluOp op, Expr *expr)
-    {
-        this->op = op;
-        this->expr = expr;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == UnopExpr; }
-};
-
-struct Binop: Expr {
-    Expr *left; // Temp or Const
-    Expr *right; // Temp or Const
-    AluOp op;
-
-    Binop(): Expr(BinopExpr) {}
-
-    void init(AluOp op, Expr *left, Expr *right)
-    {
-        this->op = op;
-        this->left = left;
-        this->right = right;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == BinopExpr; }
-};
-
-struct Call: Expr {
-    Expr *base; // Name, Member, Temp
-    ExprList *args; // List of Temps
-
-    Call(): Expr(CallExpr) {}
-
-    void init(Expr *base, ExprList *args)
-    {
-        this->base = base;
-        this->args = args;
-    }
-
-    Expr *onlyArgument() const {
-        if (args && ! args->next)
-            return args->expr;
-        return 0;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == CallExpr; }
-};
-
-struct New: Expr {
-    Expr *base; // Name, Member, Temp
-    ExprList *args; // List of Temps
-
-    New(): Expr(NewExpr) {}
-
-    void init(Expr *base, ExprList *args)
-    {
-        this->base = base;
-        this->args = args;
-    }
-
-    Expr *onlyArgument() const {
-        if (args && ! args->next)
-            return args->expr;
-        return 0;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == NewExpr; }
-};
-
-struct Subscript: Expr {
-    Expr *base;
-    Expr *index;
-
-    Subscript(): Expr(SubscriptExpr) {}
-
-    void init(Expr *base, Expr *index)
-    {
-        this->base = base;
-        this->index = index;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == SubscriptExpr; }
-};
-
-struct Member: Expr {
-    // Used for property dependency tracking
-    enum MemberKind {
-        UnspecifiedMember,
-        MemberOfEnum,
-        MemberOfQmlScopeObject,
-        MemberOfQmlContextObject,
-        MemberOfIdObjectsArray,
-        MemberOfSingletonObject,
-    };
-
-    Expr *base;
-    const QString *name;
-    QQmlPropertyData *property;
-    union {  // depending on kind
-        int attachedPropertiesId;
-        int enumValue;
-        int idIndex;
-    };
-    uchar freeOfSideEffects : 1;
-
-    // This is set for example for for QObject properties. All sorts of extra behavior
-    // is defined when writing to them, for example resettable properties are reset
-    // when writing undefined to them, and an exception is thrown when they're missing
-    // a reset function. And then there's also Qt.binding().
-    uchar inhibitTypeConversionOnWrite: 1;
-
-    uchar kind: 3; // MemberKind
-
-    Member(): Expr(MemberExpr) {}
-
-    void setEnumValue(int value) {
-        kind = MemberOfEnum;
-        enumValue = value;
-    }
-
-    void setAttachedPropertiesId(int id) {
-        Q_ASSERT(kind != MemberOfEnum && kind != MemberOfIdObjectsArray);
-        attachedPropertiesId = id;
-    }
-
-    void init(Expr *base, const QString *name, QQmlPropertyData *property = 0, uchar kind = UnspecifiedMember, int index = 0)
-    {
-        this->base = base;
-        this->name = name;
-        this->property = property;
-        this->idIndex = index;
-        this->freeOfSideEffects = false;
-        this->inhibitTypeConversionOnWrite = property != 0;
-        this->kind = kind;
-    }
-
-    static bool classof(const Expr *c) { return c->exprKind == MemberExpr; }
-};
-
-inline bool Expr::isLValue() const {
-    if (auto t = as<Temp>())
-        return !t->isReadOnly;
-    return exprKind <= LastLValue;
-}
-
-struct Stmt {
-    enum StmtKind: quint8 {
-        MoveStmt,
-        ExpStmt,
-        JumpStmt,
-        CJumpStmt,
-        RetStmt,
-        PhiStmt
-    };
-
-    template <typename To>
-    inline bool isa() const {
-        return To::classof(this);
-    }
-
-    template <typename To>
-    inline To *as() {
-        if (isa<To>())
-            return static_cast<To *>(this);
-        else
-            return nullptr;
-    }
-
-    enum { InvalidId = -1 };
-
-    QQmlJS::AST::SourceLocation location;
-
-    explicit Stmt(int id, StmtKind stmtKind): _id(id), stmtKind(stmtKind) {}
-
-    Stmt *asTerminator();
-
-    Exp *asExp();
-    Move *asMove();
-    Jump *asJump();
-    CJump *asCJump();
-    Ret *asRet();
-    Phi *asPhi();
-
-    int id() const { return _id; }
-
-private: // For memory management in BasicBlock
-    friend struct BasicBlock;
-
-private:
-    friend struct Function;
-    int _id;
-
-public:
-    const StmtKind stmtKind;
-};
-
-#define STMT_VISIT_ALL_KINDS(s) \
-    switch (s->stmtKind) { \
-    case QV4::IR::Stmt::MoveStmt: { \
-        auto casted = s->asMove(); \
-        visit(casted->target); \
-        visit(casted->source); \
-    } break; \
-    case QV4::IR::Stmt::ExpStmt: { \
-        auto casted = s->asExp(); \
-        visit(casted->expr); \
-    } break; \
-    case QV4::IR::Stmt::JumpStmt: \
-        break; \
-    case QV4::IR::Stmt::CJumpStmt: { \
-        auto casted = s->asCJump(); \
-        visit(casted->cond); \
-    } break; \
-    case QV4::IR::Stmt::RetStmt: { \
-        auto casted = s->asRet(); \
-        visit(casted->expr); \
-    } break; \
-    case QV4::IR::Stmt::PhiStmt: { \
-        auto casted = s->asPhi(); \
-        visit(casted->targetTemp); \
-        for (auto *e : casted->incoming) { \
-            visit(e); \
-        } \
-    } break; \
-    }
-
-struct Exp: Stmt {
-    Expr *expr;
-
-    Exp(int id): Stmt(id, ExpStmt) {}
-
-    void init(Expr *expr)
-    {
-        this->expr = expr;
-    }
-
-    static bool classof(const Stmt *c) { return c->stmtKind == ExpStmt; }
-};
-
-struct Move: Stmt {
-    Expr *target; // LHS - Temp, Name, Member or Subscript
-    Expr *source;
-    bool swap;
-
-    Move(int id): Stmt(id, MoveStmt) {}
-
-    void init(Expr *target, Expr *source)
-    {
-        this->target = target;
-        this->source = source;
-        this->swap = false;
-    }
-
-    static bool classof(const Stmt *c) { return c->stmtKind == MoveStmt; }
-};
-
-struct Jump: Stmt {
-    BasicBlock *target;
-
-    Jump(int id): Stmt(id, JumpStmt) {}
-
-    void init(BasicBlock *target)
-    {
-        this->target = target;
-    }
-
-    static bool classof(const Stmt *c) { return c->stmtKind == JumpStmt; }
-};
-
-struct CJump: Stmt {
-    Expr *cond; // Temp, Binop
-    BasicBlock *iftrue;
-    BasicBlock *iffalse;
-    BasicBlock *parent;
-
-    CJump(int id): Stmt(id, CJumpStmt) {}
-
-    void init(Expr *cond, BasicBlock *iftrue, BasicBlock *iffalse, BasicBlock *parent)
-    {
-        this->cond = cond;
-        this->iftrue = iftrue;
-        this->iffalse = iffalse;
-        this->parent = parent;
-    }
-
-    static bool classof(const Stmt *c) { return c->stmtKind == CJumpStmt; }
-};
-
-struct Ret: Stmt {
-    Expr *expr;
-
-    Ret(int id): Stmt(id, RetStmt) {}
-
-    void init(Expr *expr)
-    {
-        this->expr = expr;
-    }
-
-    static bool classof(const Stmt *c) { return c->stmtKind == RetStmt; }
-};
-
-// Phi nodes can only occur at the start of a basic block. If there are any, they need to be
-// subsequent to eachother, and the first phi node should be the first statement in the basic-block.
-// A number of loops rely on this behavior, so they don't need to walk through the whole list
-// of instructions in a basic-block (e.g. the calls to destroyData in BasicBlock::~BasicBlock).
-struct Phi: Stmt {
-    Temp *targetTemp;
-    VarLengthArray<Expr *, 4> incoming;
-
-    Phi(int id): Stmt(id, PhiStmt) {}
-
-    static bool classof(const Stmt *c) { return c->stmtKind == PhiStmt; }
-
-    void destroyData()
-    { incoming.~VarLengthArray(); }
-};
-
-inline Stmt *Stmt::asTerminator()
-{
-    if (auto s = asJump()) {
-        return s;
-    } else if (auto s = asCJump()) {
-        return s;
-    } else if (auto s = asRet()) {
-        return s;
-    } else {
-        return nullptr;
-    }
-}
-
-struct Q_QML_PRIVATE_EXPORT Module {
-    QQmlJS::MemoryPool pool;
-    QVector<Function *> functions;
-    Function *rootFunction;
-    QString fileName;
-    QDateTime sourceTimeStamp;
-    bool isQmlModule; // implies rootFunction is always 0
-    uint unitFlags; // flags merged into CompiledData::Unit::flags
-    QString targetABI; // fallback to QSysInfo::buildAbi() if empty
-#ifdef QT_NO_QML_DEBUGGER
-    static const bool debugMode = false;
-#else
-    bool debugMode;
-#endif
-
-    Function *newFunction(const QString &name, Function *outer);
-
-    Module(bool debugMode)
-        : rootFunction(0)
-        , isQmlModule(false)
-        , unitFlags(0)
-#ifndef QT_NO_QML_DEBUGGER
-        , debugMode(debugMode)
-    {}
-#else
-    { Q_UNUSED(debugMode); }
-#endif
-    ~Module();
-
-    void setFileName(const QString &name);
-};
-
-struct BasicBlock {
-private:
-    Q_DISABLE_COPY(BasicBlock)
-
-public:
-    typedef VarLengthArray<BasicBlock *, 4> IncomingEdges;
-    typedef VarLengthArray<BasicBlock *, 2> OutgoingEdges;
-
-    Function *function;
-    BasicBlock *catchBlock;
-    IncomingEdges in;
-    OutgoingEdges out;
-    QQmlJS::AST::SourceLocation nextLocation;
-
-    BasicBlock(Function *function, BasicBlock *catcher)
-        : function(function)
-        , catchBlock(catcher)
-        , _containingGroup(0)
-        , _index(-1)
-        , _isExceptionHandler(false)
-        , _groupStart(false)
-        , _isRemoved(false)
-    {}
-
-    ~BasicBlock()
-    {
-        for (Stmt *s : qAsConst(_statements)) {
-            if (Phi *p = s->asPhi()) {
-                p->destroyData();
-            } else {
-                break;
-            }
-        }
-    }
-
-    const QVector<Stmt *> &statements() const
-    {
-        Q_ASSERT(!isRemoved());
-        return _statements;
-    }
-
-    int statementCount() const
-    {
-        Q_ASSERT(!isRemoved());
-        return _statements.size();
-    }
-
-    void setStatements(const QVector<Stmt *> &newStatements);
-
-    template <typename Instr> inline Instr i(Instr i)
-    {
-        Q_ASSERT(!isRemoved());
-        appendStatement(i);
-        return i;
-    }
-
-    void appendStatement(Stmt *statement)
-    {
-        Q_ASSERT(!isRemoved());
-        if (nextLocation.startLine)
-            statement->location = nextLocation;
-        _statements.append(statement);
-    }
-
-    void prependStatement(Stmt *stmt)
-    {
-        Q_ASSERT(!isRemoved());
-        _statements.prepend(stmt);
-    }
-
-    void prependStatements(const QVector<Stmt *> &stmts)
-    {
-        Q_ASSERT(!isRemoved());
-        QVector<Stmt *> newStmts = stmts;
-        newStmts += _statements;
-        _statements = newStmts;
-    }
-
-    void insertStatementBefore(Stmt *before, Stmt *newStmt)
-    {
-        int idx = _statements.indexOf(before);
-        Q_ASSERT(idx >= 0);
-        _statements.insert(idx, newStmt);
-    }
-
-    void insertStatementBefore(int index, Stmt *newStmt)
-    {
-        Q_ASSERT(index >= 0);
-        _statements.insert(index, newStmt);
-    }
-
-    void insertStatementBeforeTerminator(Stmt *stmt)
-    {
-        Q_ASSERT(!isRemoved());
-        _statements.insert(_statements.size() - 1, stmt);
-    }
-
-    void replaceStatement(int index, Stmt *newStmt)
-    {
-        Q_ASSERT(!isRemoved());
-        if (Phi *p = _statements[index]->asPhi()) {
-            p->destroyData();
-        }
-        _statements[index] = newStmt;
-    }
-
-    void removeStatement(Stmt *stmt)
-    {
-        Q_ASSERT(!isRemoved());
-        if (Phi *p = stmt->asPhi()) {
-            p->destroyData();
-        }
-        _statements.remove(_statements.indexOf(stmt));
-    }
-
-    void removeStatement(int idx)
-    {
-        Q_ASSERT(!isRemoved());
-        if (Phi *p = _statements[idx]->asPhi()) {
-            p->destroyData();
-        }
-        _statements.remove(idx);
-    }
-
-    inline bool isEmpty() const {
-        Q_ASSERT(!isRemoved());
-        return _statements.isEmpty();
-    }
-
-    inline Stmt *terminator() const {
-        Q_ASSERT(!isRemoved());
-        if (! _statements.isEmpty() && _statements.last()->asTerminator() != 0)
-            return _statements.last();
-        return 0;
-    }
-
-    inline bool isTerminated() const {
-        Q_ASSERT(!isRemoved());
-        if (terminator() != 0)
-            return true;
-        return false;
-    }
-
-    unsigned newTemp();
-
-    Temp *TEMP(unsigned kind);
-    ArgLocal *ARG(unsigned index, unsigned scope);
-    ArgLocal *LOCAL(unsigned index, unsigned scope);
-
-    Expr *CONST(Type type, double value);
-    Expr *STRING(const QString *value);
-    Expr *REGEXP(const QString *value, int flags);
-
-    Name *NAME(const QString &id, quint32 line, quint32 column);
-    Name *NAME(Name::Builtin builtin, quint32 line, quint32 column);
-
-    Name *GLOBALNAME(const QString &id, quint32 line, quint32 column);
-
-    Closure *CLOSURE(int functionInModule);
-
-    Expr *CONVERT(Expr *expr, Type type);
-    Expr *UNOP(AluOp op, Expr *expr);
-    Expr *BINOP(AluOp op, Expr *left, Expr *right);
-    Expr *CALL(Expr *base, ExprList *args = 0);
-    Expr *NEW(Expr *base, ExprList *args = 0);
-    Expr *SUBSCRIPT(Expr *base, Expr *index);
-    Expr *MEMBER(Expr *base, const QString *name, QQmlPropertyData *property = 0, uchar kind = Member::UnspecifiedMember, int attachedPropertiesIdOrEnumValue = 0);
-
-    Stmt *EXP(Expr *expr);
-
-    Stmt *MOVE(Expr *target, Expr *source);
-
-    Stmt *JUMP(BasicBlock *target);
-    Stmt *CJUMP(Expr *cond, BasicBlock *iftrue, BasicBlock *iffalse);
-    Stmt *RET(Expr *expr);
-
-    BasicBlock *containingGroup() const
-    {
-        Q_ASSERT(!isRemoved());
-        return _containingGroup;
-    }
-
-    void setContainingGroup(BasicBlock *loopHeader)
-    {
-        Q_ASSERT(!isRemoved());
-        _containingGroup = loopHeader;
-    }
-
-    bool isGroupStart() const
-    {
-        Q_ASSERT(!isRemoved());
-        return _groupStart;
-    }
-
-    void markAsGroupStart(bool mark = true)
-    {
-        Q_ASSERT(!isRemoved());
-        _groupStart = mark;
-    }
-
-    // Returns the index of the basic-block.
-    // See Function for the full description.
-    int index() const
-    {
-        Q_ASSERT(!isRemoved());
-        return _index;
-    }
-
-    bool isExceptionHandler() const
-    { return _isExceptionHandler; }
-
-    void setExceptionHandler(bool onoff)
-    { _isExceptionHandler = onoff; }
-
-    bool isRemoved() const
-    { return _isRemoved; }
-
-private: // For Function's eyes only.
-    friend struct Function;
-    void setIndex(int index)
-    {
-        Q_ASSERT(_index < 0);
-        changeIndex(index);
-    }
-
-    void changeIndex(int index)
-    {
-        Q_ASSERT(index >= 0);
-        _index = index;
-    }
-
-    void markAsRemoved()
-    {
-        _isRemoved = true;
-        _index = -1;
-    }
-
-private:
-    QVector<Stmt *> _statements;
-    BasicBlock *_containingGroup;
-    int _index;
-    unsigned _isExceptionHandler : 1;
-    unsigned _groupStart : 1;
-    unsigned _isRemoved : 1;
-};
-
-template <typename T>
-class SmallSet: public QVarLengthArray<T, 8>
-{
-public:
-    void insert(int value)
-    {
-        for (auto it : *this) {
-            if (it == value)
-                return;
-        }
-        this->append(value);
-    }
-};
-
-// Map from meta property index (existence implies dependency) to notify signal index
-struct KeyValuePair
-{
-    quint32 _key;
-    quint32 _value;
-
-    KeyValuePair(): _key(0), _value(0) {}
-    KeyValuePair(quint32 key, quint32 value): _key(key), _value(value) {}
-
-    quint32 key() const { return _key; }
-    quint32 value() const { return _value; }
-};
-
-class PropertyDependencyMap: public QVarLengthArray<KeyValuePair, 8>
-{
-public:
-    void insert(quint32 key, quint32 value)
-    {
-        for (auto it = begin(), eit = end(); it != eit; ++it) {
-            if (it->_key == key) {
-                it->_value = value;
-                return;
-            }
-        }
-        append(KeyValuePair(key, value));
-    }
-};
-
-// The Function owns (manages), among things, a list of basic-blocks. All the blocks have an index,
-// which corresponds to the index in the entry/index in the vector in which they are stored. This
-// means that algorithms/classes can also store any information about a basic block in an array,
-// where the index corresponds to the index of the basic block, which can then be used to query
-// the function for a pointer to a basic block. This also means that basic-blocks cannot be removed
-// or renumbered.
-//
-// Note that currently there is one exception: after optimization and block scheduling, the
-// method setScheduledBlocks can be called once, to register a newly ordered list. For debugging
-// purposes, these blocks are not immediately renumbered, so renumberBasicBlocks should be called
-// immediately after changing the order. That will restore the property of having a corresponding
-// block-index and block-position-in-basicBlocks-vector.
-//
-// In order for optimization/transformation passes to skip uninteresting basic blocks that will be
-// removed, the block can be marked as such. After doing so, any access will result in a failing
-// assertion.
-struct Function {
-    Module *module;
-    QQmlJS::MemoryPool *pool;
-    const QString *name;
-    int tempCount;
-    int maxNumberOfArguments;
-    QSet<QString> strings;
-    QList<const QString *> formals;
-    QList<const QString *> locals;
-    QVector<Function *> nestedFunctions;
-    Function *outer;
-
-    int insideWithOrCatch;
-
-    uint hasDirectEval: 1;
-    uint usesArgumentsObject : 1;
-    uint usesThis : 1;
-    uint isStrict: 1;
-    uint isNamedExpression : 1;
-    uint hasTry: 1;
-    uint hasWith: 1;
-    uint isQmlBinding: 1;
-    uint unused : 24;
-
-    // Location of declaration in source code (0 if not specified)
-    uint line;
-    uint column;
-
-    // Qml extension:
-    SmallSet<int> idObjectDependencies;
-    PropertyDependencyMap contextObjectPropertyDependencies;
-    PropertyDependencyMap scopeObjectPropertyDependencies;
-
-    template <typename T> T *New() { return new (pool->allocate(sizeof(T))) T(); }
-    template <typename T> T *NewStmt() {
-        return new (pool->allocate(sizeof(T))) T(getNewStatementId());
-    }
-
-    Function(Module *module, Function *outer, const QString &name);
-    ~Function();
-
-    enum BasicBlockInsertMode {
-        InsertBlock,
-        DontInsertBlock
-    };
-
-    BasicBlock *newBasicBlock(BasicBlock *catchBlock, BasicBlockInsertMode mode = InsertBlock);
-    const QString *newString(const QString &text);
-
-    void RECEIVE(const QString &name) { formals.append(newString(name)); }
-    void LOCAL(const QString &name) { locals.append(newString(name)); }
-
-    BasicBlock *addBasicBlock(BasicBlock *block);
-    void removeBasicBlock(BasicBlock *block);
-
-    const QVector<BasicBlock *> &basicBlocks() const
-    { return _basicBlocks; }
-
-    BasicBlock *basicBlock(int idx) const
-    { return _basicBlocks.at(idx); }
-
-    int basicBlockCount() const
-    { return _basicBlocks.size(); }
-
-    int liveBasicBlocksCount() const;
-
-    void removeSharedExpressions();
-
-    int indexOfArgument(const QStringRef &string) const;
-
-    bool variablesCanEscape() const
-    { return hasDirectEval || !nestedFunctions.isEmpty() || module->debugMode; }
-
-    void setScheduledBlocks(const QVector<BasicBlock *> &scheduled);
-
-    int getNewStatementId() { return _statementCount++; }
-    int statementCount() const { return _statementCount; }
-
-    bool canUseSimpleCall() const {
-        return nestedFunctions.isEmpty() &&
-               locals.isEmpty() && formals.size() <= QV4::Global::ReservedArgumentCount &&
-               !hasTry && !hasWith && !isNamedExpression && !usesArgumentsObject && !hasDirectEval;
-    }
-
-    bool argLocalRequiresWriteBarrier(ArgLocal *al) const {
-        uint scope = al->scope;
-        const IR::Function *f = this;
-        while (scope) {
-            f = f->outer;
-            --scope;
-        }
-        return !f->canUseSimpleCall();
-    }
-    int localsCountForScope(ArgLocal *al) const {
-        uint scope = al->scope;
-        const IR::Function *f = this;
-        while (scope) {
-            f = f->outer;
-            --scope;
-        }
-        return f->locals.size();
-    }
-
-private:
-    BasicBlock *getOrCreateBasicBlock(int index);
-    void setStatementCount(int cnt);
-
-private:
-    QVector<BasicBlock *> _basicBlocks;
-    QVector<BasicBlock *> *_allBasicBlocks;
-    int _statementCount;
-};
-
-class CloneExpr
-{
-public:
-    explicit CloneExpr(IR::BasicBlock *block = 0);
-
-    void setBasicBlock(IR::BasicBlock *block);
-
-    template <typename ExprSubclass>
-    ExprSubclass *operator()(ExprSubclass *expr)
-    {
-        return clone(expr);
-    }
-
-    template <typename ExprSubclass>
-    ExprSubclass *clone(ExprSubclass *expr)
-    {
-        Expr *c = expr;
-        qSwap(cloned, c);
-        visit(expr);
-        qSwap(cloned, c);
-        return static_cast<ExprSubclass *>(c);
-    }
-
-    static Const *cloneConst(Const *c, Function *f)
-    {
-        Const *newConst = f->New<Const>();
-        newConst->init(c->type, c->value);
-        return newConst;
-    }
-
-    static Name *cloneName(Name *n, Function *f)
-    {
-        Name *newName = f->New<Name>();
-        newName->type = n->type;
-        newName->id = n->id;
-        newName->builtin = n->builtin;
-        newName->global = n->global;
-        newName->qmlSingleton = n->qmlSingleton;
-        newName->freeOfSideEffects = n->freeOfSideEffects;
-        newName->line = n->line;
-        newName->column = n->column;
-        return newName;
-    }
-
-    static Temp *cloneTemp(Temp *t, Function *f)
-    {
-        Temp *newTemp = f->New<Temp>();
-        newTemp->init(t->kind, t->index);
-        newTemp->type = t->type;
-        newTemp->memberResolver = t->memberResolver;
-        return newTemp;
-    }
-
-    static ArgLocal *cloneArgLocal(ArgLocal *argLocal, Function *f)
-    {
-        ArgLocal *newArgLocal = f->New<ArgLocal>();
-        newArgLocal->init(argLocal->kind, argLocal->index, argLocal->scope);
-        newArgLocal->type = argLocal->type;
-        newArgLocal->isArgumentsOrEval = argLocal->isArgumentsOrEval;
-        return newArgLocal;
-    }
-
-private:
-    IR::ExprList *clone(IR::ExprList *list);
-
-    void visit(Expr *e);
-
-protected:
-    IR::BasicBlock *block;
-
-private:
-    IR::Expr *cloned;
-};
-
-class Q_AUTOTEST_EXPORT IRPrinter
-{
-public:
-    IRPrinter(QTextStream *out);
-    virtual ~IRPrinter();
-
-    void print(Stmt *s);
-    void print(Expr *e);
-    void print(const Expr &e);
-
-    virtual void print(Function *f);
-    virtual void print(BasicBlock *bb);
-
-    void visit(Stmt *s);
-    virtual void visitExp(Exp *s);
-    virtual void visitMove(Move *s);
-    virtual void visitJump(Jump *s);
-    virtual void visitCJump(CJump *s);
-    virtual void visitRet(Ret *s);
-    virtual void visitPhi(Phi *s);
-
-    void visit(Expr *e);
-    virtual void visitConst(Const *e);
-    virtual void visitString(String *e);
-    virtual void visitRegExp(RegExp *e);
-    virtual void visitName(Name *e);
-    virtual void visitTemp(Temp *e);
-    virtual void visitArgLocal(ArgLocal *e);
-    virtual void visitClosure(Closure *e);
-    virtual void visitConvert(Convert *e);
-    virtual void visitUnop(Unop *e);
-    virtual void visitBinop(Binop *e);
-    virtual void visitCall(Call *e);
-    virtual void visitNew(New *e);
-    virtual void visitSubscript(Subscript *e);
-    virtual void visitMember(Member *e);
-
-    static QString escape(const QString &s);
-
-protected:
-    virtual void addStmtNr(Stmt *s);
-    void addJustifiedNr(int pos);
-    void printBlockStart();
-
-protected:
-    QTextStream *out;
-    int positionSize;
-    BasicBlock *currentBB;
-};
-
-inline unsigned BasicBlock::newTemp()
-{
-    Q_ASSERT(!isRemoved());
-    return function->tempCount++;
-}
-
-inline Temp *BasicBlock::TEMP(unsigned index)
-{
-    Q_ASSERT(!isRemoved());
-    Temp *e = function->New<Temp>();
-    e->init(Temp::VirtualRegister, index);
-    return e;
-}
-
-inline ArgLocal *BasicBlock::ARG(unsigned index, unsigned scope)
-{
-    Q_ASSERT(!isRemoved());
-    ArgLocal *e = function->New<ArgLocal>();
-    e->init(scope ? ArgLocal::ScopedFormal : ArgLocal::Formal, index, scope);
-    return e;
-}
-
-inline ArgLocal *BasicBlock::LOCAL(unsigned index, unsigned scope)
-{
-    Q_ASSERT(!isRemoved());
-    ArgLocal *e = function->New<ArgLocal>();
-    e->init(scope ? ArgLocal::ScopedLocal : ArgLocal::Local, index, scope);
-    return e;
-}
-
-inline Expr *BasicBlock::CONST(Type type, double value)
-{
-    Q_ASSERT(!isRemoved());
-    Const *e = function->New<Const>();
-    if (type == NumberType) {
-        int ival = (int)value;
-        // +0 != -0, so we need to convert to double when negating 0
-        if (ival == value && !(value == 0 && isNegative(value)))
-            type = SInt32Type;
-        else
-            type = DoubleType;
-    } else if (type == NullType) {
-        value = 0;
-    } else if (type == UndefinedType) {
-        value = qt_qnan();
-    }
-
-    e->init(type, value);
-    return e;
-}
-
-inline Expr *BasicBlock::STRING(const QString *value)
-{
-    Q_ASSERT(!isRemoved());
-    String *e = function->New<String>();
-    e->init(value);
-    return e;
-}
-
-inline Expr *BasicBlock::REGEXP(const QString *value, int flags)
-{
-    Q_ASSERT(!isRemoved());
-    RegExp *e = function->New<RegExp>();
-    e->init(value, flags);
-    return e;
-}
-
-inline Name *BasicBlock::NAME(const QString &id, quint32 line, quint32 column)
-{
-    Q_ASSERT(!isRemoved());
-    Name *e = function->New<Name>();
-    e->init(function->newString(id), line, column);
-    return e;
-}
-
-inline Name *BasicBlock::GLOBALNAME(const QString &id, quint32 line, quint32 column)
-{
-    Q_ASSERT(!isRemoved());
-    Name *e = function->New<Name>();
-    e->initGlobal(function->newString(id), line, column);
-    return e;
-}
-
-
-inline Name *BasicBlock::NAME(Name::Builtin builtin, quint32 line, quint32 column)
-{
-    Q_ASSERT(!isRemoved());
-    Name *e = function->New<Name>();
-    e->init(builtin, line, column);
-    return e;
-}
-
-inline Closure *BasicBlock::CLOSURE(int functionInModule)
-{
-    Q_ASSERT(!isRemoved());
-    Closure *clos = function->New<Closure>();
-    clos->init(functionInModule, function->module->functions.at(functionInModule)->name);
-    return clos;
-}
-
-inline Expr *BasicBlock::CONVERT(Expr *expr, Type type)
-{
-    Q_ASSERT(!isRemoved());
-    Convert *e = function->New<Convert>();
-    e->init(expr, type);
-    return e;
-}
-
-inline Expr *BasicBlock::UNOP(AluOp op, Expr *expr)
-{
-    Q_ASSERT(!isRemoved());
-    Unop *e = function->New<Unop>();
-    e->init(op, expr);
-    return e;
-}
-
-inline Expr *BasicBlock::BINOP(AluOp op, Expr *left, Expr *right)
-{
-    Q_ASSERT(!isRemoved());
-    Binop *e = function->New<Binop>();
-    e->init(op, left, right);
-    return e;
-}
-
-inline Expr *BasicBlock::CALL(Expr *base, ExprList *args)
-{
-    Q_ASSERT(!isRemoved());
-    Call *e = function->New<Call>();
-    e->init(base, args);
-    int argc = 0;
-    for (ExprList *it = args; it; it = it->next)
-        ++argc;
-    function->maxNumberOfArguments = qMax(function->maxNumberOfArguments, argc);
-    return e;
-}
-
-inline Expr *BasicBlock::NEW(Expr *base, ExprList *args)
-{
-    Q_ASSERT(!isRemoved());
-    New *e = function->New<New>();
-    e->init(base, args);
-    return e;
-}
-
-inline Expr *BasicBlock::SUBSCRIPT(Expr *base, Expr *index)
-{
-    Q_ASSERT(!isRemoved());
-    Subscript *e = function->New<Subscript>();
-    e->init(base, index);
-    return e;
-}
-
-inline Expr *BasicBlock::MEMBER(Expr *base, const QString *name, QQmlPropertyData *property, uchar kind, int attachedPropertiesIdOrEnumValue)
-{
-    Q_ASSERT(!isRemoved());
-    Member*e = function->New<Member>();
-    e->init(base, name, property, kind, attachedPropertiesIdOrEnumValue);
-    return e;
-}
-
-inline Stmt *BasicBlock::EXP(Expr *expr)
-{
-    Q_ASSERT(!isRemoved());
-    if (isTerminated())
-        return 0;
-
-    Exp *s = function->NewStmt<Exp>();
-    s->init(expr);
-    appendStatement(s);
-    return s;
-}
-
-inline Stmt *BasicBlock::MOVE(Expr *target, Expr *source)
-{
-    Q_ASSERT(!isRemoved());
-    if (isTerminated())
-        return 0;
-
-    Move *s = function->NewStmt<Move>();
-    s->init(target, source);
-    appendStatement(s);
-    return s;
-}
-
-inline Stmt *BasicBlock::JUMP(BasicBlock *target)
-{
-    Q_ASSERT(!isRemoved());
-    if (isTerminated())
-        return 0;
-
-    Jump *s = function->NewStmt<Jump>();
-    s->init(target);
-    appendStatement(s);
-
-    Q_ASSERT(! out.contains(target));
-    out.append(target);
-
-    Q_ASSERT(! target->in.contains(this));
-    target->in.append(this);
-
-    return s;
-}
-
-inline Stmt *BasicBlock::CJUMP(Expr *cond, BasicBlock *iftrue, BasicBlock *iffalse)
-{
-    Q_ASSERT(!isRemoved());
-    if (isTerminated())
-        return 0;
-
-    if (iftrue == iffalse) {
-        MOVE(TEMP(newTemp()), cond);
-        return JUMP(iftrue);
-    }
-
-    CJump *s = function->NewStmt<CJump>();
-    s->init(cond, iftrue, iffalse, this);
-    appendStatement(s);
-
-    Q_ASSERT(! out.contains(iftrue));
-    out.append(iftrue);
-
-    Q_ASSERT(! iftrue->in.contains(this));
-    iftrue->in.append(this);
-
-    Q_ASSERT(! out.contains(iffalse));
-    out.append(iffalse);
-
-    Q_ASSERT(! iffalse->in.contains(this));
-    iffalse->in.append(this);
-
-    return s;
-}
-
-inline Stmt *BasicBlock::RET(Expr *expr)
-{
-    Q_ASSERT(!isRemoved());
-    if (isTerminated())
-        return 0;
-
-    Ret *s = function->NewStmt<Ret>();
-    s->init(expr);
-    appendStatement(s);
-    return s;
-}
-
-inline Const *Expr::asConst() { return as<Const>(); }
-inline String *Expr::asString() { return as<String>(); }
-inline RegExp *Expr::asRegExp() { return as<RegExp>(); }
-inline Name *Expr::asName() { return as<Name>(); }
-inline Temp *Expr::asTemp() { return as<Temp>(); }
-inline ArgLocal *Expr::asArgLocal() { return as<ArgLocal>(); }
-inline Closure *Expr::asClosure() { return as<Closure>(); }
-inline Convert *Expr::asConvert() { return as<Convert>(); }
-inline Unop *Expr::asUnop() { return as<Unop>(); }
-inline Binop *Expr::asBinop() { return as<Binop>(); }
-inline Call *Expr::asCall() { return as<Call>(); }
-inline New *Expr::asNew() { return as<New>(); }
-inline Subscript *Expr::asSubscript() { return as<Subscript>(); }
-inline Member *Expr::asMember() { return as<Member>(); }
-
-inline Exp *Stmt::asExp() { return as<Exp>(); }
-inline Move *Stmt::asMove() { return as<Move>(); }
-inline Jump *Stmt::asJump() { return as<Jump>(); }
-inline CJump *Stmt::asCJump() { return as<CJump>(); }
-inline Ret *Stmt::asRet() { return as<Ret>(); }
-inline Phi *Stmt::asPhi() { return as<Phi>(); }
-
-} // end of namespace IR
-
-} // end of namespace QV4
-
-QT_END_NAMESPACE
-
-#if defined(QT_POP_CONST)
-# pragma pop_macro("CONST") // Restore peace
-# undef QT_POP_CONST
-#endif
-
-#endif // QV4IR_P_H
diff --git a/src/qml/compiler/qv4jssimplifier.cpp b/src/qml/compiler/qv4jssimplifier.cpp
deleted file mode 100644
index 7d09218fe6..0000000000
--- a/src/qml/compiler/qv4jssimplifier.cpp
+++ /dev/null
@@ -1,384 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the tools applications of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qv4jssimplifier_p.h"
-
-QT_BEGIN_NAMESPACE
-
-QQmlJavaScriptBindingExpressionSimplificationPass::QQmlJavaScriptBindingExpressionSimplificationPass(const QVector<QmlIR::Object*> &qmlObjects, QV4::IR::Module *jsModule, QV4::Compiler::JSUnitGenerator *unitGenerator)
-    : qmlObjects(qmlObjects)
-    , jsModule(jsModule)
-    , unitGenerator(unitGenerator)
-{
-
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::reduceTranslationBindings()
-{
-    for (int i = 0; i < qmlObjects.count(); ++i)
-        reduceTranslationBindings(i);
-    if (!irFunctionsToRemove.isEmpty()) {
-        QQmlIRFunctionCleanser cleanser(jsModule, qmlObjects, irFunctionsToRemove);
-        cleanser.clean();
-    }
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::reduceTranslationBindings(int objectIndex)
-{
-    const QmlIR::Object *obj = qmlObjects.at(objectIndex);
-
-    for (QmlIR::Binding *binding = obj->firstBinding(); binding; binding = binding->next) {
-        if (binding->type != QV4::CompiledData::Binding::Type_Script)
-            continue;
-
-        const int irFunctionIndex = obj->runtimeFunctionIndices.at(binding->value.compiledScriptIndex);
-        QV4::IR::Function *irFunction = jsModule->functions.at(irFunctionIndex);
-        if (simplifyBinding(irFunction, binding)) {
-            irFunctionsToRemove.append(irFunctionIndex);
-            jsModule->functions[irFunctionIndex] = 0;
-            delete irFunction;
-        }
-    }
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::visitMove(QV4::IR::Move *move)
-{
-    QV4::IR::Temp *target = move->target->asTemp();
-    if (!target || target->kind != QV4::IR::Temp::VirtualRegister) {
-        discard();
-        return;
-    }
-
-    if (QV4::IR::Call *call = move->source->asCall()) {
-        if (QV4::IR::Name *n = call->base->asName()) {
-            if (n->builtin == QV4::IR::Name::builtin_invalid) {
-                visitFunctionCall(n->id, call->args, target);
-                return;
-            }
-        }
-        discard();
-        return;
-    }
-
-    if (QV4::IR::Name *n = move->source->asName()) {
-        if (n->builtin == QV4::IR::Name::builtin_qml_context
-            || n->builtin == QV4::IR::Name::builtin_qml_imported_scripts_object) {
-            // these are free of side-effects
-            return;
-        }
-        discard();
-        return;
-    }
-
-    if (!move->source->asTemp() && !move->source->asString() && !move->source->asConst()) {
-        discard();
-        return;
-    }
-
-    _temps[target->index] = move->source;
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::visitFunctionCall(const QString *name, QV4::IR::ExprList *args, QV4::IR::Temp *target)
-{
-    // more than one function call?
-    if (_nameOfFunctionCalled) {
-        discard();
-        return;
-    }
-
-    _nameOfFunctionCalled = name;
-
-    _functionParameters.clear();
-    while (args) {
-        int slot;
-        if (QV4::IR::Temp *param = args->expr->asTemp()) {
-            if (param->kind != QV4::IR::Temp::VirtualRegister) {
-                discard();
-                return;
-            }
-            slot = param->index;
-            _functionParameters.append(slot);
-        } else if (QV4::IR::Const *param = args->expr->asConst()) {
-            slot = --_synthesizedConsts;
-            Q_ASSERT(!_temps.contains(slot));
-            _temps[slot] = param;
-            _functionParameters.append(slot);
-        }
-        args = args->next;
-    }
-
-    _functionCallReturnValue = target->index;
-}
-
-void QQmlJavaScriptBindingExpressionSimplificationPass::visitRet(QV4::IR::Ret *ret)
-{
-    // nothing initialized earlier?
-    if (_returnValueOfBindingExpression != -1) {
-        discard();
-        return;
-    }
-    QV4::IR::Temp *target = ret->expr->asTemp();
-    if (!target || target->kind != QV4::IR::Temp::VirtualRegister) {
-        discard();
-        return;
-    }
-    _returnValueOfBindingExpression = target->index;
-}
-
-bool QQmlJavaScriptBindingExpressionSimplificationPass::simplifyBinding(QV4::IR::Function *function, QmlIR::Binding *binding)
-{
-    _canSimplify = true;
-    _nameOfFunctionCalled = 0;
-    _functionParameters.clear();
-    _functionCallReturnValue = -1;
-    _temps.clear();
-    _returnValueOfBindingExpression = -1;
-    _synthesizedConsts = 0;
-
-    // It would seem unlikely that function with some many basic blocks (after optimization)
-    // consists merely of a qsTr call or a constant value return ;-)
-    if (function->basicBlockCount() > 10)
-        return false;
-
-    for (QV4::IR::BasicBlock *bb : function->basicBlocks()) {
-        for (QV4::IR::Stmt *s : bb->statements()) {
-            visit(s);
-            if (!_canSimplify)
-                return false;
-        }
-    }
-
-    if (_returnValueOfBindingExpression == -1)
-        return false;
-
-    if (_nameOfFunctionCalled) {
-        if (_functionCallReturnValue != _returnValueOfBindingExpression)
-            return false;
-        return detectTranslationCallAndConvertBinding(binding);
-    }
-
-    return false;
-}
-
-bool QQmlJavaScriptBindingExpressionSimplificationPass::detectTranslationCallAndConvertBinding(QmlIR::Binding *binding)
-{
-    if (*_nameOfFunctionCalled == QLatin1String("qsTr")) {
-        QString translation;
-        QV4::CompiledData::TranslationData translationData;
-        translationData.number = -1;
-        translationData.commentIndex = 0; // empty string
-
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        translation = *stringParam->value;
-
-        ++param;
-        if (param != end) {
-            stringParam = _temps[*param]->asString();
-            if (!stringParam)
-                return false;
-            translationData.commentIndex = unitGenerator->registerString(*stringParam->value);
-            ++param;
-
-            if (param != end) {
-                QV4::IR::Const *constParam = _temps[*param]->asConst();
-                if (!constParam || constParam->type != QV4::IR::SInt32Type)
-                    return false;
-
-                translationData.number = int(constParam->value);
-                ++param;
-            }
-        }
-
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_Translation;
-        binding->stringIndex = unitGenerator->registerString(translation);
-        binding->value.translationData = translationData;
-        return true;
-    } else if (*_nameOfFunctionCalled == QLatin1String("qsTrId")) {
-        QString id;
-        QV4::CompiledData::TranslationData translationData;
-        translationData.number = -1;
-        translationData.commentIndex = 0; // empty string, but unused
-
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        id = *stringParam->value;
-
-        ++param;
-        if (param != end) {
-            QV4::IR::Const *constParam = _temps[*param]->asConst();
-            if (!constParam || constParam->type != QV4::IR::SInt32Type)
-                return false;
-
-            translationData.number = int(constParam->value);
-            ++param;
-        }
-
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_TranslationById;
-        binding->stringIndex = unitGenerator->registerString(id);
-        binding->value.translationData = translationData;
-        return true;
-    } else if (*_nameOfFunctionCalled == QLatin1String("QT_TR_NOOP") || *_nameOfFunctionCalled == QLatin1String("QT_TRID_NOOP")) {
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        ++param;
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_String;
-        binding->stringIndex = unitGenerator->registerString(*stringParam->value);
-        return true;
-    } else if (*_nameOfFunctionCalled == QLatin1String("QT_TRANSLATE_NOOP")) {
-        QVector<int>::ConstIterator param = _functionParameters.constBegin();
-        QVector<int>::ConstIterator end = _functionParameters.constEnd();
-        if (param == end)
-            return false;
-
-        ++param;
-        if (param == end)
-            return false;
-
-        QV4::IR::String *stringParam = _temps[*param]->asString();
-        if (!stringParam)
-            return false;
-
-        ++param;
-        if (param != end)
-            return false;
-
-        binding->type = QV4::CompiledData::Binding::Type_String;
-        binding->stringIndex = unitGenerator->registerString(*stringParam->value);
-        return true;
-    }
-    return false;
-}
-
-QQmlIRFunctionCleanser::QQmlIRFunctionCleanser(QV4::IR::Module *module, const QVector<QmlIR::Object *> &qmlObjects, const QVector<int> &functionsToRemove)
-    : module(module)
-    , qmlObjects(qmlObjects)
-    , functionsToRemove(functionsToRemove)
-{
-}
-
-void QQmlIRFunctionCleanser::clean()
-{
-    QVector<QV4::IR::Function*> newFunctions;
-    newFunctions.reserve(module->functions.count() - functionsToRemove.count());
-
-    newFunctionIndices.resize(module->functions.count());
-
-    for (int i = 0; i < module->functions.count(); ++i) {
-        QV4::IR::Function *f = module->functions.at(i);
-        Q_ASSERT(f || functionsToRemove.contains(i));
-        if (f) {
-            newFunctionIndices[i] = newFunctions.count();
-            newFunctions << f;
-        }
-    }
-
-    module->functions = newFunctions;
-
-    for (QV4::IR::Function *function : qAsConst(module->functions)) {
-        for (QV4::IR::BasicBlock *block : function->basicBlocks()) {
-            for (QV4::IR::Stmt *s : block->statements()) {
-                visit(s);
-            }
-        }
-    }
-
-    for (QmlIR::Object *obj : qmlObjects) {
-        for (int i = 0; i < obj->runtimeFunctionIndices.count; ++i)
-            obj->runtimeFunctionIndices[i] = newFunctionIndices[obj->runtimeFunctionIndices.at(i)];
-    }
-}
-
-void QQmlIRFunctionCleanser::visit(QV4::IR::Stmt *s)
-{
-
-    switch (s->stmtKind) {
-    case QV4::IR::Stmt::PhiStmt:
-        // nothing to do
-        break;
-    default:
-        STMT_VISIT_ALL_KINDS(s);
-        break;
-    }
-}
-
-void QQmlIRFunctionCleanser::visit(QV4::IR::Expr *e)
-{
-    switch (e->exprKind) {
-    case QV4::IR::Expr::ClosureExpr: {
-        auto closure = e->asClosure();
-        closure->value = newFunctionIndices.at(closure->value);
-    } break;
-    default:
-        EXPR_VISIT_ALL_KINDS(e);
-        break;
-    }
-}
-
-QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4jssimplifier_p.h b/src/qml/compiler/qv4jssimplifier_p.h
deleted file mode 100644
index ae8d74135c..0000000000
--- a/src/qml/compiler/qv4jssimplifier_p.h
+++ /dev/null
@@ -1,154 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the tools applications of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#ifndef QV4JSSIMPLIFIER
-#define QV4JSSIMPLIFIER
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <private/qv4global_p.h>
-
-#include "qqmlirbuilder_p.h"
-
-QT_BEGIN_NAMESPACE
-
-namespace QmlIR {
-struct Document;
-}
-
-namespace QV4 {
-namespace CompiledData {
-struct QmlUnit;
-struct Location;
-}
-}
-
-class QQmlJavaScriptBindingExpressionSimplificationPass
-{
-public:
-    QQmlJavaScriptBindingExpressionSimplificationPass(const QVector<QmlIR::Object*> &qmlObjects, QV4::IR::Module *jsModule, QV4::Compiler::JSUnitGenerator *unitGenerator);
-
-    void reduceTranslationBindings();
-
-private:
-    void reduceTranslationBindings(int objectIndex);
-
-    void visit(QV4::IR::Stmt *s)
-    {
-        switch (s->stmtKind) {
-        case QV4::IR::Stmt::MoveStmt:
-            visitMove(s->asMove());
-            break;
-        case QV4::IR::Stmt::RetStmt:
-            visitRet(s->asRet());
-            break;
-        case QV4::IR::Stmt::CJumpStmt:
-            discard();
-            break;
-        case QV4::IR::Stmt::ExpStmt:
-            discard();
-            break;
-        case QV4::IR::Stmt::JumpStmt:
-            break;
-        case QV4::IR::Stmt::PhiStmt:
-            break;
-        }
-    }
-
-    void visitMove(QV4::IR::Move *move);
-    void visitRet(QV4::IR::Ret *ret);
-
-    void visitFunctionCall(const QString *name, QV4::IR::ExprList *args, QV4::IR::Temp *target);
-
-    void discard() { _canSimplify = false; }
-
-    bool simplifyBinding(QV4::IR::Function *function, QmlIR::Binding *binding);
-    bool detectTranslationCallAndConvertBinding(QmlIR::Binding *binding);
-
-    const QVector<QmlIR::Object*> &qmlObjects;
-    QV4::IR::Module *jsModule;
-    QV4::Compiler::JSUnitGenerator *unitGenerator;
-
-    bool _canSimplify;
-    const QString *_nameOfFunctionCalled;
-    QVector<int> _functionParameters;
-    int _functionCallReturnValue;
-
-    QHash<int, QV4::IR::Expr*> _temps;
-    int _returnValueOfBindingExpression;
-    int _synthesizedConsts;
-
-    QVector<int> irFunctionsToRemove;
-};
-
-class QQmlIRFunctionCleanser
-{
-public:
-    QQmlIRFunctionCleanser(QV4::IR::Module *module, const QVector<QmlIR::Object*> &qmlObjects, const QVector<int> &functionsToRemove);
-
-    void clean();
-
-private:
-    virtual void visitMove(QV4::IR::Move *s) {
-        visit(s->source);
-        visit(s->target);
-    }
-
-    void visit(QV4::IR::Stmt *s);
-    void visit(QV4::IR::Expr *e);
-
-private:
-    QV4::IR::Module *module;
-    const QVector<QmlIR::Object*> &qmlObjects;
-    const QVector<int> &functionsToRemove;
-
-    QVector<int> newFunctionIndices;
-};
-
-QT_END_NAMESPACE
-
-#endif // QV4JSSIMPLIFIER
diff --git a/src/qml/compiler/qv4ssa.cpp b/src/qml/compiler/qv4ssa.cpp
deleted file mode 100644
index fc136b09ff..0000000000
--- a/src/qml/compiler/qv4ssa.cpp
+++ /dev/null
@@ -1,5848 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-// When building with debug code, the macro below will enable debug helpers when using libc++.
-// For example, the std::vector<T>::operator[] will use _LIBCPP_ASSERT to check if the index is
-// within the array bounds. Note that this only works reliably with OSX 10.9 or later.
-//#define _LIBCPP_DEBUG2 2
-
-#include "qv4ssa_p.h"
-#include "qv4isel_util_p.h"
-#include "qv4util_p.h"
-
-#include <QtCore/QBuffer>
-#include <QtCore/QCoreApplication>
-#include <QtCore/QStringList>
-#include <QtCore/QSet>
-#include <QtCore/QLinkedList>
-#include <QtCore/QStack>
-#include <qv4runtime_p.h>
-#include <cmath>
-#include <iostream>
-#include <cassert>
-
-QT_USE_NAMESPACE
-
-using namespace QV4;
-using namespace IR;
-
-namespace {
-
-enum { DebugMoveMapping = 0 };
-
-#ifdef QT_NO_DEBUG
-enum { DoVerification = 0 };
-#else
-enum { DoVerification = 1 };
-#endif
-
-static void showMeTheCode(IR::Function *function, const char *marker)
-{
-    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_IR");
-    if (showCode) {
-        qDebug() << marker;
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream stream(&buf);
-        IRPrinter(&stream).print(function);
-        stream << endl;
-        qDebug("%s", buf.data().constData());
-    }
-}
-
-class ProcessedBlocks
-{
-    BitVector processed;
-
-public:
-    ProcessedBlocks(IR::Function *function)
-        : processed(function->basicBlockCount(), false)
-    {}
-
-    bool alreadyProcessed(BasicBlock *bb) const
-    {
-        Q_ASSERT(bb);
-
-        return processed.at(bb->index());
-    }
-
-    void markAsProcessed(BasicBlock *bb)
-    {
-        processed.setBit(bb->index());
-    }
-};
-
-class BasicBlockSet
-{
-    typedef BitVector Flags;
-
-    QVarLengthArray<int, 8> blockNumbers;
-    Flags *blockFlags;
-    IR::Function *function;
-    enum { MaxVectorCapacity = 8 };
-
-public:
-    class const_iterator
-    {
-        const BasicBlockSet &set;
-        // ### These two members could go into a union, but clang won't compile (https://codereview.qt-project.org/#change,74259)
-        QVarLengthArray<int, 8>::const_iterator numberIt;
-        int flagIt;
-
-        friend class BasicBlockSet;
-        const_iterator(const BasicBlockSet &set, bool end)
-            : set(set)
-        {
-            if (end || !set.function) {
-                if (!set.blockFlags)
-                    numberIt = set.blockNumbers.end();
-                else
-                    flagIt = set.blockFlags->size();
-            } else {
-                if (!set.blockFlags)
-                    numberIt = set.blockNumbers.begin();
-                else
-                    findNextWithFlags(0);
-            }
-        }
-
-        void findNextWithFlags(int start)
-        {
-            flagIt = set.blockFlags->findNext(start, true, /*wrapAround = */false);
-            Q_ASSERT(flagIt <= set.blockFlags->size());
-        }
-
-    public:
-        BasicBlock *operator*() const
-        {
-            if (!set.blockFlags) {
-                return set.function->basicBlock(*numberIt);
-            } else {
-                Q_ASSERT(flagIt <= set.function->basicBlockCount());
-                return set.function->basicBlock(flagIt);
-            }
-        }
-
-        bool operator==(const const_iterator &other) const
-        {
-            if (&set != &other.set)
-                return false;
-            if (!set.blockFlags)
-                return numberIt == other.numberIt;
-            else
-                return flagIt == other.flagIt;
-        }
-
-        bool operator!=(const const_iterator &other) const
-        { return !(*this == other); }
-
-        const_iterator &operator++()
-        {
-            if (!set.blockFlags)
-                ++numberIt;
-            else
-                findNextWithFlags(flagIt + 1);
-
-            return *this;
-        }
-    };
-
-    friend class const_iterator;
-
-public:
-    BasicBlockSet(IR::Function *f = 0): blockFlags(0), function(0)
-    {
-        if (f)
-            init(f);
-    }
-
-#ifdef Q_COMPILER_RVALUE_REFS
-    BasicBlockSet(BasicBlockSet &&other): blockFlags(0)
-    {
-        std::swap(blockNumbers, other.blockNumbers);
-        std::swap(blockFlags, other.blockFlags);
-        std::swap(function, other.function);
-    }
-#endif // Q_COMPILER_RVALUE_REFS
-
-    BasicBlockSet(const BasicBlockSet &other)
-        : blockFlags(0)
-        , function(other.function)
-    {
-        if (other.blockFlags)
-            blockFlags = new Flags(*other.blockFlags);
-        blockNumbers = other.blockNumbers;
-    }
-
-    BasicBlockSet &operator=(const BasicBlockSet &other)
-    {
-        if (blockFlags) {
-            delete blockFlags;
-            blockFlags = 0;
-        }
-        function = other.function;
-        if (other.blockFlags)
-            blockFlags = new Flags(*other.blockFlags);
-        blockNumbers = other.blockNumbers;
-        return *this;
-    }
-
-    ~BasicBlockSet()
-    {
-        delete blockFlags;
-    }
-
-    void init(IR::Function *f)
-    {
-        Q_ASSERT(!function);
-        Q_ASSERT(f);
-        function = f;
-    }
-
-    bool empty() const
-    {
-        return begin() == end();
-    }
-
-    void insert(BasicBlock *bb)
-    {
-        Q_ASSERT(function);
-
-        if (blockFlags) {
-            blockFlags->setBit(bb->index());
-            return;
-        }
-
-        for (int i = 0; i < blockNumbers.size(); ++i) {
-            if (blockNumbers[i] == bb->index())
-                return;
-        }
-
-        if (blockNumbers.size() == MaxVectorCapacity) {
-            blockFlags = new Flags(function->basicBlockCount(), false);
-            for (int i = 0; i < blockNumbers.size(); ++i) {
-                blockFlags->setBit(blockNumbers[i]);
-            }
-            blockNumbers.clear();
-            blockFlags->setBit(bb->index());
-        } else {
-            blockNumbers.append(bb->index());
-        }
-    }
-
-    void remove(BasicBlock *bb)
-    {
-        Q_ASSERT(function);
-
-        if (blockFlags) {
-            blockFlags->clearBit(bb->index());
-            return;
-        }
-
-        for (int i = 0; i < blockNumbers.size(); ++i) {
-            if (blockNumbers[i] == bb->index()) {
-                blockNumbers.remove(i);
-                return;
-            }
-        }
-    }
-
-    const_iterator begin() const { return const_iterator(*this, false); }
-    const_iterator end() const { return const_iterator(*this, true); }
-
-    void collectValues(std::vector<BasicBlock *> &bbs) const
-    {
-        Q_ASSERT(function);
-
-        for (const_iterator it = begin(), eit = end(); it != eit; ++it)
-            bbs.push_back(*it);
-    }
-
-    bool contains(BasicBlock *bb) const
-    {
-        Q_ASSERT(function);
-
-        if (blockFlags)
-            return blockFlags->at(bb->index());
-
-        for (int i = 0; i < blockNumbers.size(); ++i) {
-            if (blockNumbers[i] == bb->index())
-                return true;
-        }
-
-        return false;
-    }
-};
-
-class DominatorTree
-{
-    enum {
-        DebugDominatorFrontiers = 0,
-        DebugImmediateDominators = 0,
-
-        DebugCodeCanUseLotsOfCpu = 0
-    };
-
-    typedef int BasicBlockIndex;
-    enum { InvalidBasicBlockIndex = -1 };
-
-    struct Data
-    {
-        int N;
-        std::vector<int> dfnum; // BasicBlock index -> dfnum
-        std::vector<int> vertex;
-        std::vector<BasicBlockIndex> parent; // BasicBlock index -> parent BasicBlock index
-        std::vector<BasicBlockIndex> ancestor; // BasicBlock index -> ancestor BasicBlock index
-        std::vector<BasicBlockIndex> best; // BasicBlock index -> best BasicBlock index
-        std::vector<BasicBlockIndex> semi; // BasicBlock index -> semi dominator BasicBlock index
-        std::vector<BasicBlockIndex> samedom; // BasicBlock index -> same dominator BasicBlock index
-
-        Data(): N(0) {}
-    };
-
-    IR::Function *function;
-    QScopedPointer<Data> d;
-    std::vector<BasicBlockIndex> idom; // BasicBlock index -> immediate dominator BasicBlock index
-    std::vector<BasicBlockSet> DF; // BasicBlock index -> dominator frontier
-
-    struct DFSTodo {
-        BasicBlockIndex node, parent;
-
-        DFSTodo()
-            : node(InvalidBasicBlockIndex)
-            , parent(InvalidBasicBlockIndex)
-        {}
-
-        DFSTodo(BasicBlockIndex node, BasicBlockIndex parent)
-            : node(node)
-            , parent(parent)
-        {}
-    };
-
-    void DFS(BasicBlockIndex node) {
-        std::vector<DFSTodo> worklist;
-        worklist.reserve(d->vertex.capacity() / 2);
-        DFSTodo todo(node, InvalidBasicBlockIndex);
-
-        while (true) {
-            BasicBlockIndex n = todo.node;
-
-            if (d->dfnum[n] == 0) {
-                d->dfnum[n] = d->N;
-                d->vertex[d->N] = n;
-                d->parent[n] = todo.parent;
-                ++d->N;
-                const BasicBlock::OutgoingEdges &out = function->basicBlock(n)->out;
-                for (int i = out.size() - 1; i > 0; --i)
-                    worklist.push_back(DFSTodo(out[i]->index(), n));
-
-                if (out.size() > 0) {
-                    todo.node = out.first()->index();
-                    todo.parent = n;
-                    continue;
-                }
-            }
-
-            if (worklist.empty())
-                break;
-
-            todo = worklist.back();
-            worklist.pop_back();
-        }
-    }
-
-    BasicBlockIndex ancestorWithLowestSemi(BasicBlockIndex v, std::vector<BasicBlockIndex> &worklist) {
-        worklist.clear();
-        for (BasicBlockIndex it = v; it != InvalidBasicBlockIndex; it = d->ancestor[it])
-            worklist.push_back(it);
-
-        if (worklist.size() < 2)
-            return d->best[v];
-
-        BasicBlockIndex b = InvalidBasicBlockIndex;
-        BasicBlockIndex last = worklist.back();
-        Q_ASSERT(worklist.size() <= INT_MAX);
-        for (int it = static_cast<int>(worklist.size()) - 2; it >= 0; --it) {
-            BasicBlockIndex bbIt = worklist[it];
-            d->ancestor[bbIt] = last;
-            BasicBlockIndex &best_it = d->best[bbIt];
-            if (b != InvalidBasicBlockIndex && d->dfnum[d->semi[b]] < d->dfnum[d->semi[best_it]])
-                best_it = b;
-            else
-                b = best_it;
-        }
-        return b;
-    }
-
-    void link(BasicBlockIndex p, BasicBlockIndex n) {
-        d->ancestor[n] = p;
-        d->best[n] = n;
-    }
-
-    void calculateIDoms() {
-        Q_ASSERT(function->basicBlock(0)->in.isEmpty());
-
-        const int bbCount = function->basicBlockCount();
-        d->vertex = std::vector<int>(bbCount, InvalidBasicBlockIndex);
-        d->parent = std::vector<int>(bbCount, InvalidBasicBlockIndex);
-        d->dfnum = std::vector<int>(size_t(bbCount), 0);
-        d->semi = std::vector<BasicBlockIndex>(bbCount, InvalidBasicBlockIndex);
-        d->ancestor = std::vector<BasicBlockIndex>(bbCount, InvalidBasicBlockIndex);
-        idom = std::vector<BasicBlockIndex>(bbCount, InvalidBasicBlockIndex);
-        d->samedom = std::vector<BasicBlockIndex>(bbCount, InvalidBasicBlockIndex);
-        d->best = std::vector<BasicBlockIndex>(bbCount, InvalidBasicBlockIndex);
-
-        QHash<BasicBlockIndex, std::vector<BasicBlockIndex> > bucket;
-        bucket.reserve(bbCount);
-
-        DFS(function->basicBlock(0)->index());
-        Q_ASSERT(d->N == function->liveBasicBlocksCount());
-
-        std::vector<BasicBlockIndex> worklist;
-        worklist.reserve(d->vertex.capacity() / 2);
-
-        for (int i = d->N - 1; i > 0; --i) {
-            BasicBlockIndex n = d->vertex[i];
-            BasicBlockIndex p = d->parent[n];
-            BasicBlockIndex s = p;
-
-            for (BasicBlock *v : function->basicBlock(n)->in) {
-                BasicBlockIndex ss = InvalidBasicBlockIndex;
-                if (d->dfnum[v->index()] <= d->dfnum[n])
-                    ss = v->index();
-                else
-                    ss = d->semi[ancestorWithLowestSemi(v->index(), worklist)];
-                if (d->dfnum[ss] < d->dfnum[s])
-                    s = ss;
-            }
-            d->semi[n] = s;
-            bucket[s].push_back(n);
-            link(p, n);
-            if (bucket.contains(p)) {
-                for (BasicBlockIndex v : bucket[p]) {
-                    BasicBlockIndex y = ancestorWithLowestSemi(v, worklist);
-                    BasicBlockIndex semi_v = d->semi[v];
-                    if (d->semi[y] == semi_v)
-                        idom[v] = semi_v;
-                    else
-                        d->samedom[v] = y;
-                }
-                bucket.remove(p);
-            }
-        }
-
-        for (int i = 1; i < d->N; ++i) {
-            BasicBlockIndex n = d->vertex[i];
-            Q_ASSERT(n != InvalidBasicBlockIndex);
-            Q_ASSERT(!bucket.contains(n));
-            Q_ASSERT(d->ancestor[n] != InvalidBasicBlockIndex
-                        && ((d->semi[n] != InvalidBasicBlockIndex
-                                && d->dfnum[d->ancestor[n]] <= d->dfnum[d->semi[n]]) || d->semi[n] == n));
-            BasicBlockIndex sdn = d->samedom[n];
-            if (sdn != InvalidBasicBlockIndex)
-                idom[n] = idom[sdn];
-        }
-
-        dumpImmediateDominators();
-    }
-
-    struct NodeProgress {
-        std::vector<BasicBlockIndex> children;
-        std::vector<BasicBlockIndex> todo;
-    };
-
-public:
-    DominatorTree(IR::Function *function)
-        : function(function)
-        , d(new Data)
-    {
-        calculateIDoms();
-        d.reset();
-    }
-
-    void computeDF() {
-        DF.resize(function->basicBlockCount());
-
-        // compute children of each node in the dominator tree
-        std::vector<std::vector<BasicBlockIndex> > children; // BasicBlock index -> children
-        children.resize(function->basicBlockCount());
-        for (BasicBlock *n : function->basicBlocks()) {
-            if (n->isRemoved())
-                continue;
-            const BasicBlockIndex nodeIndex = n->index();
-            Q_ASSERT(function->basicBlock(nodeIndex) == n);
-            const BasicBlockIndex nodeDominator = idom[nodeIndex];
-            if (nodeDominator == InvalidBasicBlockIndex)
-                continue; // there is no dominator to add this node to as a child (e.g. the start node)
-            children[nodeDominator].push_back(nodeIndex);
-        }
-
-        // Fill the worklist and initialize the node status for each basic-block
-        std::vector<NodeProgress> nodeStatus;
-        nodeStatus.resize(function->basicBlockCount());
-        std::vector<BasicBlockIndex> worklist;
-        worklist.reserve(function->basicBlockCount());
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-            BasicBlockIndex nodeIndex = bb->index();
-            worklist.push_back(nodeIndex);
-            NodeProgress &np = nodeStatus[nodeIndex];
-            np.children = children[nodeIndex];
-            np.todo = children[nodeIndex];
-        }
-
-        BitVector DF_done(function->basicBlockCount(), false);
-
-        while (!worklist.empty()) {
-            BasicBlockIndex node = worklist.back();
-
-            if (DF_done.at(node)) {
-                worklist.pop_back();
-                continue;
-            }
-
-            NodeProgress &np = nodeStatus[node];
-            std::vector<BasicBlockIndex>::iterator it = np.todo.begin();
-            while (it != np.todo.end()) {
-                if (DF_done.at(*it)) {
-                    it = np.todo.erase(it);
-                } else {
-                    worklist.push_back(*it);
-                    break;
-                }
-            }
-
-            if (np.todo.empty()) {
-                BasicBlockSet &S = DF[node];
-                S.init(function);
-                for (BasicBlock *y : function->basicBlock(node)->out)
-                    if (idom[y->index()] != node)
-                        S.insert(y);
-                for (BasicBlockIndex child : np.children) {
-                    const BasicBlockSet &ws = DF[child];
-                    for (BasicBlockSet::const_iterator it = ws.begin(), eit = ws.end(); it != eit; ++it) {
-                        BasicBlock *w = *it;
-                        const BasicBlockIndex wIndex = w->index();
-                        if (node == wIndex || !dominates(node, w->index()))
-                            S.insert(w);
-                    }
-                }
-                DF_done.setBit(node);
-                worklist.pop_back();
-            }
-        }
-
-        if (DebugDominatorFrontiers) {
-            QBuffer buf;
-            buf.open(QIODevice::WriteOnly);
-            QTextStream qout(&buf);
-            qout << "Dominator Frontiers:" << endl;
-            for (BasicBlock *n : function->basicBlocks()) {
-                if (n->isRemoved())
-                    continue;
-
-                qout << "\tDF[" << n->index() << "]: {";
-                const BasicBlockSet &SList = DF[n->index()];
-                for (BasicBlockSet::const_iterator i = SList.begin(), ei = SList.end(); i != ei; ++i) {
-                    if (i != SList.begin())
-                        qout << ", ";
-                    qout << (*i)->index();
-                }
-                qout << "}" << endl;
-            }
-            qDebug("%s", buf.data().constData());
-        }
-
-        if (DebugDominatorFrontiers && DebugCodeCanUseLotsOfCpu) {
-            for (BasicBlock *n : function->basicBlocks()) {
-                if (n->isRemoved())
-                    continue;
-                const BasicBlockSet &fBlocks = DF[n->index()];
-                for (BasicBlockSet::const_iterator it = fBlocks.begin(), eit = fBlocks.end(); it != eit; ++it) {
-                    BasicBlock *fBlock = *it;
-                    Q_ASSERT(!dominates(n, fBlock) || fBlock == n);
-                    bool hasDominatedSucc = false;
-                    for (BasicBlock *succ : fBlock->in) {
-                        if (dominates(n, succ)) {
-                            hasDominatedSucc = true;
-                            break;
-                        }
-                    }
-                    if (!hasDominatedSucc) {
-                        qDebug("%d in DF[%d] has no dominated predecessors", fBlock->index(), n->index());
-                    }
-                    Q_ASSERT(hasDominatedSucc);
-                }
-            }
-        }
-    }
-
-    const BasicBlockSet &dominatorFrontier(BasicBlock *n) const {
-        return DF[n->index()];
-    }
-
-    BasicBlock *immediateDominator(BasicBlock *bb) const {
-        const BasicBlockIndex idx = idom[bb->index()];
-        if (idx == -1)
-            return 0;
-        return function->basicBlock(idx);
-    }
-
-    void dumpImmediateDominators() const
-    {
-        if (DebugImmediateDominators) {
-            QBuffer buf;
-            buf.open(QIODevice::WriteOnly);
-            QTextStream qout(&buf);
-            qout << "Immediate dominators:" << endl;
-            for (BasicBlock *to : function->basicBlocks()) {
-                if (to->isRemoved())
-                    continue;
-
-                qout << '\t';
-                BasicBlockIndex from = idom.at(to->index());
-                if (from != InvalidBasicBlockIndex)
-                    qout << from;
-                else
-                    qout << "(none)";
-                qout << " dominates " << to->index() << endl;
-            }
-            qDebug("%s", buf.data().constData());
-        }
-    }
-
-    void setImmediateDominator(BasicBlock *bb, BasicBlock *newDominator)
-    {
-        Q_ASSERT(bb->index() >= 0);
-        Q_ASSERT(!newDominator || newDominator->index() >= 0);
-
-        if (static_cast<std::vector<BasicBlockIndex>::size_type>(bb->index()) >= idom.size()) {
-            // This is a new block, probably introduced by edge splitting. So, we'll have to grow
-            // the array before inserting the immediate dominator.
-            idom.resize(function->basicBlockCount(), InvalidBasicBlockIndex);
-        }
-
-        const BasicBlockIndex newIdx = newDominator ? newDominator->index() : InvalidBasicBlockIndex;
-        if (DebugImmediateDominators)
-            qDebug() << "Setting idom of" << bb->index() << "from" << idom[bb->index()] << "to" << newIdx;
-        idom[bb->index()] = newIdx;
-    }
-
-    void collectSiblings(BasicBlock *node, BasicBlockSet &siblings)
-    {
-        siblings.insert(node);
-        const BasicBlockIndex dominator = idom[node->index()];
-        if (dominator == InvalidBasicBlockIndex)
-            return;
-        for (size_t i = 0, ei = idom.size(); i != ei; ++i) {
-            if (idom[i] == dominator) {
-                BasicBlock *bb = function->basicBlock(int(i));
-                if (!bb->isRemoved())
-                    siblings.insert(bb);
-            }
-        }
-    }
-
-    void recalculateIDoms(const BasicBlockSet &nodes, BasicBlock *limit = 0)
-    {
-        const BasicBlockIndex limitIndex = limit ? limit->index() : InvalidBasicBlockIndex;
-        BasicBlockSet todo(nodes), postponed(function);
-        while (!todo.empty())
-            recalculateIDom(*todo.begin(), todo, postponed, limitIndex);
-    }
-
-    bool dominates(BasicBlock *dominator, BasicBlock *dominated) const {
-        return dominates(dominator->index(), dominated->index());
-    }
-
-    struct Cmp {
-        std::vector<int> *nodeDepths;
-        Cmp(std::vector<int> *nodeDepths)
-            : nodeDepths(nodeDepths)
-            { Q_ASSERT(nodeDepths); }
-        bool operator()(BasicBlock *one, BasicBlock *two) const
-            {
-                if (one->isRemoved())
-                    return false;
-                if (two->isRemoved())
-                    return true;
-                return nodeDepths->at(one->index()) > nodeDepths->at(two->index());
-            }
-    };
-
-    // Calculate a depth-first iteration order on the nodes of the dominator tree.
-    //
-    // The order of the nodes in the vector is not the same as one where a recursive depth-first
-    // iteration is done on a tree. Rather, the nodes are (reverse) sorted on tree depth.
-    // So for the:
-    //    1 dominates 2
-    //    2 dominates 3
-    //    3 dominates 4
-    //    2 dominates 5
-    // the order will be:
-    //    4, 3, 5, 2, 1
-    // or:
-    //    4, 5, 3, 2, 1
-    // So the order of nodes on the same depth is undefined, but it will be after the nodes
-    // they dominate, and before the nodes that dominate them.
-    //
-    // The reason for this order is that a proper DFS pre-/post-order would require inverting
-    // the idom vector by either building a real tree datastructure or by searching the idoms
-    // for siblings and children. Both have a higher time complexity than sorting by depth.
-    QVector<BasicBlock *> calculateDFNodeIterOrder() const
-    {
-        std::vector<int> depths = calculateNodeDepths();
-        QVector<BasicBlock *> order = function->basicBlocks();
-        std::sort(order.begin(), order.end(), Cmp(&depths));
-        for (int i = 0; i < order.size(); ) {
-            if (order[i]->isRemoved())
-                order.remove(i);
-            else
-                ++i;
-        }
-        return order;
-    }
-
-    void mergeIntoPredecessor(BasicBlock *successor)
-    {
-        int succIdx = successor->index();
-        if (succIdx == InvalidBasicBlockIndex) {
-            return;
-        }
-
-        int succDom = idom[unsigned(succIdx)];
-        for (BasicBlockIndex &idx : idom) {
-            if (idx == succIdx) {
-                idx = succDom;
-            }
-        }
-    }
-
-private:
-    bool dominates(BasicBlockIndex dominator, BasicBlockIndex dominated) const {
-        // dominator can be Invalid when the dominated block has no dominator (i.e. the start node)
-        Q_ASSERT(dominated != InvalidBasicBlockIndex);
-
-        if (dominator == dominated)
-            return false;
-
-        for (BasicBlockIndex it = idom[dominated]; it != InvalidBasicBlockIndex; it = idom[it]) {
-            if (it == dominator)
-                return true;
-        }
-
-        return false;
-    }
-
-    // Algorithm:
-    //  - for each node:
-    //    - get the depth of a node. If it's unknown (-1):
-    //      - get the depth of the immediate dominator.
-    //      - if that's unknown too, calculate it by calling calculateNodeDepth
-    //      - set the current node's depth to that of immediate dominator + 1
-    std::vector<int> calculateNodeDepths() const
-    {
-        std::vector<int> nodeDepths(size_t(function->basicBlockCount()), -1);
-        nodeDepths[0] = 0;
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-
-            int &bbDepth = nodeDepths[bb->index()];
-            if (bbDepth == -1) {
-                const int immDom = idom[bb->index()];
-                int immDomDepth = nodeDepths[immDom];
-                if (immDomDepth == -1)
-                    immDomDepth = calculateNodeDepth(immDom, nodeDepths);
-                bbDepth = immDomDepth + 1;
-            }
-        }
-        return nodeDepths;
-    }
-
-    // Algorithm:
-    //   - search for the first dominator of a node that has a known depth. As all nodes are
-    //     reachable from the start node, and that node's depth is 0, this is finite.
-    //   - while doing that search, put all unknown nodes in the worklist
-    //   - pop all nodes from the worklist, and set their depth to the previous' (== dominating)
-    //     node's depth + 1
-    // This way every node's depth is calculated once, and the complexity is O(n).
-    int calculateNodeDepth(int nodeIdx, std::vector<int> &nodeDepths) const
-    {
-        std::vector<int> worklist;
-        worklist.reserve(8);
-        int depth = -1;
-
-        do {
-            worklist.push_back(nodeIdx);
-            nodeIdx = idom[nodeIdx];
-            depth = nodeDepths[nodeIdx];
-        } while (depth == -1);
-
-        for (std::vector<int>::const_reverse_iterator it = worklist.rbegin(), eit = worklist.rend(); it != eit; ++it)
-            nodeDepths[*it] = ++depth;
-
-        return depth;
-    }
-
-    // The immediate-dominator recalculation is used when edges are removed from the CFG. See
-    // [Ramalingam] for a description. Note that instead of calculating the priority, a recursive
-    // algorithm is used: when recalculating the immediate dominator of a node by looking for the
-    // least-common ancestor, and a node is hit that also needs recalculation, a recursive call
-    // is done to calculate that nodes immediate dominator first.
-    //
-    // Note that this simplified algorithm cannot cope with back-edges. It only works for
-    // non-looping edges (which is our use-case).
-    void recalculateIDom(BasicBlock *node, BasicBlockSet &todo, BasicBlockSet &postponed, BasicBlockIndex limit) {
-        Q_ASSERT(!postponed.contains(node));
-        Q_ASSERT(todo.contains(node));
-        todo.remove(node);
-
-        if (node->in.size() == 1) {
-            // Special case: if the node has only one incoming edge, then that is the immediate
-            // dominator.
-            setImmediateDominator(node, node->in.first());
-            return;
-        }
-
-        std::vector<BasicBlockIndex> prefix;
-        prefix.reserve(32);
-
-        for (BasicBlock *in : node->in) {
-            if (node == in) // back-edge to self
-                continue;
-            if (dominates(node->index(), in->index())) // a known back-edge
-                continue;
-
-            if (prefix.empty()) {
-                calculatePrefix(node, in, prefix, todo, postponed, limit);
-
-                if (!prefix.empty()) {
-                    std::reverse(prefix.begin(), prefix.end());
-                    Q_ASSERT(!prefix.empty());
-                    Q_ASSERT(prefix.front() == limit || limit == InvalidBasicBlockIndex);
-                }
-            } else {
-                std::vector<BasicBlockIndex> anotherPrefix;
-                anotherPrefix.reserve(prefix.size());
-                calculatePrefix(node, in, anotherPrefix, todo, postponed, limit);
-
-                if (!anotherPrefix.empty())
-                    commonPrefix(prefix, anotherPrefix);
-            }
-        }
-
-        Q_ASSERT(!prefix.empty());
-        idom[node->index()] = prefix.back();
-    }
-
-    void calculatePrefix(BasicBlock *node, BasicBlock *in, std::vector<BasicBlockIndex> &prefix, BasicBlockSet &todo, BasicBlockSet &postponed, BasicBlockIndex limit)
-    {
-        for (BasicBlockIndex it = in->index(); it != InvalidBasicBlockIndex; it = idom[it]) {
-            prefix.push_back(it);
-            if (it == limit)
-                return;
-            BasicBlock *n = function->basicBlock(it);
-            if (postponed.contains(n)) { // possible back-edge, bail out.
-                prefix.clear();
-                return;
-            }
-            if (todo.contains(n)) {
-                postponed.insert(node);
-                recalculateIDom(n, todo, postponed, limit);
-                postponed.remove(node);
-            }
-        }
-    }
-
-    // Calculate the LCA (Least Common Ancestor) by finding the longest common prefix between two
-    // dominator chains. Note that "anotherPrefix" has the node's immediate dominator first, while
-    // "bestPrefix" has it last (meaning: is in reverse order). The reason for this is that removing
-    // nodes from "bestPrefix" is cheaper because it's done at the end of the vector, while
-    // reversing all "anotherPrefix" nodes would take unnecessary time.
-    static void commonPrefix(std::vector<BasicBlockIndex> &bestPrefix, const std::vector<BasicBlockIndex> &anotherPrefix)
-    {
-        const size_t anotherSize = anotherPrefix.size();
-        size_t minLen = qMin(bestPrefix.size(), anotherPrefix.size());
-        while (minLen != 0) {
-            --minLen;
-            if (bestPrefix[minLen] == anotherPrefix[anotherSize - minLen - 1]) {
-                ++minLen;
-                break;
-            }
-        }
-        if (minLen != bestPrefix.size())
-            bestPrefix.erase(bestPrefix.begin() + minLen, bestPrefix.end());
-    }
-};
-
-class VariableCollector {
-    std::vector<Temp> _allTemps;
-    std::vector<BasicBlockSet> _defsites;
-    std::vector<std::vector<int> > A_orig;
-    BitVector nonLocals;
-    BitVector killed;
-
-    BasicBlock *currentBB;
-    bool isCollectable(Temp *t) const
-    {
-        Q_UNUSED(t);
-        Q_ASSERT(t->kind != Temp::PhysicalRegister && t->kind != Temp::StackSlot);
-        return true;
-    }
-
-    void addDefInCurrentBlock(Temp *t)
-    {
-        std::vector<int> &temps = A_orig[currentBB->index()];
-        if (std::find(temps.begin(), temps.end(), t->index) == temps.end())
-            temps.push_back(t->index);
-    }
-
-    void addTemp(Temp *t)
-    {
-        if (_allTemps[t->index].kind == Temp::Invalid)
-            _allTemps[t->index] = *t;
-    }
-
-public:
-    VariableCollector(IR::Function *function)
-    {
-        _allTemps.resize(function->tempCount);
-        _defsites.resize(function->tempCount);
-        for (int i = 0; i < function->tempCount; ++i)
-            _defsites[i].init(function);
-        nonLocals.resize(function->tempCount);
-        const size_t ei = function->basicBlockCount();
-        A_orig.resize(ei);
-        for (size_t i = 0; i != ei; ++i)
-            A_orig[i].reserve(8);
-
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-
-            currentBB = bb;
-            killed.assign(function->tempCount, false);
-            for (Stmt *s : bb->statements())
-                visit(s);
-        }
-    }
-
-    const std::vector<Temp> &allTemps() const
-    { return _allTemps; }
-
-    void collectDefSites(const Temp &n, std::vector<BasicBlock *> &bbs) const {
-        Q_ASSERT(!n.isInvalid());
-        Q_ASSERT(n.index < _defsites.size());
-        _defsites[n.index].collectValues(bbs);
-    }
-
-    const std::vector<int> &inBlock(BasicBlock *n) const
-    {
-        return A_orig.at(n->index());
-    }
-
-    bool isNonLocal(const Temp &var) const
-    {
-        Q_ASSERT(!var.isInvalid());
-        Q_ASSERT(static_cast<int>(var.index) < nonLocals.size());
-        return nonLocals.at(var.index);
-    }
-
-private:
-    void visit(Stmt *s)
-    {
-        if (s->asPhi()) {
-            // nothing to do
-        } else if (auto move = s->asMove()) {
-            visit(move->source);
-
-            if (Temp *t = move->target->asTemp()) {
-                addTemp(t);
-
-                if (isCollectable(t)) {
-                    _defsites[t->index].insert(currentBB);
-                    addDefInCurrentBlock(t);
-
-                    // For semi-pruned SSA:
-                    killed.setBit(t->index);
-                }
-            } else {
-                visit(move->target);
-            }
-        } else {
-            STMT_VISIT_ALL_KINDS(s)
-        }
-    }
-
-    void visit(Expr *e)
-    {
-        if (auto t = e->asTemp()) {
-            addTemp(t);
-
-            if (isCollectable(t)) {
-                if (!killed.at(t->index)) {
-                    nonLocals.setBit(t->index);
-                }
-            }
-        } else {
-            EXPR_VISIT_ALL_KINDS(e);
-        }
-    }
-};
-
-struct UntypedTemp {
-    Temp temp;
-    UntypedTemp() {}
-    UntypedTemp(const Temp &t): temp(t) {}
-};
-inline bool operator==(const UntypedTemp &t1, const UntypedTemp &t2) Q_DECL_NOTHROW
-{ return t1.temp.index == t2.temp.index && t1.temp.kind == t2.temp.kind; }
-inline bool operator!=(const UntypedTemp &t1, const UntypedTemp &t2) Q_DECL_NOTHROW
-{ return !(t1 == t2); }
-
-class DefUses
-{
-public:
-    struct DefUse {
-        DefUse()
-            : defStmt(0)
-            , blockOfStatement(0)
-        { uses.reserve(8); }
-        Temp temp;
-        Stmt *defStmt;
-        BasicBlock *blockOfStatement;
-        QVector<Stmt *> uses;
-
-        bool isValid() const
-        { return temp.kind != Temp::Invalid; }
-
-        void clear()
-        { defStmt = 0; blockOfStatement = 0; uses.clear(); }
-    };
-
-private:
-    std::vector<DefUse> _defUses;
-    typedef QVarLengthArray<Temp, 4> Temps;
-    std::vector<Temps> _usesPerStatement;
-
-    void ensure(Temp *newTemp)
-    {
-        if (_defUses.size() <= newTemp->index) {
-            _defUses.resize(newTemp->index + 1);
-        }
-    }
-
-    void ensure(Stmt *s)
-    {
-        Q_ASSERT(s->id() >= 0);
-        if (static_cast<unsigned>(s->id()) >= _usesPerStatement.size()) {
-            _usesPerStatement.resize(s->id() + 1);
-        }
-    }
-
-    void addUseForStatement(Stmt *s, const Temp &var)
-    {
-        ensure(s);
-        _usesPerStatement[s->id()].push_back(var);
-    }
-
-public:
-    DefUses(IR::Function *function)
-    {
-        _usesPerStatement.resize(function->statementCount());
-        _defUses.resize(function->tempCount);
-    }
-
-    void cleanup()
-    {
-        for (size_t i = 0, ei = _defUses.size(); i != ei; ++i) {
-            DefUse &defUse = _defUses[i];
-            if (defUse.isValid() && !defUse.defStmt)
-                defUse.clear();
-        }
-    }
-
-    unsigned statementCount() const
-    { return unsigned(_usesPerStatement.size()); }
-
-    unsigned tempCount() const
-    { return unsigned(_defUses.size()); }
-
-    const Temp &temp(int idx) const
-    { return _defUses[idx].temp; }
-
-    void addDef(Temp *newTemp, Stmt *defStmt, BasicBlock *defBlock)
-    {
-        ensure(newTemp);
-        DefUse &defUse = _defUses[newTemp->index];
-        Q_ASSERT(!defUse.isValid());
-        defUse.temp = *newTemp;
-        defUse.defStmt = defStmt;
-        defUse.blockOfStatement = defBlock;
-    }
-
-    QVector<UntypedTemp> defsUntyped() const
-    {
-        QVector<UntypedTemp> res;
-        res.reserve(tempCount());
-        for (const DefUse &du : _defUses)
-            if (du.isValid())
-                res.append(UntypedTemp(du.temp));
-        return res;
-    }
-
-    std::vector<const Temp *> defs() const {
-        std::vector<const Temp *> res;
-        const size_t ei = _defUses.size();
-        res.reserve(ei);
-        for (size_t i = 0; i != ei; ++i) {
-            const DefUse &du = _defUses.at(i);
-            if (du.isValid())
-                res.push_back(&du.temp);
-        }
-        return res;
-    }
-
-    void removeDef(const Temp &variable) {
-        Q_ASSERT(static_cast<unsigned>(variable.index) < _defUses.size());
-        _defUses[variable.index].clear();
-    }
-
-    void addUses(const Temp &variable, const QVector<Stmt *> &newUses)
-    {
-        Q_ASSERT(static_cast<unsigned>(variable.index) < _defUses.size());
-        QVector<Stmt *> &uses = _defUses[variable.index].uses;
-        for (Stmt *stmt : newUses)
-            if (std::find(uses.begin(), uses.end(), stmt) == uses.end())
-                uses.push_back(stmt);
-    }
-
-    void addUse(const Temp &variable, Stmt *newUse)
-    {
-        if (_defUses.size() <= variable.index) {
-            _defUses.resize(variable.index + 1);
-            DefUse &du = _defUses[variable.index];
-            du.temp = variable;
-            du.uses.push_back(newUse);
-            addUseForStatement(newUse, variable);
-            return;
-        }
-
-        QVector<Stmt *> &uses = _defUses[variable.index].uses;
-        if (std::find(uses.begin(), uses.end(), newUse) == uses.end())
-            uses.push_back(newUse);
-        addUseForStatement(newUse, variable);
-    }
-
-    int useCount(const Temp &variable) const
-    {
-        Q_ASSERT(static_cast<unsigned>(variable.index) < _defUses.size());
-        return _defUses[variable.index].uses.size();
-    }
-
-    Stmt *defStmt(const Temp &variable) const
-    {
-        Q_ASSERT(static_cast<unsigned>(variable.index) < _defUses.size());
-        return _defUses[variable.index].defStmt;
-    }
-
-    BasicBlock *defStmtBlock(const Temp &variable) const
-    {
-        Q_ASSERT(static_cast<unsigned>(variable.index) < _defUses.size());
-        return _defUses[variable.index].blockOfStatement;
-    }
-
-    void replaceBasicBlock(BasicBlock *from, BasicBlock *to)
-    {
-        for (auto &du : _defUses) {
-            if (du.blockOfStatement == from) {
-                du.blockOfStatement = to;
-            }
-        }
-    }
-
-    void removeUse(Stmt *usingStmt, const Temp &var)
-    {
-        Q_ASSERT(static_cast<unsigned>(var.index) < _defUses.size());
-        QVector<Stmt *> &uses = _defUses[var.index].uses;
-        uses.erase(std::remove(uses.begin(), uses.end(), usingStmt), uses.end());
-    }
-
-    void registerNewStatement(Stmt *s)
-    {
-        ensure(s);
-    }
-
-    const Temps &usedVars(Stmt *s) const
-    {
-        Q_ASSERT(s->id() >= 0);
-        Q_ASSERT(static_cast<unsigned>(s->id()) < _usesPerStatement.size());
-        return _usesPerStatement[s->id()];
-    }
-
-    const QVector<Stmt *> &uses(const Temp &var) const
-    {
-        return _defUses[var.index].uses;
-    }
-
-    QVector<Stmt*> removeDefUses(Stmt *s)
-    {
-        QVector<Stmt*> defStmts;
-        for (const Temp &usedVar : usedVars(s)) {
-            if (Stmt *ds = defStmt(usedVar))
-                defStmts += ds;
-            removeUse(s, usedVar);
-        }
-        if (Move *m = s->asMove()) {
-            if (Temp *t = m->target->asTemp())
-                removeDef(*t);
-        } else if (Phi *p = s->asPhi()) {
-            removeDef(*p->targetTemp);
-        }
-
-        return defStmts;
-    }
-
-    void dump() const
-    {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream qout(&buf);
-        qout << "Defines and uses:" << endl;
-        for (const DefUse &du : _defUses) {
-            if (!du.isValid())
-                continue;
-            qout << '%' << du.temp.index;
-            qout << " -> defined in block " << du.blockOfStatement->index()
-                 << ", statement: " << du.defStmt->id()
-                 << endl;
-            qout << "     uses:";
-            for (Stmt *s : du.uses)
-                qout << ' ' << s->id();
-            qout << endl;
-        }
-        qout << "Uses per statement:" << endl;
-        for (size_t i = 0, ei = _usesPerStatement.size(); i != ei; ++i) {
-            qout << "    " << i << ":";
-            for (const Temp &t : _usesPerStatement[i])
-                qout << ' ' << t.index;
-            qout << endl;
-        }
-        qDebug("%s", buf.data().constData());
-    }
-};
-
-void insertPhiNode(const Temp &a, BasicBlock *y, IR::Function *f) {
-    Phi *phiNode = f->NewStmt<Phi>();
-    phiNode->targetTemp = f->New<Temp>();
-    phiNode->targetTemp->init(a.kind, a.index);
-    y->prependStatement(phiNode);
-
-    phiNode->incoming.resize(y->in.size());
-    for (int i = 0, ei = y->in.size(); i < ei; ++i) {
-        Temp *t = f->New<Temp>();
-        t->init(a.kind, a.index);
-        phiNode->incoming[i] = t;
-    }
-}
-
-// High-level (recursive) algorithm:
-//   Mapping: old temp number -> new temp number
-//
-//   Start:
-//     Rename(start-node)
-//
-//   Rename(node, mapping):
-//     for each statement S in block n
-//       if S not in a phi-function
-//         for each use of some variable x in S
-//           y = mapping[x]
-//           replace the use of x with y in S
-//       for each definition of some variable a in S                        [1]
-//         a_new = generate new/unique temp
-//         mapping[a] = a_new
-//         replace definition of a with definition of a_new in S
-//     for each successor Y of block n
-//       Suppose n is the j-th predecessor of Y
-//       for each phi function in Y
-//         suppose the j-th operand of the phi-function is a
-//         i = mapping[a]
-//         replace the j-th operand with a_i
-//     for each child X of n                                                [2]
-//       Rename(X)
-//     for each newly generated temp from step [1] restore the old value    [3]
-//
-// This algorithm can run out of CPU stack space when there are lots of basic-blocks, like in a
-// switch statement with 8000 cases that all fall-through. The iterativer version below uses a
-// work-item stack, where step [1] from the algorithm above also pushes an "undo mapping change",
-// and step [2] pushes a "rename(X)" action. This eliminates step [3].
-//
-// Iterative version:
-//   Mapping: old temp number -> new temp number
-//
-//   The stack can hold two kinds of actions:
-//     "Rename basic block n"
-//     "Restore count for temp"
-//
-//   Start:
-//     counter = 0
-//     push "Rename start node" onto the stack
-//     while the stack is not empty:
-//       take the last item, and process it
-//
-//   Rename(n) =
-//     for each statement S in block n
-//       if S not in a phi-function
-//         for each use of some variable x in S
-//           y = mapping[x]
-//           replace the use of x with y in S
-//       for each definition of some variable a in S
-//         old = mapping[a]
-//         push Undo(a, old)
-//         counter = counter + 1
-//         new = counter;
-//         mapping[a] = new
-//         replace definition of a with definition of a_new in S
-//     for each successor Y of block n
-//       Suppose n is the j-th predecessor of Y
-//       for each phi function in Y
-//         suppose the j-th operand of the phi-function is a
-//         i = mapping[a]
-//         replace the j-th operand with a_i
-//     for each child X of n
-//       push Rename(X)
-//
-//   Undo(t, c) =
-//     mapping[t] = c
-class VariableRenamer
-{
-    Q_DISABLE_COPY(VariableRenamer)
-
-    IR::Function *function;
-    DefUses &defUses;
-    unsigned tempCount;
-
-    typedef std::vector<int> Mapping; // maps from existing/old temp number to the new and unique temp number.
-    enum { Absent = -1 };
-    Mapping vregMapping;
-    ProcessedBlocks processed;
-
-    BasicBlock *currentBB;
-    Stmt *currentStmt;
-
-    struct TodoAction {
-        enum { RestoreVReg, Rename } action;
-        union {
-            struct {
-                unsigned temp;
-                int previous;
-            } restoreData;
-            struct {
-                BasicBlock *basicBlock;
-            } renameData;
-        };
-
-        bool isValid() const { return action != Rename || renameData.basicBlock != 0; }
-
-        TodoAction()
-        {
-            action = Rename;
-            renameData.basicBlock = 0;
-        }
-
-        TodoAction(const Temp &t, int prev)
-        {
-            Q_ASSERT(t.kind == Temp::VirtualRegister);
-
-            action = RestoreVReg;
-            restoreData.temp = t.index;
-            restoreData.previous = prev;
-        }
-
-        TodoAction(BasicBlock *bb)
-        {
-            Q_ASSERT(bb);
-
-            action = Rename;
-            renameData.basicBlock = bb;
-        }
-    };
-
-    QVector<TodoAction> todo;
-
-public:
-    VariableRenamer(IR::Function *f, DefUses &defUses)
-        : function(f)
-        , defUses(defUses)
-        , tempCount(0)
-        , processed(f)
-    {
-        vregMapping.assign(f->tempCount, Absent);
-        todo.reserve(f->basicBlockCount());
-    }
-
-    void run() {
-        todo.append(TodoAction(function->basicBlock(0)));
-
-        while (!todo.isEmpty()) {
-            TodoAction todoAction = todo.back();
-            Q_ASSERT(todoAction.isValid());
-            todo.pop_back();
-
-            switch (todoAction.action) {
-            case TodoAction::Rename:
-                rename(todoAction.renameData.basicBlock);
-                break;
-            case TodoAction::RestoreVReg:
-                restore(vregMapping, todoAction.restoreData.temp, todoAction.restoreData.previous);
-                break;
-            default:
-                Q_UNREACHABLE();
-            }
-        }
-
-        function->tempCount = tempCount;
-    }
-
-private:
-    static inline void restore(Mapping &mapping, int temp, int previous)
-    {
-        mapping[temp] = previous;
-    }
-
-    void rename(BasicBlock *bb)
-    {
-        while (bb && !processed.alreadyProcessed(bb)) {
-            renameStatementsAndPhis(bb);
-            processed.markAsProcessed(bb);
-
-            BasicBlock *next = 0;
-            for (BasicBlock *out : bb->out) {
-                if (processed.alreadyProcessed(out))
-                    continue;
-                if (!next)
-                    next = out;
-                else
-                    todo.append(TodoAction(out));
-            }
-            bb = next;
-        }
-    }
-
-    void renameStatementsAndPhis(BasicBlock *bb)
-    {
-        currentBB = bb;
-
-        for (Stmt *s : bb->statements()) {
-            currentStmt = s;
-            visit(s);
-        }
-
-        for (BasicBlock *Y : bb->out) {
-            const int j = Y->in.indexOf(bb);
-            Q_ASSERT(j >= 0 && j < Y->in.size());
-            for (Stmt *s : Y->statements()) {
-                if (Phi *phi = s->asPhi()) {
-                    Temp *t = phi->incoming[j]->asTemp();
-                    unsigned newTmp = currentNumber(*t);
-//                    qDebug()<<"I: replacing phi use"<<a<<"with"<<newTmp<<"in L"<<Y->index;
-                    t->index = newTmp;
-                    t->kind = Temp::VirtualRegister;
-                    defUses.addUse(*t, phi);
-                } else {
-                    break;
-                }
-            }
-        }
-    }
-
-    unsigned currentNumber(const Temp &t)
-    {
-        int nr = Absent;
-        switch (t.kind) {
-        case Temp::VirtualRegister:
-            nr = vregMapping[t.index];
-            break;
-        default:
-            Q_UNREACHABLE();
-            nr = Absent;
-            break;
-        }
-        if (nr == Absent) {
-            // Special case: we didn't prune the Phi nodes yet, so for proper temps (virtual
-            // registers) the SSA algorithm might insert superfluous Phis that have uses without
-            // definition. E.g.: if a temporary got introduced in the "then" clause, it "could"
-            // reach the "end-if" block, so there will be a phi node for that temp. A later pass
-            // will clean this up by looking for uses-without-defines in phi nodes. So, what we do
-            // is to generate a new unique number, and leave it dangling.
-            nr = nextFreeTemp(t);
-        }
-
-        return nr;
-    }
-
-    unsigned nextFreeTemp(const Temp &t)
-    {
-        unsigned newIndex = tempCount++;
-        Q_ASSERT(newIndex <= INT_MAX);
-        int oldIndex = Absent;
-
-        switch (t.kind) {
-        case Temp::VirtualRegister:
-            oldIndex = vregMapping[t.index];
-            vregMapping[t.index] = newIndex;
-            break;
-        default:
-            Q_UNREACHABLE();
-        }
-
-        todo.append(TodoAction(t, oldIndex));
-
-        return newIndex;
-    }
-
-private:
-    void visit(Stmt *s)
-    {
-        if (auto move = s->asMove()) {
-            // uses:
-            visit(move->source);
-
-            // defs:
-            if (Temp *t = move->target->asTemp()) {
-                renameTemp(t);
-            } else {
-                visit(move->target);
-            }
-        } else if (auto phi = s->asPhi()) {
-            renameTemp(phi->targetTemp);
-        } else {
-            STMT_VISIT_ALL_KINDS(s);
-        }
-    }
-
-    void visit(Expr *e)
-    {
-        if (auto temp = e->asTemp()) {
-            temp->index = currentNumber(*temp);
-            temp->kind = Temp::VirtualRegister;
-            defUses.addUse(*temp, currentStmt);
-        } else {
-            EXPR_VISIT_ALL_KINDS(e);
-        }
-    }
-
-    void renameTemp(Temp *t) { // only called for defs, not uses
-        const int newIdx = nextFreeTemp(*t);
-//        qDebug()<<"I: replacing def of"<<a<<"with"<<newIdx;
-        t->kind = Temp::VirtualRegister;
-        t->index = newIdx;
-        defUses.addDef(t, currentStmt, currentBB);
-    }
-};
-
-// This function converts the IR to semi-pruned SSA form. For details about SSA and the algorightm,
-// see [Appel]. For the changes needed for semi-pruned SSA form, and for its advantages, see [Briggs].
-void convertToSSA(IR::Function *function, const DominatorTree &df, DefUses &defUses)
-{
-    // Collect all applicable variables:
-    VariableCollector variables(function);
-
-    // Prepare for phi node insertion:
-    std::vector<BitVector > A_phi;
-    const size_t ei = function->basicBlockCount();
-    A_phi.resize(ei);
-    for (size_t i = 0; i != ei; ++i)
-        A_phi[i].assign(function->tempCount, false);
-
-    std::vector<BasicBlock *> W;
-    W.reserve(8);
-
-    // Place phi functions:
-    for (const Temp &a : variables.allTemps()) {
-        if (a.isInvalid())
-            continue;
-        if (!variables.isNonLocal(a))
-            continue; // for semi-pruned SSA
-
-        W.clear();
-        variables.collectDefSites(a, W);
-        while (!W.empty()) {
-            BasicBlock *n = W.back();
-            W.pop_back();
-            const BasicBlockSet &dominatorFrontierForN = df.dominatorFrontier(n);
-            for (BasicBlockSet::const_iterator it = dominatorFrontierForN.begin(), eit = dominatorFrontierForN.end();
-                 it != eit; ++it) {
-                BasicBlock *y = *it;
-                if (!A_phi.at(y->index()).at(a.index)) {
-                    insertPhiNode(a, y, function);
-                    A_phi[y->index()].setBit(a.index);
-                    const std::vector<int> &varsInBlockY = variables.inBlock(y);
-                    if (std::find(varsInBlockY.begin(), varsInBlockY.end(), a.index) == varsInBlockY.end())
-                        W.push_back(y);
-                }
-            }
-        }
-    }
-
-    // Rename variables:
-    VariableRenamer(function, defUses).run();
-}
-
-/// Calculate if a phi node result is used only by other phi nodes, and if those uses are
-/// in turn also used by other phi nodes.
-bool hasPhiOnlyUses(Phi *phi, const DefUses &defUses, QBitArray &collectedPhis)
-{
-    collectedPhis.setBit(phi->id());
-
-    for (Stmt *use : defUses.uses(*phi->targetTemp)) {
-        Phi *dependentPhi = use->asPhi();
-        if (!dependentPhi)
-            return false; // there is a use by a non-phi node
-
-        if (collectedPhis.at(dependentPhi->id()))
-            continue; // we already found this node
-
-        if (!hasPhiOnlyUses(dependentPhi, defUses, collectedPhis))
-            return false;
-    }
-
-    return true;
-}
-
-void cleanupPhis(DefUses &defUses)
-{
-    QBitArray toRemove(defUses.statementCount());
-    QBitArray collectedPhis(defUses.statementCount());
-    std::vector<Phi *> allPhis;
-    allPhis.reserve(32);
-
-    for (const Temp *def : defUses.defs()) {
-        Stmt *defStmt = defUses.defStmt(*def);
-        if (!defStmt)
-            continue;
-
-        Phi *phi = defStmt->asPhi();
-        if (!phi)
-            continue;
-        allPhis.push_back(phi);
-        if (toRemove.at(phi->id()))
-            continue;
-
-        collectedPhis.fill(false);
-        if (hasPhiOnlyUses(phi, defUses, collectedPhis))
-            toRemove |= collectedPhis;
-    }
-
-    for (Phi *phi : allPhis) {
-        if (!toRemove.at(phi->id()))
-            continue;
-
-        const Temp &targetVar = *phi->targetTemp;
-        defUses.defStmtBlock(targetVar)->removeStatement(phi);
-
-        for (const Temp &usedVar : defUses.usedVars(phi))
-            defUses.removeUse(phi, usedVar);
-        defUses.removeDef(targetVar);
-    }
-
-    defUses.cleanup();
-}
-
-class StatementWorklist
-{
-    IR::Function *theFunction;
-    std::vector<Stmt *> stmts;
-    BitVector worklist;
-    unsigned worklistSize;
-    std::vector<int> replaced;
-    BitVector removed;
-
-    Q_DISABLE_COPY(StatementWorklist)
-
-public:
-    StatementWorklist(IR::Function *function)
-        : theFunction(function)
-        , stmts(function->statementCount(), static_cast<Stmt *>(0))
-        , worklist(function->statementCount(), false)
-        , worklistSize(0)
-        , replaced(function->statementCount(), Stmt::InvalidId)
-        , removed(function->statementCount())
-    {
-        grow();
-
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-
-            for (Stmt *s : bb->statements()) {
-                if (!s)
-                    continue;
-
-                stmts[s->id()] = s;
-                worklist.setBit(s->id());
-                ++worklistSize;
-            }
-        }
-    }
-
-    void reset()
-    {
-        worklist.assign(worklist.size(), false);
-        worklistSize = 0;
-
-        for (Stmt *s : stmts) {
-            if (!s)
-                continue;
-
-            worklist.setBit(s->id());
-            ++worklistSize;
-        }
-
-        replaced.assign(replaced.size(), Stmt::InvalidId);
-        removed.assign(removed.size(), false);
-    }
-
-    void remove(Stmt *stmt)
-    {
-        replaced[stmt->id()] = Stmt::InvalidId;
-        removed.setBit(stmt->id());
-        if (worklist.at(stmt->id())) {
-            worklist.clearBit(stmt->id());
-            Q_ASSERT(worklistSize > 0);
-            --worklistSize;
-        }
-    }
-
-    void replace(Stmt *oldStmt, Stmt *newStmt)
-    {
-        Q_ASSERT(oldStmt);
-        Q_ASSERT(replaced[oldStmt->id()] == Stmt::InvalidId);
-        Q_ASSERT(removed.at(oldStmt->id()) == false);
-
-        Q_ASSERT(newStmt);
-        registerNewStatement(newStmt);
-        Q_ASSERT(replaced[newStmt->id()] == Stmt::InvalidId);
-        Q_ASSERT(removed.at(newStmt->id()) == false);
-
-        replaced[oldStmt->id()] = newStmt->id();
-        worklist.clearBit(oldStmt->id());
-    }
-
-    void applyToFunction()
-    {
-        for (BasicBlock *bb : theFunction->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-
-            for (int i = 0; i < bb->statementCount();) {
-                Stmt *stmt = bb->statements().at(i);
-
-                int id = stmt->id();
-                Q_ASSERT(id != Stmt::InvalidId);
-                Q_ASSERT(static_cast<unsigned>(stmt->id()) < stmts.size());
-
-                for (int replacementId = replaced[id]; replacementId != Stmt::InvalidId; replacementId = replaced[replacementId])
-                    id = replacementId;
-                Q_ASSERT(id != Stmt::InvalidId);
-                Q_ASSERT(static_cast<unsigned>(stmt->id()) < stmts.size());
-
-                if (removed.at(id)) {
-                    bb->removeStatement(i);
-                } else {
-                    if (id != stmt->id())
-                        bb->replaceStatement(i, stmts[id]);
-
-                    ++i;
-                }
-            }
-        }
-
-        replaced.assign(replaced.size(), Stmt::InvalidId);
-        removed.assign(removed.size(), false);
-    }
-
-    StatementWorklist &operator+=(const QVector<Stmt *> &stmts)
-    {
-        for (Stmt *s : stmts)
-            this->operator+=(s);
-
-        return *this;
-    }
-
-    StatementWorklist &operator+=(Stmt *s)
-    {
-        if (!s)
-            return *this;
-
-        Q_ASSERT(s->id() >= 0);
-        Q_ASSERT(s->id() < worklist.size());
-
-        if (!worklist.at(s->id())) {
-            worklist.setBit(s->id());
-            ++worklistSize;
-        }
-
-        return *this;
-    }
-
-    StatementWorklist &operator-=(Stmt *s)
-    {
-        Q_ASSERT(s->id() >= 0);
-        Q_ASSERT(s->id() < worklist.size());
-
-        if (worklist.at(s->id())) {
-            worklist.clearBit(s->id());
-            Q_ASSERT(worklistSize > 0);
-            --worklistSize;
-        }
-
-        return *this;
-    }
-
-    unsigned size() const
-    {
-        return worklistSize;
-    }
-
-    Stmt *takeNext(Stmt *last)
-    {
-        if (worklistSize == 0)
-            return 0;
-
-        const int startAt = last ? last->id() + 1 : 0;
-        Q_ASSERT(startAt >= 0);
-        Q_ASSERT(startAt <= worklist.size());
-
-        Q_ASSERT(static_cast<size_t>(worklist.size()) == stmts.size());
-
-        int pos = worklist.findNext(startAt, true, /*wrapAround = */true);
-
-        worklist.clearBit(pos);
-        Q_ASSERT(worklistSize > 0);
-        --worklistSize;
-        Stmt *s = stmts.at(pos);
-        Q_ASSERT(s);
-
-        if (removed.at(s->id()))
-            return takeNext(s);
-
-        return s;
-    }
-
-    IR::Function *function() const
-    {
-        return theFunction;
-    }
-
-    void registerNewStatement(Stmt *s)
-    {
-        Q_ASSERT(s->id() >= 0);
-        if (static_cast<unsigned>(s->id()) >= stmts.size()) {
-            if (static_cast<unsigned>(s->id()) >= stmts.capacity())
-                grow();
-
-            int newSize = s->id() + 1;
-            stmts.resize(newSize, 0);
-            worklist.resize(newSize);
-            replaced.resize(newSize, Stmt::InvalidId);
-            removed.resize(newSize);
-        }
-
-        stmts[s->id()] = s;
-    }
-
-private:
-    void grow()
-    {
-        Q_ASSERT(stmts.capacity() < INT_MAX / 2);
-        int newCapacity = ((static_cast<int>(stmts.capacity()) + 1) * 3) / 2;
-        stmts.reserve(newCapacity);
-        worklist.reserve(newCapacity);
-        replaced.reserve(newCapacity);
-        removed.reserve(newCapacity);
-    }
-};
-
-class SideEffectsChecker
-{
-    bool _sideEffect;
-
-public:
-    SideEffectsChecker()
-        : _sideEffect(false)
-    {}
-
-    ~SideEffectsChecker()
-    {}
-
-    bool hasSideEffects(Expr *expr)
-    {
-        bool sideEffect = false;
-        qSwap(_sideEffect, sideEffect);
-        visit(expr);
-        qSwap(_sideEffect, sideEffect);
-        return sideEffect;
-    }
-
-protected:
-    void markAsSideEffect()
-    {
-        _sideEffect = true;
-    }
-
-    bool seenSideEffects() const { return _sideEffect; }
-
-    void visit(Expr *e)
-    {
-        if (auto n = e->asName()) {
-            visitName(n);
-        } else if (auto t = e->asTemp()) {
-            visitTemp(t);
-        } else if (auto c = e->asClosure()) {
-            visitClosure(c);
-        } else if (auto c = e->asConvert()) {
-            visitConvert(c);
-        } else if (auto u = e->asUnop()) {
-            visitUnop(u);
-        } else if (auto b = e->asBinop()) {
-            visitBinop(b);
-        } else if (auto c = e->asCall()) {
-            visitCall(c);
-        } else if (auto n = e->asNew()) {
-            visitNew(n);
-        } else if (auto s = e->asSubscript()) {
-            visitSubscript(s);
-        } else if (auto m = e->asMember()) {
-            visitMember(m);
-        }
-    }
-
-    virtual void visitTemp(Temp *) {}
-
-private:
-    void visitName(Name *e) {
-        if (e->freeOfSideEffects)
-            return;
-        // TODO: maybe we can distinguish between built-ins of which we know that they do not have
-        // a side-effect.
-        if (e->builtin == Name::builtin_invalid || (e->id && *e->id != QLatin1String("this")))
-            markAsSideEffect();
-    }
-
-    void visitClosure(Closure *) {
-        markAsSideEffect();
-    }
-
-    void visitConvert(Convert *e) {
-        visit(e->expr);
-
-        switch (e->expr->type) {
-        case QObjectType:
-        case StringType:
-        case VarType:
-            markAsSideEffect();
-            break;
-        default:
-            break;
-        }
-    }
-
-    void visitUnop(Unop *e) {
-        visit(e->expr);
-
-        switch (e->op) {
-        case OpUPlus:
-        case OpUMinus:
-        case OpNot:
-        case OpIncrement:
-        case OpDecrement:
-            if (e->expr->type == VarType || e->expr->type == StringType || e->expr->type == QObjectType)
-                markAsSideEffect();
-            break;
-
-        default:
-            break;
-        }
-    }
-
-    void visitBinop(Binop *e) {
-        // TODO: prune parts that don't have a side-effect. For example, in:
-        //   function f(x) { +x+1; return 0; }
-        // we can prune the binop and leave the unop/conversion.
-        _sideEffect = hasSideEffects(e->left);
-        _sideEffect |= hasSideEffects(e->right);
-
-        if (e->left->type == VarType || e->left->type == StringType || e->left->type == QObjectType
-                || e->right->type == VarType || e->right->type == StringType || e->right->type == QObjectType)
-            markAsSideEffect();
-    }
-
-    void visitSubscript(Subscript *e) {
-        visit(e->base);
-        visit(e->index);
-        markAsSideEffect();
-    }
-
-    void visitMember(Member *e) {
-        visit(e->base);
-        if (e->freeOfSideEffects)
-            return;
-        markAsSideEffect();
-    }
-
-    void visitCall(Call *e) {
-        visit(e->base);
-        for (ExprList *args = e->args; args; args = args->next)
-            visit(args->expr);
-        markAsSideEffect(); // TODO: there are built-in functions that have no side effect.
-    }
-
-    void visitNew(New *e) {
-        visit(e->base);
-        for (ExprList *args = e->args; args; args = args->next)
-            visit(args->expr);
-        markAsSideEffect(); // TODO: there are built-in types that have no side effect.
-    }
-};
-
-class EliminateDeadCode: public SideEffectsChecker
-{
-    DefUses &_defUses;
-    StatementWorklist &_worklist;
-    QVarLengthArray<Temp *, 8> _collectedTemps;
-
-public:
-    EliminateDeadCode(DefUses &defUses, StatementWorklist &worklist)
-        : _defUses(defUses)
-        , _worklist(worklist)
-    {}
-
-    void run(Expr *&expr, Stmt *stmt) {
-        _collectedTemps.clear();
-        if (!hasSideEffects(expr)) {
-            expr = 0;
-            for (Temp *t : _collectedTemps) {
-                _defUses.removeUse(stmt, *t);
-                _worklist += _defUses.defStmt(*t);
-            }
-        }
-    }
-
-protected:
-    void visitTemp(Temp *e) Q_DECL_OVERRIDE Q_DECL_FINAL
-    {
-        _collectedTemps.append(e);
-    }
-};
-
-class PropagateTempTypes
-{
-    const DefUses &defUses;
-    UntypedTemp theTemp;
-    DiscoveredType newType;
-
-public:
-    PropagateTempTypes(const DefUses &defUses)
-        : defUses(defUses)
-    {}
-
-    void run(const UntypedTemp &temp, const DiscoveredType &type)
-    {
-        newType = type;
-        theTemp = temp;
-        if (Stmt *defStmt = defUses.defStmt(temp.temp))
-            visit(defStmt);
-        for (Stmt *use : defUses.uses(temp.temp))
-            visit(use);
-    }
-
-private:
-    void visit(Stmt *s)
-    {
-        STMT_VISIT_ALL_KINDS(s);
-    }
-
-    void visit(Expr *e)
-    {
-        if (auto temp = e->asTemp()) {
-            if (theTemp == UntypedTemp(*temp)) {
-                temp->type = static_cast<Type>(newType.type);
-                temp->memberResolver = newType.memberResolver;
-            }
-        } else {
-            EXPR_VISIT_ALL_KINDS(e);
-        }
-    }
-};
-
-class TypeInference
-{
-    enum { DebugTypeInference = 0 };
-
-    QQmlEnginePrivate *qmlEngine;
-    const DefUses &_defUses;
-    typedef std::vector<DiscoveredType> TempTypes;
-    TempTypes _tempTypes;
-    StatementWorklist *_worklist;
-    struct TypingResult {
-        DiscoveredType type;
-        bool fullyTyped;
-
-        TypingResult(const DiscoveredType &type = DiscoveredType()) {
-#if defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 6
-            // avoid optimization bug in gcc 4.6.3 armhf
-            ((int volatile &) this->type.type) = type.type;
-#endif
-            this->type = type;
-            fullyTyped = type.type != UnknownType;
-        }
-        explicit TypingResult(MemberExpressionResolver *memberResolver)
-            : type(memberResolver)
-            , fullyTyped(true)
-        {}
-    };
-    TypingResult _ty;
-    Stmt *_currentStmt;
-
-public:
-    TypeInference(QQmlEnginePrivate *qmlEngine, const DefUses &defUses)
-        : qmlEngine(qmlEngine)
-        , _defUses(defUses)
-        , _tempTypes(_defUses.tempCount())
-        , _worklist(0)
-        , _ty(UnknownType)
-        , _currentStmt(nullptr)
-    {}
-
-    void run(StatementWorklist &w) {
-        _worklist = &w;
-
-        Stmt *s = 0;
-        while ((s = _worklist->takeNext(s))) {
-            if (s->asJump())
-                continue;
-
-            if (DebugTypeInference) {
-                QBuffer buf;
-                buf.open(QIODevice::WriteOnly);
-                QTextStream qout(&buf);
-                qout<<"Typing stmt ";
-                IRPrinter(&qout).print(s);
-                qout.flush();
-                qDebug("%s", buf.data().constData());
-
-                qDebug("%u left in the worklist", _worklist->size());
-            }
-
-            if (!run(s)) {
-                *_worklist += s;
-                if (DebugTypeInference) {
-                    QBuffer buf;
-                    buf.open(QIODevice::WriteOnly);
-                    QTextStream qout(&buf);
-                    qout<<"Pushing back stmt: ";
-                    IRPrinter(&qout).print(s);
-                    qout.flush();
-                    qDebug("%s", buf.data().constData());
-                }
-            } else {
-                if (DebugTypeInference) {
-                    QBuffer buf;
-                    buf.open(QIODevice::WriteOnly);
-                    QTextStream qout(&buf);
-                    qout<<"Finished: ";
-                    IRPrinter(&qout).print(s);
-                    qout.flush();
-                    qDebug("%s", buf.data().constData());
-                }
-            }
-        }
-
-        PropagateTempTypes propagator(_defUses);
-        for (size_t i = 0, ei = _tempTypes.size(); i != ei; ++i) {
-            const Temp &temp = _defUses.temp(int(i));
-            if (temp.kind == Temp::Invalid)
-                continue;
-            const DiscoveredType &tempType = _tempTypes[i];
-            if (tempType.type == UnknownType)
-                continue;
-            propagator.run(temp, tempType);
-        }
-
-        _worklist = 0;
-    }
-
-private:
-    bool run(Stmt *s) {
-        TypingResult ty;
-        std::swap(_ty, ty);
-        std::swap(_currentStmt, s);
-        visit(_currentStmt);
-        std::swap(_currentStmt, s);
-        std::swap(_ty, ty);
-        return ty.fullyTyped;
-    }
-
-    TypingResult run(Expr *e) {
-        TypingResult ty;
-        std::swap(_ty, ty);
-        visit(e);
-        std::swap(_ty, ty);
-
-        if (ty.type != UnknownType)
-            setType(e, ty.type);
-        return ty;
-    }
-
-    void setType(Expr *e, DiscoveredType ty) {
-        if (Temp *t = e->asTemp()) {
-            if (DebugTypeInference)
-                qDebug() << "Setting type for temp" << t->index
-                         << " to " << typeName(Type(ty.type)) << "(" << ty.type << ")"
-                         << endl;
-
-            DiscoveredType &it = _tempTypes[t->index];
-            if (it != ty) {
-                it = ty;
-
-                if (DebugTypeInference) {
-                    for (Stmt *s : _defUses.uses(*t)) {
-                        QBuffer buf;
-                        buf.open(QIODevice::WriteOnly);
-                        QTextStream qout(&buf);
-                        qout << "Pushing back dependent stmt: ";
-                        IRPrinter(&qout).print(s);
-                        qout.flush();
-                        qDebug("%s", buf.data().constData());
-                    }
-                }
-
-                for (Stmt *s : qAsConst(_defUses.uses(*t))) {
-                    if (s != _currentStmt) {
-                        *_worklist += s;
-                    }
-                }
-            }
-        } else {
-            e->type = (Type) ty.type;
-        }
-    }
-
-private:
-    void visit(Expr *e)
-    {
-        if (auto c = e->asConst()) {
-            visitConst(c);
-        } else if (auto s = e->asString()) {
-            visitString(s);
-        } else if (auto r = e->asRegExp()) {
-            visitRegExp(r);
-        } else if (auto n = e->asName()) {
-            visitName(n);
-        } else if (auto t = e->asTemp()) {
-            visitTemp(t);
-        } else if (auto a = e->asArgLocal()) {
-            visitArgLocal(a);
-        } else if (auto c = e->asClosure()) {
-            visitClosure(c);
-        } else if (auto c = e->asConvert()) {
-            visitConvert(c);
-        } else if (auto u = e->asUnop()) {
-            visitUnop(u);
-        } else if (auto b = e->asBinop()) {
-            visitBinop(b);
-        } else if (auto c = e->asCall()) {
-            visitCall(c);
-        } else if (auto n = e->asNew()) {
-            visitNew(n);
-        } else if (auto s = e->asSubscript()) {
-            visitSubscript(s);
-        } else if (auto m = e->asMember()) {
-            visitMember(m);
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitConst(Const *c) {
-        if (c->type & NumberType) {
-            if (canConvertToSignedInteger(c->value))
-                _ty = TypingResult(SInt32Type);
-            else if (canConvertToUnsignedInteger(c->value))
-                _ty = TypingResult(UInt32Type);
-            else
-                _ty = TypingResult(c->type);
-        } else
-            _ty = TypingResult(c->type);
-    }
-    void visitString(IR::String *) { _ty = TypingResult(StringType); }
-    void visitRegExp(IR::RegExp *) { _ty = TypingResult(VarType); }
-    void visitName(Name *) { _ty = TypingResult(VarType); }
-    void visitTemp(Temp *e) {
-        if (e->memberResolver && e->memberResolver->isValid())
-            _ty = TypingResult(e->memberResolver);
-        else
-            _ty = TypingResult(_tempTypes[e->index]);
-        setType(e, _ty.type);
-    }
-    void visitArgLocal(ArgLocal *e) {
-        _ty = TypingResult(VarType);
-        setType(e, _ty.type);
-    }
-
-    void visitClosure(Closure *) { _ty = TypingResult(VarType); }
-    void visitConvert(Convert *e) {
-        _ty = TypingResult(e->type);
-    }
-
-    void visitUnop(Unop *e) {
-        _ty = run(e->expr);
-        switch (e->op) {
-        case OpUPlus: _ty.type = DoubleType; return;
-        case OpUMinus: _ty.type = DoubleType; return;
-        case OpCompl: _ty.type = SInt32Type; return;
-        case OpNot: _ty.type = BoolType; return;
-
-        case OpIncrement:
-        case OpDecrement:
-            Q_ASSERT(!"Inplace operators should have been removed!");
-            Q_UNREACHABLE();
-        default:
-            Q_UNIMPLEMENTED();
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitBinop(Binop *e) {
-        TypingResult leftTy = run(e->left);
-        TypingResult rightTy = run(e->right);
-        _ty.fullyTyped = leftTy.fullyTyped && rightTy.fullyTyped;
-
-        switch (e->op) {
-        case OpAdd:
-            if (leftTy.type.test(VarType) || leftTy.type.test(QObjectType) || rightTy.type.test(VarType) || rightTy.type.test(QObjectType))
-                _ty.type = VarType;
-            else if (leftTy.type.test(StringType) || rightTy.type.test(StringType))
-                _ty.type = StringType;
-            else if (leftTy.type != UnknownType && rightTy.type != UnknownType)
-                _ty.type = DoubleType;
-            else
-                _ty.type = UnknownType;
-            break;
-        case OpSub:
-            _ty.type = DoubleType;
-            break;
-
-        case OpMul:
-        case OpDiv:
-        case OpMod:
-            _ty.type = DoubleType;
-            break;
-
-        case OpBitAnd:
-        case OpBitOr:
-        case OpBitXor:
-        case OpLShift:
-        case OpRShift:
-            _ty.type = SInt32Type;
-            break;
-        case OpURShift:
-            _ty.type = UInt32Type;
-            break;
-
-        case OpGt:
-        case OpLt:
-        case OpGe:
-        case OpLe:
-        case OpEqual:
-        case OpNotEqual:
-        case OpStrictEqual:
-        case OpStrictNotEqual:
-        case OpAnd:
-        case OpOr:
-        case OpInstanceof:
-        case OpIn:
-            _ty.type = BoolType;
-            break;
-
-        default:
-            Q_UNIMPLEMENTED();
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitCall(Call *e) {
-        _ty = run(e->base);
-        for (ExprList *it = e->args; it; it = it->next)
-            _ty.fullyTyped &= run(it->expr).fullyTyped;
-        _ty.type = VarType;
-    }
-    void visitNew(New *e) {
-        _ty = run(e->base);
-        for (ExprList *it = e->args; it; it = it->next)
-            _ty.fullyTyped &= run(it->expr).fullyTyped;
-        _ty.type = VarType;
-    }
-    void visitSubscript(Subscript *e) {
-        _ty.fullyTyped = run(e->base).fullyTyped && run(e->index).fullyTyped;
-        _ty.type = VarType;
-    }
-
-    void visitMember(Member *e) {
-        _ty = run(e->base);
-
-        if (_ty.fullyTyped && _ty.type.memberResolver && _ty.type.memberResolver->isValid()) {
-            MemberExpressionResolver *resolver = _ty.type.memberResolver;
-            _ty.type = resolver->resolveMember(qmlEngine, resolver, e);
-        } else
-            _ty.type = VarType;
-    }
-
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            visitExp(e);
-        } else if (auto m = s->asMove()) {
-            visitMove(m);
-        } else if (auto j = s->asJump()) {
-            visitJump(j);
-        } else if (auto c = s->asCJump()) {
-            visitCJump(c);
-        } else if (auto r = s->asRet()) {
-            visitRet(r);
-        } else if (auto p = s->asPhi()) {
-            visitPhi(p);
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitExp(Exp *s) { _ty = run(s->expr); }
-    void visitMove(Move *s) {
-        if (Temp *t = s->target->asTemp()) {
-            if (Name *n = s->source->asName()) {
-                if (n->builtin == Name::builtin_qml_context) {
-                    _ty = TypingResult(t->memberResolver);
-                    setType(n, _ty.type);
-                    setType(t, _ty.type);
-                    return;
-                }
-            }
-            TypingResult sourceTy = run(s->source);
-            setType(t, sourceTy.type);
-            _ty = sourceTy;
-            return;
-        }
-
-        TypingResult sourceTy = run(s->source);
-        _ty = run(s->target);
-        _ty.fullyTyped &= sourceTy.fullyTyped;
-    }
-
-    void visitJump(Jump *) { _ty = TypingResult(MissingType); }
-    void visitCJump(CJump *s) { _ty = run(s->cond); }
-    void visitRet(Ret *s) { _ty = run(s->expr); }
-    void visitPhi(Phi *s) {
-        _ty = run(s->incoming[0]);
-        for (int i = 1, ei = s->incoming.size(); i != ei; ++i) {
-            TypingResult ty = run(s->incoming[i]);
-            if (!ty.fullyTyped && _ty.fullyTyped) {
-                // When one of the temps not fully typed, we already know that we cannot completely type this node.
-                // So, pick the type we calculated upto this point, and wait until the unknown one will be typed.
-                // At that point, this statement will be re-scheduled, and then we can fully type this node.
-                _ty.fullyTyped = false;
-                break;
-            }
-            _ty.type.type |= ty.type.type;
-            _ty.fullyTyped &= ty.fullyTyped;
-            if (_ty.type.test(QObjectType) && _ty.type.memberResolver)
-                _ty.type.memberResolver->clear(); // ### TODO: find common ancestor meta-object
-        }
-
-        switch (_ty.type.type) {
-        case UnknownType:
-        case UndefinedType:
-        case NullType:
-        case BoolType:
-        case SInt32Type:
-        case UInt32Type:
-        case DoubleType:
-        case StringType:
-        case QObjectType:
-        case VarType:
-            // The type is not a combination of two or more types, so we're done.
-            break;
-
-        default:
-            // There are multiple types involved, so:
-            if (_ty.type.isNumber())
-                // The type is any combination of double/int32/uint32, but nothing else. So we can
-                // type it as double.
-                _ty.type = DoubleType;
-            else
-                // There just is no single type that can hold this combination, so:
-                _ty.type = VarType;
-        }
-
-        setType(s->targetTemp, _ty.type);
-    }
-};
-
-class ReverseInference
-{
-    const DefUses &_defUses;
-
-public:
-    ReverseInference(const DefUses &defUses)
-        : _defUses(defUses)
-    {}
-
-    void run(IR::Function *f)
-    {
-        Q_UNUSED(f);
-
-        QVector<UntypedTemp> knownOk;
-        QVector<UntypedTemp> candidates = _defUses.defsUntyped();
-        while (!candidates.isEmpty()) {
-            UntypedTemp temp = candidates.last();
-            candidates.removeLast();
-
-            if (knownOk.contains(temp))
-                continue;
-
-            if (!isUsedAsInt32(temp, knownOk))
-                continue;
-
-            Stmt *s = _defUses.defStmt(temp.temp);
-            Move *m = s->asMove();
-            if (!m)
-                continue;
-            Temp *target = m->target->asTemp();
-            if (!target || temp != UntypedTemp(*target) || target->type == SInt32Type)
-                continue;
-            if (Temp *t = m->source->asTemp()) {
-                candidates.append(*t);
-            } else if (m->source->asConvert()) {
-                break;
-            } else if (Binop *b = m->source->asBinop()) {
-                bool iterateOnOperands = true;
-
-                switch (b->op) {
-                case OpSub:
-                case OpMul:
-                case OpAdd:
-                    if (b->left->type == SInt32Type && b->right->type == SInt32Type) {
-                        iterateOnOperands = false;
-                        break;
-                    } else {
-                        continue;
-                    }
-                case OpBitAnd:
-                case OpBitOr:
-                case OpBitXor:
-                case OpLShift:
-                case OpRShift:
-                case OpURShift:
-                    break;
-                default:
-                    continue;
-                }
-
-                if (iterateOnOperands) {
-                    if (Temp *lt = b->left->asTemp())
-                        candidates.append(*lt);
-                    if (Temp *rt = b->right->asTemp())
-                        candidates.append(*rt);
-                }
-            } else if (Unop *u = m->source->asUnop()) {
-                if (u->op == OpCompl || u->op == OpUPlus) {
-                    if (Temp *t = u->expr->asTemp())
-                        candidates.append(*t);
-                }
-            } else {
-                continue;
-            }
-
-            knownOk.append(temp);
-        }
-
-        PropagateTempTypes propagator(_defUses);
-        for (const UntypedTemp &t : qAsConst(knownOk)) {
-            propagator.run(t, SInt32Type);
-            if (Stmt *defStmt = _defUses.defStmt(t.temp)) {
-                if (Move *m = defStmt->asMove()) {
-                    if (Convert *c = m->source->asConvert()) {
-                        c->type = SInt32Type;
-                    } else if (Unop *u = m->source->asUnop()) {
-                        if (u->op != OpUMinus)
-                            u->type = SInt32Type;
-                    } else if (Binop *b = m->source->asBinop()) {
-                        b->type = SInt32Type;
-                    }
-                }
-            }
-        }
-    }
-
-private:
-    bool isUsedAsInt32(const UntypedTemp &t, const QVector<UntypedTemp> &knownOk) const
-    {
-        const QVector<Stmt *> &uses = _defUses.uses(t.temp);
-        if (uses.isEmpty())
-            return false;
-
-        for (Stmt *use : uses) {
-            if (Move *m = use->asMove()) {
-                Temp *targetTemp = m->target->asTemp();
-
-                if (m->source->asTemp()) {
-                    if (!targetTemp || !knownOk.contains(*targetTemp))
-                        return false;
-                } else if (m->source->asConvert()) {
-                    continue;
-                } else if (Binop *b = m->source->asBinop()) {
-                    switch (b->op) {
-                    case OpAdd:
-                    case OpSub:
-                    case OpMul:
-                        if (!targetTemp || !knownOk.contains(*targetTemp))
-                            return false;
-                        Q_FALLTHROUGH();
-                    case OpBitAnd:
-                    case OpBitOr:
-                    case OpBitXor:
-                    case OpRShift:
-                    case OpLShift:
-                    case OpURShift:
-                        continue;
-                    default:
-                        return false;
-                    }
-                } else if (Unop *u = m->source->asUnop()) {
-                    if (u->op == OpUPlus) {
-                        if (!targetTemp || !knownOk.contains(*targetTemp))
-                            return false;
-                    } else if (u->op != OpCompl) {
-                        return false;
-                    }
-                } else {
-                    return false;
-                }
-            } else
-                return false;
-        }
-
-        return true;
-    }
-};
-
-void convertConst(Const *c, Type targetType)
-{
-    switch (targetType) {
-    case DoubleType:
-        break;
-    case SInt32Type:
-        c->value = QV4::Primitive::toInt32(c->value);
-        break;
-    case UInt32Type:
-        c->value = QV4::Primitive::toUInt32(c->value);
-        break;
-    case BoolType:
-        c->value = !(c->value == 0 || std::isnan(c->value));
-        break;
-    case NullType:
-    case UndefinedType:
-        c->value = qt_qnan();
-        c->type = targetType;
-        break;
-    default:
-        Q_UNIMPLEMENTED();
-        Q_ASSERT(!"Unimplemented!");
-        break;
-    }
-    c->type = targetType;
-}
-
-class TypePropagation
-{
-    DefUses &_defUses;
-    Type _ty;
-    IR::Function *_f;
-
-    bool run(Expr *&e, Type requestedType = UnknownType, bool insertConversion = true) {
-        qSwap(_ty, requestedType);
-        visit(e);
-        qSwap(_ty, requestedType);
-
-        if (requestedType != UnknownType) {
-            if (e->type != requestedType) {
-                if (requestedType & NumberType || requestedType == BoolType) {
-                    if (insertConversion)
-                        addConversion(e, requestedType);
-                    return true;
-                }
-            }
-        }
-
-        return false;
-    }
-
-    struct Conversion {
-        Expr **expr;
-        Type targetType;
-        Stmt *stmt;
-
-        Conversion(Expr **expr = 0, Type targetType = UnknownType, Stmt *stmt = 0)
-            : expr(expr)
-            , targetType(targetType)
-            , stmt(stmt)
-        {}
-    };
-
-    Stmt *_currStmt;
-    QVector<Conversion> _conversions;
-
-    void addConversion(Expr *&expr, Type targetType) {
-        _conversions.append(Conversion(&expr, targetType, _currStmt));
-    }
-
-public:
-    TypePropagation(DefUses &defUses) : _defUses(defUses), _ty(UnknownType) {}
-
-    void run(IR::Function *f, StatementWorklist &worklist) {
-        _f = f;
-        for (BasicBlock *bb : f->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-            _conversions.clear();
-
-            for (Stmt *s : bb->statements()) {
-                _currStmt = s;
-                visit(s);
-            }
-
-            for (const Conversion &conversion : qAsConst(_conversions)) {
-                IR::Move *move = conversion.stmt->asMove();
-
-                // Note: isel only supports move into member when source is a temp, so convert
-                // is not a supported source.
-                if (move && move->source->asTemp() && !move->target->asMember()) {
-                    *conversion.expr = bb->CONVERT(*conversion.expr, conversion.targetType);
-                } else if (Const *c = (*conversion.expr)->asConst()) {
-                    convertConst(c, conversion.targetType);
-                } else if (ArgLocal *al = (*conversion.expr)->asArgLocal()) {
-                    Temp *target = bb->TEMP(bb->newTemp());
-                    target->type = conversion.targetType;
-                    Expr *convert = bb->CONVERT(al, conversion.targetType);
-                    Move *convCall = f->NewStmt<Move>();
-                    worklist.registerNewStatement(convCall);
-                    convCall->init(target, convert);
-                    _defUses.addDef(target, convCall, bb);
-
-                    Temp *source = bb->TEMP(target->index);
-                    source->type = conversion.targetType;
-                    _defUses.addUse(*source, conversion.stmt);
-
-                    if (conversion.stmt->asPhi()) {
-                        // Only temps can be used as arguments to phi nodes, so this is a sanity check...:
-                        Q_UNREACHABLE();
-                    } else {
-                        bb->insertStatementBefore(conversion.stmt, convCall);
-                    }
-
-                    *conversion.expr = source;
-                } else if (Temp *t = (*conversion.expr)->asTemp()) {
-                    Temp *target = bb->TEMP(bb->newTemp());
-                    target->type = conversion.targetType;
-                    Expr *convert = bb->CONVERT(t, conversion.targetType);
-                    Move *convCall = f->NewStmt<Move>();
-                    worklist.registerNewStatement(convCall);
-                    convCall->init(target, convert);
-                    _defUses.addDef(target, convCall, bb);
-                    _defUses.addUse(*t, convCall);
-
-                    Temp *source = bb->TEMP(target->index);
-                    source->type = conversion.targetType;
-                    _defUses.removeUse(conversion.stmt, *t);
-                    _defUses.addUse(*source, conversion.stmt);
-
-                    if (Phi *phi = conversion.stmt->asPhi()) {
-                        int idx = phi->incoming.indexOf(t);
-                        Q_ASSERT(idx != -1);
-                        bb->in[idx]->insertStatementBeforeTerminator(convCall);
-                    } else {
-                        bb->insertStatementBefore(conversion.stmt, convCall);
-                    }
-
-                    *conversion.expr = source;
-                } else if (Unop *u = (*conversion.expr)->asUnop()) {
-                    // convert:
-                    //   int32{%2} = double{-double{%1}};
-                    // to:
-                    //   double{%3} = double{-double{%1}};
-                    //   int32{%2} = int32{convert(double{%3})};
-                    Temp *tmp = bb->TEMP(bb->newTemp());
-                    tmp->type = u->type;
-                    Move *extraMove = f->NewStmt<Move>();
-                    worklist.registerNewStatement(extraMove);
-                    extraMove->init(tmp, u);
-                    _defUses.addDef(tmp, extraMove, bb);
-
-                    if (Temp *unopOperand = u->expr->asTemp()) {
-                        _defUses.addUse(*unopOperand, extraMove);
-                        _defUses.removeUse(move, *unopOperand);
-                    }
-
-                    bb->insertStatementBefore(conversion.stmt, extraMove);
-
-                    *conversion.expr = bb->CONVERT(CloneExpr::cloneTemp(tmp, f), conversion.targetType);
-                    _defUses.addUse(*tmp, move);
-                } else {
-                    Q_UNREACHABLE();
-                }
-            }
-        }
-    }
-
-private:
-    void visit(Expr *e)
-    {
-        if (auto c = e->asConst()) {
-            visitConst(c);
-        } else if (auto c = e->asConvert()) {
-            run(c->expr, c->type);
-        } else if (auto u = e->asUnop()) {
-            run(u->expr, u->type);
-        } else if (auto b = e->asBinop()) {
-            visitBinop(b);
-        } else if (auto c = e->asCall()) {
-            visitCall(c);
-        } else if (auto n = e->asNew()) {
-            visitNew(n);
-        } else if (auto s = e->asSubscript()) {
-            visitSubscript(s);
-        } else if (auto m = e->asMember()) {
-            visitMember(m);
-        }
-    }
-
-    void visitConst(Const *c) {
-        if (_ty & NumberType && c->type & NumberType) {
-            if (_ty == SInt32Type)
-                c->value = QV4::Primitive::toInt32(c->value);
-            else if (_ty == UInt32Type)
-                c->value = QV4::Primitive::toUInt32(c->value);
-            c->type = _ty;
-        }
-    }
-
-    void visitBinop(Binop *e) {
-        // FIXME: This routine needs more tuning!
-        switch (e->op) {
-        case OpAdd:
-        case OpSub:
-        case OpMul:
-        case OpDiv:
-        case OpMod:
-        case OpBitAnd:
-        case OpBitOr:
-        case OpBitXor:
-            run(e->left, e->type);
-            run(e->right, e->type);
-            break;
-
-        case OpLShift:
-        case OpRShift:
-        case OpURShift:
-            run(e->left, SInt32Type);
-            run(e->right, SInt32Type);
-            break;
-
-        case OpGt:
-        case OpLt:
-        case OpGe:
-        case OpLe:
-        case OpEqual:
-        case OpNotEqual:
-            if (e->left->type == DoubleType) {
-                run(e->right, DoubleType);
-            } else if (e->right->type == DoubleType) {
-                run(e->left, DoubleType);
-            } else {
-                run(e->left, e->left->type);
-                run(e->right, e->right->type);
-            }
-            break;
-
-        case OpStrictEqual:
-        case OpStrictNotEqual:
-        case OpInstanceof:
-        case OpIn:
-            run(e->left, e->left->type);
-            run(e->right, e->right->type);
-            break;
-
-        default:
-            Q_UNIMPLEMENTED();
-            Q_UNREACHABLE();
-        }
-    }
-    void visitCall(Call *e) {
-        run(e->base);
-        for (ExprList *it = e->args; it; it = it->next)
-            run(it->expr);
-    }
-    void visitNew(New *e) {
-        run(e->base);
-        for (ExprList *it = e->args; it; it = it->next)
-            run(it->expr);
-    }
-    void visitSubscript(Subscript *e) { run(e->base); run(e->index); }
-    void visitMember(Member *e) { run(e->base); }
-
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            visitExp(e);
-        } else if (auto m = s->asMove()) {
-            visitMove(m);
-        } else if (auto c = s->asCJump()) {
-            visitCJump(c);
-        } else if (auto r = s->asRet()) {
-            visitRet(r);
-        } else if (auto p = s->asPhi()) {
-            visitPhi(p);
-        }
-    }
-
-    void visitExp(Exp *s) { run(s->expr); }
-    void visitMove(Move *s) {
-        if (s->source->asConvert())
-            return; // this statement got inserted for a phi-node type conversion
-
-        run(s->target);
-
-        if (Unop *u = s->source->asUnop()) {
-            if (u->op == OpUPlus) {
-                if (run(u->expr, s->target->type, false)) {
-                    Convert *convert = _f->New<Convert>();
-                    convert->init(u->expr, s->target->type);
-                    s->source = convert;
-                } else {
-                    s->source = u->expr;
-                }
-
-                return;
-            }
-        }
-
-        const Member *targetMember = s->target->asMember();
-        const bool inhibitConversion = targetMember && targetMember->inhibitTypeConversionOnWrite;
-
-        run(s->source, s->target->type, !inhibitConversion);
-    }
-    void visitCJump(CJump *s) {
-        run(s->cond, BoolType);
-    }
-    void visitRet(Ret *s) { run(s->expr); }
-    void visitPhi(Phi *s) {
-        Type ty = s->targetTemp->type;
-        for (int i = 0, ei = s->incoming.size(); i != ei; ++i)
-            run(s->incoming[i], ty);
-    }
-};
-
-void splitCriticalEdges(IR::Function *f, DominatorTree &df, StatementWorklist &worklist, DefUses &defUses)
-{
-    const QVector<BasicBlock *> copy = f->basicBlocks();
-    for (BasicBlock *toBB : copy) {
-        if (toBB->isRemoved())
-            continue;
-        if (toBB->in.size() < 2)
-            continue;
-
-        for (int inIdx = 0, eInIdx = toBB->in.size(); inIdx != eInIdx; ++inIdx) {
-            BasicBlock *fromBB = toBB->in[inIdx];
-            if (fromBB->out.size() < 2)
-                continue;
-
-            // We found a critical edge.
-            // create the basic block:
-            BasicBlock *newBB = f->newBasicBlock(toBB->catchBlock);
-            Jump *s = f->NewStmt<Jump>();
-            worklist.registerNewStatement(s);
-            defUses.registerNewStatement(s);
-            s->init(toBB);
-            newBB->appendStatement(s);
-
-            // rewire the old outgoing edge
-            int outIdx = fromBB->out.indexOf(toBB);
-            fromBB->out[outIdx] = newBB;
-            newBB->in.append(fromBB);
-
-            // rewire the old incoming edge
-            toBB->in[inIdx] = newBB;
-            newBB->out.append(toBB);
-
-            // add newBB to the correct loop group
-            if (toBB->isGroupStart()) {
-                if (fromBB == toBB) {
-                    // special case: the loop header points back to itself (so it's a small loop).
-                    newBB->setContainingGroup(toBB);
-                } else {
-                    BasicBlock *container;
-                    for (container = fromBB->containingGroup(); container; container = container->containingGroup())
-                        if (container == toBB)
-                            break;
-                    if (container == toBB) // if we were already inside the toBB loop
-                        newBB->setContainingGroup(toBB);
-                    else
-                        newBB->setContainingGroup(toBB->containingGroup());
-                }
-            } else {
-                newBB->setContainingGroup(toBB->containingGroup());
-            }
-
-            // patch the terminator
-            Stmt *terminator = fromBB->terminator();
-            if (Jump *j = terminator->asJump()) {
-                Q_ASSERT(outIdx == 0);
-                j->target = newBB;
-            } else if (CJump *j = terminator->asCJump()) {
-                if (outIdx == 0)
-                    j->iftrue = newBB;
-                else if (outIdx == 1)
-                    j->iffalse = newBB;
-                else
-                    Q_ASSERT(!"Invalid out edge index for CJUMP!");
-            } else if (terminator->asRet()) {
-                Q_ASSERT(!"A block with a RET at the end cannot have outgoing edges.");
-            } else {
-                Q_ASSERT(!"Unknown terminator!");
-            }
-
-//            qDebug() << "splitting edge" << fromBB->index() << "->" << toBB->index()
-//                     << "by inserting block" << newBB->index();
-
-            // Set the immediate dominator of the new block to inBB
-            df.setImmediateDominator(newBB, fromBB);
-
-            bool toNeedsNewIdom = true;
-            for (BasicBlock *bb : toBB->in) {
-                if (bb != newBB && bb != toBB && !df.dominates(toBB, bb)) {
-                    toNeedsNewIdom = false;
-                    break;
-                }
-            }
-            if (toNeedsNewIdom)
-                df.setImmediateDominator(toBB, newBB);
-        }
-    }
-}
-
-// Detect all (sub-)loops in a function.
-//
-// Doing loop detection on the CFG is better than relying on the statement information in
-// order to mark loops. Although JavaScript only has natural loops, it can still be the case
-// that something is not a loop even though a loop-like-statement is in the source. For
-// example:
-//    while (true) {
-//      if (i > 0)
-//        break;
-//      else
-//        break;
-//    }
-//
-// Algorithm:
-//  - do a DFS on the dominator tree, where for each node:
-//    - collect all back-edges
-//    - if there are back-edges, the node is a loop-header for a new loop, so:
-//      - walk the CFG is reverse-direction, and for every node:
-//        - if the node already belongs to a loop, we've found a nested loop:
-//          - get the loop-header for the (outermost) nested loop
-//          - add that loop-header to the current loop
-//          - continue by walking all incoming edges that do not yet belong to the current loop
-//        - if the node does not belong to a loop yet, add it to the current loop, and
-//          go on with all incoming edges
-//
-// Loop-header detection by checking for back-edges is very straight forward: a back-edge is
-// an incoming edge where the other node is dominated by the current node. Meaning: all
-// execution paths that reach that other node have to go through the current node, that other
-// node ends with a (conditional) jump back to the loop header.
-//
-// The exact order of the DFS on the dominator tree is not important. The only property has to
-// be that a node is only visited when all the nodes it dominates have been visited before.
-// The reason for the DFS is that for nested loops, the inner loop's loop-header is dominated
-// by the outer loop's header. So, by visiting depth-first, sub-loops are identified before
-// their containing loops, which makes nested-loop identification free. An added benefit is
-// that the nodes for those sub-loops are only processed once.
-//
-// Note: independent loops that share the same header are merged together. For example, in
-// the code snippet below, there are 2 back-edges into the loop-header, but only one single
-// loop will be detected.
-//    while (a) {
-//      if (b)
-//        continue;
-//      else
-//        continue;
-//    }
-class LoopDetection
-{
-    enum { DebugLoopDetection = 0 };
-
-    Q_DISABLE_COPY(LoopDetection)
-
-public:
-    struct LoopInfo
-    {
-        BasicBlock *loopHeader;
-        QVector<BasicBlock *> loopBody;
-        QVector<LoopInfo *> nestedLoops;
-        LoopInfo *parentLoop;
-
-        LoopInfo(BasicBlock *loopHeader = 0)
-            : loopHeader(loopHeader)
-            , parentLoop(0)
-        {}
-
-        bool isValid() const
-        { return loopHeader != 0; }
-
-        void addNestedLoop(LoopInfo *nested)
-        {
-            Q_ASSERT(nested);
-            Q_ASSERT(!nestedLoops.contains(nested));
-            Q_ASSERT(nested->parentLoop == 0);
-            nested->parentLoop = this;
-            nestedLoops.append(nested);
-        }
-    };
-
-public:
-    LoopDetection(const DominatorTree &dt)
-        : dt(dt)
-    {}
-
-    ~LoopDetection()
-    {
-        qDeleteAll(loopInfos);
-    }
-
-    void run(IR::Function *function)
-    {
-        std::vector<BasicBlock *> backedges;
-        backedges.reserve(4);
-
-        const auto order = dt.calculateDFNodeIterOrder();
-        for (BasicBlock *bb : order) {
-            Q_ASSERT(!bb->isRemoved());
-
-            backedges.clear();
-
-            for (BasicBlock *in : bb->in)
-                if (bb == in || dt.dominates(bb, in))
-                    backedges.push_back(in);
-
-            if (!backedges.empty()) {
-                subLoop(bb, backedges);
-            }
-        }
-
-        createLoopInfos(function);
-        dumpLoopInfo();
-    }
-
-    void dumpLoopInfo() const
-    {
-        if (!DebugLoopDetection)
-            return;
-
-        qDebug() << "Found" << loopInfos.size() << "loops";
-        for (const LoopInfo *info : loopInfos) {
-            qDebug() << "Loop header:" << info->loopHeader->index()
-                     << "for loop" << quint64(info);
-            for (BasicBlock *bb : info->loopBody)
-                qDebug() << "    " << bb->index();
-            for (LoopInfo *nested : info->nestedLoops)
-                qDebug() << "    sub loop:" << quint64(nested);
-            qDebug() << "     parent loop:" << quint64(info->parentLoop);
-        }
-    }
-
-    QVector<LoopInfo *> allLoops() const
-    { return loopInfos; }
-
-    // returns all loop headers for loops that have no nested loops.
-    QVector<LoopInfo *> innermostLoops() const
-    {
-        QVector<LoopInfo *> inner(loopInfos);
-
-        for (int i = 0; i < inner.size(); ) {
-            if (inner.at(i)->nestedLoops.isEmpty())
-                ++i;
-            else
-                inner.remove(i);
-        }
-
-        return inner;
-    }
-
-private:
-    void subLoop(BasicBlock *loopHead, const std::vector<BasicBlock *> &backedges)
-    {
-        loopHead->markAsGroupStart();
-        LoopInfo *info = new LoopInfo;
-        info->loopHeader = loopHead;
-        loopInfos.append(info);
-
-        std::vector<BasicBlock *> worklist;
-        worklist.reserve(backedges.size() + 8);
-        worklist.insert(worklist.end(), backedges.begin(), backedges.end());
-        while (!worklist.empty()) {
-            BasicBlock *predIt = worklist.back();
-            worklist.pop_back();
-
-            BasicBlock *subloop = predIt->containingGroup();
-            if (subloop) {
-                // This is a discovered block. Find its outermost discovered loop.
-                while (BasicBlock *parentLoop = subloop->containingGroup())
-                  subloop = parentLoop;
-
-                // If it is already discovered to be a subloop of this loop, continue.
-                if (subloop == loopHead)
-                    continue;
-
-                // Yay, it's a subloop of this loop.
-                subloop->setContainingGroup(loopHead);
-                predIt = subloop;
-
-                // Add all predecessors of the subloop header to the worklist, as long as
-                // those predecessors are not in the current subloop. It might be the case
-                // that they are in other loops, which we will then add as a subloop to the
-                // current loop.
-                for (BasicBlock *predIn : predIt->in)
-                    if (predIn->containingGroup() != subloop)
-                        worklist.push_back(predIn);
-            } else {
-                if (predIt == loopHead)
-                    continue;
-
-                // This is an undiscovered block. Map it to the current loop.
-                predIt->setContainingGroup(loopHead);
-
-                // Add all incoming edges to the worklist.
-                for (BasicBlock *bb : predIt->in)
-                    worklist.push_back(bb);
-            }
-        }
-    }
-
-private:
-    const DominatorTree &dt;
-    QVector<LoopInfo *> loopInfos;
-
-    void createLoopInfos(IR::Function *function)
-    {
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-            if (BasicBlock *loopHeader = bb->containingGroup())
-                findLoop(loopHeader)->loopBody.append(bb);
-        }
-
-        for (int i = 0, size = loopInfos.size(); i < size; ++i) {
-            if (BasicBlock *containingLoopHeader = loopInfos.at(i)->loopHeader->containingGroup())
-                findLoop(containingLoopHeader)->addNestedLoop(loopInfos.at(i));
-        }
-    }
-
-    LoopInfo *findLoop(BasicBlock *loopHeader)
-    {
-        for (LoopInfo *info : qAsConst(loopInfos)) {
-            if (info->loopHeader == loopHeader)
-                return info;
-        }
-
-        Q_UNREACHABLE();
-        return nullptr;
-    }
-};
-
-// High-level algorithm:
-//  0. start with the first node (the start node) of a function
-//  1. emit the node
-//  2. add all outgoing edges that are not yet emitted to the postponed stack
-//  3. When the postponed stack is empty, pop a stack from the loop stack. If that is empty too,
-//     we're done.
-//  4. pop a node from the postponed stack, and check if it can be scheduled:
-//     a. if all incoming edges are scheduled, go to 4.
-//     b. if an incoming edge is unscheduled, but it's a back-edge (an edge in a loop that jumps
-//        back to the start of the loop), ignore it
-//     c. if there is any unscheduled edge that is not a back-edge, ignore this node, and go to 4.
-//  5. if this node is the start of a loop, push the postponed stack on the loop stack.
-//  6. go back to 1.
-//
-// The postponing action in step 2 will put the node into its containing group. The case where this
-// is important is when a (labeled) continue or a (labeled) break statement occur in a loop: the
-// outgoing edge points to a node that is not part of the current loop (and possibly not of the
-// parent loop).
-//
-// Linear scan register allocation benefits greatly from short life-time intervals with few holes
-// (see for example section 4 (Lifetime Analysis) of [Wimmer1]). This algorithm makes sure that the
-// blocks of a group are scheduled together, with no non-loop blocks in between. This applies
-// recursively for nested loops. It also schedules groups of if-then-else-endif blocks together for
-// the same reason.
-class BlockScheduler
-{
-    enum { DebugBlockScheduler = 0 };
-
-    IR::Function *function;
-    const DominatorTree &dominatorTree;
-
-    struct WorkForGroup
-    {
-        BasicBlock *group;
-        QStack<BasicBlock *> postponed;
-
-        WorkForGroup(BasicBlock *group = 0): group(group) {}
-    };
-    WorkForGroup currentGroup;
-    QStack<WorkForGroup> postponedGroups;
-    QVector<BasicBlock *> sequence;
-    ProcessedBlocks emitted;
-    QHash<BasicBlock *, BasicBlock *> loopsStartEnd;
-
-    bool checkCandidate(BasicBlock *candidate)
-    {
-        Q_ASSERT(candidate->containingGroup() == currentGroup.group);
-
-        for (BasicBlock *in : candidate->in) {
-            if (emitted.alreadyProcessed(in))
-                continue;
-
-            if (dominatorTree.dominates(candidate, in))
-                // this is a loop, where there in -> candidate edge is the jump back to the top of the loop.
-                continue;
-
-            if (in == candidate)
-                // this is a very tight loop, e.g.:
-                //   L1: ...
-                //       goto L1
-                // This can happen when, for example, the basic-block merging gets rid of the empty
-                // body block. In this case, we can safely schedule this block (if all other
-                // incoming edges are either loop-back edges, or have been scheduled already).
-                continue;
-
-            return false; // an incoming edge that is not yet emitted, and is not a back-edge
-        }
-
-        if (candidate->isGroupStart()) {
-            // postpone everything, and schedule the loop first.
-            postponedGroups.push(currentGroup);
-            currentGroup = WorkForGroup(candidate);
-        }
-
-        return true;
-    }
-
-    BasicBlock *pickNext()
-    {
-        while (true) {
-            while (currentGroup.postponed.isEmpty()) {
-                if (postponedGroups.isEmpty())
-                    return 0;
-                if (currentGroup.group) // record the first and the last node of a group
-                    loopsStartEnd.insert(currentGroup.group, sequence.last());
-                currentGroup = postponedGroups.pop();
-            }
-
-            BasicBlock *next = currentGroup.postponed.pop();
-            if (checkCandidate(next))
-                return next;
-        }
-
-        Q_UNREACHABLE();
-        return 0;
-    }
-
-    void emitBlock(BasicBlock *bb)
-    {
-        Q_ASSERT(!bb->isRemoved());
-        if (emitted.alreadyProcessed(bb))
-            return;
-
-        sequence.append(bb);
-        emitted.markAsProcessed(bb);
-    }
-
-    void schedule(BasicBlock *functionEntryPoint)
-    {
-        BasicBlock *next = functionEntryPoint;
-
-        while (next) {
-            emitBlock(next);
-            for (int i = next->out.size(); i != 0; ) {
-                // postpone all outgoing edges, if they were not already processed
-                --i;
-                BasicBlock *out = next->out[i];
-                if (!emitted.alreadyProcessed(out))
-                    postpone(out);
-            }
-            next = pickNext();
-        }
-    }
-
-    void postpone(BasicBlock *bb)
-    {
-        if (currentGroup.group == bb->containingGroup()) {
-            currentGroup.postponed.append(bb);
-            return;
-        }
-
-        for (int i = postponedGroups.size(); i != 0; ) {
-            --i;
-            WorkForGroup &g = postponedGroups[i];
-            if (g.group == bb->containingGroup()) {
-                g.postponed.append(bb);
-                return;
-            }
-        }
-
-        Q_UNREACHABLE();
-    }
-
-    void dumpLoopStartsEnds() const
-    {
-        qDebug() << "Found" << loopsStartEnd.size() << "loops:";
-        for (auto key : loopsStartEnd.keys())
-            qDebug("Loop starting at L%d ends at L%d.", key->index(),
-                   loopsStartEnd.value(key)->index());
-    }
-
-public:
-    BlockScheduler(IR::Function *function, const DominatorTree &dominatorTree)
-        : function(function)
-        , dominatorTree(dominatorTree)
-        , sequence(0)
-        , emitted(function)
-    {}
-
-    QHash<BasicBlock *, BasicBlock *> go()
-    {
-        showMeTheCode(function, "Before block scheduling");
-        if (DebugBlockScheduler)
-            dominatorTree.dumpImmediateDominators();
-
-        schedule(function->basicBlock(0));
-
-        Q_ASSERT(function->liveBasicBlocksCount() == sequence.size());
-        function->setScheduledBlocks(sequence);
-        if (DebugBlockScheduler)
-            dumpLoopStartsEnds();
-        return loopsStartEnd;
-    }
-};
-
-#ifndef QT_NO_DEBUG
-void checkCriticalEdges(const QVector<BasicBlock *> &basicBlocks) {
-    for (BasicBlock *bb : basicBlocks) {
-        if (bb && bb->out.size() > 1) {
-            for (BasicBlock *bb2 : bb->out) {
-                if (bb2 && bb2->in.size() > 1) {
-                    qDebug() << "found critical edge between block"
-                             << bb->index() << "and block" << bb2->index();
-                    Q_ASSERT(false);
-                }
-            }
-        }
-    }
-}
-#endif
-
-static void cleanupBasicBlocks(IR::Function *function)
-{
-    showMeTheCode(function, "Before basic block cleanup");
-
-    // Algorithm: this is the iterative version of a depth-first search for all blocks that are
-    // reachable through outgoing edges, starting with the start block and all exception handler
-    // blocks.
-    QBitArray reachableBlocks(function->basicBlockCount());
-    QVarLengthArray<BasicBlock *, 16> postponed;
-    for (int i = 0, ei = function->basicBlockCount(); i != ei; ++i) {
-        BasicBlock *bb = function->basicBlock(i);
-        if (i == 0 || bb->isExceptionHandler())
-            postponed.append(bb);
-    }
-
-    while (!postponed.isEmpty()) {
-        BasicBlock *bb = postponed.back();
-        postponed.pop_back();
-        if (bb->isRemoved()) // this block was removed before, we don't need to clean it up.
-            continue;
-
-        reachableBlocks.setBit(bb->index());
-
-        for (BasicBlock *outBB : bb->out) {
-            if (!reachableBlocks.at(outBB->index()))
-                postponed.append(outBB);
-        }
-    }
-
-    for (BasicBlock *bb : function->basicBlocks()) {
-        if (bb->isRemoved()) // the block has already been removed, so ignore it
-            continue;
-        if (reachableBlocks.at(bb->index())) // the block is reachable, so ignore it
-            continue;
-
-        for (BasicBlock *outBB : bb->out) {
-            if (outBB->isRemoved() || !reachableBlocks.at(outBB->index()))
-                continue; // We do not need to unlink from blocks that are scheduled to be removed.
-
-            int idx = outBB->in.indexOf(bb);
-            if (idx != -1) {
-                outBB->in.remove(idx);
-                for (Stmt *s : outBB->statements()) {
-                    if (Phi *phi = s->asPhi())
-                        phi->incoming.remove(idx);
-                    else
-                        break;
-                }
-            }
-        }
-
-        function->removeBasicBlock(bb);
-    }
-
-    showMeTheCode(function, "After basic block cleanup");
-}
-
-inline Const *isConstPhi(Phi *phi)
-{
-    if (Const *c = phi->incoming[0]->asConst()) {
-        for (int i = 1, ei = phi->incoming.size(); i != ei; ++i) {
-            if (Const *cc = phi->incoming[i]->asConst()) {
-                if (c->value != cc->value)
-                    return 0;
-                if (!(c->type == cc->type || (c->type & NumberType && cc->type & NumberType)))
-                    return 0;
-                if (int(c->value) == 0 && int(cc->value) == 0)
-                    if (isNegative(c->value) != isNegative(cc->value))
-                        return 0;
-            } else {
-                return 0;
-            }
-        }
-        return c;
-    }
-    return 0;
-}
-
-static Expr *clone(Expr *e, IR::Function *function) {
-    if (Temp *t = e->asTemp()) {
-        return CloneExpr::cloneTemp(t, function);
-    } else if (Const *c = e->asConst()) {
-        return CloneExpr::cloneConst(c, function);
-    } else if (Name *n = e->asName()) {
-        return CloneExpr::cloneName(n, function);
-    } else {
-        Q_UNREACHABLE();
-        return e;
-    }
-}
-
-class ExprReplacer
-{
-    DefUses &_defUses;
-    IR::Function* _function;
-    Temp *_toReplace;
-    Expr *_replacement;
-
-public:
-    ExprReplacer(DefUses &defUses, IR::Function *function)
-        : _defUses(defUses)
-        , _function(function)
-        , _toReplace(0)
-        , _replacement(0)
-    {}
-
-    bool operator()(Temp *toReplace, Expr *replacement, StatementWorklist &W, QVector<Stmt *> *newUses = 0)
-    {
-        Q_ASSERT(replacement->asTemp() || replacement->asConst() || replacement->asName());
-
-        qSwap(_toReplace, toReplace);
-        qSwap(_replacement, replacement);
-
-        const QVector<Stmt *> &uses = _defUses.uses(*_toReplace);
-
-        // Prevent the following:
-        //   L3:
-        //     %1 = phi L1: %2, L2: %3
-        //     %4 = phi L1: %5, L2: %6
-        //     %6 = %1
-        // From turning into:
-        //   L3:
-        //     %1 = phi L1: %2, L2: %3
-        //     %4 = phi L1: %5, L2: %1
-        //
-        // Because both phi nodes are "executed in parallel", we cannot replace %6 by %1 in the
-        // second phi node. So, if the defining statement for a temp is a phi node, and one of the
-        // uses of the to-be-replaced statement is a phi node in the same block as the defining
-        // statement, bail out.
-        if (Temp *r = _replacement->asTemp()) {
-            if (_defUses.defStmt(*r)->asPhi()) {
-                BasicBlock *replacementDefBlock = _defUses.defStmtBlock(*r);
-                for (Stmt *use : uses) {
-                    if (Phi *usePhi = use->asPhi()) {
-                        if (_defUses.defStmtBlock(*usePhi->targetTemp) == replacementDefBlock)
-                            return false;
-                    }
-                }
-            }
-        }
-
-//        qout << "Replacing ";toReplace->dump(qout);qout<<" by ";replacement->dump(qout);qout<<endl;
-
-        if (newUses)
-            newUses->reserve(uses.size());
-
-//        qout << "        " << uses.size() << " uses:"<<endl;
-        for (Stmt *use : uses) {
-//            qout<<"        ";use->dump(qout);qout<<"\n";
-            visit(use);
-//            qout<<"     -> ";use->dump(qout);qout<<"\n";
-            W += use;
-            if (newUses)
-                newUses->push_back(use);
-        }
-
-        qSwap(_replacement, replacement);
-        qSwap(_toReplace, toReplace);
-        return true;
-    }
-
-private:
-    void visit(Expr *e)
-    {
-        if (auto c = e->asConst()) {
-            visitConst(c);
-        } else if (auto s = e->asString()) {
-            visitString(s);
-        } else if (auto r = e->asRegExp()) {
-            visitRegExp(r);
-        } else if (auto n = e->asName()) {
-            visitName(n);
-        } else if (auto t = e->asTemp()) {
-            visitTemp(t);
-        } else if (auto a = e->asArgLocal()) {
-            visitArgLocal(a);
-        } else if (auto c = e->asClosure()) {
-            visitClosure(c);
-        } else if (auto c = e->asConvert()) {
-            visitConvert(c);
-        } else if (auto u = e->asUnop()) {
-            visitUnop(u);
-        } else if (auto b = e->asBinop()) {
-            visitBinop(b);
-        } else if (auto c = e->asCall()) {
-            visitCall(c);
-        } else if (auto n = e->asNew()) {
-            visitNew(n);
-        } else if (auto s = e->asSubscript()) {
-            visitSubscript(s);
-        } else if (auto m = e->asMember()) {
-            visitMember(m);
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitConst(Const *) {}
-    void visitString(IR::String *) {}
-    void visitRegExp(IR::RegExp *) {}
-    void visitName(Name *) {}
-    void visitTemp(Temp *) {}
-    void visitArgLocal(ArgLocal *) {}
-    void visitClosure(Closure *) {}
-    void visitConvert(Convert *e) { check(e->expr); }
-    void visitUnop(Unop *e) { check(e->expr); }
-    void visitBinop(Binop *e) { check(e->left); check(e->right); }
-    void visitCall(Call *e) {
-        check(e->base);
-        for (ExprList *it = e->args; it; it = it->next)
-            check(it->expr);
-    }
-    void visitNew(New *e) {
-        check(e->base);
-        for (ExprList *it = e->args; it; it = it->next)
-            check(it->expr);
-    }
-    void visitSubscript(Subscript *e) { check(e->base); check(e->index); }
-    void visitMember(Member *e) { check(e->base); }
-
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            visitExp(e);
-        } else if (auto m = s->asMove()) {
-            visitMove(m);
-        } else if (auto j = s->asJump()) {
-            visitJump(j);
-        } else if (auto c = s->asCJump()) {
-            visitCJump(c);
-        } else if (auto r = s->asRet()) {
-            visitRet(r);
-        } else if (auto p = s->asPhi()) {
-            visitPhi(p);
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitExp(Exp *s) { check(s->expr); }
-    void visitMove(Move *s) { check(s->target); check(s->source); }
-    void visitJump(Jump *) {}
-    void visitCJump(CJump *s) { check(s->cond); }
-    void visitRet(Ret *s) { check(s->expr); }
-    void visitPhi(Phi *s) {
-        for (int i = 0, ei = s->incoming.size(); i != ei; ++i)
-            check(s->incoming[i]);
-    }
-
-private:
-    void check(Expr *&e) {
-        if (equals(e, _toReplace)) {
-            e = clone(_replacement, _function);
-        } else {
-            visit(e);
-        }
-    }
-
-    // This only calculates equality for everything needed by constant propagation
-    bool equals(Expr *e1, Expr *e2) const {
-        if (e1 == e2)
-            return true;
-
-        if (Const *c1 = e1->asConst()) {
-            if (Const *c2 = e2->asConst())
-                return c1->value == c2->value && (c1->type == c2->type || (c1->type & NumberType && c2->type & NumberType));
-        } else if (Temp *t1 = e1->asTemp()) {
-            if (Temp *t2 = e2->asTemp())
-                return *t1 == *t2;
-        } else if (Name *n1 = e1->asName()) {
-            if (Name *n2 = e2->asName()) {
-                if (n1->id) {
-                    if (n2->id)
-                        return *n1->id == *n2->id;
-                } else {
-                    return n1->builtin == n2->builtin;
-                }
-            }
-        }
-
-        if (e1->type == IR::NullType && e2->type == IR::NullType)
-            return true;
-        if (e1->type == IR::UndefinedType && e2->type == IR::UndefinedType)
-            return true;
-
-        return false;
-    }
-};
-
-namespace {
-/// This function removes the basic-block from the function's list, unlinks any uses and/or defs,
-/// and removes unreachable staements from the worklist, so that optimiseSSA won't consider them
-/// anymore.
-void unlink(BasicBlock *from, BasicBlock *to, IR::Function *func, DefUses &defUses,
-            StatementWorklist &W, DominatorTree &dt)
-{
-    enum { DebugUnlinking = 0 };
-
-    struct Util {
-        static void removeIncomingEdge(BasicBlock *from, BasicBlock *to, DefUses &defUses, StatementWorklist &W)
-        {
-            int idx = to->in.indexOf(from);
-            if (idx == -1)
-                return;
-
-            to->in.remove(idx);
-            for (Stmt *outStmt : to->statements()) {
-                if (!outStmt)
-                    continue;
-                if (Phi *phi = outStmt->asPhi()) {
-                    if (Temp *t = phi->incoming[idx]->asTemp()) {
-                        defUses.removeUse(phi, *t);
-                        W += defUses.defStmt(*t);
-                    }
-                    phi->incoming.remove(idx);
-                    W += phi;
-                } else {
-                    break;
-                }
-            }
-        }
-
-        static bool isReachable(BasicBlock *bb, const DominatorTree &dt)
-        {
-            for (BasicBlock *in : bb->in) {
-                if (in->isRemoved())
-                    continue;
-                if (dt.dominates(bb, in)) // a back-edge, not interesting
-                    continue;
-                return true;
-            }
-
-            return false;
-        }
-    };
-
-    Q_ASSERT(!from->isRemoved());
-    Q_ASSERT(!to->isRemoved());
-
-    // don't purge blocks that are entry points for catch statements. They might not be directly
-    // connected, but are required anyway
-    if (to->isExceptionHandler())
-        return;
-
-    if (DebugUnlinking)
-        qDebug("Unlinking L%d -> L%d...", from->index(), to->index());
-
-    // First, unlink the edge
-    from->out.removeOne(to);
-    Util::removeIncomingEdge(from, to, defUses, W);
-
-    BasicBlockSet siblings;
-    siblings.init(func);
-
-    // Check if the target is still reachable...
-    if (Util::isReachable(to, dt)) { // yes, recalculate the immediate dominator, and we're done.
-        if (DebugUnlinking)
-            qDebug(".. L%d is still reachable, recalulate idom.", to->index());
-        dt.collectSiblings(to, siblings);
-    } else {
-        if (DebugUnlinking)
-            qDebug(".. L%d is unreachable, purging it:", to->index());
-        // The target is unreachable, so purge it:
-        QVector<BasicBlock *> toPurge;
-        toPurge.reserve(8);
-        toPurge.append(to);
-        while (!toPurge.isEmpty()) {
-            BasicBlock *bb = toPurge.first();
-            toPurge.removeFirst();
-            if (DebugUnlinking)
-                qDebug("... purging L%d", bb->index());
-
-            if (bb->isRemoved())
-                continue;
-
-            // unlink all incoming edges
-            for (BasicBlock *in : bb->in) {
-                int idx = in->out.indexOf(bb);
-                if (idx != -1)
-                    in->out.remove(idx);
-            }
-
-            // unlink all outgoing edges, including "arguments" to phi statements
-            for (BasicBlock *out : bb->out) {
-                if (out->isRemoved())
-                    continue;
-
-                Util::removeIncomingEdge(bb, out, defUses, W);
-
-                if (Util::isReachable(out, dt)) {
-                    dt.collectSiblings(out, siblings);
-                } else {
-                    // if a successor has no incoming edges after unlinking the current basic block,
-                    // then it is unreachable, and can be purged too
-                    toPurge.append(out);
-                }
-            }
-
-            // unlink all defs/uses from the statements in the basic block
-            for (Stmt *s : bb->statements()) {
-                if (!s)
-                    continue;
-
-                W += defUses.removeDefUses(s);
-                W -= s;
-            }
-
-            siblings.remove(bb);
-            dt.setImmediateDominator(bb, 0);
-            func->removeBasicBlock(bb);
-        }
-    }
-
-    dt.recalculateIDoms(siblings);
-    if (DebugUnlinking)
-        qDebug("Unlinking done.");
-}
-
-bool tryOptimizingComparison(Expr *&expr)
-{
-    Binop *b = expr->asBinop();
-    if (!b)
-        return false;
-    Const *leftConst = b->left->asConst();
-    if (!leftConst || leftConst->type == StringType || leftConst->type == VarType || leftConst->type == QObjectType)
-        return false;
-    Const *rightConst = b->right->asConst();
-    if (!rightConst || rightConst->type == StringType || rightConst->type == VarType || rightConst->type == QObjectType)
-        return false;
-
-    QV4::Primitive l = convertToValue(leftConst);
-    QV4::Primitive r = convertToValue(rightConst);
-
-    switch (b->op) {
-    case OpGt:
-        leftConst->value = Runtime::method_compareGreaterThan(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpLt:
-        leftConst->value = Runtime::method_compareLessThan(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpGe:
-        leftConst->value = Runtime::method_compareGreaterEqual(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpLe:
-        leftConst->value = Runtime::method_compareLessEqual(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpStrictEqual:
-        leftConst->value = Runtime::method_compareStrictEqual(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpEqual:
-        leftConst->value = Runtime::method_compareEqual(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpStrictNotEqual:
-        leftConst->value = Runtime::method_compareStrictNotEqual(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    case OpNotEqual:
-        leftConst->value = Runtime::method_compareNotEqual(l, r);
-        leftConst->type = BoolType;
-        expr = leftConst;
-        return true;
-    default:
-        break;
-    }
-
-    return false;
-}
-
-void cfg2dot(IR::Function *f, const QVector<LoopDetection::LoopInfo *> &loops = QVector<LoopDetection::LoopInfo *>())
-{
-    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_IR");
-    if (!showCode)
-        return;
-
-    QBuffer buf;
-    buf.open(QIODevice::WriteOnly);
-    QTextStream qout(&buf);
-
-    struct Util {
-        QTextStream &qout;
-        Util(QTextStream &qout): qout(qout) {}
-        void genLoop(const LoopDetection::LoopInfo *loop)
-        {
-            qout << "  subgraph \"cluster" << quint64(loop) << "\" {\n";
-            qout << "    L" << loop->loopHeader->index() << ";\n";
-            for (BasicBlock *bb : loop->loopBody)
-                qout << "    L" << bb->index() << ";\n";
-            for (LoopDetection::LoopInfo *nested : loop->nestedLoops)
-                genLoop(nested);
-            qout << "  }\n";
-        }
-    };
-
-    QString name;
-    if (f->name) name = *f->name;
-    else name = QStringLiteral("%1").arg((unsigned long long)f);
-    qout << "digraph \"" << name << "\" { ordering=out;\n";
-
-    for (LoopDetection::LoopInfo *l : loops) {
-        if (l->parentLoop == 0)
-            Util(qout).genLoop(l);
-    }
-
-    for (BasicBlock *bb : f->basicBlocks()) {
-        if (bb->isRemoved())
-            continue;
-
-        int idx = bb->index();
-        qout << "  L" << idx << " [label=\"L" << idx << "\"";
-        if (idx == 0 || bb->terminator()->asRet())
-            qout << ", shape=doublecircle";
-        else
-            qout << ", shape=circle";
-        qout << "];\n";
-        for (BasicBlock *out : bb->out)
-            qout << "  L" << idx << " -> L" << out->index() << "\n";
-    }
-
-    qout << "}\n";
-    buf.close();
-    qDebug("%s", buf.data().constData());
-}
-
-} // anonymous namespace
-
-void optimizeSSA(StatementWorklist &W, DefUses &defUses, DominatorTree &df)
-{
-    IR::Function *function = W.function();
-    ExprReplacer replaceUses(defUses, function);
-
-    Stmt *s = 0;
-    while ((s = W.takeNext(s))) {
-
-        if (Phi *phi = s->asPhi()) {
-            // dead code elimination:
-            if (defUses.useCount(*phi->targetTemp) == 0) {
-                W += defUses.removeDefUses(phi);
-                W.remove(s);
-                continue;
-            }
-
-            // constant propagation:
-            if (Const *c = isConstPhi(phi)) {
-                replaceUses(phi->targetTemp, c, W);
-                defUses.removeDef(*phi->targetTemp);
-                W.remove(s);
-                continue;
-            }
-
-            // copy propagation:
-            if (phi->incoming.size() == 1) {
-                Temp *t = phi->targetTemp;
-                Expr *e = phi->incoming.first();
-
-                QVector<Stmt *> newT2Uses;
-                replaceUses(t, e, W, &newT2Uses);
-                if (Temp *t2 = e->asTemp()) {
-                    defUses.removeUse(s, *t2);
-                    defUses.addUses(*t2, newT2Uses);
-                    W += defUses.defStmt(*t2);
-                }
-                defUses.removeDef(*t);
-                W.remove(s);
-                continue;
-            }
-        } else  if (Move *m = s->asMove()) {
-            if (Convert *convert = m->source->asConvert()) {
-                if (Const *sourceConst = convert->expr->asConst()) {
-                    convertConst(sourceConst, convert->type);
-                    m->source = sourceConst;
-                    W += m;
-                    continue;
-                } else if (Temp *sourceTemp = convert->expr->asTemp()) {
-                    if (sourceTemp->type == convert->type) {
-                        m->source = sourceTemp;
-                        W += m;
-                        continue;
-                    }
-                }
-            }
-
-            if (Temp *targetTemp = m->target->asTemp()) {
-                // dead code elimination:
-                if (defUses.useCount(*targetTemp) == 0) {
-                    EliminateDeadCode(defUses, W).run(m->source, s);
-                    if (!m->source)
-                        W.remove(s);
-                    continue;
-                }
-
-                // constant propagation:
-                if (Const *sourceConst = m->source->asConst()) {
-                    Q_ASSERT(sourceConst->type != UnknownType);
-                    replaceUses(targetTemp, sourceConst, W);
-                    defUses.removeDef(*targetTemp);
-                    W.remove(s);
-                    continue;
-                }
-                if (Member *member = m->source->asMember()) {
-                    if (member->kind == Member::MemberOfEnum) {
-                        Const *c = function->New<Const>();
-                        const int enumValue = member->enumValue;
-                        c->init(SInt32Type, enumValue);
-                        replaceUses(targetTemp, c, W);
-                        defUses.removeDef(*targetTemp);
-                        W.remove(s);
-                        defUses.removeUse(s, *member->base->asTemp());
-                        continue;
-                    } else if (member->kind != IR::Member::MemberOfIdObjectsArray && member->attachedPropertiesId != 0 && member->property && member->base->asTemp()) {
-                        // Attached properties have no dependency on their base. Isel doesn't
-                        // need it and we can eliminate the temp used to initialize it.
-                        defUses.removeUse(s, *member->base->asTemp());
-                        Const *c = function->New<Const>();
-                        c->init(SInt32Type, 0);
-                        member->base = c;
-                        continue;
-                    }
-                }
-
-                // copy propagation:
-                if (Temp *sourceTemp = m->source->asTemp()) {
-                    QVector<Stmt *> newT2Uses;
-                    if (replaceUses(targetTemp, sourceTemp, W, &newT2Uses)) {
-                        defUses.removeUse(s, *sourceTemp);
-                        defUses.addUses(*sourceTemp, newT2Uses);
-                        defUses.removeDef(*targetTemp);
-                        W.remove(s);
-                    }
-                    continue;
-                }
-
-                if (Unop *unop = m->source->asUnop()) {
-                    // Constant unary expression evaluation:
-                    if (Const *constOperand = unop->expr->asConst()) {
-                        if (constOperand->type & NumberType || constOperand->type == BoolType) {
-                            // TODO: implement unop propagation for other constant types
-                            bool doneSomething = false;
-                            switch (unop->op) {
-                            case OpNot:
-                                constOperand->value = !constOperand->value;
-                                constOperand->type = BoolType;
-                                doneSomething = true;
-                                break;
-                            case OpUMinus:
-                                if (int(constOperand->value) == 0 && int(constOperand->value) == constOperand->value) {
-                                    if (isNegative(constOperand->value))
-                                        constOperand->value = 0;
-                                    else
-                                        constOperand->value = -1 / Q_INFINITY;
-                                    constOperand->type = DoubleType;
-                                    doneSomething = true;
-                                    break;
-                                }
-
-                                constOperand->value = -constOperand->value;
-                                doneSomething = true;
-                                break;
-                            case OpUPlus:
-                                if (unop->type != UnknownType)
-                                    constOperand->type = unop->type;
-                                doneSomething = true;
-                                break;
-                            case OpCompl:
-                                constOperand->value = ~QV4::Primitive::toInt32(constOperand->value);
-                                constOperand->type = SInt32Type;
-                                doneSomething = true;
-                                break;
-                            case OpIncrement:
-                                constOperand->value = constOperand->value + 1;
-                                doneSomething = true;
-                                break;
-                            case OpDecrement:
-                                constOperand->value = constOperand->value - 1;
-                                doneSomething = true;
-                                break;
-                            default:
-                                break;
-                            };
-
-                            if (doneSomething) {
-                                m->source = constOperand;
-                                W += m;
-                            }
-                        }
-                    }
-                    // TODO: if the result of a unary not operation is only used in a cjump,
-                    //       then inline it.
-
-                    continue;
-                }
-
-                if (Binop *binop = m->source->asBinop()) {
-                    Const *leftConst = binop->left->asConst();
-                    Const *rightConst = binop->right->asConst();
-
-                    { // Typical casts to int32:
-                        Expr *casted = 0;
-                        switch (binop->op) {
-                        case OpBitAnd:
-                            if (leftConst && !rightConst && QV4::Primitive::toUInt32(leftConst->value) == 0xffffffff)
-                                casted = binop->right;
-                            else if (!leftConst && rightConst && QV4::Primitive::toUInt32(rightConst->value) == 0xffffffff)
-                                casted = binop->left;
-                            break;
-                        case OpBitOr:
-                            if (leftConst && !rightConst && QV4::Primitive::toInt32(leftConst->value) == 0)
-                                casted = binop->right;
-                            else if (!leftConst && rightConst && QV4::Primitive::toUInt32(rightConst->value) == 0)
-                                casted = binop->left;
-                            break;
-                        default:
-                            break;
-                        }
-                        if (casted && casted->type == SInt32Type) {
-                            m->source = casted;
-                            W += m;
-                            continue;
-                        }
-                    }
-                    if (rightConst) {
-                        switch (binop->op) {
-                        case OpLShift:
-                        case OpRShift:
-                            if (double v = QV4::Primitive::toInt32(rightConst->value) & 0x1f) {
-                                // mask right hand side of shift operations
-                                rightConst->value = v;
-                                rightConst->type = SInt32Type;
-                            } else {
-                                // shifting a value over 0 bits is a move:
-                                if (rightConst->value == 0) {
-                                    m->source = binop->left;
-                                    W += m;
-                                }
-                            }
-
-                            break;
-                        default:
-                            break;
-                        }
-                    }
-
-                    // TODO: More constant binary expression evaluation
-                    // TODO: If the result of the move is only used in one single cjump, then
-                    //       inline the binop into the cjump.
-                    if (!leftConst || leftConst->type == StringType || leftConst->type == VarType || leftConst->type == QObjectType)
-                        continue;
-                    if (!rightConst || rightConst->type == StringType || rightConst->type == VarType || rightConst->type == QObjectType)
-                        continue;
-
-                    QV4::Primitive lc = convertToValue(leftConst);
-                    QV4::Primitive rc = convertToValue(rightConst);
-                    double l = lc.toNumber();
-                    double r = rc.toNumber();
-
-                    switch (binop->op) {
-                    case OpMul:
-                        leftConst->value = l * r;
-                        leftConst->type = DoubleType;
-                        m->source = leftConst;
-                        W += m;
-                        break;
-                    case OpAdd:
-                        leftConst->value = l + r;
-                        leftConst->type = DoubleType;
-                        m->source = leftConst;
-                        W += m;
-                        break;
-                    case OpSub:
-                        leftConst->value = l - r;
-                        leftConst->type = DoubleType;
-                        m->source = leftConst;
-                        W += m;
-                        break;
-                    case OpDiv:
-                        leftConst->value = l / r;
-                        leftConst->type = DoubleType;
-                        m->source = leftConst;
-                        W += m;
-                        break;
-                    case OpMod:
-                        leftConst->value = std::fmod(l, r);
-                        leftConst->type = DoubleType;
-                        m->source = leftConst;
-                        W += m;
-                        break;
-                    default:
-                        if (tryOptimizingComparison(m->source))
-                            W += m;
-                        break;
-                    }
-
-                    continue;
-                }
-            } // TODO: var{#0} = double{%10} where %10 is defined once and used once. E.g.: function(t){t = t % 2; return t; }
-
-        } else if (CJump *cjump = s->asCJump()) {
-            if (Const *constantCondition = cjump->cond->asConst()) {
-                // Note: this assumes that there are no critical edges! Meaning, we can safely purge
-                //       any basic blocks that are found to be unreachable.
-                Jump *jump = function->NewStmt<Jump>();
-                W.registerNewStatement(jump);
-                if (convertToValue(constantCondition).toBoolean()) {
-                    jump->target = cjump->iftrue;
-                    unlink(cjump->parent, cjump->iffalse, function, defUses, W, df);
-                } else {
-                    jump->target = cjump->iffalse;
-                    unlink(cjump->parent, cjump->iftrue, function, defUses, W, df);
-                }
-                W.replace(s, jump);
-
-                continue;
-            } else if (cjump->cond->asBinop()) {
-                if (tryOptimizingComparison(cjump->cond))
-                    W += cjump;
-                continue;
-            }
-            // TODO: Constant unary expression evaluation
-            // TODO: if the expression is an unary not operation, lift the expression, and switch
-            //       the then/else blocks.
-        }
-    }
-
-    W.applyToFunction();
-}
-
-//### TODO: use DefUses from the optimizer, because it already has all this information
-class InputOutputCollector
-{
-    void setOutput(Temp *out)
-    {
-        Q_ASSERT(!output);
-        output = out;
-    }
-
-public:
-    std::vector<Temp *> inputs;
-    Temp *output;
-
-    InputOutputCollector()
-    { inputs.reserve(4); }
-
-    void collect(Stmt *s) {
-        inputs.resize(0);
-        output = 0;
-        visit(s);
-    }
-
-private:
-    void visit(Expr *e)
-    {
-        if (auto t = e->asTemp()) {
-            inputs.push_back(t);
-        } else {
-            EXPR_VISIT_ALL_KINDS(e);
-        }
-    }
-
-    void visit(Stmt *s)
-    {
-        if (auto m = s->asMove()) {
-            visit(m->source);
-            if (Temp *t = m->target->asTemp()) {
-                setOutput(t);
-            } else {
-                visit(m->target);
-            }
-        } else if (s->asPhi()) {
-            // Handled separately
-        } else {
-            STMT_VISIT_ALL_KINDS(s);
-        }
-    }
-};
-
-/*
- * The algorithm is described in:
- *
- *   Linear Scan Register Allocation on SSA Form
- *   Christian Wimmer & Michael Franz, CGO'10, April 24-28, 2010
- *
- * See LifeTimeIntervals::renumber for details on the numbering.
- */
-class LifeRanges {
-    class LiveRegs
-    {
-        typedef std::vector<int> Storage;
-        Storage regs;
-
-    public:
-        void insert(int r)
-        {
-            if (find(r) == end())
-                regs.push_back(r);
-        }
-
-        void unite(const LiveRegs &other)
-        {
-            if (other.empty())
-                return;
-            if (empty()) {
-                regs = other.regs;
-                return;
-            }
-            for (int r : other.regs)
-                insert(r);
-        }
-
-        typedef Storage::iterator iterator;
-        iterator find(int r)
-        { return std::find(regs.begin(), regs.end(), r); }
-
-        iterator begin()
-        { return regs.begin(); }
-
-        iterator end()
-        { return regs.end(); }
-
-        void erase(iterator it)
-        { regs.erase(it); }
-
-        void remove(int r)
-        {
-            iterator it = find(r);
-            if (it != end())
-                erase(it);
-        }
-
-        bool empty() const
-        { return regs.empty(); }
-
-        int size() const
-        { return int(regs.size()); }
-
-        int at(int idx) const
-        { return regs.at(idx); }
-    };
-
-    std::vector<LiveRegs> _liveIn;
-    std::vector<LifeTimeInterval *> _intervals;
-    LifeTimeIntervals::Ptr _sortedIntervals;
-
-    LifeTimeInterval &interval(const Temp *temp)
-    {
-        LifeTimeInterval *lti = _intervals[temp->index];
-        Q_ASSERT(lti);
-        return *lti;
-    }
-
-    void ensureInterval(const IR::Temp &temp)
-    {
-        Q_ASSERT(!temp.isInvalid());
-        LifeTimeInterval *&lti = _intervals[temp.index];
-        if (lti)
-            return;
-        lti = new LifeTimeInterval;
-        lti->setTemp(temp);
-    }
-
-    int defPosition(IR::Stmt *s) const
-    {
-        return usePosition(s) + 1;
-    }
-
-    int usePosition(IR::Stmt *s) const
-    {
-        return _sortedIntervals->positionForStatement(s);
-    }
-
-    int start(IR::BasicBlock *bb) const
-    {
-        return _sortedIntervals->startPosition(bb);
-    }
-
-    int end(IR::BasicBlock *bb) const
-    {
-        return _sortedIntervals->endPosition(bb);
-    }
-
-public:
-    LifeRanges(IR::Function *function, const QHash<BasicBlock *, BasicBlock *> &startEndLoops)
-        : _intervals(function->tempCount)
-    {
-        _sortedIntervals = LifeTimeIntervals::create(function);
-        _liveIn.resize(function->basicBlockCount());
-
-        for (int i = function->basicBlockCount() - 1; i >= 0; --i) {
-            BasicBlock *bb = function->basicBlock(i);
-            buildIntervals(bb, startEndLoops.value(bb, 0));
-        }
-
-        _intervals.clear();
-    }
-
-    LifeTimeIntervals::Ptr intervals() const { return _sortedIntervals; }
-
-    void dump() const
-    {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream qout(&buf);
-
-        qout << "Life ranges:" << endl;
-        qout << "Intervals:" << endl;
-        const auto intervals = _sortedIntervals->intervals();
-        for (const LifeTimeInterval *range : intervals) {
-            range->dump(qout);
-            qout << endl;
-        }
-
-        IRPrinter printer(&qout);
-        for (size_t i = 0, ei = _liveIn.size(); i != ei; ++i) {
-            qout << "L" << i <<" live-in: ";
-            auto live = _liveIn.at(i);
-            if (live.empty())
-                qout << "(none)";
-            std::sort(live.begin(), live.end());
-            for (int i = 0; i < live.size(); ++i) {
-                if (i > 0) qout << ", ";
-                qout << '%' << live.at(i);
-            }
-            qout << endl;
-        }
-        buf.close();
-        qDebug("%s", buf.data().constData());
-    }
-
-private:
-    void buildIntervals(BasicBlock *bb, BasicBlock *loopEnd)
-    {
-        LiveRegs live;
-        for (BasicBlock *successor : bb->out) {
-            live.unite(_liveIn[successor->index()]);
-            const int bbIndex = successor->in.indexOf(bb);
-            Q_ASSERT(bbIndex >= 0);
-
-            for (Stmt *s : successor->statements()) {
-                if (Phi *phi = s->asPhi()) {
-                    if (Temp *t = phi->incoming.at(bbIndex)->asTemp()) {
-                        ensureInterval(*t);
-                        live.insert(t->index);
-                    }
-                } else {
-                    break;
-                }
-            }
-        }
-
-        const QVector<Stmt *> &statements = bb->statements();
-
-        for (int reg : live)
-            _intervals[reg]->addRange(start(bb), end(bb));
-
-        InputOutputCollector collector;
-        for (int i = statements.size() - 1; i >= 0; --i) {
-            Stmt *s = statements.at(i);
-            if (Phi *phi = s->asPhi()) {
-                ensureInterval(*phi->targetTemp);
-                LiveRegs::iterator it = live.find(phi->targetTemp->index);
-                if (it == live.end()) {
-                    // a phi node target that is only defined, but never used
-                    interval(phi->targetTemp).setFrom(start(bb));
-                } else {
-                    live.erase(it);
-                }
-                _sortedIntervals->add(&interval(phi->targetTemp));
-                continue;
-            }
-            collector.collect(s);
-            //### TODO: use DefUses from the optimizer, because it already has all this information
-            if (Temp *opd = collector.output) {
-                ensureInterval(*opd);
-                LifeTimeInterval &lti = interval(opd);
-                lti.setFrom(defPosition(s));
-                live.remove(lti.temp().index);
-                _sortedIntervals->add(&lti);
-            }
-            //### TODO: use DefUses from the optimizer, because it already has all this information
-            for (size_t i = 0, ei = collector.inputs.size(); i != ei; ++i) {
-                Temp *opd = collector.inputs[i];
-                ensureInterval(*opd);
-                interval(opd).addRange(start(bb), usePosition(s));
-                live.insert(opd->index);
-            }
-        }
-
-        if (loopEnd) { // Meaning: bb is a loop header, because loopEnd is set to non-null.
-            for (int reg : live)
-                _intervals[reg]->addRange(start(bb), usePosition(loopEnd->terminator()));
-        }
-
-        _liveIn[bb->index()] = std::move(live);
-    }
-};
-
-void removeUnreachleBlocks(IR::Function *function)
-{
-    QVector<BasicBlock *> newSchedule;
-    newSchedule.reserve(function->basicBlockCount());
-    for (BasicBlock *bb : function->basicBlocks())
-        if (!bb->isRemoved())
-            newSchedule.append(bb);
-    function->setScheduledBlocks(newSchedule);
-}
-
-class ConvertArgLocals
-{
-public:
-    ConvertArgLocals(IR::Function *function)
-        : function(function)
-        , convertArgs(!function->usesArgumentsObject)
-    {
-        tempForFormal.resize(function->formals.size(), -1);
-        tempForLocal.resize(function->locals.size(), -1);
-    }
-
-    void toTemps()
-    {
-        if (function->variablesCanEscape())
-            return;
-
-        QVector<Stmt *> extraMoves;
-        if (convertArgs) {
-            const int formalCount = function->formals.size();
-            extraMoves.reserve(formalCount + function->basicBlock(0)->statementCount());
-            extraMoves.resize(formalCount);
-
-            for (int i = 0; i != formalCount; ++i) {
-                const int newTemp = function->tempCount++;
-                tempForFormal[i] = newTemp;
-
-                ArgLocal *source = function->New<ArgLocal>();
-                source->init(ArgLocal::Formal, i, 0);
-
-                Temp *target = function->New<Temp>();
-                target->init(Temp::VirtualRegister, newTemp);
-
-                Move *m = function->NewStmt<Move>();
-                m->init(target, source);
-                extraMoves[i] = m;
-            }
-        }
-
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (!bb->isRemoved()) {
-                for (Stmt *s : bb->statements()) {
-                    visit(s);
-                }
-            }
-        }
-
-        if (convertArgs && function->formals.size() > 0)
-            function->basicBlock(0)->prependStatements(extraMoves);
-
-        function->locals.clear();
-    }
-
-private:
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            check(e->expr);
-        } else if (auto m = s->asMove()) {
-            check(m->target); check(m->source);
-        } else if (auto c = s->asCJump()) {
-            check(c->cond);
-        } else if (auto r = s->asRet()) {
-            check(r->expr);
-        }
-    }
-
-    void visit(Expr *e)
-    {
-        if (auto c = e->asConvert()) {
-            check(c->expr);
-        } else if (auto u = e->asUnop()) {
-            check(u->expr);
-        } else if (auto b = e->asBinop()) {
-            check(b->left); check(b->right);
-        } else if (auto c = e->asCall()) {
-            check(c->base);
-            for (ExprList *it = c->args; it; it = it->next) {
-                check(it->expr);
-            }
-        } else if (auto n = e->asNew()) {
-            check(n->base);
-            for (ExprList *it = n->args; it; it = it->next) {
-                check(it->expr);
-            }
-        } else if (auto s = e->asSubscript()) {
-            check(s->base); check(s->index);
-        } else if (auto m = e->asMember()) {
-            check(m->base);
-        }
-    }
-
-    void check(Expr *&e) {
-        if (ArgLocal *al = e->asArgLocal()) {
-            if (al->kind == ArgLocal::Local) {
-                Temp *t = function->New<Temp>();
-                t->init(Temp::VirtualRegister, fetchTempForLocal(al->index));
-                e = t;
-            } else if (convertArgs && al->kind == ArgLocal::Formal) {
-                Temp *t = function->New<Temp>();
-                t->init(Temp::VirtualRegister, fetchTempForFormal(al->index));
-                e = t;
-            }
-        } else {
-            visit(e);
-        }
-    }
-
-    int fetchTempForLocal(int local)
-    {
-        int &ref = tempForLocal[local];
-        if (ref == -1)
-            ref = function->tempCount++;
-        return ref;
-    }
-
-    int fetchTempForFormal(int formal)
-    {
-        return tempForFormal[formal];
-    }
-
-    IR::Function *function;
-    bool convertArgs;
-    std::vector<int> tempForFormal;
-    std::vector<int> tempForLocal;
-};
-
-class CloneBasicBlock: protected CloneExpr
-{
-public:
-    BasicBlock *operator()(IR::BasicBlock *originalBlock)
-    {
-        block = new BasicBlock(originalBlock->function, 0);
-
-        for (Stmt *s : originalBlock->statements()) {
-            visit(s);
-            clonedStmt->location = s->location;
-        }
-
-        return block;
-    }
-
-private:
-    void visit(Stmt *s)
-    {
-        if (auto e = s->asExp()) {
-            clonedStmt = block->EXP(clone(e->expr));
-        } else if (auto m = s->asMove()) {
-            clonedStmt = block->MOVE(clone(m->target), clone(m->source));
-        } else if (auto j = s->asJump()) {
-            clonedStmt = block->JUMP(j->target);
-        } else if (auto c = s->asCJump()) {
-            clonedStmt = block->CJUMP(clone(c->cond), c->iftrue, c->iffalse);
-        } else if (auto r = s->asRet()) {
-            clonedStmt = block->RET(clone(r->expr));
-        } else if (auto p = s->asPhi()) {
-            Phi *phi = block->function->NewStmt<Phi>();
-            clonedStmt = phi;
-
-            phi->targetTemp = clone(p->targetTemp);
-            for (Expr *in : p->incoming)
-                phi->incoming.append(clone(in));
-            block->appendStatement(phi);
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-private:
-    IR::Stmt *clonedStmt;
-};
-
-static void verifyCFG(IR::Function *function)
-{
-    if (!DoVerification)
-        return;
-
-    for (BasicBlock *bb : function->basicBlocks()) {
-        if (bb->isRemoved()) {
-            Q_ASSERT(bb->in.isEmpty());
-            Q_ASSERT(bb->out.isEmpty());
-            continue;
-        }
-
-        Q_ASSERT(function->basicBlock(bb->index()) == bb);
-
-        // Check the terminators:
-        Stmt *terminator = bb->terminator();
-        if (terminator == nullptr) {
-            Stmt *last = bb->statements().last();
-            Call *call = last->asExp()->expr->asCall();
-            Name *baseName = call->base->asName();
-            Q_ASSERT(baseName->builtin == Name::builtin_rethrow);
-            Q_UNUSED(baseName);
-        } else if (Jump *jump = terminator->asJump()) {
-            Q_UNUSED(jump);
-            Q_ASSERT(jump->target);
-            Q_ASSERT(!jump->target->isRemoved());
-            Q_ASSERT(bb->out.size() == 1);
-            Q_ASSERT(bb->out.first() == jump->target);
-        } else if (CJump *cjump = terminator->asCJump()) {
-            Q_UNUSED(cjump);
-            Q_ASSERT(bb->out.size() == 2);
-            Q_ASSERT(cjump->iftrue);
-            Q_ASSERT(!cjump->iftrue->isRemoved());
-            Q_ASSERT(cjump->iftrue == bb->out[0]);
-            Q_ASSERT(cjump->iffalse);
-            Q_ASSERT(!cjump->iffalse->isRemoved());
-            Q_ASSERT(cjump->iffalse == bb->out[1]);
-        } else if (terminator->asRet()) {
-            Q_ASSERT(bb->out.size() == 0);
-        } else {
-            Q_UNREACHABLE();
-        }
-
-        // Check the outgoing edges:
-        for (BasicBlock *out : bb->out) {
-            Q_UNUSED(out);
-            Q_ASSERT(!out->isRemoved());
-            Q_ASSERT(out->in.contains(bb));
-        }
-
-        // Check the incoming edges:
-        for (BasicBlock *in : bb->in) {
-            Q_UNUSED(in);
-            Q_ASSERT(!in->isRemoved());
-            Q_ASSERT(in->out.contains(bb));
-        }
-    }
-}
-
-static void verifyImmediateDominators(const DominatorTree &dt, IR::Function *function)
-{
-    if (!DoVerification)
-        return;
-
-    cfg2dot(function);
-    dt.dumpImmediateDominators();
-    DominatorTree referenceTree(function);
-
-    for (BasicBlock *bb : function->basicBlocks()) {
-        if (bb->isRemoved())
-            continue;
-
-        BasicBlock *idom = dt.immediateDominator(bb);
-        BasicBlock *referenceIdom = referenceTree.immediateDominator(bb);
-        Q_UNUSED(idom);
-        Q_UNUSED(referenceIdom);
-        Q_ASSERT(idom == referenceIdom);
-    }
-}
-
-static void verifyNoPointerSharing(IR::Function *function)
-{
-    if (!DoVerification)
-        return;
-
-    class {
-    public:
-        void operator()(IR::Function *f)
-        {
-            for (BasicBlock *bb : f->basicBlocks()) {
-                if (bb->isRemoved())
-                    continue;
-
-                for (Stmt *s : bb->statements()) {
-                    visit(s);
-                }
-            }
-        }
-
-    private:
-        void visit(Stmt *s)
-        {
-            check(s);
-            STMT_VISIT_ALL_KINDS(s);
-        }
-
-        void visit(Expr *e)
-        {
-            check(e);
-            EXPR_VISIT_ALL_KINDS(e);
-        }
-
-    private:
-        void check(Stmt *s)
-        {
-            Q_ASSERT(!stmts.contains(s));
-            stmts.insert(s);
-        }
-
-        void check(Expr *e)
-        {
-            Q_ASSERT(!exprs.contains(e));
-            exprs.insert(e);
-        }
-
-        QSet<Stmt *> stmts;
-        QSet<Expr *> exprs;
-    } V;
-    V(function);
-}
-
-// Loop-peeling is done by unfolding the loop once. The "original" loop basic blocks stay where they
-// are, and a copy of the loop is placed after it. Special care is taken while copying the loop body:
-// by having the copies of the basic-blocks point to the same nodes as the "original" basic blocks,
-// updating the immediate dominators is easy: if the edge of a copied basic-block B points to a
-// block C that has also been copied, set the immediate dominator of B to the corresponding
-// immediate dominator of C. Finally, for any node outside the loop that gets a new edge attached,
-// the immediate dominator has to be re-calculated.
-class LoopPeeling
-{
-    DominatorTree &dt;
-
-public:
-    LoopPeeling(DominatorTree &dt)
-        : dt(dt)
-    {}
-
-    void run(const QVector<LoopDetection::LoopInfo *> &loops)
-    {
-        for (LoopDetection::LoopInfo *loopInfo : loops)
-            peelLoop(loopInfo);
-    }
-
-private:
-    // All copies have their outgoing edges pointing to the same successor block as the originals.
-    // For each copied block, check where the outgoing edges point to. If it's a block inside the
-    // (original) loop, rewire it to the corresponding copy. Otherwise, which is when it points
-    // out of the loop, leave it alone.
-    // As an extra, collect all edges that point out of the copied loop, because the targets need
-    // to have their immediate dominator rechecked.
-    void rewire(BasicBlock *newLoopBlock, const QVector<BasicBlock *> &from, const QVector<BasicBlock *> &to, QVector<BasicBlock *> &loopExits)
-    {
-        for (int i = 0, ei = newLoopBlock->out.size(); i != ei; ++i) {
-            BasicBlock *&out = newLoopBlock->out[i];
-            const int idx = from.indexOf(out);
-            if (idx == -1) {
-                if (!loopExits.contains(out))
-                    loopExits.append(out);
-            } else {
-                out->in.removeOne(newLoopBlock);
-                BasicBlock *newTo = to.at(idx);
-                newTo->in.append(newLoopBlock);
-                out = newTo;
-
-                Stmt *terminator = newLoopBlock->terminator();
-                if (Jump *jump = terminator->asJump()) {
-                    Q_ASSERT(i == 0);
-                    jump->target = newTo;
-                } else if (CJump *cjump = terminator->asCJump()) {
-                    Q_ASSERT(i == 0 || i == 1);
-                    if (i == 0)
-                        cjump->iftrue = newTo;
-                    else
-                        cjump->iffalse = newTo;
-                }
-            }
-        }
-    }
-
-    void peelLoop(LoopDetection::LoopInfo *loop)
-    {
-        IR::Function *f = loop->loopHeader->function;
-        CloneBasicBlock clone;
-
-        LoopDetection::LoopInfo unpeeled(*loop);
-        unpeeled.loopHeader = clone(unpeeled.loopHeader);
-        unpeeled.loopHeader->setContainingGroup(loop->loopHeader->containingGroup());
-        unpeeled.loopHeader->markAsGroupStart(true);
-        f->addBasicBlock(unpeeled.loopHeader);
-        for (int i = 0, ei = unpeeled.loopBody.size(); i != ei; ++i) {
-            BasicBlock *&bodyBlock = unpeeled.loopBody[i];
-            bodyBlock = clone(bodyBlock);
-            bodyBlock->setContainingGroup(unpeeled.loopHeader);
-            Q_ASSERT(bodyBlock->statementCount() == loop->loopBody[i]->statementCount());
-        }
-
-        // The cloned blocks will have no incoming edges, but they do have outgoing ones (copying
-        // the terminators will automatically insert that edge). The blocks where the originals
-        // pointed to will have an extra incoming edge from the copied blocks.
-
-        BasicBlock::IncomingEdges inCopy = loop->loopHeader->in;
-        for (BasicBlock *in : inCopy) {
-            if (loop->loopHeader != in // this can happen for really tight loops (where there are no body blocks). This is a back-edge in that case.
-                    && unpeeled.loopHeader != in && !unpeeled.loopBody.contains(in) // if the edge is not coming from within the copied set, leave it alone
-                    && !dt.dominates(loop->loopHeader, in)) // an edge coming from within the loop (so a back-edge): this is handled when rewiring all outgoing edges
-                continue;
-
-            unpeeled.loopHeader->in.append(in);
-            loop->loopHeader->in.removeOne(in);
-
-            Stmt *terminator = in->terminator();
-            if (Jump *jump = terminator->asJump()) {
-                jump->target = unpeeled.loopHeader;
-                in->out[0] = unpeeled.loopHeader;
-            } else if (CJump *cjump = terminator->asCJump()) {
-                if (cjump->iftrue == loop->loopHeader) {
-                    cjump->iftrue = unpeeled.loopHeader;
-                    Q_ASSERT(in->out[0] == loop->loopHeader);
-                    in->out[0] = unpeeled.loopHeader;
-                } else if (cjump->iffalse == loop->loopHeader) {
-                    cjump->iffalse = unpeeled.loopHeader;
-                    Q_ASSERT(in->out[1] == loop->loopHeader);
-                    in->out[1] = unpeeled.loopHeader;
-                } else {
-                    Q_UNREACHABLE();
-                }
-            }
-        }
-
-        QVector<BasicBlock *> loopExits;
-        loopExits.reserve(8);
-        loopExits.append(unpeeled.loopHeader);
-
-        rewire(unpeeled.loopHeader, loop->loopBody, unpeeled.loopBody, loopExits);
-        for (int i = 0, ei = unpeeled.loopBody.size(); i != ei; ++i) {
-            BasicBlock *bodyBlock = unpeeled.loopBody.at(i);
-            rewire(bodyBlock, loop->loopBody, unpeeled.loopBody, loopExits);
-            f->addBasicBlock(bodyBlock);
-        }
-
-        // The original loop is now peeled off, and won't jump back to the loop header. Meaning, it
-        // is not a loop anymore, so unmark it.
-        loop->loopHeader->markAsGroupStart(false);
-        for (BasicBlock *bb : qAsConst(loop->loopBody))
-            bb->setContainingGroup(loop->loopHeader->containingGroup());
-
-        // Set the immediate dominator of the new loop header to the old one. The real immediate
-        // dominator will be calculated later.
-        dt.setImmediateDominator(unpeeled.loopHeader, loop->loopHeader);
-        // calculate the idoms in a separate loop, because addBasicBlock in the previous loop will
-        // set the block index, which in turn is used by the dominator tree.
-        for (int i = 0, ei = unpeeled.loopBody.size(); i != ei; ++i) {
-            BasicBlock *bodyBlock = unpeeled.loopBody.at(i);
-            BasicBlock *idom = dt.immediateDominator(loop->loopBody.at(i));
-            const int idx = loop->loopBody.indexOf(idom);
-            if (idom == loop->loopHeader)
-                idom = unpeeled.loopHeader;
-            else if (idx != -1)
-                idom = unpeeled.loopBody.at(idx);
-            Q_ASSERT(idom);
-            dt.setImmediateDominator(bodyBlock, idom);
-        }
-
-        BasicBlockSet siblings(f);
-        for (BasicBlock *bb : qAsConst(loopExits))
-            dt.collectSiblings(bb, siblings);
-
-        siblings.insert(unpeeled.loopHeader);
-        dt.recalculateIDoms(siblings, loop->loopHeader);
-        dt.dumpImmediateDominators();
-        verifyImmediateDominators(dt, f);
-    }
-};
-
-class RemoveLineNumbers: private SideEffectsChecker
-{
-public:
-    static void run(IR::Function *function)
-    {
-        for (BasicBlock *bb : function->basicBlocks()) {
-            if (bb->isRemoved())
-                continue;
-
-            for (Stmt *s : bb->statements()) {
-                if (!hasSideEffects(s)) {
-                    s->location = QQmlJS::AST::SourceLocation();
-                }
-            }
-        }
-    }
-
-private:
-    ~RemoveLineNumbers() {}
-
-    static bool hasSideEffects(Stmt *stmt)
-    {
-        RemoveLineNumbers checker;
-        if (auto e = stmt->asExp()) {
-            checker.visit(e->expr);
-        } else if (auto m = stmt->asMove()) {
-            checker.visit(m->source);
-            if (!checker.seenSideEffects()) {
-                checker.visit(m->target);
-            }
-        } else if (auto c = stmt->asCJump()) {
-            checker.visit(c->cond);
-        } else if (auto r = stmt->asRet()) {
-            checker.visit(r->expr);
-        }
-        return checker.seenSideEffects();
-    }
-
-    void visitTemp(Temp *) Q_DECL_OVERRIDE Q_DECL_FINAL {}
-};
-
-void mergeBasicBlocks(IR::Function *function, DefUses *du, DominatorTree *dt)
-{
-    enum { DebugBlockMerging = 0 };
-
-    if (function->hasTry)
-        return;
-
-    showMeTheCode(function, "Before basic block merging");
-
-    // Now merge a basic block with its successor when there is one outgoing edge, and the
-    // successor has one incoming edge.
-    for (int i = 0, ei = function->basicBlockCount(); i != ei; ++i) {
-        BasicBlock *bb = function->basicBlock(i);
-
-        bb->nextLocation = QQmlJS::AST::SourceLocation(); // make sure appendStatement doesn't mess with the line info
-
-        if (bb->isRemoved()) continue; // the block has been removed, so ignore it
-        if (bb->out.size() != 1) continue; // more than one outgoing edge
-        BasicBlock *successor = bb->out.first();
-        if (successor->in.size() != 1) continue; // more than one incoming edge
-
-        // Loop header? No efficient way to update the other blocks that refer to this as containing group,
-        // so don't do merging yet.
-        if (successor->isGroupStart()) continue;
-
-        // Ok, we can merge the two basic blocks.
-        if (DebugBlockMerging) {
-            qDebug("Merging L%d into L%d", successor->index(), bb->index());
-        }
-        Q_ASSERT(bb->terminator()->asJump());
-        bb->removeStatement(bb->statementCount() - 1); // remove the terminator, and replace it with:
-        for (Stmt *s : successor->statements()) {
-            bb->appendStatement(s); // add all statements from the successor to the current basic block
-            if (auto cjump = s->asCJump())
-                cjump->parent = bb;
-        }
-        bb->out = successor->out; // set the outgoing edges to the successor's so they're now in sync with our new terminator
-        for (auto newSuccessor : bb->out) {
-            for (auto &backlink : newSuccessor->in) {
-                if (backlink == successor) {
-                    backlink = bb; // for all successors of our successor: set the incoming edges to come from bb, because we'll now jump there.
-                }
-            }
-        }
-        if (du) {
-            // all statements in successor have moved to bb, so make sure that the containing blocks
-            // stored in DefUses get updated (meaning: point to bb)
-            du->replaceBasicBlock(successor, bb);
-        }
-        if (dt) {
-            // update the immediate dominators to: any block that was dominated by the successor
-            // will now need to point to bb's immediate dominator. The reason is that bb itself
-            // won't be anyones immediate dominator, because it had just one outgoing edge.
-            dt->mergeIntoPredecessor(successor);
-        }
-        function->removeBasicBlock(successor);
-        --i; // re-run on the current basic-block, so any chain gets collapsed.
-    }
-
-    showMeTheCode(function, "After basic block merging");
-    verifyCFG(function);
-}
-
-} // anonymous namespace
-
-void LifeTimeInterval::setFrom(int from) {
-    Q_ASSERT(from > 0);
-
-    if (_ranges.isEmpty()) { // this is the case where there is no use, only a define
-        _ranges.prepend(LifeTimeIntervalRange(from, from));
-        if (_end == InvalidPosition)
-            _end = from;
-    } else {
-        _ranges.first().start = from;
-    }
-}
-
-void LifeTimeInterval::addRange(int from, int to) {
-    Q_ASSERT(from > 0);
-    Q_ASSERT(to > 0);
-    Q_ASSERT(to >= from);
-
-    if (_ranges.isEmpty()) {
-        _ranges.prepend(LifeTimeIntervalRange(from, to));
-        _end = to;
-        return;
-    }
-
-    LifeTimeIntervalRange *p = &_ranges.first();
-    if (to + 1 >= p->start && p->end + 1 >= from) {
-        p->start = qMin(p->start, from);
-        p->end = qMax(p->end, to);
-        while (_ranges.count() > 1) {
-            LifeTimeIntervalRange *p1 = p + 1;
-            if (p->end + 1 < p1->start || p1->end + 1 < p->start)
-                break;
-            p1->start = qMin(p->start, p1->start);
-            p1->end = qMax(p->end, p1->end);
-            _ranges.remove(0);
-            p = &_ranges.first();
-        }
-    } else {
-        if (to < p->start) {
-            _ranges.prepend(LifeTimeIntervalRange(from, to));
-        } else {
-            Q_ASSERT(from > _ranges.last().end);
-            _ranges.push_back(LifeTimeIntervalRange(from, to));
-        }
-    }
-
-    _end = _ranges.last().end;
-}
-
-LifeTimeInterval LifeTimeInterval::split(int atPosition, int newStart)
-{
-    Q_ASSERT(atPosition < newStart || newStart == InvalidPosition);
-    Q_ASSERT(atPosition <= _end);
-    Q_ASSERT(newStart <= _end || newStart == InvalidPosition);
-
-    if (_ranges.isEmpty() || atPosition < _ranges.first().start)
-        return LifeTimeInterval();
-
-    LifeTimeInterval newInterval = *this;
-    newInterval.setSplitFromInterval(true);
-
-    // search where to split the interval
-    for (int i = 0, ei = _ranges.size(); i < ei; ++i) {
-        if (_ranges.at(i).start <= atPosition) {
-            if (_ranges.at(i).end >= atPosition) {
-                // split happens in the middle of a range. Keep this range in both the old and the
-                // new interval, and correct the end/start later
-                _ranges.resize(i + 1);
-                newInterval._ranges.remove(0, i);
-                break;
-            }
-        } else {
-            // split happens between two ranges.
-            _ranges.resize(i);
-            newInterval._ranges.remove(0, i);
-            break;
-        }
-    }
-
-    if (newInterval._ranges.first().end == atPosition)
-        newInterval._ranges.remove(0);
-
-    if (newStart == InvalidPosition) {
-        // the temp stays inactive for the rest of its lifetime
-        newInterval = LifeTimeInterval();
-    } else {
-        // find the first range where the temp will get active again:
-        while (!newInterval._ranges.isEmpty()) {
-            const LifeTimeIntervalRange &range = newInterval._ranges.first();
-            if (range.start > newStart) {
-                // The split position is before the start of the range. Either we managed to skip
-                // over the correct range, or we got an invalid split request. Either way, this
-                // Should Never Happen <TM>.
-                Q_ASSERT(range.start > newStart);
-                return LifeTimeInterval();
-            } else if (range.start <= newStart && range.end >= newStart) {
-                // yay, we found the range that should be the new first range in the new interval!
-                break;
-            } else {
-                // the temp stays inactive for this interval, so remove it.
-                newInterval._ranges.remove(0);
-            }
-        }
-        Q_ASSERT(!newInterval._ranges.isEmpty());
-        newInterval._ranges.first().start = newStart;
-        _end = newStart;
-    }
-
-    // if we're in the middle of a range, set the end to the split position
-    if (_ranges.last().end > atPosition)
-        _ranges.last().end = atPosition;
-
-    validate();
-    newInterval.validate();
-
-    return newInterval;
-}
-
-void LifeTimeInterval::dump(QTextStream &out) const {
-    IRPrinter(&out).print(const_cast<Temp *>(&_temp));
-    out << ": ends at " << _end << " with ranges ";
-    if (_ranges.isEmpty())
-        out << "(none)";
-    for (int i = 0; i < _ranges.size(); ++i) {
-        if (i > 0) out << ", ";
-        out << _ranges[i].start << " - " << _ranges[i].end;
-    }
-    if (_reg != InvalidRegister)
-        out << " (register " << _reg << ")";
-}
-
-
-bool LifeTimeInterval::lessThanForTemp(const LifeTimeInterval *r1, const LifeTimeInterval *r2)
-{
-    return r1->temp() < r2->temp();
-}
-
-LifeTimeIntervals::LifeTimeIntervals(IR::Function *function)
-    : _basicBlockPosition(function->basicBlockCount())
-    , _positionForStatement(function->statementCount(), IR::Stmt::InvalidId)
-    , _lastPosition(0)
-{
-    _intervals.reserve(function->tempCount + 32); // we reserve a bit more space for intervals, because the register allocator will add intervals with fixed ranges for each register.
-    renumber(function);
-}
-
-// Renumbering works as follows:
-//  - phi statements are not numbered
-//  - statement numbers start at 0 (zero) and increment get an even number (lastPosition + 2)
-//  - basic blocks start at firstStatementNumber - 1, or rephrased: lastPosition + 1
-//  - basic blocks end at the number of the last statement
-// And during life-time calculation the next rule is used:
-//  - any temporary starts its life-time at definingStatementPosition + 1
-//
-// This numbering simulates half-open intervals. For example:
-//   0: %1 = 1
-//   2: %2 = 2
-//   4: %3 = %1 + %2
-//   6: print(%3)
-// Here the half-open life-time intervals would be:
-//   %1: (0-4]
-//   %2: (2-4]
-//   %3: (4-6]
-// Instead, we use the even statement positions for uses of temporaries, and the odd positions for
-// their definitions:
-//   %1: [1-4]
-//   %2: [3-4]
-//   %3: [5-6]
-// This has the nice advantage that placing %3 (for example) is really easy: the start will
-// never overlap with the end of the uses of the operands used in the defining statement.
-//
-// The reason to start a basic-block at firstStatementPosition - 1 is to have correct start
-// positions for target temporaries of phi-nodes. Those temporaries will now start before the
-// first statement. This also means that any moves that get generated when transforming out of SSA
-// form, will not interfere with (read: overlap) any defining statements in the preceding
-// basic-block.
-void LifeTimeIntervals::renumber(IR::Function *function)
-{
-    for (BasicBlock *bb : function->basicBlocks()) {
-        if (bb->isRemoved())
-            continue;
-
-        _basicBlockPosition[bb->index()].start = _lastPosition + 1;
-
-        for (Stmt *s : bb->statements()) {
-            if (s->asPhi())
-                continue;
-
-            _lastPosition += 2;
-            _positionForStatement[s->id()] = _lastPosition;
-        }
-
-        _basicBlockPosition[bb->index()].end = _lastPosition;
-    }
-}
-
-LifeTimeIntervals::~LifeTimeIntervals()
-{
-    qDeleteAll(_intervals);
-}
-
-Optimizer::Optimizer(IR::Function *function)
-    : function(function)
-    , inSSA(false)
-{}
-
-void Optimizer::run(QQmlEnginePrivate *qmlEngine, bool doTypeInference, bool peelLoops)
-{
-    showMeTheCode(function, "Before running the optimizer");
-
-    cleanupBasicBlocks(function);
-
-    function->removeSharedExpressions();
-    int statementCount = 0;
-    for (BasicBlock *bb : function->basicBlocks())
-        if (!bb->isRemoved())
-            statementCount += bb->statementCount();
-//    showMeTheCode(function);
-
-    static bool doSSA = qEnvironmentVariableIsEmpty("QV4_NO_SSA");
-
-    if (!function->hasTry && !function->hasWith && !function->module->debugMode && doSSA && statementCount <= 300) {
-//        qout << "SSA for " << (function->name ? qPrintable(*function->name) : "<anonymous>") << endl;
-
-        mergeBasicBlocks(function, nullptr, nullptr);
-
-        ConvertArgLocals(function).toTemps();
-        showMeTheCode(function, "After converting arguments to locals");
-
-        // Calculate the dominator tree:
-        DominatorTree df(function);
-
-        {
-            // This is in a separate scope, because loop-peeling doesn't (yet) update the LoopInfo
-            // calculated by the LoopDetection. So by putting it in a separate scope, it is not
-            // available after peeling.
-
-            LoopDetection loopDetection(df);
-            loopDetection.run(function);
-            showMeTheCode(function, "After loop detection");
-//            cfg2dot(function, loopDetection.allLoops());
-
-            // ### disable loop peeling for now. It doesn't give any measurable performance
-            // improvements at this time, but significantly increases the size of the
-            // JIT generated code
-            Q_UNUSED(peelLoops);
-            if (0 && peelLoops) {
-                QVector<LoopDetection::LoopInfo *> innerLoops = loopDetection.innermostLoops();
-                LoopPeeling(df).run(innerLoops);
-
-//                cfg2dot(function, loopDetection.allLoops());
-                showMeTheCode(function, "After loop peeling");
-                if (!innerLoops.isEmpty())
-                    verifyImmediateDominators(df, function);
-            }
-        }
-
-        verifyCFG(function);
-        verifyNoPointerSharing(function);
-
-        df.computeDF();
-
-        verifyCFG(function);
-        verifyImmediateDominators(df, function);
-
-        DefUses defUses(function);
-
-//        qout << "Converting to SSA..." << endl;
-        convertToSSA(function, df, defUses);
-//        showMeTheCode(function);
-//        defUses.dump();
-
-//        qout << "Cleaning up phi nodes..." << endl;
-        cleanupPhis(defUses);
-        showMeTheCode(function, "After cleaning up phi-nodes");
-
-        StatementWorklist worklist(function);
-
-        if (doTypeInference) {
-//            qout << "Running type inference..." << endl;
-            TypeInference(qmlEngine, defUses).run(worklist);
-            showMeTheCode(function, "After type inference");
-
-//            qout << "Doing reverse inference..." << endl;
-            ReverseInference(defUses).run(function);
-//            showMeTheCode(function);
-
-//            qout << "Doing type propagation..." << endl;
-            TypePropagation(defUses).run(function, worklist);
-//            showMeTheCode(function);
-            verifyNoPointerSharing(function);
-        }
-
-        static const bool doOpt = qEnvironmentVariableIsEmpty("QV4_NO_OPT");
-        if (doOpt) {
-//            qout << "Running SSA optimization..." << endl;
-            worklist.reset();
-            optimizeSSA(worklist, defUses, df);
-            showMeTheCode(function, "After optimization");
-
-            verifyImmediateDominators(df, function);
-            verifyCFG(function);
-        }
-
-        verifyNoPointerSharing(function);
-        mergeBasicBlocks(function, &defUses, &df);
-
-        verifyImmediateDominators(df, function);
-        verifyCFG(function);
-
-        // Basic-block cycles that are unreachable (i.e. for loops in a then-part where the
-        // condition is calculated to be always false) are not yet removed. This will choke the
-        // block scheduling, so remove those now.
-//        qout << "Cleaning up unreachable basic blocks..." << endl;
-        cleanupBasicBlocks(function);
-//        showMeTheCode(function);
-
-        verifyImmediateDominators(df, function);
-        verifyCFG(function);
-
-        // Transform the CFG into edge-split SSA.
-        showMeTheCode(function, "Before edge splitting");
-        splitCriticalEdges(function, df, worklist, defUses);
-        showMeTheCode(function, "After edge splitting");
-
-        verifyImmediateDominators(df, function);
-        verifyCFG(function);
-
-//        qout << "Doing block scheduling..." << endl;
-//        df.dumpImmediateDominators();
-        startEndLoops = BlockScheduler(function, df).go();
-        showMeTheCode(function, "After basic block scheduling");
-//        cfg2dot(function);
-
-#ifndef QT_NO_DEBUG
-        checkCriticalEdges(function->basicBlocks());
-#endif
-
-        if (!function->module->debugMode) {
-            RemoveLineNumbers::run(function);
-            showMeTheCode(function, "After line number removal");
-        }
-
-//        qout << "Finished SSA." << endl;
-        inSSA = true;
-    } else {
-        removeUnreachleBlocks(function);
-        inSSA = false;
-    }
-}
-
-void Optimizer::convertOutOfSSA() {
-    if (!inSSA)
-        return;
-
-    // There should be no critical edges at this point.
-
-    for (BasicBlock *bb : function->basicBlocks()) {
-        MoveMapping moves;
-
-        for (BasicBlock *successor : bb->out) {
-            const int inIdx = successor->in.indexOf(bb);
-            Q_ASSERT(inIdx >= 0);
-            for (Stmt *s : successor->statements()) {
-                if (Phi *phi = s->asPhi()) {
-                    moves.add(clone(phi->incoming[inIdx], function),
-                              clone(phi->targetTemp, function)->asTemp());
-                } else {
-                    break;
-                }
-            }
-        }
-
-        if (DebugMoveMapping) {
-            QBuffer buf;
-            buf.open(QIODevice::WriteOnly);
-            QTextStream os(&buf);
-            os << "Move mapping for function ";
-            if (function->name)
-                os << *function->name;
-            else
-                os << (void *) function;
-            os << " on basic-block L" << bb->index() << ":" << endl;
-            moves.dump();
-            buf.close();
-            qDebug("%s", buf.data().constData());
-        }
-
-        moves.order();
-
-        moves.insertMoves(bb, function, true);
-    }
-
-    for (BasicBlock *bb : function->basicBlocks()) {
-        while (!bb->isEmpty()) {
-            if (bb->statements().first()->asPhi()) {
-                bb->removeStatement(0);
-            } else {
-                break;
-            }
-        }
-    }
-}
-
-LifeTimeIntervals::Ptr Optimizer::lifeTimeIntervals() const
-{
-    Q_ASSERT(isInSSA());
-
-    LifeRanges lifeRanges(function, startEndLoops);
-//    lifeRanges.dump();
-//    showMeTheCode(function);
-    return lifeRanges.intervals();
-}
-
-static int countPhis(BasicBlock *bb)
-{
-    int count = 0;
-    for (Stmt *s : bb->statements()) {
-        if (s->isa<Phi>())
-            ++count;
-        else
-            break;
-    }
-
-    return count;
-}
-
-// Basic blocks can have only 1 terminator. This function returns a bit vector, where a 1 on a
-// certain index indicates that the terminator (jump) at the end of the basic block with that index
-// can be omitted.
-BitVector Optimizer::calculateOptionalJumps()
-{
-    const int maxSize = function->basicBlockCount();
-    BitVector optional(maxSize, false);
-    if (maxSize < 2)
-        return optional;
-
-    BitVector reachableWithoutJump(maxSize, false);
-
-    for (int i = maxSize - 1; i >= 0; --i) {
-        BasicBlock *bb = function->basicBlock(i);
-        if (bb->isRemoved())
-            continue;
-
-        if (Jump *jump = bb->statements().last()->asJump()) {
-            if (reachableWithoutJump.at(jump->target->index())) {
-                if (bb->statements().size() - countPhis(bb)> 1)
-                    reachableWithoutJump.clear();
-                optional.setBit(bb->index());
-                reachableWithoutJump.setBit(bb->index());
-                continue;
-            }
-        }
-
-        reachableWithoutJump.clear();
-        reachableWithoutJump.setBit(bb->index());
-    }
-
-    return optional;
-}
-
-void Optimizer::showMeTheCode(IR::Function *function, const char *marker)
-{
-    ::showMeTheCode(function, marker);
-}
-
-static inline bool overlappingStorage(const Temp &t1, const Temp &t2)
-{
-    // This is the same as the operator==, but for one detail: memory locations are not sensitive
-    // to types, and neither are general-purpose registers.
-
-    if (t1.index != t2.index)
-        return false; // different position, where-ever that may (physically) be.
-    if (t1.kind != t2.kind)
-        return false; // formal/local/(physical-)register/stack do never overlap
-    if (t1.kind != Temp::PhysicalRegister) // Other than registers, ...
-        return t1.kind == t2.kind; // ... everything else overlaps: any memory location can hold everything.
-
-    // So now the index is the same, and we know that both stored in a register. If both are
-    // floating-point registers, they are the same. Or, if both are non-floating-point registers,
-    // generally called general-purpose registers, they are also the same.
-    return (t1.type == DoubleType && t2.type == DoubleType)
-            || (t1.type != DoubleType && t2.type != DoubleType);
-}
-
-MoveMapping::Moves MoveMapping::sourceUsages(Expr *e, const Moves &moves)
-{
-    Moves usages;
-
-    if (Temp *t = e->asTemp()) {
-        for (int i = 0, ei = moves.size(); i != ei; ++i) {
-            const Move &move = moves[i];
-            if (Temp *from = move.from->asTemp())
-                if (overlappingStorage(*from, *t))
-                    usages.append(move);
-        }
-    }
-
-    return usages;
-}
-
-void MoveMapping::add(Expr *from, Temp *to) {
-    if (Temp *t = from->asTemp()) {
-        if (overlappingStorage(*t, *to)) {
-            // assignments like fp1 = fp1 or var{&1} = double{&1} can safely be skipped.
-            if (DebugMoveMapping) {
-                QBuffer buf;
-                buf.open(QIODevice::WriteOnly);
-                QTextStream os(&buf);
-                IRPrinter printer(&os);
-                os << "Skipping ";
-                printer.print(to);
-                os << " <- ";
-                printer.print(from);
-                buf.close();
-                qDebug("%s", buf.data().constData());
-            }
-            return;
-        }
-    }
-
-    Move m(from, to);
-    if (_moves.contains(m))
-        return;
-    _moves.append(m);
-}
-
-// Order the moves that are generated when resolving edges during register allocation (see [Wimmer1]
-// section 6 for details). Now these moves form one or more graphs, so we have to output them in
-// such an order that values don't get overwritten:
-//   r1 <- r0
-//   r2 <- r1
-// That input has to be ordered as follows in order to prevent the value in r1 from being lost:
-//   r2 <- r1
-//   r1 <- r0
-//
-// So, the algorithm is to output the leaves first, and take them out of the input. This will result
-// in some moves to become leaves (in the above example: when leaf r2 <- r1 is generated and taken
-// away, the r1 <- r0 is now a leaf), so we can output those and take those out, and repeat until
-// there are no more leafs.
-//
-// The tricky part is that there might be cycles:
-//   r4 <- r5
-//   r5 <- r4
-// These have to be turned into a "register swap":
-//   r4 <=> r5
-//
-// So after running the above algorithm where we progressively remove the leaves, we are left with
-// zero or more cycles. To resolve those, we break one of the edges of the cycle, and for all other
-// edges we generate swaps. Note that the swaps will always occur as the last couple of moves,
-// because otherwise they might clobber sources for moves:
-//   r4 <=> r5
-//   r6 <- r5
-// Here, the value of r5 is already overwritten with the one in r4, so the correct order is:
-//   r6 <- r5
-//   r4 <=> r5
-void MoveMapping::order()
-{
-    QList<Move> output;
-    output.reserve(_moves.size());
-
-    while (!_moves.isEmpty()) {
-        // Take out all leaf edges, because we can output them without any problems.
-        int nextLeaf = findLeaf();
-        if (nextLeaf == -1)
-            break; // No more leafs left, we're done here.
-        output.append(_moves.takeAt(nextLeaf));
-        // Now there might be new leaf edges: any move that had the input of the previously found
-        // leaf as an output, so loop around.
-    }
-
-    while (!_moves.isEmpty()) {
-        // We're now left with one or more cycles.
-        // Step one: break the/a cycle.
-        _moves.removeFirst();
-        // Step two: find the other edges of the cycle, starting with the one of that is now a leaf.
-        while (!_moves.isEmpty()) {
-            int nextLeaf = findLeaf();
-            if (nextLeaf == -1)
-                break; // We're done with this cycle.
-            Move m = _moves.takeAt(nextLeaf);
-            // Step three: get the edges from the cycle and turn it into a swap
-            m.needsSwap = true;
-            output.append(m);
-            // Because we took out a leaf, find the next one.
-        }
-        // We're done with the cycle, let's see if there are more.
-    }
-
-    _moves = output;
-}
-
-int MoveMapping::findLeaf() const
-{
-    for (int i = 0, e = _moves.size(); i != e; ++i) {
-        // Take an edge from the list...
-        const Temp *target = _moves.at(i).to;
-        // ... and see if its target is used as a source...
-        bool targetUsedAsSource = false;
-        for (int j = 0; j != e; ++j) {
-            if (i == j)
-                continue;
-
-            Expr *source = _moves.at(j).from;
-            if (const Temp *sourceTemp = source->asTemp()) {
-                if (overlappingStorage(*target, *sourceTemp)) {
-                    targetUsedAsSource = true;
-                    break;
-                }
-            }
-        }
-        // ... if not, we have a leaf edge ...
-        if (!targetUsedAsSource)
-            return i;
-        // .. otherwise we try the next one.
-    }
-
-    return -1; // No leaf found
-}
-
-QList<IR::Move *> MoveMapping::insertMoves(BasicBlock *bb, IR::Function *function, bool atEnd) const
-{
-    QList<IR::Move *> newMoves;
-    newMoves.reserve(_moves.size());
-
-    int insertionPoint = atEnd ? bb->statements().size() - 1 : 0;
-    for (const Move &m : _moves) {
-        IR::Move *move = function->NewStmt<IR::Move>();
-        move->init(clone(m.to, function), clone(m.from, function));
-        move->swap = m.needsSwap;
-        bb->insertStatementBefore(insertionPoint++, move);
-        newMoves.append(move);
-    }
-
-    return newMoves;
-}
-
-void MoveMapping::dump() const
-{
-    if (DebugMoveMapping) {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream os(&buf);
-        IRPrinter printer(&os);
-        os << "Move mapping has " << _moves.size() << " moves..." << endl;
-        for (const Move &m : _moves) {
-            os << "\t";
-            printer.print(m.to);
-            if (m.needsSwap)
-                os << " <-> ";
-            else
-                os << " <-- ";
-            printer.print(m.from);
-            os << endl;
-        }
-        qDebug("%s", buf.data().constData());
-    }
-}
-
-// References:
-//  [Wimmer1] C. Wimmer and M. Franz. Linear Scan Register Allocation on SSA Form. In Proceedings of
-//            CGO'10, ACM Press, 2010
-//  [Wimmer2] C. Wimmer and H. Mossenbock. Optimized Interval Splitting in a Linear Scan Register
-//            Allocator. In Proceedings of the ACM/USENIX International Conference on Virtual
-//            Execution Environments, pages 132-141. ACM Press, 2005.
-//  [Briggs]  P. Briggs, K.D. Cooper, T.J. Harvey, and L.T. Simpson. Practical Improvements to the
-//            Construction and Destruction of Static Single Assignment Form.
-//  [Appel]   A.W. Appel. Modern Compiler Implementation in Java. Second edition, Cambridge
-//            University Press.
-//  [Ramalingam] G. Ramalingam and T. Reps. An Incremental Algorithm for Maintaining the Dominator
-//               Tree of a Reducible Flowgraph.
diff --git a/src/qml/compiler/qv4ssa_p.h b/src/qml/compiler/qv4ssa_p.h
deleted file mode 100644
index 24257e99e9..0000000000
--- a/src/qml/compiler/qv4ssa_p.h
+++ /dev/null
@@ -1,472 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QV4SSA_P_H
-#define QV4SSA_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "qv4jsir_p.h"
-#include "qv4isel_util_p.h"
-#include <private/qv4util_p.h>
-#include <QtCore/QSharedPointer>
-
-QT_BEGIN_NAMESPACE
-class QTextStream;
-class QQmlEnginePrivate;
-
-namespace QV4 {
-namespace IR {
-
-struct LifeTimeIntervalRange {
-    int start;
-    int end;
-
-    LifeTimeIntervalRange(int start = -1, int end = -1)
-        : start(start)
-        , end(end)
-    {}
-
-    bool covers(int position) const { return start <= position && position <= end; }
-};
-} // IR namespace
-} // QV4 namespace
-
-Q_DECLARE_TYPEINFO(QV4::IR::LifeTimeIntervalRange, Q_PRIMITIVE_TYPE);
-
-namespace QV4 {
-namespace IR {
-
-class Q_AUTOTEST_EXPORT LifeTimeInterval {
-public:
-    typedef QVarLengthArray<LifeTimeIntervalRange, 4> Ranges;
-
-private:
-    Temp _temp;
-    Ranges _ranges;
-    int _end;
-    int _reg;
-    unsigned _isFixedInterval : 1;
-    unsigned _isSplitFromInterval : 1;
-
-public:
-    enum { InvalidPosition = -1 };
-    enum { InvalidRegister = -1 };
-
-    explicit LifeTimeInterval(int rangeCapacity = 4)
-        : _end(InvalidPosition)
-        , _reg(InvalidRegister)
-        , _isFixedInterval(0)
-        , _isSplitFromInterval(0)
-    { _ranges.reserve(rangeCapacity); }
-
-    bool isValid() const { return _end != InvalidRegister; }
-
-    void setTemp(const Temp &temp) { this->_temp = temp; }
-    Temp temp() const { return _temp; }
-    bool isFP() const { return _temp.type == IR::DoubleType; }
-
-    void setFrom(int from);
-    void addRange(int from, int to);
-    const Ranges &ranges() const { return _ranges; }
-
-    int start() const { return _ranges.first().start; }
-    int end() const { return _end; }
-    bool covers(int position) const
-    {
-        for (int i = 0, ei = _ranges.size(); i != ei; ++i) {
-            if (_ranges.at(i).covers(position))
-                return true;
-        }
-        return false;
-    }
-
-    int reg() const { return _reg; }
-    void setReg(int reg) { Q_ASSERT(!_isFixedInterval); _reg = reg; }
-
-    bool isFixedInterval() const { return _isFixedInterval; }
-    void setFixedInterval(bool isFixedInterval) { _isFixedInterval = isFixedInterval; }
-
-    LifeTimeInterval split(int atPosition, int newStart);
-    bool isSplitFromInterval() const { return _isSplitFromInterval; }
-    void setSplitFromInterval(bool isSplitFromInterval) { _isSplitFromInterval = isSplitFromInterval; }
-
-    void dump(QTextStream &out) const;
-    static bool lessThan(const LifeTimeInterval *r1, const LifeTimeInterval *r2);
-    static bool lessThanForTemp(const LifeTimeInterval *r1, const LifeTimeInterval *r2);
-
-    void validate() const {
-#if !defined(QT_NO_DEBUG)
-        // Validate the new range
-        if (_end != InvalidPosition) {
-            Q_ASSERT(!_ranges.isEmpty());
-            for (const LifeTimeIntervalRange &range : qAsConst(_ranges)) {
-                Q_ASSERT(range.start >= 0);
-                Q_ASSERT(range.end >= 0);
-                Q_ASSERT(range.start <= range.end);
-            }
-        }
-#endif
-    }
-};
-
-inline bool LifeTimeInterval::lessThan(const LifeTimeInterval *r1, const LifeTimeInterval *r2)
-{
-    if (r1->_ranges.first().start == r2->_ranges.first().start) {
-        if (r1->isSplitFromInterval() == r2->isSplitFromInterval())
-            return r1->_ranges.last().end < r2->_ranges.last().end;
-        else
-            return r1->isSplitFromInterval();
-    } else
-        return r1->_ranges.first().start < r2->_ranges.first().start;
-}
-
-class LifeTimeIntervals
-{
-    Q_DISABLE_COPY(LifeTimeIntervals)
-
-    LifeTimeIntervals(IR::Function *function);
-    void renumber(IR::Function *function);
-
-public:
-    typedef QSharedPointer<LifeTimeIntervals> Ptr;
-    static Ptr create(IR::Function *function)
-    { return Ptr(new LifeTimeIntervals(function)); }
-
-    ~LifeTimeIntervals();
-
-    // takes ownership of the pointer
-    void add(LifeTimeInterval *interval)
-    { _intervals.append(interval); }
-
-    // After calling Optimizer::lifeTimeIntervals() the result will have all intervals in descending order of start position.
-    QVector<LifeTimeInterval *> intervals() const
-    { return _intervals; }
-
-    int size() const
-    { return _intervals.size(); }
-
-    int positionForStatement(Stmt *stmt) const
-    {
-        Q_ASSERT(stmt->id() >= 0);
-        if (static_cast<unsigned>(stmt->id()) < _positionForStatement.size())
-            return _positionForStatement[stmt->id()];
-
-        return Stmt::InvalidId;
-    }
-
-    int startPosition(BasicBlock *bb) const
-    {
-        Q_ASSERT(bb->index() >= 0);
-        Q_ASSERT(static_cast<unsigned>(bb->index()) < _basicBlockPosition.size());
-
-        return _basicBlockPosition.at(bb->index()).start;
-    }
-
-    int endPosition(BasicBlock *bb) const
-    {
-        Q_ASSERT(bb->index() >= 0);
-        Q_ASSERT(static_cast<unsigned>(bb->index()) < _basicBlockPosition.size());
-
-        return _basicBlockPosition.at(bb->index()).end;
-    }
-
-    int lastPosition() const
-    {
-        return _lastPosition;
-    }
-
-private:
-    struct BasicBlockPositions {
-        int start;
-        int end;
-
-        BasicBlockPositions()
-            : start(IR::Stmt::InvalidId)
-            , end(IR::Stmt::InvalidId)
-        {}
-    };
-
-    std::vector<BasicBlockPositions> _basicBlockPosition;
-    std::vector<int> _positionForStatement;
-    QVector<LifeTimeInterval *> _intervals;
-    int _lastPosition;
-};
-
-class Q_QML_PRIVATE_EXPORT Optimizer
-{
-    Q_DISABLE_COPY(Optimizer)
-
-public:
-    Optimizer(Function *function);
-
-    void run(QQmlEnginePrivate *qmlEngine, bool doTypeInference = true, bool peelLoops = true);
-    void convertOutOfSSA();
-
-    bool isInSSA() const
-    { return inSSA; }
-
-    QHash<BasicBlock *, BasicBlock *> loopStartEndBlocks() const { return startEndLoops; }
-
-    LifeTimeIntervals::Ptr lifeTimeIntervals() const;
-
-    BitVector calculateOptionalJumps();
-
-    static void showMeTheCode(Function *function, const char *marker);
-
-private:
-    Function *function;
-    bool inSSA;
-    QHash<BasicBlock *, BasicBlock *> startEndLoops;
-};
-
-class Q_AUTOTEST_EXPORT MoveMapping
-{
-#ifdef V4_AUTOTEST
-public:
-#endif
-    struct Move {
-        Expr *from;
-        Temp *to;
-        bool needsSwap;
-
-        Move(Expr *from, Temp *to, bool needsSwap = false)
-            : from(from), to(to), needsSwap(needsSwap)
-        {}
-
-        bool operator==(const Move &other) const
-        { return from == other.from && to == other.to; }
-    };
-    typedef QList<Move> Moves;
-
-    Moves _moves;
-
-    static Moves sourceUsages(Expr *e, const Moves &moves);
-
-public:
-    void add(Expr *from, Temp *to);
-    void order();
-    QList<IR::Move *> insertMoves(BasicBlock *bb, Function *function, bool atEnd) const;
-
-    void dump() const;
-
-private:
-    int findLeaf() const;
-};
-
-/*
- * stack slot allocation:
- *
- * foreach bb do
- *   foreach stmt do
- *     if the current statement is not a phi-node:
- *       purge ranges that end before the current statement
- *       check for life ranges to activate, and if they don't have a stackslot associated then allocate one
- *       renumber temps to stack
- *     for phi nodes: check if all temps (src+dst) are assigned stack slots and marked as allocated
- *     if it's a jump:
- *       foreach phi node in the successor:
- *         allocate slots for each temp (both sources and targets) if they don't have one allocated already
- *         insert moves before the jump
- */
-class AllocateStackSlots: protected ConvertTemps
-{
-    IR::LifeTimeIntervals::Ptr _intervals;
-    QVector<IR::LifeTimeInterval *> _unhandled;
-    QVector<IR::LifeTimeInterval *> _live;
-    QBitArray _slotIsInUse;
-    IR::Function *_function;
-
-    int defPosition(IR::Stmt *s) const
-    {
-        return usePosition(s) + 1;
-    }
-
-    int usePosition(IR::Stmt *s) const
-    {
-        return _intervals->positionForStatement(s);
-    }
-
-public:
-    AllocateStackSlots(const IR::LifeTimeIntervals::Ptr &intervals)
-        : _intervals(intervals)
-        , _slotIsInUse(intervals->size(), false)
-        , _function(0)
-    {
-        _live.reserve(8);
-        _unhandled = _intervals->intervals();
-    }
-
-    void forFunction(IR::Function *function)
-    {
-        IR::Optimizer::showMeTheCode(function, "Before stack slot allocation");
-        _function = function;
-        toStackSlots(function);
-    }
-
-protected:
-    int allocateFreeSlot() override
-    {
-        for (int i = 0, ei = _slotIsInUse.size(); i != ei; ++i) {
-            if (!_slotIsInUse[i]) {
-                if (_nextUnusedStackSlot <= i) {
-                    Q_ASSERT(_nextUnusedStackSlot == i);
-                    _nextUnusedStackSlot = i + 1;
-                }
-                _slotIsInUse[i] = true;
-                return i;
-            }
-        }
-
-        Q_UNREACHABLE();
-        return -1;
-    }
-
-    void process(IR::Stmt *s) override
-    {
-//        qDebug("L%d statement %d:", _currentBasicBlock->index, s->id);
-
-        if (IR::Phi *phi = s->asPhi()) {
-            visitPhi(phi);
-        } else {
-            // purge ranges no longer alive:
-            for (int i = 0; i < _live.size(); ) {
-                const IR::LifeTimeInterval *lti = _live.at(i);
-                if (lti->end() < usePosition(s)) {
-//                    qDebug() << "\t - moving temp" << lti->temp().index << "to handled, freeing slot" << _stackSlotForTemp[lti->temp().index];
-                    _live.remove(i);
-                    Q_ASSERT(_slotIsInUse[_stackSlotForTemp[lti->temp().index]]);
-                    _slotIsInUse[_stackSlotForTemp[lti->temp().index]] = false;
-                    continue;
-                } else {
-                    ++i;
-                }
-            }
-
-            // active new ranges:
-            while (!_unhandled.isEmpty()) {
-                IR::LifeTimeInterval *lti = _unhandled.last();
-                if (lti->start() > defPosition(s))
-                    break; // we're done
-                Q_ASSERT(!_stackSlotForTemp.contains(lti->temp().index));
-                _stackSlotForTemp[lti->temp().index] = allocateFreeSlot();
-//                qDebug() << "\t - activating temp" << lti->temp().index << "on slot" << _stackSlotForTemp[lti->temp().index];
-                _live.append(lti);
-                _unhandled.removeLast();
-            }
-
-            visit(s);
-        }
-
-        if (IR::Jump *jump = s->asJump()) {
-            IR::MoveMapping moves;
-            for (IR::Stmt *succStmt : jump->target->statements()) {
-                if (IR::Phi *phi = succStmt->asPhi()) {
-                    forceActivation(*phi->targetTemp);
-                    for (int i = 0, ei = phi->incoming.size(); i != ei; ++i) {
-                        IR::Expr *e = phi->incoming[i];
-                        if (IR::Temp *t = e->asTemp()) {
-                            forceActivation(*t);
-                        }
-                        if (jump->target->in[i] == _currentBasicBlock)
-                            moves.add(phi->incoming[i], phi->targetTemp);
-                    }
-                } else {
-                    break;
-                }
-            }
-            moves.order();
-            const QList<IR::Move *> newMoves = moves.insertMoves(_currentBasicBlock, _function, true);
-            for (IR::Move *move : newMoves)
-                visit(move);
-        }
-    }
-
-    void forceActivation(const IR::Temp &t)
-    {
-        if (_stackSlotForTemp.contains(t.index))
-            return;
-
-        int i = _unhandled.size() - 1;
-        for (; i >= 0; --i) {
-            IR::LifeTimeInterval *lti = _unhandled[i];
-            if (lti->temp() == t) {
-                _live.append(lti);
-                _unhandled.remove(i);
-                break;
-            }
-        }
-        Q_ASSERT(i >= 0); // check that we always found the entry
-
-        _stackSlotForTemp[t.index] = allocateFreeSlot();
-//        qDebug() << "\t - force activating temp" << t.index << "on slot" << _stackSlotForTemp[t.index];
-    }
-
-    void visitPhi(IR::Phi *phi) override
-    {
-        Q_UNUSED(phi);
-#if !defined(QT_NO_DEBUG)
-        Q_ASSERT(_stackSlotForTemp.contains(phi->targetTemp->index));
-        Q_ASSERT(_slotIsInUse[_stackSlotForTemp[phi->targetTemp->index]]);
-        for (IR::Expr *e : phi->incoming) {
-            if (IR::Temp *t = e->asTemp())
-                Q_ASSERT(_stackSlotForTemp.contains(t->index));
-        }
-#endif // defined(QT_NO_DEBUG)
-    }
-};
-
-} // IR namespace
-} // QV4 namespace
-
-
-Q_DECLARE_TYPEINFO(QV4::IR::LifeTimeInterval, Q_MOVABLE_TYPE);
-
-QT_END_NAMESPACE
-
-#endif // QV4SSA_P_H
diff --git a/src/qml/configure.json b/src/qml/configure.json
index 257bedecbc..c35f5be06b 100644
--- a/src/qml/configure.json
+++ b/src/qml/configure.json
@@ -7,22 +7,50 @@
 
     "commandline": {
         "options": {
-            "qml-interpreter": "boolean",
-            "qml-network": "boolean"
+            "qml-network": "boolean",
+            "qml-tracing": "boolean",
+            "qml-debug": "boolean"
+        }
+    },
+
+    "tests": {
+        "cxx14_make_unique": {
+            "label": "C++14 make_unique()",
+            "type": "compile",
+            "test": {
+                "include": "memory",
+                "main": [
+                    "std::unique_ptr<int> ptr = std::make_unique<int>();"
+                ],
+                "qmake": "CONFIG += c++11"
+            }
         }
     },
 
     "features": {
-        "qml-interpreter": {
-            "label": "QML interpreter",
-            "purpose": "Provides the QML interpreter.",
-            "section": "QML",
+        "cxx14_make_unique": {
+            "label": "C++14 make_unique",
+            "condition": "features.c++14 || tests.cxx14_make_unique",
             "output": [ "privateFeature" ]
         },
         "qml-network": {
             "label": "QML network support",
             "purpose": "Provides network transparency.",
             "section": "QML",
+            "condition": "features.network",
+            "output": [ "publicFeature" ]
+        },
+        "qml-tracing": {
+            "label": "QML tracing JIT support",
+            "purpose": "Provides a JIT that uses trace information generated by the interpreter.",
+            "section": "QML",
+            "output": [ "privateFeature" ],
+            "autoDetect": false
+        },
+        "qml-debug": {
+            "label": "QML debugging and profiling support",
+            "purpose": "Provides infrastructure and plugins for debugging and profiling.",
+            "section": "QML",
             "output": [ "publicFeature" ]
         },
         "qml-profiler": {
@@ -31,13 +59,78 @@
             "section": "QML",
             "condition": [
                 "features.commandlineparser",
-                "features.localserver",
-                "features.process",
                 "features.qml-debug",
-                "features.qml-network",
+                "features.qml-network && features.localserver",
                 "features.xmlstreamwriter"
             ],
             "output": [ "privateFeature" ]
+        },
+        "qml-preview": {
+            "label": "Command line QML Preview tool",
+            "purpose": "Updates QML documents in your application live as you change them on disk",
+            "section": "QML",
+            "condition": [
+                "features.commandlineparser",
+                "features.filesystemwatcher",
+                "features.qml-network && features.localserver",
+                "features.process",
+                "features.qml-debug"
+            ],
+            "output": [ "privateFeature" ]
+        },
+        "qml-devtools": {
+            "label": "QML Development Tools",
+            "purpose": "Provides the QmlDevtools library and various utilities.",
+            "section": "QML",
+            "output": [ "privateFeature" ]
+        },
+        "qml-sequence-object": {
+            "label": "QML sequence object",
+            "purpose": "Supports mapping sequence types into QML.",
+            "section": "QML",
+            "output": [ "privateFeature" ]
+        },
+        "qml-list-model": {
+            "label": "QML list model",
+            "purpose": "Provides the ListModel QML type.",
+            "section": "QML",
+            "output": [ "privateFeature" ]
+        },
+        "qml-xml-http-request": {
+            "label": "QML XML http request",
+            "purpose": "Provides support for sending XML http requests.",
+            "section": "QML",
+            "condition": [
+                "features.xmlstreamreader",
+                "features.qml-network"
+            ],
+            "output": [ "privateFeature" ]
+        },
+        "qml-locale": {
+            "label": "QML Locale",
+            "purpose": "Provides support for locales in QML.",
+            "section": "QML",
+            "output": [ "privateFeature" ]
+        },
+        "qml-animation": {
+            "label": "QML Animations",
+            "purpose": "Provides support for animations and timers in QML.",
+            "section": "QML",
+            "condition": "features.animation",
+            "output": [ "privateFeature" ]
+        },
+        "qml-delegate-model": {
+            "label": "QML delegate model",
+            "purpose": "Provides the DelegateModel QML type.",
+            "section": "QML",
+            "output": [ "privateFeature" ]
+        },
+        "qml-worker-script": {
+            "label": "QML WorkerScript",
+            "purpose": "Enables the use of threads in QML.",
+            "section": "QML",
+            "condition": "features.thread",
+            "output": [ "privateFeature" ]
         }
     },
 
@@ -45,8 +138,14 @@
         {
             "section": "Qt QML",
             "entries": [
-                "qml-interpreter",
-                "qml-network"
+                "qml-network",
+                "qml-debug",
+                "qml-tracing",
+                "qml-sequence-object",
+                "qml-list-model",
+                "qml-xml-http-request",
+                "qml-locale",
+                "qml-delegate-model"
             ]
         }
     ]
diff --git a/src/qml/debugger/debugger.pri b/src/qml/debugger/debugger.pri
index da1ab867d4..202a46e550 100644
--- a/src/qml/debugger/debugger.pri
+++ b/src/qml/debugger/debugger.pri
@@ -1,10 +1,13 @@
-contains(QT_CONFIG, no-qml-debug) {
-    DEFINES += QT_NO_QML_DEBUGGER
-    MODULE_DEFINES += QT_NO_QML_DEBUGGER
-} else {
+qtConfig(qml-debug) {
     HEADERS += \
+        $$PWD/qqmlabstractprofileradapter_p.h \
+        $$PWD/qqmlconfigurabledebugservice_p.h \
         $$PWD/qqmldebugpluginmanager_p.h \
-        $$PWD/qqmldebugservicefactory_p.h
+        $$PWD/qqmldebugservice_p.h \
+        $$PWD/qqmldebugservicefactory_p.h \
+        $$PWD/qqmldebugserver_p.h \
+        $$PWD/qqmldebugserverconnection_p.h \
+        $$PWD/qqmlprofilerdefinitions_p.h
 
     SOURCES += \
         $$PWD/qqmldebug.cpp \
@@ -18,13 +21,10 @@ contains(QT_CONFIG, no-qml-debug) {
 
 HEADERS += \
     $$PWD/qqmldebugconnector_p.h \
-    $$PWD/qqmldebugservice_p.h \
     $$PWD/qqmldebugserviceinterfaces_p.h \
     $$PWD/qqmldebugstatesdelegate_p.h \
     $$PWD/qqmldebug.h \
     $$PWD/qqmlmemoryprofiler_p.h \
-    $$PWD/qqmlprofilerdefinitions_p.h \
-    $$PWD/qqmlabstractprofileradapter_p.h \
     $$PWD/qqmlprofiler_p.h
 
 INCLUDEPATH += $$PWD
diff --git a/src/qml/debugger/qqmlabstractprofileradapter_p.h b/src/qml/debugger/qqmlabstractprofileradapter_p.h
index 6a05a80f37..f39f8fccd2 100644
--- a/src/qml/debugger/qqmlabstractprofileradapter_p.h
+++ b/src/qml/debugger/qqmlabstractprofileradapter_p.h
@@ -59,7 +59,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_QML_DEBUGGER
+QT_REQUIRE_CONFIG(qml_debug);
 
 class QQmlProfilerService;
 class Q_QML_PRIVATE_EXPORT QQmlAbstractProfilerAdapter : public QObject, public QQmlProfilerDefinitions {
@@ -68,18 +68,18 @@ class Q_QML_PRIVATE_EXPORT QQmlAbstractProfilerAdapter : public QObject, public
 public:
     static const int s_numMessagesPerBatch = 1000;
 
-    QQmlAbstractProfilerAdapter(QObject *parent = 0) :
-        QObject(parent), service(0), waiting(true), featuresEnabled(0) {}
-    virtual ~QQmlAbstractProfilerAdapter() {}
+    QQmlAbstractProfilerAdapter(QObject *parent = nullptr) :
+        QObject(parent), service(nullptr), waiting(true), featuresEnabled(0) {}
+    ~QQmlAbstractProfilerAdapter() override {}
     void setService(QQmlProfilerService *new_service) { service = new_service; }
 
-    virtual qint64 sendMessages(qint64 until, QList<QByteArray> &messages, bool trackLocations) = 0;
+    virtual qint64 sendMessages(qint64 until, QList<QByteArray> &messages) = 0;
 
     void startProfiling(quint64 features);
 
     void stopProfiling();
 
-    void reportData(bool trackLocations) { emit dataRequested(trackLocations); }
+    void reportData() { emit dataRequested(); }
 
     void stopWaiting() { waiting = false; }
     void startWaiting() { waiting = true; }
@@ -96,7 +96,7 @@ signals:
     void profilingDisabled();
     void profilingDisabledWhileWaiting();
 
-    void dataRequested(bool trackLocations);
+    void dataRequested();
     void referenceTimeKnown(const QElapsedTimer &timer);
 
 protected:
@@ -116,8 +116,6 @@ public:
 
 #define QQmlAbstractProfilerAdapterFactory_iid "org.qt-project.Qt.QQmlAbstractProfilerAdapterFactory"
 
-#endif // QT_NO_QML_DEBUGGER
-
 QT_END_NAMESPACE
 
 #endif // QQMLABSTRACTPROFILERADAPTER_P_H
diff --git a/src/qml/debugger/qqmlconfigurabledebugservice_p.h b/src/qml/debugger/qqmlconfigurabledebugservice_p.h
new file mode 100644
index 0000000000..96ec46f475
--- /dev/null
+++ b/src/qml/debugger/qqmlconfigurabledebugservice_p.h
@@ -0,0 +1,113 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#ifndef QQMLCONFIGURABLEDEBUGSEVICE_P_H
+#define QQMLCONFIGURABLEDEBUGSEVICE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qqmldebugservice_p.h"
+#include "qqmldebugconnector_p.h"
+
+#include <QtCore/qmutex.h>
+
+QT_BEGIN_NAMESPACE
+
+template <class Base>
+class QQmlConfigurableDebugService : public Base
+{
+protected:
+    QQmlConfigurableDebugService(float version, QObject *parent = nullptr) :
+        Base(version, parent), m_configMutex(QMutex::Recursive)
+    {
+        init();
+    }
+
+    void stopWaiting()
+    {
+        QMutexLocker lock(&m_configMutex);
+        m_waitingForConfiguration = false;
+        for (QJSEngine *engine : qAsConst(m_waitingEngines))
+            emit Base::attachedToEngine(engine);
+        m_waitingEngines.clear();
+    }
+
+    void init()
+    {
+        QMutexLocker lock(&m_configMutex);
+        // If we're not enabled or not blocking, don't wait for configuration
+        m_waitingForConfiguration = (Base::state() == QQmlDebugService::Enabled &&
+                                     QQmlDebugConnector::instance()->blockingMode());
+    }
+
+    void stateChanged(QQmlDebugService::State newState) override
+    {
+        if (newState != QQmlDebugService::Enabled)
+            stopWaiting();
+        else
+            init();
+    }
+
+    void engineAboutToBeAdded(QJSEngine *engine) override
+    {
+        QMutexLocker lock(&m_configMutex);
+        if (m_waitingForConfiguration)
+            m_waitingEngines.append(engine);
+        else
+            emit Base::attachedToEngine(engine);
+    }
+
+    QMutex m_configMutex;
+    QList<QJSEngine *> m_waitingEngines;
+    bool m_waitingForConfiguration;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLCONFIGURABLEDEBUGSEVICE_P_H
diff --git a/src/qml/debugger/qqmldebug.cpp b/src/qml/debugger/qqmldebug.cpp
index 681dc06215..6532576e03 100644
--- a/src/qml/debugger/qqmldebug.cpp
+++ b/src/qml/debugger/qqmldebug.cpp
@@ -44,14 +44,16 @@
 #include <private/qqmlengine_p.h>
 #include <private/qv4compileddata_p.h>
 
+#include <cstdio>
+
+QT_REQUIRE_CONFIG(qml_debug);
+
 QT_BEGIN_NAMESPACE
 
 QQmlDebuggingEnabler::QQmlDebuggingEnabler(bool printWarning)
 {
-    if (!QQmlEnginePrivate::qml_debugging_enabled
-            && printWarning) {
-        qDebug("QML debugging is enabled. Only use this in a safe environment.");
-    }
+    if (!QQmlEnginePrivate::qml_debugging_enabled && printWarning)
+        fprintf(stderr, "QML debugging is enabled. Only use this in a safe environment.\n");
     QQmlEnginePrivate::qml_debugging_enabled = true;
 }
 
diff --git a/src/qml/debugger/qqmldebug.h b/src/qml/debugger/qqmldebug.h
index 6a0cfdc709..d0ceb28cdc 100644
--- a/src/qml/debugger/qqmldebug.h
+++ b/src/qml/debugger/qqmldebug.h
@@ -46,7 +46,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_QML_DEBUGGER
+#if QT_CONFIG(qml_debug)
 
 struct Q_QML_EXPORT QQmlDebuggingEnabler
 {
diff --git a/src/qml/debugger/qqmldebugconnector.cpp b/src/qml/debugger/qqmldebugconnector.cpp
index 01f74f08be..0ef40d6911 100644
--- a/src/qml/debugger/qqmldebugconnector.cpp
+++ b/src/qml/debugger/qqmldebugconnector.cpp
@@ -66,7 +66,7 @@ struct QQmlDebugConnectorParams {
     QString arguments;
     QQmlDebugConnector *instance;
 
-    QQmlDebugConnectorParams() : instance(0)
+    QQmlDebugConnectorParams() : instance(nullptr)
     {
         if (qApp) {
             QCoreApplicationPrivate *appD =
@@ -82,7 +82,7 @@ Q_GLOBAL_STATIC(QQmlDebugConnectorParams, qmlDebugConnectorParams)
 void QQmlDebugConnector::setPluginKey(const QString &key)
 {
     QQmlDebugConnectorParams *params = qmlDebugConnectorParams();
-    if (params) {
+    if (params && params->pluginKey != key) {
         if (params->instance)
             qWarning() << "QML debugger: Cannot set plugin key after loading the plugin.";
         else
@@ -109,7 +109,7 @@ QQmlDebugConnector *QQmlDebugConnector::instance()
 {
     QQmlDebugConnectorParams *params = qmlDebugConnectorParams();
     if (!params)
-        return 0;
+        return nullptr;
 
     if (!QQmlEnginePrivate::qml_debugging_enabled) {
         if (!params->arguments.isEmpty()) {
@@ -118,14 +118,14 @@ QQmlDebugConnector *QQmlDebugConnector::instance()
                                         "has not been enabled.").arg(params->arguments);
             params->arguments.clear();
         }
-        return 0;
+        return nullptr;
     }
 
     if (!params->instance) {
         if (!params->pluginKey.isEmpty()) {
             params->instance = loadQQmlDebugConnector(params->pluginKey);
         } else if (params->arguments.isEmpty()) {
-            return 0; // no explicit class name given and no command line arguments
+            return nullptr; // no explicit class name given and no command line arguments
         } else if (params->arguments.startsWith(QLatin1String("connector:"))) {
             static const int connectorBegin = int(strlen("connector:"));
 
@@ -169,7 +169,7 @@ QQmlDebugConnectorFactory::~QQmlDebugConnectorFactory()
         params->arguments.clear();
         params->services.clear();
         delete params->instance;
-        params->instance = 0;
+        params->instance = nullptr;
     }
 }
 
diff --git a/src/qml/debugger/qqmldebugconnector_p.h b/src/qml/debugger/qqmldebugconnector_p.h
index 0d3e2e2e47..d1ad90adfd 100644
--- a/src/qml/debugger/qqmldebugconnector_p.h
+++ b/src/qml/debugger/qqmldebugconnector_p.h
@@ -44,7 +44,9 @@
 #include <QtQml/qjsengine.h>
 #include <QtCore/QVariantList>
 
+#if QT_CONFIG(qml_debug)
 #include <private/qqmldebugservice_p.h>
+#endif
 
 //
 //  W A R N I N G
@@ -59,7 +61,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 class Q_QML_PRIVATE_EXPORT QQmlDebugConnector
 {
@@ -112,7 +114,7 @@ public:
     static Service *service()
     {
         QQmlDebugConnector *inst = instance();
-        return inst ? static_cast<Service *>(inst->service(Service::s_key)) : 0;
+        return inst ? static_cast<Service *>(inst->service(Service::s_key)) : nullptr;
     }
 
 protected:
@@ -124,7 +126,7 @@ class Q_QML_PRIVATE_EXPORT QQmlDebugConnectorFactory : public QObject {
     Q_OBJECT
 public:
     virtual QQmlDebugConnector *create(const QString &key) = 0;
-    ~QQmlDebugConnectorFactory();
+    ~QQmlDebugConnectorFactory() override;
 };
 
 #define QQmlDebugConnectorFactory_iid "org.qt-project.Qt.QQmlDebugConnectorFactory"
diff --git a/src/qml/debugger/qqmldebugpluginmanager_p.h b/src/qml/debugger/qqmldebugpluginmanager_p.h
index 8f52b65b17..2575cbb96a 100644
--- a/src/qml/debugger/qqmldebugpluginmanager_p.h
+++ b/src/qml/debugger/qqmldebugpluginmanager_p.h
@@ -57,7 +57,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#if defined(QT_NO_QML_DEBUGGER)
+#if !QT_CONFIG(qml_debug)
 
 #define Q_QML_DEBUG_PLUGIN_LOADER(interfaceName)\
     interfaceName *load##interfaceName(const QString &key)\
@@ -72,7 +72,7 @@ QT_BEGIN_NAMESPACE
     }
 #define Q_QML_IMPORT_DEBUG_PLUGIN(className)
 
-#else // QT_NO_QML_DEBUGGER
+#else // QT_CONFIG(qml_debug)
 
 #define Q_QML_DEBUG_PLUGIN_LOADER(interfaceName)\
     Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, interfaceName##Loader,\
@@ -86,7 +86,7 @@ QT_BEGIN_NAMESPACE
         return interfaceName##Loader()->metaData();\
     }
 
-#endif // QT_NO_QML_DEBUGGER
+#endif // QT_CONFIG(qml_debug)
 
 QT_END_NAMESPACE
 #endif // QQMLDEBUGPLUGINMANAGER_P_H
diff --git a/src/qml/qml/ftw/qdeferredcleanup_p.h b/src/qml/debugger/qqmldebugserver_p.h
index 6b59f04a77..e848b00bda 100644
--- a/src/qml/qml/ftw/qdeferredcleanup_p.h
+++ b/src/qml/debugger/qqmldebugserver_p.h
@@ -37,8 +37,13 @@
 **
 ****************************************************************************/
 
-#ifndef QDEFERREDCLEANUP_P_H
-#define QDEFERREDCLEANUP_P_H
+#ifndef QQMLDEBUGSERVER_P_H
+#define QQMLDEBUGSERVER_P_H
+
+#include "qqmldebugconnector_p.h"
+
+#include <private/qtqmlglobal_p.h>
+#include <QtCore/QIODevice>
 
 //
 //  W A R N I N G
@@ -51,24 +56,15 @@
 // We mean it.
 //
 
-#include <QtCore/qglobal.h>
-
-#include <functional>
-
 QT_BEGIN_NAMESPACE
 
-struct QDeferredCleanup
+class Q_QML_PRIVATE_EXPORT QQmlDebugServer : public QQmlDebugConnector
 {
-    std::function<void()> callback;
-    template <typename Callback>
-    QDeferredCleanup(Callback &&cb)
-        : callback(cb)
-    {}
-    ~QDeferredCleanup() { callback(); }
-    QDeferredCleanup(const QDeferredCleanup &) = delete;
-    QDeferredCleanup &operator=(const QDeferredCleanup &) = delete;
+    Q_OBJECT
+public:
+    virtual void setDevice(QIODevice *socket) = 0;
 };
 
 QT_END_NAMESPACE
 
-#endif // QDEFERREDCLEANUP_P_H
+#endif // QQMLDEBUGSERVER_P_H
diff --git a/src/qml/jit/qv4registerinfo_p.h b/src/qml/debugger/qqmldebugserverconnection_p.h
index 214206db91..9c4af4d225 100644
--- a/src/qml/jit/qv4registerinfo_p.h
+++ b/src/qml/debugger/qqmldebugserverconnection_p.h
@@ -37,8 +37,11 @@
 **
 ****************************************************************************/
 
-#ifndef QV4REGISTERINFO_P_H
-#define QV4REGISTERINFO_P_H
+#ifndef QQMLDEBUGSERVERCONNECTION_P_H
+#define QQMLDEBUGSERVERCONNECTION_P_H
+
+#include <private/qtqmlglobal_p.h>
+#include <QtCore/qobject.h>
 
 //
 //  W A R N I N G
@@ -51,62 +54,34 @@
 // We mean it.
 //
 
-#include <QtCore/QString>
-
 QT_BEGIN_NAMESPACE
 
-namespace QV4 {
-namespace JIT {
-
-class RegisterInfo
+class QQmlDebugServer;
+class Q_QML_PRIVATE_EXPORT QQmlDebugServerConnection : public QObject
 {
+    Q_OBJECT
 public:
-    enum { InvalidRegister = (1 << 29) - 1 };
-    enum SavedBy { CallerSaved, CalleeSaved };
-    enum RegisterType { RegularRegister, FloatingPointRegister };
-    enum Usage { Predefined, RegAlloc };
-
-public:
-    RegisterInfo()
-        : _savedBy(CallerSaved)
-        , _usage(Predefined)
-        , _type(RegularRegister)
-        , _reg(InvalidRegister)
-    {}
+    QQmlDebugServerConnection(QObject *parent = nullptr) : QObject(parent) {}
 
-    RegisterInfo(int reg, const QString &prettyName, RegisterType type, SavedBy savedBy, Usage usage)
-        : _prettyName(prettyName)
-        , _savedBy(savedBy)
-        , _usage(usage)
-        , _type(type)
-        , _reg(reg)
-    {}
-
-    bool operator==(const RegisterInfo &other) const
-    { return _type == other._type && _reg == other._reg; }
-
-    bool isValid() const { return _reg != InvalidRegister; }
-    template <typename T> T reg() const { return static_cast<T>(_reg); }
-    QString prettyName() const { return _prettyName; }
-    bool isCallerSaved() const { return _savedBy == CallerSaved; }
-    bool isCalleeSaved() const { return _savedBy == CalleeSaved; }
-    bool isFloatingPoint() const { return _type == FloatingPointRegister; }
-    bool isRegularRegister() const { return _type == RegularRegister; }
-    bool useForRegAlloc() const { return _usage == RegAlloc; }
-    bool isPredefined() const { return _usage == Predefined; }
+    virtual void setServer(QQmlDebugServer *server) = 0;
+    virtual bool setPortRange(int portFrom, int portTo, bool block, const QString &hostaddress) = 0;
+    virtual bool setFileName(const QString &fileName, bool block) = 0;
+    virtual bool isConnected() const = 0;
+    virtual void disconnect() = 0;
+    virtual void waitForConnection() = 0;
+    virtual void flush() = 0;
+};
 
-private:
-    QString _prettyName;
-    unsigned _savedBy : 1;
-    unsigned _usage   : 1;
-    unsigned _type    : 1;
-    unsigned _reg     : 29;
+class Q_QML_PRIVATE_EXPORT QQmlDebugServerConnectionFactory : public QObject
+{
+    Q_OBJECT
+public:
+    virtual QQmlDebugServerConnection *create(const QString &key) = 0;
 };
-typedef QVector<RegisterInfo> RegisterInformation;
 
-} // JIT namespace
-} // QV4 namespace
+#define QQmlDebugServerConnectionFactory_iid "org.qt-project.Qt.QQmlDebugServerConnectionFactory"
+Q_DECLARE_INTERFACE(QQmlDebugServerConnectionFactory, QQmlDebugServerConnectionFactory_iid)
 
 QT_END_NAMESPACE
 
-#endif // QV4REGISTERINFO_P_H
+#endif // QQMLDEBUGSERVERCONNECTION_H
diff --git a/src/qml/debugger/qqmldebugservice_p.h b/src/qml/debugger/qqmldebugservice_p.h
index 42a57a39f2..c52ba90a79 100644
--- a/src/qml/debugger/qqmldebugservice_p.h
+++ b/src/qml/debugger/qqmldebugservice_p.h
@@ -56,9 +56,9 @@
 // We mean it.
 //
 
-QT_BEGIN_NAMESPACE
+QT_REQUIRE_CONFIG(qml_debug);
 
-#ifndef QT_NO_QML_DEBUGGER
+QT_BEGIN_NAMESPACE
 
 class QJSEngine;
 
@@ -69,7 +69,7 @@ class Q_QML_PRIVATE_EXPORT QQmlDebugService : public QObject
     Q_DECLARE_PRIVATE(QQmlDebugService)
 
 public:
-    ~QQmlDebugService();
+    ~QQmlDebugService() override;
 
     const QString &name() const;
     float version() const;
@@ -93,7 +93,7 @@ public:
     static QObject *objectForId(int id) { return objectsForIds().value(id); }
 
 protected:
-    explicit QQmlDebugService(const QString &, float version, QObject *parent = 0);
+    explicit QQmlDebugService(const QString &, float version, QObject *parent = nullptr);
 
 signals:
     void attachedToEngine(QJSEngine *);
@@ -103,8 +103,6 @@ signals:
     void messagesToClient(const QString &name, const QList<QByteArray> &messages);
 };
 
-#endif
-
 QT_END_NAMESPACE
 
 #endif // QQMLDEBUGSERVICE_H
diff --git a/src/qml/debugger/qqmldebugserviceinterfaces_p.h b/src/qml/debugger/qqmldebugserviceinterfaces_p.h
index 707ef1a937..01693aee24 100644
--- a/src/qml/debugger/qqmldebugserviceinterfaces_p.h
+++ b/src/qml/debugger/qqmldebugserviceinterfaces_p.h
@@ -53,9 +53,10 @@
 
 #include <QtCore/qstring.h>
 #include <private/qtqmlglobal_p.h>
+#if QT_CONFIG(qml_debug)
 #include <private/qqmldebugservice_p.h>
+#endif
 #include <private/qqmldebugstatesdelegate_p.h>
-#include <private/qqmlabstractprofileradapter_p.h>
 #include <private/qqmlboundsignal_p.h>
 
 #include <limits>
@@ -65,7 +66,7 @@ QT_BEGIN_NAMESPACE
 class QWindow;
 class QQuickWindow;
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 class QV4DebugService
 {
@@ -116,10 +117,11 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QV4DebugService(float version, QObject *parent = 0) :
+    QV4DebugService(float version, QObject *parent = nullptr) :
         QQmlDebugService(s_key, version, parent) {}
 };
 
+class QQmlAbstractProfilerAdapter;
 class Q_QML_PRIVATE_EXPORT QQmlProfilerService : public QQmlDebugService
 {
     Q_OBJECT
@@ -138,7 +140,7 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QQmlProfilerService(float version, QObject *parent = 0) :
+    QQmlProfilerService(float version, QObject *parent = nullptr) :
         QQmlDebugService(s_key, version, parent) {}
 };
 
@@ -154,7 +156,7 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QQmlEngineDebugService(float version, QObject *parent = 0) :
+    QQmlEngineDebugService(float version, QObject *parent = nullptr) :
         QQmlDebugService(s_key, version, parent) {}
 
     QQmlBoundSignal *nextSignal(QQmlBoundSignal *prev) { return prev->m_nextSignal; }
@@ -173,7 +175,7 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QQmlInspectorService(float version, QObject *parent = 0) :
+    QQmlInspectorService(float version, QObject *parent = nullptr) :
         QQmlDebugService(s_key, version, parent) {}
 };
 
@@ -188,7 +190,7 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QDebugMessageService(float version, QObject *parent = 0) :
+    QDebugMessageService(float version, QObject *parent = nullptr) :
         QQmlDebugService(s_key, version, parent) {}
 };
 
@@ -201,7 +203,7 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QQmlEngineControlService(float version, QObject *parent = 0) :
+    QQmlEngineControlService(float version, QObject *parent = nullptr) :
         QQmlDebugService(s_key, version, parent) {}
 
 };
@@ -215,7 +217,7 @@ public:
 protected:
     friend class QQmlDebugConnector;
 
-    QQmlNativeDebugService(float version, QObject *parent = 0)
+    QQmlNativeDebugService(float version, QObject *parent = nullptr)
         : QQmlDebugService(s_key, version,  parent) {}
 };
 
diff --git a/src/qml/debugger/qqmldebugstatesdelegate_p.h b/src/qml/debugger/qqmldebugstatesdelegate_p.h
index 95f727fb2d..b2e14873dc 100644
--- a/src/qml/debugger/qqmldebugstatesdelegate_p.h
+++ b/src/qml/debugger/qqmldebugstatesdelegate_p.h
@@ -57,7 +57,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 class QQmlDebugStatesDelegate {};
 
diff --git a/src/qml/debugger/qqmlmemoryprofiler_p.h b/src/qml/debugger/qqmlmemoryprofiler_p.h
index fb71c999c3..12a31a851f 100644
--- a/src/qml/debugger/qqmlmemoryprofiler_p.h
+++ b/src/qml/debugger/qqmlmemoryprofiler_p.h
@@ -56,7 +56,7 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 #define QML_MEMORY_SCOPE_URL(url)
 #define QML_MEMORY_SCOPE_STRING(s)
diff --git a/src/qml/debugger/qqmlprofiler.cpp b/src/qml/debugger/qqmlprofiler.cpp
index 8c0bd73822..da0b14dd85 100644
--- a/src/qml/debugger/qqmlprofiler.cpp
+++ b/src/qml/debugger/qqmlprofiler.cpp
@@ -59,19 +59,18 @@ void QQmlProfiler::startProfiling(quint64 features)
 void QQmlProfiler::stopProfiling()
 {
     featuresEnabled = false;
-    reportData(true);
+    reportData();
     m_locations.clear();
 }
 
-void QQmlProfiler::reportData(bool trackLocations)
+void QQmlProfiler::reportData()
 {
     LocationHash resolved;
     resolved.reserve(m_locations.size());
     for (auto it = m_locations.begin(), end = m_locations.end(); it != end; ++it) {
-        if (!trackLocations || !it->sent) {
+        if (!it->sent) {
             resolved.insert(it.key(), it.value());
-            if (trackLocations)
-                it->sent = true;
+            it->sent = true;
         }
     }
 
diff --git a/src/qml/debugger/qqmlprofiler_p.h b/src/qml/debugger/qqmlprofiler_p.h
index 88f8e94f25..d01e2bc429 100644
--- a/src/qml/debugger/qqmlprofiler_p.h
+++ b/src/qml/debugger/qqmlprofiler_p.h
@@ -55,15 +55,17 @@
 #include <private/qqmlboundsignal_p.h>
 #include <private/qfinitestack_p.h>
 #include <private/qqmlbinding_p.h>
+#if QT_CONFIG(qml_debug)
 #include "qqmlprofilerdefinitions_p.h"
 #include "qqmlabstractprofileradapter_p.h"
+#endif
 
 #include <QUrl>
 #include <QString>
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 #define Q_QML_PROFILE_IF_ENABLED(feature, profiler, Code)
 #define Q_QML_PROFILE(feature, profiler, Method)
@@ -149,82 +151,144 @@ class Q_QML_PRIVATE_EXPORT QQmlProfiler : public QObject, public QQmlProfilerDef
     Q_OBJECT
 public:
 
-    class FunctionRefCount : public QQmlRefCount {
-    public:
-        FunctionRefCount(QV4::Function *function):
-            m_function(function)
+    struct Location {
+        Location(const QQmlSourceLocation &location = QQmlSourceLocation(),
+                 const QUrl &url = QUrl()) :
+            location(location), url(url) {}
+        QQmlSourceLocation location;
+        QUrl url;
+    };
+
+    // Unfortunately we have to resolve the locations right away because the QML context might not
+    // be available anymore when we send the data.
+    struct RefLocation : public Location {
+        RefLocation()
+            : Location(), locationType(MaximumRangeType), something(nullptr), sent(false)
         {
-            m_function->compilationUnit->addref();
         }
 
-        FunctionRefCount(const FunctionRefCount &other) :
-            QQmlRefCount(other), m_function(other.m_function)
+        RefLocation(QV4::Function *ref)
+            : Location(ref->sourceLocation()), locationType(Binding), sent(false)
         {
-            m_function->compilationUnit->addref();
+            function = ref;
+            function->compilationUnit->addref();
         }
 
-        FunctionRefCount &operator=(const FunctionRefCount &other)
+        RefLocation(QV4::CompiledData::CompilationUnit *ref, const QUrl &url, const QV4::CompiledData::Object *obj, const QString &type)
+            : Location(QQmlSourceLocation(type, obj->location.line, obj->location.column), url),
+              locationType(Creating), sent(false)
+        {
+            unit = ref;
+            unit->addref();
+        }
+
+        RefLocation(QQmlBoundSignalExpression *ref)
+            : Location(ref->sourceLocation()), locationType(HandlingSignal), sent(false)
+        {
+            boundSignal = ref;
+            boundSignal->addref();
+        }
+
+        RefLocation(QQmlDataBlob *ref)
+            : Location(QQmlSourceLocation(), ref->url()), locationType(Compiling), sent(false)
+        {
+            blob = ref;
+            blob->addref();
+        }
+
+        RefLocation(const RefLocation &other)
+            : Location(other),
+              locationType(other.locationType),
+              function(other.function),
+              sent(other.sent)
+        {
+            addref();
+        }
+
+        RefLocation &operator=(const RefLocation &other)
         {
             if (this != &other) {
-                QQmlRefCount::operator=(other);
-                other.m_function->compilationUnit->addref();
-                m_function->compilationUnit->release();
-                m_function = other.m_function;
+                release();
+                Location::operator=(other);
+                locationType = other.locationType;
+                function = other.function;
+                sent = other.sent;
+                addref();
             }
             return *this;
         }
 
-        ~FunctionRefCount()
+        ~RefLocation()
         {
-            m_function->compilationUnit->release();
+            release();
         }
 
-    private:
-        QV4::Function *m_function;
-    };
-
-    struct Location {
-        Location(const QQmlSourceLocation &location = QQmlSourceLocation(),
-                 const QUrl &url = QUrl()) :
-            location(location), url(url) {}
-        QQmlSourceLocation location;
-        QUrl url;
-    };
+        void addref()
+        {
+            if (isNull())
+                return;
+
+            switch (locationType) {
+            case Binding:
+                function->compilationUnit->addref();
+                break;
+            case Creating:
+                unit->addref();
+                break;
+            case HandlingSignal:
+                boundSignal->addref();
+                break;
+            case Compiling:
+                blob->addref();
+                break;
+            default:
+                Q_ASSERT(locationType == MaximumRangeType);
+                break;
+            }
+        }
 
-    // Unfortunately we have to resolve the locations right away because the QML context might not
-    // be available anymore when we send the data.
-    struct RefLocation : public Location {
-        RefLocation() : Location(), locationType(MaximumRangeType), ref(nullptr), sent(false)
-        {}
-
-        RefLocation(QV4::Function *function) :
-            Location(function->sourceLocation()), locationType(Binding),
-            ref(new FunctionRefCount(function),
-                QQmlRefPointer<QQmlRefCount>::Adopt), sent(false)
-        {}
-
-        RefLocation(QV4::CompiledData::CompilationUnit *ref, const QUrl &url, const QV4::CompiledData::Object *obj,
-                    const QString &type) :
-            Location(QQmlSourceLocation(type, obj->location.line, obj->location.column), url),
-            locationType(Creating), ref(ref), sent(false)
-        {}
-
-        RefLocation(QQmlBoundSignalExpression *ref) :
-            Location(ref->sourceLocation()), locationType(HandlingSignal), ref(ref), sent(false)
-        {}
-
-        RefLocation(QQmlDataBlob *ref) :
-            Location(QQmlSourceLocation(), ref->url()), locationType(Compiling), ref(ref),
-            sent(false)
-        {}
+        void release()
+        {
+            if (isNull())
+                return;
+
+            switch (locationType) {
+            case Binding:
+                function->compilationUnit->release();
+                break;
+            case Creating:
+                unit->release();
+                break;
+            case HandlingSignal:
+                boundSignal->release();
+                break;
+            case Compiling:
+                blob->release();
+                break;
+            default:
+                Q_ASSERT(locationType == MaximumRangeType);
+                break;
+            }
+        }
 
         bool isValid() const
         {
             return locationType != MaximumRangeType;
         }
 
+        bool isNull() const
+        {
+            return !something;
+        }
+
         RangeType locationType;
-        QQmlRefPointer<QQmlRefCount> ref;
+        union {
+            QV4::Function *function;
+            QV4::CompiledData::CompilationUnit *unit;
+            QQmlBoundSignalExpression *boundSignal;
+            QQmlDataBlob *blob;
+            void *something;
+        };
         bool sent;
     };
 
@@ -234,17 +298,23 @@ public:
     {
         // Use the QV4::Function as ID, as that is common among different instances of the same
         // component. QQmlBinding is per instance.
-        // Add 1 to the ID, to make it different from the IDs the V4 profiler produces. The +1 makes
-        // the pointer point into the middle of the QV4::Function. Thus it still points to valid
-        // memory but we cannot accidentally create a duplicate key from another object.
-        quintptr locationId(id(function) + 1);
+        // Add 1 to the ID, to make it different from the IDs the V4 and signal handling profilers
+        // produce. The +1 makes the pointer point into the middle of the QV4::Function. Thus it
+        // still points to valid memory but we cannot accidentally create a duplicate key from
+        // another object.
+        // If there is no function, use a static but valid address: The profiler itself.
+        quintptr locationId = function ? id(function) + 1 : id(this);
         m_data.append(QQmlProfilerData(m_timer.nsecsElapsed(),
                                        (1 << RangeStart | 1 << RangeLocation), Binding,
                                        locationId));
 
         RefLocation &location = m_locations[locationId];
-        if (!location.isValid())
-            location = RefLocation(function);
+        if (!location.isValid()) {
+            if (function)
+                location = RefLocation(function);
+            else // Make it valid without actually providing a location
+                location.locationType = Binding;
+        }
     }
 
     // Have toByteArrays() construct another RangeData event from the same QString later.
@@ -263,7 +333,12 @@ public:
 
     void startHandlingSignal(QQmlBoundSignalExpression *expression)
     {
-        quintptr locationId(id(expression));
+        // Use the QV4::Function as ID, as that is common among different instances of the same
+        // component. QQmlBoundSignalExpression is per instance.
+        // Add 2 to the ID, to make it different from the IDs the V4 and binding profilers produce.
+        // The +2 makes the pointer point into the middle of the QV4::Function. Thus it still points
+        // to valid memory but we cannot accidentally create a duplicate key from another object.
+        quintptr locationId(id(expression->function()) + 2);
         m_data.append(QQmlProfilerData(m_timer.nsecsElapsed(),
                                        (1 << RangeStart | 1 << RangeLocation), HandlingSignal,
                                        locationId));
@@ -308,7 +383,7 @@ public:
 
     void startProfiling(quint64 features);
     void stopProfiling();
-    void reportData(bool trackLocations);
+    void reportData();
     void setTimer(const QElapsedTimer &timer) { m_timer = timer; }
 
 signals:
@@ -375,7 +450,7 @@ struct QQmlCompilingProfiler : public QQmlProfilerHelper {
 struct QQmlVmeProfiler : public QQmlProfilerDefinitions {
 public:
 
-    QQmlVmeProfiler() : profiler(0) {}
+    QQmlVmeProfiler() : profiler(nullptr) {}
 
     void init(QQmlProfiler *p, int maxDepth)
     {
@@ -446,10 +521,15 @@ private:
     QQmlProfiler *profiler;
 };
 
+#endif // QT_CONFIG(qml_debug)
+
 QT_END_NAMESPACE
+
+#if QT_CONFIG(qml_debug)
+
 Q_DECLARE_METATYPE(QVector<QQmlProfilerData>)
 Q_DECLARE_METATYPE(QQmlProfiler::LocationHash)
 
-#endif // QT_NO_QML_DEBUGGER
+#endif // QT_CONFIG(qml_debug)
 
 #endif // QQMLPROFILER_P_H
diff --git a/src/qml/debugger/qqmlprofilerdefinitions_p.h b/src/qml/debugger/qqmlprofilerdefinitions_p.h
index c6ae4593a9..7b972c5d0d 100644
--- a/src/qml/debugger/qqmlprofilerdefinitions_p.h
+++ b/src/qml/debugger/qqmlprofilerdefinitions_p.h
@@ -43,6 +43,8 @@
 #include <private/qtqmlglobal_p.h>
 #include <private/qv4profiling_p.h>
 
+QT_REQUIRE_CONFIG(qml_debug);
+
 //
 //  W A R N I N G
 //  -------------
@@ -56,8 +58,6 @@
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_QML_DEBUGGER
-
 struct QQmlProfilerDefinitions {
     enum Message {
         Event,
@@ -69,6 +69,7 @@ struct QQmlProfilerDefinitions {
         PixmapCacheEvent,
         SceneGraphFrame,
         MemoryAllocation,
+        DebugMessage,
 
         MaximumMessage
     };
@@ -95,11 +96,6 @@ struct QQmlProfilerDefinitions {
         MaximumRangeType
     };
 
-    enum BindingType {
-        QmlBinding,
-        MaximumBindingType
-    };
-
     enum PixmapEventType {
         PixmapSizeKnown,
         PixmapReferenceCountChanged,
@@ -128,8 +124,6 @@ struct QQmlProfilerDefinitions {
         NumGUIThreadFrameTypes = MaximumSceneGraphFrameType - NumRenderThreadFrameTypes
     };
 
-    typedef QV4::Profiling::MemoryType MemoryType;
-
     enum ProfileFeature {
         ProfileJavaScript,
         ProfileMemory,
@@ -163,8 +157,6 @@ struct QQmlProfilerDefinitions {
     };
 };
 
-#endif // QT_NO_QML_DEBUGGER
-
 QT_END_NAMESPACE
 
 #endif
diff --git a/src/qml/doc/images/cpp-qml-integration-flowchart.odg b/src/qml/doc/images/cpp-qml-integration-flowchart.odg
new file mode 100644
index 0000000000..f24021635e
--- /dev/null
+++ b/src/qml/doc/images/cpp-qml-integration-flowchart.odg
diff --git a/src/qml/doc/images/cpp-qml-integration-flowchart.png b/src/qml/doc/images/cpp-qml-integration-flowchart.png
new file mode 100644
index 0000000000..3649ff9e41
--- /dev/null
+++ b/src/qml/doc/images/cpp-qml-integration-flowchart.png
diff --git a/src/qml/doc/images/cppintegration-ex.png b/src/qml/doc/images/cppintegration-ex.png
new file mode 100644
index 0000000000..0b476ccb93
--- /dev/null
+++ b/src/qml/doc/images/cppintegration-ex.png
diff --git a/src/qml/doc/images/visualitemmodel.png b/src/qml/doc/images/objectmodel.png
index 5e6d1325b2..5e6d1325b2 100644
--- a/src/qml/doc/images/visualitemmodel.png
+++ b/src/qml/doc/images/objectmodel.png
diff --git a/src/qml/doc/qtqml.qdocconf b/src/qml/doc/qtqml.qdocconf
index 74b61fd6e1..ba4155c08b 100644
--- a/src/qml/doc/qtqml.qdocconf
+++ b/src/qml/doc/qtqml.qdocconf
@@ -33,7 +33,7 @@ qhp.QtQml.subprojects.qmltypes.sortPages = true
 
 tagfile                 = ../../../doc/qtqml/qtqml.tags
 
-depends += qtcore qtxmlpatterns qtgui qtquick qtdoc qtlinguist qmake qtscript qtwidgets
+depends += qtcore qtgui qtquick qtdoc qtlinguist qmake qtscript qtwidgets qtxmlpatterns qtquickcontrols
 
 headerdirs  += .. \
                ../../imports/models
@@ -53,6 +53,8 @@ manifestmeta.thumbnail.names += "QtQml/Chapter 4*" \
                                 "QtQml/Chapter 6*" \
                                 "QtQml/C++ Extensions: *"
 
+manifestmeta.highlighted.names = "QtQml/Writing QML Extensions with C++"
+
 navigation.landingpage = "Qt QML"
 navigation.cppclassespage = "Qt QML C++ Classes"
 navigation.qmltypespage = "Qt QML QML Types"
diff --git a/src/qml/doc/snippets/code/backend/backend.cpp b/src/qml/doc/snippets/code/backend/backend.cpp
new file mode 100644
index 0000000000..58f5a15e2a
--- /dev/null
+++ b/src/qml/doc/snippets/code/backend/backend.cpp
@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//! [backend_cpp]
+#include "backend.h"
+
+BackEnd::BackEnd(QObject *parent) :
+    QObject(parent)
+{
+}
+
+QString BackEnd::userName()
+{
+    return m_userName;
+}
+
+void BackEnd::setUserName(const QString &userName)
+{
+    if (userName == m_userName)
+        return;
+
+    m_userName = userName;
+    emit userNameChanged();
+}
+//! [backend_cpp]
diff --git a/src/qml/doc/snippets/code/backend/backend.h b/src/qml/doc/snippets/code/backend/backend.h
new file mode 100644
index 0000000000..fa7ce9eb86
--- /dev/null
+++ b/src/qml/doc/snippets/code/backend/backend.h
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//! [backend_header]
+#ifndef BACKEND_H
+#define BACKEND_H
+
+#include <QObject>
+#include <QString>
+
+class BackEnd : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QString userName READ userName WRITE setUserName NOTIFY userNameChanged)
+
+public:
+    explicit BackEnd(QObject *parent = nullptr);
+
+    QString userName();
+    void setUserName(const QString &userName);
+
+signals:
+    void userNameChanged();
+
+private:
+    QString m_userName;
+};
+
+#endif // BACKEND_H
+//! [backend_header]
diff --git a/src/qml/doc/snippets/code/backend/main.cpp b/src/qml/doc/snippets/code/backend/main.cpp
new file mode 100644
index 0000000000..91a012dfda
--- /dev/null
+++ b/src/qml/doc/snippets/code/backend/main.cpp
@@ -0,0 +1,67 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//! [main_cpp]
+#include <QGuiApplication>
+#include <QQmlApplicationEngine>
+
+#include "backend.h"
+
+int main(int argc, char *argv[])
+{
+    QGuiApplication app(argc, argv);
+
+    qmlRegisterType<BackEnd>("io.qt.examples.backend", 1, 0, "BackEnd");
+
+    QQmlApplicationEngine engine;
+    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
+
+    return app.exec();
+}
+//! [main_cpp]
diff --git a/src/qml/doc/snippets/code/backend/main.qml b/src/qml/doc/snippets/code/backend/main.qml
new file mode 100644
index 0000000000..fadc9cd768
--- /dev/null
+++ b/src/qml/doc/snippets/code/backend/main.qml
@@ -0,0 +1,79 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//! [main_qml]
+import QtQuick 2.6
+import QtQuick.Controls 2.0
+//![import]
+import io.qt.examples.backend 1.0
+//![import]
+
+ApplicationWindow {
+    id: root
+    width: 300
+    height: 480
+    visible: true
+
+//![backend]
+    BackEnd {
+        id: backend
+    }
+//![backend]
+
+//![username_input]
+    TextField {
+        text: backend.userName
+        placeholderText: qsTr("User name")
+        anchors.centerIn: parent
+
+        onTextChanged: backend.userName = text
+    }
+//![username_input]
+}
+//! [main_qml]
diff --git a/src/qml/doc/snippets/code/doc_src_qtqml.cpp b/src/qml/doc/snippets/code/doc_src_qtqml.cpp
new file mode 100644
index 0000000000..745e2f8f94
--- /dev/null
+++ b/src/qml/doc/snippets/code/doc_src_qtqml.cpp
@@ -0,0 +1,53 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [0]
+#include <QtQml>
+//! [0]
diff --git a/src/qml/doc/snippets/code/doc_src_qtqml.pro b/src/qml/doc/snippets/code/doc_src_qtqml.pro
new file mode 100644
index 0000000000..48dc3ebf6c
--- /dev/null
+++ b/src/qml/doc/snippets/code/doc_src_qtqml.pro
@@ -0,0 +1,3 @@
+#! [0]
+QT += qml
+#! [0]
diff --git a/src/qml/doc/snippets/code/src_script_qjsengine.cpp b/src/qml/doc/snippets/code/src_script_qjsengine.cpp
index c9bd7dfcd9..6c58fd8a18 100644
--- a/src/qml/doc/snippets/code/src_script_qjsengine.cpp
+++ b/src/qml/doc/snippets/code/src_script_qjsengine.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
@@ -48,7 +58,7 @@ QJSValue three = myEngine.evaluate("1 + 2");
 QJSValue fun = myEngine.evaluate("(function(a, b) { return a + b; })");
 QJSValueList args;
 args << 1 << 2;
-QJSValue threeAgain = fun.call(QJSValue(), args);
+QJSValue threeAgain = fun.call(args);
 //! [1]
 
 
@@ -91,3 +101,36 @@ myEngine.evaluate("button.checkable = true");
 qDebug() << scriptButton.property("checkable").toBool();
 scriptButton.property("show").call(); // call the show() slot
 //! [5]
+
+
+//! [6]
+QJSEngine engine;
+
+QObject *myQObject = new QObject();
+myQObject->setProperty("dynamicProperty", 3);
+
+QJSValue myScriptQObject = engine.newQObject(myQObject);
+engine.globalObject().setProperty("myObject", myScriptQObject);
+
+qDebug() << engine.evaluate("myObject.dynamicProperty").toInt();
+//! [6]
+
+
+//! [7]
+class MyObject : public QObject
+{
+    Q_OBJECT
+
+public:
+    Q_INVOKABLE MyObject() {}
+};
+//! [7]
+
+//! [8]
+QJSValue jsMetaObject = engine.newQMetaObject(&MyObject::staticMetaObject);
+engine.globalObject().setProperty("MyObject", jsMetaObject);
+//! [8]
+
+//! [9]
+engine.evaluate("var myObject = new MyObject()");
+//! [9]
diff --git a/src/qml/doc/snippets/code/src_script_qjsvalue.cpp b/src/qml/doc/snippets/code/src_script_qjsvalue.cpp
index 4068ff9e26..1386ffb760 100644
--- a/src/qml/doc/snippets/code/src_script_qjsvalue.cpp
+++ b/src/qml/doc/snippets/code/src_script_qjsvalue.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/code/src_script_qjsvalueiterator.cpp b/src/qml/doc/snippets/code/src_script_qjsvalueiterator.cpp
index 604efc82ad..3cb43bc327 100644
--- a/src/qml/doc/snippets/code/src_script_qjsvalueiterator.cpp
+++ b/src/qml/doc/snippets/code/src_script_qjsvalueiterator.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/delegatemodel/visualdatamodel.qml b/src/qml/doc/snippets/delegatemodel/delegatemodel.qml
index 438eafeed1..1a7baa6b1e 100644
--- a/src/qml/doc/snippets/delegatemodel/visualdatamodel.qml
+++ b/src/qml/doc/snippets/delegatemodel/delegatemodel.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/delegatemodel/visualdatamodel_rootindex/main.cpp b/src/qml/doc/snippets/delegatemodel/delegatemodel_rootindex/main.cpp
index 25dd48ef2d..a56eb69616 100644
--- a/src/qml/doc/snippets/delegatemodel/visualdatamodel_rootindex/main.cpp
+++ b/src/qml/doc/snippets/delegatemodel/delegatemodel_rootindex/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/delegatemodel/visualdatamodel_rootindex/view.qml b/src/qml/doc/snippets/delegatemodel/delegatemodel_rootindex/view.qml
index 719d16ff7d..2e17eed8f0 100644
--- a/src/qml/doc/snippets/delegatemodel/visualdatamodel_rootindex/view.qml
+++ b/src/qml/doc/snippets/delegatemodel/delegatemodel_rootindex/view.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/delegatemodel/visualdatagroup.qml b/src/qml/doc/snippets/delegatemodel/delegatemodelgroup.qml
index 85ac83ae52..8562deeeda 100644
--- a/src/qml/doc/snippets/delegatemodel/visualdatagroup.qml
+++ b/src/qml/doc/snippets/delegatemodel/delegatemodelgroup.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/package/Delegate.qml b/src/qml/doc/snippets/package/Delegate.qml
index a6b9783a53..7c73f35c3d 100644
--- a/src/qml/doc/snippets/package/Delegate.qml
+++ b/src/qml/doc/snippets/package/Delegate.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/package/view.qml b/src/qml/doc/snippets/package/view.qml
index 70056b617a..311cc3be8e 100644
--- a/src/qml/doc/snippets/package/view.qml
+++ b/src/qml/doc/snippets/package/view.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/Button.qml b/src/qml/doc/snippets/qml/Button.qml
index fcbe902864..964bebb575 100644
--- a/src/qml/doc/snippets/qml/Button.qml
+++ b/src/qml/doc/snippets/qml/Button.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/DynamicText.qml b/src/qml/doc/snippets/qml/DynamicText.qml
index e90c818c02..e8068a7a16 100644
--- a/src/qml/doc/snippets/qml/DynamicText.qml
+++ b/src/qml/doc/snippets/qml/DynamicText.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/SelfDestroyingRect.qml b/src/qml/doc/snippets/qml/SelfDestroyingRect.qml
index 8a51a64b4c..ebbca20a96 100644
--- a/src/qml/doc/snippets/qml/SelfDestroyingRect.qml
+++ b/src/qml/doc/snippets/qml/SelfDestroyingRect.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/Sprite.qml b/src/qml/doc/snippets/qml/Sprite.qml
index 0b83fa589d..60d046c77d 100644
--- a/src/qml/doc/snippets/qml/Sprite.qml
+++ b/src/qml/doc/snippets/qml/Sprite.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/application.qml b/src/qml/doc/snippets/qml/application.qml
index 2b42a7f601..3deccf4a00 100644
--- a/src/qml/doc/snippets/qml/application.qml
+++ b/src/qml/doc/snippets/qml/application.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/comments.qml b/src/qml/doc/snippets/qml/comments.qml
index 566254e1b5..a6a5280d56 100644
--- a/src/qml/doc/snippets/qml/comments.qml
+++ b/src/qml/doc/snippets/qml/comments.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/component.qml b/src/qml/doc/snippets/qml/component.qml
index bcba300b52..ea2ae75fc5 100644
--- a/src/qml/doc/snippets/qml/component.qml
+++ b/src/qml/doc/snippets/qml/component.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/component/MyItem.qml b/src/qml/doc/snippets/qml/component/MyItem.qml
index 5d09fbaa2f..482a2ad833 100644
--- a/src/qml/doc/snippets/qml/component/MyItem.qml
+++ b/src/qml/doc/snippets/qml/component/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/component/main.qml b/src/qml/doc/snippets/qml/component/main.qml
index 11436c2baa..a58e66b2d4 100644
--- a/src/qml/doc/snippets/qml/component/main.qml
+++ b/src/qml/doc/snippets/qml/component/main.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/createComponent-simple.qml b/src/qml/doc/snippets/qml/createComponent-simple.qml
index 1f5d1a6ac8..887890fcfa 100644
--- a/src/qml/doc/snippets/qml/createComponent-simple.qml
+++ b/src/qml/doc/snippets/qml/createComponent-simple.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/createComponent.qml b/src/qml/doc/snippets/qml/createComponent.qml
index 0af198d485..e79835af77 100644
--- a/src/qml/doc/snippets/qml/createComponent.qml
+++ b/src/qml/doc/snippets/qml/createComponent.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/createQmlObject.qml b/src/qml/doc/snippets/qml/createQmlObject.qml
index b12c6c2ea5..8a082a71de 100644
--- a/src/qml/doc/snippets/qml/createQmlObject.qml
+++ b/src/qml/doc/snippets/qml/createQmlObject.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/dynamicObjects-destroy.qml b/src/qml/doc/snippets/qml/dynamicObjects-destroy.qml
index 099e039dc1..fbf5d856f4 100644
--- a/src/qml/doc/snippets/qml/dynamicObjects-destroy.qml
+++ b/src/qml/doc/snippets/qml/dynamicObjects-destroy.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/events.qml b/src/qml/doc/snippets/qml/events.qml
index 19eac2f30d..90bf5d7b3d 100644
--- a/src/qml/doc/snippets/qml/events.qml
+++ b/src/qml/doc/snippets/qml/events.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/chart.qml b/src/qml/doc/snippets/qml/imports/chart.qml
index 204a6fc0d9..6f205b952b 100644
--- a/src/qml/doc/snippets/qml/imports/chart.qml
+++ b/src/qml/doc/snippets/qml/imports/chart.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/installed-module.qml b/src/qml/doc/snippets/qml/imports/installed-module.qml
index 844929239e..b0d0e0bb5d 100644
--- a/src/qml/doc/snippets/qml/imports/installed-module.qml
+++ b/src/qml/doc/snippets/qml/imports/installed-module.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/merged-named-imports.qml b/src/qml/doc/snippets/qml/imports/merged-named-imports.qml
index bede8601e3..8fab0436bd 100644
--- a/src/qml/doc/snippets/qml/imports/merged-named-imports.qml
+++ b/src/qml/doc/snippets/qml/imports/merged-named-imports.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/named-imports.qml b/src/qml/doc/snippets/qml/imports/named-imports.qml
index 784f013177..b4141ba829 100644
--- a/src/qml/doc/snippets/qml/imports/named-imports.qml
+++ b/src/qml/doc/snippets/qml/imports/named-imports.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/network-imports.qml b/src/qml/doc/snippets/qml/imports/network-imports.qml
index e0553096fa..08cd784eb8 100644
--- a/src/qml/doc/snippets/qml/imports/network-imports.qml
+++ b/src/qml/doc/snippets/qml/imports/network-imports.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/qtquick-1.0.qml b/src/qml/doc/snippets/qml/imports/qtquick-1.0.qml
index 3de2f0fc29..26df4de76b 100644
--- a/src/qml/doc/snippets/qml/imports/qtquick-1.0.qml
+++ b/src/qml/doc/snippets/qml/imports/qtquick-1.0.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/imports/timeexample.qml b/src/qml/doc/snippets/qml/imports/timeexample.qml
index 6b50f02c18..bff92e1310 100644
--- a/src/qml/doc/snippets/qml/imports/timeexample.qml
+++ b/src/qml/doc/snippets/qml/imports/timeexample.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/connectjs.qml b/src/qml/doc/snippets/qml/integrating-javascript/connectjs.qml
index 715e832d48..3f50c67aba 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/connectjs.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/connectjs.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
@@ -38,20 +48,19 @@
 **
 ****************************************************************************/
 //![0]
-import QtQuick 2.0
+import QtQuick 2.12
 import "script.js" as MyScript
 
 Item {
     id: item
     width: 200; height: 200
 
-    MouseArea {
-        id: mouseArea
-        anchors.fill: parent
+    TapHandler {
+        id: inputHandler
     }
 
     Component.onCompleted: {
-        mouseArea.clicked.connect(MyScript.jsFunction)
+        inputHandler.tapped.connect(MyScript.jsFunction)
     }
 }
 //![0]
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/includejs/app.qml b/src/qml/doc/snippets/qml/integrating-javascript/includejs/app.qml
index c5a4a74953..e2104f8740 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/includejs/app.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/includejs/app.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
@@ -39,7 +49,7 @@
 ****************************************************************************/
 //![0]
 import QtQuick 2.0
-import "script.js" as MyScript
+import "script.mjs" as MyScript
 
 Item {
     width: 100; height: 100
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/includejs/factorial.js b/src/qml/doc/snippets/qml/integrating-javascript/includejs/factorial.mjs
index 5e1b7d3473..d0a09b68ad 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/includejs/factorial.js
+++ b/src/qml/doc/snippets/qml/integrating-javascript/includejs/factorial.mjs
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
@@ -38,8 +48,8 @@
 **
 ****************************************************************************/
 //![0]
-// factorial.js
-function factorial(a) {
+// factorial.mjs
+export function factorial(a) {
     a = parseInt(a);
     if (a <= 0)
         return 1;
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/includejs/script.js b/src/qml/doc/snippets/qml/integrating-javascript/includejs/script.mjs
index 814e0b444f..ef7688693d 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/includejs/script.js
+++ b/src/qml/doc/snippets/qml/integrating-javascript/includejs/script.mjs
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
@@ -39,7 +49,7 @@
 ****************************************************************************/
 //![0]
 // script.js
-Qt.include("factorial.js")
+import { factorial } from "factorial.mjs"
 
 function showCalculations(value) {
     console.log(
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.cpp b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.cpp
index ed44da8464..d74cc13d04 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.cpp
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.h b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.h
index 50bd53142a..fb9e238512 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.h
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/avatarExample.h
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFive.qml b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFive.qml
index 3ddf413310..5b90336775 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFive.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFive.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.js b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.js
index 46ea091c44..7b1e37b03f 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.js
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.js
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.qml b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.qml
index 8a8dd8a155..92e0805114 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleFour.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleOne.qml b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleOne.qml
index ccbcb310a6..47963bf0b0 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleOne.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleOne.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.js b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.js
index dce7aa4a9b..3700a072ea 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.js
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.js
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.qml b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.qml
index a1ed413e3f..579e17fa20 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleThree.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleTwo.qml b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleTwo.qml
index 8498dbdb46..e222d03c2d 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleTwo.qml
+++ b/src/qml/doc/snippets/qml/integrating-javascript/scarceresources/exampleTwo.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/integrating-javascript/script.js b/src/qml/doc/snippets/qml/integrating-javascript/script.js
index 25e44bc36b..f5843a8bad 100644
--- a/src/qml/doc/snippets/qml/integrating-javascript/script.js
+++ b/src/qml/doc/snippets/qml/integrating-javascript/script.js
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/listmodel/listelements.qml b/src/qml/doc/snippets/qml/listmodel/listelements.qml
index 38e1d1a3c0..12146c1420 100644
--- a/src/qml/doc/snippets/qml/listmodel/listelements.qml
+++ b/src/qml/doc/snippets/qml/listmodel/listelements.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/listmodel/listmodel-modify.qml b/src/qml/doc/snippets/qml/listmodel/listmodel-modify.qml
index 202e1c6209..f293eff8ec 100644
--- a/src/qml/doc/snippets/qml/listmodel/listmodel-modify.qml
+++ b/src/qml/doc/snippets/qml/listmodel/listmodel-modify.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/listmodel/listmodel-nested.qml b/src/qml/doc/snippets/qml/listmodel/listmodel-nested.qml
index 898d496c49..8c193d6a5e 100644
--- a/src/qml/doc/snippets/qml/listmodel/listmodel-nested.qml
+++ b/src/qml/doc/snippets/qml/listmodel/listmodel-nested.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/listmodel/listmodel-simple.qml b/src/qml/doc/snippets/qml/listmodel/listmodel-simple.qml
index f1d9ebe120..d07f868476 100644
--- a/src/qml/doc/snippets/qml/listmodel/listmodel-simple.qml
+++ b/src/qml/doc/snippets/qml/listmodel/listmodel-simple.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/listmodel/listmodel.qml b/src/qml/doc/snippets/qml/listmodel/listmodel.qml
index 7e9ec987bd..c2a69d6e8f 100644
--- a/src/qml/doc/snippets/qml/listmodel/listmodel.qml
+++ b/src/qml/doc/snippets/qml/listmodel/listmodel.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/properties.qml b/src/qml/doc/snippets/qml/properties.qml
index 69e5628d8f..e924ba5439 100644
--- a/src/qml/doc/snippets/qml/properties.qml
+++ b/src/qml/doc/snippets/qml/properties.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qml-documents/inline-component.qml b/src/qml/doc/snippets/qml/qml-documents/inline-component.qml
index 2a577317e1..0b0429511f 100644
--- a/src/qml/doc/snippets/qml/qml-documents/inline-component.qml
+++ b/src/qml/doc/snippets/qml/qml-documents/inline-component.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qml-documents/inline-text-component.qml b/src/qml/doc/snippets/qml/qml-documents/inline-text-component.qml
index 9b43ae3e59..9885705308 100644
--- a/src/qml/doc/snippets/qml/qml-documents/inline-text-component.qml
+++ b/src/qml/doc/snippets/qml/qml-documents/inline-text-component.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qml-documents/non-trivial.qml b/src/qml/doc/snippets/qml/qml-documents/non-trivial.qml
index 58fe0cf1ac..fd942bf655 100644
--- a/src/qml/doc/snippets/qml/qml-documents/non-trivial.qml
+++ b/src/qml/doc/snippets/qml/qml-documents/non-trivial.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qml-documents/qmldocuments.qml b/src/qml/doc/snippets/qml/qml-documents/qmldocuments.qml
index 02de077c1f..de1106feac 100644
--- a/src/qml/doc/snippets/qml/qml-documents/qmldocuments.qml
+++ b/src/qml/doc/snippets/qml/qml-documents/qmldocuments.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qsTr.qml b/src/qml/doc/snippets/qml/qsTr.qml
index 8298eb0ef5..da0e35199f 100644
--- a/src/qml/doc/snippets/qml/qsTr.qml
+++ b/src/qml/doc/snippets/qml/qsTr.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qsTrId.1.qml b/src/qml/doc/snippets/qml/qsTrId.1.qml
index cffe0c0d2d..44298cb6c6 100644
--- a/src/qml/doc/snippets/qml/qsTrId.1.qml
+++ b/src/qml/doc/snippets/qml/qsTrId.1.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qsTrId.qml b/src/qml/doc/snippets/qml/qsTrId.qml
index 11939f34c2..1f62c9176a 100644
--- a/src/qml/doc/snippets/qml/qsTrId.qml
+++ b/src/qml/doc/snippets/qml/qsTrId.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qsTranslate.qml b/src/qml/doc/snippets/qml/qsTranslate.qml
index 061b4e3210..bfcf496d82 100644
--- a/src/qml/doc/snippets/qml/qsTranslate.qml
+++ b/src/qml/doc/snippets/qml/qsTranslate.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtBinding.1.qml b/src/qml/doc/snippets/qml/qtBinding.1.qml
index f9bc0e08f7..b6327ec700 100644
--- a/src/qml/doc/snippets/qml/qtBinding.1.qml
+++ b/src/qml/doc/snippets/qml/qtBinding.1.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtBinding.2.qml b/src/qml/doc/snippets/qml/qtBinding.2.qml
index 6159b31748..3d5e8b57d5 100644
--- a/src/qml/doc/snippets/qml/qtBinding.2.qml
+++ b/src/qml/doc/snippets/qml/qtBinding.2.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtBinding.3.qml b/src/qml/doc/snippets/qml/qtBinding.3.qml
index dc5b74a897..23e04ef21d 100644
--- a/src/qml/doc/snippets/qml/qtBinding.3.qml
+++ b/src/qml/doc/snippets/qml/qtBinding.3.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtBinding.4.qml b/src/qml/doc/snippets/qml/qtBinding.4.qml
index 12a082ba69..1c81631f05 100644
--- a/src/qml/doc/snippets/qml/qtBinding.4.qml
+++ b/src/qml/doc/snippets/qml/qtBinding.4.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtLater.qml b/src/qml/doc/snippets/qml/qtLater.qml
index e2bc02edb4..035929f874 100644
--- a/src/qml/doc/snippets/qml/qtLater.qml
+++ b/src/qml/doc/snippets/qml/qtLater.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtTrIdNoOp.qml b/src/qml/doc/snippets/qml/qtTrIdNoOp.qml
index 55d073dbd0..9411385ecd 100644
--- a/src/qml/doc/snippets/qml/qtTrIdNoOp.qml
+++ b/src/qml/doc/snippets/qml/qtTrIdNoOp.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtTrNoOp.qml b/src/qml/doc/snippets/qml/qtTrNoOp.qml
index 38c339c8d4..fba1a50ecb 100644
--- a/src/qml/doc/snippets/qml/qtTrNoOp.qml
+++ b/src/qml/doc/snippets/qml/qtTrNoOp.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtTranslateNoOp.qml b/src/qml/doc/snippets/qml/qtTranslateNoOp.qml
index eb998a093a..fd840eb462 100644
--- a/src/qml/doc/snippets/qml/qtTranslateNoOp.qml
+++ b/src/qml/doc/snippets/qml/qtTranslateNoOp.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/context-advanced/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/context-advanced/MyItem.qml
index 8cae690fa3..38e5eeb1bc 100644
--- a/src/qml/doc/snippets/qml/qtbinding/context-advanced/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/context-advanced/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/context-advanced/applicationdata.h b/src/qml/doc/snippets/qml/qtbinding/context-advanced/applicationdata.h
index 6bf3c27e76..c5973afafc 100644
--- a/src/qml/doc/snippets/qml/qtbinding/context-advanced/applicationdata.h
+++ b/src/qml/doc/snippets/qml/qtbinding/context-advanced/applicationdata.h
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/context-advanced/connections.qml b/src/qml/doc/snippets/qml/qtbinding/context-advanced/connections.qml
index adbfaf75ee..60adf6bc14 100644
--- a/src/qml/doc/snippets/qml/qtbinding/context-advanced/connections.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/context-advanced/connections.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/context-advanced/main.cpp b/src/qml/doc/snippets/qml/qtbinding/context-advanced/main.cpp
index c32cd2b3db..e44bcb37ac 100644
--- a/src/qml/doc/snippets/qml/qtbinding/context-advanced/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/context-advanced/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/context/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/context/MyItem.qml
index e8cccf4db1..b78ef6ee60 100644
--- a/src/qml/doc/snippets/qml/qtbinding/context/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/context/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/context/main.cpp b/src/qml/doc/snippets/qml/qtbinding/context/main.cpp
index 0a300e36ab..d8f7515bb3 100644
--- a/src/qml/doc/snippets/qml/qtbinding/context/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/context/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/functions-qml/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/functions-qml/MyItem.qml
index 5fa6838c10..073a5dc361 100644
--- a/src/qml/doc/snippets/qml/qtbinding/functions-qml/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/functions-qml/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/functions-qml/main.cpp b/src/qml/doc/snippets/qml/qtbinding/functions-qml/main.cpp
index 760b648f28..c82f71f749 100644
--- a/src/qml/doc/snippets/qml/qtbinding/functions-qml/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/functions-qml/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/loading/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/loading/MyItem.qml
index ee86938136..c9f7b60144 100644
--- a/src/qml/doc/snippets/qml/qtbinding/loading/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/loading/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/loading/main.cpp b/src/qml/doc/snippets/qml/qtbinding/loading/main.cpp
index a2048d9bfd..1df6905278 100644
--- a/src/qml/doc/snippets/qml/qtbinding/loading/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/loading/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/properties-qml/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/properties-qml/MyItem.qml
index c7371cd456..0bf0c9dddf 100644
--- a/src/qml/doc/snippets/qml/qtbinding/properties-qml/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/properties-qml/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/properties-qml/main.cpp b/src/qml/doc/snippets/qml/qtbinding/properties-qml/main.cpp
index 87857f31d1..d55eb7e436 100644
--- a/src/qml/doc/snippets/qml/qtbinding/properties-qml/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/properties-qml/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/resources/example.qdoc b/src/qml/doc/snippets/qml/qtbinding/resources/example.qdoc
index 8f6633cffe..b26ad10b94 100644
--- a/src/qml/doc/snippets/qml/qtbinding/resources/example.qdoc
+++ b/src/qml/doc/snippets/qml/qtbinding/resources/example.qdoc
@@ -1,39 +1,26 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
-** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
-**
-** "Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions are
-** met:
-**   * Redistributions of source code must retain the above copyright
-**     notice, this list of conditions and the following disclaimer.
-**   * Redistributions in binary form must reproduce the above copyright
-**     notice, this list of conditions and the following disclaimer in
-**     the documentation and/or other materials provided with the
-**     distribution.
-**   * Neither the name of The Qt Company Ltd nor the names of its
-**     contributors may be used to endorse or promote products derived
-**     from this software without specific prior written permission.
-**
-**
-** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
-**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/snippets/qml/qtbinding/signals-qml/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/signals-qml/MyItem.qml
index 2532660a0f..eebf2db832 100644
--- a/src/qml/doc/snippets/qml/qtbinding/signals-qml/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/signals-qml/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/signals-qml/main.cpp b/src/qml/doc/snippets/qml/qtbinding/signals-qml/main.cpp
index b0c7607872..cd4e538963 100644
--- a/src/qml/doc/snippets/qml/qtbinding/signals-qml/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/signals-qml/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/signals-qml/myclass.h b/src/qml/doc/snippets/qml/qtbinding/signals-qml/myclass.h
index c7246aee40..f584b5b792 100644
--- a/src/qml/doc/snippets/qml/qtbinding/signals-qml/myclass.h
+++ b/src/qml/doc/snippets/qml/qtbinding/signals-qml/myclass.h
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/variantlistmap/MyItem.qml b/src/qml/doc/snippets/qml/qtbinding/variantlistmap/MyItem.qml
index fc28a30490..b0f910af17 100644
--- a/src/qml/doc/snippets/qml/qtbinding/variantlistmap/MyItem.qml
+++ b/src/qml/doc/snippets/qml/qtbinding/variantlistmap/MyItem.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtbinding/variantlistmap/main.cpp b/src/qml/doc/snippets/qml/qtbinding/variantlistmap/main.cpp
index 0978f238a2..ddd2c71a96 100644
--- a/src/qml/doc/snippets/qml/qtbinding/variantlistmap/main.cpp
+++ b/src/qml/doc/snippets/qml/qtbinding/variantlistmap/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/qtobject.qml b/src/qml/doc/snippets/qml/qtobject.qml
index 98b19a0e15..9f342e41cd 100644
--- a/src/qml/doc/snippets/qml/qtobject.qml
+++ b/src/qml/doc/snippets/qml/qtobject.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/reusablecomponents/Button.qml b/src/qml/doc/snippets/qml/reusablecomponents/Button.qml
index 2bd454f122..1142b8abf3 100644
--- a/src/qml/doc/snippets/qml/reusablecomponents/Button.qml
+++ b/src/qml/doc/snippets/qml/reusablecomponents/Button.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/reusablecomponents/application.qml b/src/qml/doc/snippets/qml/reusablecomponents/application.qml
index b90b42fea7..507080d056 100644
--- a/src/qml/doc/snippets/qml/reusablecomponents/application.qml
+++ b/src/qml/doc/snippets/qml/reusablecomponents/application.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/reusablecomponents/component.qml b/src/qml/doc/snippets/qml/reusablecomponents/component.qml
index 2d5e0bf292..a2bd0cf01b 100644
--- a/src/qml/doc/snippets/qml/reusablecomponents/component.qml
+++ b/src/qml/doc/snippets/qml/reusablecomponents/component.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/reusablecomponents/focusbutton.qml b/src/qml/doc/snippets/qml/reusablecomponents/focusbutton.qml
index bdb1746bb8..f6903a6c09 100644
--- a/src/qml/doc/snippets/qml/reusablecomponents/focusbutton.qml
+++ b/src/qml/doc/snippets/qml/reusablecomponents/focusbutton.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/Button.qml b/src/qml/doc/snippets/qml/statemachine/Button.qml
index 3f57e6e796..38d13475a9 100644
--- a/src/qml/doc/snippets/qml/statemachine/Button.qml
+++ b/src/qml/doc/snippets/qml/statemachine/Button.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/basicstate.qml b/src/qml/doc/snippets/qml/statemachine/basicstate.qml
index e61898c77b..d8da3f939d 100644
--- a/src/qml/doc/snippets/qml/statemachine/basicstate.qml
+++ b/src/qml/doc/snippets/qml/statemachine/basicstate.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/finalstate.qml b/src/qml/doc/snippets/qml/statemachine/finalstate.qml
index 3441b6095e..984daadf36 100644
--- a/src/qml/doc/snippets/qml/statemachine/finalstate.qml
+++ b/src/qml/doc/snippets/qml/statemachine/finalstate.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/guardcondition.qml b/src/qml/doc/snippets/qml/statemachine/guardcondition.qml
index f5c4873b63..8388b96c21 100644
--- a/src/qml/doc/snippets/qml/statemachine/guardcondition.qml
+++ b/src/qml/doc/snippets/qml/statemachine/guardcondition.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/historystate.qml b/src/qml/doc/snippets/qml/statemachine/historystate.qml
index f93d948a36..28e4e06756 100644
--- a/src/qml/doc/snippets/qml/statemachine/historystate.qml
+++ b/src/qml/doc/snippets/qml/statemachine/historystate.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/signaltransition.qml b/src/qml/doc/snippets/qml/statemachine/signaltransition.qml
index 9712060997..925d728ed7 100644
--- a/src/qml/doc/snippets/qml/statemachine/signaltransition.qml
+++ b/src/qml/doc/snippets/qml/statemachine/signaltransition.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/signaltransitionsignal.qml b/src/qml/doc/snippets/qml/statemachine/signaltransitionsignal.qml
index 2893d15b9e..d5510cb44d 100644
--- a/src/qml/doc/snippets/qml/statemachine/signaltransitionsignal.qml
+++ b/src/qml/doc/snippets/qml/statemachine/signaltransitionsignal.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/simplestatemachine.qml b/src/qml/doc/snippets/qml/statemachine/simplestatemachine.qml
index e3a4e90a68..fc1768f4a0 100644
--- a/src/qml/doc/snippets/qml/statemachine/simplestatemachine.qml
+++ b/src/qml/doc/snippets/qml/statemachine/simplestatemachine.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/statemachine-button-history.qml b/src/qml/doc/snippets/qml/statemachine/statemachine-button-history.qml
index 4d7f417333..b6cd325c03 100644
--- a/src/qml/doc/snippets/qml/statemachine/statemachine-button-history.qml
+++ b/src/qml/doc/snippets/qml/statemachine/statemachine-button-history.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested-ignore-quit.qml b/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested-ignore-quit.qml
index 8f34ebd1c1..77cf253b73 100644
--- a/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested-ignore-quit.qml
+++ b/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested-ignore-quit.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested.qml b/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested.qml
index 0a0946b103..19ab69315b 100644
--- a/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested.qml
+++ b/src/qml/doc/snippets/qml/statemachine/statemachine-button-nested.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/statemachine-button.qml b/src/qml/doc/snippets/qml/statemachine/statemachine-button.qml
index 5c38586e23..8fcbe6195f 100644
--- a/src/qml/doc/snippets/qml/statemachine/statemachine-button.qml
+++ b/src/qml/doc/snippets/qml/statemachine/statemachine-button.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/statemachine/timeouttransition.qml b/src/qml/doc/snippets/qml/statemachine/timeouttransition.qml
index a554e35175..b629e84941 100644
--- a/src/qml/doc/snippets/qml/statemachine/timeouttransition.qml
+++ b/src/qml/doc/snippets/qml/statemachine/timeouttransition.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 Ford Motor Company
-** Contact: http://www.qt.io/licensing/
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qml/tablemodel/fruit-example-delegatechooser.qml b/src/qml/doc/snippets/qml/tablemodel/fruit-example-delegatechooser.qml
new file mode 100644
index 0000000000..3d44f61668
--- /dev/null
+++ b/src/qml/doc/snippets/qml/tablemodel/fruit-example-delegatechooser.qml
@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//![file]
+import QtQuick 2.12
+import QtQuick.Controls 2.5
+import Qt.labs.qmlmodels 1.0
+
+ApplicationWindow {
+    width: 400
+    height: 400
+    visible: true
+
+    TableView {
+        anchors.fill: parent
+        columnSpacing: 1
+        rowSpacing: 1
+        boundsBehavior: Flickable.StopAtBounds
+
+        model: TableModel {
+            // Each row is one type of fruit that can be ordered
+//![rows]
+            rows: [
+                [
+                    // Each object (line) is one cell/column,
+                    // and each property in that object is a role.
+                    { checked: false, checkable: true },
+                    { amount: 1 },
+                    { fruitType: "Apple" },
+                    { fruitName: "Granny Smith" },
+                    { fruitPrice: 1.50 }
+                ],
+                [
+                    { checked: true, checkable: true },
+                    { amount: 4 },
+                    { fruitType: "Orange" },
+                    { fruitName: "Navel" },
+                    { fruitPrice: 2.50 }
+                ],
+                [
+                    { checked: false, checkable: true },
+                    { amount: 1 },
+                    { fruitType: "Banana" },
+                    { fruitName: "Cavendish" },
+                    { fruitPrice: 3.50 }
+                ]
+            ]
+//![rows]
+        }
+//![delegate]
+        delegate: DelegateChooser {
+            DelegateChoice {
+                column: 0
+                delegate: CheckBox {
+                    checked: model.checked
+                    onToggled: model.checked = checked
+                }
+            }
+            DelegateChoice {
+                column: 1
+                delegate: SpinBox {
+                    value: model.amount
+                    onValueModified: model.amount = value
+                }
+            }
+            DelegateChoice {
+                delegate: TextField {
+                    text: model.display
+                    selectByMouse: true
+                    implicitWidth: 140
+                    onAccepted: model.display = text
+                }
+            }
+        }
+//![delegate]
+    }
+}
+//![file]
diff --git a/src/qml/doc/snippets/qml/tablemodel/fruit-example-simpledelegate.qml b/src/qml/doc/snippets/qml/tablemodel/fruit-example-simpledelegate.qml
new file mode 100644
index 0000000000..5f00eb484b
--- /dev/null
+++ b/src/qml/doc/snippets/qml/tablemodel/fruit-example-simpledelegate.qml
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//![file]
+import QtQuick 2.12
+import QtQuick.Window 2.12
+import Qt.labs.qmlmodels 1.0
+
+Window {
+    width: 400
+    height: 400
+    visible: true
+
+    TableView {
+        anchors.fill: parent
+        columnSpacing: 1
+        rowSpacing: 1
+        boundsBehavior: Flickable.StopAtBounds
+
+        model: TableModel {
+            // Each row is one type of fruit that can be ordered
+//![rows]
+            rows: [
+                [
+                    // Each object (line) is one cell/column,
+                    // and each property in that object is a role.
+                    { checked: false, checkable: true },
+                    { amount: 1 },
+                    { fruitType: "Apple" },
+                    { fruitName: "Granny Smith" },
+                    { fruitPrice: 1.50 }
+                ],
+                [
+                    { checked: true, checkable: true },
+                    { amount: 4 },
+                    { fruitType: "Orange" },
+                    { fruitName: "Navel" },
+                    { fruitPrice: 2.50 }
+                ],
+                [
+                    { checked: false, checkable: true },
+                    { amount: 1 },
+                    { fruitType: "Banana" },
+                    { fruitName: "Cavendish" },
+                    { fruitPrice: 3.50 }
+                ]
+            ]
+//![rows]
+        }
+//![delegate]
+        delegate:  TextInput {
+            text: model.display
+            padding: 12
+            selectByMouse: true
+
+            // TODO: the property used here is undefined
+            onAccepted: model.display = text
+
+            Rectangle {
+                anchors.fill: parent
+                color: "#efefef"
+                z: -1
+            }
+        }
+//![delegate]
+    }
+}
+//![file]
diff --git a/src/qml/doc/snippets/qml/tablemodel/roleDataProvider.qml b/src/qml/doc/snippets/qml/tablemodel/roleDataProvider.qml
new file mode 100644
index 0000000000..63978a370d
--- /dev/null
+++ b/src/qml/doc/snippets/qml/tablemodel/roleDataProvider.qml
@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//![0]
+import QtQuick 2.12
+import Qt.labs.qmlmodels 1.0
+
+TableView {
+    columnSpacing: 1; rowSpacing: 1
+    model:  TableModel {
+        property real taxPercent: 10
+        rows: [
+            [{ fruitType: "Apple" }, { fruitPrice: 1.50 }],
+            [{ fruitType: "Orange" }, { fruitPrice: 2.50 }]
+        ]
+        roleDataProvider: function(index, role, cellData) {
+            if (role === "display") {
+                if (cellData.hasOwnProperty("fruitPrice")) {
+                    console.log("row", index.row, "taxing your fruit", JSON.stringify(cellData))
+                    return (cellData.fruitPrice * (1 + taxPercent / 100)).toFixed(2);
+                }
+                else if (cellData.hasOwnProperty("fruitType"))
+                    return cellData.fruitType;
+            }
+            return cellData;
+        }
+    }
+    delegate: Rectangle {
+        implicitWidth: 150; implicitHeight: 30
+        color: "lightsteelblue"
+        Text {
+            x: 6; anchors.verticalCenter: parent.verticalCenter
+            text: display
+        }
+    }
+}
+//![0]
diff --git a/src/qml/doc/snippets/qml/workerscript/script.js b/src/qml/doc/snippets/qml/workerscript/script.mjs
index f55dee3507..f55dee3507 100644
--- a/src/qml/doc/snippets/qml/workerscript/script.js
+++ b/src/qml/doc/snippets/qml/workerscript/script.mjs
diff --git a/src/qml/doc/snippets/qml/workerscript/workerscript.qml b/src/qml/doc/snippets/qml/workerscript/workerscript.qml
index a00431f98b..cc637d34cf 100644
--- a/src/qml/doc/snippets/qml/workerscript/workerscript.qml
+++ b/src/qml/doc/snippets/qml/workerscript/workerscript.qml
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
@@ -51,7 +61,7 @@ Rectangle {
 
     WorkerScript {
         id: myWorker
-        source: "script.js"
+        source: "script.mjs"
 
         onMessage: myText.text = messageObject.reply
     }
diff --git a/src/qml/doc/snippets/qtjavascript/evaluation/main.cpp b/src/qml/doc/snippets/qtjavascript/evaluation/main.cpp
index 1d46db7f20..5ff0e5dbbd 100644
--- a/src/qml/doc/snippets/qtjavascript/evaluation/main.cpp
+++ b/src/qml/doc/snippets/qtjavascript/evaluation/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qtjavascript/registeringobjects/main.cpp b/src/qml/doc/snippets/qtjavascript/registeringobjects/main.cpp
index 80ff1aa315..5c2acb2812 100644
--- a/src/qml/doc/snippets/qtjavascript/registeringobjects/main.cpp
+++ b/src/qml/doc/snippets/qtjavascript/registeringobjects/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/snippets/qtjavascript/registeringvalues/main.cpp b/src/qml/doc/snippets/qtjavascript/registeringvalues/main.cpp
index 001f71e956..ceaca5f752 100644
--- a/src/qml/doc/snippets/qtjavascript/registeringvalues/main.cpp
+++ b/src/qml/doc/snippets/qtjavascript/registeringvalues/main.cpp
@@ -1,12 +1,22 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
-** You may use this file under the terms of the BSD license as follows:
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
diff --git a/src/qml/doc/src/cppclasses/topic.qdoc b/src/qml/doc/src/cppclasses/topic.qdoc
index 133f9bc72c..6b23dfd433 100644
--- a/src/qml/doc/src/cppclasses/topic.qdoc
+++ b/src/qml/doc/src/cppclasses/topic.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/cppintegration/contextproperties.qdoc b/src/qml/doc/src/cppintegration/contextproperties.qdoc
index 83f49bdcf0..869e01c69e 100644
--- a/src/qml/doc/src/cppintegration/contextproperties.qdoc
+++ b/src/qml/doc/src/cppintegration/contextproperties.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/cppintegration/data.qdoc b/src/qml/doc/src/cppintegration/data.qdoc
index 9cc7291583..171b2b6a11 100644
--- a/src/qml/doc/src/cppintegration/data.qdoc
+++ b/src/qml/doc/src/cppintegration/data.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -91,7 +91,7 @@ when passed from C++ to QML and vice-versa:
         \li QFont
         \li \l font
     \row
-        \li QDate
+        \li QDateTime
         \li \l date
     \row
         \li QPoint, QPointF
@@ -174,7 +174,6 @@ function, passing a QVariantList and a QVariantMap, which are automatically
 converted to JavaScript array and object values, repectively:
 
 \table
-\header
 \row
 \li QML
 \li \snippet qml/qtbinding/variantlistmap/MyItem.qml 0
@@ -213,7 +212,6 @@ a \c Date object that is automatically converted into a QDateTime value when it
 is received in C++:
 
 \table
-\header
 \row
 \li QML
 \li
@@ -249,23 +247,23 @@ Similarly, if a C++ type uses a QDateTime for a property type or method
 parameter, the value can be created as a JavaScript \c Date object in QML, and
 is automatically converted to a QDateTime value when it is passed to C++.
 
-
-\section2 QTime to JavaScript Date
+//! Target adds an anchor, so renaming the section won't break incoming links.
+\target QTime to JavaScript Date
+\section2 QTime and JavaScript Date
 
 The QML engine provides automatic type conversion from QTime values to
-JavaScript \c Date objects. The date component of the resulting Date
-object should not be relied upon, as it is operating system dependent.
-Specifically, the year (and month and day) are set to zero. Conversion
-from a JavaScript \c Date object to QTime is done by converting to a
-QDateTime, and then relying on QVariant to convert it to a QTime. The end
-effect is that the date part of the \c Date object is ignored, but the
-local timezone will be used ignoring any DST complications it may have.
+JavaScript \c Date objects. As QTime values do not contain a date component,
+one is created for the conversion only. Thus, you should not rely on the date
+component of the resulting Date object.
 
+Under the hood, conversion from a JavaScript \c Date object to QTime is done by
+converting to a QDateTime object and calling its \l {QDateTime::}{time()}
+method.
 
 \section2 Sequence Type to JavaScript Array
 
-Certain C++ sequence types are supported transparently in QML as JavaScript
-\c Array types.
+Certain C++ sequence types are supported transparently in QML to behave like
+JavaScript \c Array types.
 
 In particular, QML currently supports:
 \list
@@ -286,6 +284,9 @@ In particular, QML currently supports:
   \li \c {std::vector<bool>}
 \endlist
 
+and all registered QList, QVector, QQueue, QStack, QSet, QLinkedList, std::list,
+std::vector that contain a type marked with \l Q_DECLARE_METATYPE.
+
 These sequence types are implemented directly in terms of the underlying C++
 sequence. There are two ways in which such sequences can be exposed to QML:
 as a Q_PROPERTY of the given sequence type; or as the return type of a
@@ -347,7 +348,12 @@ them with default constructed values, do not use the indexed delete operator
 ("delete sequence[i]") but instead use the \c {splice} function
 ("sequence.splice(startIndex, deleteCount)").
 
-\section2 Value types
+\section2 QByteArray to JavaScript ArrayBuffer
+
+The QML engine provides automatic type conversion between QByteArray values and
+JavaScript \c ArrayBuffer objects.
+
+\section2 Value Types
 
 Some value types in Qt such as QPoint are represented in JavaScript as objects
 that have the same properties and functions like in the C++ API. The same
@@ -370,7 +376,7 @@ properties:
 
  private:
      QString m_name;
- }
+ };
 
  Q_DECLARE_METATYPE(Actor)
 \endcode
@@ -417,6 +423,47 @@ To use an enum as a \l {QFlags}{flags} type in QML, see \l Q_FLAG().
 \note The names of enum values must begin with a capital letter in order to
 be accessible from QML.
 
+\code
+...
+enum class Status {
+          Ready,
+          Loading,
+          Error
+}
+Q_ENUM(Status)
+...
+\endcode
+
+Enum classes are registered in QML as scoped and unscoped properties.
+The \c Ready value will be registered at \c Message.Status.Ready and \c Message.Ready .
+
+When using enum classes, there can be multiple enums using the same identifiers.
+The unscoped registration will be overwriten by the last registered enum. For classes
+that contain such name conficts it is possible to disable the unscoped registration by
+annotating your class with a special Q_CLASSINFO macro.
+Use the name \c RegisterEnumClassesUnscoped with the value \c false to prevent scoped
+enums from being merged into the same name space.
+
+\code
+class Message : public QObject
+    {
+        Q_OBJECT
+        Q_CLASSINFO("RegisterEnumClassesUnscoped", "false")
+        Q_ENUM(ScopedEnum)
+        Q_ENUM(OtherValue)
+
+    public:
+        enum class ScopedEnum {
+              Value1,
+              Value2,
+              OtherValue
+        };
+        enum class OtherValue {
+              Value1,
+              Value2
+        };
+    };
+\endcode
 
 \section2 Enumeration Types as Signal and Method Parameters
 
diff --git a/src/qml/doc/src/cppintegration/definetypes.qdoc b/src/qml/doc/src/cppintegration/definetypes.qdoc
index 32084bd308..f6f630c749 100644
--- a/src/qml/doc/src/cppintegration/definetypes.qdoc
+++ b/src/qml/doc/src/cppintegration/definetypes.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -66,6 +66,8 @@ this manner, but the type cannot be used instantiated as a QML object type
 from QML. This is useful, for example, if a type has enums that should be
 exposed to QML but the type itself should not be instantiable.
 
+For a quick guide to choosing the correct approach to expose C++ types to QML,
+see \l {Choosing the Correct Integration Method Between C++ and QML}.
 
 \section2 Registering an Instantiable Object Type
 
@@ -297,6 +299,8 @@ qmlRegisterRevision<BaseType,1>("MyTypes", 1, 1);
 This is useful when deriving from base classes provided by other authors,
 e.g. when extending classes from the Qt Quick module.
 
+\note The QML engine does not support revisions for properties or signals of
+grouped and attached property objects.
 
 \section2 Registering Extension Objects
 
@@ -346,8 +350,8 @@ demonstrates a usage of extension objects.
 
 \section1 Defining QML-Specific Types and Attributes
 
-
-\section2 Providing Attached Objects for Data Annotations
+\section2 Providing Attached Properties
+\keyword Integrating QML and C++ - Attached Properties
 
 In the QML language syntax, there is a notion of \l{Attached properties and
 attached signal handlers}{\e {attached properties} and \e {attached signal
@@ -606,7 +610,6 @@ public:
     RandomNumberGenerator(QObject *parent)
         : QObject(parent), m_maxValue(100)
     {
-        qsrand(QDateTime::currentMSecsSinceEpoch() / 1000);
         QObject::connect(&m_timer, SIGNAL(timeout()), SLOT(updateProperty()));
         m_timer.start(500);
     }
@@ -621,7 +624,7 @@ signals:
 
 private slots:
     void updateProperty() {
-        m_targetProperty.write(qrand() % m_maxValue);
+        m_targetProperty.write(QRandomGenerator::global()->bounded(m_maxValue));
     }
 
 private:
@@ -690,7 +693,7 @@ public:
     QQmlListProperty<Message> messages();
 
 private:
-    QList<Message *> messages;
+    QList<Message *> m_messages;
 };
 \endcode
 
diff --git a/src/qml/doc/src/cppintegration/exposecppattributes.qdoc b/src/qml/doc/src/cppintegration/exposecppattributes.qdoc
index c4c58c2821..52534b4a62 100644
--- a/src/qml/doc/src/cppintegration/exposecppattributes.qdoc
+++ b/src/qml/doc/src/cppintegration/exposecppattributes.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -255,9 +255,6 @@ type, and so cannot provide the necessary QML property characteristics
 through the Qt meta object system, such as signal notifications when a list
 is modified.
 
-QQmlListProperty is a template class that can be conveniently constructed from
-a QList value.
-
 For example, the \c MessageBoard class below has a \c messages property of
 type QQmlListProperty that stores a list of \c Message instances:
 
@@ -301,6 +298,7 @@ Note that the template class type for the QQmlListProperty — in this case,
 
 
 \section2 Grouped Properties
+\keyword Integrating QML and C++ - Grouped Properties
 
 Any read-only object-type property is accessible from QML code as a
 \e {grouped property}. This can be used to expose a group of related
diff --git a/src/qml/doc/src/cppintegration/extending-tutorial.qdoc b/src/qml/doc/src/cppintegration/extending-tutorial.qdoc
index 58cc650e01..26556644d6 100644
--- a/src/qml/doc/src/cppintegration/extending-tutorial.qdoc
+++ b/src/qml/doc/src/cppintegration/extending-tutorial.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -150,6 +150,10 @@ Now we can build and run the application:
       cannot update the binding if the \c name value changes. This is addressed in
       the following chapters.
 
+The source code from the following files are referred to in this chapter:
+\noautolist
+\generatelist examplefiles .*chapter1.*
+
 \section1 Chapter 2: Connecting to C++ Methods and Signals
 \c extending-qml/chapter2-methods
 
@@ -189,6 +193,9 @@ disappears, and the application outputs:
     qml: The chart has been cleared
 \endcode
 
+The source code from the following files are referred to in this chapter:
+\generatelist examplefiles .*chapter2.*
+
 \section1 Chapter 3: Adding Property Bindings
 \c extending-qml/chapter3-bindings
 
@@ -237,6 +244,9 @@ automatically updated and cannot be used as flexibly in QML. Also, since
 bindings are invoked so often and relied upon in QML usage, users of your
 custom QML types may see unexpected behavior if bindings are not implemented.
 
+The source code from the following files are referred to in this chapter:
+\generatelist examplefiles .*chapter3.*
+
 \section1 Chapter 4: Using Custom Property Types
 
 \c extending-qml/chapter4-customPropertyTypes
@@ -314,6 +324,9 @@ type to the "Charts" type namespace, version 1.0:
 \dots
 \snippet tutorials/extending-qml/chapter4-customPropertyTypes/main.cpp 2
 
+The source code from the following files are referred to in this chapter:
+\generatelist examplefiles .*chapter4.*
+
 \section1 Chapter 5: Using List Property Types
 \c extending-qml/chapter5-listproperties
 
@@ -356,6 +369,9 @@ The \c PieSlice class has also been modified to include \c fromAngle and \c angl
 properties and to draw the slice according to these values. This is a straightforward
 modification if you have read the previous pages in this tutorial, so the code is not shown here.
 
+The source code from the following files are referred to in this chapter:
+\generatelist examplefiles .*chapter5.*
+
 \section1 Chapter 6: Writing an Extension Plugin
 
 \c extending-qml/chapter6-plugins
@@ -429,6 +445,9 @@ import path to the current directory so that it finds the \c qmldir file:
 The module "Charts" will be loaded by the QML engine, and the types provided by that
 module will be available for use in any QML document which imports it.
 
+The source code from the following files are referred to in this chapter:
+\generatelist examplefiles .*chapter6.*
+
 \section1 Chapter 7: Summary
 
 In this tutorial, we've shown the basic steps for creating a QML extension:
diff --git a/src/qml/doc/src/cppintegration/interactqmlfromcpp.qdoc b/src/qml/doc/src/cppintegration/interactqmlfromcpp.qdoc
index 2a644cafff..9c33979f40 100644
--- a/src/qml/doc/src/cppintegration/interactqmlfromcpp.qdoc
+++ b/src/qml/doc/src/cppintegration/interactqmlfromcpp.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -75,11 +75,26 @@ component, which is accessible via QQuickView::rootObject():
 \endtable
 
 This \c object is the instance of the \c MyItem.qml component that has been
-created. You can now modify the item's properties using QObject::setProperty()
-or QQmlProperty:
+created. You can now modify the item's properties using
+\l QObject::setProperty() or \l QQmlProperty::write():
 
 \snippet qml/qtbinding/loading/main.cpp properties
 
+The difference between \c QObject::setProperty() and \c QQmlProperty::write()
+is that the latter will also remove the binding in addition to setting the
+property value. For example, suppose the \c width assignment above had been a
+binding to \c height:
+
+\code
+    width: height
+\endcode
+
+If the \c height of the \c Item changed after the
+\c {object->setProperty("width", 500)} call, the \c width would be updated
+again, as the binding remains active. However, if the \c height changes after the
+\c {QQmlProperty(object, "width").write(500)} call, the \c width will not be
+changed, as the binding does not exist anymore.
+
 Alternatively, you can cast the object to its actual type and call methods with
 compile-time safety. In this case the base object of \c MyItem.qml is an
 \l Item, which is defined by the QQuickItem class:
@@ -114,17 +129,7 @@ multiple children with the same \c objectName. In this case,
 QObject::findChildren() can be used to find all children with a matching
 \c objectName.
 
-\warning While it is possible to use C++ to access and manipulate QML objects
-deep into the object tree, we recommend that you do not take this approach
-outside of application testing and prototyping. One strength of QML and C++
-integration is the ability to implement the QML user interface separately
-from the C++ logic and dataset backend, and this strategy breaks if the C++
-side reaches deep into the QML components to manipulate them directly. This
-would make it difficult to, for example, swap a QML view component for
-another view, if the new component was missing a required \c objectName. It
-is better for the C++ implementation to know as little as possible about the
-QML user interface implementation and the composition of the QML object tree.
-
+\include warning.qdocinc
 
 \section1 Accessing Members of a QML Object Type from C++
 
diff --git a/src/qml/doc/src/cppintegration/topic.qdoc b/src/qml/doc/src/cppintegration/topic.qdoc
index 1aa3bb6ab5..fbb654378d 100644
--- a/src/qml/doc/src/cppintegration/topic.qdoc
+++ b/src/qml/doc/src/cppintegration/topic.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,14 +20,75 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
 /*!
 \page qtqml-cppintegration-topic.html
 \title Integrating QML and C++
-\brief Description of how to integrate QML and C++ code
+\brief Provides instruction to integrate QML and C++
+
+QML applications often need to handle more advanced and performance-intensive
+tasks in C++. The most common and quickest way to do this is to expose the C++
+class to the QML runtime, provided the C++ implementation is derived from
+QObject. Assuming that you have Qt 5.7 or later installed, the following
+step-by-step instructions guide you through the process of using the C++ class,
+BackEnd, in a QML application:
+
+\list 1
+
+\li Create a new project using the "Qt Quick Application" template in Qt Creator
+
+\note Uncheck the \uicontrol {With ui.qml file} option in the
+\uicontrol {Define Project Details} section of \uicontrol {New Project Wizard}.
+
+\li Add a new C++ class called \c BackEnd to the project and replace its header
+file contents with:
+
+\snippet code/backend/backend.h backend_header
+
+The \c Q_PROPERTY macro declares a property that could be accessed from QML.
+
+\li Replace its C++ file contents with:
+
+\snippet code/backend/backend.cpp backend_cpp
+
+The \c setUserName function emits the \c userNameChanged signal every time
+\c m_userName value changes. The signal can be handled from QML using the
+\c onUserNameChanged handler.
+
+\li Include \c "backend.h" in \c main.cpp and register the class as a QML type
+under a import URL as shown below:
+
+\snippet code/backend/main.cpp main_cpp
+
+The BackEnd class is registered as a type, which is accessible from QML by
+importing the URL, "\c{io.qt.examples.backend 1.0}".
+
+\li Replace the contents of \c main.qml with the following code:
+
+\snippet code/backend/main.qml main_qml
+
+The \c BackEnd instance lets you access the \c userName property, which
+is updated when the TextField's \c text property changes.
+
+\endlist
+
+Now the application can be run.
+
+\borderedimage cppintegration-ex.png
+\caption Application running on Ubuntu
+
+Qt offers several methods to integrate C++ with QML, and the method discussed
+in this tutorial is just one of them. For more details about these methods,
+refer to \l{Overview - QML and C++ Integration}.
+*/
+
+/*!
+\page qtqml-cppintegration-overview.html
+\title Overview - QML and C++ Integration
+\brief Highlights important points about integrating C++ with QML.
 
 QML is designed to be easily extensible through C++ code. The classes in the \l {Qt QML} module
 enable QML objects to be loaded and manipulated from C++, and the nature of QML engine's
@@ -82,6 +143,12 @@ with a QML module that can then be imported and used by QML code in other applic
 \l{qtqml-modules-cppplugins.html}{Providing Types and Functionality in a C++ Plugin} for more
 information.
 
+\section1 Choosing the Correct Integration Method Between C++ and QML
+
+To quickly determine which integration method is appropriate for your situation, the following
+flowchart can be used:
+
+\image cpp-qml-integration-flowchart
 
 \section1 Exposing Attributes of C++ Classes to QML
 
@@ -129,6 +196,8 @@ invoke their methods and receive their signal notifications. This is possible du
 all QML object types are implemented using QObject-derived classes, enabling the QML engine to
 dynamically load and introspect objects through the Qt meta object system.
 
+\include warning.qdocinc
+
 For more information on accessing QML objects from C++, see the documentation on
 \l{qtqml-cppintegration-interactqmlfromcpp.html}{Interacting with QML Objects from C++}.
 
diff --git a/src/qml/doc/src/cppintegration/warning.qdocinc b/src/qml/doc/src/cppintegration/warning.qdocinc
new file mode 100644
index 0000000000..a5da22b2a7
--- /dev/null
+++ b/src/qml/doc/src/cppintegration/warning.qdocinc
@@ -0,0 +1,6 @@
+\warning Although it is possible to access QML objects from C++ and manipulate
+them, it is not the recommended approach, except for testing and prototyping
+purposes. One of the strengths of QML and C++ integration is the ability to
+implement UIs in QML separate from the C++ logic and dataset backend, and this
+fails if the C++ side starts manipulating QML directly. Such an approach also
+makes changing the QML UI difficult without affecting its C++ counterpart.
diff --git a/src/qml/doc/src/examples.qdoc b/src/qml/doc/src/examples.qdoc
index 4f12d42f48..7aad09ecee 100644
--- a/src/qml/doc/src/examples.qdoc
+++ b/src/qml/doc/src/examples.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/external-resources.qdoc b/src/qml/doc/src/external-resources.qdoc
index 63f59bf3be..68c5ab4664 100644
--- a/src/qml/doc/src/external-resources.qdoc
+++ b/src/qml/doc/src/external-resources.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -44,3 +44,35 @@
     \externalpage https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
     \title Mozilla Developer Network Date Reference
 */
+/*!
+    \externalpage hhttps://www.froglogic.com/squish/gui-testing
+    \title Squish
+*/
+/*!
+    \externalpage http://doc.qt.io/GammaRay
+    \title GammaRay
+*/
+/*!
+    \externalpage http://doc.qt.io/QtQmlLive
+    \title QmlLive
+*/
+/*!
+    \externalpage http://doc.qt.io/qtcreator/creator-debugging-qml.html
+    \title QML Debugger
+*/
+/*!
+    \externalpage http://doc.qt.io/qtcreator/creator-qml-performance-monitor.html
+    \title QML Profiler
+*/
+/*!
+    \externalpage http://doc.qt.io/qtcreator/index.html
+    \title Qt Creator Manual
+*/
+/*!
+    \externalpage https://doc.qt.io/qtcreator/creator-project-creating.html#creating-resource-files
+    \title Creating Resource Files
+*/
+/*!
+    \externalpage https://fontawesome.com/
+    \title Font Awesome
+*/
diff --git a/src/qml/doc/src/includes/qqmlcomponent.qdoc b/src/qml/doc/src/includes/qqmlcomponent.qdoc
new file mode 100644
index 0000000000..6949d8823a
--- /dev/null
+++ b/src/qml/doc/src/includes/qqmlcomponent.qdoc
@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [url-note]
+Ensure that the URL provided is full and correct, in particular, use
+\l QUrl::fromLocalFile() when loading a file from the local filesystem.
+
+Relative paths will be resolved against
+\l {QQmlEngine::baseUrl}{QQmlEngine::baseUrl()}, which is the current working directory
+unless specified.
+//! [url-note]
diff --git a/src/qml/doc/src/javascript/date.qdoc b/src/qml/doc/src/javascript/date.qdoc
index fd1be1b65c..431f9649a0 100644
--- a/src/qml/doc/src/javascript/date.qdoc
+++ b/src/qml/doc/src/javascript/date.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -28,7 +28,7 @@
 /*!
     \qmltype Date
     \inqmlmodule QtQml
-    \brief Provides date functions
+    \brief Provides date functions.
 
     The QML Date object extends the
     \l{Mozilla Developer Network Date Reference}{JS Date object} with
diff --git a/src/qml/doc/src/javascript/dynamicobjectcreation.qdoc b/src/qml/doc/src/javascript/dynamicobjectcreation.qdoc
index fffa783851..be4db4c917 100644
--- a/src/qml/doc/src/javascript/dynamicobjectcreation.qdoc
+++ b/src/qml/doc/src/javascript/dynamicobjectcreation.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -157,7 +157,7 @@ to inside the string literals.
 
 When managing dynamically created objects, you must ensure the creation context
 outlives the created object. Otherwise, if the creation context is destroyed
-first, the bindings in the dynamic object will no longer work.
+first, the bindings and signal handlers in the dynamic object will no longer work.
 
 The actual creation context depends on how an object is created:
 
diff --git a/src/qml/doc/src/javascript/expressions.qdoc b/src/qml/doc/src/javascript/expressions.qdoc
index 0782960d82..b83127389a 100644
--- a/src/qml/doc/src/javascript/expressions.qdoc
+++ b/src/qml/doc/src/javascript/expressions.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -32,15 +32,15 @@
 
 The \l{JavaScript Host Environment} provided by QML can run valid standard
 JavaScript constructs such as conditional operators, arrays, variable setting,
-loops. In addition to the standard JavaScript properties, the \l {QML Global
+and loops. In addition to the standard JavaScript properties, the \l {QML Global
 Object} includes a number of helper methods that simplify building UIs and
 interacting with the QML environment.
 
 The JavaScript environment provided by QML is stricter than that in a web
-browser.  For example, in QML you cannot add to, or modify, members of the
-JavaScript global object.  In regular JavaScript, it is possible to do this
+browser. For example, in QML you cannot add to, or modify, members of the
+JavaScript global object. In regular JavaScript, it is possible to do this
 accidentally by using a variable without declaring it. In QML this will throw
-an exception, so all local variables must be explicitly declared.  See
+an exception, so all local variables must be explicitly declared. See
 \l{JavaScript Environment Restrictions} for a complete description of the
 restrictions on JavaScript code executed from QML.
 
@@ -49,7 +49,7 @@ Various parts of \l{QML Documents}{QML documents} can contain JavaScript code:
 \list 1
   \li The body of \l{Property Binding}{property bindings}. These JavaScript
       expressions describe relationships between QML object \l{Property Attributes}
-      {properties}. When any of a property's \e dependencies change, the property
+      {properties}. When \e dependencies of a property change, the property
       is automatically updated too, according to the specified relationship.
   \li The body of \l{Signal Attributes}{Signal handlers}. These JavaScript
       statements are automatically evaluated whenever a QML object emits the
@@ -66,42 +66,41 @@ Various parts of \l{QML Documents}{QML documents} can contain JavaScript code:
 
 
 
-\section1 JavaScript in Property Bindings
+\section1 JavaScript in property bindings
 
-In the following example, the \l Rectangle's \c color depends on the
-\l MouseArea's \c pressed property. This relationship is described using a
+In the following example, the \c color property of \l Rectangle depends on the
+\c pressed property of \l TapHandler. This relationship is described using a
 conditional expression:
 
 \qml
-import QtQuick 2.0
+import QtQuick 2.12
 
 Rectangle {
     id: colorbutton
     width: 200; height: 80;
 
-    color: mousearea.pressed ? "steelblue" : "lightsteelblue"
+    color: inputHandler.pressed ? "steelblue" : "lightsteelblue"
 
-    MouseArea {
-        id: mousearea
-        anchors.fill: parent
+    TapHandler {
+        id: inputHandler
     }
 }
 \endqml
 
 In fact, any JavaScript expression (no matter how complex) may be used in a
 property binding definition, as long as the result of the expression is a
-value whose type can be assigned to the property.  This includes side effects.
+value whose type can be assigned to the property. This includes side effects.
 However, complex bindings and side effects are discouraged because they can
 reduce the performance, readability, and maintainability of the code.
 
-There are two ways to define a property binding: the first (and most common)
-is, as previously shown, in a \l{QML Object Attributes#Value Assignment on Initialization}
-{property initialization}.  The second (and much rarer) way is to assign the
+There are two ways to define a property binding: the most common one
+is shown in the example earlier, in a \l{QML Object Attributes#Value Assignment on Initialization}
+{property initialization}. The second (and much rarer) way is to assign the
 property a function returned from the \l{Qt::binding()}{Qt.binding()} function,
 from within imperative JavaScript code, as shown below:
 
 \qml
-import QtQuick 2.0
+import QtQuick 2.12
 
 Rectangle {
     id: colorbutton
@@ -109,13 +108,12 @@ Rectangle {
 
     color: "red"
 
-    MouseArea {
-        id: mousearea
-        anchors.fill: parent
+    TapHandler {
+        id: inputHandler
     }
 
     Component.onCompleted: {
-        color = Qt.binding(function() { return mousearea.pressed ? "steelblue" : "lightsteelblue" });
+        color = Qt.binding(function() { return inputHandler.pressed ? "steelblue" : "lightsteelblue" });
     }
 }
 \endqml
@@ -126,126 +124,111 @@ about \l{qml-javascript-assignment}
 {Property Assignment versus Property Binding} for information about how
 bindings differ from value assignments.
 
-
-
-\section1 JavaScript in Signal Handlers
+\section1 JavaScript in signal handlers
 
 QML object types can emit signals in reaction to certain events occurring.
 Those signals can be handled by signal handler functions, which can be defined
 by clients to implement custom program logic.
 
-Suppose that a button represented by a Rectangle type has a MouseArea and a
-Text label. The MouseArea will emit its \l{MouseArea::}{pressed} signal when the
-user presses the defined interactive area, which will automatically trigger the
-\c onPressed handler, which can be defined by clients. The QML
-engine will execute the JavaScript expressions defined in the \c onPressed and
-\c onReleased handlers, as required. Typically, a signal handler is bound to
-JavaScript expressions to initiate other events or to simply assign property
+Suppose that a button represented by a Rectangle type has a TapHandler and a
+Text label. The TapHandler emits its \l{TapHandler::}{tapped} signal when the
+user presses the button. The clients can react to the signal in the \c onTapped
+handler using JavaScript expressions. The QML engine executes these JavaScript
+expressions defined in the handler as required. Typically, a signal handler is
+bound to JavaScript expressions to initiate other events or to assign property
 values.
 
 \qml
-import QtQuick 2.0
+import QtQuick 2.12
 
 Rectangle {
     id: button
     width: 200; height: 80; color: "lightsteelblue"
 
-    MouseArea {
-        id: mousearea
-        anchors.fill: parent
-
-        onPressed: {
+    TapHandler {
+        id: inputHandler
+        onTapped: {
             // arbitrary JavaScript expression
-            label.text = "I am Pressed!"
+            console.log("Tapped!")
         }
-        onReleased: {
-            // arbitrary JavaScript expression
-            label.text = "Click Me!"
-        }
-
     }
 
     Text {
         id: label
         anchors.centerIn: parent
-        text: "Press Me!"
+        text: inputHandler.pressed ? "Pressed!" : "Press here!"
     }
 }
 \endqml
 
-Please see the \l{Signal and Handler Event System} documentation for in-depth
-discussion of signals and signal handlers, and see the
-\l{QML Object Attributes} documentation for in-depth discussion of how
-to define the implementation of signal handlers in QML with JavaScript.
-
+For more details about signals and signal handlers, refer to the following
+topics:
 
+\list
+    \li \l{Signal and Handler Event System}
+    \li \l{QML Object Attributes}
+\endlist
 
-\section1 JavaScript in Standalone Functions
+\section1 JavaScript in standalone functions
 
-Program logic can also be defined in JavaScript functions.  These functions can
+Program logic can also be defined in JavaScript functions. These functions can
 be defined inline in QML documents (as custom methods) or externally in
 imported JavaScript files.
 
-
-
-\section2 JavaScript in Custom Object Methods
+\section2 JavaScript in custom methods
 
 Custom methods can be defined in QML documents and may be called from signal
-handlers, property bindings, or functions in other QML objects.  Methods
-defined in this way are often referred to as \e{inline JavaScript functions}
-because their implementation is included in the QML object type definition
-(QML document), as opposed to an external JavaScript file.
+handlers, property bindings, or functions in other QML objects. Such methods
+are often referred to as \e{inline JavaScript functions} because their
+implementation is included in the QML object type definition
+(QML document), instead of in an external JavaScript file.
 
 An example of an inline custom method is as follows:
 
 \qml
-import QtQuick 2.0
+import QtQuick 2.12
 
 Item {
-    function factorial(a) {
-        a = parseInt(a);
-        if (a <= 0)
-            return 1;
-        else
-            return a * factorial(a - 1);
-    }
+    function fibonacci(n){
+        var arr = [0, 1];
+        for (var i = 2; i < n + 1; i++)
+            arr.push(arr[i - 2] + arr[i -1]);
 
-    MouseArea {
-        anchors.fill: parent
-        onClicked: console.log(factorial(10))
+        return arr;
+    }
+    TapHandler {
+        onTapped: console.log(fibonacci(10))
     }
 }
 \endqml
 
-The factorial function will run whenever the MouseArea detects a \c clicked signal.
+The fibonacci function is run whenever the TapHandler emits a \c tapped signal.
 
-Importantly, custom methods defined inline in a QML document are exposed to
+\note The custom methods defined inline in a QML document are exposed to
 other objects, and therefore inline functions on the root object in a QML
-component can be invoked by callers outside the component.  If this is not
+component can be invoked by callers outside the component. If this is not
 desired, the method can be added to a non-root object or, preferably, written
 in an external JavaScript file.
 
-See the \l{QML Object Attributes} documentation for in-depth discussion of how
-to define custom methods in QML with JavaScript code implementations.
-
-
+See the \l{QML Object Attributes} documentation for more information on
+defining custom methods in QML using JavaScript.
 
-\section2 Functions in Imported JavaScript Files
+\section2 Functions defined in a JavaScript file
 
-Non-trivial program logic is best separated into external JavaScript files.
-These files can be imported into QML files using an \c import statement, in
-the same way that \l {QML Modules}{modules} are imported.
+Non-trivial program logic is best separated into a separate JavaScript file.
+This file can be imported into QML using an \c import statement, like the
+QML \l {QML Modules}{modules}.
 
-For example, the \c {factorial()} method in the above example could be moved
-into an external file named \c factorial.js, and accessed like this:
+For example, the \c {fibonacci()} method in the earlier example could be moved
+into an external file named \c fib.js, and accessed like this:
 
 \qml
-import "factorial.js" as MathFunctions
+import QtQuick 2.12
+import "fib.js" as MathFunctions
 
 Item {
-    MouseArea {
-        anchors.fill: parent
-        onClicked: console.log(MathFunctions.factorial(10))
+    TapHandler {
+        onTapped: console.log(MathFunctions.fibonacci(10))
     }
 }
 \endqml
@@ -253,20 +236,18 @@ Item {
 For more information about loading external JavaScript files into QML, read
 the section about \l{Importing JavaScript Resources in QML}.
 
+\section2 Connecting signals to JavaScript functions
 
-
-\section2 Connecting Signals to JavaScript Functions
-
-QML object types which emit signals also provide default signal handlers for
-their signals, as described in a previous section.  Sometimes, however, a
-client will want to cause a signal emitted from one object to trigger a
-function defined in another object; and in that case, a signal connection
-is often preferable.
+QML object types that emit signals also provide default signal handlers for
+their signals, as described in the \l{JavaScript in signal handlers}{previous}
+section. Sometimes, however, a client wants to trigger a function defined in a
+QML object when another QML object emits a signal. Such scenarios can be handled
+by a signal connection.
 
 A signal emitted by a QML object may be connected to a JavaScript function
 by calling the signal's \c connect() method and passing the JavaScript function
-as an argument.  For example, the following code connects the MouseArea
-\c clicked signal to the \c jsFunction() in \c script.js:
+as an argument. For example, the following code connects the TapHandler's
+\c tapped signal to the \c jsFunction() in \c script.js:
 
 \table
 \row
@@ -274,34 +255,30 @@ as an argument.  For example, the following code connects the MouseArea
 \li \snippet qml/integrating-javascript/script.js 0
 \endtable
 
-The \c jsFunction() will now be called whenever MouseArea's \c clicked signal
+The \c jsFunction() is called whenever the TapHandler's \c tapped signal
 is emitted.
 
 See \l{qtqml-syntax-signals.html}
 {Connecting Signals to Methods and Signals} for more information.
 
-
-
-
-
-\section1 JavaScript in Application Startup Code
+\section1 JavaScript in application startup code
 
 It is occasionally necessary to run some imperative code at application (or
-component instance) startup.  While it is tempting to just include the startup
+component instance) startup. While it is tempting to just include the startup
 script as \e {global code} in an external script file, this can have severe
-limitations as the QML environment may not have been fully established.  For
+limitations as the QML environment may not have been fully established. For
 example, some objects might not have been created or some
 \l {Property Binding}{property bindings} may not have been established. See
 \l {JavaScript Environment Restrictions} for the exact limitations of global
 script code.
 
-A QML object will emit the \c{Component.completed} \l{Signal and Handler Event
+A QML object emits the \c{Component.completed} \l{Signal and Handler Event
 System#Attached Signal Handlers}{attached signal} when its instantiation is
-complete.  JavaScript code in the corresponding \c{Component.onCompleted} handler
-runs after the object is instantiated.  Thus, the best place to write application
-startup code is in the \c{Component.onCompleted} handler of the top-level
-object, because this object emits \c{Component.completed} when the QML environment
-is fully established.
+complete. The JavaScript code in the corresponding \c{Component.onCompleted}
+handler runs after the object is instantiated. Thus, the best place to write
+application startup code is in the \c{Component.onCompleted} handler of the
+top-level object, because this object emits \c{Component.completed} when the
+QML environment is fully established.
 
 For example:
 
@@ -318,11 +295,11 @@ Rectangle {
 \endqml
 
 Any object in a QML file - including nested objects and nested QML component
-instances - can use this attached property.  If there is more than one
+instances - can use this attached property. If there is more than one
 \c onCompleted() handler to execute at startup, they are run sequentially in
 an undefined order.
 
-Likewise, every \c Component will emit a \l {Component::destruction}{destruction()}
+Likewise, every \c Component emits a \l {Component::destruction}{destruction()}
 signal just before being destroyed.
 
 */
@@ -341,7 +318,7 @@ signal just before being destroyed.
 \section1 Scarce Resources in JavaScript
 
 As described in the documentation for \l{QML Basic Types}, a \c var type
-property may hold a \e{scarce resource} (image or pixmap).  There are several
+property may hold a \e{scarce resource} (image or pixmap). There are several
 important semantics of scarce resources which should be noted:
 
 \list
@@ -351,7 +328,7 @@ important semantics of scarce resources which should be noted:
 \endlist
 
 In most cases, allowing the engine to automatically release the resource is
-the correct choice.  In some cases, however, this may result in an invalid
+the correct choice. In some cases, however, this may result in an invalid
 variant being returned from a function in JavaScript, and in those cases it
 may be necessary for clients to manually preserve or destroy resources for
 themselves.
@@ -364,9 +341,9 @@ and that we have registered it with the QML type-system as follows:
 
 \snippet qml/integrating-javascript/scarceresources/avatarExample.cpp 0
 
-The AvatarExample class has a property which is a pixmap.  When the property
+The AvatarExample class has a property which is a pixmap. When the property
 is accessed in JavaScript scope, a copy of the resource will be created and
-stored in a JavaScript object which can then be used within JavaScript.  This
+stored in a JavaScript object which can then be used within JavaScript. This
 copy will take up valuable system resources, and so by default the scarce
 resource copy in the JavaScript object will be released automatically by the
 declarative engine once evaluation of the JavaScript expression is complete,
@@ -414,7 +391,7 @@ Run it in C++:
 \section2 Example Four: Explicit Destruction
 
 In the following example, we release (via destroy()) an explicitly preserved
-scarce resource variant.  This example shows how a client may free system
+scarce resource variant. This example shows how a client may free system
 resources by releasing the scarce resource held in a JavaScript object, if
 required, during evaluation of a JavaScript expression.
 
@@ -430,7 +407,7 @@ Run it in C++:
 \section2 Example Five: Explicit Destruction and JavaScript References
 
 One thing to be aware of when using "var" type properties is that they
-hold references to JavaScript objects.  As such, if multiple references
+hold references to JavaScript objects. As such, if multiple references
 to one scarce resource is held, and the client calls destroy() on one
 of those references (to explicitly release the scarce resource), all of
 the references will be affected.
diff --git a/src/qml/doc/src/javascript/functionlist.qdoc b/src/qml/doc/src/javascript/functionlist.qdoc
index fd916e1e24..24ff640284 100644
--- a/src/qml/doc/src/javascript/functionlist.qdoc
+++ b/src/qml/doc/src/javascript/functionlist.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/javascript/hostenvironment.qdoc b/src/qml/doc/src/javascript/hostenvironment.qdoc
index 7e9a22f5d3..eb40f10065 100644
--- a/src/qml/doc/src/javascript/hostenvironment.qdoc
+++ b/src/qml/doc/src/javascript/hostenvironment.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -154,10 +154,11 @@ This restriction exists as the QML environment is not yet fully established.
 To run code after the environment setup has completed, see
 \l {JavaScript in Application Startup Code}.
 
-\li The value of \c this is currently undefined in QML in the majority of contexts.
+\li The value of \c this is undefined in QML in the majority of contexts.
 
 The \c this keyword is supported when binding properties from JavaScript.
-In all other situations, the value of
+In QML binding expressions, QML signal handlers, and QML declared functions,
+\c this refers to the scope object. In all other situations, the value of
 \c this is undefined in QML.
 
 To refer to a specific object, provide an \c id.  For example:
@@ -168,20 +169,17 @@ Item {
     function mouseAreaClicked(area) {
         console.log("Clicked in area at: " + area.x + ", " + area.y);
     }
-    // This will not work because this is undefined
+    // This will pass area to the function
     MouseArea {
-        height: 50; width: 200
-        onClicked: mouseAreaClicked(this)
-    }
-    // This will pass area2 to the function
-    MouseArea {
-        id: area2
+        id: area
         y: 50; height: 50; width: 200
-        onClicked: mouseAreaClicked(area2)
+        onClicked: mouseAreaClicked(area)
     }
 }
 \endqml
 
+\sa {Scope and Naming Resolution}
+
 \endlist
 
 
diff --git a/src/qml/doc/src/javascript/imports.qdoc b/src/qml/doc/src/javascript/imports.qdoc
index 489da08ada..974f2e154f 100644
--- a/src/qml/doc/src/javascript/imports.qdoc
+++ b/src/qml/doc/src/javascript/imports.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -99,9 +99,44 @@ A JavaScript resource may import another in the following fashion:
 \endcode
 For example:
 \code
-.import "factorial.js" as MathFunctions
+import * as MathFunctions from "factorial.mjs";
 \endcode
 
+The latter is standard ECMAScript syntax for importing ECMAScript modules, and
+only works from within ECMAScript modules as denoted by the \c mjs file
+extension. The former is an extension to JavaScript provided by the \c QML
+engine and will work also with non-modules.
+
+When a JavaScript file is imported this way, it is imported with a qualifier.
+The functions in that file are then accessible from the importing script via the
+qualifier (that is, as \tt{Qualifier.functionName(params)}).
+
+Sometimes it is desirable to have the functions made available in the importing
+context without needing to qualify them. In this case ECMAScript modules and the
+JavaScript \c import statement should be used without the \c as qualifier.
+
+For example, the QML code below left calls \c showCalculations() in \c script.mjs,
+which in turn can call \c factorial() in \c factorial.mjs, as it has included
+\c factorial.mjs using \c import.
+
+\table
+\row
+\li {1,2} \snippet qml/integrating-javascript/includejs/app.qml 0
+\li \snippet qml/integrating-javascript/includejs/script.mjs 0
+\row
+\li \snippet qml/integrating-javascript/includejs/factorial.mjs 0
+\endtable
+
+The \l{QtQml::Qt::include()} {Qt.include()} function includes one JavaScript
+file from another without using ECMAScript modules and without qualifying the
+import. It makes all functions and variables from the other file available in
+the current file's namespace, but ignores all pragmas and imports defined in
+that file. This is not a good idea as a function call should never modify the
+caller's context.
+
+\l{QtQml::Qt::include()} {Qt.include()} is deprecated and should be avoided. It
+will be removed in a future version of Qt.
+
 \section2 Importing a QML Module from a JavaScript Resource
 
 A JavaScript resource may import a QML module in the following fashion:
@@ -119,32 +154,4 @@ via a singleton type; see qmlRegisterSingletonType() for more information.
 
 \note The .import syntax doesn't work for scripts used in the \l {WorkerScript}
 
-\section1 Including a JavaScript Resource from Another JavaScript Resource
-
-When a JavaScript file is imported, it must be imported with a qualifier.  The
-functions in that file are then accessible from the importing script via the
-qualifier (that is, as \tt{Qualifier.functionName(params)}).  Sometimes it is
-desirable to have the functions made available in the importing context without
-needing to qualify them, and in this circumstance the \l{QtQml::Qt::include()}
-{Qt.include()} function may be used to include one JavaScript file from another.
-This copies all functions from the other file into the current file's
-namespace, but ignores all pragmas and imports defined in that file.
-
-For example, the QML code below left calls \c showCalculations() in \c script.js,
-which in turn can call \c factorial() in \c factorial.js, as it has included
-\c factorial.js using \l {QtQml::Qt::include()}{Qt.include()}.
-
-\table
-\row
-\li {1,2} \snippet qml/integrating-javascript/includejs/app.qml 0
-\li \snippet qml/integrating-javascript/includejs/script.js 0
-\row
-\li \snippet qml/integrating-javascript/includejs/factorial.js 0
-\endtable
-
-Notice that calling \l {QtQml::Qt::include()}{Qt.include()} copies all functions
-from \c factorial.js into the \c MyScript namespace, which means the QML
-component can also access \c factorial() directly as \c MyScript.factorial().
-
-
 */
diff --git a/src/qml/doc/src/javascript/number.qdoc b/src/qml/doc/src/javascript/number.qdoc
index 94d90d4070..b6f80f474a 100644
--- a/src/qml/doc/src/javascript/number.qdoc
+++ b/src/qml/doc/src/javascript/number.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -28,7 +28,7 @@
 /*!
     \qmltype Number
     \inqmlmodule QtQml
-    \brief The Number object provides represents a number value
+    \brief The Number object provides represents a number value.
 
     The QML Number object extends the JS Number object with
     locale aware functions.
diff --git a/src/qml/doc/src/javascript/qmlglobalobject.qdoc b/src/qml/doc/src/javascript/qmlglobalobject.qdoc
index b3d8a2b2a5..bba796f9ea 100644
--- a/src/qml/doc/src/javascript/qmlglobalobject.qdoc
+++ b/src/qml/doc/src/javascript/qmlglobalobject.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/javascript/qtjavascript.qdoc b/src/qml/doc/src/javascript/qtjavascript.qdoc
index 8df1330f64..ad93d9d9ac 100644
--- a/src/qml/doc/src/javascript/qtjavascript.qdoc
+++ b/src/qml/doc/src/javascript/qtjavascript.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -90,4 +90,16 @@
   underlying C++ object. Note that the name of the script variable
   can be anything; i.e., it is not dependent upon QObject::objectName().
 
+  \section1 Implications for Application Security
+
+  The security model of application scripting with JavaScript follows
+  the same model as for C++ code: the user installs scripts to run
+  that they trust in the same way as they install Qt applications.
+
+  In order to preserve the trust of users, application developers should
+  not evaluate arbitrary JavaScript code. The JavaScript engine's sandbox is
+  only a semantic barrier. The script is evaluated in the same process and
+  with the same privileges as the rest of the application and shares the
+  same memory. As a consequence, C++ objects exposed to scripts are
+  accessible without additional security guards.
  */
diff --git a/src/qml/doc/src/javascript/resources.qdoc b/src/qml/doc/src/javascript/resources.qdoc
index 4f9b40f1d7..60f97c2007 100644
--- a/src/qml/doc/src/javascript/resources.qdoc
+++ b/src/qml/doc/src/javascript/resources.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,13 +20,13 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
 /*!
 \page qtqml-javascript-resources.html
-\title Defining JavaScript Resources In QML
+\title Defining JavaScript Resources in QML
 \brief Description of how JavaScript files may be defined for use in QML
 
 The program logic for a QML application may be defined in JavaScript.  The
@@ -60,7 +60,8 @@ An example of a code-behind implementation resource follows:
 \code
 // MyButton.qml
 import QtQuick 2.0
-import "my_button_impl.js" as Logic // a new instance of this JavaScript resource is loaded for each instance of Button.qml
+import "my_button_impl.js" as Logic // A new instance of this JavaScript resource
+                                    // is loaded for each instance of Button.qml.
 
 Rectangle {
     id: rect
@@ -95,13 +96,18 @@ for maintainability and readability.
 
 \section1 Shared JavaScript Resources (Libraries)
 
-Some JavaScript files act more like libraries - they provide a set of helper
-functions that take input and compute output, but never manipulate QML
-component instances directly.
+By default, JavaScript files imported from QML share their context with the QML
+component. That means the JavaScript files have access to the same QML objects
+and can modify them. As a consequence, each import must have a unique copy of
+these files.
 
-As it would be wasteful for each QML component instance to have a unique copy of
-these libraries, the JavaScript programmer can indicate a particular file is a
-shared library through the use of a pragma, as shown in the following example.
+\l {Defining JavaScript Resources in QML#Code-Behind Implementation Resource}
+{The previous section} covers stateful imports of JavaScript files. However,
+some JavaScript files are stateless and act more like reusable libraries, in
+the sense that they provide a set of helper functions that do not require
+anything from where they were imported from. You can save significant amounts
+of memory and speed up the instantiation of QML components if you mark such
+libraries with a special pragma, as shown in the following example.
 
 \code
 // factorial.js
@@ -141,7 +147,10 @@ For example:
 \code
 // Calculator.qml
 import QtQuick 2.0
-import "factorial.js" as FactorialCalculator // this JavaScript resource is only ever loaded once by the engine, even if multiple instances of Calculator.qml are created
+import "factorial.js" as FactorialCalculator // This JavaScript resource is only
+                                             // ever loaded once by the engine,
+                                             // even if multiple instances of
+                                             // Calculator.qml are created.
 
 Text {
     width: 500
diff --git a/src/qml/doc/src/javascript/string.qdoc b/src/qml/doc/src/javascript/string.qdoc
index abce72a639..f896af3378 100644
--- a/src/qml/doc/src/javascript/string.qdoc
+++ b/src/qml/doc/src/javascript/string.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -28,7 +28,7 @@
 /*!
     \qmltype String
     \inqmlmodule QtQml
-    \brief The String object represents a string value
+    \brief The String object represents a string value.
 
     The QML String object extends the JS String object with
     the arg() function.
diff --git a/src/qml/doc/src/javascript/topic.qdoc b/src/qml/doc/src/javascript/topic.qdoc
index 24a7a40715..0c06e14b4c 100644
--- a/src/qml/doc/src/javascript/topic.qdoc
+++ b/src/qml/doc/src/javascript/topic.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmlfunctions.qdoc b/src/qml/doc/src/qmlfunctions.qdoc
index 834684fe6d..969dd51433 100644
--- a/src/qml/doc/src/qmlfunctions.qdoc
+++ b/src/qml/doc/src/qmlfunctions.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -105,6 +105,8 @@
   than the actual version of the library. Indeed, it is normal for the new library to allow
   QML written to previous versions to continue to work, even if more advanced versions of
   some of its types are available.
+
+  \sa {Choosing the Correct Integration Method Between C++ and QML}
 */
 
 /*!
@@ -141,7 +143,8 @@
 
   Returns the QML type id.
 
-  \sa qmlRegisterTypeNotAvailable()
+  \sa qmlRegisterTypeNotAvailable(),
+      {Choosing the Correct Integration Method Between C++ and QML}
 */
 
 /*!
@@ -266,7 +269,8 @@
 
   Without this, a generic "Game is not a type" message would be given.
 
-  \sa qmlRegisterUncreatableType()
+  \sa qmlRegisterUncreatableType(),
+      {Choosing the Correct Integration Method Between C++ and QML}
 */
 
 /*!
@@ -278,17 +282,110 @@
   system. Instances of this type cannot be created from the QML
   system.
 
+  This function should be used when the type will not be referenced by name.
+  Specifically, it has to be used for C++ types that are used as the left-hand
+  side of a property binding.
+
+  For example, consider the following two classes:
+
+    \code
+    class Bar : public QObject
+    {
+        Q_OBJECT
+        Q_PROPERTY(QString baz READ baz WRITE setBaz NOTIFY bazChanged)
+
+    public:
+        Bar() {}
+
+        QString baz() const { return mBaz; }
+
+        void setBaz(const QString &baz)
+        {
+            if (baz == mBaz)
+                return;
+
+            mBaz = baz;
+            emit bazChanged();
+        }
+
+    signals:
+        void bazChanged();
+
+    private:
+        QString mBaz;
+    };
+
+    class Foo : public QObject
+    {
+        Q_OBJECT
+        Q_PROPERTY(Bar *bar READ bar CONSTANT FINAL)
+
+    public:
+        Foo() {}
+
+        Bar *bar() { return &mBar; }
+
+    private:
+        Bar mBar;
+    };
+    \endcode
+
+  In QML, we assign a string to the \c baz property of \c bar:
+
+    \code
+    Foo {
+        bar.baz: "abc"
+        Component.onCompleted: print(bar.baz)
+    }
+    \endcode
+
+  For the QML engine to know that the \c Bar type has a \c baz property,
+  we have to make \c Bar known:
+
+    \code
+    qmlRegisterType<Foo>("App", 1, 0, "Foo");
+    qmlRegisterType<Bar>();
+    \endcode
+
+  As the \c Foo type is instantiated in QML, it must be registered
+  with the version of \l qmlRegisterType() that takes an import URI.
+
   Returns the QML type id.
+
+  \sa {Choosing the Correct Integration Method Between C++ and QML}
 */
 
 /*!
-  \fn int qmlRegisterInterface(const char *typeName)
-  \relates QQmlEngine
+    \fn int qmlRegisterInterface(const char *typeName)
+    \relates QQmlEngine
 
-  This template function registers the C++ type in the QML system
-  under the name \a typeName.
+    This template function registers the C++ type in the QML system
+    under the name \a typeName.
 
-  Returns the QML type id.
+    Types registered as an interface with the engine should also
+    declare themselves as an interface with the
+    \l {The Meta-Object System}{meta object system}. For example:
+
+    \code
+    struct FooInterface
+    {
+    public:
+        virtual ~FooInterface();
+        virtual void doSomething() = 0;
+    };
+
+    Q_DECLARE_INTERFACE(FooInterface, "org.foo.FooInterface")
+    \endcode
+
+    When registered with the QML engine in this way, they can be used as
+    property types:
+
+    Q_PROPERTY(FooInterface *foo READ foo WRITE setFoo)
+
+    When you assign a \l QObject sub-class to this property, the QML engine does
+    the interface cast to \c FooInterface* automatically.
+
+    Returns the QML type id.
 */
 
 /*!
@@ -324,6 +421,19 @@
    qmlRegisterSingletonType("Qt.example.qjsvalueApi", 1, 0, "MyApi", example_qjsvalue_singletontype_provider);
    \endcode
 
+   Alternatively, you can use a C++11 lambda:
+
+   \code
+   qmlRegisterSingletonType("Qt.example.qjsvalueApi", 1, 0, "MyApi", [](QQmlEngine *engine, QJSEngine *scriptEngine) -> QJSValue {
+       Q_UNUSED(engine)
+
+       static int seedValue = 5;
+       QJSValue example = scriptEngine->newObject();
+       example.setProperty("someProperty", seedValue++);
+       return example;
+   });
+   \endcode
+
    In order to use the registered singleton type in QML, you must import the singleton type.
    \qml
    import QtQuick 2.0
@@ -333,10 +443,12 @@
        property int someValue: ExampleApi.MyApi.someProperty
    }
    \endqml
-  */
+
+   \sa {Choosing the Correct Integration Method Between C++ and QML}
+*/
 
 /*!
-    \fn Object *qmlAttachedPropertiesObject(const QObject *attachee, bool create = true)
+    \fn template<typename T> QObject *qmlAttachedPropertiesObject(const QObject *attachee, bool create = true)
     \relates QQmlEngine
 
     The form of this template function is:
@@ -354,7 +466,7 @@
     Returns 0 if type \e T is not a valid attaching type, or if \a create is false and no
     attachment object instance has previously been created for \a attachee.
 
-    \sa {Providing Attached Objects for Data Annotations}
+    \sa {Providing Attached Properties}
 
 */
 
@@ -423,6 +535,18 @@
    qmlRegisterSingletonType<SingletonTypeExample>("Qt.example.qobjectSingleton", 1, 0, "MyApi", example_qobject_singletontype_provider);
    \endcode
 
+   Alternatively, you can use a C++11 lambda:
+
+   \code
+   qmlRegisterSingletonType<SingletonTypeExample>("Qt.example.qjsvalueApi", 1, 0, "MyApi", [](QQmlEngine *engine, QJSEngine *scriptEngine) -> QObject * {
+       Q_UNUSED(engine)
+       Q_UNUSED(scriptEngine)
+
+       SingletonTypeExample *example = new SingletonTypeExample();
+       return example;
+   });
+   \endcode
+
    In order to use the registered singleton type in QML, you must import the singleton type.
    \qml
    import QtQuick 2.0
@@ -437,31 +561,8 @@
    }
    \endqml
 
-   Since singleton types do not have an associated QQmlContext object, then within the functions of a QObject-derived
-   type that is registered as a singleton type implementation the QML context and engine information is not available.
-   The QQmlEngine::contextForObject() function returns NULL when supplied with a pointer to an QObject that
-   implements a singleton type.
-
-   Extending the above example:
-
-   \code
-   class SingletonTypeExample : public QObject
-   {
-       ...
-
-       Q_INVOKABLE void doSomethingElse()
-       {
-           // QML Engine/Context information is not accessible here:
-           Q_ASSERT(QQmlEngine::contextForObject(this) == 0);
-           Q_ASSERT(qmlContext(this) == 0);
-           Q_ASSERT(qmlEngine(this) == 0);
-       }
-
-       ...
-   }
-   \endcode
-
-  */
+   \sa {Choosing the Correct Integration Method Between C++ and QML}
+*/
 
 /*!
    \fn int qmlRegisterSingletonType(const QUrl &url, const char *uri, int versionMajor, int versionMinor, const char *qmlName)
@@ -560,3 +661,25 @@
   are registered for that version. This is particularly useful for keeping the
   versions of related modules in sync.
 */
+
+/*!
+  \since 5.12
+  \fn int qmlTypeId(const char* uri, int versionMajor, int versionMinor, const char *qmlName);
+  \relates QQmlEngine
+
+  Returns the QML type id of a type that was registered with the
+  name \a qmlName in a particular \a uri and a version specified in \a
+  versionMajor and \a versionMinor.
+
+  This function returns the same value as the QML type registration functions
+  such as qmlRegisterType() and qmlRegisterSingletonType().
+
+  If \a qmlName, \a uri and \a versionMajor match a registered type, but the
+  specified minor version in \a versionMinor is higher, then the id of the type
+  with the closest minor version is returned.
+
+  Returns -1 if no matching type was found or one of the given parameters
+  was invalid.
+
+  \sa qmlRegisterType(), qmlRegisterSingletonType()
+*/
diff --git a/src/qml/doc/src/qmllanguageref/documents/definetypes.qdoc b/src/qml/doc/src/qmllanguageref/documents/definetypes.qdoc
index 03a7ddfb19..2de4eb0c18 100644
--- a/src/qml/doc/src/qmllanguageref/documents/definetypes.qdoc
+++ b/src/qml/doc/src/qmllanguageref/documents/definetypes.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -34,7 +34,18 @@ One of the core features of QML is that it enables QML object types to be easily
 
 \section1 Defining an Object Type with a QML File
 
-To create an object type, a QML document should be placed into a text file named as \e <TypeName>.qml where \e <TypeName> is the desired name of the type, which must be comprised of alphanumeric characters or underscores and beginning with an uppercase letter. This document is then automatically recognized by the engine as a definition of a QML type. Additionally, a type defined in this manner is automatically made available to other QML files within the same directory as the engine searches within the immediate directory when resolving QML type names.
+\section2 Naming Custom QML Object Types
+
+To create an object type, a QML document should be placed into a text file named as \e <TypeName>.qml where \e <TypeName> is the desired name of the type. The type name has the following requirements:
+
+\list
+    \li It must be comprised of alphanumeric characters or underscores.
+    \li It must begin with an uppercase letter.
+\endlist
+
+This document is then automatically recognized by the engine as a definition of a QML type. Additionally, a type defined in this manner is automatically made available to other QML files within the same directory as the engine searches within the immediate directory when resolving QML type names.
+
+\section2 Custom QML Type Definition
 
 For example, below is a document that declares a \l Rectangle with a child \l MouseArea. The document has been saved to file named \c SquareButton.qml:
 
diff --git a/src/qml/doc/src/qmllanguageref/documents/networktransparency.qdoc b/src/qml/doc/src/qmllanguageref/documents/networktransparency.qdoc
index 5cfd80f8a0..d762621d6c 100644
--- a/src/qml/doc/src/qmllanguageref/documents/networktransparency.qdoc
+++ b/src/qml/doc/src/qmllanguageref/documents/networktransparency.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/documents/scope.qdoc b/src/qml/doc/src/qmllanguageref/documents/scope.qdoc
index eaf1747a6d..7ecf0b0a0a 100644
--- a/src/qml/doc/src/qmllanguageref/documents/scope.qdoc
+++ b/src/qml/doc/src/qmllanguageref/documents/scope.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/documents/structure.qdoc b/src/qml/doc/src/qmllanguageref/documents/structure.qdoc
index 015b0e8b6b..666039c73a 100644
--- a/src/qml/doc/src/qmllanguageref/documents/structure.qdoc
+++ b/src/qml/doc/src/qmllanguageref/documents/structure.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/documents/topic.qdoc b/src/qml/doc/src/qmllanguageref/documents/topic.qdoc
index 840afa9a0e..47130ce39e 100644
--- a/src/qml/doc/src/qmllanguageref/documents/topic.qdoc
+++ b/src/qml/doc/src/qmllanguageref/documents/topic.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -86,7 +86,7 @@ Please see the documentation about the \l{qtqml-syntax-basics.html}
 documentation about \l{qtqml-javascript-topic.html}
 {integrating QML and JavaScript} for in-depth information on that topic.
 
-\section1 Defining Object Types through QML Documents
+\section1 Defining Object Types Through QML Documents
 
 As described briefly in the previous section, a document implicitly defines
 a QML object type.  One of the core principles of QML is the ability to define
diff --git a/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc b/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc
index a2397b6cfb..32ba948359 100644
--- a/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc
+++ b/src/qml/doc/src/qmllanguageref/modules/cppplugins.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/modules/identifiedmodules.qdoc b/src/qml/doc/src/qmllanguageref/modules/identifiedmodules.qdoc
index 0bd9c3603f..914a40599c 100644
--- a/src/qml/doc/src/qmllanguageref/modules/identifiedmodules.qdoc
+++ b/src/qml/doc/src/qmllanguageref/modules/identifiedmodules.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/modules/legacymodules.qdoc b/src/qml/doc/src/qmllanguageref/modules/legacymodules.qdoc
index 64cd2e41cb..a84f8f07a1 100644
--- a/src/qml/doc/src/qmllanguageref/modules/legacymodules.qdoc
+++ b/src/qml/doc/src/qmllanguageref/modules/legacymodules.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/modules/qmldir.qdoc b/src/qml/doc/src/qmllanguageref/modules/qmldir.qdoc
index f4046c91ac..0faad43f4f 100644
--- a/src/qml/doc/src/qmllanguageref/modules/qmldir.qdoc
+++ b/src/qml/doc/src/qmllanguageref/modules/qmldir.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc b/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc
index 7c1d65b095..01e81e7c19 100644
--- a/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc
+++ b/src/qml/doc/src/qmllanguageref/modules/qqmlextensionplugin.qdocinc
@@ -23,7 +23,7 @@ plugins. Library plugins should limit themselves to registering types, as
 any manipulation of the engine's root context may cause conflicts or other
 issues in the library user's code.
 
-\section1 Plugin Example
+\section1 TimeExample QML extension plugin
 
 Suppose there is a new \c TimeModel C++ class that should be made available
 as a new QML type. It provides the current time through \c hour and \c minute
@@ -47,6 +47,8 @@ imported correctly by any QML components that use this plugin. The
 \l{Defining QML Types from C++} article has more information about registering C++
 types into the runtime.
 
+\section1 Project settings for the plugin
+
 Additionally, the project file (\c .pro) defines the project as a plugin library,
 specifies it should be built into the \c imports/TimeExample directory, and registers
 the plugin target name and various other details:
@@ -61,6 +63,8 @@ TARGET = qmlqtimeexampleplugin
 SOURCES += qexampleqmlplugin.cpp
 \endcode
 
+\section1 Plugin definition in the qmldir
+
 Finally, a \l{Module Definition qmldir Files}{qmldir file} is required
 in the \c imports/TimeExample directory to describe the plugin and the types that it
 exports. The plugin includes a \c Clock.qml file along with the \c qmlqtimeexampleplugin
diff --git a/src/qml/doc/src/qmllanguageref/modules/topic.qdoc b/src/qml/doc/src/qmllanguageref/modules/topic.qdoc
index 1a5504e277..3462e474c2 100644
--- a/src/qml/doc/src/qmllanguageref/modules/topic.qdoc
+++ b/src/qml/doc/src/qmllanguageref/modules/topic.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/qmlreference.qdoc b/src/qml/doc/src/qmllanguageref/qmlreference.qdoc
index d832367f7f..901a4a57fe 100644
--- a/src/qml/doc/src/qmllanguageref/qmlreference.qdoc
+++ b/src/qml/doc/src/qmllanguageref/qmlreference.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -59,6 +59,7 @@ modules.
         \li \l{qtqml-syntax-objectattributes.html#signal-attributes}{Signal Attributes}
         \li \l{qtqml-syntax-objectattributes.html#method-attributes}{Method Attributes}
         \li \l{qtqml-syntax-objectattributes.html#attached-properties-and-attached-signal-handlers}{Attached Properties and Attached Signal Handlers}
+        \li \l{qtqml-syntax-objectattributes.html#enumeration-attributes}{Enumeration Attributes}
         \endlist
 
     \li \l{qtqml-syntax-propertybinding.html}{Property Binding}
diff --git a/src/qml/doc/src/qmllanguageref/syntax/basics.qdoc b/src/qml/doc/src/qmllanguageref/syntax/basics.qdoc
index 50767bfc8f..9eb8f72cf2 100644
--- a/src/qml/doc/src/qmllanguageref/syntax/basics.qdoc
+++ b/src/qml/doc/src/qmllanguageref/syntax/basics.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -38,6 +38,8 @@ imperative code, in the case where complex custom application behavior is needed
 
 QML source code is generally loaded by the engine through QML \e documents, which are
 standalone documents of QML code. These can be used to define \l {QML Object Types}{QML object types} that can then be reused throughout an application.
+Note that type names must begin with an uppercase letter in order
+to be declared as QML object types in a QML file.
 
 
 \section1 Import Statements
diff --git a/src/qml/doc/src/qmllanguageref/syntax/directoryimports.qdoc b/src/qml/doc/src/qmllanguageref/syntax/directoryimports.qdoc
index 8c512b65db..7ec8a4ff34 100644
--- a/src/qml/doc/src/qmllanguageref/syntax/directoryimports.qdoc
+++ b/src/qml/doc/src/qmllanguageref/syntax/directoryimports.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/syntax/imports.qdoc b/src/qml/doc/src/qmllanguageref/syntax/imports.qdoc
index 71db34695c..57e0ba1a14 100644
--- a/src/qml/doc/src/qmllanguageref/syntax/imports.qdoc
+++ b/src/qml/doc/src/qmllanguageref/syntax/imports.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc b/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc
index 33f58dc1b9..15e8e4c52c 100644
--- a/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc
+++ b/src/qml/doc/src/qmllanguageref/syntax/objectattributes.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -50,6 +50,7 @@ The set of QML object-type attribute types is as follows:
 \li signal handler attributes
 \li method attributes
 \li attached properties and attached signal handler attributes
+\li enumeration attributes
 \endlist
 
 These attributes are discussed in detail below.
@@ -448,13 +449,40 @@ right-hand-side of the property declaration must be a valid alias reference:
 [default] property alias <name>: <alias reference>
 \endcode
 
-Unlike an ordinary property, an alias can only refer to an object, or the
-property of an object, that is within the scope of the \l{QML Object Types}
-{type} within which the alias is declared. It cannot contain arbitrary
-JavaScript expressions and it cannot refer to objects declared outside of
-the scope of its type. Also note the \e {alias reference} is not optional,
-unlike the optional default value for an ordinary property; the alias reference
-must be provided when the alias is first declared.
+Unlike an ordinary property, an alias has the following restrictions:
+
+\list
+\li It can only refer to an object, or the
+    property of an object, that is within the scope of the \l{QML Object Types}
+    {type} within which the alias is declared.
+\li It cannot contain arbitrary
+    JavaScript expressions
+\li It cannot refer to objects declared outside of
+    the scope of its type.
+\li The \e {alias reference} is not optional,
+    unlike the optional default value for an ordinary property; the alias reference
+    must be provided when the alias is first declared.
+\li It cannot refer to \l {Attached Properties and Attached Signal Handlers}
+    {attached properties}.
+\li It cannot refer to grouped properties; the following code will not work:
+    \code
+    property alias color: rectangle.border.color
+
+    Rectangle {
+        id: rectangle
+    }
+    \endcode
+
+    However, aliases to \l {QML Basic Types}{value type} properties do work:
+    \code
+    property alias rectX: object.rectProperty.x
+
+    Item {
+        id: object
+        property rect rectProperty
+    }
+    \endcode
+\endlist
 
 For example, below is a \c Button type with a \c buttonText aliased property
 which is connected to the \c text object of the \l Text child:
@@ -512,6 +540,58 @@ Internally, however, the rectangle can correctly set its \c color
 property and refer to the actual defined property rather than the alias.
 
 
+\section4 Property Aliases and Types
+
+Property aliases cannot have explicit type specifications. The type of a
+property alias is the \e declared type of the property or object it refers to.
+Therefore, if you create an alias to an object referenced via id with extra
+properties declared inline, the extra properties won't be accessible through
+the alias:
+
+\code
+// MyItem.qml
+Item {
+    property alias inner: innerItem
+
+    Item {
+        id: innerItem
+        property int extraProperty
+    }
+}
+\code
+
+You cannot initialize \a inner.extraProperty from outside of this component, as
+inner is only an \a Item:
+
+\code
+// main.qml
+MyItem {
+    inner.extraProperty: 5 // fails
+}
+\code
+
+However, if you extract the inner object into a separate component with a
+dedicated .qml file, you can instantiate that component instead and have all
+its properties available through the alias:
+
+\code
+// MainItem.qml
+Item {
+    // Now you can access inner.extraProperty, as inner is now an ExtraItem
+    property alias inner: innerItem
+
+    ExtraItem {
+        id: innerItem
+    }
+}
+
+// ExtraItem.qml
+Item {
+    property int extraProperty
+}
+\code
+
+
 \section3 Default Properties
 
 An object definition can have a single \e default property. A default property
@@ -856,8 +936,7 @@ are otherwise unavailable to the object. In particular, they allow objects to
 access properties or signals that are specifically relevant to the individual
 object.
 
-A QML type implementation may choose to \l {Providing Attached Objects for
-Data Annotations}{create an \e {attaching type} in C++} with
+A QML type implementation may choose to \l {Providing Attached Properties}{create an \e {attaching type} in C++} with
 particular properties and signals. Instances of this type can then be created
 and \e attached to specific objects at run time, allowing those objects to
 access the properties and signals of the attaching type. These are accessed by
@@ -975,4 +1054,41 @@ ListView {
 Now \c delegateItem.ListView.isCurrentItem correctly refers to the
 \c isCurrentItem attached property of the delegate.
 
+\section2 Enumeration Attributes
+
+Enumerations provide a fixed set of named choices. They can be declared in QML using the \c enum keyword:
+
+\qml
+// MyText.qml
+Text {
+    enum TextType {
+        Normal,
+        Heading
+    }
+}
+\endqml
+
+As shown above, enumeration types (e.g. \c TextType) and values (e.g. \c Normal) must begin with an uppercase letter.
+
+Values are referred to via \c {<Type>.<EnumerationType>.<Value>} or \c {<Type>.<Value>}.
+
+\qml
+// MyText.qml
+Text {
+    enum TextType {
+        Normal,
+        Heading
+    }
+
+    property int textType: MyText.TextType.Normal
+
+    font.bold: textType == MyText.TextType.Heading
+    font.pixelSize: textType == MyText.TextType.Heading ? 24 : 12
+}
+\endqml
+
+More information on enumeration usage in QML can be found in the \l {QML Basic Types} \l enumeration documentation.
+
+The ability to declare enumerations in QML was introduced in Qt 5.10.
+
 */
diff --git a/src/qml/doc/src/qmllanguageref/syntax/propertybinding.qdoc b/src/qml/doc/src/qmllanguageref/syntax/propertybinding.qdoc
index 99426d984d..a5ad6af4a2 100644
--- a/src/qml/doc/src/qmllanguageref/syntax/propertybinding.qdoc
+++ b/src/qml/doc/src/qmllanguageref/syntax/propertybinding.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/doc/src/qmllanguageref/syntax/signals.qdoc b/src/qml/doc/src/qmllanguageref/syntax/signals.qdoc
index 4a022f2b0b..cd73ccc025 100644
--- a/src/qml/doc/src/qmllanguageref/syntax/signals.qdoc
+++ b/src/qml/doc/src/qmllanguageref/syntax/signals.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -39,99 +39,100 @@ application may need to relay this clicking event to other applications.
 
 QML has a signal and handler mechanism, where the \e signal is the event
 and the signal is responded to through a \e {signal handler}. When a signal
-is emitted, the corresponding signal handler is invoked. Placing logic such as scripts or other
-operations in the handler allows the component to respond to the event.
+is emitted, the corresponding signal handler is invoked. Placing logic such as
+a script or other operations in the handler allows the component to respond to
+the event.
 
 \target qml-signals-and-handlers
-\section1 Receiving Signals with Signal Handlers
+\section1 Receiving signals with signal handlers
 
-To receive a notification when a particular signal is emitted for a particular object, the object definition should declare a signal handler named \e on<Signal> where \e <Signal> is the name of the signal, with the first letter capitalized. The signal handler should contain the JavaScript code to be executed when the signal handler is invoked.
+To receive a notification when a particular signal is emitted for a particular
+object, the object definition should declare a signal handler named
+\e on<Signal>, where \e <Signal> is the name of the signal, with the first
+letter capitalized. The signal handler should contain the JavaScript code to be
+executed when the signal handler is invoked.
 
-For example, the \l MouseArea type from the \c QtQuick module has a \c clicked signal that is emitted whenever the mouse is clicked within the area. Since the signal name is \c clicked, the signal handler for receiving this signal should be named \c onClicked. In the example below, whenever the mouse area is clicked, the \c onClicked handler is invoked, applying a random color to the \l Rectangle:
+For example, the \l [QtQuickControls]{Button} type from the
+\l{Qt Quick Controls} module has a \c clicked signal, which
+is emitted whenever the button is clicked. In this case, the signal handler for
+receiving this signal should be \c onClicked. In the example below, whenever
+the button is clicked, the \c onClicked handler is invoked, applying a random
+color to the parent \l Rectangle:
 
-\qml
-import QtQuick 2.0
-
-Rectangle {
-    id: rect
-    width: 100; height: 100
-
-    MouseArea {
-        anchors.fill: parent
-        onClicked: {
-            rect.color = Qt.rgba(Math.random(), Math.random(), Math.random(), 1);
-        }
-    }
-}
-\endqml
-
-Looking at the \l MouseArea documentation, you can see the \l {MouseArea::}{clicked} signal is emitted with a parameter named \c mouse which is a \l MouseEvent object that contains further details about the mouse click event. This name can be referred to in our \c onClicked handler to access this parameter. For example, the \l MouseEvent type has \c x and \c y coordinates that allows us to print out the exact location where the mouse was clicked:
-
-\qml
-import QtQuick 2.0
+\qml \QtMinorVersion
+import QtQuick 2.\1
+import QtQuick.Controls 2.\1
 
 Rectangle {
     id: rect
-    width: 100; height: 100
+    width: 250; height: 250
 
-    MouseArea {
-        anchors.fill: parent
+    Button {
+        anchors.bottom: parent.bottom
+        anchors.horizontalCenter: parent.horizontalCenter
+        text: "Change color!"
         onClicked: {
             rect.color = Qt.rgba(Math.random(), Math.random(), Math.random(), 1);
-
-            // access 'mouse' parameter
-            console.log("Clicked mouse at", mouse.x, mouse.y)
         }
     }
 }
 \endqml
 
+\section2 Property change signal handlers
 
-\section2 Property Change Signal Handlers
-
-A signal is automatically emitted when the value of a QML property changes. This type of signal is a \e {property change signal} and signal handlers for these signals are written in the form \e on<Property>Changed where \e <Property> is the name of the property, with the first letter capitalized.
+A signal is automatically emitted when the value of a QML property changes.
+This type of signal is a \e {property change signal} and signal handlers for
+these signals are written in the form \e on<Property>Changed, where
+\e <Property> is the name of the property, with the first letter capitalized.
 
 For example, the \l MouseArea type has a \l {MouseArea::pressed}{pressed} property. To receive a notification whenever this property changes, write a signal handler named \c onPressedChanged:
 
-\qml
-import QtQuick 2.0
+\qml \QtMinorVersion
+import QtQuick 2.\1
 
 Rectangle {
     id: rect
     width: 100; height: 100
 
-    MouseArea {
-        anchors.fill: parent
-        onPressedChanged: {
-            console.log("Mouse area is pressed?", pressed)
-        }
+    TapHandler {
+        onPressedChanged: console.log("taphandler pressed?", pressed)
     }
 }
 \endqml
 
-Even though the \l MouseArea documentation does not document a signal handler named \c onPressedChanged, the signal is implicitly provided by the fact that the \c pressed property exists.
+Even though the \l TapHandler documentation does not document a signal handler
+named \c onPressedChanged, the signal is implicitly provided by the fact that
+the \c pressed property exists.
 
+\section2 Using the Connections type
 
-\section2 Using the Connections Type
+In some cases it may be desirable to access a signal outside of the object that
+emits it. For these purposes, the \c QtQuick module provides the \l Connections
+type for connecting to signals of arbitrary objects. A \l Connections object
+can receive any signal from its specified \l {Connections::target}{target}.
 
-In some cases it may be desirable to access a signal outside of the object that emits it. For these purposes, the \c QtQuick module provides the \l Connections type for connecting to signals of arbitrary objects. A \l Connections object can receive any signal from its specified \l {Connections::target}{target}.
+For example, the \c onClicked handler in the earlier example could have been
+received by the root \l Rectangle instead, by placing the \c onClicked handler
+in a \l Connections object that has its \l {Connections::target}{target} set to
+the \c button:
 
-For example, the \c onClicked handler in the earlier example could have been received by the root \l Rectangle instead, by placing the \c onClicked handler in a \l Connections object that has its \l {Connections::target}{target} set to the \l MouseArea:
-
-\qml
-import QtQuick 2.0
+\qml \QtMinorVersion
+import QtQuick 2.\1
+import QtQuick.Controls 2.\1
 
 Rectangle {
     id: rect
-    width: 100; height: 100
+    width: 250; height: 250
 
-    MouseArea {
-        id: mouseArea
-        anchors.fill: parent
+    Button {
+        id: button
+        anchors.bottom: parent.bottom
+        anchors.horizontalCenter: parent.horizontalCenter
+        text: "Change color!"
     }
 
     Connections {
-        target: mouseArea
+        target: button
         onClicked: {
             rect.color = Qt.rgba(Math.random(), Math.random(), Math.random(), 1);
         }
@@ -140,16 +141,18 @@ Rectangle {
 \endqml
 
 
-\section2 Attached Signal Handlers
+\section2 Attached signal handlers
 
-An \l {Attached Properties and Attached Signal Handlers}{attached signal handler} is a signal handler that receives a signal from an \e {attaching type} rather than the object within which the handler is declared.
+An \l {Attached Properties and Attached Signal Handlers}{attached signal handler}
+receives a signal from an \e {attaching type} rather than the object within which
+the handler is declared.
 
 For example, \l{Component::completed}{Component.onCompleted} is an attached
-signal handler. This handler is often used to execute some JavaScript code when
-its creation process has been completed, as in the example below:
+signal handler. It is often used to execute some JavaScript code when its
+creation process is complete. Here is an example:
 
-\qml
-import QtQuick 2.0
+\qml \QtMinorVersion
+import QtQuick 2.\1
 
 Rectangle {
     width: 200; height: 200
@@ -161,14 +164,23 @@ Rectangle {
 }
 \endqml
 
-The \c onCompleted handler is not responding to some \c completed signal from the \l Rectangle type. Instead, an object of the \c Component \e {attaching type} with a \c completed signal has automatically been \e attached to the \l Rectangle object by the QML engine, and the engine emits this signal when the object is fully created, thus triggering the \c Component.onCompleted signal handler.
+The \c onCompleted handler is not responding to a \c completed signal from
+the \l Rectangle type. Instead, an object of the \c Component \e{attaching type}
+with a \c completed signal has automatically been \e attached to the \l Rectangle
+object by the QML engine. The engine emits this signal when the Rectangle object is
+created, thus triggering the \c Component.onCompleted signal handler.
 
-Attached signal handlers allow objects to be notified of particular signals that are significant to each individual object. If there was no \c Component.onCompleted attached signal handler, for example, then an object could not receive this notification without registering for some special signal from some special object. The \e {attached signal handler} mechanism enables objects to receive particular signals without these extra processes.
+Attached signal handlers allow objects to be notified of particular signals that are
+significant to each individual object. If there was no \c Component.onCompleted
+attached signal handler, for example, an object could not receive this notification
+without registering for some special signal from some special object.
+The \e {attached signal handler} mechanism enables objects to receive particular
+signals without extra code.
 
-See \l {Attached properties and attached signal handlers} for more information on attached signal handlers.
+See \l {Attached properties and attached signal handlers} for more information on
+attached signal handlers.
 
-
-\section1 Adding Signals to Custom QML Types
+\section1 Adding signals to custom QML types
 
 Signals can be added to custom QML types through the \c signal keyword.
 
@@ -178,21 +190,27 @@ The syntax for defining a new signal is:
 
 A signal is emitted by invoking the signal as a method.
 
-For example, say the code below is defined in a file named \c SquareButton.qml. The root \l Rectangle object has an \c activated signal. When the child \l MouseArea is clicked, it emits the parent's \c activated signal with the coordinates of the mouse click:
+For example, the code below is defined in a file named \c SquareButton.qml. The
+root \l Rectangle object has an \c activated signal, which is emitted whenever the
+child \l TapHandler is \c tapped. In this particular example the activated signal
+is emitted with the x and y coordinates of the mouse click:
 
-\qml
+\qml \QtMinorVersion
 // SquareButton.qml
+import QtQuick 2.\1
+
 Rectangle {
     id: root
 
     signal activated(real xPosition, real yPosition)
-
+    property point mouseXY
     property int side: 100
     width: side; height: side
 
-    MouseArea {
-        anchors.fill: parent
-        onPressed: root.activated(mouse.x, mouse.y)
+    TapHandler {
+        id: handler
+        onTapped: root.activated(mouseXY.x, mouseXY.y)
+        onPressedChanged: mouseXY = handler.point.position
     }
 }
 \endqml
@@ -210,7 +228,7 @@ See \l {Signal Attributes} for more details on writing signals for custom QML ty
 
 
 \target qml-connect-signals-to-method
-\section1 Connecting Signals to Methods and Signals
+\section1 Connecting signals to methods and signals
 
 Signal objects have a \c connect() method to a connect a signal either to a
 method or another signal. When a signal is connected to a method, the method is
@@ -219,7 +237,9 @@ signal to be received by a method instead of a signal handler.
 
 Below, the \c messageReceived signal is connected to three methods using the \c connect() method:
 
-\qml
+\qml \QtMinorVersion
+import QtQuick 2.\1
+
 Rectangle {
     id: relay
 
@@ -244,7 +264,12 @@ Rectangle {
 }
 \endqml
 
-In many cases it is sufficient to receive signals through signal handlers rather than using the connect() function. However, using the \c connect method allows a signal to be received by multiple methods as shown above, which would not be possible with signal handlers as they must be uniquely named. Also, the \c connect method is useful when connecting signals to \l {Dynamic QML Object Creation from JavaScript}{dynamically created objects}.
+In many cases it is sufficient to receive signals through signal handlers
+rather than using the connect() function. However, using the \c connect
+method allows a signal to be received by multiple methods as shown earlier,
+which would not be possible with signal handlers as they must be uniquely
+named. Also, the \c connect method is useful when connecting signals to
+\l {Dynamic QML Object Creation from JavaScript}{dynamically created objects}.
 
 There is a corresponding \c disconnect() method for removing connected signals:
 
@@ -259,12 +284,14 @@ Rectangle {
 }
 \endqml
 
-\section3 Signal to Signal Connect
+\section3 Signal to signal connect
 
 By connecting signals to other signals, the \c connect() method can form different
 signal chains.
 
-\qml
+\qml \QtMinorVersion
+import QtQuick 2.\1
+
 Rectangle {
     id: forwarder
     width: 100; height: 100
@@ -272,20 +299,20 @@ Rectangle {
     signal send()
     onSend: console.log("Send clicked")
 
-    MouseArea {
+    TapHandler {
         id: mousearea
         anchors.fill: parent
-        onClicked: console.log("MouseArea clicked")
+        onTapped: console.log("Mouse clicked")
     }
 
     Component.onCompleted: {
-        mousearea.clicked.connect(send)
+        mousearea.tapped.connect(send)
     }
 }
 \endqml
 
 
-Whenever the \l MouseArea \c clicked signal is emitted, the \c send
+Whenever the \l TapHandler's \c tapped signal is emitted, the \c send
 signal will automatically be emitted as well.
 
 \code
@@ -293,6 +320,4 @@ output:
     MouseArea clicked
     Send clicked
 \endcode
-
-
 */
diff --git a/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc b/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc
index a486b47f03..c4c1b61693 100644
--- a/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc
+++ b/src/qml/doc/src/qmllanguageref/typesystem/basictypes.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -673,4 +673,5 @@ property is only invoked when the property is reassigned to a different object v
     \endqml
 
     \sa {QML Basic Types}
+    \sa {qtqml-syntax-objectattributes.html#enumeration-attributes}{Enumeration Attributes}
 */
diff --git a/src/qml/doc/src/qmllanguageref/typesystem/objecttypes.qdoc b/src/qml/doc/src/qmllanguageref/typesystem/objecttypes.qdoc
index b0aab1c73a..5f089b5ebc 100644
--- a/src/qml/doc/src/qmllanguageref/typesystem/objecttypes.qdoc
+++ b/src/qml/doc/src/qmllanguageref/typesystem/objecttypes.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -45,12 +45,14 @@ type, as discussed in \l {qtqml-documents-definetypes.html}
 {Documents as QML object type definitions}, or by defining a QML type from C++
 and registering the type with the QML engine, as discussed in
 \l{qtqml-cppintegration-definetypes.html}{Defining QML Types from C++}.
+Note that in both cases, the type name must begin with an uppercase letter in
+order to be declared as a QML object type in a QML file.
 
 
 \section1 Defining Object Types from QML
 
 
-\section2 Defining Object Types through QML Documents
+\section2 Defining Object Types Through QML Documents
 
 Plugin writers and application developers may provide types defined as QML
 documents.  A QML document, when visible to the QML import system, defines a
diff --git a/src/qml/doc/src/qmllanguageref/typesystem/topic.qdoc b/src/qml/doc/src/qmllanguageref/typesystem/topic.qdoc
index 26e7a072da..a5f730e8d4 100644
--- a/src/qml/doc/src/qmllanguageref/typesystem/topic.qdoc
+++ b/src/qml/doc/src/qmllanguageref/typesystem/topic.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -67,7 +67,7 @@ For example, the standard \c Date and \c Array types are available, as below:
 import QtQuick 2.0
 
 Item {
-    property var theArray: new Array()
+    property var theArray: []
     property var theDate: new Date()
 
     Component.onCompleted: {
diff --git a/src/qml/doc/src/qmltypereference.qdoc b/src/qml/doc/src/qmltypereference.qdoc
index b2bb9ebd18..ae36ebbcc9 100644
--- a/src/qml/doc/src/qmltypereference.qdoc
+++ b/src/qml/doc/src/qmltypereference.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,13 +20,13 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
 
 /*!
-\qmlmodule QtQml 2.2
+\qmlmodule QtQml 2.\QtMinorVersion
 \title Qt QML QML Types
 \ingroup qmlmodules
 \brief List of QML types provided by the Qt QML module
@@ -43,19 +43,19 @@ The types provided by the \c QtQml module are only available in a QML document
 if that document imports the \c QtQml namespace (or if the document imports the
 \c QtQuick namespace, as noted below).
 
-The current version of the \c QtQml module is version 2.2, and thus it may be
-imported via the following statement:
+The current version of the \c QtQml module is version 2.\QtMinorVersion, and
+thus it may be imported via the following statement:
 
-\qml
-import QtQml 2.2
+\qml \QtMinorVersion
+import QtQml 2.\1
 \endqml
 
 Most clients will never need to use the \c QtQml import, as all of the types
 are also provided by the \c QtQuick namespace which may be imported as
 follows:
 
-\qml
-import QtQuick 2.7
+\qml \QtMinorVersion
+import QtQuick 2.\1
 \endqml
 
 See the \l{Qt Quick} module documentation for more information about the \c
@@ -91,10 +91,17 @@ provided:
 
 The \c date type refers to a date value, including the time of the day.
 
-To create a \c date value, specify it as a "YYYY-MM-DD" string:
+To create a \c date value, specify it as a "YYYY-MM-DDThh:mm:ss.zzzZ" string.
+(The T is literal, YYYY is a full year number, MM and DD are month and day
+numbers, hh, mm and ss are hours, minutes and seconds, with .zzz as
+milliseconds and Z as time-zone offset. The T and following time are optional.
+If they are omitted, the date is handled as the start of UTC's day, which
+falls on other dates in some time-zones. When T is included, the :ss.zzz or
+just .zzz part can be omitted. With or without those, the zone offset can be
+omitted, in which case local time is used.)  For example:
 
 \qml
-MyDatePicker { minDate: "2000-01-01"; maxDate: "2020-12-31" }
+MyDatePicker { minDate: "2000-01-01 0:0"; maxDate: "2020-12-31 23:59" }
 \endqml
 
 To read a date value returned from a C++ extension class, use
@@ -102,7 +109,13 @@ To read a date value returned from a C++ extension class, use
 
 When integrating with C++, note that any QDate or QDateTime value
 \l{qtqml-cppintegration-data.html}{passed into QML from C++} is automatically
-converted into a \c date value, and vice-versa.
+converted into a \c date value, and vice-versa. Note, however, that
+converting a QDate will result in UTC's start of the day, which falls on
+a different date in some other time-zones. It is usually more robust
+to convert the QDate via a QDateTime explicitly, specifying local-time
+or a relevant time-zone and selecting a time of day (such as noon)
+that reliably exists (daylight-savings transitions skip an hour, near
+one end or the other of a day).
 
 This basic type is provided by the QML language. It can be implicitly converted
 to a \l{QtQml::Date}{Date} object.
diff --git a/src/qml/doc/src/qtqml-cpp.qdoc b/src/qml/doc/src/qtqml-cpp.qdoc
index dc6171c32e..2c4d2a5ade 100644
--- a/src/qml/doc/src/qtqml-cpp.qdoc
+++ b/src/qml/doc/src/qtqml-cpp.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -29,21 +29,19 @@
 \title Qt QML C++ Classes
 \ingroup modules
 \qtvariable qml
-\brief The C++ API provided by the Qt QML module
+\brief The C++ API provided by the Qt QML module.
 
 To include the definitions of the module's classes, use the
 following directive:
 
-\code
-#include <QtQml>
-\endcode
+\snippet code/doc_src_qtqml.cpp 0
 
+\if !defined(qtforpython)
 To link against the module, add this line to your \l qmake \c
 .pro file:
 
-\code
-QT += qml
-\endcode
+\snippet code/doc_src_qtqml.pro 0
+\endif
 
 For more information on the Qt QML module, see the
 \l{Qt QML} module documentation.
diff --git a/src/qml/doc/src/qtqml.qdoc b/src/qml/doc/src/qtqml.qdoc
index 747466281e..68d2b66950 100644
--- a/src/qml/doc/src/qtqml.qdoc
+++ b/src/qml/doc/src/qtqml.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -55,11 +55,12 @@ following directive:
 #include <QtQml>
 \endcode
 
-The QML types in Qt QML are available through the \c QtQML import. To use the
+The QML types in Qt QML are available through the \c QtQml import. To use the
 types, add the following import statement to your .qml file:
-\code
-import QtQml 2.0
-\endcode
+
+\qml \QtMinorVersion
+import QtQml 2.\1
+\endqml
 
 
 To link against the module, add this line to your \l qmake \c
@@ -134,12 +135,13 @@ the QML code to interact with C++ code.
 \section1 Licenses and Attributions
 
 Qt QML is available under commercial licenses from \l{The Qt Company}.
-In addition, it is available under the
+In addition, it is available under free software licenses. Since Qt 5.4,
+these free software licenses are
 \l{GNU Lesser General Public License, version 3}, or
 the \l{GNU General Public License, version 2}.
 See \l{Qt Licensing} for further details.
 
-Furthermore Qt QML potentially contains third party
+Furthermore Qt QML in Qt \QtVersion may contain third party
 modules under following permissive licenses:
 
 \generatelist{groupsbymodule attributions-qtqml}
diff --git a/src/qml/doc/src/statemachine.qdoc b/src/qml/doc/src/statemachine.qdoc
index 56a8746e1e..6986f1baa0 100644
--- a/src/qml/doc/src/statemachine.qdoc
+++ b/src/qml/doc/src/statemachine.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,13 +20,13 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
 
 /*!
-  \qmlmodule QtQml.StateMachine 1.0
+  \qmlmodule QtQml.StateMachine 1.\QtMinorVersion
   \title Declarative State Machine QML Types
   \brief Provides QML types to create and execute state graphs.
 
@@ -61,16 +61,16 @@
 
   \annotatedlist statemachine-qmltypes
 
-  \section1 Using both QtQuick and QtQml.StateMachine imports
+  \section1 Using Both QtQuick and QtQml.StateMachine Imports
 
   \warning If you're attempting to import both \l{QtQuick} and
     \e{QtQml.StateMachine} in one single QML file, make sure to import
     \e{QtQml.StateMachine} \e{last}. This way, the \e{State} type is provided
     by the Declarative State Machine Framework and not by \l{QtQuick}:
 
-  \qml
-    import QtQuick 2.0
-    import QtQml.StateMachine 1.0
+  \qml \QtMinorVersion
+    import QtQuick 2.\1
+    import QtQml.StateMachine 1.\1
 
     StateMachine {
         State {
@@ -82,9 +82,9 @@
   Alternatively, you can import \e{QtQml.StateMachine} into a separate
   namespace to avoid any ambiguity with QtQuick's \e{State} item:
 
-  \qml
-    import QtQuick 2.0
-    import QtQml.StateMachine 1.0 as DSM
+  \qml \QtMinorVersion
+    import QtQuick 2.\1
+    import QtQml.StateMachine 1.\1 as DSM
 
     DSM.StateMachine {
         DSM.State {
diff --git a/src/qml/jit/jit.pri b/src/qml/jit/jit.pri
index 7ea4e951d5..49eb2e8a37 100644
--- a/src/qml/jit/jit.pri
+++ b/src/qml/jit/jit.pri
@@ -1,22 +1,30 @@
-include(../../3rdparty/masm/masm-defs.pri)
-
 INCLUDEPATH += $$PWD
 INCLUDEPATH += $$OUT_PWD
 
+SOURCES += \
+    $$PWD/qv4baselinejit.cpp \
+    $$PWD/qv4baselineassembler.cpp \
+    $$PWD/qv4assemblercommon.cpp
+
 HEADERS += \
-    $$PWD/qv4assembler_p.h \
-    $$PWD/qv4regalloc_p.h \
-    $$PWD/qv4targetplatform_p.h \
-    $$PWD/qv4isel_masm_p.h \
-    $$PWD/qv4binop_p.h \
-    $$PWD/qv4unop_p.h \
-    $$PWD/qv4registerinfo_p.h
+    $$PWD/qv4baselinejit_p.h \
+    $$PWD/qv4baselineassembler_p.h \
+    $$PWD/qv4assemblercommon_p.h
 
+qtConfig(qml-tracing) {
 SOURCES += \
-    $$PWD/qv4assembler.cpp \
-    $$PWD/qv4regalloc.cpp \
-    $$PWD/qv4isel_masm.cpp \
-    $$PWD/qv4binop.cpp \
-    $$PWD/qv4unop.cpp \
+    $$PWD/qv4ir.cpp \
+    $$PWD/qv4operation.cpp \
+    $$PWD/qv4node.cpp \
+    $$PWD/qv4graph.cpp \
+    $$PWD/qv4graphbuilder.cpp \
+    $$PWD/qv4tracingjit.cpp \
 
-include(../../3rdparty/masm/masm.pri)
+HEADERS += \
+    $$PWD/qv4ir_p.h \
+    $$PWD/qv4operation_p.h \
+    $$PWD/qv4runtimesupport_p.h \
+    $$PWD/qv4node_p.h \
+    $$PWD/qv4graph_p.h \
+    $$PWD/qv4graphbuilder_p.h \
+}
diff --git a/src/qml/jit/qv4assembler.cpp b/src/qml/jit/qv4assembler.cpp
deleted file mode 100644
index d062f3bbb2..0000000000
--- a/src/qml/jit/qv4assembler.cpp
+++ /dev/null
@@ -1,726 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qv4isel_masm_p.h"
-#include "qv4runtime_p.h"
-#include "qv4ssa_p.h"
-#include "qv4regalloc_p.h"
-#include "qv4assembler_p.h"
-
-#include <assembler/LinkBuffer.h>
-#include <WTFStubs.h>
-
-#if !defined(V4_BOOTSTRAP)
-#include "qv4function_p.h"
-#endif
-
-#include <iostream>
-#include <QBuffer>
-#include <QCoreApplication>
-
-#if ENABLE(ASSEMBLER)
-
-#if USE(UDIS86)
-#  include <udis86.h>
-#endif
-
-using namespace QV4;
-using namespace QV4::JIT;
-
-CompilationUnit::~CompilationUnit()
-{
-}
-
-#if !defined(V4_BOOTSTRAP)
-
-void CompilationUnit::linkBackendToEngine(ExecutionEngine *engine)
-{
-    runtimeFunctions.resize(data->functionTableSize);
-    runtimeFunctions.fill(0);
-    for (int i = 0 ;i < runtimeFunctions.size(); ++i) {
-        const CompiledData::Function *compiledFunction = data->functionAt(i);
-
-        QV4::Function *runtimeFunction = new QV4::Function(engine, this, compiledFunction,
-                                                           (ReturnedValue (*)(QV4::ExecutionEngine *, const uchar *)) codeRefs[i].code().executableAddress());
-        runtimeFunctions[i] = runtimeFunction;
-    }
-}
-
-bool CompilationUnit::memoryMapCode(QString *errorString)
-{
-    Q_UNUSED(errorString);
-    codeRefs.resize(data->functionTableSize);
-
-    const char *basePtr = reinterpret_cast<const char *>(data);
-
-    for (uint i = 0; i < data->functionTableSize; ++i) {
-        const CompiledData::Function *compiledFunction = data->functionAt(i);
-        void *codePtr = const_cast<void *>(reinterpret_cast<const void *>(basePtr + compiledFunction->codeOffset));
-        JSC::MacroAssemblerCodeRef codeRef = JSC::MacroAssemblerCodeRef::createSelfManagedCodeRef(JSC::MacroAssemblerCodePtr(codePtr));
-        JSC::ExecutableAllocator::makeExecutable(codePtr, compiledFunction->codeSize);
-        codeRefs[i] = codeRef;
-
-        static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_ASM");
-        if (showCode) {
-            WTF::dataLogF("Mapped JIT code for %s\n", qPrintable(stringAt(compiledFunction->nameIndex)));
-            disassemble(codeRef.code(), compiledFunction->codeSize, "    ", WTF::dataFile());
-        }
-    }
-
-    return true;
-}
-
-#endif // !defined(V4_BOOTSTRAP)
-
-void CompilationUnit::prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit)
-{
-    const int codeAlignment = 16;
-    quint64 offset = WTF::roundUpToMultipleOf(codeAlignment, unit->unitSize);
-    Q_ASSERT(int(unit->functionTableSize) == codeRefs.size());
-    for (int i = 0; i < codeRefs.size(); ++i) {
-        CompiledData::Function *compiledFunction = const_cast<CompiledData::Function *>(unit->functionAt(i));
-        compiledFunction->codeOffset = offset;
-        compiledFunction->codeSize = codeRefs.at(i).size();
-        offset = WTF::roundUpToMultipleOf(codeAlignment, offset + compiledFunction->codeSize);
-    }
-}
-
-bool CompilationUnit::saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString)
-{
-    Q_ASSERT(device->pos() == unit->unitSize);
-    Q_ASSERT(device->atEnd());
-    Q_ASSERT(int(unit->functionTableSize) == codeRefs.size());
-
-    QByteArray padding;
-
-    for (int i = 0; i < codeRefs.size(); ++i) {
-        const CompiledData::Function *compiledFunction = unit->functionAt(i);
-
-        if (device->pos() > qint64(compiledFunction->codeOffset)) {
-            *errorString = QStringLiteral("Invalid state of cache file to write.");
-            return false;
-        }
-
-        const quint64 paddingSize = compiledFunction->codeOffset - device->pos();
-        padding.fill(0, paddingSize);
-        qint64 written = device->write(padding);
-        if (written != padding.size()) {
-            *errorString = device->errorString();
-            return false;
-        }
-
-        const void *undecoratedCodePtr = codeRefs.at(i).code().dataLocation();
-        written = device->write(reinterpret_cast<const char *>(undecoratedCodePtr), compiledFunction->codeSize);
-        if (written != qint64(compiledFunction->codeSize)) {
-            *errorString = device->errorString();
-            return false;
-        }
-    }
-    return true;
-}
-
-template <typename TargetConfiguration>
-Assembler<TargetConfiguration>::Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function* function, QV4::ExecutableAllocator *executableAllocator)
-    : _function(function)
-    , _nextBlock(0)
-    , _executableAllocator(executableAllocator)
-    , _jsGenerator(jsGenerator)
-{
-    _addrs.resize(_function->basicBlockCount());
-    _patches.resize(_function->basicBlockCount());
-    _labelPatches.resize(_function->basicBlockCount());
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::registerBlock(IR::BasicBlock* block, IR::BasicBlock *nextBlock)
-{
-    _addrs[block->index()] = label();
-    catchBlock = block->catchBlock;
-    _nextBlock = nextBlock;
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::jumpToBlock(IR::BasicBlock* current, IR::BasicBlock *target)
-{
-    Q_UNUSED(current);
-
-    if (target != _nextBlock)
-        _patches[target->index()].push_back(jump());
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::addPatch(IR::BasicBlock* targetBlock, Jump targetJump)
-{
-    _patches[targetBlock->index()].push_back(targetJump);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::addPatch(DataLabelPtr patch, Label target)
-{
-    DataLabelPatch p;
-    p.dataLabel = patch;
-    p.target = target;
-    _dataLabelPatches.push_back(p);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::addPatch(DataLabelPtr patch, IR::BasicBlock *target)
-{
-    _labelPatches[target->index()].push_back(patch);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::generateCJumpOnNonZero(RegisterID reg, IR::BasicBlock *currentBlock,
-                                       IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
-{
-    generateCJumpOnCompare(RelationalCondition::NotEqual, reg, TrustedImm32(0), currentBlock, trueBlock, falseBlock);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::generateCJumpOnCompare(RelationalCondition cond,
-                                       RegisterID left,
-                                       TrustedImm32 right,
-                                       IR::BasicBlock *currentBlock,
-                                       IR::BasicBlock *trueBlock,
-                                       IR::BasicBlock *falseBlock)
-{
-    if (trueBlock == _nextBlock) {
-        Jump target = branch32(invert(cond), left, right);
-        addPatch(falseBlock, target);
-    } else {
-        Jump target = branch32(cond, left, right);
-        addPatch(trueBlock, target);
-        jumpToBlock(currentBlock, falseBlock);
-    }
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::generateCJumpOnCompare(RelationalCondition cond,
-                                       RegisterID left,
-                                       RegisterID right,
-                                       IR::BasicBlock *currentBlock,
-                                       IR::BasicBlock *trueBlock,
-                                       IR::BasicBlock *falseBlock)
-{
-    if (trueBlock == _nextBlock) {
-        Jump target = branch32(invert(cond), left, right);
-        addPatch(falseBlock, target);
-    } else {
-        Jump target = branch32(cond, left, right);
-        addPatch(trueBlock, target);
-        jumpToBlock(currentBlock, falseBlock);
-    }
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Pointer
-Assembler<TargetConfiguration>::loadAddressForWriting(RegisterID tmp, IR::Expr *e, WriteBarrier::Type *barrier)
-{
-    if (barrier)
-        *barrier = WriteBarrier::NoBarrier;
-    IR::Temp *t = e->asTemp();
-    if (t)
-        return loadTempAddress(t);
-    else
-        return loadArgLocalAddressForWriting(tmp, e->asArgLocal(), barrier);
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadTempAddress(IR::Temp *t)
-{
-    if (t->kind == IR::Temp::StackSlot)
-        return stackSlotPointer(t);
-    else
-        Q_UNREACHABLE();
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Pointer
-Assembler<TargetConfiguration>::loadArgLocalAddressForWriting(RegisterID baseReg, IR::ArgLocal *al, WriteBarrier::Type *barrier)
-{
-    if (barrier)
-        *barrier = _function->argLocalRequiresWriteBarrier(al) ? WriteBarrier::Barrier : WriteBarrier::NoBarrier;
-
-    int32_t offset = 0;
-    int scope = al->scope;
-    loadPtr(Address(EngineRegister, targetStructureOffset(offsetof(EngineBase, current))), baseReg);
-
-    const qint32 outerOffset = targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, outer));
-    const qint32 localsOffset = targetStructureOffset(Heap::CallContextData::baseOffset + offsetof(Heap::CallContextData, function))
-                                + 8 // locals is always 8 bytes away from function, regardless of pointer size.
-                                + offsetof(ValueArray<0>, values);
-
-    while (scope) {
-        loadPtr(Address(baseReg, outerOffset), baseReg);
-        --scope;
-    }
-    switch (al->kind) {
-    case IR::ArgLocal::Formal:
-    case IR::ArgLocal::ScopedFormal: {
-        if (barrier && *barrier == WriteBarrier::Barrier) {
-            // if we need a barrier, the baseReg has to point to the ExecutionContext
-            // callData comes directly after locals, calculate the offset using that
-            offset = localsOffset + _function->localsCountForScope(al) * sizeof(Value);
-            offset += sizeof(CallData) + (al->index - 1) * sizeof(Value);
-        } else {
-            const qint32 callDataOffset = targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, callData));
-            loadPtr(Address(baseReg, callDataOffset), baseReg);
-            offset = sizeof(CallData) + (al->index - 1) * sizeof(Value);
-        }
-    } break;
-    case IR::ArgLocal::Local:
-    case IR::ArgLocal::ScopedLocal: {
-        offset = localsOffset + al->index * sizeof(Value);
-    } break;
-    default:
-        Q_UNREACHABLE();
-    }
-    return Pointer(baseReg, offset);
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Pointer Assembler<TargetConfiguration>::loadStringAddress(RegisterID reg, const QString &string)
-{
-    loadPtr(Address(Assembler::EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, current))), Assembler::ScratchRegister);
-    loadPtr(Address(Assembler::ScratchRegister, targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, compilationUnit))), Assembler::ScratchRegister);
-    loadPtr(Address(Assembler::ScratchRegister, offsetof(CompiledData::CompilationUnitBase, runtimeStrings)), reg);
-    const int id = _jsGenerator->registerString(string);
-    return Pointer(reg, id * RegisterSize);
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(IR::Const *c, RegisterID baseReg)
-{
-    return loadConstant(convertToValue<TargetPrimitive>(c), baseReg);
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Address Assembler<TargetConfiguration>::loadConstant(const TargetPrimitive &v, RegisterID baseReg)
-{
-    loadPtr(Address(Assembler::EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, current))), baseReg);
-    loadPtr(Address(baseReg, targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, constantTable))), baseReg);
-    const int index = _jsGenerator->registerConstant(v.rawValue());
-    return Address(baseReg, index * sizeof(QV4::Value));
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::loadStringRef(RegisterID reg, const QString &string)
-{
-    const int id = _jsGenerator->registerString(string);
-    move(TrustedImm32(id), reg);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::storeValue(TargetPrimitive value, IR::Expr *destination)
-{
-    WriteBarrier::Type barrier;
-    Address addr = loadAddressForWriting(ScratchRegister, destination, &barrier);
-    storeValue(value, addr, barrier);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::enterStandardStackFrame(const RegisterInformation &regularRegistersToSave,
-                                        const RegisterInformation &fpRegistersToSave)
-{
-    platformEnterStandardStackFrame(this);
-
-    move(StackPointerRegister, JITTargetPlatform::FramePointerRegister);
-
-    const int frameSize = _stackLayout->calculateStackFrameSize();
-    subPtr(TrustedImm32(frameSize), StackPointerRegister);
-
-    Address slotAddr(JITTargetPlatform::FramePointerRegister, 0);
-    for (int i = 0, ei = fpRegistersToSave.size(); i < ei; ++i) {
-        Q_ASSERT(fpRegistersToSave.at(i).isFloatingPoint());
-        slotAddr.offset -= sizeof(double);
-        TargetConfiguration::MacroAssembler::storeDouble(fpRegistersToSave.at(i).reg<FPRegisterID>(), slotAddr);
-    }
-    for (int i = 0, ei = regularRegistersToSave.size(); i < ei; ++i) {
-        Q_ASSERT(regularRegistersToSave.at(i).isRegularRegister());
-        slotAddr.offset -= RegisterSize;
-        storePtr(regularRegistersToSave.at(i).reg<RegisterID>(), slotAddr);
-    }
-
-    platformFinishEnteringStandardStackFrame(this);
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::leaveStandardStackFrame(const RegisterInformation &regularRegistersToSave,
-                                        const RegisterInformation &fpRegistersToSave)
-{
-    Address slotAddr(JITTargetPlatform::FramePointerRegister, -regularRegistersToSave.size() * RegisterSize - fpRegistersToSave.size() * sizeof(double));
-
-    // restore the callee saved registers
-    for (int i = regularRegistersToSave.size() - 1; i >= 0; --i) {
-        Q_ASSERT(regularRegistersToSave.at(i).isRegularRegister());
-        loadPtr(slotAddr, regularRegistersToSave.at(i).reg<RegisterID>());
-        slotAddr.offset += RegisterSize;
-    }
-    for (int i = fpRegistersToSave.size() - 1; i >= 0; --i) {
-        Q_ASSERT(fpRegistersToSave.at(i).isFloatingPoint());
-        TargetConfiguration::MacroAssembler::loadDouble(slotAddr, fpRegistersToSave.at(i).reg<FPRegisterID>());
-        slotAddr.offset += sizeof(double);
-    }
-
-    Q_ASSERT(slotAddr.offset == 0);
-
-    const int frameSize = _stackLayout->calculateStackFrameSize();
-    platformLeaveStandardStackFrame(this, frameSize);
-}
-
-
-
-
-// Try to load the source expression into the destination FP register. This assumes that two
-// general purpose (integer) registers are available: the ScratchRegister and the
-// ReturnValueRegister. It returns a Jump if no conversion can be performed.
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::genTryDoubleConversion(IR::Expr *src, FPRegisterID dest)
-{
-    switch (src->type) {
-    case IR::DoubleType:
-        moveDouble(toDoubleRegister(src, dest), dest);
-        return Assembler::Jump();
-    case IR::SInt32Type:
-        convertInt32ToDouble(toInt32Register(src, Assembler::ScratchRegister),
-                                  dest);
-        return Assembler::Jump();
-    case IR::UInt32Type:
-        convertUInt32ToDouble(toUInt32Register(src, Assembler::ScratchRegister),
-                                   dest, Assembler::ReturnValueRegister);
-        return Assembler::Jump();
-    case IR::NullType:
-    case IR::UndefinedType:
-    case IR::BoolType:
-        // TODO?
-    case IR::StringType:
-        return jump();
-    default:
-        break;
-    }
-
-    Q_ASSERT(src->asTemp() || src->asArgLocal());
-
-    // It's not a number type, so it cannot be in a register.
-    Q_ASSERT(src->asArgLocal() || src->asTemp()->kind != IR::Temp::PhysicalRegister || src->type == IR::BoolType);
-
-    Assembler::Pointer tagAddr = loadAddressForReading(Assembler::ScratchRegister, src);
-    tagAddr.offset += 4;
-    load32(tagAddr, Assembler::ScratchRegister);
-
-    // check if it's an int32:
-    Assembler::Jump isNoInt = branch32(Assembler::NotEqual, Assembler::ScratchRegister,
-                                       Assembler::TrustedImm32(quint32(ValueTypeInternal::Integer)));
-    convertInt32ToDouble(toInt32Register(src, Assembler::ScratchRegister), dest);
-    Assembler::Jump intDone = jump();
-
-    // not an int, check if it's a double:
-    isNoInt.link(this);
-    Assembler::Jump isNoDbl = RegisterSizeDependentOps::checkIfTagRegisterIsDouble(this, ScratchRegister);
-    toDoubleRegister(src, dest);
-    intDone.link(this);
-
-    return isNoDbl;
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::branchDouble(bool invertCondition, IR::AluOp op,
-                                                   IR::Expr *left, IR::Expr *right)
-{
-    DoubleCondition cond;
-    switch (op) {
-    case IR::OpGt: cond = Assembler::DoubleGreaterThan; break;
-    case IR::OpLt: cond = Assembler::DoubleLessThan; break;
-    case IR::OpGe: cond = Assembler::DoubleGreaterThanOrEqual; break;
-    case IR::OpLe: cond = Assembler::DoubleLessThanOrEqual; break;
-    case IR::OpEqual:
-    case IR::OpStrictEqual: cond = Assembler::DoubleEqual; break;
-    case IR::OpNotEqual:
-    case IR::OpStrictNotEqual: cond = Assembler::DoubleNotEqualOrUnordered; break; // No, the inversion of DoubleEqual is NOT DoubleNotEqual.
-    default:
-        Q_UNREACHABLE();
-    }
-    if (invertCondition)
-        cond = TargetConfiguration::MacroAssembler::invert(cond);
-
-    return TargetConfiguration::MacroAssembler::branchDouble(cond, toDoubleRegister(left, FPGpr0), toDoubleRegister(right, JITTargetPlatform::FPGpr1));
-}
-
-template <typename TargetConfiguration>
-typename Assembler<TargetConfiguration>::Jump Assembler<TargetConfiguration>::branchInt32(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right)
-{
-    Assembler::RelationalCondition cond;
-    switch (op) {
-    case IR::OpGt: cond = Assembler::GreaterThan; break;
-    case IR::OpLt: cond = Assembler::LessThan; break;
-    case IR::OpGe: cond = Assembler::GreaterThanOrEqual; break;
-    case IR::OpLe: cond = Assembler::LessThanOrEqual; break;
-    case IR::OpEqual:
-    case IR::OpStrictEqual: cond = Assembler::Equal; break;
-    case IR::OpNotEqual:
-    case IR::OpStrictNotEqual: cond = Assembler::NotEqual; break;
-    default:
-        Q_UNREACHABLE();
-    }
-    if (invertCondition)
-        cond = TargetConfiguration::MacroAssembler::invert(cond);
-
-    return TargetConfiguration::MacroAssembler::branch32(cond,
-                                                         toInt32Register(left, Assembler::ScratchRegister),
-                                                         toInt32Register(right, Assembler::ReturnValueRegister));
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::setStackLayout(int maxArgCountForBuiltins, int regularRegistersToSave, int fpRegistersToSave)
-{
-    _stackLayout.reset(new StackLayout(_function, maxArgCountForBuiltins, regularRegistersToSave, fpRegistersToSave));
-}
-
-template <typename TargetConfiguration>
-void Assembler<TargetConfiguration>::returnFromFunction(IR::Ret *s, RegisterInformation regularRegistersToSave, RegisterInformation fpRegistersToSave)
-{
-    if (!s) {
-        // this only happens if the method doesn't have a return statement and can
-        // only exit through an exception
-    } else if (IR::Temp *t = s->expr->asTemp()) {
-        RegisterSizeDependentOps::setFunctionReturnValueFromTemp(this, t);
-    } else if (IR::Const *c = s->expr->asConst()) {
-        auto retVal = convertToValue<TargetPrimitive>(c);
-        RegisterSizeDependentOps::setFunctionReturnValueFromConst(this, retVal);
-    } else {
-        Q_UNREACHABLE();
-        Q_UNUSED(s);
-    }
-
-    Label leaveStackFrame = label();
-
-    const int locals = stackLayout().calculateJSStackFrameSize();
-    subPtr(TrustedImm32(sizeof(QV4::Value)*locals), JITTargetPlatform::LocalsRegister);
-    storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::EngineRegister, targetStructureOffset(offsetof(EngineBase, jsStackTop))));
-
-    leaveStandardStackFrame(regularRegistersToSave, fpRegistersToSave);
-    ret();
-
-    exceptionReturnLabel = label();
-    auto retVal = TargetPrimitive::undefinedValue();
-    RegisterSizeDependentOps::setFunctionReturnValueFromConst(this, retVal);
-    jump(leaveStackFrame);
-}
-
-namespace {
-class QIODevicePrintStream: public FilePrintStream
-{
-    Q_DISABLE_COPY(QIODevicePrintStream)
-
-public:
-    explicit QIODevicePrintStream(QIODevice *dest)
-        : FilePrintStream(0)
-        , dest(dest)
-        , buf(4096, '0')
-    {
-        Q_ASSERT(dest);
-    }
-
-    ~QIODevicePrintStream()
-    {}
-
-    void vprintf(const char* format, va_list argList) override WTF_ATTRIBUTE_PRINTF(2, 0)
-    {
-        const int written = qvsnprintf(buf.data(), buf.size(), format, argList);
-        if (written > 0)
-            dest->write(buf.constData(), written);
-        memset(buf.data(), 0, qMin(written, buf.size()));
-    }
-
-    void flush() override
-    {}
-
-private:
-    QIODevice *dest;
-    QByteArray buf;
-};
-} // anonymous namespace
-
-static void printDisassembledOutputWithCalls(QByteArray processedOutput, const QHash<void*, const char*>& functions)
-{
-    for (QHash<void*, const char*>::ConstIterator it = functions.begin(), end = functions.end();
-         it != end; ++it) {
-        const QByteArray ptrString = "0x" + QByteArray::number(quintptr(it.key()), 16);
-        int idx = processedOutput.indexOf(ptrString);
-        if (idx < 0)
-            continue;
-        idx = processedOutput.lastIndexOf('\n', idx);
-        if (idx < 0)
-            continue;
-        processedOutput = processedOutput.insert(idx, QByteArrayLiteral("                          ; call ") + it.value());
-    }
-
-    qDebug("%s", processedOutput.constData());
-}
-
-#if defined(Q_OS_LINUX)
-static FILE *pmap;
-
-static void qt_closePmap()
-{
-    if (pmap) {
-        fclose(pmap);
-        pmap = 0;
-    }
-}
-
-#endif
-
-template <typename TargetConfiguration>
-JSC::MacroAssemblerCodeRef Assembler<TargetConfiguration>::link(int *codeSize)
-{
-    Label endOfCode = label();
-
-    {
-        for (size_t i = 0, ei = _patches.size(); i != ei; ++i) {
-            Label target = _addrs.at(i);
-            Q_ASSERT(target.isSet());
-            for (Jump jump : qAsConst(_patches.at(i)))
-                jump.linkTo(target, this);
-        }
-    }
-
-    JSC::JSGlobalData dummy(_executableAllocator);
-    JSC::LinkBuffer<typename TargetConfiguration::MacroAssembler> linkBuffer(dummy, this, 0);
-
-    for (const DataLabelPatch &p : qAsConst(_dataLabelPatches))
-        linkBuffer.patch(p.dataLabel, linkBuffer.locationOf(p.target));
-
-    // link exception handlers
-    for (Jump jump : qAsConst(exceptionPropagationJumps))
-        linkBuffer.link(jump, linkBuffer.locationOf(exceptionReturnLabel));
-
-    {
-        for (size_t i = 0, ei = _labelPatches.size(); i != ei; ++i) {
-            Label target = _addrs.at(i);
-            Q_ASSERT(target.isSet());
-            for (DataLabelPtr label : _labelPatches.at(i))
-                linkBuffer.patch(label, linkBuffer.locationOf(target));
-        }
-    }
-
-    *codeSize = linkBuffer.offsetOf(endOfCode);
-
-    QByteArray name;
-
-    JSC::MacroAssemblerCodeRef codeRef;
-
-    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_ASM");
-    if (showCode) {
-        QHash<void*, const char*> functions;
-#ifndef QT_NO_DEBUG
-        for (CallInfo call : qAsConst(_callInfos))
-            functions[linkBuffer.locationOf(call.label).dataLocation()] = call.functionName;
-#endif
-
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        WTF::setDataFile(new QIODevicePrintStream(&buf));
-
-        name = _function->name->toUtf8();
-        if (name.isEmpty())
-            name = "IR::Function(0x" + QByteArray::number(quintptr(_function), 16) + ')';
-        codeRef = linkBuffer.finalizeCodeWithDisassembly("%s", name.data());
-
-        WTF::setDataFile(stderr);
-        printDisassembledOutputWithCalls(buf.data(), functions);
-    } else {
-        codeRef = linkBuffer.finalizeCodeWithoutDisassembly();
-    }
-
-#if defined(Q_OS_LINUX)
-    // This implements writing of JIT'd addresses so that perf can find the
-    // symbol names.
-    //
-    // Perf expects the mapping to be in a certain place and have certain
-    // content, for more information, see:
-    // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/jit-interface.txt
-    static bool doProfile = !qEnvironmentVariableIsEmpty("QV4_PROFILE_WRITE_PERF_MAP");
-    static bool profileInitialized = false;
-    if (doProfile && !profileInitialized) {
-        profileInitialized = true;
-
-        char pname[PATH_MAX];
-        snprintf(pname, PATH_MAX - 1, "/tmp/perf-%lu.map",
-                                      (unsigned long)QCoreApplication::applicationPid());
-
-        pmap = fopen(pname, "w");
-        if (!pmap)
-            qWarning("QV4: Can't write %s, call stacks will not contain JavaScript function names", pname);
-
-        // make sure we clean up nicely
-        std::atexit(qt_closePmap);
-    }
-
-    if (pmap) {
-        // this may have been pre-populated, if QV4_SHOW_ASM was on
-        if (name.isEmpty()) {
-            name = _function->name->toUtf8();
-            if (name.isEmpty())
-                name = "IR::Function(0x" + QByteArray::number(quintptr(_function), 16) + ')';
-        }
-
-        fprintf(pmap, "%llx %x %.*s\n",
-                      (long long unsigned int)codeRef.code().executableAddress(),
-                      *codeSize,
-                      name.length(),
-                      name.constData());
-        fflush(pmap);
-    }
-#endif
-
-    return codeRef;
-}
-
-template class QV4::JIT::Assembler<DefaultAssemblerTargetConfiguration>;
-#if defined(V4_BOOTSTRAP)
-#if !CPU(ARM_THUMB2)
-template class QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>;
-#endif
-#if !CPU(ARM64)
-template class QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>>;
-#endif
-#endif
-
-#endif
diff --git a/src/qml/jit/qv4assembler_p.h b/src/qml/jit/qv4assembler_p.h
deleted file mode 100644
index 9e38696d7a..0000000000
--- a/src/qml/jit/qv4assembler_p.h
+++ /dev/null
@@ -1,1851 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#ifndef QV4ASSEMBLER_P_H
-#define QV4ASSEMBLER_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "private/qv4global_p.h"
-#include "private/qv4jsir_p.h"
-#include "private/qv4isel_p.h"
-#include "private/qv4isel_util_p.h"
-#include "private/qv4value_p.h"
-#include "private/qv4context_p.h"
-#include "private/qv4engine_p.h"
-#include "private/qv4writebarrier_p.h"
-#include "qv4targetplatform_p.h"
-
-#include <config.h>
-#include <wtf/Vector.h>
-
-#include <climits>
-
-#if ENABLE(ASSEMBLER)
-
-#include <assembler/MacroAssembler.h>
-#include <assembler/MacroAssemblerCodeRef.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace JIT {
-
-struct CompilationUnit : public QV4::CompiledData::CompilationUnit
-{
-    virtual ~CompilationUnit();
-
-#if !defined(V4_BOOTSTRAP)
-    void linkBackendToEngine(QV4::ExecutionEngine *engine) Q_DECL_OVERRIDE;
-    bool memoryMapCode(QString *errorString) Q_DECL_OVERRIDE;
-#endif
-    void prepareCodeOffsetsForDiskStorage(CompiledData::Unit *unit) Q_DECL_OVERRIDE;
-    bool saveCodeToDisk(QIODevice *device, const CompiledData::Unit *unit, QString *errorString) Q_DECL_OVERRIDE;
-
-    // Coderef + execution engine
-
-    QVector<JSC::MacroAssemblerCodeRef> codeRefs;
-};
-
-template <typename PlatformAssembler, TargetOperatingSystemSpecialization Specialization>
-struct AssemblerTargetConfiguration
-{
-    typedef JSC::MacroAssembler<PlatformAssembler> MacroAssembler;
-    typedef TargetPlatform<PlatformAssembler, Specialization> Platform;
-    // More things coming here in the future, such as Target OS
-};
-
-#if CPU(ARM_THUMB2)
-typedef JSC::MacroAssemblerARMv7 DefaultPlatformMacroAssembler;
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#elif CPU(ARM64)
-typedef JSC::MacroAssemblerARM64 DefaultPlatformMacroAssembler;
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#elif CPU(ARM_TRADITIONAL)
-typedef JSC::MacroAssemblerARM DefaultPlatformMacroAssembler;
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#elif CPU(MIPS)
-typedef JSC::MacroAssemblerMIPS DefaultPlatformMacroAssembler;
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#elif CPU(X86)
-typedef JSC::MacroAssemblerX86 DefaultPlatformMacroAssembler;
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#elif CPU(X86_64)
-typedef JSC::MacroAssemblerX86_64 DefaultPlatformMacroAssembler;
-
-#if OS(WINDOWS)
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, WindowsSpecialization> DefaultAssemblerTargetConfiguration;
-#else
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#endif
-
-#elif CPU(SH4)
-typedef JSC::MacroAssemblerSH4 DefaultPlatformMacroAssembler;
-typedef AssemblerTargetConfiguration<DefaultPlatformMacroAssembler, NoOperatingSystemSpecialization> DefaultAssemblerTargetConfiguration;
-#endif
-
-#define isel_stringIfyx(s) #s
-#define isel_stringIfy(s) isel_stringIfyx(s)
-
-#define generateRuntimeCall(as, t, function, ...) \
-    as->generateFunctionCallImp(Runtime::Method_##function##_NeedsExceptionCheck, t, "Runtime::" isel_stringIfy(function), typename JITAssembler::RuntimeCall(QV4::Runtime::function), __VA_ARGS__)
-
-
-template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform, int RegisterSize>
-struct RegisterSizeDependentAssembler
-{
-};
-
-template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform>
-struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatform, 4>
-{
-    using RegisterID = typename JITAssembler::RegisterID;
-    using FPRegisterID = typename JITAssembler::FPRegisterID;
-    using RelationalCondition = typename JITAssembler::RelationalCondition;
-    using ResultCondition = typename JITAssembler::ResultCondition;
-    using Address = typename JITAssembler::Address;
-    using Pointer = typename JITAssembler::Pointer;
-    using TrustedImm32 = typename JITAssembler::TrustedImm32;
-    using TrustedImm64 = typename JITAssembler::TrustedImm64;
-    using Jump = typename JITAssembler::Jump;
-    using Label = typename JITAssembler::Label;
-    using ValueTypeInternal = Value::ValueTypeInternal_32;
-    using TargetPrimitive = TargetPrimitive32;
-
-    static void emitSetGrayBit(JITAssembler *as, RegisterID base)
-    {
-        bool returnValueUsed = (base == TargetPlatform::ReturnValueRegister);
-
-        as->push(TargetPlatform::EngineRegister); // free up one register for work
-
-        RegisterID grayBitmap = returnValueUsed ? TargetPlatform::ScratchRegister : TargetPlatform::ReturnValueRegister;
-        as->move(base, grayBitmap);
-        Q_ASSERT(base != grayBitmap);
-        as->urshift32(TrustedImm32(Chunk::ChunkShift), grayBitmap);
-        as->lshift32(TrustedImm32(Chunk::ChunkShift), grayBitmap);
-        Q_STATIC_ASSERT(offsetof(Chunk, grayBitmap) == 0);
-
-        RegisterID index = base;
-        as->move(base, index);
-        as->sub32(grayBitmap, index);
-        as->urshift32(TrustedImm32(Chunk::SlotSizeShift), index);
-        RegisterID grayIndex = TargetPlatform::EngineRegister;
-        as->move(index, grayIndex);
-        as->urshift32(TrustedImm32(Chunk::BitShift), grayIndex);
-        as->lshift32(TrustedImm32(2), grayIndex); // 4 bytes per quintptr
-        as->add32(grayIndex, grayBitmap);
-        as->and32(TrustedImm32(Chunk::Bits - 1), index);
-
-        RegisterID bit = TargetPlatform::EngineRegister;
-        as->move(TrustedImm32(1), bit);
-        as->lshift32(index, bit);
-
-        as->load32(Pointer(grayBitmap, 0), index);
-        as->or32(bit, index);
-        as->store32(index, Pointer(grayBitmap, 0));
-
-        as->pop(TargetPlatform::EngineRegister);
-    }
-
-#if WRITEBARRIER(none)
-    static Q_ALWAYS_INLINE void emitWriteBarrier(JITAssembler *, Address) {}
-#endif
-
-    static void loadDouble(JITAssembler *as, Address addr, FPRegisterID dest)
-    {
-        as->MacroAssembler::loadDouble(addr, dest);
-    }
-
-    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr, WriteBarrier::Type barrier)
-    {
-        as->MacroAssembler::storeDouble(source, addr);
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, addr);
-    }
-
-    static void storeDouble(JITAssembler *as, FPRegisterID source, IR::Expr* target)
-    {
-        WriteBarrier::Type barrier;
-        Pointer ptr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
-        as->storeDouble(source, ptr, barrier);
-    }
-
-    static void storeValue(JITAssembler *as, TargetPrimitive value, Address destination, WriteBarrier::Type barrier)
-    {
-        as->store32(TrustedImm32(value.value()), destination);
-        destination.offset += 4;
-        as->store32(TrustedImm32(value.tag()), destination);
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, destination);
-    }
-
-    template <typename Source, typename Destination>
-    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination, WriteBarrier::Type barrier)
-    {
-        as->loadDouble(source, TargetPlatform::FPGpr0);
-        // We need to pass NoBarrier to storeDouble and call emitWriteBarrier ourselves, as the
-        // code in storeDouble assumes the type we're storing is actually a double, something
-        // that isn't always the case here.
-        as->storeDouble(TargetPlatform::FPGpr0, destination, WriteBarrier::NoBarrier);
-        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, destination);
-    }
-
-    static void loadDoubleConstant(JITAssembler *as, IR::Const *c, FPRegisterID target)
-    {
-        as->MacroAssembler::loadDouble(as->loadConstant(c, TargetPlatform::ScratchRegister), target);
-    }
-
-    static void storeReturnValue(JITAssembler *as, FPRegisterID dest)
-    {
-        as->moveIntsToDouble(TargetPlatform::LowReturnValueRegister, TargetPlatform::HighReturnValueRegister, dest, TargetPlatform::FPGpr0);
-    }
-
-    static void storeReturnValue(JITAssembler *as, const Pointer &dest, WriteBarrier::Type barrier)
-    {
-        Address destination = dest;
-        as->store32(TargetPlatform::LowReturnValueRegister, destination);
-        destination.offset += 4;
-        as->store32(TargetPlatform::HighReturnValueRegister, destination);
-        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, dest);
-    }
-
-    static void setFunctionReturnValueFromTemp(JITAssembler *as, IR::Temp *t)
-    {
-        const auto lowReg = TargetPlatform::LowReturnValueRegister;
-        const auto highReg = TargetPlatform::HighReturnValueRegister;
-
-        if (t->kind == IR::Temp::PhysicalRegister) {
-            switch (t->type) {
-            case IR::DoubleType:
-                as->moveDoubleToInts((FPRegisterID) t->index, lowReg, highReg);
-                break;
-            case IR::UInt32Type: {
-                RegisterID srcReg = (RegisterID) t->index;
-                Jump intRange = as->branch32(JITAssembler::GreaterThanOrEqual, srcReg, TrustedImm32(0));
-                as->convertUInt32ToDouble(srcReg, TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister);
-                as->moveDoubleToInts(TargetPlatform::FPGpr0, lowReg, highReg);
-                Jump done = as->jump();
-                intRange.link(as);
-                as->move(srcReg, lowReg);
-                as->move(TrustedImm32(quint32(QV4::Value::ValueTypeInternal_32::Integer)), highReg);
-                done.link(as);
-            } break;
-            case IR::SInt32Type:
-                as->move((RegisterID) t->index, lowReg);
-                as->move(TrustedImm32(quint32(QV4::Value::ValueTypeInternal_32::Integer)), highReg);
-                break;
-            case IR::BoolType:
-                as->move((RegisterID) t->index, lowReg);
-                as->move(TrustedImm32(quint32(QV4::Value::ValueTypeInternal_32::Boolean)), highReg);
-                break;
-            default:
-                Q_UNREACHABLE();
-            }
-        } else {
-            Pointer addr = as->loadAddressForReading(TargetPlatform::ScratchRegister, t);
-            as->load32(addr, lowReg);
-            addr.offset += 4;
-            as->load32(addr, highReg);
-        }
-    }
-
-    static void setFunctionReturnValueFromConst(JITAssembler *as, TargetPrimitive retVal)
-    {
-        as->move(TrustedImm32(retVal.value()), TargetPlatform::LowReturnValueRegister);
-        as->move(TrustedImm32(retVal.tag()), TargetPlatform::HighReturnValueRegister);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::Temp* temp, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(temp);
-        Q_UNUSED(dest);
-        Q_UNUSED(argumentNumber);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::ArgLocal* al, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(al);
-        Q_UNUSED(dest);
-        Q_UNUSED(argumentNumber);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::Const* c, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(c);
-        Q_UNUSED(dest);
-        Q_UNUSED(argumentNumber);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::Expr* expr, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(expr);
-        Q_UNUSED(dest);
-        Q_UNUSED(argumentNumber);
-    }
-
-    static void zeroRegister(JITAssembler *as, RegisterID reg)
-    {
-        as->move(TrustedImm32(0), reg);
-    }
-
-    static void zeroStackSlot(JITAssembler *as, int slot)
-    {
-        as->poke(TrustedImm32(0), slot);
-    }
-
-    static void generateCJumpOnUndefined(JITAssembler *as,
-                                  RelationalCondition cond, IR::Expr *right,
-                                  RegisterID scratchRegister, RegisterID tagRegister,
-                                  IR::BasicBlock *nextBlock, IR::BasicBlock *currentBlock,
-                                  IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
-    {
-        Pointer tagAddr = as->loadAddressForReading(scratchRegister, right);
-        as->load32(tagAddr, tagRegister);
-        Jump j = as->branch32(JITAssembler::invert(cond), tagRegister, TrustedImm32(0));
-        as->addPatch(falseBlock, j);
-
-        tagAddr.offset += 4;
-        as->load32(tagAddr, tagRegister);
-        const TrustedImm32 tag(QV4::Value::Managed_Type_Internal);
-        Q_ASSERT(nextBlock == as->nextBlock());
-        Q_UNUSED(nextBlock);
-        as->generateCJumpOnCompare(cond, tagRegister, tag, currentBlock, trueBlock, falseBlock);
-    }
-
-    static void convertVarToSInt32(JITAssembler *as, IR::Expr *source, IR::Expr *target)
-    {
-        Q_ASSERT(source->type == IR::VarType);
-        // load the tag:
-        Pointer addr = as->loadAddressForReading(TargetPlatform::ScratchRegister, source);
-        Pointer tagAddr = addr;
-        tagAddr.offset += 4;
-        as->load32(tagAddr, TargetPlatform::ReturnValueRegister);
-
-        // check if it's an int32:
-        Jump fallback = as->branch32(RelationalCondition::NotEqual, TargetPlatform::ReturnValueRegister,
-                                     TrustedImm32(quint32(Value::ValueTypeInternal_32::Integer)));
-        IR::Temp *targetTemp = target->asTemp();
-        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            as->load32(addr, TargetPlatform::ReturnValueRegister);
-            WriteBarrier::Type barrier;
-            Pointer targetAddr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
-            as->store32(TargetPlatform::ReturnValueRegister, targetAddr);
-            targetAddr.offset += 4;
-            as->store32(TrustedImm32(quint32(Value::ValueTypeInternal_32::Integer)), targetAddr);
-            if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-                emitWriteBarrier(as, targetAddr);
-        } else {
-            as->load32(addr, (RegisterID) targetTemp->index);
-        }
-        Jump intDone = as->jump();
-
-        // not an int:
-        fallback.link(as);
-        generateRuntimeCall(as, TargetPlatform::ReturnValueRegister, toInt,
-                            as->loadAddressForReading(TargetPlatform::ScratchRegister, source));
-        as->storeInt32(TargetPlatform::ReturnValueRegister, target);
-
-        intDone.link(as);
-    }
-
-    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr, WriteBarrier::Type barrier)
-    {
-        as->store32(registerWithPtr, destAddr);
-        destAddr.offset += 4;
-        as->store32(TrustedImm32(QV4::Value::Managed_Type_Internal_32), destAddr);
-        if (WriteBarrier::isRequired<WriteBarrier::Object>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, destAddr);
-    }
-
-    static Jump generateIsDoubleCheck(JITAssembler *as, RegisterID tagOrValueRegister)
-    {
-        as->and32(TrustedImm32(Value::NotDouble_Mask), tagOrValueRegister);
-        return as->branch32(RelationalCondition::NotEqual, tagOrValueRegister,
-                            TrustedImm32(Value::NotDouble_Mask));
-    }
-
-    static void initializeLocalVariables(JITAssembler *as, int localsCount)
-    {
-        as->move(TrustedImm32(0), TargetPlatform::ReturnValueRegister);
-        as->move(TrustedImm32(localsCount), TargetPlatform::ScratchRegister);
-        Label loop = as->label();
-        as->store32(TargetPlatform::ReturnValueRegister, Address(TargetPlatform::LocalsRegister));
-        as->add32(TrustedImm32(4), TargetPlatform::LocalsRegister);
-        as->store32(TargetPlatform::ReturnValueRegister, Address(TargetPlatform::LocalsRegister));
-        as->add32(TrustedImm32(4), TargetPlatform::LocalsRegister);
-        Jump jump = as->branchSub32(ResultCondition::NonZero, TrustedImm32(1), TargetPlatform::ScratchRegister);
-        jump.linkTo(loop, as);
-    }
-
-    static Jump checkIfTagRegisterIsDouble(JITAssembler *as, RegisterID tagRegister)
-    {
-        as->and32(TrustedImm32(Value::NotDouble_Mask), tagRegister);
-        Jump isNoDbl = as->branch32(RelationalCondition::Equal, tagRegister, TrustedImm32(Value::NotDouble_Mask));
-        return isNoDbl;
-    }
-};
-
-template <typename JITAssembler, typename MacroAssembler, typename TargetPlatform>
-struct RegisterSizeDependentAssembler<JITAssembler, MacroAssembler, TargetPlatform, 8>
-{
-    using RegisterID = typename JITAssembler::RegisterID;
-    using FPRegisterID = typename JITAssembler::FPRegisterID;
-    using Address = typename JITAssembler::Address;
-    using TrustedImm32 = typename JITAssembler::TrustedImm32;
-    using TrustedImm64 = typename JITAssembler::TrustedImm64;
-    using Pointer = typename JITAssembler::Pointer;
-    using RelationalCondition = typename JITAssembler::RelationalCondition;
-    using ResultCondition = typename JITAssembler::ResultCondition;
-    using BranchTruncateType = typename JITAssembler::BranchTruncateType;
-    using Jump = typename JITAssembler::Jump;
-    using Label = typename JITAssembler::Label;
-    using ValueTypeInternal = Value::ValueTypeInternal_64;
-    using TargetPrimitive = TargetPrimitive64;
-
-    static void emitSetGrayBit(JITAssembler *as, RegisterID base)
-    {
-        bool returnValueUsed = (base == TargetPlatform::ReturnValueRegister);
-
-        as->push(TargetPlatform::EngineRegister); // free up one register for work
-
-        RegisterID grayBitmap = returnValueUsed ? TargetPlatform::ScratchRegister : TargetPlatform::ReturnValueRegister;
-        as->move(base, grayBitmap);
-        Q_ASSERT(base != grayBitmap);
-        as->urshift64(TrustedImm32(Chunk::ChunkShift), grayBitmap);
-        as->lshift64(TrustedImm32(Chunk::ChunkShift), grayBitmap);
-        Q_STATIC_ASSERT(offsetof(Chunk, grayBitmap) == 0);
-
-        RegisterID index = base;
-        as->move(base, index);
-        as->sub64(grayBitmap, index);
-        as->urshift64(TrustedImm32(Chunk::SlotSizeShift), index);
-        RegisterID grayIndex = TargetPlatform::EngineRegister;
-        as->move(index, grayIndex);
-        as->urshift64(TrustedImm32(Chunk::BitShift), grayIndex);
-        as->lshift64(TrustedImm32(3), grayIndex); // 8 bytes per quintptr
-        as->add64(grayIndex, grayBitmap);
-        as->and64(TrustedImm32(Chunk::Bits - 1), index);
-
-        RegisterID bit = TargetPlatform::EngineRegister;
-        as->move(TrustedImm32(1), bit);
-        as->lshift64(index, bit);
-
-        as->load64(Pointer(grayBitmap, 0), index);
-        as->or64(bit, index);
-        as->store64(index, Pointer(grayBitmap, 0));
-
-        as->pop(TargetPlatform::EngineRegister);
-    }
-
-#if WRITEBARRIER(none)
-    static Q_ALWAYS_INLINE void emitWriteBarrier(JITAssembler *, Address) {}
-#endif
-
-    static void loadDouble(JITAssembler *as, Address addr, FPRegisterID dest)
-    {
-        as->load64(addr, TargetPlatform::ReturnValueRegister);
-        as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-        as->move64ToDouble(TargetPlatform::ReturnValueRegister, dest);
-    }
-
-    static void storeDouble(JITAssembler *as, FPRegisterID source, Address addr, WriteBarrier::Type barrier)
-    {
-        as->moveDoubleTo64(source, TargetPlatform::ReturnValueRegister);
-        as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-        as->store64(TargetPlatform::ReturnValueRegister, addr);
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, addr);
-    }
-
-    static void storeDouble(JITAssembler *as, FPRegisterID source, IR::Expr* target)
-    {
-        as->moveDoubleTo64(source, TargetPlatform::ReturnValueRegister);
-        as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-        WriteBarrier::Type barrier;
-        Pointer ptr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
-        as->store64(TargetPlatform::ReturnValueRegister, ptr);
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, ptr);
-    }
-
-    static void storeReturnValue(JITAssembler *as, FPRegisterID dest)
-    {
-        as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-        as->move64ToDouble(TargetPlatform::ReturnValueRegister, dest);
-    }
-
-    static void storeReturnValue(JITAssembler *as, const Pointer &dest, WriteBarrier::Type barrier)
-    {
-        as->store64(TargetPlatform::ReturnValueRegister, dest);
-        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, dest);
-    }
-
-    static void setFunctionReturnValueFromTemp(JITAssembler *as, IR::Temp *t)
-    {
-        if (t->kind == IR::Temp::PhysicalRegister) {
-            if (t->type == IR::DoubleType) {
-                as->moveDoubleTo64((FPRegisterID) t->index,
-                                    TargetPlatform::ReturnValueRegister);
-                as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-            } else if (t->type == IR::UInt32Type) {
-                RegisterID srcReg = (RegisterID) t->index;
-                Jump intRange = as->branch32(RelationalCondition::GreaterThanOrEqual, srcReg, TrustedImm32(0));
-                as->convertUInt32ToDouble(srcReg, TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister);
-                as->moveDoubleTo64(TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister);
-                as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-                Jump done = as->jump();
-                intRange.link(as);
-                as->zeroExtend32ToPtr(srcReg, TargetPlatform::ReturnValueRegister);
-                quint64 tag = quint64(QV4::Value::ValueTypeInternal_64::Integer);
-                as->or64(TrustedImm64(tag << 32),
-                         TargetPlatform::ReturnValueRegister);
-                done.link(as);
-            } else {
-                as->zeroExtend32ToPtr((RegisterID) t->index, TargetPlatform::ReturnValueRegister);
-                quint64 tag;
-                switch (t->type) {
-                case IR::SInt32Type:
-                    tag = quint64(QV4::Value::ValueTypeInternal_64::Integer);
-                    break;
-                case IR::BoolType:
-                    tag = quint64(QV4::Value::ValueTypeInternal_64::Boolean);
-                    break;
-                default:
-                    tag = 31337; // bogus value
-                    Q_UNREACHABLE();
-                }
-                as->or64(TrustedImm64(tag << 32),
-                         TargetPlatform::ReturnValueRegister);
-            }
-        } else {
-            as->copyValue(TargetPlatform::ReturnValueRegister, t, WriteBarrier::NoBarrier);
-        }
-    }
-
-    static void setFunctionReturnValueFromConst(JITAssembler *as, TargetPrimitive retVal)
-    {
-        as->move(TrustedImm64(retVal.rawValue()), TargetPlatform::ReturnValueRegister);
-    }
-
-    static void storeValue(JITAssembler *as, TargetPrimitive value, Address destination, WriteBarrier::Type barrier)
-    {
-        as->store64(TrustedImm64(value.rawValue()), destination);
-        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, destination);
-    }
-
-    template <typename Source, typename Destination>
-    static void copyValueViaRegisters(JITAssembler *as, Source source, Destination destination, WriteBarrier::Type barrier)
-    {
-        // Use ReturnValueRegister as "scratch" register because loadArgument
-        // and storeArgument are functions that may need a scratch register themselves.
-        loadArgumentInRegister(as, source, TargetPlatform::ReturnValueRegister, 0);
-        as->storeReturnValue(destination, barrier);
-    }
-
-    static void loadDoubleConstant(JITAssembler *as, IR::Const *c, FPRegisterID target)
-    {
-        Q_STATIC_ASSERT(sizeof(int64_t) == sizeof(double));
-        int64_t i;
-        memcpy(&i, &c->value, sizeof(double));
-        as->move(TrustedImm64(i), TargetPlatform::ReturnValueRegister);
-        as->move64ToDouble(TargetPlatform::ReturnValueRegister, target);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, Address addressOfValue, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-        as->load64(addressOfValue, dest);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::Temp* temp, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        if (temp) {
-            Pointer addr = as->loadTempAddress(temp);
-            as->load64(addr, dest);
-        } else {
-            auto undefined = TargetPrimitive::undefinedValue();
-            as->move(TrustedImm64(undefined.rawValue()), dest);
-        }
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::ArgLocal* al, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        if (al) {
-            Pointer addr = as->loadArgLocalAddressForReading(dest, al);
-            as->load64(addr, dest);
-        } else {
-            auto undefined = TargetPrimitive::undefinedValue();
-            as->move(TrustedImm64(undefined.rawValue()), dest);
-        }
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::Const* c, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        auto v = convertToValue<TargetPrimitive64>(c);
-        as->move(TrustedImm64(v.rawValue()), dest);
-    }
-
-    static void loadArgumentInRegister(JITAssembler *as, IR::Expr* expr, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        if (!expr) {
-            auto undefined = TargetPrimitive::undefinedValue();
-            as->move(TrustedImm64(undefined.rawValue()), dest);
-        } else if (IR::Temp *t = expr->asTemp()){
-            loadArgumentInRegister(as, t, dest, argumentNumber);
-        } else if (IR::ArgLocal *al = expr->asArgLocal()) {
-            loadArgumentInRegister(as, al, dest, argumentNumber);
-        } else if (IR::Const *c = expr->asConst()) {
-            loadArgumentInRegister(as, c, dest, argumentNumber);
-        } else {
-            Q_ASSERT(!"unimplemented expression type in loadArgument");
-        }
-    }
-
-    static void zeroRegister(JITAssembler *as, RegisterID reg)
-    {
-        as->move(TrustedImm64(0), reg);
-    }
-
-    static void zeroStackSlot(JITAssembler *as, int slot)
-    {
-        as->store64(TrustedImm64(0), as->addressForPoke(slot));
-    }
-
-    static void generateCJumpOnCompare(JITAssembler *as,
-                                       RelationalCondition cond,
-                                       RegisterID left,
-                                       TrustedImm64 right,
-                                       IR::BasicBlock *nextBlock,
-                                       IR::BasicBlock *currentBlock,
-                                       IR::BasicBlock *trueBlock,
-                                       IR::BasicBlock *falseBlock)
-    {
-        if (trueBlock == nextBlock) {
-            Jump target = as->branch64(as->invert(cond), left, right);
-            as->addPatch(falseBlock, target);
-        } else {
-            Jump target = as->branch64(cond, left, right);
-            as->addPatch(trueBlock, target);
-            as->jumpToBlock(currentBlock, falseBlock);
-        }
-    }
-
-    static void generateCJumpOnUndefined(JITAssembler *as,
-                                  RelationalCondition cond, IR::Expr *right,
-                                  RegisterID scratchRegister, RegisterID tagRegister,
-                                  IR::BasicBlock *nextBlock,  IR::BasicBlock *currentBlock,
-                                  IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock)
-    {
-        Pointer addr = as->loadAddressForReading(scratchRegister, right);
-        as->load64(addr, tagRegister);
-        const TrustedImm64 tag(0);
-        generateCJumpOnCompare(as, cond, tagRegister, tag, nextBlock, currentBlock, trueBlock, falseBlock);
-    }
-
-    static void convertVarToSInt32(JITAssembler *as, IR::Expr *source, IR::Expr *target)
-    {
-        Q_ASSERT(source->type == IR::VarType);
-        Pointer addr = as->loadAddressForReading(TargetPlatform::ScratchRegister, source);
-        as->load64(addr, TargetPlatform::ScratchRegister);
-        as->move(TargetPlatform::ScratchRegister, TargetPlatform::ReturnValueRegister);
-
-        // check if it's integer convertible
-        as->urshift64(TrustedImm32(QV4::Value::IsIntegerConvertible_Shift), TargetPlatform::ScratchRegister);
-        Jump isIntConvertible = as->branch32(RelationalCondition::Equal, TargetPlatform::ScratchRegister, TrustedImm32(3));
-
-        // nope, not integer convertible, so check for a double:
-        as->urshift64(TrustedImm32(
-                           QV4::Value::IsDoubleTag_Shift - QV4::Value::IsIntegerConvertible_Shift),
-                       TargetPlatform::ScratchRegister);
-        Jump fallback = as->branch32(RelationalCondition::GreaterThan, TargetPlatform::ScratchRegister, TrustedImm32(0));
-
-        // it's a double
-        as->xor64(TargetPlatform::DoubleMaskRegister, TargetPlatform::ReturnValueRegister);
-        as->move64ToDouble(TargetPlatform::ReturnValueRegister, TargetPlatform::FPGpr0);
-        Jump success =
-                as->branchTruncateDoubleToInt32(TargetPlatform::FPGpr0, TargetPlatform::ReturnValueRegister,
-                                                 BranchTruncateType::BranchIfTruncateSuccessful);
-
-        // not an int:
-        fallback.link(as);
-        generateRuntimeCall(as, TargetPlatform::ReturnValueRegister, toInt,
-                            as->loadAddressForReading(TargetPlatform::ScratchRegister, source));
-
-
-        isIntConvertible.link(as);
-        success.link(as);
-        IR::Temp *targetTemp = target->asTemp();
-        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            WriteBarrier::Type barrier;
-            Pointer targetAddr = as->loadAddressForWriting(TargetPlatform::ScratchRegister, target, &barrier);
-            as->store32(TargetPlatform::ReturnValueRegister, targetAddr);
-            targetAddr.offset += 4;
-            as->store32(TrustedImm32(quint32(Value::ValueTypeInternal_64::Integer)), targetAddr);
-            if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-                emitWriteBarrier(as, targetAddr);
-        } else {
-            as->storeInt32(TargetPlatform::ReturnValueRegister, target);
-        }
-    }
-
-    static void loadManagedPointer(JITAssembler *as, RegisterID registerWithPtr, Pointer destAddr, WriteBarrier::Type barrier)
-    {
-        as->store64(registerWithPtr, destAddr);
-        if (WriteBarrier::isRequired<WriteBarrier::Object>() && barrier == WriteBarrier::Barrier)
-            emitWriteBarrier(as, destAddr);
-    }
-
-    static Jump generateIsDoubleCheck(JITAssembler *as, RegisterID tagOrValueRegister)
-    {
-        as->rshift32(TrustedImm32(Value::IsDoubleTag_Shift), tagOrValueRegister);
-        return as->branch32(RelationalCondition::NotEqual, tagOrValueRegister,
-                            TrustedImm32(0));
-    }
-
-    static void initializeLocalVariables(JITAssembler *as, int localsCount)
-    {
-        as->move(TrustedImm64(0), TargetPlatform::ReturnValueRegister);
-        as->move(TrustedImm32(localsCount), TargetPlatform::ScratchRegister);
-        Label loop = as->label();
-        as->store64(TargetPlatform::ReturnValueRegister, Address(TargetPlatform::LocalsRegister));
-        as->add64(TrustedImm32(8), TargetPlatform::LocalsRegister);
-        Jump jump = as->branchSub32(ResultCondition::NonZero, TrustedImm32(1), TargetPlatform::ScratchRegister);
-        jump.linkTo(loop, as);
-    }
-
-    static Jump checkIfTagRegisterIsDouble(JITAssembler *as, RegisterID tagRegister)
-    {
-        as->rshift32(TrustedImm32(Value::IsDoubleTag_Shift), tagRegister);
-        Jump isNoDbl = as->branch32(RelationalCondition::Equal, tagRegister, TrustedImm32(0));
-        return isNoDbl;
-    }
-};
-
-template <typename TargetConfiguration>
-class Assembler : public TargetConfiguration::MacroAssembler, public TargetConfiguration::Platform
-{
-    Q_DISABLE_COPY(Assembler)
-
-public:
-    Assembler(QV4::Compiler::JSUnitGenerator *jsGenerator, IR::Function* function, QV4::ExecutableAllocator *executableAllocator);
-
-    using MacroAssembler = typename TargetConfiguration::MacroAssembler;
-    using RegisterID = typename MacroAssembler::RegisterID;
-    using FPRegisterID = typename MacroAssembler::FPRegisterID;
-    using Address = typename MacroAssembler::Address;
-    using Label = typename MacroAssembler::Label;
-    using Jump = typename MacroAssembler::Jump;
-    using DataLabelPtr = typename MacroAssembler::DataLabelPtr;
-    using TrustedImm32 = typename MacroAssembler::TrustedImm32;
-    using TrustedImm64 = typename MacroAssembler::TrustedImm64;
-    using TrustedImmPtr = typename MacroAssembler::TrustedImmPtr;
-    using RelationalCondition = typename MacroAssembler::RelationalCondition;
-    using typename MacroAssembler::DoubleCondition;
-    using MacroAssembler::label;
-    using MacroAssembler::move;
-    using MacroAssembler::jump;
-    using MacroAssembler::add32;
-    using MacroAssembler::and32;
-    using MacroAssembler::store32;
-    using MacroAssembler::loadPtr;
-    using MacroAssembler::load32;
-    using MacroAssembler::branch32;
-    using MacroAssembler::subDouble;
-    using MacroAssembler::subPtr;
-    using MacroAssembler::addPtr;
-    using MacroAssembler::call;
-    using MacroAssembler::poke;
-    using MacroAssembler::branchTruncateDoubleToUint32;
-    using MacroAssembler::or32;
-    using MacroAssembler::moveDouble;
-    using MacroAssembler::convertUInt32ToDouble;
-    using MacroAssembler::invert;
-    using MacroAssembler::convertInt32ToDouble;
-    using MacroAssembler::rshift32;
-    using MacroAssembler::storePtr;
-    using MacroAssembler::ret;
-
-    using JITTargetPlatform = typename TargetConfiguration::Platform;
-    using JITTargetPlatform::RegisterArgumentCount;
-    using JITTargetPlatform::StackSpaceAllocatedUponFunctionEntry;
-    using JITTargetPlatform::RegisterSize;
-    using JITTargetPlatform::StackAlignment;
-    using JITTargetPlatform::ReturnValueRegister;
-    using JITTargetPlatform::StackPointerRegister;
-    using JITTargetPlatform::ScratchRegister;
-    using JITTargetPlatform::EngineRegister;
-    using JITTargetPlatform::StackShadowSpace;
-    using JITTargetPlatform::registerForArgument;
-    using JITTargetPlatform::FPGpr0;
-    using JITTargetPlatform::platformEnterStandardStackFrame;
-    using JITTargetPlatform::platformFinishEnteringStandardStackFrame;
-    using JITTargetPlatform::platformLeaveStandardStackFrame;
-
-    static qint32 targetStructureOffset(qint32 hostOffset)
-    {
-        Q_ASSERT(hostOffset % QT_POINTER_SIZE == 0);
-        return (hostOffset * RegisterSize) / QT_POINTER_SIZE;
-    }
-
-    struct LookupCall {
-        Address addr;
-        uint getterSetterOffset;
-
-        LookupCall(const Address &addr, uint getterSetterOffset)
-            : addr(addr)
-            , getterSetterOffset(getterSetterOffset)
-        {}
-    };
-
-    struct RuntimeCall {
-        Address addr;
-
-        inline RuntimeCall(Runtime::RuntimeMethods method = Runtime::InvalidRuntimeMethod);
-        bool isValid() const { return addr.offset >= 0; }
-    };
-
-    // Explicit type to allow distinguishing between
-    // pushing an address itself or the value it points
-    // to onto the stack when calling functions.
-    struct Pointer : public Address
-    {
-        explicit Pointer(const Address& addr)
-            : Address(addr)
-        {}
-        explicit Pointer(RegisterID reg, int32_t offset)
-            : Address(reg, offset)
-        {}
-    };
-
-    using RegisterSizeDependentOps = RegisterSizeDependentAssembler<Assembler<TargetConfiguration>, MacroAssembler, JITTargetPlatform, RegisterSize>;
-    using ValueTypeInternal = typename RegisterSizeDependentOps::ValueTypeInternal;
-    using TargetPrimitive = typename RegisterSizeDependentOps::TargetPrimitive;
-
-    // V4 uses two stacks: one stack with QV4::Value items, which is checked by the garbage
-    // collector, and one stack used by the native C/C++/ABI code. This C++ stack is not scanned
-    // by the garbage collector, so if any JS object needs to be retained, it should be put on the
-    // JS stack.
-    //
-    // The "saved reg arg X" are on the C++ stack is used to store values in registers that need to
-    // be passed by reference to native functions. It is fine to use the C++ stack, because only
-    // non-object values can be stored in registers.
-    //
-    // Stack layout for the C++ stack:
-    //   return address
-    //   old FP                     <- FP
-    //   callee saved reg n
-    //   ...
-    //   callee saved reg 0
-    //   saved reg arg n
-    //   ...
-    //   saved reg arg 0            <- SP
-    //
-    // Stack layout for the JS stack:
-    //   function call argument n   <- LocalsRegister
-    //   ...
-    //   function call argument 0
-    //   local 0
-    //   ...
-    //   local n
-    class StackLayout
-    {
-    public:
-        StackLayout(IR::Function *function, int maxArgCountForBuiltins, int normalRegistersToSave, int fpRegistersToSave)
-            : normalRegistersToSave(normalRegistersToSave)
-            , fpRegistersToSave(fpRegistersToSave)
-            , maxOutgoingArgumentCount(function->maxNumberOfArguments)
-            , localCount(function->tempCount)
-            , savedRegCount(maxArgCountForBuiltins)
-        {
-#if 0 // debug code
-            qDebug("calleeSavedRegCount.....: %d",calleeSavedRegCount);
-            qDebug("maxOutgoingArgumentCount: %d",maxOutgoingArgumentCount);
-            qDebug("localCount..............: %d",localCount);
-            qDebug("savedConstCount.........: %d",savedRegCount);
-            for (int i = 0; i < maxOutgoingArgumentCount; ++i)
-                qDebug("argumentAddressForCall(%d) = 0x%x / -0x%x", i,
-                       argumentAddressForCall(i).offset, -argumentAddressForCall(i).offset);
-            for (int i = 0; i < localCount; ++i)
-                qDebug("local(%d) = 0x%x / -0x%x", i, stackSlotPointer(i).offset,
-                       -stackSlotPointer(i).offset);
-            qDebug("savedReg(0) = 0x%x / -0x%x", savedRegPointer(0).offset, -savedRegPointer(0).offset);
-            qDebug("savedReg(1) = 0x%x / -0x%x", savedRegPointer(1).offset, -savedRegPointer(1).offset);
-            qDebug("savedReg(2) = 0x%x / -0x%x", savedRegPointer(2).offset, -savedRegPointer(2).offset);
-            qDebug("savedReg(3) = 0x%x / -0x%x", savedRegPointer(3).offset, -savedRegPointer(3).offset);
-            qDebug("savedReg(4) = 0x%x / -0x%x", savedRegPointer(4).offset, -savedRegPointer(4).offset);
-            qDebug("savedReg(5) = 0x%x / -0x%x", savedRegPointer(5).offset, -savedRegPointer(5).offset);
-
-            qDebug("callDataAddress(0) = 0x%x", callDataAddress(0).offset);
-#endif
-        }
-
-        int calculateStackFrameSize() const
-        {
-            // sp was aligned before executing the call instruction. So, calculate all contents
-            // that were saved after that aligned stack...:
-            const int stackSpaceAllocatedOtherwise = StackSpaceAllocatedUponFunctionEntry
-                                                     + RegisterSize; // saved FramePointerRegister
-
-            // ... then calculate the stuff we want to store ...:
-            int frameSize = RegisterSize * normalRegistersToSave + sizeof(double) * fpRegistersToSave;
-            frameSize += savedRegCount * sizeof(QV4::Value); // (these get written out as Values, not as native registers)
-
-            Q_ASSERT(frameSize + stackSpaceAllocatedOtherwise < INT_MAX);
-            // .. then align that chunk ..:
-            frameSize = static_cast<int>(WTF::roundUpToMultipleOf(StackAlignment, frameSize + stackSpaceAllocatedOtherwise));
-            // ... which now holds our frame size + the extra stuff that was pushed due to the call.
-            // So subtract that extra stuff, and we have our frame size:
-            frameSize -= stackSpaceAllocatedOtherwise;
-
-            return frameSize;
-        }
-
-        /// \return the stack frame size in number of Value items.
-        int calculateJSStackFrameSize() const
-        {
-            return (localCount + sizeof(QV4::CallData)/sizeof(QV4::Value) - 1 + maxOutgoingArgumentCount) + 1;
-        }
-
-        Address stackSlotPointer(int idx) const
-        {
-            Q_ASSERT(idx >= 0);
-            Q_ASSERT(idx < localCount);
-
-            Pointer addr = callDataAddress(0);
-            addr.offset -= sizeof(QV4::Value) * (idx + 1);
-            return addr;
-        }
-
-        // Some run-time functions take (Value* args, int argc). This function is for populating
-        // the args.
-        Pointer argumentAddressForCall(int argument) const
-        {
-            Q_ASSERT(argument >= 0);
-            Q_ASSERT(argument < maxOutgoingArgumentCount);
-
-            const int index = maxOutgoingArgumentCount - argument;
-            return Pointer(Assembler::LocalsRegister, sizeof(QV4::Value) * (-index));
-        }
-
-        Pointer callDataAddress(int offset = 0) const {
-            return Pointer(Assembler::LocalsRegister, offset - (sizeof(QV4::CallData) + sizeof(QV4::Value) * (maxOutgoingArgumentCount - 1)));
-        }
-
-        Address savedRegPointer(int offset) const
-        {
-            Q_ASSERT(offset >= 0);
-            Q_ASSERT(offset < savedRegCount);
-
-            // Get the address of the bottom-most element of our frame:
-            Address ptr(Assembler::FramePointerRegister, -calculateStackFrameSize());
-            // This now is the element with offset 0. So:
-            ptr.offset += offset * sizeof(QV4::Value);
-            // and we're done!
-            return ptr;
-        }
-
-    private:
-        int normalRegistersToSave;
-        int fpRegistersToSave;
-
-        /// arg count for calls to JS functions
-        int maxOutgoingArgumentCount;
-
-        /// the number of spill slots needed by this function
-        int localCount;
-
-        /// used by built-ins to save arguments (e.g. constants) to the stack when they need to be
-        /// passed by reference.
-        int savedRegCount;
-    };
-
-    struct VoidType { VoidType() {} };
-    static const VoidType Void;
-
-    typedef JSC::FunctionPtr FunctionPtr;
-
-#ifndef QT_NO_DEBUG
-    struct CallInfo {
-        Label label;
-        const char* functionName;
-    };
-#endif
-    struct PointerToValue {
-        PointerToValue(IR::Expr *value)
-            : value(value)
-        {}
-        IR::Expr *value;
-    };
-    struct StringToIndex {
-        explicit StringToIndex(const QString &string) : string(string) {}
-        QString string;
-    };
-    struct Reference {
-        Reference(IR::Expr *value) : value(value) {
-            Q_ASSERT(value->asTemp() || value->asArgLocal());
-        }
-        IR::Expr *value;
-    };
-
-    void callAbsolute(const char* /*functionName*/, const LookupCall &lookupCall)
-    {
-        call(lookupCall.addr);
-    }
-
-    void callAbsolute(const char *functionName, const RuntimeCall &runtimeCall)
-    {
-        call(runtimeCall.addr);
-#ifndef QT_NO_DEBUG
-        // the code below is to get proper function names in the disassembly
-        CallInfo info;
-        info.functionName = functionName;
-        info.label = label();
-        _callInfos.append(info);
-#else
-        Q_UNUSED(functionName)
-#endif
-    }
-
-    void registerBlock(IR::BasicBlock*, IR::BasicBlock *nextBlock);
-    IR::BasicBlock *nextBlock() const { return _nextBlock; }
-    void jumpToBlock(IR::BasicBlock* current, IR::BasicBlock *target);
-    void addPatch(IR::BasicBlock* targetBlock, Jump targetJump);
-    void addPatch(DataLabelPtr patch, Label target);
-    void addPatch(DataLabelPtr patch, IR::BasicBlock *target);
-    void generateCJumpOnNonZero(RegisterID reg, IR::BasicBlock *currentBlock,
-                             IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-    void generateCJumpOnCompare(RelationalCondition cond, RegisterID left, TrustedImm32 right,
-                                IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
-                                IR::BasicBlock *falseBlock);
-    void generateCJumpOnCompare(RelationalCondition cond, RegisterID left, RegisterID right,
-                                IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
-                                IR::BasicBlock *falseBlock);
-    void generateCJumpOnUndefined(RelationalCondition cond, IR::Expr *right,
-                                  RegisterID scratchRegister, RegisterID tagRegister,
-                                  IR::BasicBlock *currentBlock, IR::BasicBlock *trueBlock,
-                                  IR::BasicBlock *falseBlock)
-    {
-        RegisterSizeDependentOps::generateCJumpOnUndefined(this, cond, right, scratchRegister, tagRegister,
-                                                           _nextBlock, currentBlock, trueBlock, falseBlock);
-    }
-
-    Jump generateIsDoubleCheck(RegisterID tagOrValueRegister)
-    {
-        return RegisterSizeDependentOps::generateIsDoubleCheck(this, tagOrValueRegister);
-    }
-
-    Jump genTryDoubleConversion(IR::Expr *src, FPRegisterID dest);
-    Jump branchDouble(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
-    Jump branchInt32(bool invertCondition, IR::AluOp op, IR::Expr *left, IR::Expr *right);
-
-    Pointer loadAddressForWriting(RegisterID tmp, IR::Expr *t, WriteBarrier::Type *barrier);
-    Pointer loadAddressForReading(RegisterID tmp, IR::Expr *t) {
-        return loadAddressForWriting(tmp, t, 0);
-    }
-
-    Pointer loadTempAddress(IR::Temp *t);
-    Pointer loadArgLocalAddressForWriting(RegisterID baseReg, IR::ArgLocal *al, WriteBarrier::Type *barrier);
-    Pointer loadArgLocalAddressForReading(RegisterID baseReg, IR::ArgLocal *al) {
-        return loadArgLocalAddressForWriting(baseReg, al, 0);
-    }
-    Pointer loadStringAddress(RegisterID reg, const QString &string);
-    Address loadConstant(IR::Const *c, RegisterID baseReg);
-    Address loadConstant(const TargetPrimitive &v, RegisterID baseReg);
-    void loadStringRef(RegisterID reg, const QString &string);
-    Pointer stackSlotPointer(IR::Temp *t) const
-    {
-        Q_ASSERT(t->kind == IR::Temp::StackSlot);
-
-        return Pointer(_stackLayout->stackSlotPointer(t->index));
-    }
-
-    template <int argumentNumber>
-    void saveOutRegister(PointerToValue arg)
-    {
-        if (!arg.value)
-            return;
-        if (IR::Temp *t = arg.value->asTemp()) {
-            if (t->kind == IR::Temp::PhysicalRegister) {
-                Pointer addr(_stackLayout->savedRegPointer(argumentNumber));
-                switch (t->type) {
-                case IR::BoolType:
-                    storeBool((RegisterID) t->index, addr, WriteBarrier::NoBarrier);
-                    break;
-                case IR::SInt32Type:
-                    storeInt32((RegisterID) t->index, addr, WriteBarrier::NoBarrier);
-                    break;
-                case IR::UInt32Type:
-                    storeUInt32((RegisterID) t->index, addr, WriteBarrier::NoBarrier);
-                    break;
-                case IR::DoubleType:
-                    storeDouble((FPRegisterID) t->index, addr, WriteBarrier::NoBarrier);
-                    break;
-                default:
-                    Q_UNIMPLEMENTED();
-                }
-            }
-        }
-    }
-
-    template <int, typename ArgType>
-    void saveOutRegister(ArgType)
-    {}
-
-    void loadArgumentInRegister(RegisterID source, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        move(source, dest);
-    }
-
-    void loadArgumentInRegister(const Pointer& ptr, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-        addPtr(TrustedImm32(ptr.offset), ptr.base, dest);
-    }
-
-    void loadArgumentInRegister(PointerToValue temp, RegisterID dest, int argumentNumber)
-    {
-        if (!temp.value) {
-            RegisterSizeDependentOps::zeroRegister(this, dest);
-        } else {
-            Pointer addr = toAddress(dest, temp.value, argumentNumber, 0);
-            loadArgumentInRegister(addr, dest, argumentNumber);
-        }
-    }
-    void loadArgumentInRegister(StringToIndex temp, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-        loadStringRef(dest, temp.string);
-    }
-
-    void loadArgumentInRegister(Reference temp, RegisterID dest, int argumentNumber)
-    {
-        Q_ASSERT(temp.value);
-        Pointer addr = loadAddressForReading(dest, temp.value);
-        loadArgumentInRegister(addr, dest, argumentNumber);
-    }
-
-    void loadArgumentInRegister(IR::Temp* temp, RegisterID dest, int argumentNumber)
-    {
-        RegisterSizeDependentOps::loadArgumentInRegister(this, temp, dest, argumentNumber);
-    }
-
-    void loadArgumentInRegister(IR::ArgLocal* al, RegisterID dest, int argumentNumber)
-    {
-        RegisterSizeDependentOps::loadArgumentInRegister(this, al, dest, argumentNumber);
-    }
-
-    void loadArgumentInRegister(IR::Const* c, RegisterID dest, int argumentNumber)
-    {
-        RegisterSizeDependentOps::loadArgumentInRegister(this, c, dest, argumentNumber);
-    }
-
-    void loadArgumentInRegister(IR::Expr* expr, RegisterID dest, int argumentNumber)
-    {
-        RegisterSizeDependentOps::loadArgumentInRegister(this, expr, dest, argumentNumber);
-    }
-
-    void loadArgumentInRegister(TrustedImm32 imm32, RegisterID dest, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        RegisterSizeDependentOps::zeroRegister(this, dest);
-        if (imm32.m_value)
-            move(imm32, dest);
-    }
-
-    void storeReturnValue(RegisterID dest, WriteBarrier::Type barrier = WriteBarrier::NoBarrier)
-    {
-        Q_UNUSED(barrier);
-        Q_ASSERT(barrier == WriteBarrier::NoBarrier);
-        move(ReturnValueRegister, dest);
-    }
-
-    void storeUInt32ReturnValue(RegisterID dest)
-    {
-        subPtr(TrustedImm32(sizeof(QV4::Value)), StackPointerRegister);
-        Pointer tmp(StackPointerRegister, 0);
-        storeReturnValue(tmp, WriteBarrier::NoBarrier);
-        toUInt32Register(tmp, dest);
-        addPtr(TrustedImm32(sizeof(QV4::Value)), StackPointerRegister);
-    }
-
-    void storeReturnValue(FPRegisterID dest)
-    {
-        RegisterSizeDependentOps::storeReturnValue(this, dest);
-    }
-
-    void storeReturnValue(const Pointer &dest, WriteBarrier::Type barrier)
-    {
-        RegisterSizeDependentOps::storeReturnValue(this, dest, barrier);
-    }
-
-    void storeReturnValue(IR::Expr *target)
-    {
-        if (!target)
-            return;
-
-        IR::Temp *temp = target->asTemp();
-        if (temp && temp->kind == IR::Temp::PhysicalRegister) {
-            if (temp->type == IR::DoubleType)
-                storeReturnValue((FPRegisterID) temp->index);
-            else if (temp->type == IR::UInt32Type)
-                storeUInt32ReturnValue((RegisterID) temp->index);
-            else
-                storeReturnValue((RegisterID) temp->index);
-            return;
-        } else {
-            WriteBarrier::Type barrier;
-            Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
-            storeReturnValue(addr, barrier);
-        }
-    }
-
-    void storeReturnValue(VoidType)
-    {
-    }
-
-    template <int StackSlot>
-    void loadArgumentOnStack(RegisterID reg, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        poke(reg, StackSlot);
-    }
-
-    template <int StackSlot>
-    void loadArgumentOnStack(TrustedImm32 value, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        poke(value, StackSlot);
-    }
-
-    template <int StackSlot>
-    void loadArgumentOnStack(const Pointer& ptr, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-
-        addPtr(TrustedImm32(ptr.offset), ptr.base, ScratchRegister);
-        poke(ScratchRegister, StackSlot);
-    }
-
-    template <int StackSlot>
-    void loadArgumentOnStack(PointerToValue temp, int argumentNumber)
-    {
-        if (temp.value) {
-            Pointer ptr = toAddress(ScratchRegister, temp.value, argumentNumber, 0);
-            loadArgumentOnStack<StackSlot>(ptr, argumentNumber);
-        } else {
-            RegisterSizeDependentOps::zeroStackSlot(this, StackSlot);
-        }
-    }
-
-    template <int StackSlot>
-    void loadArgumentOnStack(StringToIndex temp, int argumentNumber)
-    {
-        Q_UNUSED(argumentNumber);
-        loadStringRef(ScratchRegister, temp.string);
-        poke(ScratchRegister, StackSlot);
-    }
-
-    template <int StackSlot>
-    void loadArgumentOnStack(Reference temp, int argumentNumber)
-    {
-        Q_ASSERT (temp.value);
-
-        Pointer ptr = loadAddressForReading(ScratchRegister, temp.value);
-        loadArgumentOnStack<StackSlot>(ptr, argumentNumber);
-    }
-
-    void loadDouble(IR::Expr *source, FPRegisterID dest)
-    {
-        IR::Temp *sourceTemp = source->asTemp();
-        if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
-            moveDouble((FPRegisterID) sourceTemp->index, dest);
-            return;
-        }
-        Pointer ptr = loadAddressForReading(ScratchRegister, source);
-        loadDouble(ptr, dest);
-    }
-
-    void storeDouble(FPRegisterID source, IR::Expr* target)
-    {
-        IR::Temp *targetTemp = target->asTemp();
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-            moveDouble(source, (FPRegisterID) targetTemp->index);
-            return;
-        }
-        RegisterSizeDependentOps::storeDouble(this, source, target);
-    }
-
-    void loadDouble(Address addr, FPRegisterID dest)
-    {
-        RegisterSizeDependentOps::loadDouble(this, addr, dest);
-    }
-
-    void storeDouble(FPRegisterID source, Address addr, WriteBarrier::Type barrier)
-    {
-        RegisterSizeDependentOps::storeDouble(this, source, addr, barrier);
-    }
-
-    template <typename Result, typename Source>
-    void copyValue(Result result, Source source, WriteBarrier::Type barrier);
-    template <typename Result>
-    void copyValue(Result result, IR::Expr* source, WriteBarrier::Type barrier);
-
-    // The scratch register is used to calculate the temp address for the source.
-    void memcopyValue(Pointer target, IR::Expr *source, RegisterID scratchRegister, WriteBarrier::Type barrier)
-    {
-        Q_ASSERT(!source->asTemp() || source->asTemp()->kind != IR::Temp::PhysicalRegister);
-        Q_ASSERT(target.base != scratchRegister);
-        loadRawValue(loadAddressForReading(scratchRegister, source), FPGpr0);
-        storeRawValue(FPGpr0, target, barrier);
-    }
-
-    // The scratch register is used to calculate the temp address for the source.
-    void memcopyValue(IR::Expr *target, Pointer source, FPRegisterID fpScratchRegister, RegisterID scratchRegister)
-    {
-        loadRawValue(source, fpScratchRegister);
-        WriteBarrier::Type barrier;
-        Pointer dest = loadAddressForWriting(scratchRegister, target, &barrier);
-        storeRawValue(fpScratchRegister, dest, barrier);
-    }
-
-    void loadRawValue(Pointer source, FPRegisterID dest)
-    {
-        TargetConfiguration::MacroAssembler::loadDouble(source, dest);
-    }
-
-    void storeRawValue(FPRegisterID source, Pointer dest, WriteBarrier::Type barrier)
-    {
-        TargetConfiguration::MacroAssembler::storeDouble(source, dest);
-        if (WriteBarrier::isRequired<WriteBarrier::Unknown>() && barrier == WriteBarrier::Barrier)
-            RegisterSizeDependentOps::emitWriteBarrier(this, dest);
-    }
-
-    void storeValue(TargetPrimitive value, Address destination, WriteBarrier::Type barrier)
-    {
-        RegisterSizeDependentOps::storeValue(this, value, destination, barrier);
-    }
-
-    void storeValue(TargetPrimitive value, IR::Expr* temp);
-
-    void emitWriteBarrier(Address addr, WriteBarrier::Type barrier) {
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            RegisterSizeDependentOps::emitWriteBarrier(this, addr);
-    }
-
-    void enterStandardStackFrame(const RegisterInformation &regularRegistersToSave,
-                                 const RegisterInformation &fpRegistersToSave);
-    void leaveStandardStackFrame(const RegisterInformation &regularRegistersToSave,
-                                 const RegisterInformation &fpRegistersToSave);
-
-    void checkException() {
-        this->load8(Address(EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, hasException))), ScratchRegister);
-        Jump exceptionThrown = branch32(RelationalCondition::NotEqual, ScratchRegister, TrustedImm32(0));
-        if (catchBlock)
-            addPatch(catchBlock, exceptionThrown);
-        else
-            exceptionPropagationJumps.append(exceptionThrown);
-    }
-    void jumpToExceptionHandler() {
-        Jump exceptionThrown = jump();
-        if (catchBlock)
-            addPatch(catchBlock, exceptionThrown);
-        else
-            exceptionPropagationJumps.append(exceptionThrown);
-    }
-
-    template <int argumentNumber, typename T>
-    void loadArgumentOnStackOrRegister(const T &value)
-    {
-        if (argumentNumber < RegisterArgumentCount)
-            loadArgumentInRegister(value, registerForArgument(argumentNumber), argumentNumber);
-        else
-            loadArgumentOnStack<argumentNumber - RegisterArgumentCount + (StackShadowSpace / RegisterSize)>(value, argumentNumber);
-    }
-
-    template <int argumentNumber>
-    void loadArgumentOnStackOrRegister(const VoidType &value)
-    {
-        Q_UNUSED(value);
-    }
-
-    template <bool selectFirst, int First, int Second>
-    struct Select
-    {
-        enum { Chosen = First };
-    };
-
-    template <int First, int Second>
-    struct Select<false, First, Second>
-    {
-        enum { Chosen = Second };
-    };
-
-    template <int ArgumentIndex, typename Parameter>
-    struct SizeOnStack
-    {
-        enum { Size = Select<ArgumentIndex >= RegisterArgumentCount, RegisterSize, 0>::Chosen };
-    };
-
-    template <int ArgumentIndex>
-    struct SizeOnStack<ArgumentIndex, VoidType>
-    {
-        enum { Size = 0 };
-    };
-
-    template <typename T> bool prepareCall(T &)
-    { return true; }
-
-    bool prepareCall(LookupCall &lookupCall)
-    {
-        // IMPORTANT! See generateLookupCall in qv4isel_masm_p.h for details!
-
-        // load the table from the context
-        loadPtr(Address(EngineRegister, targetStructureOffset(offsetof(QV4::EngineBase, current))), ScratchRegister);
-        loadPtr(Address(ScratchRegister, targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, lookups))),
-                    lookupCall.addr.base);
-        // pre-calculate the indirect address for the lookupCall table:
-        if (lookupCall.addr.offset)
-            addPtr(TrustedImm32(lookupCall.addr.offset), lookupCall.addr.base);
-        // store it as the first argument
-        loadArgumentOnStackOrRegister<0>(lookupCall.addr.base);
-        // set the destination addresses offset to the getterSetterOffset. The base is the lookupCall table's address
-        lookupCall.addr.offset = lookupCall.getterSetterOffset;
-        return false;
-    }
-
-    template <typename ArgRet, typename Callable, typename Arg1, typename Arg2, typename Arg3, typename Arg4, typename Arg5, typename Arg6>
-    void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4, Arg5 arg5, Arg6 arg6)
-    {
-        int stackSpaceNeeded =   SizeOnStack<0, Arg1>::Size
-                               + SizeOnStack<1, Arg2>::Size
-                               + SizeOnStack<2, Arg3>::Size
-                               + SizeOnStack<3, Arg4>::Size
-                               + SizeOnStack<4, Arg5>::Size
-                               + SizeOnStack<5, Arg6>::Size
-                               + StackShadowSpace;
-
-        if (stackSpaceNeeded) {
-            Q_ASSERT(stackSpaceNeeded < (INT_MAX - StackAlignment));
-            stackSpaceNeeded = static_cast<int>(WTF::roundUpToMultipleOf(StackAlignment, stackSpaceNeeded));
-            subPtr(TrustedImm32(stackSpaceNeeded), StackPointerRegister);
-        }
-
-        // First save any arguments that reside in registers, because they could be overwritten
-        // if that register is also used to pass arguments.
-        saveOutRegister<5>(arg6);
-        saveOutRegister<4>(arg5);
-        saveOutRegister<3>(arg4);
-        saveOutRegister<2>(arg3);
-        saveOutRegister<1>(arg2);
-        saveOutRegister<0>(arg1);
-
-        loadArgumentOnStackOrRegister<5>(arg6);
-        loadArgumentOnStackOrRegister<4>(arg5);
-        loadArgumentOnStackOrRegister<3>(arg4);
-        loadArgumentOnStackOrRegister<2>(arg3);
-        loadArgumentOnStackOrRegister<1>(arg2);
-
-        if (prepareCall(function))
-            loadArgumentOnStackOrRegister<0>(arg1);
-
-        if (JITTargetPlatform::gotRegister != -1)
-            load32(Address(JITTargetPlatform::FramePointerRegister, JITTargetPlatform::savedGOTRegisterSlotOnStack()), static_cast<RegisterID>(JITTargetPlatform::gotRegister)); // restore the GOT ptr
-
-        callAbsolute(functionName, function);
-
-        if (stackSpaceNeeded)
-            addPtr(TrustedImm32(stackSpaceNeeded), StackPointerRegister);
-
-        if (needsExceptionCheck) {
-            checkException();
-        }
-
-        storeReturnValue(r);
-
-    }
-
-    template <typename ArgRet, typename Callable, typename Arg1, typename Arg2, typename Arg3, typename Arg4, typename Arg5>
-    void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4, Arg5 arg5)
-    {
-        generateFunctionCallImp(needsExceptionCheck, r, functionName, function, arg1, arg2, arg3, arg4, arg5, VoidType());
-    }
-
-    template <typename ArgRet, typename Callable, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
-    void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4)
-    {
-        generateFunctionCallImp(needsExceptionCheck, r, functionName, function, arg1, arg2, arg3, arg4, VoidType(), VoidType());
-    }
-
-    template <typename ArgRet, typename Callable, typename Arg1, typename Arg2, typename Arg3>
-    void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1, Arg2 arg2, Arg3 arg3)
-    {
-        generateFunctionCallImp(needsExceptionCheck, r, functionName, function, arg1, arg2, arg3, VoidType(), VoidType(), VoidType());
-    }
-
-    template <typename ArgRet, typename Callable, typename Arg1, typename Arg2>
-    void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1, Arg2 arg2)
-    {
-        generateFunctionCallImp(needsExceptionCheck, r, functionName, function, arg1, arg2, VoidType(), VoidType(), VoidType(), VoidType());
-    }
-
-    template <typename ArgRet, typename Callable, typename Arg1>
-    void generateFunctionCallImp(bool needsExceptionCheck, ArgRet r, const char* functionName, Callable function, Arg1 arg1)
-    {
-        generateFunctionCallImp(needsExceptionCheck, r, functionName, function, arg1, VoidType(), VoidType(), VoidType(), VoidType(), VoidType());
-    }
-
-    Pointer toAddress(RegisterID tmpReg, IR::Expr *e, int offset, WriteBarrier::Type *barrier)
-    {
-        if (barrier)
-            *barrier = WriteBarrier::NoBarrier;
-        if (IR::Const *c = e->asConst()) {
-            Address addr = _stackLayout->savedRegPointer(offset);
-            Address tagAddr = addr;
-            tagAddr.offset += 4;
-
-            auto v = convertToValue<TargetPrimitive>(c);
-            store32(TrustedImm32(v.value()), addr);
-            store32(TrustedImm32(v.tag()), tagAddr);
-            return Pointer(addr);
-        }
-
-        if (IR::Temp *t = e->asTemp())
-            if (t->kind == IR::Temp::PhysicalRegister)
-                return Pointer(_stackLayout->savedRegPointer(offset));
-
-        return loadAddressForWriting(tmpReg, e, barrier);
-    }
-
-    void storeBool(RegisterID reg, Pointer addr, WriteBarrier::Type barrier)
-    {
-        store32(reg, addr);
-        addr.offset += 4;
-        store32(TrustedImm32(TargetPrimitive::fromBoolean(0).tag()), addr);
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            RegisterSizeDependentOps::emitWriteBarrier(this, addr);
-    }
-
-    void storeBool(RegisterID src, RegisterID dest)
-    {
-        move(src, dest);
-    }
-
-    void storeBool(RegisterID reg, IR::Expr *target)
-    {
-        if (IR::Temp *targetTemp = target->asTemp()) {
-            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-                move(reg, (RegisterID) targetTemp->index);
-                return;
-            }
-        }
-
-        WriteBarrier::Type barrier;
-        Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
-        storeBool(reg, addr, barrier);
-    }
-
-    void storeBool(bool value, IR::Expr *target) {
-        TrustedImm32 trustedValue(value ? 1 : 0);
-
-        if (IR::Temp *targetTemp = target->asTemp()) {
-            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-                move(trustedValue, (RegisterID) targetTemp->index);
-                return;
-            }
-        }
-
-        move(trustedValue, ScratchRegister);
-        storeBool(ScratchRegister, target);
-    }
-
-    void storeInt32(RegisterID src, RegisterID dest)
-    {
-        move(src, dest);
-    }
-
-    void storeInt32(RegisterID reg, Pointer addr, WriteBarrier::Type barrier)
-    {
-        store32(reg, addr);
-        addr.offset += 4;
-        store32(TrustedImm32(TargetPrimitive::fromInt32(0).tag()), addr);
-        if (WriteBarrier::isRequired<WriteBarrier::Primitive>() && barrier == WriteBarrier::Barrier)
-            RegisterSizeDependentOps::emitWriteBarrier(this, addr);
-    }
-
-    void storeInt32(RegisterID reg, IR::Expr *target)
-    {
-        IR::Temp *targetTemp = target->asTemp();
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-            move(reg, (RegisterID) targetTemp->index);
-        } else {
-            WriteBarrier::Type barrier;
-            Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
-            storeInt32(reg, addr, barrier);
-        }
-    }
-
-    void storeUInt32(RegisterID src, RegisterID dest)
-    {
-        move(src, dest);
-    }
-
-    void storeUInt32(RegisterID reg, Pointer addr, WriteBarrier::Type barrier)
-    {
-        // The UInt32 representation in QV4::Value is really convoluted. See also toUInt32Register.
-        Jump intRange = branch32(RelationalCondition::GreaterThanOrEqual, reg, TrustedImm32(0));
-        convertUInt32ToDouble(reg, FPGpr0, ReturnValueRegister);
-        storeDouble(FPGpr0, addr, barrier);
-        Jump done = jump();
-        intRange.link(this);
-        storeInt32(reg, addr, barrier);
-        done.link(this);
-    }
-
-    void storeUInt32(RegisterID reg, IR::Expr *target)
-    {
-        IR::Temp *targetTemp = target->asTemp();
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-            move(reg, (RegisterID) targetTemp->index);
-        } else {
-            WriteBarrier::Type barrier;
-            Pointer addr = loadAddressForWriting(ScratchRegister, target, &barrier);
-            storeUInt32(reg, addr, barrier);
-        }
-    }
-
-    FPRegisterID toDoubleRegister(IR::Expr *e, FPRegisterID target = FPGpr0)
-    {
-        if (IR::Const *c = e->asConst()) {
-            RegisterSizeDependentOps::loadDoubleConstant(this, c, target);
-            return target;
-        }
-
-        if (IR::Temp *t = e->asTemp())
-            if (t->kind == IR::Temp::PhysicalRegister)
-                return (FPRegisterID) t->index;
-
-        loadDouble(e, target);
-        return target;
-    }
-
-    RegisterID toBoolRegister(IR::Expr *e, RegisterID scratchReg)
-    {
-        return toInt32Register(e, scratchReg);
-    }
-
-    RegisterID toInt32Register(IR::Expr *e, RegisterID scratchReg)
-    {
-        if (IR::Const *c = e->asConst()) {
-            move(TrustedImm32(convertToValue<Primitive>(c).int_32()), scratchReg);
-            return scratchReg;
-        }
-
-        if (IR::Temp *t = e->asTemp())
-            if (t->kind == IR::Temp::PhysicalRegister)
-                return (RegisterID) t->index;
-
-        return toInt32Register(loadAddressForReading(scratchReg, e), scratchReg);
-    }
-
-    RegisterID toInt32Register(Pointer addr, RegisterID scratchReg)
-    {
-        load32(addr, scratchReg);
-        return scratchReg;
-    }
-
-    RegisterID toUInt32Register(IR::Expr *e, RegisterID scratchReg)
-    {
-        if (IR::Const *c = e->asConst()) {
-            move(TrustedImm32(unsigned(c->value)), scratchReg);
-            return scratchReg;
-        }
-
-        if (IR::Temp *t = e->asTemp())
-            if (t->kind == IR::Temp::PhysicalRegister)
-                return (RegisterID) t->index;
-
-        return toUInt32Register(loadAddressForReading(scratchReg, e), scratchReg);
-    }
-
-    RegisterID toUInt32Register(Pointer addr, RegisterID scratchReg)
-    {
-        Q_ASSERT(addr.base != scratchReg);
-
-        // The UInt32 representation in QV4::Value is really convoluted. See also storeUInt32.
-        Pointer tagAddr = addr;
-        tagAddr.offset += 4;
-        load32(tagAddr, scratchReg);
-        Jump inIntRange = branch32(RelationalCondition::Equal, scratchReg, TrustedImm32(quint32(ValueTypeInternal::Integer)));
-
-        // it's not in signed int range, so load it as a double, and truncate it down
-        loadDouble(addr, FPGpr0);
-        Address inversionAddress = loadConstant(TargetPrimitive::fromDouble(double(INT_MAX) + 1), scratchReg);
-        subDouble(inversionAddress, FPGpr0);
-        Jump canNeverHappen = branchTruncateDoubleToUint32(FPGpr0, scratchReg);
-        canNeverHappen.link(this);
-        or32(TrustedImm32(1 << 31), scratchReg);
-        Jump done = jump();
-
-        inIntRange.link(this);
-        load32(addr, scratchReg);
-
-        done.link(this);
-        return scratchReg;
-    }
-
-    void returnFromFunction(IR::Ret *s, RegisterInformation regularRegistersToSave, RegisterInformation fpRegistersToSave);
-
-    JSC::MacroAssemblerCodeRef link(int *codeSize);
-
-    void setStackLayout(int maxArgCountForBuiltins, int regularRegistersToSave, int fpRegistersToSave);
-    const StackLayout &stackLayout() const { return *_stackLayout.data(); }
-    void initializeLocalVariables()
-    {
-        const int locals = _stackLayout->calculateJSStackFrameSize();
-        if (locals <= 0)
-            return;
-        loadPtr(Address(JITTargetPlatform::EngineRegister, targetStructureOffset(offsetof(EngineBase, jsStackTop))), JITTargetPlatform::LocalsRegister);
-        RegisterSizeDependentOps::initializeLocalVariables(this, locals);
-        storePtr(JITTargetPlatform::LocalsRegister, Address(JITTargetPlatform::EngineRegister, targetStructureOffset(offsetof(EngineBase, jsStackTop))));
-    }
-
-    Label exceptionReturnLabel;
-    IR::BasicBlock * catchBlock;
-    QVector<Jump> exceptionPropagationJumps;
-private:
-    QScopedPointer<const StackLayout> _stackLayout;
-    IR::Function *_function;
-    std::vector<Label> _addrs;
-    std::vector<std::vector<Jump>> _patches;
-#ifndef QT_NO_DEBUG
-    QVector<CallInfo> _callInfos;
-#endif
-
-    struct DataLabelPatch {
-        DataLabelPtr dataLabel;
-        Label target;
-    };
-    std::vector<DataLabelPatch> _dataLabelPatches;
-
-    std::vector<std::vector<DataLabelPtr>> _labelPatches;
-    IR::BasicBlock *_nextBlock;
-
-    QV4::ExecutableAllocator *_executableAllocator;
-    QV4::Compiler::JSUnitGenerator *_jsGenerator;
-};
-
-template <typename TargetConfiguration>
-const typename Assembler<TargetConfiguration>::VoidType Assembler<TargetConfiguration>::Void;
-
-template <typename TargetConfiguration>
-template <typename Result, typename Source>
-void Assembler<TargetConfiguration>::copyValue(Result result, Source source, WriteBarrier::Type barrier)
-{
-    RegisterSizeDependentOps::copyValueViaRegisters(this, source, result, barrier);
-}
-
-template <typename TargetConfiguration>
-template <typename Result>
-void Assembler<TargetConfiguration>::copyValue(Result result, IR::Expr* source, WriteBarrier::Type barrier)
-{
-    if (source->type == IR::BoolType) {
-        RegisterID reg = toInt32Register(source, ScratchRegister);
-        storeBool(reg, result, barrier);
-    } else if (source->type == IR::SInt32Type) {
-        RegisterID reg = toInt32Register(source, ScratchRegister);
-        storeInt32(reg, result, barrier);
-    } else if (source->type == IR::UInt32Type) {
-        RegisterID reg = toUInt32Register(source, ScratchRegister);
-        storeUInt32(reg, result, barrier);
-    } else if (source->type == IR::DoubleType) {
-        storeDouble(toDoubleRegister(source), result, barrier);
-    } else if (source->asTemp() || source->asArgLocal()) {
-        RegisterSizeDependentOps::copyValueViaRegisters(this, source, result, barrier);
-    } else if (IR::Const *c = source->asConst()) {
-        auto v = convertToValue<TargetPrimitive>(c);
-        storeValue(v, result, barrier);
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-template <typename TargetConfiguration>
-inline Assembler<TargetConfiguration>::RuntimeCall::RuntimeCall(Runtime::RuntimeMethods method)
-    : addr(Assembler::EngineRegister,
-           method == Runtime::InvalidRuntimeMethod ? -1 : (Assembler<TargetConfiguration>::targetStructureOffset(offsetof(EngineBase, runtime) + Runtime::runtimeMethodOffset(method))))
-{
-}
-
-} // end of namespace JIT
-} // end of namespace QV4
-
-QT_END_NAMESPACE
-
-#endif // ENABLE(ASSEMBLER)
-
-#endif // QV4ISEL_MASM_P_H
diff --git a/src/qml/jit/qv4assemblercommon.cpp b/src/qml/jit/qv4assemblercommon.cpp
new file mode 100644
index 0000000000..dd810d9d70
--- /dev/null
+++ b/src/qml/jit/qv4assemblercommon.cpp
@@ -0,0 +1,370 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QBuffer>
+#include <QFile>
+#include <QLoggingCategory>
+
+#include "qv4engine_p.h"
+#include "qv4assemblercommon_p.h"
+#include <private/qv4function_p.h>
+#include <private/qv4functiontable_p.h>
+#include <private/qv4runtime_p.h>
+
+#include <assembler/MacroAssemblerCodeRef.h>
+#include <assembler/LinkBuffer.h>
+#include <WTFStubs.h>
+
+#undef ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES
+
+#ifdef V4_ENABLE_JIT
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace JIT {
+
+Q_LOGGING_CATEGORY(lcAsm, "qt.v4.asm")
+
+namespace {
+class QIODevicePrintStream: public FilePrintStream
+{
+    Q_DISABLE_COPY(QIODevicePrintStream)
+
+public:
+    explicit QIODevicePrintStream(QIODevice *dest)
+        : FilePrintStream(nullptr)
+        , dest(dest)
+        , buf(4096, '0')
+    {
+        Q_ASSERT(dest);
+    }
+
+    ~QIODevicePrintStream()
+    {}
+
+    void vprintf(const char* format, va_list argList) WTF_ATTRIBUTE_PRINTF(2, 0)
+    {
+        const int written = qvsnprintf(buf.data(), buf.size(), format, argList);
+        if (written > 0)
+            dest->write(buf.constData(), written);
+        memset(buf.data(), 0, qMin(written, buf.size()));
+    }
+
+    void flush()
+    {}
+
+private:
+    QIODevice *dest;
+    QByteArray buf;
+};
+} // anonymous namespace
+
+static void printDisassembledOutputWithCalls(QByteArray processedOutput,
+                                             const QHash<const void*, const char*>& functions)
+{
+    for (QHash<const void*, const char*>::ConstIterator it = functions.begin(), end = functions.end();
+         it != end; ++it) {
+        const QByteArray ptrString = "0x" + QByteArray::number(quintptr(it.key()), 16);
+        int idx = 0;
+        while (idx >= 0) {
+            idx = processedOutput.indexOf(ptrString, idx);
+            if (idx < 0)
+                break;
+            idx = processedOutput.indexOf('\n', idx);
+            if (idx < 0)
+                break;
+            processedOutput = processedOutput.insert(idx, QByteArrayLiteral("                          ; ") + it.value());
+        }
+    }
+
+    auto lines = processedOutput.split('\n');
+    for (const auto &line : lines)
+        qCDebug(lcAsm, "%s", line.constData());
+}
+
+JIT::PlatformAssemblerCommon::~PlatformAssemblerCommon()
+{}
+
+void PlatformAssemblerCommon::link(Function *function, const char *jitKind)
+{
+    for (const auto &jumpTarget : jumpsToLink)
+        jumpTarget.jump.linkTo(labelForOffset[jumpTarget.offset], this);
+
+    JSC::JSGlobalData dummy(function->internalClass->engine->executableAllocator);
+    JSC::LinkBuffer<MacroAssembler> linkBuffer(dummy, this, nullptr);
+
+    for (const auto &ehTarget : ehTargets) {
+        auto targetLabel = labelForOffset.value(ehTarget.offset);
+        linkBuffer.patch(ehTarget.label, linkBuffer.locationOf(targetLabel));
+    }
+
+    JSC::MacroAssemblerCodeRef codeRef;
+
+    static const bool showCode = lcAsm().isDebugEnabled();
+    if (showCode) {
+        QBuffer buf;
+        buf.open(QIODevice::WriteOnly);
+        WTF::setDataFile(new QIODevicePrintStream(&buf));
+
+        // We use debugAddress here because it's actually for debugging and hidden behind an
+        // environment variable.
+        const QByteArray name = Function::prettyName(function, linkBuffer.debugAddress()).toUtf8();
+        codeRef = linkBuffer.finalizeCodeWithDisassembly(jitKind, "function %s", name.constData());
+
+        WTF::setDataFile(stderr);
+        printDisassembledOutputWithCalls(buf.data(), functions);
+    } else {
+        codeRef = linkBuffer.finalizeCodeWithoutDisassembly();
+    }
+
+    function->codeRef = new JSC::MacroAssemblerCodeRef(codeRef);
+    function->jittedCode = reinterpret_cast<Function::JittedCode>(function->codeRef->code().executableAddress());
+
+    generateFunctionTable(function, &codeRef);
+
+    linkBuffer.makeExecutable();
+}
+
+void PlatformAssemblerCommon::prepareCallWithArgCount(int argc)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(remainingArgcForCall == NoCall);
+    remainingArgcForCall = argc;
+#endif
+
+    if (argc > ArgInRegCount) {
+        argcOnStackForCall = int(WTF::roundUpToMultipleOf(16, size_t(argc - ArgInRegCount) * PointerSize));
+        subPtr(TrustedImm32(argcOnStackForCall), StackPointerRegister);
+    }
+}
+
+void PlatformAssemblerCommon::storeInstructionPointer(int instructionOffset)
+{
+    Address addr(CppStackFrameRegister, offsetof(QV4::CppStackFrame, instructionPointer));
+    store32(TrustedImm32(instructionOffset), addr);
+}
+
+PlatformAssemblerCommon::Address PlatformAssemblerCommon::argStackAddress(int arg)
+{
+    int offset = arg - ArgInRegCount;
+    Q_ASSERT(offset >= 0);
+    return Address(StackPointerRegister, offset * PointerSize);
+}
+
+void PlatformAssemblerCommon::passAccumulatorAsArg(int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    passAccumulatorAsArg_internal(arg, false);
+}
+
+void JIT::PlatformAssemblerCommon::pushAccumulatorAsArg(int arg)
+{
+    passAccumulatorAsArg_internal(arg, true);
+}
+
+void PlatformAssemblerCommon::passAccumulatorAsArg_internal(int arg, bool doPush)
+{
+    if (arg < ArgInRegCount) {
+        addPtr(TrustedImm32(offsetof(CallData, accumulator)), JSStackFrameRegister, registerForArg(arg));
+    } else {
+        addPtr(TrustedImm32(offsetof(CallData, accumulator)), JSStackFrameRegister, ScratchRegister);
+        if (doPush)
+            push(ScratchRegister);
+        else
+            storePtr(ScratchRegister, argStackAddress(arg));
+    }
+}
+
+void PlatformAssemblerCommon::passFunctionAsArg(int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    if (arg < ArgInRegCount) {
+        loadFunctionPtr(registerForArg(arg));
+    } else {
+        loadFunctionPtr(ScratchRegister);
+        storePtr(ScratchRegister, argStackAddress(arg));
+    }
+}
+
+void PlatformAssemblerCommon::passEngineAsArg(int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    if (arg < ArgInRegCount) {
+        move(EngineRegister, registerForArg(arg));
+    } else {
+        storePtr(EngineRegister, argStackAddress(arg));
+    }
+}
+
+void PlatformAssemblerCommon::passJSSlotAsArg(int reg, int arg)
+{
+    Address addr(JSStackFrameRegister, reg * int(sizeof(QV4::Value)));
+    passAddressAsArg(addr, arg);
+}
+
+void JIT::PlatformAssemblerCommon::passAddressAsArg(Address addr, int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    if (arg < ArgInRegCount) {
+        addPtr(TrustedImm32(addr.offset), addr.base, registerForArg(arg));
+    } else {
+        addPtr(TrustedImm32(addr.offset), addr.base, ScratchRegister);
+        storePtr(ScratchRegister, argStackAddress(arg));
+    }
+}
+
+void PlatformAssemblerCommon::passCppFrameAsArg(int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    if (arg < ArgInRegCount)
+        move(CppStackFrameRegister, registerForArg(arg));
+    else
+        store32(CppStackFrameRegister, argStackAddress(arg));
+}
+
+void PlatformAssemblerCommon::passInt32AsArg(int value, int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    if (arg < ArgInRegCount)
+        move(TrustedImm32(value), registerForArg(arg));
+    else
+        store32(TrustedImm32(value), argStackAddress(arg));
+}
+
+void JIT::PlatformAssemblerCommon::passPointerAsArg(void *ptr, int arg)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(arg < remainingArgcForCall);
+    --remainingArgcForCall;
+#endif
+
+    if (arg < ArgInRegCount)
+        move(TrustedImmPtr(ptr), registerForArg(arg));
+    else
+        storePtr(TrustedImmPtr(ptr), argStackAddress(arg));
+}
+
+void PlatformAssemblerCommon::callRuntime(const char *functionName, const void *funcPtr)
+{
+#ifndef QT_NO_DEBUG
+    Q_ASSERT(remainingArgcForCall == 0);
+    remainingArgcForCall = NoCall;
+#endif
+    callRuntimeUnchecked(functionName, funcPtr);
+    if (argcOnStackForCall > 0) {
+        addPtr(TrustedImm32(argcOnStackForCall), StackPointerRegister);
+        argcOnStackForCall = 0;
+    }
+}
+
+void PlatformAssemblerCommon::callRuntimeUnchecked(const char *functionName, const void *funcPtr)
+{
+    functions.insert(funcPtr, functionName);
+    callAbsolute(funcPtr);
+}
+
+void PlatformAssemblerCommon::tailCallRuntime(const char *functionName, const void *funcPtr)
+{
+    functions.insert(funcPtr, functionName);
+    setTailCallArg(EngineRegister, 1);
+    setTailCallArg(CppStackFrameRegister, 0);
+    freeStackSpace();
+    generatePlatformFunctionExit(/*tailCall =*/ true);
+    jumpAbsolute(funcPtr);
+}
+
+void PlatformAssemblerCommon::setTailCallArg(RegisterID src, int arg)
+{
+    if (arg < ArgInRegCount) {
+        move(src, registerForArg(arg));
+    } else {
+        // We never write to the incoming arguments space on the stack, and the tail call runtime
+        // method has the same signature as the jitted function, so it is safe for us to just reuse
+        // the arguments that we got in.
+    }
+}
+
+JSC::MacroAssemblerBase::Address PlatformAssemblerCommon::jsAlloca(int slotCount)
+{
+    Address jsStackTopAddr(EngineRegister, offsetof(EngineBase, jsStackTop));
+    RegisterID jsStackTop = AccumulatorRegisterValue;
+    loadPtr(jsStackTopAddr, jsStackTop);
+    addPtr(TrustedImm32(sizeof(Value) * slotCount), jsStackTop);
+    storePtr(jsStackTop, jsStackTopAddr);
+    return Address(jsStackTop, 0);
+}
+
+void PlatformAssemblerCommon::storeInt32AsValue(int srcInt, Address destAddr)
+{
+    store32(TrustedImm32(srcInt),
+            Address(destAddr.base, destAddr.offset + QV4::Value::valueOffset()));
+    store32(TrustedImm32(int(QV4::Value::ValueTypeInternal::Integer)),
+            Address(destAddr.base, destAddr.offset + QV4::Value::tagOffset()));
+}
+
+} // JIT namespace
+} // QV4 namepsace
+
+QT_END_NAMESPACE
+
+#endif // V4_ENABLE_JIT
diff --git a/src/qml/jit/qv4assemblercommon_p.h b/src/qml/jit/qv4assemblercommon_p.h
new file mode 100644
index 0000000000..d3d7eedae2
--- /dev/null
+++ b/src/qml/jit/qv4assemblercommon_p.h
@@ -0,0 +1,740 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4PLATFORMASSEMBLER_P_H
+#define QV4PLATFORMASSEMBLER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4engine_p.h>
+#include <private/qv4global_p.h>
+#include <private/qv4function_p.h>
+#include <QHash>
+#include <wtf/Vector.h>
+#include <assembler/MacroAssembler.h>
+
+#ifdef V4_ENABLE_JIT
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace JIT {
+
+#if defined(Q_PROCESSOR_X86_64) || defined(ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES)
+#if defined(Q_OS_LINUX) || defined(Q_OS_QNX) || defined(Q_OS_FREEBSD) || defined(Q_OS_DARWIN)
+
+class PlatformAssembler_X86_64_SysV : public JSC::MacroAssembler<JSC::MacroAssemblerX86_64>
+{
+public:
+    static constexpr int NativeStackAlignment = 16;
+
+    static const RegisterID NoRegister = RegisterID(-1);
+
+    static const RegisterID ReturnValueRegister   = RegisterID::eax;
+    static const RegisterID ReturnValueRegisterValue = ReturnValueRegister;
+    static const RegisterID AccumulatorRegister   = RegisterID::eax;
+    static const RegisterID AccumulatorRegisterValue = AccumulatorRegister;
+    static const RegisterID ScratchRegister       = RegisterID::r10;
+    static const RegisterID ScratchRegister2      = RegisterID::r9; // Note: overlaps with Arg5Reg, so do not use while setting up a call!
+    static const RegisterID JSStackFrameRegister  = RegisterID::r12;
+    static const RegisterID CppStackFrameRegister = RegisterID::r13;
+    static const RegisterID EngineRegister        = RegisterID::r14;
+    static const RegisterID StackPointerRegister  = RegisterID::esp;
+    static const RegisterID FramePointerRegister  = RegisterID::ebp;
+    static const FPRegisterID FPScratchRegister   = FPRegisterID::xmm1;
+    static const FPRegisterID FPScratchRegister2  = FPRegisterID::xmm2;
+
+    static const RegisterID Arg0Reg = RegisterID::edi;
+    static const RegisterID Arg1Reg = RegisterID::esi;
+    static const RegisterID Arg2Reg = RegisterID::edx;
+    static const RegisterID Arg3Reg = RegisterID::ecx;
+    static const RegisterID Arg4Reg = RegisterID::r8;
+    static const RegisterID Arg5Reg = RegisterID::r9;
+    static const RegisterID Arg6Reg = NoRegister;
+    static const RegisterID Arg7Reg = NoRegister;
+    static const int ArgInRegCount = 6;
+
+    void popValue()
+    {
+        addPtr(TrustedImmPtr(sizeof(ReturnedValue)), StackPointerRegister);
+    }
+
+    void generatePlatformFunctionEntry()
+    {
+        push(FramePointerRegister);
+        move(StackPointerRegister, FramePointerRegister);
+        move(TrustedImmPtr(nullptr), AccumulatorRegister); push(AccumulatorRegister); // exceptionHandler
+        push(JSStackFrameRegister);
+        push(CppStackFrameRegister);
+        push(EngineRegister);
+        move(Arg0Reg, CppStackFrameRegister);
+        move(Arg1Reg, EngineRegister);
+    }
+
+    void generatePlatformFunctionExit(bool tailCall = false)
+    {
+        pop(EngineRegister);
+        pop(CppStackFrameRegister);
+        pop(JSStackFrameRegister);
+        pop(); // exceptionHandler
+        pop(FramePointerRegister);
+        if (!tailCall)
+            ret();
+    }
+
+    void callAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        call(ScratchRegister);
+    }
+
+    void jumpAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        jump(ScratchRegister);
+    }
+
+    void pushAligned(RegisterID reg)
+    {
+        subPtr(TrustedImm32(PointerSize), StackPointerRegister);
+        push(reg);
+    }
+
+    void popAligned(RegisterID reg)
+    {
+        pop(reg);
+        addPtr(TrustedImm32(PointerSize), StackPointerRegister);
+    }
+};
+
+typedef PlatformAssembler_X86_64_SysV PlatformAssemblerBase;
+
+#endif
+#if defined(Q_OS_WIN)
+
+class PlatformAssembler_Win64 : public JSC::MacroAssembler<JSC::MacroAssemblerX86_64>
+{
+public:
+    static const RegisterID NoRegister = RegisterID(-1);
+
+    static const RegisterID ReturnValueRegister   = RegisterID::eax;
+    static const RegisterID ReturnValueRegisterValue = ReturnValueRegister;
+    static const RegisterID AccumulatorRegister   = RegisterID::eax;
+    static const RegisterID AccumulatorRegisterValue = AccumulatorRegister;
+    static const RegisterID ScratchRegister       = RegisterID::r10;
+    static const RegisterID ScratchRegister2      = RegisterID::r9; // Note: overlaps with Arg3Reg, so do not use while setting up a call!
+    static const RegisterID JSStackFrameRegister  = RegisterID::r12;
+    static const RegisterID CppStackFrameRegister = RegisterID::r13;
+    static const RegisterID EngineRegister        = RegisterID::r14;
+    static const RegisterID StackPointerRegister  = RegisterID::esp;
+    static const RegisterID FramePointerRegister  = RegisterID::ebp;
+    static const FPRegisterID FPScratchRegister   = FPRegisterID::xmm1;
+
+    static const RegisterID Arg0Reg = RegisterID::ecx;
+    static const RegisterID Arg1Reg = RegisterID::edx;
+    static const RegisterID Arg2Reg = RegisterID::r8;
+    static const RegisterID Arg3Reg = RegisterID::r9;
+    static const RegisterID Arg4Reg = NoRegister;
+    static const RegisterID Arg5Reg = NoRegister;
+    static const RegisterID Arg6Reg = NoRegister;
+    static const RegisterID Arg7Reg = NoRegister;
+    static const int ArgInRegCount = 4;
+
+    void popValue()
+    {
+        addPtr(TrustedImmPtr(sizeof(ReturnedValue)), StackPointerRegister);
+    }
+
+    void generatePlatformFunctionEntry()
+    {
+        push(FramePointerRegister);
+        move(StackPointerRegister, FramePointerRegister);
+        move(TrustedImmPtr(nullptr), AccumulatorRegister); push(AccumulatorRegister); // exceptionHandler
+        push(JSStackFrameRegister);
+        push(CppStackFrameRegister);
+        push(EngineRegister);
+        move(Arg0Reg, CppStackFrameRegister);
+        move(Arg1Reg, EngineRegister);
+    }
+
+    void generatePlatformFunctionExit(bool tailCall = false)
+    {
+        pop(EngineRegister);
+        pop(CppStackFrameRegister);
+        pop(JSStackFrameRegister);
+        pop(); // exceptionHandler
+        pop(FramePointerRegister);
+        if (!tailCall)
+            ret();
+    }
+
+    void callAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        subPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+        call(ScratchRegister);
+        addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+    }
+
+    void jumpAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        jump(ScratchRegister);
+    }
+
+    void pushAligned(RegisterID reg)
+    {
+        subPtr(TrustedImm32(PointerSize), StackPointerRegister);
+        push(reg);
+    }
+
+    void popAligned(RegisterID reg)
+    {
+        pop(reg);
+        addPtr(TrustedImm32(PointerSize), StackPointerRegister);
+    }
+};
+
+typedef PlatformAssembler_Win64 PlatformAssemblerBase;
+
+#endif
+#endif
+
+#if (defined(Q_PROCESSOR_X86) && !defined(Q_PROCESSOR_X86_64)) || defined(ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES)
+
+class PlatformAssembler_X86_All : public JSC::MacroAssembler<JSC::MacroAssemblerX86>
+{
+public:
+    static const RegisterID NoRegister = RegisterID(-1);
+
+    static const RegisterID ReturnValueRegisterValue = RegisterID::eax;
+    static const RegisterID ReturnValueRegisterTag   = RegisterID::edx;
+    static const RegisterID ScratchRegister          = RegisterID::ecx;
+    static const RegisterID AccumulatorRegisterValue = ReturnValueRegisterValue;
+    static const RegisterID AccumulatorRegisterTag   = ReturnValueRegisterTag;
+    static const RegisterID JSStackFrameRegister  = RegisterID::ebx;
+    static const RegisterID CppStackFrameRegister = RegisterID::esi;
+    static const RegisterID EngineRegister        = RegisterID::edi;
+    static const RegisterID StackPointerRegister  = RegisterID::esp;
+    static const RegisterID FramePointerRegister  = RegisterID::ebp;
+    static const FPRegisterID FPScratchRegister   = FPRegisterID::xmm1;
+
+    static const RegisterID Arg0Reg = NoRegister;
+    static const RegisterID Arg1Reg = NoRegister;
+    static const RegisterID Arg2Reg = NoRegister;
+    static const RegisterID Arg3Reg = NoRegister;
+    static const RegisterID Arg4Reg = NoRegister;
+    static const RegisterID Arg5Reg = NoRegister;
+    static const RegisterID Arg6Reg = NoRegister;
+    static const RegisterID Arg7Reg = NoRegister;
+    static const int ArgInRegCount = 0;
+
+    void popValue()
+    {
+        addPtr(TrustedImmPtr(sizeof(ReturnedValue)), StackPointerRegister);
+    }
+
+    void generatePlatformFunctionEntry()
+    {
+        push(RegisterID::ebp);
+        move(RegisterID::esp, RegisterID::ebp);
+        move(TrustedImmPtr(nullptr), AccumulatorRegisterValue); push(AccumulatorRegisterValue); // exceptionHandler
+        push(JSStackFrameRegister);
+        push(CppStackFrameRegister);
+        push(EngineRegister);
+        // Ensure the stack is 16-byte aligned in order for compiler generated aligned SSE2
+        // instructions to be able to target the stack.
+        subPtr(TrustedImm32(8), StackPointerRegister);
+        loadPtr(Address(FramePointerRegister, 2 * PointerSize), CppStackFrameRegister);
+        loadPtr(Address(FramePointerRegister, 3 * PointerSize), EngineRegister);
+    }
+
+    void generatePlatformFunctionExit(bool tailCall = false)
+    {
+        addPtr(TrustedImm32(8), StackPointerRegister);
+        pop(EngineRegister);
+        pop(CppStackFrameRegister);
+        pop(JSStackFrameRegister);
+        pop(); // exceptionHandler
+        pop(RegisterID::ebp);
+        if (!tailCall)
+            ret();
+    }
+
+    void callAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        call(ScratchRegister);
+    }
+
+    void jumpAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        jump(ScratchRegister);
+    }
+
+    void pushAligned(RegisterID reg)
+    {
+        subPtr(TrustedImm32(3 * PointerSize), StackPointerRegister);
+        push(reg);
+    }
+
+    void popAligned(RegisterID reg)
+    {
+        pop(reg);
+        addPtr(TrustedImm32(3 * PointerSize), StackPointerRegister);
+    }
+};
+
+typedef PlatformAssembler_X86_All PlatformAssemblerBase;
+
+#endif
+
+#if defined(Q_PROCESSOR_ARM_64) || defined(ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES)
+
+class PlatformAssembler_ARM64 : public JSC::MacroAssembler<JSC::MacroAssemblerARM64>
+{
+public:
+    static const RegisterID NoRegister = RegisterID(-1);
+
+    static const RegisterID ReturnValueRegister   = JSC::ARM64Registers::x0;
+    static const RegisterID ReturnValueRegisterValue = ReturnValueRegister;
+    static const RegisterID AccumulatorRegister   = JSC::ARM64Registers::x9;
+    static const RegisterID AccumulatorRegisterValue = AccumulatorRegister;
+    static const RegisterID ScratchRegister       = JSC::ARM64Registers::x10;
+    static const RegisterID ScratchRegister2      = JSC::ARM64Registers::x7; // Note: overlaps with Arg7Reg, so do not use while setting up a call!
+    static const RegisterID JSStackFrameRegister  = JSC::ARM64Registers::x19;
+    static const RegisterID CppStackFrameRegister = JSC::ARM64Registers::x20;
+    static const RegisterID EngineRegister        = JSC::ARM64Registers::x21;
+    static const RegisterID StackPointerRegister  = JSC::ARM64Registers::sp;
+    static const RegisterID FramePointerRegister  = JSC::ARM64Registers::fp;
+    static const FPRegisterID FPScratchRegister   = JSC::ARM64Registers::q1;
+
+    static const RegisterID Arg0Reg = JSC::ARM64Registers::x0;
+    static const RegisterID Arg1Reg = JSC::ARM64Registers::x1;
+    static const RegisterID Arg2Reg = JSC::ARM64Registers::x2;
+    static const RegisterID Arg3Reg = JSC::ARM64Registers::x3;
+    static const RegisterID Arg4Reg = JSC::ARM64Registers::x4;
+    static const RegisterID Arg5Reg = JSC::ARM64Registers::x5;
+    static const RegisterID Arg6Reg = JSC::ARM64Registers::x6;
+    static const RegisterID Arg7Reg = JSC::ARM64Registers::x7;
+    static const int ArgInRegCount = 8;
+
+    void push(RegisterID src)
+    {
+        pushToSave(src);
+    }
+
+    void pop(RegisterID dest)
+    {
+        popToRestore(dest);
+    }
+
+    void pop()
+    {
+        add64(TrustedImm32(16), stackPointerRegister);
+    }
+
+    void popValue()
+    {
+        pop();
+    }
+
+    void generatePlatformFunctionEntry()
+    {
+        pushPair(JSC::ARM64Registers::fp, JSC::ARM64Registers::lr);
+        move(RegisterID::sp, RegisterID::fp);
+        move(TrustedImmPtr(nullptr), AccumulatorRegister); // exceptionHandler
+        pushPair(JSStackFrameRegister, AccumulatorRegister);
+        pushPair(EngineRegister, CppStackFrameRegister);
+        move(Arg0Reg, CppStackFrameRegister);
+        move(Arg1Reg, EngineRegister);
+    }
+
+    void generatePlatformFunctionExit(bool tailCall = false)
+    {
+        if (!tailCall) // do not overwrite arg0 (used in the tail call)
+            move(AccumulatorRegister, ReturnValueRegister);
+        popPair(EngineRegister, CppStackFrameRegister);
+        popPair(JSStackFrameRegister, AccumulatorRegister);
+        popPair(JSC::ARM64Registers::fp, JSC::ARM64Registers::lr);
+        if (!tailCall)
+            ret();
+    }
+
+    void callAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        call(ScratchRegister);
+    }
+
+    void jumpAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), ScratchRegister);
+        jump(ScratchRegister);
+    }
+
+    void pushAligned(RegisterID reg)
+    {
+        pushToSave(reg);
+    }
+
+    void popAligned(RegisterID reg)
+    {
+        popToRestore(reg);
+    }
+};
+
+typedef PlatformAssembler_ARM64 PlatformAssemblerBase;
+
+#endif
+
+#if defined(Q_PROCESSOR_ARM_32) || defined(ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES)
+
+class PlatformAssembler_ARM32 : public JSC::MacroAssembler<JSC::MacroAssemblerARMv7>
+{
+public:
+    static const RegisterID NoRegister = RegisterID(-1);
+
+    static const RegisterID ReturnValueRegisterValue = JSC::ARMRegisters::r0;
+    static const RegisterID ReturnValueRegisterTag   = JSC::ARMRegisters::r1;
+    static const RegisterID ScratchRegister          = JSC::ARMRegisters::r2;
+    static const RegisterID AccumulatorRegisterValue = JSC::ARMRegisters::r4;
+    static const RegisterID AccumulatorRegisterTag   = JSC::ARMRegisters::r5;
+    // r6 is used by MacroAssemblerARMv7
+    static const RegisterID JSStackFrameRegister     = JSC::ARMRegisters::r8;
+    static const RegisterID CppStackFrameRegister    = JSC::ARMRegisters::r10;
+#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
+    static const RegisterID FramePointerRegister     = JSC::ARMRegisters::r7;
+    static const RegisterID EngineRegister           = JSC::ARMRegisters::r11;
+#else // Thumbs down
+    static const RegisterID FramePointerRegister     = JSC::ARMRegisters::r11;
+    static const RegisterID EngineRegister           = JSC::ARMRegisters::r7;
+#endif
+    static const RegisterID StackPointerRegister     = JSC::ARMRegisters::r13;
+    static const FPRegisterID FPScratchRegister      = JSC::ARMRegisters::d1;
+
+    static const RegisterID Arg0Reg = JSC::ARMRegisters::r0;
+    static const RegisterID Arg1Reg = JSC::ARMRegisters::r1;
+    static const RegisterID Arg2Reg = JSC::ARMRegisters::r2;
+    static const RegisterID Arg3Reg = JSC::ARMRegisters::r3;
+    static const RegisterID Arg4Reg = NoRegister;
+    static const RegisterID Arg5Reg = NoRegister;
+    static const RegisterID Arg6Reg = NoRegister;
+    static const RegisterID Arg7Reg = NoRegister;
+    static const int ArgInRegCount = 4;
+
+    void popValue()
+    {
+        addPtr(TrustedImm32(sizeof(ReturnedValue)), StackPointerRegister);
+    }
+
+    void generatePlatformFunctionEntry()
+    {
+        push(JSC::ARMRegisters::lr);
+        push(FramePointerRegister);
+        move(StackPointerRegister, FramePointerRegister);
+        push(TrustedImm32(0)); // exceptionHandler
+        push(AccumulatorRegisterValue);
+        push(AccumulatorRegisterTag);
+        push(addressTempRegister);
+        push(JSStackFrameRegister);
+        push(CppStackFrameRegister);
+        push(EngineRegister);
+        subPtr(TrustedImm32(4), StackPointerRegister); // stack alignment
+        move(Arg0Reg, CppStackFrameRegister);
+        move(Arg1Reg, EngineRegister);
+    }
+
+    void generatePlatformFunctionExit(bool tailCall = false)
+    {
+        if (!tailCall) { // do not overwrite arg0 and arg1 (used in the tail call)
+            move(AccumulatorRegisterValue, ReturnValueRegisterValue);
+            move(AccumulatorRegisterTag, ReturnValueRegisterTag);
+        }
+        addPtr(TrustedImm32(4), StackPointerRegister); // stack alignment
+        pop(EngineRegister);
+        pop(CppStackFrameRegister);
+        pop(JSStackFrameRegister);
+        pop(addressTempRegister);
+        pop(AccumulatorRegisterTag);
+        pop(AccumulatorRegisterValue);
+        pop(); // exceptionHandler
+        pop(FramePointerRegister);
+        pop(JSC::ARMRegisters::lr);
+        if (!tailCall)
+            ret();
+    }
+
+    void callAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), dataTempRegister);
+        call(dataTempRegister);
+    }
+
+    void jumpAbsolute(const void *funcPtr)
+    {
+        move(TrustedImmPtr(funcPtr), dataTempRegister);
+        jump(dataTempRegister);
+    }
+
+    void pushAligned(RegisterID reg)
+    {
+        subPtr(TrustedImm32(PointerSize), StackPointerRegister);
+        push(reg);
+    }
+
+    void popAligned(RegisterID reg)
+    {
+        pop(reg);
+        addPtr(TrustedImm32(PointerSize), StackPointerRegister);
+    }
+};
+
+typedef PlatformAssembler_ARM32 PlatformAssemblerBase;
+#endif
+
+class PlatformAssemblerCommon : public JIT::PlatformAssemblerBase
+{
+public:
+    PlatformAssemblerCommon(const Value *constantTable)
+        : constantTable(constantTable)
+    {}
+
+    virtual ~PlatformAssemblerCommon();
+
+    Address exceptionHandlerAddress() const
+    {
+        return Address(FramePointerRegister, -1 * PointerSize);
+    }
+
+    Address contextAddress() const
+    {
+        return Address(JSStackFrameRegister, offsetof(CallData, context));
+    }
+
+    RegisterID registerForArg(int arg) const
+    {
+        Q_ASSERT(arg >= 0);
+        Q_ASSERT(arg < ArgInRegCount);
+        switch (arg) {
+        case 0: return Arg0Reg;
+        case 1: return Arg1Reg;
+        case 2: return Arg2Reg;
+        case 3: return Arg3Reg;
+        case 4: return Arg4Reg;
+        case 5: return Arg5Reg;
+        case 6: return Arg6Reg;
+        case 7: return Arg7Reg;
+        default:
+            Q_UNIMPLEMENTED();
+            Q_UNREACHABLE();
+        }
+    }
+
+    Address loadFunctionPtr(RegisterID target)
+    {
+        Address addr(CppStackFrameRegister, offsetof(CppStackFrame, v4Function));
+        loadPtr(addr, target);
+        return Address(target);
+    }
+
+    Address loadCompilationUnitPtr(RegisterID target)
+    {
+        Address addr = loadFunctionPtr(target);
+        addr.offset = offsetof(QV4::FunctionData, compilationUnit);
+        loadPtr(addr, target);
+        return Address(target);
+    }
+
+    Address loadConstAddress(int constIndex, RegisterID baseReg = ScratchRegister)
+    {
+        Address addr = loadCompilationUnitPtr(baseReg);
+        addr.offset = offsetof(QV4::CompiledData::CompilationUnitBase, constants);
+        loadPtr(addr, baseReg);
+        addr.offset = constIndex * int(sizeof(QV4::Value));
+        return addr;
+    }
+
+    Address loadStringAddress(int stringId)
+    {
+        Address addr = loadCompilationUnitPtr(ScratchRegister);
+        addr.offset = offsetof(QV4::CompiledData::CompilationUnitBase, runtimeStrings);
+        loadPtr(addr, ScratchRegister);
+        return Address(ScratchRegister, stringId * PointerSize);
+    }
+
+    void passAsArg(RegisterID src, int arg)
+    {
+        move(src, registerForArg(arg));
+    }
+
+    void generateCatchTrampoline(std::function<void()> loadUndefined)
+    {
+        for (Jump j : catchyJumps)
+            j.link(this);
+
+        loadPtr(exceptionHandlerAddress(), ScratchRegister);
+        Jump exitFunction = branchPtr(Equal, ScratchRegister, TrustedImmPtr(0));
+        jump(ScratchRegister);
+        exitFunction.link(this);
+        loadUndefined();
+
+        if (functionExit.isSet())
+            jump(functionExit);
+        else
+            generateFunctionExit();
+    }
+
+    void checkException()
+    {
+        addCatchyJump(
+                    branch32(NotEqual,
+                             Address(EngineRegister, offsetof(EngineBase, hasException)),
+                             TrustedImm32(0)));
+    }
+
+    void addCatchyJump(Jump j)
+    {
+        Q_ASSERT(j.isSet());
+        catchyJumps.push_back(j);
+    }
+
+    void generateFunctionEntry()
+    {
+        generatePlatformFunctionEntry();
+        loadPtr(Address(CppStackFrameRegister, offsetof(CppStackFrame, jsFrame)), JSStackFrameRegister);
+        allocateStackSpace();
+    }
+
+    virtual void allocateStackSpace() {}
+
+    void generateFunctionExit()
+    {
+        if (functionExit.isSet()) {
+            jump(functionExit);
+            return;
+        }
+
+        functionExit = label();
+        freeStackSpace();
+        generatePlatformFunctionExit();
+    }
+
+    virtual void freeStackSpace() {}
+
+    void addLabelForOffset(int offset)
+    {
+        if (!labelForOffset.contains(offset))
+            labelForOffset.insert(offset, label());
+    }
+
+    void addJumpToOffset(const Jump &jump, int offset)
+    {
+        jumpsToLink.push_back({ jump, offset });
+    }
+
+    void addEHTarget(const DataLabelPtr &label, int offset)
+    {
+        ehTargets.push_back({ label, offset });
+    }
+
+    void link(Function *function, const char *jitKind);
+
+    Value constant(int idx) const
+    { return constantTable[idx]; }
+
+    // stuff for runtime calls
+    void prepareCallWithArgCount(int argc);
+    void storeInstructionPointer(int instructionOffset);
+    void passAccumulatorAsArg(int arg);
+    void pushAccumulatorAsArg(int arg);
+    void passFunctionAsArg(int arg);
+    void passEngineAsArg(int arg);
+    void passJSSlotAsArg(int reg, int arg);
+    void passAddressAsArg(Address addr, int arg);
+    void passCppFrameAsArg(int arg);
+    void passInt32AsArg(int value, int arg);
+    void passPointerAsArg(void *ptr, int arg);
+    void callRuntime(const char *functionName, const void *funcPtr);
+    void callRuntimeUnchecked(const char *functionName, const void *funcPtr);
+    void tailCallRuntime(const char *functionName, const void *funcPtr);
+    void setTailCallArg(RegisterID src, int arg);
+    Address jsAlloca(int slotCount);
+    void storeInt32AsValue(int srcInt, Address destAddr);
+
+private:
+    void passAccumulatorAsArg_internal(int arg, bool doPush);
+    static Address argStackAddress(int arg);
+
+private:
+    const Value* constantTable;
+    struct JumpTarget { JSC::MacroAssemblerBase::Jump jump; int offset; };
+    std::vector<JumpTarget> jumpsToLink;
+    struct ExceptionHanlderTarget { JSC::MacroAssemblerBase::DataLabelPtr label; int offset; };
+    std::vector<ExceptionHanlderTarget> ehTargets;
+    QHash<int, JSC::MacroAssemblerBase::Label> labelForOffset;
+    QHash<const void *, const char *> functions;
+    std::vector<Jump> catchyJumps;
+    Label functionExit;
+
+#ifndef QT_NO_DEBUG
+    enum { NoCall = -1 };
+    int remainingArgcForCall = NoCall;
+#endif
+    int argcOnStackForCall = 0;
+};
+
+} // JIT namespace
+} // QV4 namespace
+
+QT_END_NAMESPACE
+
+#endif // V4_ENABLE_JIT
+
+#endif // QV4PLATFORMASSEMBLER_P_H
diff --git a/src/qml/jit/qv4baselineassembler.cpp b/src/qml/jit/qv4baselineassembler.cpp
new file mode 100644
index 0000000000..1b60e96f2c
--- /dev/null
+++ b/src/qml/jit/qv4baselineassembler.cpp
@@ -0,0 +1,1624 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QBuffer>
+#include <QFile>
+
+#include "qv4engine_p.h"
+#include "qv4baselineassembler_p.h"
+#include "qv4assemblercommon_p.h"
+#include <private/qv4function_p.h>
+#include <private/qv4runtime_p.h>
+#include <private/qv4stackframe_p.h>
+
+#include <wtf/Vector.h>
+#include <assembler/MacroAssembler.h>
+#include <assembler/MacroAssemblerCodeRef.h>
+#include <assembler/LinkBuffer.h>
+#include <WTFStubs.h>
+
+#undef ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES
+
+#ifdef V4_ENABLE_JIT
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace JIT {
+
+#define ASM_GENERATE_RUNTIME_CALL(function, destination) \
+    pasm()->GENERATE_RUNTIME_CALL(function, destination)
+#define callHelper(x) PlatformAssemblerCommon::callRuntimeUnchecked(#x, reinterpret_cast<void *>(&x))
+
+const QV4::Value::ValueTypeInternal IntegerTag = QV4::Value::ValueTypeInternal::Integer;
+
+static ReturnedValue toNumberHelper(ReturnedValue v)
+{
+    return Encode(Value::fromReturnedValue(v).toNumber());
+}
+
+static ReturnedValue toInt32Helper(ReturnedValue v)
+{
+    return Encode(Value::fromReturnedValue(v).toInt32());
+}
+
+#if QT_POINTER_SIZE == 8 || defined(ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES)
+class PlatformAssembler64 : public PlatformAssemblerCommon
+{
+public:
+    PlatformAssembler64(const Value *constantTable)
+        : PlatformAssemblerCommon(constantTable)
+    {}
+
+    void callRuntime(const char *functionName, const void *funcPtr,
+                     CallResultDestination dest)
+    {
+        PlatformAssemblerCommon::callRuntime(functionName, funcPtr);
+        if (dest == CallResultDestination::InAccumulator)
+            saveReturnValueInAccumulator();
+    }
+
+    void saveReturnValueInAccumulator()
+    {
+        move(ReturnValueRegister, AccumulatorRegister);
+    }
+
+    void loadUndefined(RegisterID dest = AccumulatorRegister)
+    {
+        move(TrustedImm64(0), dest);
+    }
+
+    void copyConst(int constIndex, Address dest)
+    {
+        //###
+        if (constant(constIndex).isUndefined()) {
+            loadUndefined(ScratchRegister);
+        } else {
+            load64(loadConstAddress(constIndex, ScratchRegister), ScratchRegister);
+        }
+        store64(ScratchRegister, dest);
+    }
+
+    void copyReg(Address src, Address dst)
+    {
+        load64(src, ScratchRegister);
+        store64(ScratchRegister, dst);
+    }
+
+    void loadPointerFromValue(Address addr, RegisterID dest = AccumulatorRegister)
+    {
+        load64(addr, dest);
+    }
+
+    void loadAccumulator(Address addr)
+    {
+        load64(addr, AccumulatorRegister);
+    }
+
+    void storeAccumulator(Address addr)
+    {
+        store64(AccumulatorRegister, addr);
+    }
+
+    void moveReg(Address sourceRegAddress, Address destRegAddress)
+    {
+        load64(sourceRegAddress, ScratchRegister);
+        store64(ScratchRegister, destRegAddress);
+    }
+
+    void loadString(int stringId)
+    {
+        loadAccumulator(loadStringAddress(stringId));
+    }
+
+    void loadValue(ReturnedValue value)
+    {
+        move(TrustedImm64(value), AccumulatorRegister);
+    }
+
+    void storeHeapObject(RegisterID source, Address addr)
+    {
+        store64(source, addr);
+    }
+
+    void generateCatchTrampoline()
+    {
+        PlatformAssemblerCommon::generateCatchTrampoline([this](){loadUndefined();});
+    }
+
+    void jumpNotUndefined(int offset)
+    {
+        auto jump = branch64(NotEqual, AccumulatorRegister, TrustedImm64(0));
+        addJumpToOffset(jump, offset);
+    }
+
+    Jump jumpEmpty()
+    {
+        return branch64(Equal, AccumulatorRegister, TrustedImm64(Value::emptyValue().asReturnedValue()));
+    }
+
+    Jump jumpNotEmpty()
+    {
+        return branch64(NotEqual, AccumulatorRegister, TrustedImm64(Value::emptyValue().asReturnedValue()));
+    }
+
+    void toBoolean(std::function<void(RegisterID)> continuation)
+    {
+        urshift64(AccumulatorRegister, TrustedImm32(Value::IsIntegerConvertible_Shift), ScratchRegister);
+        auto needsConversion = branch32(NotEqual, TrustedImm32(1), ScratchRegister);
+        continuation(AccumulatorRegister);
+        Jump done = jump();
+
+        // slow path:
+        needsConversion.link(this);
+        push(AccumulatorRegister);
+        move(AccumulatorRegister, registerForArg(0));
+        callHelper(Value::toBooleanImpl);
+        and32(TrustedImm32(1), ReturnValueRegister, ScratchRegister);
+        pop(AccumulatorRegister);
+        continuation(ScratchRegister);
+
+        done.link(this);
+    }
+
+    void toNumber()
+    {
+        urshift64(AccumulatorRegister, TrustedImm32(Value::QuickType_Shift), ScratchRegister);
+        auto isNumber = branch32(GreaterThanOrEqual, ScratchRegister, TrustedImm32(Value::QT_Int));
+
+        move(AccumulatorRegister, registerForArg(0));
+        callHelper(toNumberHelper);
+        saveReturnValueInAccumulator();
+
+        isNumber.link(this);
+    }
+
+    void toInt32LhsAcc(Address lhs, RegisterID lhsTarget)
+    {
+        load64(lhs, lhsTarget);
+        urshift64(lhsTarget, TrustedImm32(Value::QuickType_Shift), ScratchRegister2);
+        auto lhsIsInt = branch32(Equal, TrustedImm32(Value::QT_Int), ScratchRegister2);
+
+        pushAligned(AccumulatorRegister);
+        move(lhsTarget, registerForArg(0));
+        callHelper(toInt32Helper);
+        move(ReturnValueRegister, lhsTarget);
+        popAligned(AccumulatorRegister);
+
+        lhsIsInt.link(this);
+        urshift64(AccumulatorRegister, TrustedImm32(Value::QuickType_Shift), ScratchRegister2);
+        auto isInt = branch32(Equal, TrustedImm32(Value::QT_Int), ScratchRegister2);
+
+        pushAligned(lhsTarget);
+        move(AccumulatorRegister, registerForArg(0));
+        callHelper(toInt32Helper);
+        saveReturnValueInAccumulator();
+        popAligned(lhsTarget);
+
+        isInt.link(this);
+    }
+
+    void toInt32()
+    {
+        urshift64(AccumulatorRegister, TrustedImm32(Value::QuickType_Shift), ScratchRegister2);
+        auto isInt = branch32(Equal, TrustedImm32(Value::QT_Int), ScratchRegister2);
+
+        move(AccumulatorRegister, registerForArg(0));
+        callRuntimeUnchecked("toInt32Helper", reinterpret_cast<void *>(&toInt32Helper));
+        saveReturnValueInAccumulator();
+
+        isInt.link(this);
+    }
+
+    void regToInt32(Address srcReg, RegisterID targetReg)
+    {
+        load64(srcReg, targetReg);
+        urshift64(targetReg, TrustedImm32(Value::QuickType_Shift), ScratchRegister2);
+        auto isInt = branch32(Equal, TrustedImm32(Value::QT_Int), ScratchRegister2);
+
+        pushAligned(AccumulatorRegister);
+        move(targetReg, registerForArg(0));
+        callHelper(toInt32Helper);
+        move(ReturnValueRegister, targetReg);
+        popAligned(AccumulatorRegister);
+
+        isInt.link(this);
+    }
+
+    void isNullOrUndefined()
+    {
+        move(AccumulatorRegister, ScratchRegister);
+        compare64(Equal, ScratchRegister, TrustedImm32(0), AccumulatorRegister);
+        Jump isUndef = branch32(NotEqual, TrustedImm32(0), AccumulatorRegister);
+
+        // not undefined
+        rshift64(TrustedImm32(32), ScratchRegister);
+        compare32(Equal, ScratchRegister, TrustedImm32(int(QV4::Value::ValueTypeInternal::Null)),
+                  AccumulatorRegister);
+
+        isUndef.link(this);
+    }
+
+    Jump isIntOrBool()
+    {
+        urshift64(AccumulatorRegister, TrustedImm32(Value::IsIntegerOrBool_Shift), ScratchRegister);
+        return branch32(Equal, TrustedImm32(3), ScratchRegister);
+    }
+
+    void jumpStrictEqualStackSlotInt(int lhs, int rhs, int offset)
+    {
+        Address lhsAddr(JSStackFrameRegister, lhs * int(sizeof(Value)));
+        load64(lhsAddr, ScratchRegister);
+        Jump isUndef = branch64(Equal, ScratchRegister, TrustedImm64(0));
+        Jump equal = branch32(Equal, TrustedImm32(rhs), ScratchRegister);
+        addJumpToOffset(equal, offset);
+        isUndef.link(this);
+    }
+
+    void jumpStrictNotEqualStackSlotInt(int lhs, int rhs, int offset)
+    {
+        Address lhsAddr(JSStackFrameRegister, lhs * int(sizeof(Value)));
+        load64(lhsAddr, ScratchRegister);
+        Jump isUndef = branch64(Equal, ScratchRegister, TrustedImm64(0));
+        addJumpToOffset(isUndef, offset);
+        Jump notEqual = branch32(NotEqual, TrustedImm32(rhs), ScratchRegister);
+        addJumpToOffset(notEqual, offset);
+    }
+
+    void setAccumulatorTag(QV4::Value::ValueTypeInternal tag, RegisterID sourceReg = NoRegister)
+    {
+        if (sourceReg == NoRegister)
+            or64(TrustedImm64(int64_t(tag) << 32), AccumulatorRegister);
+        else
+            or64(TrustedImm64(int64_t(tag) << 32), sourceReg, AccumulatorRegister);
+    }
+
+    void encodeDoubleIntoAccumulator(FPRegisterID src)
+    {
+        moveDoubleTo64(src, AccumulatorRegister);
+        move(TrustedImm64(Value::NaNEncodeMask), ScratchRegister);
+        xor64(ScratchRegister, AccumulatorRegister);
+    }
+
+    void pushValueAligned(ReturnedValue v)
+    {
+        loadValue(v);
+        pushAligned(AccumulatorRegister);
+    }
+
+    void popValueAligned()
+    {
+        addPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+    }
+
+    Jump binopBothIntPath(Address lhsAddr, std::function<Jump(void)> fastPath)
+    {
+        urshift64(AccumulatorRegister, TrustedImm32(32), ScratchRegister);
+        Jump accNotInt = branch32(NotEqual, TrustedImm32(int(IntegerTag)), ScratchRegister);
+        load64(lhsAddr, ScratchRegister);
+        urshift64(ScratchRegister, TrustedImm32(32), ScratchRegister2);
+        Jump lhsNotInt = branch32(NotEqual, TrustedImm32(int(IntegerTag)), ScratchRegister2);
+
+        // both integer
+        Jump failure = fastPath();
+        Jump done = jump();
+
+        // all other cases
+        if (failure.isSet())
+            failure.link(this);
+        accNotInt.link(this);
+        lhsNotInt.link(this);
+
+        return done;
+    }
+
+    Jump unopIntPath(std::function<Jump(void)> fastPath)
+    {
+        urshift64(AccumulatorRegister, TrustedImm32(Value::IsIntegerConvertible_Shift), ScratchRegister);
+        Jump accNotIntConvertible = branch32(NotEqual, TrustedImm32(1), ScratchRegister);
+
+        // both integer
+        Jump failure = fastPath();
+        Jump done = jump();
+
+        // all other cases
+        if (failure.isSet())
+            failure.link(this);
+        accNotIntConvertible.link(this);
+
+        return done;
+    }
+
+    void callWithAccumulatorByValueAsFirstArgument(std::function<void()> doCall)
+    {
+        passAsArg(AccumulatorRegister, 0);
+        doCall();
+    }
+};
+
+typedef PlatformAssembler64 PlatformAssembler;
+#endif
+
+#if QT_POINTER_SIZE == 4 || defined(ENABLE_ALL_ASSEMBLERS_FOR_REFACTORING_PURPOSES)
+class PlatformAssembler32 : public PlatformAssemblerCommon
+{
+public:
+    PlatformAssembler32(const Value *constantTable)
+        : PlatformAssemblerCommon(constantTable)
+    {}
+
+    void callRuntime(const char *functionName, const void *funcPtr,
+                     CallResultDestination dest)
+    {
+        PlatformAssemblerCommon::callRuntime(functionName, funcPtr);
+        if (dest == CallResultDestination::InAccumulator)
+            saveReturnValueInAccumulator();
+    }
+
+    void saveReturnValueInAccumulator()
+    {
+        move(ReturnValueRegisterValue, AccumulatorRegisterValue);
+        move(ReturnValueRegisterTag, AccumulatorRegisterTag);
+    }
+
+    void loadUndefined()
+    {
+        move(TrustedImm32(0), AccumulatorRegisterValue);
+        move(TrustedImm32(0), AccumulatorRegisterTag);
+    }
+
+    void copyConst(int constIndex, Address destRegAddr)
+    {
+        //###
+        if (constant(constIndex).isUndefined()) {
+            move(TrustedImm32(0), ScratchRegister);
+            store32(ScratchRegister, destRegAddr);
+            destRegAddr.offset += 4;
+            store32(ScratchRegister, destRegAddr);
+        } else {
+            Address src = loadConstAddress(constIndex);
+            loadDouble(src, FPScratchRegister);
+            storeDouble(FPScratchRegister, destRegAddr);
+        }
+    }
+
+    void copyReg(Address src, Address dest)
+    {
+        loadDouble(src, FPScratchRegister);
+        storeDouble(FPScratchRegister, dest);
+    }
+
+    void loadPointerFromValue(Address addr, RegisterID dest = AccumulatorRegisterValue)
+    {
+        load32(addr, dest);
+    }
+
+    void loadAccumulator(Address src)
+    {
+        load32(src, AccumulatorRegisterValue);
+        src.offset += 4;
+        load32(src, AccumulatorRegisterTag);
+    }
+
+    void storeAccumulator(Address addr)
+    {
+        store32(AccumulatorRegisterValue, addr);
+        addr.offset += 4;
+        store32(AccumulatorRegisterTag, addr);
+    }
+
+    void moveReg(Address sourceRegAddress, Address destRegAddress)
+    {
+        load32(sourceRegAddress, ScratchRegister);
+        store32(ScratchRegister, destRegAddress);
+        sourceRegAddress.offset += 4;
+        destRegAddress.offset += 4;
+        load32(sourceRegAddress, ScratchRegister);
+        store32(ScratchRegister, destRegAddress);
+    }
+
+    void loadString(int stringId)
+    {
+        load32(loadStringAddress(stringId), AccumulatorRegisterValue);
+        move(TrustedImm32(0), AccumulatorRegisterTag);
+    }
+
+    void loadValue(ReturnedValue value)
+    {
+        move(TrustedImm32(Value::fromReturnedValue(value).value()), AccumulatorRegisterValue);
+        move(TrustedImm32(Value::fromReturnedValue(value).tag()), AccumulatorRegisterTag);
+    }
+
+    void storeHeapObject(RegisterID source, Address addr)
+    {
+        store32(source, addr);
+        addr.offset += 4;
+        store32(TrustedImm32(0), addr);
+    }
+
+
+    void generateCatchTrampoline()
+    {
+        PlatformAssemblerCommon::generateCatchTrampoline([this](){loadUndefined();});
+    }
+
+    void toNumber()
+    {
+        urshift32(AccumulatorRegisterTag, TrustedImm32(Value::QuickType_Shift - 32), ScratchRegister);
+        auto isNumber = branch32(GreaterThanOrEqual, ScratchRegister, TrustedImm32(Value::QT_Int));
+
+        if (ArgInRegCount < 2) {
+            subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister); // stack alignment
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        } else {
+            move(AccumulatorRegisterValue, registerForArg(0));
+            move(AccumulatorRegisterTag, registerForArg(1));
+        }
+        callRuntimeUnchecked("toNumberHelper", reinterpret_cast<void *>(&toNumberHelper));
+        saveReturnValueInAccumulator();
+        if (ArgInRegCount < 2)
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+
+        isNumber.link(this);
+    }
+
+    void toInt32LhsAcc(Address lhs, RegisterID lhsTarget)
+    {
+        bool accumulatorNeedsSaving = AccumulatorRegisterValue == ReturnValueRegisterValue
+                || AccumulatorRegisterTag == ReturnValueRegisterTag;
+        lhs.offset += 4;
+        load32(lhs, lhsTarget);
+        lhs.offset -= 4;
+        auto lhsIsNotInt = branch32(NotEqual, TrustedImm32(int(IntegerTag)), lhsTarget);
+        load32(lhs, lhsTarget);
+        auto lhsIsInt = jump();
+
+        lhsIsNotInt.link(this);
+        if (accumulatorNeedsSaving) {
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        }
+
+        if (ArgInRegCount < 2) {
+            if (!accumulatorNeedsSaving)
+                subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            push(lhsTarget);
+            load32(lhs, lhsTarget);
+            push(lhsTarget);
+        } else {
+            if (accumulatorNeedsSaving)
+                subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            move(lhsTarget, registerForArg(1));
+            load32(lhs, registerForArg(0));
+        }
+        callHelper(toInt32Helper);
+        move(ReturnValueRegisterValue, lhsTarget);
+        if (accumulatorNeedsSaving) {
+            addPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            pop(AccumulatorRegisterValue);
+            pop(AccumulatorRegisterTag);
+        } else if (ArgInRegCount < 2) {
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+        }
+
+        lhsIsInt.link(this);
+
+        auto rhsIsInt = branch32(Equal, TrustedImm32(int(IntegerTag)), AccumulatorRegisterTag);
+
+        pushAligned(lhsTarget);
+        if (ArgInRegCount < 2) {
+            subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        } else {
+            move(AccumulatorRegisterValue, registerForArg(0));
+            move(AccumulatorRegisterTag, registerForArg(1));
+        }
+        callRuntimeUnchecked("toInt32Helper", reinterpret_cast<void *>(&toInt32Helper));
+        saveReturnValueInAccumulator();
+        if (ArgInRegCount < 2)
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+        popAligned(lhsTarget);
+
+        rhsIsInt.link(this);
+    }
+
+    void toInt32()
+    {
+        urshift32(AccumulatorRegisterTag, TrustedImm32(Value::QuickType_Shift - 32), ScratchRegister);
+        auto isInt = branch32(Equal, TrustedImm32(Value::QT_Int), ScratchRegister);
+
+        if (ArgInRegCount < 2) {
+            subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister); // align the stack on a 16-byte boundary
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        } else {
+            move(AccumulatorRegisterValue, registerForArg(0));
+            move(AccumulatorRegisterTag, registerForArg(1));
+        }
+        callRuntimeUnchecked("toInt32Helper", reinterpret_cast<void *>(&toInt32Helper));
+        saveReturnValueInAccumulator();
+        if (ArgInRegCount < 2)
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+
+        isInt.link(this);
+    }
+
+    void regToInt32(Address srcReg, RegisterID targetReg)
+    {
+        bool accumulatorNeedsSaving = AccumulatorRegisterValue == ReturnValueRegisterValue
+                || AccumulatorRegisterTag == ReturnValueRegisterTag;
+        if (accumulatorNeedsSaving) {
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        }
+        if (ArgInRegCount < 2) {
+            if (!accumulatorNeedsSaving)
+                subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            srcReg.offset += 4;
+            load32(srcReg, targetReg);
+            push(targetReg);
+            srcReg.offset -= 4;
+            load32(srcReg, targetReg);
+            push(targetReg);
+        } else {
+            if (accumulatorNeedsSaving)
+                subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            load32(srcReg, registerForArg(0));
+            srcReg.offset += 4;
+            load32(srcReg, registerForArg(1));
+        }
+        callHelper(toInt32Helper);
+        move(ReturnValueRegisterValue, targetReg);
+        if (accumulatorNeedsSaving) {
+            addPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            pop(AccumulatorRegisterValue);
+            pop(AccumulatorRegisterTag);
+        } else if (ArgInRegCount < 2) {
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+        }
+    }
+
+    void isNullOrUndefined()
+    {
+        Jump notUndefOrPtr = branch32(NotEqual, TrustedImm32(0), AccumulatorRegisterTag);
+        compare32(Equal, AccumulatorRegisterValue, TrustedImm32(0), AccumulatorRegisterValue);
+        auto done = jump();
+
+        // not undefined or managed
+        notUndefOrPtr.link(this);
+        compare32(Equal, AccumulatorRegisterTag, TrustedImm32(int(QV4::Value::ValueTypeInternal::Null)),
+                  AccumulatorRegisterValue);
+
+        done.link(this);
+    }
+
+    Jump isIntOrBool()
+    {
+        urshift32(AccumulatorRegisterTag, TrustedImm32(Value::IsIntegerOrBool_Shift - 32), ScratchRegister);
+        return branch32(Equal, TrustedImm32(3), ScratchRegister);
+    }
+
+    void pushValue(ReturnedValue v)
+    {
+        push(TrustedImm32(v >> 32));
+        push(TrustedImm32(v));
+    }
+
+    void jumpNotUndefined(int offset)
+    {
+        move(AccumulatorRegisterTag, ScratchRegister);
+        or32(AccumulatorRegisterValue, ScratchRegister);
+        auto jump = branch32(NotEqual, ScratchRegister, TrustedImm32(0));
+        addJumpToOffset(jump, offset);
+    }
+
+    Jump jumpEmpty()
+    {
+        return branch32(Equal, AccumulatorRegisterTag, TrustedImm32(Value::emptyValue().asReturnedValue() >> 32));
+    }
+
+    Jump jumpNotEmpty()
+    {
+        return branch32(NotEqual, AccumulatorRegisterTag, TrustedImm32(Value::emptyValue().asReturnedValue() >> 32));
+    }
+
+    void toBoolean(std::function<void(RegisterID)> continuation)
+    {
+        urshift32(AccumulatorRegisterTag, TrustedImm32(Value::IsIntegerConvertible_Shift - 32),
+                  ScratchRegister);
+        auto needsConversion = branch32(NotEqual, TrustedImm32(1), ScratchRegister);
+        continuation(AccumulatorRegisterValue);
+        Jump done = jump();
+
+        // slow path:
+        needsConversion.link(this);
+
+        bool accumulatorNeedsSaving = AccumulatorRegisterValue == ReturnValueRegisterValue
+                || AccumulatorRegisterTag == ReturnValueRegisterTag;
+        if (accumulatorNeedsSaving) {
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        }
+
+        if (ArgInRegCount < 2) {
+            if (!accumulatorNeedsSaving)
+                subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        } else {
+            if (accumulatorNeedsSaving)
+                subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            move(AccumulatorRegisterValue, registerForArg(0));
+            move(AccumulatorRegisterTag, registerForArg(1));
+        }
+        callHelper(Value::toBooleanImpl);
+        and32(TrustedImm32(1), ReturnValueRegisterValue, ScratchRegister);
+        if (accumulatorNeedsSaving) {
+            addPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            pop(AccumulatorRegisterValue);
+            pop(AccumulatorRegisterTag);
+        } else if (ArgInRegCount < 2) {
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+        }
+        continuation(ScratchRegister);
+
+        done.link(this);
+    }
+
+    void jumpStrictEqualStackSlotInt(int lhs, int rhs, int offset)
+    {
+        Address lhsAddr(JSStackFrameRegister, lhs * int(sizeof(Value)));
+        load32(lhsAddr, ScratchRegister);
+        Jump notEqInt = branch32(NotEqual, ScratchRegister, TrustedImm32(rhs));
+        Jump notEqUndefVal = branch32(NotEqual, ScratchRegister, TrustedImm32(0));
+        addJumpToOffset(notEqUndefVal, offset);
+        lhsAddr.offset += 4;
+        load32(lhsAddr, ScratchRegister);
+        Jump notEqUndefTag = branch32(NotEqual, ScratchRegister, TrustedImm32(0));
+        addJumpToOffset(notEqUndefTag, offset);
+        notEqInt.link(this);
+    }
+
+    void jumpStrictNotEqualStackSlotInt(int lhs, int rhs, int offset)
+    {
+        Address lhsAddr(JSStackFrameRegister, lhs * int(sizeof(Value)));
+        load32(lhsAddr, ScratchRegister);
+        Jump notEqual = branch32(NotEqual, TrustedImm32(rhs), ScratchRegister);
+        addJumpToOffset(notEqual, offset);
+        Jump notUndefValue = branch32(NotEqual, TrustedImm32(0), ScratchRegister);
+        lhsAddr.offset += 4;
+        load32(lhsAddr, ScratchRegister);
+        Jump equalUndef = branch32(Equal, TrustedImm32(0), ScratchRegister);
+        addJumpToOffset(equalUndef, offset);
+        notUndefValue.link(this);
+    }
+
+    void setAccumulatorTag(QV4::Value::ValueTypeInternal tag, RegisterID sourceReg = NoRegister)
+    {
+        if (sourceReg != NoRegister)
+            move(sourceReg, AccumulatorRegisterValue);
+        move(TrustedImm32(int(tag)), AccumulatorRegisterTag);
+    }
+
+    void encodeDoubleIntoAccumulator(FPRegisterID src)
+    {
+        moveDoubleToInts(src, AccumulatorRegisterValue, AccumulatorRegisterTag);
+        xor32(TrustedImm32(Value::NaNEncodeMask >> 32), AccumulatorRegisterTag);
+    }
+
+    void pushValueAligned(ReturnedValue v)
+    {
+        pushValue(v);
+    }
+
+    void popValueAligned()
+    {
+        popValue();
+    }
+
+    Jump binopBothIntPath(Address lhsAddr, std::function<Jump(void)> fastPath)
+    {
+        Jump accNotInt = branch32(NotEqual, TrustedImm32(int(IntegerTag)), AccumulatorRegisterTag);
+        Address lhsAddrTag = lhsAddr; lhsAddrTag.offset += Value::tagOffset();
+        load32(lhsAddrTag, ScratchRegister);
+        Jump lhsNotInt = branch32(NotEqual, TrustedImm32(int(IntegerTag)), ScratchRegister);
+
+        // both integer
+        Address lhsAddrValue = lhsAddr; lhsAddrValue.offset += Value::valueOffset();
+        load32(lhsAddrValue, ScratchRegister);
+        Jump failure = fastPath();
+        Jump done = jump();
+
+        // all other cases
+        if (failure.isSet())
+            failure.link(this);
+        accNotInt.link(this);
+        lhsNotInt.link(this);
+
+        return done;
+    }
+
+    Jump unopIntPath(std::function<Jump(void)> fastPath)
+    {
+        Jump accNotInt = branch32(NotEqual, TrustedImm32(int(IntegerTag)), AccumulatorRegisterTag);
+
+        // both integer
+        Jump failure = fastPath();
+        Jump done = jump();
+
+        // all other cases
+        if (failure.isSet())
+            failure.link(this);
+        accNotInt.link(this);
+
+        return done;
+    }
+
+    void callWithAccumulatorByValueAsFirstArgument(std::function<void()> doCall)
+    {
+        if (ArgInRegCount < 2) {
+            subPtr(TrustedImm32(2 * PointerSize), StackPointerRegister);
+            push(AccumulatorRegisterTag);
+            push(AccumulatorRegisterValue);
+        } else {
+            move(AccumulatorRegisterValue, registerForArg(0));
+            move(AccumulatorRegisterTag, registerForArg(1));
+        }
+        doCall();
+        if (ArgInRegCount < 2)
+            addPtr(TrustedImm32(4 * PointerSize), StackPointerRegister);
+    }
+};
+
+typedef PlatformAssembler32 PlatformAssembler;
+#endif
+
+#define pasm() reinterpret_cast<PlatformAssembler *>(this->d)
+
+typedef PlatformAssembler::TrustedImmPtr TrustedImmPtr;
+typedef PlatformAssembler::TrustedImm32 TrustedImm32;
+typedef PlatformAssembler::TrustedImm64 TrustedImm64;
+typedef PlatformAssembler::Address Address;
+typedef PlatformAssembler::RegisterID RegisterID;
+typedef PlatformAssembler::FPRegisterID FPRegisterID;
+
+static Address regAddr(int reg)
+{
+    return Address(PlatformAssembler::JSStackFrameRegister, reg * int(sizeof(QV4::Value)));
+}
+
+BaselineAssembler::BaselineAssembler(const Value *constantTable)
+    : d(new PlatformAssembler(constantTable))
+{
+}
+
+BaselineAssembler::~BaselineAssembler()
+{
+    delete pasm();
+}
+
+void BaselineAssembler::generatePrologue()
+{
+    pasm()->generateFunctionEntry();
+}
+
+void BaselineAssembler::generateEpilogue()
+{
+    pasm()->generateCatchTrampoline();
+}
+
+void BaselineAssembler::link(Function *function)
+{
+    pasm()->link(function, "BaselineJIT");
+}
+
+void BaselineAssembler::addLabel(int offset)
+{
+    pasm()->addLabelForOffset(offset);
+}
+
+void BaselineAssembler::loadConst(int constIndex)
+{
+    //###
+    if (pasm()->constant(constIndex).isUndefined()) {
+        pasm()->loadUndefined();
+    } else {
+        pasm()->loadAccumulator(pasm()->loadConstAddress(constIndex));
+    }
+}
+
+void BaselineAssembler::copyConst(int constIndex, int destReg)
+{
+    pasm()->copyConst(constIndex, regAddr(destReg));
+}
+
+void BaselineAssembler::loadReg(int reg)
+{
+    pasm()->loadAccumulator(regAddr(reg));
+}
+
+void JIT::BaselineAssembler::moveReg(int sourceReg, int destReg)
+{
+    pasm()->moveReg(regAddr(sourceReg), regAddr(destReg));
+}
+
+void BaselineAssembler::storeReg(int reg)
+{
+    pasm()->storeAccumulator(regAddr(reg));
+}
+
+void BaselineAssembler::loadLocal(int index, int level)
+{
+    Heap::CallContext ctx;
+    Q_UNUSED(ctx)
+    pasm()->loadPointerFromValue(regAddr(CallData::Context), PlatformAssembler::ScratchRegister);
+    while (level) {
+        pasm()->loadPtr(Address(PlatformAssembler::ScratchRegister, ctx.outer.offset), PlatformAssembler::ScratchRegister);
+        --level;
+    }
+    pasm()->loadAccumulator(Address(PlatformAssembler::ScratchRegister, ctx.locals.offset + offsetof(ValueArray<0>, values) + sizeof(Value)*index));
+}
+
+void BaselineAssembler::storeLocal(int index, int level)
+{
+    Heap::CallContext ctx;
+    Q_UNUSED(ctx)
+    pasm()->loadPtr(regAddr(CallData::Context), PlatformAssembler::ScratchRegister);
+    while (level) {
+        pasm()->loadPtr(Address(PlatformAssembler::ScratchRegister, ctx.outer.offset), PlatformAssembler::ScratchRegister);
+        --level;
+    }
+    pasm()->storeAccumulator(Address(PlatformAssembler::ScratchRegister, ctx.locals.offset + offsetof(ValueArray<0>, values) + sizeof(Value)*index));
+}
+
+void BaselineAssembler::loadString(int stringId)
+{
+    pasm()->loadString(stringId);
+}
+
+void BaselineAssembler::loadValue(ReturnedValue value)
+{
+    pasm()->loadValue(value);
+}
+
+void BaselineAssembler::storeHeapObject(int reg)
+{
+    pasm()->storeHeapObject(PlatformAssembler::ReturnValueRegisterValue, regAddr(reg));
+}
+
+void BaselineAssembler::loadImport(int index)
+{
+    Address addr = pasm()->loadCompilationUnitPtr(PlatformAssembler::ScratchRegister);
+    addr.offset = offsetof(QV4::CompiledData::CompilationUnitBase, imports);
+    pasm()->loadPtr(addr, PlatformAssembler::ScratchRegister);
+    addr.offset = index * int(sizeof(QV4::Value*));
+    pasm()->loadPtr(addr, PlatformAssembler::ScratchRegister);
+    pasm()->loadAccumulator(Address(PlatformAssembler::ScratchRegister));
+}
+
+void BaselineAssembler::toNumber()
+{
+    pasm()->toNumber();
+}
+
+void BaselineAssembler::uminus()
+{
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(1);
+    pasm()->passAccumulatorAsArg(0);
+    ASM_GENERATE_RUNTIME_CALL(UMinus, CallResultDestination::InAccumulator);
+    checkException();
+}
+
+void BaselineAssembler::ucompl()
+{
+    pasm()->toInt32();
+    pasm()->xor32(TrustedImm32(-1), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+static ReturnedValue incHelper(const Value v)
+{
+    double d;
+    if (Q_LIKELY(v.isDouble()))
+        d =  v.doubleValue();
+    else
+        d = v.toNumberImpl();
+    return Encode(d + 1.);
+}
+
+void BaselineAssembler::inc()
+{
+    auto done = pasm()->unopIntPath([this](){
+        auto overflowed = pasm()->branchAdd32(PlatformAssembler::Overflow,
+                                              PlatformAssembler::AccumulatorRegisterValue,
+                                              TrustedImm32(1),
+                                              PlatformAssembler::ScratchRegister);
+        pasm()->setAccumulatorTag(IntegerTag, PlatformAssembler::ScratchRegister);
+        return overflowed;
+    });
+
+    // slow path:
+    pasm()->callWithAccumulatorByValueAsFirstArgument([this]() {
+        pasm()->callHelper(incHelper);
+        pasm()->saveReturnValueInAccumulator();
+    });
+    checkException();
+
+    // done.
+    done.link(pasm());
+}
+
+static ReturnedValue decHelper(const Value v)
+{
+    double d;
+    if (Q_LIKELY(v.isDouble()))
+        d =  v.doubleValue();
+    else
+        d = v.toNumberImpl();
+    return Encode(d - 1.);
+}
+
+void BaselineAssembler::dec()
+{
+    auto done = pasm()->unopIntPath([this](){
+        auto overflowed = pasm()->branchSub32(PlatformAssembler::Overflow,
+                                              PlatformAssembler::AccumulatorRegisterValue,
+                                              TrustedImm32(1),
+                                              PlatformAssembler::ScratchRegister);
+        pasm()->setAccumulatorTag(IntegerTag, PlatformAssembler::ScratchRegister);
+        return overflowed;
+    });
+
+    // slow path:
+    pasm()->callWithAccumulatorByValueAsFirstArgument([this]() {
+        pasm()->callHelper(decHelper);
+        pasm()->saveReturnValueInAccumulator();
+    });
+    checkException();
+
+    // done.
+    done.link(pasm());
+}
+
+void BaselineAssembler::unot()
+{
+    pasm()->toBoolean([this](PlatformAssembler::RegisterID resultReg){
+        pasm()->compare32(PlatformAssembler::Equal, resultReg,
+                          TrustedImm32(0), PlatformAssembler::AccumulatorRegisterValue);
+        pasm()->setAccumulatorTag(QV4::Value::ValueTypeInternal::Boolean);
+    });
+}
+
+void BaselineAssembler::add(int lhs)
+{
+    auto done = pasm()->binopBothIntPath(regAddr(lhs), [this](){
+        auto overflowed = pasm()->branchAdd32(PlatformAssembler::Overflow,
+                                              PlatformAssembler::AccumulatorRegisterValue,
+                                              PlatformAssembler::ScratchRegister);
+        pasm()->setAccumulatorTag(IntegerTag,
+                                  PlatformAssembler::ScratchRegister);
+        return overflowed;
+    });
+
+    // slow path:
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(3);
+    pasm()->passAccumulatorAsArg(2);
+    pasm()->passJSSlotAsArg(lhs, 1);
+    pasm()->passEngineAsArg(0);
+    ASM_GENERATE_RUNTIME_CALL(Add, CallResultDestination::InAccumulator);
+    checkException();
+
+    // done.
+    done.link(pasm());
+}
+
+void BaselineAssembler::bitAnd(int lhs)
+{
+    PlatformAssembler::Address lhsAddr = regAddr(lhs);
+    pasm()->toInt32LhsAcc(lhsAddr, PlatformAssembler::ScratchRegister);
+    pasm()->and32(PlatformAssembler::ScratchRegister, PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::bitOr(int lhs)
+{
+    PlatformAssembler::Address lhsAddr = regAddr(lhs);
+    pasm()->toInt32LhsAcc(lhsAddr, PlatformAssembler::ScratchRegister);
+    pasm()->or32(PlatformAssembler::ScratchRegister, PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::bitXor(int lhs)
+{
+    PlatformAssembler::Address lhsAddr = regAddr(lhs);
+    pasm()->toInt32LhsAcc(lhsAddr, PlatformAssembler::ScratchRegister);
+    pasm()->xor32(PlatformAssembler::ScratchRegister, PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::ushr(int lhs)
+{
+    PlatformAssembler::Address lhsAddr = regAddr(lhs);
+    pasm()->toInt32LhsAcc(lhsAddr, PlatformAssembler::ScratchRegister);
+    pasm()->and32(TrustedImm32(0x1f), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->urshift32(PlatformAssembler::AccumulatorRegisterValue, PlatformAssembler::ScratchRegister);
+    pasm()->move(PlatformAssembler::ScratchRegister, PlatformAssembler::AccumulatorRegisterValue);
+    auto doubleEncode = pasm()->branch32(PlatformAssembler::LessThan,
+                                         PlatformAssembler::AccumulatorRegisterValue,
+                                         TrustedImm32(0));
+    pasm()->setAccumulatorTag(IntegerTag);
+    auto done = pasm()->jump();
+
+    doubleEncode.link(pasm());
+    pasm()->convertUInt32ToDouble(PlatformAssembler::AccumulatorRegisterValue,
+                                  PlatformAssembler::FPScratchRegister,
+                                  PlatformAssembler::ScratchRegister);
+    pasm()->encodeDoubleIntoAccumulator(PlatformAssembler::FPScratchRegister);
+    done.link(pasm());
+}
+
+void BaselineAssembler::shr(int lhs)
+{
+    PlatformAssembler::Address lhsAddr = regAddr(lhs);
+    pasm()->toInt32LhsAcc(lhsAddr, PlatformAssembler::ScratchRegister);
+    pasm()->and32(TrustedImm32(0x1f), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->rshift32(PlatformAssembler::AccumulatorRegisterValue, PlatformAssembler::ScratchRegister);
+    pasm()->move(PlatformAssembler::ScratchRegister, PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::shl(int lhs)
+{
+    PlatformAssembler::Address lhsAddr = regAddr(lhs);
+    pasm()->toInt32LhsAcc(lhsAddr, PlatformAssembler::ScratchRegister);
+    pasm()->and32(TrustedImm32(0x1f), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->lshift32(PlatformAssembler::AccumulatorRegisterValue, PlatformAssembler::ScratchRegister);
+    pasm()->move(PlatformAssembler::ScratchRegister, PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::bitAndConst(int rhs)
+{
+    pasm()->toInt32();
+    pasm()->and32(TrustedImm32(rhs), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::bitOrConst(int rhs)
+{
+    pasm()->toInt32();
+    pasm()->or32(TrustedImm32(rhs), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::bitXorConst(int rhs)
+{
+    pasm()->toInt32();
+    pasm()->xor32(TrustedImm32(rhs), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::ushrConst(int rhs)
+{
+    rhs &= 0x1f;
+    pasm()->toInt32();
+    if (rhs) {
+        // a non zero shift will always give a number encodable as an int
+        pasm()->urshift32(TrustedImm32(rhs), PlatformAssembler::AccumulatorRegisterValue);
+        pasm()->setAccumulatorTag(IntegerTag);
+    } else {
+        // shift with 0 can lead to a negative result
+        auto doubleEncode = pasm()->branch32(PlatformAssembler::LessThan,
+                                             PlatformAssembler::AccumulatorRegisterValue,
+                                             TrustedImm32(0));
+        pasm()->setAccumulatorTag(IntegerTag);
+        auto done = pasm()->jump();
+
+        doubleEncode.link(pasm());
+        pasm()->convertUInt32ToDouble(PlatformAssembler::AccumulatorRegisterValue,
+                                      PlatformAssembler::FPScratchRegister,
+                                      PlatformAssembler::ScratchRegister);
+        pasm()->encodeDoubleIntoAccumulator(PlatformAssembler::FPScratchRegister);
+        done.link(pasm());
+    }
+}
+
+void BaselineAssembler::shrConst(int rhs)
+{
+    rhs &= 0x1f;
+    pasm()->toInt32();
+    if (rhs)
+        pasm()->rshift32(TrustedImm32(rhs), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::shlConst(int rhs)
+{
+    rhs &= 0x1f;
+    pasm()->toInt32();
+    if (rhs)
+        pasm()->lshift32(TrustedImm32(rhs), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(IntegerTag);
+}
+
+void BaselineAssembler::mul(int lhs)
+{
+    auto done = pasm()->binopBothIntPath(regAddr(lhs), [this](){
+        auto overflowed = pasm()->branchMul32(PlatformAssembler::Overflow,
+                                              PlatformAssembler::AccumulatorRegisterValue,
+                                              PlatformAssembler::ScratchRegister);
+        pasm()->setAccumulatorTag(IntegerTag,
+                                  PlatformAssembler::ScratchRegister);
+        return overflowed;
+    });
+
+    // slow path:
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(2);
+    pasm()->passAccumulatorAsArg(1);
+    pasm()->passJSSlotAsArg(lhs, 0);
+    ASM_GENERATE_RUNTIME_CALL(Mul, CallResultDestination::InAccumulator);
+    checkException();
+
+    // done.
+    done.link(pasm());
+}
+
+void BaselineAssembler::div(int lhs)
+{
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(2);
+    pasm()->passAccumulatorAsArg(1);
+    pasm()->passJSSlotAsArg(lhs, 0);
+    ASM_GENERATE_RUNTIME_CALL(Div, CallResultDestination::InAccumulator);
+    checkException();
+}
+
+void BaselineAssembler::mod(int lhs)
+{
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(2);
+    pasm()->passAccumulatorAsArg(1);
+    pasm()->passJSSlotAsArg(lhs, 0);
+    ASM_GENERATE_RUNTIME_CALL(Mod, CallResultDestination::InAccumulator);
+    checkException();
+}
+
+void BaselineAssembler::sub(int lhs)
+{
+    auto done = pasm()->binopBothIntPath(regAddr(lhs), [this](){
+        auto overflowed = pasm()->branchSub32(PlatformAssembler::Overflow,
+                                              PlatformAssembler::AccumulatorRegisterValue,
+                                              PlatformAssembler::ScratchRegister);
+        pasm()->setAccumulatorTag(IntegerTag,
+                                  PlatformAssembler::ScratchRegister);
+        return overflowed;
+    });
+
+    // slow path:
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(2);
+    pasm()->passAccumulatorAsArg(1);
+    pasm()->passJSSlotAsArg(lhs, 0);
+    ASM_GENERATE_RUNTIME_CALL(Sub, CallResultDestination::InAccumulator);
+    checkException();
+
+    // done.
+    done.link(pasm());
+}
+
+void BaselineAssembler::cmpeqNull()
+{
+    pasm()->isNullOrUndefined();
+    pasm()->setAccumulatorTag(QV4::Value::ValueTypeInternal::Boolean);
+}
+
+void BaselineAssembler::cmpneNull()
+{
+    pasm()->isNullOrUndefined();
+    pasm()->xor32(TrustedImm32(1), PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(QV4::Value::ValueTypeInternal::Boolean);
+}
+
+void BaselineAssembler::cmpeqInt(int lhs)
+{
+    auto isIntOrBool = pasm()->isIntOrBool();
+    saveAccumulatorInFrame();
+    pasm()->pushValueAligned(Encode(lhs));
+    if (PlatformAssembler::ArgInRegCount < 2)
+        pasm()->push(PlatformAssembler::StackPointerRegister);
+    else
+        pasm()->move(PlatformAssembler::StackPointerRegister, pasm()->registerForArg(1));
+    pasm()->pushAccumulatorAsArg(0);
+    pasm()->callRuntimeUnchecked("Equal", (void*)Runtime::Equal::call);
+    pasm()->saveReturnValueInAccumulator();
+    if (PlatformAssembler::ArgInRegCount < 2)
+        pasm()->addPtr(TrustedImm32(2 * PlatformAssembler::PointerSize), PlatformAssembler::StackPointerRegister);
+    pasm()->popValueAligned();
+    auto done = pasm()->jump();
+    isIntOrBool.link(pasm());
+    pasm()->compare32(PlatformAssembler::Equal, PlatformAssembler::AccumulatorRegisterValue,
+                      TrustedImm32(lhs),
+                      PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(QV4::Value::ValueTypeInternal::Boolean);
+    done.link(pasm());
+}
+
+void BaselineAssembler::cmpneInt(int lhs)
+{
+    auto isIntOrBool = pasm()->isIntOrBool();
+    saveAccumulatorInFrame();
+    pasm()->pushValueAligned(Encode(lhs));
+    if (PlatformAssembler::ArgInRegCount < 2)
+        pasm()->push(PlatformAssembler::StackPointerRegister);
+    else
+        pasm()->move(PlatformAssembler::StackPointerRegister, pasm()->registerForArg(1));
+    pasm()->pushAccumulatorAsArg(0);
+    pasm()->callRuntimeUnchecked("NotEqual", (void*)Runtime::NotEqual::call);
+    pasm()->saveReturnValueInAccumulator();
+    if (PlatformAssembler::ArgInRegCount < 2)
+        pasm()->addPtr(TrustedImm32(2 * PlatformAssembler::PointerSize), PlatformAssembler::StackPointerRegister);
+    pasm()->popValueAligned();
+    auto done = pasm()->jump();
+    isIntOrBool.link(pasm());
+    pasm()->compare32(PlatformAssembler::NotEqual, PlatformAssembler::AccumulatorRegisterValue,
+                      TrustedImm32(lhs),
+                      PlatformAssembler::AccumulatorRegisterValue);
+    pasm()->setAccumulatorTag(QV4::Value::ValueTypeInternal::Boolean);
+    done.link(pasm());
+}
+
+void BaselineAssembler::cmp(int cond, CmpFunc function, const char *functionName, int lhs)
+{
+    auto c = static_cast<PlatformAssembler::RelationalCondition>(cond);
+    auto done = pasm()->binopBothIntPath(regAddr(lhs), [this, c](){
+        pasm()->compare32(c, PlatformAssembler::ScratchRegister,
+                          PlatformAssembler::AccumulatorRegisterValue,
+                          PlatformAssembler::AccumulatorRegisterValue);
+        return PlatformAssembler::Jump();
+    });
+
+    // slow path:
+    saveAccumulatorInFrame();
+    pasm()->prepareCallWithArgCount(2);
+    pasm()->passAccumulatorAsArg(1);
+    pasm()->passJSSlotAsArg(lhs, 0);
+
+    callRuntime(functionName, reinterpret_cast<void*>(function), CallResultDestination::InAccumulator);
+    checkException();
+
+    // done.
+    done.link(pasm());
+    pasm()->setAccumulatorTag(QV4::Value::ValueTypeInternal::Boolean);
+}
+
+void BaselineAssembler::cmpeq(int lhs)
+{
+    cmp(PlatformAssembler::Equal, &Runtime::CompareEqual::call,
+        "CompareEqual", lhs);
+}
+
+void BaselineAssembler::cmpne(int lhs)
+{
+    cmp(PlatformAssembler::NotEqual, &Runtime::CompareNotEqual::call,
+        "CompareNotEqual", lhs);
+}
+
+void BaselineAssembler::cmpgt(int lhs)
+{
+    cmp(PlatformAssembler::GreaterThan, &Runtime::CompareGreaterThan::call,
+        "CompareGreaterThan", lhs);
+}
+
+void BaselineAssembler::cmpge(int lhs)
+{
+    cmp(PlatformAssembler::GreaterThanOrEqual, &Runtime::CompareGreaterEqual::call,
+        "CompareGreaterEqual", lhs);
+}
+
+void BaselineAssembler::cmplt(int lhs)
+{
+    cmp(PlatformAssembler::LessThan, &Runtime::CompareLessThan::call,
+        "CompareLessThan", lhs);
+}
+
+void BaselineAssembler::cmple(int lhs)
+{
+    cmp(PlatformAssembler::LessThanOrEqual, &Runtime::CompareLessEqual::call,
+        "CompareLessEqual", lhs);
+}
+
+void BaselineAssembler::cmpStrictEqual(int lhs)
+{
+    cmp(PlatformAssembler::Equal, &Runtime::CompareStrictEqual::call,
+        "RuntimeHelpers::strictEqual", lhs);
+}
+
+void BaselineAssembler::cmpStrictNotEqual(int lhs)
+{
+    cmp(PlatformAssembler::NotEqual, &Runtime::CompareStrictNotEqual::call,
+        "RuntimeHelpers::strictNotEqual", lhs);
+}
+
+int BaselineAssembler::jump(int offset)
+{
+    pasm()->addJumpToOffset(pasm()->jump(), offset);
+    return offset;
+}
+
+int BaselineAssembler::jumpTrue(int offset)
+{
+    pasm()->toBoolean([this, offset](PlatformAssembler::RegisterID resultReg) {
+        auto jump = pasm()->branch32(PlatformAssembler::NotEqual, TrustedImm32(0), resultReg);
+        pasm()->addJumpToOffset(jump, offset);
+    });
+    return offset;
+}
+
+int BaselineAssembler::jumpFalse(int offset)
+{
+    pasm()->toBoolean([this, offset](PlatformAssembler::RegisterID resultReg) {
+        auto jump = pasm()->branch32(PlatformAssembler::Equal, TrustedImm32(0), resultReg);
+        pasm()->addJumpToOffset(jump, offset);
+    });
+    return offset;
+}
+
+int BaselineAssembler::jumpNoException(int offset)
+{
+    auto jump = pasm()->branch32(
+        PlatformAssembler::Equal,
+        PlatformAssembler::Address(PlatformAssembler::EngineRegister,
+                                   offsetof(EngineBase, hasException)),
+        TrustedImm32(0));
+    pasm()->addJumpToOffset(jump, offset);
+    return offset;
+}
+
+int BaselineAssembler::jumpNotUndefined(int offset)
+{
+    pasm()->jumpNotUndefined(offset);
+    return offset;
+}
+
+void BaselineAssembler::prepareCallWithArgCount(int argc)
+{
+    pasm()->prepareCallWithArgCount(argc);
+}
+
+void BaselineAssembler::storeInstructionPointer(int instructionOffset)
+{
+    pasm()->storeInstructionPointer(instructionOffset);
+}
+
+void BaselineAssembler::passAccumulatorAsArg(int arg)
+{
+    pasm()->passAccumulatorAsArg(arg);
+}
+
+void BaselineAssembler::passFunctionAsArg(int arg)
+{
+    pasm()->passFunctionAsArg(arg);
+}
+
+void BaselineAssembler::passEngineAsArg(int arg)
+{
+    pasm()->passEngineAsArg(arg);
+}
+
+void BaselineAssembler::passJSSlotAsArg(int reg, int arg)
+{
+    pasm()->passJSSlotAsArg(reg, arg);
+}
+
+void BaselineAssembler::passCppFrameAsArg(int arg)
+{
+    pasm()->passCppFrameAsArg(arg);
+}
+
+void BaselineAssembler::passInt32AsArg(int value, int arg)
+{
+    pasm()->passInt32AsArg(value, arg);
+}
+
+void BaselineAssembler::passPointerAsArg(void *ptr, int arg)
+{
+    pasm()->passPointerAsArg(ptr, arg);
+}
+
+void BaselineAssembler::callRuntime(const char *functionName, const void *funcPtr, CallResultDestination dest)
+{
+    pasm()->callRuntime(functionName, funcPtr, dest);
+}
+
+void BaselineAssembler::saveAccumulatorInFrame()
+{
+    pasm()->storeAccumulator(PlatformAssembler::Address(PlatformAssembler::JSStackFrameRegister,
+                                                        offsetof(CallData, accumulator)));
+}
+
+static ReturnedValue TheJitIs__Tail_Calling__ToTheRuntimeSoTheJitFrameIsMissing(CppStackFrame *frame, ExecutionEngine *engine)
+{
+    return Runtime::TailCall::call(frame, engine);
+}
+
+void BaselineAssembler::jsTailCall(int func, int thisObject, int argc, int argv)
+{
+    Address tos = pasm()->jsAlloca(4);
+
+    int32_t argcOffset = tos.offset + int32_t(sizeof(Value)) * Runtime::StackOffsets::tailCall_argc;
+    int32_t argvOffset = tos.offset + int32_t(sizeof(Value)) * Runtime::StackOffsets::tailCall_argv;
+    int32_t thisOffset = tos.offset + int32_t(sizeof(Value)) * Runtime::StackOffsets::tailCall_thisObject;
+    int32_t funcOffset = tos.offset + int32_t(sizeof(Value)) * Runtime::StackOffsets::tailCall_function;
+
+    pasm()->storeInt32AsValue(argc,      Address(tos.base, argcOffset));
+    pasm()->storeInt32AsValue(argv,      Address(tos.base, argvOffset));
+    pasm()->moveReg(regAddr(thisObject), Address(tos.base, thisOffset));
+    pasm()->moveReg(regAddr(func),       Address(tos.base, funcOffset));
+    pasm()->tailCallRuntime("TheJitIs__Tail_Calling__ToTheRuntimeSoTheJitFrameIsMissing",
+                            reinterpret_cast<void *>(TheJitIs__Tail_Calling__ToTheRuntimeSoTheJitFrameIsMissing));
+}
+
+void BaselineAssembler::checkException()
+{
+    pasm()->checkException();
+}
+
+void BaselineAssembler::gotoCatchException()
+{
+    pasm()->addCatchyJump(pasm()->jump());
+}
+
+void BaselineAssembler::getException()
+{
+    Q_STATIC_ASSERT(sizeof(QV4::EngineBase::hasException) == 1);
+
+    Address hasExceptionAddr(PlatformAssembler::EngineRegister,
+                             offsetof(EngineBase, hasException));
+    PlatformAssembler::Jump nope = pasm()->branch8(PlatformAssembler::Equal,
+                                                  hasExceptionAddr,
+                                                  TrustedImm32(0));
+    pasm()->loadPtr(Address(PlatformAssembler::EngineRegister,
+                            offsetof(EngineBase, exceptionValue)),
+                    PlatformAssembler::ScratchRegister);
+    pasm()->loadAccumulator(Address(PlatformAssembler::ScratchRegister));
+    pasm()->store8(TrustedImm32(0), hasExceptionAddr);
+    auto done = pasm()->jump();
+    nope.link(pasm());
+    pasm()->loadValue(Value::emptyValue().asReturnedValue());
+
+    done.link(pasm());
+}
+
+void BaselineAssembler::setException()
+{
+    auto noException = pasm()->jumpEmpty();
+    Address addr(PlatformAssembler::EngineRegister, offsetof(EngineBase, exceptionValue));
+    pasm()->loadPtr(addr, PlatformAssembler::ScratchRegister);
+    pasm()->storeAccumulator(Address(PlatformAssembler::ScratchRegister));
+    addr.offset = offsetof(EngineBase, hasException);
+    Q_STATIC_ASSERT(sizeof(QV4::EngineBase::hasException) == 1);
+    pasm()->store8(TrustedImm32(1), addr);
+    noException.link(pasm());
+}
+
+int BaselineAssembler::setUnwindHandler(int offset)
+{
+    auto l = pasm()->storePtrWithPatch(TrustedImmPtr(nullptr), pasm()->exceptionHandlerAddress());
+    pasm()->addEHTarget(l, offset);
+    return offset;
+}
+
+
+void BaselineAssembler::clearUnwindHandler()
+{
+    pasm()->storePtr(TrustedImmPtr(nullptr), pasm()->exceptionHandlerAddress());
+}
+
+void JIT::BaselineAssembler::unwindDispatch()
+{
+    checkException();
+    pasm()->load32(Address(PlatformAssembler::CppStackFrameRegister, offsetof(CppStackFrame, unwindLevel)), PlatformAssembler::ScratchRegister);
+    auto noUnwind = pasm()->branch32(PlatformAssembler::Equal, PlatformAssembler::ScratchRegister, TrustedImm32(0));
+    pasm()->sub32(TrustedImm32(1), PlatformAssembler::ScratchRegister);
+    pasm()->store32(PlatformAssembler::ScratchRegister, Address(PlatformAssembler::CppStackFrameRegister, offsetof(CppStackFrame, unwindLevel)));
+    auto jump = pasm()->branch32(PlatformAssembler::Equal, PlatformAssembler::ScratchRegister, TrustedImm32(0));
+    gotoCatchException();
+    jump.link(pasm());
+
+    pasm()->loadPtr(Address(PlatformAssembler::CppStackFrameRegister, offsetof(CppStackFrame, unwindLabel)), PlatformAssembler::ScratchRegister);
+    pasm()->jump(PlatformAssembler::ScratchRegister);
+
+    noUnwind.link(pasm());
+}
+
+int JIT::BaselineAssembler::unwindToLabel(int level, int offset)
+{
+    auto l = pasm()->storePtrWithPatch(TrustedImmPtr(nullptr), Address(PlatformAssembler::CppStackFrameRegister, offsetof(CppStackFrame, unwindLabel)));
+    pasm()->addEHTarget(l, offset);
+    pasm()->store32(TrustedImm32(level), Address(PlatformAssembler::CppStackFrameRegister, offsetof(CppStackFrame, unwindLevel)));
+    gotoCatchException();
+    return offset;
+}
+
+void BaselineAssembler::pushCatchContext(int index, int name)
+{
+    pasm()->prepareCallWithArgCount(3);
+    pasm()->passInt32AsArg(name, 2);
+    pasm()->passInt32AsArg(index, 1);
+    pasm()->passEngineAsArg(0);
+    ASM_GENERATE_RUNTIME_CALL(PushCatchContext, CallResultDestination::Ignore);
+}
+
+void BaselineAssembler::popContext()
+{
+    Heap::CallContext ctx;
+    Q_UNUSED(ctx)
+    pasm()->loadPointerFromValue(regAddr(CallData::Context), PlatformAssembler::ScratchRegister);
+    pasm()->loadPtr(Address(PlatformAssembler::ScratchRegister, ctx.outer.offset), PlatformAssembler::ScratchRegister);
+    pasm()->storeHeapObject(PlatformAssembler::ScratchRegister, regAddr(CallData::Context));
+}
+
+void BaselineAssembler::deadTemporalZoneCheck(int offsetForSavedIP, int variableName)
+{
+    auto valueIsAliveJump = pasm()->jumpNotEmpty();
+    storeInstructionPointer(offsetForSavedIP);
+    saveAccumulatorInFrame();
+    prepareCallWithArgCount(2);
+    passInt32AsArg(variableName, 1);
+    passEngineAsArg(0);
+    ASM_GENERATE_RUNTIME_CALL(ThrowReferenceError, CallResultDestination::Ignore);
+    gotoCatchException();
+    valueIsAliveJump.link(pasm());
+}
+
+void BaselineAssembler::ret()
+{
+    pasm()->generateFunctionExit();
+}
+
+} // JIT namespace
+} // QV4 namepsace
+
+QT_END_NAMESPACE
+
+#endif // V4_ENABLE_JIT
diff --git a/src/qml/jit/qv4baselineassembler_p.h b/src/qml/jit/qv4baselineassembler_p.h
new file mode 100644
index 0000000000..3bbaefd000
--- /dev/null
+++ b/src/qml/jit/qv4baselineassembler_p.h
@@ -0,0 +1,187 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4BASELINEASSEMBLER_P_H
+#define QV4BASELINEASSEMBLER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+#include <private/qv4function_p.h>
+#include <QHash>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace JIT {
+
+#define JIT_STRINGIFYx(s) #s
+#define JIT_STRINGIFY(s) JIT_STRINGIFYx(s)
+
+#define GENERATE_RUNTIME_CALL(function, destination) \
+    callRuntime(JIT_STRINGIFY(function), \
+                reinterpret_cast<void *>(&Runtime::function::call), \
+                destination)
+#define GENERATE_TAIL_CALL(function) \
+    tailCallRuntime(JIT_STRINGIFY(function), \
+                reinterpret_cast<void *>(&function))
+
+class BaselineAssembler {
+public:
+    BaselineAssembler(const Value* constantTable);
+    ~BaselineAssembler();
+
+    // codegen infrastructure
+    void generatePrologue();
+    void generateEpilogue();
+    void link(Function *function);
+    void addLabel(int offset);
+
+    // loads/stores/moves
+    void loadConst(int constIndex);
+    void copyConst(int constIndex, int destReg);
+    void loadReg(int reg);
+    void moveReg(int sourceReg, int destReg);
+    void storeReg(int reg);
+    void loadLocal(int index, int level = 0);
+    void storeLocal(int index, int level = 0);
+    void loadString(int stringId);
+    void loadValue(ReturnedValue value);
+    void storeHeapObject(int reg);
+    void loadImport(int index);
+
+    // numeric ops
+    void unot();
+    void toNumber();
+    void uminus();
+    void ucompl();
+    void inc();
+    void dec();
+    void add(int lhs);
+    void bitAnd(int lhs);
+    void bitOr(int lhs);
+    void bitXor(int lhs);
+    void ushr(int lhs);
+    void shr(int lhs);
+    void shl(int lhs);
+    void bitAndConst(int rhs);
+    void bitOrConst(int rhs);
+    void bitXorConst(int rhs);
+    void ushrConst(int rhs);
+    void shrConst(int rhs);
+    void shlConst(int rhs);
+    void mul(int lhs);
+    void div(int lhs);
+    void mod(int lhs);
+    void sub(int lhs);
+
+    // comparissons
+    void cmpeqNull();
+    void cmpneNull();
+    void cmpeqInt(int lhs);
+    void cmpneInt(int lhs);
+    void cmpeq(int lhs);
+    void cmpne(int lhs);
+    void cmpgt(int lhs);
+    void cmpge(int lhs);
+    void cmplt(int lhs);
+    void cmple(int lhs);
+    void cmpStrictEqual(int lhs);
+    void cmpStrictNotEqual(int lhs);
+
+    // jumps
+    Q_REQUIRED_RESULT int jump(int offset);
+    Q_REQUIRED_RESULT int jumpTrue(int offset);
+    Q_REQUIRED_RESULT int jumpFalse(int offset);
+    Q_REQUIRED_RESULT int jumpNoException(int offset);
+    Q_REQUIRED_RESULT int jumpNotUndefined(int offset);
+
+    // stuff for runtime calls
+    void prepareCallWithArgCount(int argc);
+    void storeInstructionPointer(int instructionOffset);
+    void passAccumulatorAsArg(int arg);
+    void passFunctionAsArg(int arg);
+    void passEngineAsArg(int arg);
+    void passJSSlotAsArg(int reg, int arg);
+    void passCppFrameAsArg(int arg);
+    void passInt32AsArg(int value, int arg);
+    void passPointerAsArg(void *ptr, int arg);
+    void callRuntime(const char *functionName, const void *funcPtr, CallResultDestination dest);
+    void saveAccumulatorInFrame();
+    void jsTailCall(int func, int thisObject, int argc, int argv);
+
+    // exception/context stuff
+    void checkException();
+    void gotoCatchException();
+    void getException();
+    void setException();
+    Q_REQUIRED_RESULT int setUnwindHandler(int offset);
+    void clearUnwindHandler();
+    void unwindDispatch();
+    Q_REQUIRED_RESULT int unwindToLabel(int level, int offset);
+    void pushCatchContext(int index, int name);
+    void popContext();
+    void deadTemporalZoneCheck(int offsetForSavedIP, int variableName);
+
+    // other stuff
+    void ret();
+
+protected:
+    void *d;
+
+private:
+    typedef unsigned(*CmpFunc)(const Value&,const Value&);
+    void cmp(int cond, CmpFunc function, const char *functionName, int lhs);
+};
+
+} // namespace JIT
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4BASELINEASSEMBLER_P_H
diff --git a/src/qml/jit/qv4baselinejit.cpp b/src/qml/jit/qv4baselinejit.cpp
new file mode 100644
index 0000000000..f2f7a12598
--- /dev/null
+++ b/src/qml/jit/qv4baselinejit.cpp
@@ -0,0 +1,993 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4baselinejit_p.h"
+#include "qv4baselineassembler_p.h"
+#include <private/qv4lookup_p.h>
+#include <private/qv4generatorobject_p.h>
+
+#ifdef V4_ENABLE_JIT
+
+QT_USE_NAMESPACE
+using namespace QV4;
+using namespace QV4::JIT;
+using namespace QV4::Moth;
+
+BaselineJIT::BaselineJIT(Function *function)
+    : function(function)
+    , as(new BaselineAssembler(function->compilationUnit->constants))
+{}
+
+BaselineJIT::~BaselineJIT()
+{}
+
+void BaselineJIT::generate()
+{
+//    qDebug()<<"jitting" << function->name()->toQString();
+    const char *code = function->codeData;
+    uint len = function->compiledFunction->codeSize;
+
+    for (unsigned i = 0, ei = function->compiledFunction->nLabelInfos; i != ei; ++i)
+        labels.insert(int(function->compiledFunction->labelInfoTable()[i]));
+
+    as->generatePrologue();
+    decode(code, len);
+    as->generateEpilogue();
+
+    as->link(function);
+//    qDebug()<<"done";
+}
+
+#define STORE_IP() as->storeInstructionPointer(nextInstructionOffset())
+#define STORE_ACC() as->saveAccumulatorInFrame()
+#define BASELINEJIT_GENERATE_RUNTIME_CALL(function, destination) { \
+    as->GENERATE_RUNTIME_CALL(function, destination); \
+    if (Runtime::function::throws) \
+        as->checkException(); \
+    else {} } // this else prevents else statements after the macro from attaching to the if above
+
+void BaselineJIT::generate_Ret()
+{
+    as->ret();
+}
+
+void BaselineJIT::generate_Debug() { Q_UNREACHABLE(); }
+
+void BaselineJIT::generate_LoadConst(int index)
+{
+    as->loadConst(index);
+}
+
+void BaselineJIT::generate_LoadZero()
+{
+    as->loadValue(Encode(int(0)));
+}
+
+void BaselineJIT::generate_LoadTrue()
+{
+    as->loadValue(Encode(true));
+}
+
+void BaselineJIT::generate_LoadFalse()
+{
+    as->loadValue(Encode(false));
+}
+
+void BaselineJIT::generate_LoadNull()
+{
+    as->loadValue(Encode::null());
+}
+
+void BaselineJIT::generate_LoadUndefined()
+{
+    as->loadValue(Encode::undefined());
+}
+
+void BaselineJIT::generate_LoadInt(int value)
+{
+    //###
+    as->loadValue(Encode(value));
+}
+
+void BaselineJIT::generate_MoveConst(int constIndex, int destTemp)
+{
+    as->copyConst(constIndex, destTemp);
+}
+
+void BaselineJIT::generate_LoadReg(int reg)
+{
+    as->loadReg(reg);
+}
+
+void BaselineJIT::generate_StoreReg(int reg)
+{
+    as->storeReg(reg);
+}
+
+void BaselineJIT::generate_MoveReg(int srcReg, int destReg)
+{
+    // Don't clobber the accumulator.
+    as->moveReg(srcReg, destReg);
+}
+
+void BaselineJIT::generate_LoadImport(int index)
+{
+    as->loadImport(index);
+}
+
+void BaselineJIT::generate_LoadLocal(int index, int /*traceSlot*/)
+{
+    as->loadLocal(index);
+}
+
+void BaselineJIT::generate_StoreLocal(int index)
+{
+    as->checkException();
+    as->storeLocal(index);
+}
+
+void BaselineJIT::generate_LoadScopedLocal(int scope, int index, int /*traceSlot*/)
+{
+    as->loadLocal(index, scope);
+}
+
+void BaselineJIT::generate_StoreScopedLocal(int scope, int index)
+{
+    as->checkException();
+    as->storeLocal(index, scope);
+}
+
+void BaselineJIT::generate_LoadRuntimeString(int stringId)
+{
+    as->loadString(stringId);
+}
+
+void BaselineJIT::generate_MoveRegExp(int regExpId, int destReg)
+{
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(regExpId, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(RegexpLiteral, CallResultDestination::InAccumulator);
+    as->storeReg(destReg);
+}
+
+void BaselineJIT::generate_LoadClosure(int value)
+{
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(value, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(Closure, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_LoadName(int name, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadName, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_LoadGlobalLookup(int index, int /*traceSlot*/)
+{
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(index, 2);
+    as->passFunctionAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadGlobalLookup, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_StoreNameSloppy(int name)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passAccumulatorAsArg(2);
+    as->passInt32AsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreNameSloppy, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_StoreNameStrict(int name)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passAccumulatorAsArg(2);
+    as->passInt32AsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreNameStrict, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_LoadElement(int base, int /*traceSlot*/)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passAccumulatorAsArg(2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadElement, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_StoreElement(int base, int index, int /*traceSlot*/)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(4);
+    as->passAccumulatorAsArg(3);
+    as->passJSSlotAsArg(index, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreElement, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_LoadProperty(int name, int /*traceSlot*/)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(name, 2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_GetLookup(int index, int /*traceSlot*/)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(index, 3);
+    as->passAccumulatorAsArg(2);
+    as->passFunctionAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(GetLookup, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_StoreProperty(int name, int base)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(4);
+    as->passAccumulatorAsArg(3);
+    as->passInt32AsArg(name, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreProperty, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_SetLookup(int index, int base)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(4);
+    as->passAccumulatorAsArg(3);
+    as->passInt32AsArg(index, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passFunctionAsArg(0);
+    if (function->isStrict())
+        BASELINEJIT_GENERATE_RUNTIME_CALL(SetLookupStrict, CallResultDestination::InAccumulator)
+    else
+        BASELINEJIT_GENERATE_RUNTIME_CALL(SetLookupSloppy, CallResultDestination::InAccumulator)
+}
+
+void BaselineJIT::generate_LoadSuperProperty(int property)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passJSSlotAsArg(property, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadSuperProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_StoreSuperProperty(int property)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passAccumulatorAsArg(2);
+    as->passJSSlotAsArg(property, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreSuperProperty, CallResultDestination::Ignore);
+}
+
+
+void BaselineJIT::generate_StoreScopeObjectProperty(int base, int propertyIndex)
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(4);
+    as->passAccumulatorAsArg(3);
+    as->passInt32AsArg(propertyIndex, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreQmlScopeObjectProperty, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_StoreContextObjectProperty(int base, int propertyIndex)
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(4);
+    as->passAccumulatorAsArg(3);
+    as->passInt32AsArg(propertyIndex, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(StoreQmlContextObjectProperty, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_LoadScopeObjectProperty(int propertyIndex, int base, int captureRequired)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(captureRequired, 3);
+    as->passInt32AsArg(propertyIndex, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadQmlScopeObjectProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_LoadContextObjectProperty(int propertyIndex, int base, int captureRequired)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(captureRequired, 3);
+    as->passInt32AsArg(propertyIndex, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadQmlContextObjectProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_LoadIdObject(int index, int base)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(index, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadQmlIdObject, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_Yield()
+{
+    // #####
+    Q_UNREACHABLE();
+}
+
+void BaselineJIT::generate_YieldStar()
+{
+    // #####
+    Q_UNREACHABLE();
+}
+
+void BaselineJIT::generate_Resume(int)
+{
+    // #####
+    Q_UNREACHABLE();
+}
+
+void BaselineJIT::generate_CallValue(int name, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(argc, 3);
+    as->passJSSlotAsArg(argv, 2);
+    as->passJSSlotAsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallValue, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallWithReceiver(int name, int thisObject, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passJSSlotAsArg(thisObject, 2);
+    as->passJSSlotAsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallWithReceiver, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallProperty(int name, int base, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passInt32AsArg(name, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallPropertyLookup(int lookupIndex, int base, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passInt32AsArg(lookupIndex, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallPropertyLookup, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallElement(int base, int index, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passJSSlotAsArg(index, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallElement, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallName(int name, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(argc, 3);
+    as->passJSSlotAsArg(argv, 2);
+    as->passInt32AsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallName, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallPossiblyDirectEval(int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(argc, 2);
+    as->passJSSlotAsArg(argv, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallPossiblyDirectEval, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallGlobalLookup(int index, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(argc, 3);
+    as->passJSSlotAsArg(argv, 2);
+    as->passInt32AsArg(index, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallGlobalLookup, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallScopeObjectProperty(int propIdx, int base, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passInt32AsArg(propIdx, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallQmlScopeObjectProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CallContextObjectProperty(int propIdx, int base, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passInt32AsArg(propIdx, 2);
+    as->passJSSlotAsArg(base, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallQmlContextObjectProperty, CallResultDestination::InAccumulator);
+}
+
+
+void BaselineJIT::generate_CallWithSpread(int func, int thisObject, int argc, int argv, int /*traceSlot*/)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passJSSlotAsArg(thisObject, 2);
+    as->passJSSlotAsArg(func, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CallWithSpread, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_TailCall(int func, int thisObject, int argc, int argv)
+{
+    STORE_IP();
+    as->jsTailCall(func, thisObject, argc, argv);
+}
+
+void BaselineJIT::generate_Construct(int func, int argc, int argv)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passAccumulatorAsArg(2);
+    as->passJSSlotAsArg(func, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(Construct, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_ConstructWithSpread(int func, int argc, int argv)
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(5);
+    as->passInt32AsArg(argc, 4);
+    as->passJSSlotAsArg(argv, 3);
+    as->passAccumulatorAsArg(2);
+    as->passJSSlotAsArg(func, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ConstructWithSpread, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_SetUnwindHandler(int offset)
+{
+    if (offset)
+        labels.insert(as->setUnwindHandler(absoluteOffset(offset)));
+    else
+        as->clearUnwindHandler();
+}
+
+void BaselineJIT::generate_UnwindDispatch()
+{
+    as->unwindDispatch();
+}
+
+void BaselineJIT::generate_UnwindToLabel(int level, int offset)
+{
+    labels.insert(as->unwindToLabel(level, absoluteOffset(offset)));
+}
+
+void BaselineJIT::generate_DeadTemporalZoneCheck(int name)
+{
+    as->deadTemporalZoneCheck(nextInstructionOffset(), name);
+}
+
+void BaselineJIT::generate_ThrowException()
+{
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ThrowException, CallResultDestination::Ignore);
+    as->gotoCatchException();
+}
+
+void BaselineJIT::generate_GetException() { as->getException(); }
+void BaselineJIT::generate_SetException() { as->setException(); }
+
+void BaselineJIT::generate_CreateCallContext()
+{
+    as->prepareCallWithArgCount(1);
+    as->passCppFrameAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(PushCallContext, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_PushCatchContext(int index, int name) { as->pushCatchContext(index, name); }
+
+void BaselineJIT::generate_PushWithContext()
+{
+    STORE_IP();
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(2);
+    as->passJSSlotAsArg(CallData::Accumulator, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(PushWithContext, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_PushBlockContext(int index)
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(index, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(PushBlockContext, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_CloneBlockContext()
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CloneBlockContext, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_PushScriptContext(int index)
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(index, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(PushScriptContext, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_PopScriptContext()
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(PopScriptContext, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_PopContext() { as->popContext(); }
+
+void BaselineJIT::generate_GetIterator(int iterator)
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(iterator, 2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(GetIterator, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_IteratorNext(int value, int done)
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(3);
+    as->passJSSlotAsArg(value, 2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(IteratorNext, CallResultDestination::InAccumulator);
+    as->storeReg(done);
+}
+
+void BaselineJIT::generate_IteratorNextForYieldStar(int iterator, int object)
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(4);
+    as->passJSSlotAsArg(object, 3);
+    as->passJSSlotAsArg(iterator, 2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(IteratorNextForYieldStar, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_IteratorClose(int done)
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(3);
+    as->passJSSlotAsArg(done, 2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(IteratorClose, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_DestructureRestElement()
+{
+    as->saveAccumulatorInFrame();
+    as->prepareCallWithArgCount(2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(DestructureRestElement, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_DeleteProperty(int base, int index)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(4);
+    as->passJSSlotAsArg(index, 3);
+    as->passJSSlotAsArg(base, 2);
+    as->passFunctionAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(DeleteProperty, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_DeleteName(int name)
+{
+    STORE_IP();
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(name, 2);
+    as->passFunctionAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(DeleteName, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_TypeofName(int name)
+{
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(name, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(TypeofName, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_TypeofValue()
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(TypeofValue, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_DeclareVar(int varName, int isDeletable)
+{
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(varName, 2);
+    as->passInt32AsArg(isDeletable, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(DeclareVar, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_DefineArray(int argc, int args)
+{
+    as->prepareCallWithArgCount(3);
+    as->passInt32AsArg(argc, 2);
+    as->passJSSlotAsArg(args, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ArrayLiteral, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_DefineObjectLiteral(int internalClassId, int argc, int args)
+{
+    as->prepareCallWithArgCount(4);
+    as->passInt32AsArg(argc, 3);
+    as->passJSSlotAsArg(args, 2);
+    as->passInt32AsArg(internalClassId, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ObjectLiteral, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CreateClass(int classIndex, int heritage, int computedNames)
+{
+    as->prepareCallWithArgCount(4);
+    as->passJSSlotAsArg(computedNames, 3);
+    as->passJSSlotAsArg(heritage, 2);
+    as->passInt32AsArg(classIndex, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CreateClass, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CreateMappedArgumentsObject()
+{
+    as->prepareCallWithArgCount(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CreateMappedArgumentsObject,
+                              CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CreateUnmappedArgumentsObject()
+{
+    as->prepareCallWithArgCount(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CreateUnmappedArgumentsObject,
+                              CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CreateRestParameter(int argIndex)
+{
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(argIndex, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(CreateRestParameter, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_ConvertThisToObject()
+{
+    as->prepareCallWithArgCount(2);
+    as->passJSSlotAsArg(CallData::This, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ConvertThisToObject, CallResultDestination::InAccumulator);
+    as->storeReg(CallData::This);
+}
+
+void BaselineJIT::generate_LoadSuperConstructor()
+{
+    as->prepareCallWithArgCount(2);
+    as->passJSSlotAsArg(CallData::Function, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadSuperConstructor, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_ToObject()
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ToObject, CallResultDestination::InAccumulator);
+
+}
+
+void BaselineJIT::generate_Jump(int offset)
+{
+    labels.insert(as->jump(absoluteOffset(offset)));
+}
+
+void BaselineJIT::generate_JumpTrue(int /*traceSlot*/, int offset)
+{
+    labels.insert(as->jumpTrue(absoluteOffset(offset)));
+}
+
+void BaselineJIT::generate_JumpFalse(int /*traceSlot*/, int offset)
+{
+    labels.insert(as->jumpFalse(absoluteOffset(offset)));
+}
+
+void BaselineJIT::generate_JumpNoException(int offset)
+{
+    labels.insert(as->jumpNoException(absoluteOffset(offset)));
+}
+
+void BaselineJIT::generate_JumpNotUndefined(int offset)
+{
+    labels.insert(as->jumpNotUndefined(absoluteOffset(offset)));
+}
+
+void BaselineJIT::generate_CmpEqNull() { as->cmpeqNull(); }
+void BaselineJIT::generate_CmpNeNull() { as->cmpneNull(); }
+void BaselineJIT::generate_CmpEqInt(int lhs) { as->cmpeqInt(lhs); }
+void BaselineJIT::generate_CmpNeInt(int lhs) { as->cmpneInt(lhs); }
+void BaselineJIT::generate_CmpEq(int lhs) { as->cmpeq(lhs); }
+void BaselineJIT::generate_CmpNe(int lhs) { as->cmpne(lhs); }
+void BaselineJIT::generate_CmpGt(int lhs) { as->cmpgt(lhs); }
+void BaselineJIT::generate_CmpGe(int lhs) { as->cmpge(lhs); }
+void BaselineJIT::generate_CmpLt(int lhs) { as->cmplt(lhs); }
+void BaselineJIT::generate_CmpLe(int lhs) { as->cmple(lhs); }
+void BaselineJIT::generate_CmpStrictEqual(int lhs) { as->cmpStrictEqual(lhs); }
+void BaselineJIT::generate_CmpStrictNotEqual(int lhs) { as->cmpStrictNotEqual(lhs); }
+
+void BaselineJIT::generate_CmpIn(int lhs)
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passAccumulatorAsArg(2);
+    as->passJSSlotAsArg(lhs, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(In, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_CmpInstanceOf(int lhs)
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(3);
+    as->passAccumulatorAsArg(2);
+    as->passJSSlotAsArg(lhs, 1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(Instanceof, CallResultDestination::InAccumulator);
+}
+
+void BaselineJIT::generate_UNot() { as->unot(); }
+void BaselineJIT::generate_UPlus() { as->toNumber(); }
+void BaselineJIT::generate_UMinus(int /*traceSlot*/) { as->uminus(); }
+void BaselineJIT::generate_UCompl() { as->ucompl(); }
+void BaselineJIT::generate_Increment(int /*traceSlot*/) { as->inc(); }
+void BaselineJIT::generate_Decrement(int /*traceSlot*/) { as->dec(); }
+void BaselineJIT::generate_Add(int lhs, int /*traceSlot*/) { as->add(lhs); }
+
+void BaselineJIT::generate_BitAnd(int lhs) { as->bitAnd(lhs); }
+void BaselineJIT::generate_BitOr(int lhs) { as->bitOr(lhs); }
+void BaselineJIT::generate_BitXor(int lhs) { as->bitXor(lhs); }
+void BaselineJIT::generate_UShr(int lhs) { as->ushr(lhs); }
+void BaselineJIT::generate_Shr(int lhs) { as->shr(lhs); }
+void BaselineJIT::generate_Shl(int lhs) { as->shl(lhs); }
+
+void BaselineJIT::generate_BitAndConst(int rhs) { as->bitAndConst(rhs); }
+void BaselineJIT::generate_BitOrConst(int rhs) { as->bitOrConst(rhs); }
+void BaselineJIT::generate_BitXorConst(int rhs) { as->bitXorConst(rhs); }
+void BaselineJIT::generate_UShrConst(int rhs) { as->ushrConst(rhs); }
+void BaselineJIT::generate_ShrConst(int rhs) { as->shrConst(rhs); }
+void BaselineJIT::generate_ShlConst(int rhs) { as->shlConst(rhs); }
+
+void BaselineJIT::generate_Exp(int lhs) {
+    STORE_IP();
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passAccumulatorAsArg(1);
+    as->passJSSlotAsArg(lhs, 0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(Exp, CallResultDestination::InAccumulator);
+}
+void BaselineJIT::generate_Mul(int lhs, int /*traceSlot*/) { as->mul(lhs); }
+void BaselineJIT::generate_Div(int lhs) { as->div(lhs); }
+void BaselineJIT::generate_Mod(int lhs, int /*traceSlot*/) { as->mod(lhs); }
+void BaselineJIT::generate_Sub(int lhs, int /*traceSlot*/) { as->sub(lhs); }
+
+//void BaselineJIT::generate_BinopContext(int alu, int lhs)
+//{
+//    auto engine = function->internalClass->engine;
+//    void *op = engine->runtime.runtimeMethods[alu];
+//    STORE_ACC();
+//    as->passAccumulatorAsArg(2);
+//    as->passRegAsArg(lhs, 1);
+//    as->passEngineAsArg(0);
+//    as->callRuntime("binopContext", op, CallResultDestination::InAccumulator);
+//    as->checkException();
+//}
+
+void BaselineJIT::generate_LoadQmlContext(int result)
+{
+    as->prepareCallWithArgCount(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadQmlContext, CallResultDestination::InAccumulator);
+    as->storeReg(result);
+}
+
+void BaselineJIT::generate_LoadQmlImportedScripts(int result)
+{
+    as->prepareCallWithArgCount(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(LoadQmlImportedScripts, CallResultDestination::InAccumulator);
+    as->storeReg(result);
+}
+
+void BaselineJIT::generate_InitializeBlockDeadTemporalZone(int firstReg, int count)
+{
+    as->loadValue(Value::emptyValue().rawValue());
+    for (int i = firstReg, end = firstReg + count; i < end; ++i)
+        as->storeReg(i);
+}
+
+void BaselineJIT::generate_ThrowOnNullOrUndefined()
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passAccumulatorAsArg(1);
+    as->passEngineAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(ThrowOnNullOrUndefined, CallResultDestination::Ignore);
+}
+
+void BaselineJIT::generate_GetTemplateObject(int index)
+{
+    STORE_ACC();
+    as->prepareCallWithArgCount(2);
+    as->passInt32AsArg(index, 1);
+    as->passFunctionAsArg(0);
+    BASELINEJIT_GENERATE_RUNTIME_CALL(GetTemplateObject, CallResultDestination::InAccumulator);
+}
+
+ByteCodeHandler::Verdict BaselineJIT::startInstruction(Instr::Type /*instr*/)
+{
+    if (labels.contains(currentInstructionOffset()))
+        as->addLabel(currentInstructionOffset());
+    return ProcessInstruction;
+}
+
+void BaselineJIT::endInstruction(Instr::Type instr)
+{
+    Q_UNUSED(instr);
+}
+
+#endif // V4_ENABLE_JIT
diff --git a/src/qml/jit/qv4baselinejit_p.h b/src/qml/jit/qv4baselinejit_p.h
new file mode 100644
index 0000000000..5f3cb7eb2e
--- /dev/null
+++ b/src/qml/jit/qv4baselinejit_p.h
@@ -0,0 +1,235 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4JIT_P_H
+#define QV4JIT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+#include <private/qv4function_p.h>
+#include <private/qv4instr_moth_p.h>
+#include <private/qv4bytecodehandler_p.h>
+
+//QT_REQUIRE_CONFIG(qml_jit);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace JIT {
+
+class BaselineAssembler;
+
+#ifdef V4_ENABLE_JIT
+class BaselineJIT final: public Moth::ByteCodeHandler
+{
+public:
+    BaselineJIT(QV4::Function *);
+    virtual ~BaselineJIT() Q_DECL_OVERRIDE;
+
+    void generate();
+
+    void generate_Ret() override;
+    void generate_Debug() override;
+    void generate_LoadConst(int index) override;
+    void generate_LoadZero() override;
+    void generate_LoadTrue() override;
+    void generate_LoadFalse() override;
+    void generate_LoadNull() override;
+    void generate_LoadUndefined() override;
+    void generate_LoadInt(int value) override;
+    void generate_MoveConst(int constIndex, int destTemp) override;
+    void generate_LoadReg(int reg) override;
+    void generate_StoreReg(int reg) override;
+    void generate_MoveReg(int srcReg, int destReg) override;
+    void generate_LoadImport(int index) override;
+    void generate_LoadLocal(int index, int traceSlot) override;
+    void generate_StoreLocal(int index) override;
+    void generate_LoadScopedLocal(int scope, int index, int traceSlot) override;
+    void generate_StoreScopedLocal(int scope, int index) override;
+    void generate_LoadRuntimeString(int stringId) override;
+    void generate_MoveRegExp(int regExpId, int destReg) override;
+    void generate_LoadClosure(int value) override;
+    void generate_LoadName(int name, int traceSlot) override;
+    void generate_LoadGlobalLookup(int index, int traceSlot) override;
+    void generate_StoreNameSloppy(int name) override;
+    void generate_StoreNameStrict(int name) override;
+    void generate_LoadElement(int base, int traceSlot) override;
+    void generate_StoreElement(int base, int index, int traceSlot) override;
+    void generate_LoadProperty(int name, int traceSlot) override;
+    void generate_GetLookup(int index, int traceSlot) override;
+    void generate_StoreProperty(int name, int base) override;
+    void generate_SetLookup(int index, int base) override;
+    void generate_LoadSuperProperty(int property) override;
+    void generate_StoreSuperProperty(int property) override;
+    void generate_StoreScopeObjectProperty(int base,
+                                           int propertyIndex) override;
+    void generate_StoreContextObjectProperty(int base,
+                                             int propertyIndex) override;
+    void generate_LoadScopeObjectProperty(int propertyIndex, int base,
+                                          int captureRequired) override;
+    void generate_LoadContextObjectProperty(int propertyIndex, int base,
+                                            int captureRequired) override;
+    void generate_LoadIdObject(int index, int base) override;
+    void generate_Yield() override;
+    void generate_YieldStar() override;
+    void generate_Resume(int) override;
+
+    void generate_CallValue(int name, int argc, int argv, int traceSlot) override;
+    void generate_CallWithReceiver(int name, int thisObject, int argc, int argv, int traceSlot) override;
+    void generate_CallProperty(int name, int base, int argc, int argv, int traceSlot) override;
+    void generate_CallPropertyLookup(int lookupIndex, int base, int argc, int argv, int traceSlot) override;
+    void generate_CallElement(int base, int index, int argc, int argv, int traceSlot) override;
+    void generate_CallName(int name, int argc, int argv, int traceSlot) override;
+    void generate_CallPossiblyDirectEval(int argc, int argv, int traceSlot) override;
+    void generate_CallGlobalLookup(int index, int argc, int argv, int traceSlot) override;
+    void generate_CallScopeObjectProperty(int propIdx, int base, int argc, int argv, int traceSlot) override;
+    void generate_CallContextObjectProperty(int propIdx, int base, int argc, int argv, int traceSlot) override;
+    void generate_CallWithSpread(int func, int thisObject, int argc, int argv, int traceSlot) override;
+    void generate_TailCall(int func, int thisObject, int argc, int argv) override;
+    void generate_Construct(int func, int argc, int argv) override;
+    void generate_ConstructWithSpread(int func, int argc, int argv) override;
+    void generate_SetUnwindHandler(int offset) override;
+    void generate_UnwindDispatch() override;
+    void generate_UnwindToLabel(int level, int offset) override;
+    void generate_DeadTemporalZoneCheck(int name) override;
+    void generate_ThrowException() override;
+    void generate_GetException() override;
+    void generate_SetException() override;
+    void generate_CreateCallContext() override;
+    void generate_PushCatchContext(int index, int name) override;
+    void generate_PushWithContext() override;
+    void generate_PushBlockContext(int index) override;
+    void generate_CloneBlockContext() override;
+    void generate_PushScriptContext(int index) override;
+    void generate_PopScriptContext() override;
+    void generate_PopContext() override;
+    void generate_GetIterator(int iterator) override;
+    void generate_IteratorNext(int value, int done) override;
+    void generate_IteratorNextForYieldStar(int iterator, int object) override;
+    void generate_IteratorClose(int done) override;
+    void generate_DestructureRestElement() override;
+    void generate_DeleteProperty(int base, int index) override;
+    void generate_DeleteName(int name) override;
+    void generate_TypeofName(int name) override;
+    void generate_TypeofValue() override;
+    void generate_DeclareVar(int varName, int isDeletable) override;
+    void generate_DefineArray(int argc, int args) override;
+    void generate_DefineObjectLiteral(int internalClassId, int argc, int args) override;
+    void generate_CreateClass(int classIndex, int heritage, int computedNames) override;
+    void generate_CreateMappedArgumentsObject() override;
+    void generate_CreateUnmappedArgumentsObject() override;
+    void generate_CreateRestParameter(int argIndex) override;
+    void generate_ConvertThisToObject() override;
+    void generate_LoadSuperConstructor() override;
+    void generate_ToObject() override;
+    void generate_Jump(int offset) override;
+    void generate_JumpTrue(int traceSlot, int offset) override;
+    void generate_JumpFalse(int traceSlot, int offset) override;
+    void generate_JumpNoException(int offset) override;
+    void generate_JumpNotUndefined(int offset) override;
+    void generate_CmpEqNull() override;
+    void generate_CmpNeNull() override;
+    void generate_CmpEqInt(int lhs) override;
+    void generate_CmpNeInt(int lhs) override;
+    void generate_CmpEq(int lhs) override;
+    void generate_CmpNe(int lhs) override;
+    void generate_CmpGt(int lhs) override;
+    void generate_CmpGe(int lhs) override;
+    void generate_CmpLt(int lhs) override;
+    void generate_CmpLe(int lhs) override;
+    void generate_CmpStrictEqual(int lhs) override;
+    void generate_CmpStrictNotEqual(int lhs) override;
+    void generate_CmpIn(int lhs) override;
+    void generate_CmpInstanceOf(int lhs) override;
+    void generate_UNot() override;
+    void generate_UPlus() override;
+    void generate_UMinus(int traceSlot) override;
+    void generate_UCompl() override;
+    void generate_Increment(int traceSlot) override;
+    void generate_Decrement(int traceSlot) override;
+    void generate_Add(int lhs, int traceSlot) override;
+    void generate_BitAnd(int lhs) override;
+    void generate_BitOr(int lhs) override;
+    void generate_BitXor(int lhs) override;
+    void generate_UShr(int lhs) override;
+    void generate_Shr(int lhs) override;
+    void generate_Shl(int lhs) override;
+    void generate_BitAndConst(int rhs) override;
+    void generate_BitOrConst(int rhs) override;
+    void generate_BitXorConst(int rhs) override;
+    void generate_UShrConst(int rhs) override;
+    void generate_ShrConst(int rhs) override;
+    void generate_ShlConst(int rhs) override;
+    void generate_Exp(int lhs) override;
+    void generate_Mul(int lhs, int traceSlot) override;
+    void generate_Div(int lhs) override;
+    void generate_Mod(int lhs, int traceSlot) override;
+    void generate_Sub(int lhs, int traceSlot) override;
+    void generate_LoadQmlContext(int result) override;
+    void generate_LoadQmlImportedScripts(int result) override;
+    void generate_InitializeBlockDeadTemporalZone(int firstReg, int count) override;
+    void generate_ThrowOnNullOrUndefined() override;
+    void generate_GetTemplateObject(int index) override;
+
+    Verdict startInstruction(Moth::Instr::Type instr) override;
+    void endInstruction(Moth::Instr::Type instr) override;
+
+private:
+    QV4::Function *function;
+    QScopedPointer<BaselineAssembler> as;
+    QSet<int> labels;
+};
+#endif // V4_ENABLE_JIT
+
+} // namespace JIT
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4JIT_P_H
diff --git a/src/qml/jit/qv4binop.cpp b/src/qml/jit/qv4binop.cpp
deleted file mode 100644
index a1c65f644c..0000000000
--- a/src/qml/jit/qv4binop.cpp
+++ /dev/null
@@ -1,665 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#include <qv4binop_p.h>
-#include <qv4assembler_p.h>
-
-#if ENABLE(ASSEMBLER)
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace JIT {
-
-template <typename JITAssembler>
-struct ArchitectureSpecificBinaryOperation
-{
-    using FPRegisterID = typename JITAssembler::FPRegisterID;
-
-    static bool doubleAdd(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(lhs);
-        Q_UNUSED(rhs);
-        Q_UNUSED(targetReg);
-        return false;
-    }
-    static bool doubleMul(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(lhs);
-        Q_UNUSED(rhs);
-        Q_UNUSED(targetReg);
-        return false;
-    }
-    static bool doubleSub(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(lhs);
-        Q_UNUSED(rhs);
-        Q_UNUSED(targetReg);
-        return false;
-    }
-    static bool doubleDiv(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        Q_UNUSED(as);
-        Q_UNUSED(lhs);
-        Q_UNUSED(rhs);
-        Q_UNUSED(targetReg);
-        return false;
-    }
-};
-
-#if CPU(X86)
-template <>
-struct ArchitectureSpecificBinaryOperation<Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerX86, NoOperatingSystemSpecialization>>>
-{
-    using JITAssembler = Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerX86, NoOperatingSystemSpecialization>>;
-    using FPRegisterID = JITAssembler::FPRegisterID;
-    using Address = JITAssembler::Address;
-
-    static bool doubleAdd(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        if (IR::Const *c = rhs->asConst()) { // Y = X + constant -> Y = X; Y += [constant-address]
-            as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
-            as->addDouble(addr, targetReg);
-            return true;
-        }
-        if (IR::Temp *t = rhs->asTemp()) { // Y = X + [temp-memory-address] -> Y = X; Y += [temp-memory-address]
-            if (t->kind != IR::Temp::PhysicalRegister) {
-                as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-                as->addDouble(as->loadTempAddress(t), targetReg);
-                return true;
-            }
-        }
-        return false;
-    }
-    static bool doubleMul(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        if (IR::Const *c = rhs->asConst()) { // Y = X * constant -> Y = X; Y *= [constant-address]
-            as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
-            as->mulDouble(addr, targetReg);
-            return true;
-        }
-        if (IR::Temp *t = rhs->asTemp()) { // Y = X * [temp-memory-address] -> Y = X; Y *= [temp-memory-address]
-            if (t->kind != IR::Temp::PhysicalRegister) {
-                as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-                as->mulDouble(as->loadTempAddress(t), targetReg);
-                return true;
-            }
-        }
-        return false;
-    }
-    static bool doubleSub(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        if (IR::Const *c = rhs->asConst()) { // Y = X - constant -> Y = X; Y -= [constant-address]
-            as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
-            as->subDouble(addr, targetReg);
-            return true;
-        }
-        if (IR::Temp *t = rhs->asTemp()) { // Y = X - [temp-memory-address] -> Y = X; Y -= [temp-memory-address]
-            if (t->kind != IR::Temp::PhysicalRegister) {
-                as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-                as->subDouble(as->loadTempAddress(t), targetReg);
-                return true;
-            }
-        }
-        return false;
-    }
-    static bool doubleDiv(JITAssembler *as, IR::Expr *lhs, IR::Expr *rhs, FPRegisterID targetReg)
-    {
-        if (IR::Const *c = rhs->asConst()) { // Y = X / constant -> Y = X; Y /= [constant-address]
-            as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-            Address addr = as->loadConstant(c, JITAssembler::ScratchRegister);
-            as->divDouble(addr, targetReg);
-            return true;
-        }
-        if (IR::Temp *t = rhs->asTemp()) { // Y = X / [temp-memory-address] -> Y = X; Y /= [temp-memory-address]
-            if (t->kind != IR::Temp::PhysicalRegister) {
-                as->moveDouble(as->toDoubleRegister(lhs, targetReg), targetReg);
-                as->divDouble(as->loadTempAddress(t), targetReg);
-                return true;
-            }
-        }
-        return false;
-    }
-};
-#endif
-
-#define OP(op) \
-    { "Runtime::" isel_stringIfy(op), QV4::Runtime::op, QV4::Runtime::InvalidRuntimeMethod, 0, 0, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
-#define OPCONTEXT(op) \
-    { "Runtime::" isel_stringIfy(op), QV4::Runtime::InvalidRuntimeMethod, QV4::Runtime::op, 0, 0, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
-
-#define INLINE_OP(op, memOp, immOp) \
-    { "Runtime::" isel_stringIfy(op), QV4::Runtime::op, QV4::Runtime::InvalidRuntimeMethod, memOp, immOp, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
-#define INLINE_OPCONTEXT(op, memOp, immOp) \
-    { "Runtime::" isel_stringIfy(op), QV4::Runtime::InvalidRuntimeMethod, QV4::Runtime::op, memOp, immOp, QV4::Runtime::Method_##op##_NeedsExceptionCheck }
-
-#define NULL_OP \
-    { 0, QV4::Runtime::InvalidRuntimeMethod, QV4::Runtime::InvalidRuntimeMethod, 0, 0, false }
-
-template <typename JITAssembler>
-const typename Binop<JITAssembler>::OpInfo Binop<JITAssembler>::operations[IR::LastAluOp + 1] = {
-    NULL_OP, // OpInvalid
-    NULL_OP, // OpIfTrue
-    NULL_OP, // OpNot
-    NULL_OP, // OpUMinus
-    NULL_OP, // OpUPlus
-    NULL_OP, // OpCompl
-    NULL_OP, // OpIncrement
-    NULL_OP, // OpDecrement
-
-    INLINE_OP(bitAnd, &Binop<JITAssembler>::inline_and32, &Binop<JITAssembler>::inline_and32), // OpBitAnd
-    INLINE_OP(bitOr, &Binop<JITAssembler>::inline_or32, &Binop<JITAssembler>::inline_or32), // OpBitOr
-    INLINE_OP(bitXor, &Binop<JITAssembler>::inline_xor32, &Binop<JITAssembler>::inline_xor32), // OpBitXor
-
-    INLINE_OPCONTEXT(add, &Binop<JITAssembler>::inline_add32, &Binop<JITAssembler>::inline_add32), // OpAdd
-    INLINE_OP(sub, &Binop<JITAssembler>::inline_sub32, &Binop<JITAssembler>::inline_sub32), // OpSub
-    INLINE_OP(mul, &Binop<JITAssembler>::inline_mul32, &Binop<JITAssembler>::inline_mul32), // OpMul
-
-    OP(div), // OpDiv
-    OP(mod), // OpMod
-
-    INLINE_OP(shl, &Binop<JITAssembler>::inline_shl32, &Binop<JITAssembler>::inline_shl32), // OpLShift
-    INLINE_OP(shr, &Binop<JITAssembler>::inline_shr32, &Binop<JITAssembler>::inline_shr32), // OpRShift
-    INLINE_OP(ushr, &Binop<JITAssembler>::inline_ushr32, &Binop<JITAssembler>::inline_ushr32), // OpURShift
-
-    OP(greaterThan), // OpGt
-    OP(lessThan), // OpLt
-    OP(greaterEqual), // OpGe
-    OP(lessEqual), // OpLe
-    OP(equal), // OpEqual
-    OP(notEqual), // OpNotEqual
-    OP(strictEqual), // OpStrictEqual
-    OP(strictNotEqual), // OpStrictNotEqual
-
-    OPCONTEXT(instanceof), // OpInstanceof
-    OPCONTEXT(in), // OpIn
-
-    NULL_OP, // OpAnd
-    NULL_OP // OpOr
-};
-
-
-
-template <typename JITAssembler>
-void Binop<JITAssembler>::generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
-{
-    if (op != IR::OpMod
-            && lhs->type == IR::DoubleType && rhs->type == IR::DoubleType) {
-        doubleBinop(lhs, rhs, target);
-        return;
-    }
-    if (lhs->type == IR::SInt32Type && rhs->type == IR::SInt32Type) {
-        if (int32Binop(lhs, rhs, target))
-            return;
-    }
-
-    Jump done;
-    if (lhs->type != IR::StringType && rhs->type != IR::StringType)
-        done = genInlineBinop(lhs, rhs, target);
-
-    // TODO: inline var===null and var!==null
-    Binop::OpInfo info = Binop::operation(op);
-
-    if (op == IR::OpAdd &&
-            (lhs->type == IR::StringType || rhs->type == IR::StringType)) {
-        const Binop::OpInfo stringAdd = OPCONTEXT(addString);
-        info = stringAdd;
-    }
-
-    typename JITAssembler::RuntimeCall fallBack(info.fallbackImplementation);
-    typename JITAssembler::RuntimeCall context(info.contextImplementation);
-    if (fallBack.isValid()) {
-        as->generateFunctionCallImp(info.needsExceptionCheck, target, info.name, fallBack,
-                                     PointerToValue(lhs),
-                                     PointerToValue(rhs));
-    } else if (context.isValid()) {
-        as->generateFunctionCallImp(info.needsExceptionCheck, target, info.name, context,
-                                     JITAssembler::EngineRegister,
-                                     PointerToValue(lhs),
-                                     PointerToValue(rhs));
-    } else {
-        Q_ASSERT(!"unreachable");
-    }
-
-    if (done.isSet())
-        done.link(as);
-
-}
-
-template <typename JITAssembler>
-void Binop<JITAssembler>::doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target)
-{
-    IR::Temp *targetTemp = target->asTemp();
-    FPRegisterID targetReg;
-    if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-        targetReg = (FPRegisterID) targetTemp->index;
-    else
-        targetReg = JITAssembler::FPGpr0;
-
-    switch (op) {
-    case IR::OpAdd:
-        if (lhs->asConst())
-            std::swap(lhs, rhs); // Y = constant + X -> Y = X + constant
-
-        if (ArchitectureSpecificBinaryOperation<JITAssembler>::doubleAdd(as, lhs, rhs, targetReg))
-            break;
-
-        as->addDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
-        break;
-
-    case IR::OpMul:
-        if (lhs->asConst())
-            std::swap(lhs, rhs); // Y = constant * X -> Y = X * constant
-
-        if (ArchitectureSpecificBinaryOperation<JITAssembler>::doubleMul(as, lhs, rhs, targetReg))
-            break;
-
-        as->mulDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
-        break;
-
-    case IR::OpSub:
-        if (ArchitectureSpecificBinaryOperation<JITAssembler>::doubleSub(as, lhs, rhs, targetReg))
-            break;
-
-        if (rhs->asTemp() && rhs->asTemp()->kind == IR::Temp::PhysicalRegister
-                && targetTemp
-                && targetTemp->kind == IR::Temp::PhysicalRegister
-                && targetTemp->index == rhs->asTemp()->index) { // Y = X - Y -> Tmp = Y; Y = X - Tmp
-            as->moveDouble(as->toDoubleRegister(rhs, JITAssembler::FPGpr1), JITAssembler::FPGpr1);
-            as->subDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), JITAssembler::FPGpr1, targetReg);
-            break;
-        }
-
-        as->subDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
-        break;
-
-    case IR::OpDiv:
-        if (ArchitectureSpecificBinaryOperation<JITAssembler>::doubleDiv(as, lhs, rhs, targetReg))
-            break;
-
-        if (rhs->asTemp() && rhs->asTemp()->kind == IR::Temp::PhysicalRegister
-                && targetTemp
-                && targetTemp->kind == IR::Temp::PhysicalRegister
-                && targetTemp->index == rhs->asTemp()->index) { // Y = X / Y -> Tmp = Y; Y = X / Tmp
-            as->moveDouble(as->toDoubleRegister(rhs, JITAssembler::FPGpr1), JITAssembler::FPGpr1);
-            as->divDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), JITAssembler::FPGpr1, targetReg);
-            break;
-        }
-
-        as->divDouble(as->toDoubleRegister(lhs, JITAssembler::FPGpr0), as->toDoubleRegister(rhs, JITAssembler::FPGpr1), targetReg);
-        break;
-
-    default: {
-        Jump trueCase = as->branchDouble(false, op, lhs, rhs);
-        as->storeBool(false, target);
-        Jump done = as->jump();
-        trueCase.link(as);
-        as->storeBool(true, target);
-        done.link(as);
-    } return;
-    }
-
-    if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
-        as->storeDouble(targetReg, target);
-}
-
-template <typename JITAssembler>
-bool Binop<JITAssembler>::int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
-{
-    Q_ASSERT(leftSource->type == IR::SInt32Type);
-    Q_ASSERT(rightSource->type == IR::SInt32Type);
-
-    switch (op) {
-    case IR::OpBitAnd:
-    case IR::OpBitOr:
-    case IR::OpBitXor:
-    case IR::OpAdd:
-    case IR::OpMul:
-        if (leftSource->asConst()) // X = Const op Y -> X = Y op Const
-            std::swap(leftSource, rightSource);
-        else if (IR::Temp *t = leftSource->asTemp()) {
-            if (t->kind != IR::Temp::PhysicalRegister) // X = [address] op Y -> X = Y op [address]
-                std::swap(leftSource, rightSource);
-        }
-        break;
-
-    case IR::OpLShift:
-    case IR::OpRShift:
-    case IR::OpURShift:
-    case IR::OpSub:
-        // handled by this method, but we can't flip operands.
-        break;
-
-    default:
-        return false; // not handled by this method, stop here.
-    }
-
-    bool inplaceOpWithAddress = false;
-
-    IR::Temp *targetTemp = target->asTemp();
-    RegisterID targetReg = JITAssembler::ReturnValueRegister;
-    if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-        IR::Temp *rhs = rightSource->asTemp();
-        if (!rhs || rhs->kind != IR::Temp::PhysicalRegister || rhs->index != targetTemp->index) {
-            // We try to load leftSource into the target's register, but we can't do that if
-            // the target register is the same as rightSource.
-            targetReg = (RegisterID) targetTemp->index;
-        } else if (rhs && rhs->kind == IR::Temp::PhysicalRegister && targetTemp->index == rhs->index) {
-            // However, if the target register is the same as the rightSource register, we can flip
-            // the operands for certain operations.
-            switch (op) {
-            case IR::OpBitAnd:
-            case IR::OpBitOr:
-            case IR::OpBitXor:
-            case IR::OpAdd:
-            case IR::OpMul:
-                // X = Y op X -> X = X op Y (or rephrased: X op= Y (so an in-place operation))
-                std::swap(leftSource, rightSource);
-                targetReg = (RegisterID) targetTemp->index;
-                break;
-
-            case IR::OpLShift:
-            case IR::OpRShift:
-            case IR::OpURShift:
-            case IR::OpSub:
-                break;
-
-            default:
-                Q_UNREACHABLE();
-                return false;
-            }
-        }
-
-        // determine if we have X op= [address]
-        if (IR::Temp *lhs = leftSource->asTemp()) {
-            if (lhs->kind == IR::Temp::PhysicalRegister && lhs->index == targetTemp->index) {
-                if (IR::Temp *rhs = rightSource->asTemp()) {
-                    if (rhs->kind != IR::Temp::PhysicalRegister) {
-                        switch (op) {
-                        case IR::OpBitAnd:
-                        case IR::OpBitOr:
-                        case IR::OpBitXor:
-                        case IR::OpAdd:
-                        case IR::OpMul:
-                            inplaceOpWithAddress = true;
-                            break;
-                        default:
-                            break;
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    // Special cases:
-    switch (op) {
-    case IR::OpSub:
-        if (rightSource->asTemp() && rightSource->asTemp()->kind == IR::Temp::PhysicalRegister
-                && targetTemp
-                && targetTemp->kind == IR::Temp::PhysicalRegister
-                && targetTemp->index == rightSource->asTemp()->index) {
-            // X = Y - X -> Tmp = X; X = Y; X -= Tmp
-            targetReg = (RegisterID) targetTemp->index;
-            as->move(targetReg, JITAssembler::ScratchRegister);
-            as->move(as->toInt32Register(leftSource, targetReg), targetReg);
-            as->sub32(JITAssembler::ScratchRegister, targetReg);
-        } else {
-            as->move(as->toInt32Register(leftSource, targetReg), targetReg);
-            as->sub32(as->toInt32Register(rightSource, JITAssembler::ScratchRegister), targetReg);
-        }
-        as->storeInt32(targetReg, target);
-        return true;
-
-    case IR::OpLShift:
-    case IR::OpRShift:
-    case IR::OpURShift:
-        if (IR::Const *c = rightSource->asConst()) {
-            if ((QV4::Primitive::toUInt32(c->value) & 0x1f) == 0) {
-                RegisterID r = as->toInt32Register(leftSource, targetReg);
-                as->storeInt32(r, target);
-                return true;
-            }
-        }
-        break;
-
-    default:
-        break;
-    }
-
-    RegisterID l = as->toInt32Register(leftSource, targetReg);
-    if (IR::Const *c = rightSource->asConst()) { // All cases of Y = X op Const
-        TrustedImm32 r(int(c->value));
-        TrustedImm32 ur(QV4::Primitive::toUInt32(c->value) & 0x1f);
-
-        switch (op) {
-        case IR::OpBitAnd: as->and32(r, l, targetReg); break;
-        case IR::OpBitOr:  as->or32 (r, l, targetReg); break;
-        case IR::OpBitXor: as->xor32(r, l, targetReg); break;
-        case IR::OpAdd:    as->add32(r, l, targetReg); break;
-        case IR::OpMul:    as->mul32(r, l, targetReg); break;
-
-        case IR::OpLShift:  as->lshift32(l, ur, targetReg); break;
-        case IR::OpRShift:  as->rshift32(l, ur, targetReg); break;
-        case IR::OpURShift: as->urshift32(l, ur, targetReg);
-            as->storeUInt32(targetReg, target); // IMPORTANT: do NOT do a break here! The stored type of an urshift is different from the other binary operations!
-            return true;
-
-        case IR::OpSub: // already handled before
-        default: // not handled by this method:
-            Q_UNREACHABLE();
-            return false;
-        }
-    } else if (inplaceOpWithAddress) { // All cases of X = X op [address-of-Y]
-        Pointer rhsAddr = as->loadAddressForReading(JITAssembler::ScratchRegister, rightSource);
-        switch (op) {
-        case IR::OpBitAnd: as->and32(rhsAddr, targetReg); break;
-        case IR::OpBitOr:  as->or32 (rhsAddr, targetReg); break;
-        case IR::OpBitXor: as->xor32(rhsAddr, targetReg); break;
-        case IR::OpAdd:    as->add32(rhsAddr, targetReg); break;
-        case IR::OpMul:    as->mul32(rhsAddr, targetReg); break;
-            break;
-
-        default: // not handled by this method:
-            Q_UNREACHABLE();
-            return false;
-        }
-    } else { // All cases of Z = X op Y
-        RegisterID r = as->toInt32Register(rightSource, JITAssembler::ScratchRegister);
-        switch (op) {
-        case IR::OpBitAnd: as->and32(l, r, targetReg); break;
-        case IR::OpBitOr:  as->or32 (l, r, targetReg); break;
-        case IR::OpBitXor: as->xor32(l, r, targetReg); break;
-        case IR::OpAdd:    as->add32(l, r, targetReg); break;
-        case IR::OpMul:    as->mul32(l, r, targetReg); break;
-
-#if CPU(X86) || CPU(X86_64)
-        // Intel does the & 0x1f on the CPU, so:
-        case IR::OpLShift:  as->lshift32(l, r, targetReg); break;
-        case IR::OpRShift:  as->rshift32(l, r, targetReg); break;
-        case IR::OpURShift: as->urshift32(l, r, targetReg);
-            as->storeUInt32(targetReg, target); // IMPORTANT: do NOT do a break here! The stored type of an urshift is different from the other binary operations!
-            return true;
-#else
-        // Not all CPUs accept shifts over more than 31 bits, and some CPUs (like ARM) will do
-        // surprising stuff when shifting over 0 bits.
-#define CHECK_RHS(op) { \
-    as->and32(TrustedImm32(0x1f), r, JITAssembler::ScratchRegister); \
-    Jump notZero = as->branch32(RelationalCondition::NotEqual, JITAssembler::ScratchRegister, TrustedImm32(0)); \
-    as->move(l, targetReg); \
-    Jump done = as->jump(); \
-    notZero.link(as); \
-    op; \
-    done.link(as); \
-}
-        case IR::OpLShift: CHECK_RHS(as->lshift32(l, JITAssembler::ScratchRegister, targetReg)); break;
-        case IR::OpRShift: CHECK_RHS(as->rshift32(l, JITAssembler::ScratchRegister, targetReg)); break;
-        case IR::OpURShift:
-            CHECK_RHS(as->urshift32(l, JITAssembler::ScratchRegister, targetReg));
-            as->storeUInt32(targetReg, target);
-            // IMPORTANT: do NOT do a break here! The stored type of an urshift is different from the other binary operations!
-            return true;
-#undef CHECK_RHS
-#endif
-
-        case IR::OpSub: // already handled before
-        default: // not handled by this method:
-            Q_UNREACHABLE();
-            return false;
-        }
-    }
-
-    as->storeInt32(targetReg, target);
-    return true;
-}
-
-template <typename JITAssembler>
-inline typename JITAssembler::FPRegisterID getFreeFPReg(IR::Expr *shouldNotOverlap, unsigned hint)
-{
-    if (IR::Temp *t = shouldNotOverlap->asTemp())
-        if (t->type == IR::DoubleType)
-            if (t->kind == IR::Temp::PhysicalRegister)
-                if (t->index == hint)
-                    return typename JITAssembler::FPRegisterID(hint + 1);
-    return typename JITAssembler::FPRegisterID(hint);
-}
-
-template <typename JITAssembler>
-typename JITAssembler::Jump Binop<JITAssembler>::genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
-{
-    Jump done;
-
-    // Try preventing a call for a few common binary operations. This is used in two cases:
-    // - no register allocation was performed (not available for the platform, or the IR was
-    //   not transformed into SSA)
-    // - type inference found that either or both operands can be of non-number type, and the
-    //   register allocator will have prepared for a call (meaning: all registers that do not
-    //   hold operands are spilled to the stack, which makes them available here)
-    // Note: FPGPr0 can still not be used, because uint32->double conversion uses it as a scratch
-    //       register.
-    switch (op) {
-    case IR::OpAdd: {
-        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
-        Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
-        Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
-
-        as->addDouble(rReg, lReg);
-        as->storeDouble(lReg, target);
-        done = as->jump();
-
-        if (leftIsNoDbl.isSet())
-            leftIsNoDbl.link(as);
-        if (rightIsNoDbl.isSet())
-            rightIsNoDbl.link(as);
-    } break;
-    case IR::OpMul: {
-        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
-        Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
-        Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
-
-        as->mulDouble(rReg, lReg);
-        as->storeDouble(lReg, target);
-        done = as->jump();
-
-        if (leftIsNoDbl.isSet())
-            leftIsNoDbl.link(as);
-        if (rightIsNoDbl.isSet())
-            rightIsNoDbl.link(as);
-    } break;
-    case IR::OpSub: {
-        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
-        Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
-        Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
-
-        as->subDouble(rReg, lReg);
-        as->storeDouble(lReg, target);
-        done = as->jump();
-
-        if (leftIsNoDbl.isSet())
-            leftIsNoDbl.link(as);
-        if (rightIsNoDbl.isSet())
-            rightIsNoDbl.link(as);
-    } break;
-    case IR::OpDiv: {
-        FPRegisterID lReg = getFreeFPReg<JITAssembler>(rightSource, 2);
-        FPRegisterID rReg = getFreeFPReg<JITAssembler>(leftSource, 4);
-        Jump leftIsNoDbl = as->genTryDoubleConversion(leftSource, lReg);
-        Jump rightIsNoDbl = as->genTryDoubleConversion(rightSource, rReg);
-
-        as->divDouble(rReg, lReg);
-        as->storeDouble(lReg, target);
-        done = as->jump();
-
-        if (leftIsNoDbl.isSet())
-            leftIsNoDbl.link(as);
-        if (rightIsNoDbl.isSet())
-            rightIsNoDbl.link(as);
-    } break;
-    default:
-        break;
-    }
-
-    return done;
-}
-
-template struct QV4::JIT::Binop<QV4::JIT::Assembler<DefaultAssemblerTargetConfiguration>>;
-#if defined(V4_BOOTSTRAP)
-#if !CPU(ARM_THUMB2)
-template struct QV4::JIT::Binop<QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>>;
-#endif
-#if !CPU(ARM64)
-template struct QV4::JIT::Binop<QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>>>;
-#endif
-#endif
-
-} // end of namespace JIT
-} // end of namespace QV4
-
-QT_END_NAMESPACE
-
-
-#endif
diff --git a/src/qml/jit/qv4binop_p.h b/src/qml/jit/qv4binop_p.h
deleted file mode 100644
index 1b1ab7f24d..0000000000
--- a/src/qml/jit/qv4binop_p.h
+++ /dev/null
@@ -1,256 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#ifndef QV4BINOP_P_H
-#define QV4BINOP_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <qv4jsir_p.h>
-#include <qv4isel_masm_p.h>
-#include <qv4assembler_p.h>
-
-QT_BEGIN_NAMESPACE
-
-#if ENABLE(ASSEMBLER)
-
-namespace QV4 {
-namespace JIT {
-
-template <typename JITAssembler>
-struct Binop {
-    Binop(JITAssembler *assembler, IR::AluOp operation)
-        : as(assembler)
-        , op(operation)
-    {}
-
-    using Jump = typename JITAssembler::Jump;
-    using Address = typename JITAssembler::Address;
-    using RegisterID = typename JITAssembler::RegisterID;
-    using FPRegisterID = typename JITAssembler::FPRegisterID;
-    using TrustedImm32 = typename JITAssembler::TrustedImm32;
-    using ResultCondition = typename JITAssembler::ResultCondition;
-    using RelationalCondition = typename JITAssembler::RelationalCondition;
-    using Pointer = typename JITAssembler::Pointer;
-    using PointerToValue = typename JITAssembler::PointerToValue;
-
-    void generate(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target);
-    void doubleBinop(IR::Expr *lhs, IR::Expr *rhs, IR::Expr *target);
-    bool int32Binop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target);
-    Jump genInlineBinop(IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target);
-
-    typedef Jump (Binop::*MemRegOp)(Address, RegisterID);
-    typedef Jump (Binop::*ImmRegOp)(TrustedImm32, RegisterID);
-
-    struct OpInfo {
-        const char *name;
-        Runtime::RuntimeMethods fallbackImplementation;
-        Runtime::RuntimeMethods contextImplementation;
-        MemRegOp inlineMemRegOp;
-        ImmRegOp inlineImmRegOp;
-        bool needsExceptionCheck;
-    };
-
-    static const OpInfo operations[IR::LastAluOp + 1];
-    static const OpInfo &operation(IR::AluOp operation)
-    { return operations[operation]; }
-
-    Jump inline_add32(Address addr, RegisterID reg)
-    {
-#if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        return as->branchAdd32(ResultCondition::Overflow, addr, reg);
-#else
-        as->load32(addr, JITAssembler::ScratchRegister);
-        return as->branchAdd32(ResultCondition::Overflow, JITAssembler::ScratchRegister, reg);
-#endif
-    }
-
-    Jump inline_add32(TrustedImm32 imm, RegisterID reg)
-    {
-        return as->branchAdd32(ResultCondition::Overflow, imm, reg);
-    }
-
-    Jump inline_sub32(Address addr, RegisterID reg)
-    {
-#if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        return as->branchSub32(ResultCondition::Overflow, addr, reg);
-#else
-        as->load32(addr, JITAssembler::ScratchRegister);
-        return as->branchSub32(ResultCondition::Overflow, JITAssembler::ScratchRegister, reg);
-#endif
-    }
-
-    Jump inline_sub32(TrustedImm32 imm, RegisterID reg)
-    {
-        return as->branchSub32(ResultCondition::Overflow, imm, reg);
-    }
-
-    Jump inline_mul32(Address addr, RegisterID reg)
-    {
-#if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        return as->branchMul32(JITAssembler::Overflow, addr, reg);
-#else
-        as->load32(addr, JITAssembler::ScratchRegister);
-        return as->branchMul32(ResultCondition::Overflow, JITAssembler::ScratchRegister, reg);
-#endif
-    }
-
-    Jump inline_mul32(TrustedImm32 imm, RegisterID reg)
-    {
-        return as->branchMul32(ResultCondition::Overflow, imm, reg, reg);
-    }
-
-    Jump inline_shl32(Address addr, RegisterID reg)
-    {
-        as->load32(addr, JITAssembler::ScratchRegister);
-        as->and32(TrustedImm32(0x1f), JITAssembler::ScratchRegister);
-        as->lshift32(JITAssembler::ScratchRegister, reg);
-        return Jump();
-    }
-
-    Jump inline_shl32(TrustedImm32 imm, RegisterID reg)
-    {
-        imm.m_value &= 0x1f;
-        as->lshift32(imm, reg);
-        return Jump();
-    }
-
-    Jump inline_shr32(Address addr, RegisterID reg)
-    {
-        as->load32(addr, JITAssembler::ScratchRegister);
-        as->and32(TrustedImm32(0x1f), JITAssembler::ScratchRegister);
-        as->rshift32(JITAssembler::ScratchRegister, reg);
-        return Jump();
-    }
-
-    Jump inline_shr32(TrustedImm32 imm, RegisterID reg)
-    {
-        imm.m_value &= 0x1f;
-        as->rshift32(imm, reg);
-        return Jump();
-    }
-
-    Jump inline_ushr32(Address addr, RegisterID reg)
-    {
-        as->load32(addr, JITAssembler::ScratchRegister);
-        as->and32(TrustedImm32(0x1f), JITAssembler::ScratchRegister);
-        as->urshift32(JITAssembler::ScratchRegister, reg);
-        return as->branchTest32(ResultCondition::Signed, reg, reg);
-    }
-
-    Jump inline_ushr32(TrustedImm32 imm, RegisterID reg)
-    {
-        imm.m_value &= 0x1f;
-        as->urshift32(imm, reg);
-        return as->branchTest32(ResultCondition::Signed, reg, reg);
-    }
-
-    Jump inline_and32(Address addr, RegisterID reg)
-    {
-#if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        as->and32(addr, reg);
-#else
-        as->load32(addr, JITAssembler::ScratchRegister);
-        as->and32(JITAssembler::ScratchRegister, reg);
-#endif
-        return Jump();
-    }
-
-    Jump inline_and32(TrustedImm32 imm, RegisterID reg)
-    {
-        as->and32(imm, reg);
-        return Jump();
-    }
-
-    Jump inline_or32(Address addr, RegisterID reg)
-    {
-#if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        as->or32(addr, reg);
-#else
-        as->load32(addr, JITAssembler::ScratchRegister);
-        as->or32(JITAssembler::ScratchRegister, reg);
-#endif
-        return Jump();
-    }
-
-    Jump inline_or32(TrustedImm32 imm, RegisterID reg)
-    {
-        as->or32(imm, reg);
-        return Jump();
-    }
-
-    Jump inline_xor32(Address addr, RegisterID reg)
-    {
-#if HAVE(ALU_OPS_WITH_MEM_OPERAND)
-        as->xor32(addr, reg);
-#else
-        as->load32(addr, JITAssembler::ScratchRegister);
-        as->xor32(JITAssembler::ScratchRegister, reg);
-#endif
-        return Jump();
-    }
-
-    Jump inline_xor32(TrustedImm32 imm, RegisterID reg)
-    {
-        as->xor32(imm, reg);
-        return Jump();
-    }
-
-
-
-    JITAssembler *as;
-    IR::AluOp op;
-};
-
-}
-}
-
-#endif
-
-QT_END_NAMESPACE
-
-#endif
diff --git a/src/qml/jit/qv4graph.cpp b/src/qml/jit/qv4graph.cpp
new file mode 100644
index 0000000000..4025ceb993
--- /dev/null
+++ b/src/qml/jit/qv4graph.cpp
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4graph_p.h"
+#include "qv4operation_p.h"
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace IR {
+
+Graph *Graph::create(Function *function)
+{
+    auto storage = function->pool()->allocate(sizeof(Graph));
+    auto g = new (storage) Graph(function);
+    g->m_undefinedNode = g->createNode(g->opBuilder()->get<Meta::Undefined>());
+    g->m_emptyNode = g->createNode(g->opBuilder()->get<Meta::Empty>());
+    g->m_nullNode = g->createNode(g->opBuilder()->getConstant(QV4::Value::nullValue()));
+    g->m_trueNode = g->createNode(g->opBuilder()->getConstant(QV4::Value::fromBoolean(true)));
+    g->m_falseNode = g->createNode(g->opBuilder()->getConstant(QV4::Value::fromBoolean(false)));
+    return g;
+}
+
+Graph::MemoryPool *Graph::pool() const
+{
+    return m_function->pool();
+}
+
+Node *Graph::createNode(const Operation *op, Node *const operands[], size_t opCount,
+                        bool incomplete)
+{
+    return Node::create(pool(), m_nextNodeId++, op, opCount, operands, incomplete);
+}
+
+Node *Graph::createConstantBoolNode(bool value)
+{
+    return createNode(opBuilder()->getConstant(Primitive::fromBoolean(value)));
+}
+
+Node *Graph::createConstantIntNode(int value)
+{
+    return createNode(opBuilder()->getConstant(Primitive::fromInt32(value)));
+}
+
+Graph::Graph(Function *function)
+    : m_function(function)
+    , m_opBuilder(OperationBuilder::create(pool()))
+{}
+
+Node *Graph::createConstantHeapNode(Heap::Base *heap)
+{
+    return createNode(opBuilder()->getConstant(Primitive::fromHeapObject(heap)));
+}
+
+void Graph::addEndInput(Node *n)
+{
+    if (m_endNode) {
+        auto newEnd = m_opBuilder->getEnd(m_endNode->operation()->controlInputCount() + 1);
+        m_endNode->setOperation(newEnd);
+        m_endNode->addInput(m_function->pool(), n);
+    }
+}
+
+} // IR namespace
+} // QV4 namespace
+QT_END_NAMESPACE
diff --git a/src/qml/jit/qv4graph_p.h b/src/qml/jit/qv4graph_p.h
new file mode 100644
index 0000000000..4706399c94
--- /dev/null
+++ b/src/qml/jit/qv4graph_p.h
@@ -0,0 +1,146 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4GRAPH_P_H
+#define QV4GRAPH_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmljsmemorypool_p.h>
+#include <private/qv4global_p.h>
+#include <private/qv4node_p.h>
+
+#include <array>
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace IR {
+
+class Function;
+class Operation;
+class OperationBuilder;
+
+class Graph final
+{
+    Q_DISABLE_COPY_MOVE(Graph)
+
+public:
+    using MemoryPool = QQmlJS::MemoryPool;
+
+public:
+    static Graph *create(Function *function);
+    ~Graph() = delete;
+
+    MemoryPool *pool() const;
+    OperationBuilder *opBuilder() const
+    { return m_opBuilder; }
+
+    Node *createNode(const Operation *op, Node * const operands[] = nullptr, size_t opCount = 0,
+                     bool incomplete = false);
+    template <typename... Nodes>
+    Node *createNode(Operation *op, Nodes*... nodes) {
+        std::array<Node *, sizeof...(nodes)> nodesArray {{ nodes... }};
+        return createNode(op, nodesArray.data(), nodesArray.size());
+    }
+    Node *createConstantBoolNode(bool value);
+    Node *createConstantIntNode(int value);
+    Node *createConstantHeapNode(Heap::Base *heap);
+
+    Node *undefinedNode() const { return m_undefinedNode; }
+    Node *emptyNode() const { return m_emptyNode; }
+    Node *nullNode() const { return m_nullNode; }
+    Node *trueConstant() const { return m_trueNode; }
+    Node *falseConstant() const { return m_falseNode; }
+
+    Node *startNode() const { return m_startNode; }
+    Node *engineNode() const { return m_engineNode; }
+    Node *functionNode() const { return m_functionNode; }
+    Node *cppFrameNode() const { return m_cppFrameNode; }
+    Node *endNode() const { return m_endNode; }
+    Node *initialFrameState() const { return m_initialFrameState; }
+    void setStartNode(Node *n) { m_startNode = n; }
+    void setEngineNode(Node *n) { m_engineNode = n; }
+    void setFunctionNode(Node *n) { m_functionNode = n; }
+    void setCppFrameNode(Node *n) { m_cppFrameNode = n; }
+    void setEndNode(Node *n) { m_endNode = n; }
+    void setInitialFrameState(Node *n) { m_initialFrameState = n; }
+
+    unsigned nodeCount() const
+    { return unsigned(m_nextNodeId); }
+
+    void addEndInput(Node *n);
+
+private: // types and methods
+    Graph(Function *function);
+
+private: // fields
+    Function *m_function;
+    OperationBuilder *m_opBuilder;
+    Node::Id m_nextNodeId = 0;
+    Node *m_undefinedNode = nullptr;
+    Node *m_emptyNode = nullptr;
+    Node *m_nullNode = nullptr;
+    Node *m_trueNode = nullptr;
+    Node *m_falseNode = nullptr;
+    Node *m_startNode = nullptr;
+    Node *m_engineNode = nullptr;
+    Node *m_functionNode = nullptr;
+    Node *m_cppFrameNode = nullptr;
+    Node *m_endNode = nullptr;
+    Node *m_initialFrameState = nullptr;
+};
+
+} // namespace IR
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4GRAPH_P_H
diff --git a/src/qml/jit/qv4graphbuilder.cpp b/src/qml/jit/qv4graphbuilder.cpp
new file mode 100644
index 0000000000..94b8e86e08
--- /dev/null
+++ b/src/qml/jit/qv4graphbuilder.cpp
@@ -0,0 +1,1739 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qloggingcategory.h>
+
+#include "qv4graphbuilder_p.h"
+#include "qv4function_p.h"
+#include "qv4lookup_p.h"
+#include "qv4stackframe_p.h"
+#include "qv4operation_p.h"
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace IR {
+
+Q_LOGGING_CATEGORY(lcIRGraphBuilder, "qt.v4.ir.graphbuilder")
+
+using MemoryPool = QQmlJS::MemoryPool;
+
+namespace {
+template <typename T, size_t N>
+char (&ArraySizeHelper(T (&array)[N]))[N];
+template <typename T, size_t N>
+char (&ArraySizeHelper(const T (&array)[N]))[N];
+
+template <typename Array>
+inline size_t arraySize(const Array &array)
+{
+    Q_UNUSED(array); // for MSVC
+    return sizeof(ArraySizeHelper(array));
+}
+} // anonymous namespace
+
+class GraphBuilder::InterpreterEnvironment
+{
+public:
+    struct FrameState: public QQmlJS::FixedPoolArray<Node *>
+    {
+        FrameState(MemoryPool *pool, int totalSlotCount)
+            : FixedPoolArray(pool, totalSlotCount)
+        {}
+
+        Node *&unwindHandlerOffset()
+        { return at(size() - 1); }
+
+        static FrameState *create(MemoryPool *pool, int jsSlotCount)
+        {
+            auto totalSlotCount = jsSlotCount;
+            auto fs = pool->New<FrameState>(pool, totalSlotCount);
+            return fs;
+        }
+
+        static FrameState *clone(MemoryPool *pool, FrameState *other)
+        {
+            FrameState *fs = create(pool, other->size());
+
+            for (int i = 0, ei = other->size(); i != ei; ++i)
+                fs->at(i) = other->at(i);
+
+            return fs;
+        }
+    };
+
+public:
+    InterpreterEnvironment(GraphBuilder *graphBuilder, Node *controlDependency)
+        : m_graphBuilder(graphBuilder)
+        , m_effectDependency(controlDependency)
+        , m_controlDependency(controlDependency)
+        , m_currentFrame(nullptr)
+    {}
+
+    void createEnvironment()
+    {
+        Function *f = function();
+        QV4::Function *v4Function = f->v4Function();
+        const size_t nRegisters = v4Function->compiledFunction->nRegisters;
+
+        // 1 extra slot for the unwindHandlerOffset
+        m_currentFrame = FrameState::create(graph()->pool(), int(nRegisters + 1));
+    }
+
+    void setupStartEnvironment()
+    {
+        Function *f = function();
+        QV4::Function *v4Function = f->v4Function();
+        const size_t nFormals = v4Function->compiledFunction->nFormals;
+        const size_t nRegisters = v4Function->compiledFunction->nRegisters;
+
+        createEnvironment();
+
+        Node *startNode = graph()->startNode();
+        auto opB = opBuilder();
+        auto create = [&](int index, const char *name) {
+            m_currentFrame->at(index) = graph()->createNode(
+                        opB->getParam(index, f->addString(QLatin1String(name))), startNode);
+        };
+        create(0, "%function");
+        create(1, "%context");
+        create(2, "%acc");
+        create(3, "%this");
+        create(4, "%newTarget");
+        create(5, "%argc");
+        const quint32_le *formalNameIdx = v4Function->compiledFunction->formalsTable();
+        for (size_t i = 0; i < nFormals; ++i, ++formalNameIdx) {
+            const int slot = int(CallData::HeaderSize() + i);
+            Q_ASSERT(*formalNameIdx <= quint32(std::numeric_limits<int>::max()));
+            auto op = opB->getParam(
+                        slot,
+                        f->addString(v4Function->compilationUnit->stringAt(int(*formalNameIdx))));
+            Node *argNode = graph()->createNode(op, startNode);
+            m_currentFrame->at(slot) = argNode;
+        }
+        Node *undefinedNode = graph()->undefinedNode();
+        Node *emptyNode = graph()->emptyNode();
+        const auto firstDeadZoneRegister
+                = v4Function->compiledFunction->firstTemporalDeadZoneRegister;
+        const auto registerDeadZoneSize
+                = v4Function->compiledFunction->sizeOfRegisterTemporalDeadZone;
+        for (size_t i = CallData::HeaderSize() + nFormals; i < nRegisters; ++i) {
+            const bool isDead = i >= firstDeadZoneRegister
+                    && i < size_t(firstDeadZoneRegister + registerDeadZoneSize);
+            m_currentFrame->at(int(i)) = isDead ? emptyNode : undefinedNode;
+        }
+        setUnwindHandlerOffset(0);
+    }
+
+    Function *function() const { return m_graphBuilder->function(); }
+    Graph *graph() const { return function()->graph(); }
+    OperationBuilder *opBuilder() const { return graph()->opBuilder(); }
+    GraphBuilder *graphBuilder() const { return m_graphBuilder; }
+
+    Node *bindAcc(Node *node)
+    {
+        bindNodeToSlot(node, CallData::Accumulator);
+        return node;
+    }
+
+    Node *accumulator() const
+    { return slot(CallData::Accumulator); }
+
+    Node *bindNodeToSlot(Node *node, int slot)
+    {
+        m_currentFrame->at(size_t(slot)) = node;
+        return node;
+    }
+
+    Node *slot(int slot) const
+    { return m_currentFrame->at(slot); }
+
+    int slotCount() const
+    { return m_currentFrame->size(); }
+
+    Node *effectDependency() const
+    { return m_effectDependency; }
+
+    void setEffectDependency(Node *newNode)
+    { m_effectDependency = newNode; }
+
+    Node *controlDependency() const
+    { return m_controlDependency; }
+
+    void setControlDependency(Node *newNode)
+    { m_controlDependency = newNode; }
+
+    Node *createFrameState()
+    {
+        return graph()->createNode(graphBuilder()->opBuilder()->getFrameState(slotCount()),
+                                   m_currentFrame->begin(), slotCount());
+    }
+
+    Node *merge(InterpreterEnvironment *other);
+
+    InterpreterEnvironment *copy() const
+    {
+        auto *newEnv = graph()->pool()->New<InterpreterEnvironment>(graphBuilder(),
+                                                                    controlDependency());
+        newEnv->setEffectDependency(effectDependency());
+        newEnv->m_currentFrame = FrameState::clone(graph()->pool(), m_currentFrame);
+        return newEnv;
+    }
+
+    int unwindHandlerOffset() const
+    {
+        auto uhOp = m_currentFrame->unwindHandlerOffset()->operation();
+        Q_ASSERT(uhOp->kind() == Meta::Constant);
+        return ConstantPayload::get(*uhOp)->value().int_32();
+    }
+
+    void setUnwindHandlerOffset(int newOffset)
+    { m_currentFrame->unwindHandlerOffset() = graphBuilder()->createConstant(newOffset); }
+
+    FrameState *frameState() const
+    { return m_currentFrame; }
+
+private:
+    GraphBuilder *m_graphBuilder;
+    Node *m_effectDependency;
+    Node *m_controlDependency;
+    FrameState *m_currentFrame;
+};
+
+namespace {
+class InterpreterSubEnvironment final
+{
+    Q_DISABLE_COPY_MOVE(InterpreterSubEnvironment)
+
+public:
+    explicit InterpreterSubEnvironment(GraphBuilder *builder)
+        : m_builder(builder)
+        , m_parent(builder->env()->copy())
+    {}
+
+    ~InterpreterSubEnvironment()
+    { m_builder->setEnv(m_parent); }
+
+private:
+    GraphBuilder *m_builder;
+    GraphBuilder::InterpreterEnvironment *m_parent;
+};
+} // anonymous namespace
+
+Node *GraphBuilder::InterpreterEnvironment::merge(InterpreterEnvironment *other)
+{
+    Q_ASSERT(m_currentFrame->size() == other->m_currentFrame->size());
+
+    auto gb = graphBuilder();
+    Node *mergedControl = gb->mergeControl(controlDependency(), other->controlDependency());
+    setControlDependency(mergedControl);
+    setEffectDependency(gb->mergeEffect(effectDependency(), other->effectDependency(), mergedControl));
+
+    // insert/update phi nodes, but not for the unwind handler:
+    for (int i = 0, ei = m_currentFrame->size() - 1; i != ei; ++i) {
+        //### use lifeness info to trim this!
+        m_currentFrame->at(i) = gb->mergeValue(m_currentFrame->at(i),
+                                              other->m_currentFrame->at(i),
+                                              mergedControl);
+    }
+    Q_ASSERT(unwindHandlerOffset() >= 0); // specifically: don't crash
+    return mergedControl;
+}
+
+void GraphBuilder::buildGraph(IR::Function *function)
+{
+    const char *code = function->v4Function()->codeData;
+    uint len = function->v4Function()->compiledFunction->codeSize;
+
+    GraphBuilder builder(function);
+    builder.startGraph();
+
+    InterpreterEnvironment initial(&builder, function->graph()->startNode());
+    initial.setupStartEnvironment();
+    builder.setEnv(&initial);
+    builder.graph()->setInitialFrameState(initial.createFrameState());
+    builder.decode(code, len);
+    builder.endGraph();
+};
+
+GraphBuilder::GraphBuilder(IR::Function *function)
+    : m_func(function)
+    , m_graph(function->graph())
+    , m_currentEnv(nullptr)
+{
+    for (unsigned i = 0, ei = m_func->v4Function()->compiledFunction->nLabelInfos; i != ei; ++i) {
+        unsigned label = m_func->v4Function()->compiledFunction->labelInfoTable()[i];
+        m_labelInfos.emplace_back(label);
+        if (lcIRGraphBuilder().isDebugEnabled()) {
+            const LabelInfo &li = m_labelInfos.back();
+            qCDebug(lcIRGraphBuilder) << "Loop start at" << li.labelOffset;
+        }
+    }
+}
+
+void GraphBuilder::startGraph()
+{
+    size_t nValuesOut = 1 + CallData::HeaderSize()
+            + m_func->v4Function()->compiledFunction->nFormals;
+    Node *start = m_graph->createNode(opBuilder()->getStart(uint16_t(nValuesOut)), nullptr, 0);
+    m_func->nodeInfo(start)->setBytecodeOffsets(0, 0);
+    m_graph->setStartNode(start);
+    m_graph->setEngineNode(m_graph->createNode(opBuilder()->get<Meta::Engine>(), &start, 1));
+    auto frame = m_graph->createNode(opBuilder()->get<Meta::CppFrame>(), &start, 1);
+    m_graph->setCppFrameNode(frame);
+    m_graph->setFunctionNode(m_graph->createNode(opBuilder()->get<Meta::Function>(),
+                                                 &frame, 1));
+}
+
+void GraphBuilder::endGraph()
+{
+    const auto inputCount = uint16_t(m_exitControls.size());
+    Node **inputs = &m_exitControls.front();
+    Q_ASSERT(m_graph->endNode() == nullptr);
+    m_graph->setEndNode(m_graph->createNode(opBuilder()->getEnd(inputCount), inputs, inputCount));
+}
+
+Node *GraphBuilder::bindAcc(Node *n)
+{
+    return env()->bindAcc(n);
+}
+
+/* IMPORTANT!!!
+ *
+ * This might change the success environment, so don't call:
+ *   env()->bindAcc(createNode(...))
+ * because the binding should only happen on success, but the call to env() will get the
+ * environment from *before* the new success environment was created. Instead, do:
+ *   bindAcc(createNode(....))
+ */
+Node *GraphBuilder::createAndLinkNode(Operation *op, Node *operands[], size_t opCount,
+                                      bool incomplete)
+{
+    Q_ASSERT(op->effectInputCount() < 2);
+    Q_ASSERT(op->controlInputCount() < 2);
+
+    QVarLengthArray<Node *, 32> inputs(static_cast<int>(opCount));
+    std::copy_n(operands, opCount, inputs.data());
+
+    if (op->effectInputCount() == 1)
+        inputs.append(env()->effectDependency());
+    if (op->controlInputCount() == 1)
+        inputs.append(env()->controlDependency());
+    if (op->hasFrameStateInput())
+        inputs.append(env()->createFrameState());
+
+    Node *node = m_graph->createNode(op, inputs.data(), inputs.size(), incomplete);
+
+    if (op->needsBytecodeOffsets()) {
+        m_func->nodeInfo(node)->setBytecodeOffsets(currentInstructionOffset(),
+                                                   nextInstructionOffset());
+    }
+
+    if (op->effectOutputCount() > 0)
+        env()->setEffectDependency(node);
+    if (op->controlOutputCount() > 0)
+        env()->setControlDependency(node);
+
+    if (op->canThrow() && env()->unwindHandlerOffset()) {
+        InterpreterSubEnvironment successEnv(this);
+        Node *control = env()->controlDependency();
+        control = m_graph->createNode(opBuilder()->get<Meta::OnException>(), &control, 1);
+        env()->setControlDependency(control);
+        auto unwindHandlerOffset = env()->unwindHandlerOffset();
+        mergeIntoSuccessor(unwindHandlerOffset);
+    }
+
+    return node;
+}
+
+Node *GraphBuilder::createNode(Operation *op, bool incomplete)
+{
+    return createAndLinkNode(op, nullptr, 0, incomplete);
+}
+
+Node *GraphBuilder::createNode(Operation *op, Node *n1)
+{
+    Node *buf[] = { n1 };
+    return createAndLinkNode(op, buf, arraySize(buf));
+}
+
+Node *GraphBuilder::createNode(Operation *op, Node *n1, Node *n2)
+{
+    Node *buf[] = { n1, n2 };
+    return createAndLinkNode(op, buf, arraySize(buf));
+}
+
+Node *GraphBuilder::createNode(Operation *op, Node *n1, Node *n2, Node *n3)
+{
+    Node *buf[] = { n1, n2, n3 };
+    return createAndLinkNode(op, buf, arraySize(buf));
+}
+
+Node *GraphBuilder::createNode(Operation *op, Node *n1, Node *n2, Node *n3, Node *n4)
+{
+    Node *buf[] = { n1, n2, n3, n4 };
+    return createAndLinkNode(op, buf, arraySize(buf));
+}
+
+Node *GraphBuilder::createRegion(unsigned nControlInputs)
+{
+    return createNode(opBuilder()->getRegion(nControlInputs), true);
+}
+
+Node *GraphBuilder::createIfTrue()
+{
+    return createNode(opBuilder()->get<Meta::IfTrue>());
+}
+
+Node *GraphBuilder::createIfFalse()
+{
+    return createNode(opBuilder()->get<Meta::IfFalse>());
+}
+
+Node *GraphBuilder::createConstant(int v)
+{
+    return m_graph->createNode(opBuilder()->getConstant(Primitive::fromInt32(v)));
+}
+
+Node *GraphBuilder::createPhi(unsigned nInputs, Node *input, Node *control)
+{
+    auto phiOp = opBuilder()->getPhi(nInputs);
+    QVarLengthArray<Node *, 32> buffer(int(nInputs + 1));
+    std::fill_n(buffer.data(), nInputs, input);
+    buffer[int(nInputs)] = control;
+    return m_graph->createNode(phiOp, buffer.data(), nInputs + 1, true);
+}
+
+Node *GraphBuilder::createEffectPhi(unsigned nInputs, Node *input, Node *control)
+{
+    auto phiOp = opBuilder()->getEffectPhi(nInputs);
+    QVarLengthArray<Node *, 32> buffer(int(nInputs + 1));
+    std::fill_n(buffer.data(), nInputs, input);
+    buffer[int(nInputs)] = control;
+    return m_graph->createNode(phiOp, buffer.data(), nInputs + 1, true);
+}
+
+Node *GraphBuilder::createHandleUnwind(int offset)
+{
+    return createNode(opBuilder()->getHandleUnwind(offset));
+}
+
+Node *GraphBuilder::mergeControl(Node *c1, Node *c2)
+{
+    if (c1->operation()->kind() == Meta::Region) {
+        const unsigned nInputs = c1->operation()->controlInputCount() + 1;
+        c1->addInput(m_graph->pool(), c2);
+        c1->setOperation(opBuilder()->getRegion(nInputs));
+        return c1;
+    }
+    auto op = opBuilder()->getRegion(2);
+    Node *inputs[] = { c1, c2 };
+    return m_graph->createNode(op, inputs, 2);
+}
+
+Node *GraphBuilder::mergeEffect(Node *e1, Node *e2, Node *control)
+{
+    const unsigned nInputs = control->operation()->controlInputCount();
+    if (e1->operation()->kind() == Meta::EffectPhi && e1->controlInput() == control) {
+        e1->insertInput(m_graph->pool(), nInputs - 1, e2);
+        e1->setOperation(opBuilder()->getEffectPhi(nInputs));
+        return e1;
+    }
+
+    if (e1 != e2) {
+        Node *phi = createEffectPhi(nInputs, e1, control);
+        phi->replaceInput(nInputs - 1, e2);
+        return phi;
+    }
+
+    return e1;
+}
+
+Node *GraphBuilder::mergeValue(Node *v1, Node *v2, Node *control)
+{
+    const unsigned nInputs = control->operation()->controlInputCount();
+    if (v1->operation()->kind() == Meta::Phi && v1->controlInput() == control) {
+        v1->insertInput(m_graph->pool(), nInputs - 1, v2);
+        v1->setOperation(opBuilder()->getPhi(nInputs));
+        return v1;
+    }
+
+    if (v1 != v2) {
+        Node *phi = createPhi(nInputs, v1, control);
+        phi->replaceInput(nInputs - 1, v2);
+        return phi;
+    }
+
+    return v1;
+}
+
+Node *GraphBuilder::createToBoolean(Node *input)
+{
+    return createNode(opBuilder()->get<Meta::ToBoolean>(), input);
+}
+
+void GraphBuilder::populate(VarArgNodes &args, int argc, int argv)
+{
+    for (int i = 0; i < argc; ++i)
+        args.append(env()->slot(argv + i));
+    Q_ASSERT(argc >= 0 && argc <= std::numeric_limits<uint16_t>::max());
+}
+
+void GraphBuilder::queueFunctionExit(Node *exitNode)
+{
+    m_exitControls.push_back(exitNode);
+    setEnv(nullptr);
+}
+
+Node *GraphBuilder::mergeIntoSuccessor(int offset)
+{
+    InterpreterEnvironment *&successorEnvironment = m_envForOffset[offset];
+
+    Node *region = nullptr;
+    if (successorEnvironment == nullptr) {
+        region = createRegion(1);
+        successorEnvironment = env();
+    } else {
+        // Merge any values which are live coming into the successor.
+        region = successorEnvironment->merge(env());
+    }
+    setEnv(nullptr);
+    return region;
+}
+
+const GraphBuilder::LabelInfo *GraphBuilder::labelInfoAt(unsigned offset) const
+{
+    for (const LabelInfo &li : m_labelInfos) {
+        if (li.labelOffset == offset)
+            return &li;
+    }
+    return nullptr;
+}
+
+const GraphBuilder::LabelInfo *GraphBuilder::isLoopStart(unsigned offset) const
+{
+    if (auto li = labelInfoAt(offset)) {
+        //### in the future, check if this is a loop start, or some other label
+        return li;
+    }
+
+    return nullptr;
+}
+
+void GraphBuilder::handleLoopStart(const LabelInfo &labelInfo)
+{
+    Q_ASSERT(env() != nullptr);
+
+    // We unconditionally insert a region node with phi nodes here. Now there might already be
+    // such a node, (e.g. the region after an if-then-else), but for simplicity we ignore that.
+    // A subsequent pass will fold/remove chains of Region nodes.
+    //### FIXME: add a DCE pass
+
+    const auto offset = int(labelInfo.labelOffset);
+    Node *control = createRegion(1);
+    env()->setControlDependency(control);
+    Node *effect = createEffectPhi(1, env()->effectDependency(), control);
+    env()->setEffectDependency(effect);
+
+    // insert/update phi nodes, but not for the unwind handler:
+    for (int i = 0, ei = env()->slotCount() - 1; i != ei; ++i) {
+        //### use lifeness info to trim this further!
+        if (i == CallData::Accumulator)
+            continue; // should never be alive on loop entry
+        env()->bindNodeToSlot(createPhi(1, env()->slot(i), control), i);
+    }
+
+    m_envForOffset.insert(offset, env()->copy());
+}
+
+void GraphBuilder::startUnwinding()
+{
+    if (int target = env()->unwindHandlerOffset()) {
+        mergeIntoSuccessor(target);
+    } else {
+        bindAcc(graph()->undefinedNode());
+        generate_Ret();
+    }
+}
+
+void GraphBuilder::generate_Ret()
+{
+    Node* control = createNode(opBuilder()->get<Meta::Return>(), env()->accumulator());
+    queueFunctionExit(control);
+}
+
+void GraphBuilder::generate_Debug() { Q_UNREACHABLE(); }
+
+void GraphBuilder::generate_LoadConst(int index)
+{
+    auto func = function()->v4Function();
+    Value v = func->compilationUnit->constants[index];
+    bindAcc(createNode(opBuilder()->getConstant(v)));
+}
+
+void GraphBuilder::generate_LoadZero()
+{
+    bindAcc(createConstant(0));
+}
+
+void GraphBuilder::generate_LoadTrue()
+{
+    bindAcc(m_graph->trueConstant());
+}
+
+void GraphBuilder::generate_LoadFalse()
+{
+    bindAcc(m_graph->falseConstant());
+}
+
+void GraphBuilder::generate_LoadNull()
+{
+    bindAcc(m_graph->nullNode());
+}
+
+void GraphBuilder::generate_LoadUndefined()
+{
+    bindAcc(m_graph->undefinedNode());
+}
+
+void GraphBuilder::generate_LoadInt(int value)
+{
+    bindAcc(m_graph->createNode(opBuilder()->getConstant(Primitive::fromInt32(value))));
+}
+
+void GraphBuilder::generate_MoveConst(int constIndex, int destTemp)
+{
+    auto func = function()->v4Function();
+    Value v = func->compilationUnit->constants[constIndex];
+    env()->bindNodeToSlot(createNode(opBuilder()->getConstant(v)), destTemp);
+}
+
+void GraphBuilder::generate_LoadReg(int reg)
+{
+    bindAcc(env()->slot(reg));
+}
+
+void GraphBuilder::generate_StoreReg(int reg)
+{
+    Node *n = env()->accumulator();
+    if (reg == CallData::This)
+        n = createNode(opBuilder()->get<Meta::StoreThis>(), n);
+    env()->bindNodeToSlot(n, reg);
+}
+
+void GraphBuilder::generate_MoveReg(int srcReg, int destReg)
+{
+    env()->bindNodeToSlot(env()->slot(srcReg), destReg);
+}
+
+void GraphBuilder::generate_LoadImport(int index)
+{
+    auto func = function()->v4Function();
+    Value v = *func->compilationUnit->imports[index];
+    bindAcc(createNode(opBuilder()->getConstant(v)));
+}
+
+void GraphBuilder::generate_LoadLocal(int index, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::ScopedLoad>(),
+                       createConstant(0),
+                       createConstant(index)));
+}
+
+void GraphBuilder::generate_StoreLocal(int index)
+{
+    createNode(opBuilder()->get<Meta::ScopedStore>(),
+               createConstant(0),
+               createConstant(index),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_LoadScopedLocal(int scope, int index, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::ScopedLoad>(),
+                       createConstant(scope),
+                       createConstant(index)));
+}
+
+void GraphBuilder::generate_StoreScopedLocal(int scope, int index)
+{
+    createNode(opBuilder()->get<Meta::ScopedStore>(),
+               createConstant(scope),
+               createConstant(index),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_LoadRuntimeString(int stringId)
+{
+    auto func = function()->v4Function();
+    Value v = Value::fromHeapObject(func->compilationUnit->runtimeStrings[stringId]);
+    bindAcc(createNode(opBuilder()->getConstant(v)));
+}
+
+void GraphBuilder::generate_MoveRegExp(int regExpId, int destReg)
+{
+    env()->bindNodeToSlot(createNode(opBuilder()->get<Meta::LoadRegExp>(),
+                                     createConstant(regExpId)), destReg);
+}
+
+void GraphBuilder::generate_LoadClosure(int value)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSLoadClosure>(),
+                       createConstant(value)));
+}
+
+void GraphBuilder::generate_LoadName(int name, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSLoadName>(),
+                       createConstant(name)));
+}
+
+void GraphBuilder::generate_LoadGlobalLookup(int index, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSLoadGlobalLookup>(), createConstant(index)));
+}
+
+void GraphBuilder::generate_StoreNameSloppy(int name)
+{
+    createNode(opBuilder()->get<Meta::JSStoreNameSloppy>(), createConstant(name), env()->accumulator());
+}
+
+void GraphBuilder::generate_StoreNameStrict(int name)
+{
+    createNode(opBuilder()->get<Meta::JSStoreNameStrict>(), createConstant(name), env()->accumulator());
+}
+
+void GraphBuilder::generate_LoadElement(int base, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSLoadElement>(),
+                       env()->slot(base),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_StoreElement(int base, int index, int /*traceSlot*/)
+{
+    createNode(opBuilder()->get<Meta::JSStoreElement>(),
+               env()->slot(base),
+               env()->slot(index),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_LoadProperty(int name, int /*traceSlot*/)
+{
+    Node *n = createNode(opBuilder()->get<Meta::JSLoadProperty>(),
+                         env()->accumulator(),
+                         createConstant(name));
+    bindAcc(n);
+}
+
+void GraphBuilder::generate_GetLookup(int index, int /*traceSlot*/)
+{
+    Node *n = createNode(opBuilder()->get<Meta::JSGetLookup>(),
+                         env()->accumulator(),
+                         createConstant(index));
+    bindAcc(n);
+}
+
+void GraphBuilder::generate_StoreProperty(int name, int base)
+{
+    createNode(opBuilder()->get<Meta::JSStoreProperty>(),
+               env()->slot(base),
+               createConstant(name),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_SetLookup(int index, int base)
+{
+
+    function()->v4Function()->isStrict()
+            ? createNode(opBuilder()->get<Meta::JSSetLookupStrict>(), env()->slot(base),
+                         createConstant(index), env()->accumulator())
+            : createNode(opBuilder()->get<Meta::JSSetLookupSloppy>(), env()->slot(base),
+                         createConstant(index), env()->accumulator());
+}
+
+void GraphBuilder::generate_LoadSuperProperty(int property)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSLoadSuperProperty>(),
+                       env()->slot(property)));
+}
+
+void GraphBuilder::generate_StoreSuperProperty(int property)
+{
+    createNode(opBuilder()->get<Meta::JSStoreSuperProperty>(),
+               createConstant(property),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_StoreScopeObjectProperty(int base, int propertyIndex)
+{
+    createNode(opBuilder()->get<Meta::QMLStoreScopeObjectProperty>(),
+               env()->slot(base),
+               createConstant(propertyIndex),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_StoreContextObjectProperty(int base, int propertyIndex)
+{
+    createNode(opBuilder()->get<Meta::QMLStoreContextObjectProperty>(),
+               env()->slot(base),
+               createConstant(propertyIndex),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_LoadScopeObjectProperty(int propertyIndex, int base,
+                                                    int captureRequired)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::QMLLoadScopeObjectProperty>(),
+                       env()->slot(base),
+                       createConstant(propertyIndex),
+                       createConstant(captureRequired)));
+}
+
+void GraphBuilder::generate_LoadContextObjectProperty(int propertyIndex, int base,
+                                                      int captureRequired)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::QMLLoadContextObjectProperty>(),
+                       env()->slot(base),
+                       createConstant(propertyIndex),
+                       createConstant(captureRequired)));
+}
+
+void GraphBuilder::generate_LoadIdObject(int index, int base)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::QMLLoadIdObject>(),
+                       env()->slot(base),
+                       createConstant(index)));
+}
+
+void GraphBuilder::generate_Yield() { Q_UNREACHABLE(); }
+void GraphBuilder::generate_YieldStar() { Q_UNREACHABLE(); }
+void GraphBuilder::generate_Resume(int /*offset*/) { Q_UNREACHABLE(); }
+
+void GraphBuilder::finalizeCall(Operation::Kind kind, VarArgNodes &args, int argc, int argv)
+{
+    populate(args, argc, argv);
+    bindAcc(createAndLinkNode(opBuilder()->getJSVarArgsCall(kind, uint16_t(args.size())),
+                              args.data(), size_t(args.size())));
+}
+
+void GraphBuilder::generate_CallValue(int name, int argc, int argv, int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(name));
+    finalizeCall(Meta::JSCallValue, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallWithReceiver(int name, int thisObject, int argc, int argv,
+                                             int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(name));
+    args.append(env()->slot(thisObject));
+    finalizeCall(Meta::JSCallWithReceiver, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallProperty(int name, int base, int argc, int argv, int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(base));
+    args.append(createConstant(name));
+    finalizeCall(Meta::JSCallProperty, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallPropertyLookup(int lookupIndex, int base, int argc, int argv,
+                                               int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(base));
+    args.append(createConstant(lookupIndex));
+    finalizeCall(Meta::JSCallLookup, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallElement(int base, int index, int argc, int argv, int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(base));
+    args.append(env()->slot(index));
+    finalizeCall(Meta::JSCallElement, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallName(int name, int argc, int argv, int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(createConstant(name));
+    finalizeCall(Meta::JSCallName, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallPossiblyDirectEval(int argc, int argv, int /*traceSlot*/)
+{
+    VarArgNodes args;
+    finalizeCall(Meta::JSCallPossiblyDirectEval, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallGlobalLookup(int index, int argc, int argv, int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(createConstant(index));
+    finalizeCall(Meta::JSCallGlobalLookup, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallScopeObjectProperty(int propIdx, int base, int argc, int argv,
+                                                    int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(base));
+    args.append(createConstant(propIdx));
+    finalizeCall(Meta::QMLCallScopeObjectProperty, args, argc, argv);
+}
+
+void GraphBuilder::generate_CallContextObjectProperty(int propIdx, int base, int argc, int argv,
+                                                      int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(base));
+    args.append(createConstant(propIdx));
+    finalizeCall(Meta::QMLCallContextObjectProperty, args, argc, argv);
+}
+
+void GraphBuilder::generate_SetUnwindHandler(int offset)
+{
+    m_currentUnwindHandlerOffset = offset ? absoluteOffset(offset) : 0;
+    env()->setUnwindHandlerOffset(m_currentUnwindHandlerOffset);
+}
+
+void GraphBuilder::generate_UnwindDispatch()
+{
+    auto e = createNode(opBuilder()->get<Meta::HasException>(), graph()->engineNode());
+    createNode(opBuilder()->get<Meta::Branch>(), e);
+    {
+        InterpreterSubEnvironment subEnvironment(this);
+        createIfTrue();
+        startUnwinding();
+    }
+
+    createIfFalse();
+
+    const auto unwindHandlerOffset = env()->unwindHandlerOffset();
+    const auto fallthroughSuccessor = nextInstructionOffset();
+    auto nContinuations = m_func->unwindLabelOffsets().size() + 1;
+    if (unwindHandlerOffset)
+        ++nContinuations;
+    Q_ASSERT(nContinuations <= std::numeric_limits<unsigned>::max());
+    createNode(opBuilder()->getUnwindDispatch(unsigned(nContinuations), unwindHandlerOffset,
+                                              fallthroughSuccessor));
+
+    {
+        InterpreterSubEnvironment fallthroughEnv(this);
+        mergeIntoSuccessor(fallthroughSuccessor);
+    }
+
+    if (unwindHandlerOffset) {
+        InterpreterSubEnvironment unwindHandlerEnv(this);
+        createHandleUnwind(unwindHandlerOffset);
+        mergeIntoSuccessor(unwindHandlerOffset);
+    }
+
+    for (int unwindLabelOffset : m_func->unwindLabelOffsets()) {
+        if (unwindLabelOffset <= currentInstructionOffset())
+            continue;
+        InterpreterSubEnvironment unwindLabelEnv(this);
+        createHandleUnwind(unwindLabelOffset);
+        mergeIntoSuccessor(unwindLabelOffset);
+    }
+
+    setEnv(nullptr);
+}
+
+void GraphBuilder::generate_UnwindToLabel(int level, int offset)
+{
+    //### For de-optimization, the relative offset probably also needs to be stored
+    int unwinder = absoluteOffset(offset);
+    createNode(opBuilder()->get<Meta::UnwindToLabel>(),
+               createConstant(level),
+               createConstant(unwinder));
+    m_func->addUnwindLabelOffset(unwinder);
+    startUnwinding();
+}
+
+void GraphBuilder::generate_DeadTemporalZoneCheck(int name)
+{
+    Node *check = createNode(opBuilder()->get<Meta::IsEmpty>(), env()->accumulator());
+    createNode(opBuilder()->get<Meta::Branch>(), check);
+
+    { //### it's probably better to handle this by de-optimizing
+        InterpreterSubEnvironment subEnvironment(this);
+        createIfTrue();
+        createNode(opBuilder()->get<Meta::ThrowReferenceError>(),
+                   createConstant(name));
+        startUnwinding();
+    }
+
+    createIfFalse();
+}
+
+void GraphBuilder::generate_ThrowException()
+{
+    createNode(opBuilder()->get<Meta::Throw>(), env()->accumulator());
+    startUnwinding();
+}
+
+void GraphBuilder::generate_GetException()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::GetException>()));
+}
+
+void GraphBuilder::generate_SetException()
+{
+    createNode(opBuilder()->get<Meta::SetException>(),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_CreateCallContext()
+{
+    createNode(opBuilder()->get<Meta::JSCreateCallContext>());
+}
+
+void GraphBuilder::generate_PushCatchContext(int index, int name)
+{
+    createNode(opBuilder()->get<Meta::JSCreateCatchContext>(),
+               createConstant(index),
+               createConstant(name));
+}
+
+void GraphBuilder::generate_PushWithContext()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSCreateWithContext>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_PushBlockContext(int index)
+{
+    createNode(opBuilder()->get<Meta::JSCreateBlockContext>(),
+               createConstant(index));
+}
+
+void GraphBuilder::generate_CloneBlockContext()
+{
+    createNode(opBuilder()->get<Meta::JSCloneBlockContext>());
+}
+
+void GraphBuilder::generate_PushScriptContext(int index)
+{
+    createNode(opBuilder()->get<Meta::JSCreateScriptContext>(), createConstant(index));
+}
+
+void GraphBuilder::generate_PopScriptContext()
+{
+    createNode(opBuilder()->get<Meta::JSPopScriptContext>());
+}
+
+void GraphBuilder::generate_PopContext()
+{
+    createNode(opBuilder()->get<Meta::PopContext>());
+}
+
+void GraphBuilder::generate_GetIterator(int iterator)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSGetIterator>(),
+                       env()->accumulator(),
+                       createConstant(iterator)));
+}
+
+void GraphBuilder::generate_IteratorNextAndFriends_TrailingStuff(Node *iterationNode,
+                                                                 int resultSlot)
+{
+    // See generate_IteratorNext for why this method exists.
+
+    // check that no-one messed around with the operation and made it throwing
+    Q_ASSERT(iterationNode->operation()->controlOutputCount() == 1);
+
+    // check that it's in the effect chain, because HasException relies on that
+    Q_ASSERT(iterationNode->operation()->effectOutputCount() == 1);
+
+    env()->bindNodeToSlot(createNode(opBuilder()->get<Meta::SelectOutput>(),
+                                     iterationNode,
+                                     createConstant(1),
+                                     graph()->undefinedNode()),
+                          resultSlot);
+    // Note: the following will NOT set the accumulator, because it contains the return value of
+    // the runtime call!
+    Node *ehCheck = createNode(opBuilder()->get<Meta::HasException>(), graph()->engineNode());
+    createNode(opBuilder()->get<Meta::Branch>(), ehCheck);
+
+    { // EH path:
+        InterpreterSubEnvironment subEnvironment(this);
+        createIfTrue();
+        if (auto ehOffset = env()->unwindHandlerOffset()) {
+            // Ok, there is an exception handler, so go there:
+            mergeIntoSuccessor(ehOffset);
+        } else {
+            // No Exception Handler, so keep the exception set in the engine, and leave the function
+            // a.s.a.p.:
+            bindAcc(graph()->undefinedNode());
+            generate_Ret();
+        }
+    }
+
+    // Normal control flow:
+    createIfFalse();
+}
+
+void GraphBuilder::generate_IteratorNext(int value, int done)
+{
+    // The way we model exceptions in the graph is that a runtime function will either succeed and
+    // return a value, or it fails and throws an exception. If it throws, the return value is not
+    // used because the method did not complete normally, and therefore it might be tainted.
+    //
+    // This is a problem for (and only for) IteratorNext and IteratorNextForYieldStart.
+    //
+    // What would happen in the normal case, is that the return value (done) is not used/assigned
+    // when IteratorNext throws, because the exception handling path is chosen. However, the
+    // interpreter *does* assign it, and will only check for an exception *after* that assignment.
+    //
+    // So, in order to work around this odd-duck behavior, we mark the operation as NoThrow,
+    // override the runtime method and flag it to not throw, and insert extra exception check nodes
+    // after the SelectOutput that follows the IteratorNext(ForYieldStar).
+    //
+    // Also note that the IteratorNext and IteratorNextForYieldStar are the only operations that
+    // have an inout parameter, and thus require a SelectOutput node to retrieve this.
+
+    Node *n = createNode(opBuilder()->get<Meta::JSIteratorNext>(),
+                         env()->accumulator(),
+                         graph()->undefinedNode());
+    bindAcc(n);
+    env()->bindNodeToSlot(n, done);
+    generate_IteratorNextAndFriends_TrailingStuff(n, value);
+}
+
+void GraphBuilder::generate_IteratorNextForYieldStar(int iterator, int object)
+{
+    // Please, PLEASE read the comment in generate_IteratorNext.
+    Node *n = createNode(opBuilder()->get<Meta::JSIteratorNextForYieldStar>(),
+                         env()->accumulator(),
+                         env()->slot(iterator),
+                         graph()->undefinedNode());
+    // Note: the following is a tiny bit different from what generate_IteratorNext does.
+    bindAcc(n);
+    generate_IteratorNextAndFriends_TrailingStuff(n, object);
+}
+
+void GraphBuilder::generate_IteratorClose(int done)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSIteratorClose>(),
+                       env()->accumulator(),
+                       env()->slot(done)));
+}
+
+void GraphBuilder::generate_DestructureRestElement()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSDestructureRestElement>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_DeleteProperty(int base, int index)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSDeleteProperty>(),
+                       env()->slot(base),
+                       env()->slot(index)));
+}
+
+void GraphBuilder::generate_DeleteName(int name)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSDeleteName>(),
+                       createConstant(name)));
+}
+
+void GraphBuilder::generate_TypeofName(int name)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSTypeofName>(),
+                       createConstant(name)));
+}
+
+void GraphBuilder::generate_TypeofValue()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSTypeofValue>(), env()->accumulator()));
+}
+
+void GraphBuilder::generate_DeclareVar(int varName, int isDeletable)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSDeclareVar>(),
+                       createConstant(isDeletable),
+                       createConstant(varName)));
+}
+
+void GraphBuilder::generate_DefineArray(int argc, int argv)
+{
+    VarArgNodes args;
+    finalizeCall(Meta::JSDefineArray, args, argc, argv);
+}
+
+void GraphBuilder::generate_DefineObjectLiteral(int internalClassId, int argc, int argv)
+{
+    VarArgNodes args;
+    args.append(createConstant(internalClassId));
+    finalizeCall(Meta::JSDefineObjectLiteral, args, argc, argv);
+}
+
+void GraphBuilder::generate_CreateClass(int classIndex, int heritage, int computedNames)
+{
+    int argc = 0;
+    int argv = computedNames;
+
+    const QV4::CompiledData::Class *cls = function()->v4Function()->compilationUnit->unitData()
+                                                  ->classAt(classIndex);
+    const CompiledData::Method *methods = cls->methodTable();
+    for (uint i = 0; i < cls->nStaticMethods + cls->nMethods; ++i) {
+        if (methods[i].name == std::numeric_limits<unsigned>::max())
+            ++argc;
+    }
+
+    VarArgNodes args;
+    args.append(createConstant(classIndex));
+    args.append(env()->slot(heritage));
+    finalizeCall(Meta::JSCreateClass, args, argc, argv);
+}
+
+void GraphBuilder::generate_CreateMappedArgumentsObject()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSCreateMappedArgumentsObject>()));
+}
+
+void GraphBuilder::generate_CreateUnmappedArgumentsObject()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSCreateUnmappedArgumentsObject>()));
+}
+
+void GraphBuilder::generate_CreateRestParameter(int argIndex)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSCreateRestParameter>(),
+                       createConstant(argIndex)));
+}
+
+void GraphBuilder::generate_ConvertThisToObject()
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSThisToObject>(),
+                               env()->slot(CallData::This));
+    env()->bindNodeToSlot(control, CallData::This);
+}
+
+void GraphBuilder::generate_LoadSuperConstructor()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSLoadSuperConstructor>(),
+                       env()->slot(CallData::Function)));
+}
+
+void GraphBuilder::generate_ToObject()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::ToObject>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_CallWithSpread(int func, int thisObject, int argc, int argv,
+                                           int /*traceSlot*/)
+{
+    VarArgNodes args;
+    args.append(env()->slot(func));
+    args.append(env()->slot(thisObject));
+    finalizeCall(Meta::JSCallWithSpread, args, argc, argv);
+}
+
+void GraphBuilder::generate_TailCall(int func, int thisObject, int argc, int argv)
+{
+    VarArgNodes args;
+    args.append(env()->slot(func));
+    args.append(env()->slot(thisObject));
+    populate(args, argc, argv);
+    Node *n = createAndLinkNode(opBuilder()->getJSTailCall(uint16_t(args.size())), args.data(),
+                                size_t(args.size()));
+    queueFunctionExit(n);
+}
+
+void GraphBuilder::generate_Construct(int func, int argc, int argv)
+{
+    VarArgNodes args;
+    args.append(env()->slot(func));
+    args.append(env()->accumulator());
+    finalizeCall(Meta::JSConstruct, args, argc, argv);
+}
+
+void GraphBuilder::generate_ConstructWithSpread(int func, int argc, int argv)
+{
+    VarArgNodes args;
+    args.append(env()->slot(func));
+    args.append(env()->accumulator());
+    finalizeCall(Meta::JSConstructWithSpread, args, argc, argv);
+}
+
+void GraphBuilder::generate_Jump(int offset)
+{
+    auto jumpTarget = absoluteOffset(offset);
+    mergeIntoSuccessor(jumpTarget);
+}
+
+void GraphBuilder::generate_JumpTrue(int /*traceSlot*/, int offset)
+{
+    createNode(opBuilder()->get<Meta::Branch>(), createToBoolean(env()->accumulator()));
+
+    {
+        InterpreterSubEnvironment subEnvironment(this);
+        auto jumpTarget = absoluteOffset(offset);
+        createIfTrue();
+        mergeIntoSuccessor(jumpTarget);
+    }
+
+    createIfFalse();
+}
+
+void GraphBuilder::generate_JumpFalse(int traceSlot, int offset)
+{
+    generate_JumpFalse(env()->accumulator(), traceSlot, offset);
+}
+
+void GraphBuilder::generate_JumpFalse(Node *condition, int /*traceSlot*/, int offset)
+{
+    createNode(opBuilder()->get<Meta::Branch>(), createToBoolean(condition));
+
+    {
+        InterpreterSubEnvironment subEnvironment(this);
+        auto jumpTarget = absoluteOffset(offset);
+        createIfFalse();
+        mergeIntoSuccessor(jumpTarget);
+    }
+
+    createIfTrue();
+}
+
+void GraphBuilder::generate_JumpNoException(int offset)
+{
+    auto e = createNode(opBuilder()->get<Meta::HasException>(), graph()->engineNode());
+    createNode(opBuilder()->get<Meta::Branch>(), e);
+
+    {
+        InterpreterSubEnvironment subEnvironment(this);
+        auto jumpTarget = absoluteOffset(offset);
+        createIfFalse();
+        mergeIntoSuccessor(jumpTarget);
+    }
+
+    createIfTrue();
+}
+
+void GraphBuilder::generate_JumpNotUndefined(int offset)
+{
+    Node *condition = createNode(opBuilder()->get<Meta::JSStrictEqual>(),
+                                 env()->accumulator(),
+                                 graph()->undefinedNode());
+    generate_JumpFalse(condition, NoTraceSlot, offset);
+}
+
+void GraphBuilder::generate_CmpEqNull()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSEqual>(),
+                       env()->accumulator(),
+                       graph()->nullNode()));
+}
+
+void GraphBuilder::generate_CmpNeNull()
+{
+    generate_CmpEqNull();
+    bindAcc(createNode(opBuilder()->get<Meta::BooleanNot>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_CmpEqInt(int lhs)
+{
+    auto left = createConstant(lhs);
+    Node* control = createNode(opBuilder()->get<Meta::JSEqual>(),
+                               left,
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpNeInt(int lhs)
+{
+    generate_CmpEqInt(lhs);
+    bindAcc(createNode(opBuilder()->get<Meta::BooleanNot>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_CmpEq(int lhs)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSEqual>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpNe(int lhs)
+{
+    generate_CmpEq(lhs);
+    bindAcc(createNode(opBuilder()->get<Meta::BooleanNot>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_CmpGt(int lhs)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSGreaterThan>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpGe(int lhs)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSGreaterEqual>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpLt(int lhs)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSLessThan>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpLe(int lhs)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSLessEqual>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpStrictEqual(int lhs)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSStrictEqual>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_CmpStrictNotEqual(int lhs)
+{
+    generate_CmpStrictEqual(lhs);
+    bindAcc(createNode(opBuilder()->get<Meta::BooleanNot>(),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_CmpIn(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSIn>(), env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_CmpInstanceOf(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSInstanceOf>(), env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_UNot()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::BooleanNot>(),
+                       createToBoolean(env()->accumulator())));
+}
+
+void GraphBuilder::generate_UPlus()
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSToNumber>(),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_UMinus(int /*traceSlot*/)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSNegate>(),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_UCompl()
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitXor>(),
+                       env()->accumulator(),
+                       createConstant(-1)));
+}
+
+void GraphBuilder::generate_Increment(int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSAdd>(),
+                       env()->accumulator(),
+                       createConstant(1)));
+}
+
+
+void GraphBuilder::generate_Decrement(int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSSubtract>(),
+                       env()->accumulator(),
+                       createConstant(1)));
+}
+
+void GraphBuilder::generate_Add(int lhs, int /*traceSlot*/)
+{
+    Node* control = createNode(opBuilder()->get<Meta::JSAdd>(),
+                               env()->slot(lhs),
+                               env()->accumulator());
+    bindAcc(control);
+}
+
+void GraphBuilder::generate_BitAnd(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitAnd>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_BitOr(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitOr>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_BitXor(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitXor>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_UShr(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSUnsignedShiftRight>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_Shr(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSShiftRight>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_Shl(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSShiftLeft>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+
+void GraphBuilder::generate_BitAndConst(int rhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitAnd>(),
+                       env()->accumulator(),
+                       createConstant(rhs)));
+}
+
+void GraphBuilder::generate_BitOrConst(int rhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitOr>(),
+                       env()->accumulator(),
+                       createConstant(rhs)));
+}
+
+void GraphBuilder::generate_BitXorConst(int rhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSBitXor>(),
+                       env()->accumulator(),
+                       createConstant(rhs)));
+}
+
+void GraphBuilder::generate_UShrConst(int rhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSUnsignedShiftRight>(),
+                       env()->accumulator(),
+                       createConstant(rhs)));
+}
+
+void GraphBuilder::generate_ShrConst(int rhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSShiftRight>(),
+                       env()->accumulator(),
+                       createConstant(rhs)));
+}
+
+void GraphBuilder::generate_ShlConst(int rhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSShiftLeft>(),
+                       env()->accumulator(),
+                       createConstant(rhs)));
+}
+
+void GraphBuilder::generate_Exp(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSExponentiate>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_Mul(int lhs, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSMultiply>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_Div(int lhs)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSDivide>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_Mod(int lhs, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSModulo>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_Sub(int lhs, int /*traceSlot*/)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSSubtract>(),
+                       env()->slot(lhs),
+                       env()->accumulator()));
+}
+
+void GraphBuilder::generate_LoadQmlContext(int result)
+{
+    env()->bindNodeToSlot(createNode(opBuilder()->get<Meta::QMLLoadContext>()), result);
+}
+
+void GraphBuilder::generate_LoadQmlImportedScripts(int result)
+{
+    env()->bindNodeToSlot(createNode(opBuilder()->get<Meta::QMLLoadImportedScripts>()),
+                          result);
+}
+
+void GraphBuilder::generate_InitializeBlockDeadTemporalZone(int firstReg, int count)
+{
+    for (int reg = firstReg; reg < firstReg + count; ++reg)
+        env()->bindNodeToSlot(graph()->emptyNode(), reg);
+}
+
+void GraphBuilder::generate_ThrowOnNullOrUndefined()
+{
+    createNode(opBuilder()->get<Meta::JSThrowOnNullOrUndefined>(),
+               env()->accumulator());
+}
+
+void GraphBuilder::generate_GetTemplateObject(int index)
+{
+    bindAcc(createNode(opBuilder()->get<Meta::JSGetTemplateObject>(),
+                       createConstant(index)));
+}
+
+GraphBuilder::Verdict GraphBuilder::startInstruction(Moth::Instr::Type /*instr*/)
+{
+    // This handles a couple of cases on how flow control can end up at this instruction.
+
+    const auto off = currentInstructionOffset();
+    if (auto newEnv = m_envForOffset[off]) {
+        // Ok, there was a jump from before to this point (which registered an environment), so we
+        // have two options:
+        if (env() != newEnv && env() != nullptr) {
+            // There is a current environment different from the environment active when we took the
+            // jump. This happens with e.g. an if-then-else:
+            //
+            //     acc = condition
+            //     JumpFalse else-block
+            //     ... then block
+            //     Jump end-if
+            //   else-block:
+            //     ... else block
+            //   end-if:
+            //     .. some instruction   <--- we're here
+            //
+            // in that case we merge the after-else environment into the after-then environment:
+            newEnv->merge(env());
+        } else {
+            // There is not a current environment. This can happen with e.g. a loop:
+            //  loop-start:
+            //     acc = condition
+            //     JumpFalse loop-end
+            //     ... loop body
+            //     Jump loop-start
+            //  loop-end:
+            //     .... some instruction   <--- we're here
+            //
+            // The last jump of the loop will clear the environment, so at this point we only have
+            // the environment registered by the JumpFalse. This is the asy case: no merges, just
+            // take the registered environment unchanged.
+        }
+
+        // Leave the merged environment as-is, and continue with a copy. We cannot change the
+        // registered environment in case this point also happens to be a loop start.
+        setEnv(newEnv->copy());
+    }
+
+    if (env() == nullptr) {
+        // Ok, there is no environment, meaning nobody jumped to this instruction, and the previous
+        // instruction doesn't let control flow end up here. So, this is dead code.
+        // This can happen for JS like:
+        //
+        //   if (condition) {
+        //     return something
+        //   } else {
+        //     return somethingElse
+        //   }
+        //   someCode   <--- we're here
+        return SkipInstruction;
+    }
+
+    const LabelInfo *info = isLoopStart(off);
+    if (info && env()) {
+        // Ok, this instruction is the start of a loop, meaning there will be a jump backwards to
+        // this point. Make sure there is a Region node with Phi nodes here.
+        handleLoopStart(*info);
+    }
+
+    return ProcessInstruction;
+}
+
+void GraphBuilder::endInstruction(Moth::Instr::Type /*instr*/) {}
+
+} // IR namespace
+} // QV4 namespace
+QT_END_NAMESPACE
diff --git a/src/qml/jit/qv4graphbuilder_p.h b/src/qml/jit/qv4graphbuilder_p.h
new file mode 100644
index 0000000000..6393cab9ef
--- /dev/null
+++ b/src/qml/jit/qv4graphbuilder_p.h
@@ -0,0 +1,311 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4GRAPHBUILDER_P_H
+#define QV4GRAPHBUILDER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+#include <private/qv4bytecodehandler_p.h>
+#include <private/qv4ir_p.h>
+#include "qv4graph_p.h"
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace IR {
+
+// The graph builder walks the byte-code, and produces a graph. The graph is a digraph, where the
+// nodes have operations, and the edges are dependencies (or inputs).
+class GraphBuilder: protected Moth::ByteCodeHandler
+{
+    Q_DISABLE_COPY_MOVE(GraphBuilder)
+
+    enum { NoTraceSlot = -1 };
+
+    struct LabelInfo { //### extend this to also capture the amount of slots that are live
+        LabelInfo() = default;
+        LabelInfo(unsigned label) : labelOffset(label) {}
+        unsigned labelOffset = 0;
+    };
+
+public:
+    static void buildGraph(IR::Function *function);
+
+    class InterpreterEnvironment;
+
+    void setEnv(InterpreterEnvironment *newEnv)
+    { m_currentEnv = newEnv; }
+
+    InterpreterEnvironment *env() const
+    { return m_currentEnv; }
+
+private:
+    GraphBuilder(IR::Function *function);
+    ~GraphBuilder() override = default;
+
+    void startGraph();
+    void endGraph();
+
+    Node *bindAcc(Node *n);
+    Node *createAndLinkNode(Operation *op, Node *operands[], size_t opCount, bool incomplete = false);
+    Node *createNode(Operation *op, bool incomplete = false);
+    Node *createNode(Operation *op, Node *n1);
+    Node *createNode(Operation *op, Node *n1, Node *n2);
+    Node *createNode(Operation *op, Node *n1, Node *n2, Node *n3);
+    Node *createNode(Operation *op, Node *n1, Node *n2, Node *n3, Node *n4);
+    Node *createRegion(unsigned nControlInputs);
+    Node *createIfTrue();
+    Node *createIfFalse();
+    Node *createConstant(int v);
+    Node *createPhi(unsigned nInputs, Node *input, Node *control);
+    Node *createEffectPhi(unsigned nInputs, Node *input, Node *control);
+    Node *createHandleUnwind(int offset);
+    Node *mergeControl(Node *c1, Node *c2);
+    Node *mergeEffect(Node *e1, Node *e2, Node *control);
+    Node *mergeValue(Node *v1, Node *v2, Node *control);
+
+    Node *createToBoolean(Node *input);
+
+    using VarArgNodes = QVarLengthArray<Node *, 32>;
+    void populate(VarArgNodes &args, int argc, int argv);
+
+    void queueFunctionExit(Node *exitNode);
+
+    Function *function() const
+    { return m_func; }
+
+    Graph *graph()
+    { return m_graph; }
+
+    Node *mergeIntoSuccessor(int offset);
+
+    OperationBuilder *opBuilder() const
+    { return m_graph->opBuilder(); }
+
+    int absoluteOffset(int offset) const
+    { return offset + nextInstructionOffset(); }
+
+    const LabelInfo *labelInfoAt(unsigned offset) const;
+    const LabelInfo *isLoopStart(unsigned offset) const;
+    void handleLoopStart(const LabelInfo &labelInfo);
+    void startUnwinding();
+
+protected: // ByteCodeHandler
+    void generate_Ret() override;
+    void generate_Debug() override;
+    void generate_LoadConst(int index) override;
+    void generate_LoadZero() override;
+    void generate_LoadTrue() override;
+    void generate_LoadFalse() override;
+    void generate_LoadNull() override;
+    void generate_LoadUndefined() override;
+    void generate_LoadInt(int value) override;
+    void generate_MoveConst(int constIndex, int destTemp) override;
+    void generate_LoadReg(int reg) override;
+    void generate_StoreReg(int reg) override;
+    void generate_MoveReg(int srcReg, int destReg) override;
+    void generate_LoadImport(int index) override;
+    void generate_LoadLocal(int index, int traceSlot) override;
+    void generate_StoreLocal(int index) override;
+    void generate_LoadScopedLocal(int scope, int index, int traceSlot) override;
+    void generate_StoreScopedLocal(int scope, int index) override;
+    void generate_LoadRuntimeString(int stringId) override;
+    void generate_MoveRegExp(int regExpId, int destReg) override;
+    void generate_LoadClosure(int value) override;
+    void generate_LoadName(int name, int traceSlot) override;
+    void generate_LoadGlobalLookup(int index, int traceSlot) override;
+    void generate_StoreNameSloppy(int name) override;
+    void generate_StoreNameStrict(int name) override;
+    void generate_LoadElement(int base, int traceSlot) override;
+    void generate_StoreElement(int base, int index, int traceSlot) override;
+    void generate_LoadProperty(int name, int traceSlot) override;
+    void generate_GetLookup(int index, int traceSlot) override;
+    void generate_StoreProperty(int name, int base) override;
+    void generate_SetLookup(int index, int base) override;
+    void generate_LoadSuperProperty(int property) override;
+    void generate_StoreSuperProperty(int property) override;
+    void generate_StoreScopeObjectProperty(int base,
+                                           int propertyIndex) override;
+    void generate_StoreContextObjectProperty(int base,
+                                             int propertyIndex) override;
+    void generate_LoadScopeObjectProperty(int propertyIndex, int base,
+                                          int captureRequired) override;
+    void generate_LoadContextObjectProperty(int propertyIndex, int base,
+                                            int captureRequired) override;
+    void generate_LoadIdObject(int index, int base) override;
+    void generate_Yield() override;
+    void generate_YieldStar() override;
+    void generate_Resume(int offset) override;
+    void finalizeCall(Operation::Kind kind, VarArgNodes &args, int argc, int argv);
+    void generate_CallValue(int name, int argc, int argv, int traceSlot) override;
+    void generate_CallWithReceiver(int name, int thisObject, int argc, int argv,
+                                   int traceSlot) override;
+    void generate_CallProperty(int name, int base, int argc, int argv, int traceSlot) override;
+    void generate_CallPropertyLookup(int lookupIndex, int base, int argc, int argv,
+                                     int traceSlot) override;
+    void generate_CallElement(int base, int index, int argc, int argv, int traceSlot) override;
+    void generate_CallName(int name, int argc, int argv, int traceSlot) override;
+    void generate_CallPossiblyDirectEval(int argc, int argv, int traceSlot) override;
+    void generate_CallGlobalLookup(int index, int argc, int argv, int traceSlot) override;
+    void generate_CallScopeObjectProperty(int propIdx, int base, int argc, int argv,
+                                          int traceSlot) override;
+    void generate_CallContextObjectProperty(int propIdx, int base, int argc, int argv,
+                                            int traceSlot) override;
+    void generate_SetUnwindHandler(int offset) override;
+    void generate_UnwindDispatch() override;
+    void generate_UnwindToLabel(int level, int offset) override;
+    void generate_DeadTemporalZoneCheck(int name) override;
+    void generate_ThrowException() override;
+    void generate_GetException() override;
+    void generate_SetException() override;
+    void generate_CreateCallContext() override;
+    void generate_PushCatchContext(int index, int name) override;
+    void generate_PushWithContext() override;
+    void generate_PushBlockContext(int index) override;
+    void generate_CloneBlockContext() override;
+    void generate_PushScriptContext(int index) override;
+    void generate_PopScriptContext() override;
+    void generate_PopContext() override;
+    void generate_GetIterator(int iterator) override;
+    void generate_IteratorNextAndFriends_TrailingStuff(Node *iterationNode, int resultSlot);
+    void generate_IteratorNext(int value, int done) override;
+    void generate_IteratorNextForYieldStar(int iterator, int object) override;
+    void generate_IteratorClose(int done) override;
+    void generate_DestructureRestElement() override;
+    void generate_DeleteProperty(int base, int index) override;
+    void generate_DeleteName(int name) override;
+    void generate_TypeofName(int name) override;
+    void generate_TypeofValue() override;
+    void generate_DeclareVar(int varName, int isDeletable) override;
+    void generate_DefineArray(int argc, int argv) override;
+    void generate_DefineObjectLiteral(int internalClassId, int argc, int argv) override;
+    void generate_CreateClass(int classIndex, int heritage, int computedNames) override;
+    void generate_CreateMappedArgumentsObject() override;
+    void generate_CreateUnmappedArgumentsObject() override;
+    void generate_CreateRestParameter(int argIndex) override;
+    void generate_ConvertThisToObject() override;
+    void generate_LoadSuperConstructor() override;
+    void generate_ToObject() override;
+    void generate_CallWithSpread(int func, int thisObject, int argc, int argv,
+                                 int traceSlot) override;
+    void generate_TailCall(int func, int thisObject, int argc, int argv) override;
+    void generate_Construct(int func, int argc, int argv) override;
+    void generate_ConstructWithSpread(int func, int argc, int argv) override;
+    void generate_Jump(int offset) override;
+    void generate_JumpTrue(int traceSlot, int offset) override;
+    void generate_JumpFalse(int traceSlot, int offset) override;
+    void generate_JumpFalse(Node *condition, int traceSlot, int offset);
+    void generate_JumpNoException(int offset) override;
+    void generate_JumpNotUndefined(int offset) override;
+    void generate_CmpEqNull() override;
+    void generate_CmpNeNull() override;
+    void generate_CmpEqInt(int lhs) override;
+    void generate_CmpNeInt(int lhs) override;
+    void generate_CmpEq(int lhs) override;
+    void generate_CmpNe(int lhs) override;
+    void generate_CmpGt(int lhs) override;
+    void generate_CmpGe(int lhs) override;
+    void generate_CmpLt(int lhs) override;
+    void generate_CmpLe(int lhs) override;
+    void generate_CmpStrictEqual(int lhs) override;
+    void generate_CmpStrictNotEqual(int lhs) override;
+    void generate_CmpIn(int lhs) override;
+    void generate_CmpInstanceOf(int lhs) override;
+    void generate_UNot() override;
+    void generate_UPlus() override;
+    void generate_UMinus(int traceSlot) override;
+    void generate_UCompl() override;
+    void generate_Increment(int traceSlot) override;
+    void generate_Decrement(int traceSlot) override;
+    void generate_Add(int lhs, int traceSlot) override;
+    void generate_BitAnd(int lhs) override;
+    void generate_BitOr(int lhs) override;
+    void generate_BitXor(int lhs) override;
+    void generate_UShr(int lhs) override;
+    void generate_Shr(int lhs) override;
+    void generate_Shl(int lhs) override;
+    void generate_BitAndConst(int rhs) override;
+    void generate_BitOrConst(int rhs) override;
+    void generate_BitXorConst(int rhs) override;
+    void generate_UShrConst(int rhs) override;
+    void generate_ShrConst(int rhs) override;
+    void generate_ShlConst(int rhs) override;
+    void generate_Exp(int lhs) override;
+    void generate_Mul(int lhs, int traceSlot) override;
+    void generate_Div(int lhs) override;
+    void generate_Mod(int lhs, int traceSlot) override;
+    void generate_Sub(int lhs, int traceSlot) override;
+    void generate_LoadQmlContext(int result) override;
+    void generate_LoadQmlImportedScripts(int result) override;
+    void generate_InitializeBlockDeadTemporalZone(int firstReg, int count) override;
+    void generate_ThrowOnNullOrUndefined() override;
+    void generate_GetTemplateObject(int index) override;
+
+    Verdict startInstruction(Moth::Instr::Type instr) override;
+    void endInstruction(Moth::Instr::Type instr) override;
+
+private:
+    IR::Function *m_func;
+    Graph *m_graph;
+    InterpreterEnvironment *m_currentEnv;
+    std::vector<Node *> m_exitControls;
+    QHash<int, InterpreterEnvironment *> m_envForOffset;
+    std::vector<LabelInfo> m_labelInfos;
+    int m_currentUnwindHandlerOffset = 0;
+};
+
+} // namespace IR
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4GRAPHBUILDER_P_H
diff --git a/src/qml/jit/qv4ir.cpp b/src/qml/jit/qv4ir.cpp
new file mode 100644
index 0000000000..0b82330394
--- /dev/null
+++ b/src/qml/jit/qv4ir.cpp
@@ -0,0 +1,382 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qqmlglobal_p.h>
+#include "qv4ir_p.h"
+#include "qv4node_p.h"
+#include "qv4function_p.h"
+#include <qv4graph_p.h>
+#include "qv4stackframe_p.h"
+#include "qv4operation_p.h"
+#include "qv4util_p.h"
+
+#include <QtCore/qloggingcategory.h>
+#include <QtCore/qjsonobject.h>
+#include <QtCore/qjsonarray.h>
+#include <QtCore/qfile.h>
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace IR {
+
+Q_LOGGING_CATEGORY(lcJsonIR, "qt.v4.ir.json");
+Q_LOGGING_CATEGORY(lcDotIR, "qt.v4.ir.dot");
+Q_LOGGING_CATEGORY(lcVerify, "qt.v4.ir.verify");
+
+Function::Function(QV4::Function *qv4Function)
+    : qv4Function(qv4Function)
+    , m_graph(Graph::create(this))
+    , m_dumper(nullptr)
+    , m_nodeInfo(128, nullptr)
+{
+}
+
+Function::~Function()
+{
+    delete m_dumper;
+}
+
+QString Function::name() const
+{
+    QString name;
+    if (auto n = v4Function()->name())
+        name = n->toQString();
+    if (name.isEmpty())
+        name.sprintf("%p", static_cast<void *>(v4Function()));
+    auto loc = v4Function()->sourceLocation();
+    return name + QStringLiteral(" (%1:%2:%3)").arg(loc.sourceFile, QString::number(loc.line),
+                                                    QString::number(loc.column));
+}
+
+void Function::dump(const QString &description) const
+{
+    Dumper::dump(this, description);
+}
+
+void Function::dump() const
+{
+    dump(QStringLiteral("Debug:"));
+}
+
+Dumper *Function::dumper() const
+{
+    if (!m_dumper)
+        m_dumper = new Dumper(this);
+    return m_dumper;
+}
+
+Function::StringId Function::addString(const QString &s)
+{
+    m_stringPool.push_back(s);
+    return m_stringPool.size() - 1;
+}
+
+NodeInfo *Function::nodeInfo(Node *n, bool createIfNecessary) const
+{
+    if (n->id() >= m_nodeInfo.size())
+        m_nodeInfo.resize(n->id() * 2, nullptr);
+
+    NodeInfo *&info = m_nodeInfo[n->id()];
+    if (info == nullptr && createIfNecessary) {
+        info = m_pool.New<NodeInfo>();
+        info->setType(n->operation()->type());
+    }
+    return info;
+}
+
+void Function::copyBytecodeOffsets(Node *from, Node *to)
+{
+    auto toInfo = nodeInfo(to);
+    if (auto fromInfo = nodeInfo(from)) {
+        toInfo->setBytecodeOffsets(fromInfo->currentInstructionOffset(),
+                                   fromInfo->nextInstructionOffset());
+    }
+}
+
+Dumper::Dumper(const Function *f)
+{
+    if (!f)
+        return;
+}
+
+void Dumper::dump(const Function *f, const QString &description)
+{
+    if (false && lcJsonIR().isDebugEnabled()) {
+        Dumper *dumper = f->dumper();
+
+        qCDebug(lcJsonIR).noquote().nospace() << description + QLatin1String(":\n");
+        for (const auto &line : dumper->dump(f).split('\n'))
+            qCDebug(lcJsonIR).noquote().nospace() << line;
+    }
+
+    if (lcDotIR().isDebugEnabled())
+        dot(f, description);
+}
+
+QByteArray Dumper::dump(const Function *f)
+{
+    QJsonObject fo;
+
+    {
+        QString name;
+        if (auto n = f->v4Function()->name())
+            name = n->toQString();
+        fo[QLatin1String("_searchKey")] = QStringLiteral("function %1").arg(name);
+        if (name.isEmpty())
+            name.sprintf("%p", static_cast<void *>(f->v4Function()));
+        fo[QLatin1String("name")] = name;
+    }
+
+    auto loc = f->v4Function()->sourceLocation();
+    fo[QLatin1String("source")] = loc.sourceFile;
+    fo[QLatin1String("line")] = loc.line;
+    fo[QLatin1String("column")] = loc.column;
+
+    {
+        QJsonArray gn;
+        QJsonArray ge;
+        NodeCollector nodes(f->graph(), /*collectUses =*/ true);
+        nodes.sortById();
+        for (Node *n : nodes.reachable()) {
+            gn.append(dump(n, f));
+            int inputIndex = 0;
+            for (Node *input : n->inputs()) {
+                QJsonObject edge;
+                edge[QLatin1String("from")] = int(input->id());
+                edge[QLatin1String("to")] = int(n->id());
+                edge[QLatin1String("index")] = inputIndex;
+                if (inputIndex < n->operation()->valueInputCount()) {
+                    edge[QLatin1String("type")] = QLatin1String("value");
+                } else if (inputIndex < n->operation()->valueInputCount()
+                           + n->operation()->effectInputCount()) {
+                    edge[QLatin1String("type")] = QLatin1String("effect");
+                } else {
+                    edge[QLatin1String("type")] = QLatin1String("control");
+                }
+                Q_ASSERT(inputIndex < n->operation()->valueInputCount()
+                         + n->operation()->effectInputCount()
+                         + n->operation()->controlInputCount());
+                ge.append(edge);
+                ++inputIndex;
+            }
+        }
+        QJsonObject g;
+        g[QLatin1String("nodes")] = gn;
+        g[QLatin1String("edges")] = ge;
+        fo[QLatin1String("graph")] = g;
+    }
+
+    m_doc.setObject(fo);
+    return m_doc.toJson(QJsonDocument::Indented);
+}
+
+QJsonValue toJSonValue(QV4::Value v)
+{
+    switch (v.type()) {
+    case QV4::Value::Undefined_Type: return QJsonValue(QJsonValue::Undefined);
+    case QV4::Value::Null_Type: return QJsonValue(QJsonValue::Null);
+    case QV4::Value::Boolean_Type: return QJsonValue(v.booleanValue());
+    case QV4::Value::Integer_Type: return QJsonValue(v.int_32());
+    case QV4::Value::Managed_Type:
+        if (String *s = v.stringValue())
+            return QJsonValue(s->toQString());
+        else
+            return QJsonValue(QLatin1String("<managed>"));
+    default: return QJsonValue(v.doubleValue());
+    }
+}
+
+QJsonValue Dumper::dump(const Node * const node, const Function *f)
+{
+    QJsonObject n;
+    n[QLatin1String("id")] = int(node->id());
+    n[QLatin1String("kind")] = node->operation()->debugString();
+    switch (node->operation()->kind()) {
+    case Meta::Parameter: {
+        auto info = ParameterPayload::get(*node->operation());
+        n[QLatin1String("name")] = f->string(info->stringId());
+        n[QLatin1String("index")] = int(info->parameterIndex());
+        break;
+    }
+    case Meta::Constant: {
+        auto info = ConstantPayload::get(*node->operation());
+        n[QLatin1String("value")] = toJSonValue(info->value());
+        break;
+    }
+    default:
+        break;
+    }
+    return n;
+}
+
+void Dumper::dot(const Function *f, const QString &description)
+{
+    static const bool skipFramestate = qEnvironmentVariableIsSet("QV4_JIT_DOT_SKIP_FRAMESTATE");
+
+    auto node = [](Node *n) {
+        return QStringLiteral("n%1[label=\"%1: %2%3\"];\n").arg(QString::number(n->id()),
+                                                                n->operation()->debugString(),
+                                                                n->isDead() ? QStringLiteral(" (dead)")
+                                                                            : QString());
+    };
+
+    Graph *g = f->graph();
+    QString out;
+    out += QLatin1Char('\n');
+    out += QStringLiteral("digraph{root=\"n%1\" label=\"%2\";"
+                          "node[shape=rect];"
+                          "edge[dir=back fontsize=10];\n")
+            .arg(g->startNode()->id())
+            .arg(description);
+    out += node(g->startNode());
+    const bool dumpUses = false; // set to true to see all nodes
+    NodeCollector nodes(g, dumpUses, skipFramestate);
+    for (Node *n : nodes.reachable()) {
+        if (n == g->startNode())
+            continue;
+
+        out += node(n);
+
+        unsigned inputIndex = 0;
+        for (Node *input : n->inputs()) {
+            if (input == nullptr)
+                continue;
+            out += QStringLiteral("n%2->n%1[style=").arg(QString::number(n->id()),
+                                                         QString::number(input->id()));
+            if (inputIndex < n->operation()->valueInputCount() ||
+                    inputIndex == n->operation()->indexOfFrameStateInput()) {
+                out += QStringLiteral("solid headlabel=\"%1\"").arg(inputIndex);
+            } else if (inputIndex < unsigned(n->operation()->valueInputCount()
+                                             + n->operation()->effectInputCount())) {
+                out += QStringLiteral("dotted headlabel=\"%1\"").arg(inputIndex);
+            } else {
+                out += QStringLiteral("dashed headlabel=\"%1\"").arg(inputIndex);
+            }
+            out += QStringLiteral("];\n");
+            ++inputIndex;
+        }
+    }
+    out += QStringLiteral("}\n");
+    qCDebug(lcDotIR).nospace().noquote() << out;
+
+    QFile of(description + QStringLiteral(".dot"));
+    of.open(QIODevice::WriteOnly);
+    of.write(out.toUtf8());
+    of.close();
+}
+
+void Function::verify() const
+{
+#ifndef QT_NO_DEBUG
+    unsigned problemsFound = 0;
+
+    auto verifyNodeAgainstOperation = [&problemsFound](const Node *n) {
+        const Operation *op = n->operation();
+        if (op->totalInputCount() != n->inputCount()) {
+            ++problemsFound;
+            qCDebug(lcVerify()) << "Node" << n->id() << "has" << n->inputCount()
+                                << "inputs, but it's operation" << op->debugString()
+                                << "requires" << op->totalInputCount() << "inputs";
+        }
+
+        if (n->opcode() == Meta::Phi || n->opcode() == Meta::EffectPhi) {
+            if (n->controlInput()->opcode() != Meta::Region) {
+                ++problemsFound;
+                qCDebug(lcVerify()) << "Control input of phi node" << n->id() << "is not a region";
+            }
+            if (n->controlInput()->inputCount() + 1 != n->inputCount()) {
+                ++problemsFound;
+                qCDebug(lcVerify()) << "Control input of phi node" << n->id()
+                                    << "has" << n->controlInput()->inputCount()
+                                    << "inputs while phi node has" << n->inputCount()
+                                    << "inputs";
+            }
+        }
+
+        //### todo: verify outputs: value outputs are allowed to be unused, but the effect and
+        //          control outputs have to be linked up, except:
+        //### todo: verify if no use is a nullptr, except for operations that can throw, where the
+        //          last one is allowed to be a nullptr when an unwind handler is missing.
+    };
+
+    NodeWorkList todo(graph());
+    todo.enqueue(graph()->endNode());
+    while (Node *n = todo.dequeueNextNodeForVisiting()) {
+        todo.enqueueAllInputs(n);
+        todo.enqueueAllUses(n);
+
+        verifyNodeAgainstOperation(n);
+    }
+    //### TODO:
+    if (problemsFound != 0) {
+        dump(QStringLiteral("Problematic graph"));
+        qFatal("Found %u problems during graph verification!", problemsFound);
+    }
+#endif // QT_NO_xDEBUG
+}
+
+QString Type::debugString() const
+{
+    if (isNone())
+        return QStringLiteral("none");
+    if (isInvalid())
+        return QStringLiteral("invalid");
+
+    QStringList s;
+    if (m_t & Bool)
+        s += QStringLiteral("boolean");
+    if (m_t & Int32)
+        s += QStringLiteral("int32");
+    if (m_t & Double)
+        s += QStringLiteral("double");
+    if (m_t & Undefined)
+        s += QStringLiteral("undefined");
+    if (m_t & Null)
+        s += QStringLiteral("null");
+    if (m_t & Empty)
+        s += QStringLiteral("empty");
+    if (m_t & RawPointer)
+        s += QStringLiteral("raw pointer");
+
+    return s.join(QLatin1String(" "));
+}
+
+} // IR namespace
+} // QV4 namespace
+QT_END_NAMESPACE
diff --git a/src/qml/jit/qv4ir_p.h b/src/qml/jit/qv4ir_p.h
new file mode 100644
index 0000000000..e21a80528d
--- /dev/null
+++ b/src/qml/jit/qv4ir_p.h
@@ -0,0 +1,228 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4IR_P_H
+#define QV4IR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4function_p.h>
+#include <QtCore/qjsondocument.h>
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace IR {
+
+class Dumper;
+class Graph;
+
+class Node;
+class NodeInfo;
+
+class Function
+{
+    Q_DISABLE_COPY_MOVE(Function)
+public:
+    Function(QV4::Function *qv4Function);
+    ~Function();
+
+    void verify() const;
+
+    QV4::Function *v4Function() const
+    { return qv4Function; }
+
+    QString name() const;
+
+    QQmlJS::MemoryPool *pool()
+    { return &m_pool; }
+
+    Graph *graph() const
+    { return m_graph; }
+
+    void dump(const QString &description) const;
+    void dump() const; // for calling in the debugger
+    Dumper *dumper() const;
+
+    using StringId = size_t;
+    StringId addString(const QString &s);
+    QString string(StringId id) const
+    { return m_stringPool[id]; }
+
+    NodeInfo *nodeInfo(Node *n, bool createIfNecessary = true) const;
+    void copyBytecodeOffsets(Node *from, Node *to);
+
+    void addUnwindLabelOffset(int absoluteOffset)
+    { m_unwindLabelOffsets.push_back(absoluteOffset); }
+
+    const std::vector<int> &unwindLabelOffsets() const
+    { return m_unwindLabelOffsets; }
+
+private:
+    QV4::Function *qv4Function;
+    mutable QQmlJS::MemoryPool m_pool;
+    Graph *m_graph;
+    mutable Dumper *m_dumper;
+    std::vector<QString> m_stringPool;
+    mutable std::vector<NodeInfo *> m_nodeInfo; //### move the into the _pool
+    std::vector<int> m_unwindLabelOffsets;
+};
+
+class Dumper
+{
+    Q_DISABLE_COPY_MOVE(Dumper)
+
+public:
+    Dumper(const Function *f);
+    ~Dumper() = default;
+
+    static void dump(const Function *f, const QString &description);
+    static void dot(const Function *f, const QString &description);
+
+private:
+    QByteArray dump(const Function *f);
+    QJsonValue dump(const Node *node, const Function *f);
+
+private:
+    QJsonDocument m_doc;
+};
+
+class Type
+{
+    // None is for nodes with no type (e.g. a Return)
+    // The others form a lattice:
+    // Any -> Object                       -> Invalid
+    // ^^^ -> Number -> Integral -> Int32  -> ^^^^^^^
+    // ^^^ -> Number -> Integral -> UInt32 -> ^^^^^^^
+    // ^^^ -> Number -> Integral -> Bool   -> ^^^^^^^
+    // ^^^ -> Number -> Double             -> ^^^^^^^
+    // ^^^ -> Undefined                    -> ^^^^^^^
+    // ^^^ -> Null                         -> ^^^^^^^
+    // ^^^ -> Empty                        -> ^^^^^^^
+    enum InternalType: int16_t {
+        None = 0,
+
+        Object     = 1 << 0,
+        Bool       = 1 << 1,
+        Int32      = 1 << 2,
+        UInt32     = 1 << 3,
+        Double     = 1 << 4,
+        Undefined  = 1 << 5,
+        Null       = 1 << 6,
+        Empty      = 1 << 7,
+        RawPointer = 1 << 8,
+        Invalid    = -1,
+
+        Integral = Int32 | UInt32 | Bool,
+        Number = Integral | Double,
+        Any = Object | Number | Undefined | Empty | Null,
+    };
+
+    Type(InternalType t) : m_t(t) {}
+
+public:
+    Type() = default;
+
+    bool operator==(const Type &other) const
+    { return m_t == other.m_t; }
+
+    static Type noneType() { return Type(None); }
+    static Type anyType() { return Type(Any); }
+    static Type undefinedType() { return Type(Undefined); }
+    static Type emptyType() { return Type(Empty); }
+    static Type booleanType() { return Type(Bool); }
+    static Type int32Type() { return Type(Int32); }
+    static Type doubleType() { return Type(Double); }
+    static Type numberType() { return Type(Number); }
+    static Type nullType() { return Type(Null); }
+    static Type objectType() { return Type(Object); }
+    static Type rawPointerType() { return Type(RawPointer); }
+
+    bool isAny() const { return m_t == Any; }
+    bool isBoolean() const { return m_t == Bool; }
+    bool isInt32() const { return m_t == Int32; }
+    bool isInvalid() const { return m_t == Invalid; }
+    bool isNone() const { return m_t == None; }
+    bool isDouble() const { return m_t == Double; }
+    bool isUndefined() const { return m_t == Undefined; }
+    bool isNull() const { return m_t == Null; }
+    bool isEmpty() const { return m_t == Empty; }
+    bool isObject() const { return m_t == Object; }
+    bool isRawPointer() const { return m_t == RawPointer; }
+    bool isIntegral() const { return matches(Integral); }
+    bool isNumber() const { return matches(Number); }
+
+    Type operator|(Type other) const
+    { return Type(InternalType(int16_t(m_t) | int16_t(other.m_t))); }
+
+    Type &operator|=(Type other)
+    {
+        m_t = (InternalType(int16_t(m_t) | int16_t(other.m_t)));
+        return *this;
+    }
+
+    QString debugString() const;
+
+private:
+    bool matches(InternalType it) const
+    {
+        return (m_t & ~it) == 0 && (m_t & it) != 0;
+    }
+
+private:
+    InternalType m_t = None;
+};
+
+} // namespace IR
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4IR_P_H
diff --git a/src/qml/jit/qv4isel_masm.cpp b/src/qml/jit/qv4isel_masm.cpp
deleted file mode 100644
index 7784eb364e..0000000000
--- a/src/qml/jit/qv4isel_masm.cpp
+++ /dev/null
@@ -1,1684 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qv4isel_masm_p.h"
-#include "qv4runtime_p.h"
-#include "qv4lookup_p.h"
-#include "qv4ssa_p.h"
-#include "qv4regalloc_p.h"
-#include "qv4assembler_p.h"
-#include "qv4unop_p.h"
-#include "qv4binop_p.h"
-
-#include <QtCore/QBuffer>
-#include <QtCore/QCoreApplication>
-
-#include <assembler/LinkBuffer.h>
-#include <WTFStubs.h>
-
-#include <iostream>
-
-#if ENABLE(ASSEMBLER)
-
-#if USE(UDIS86)
-#  include <udis86.h>
-#endif
-
-using namespace QV4;
-using namespace QV4::JIT;
-
-
-template <typename JITAssembler>
-InstructionSelection<JITAssembler>::InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory)
-    : EvalInstructionSelection(execAllocator, module, jsGenerator, iselFactory)
-    , _block(0)
-    , _as(0)
-    , compilationUnit(new CompilationUnit)
-    , qmlEngine(qmlEngine)
-{
-    compilationUnit->codeRefs.resize(module->functions.size());
-    module->unitFlags |= QV4::CompiledData::Unit::ContainsMachineCode;
-}
-
-template <typename JITAssembler>
-InstructionSelection<JITAssembler>::~InstructionSelection()
-{
-    delete _as;
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::run(int functionIndex)
-{
-    IR::Function *function = irModule->functions[functionIndex];
-    qSwap(_function, function);
-
-    IR::Optimizer opt(_function);
-    opt.run(qmlEngine);
-
-    static const bool withRegisterAllocator = qEnvironmentVariableIsEmpty("QV4_NO_REGALLOC");
-    if (JITTargetPlatform::RegAllocIsSupported && opt.isInSSA() && withRegisterAllocator) {
-        RegisterAllocator regalloc(JITTargetPlatform::getRegisterInfo());
-        regalloc.run(_function, opt);
-        calculateRegistersToSave(regalloc.usedRegisters());
-    } else {
-        if (opt.isInSSA())
-            // No register allocator available for this platform, or env. var was set, so:
-            opt.convertOutOfSSA();
-        ConvertTemps().toStackSlots(_function);
-        IR::Optimizer::showMeTheCode(_function, "After stack slot allocation");
-        calculateRegistersToSave(JITTargetPlatform::getRegisterInfo()); // FIXME: this saves all registers. We can probably do with a subset: those that are not used by the register allocator.
-    }
-    BitVector removableJumps = opt.calculateOptionalJumps();
-    qSwap(_removableJumps, removableJumps);
-
-    JITAssembler* oldAssembler = _as;
-    _as = new JITAssembler(jsGenerator, _function, executableAllocator);
-    _as->setStackLayout(6, // 6 == max argc for calls to built-ins with an argument array
-                        regularRegistersToSave.size(),
-                        fpRegistersToSave.size());
-    _as->enterStandardStackFrame(regularRegistersToSave, fpRegistersToSave);
-
-    if (JITTargetPlatform::RegisterArgumentCount > 0)
-        _as->move(_as->registerForArgument(0), JITTargetPlatform::EngineRegister);
-    else
-        _as->loadPtr(addressForArgument(0), JITTargetPlatform::EngineRegister);
-
-    _as->initializeLocalVariables();
-
-    int lastLine = 0;
-    for (int i = 0, ei = _function->basicBlockCount(); i != ei; ++i) {
-        IR::BasicBlock *nextBlock = (i < ei - 1) ? _function->basicBlock(i + 1) : 0;
-        _block = _function->basicBlock(i);
-        if (_block->isRemoved())
-            continue;
-        _as->registerBlock(_block, nextBlock);
-
-        for (IR::Stmt *s : _block->statements()) {
-            if (s->location.isValid()) {
-                if (int(s->location.startLine) != lastLine) {
-                    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, JITAssembler::targetStructureOffset(offsetof(QV4::EngineBase, current))), JITTargetPlatform::ScratchRegister);
-                    Address lineAddr(JITTargetPlatform::ScratchRegister, JITAssembler::targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, lineNumber)));
-                    _as->store32(TrustedImm32(s->location.startLine), lineAddr);
-                    lastLine = s->location.startLine;
-                }
-            }
-            visit(s);
-        }
-    }
-
-    if (!_as->exceptionReturnLabel.isSet())
-        visitRet(0);
-
-    int dummySize;
-    JSC::MacroAssemblerCodeRef codeRef =_as->link(&dummySize);
-    compilationUnit->codeRefs[functionIndex] = codeRef;
-
-    qSwap(_function, function);
-    delete _as;
-    _as = oldAssembler;
-    qSwap(_removableJumps, removableJumps);
-}
-
-template <typename JITAssembler>
-QQmlRefPointer<QV4::CompiledData::CompilationUnit> InstructionSelection<JITAssembler>::backendCompileStep()
-{
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> result;
-    result.adopt(compilationUnit.take());
-    return result;
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result)
-{
-    prepareCallData(args, 0);
-
-    if (useFastLookups && func->global) {
-        uint index = registerGlobalGetterLookup(*func->id);
-        generateRuntimeCall(_as, result, callGlobalLookup,
-                             JITTargetPlatform::EngineRegister,
-                             TrustedImm32(index),
-                             baseAddressForCallData());
-    } else {
-        generateRuntimeCall(_as, result, callActivationProperty,
-                             JITTargetPlatform::EngineRegister,
-                             StringToIndex(*func->id),
-                             baseAddressForCallData());
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinTypeofQmlContextProperty(IR::Expr *base,
-                                                               IR::Member::MemberKind kind,
-                                                               int propertyIndex, IR::Expr *result)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject) {
-        generateRuntimeCall(_as, result, typeofScopeObjectProperty, JITTargetPlatform::EngineRegister,
-                             PointerToValue(base),
-                             TrustedImm32(propertyIndex));
-    } else if (kind == IR::Member::MemberOfQmlContextObject) {
-        generateRuntimeCall(_as, result, typeofContextObjectProperty,
-                             JITTargetPlatform::EngineRegister, PointerToValue(base),
-                             TrustedImm32(propertyIndex));
-    } else {
-        Q_UNREACHABLE();
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinTypeofMember(IR::Expr *base, const QString &name,
-                                                   IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, typeofMember, JITTargetPlatform::EngineRegister,
-                         PointerToValue(base), StringToIndex(name));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index,
-                                                      IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, typeofElement,
-                         JITTargetPlatform::EngineRegister,
-                         PointerToValue(base), PointerToValue(index));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinTypeofName(const QString &name, IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, typeofName, JITTargetPlatform::EngineRegister,
-                         StringToIndex(name));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, typeofValue, JITTargetPlatform::EngineRegister,
-                         PointerToValue(value));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, deleteMember, JITTargetPlatform::EngineRegister,
-                         Reference(base), StringToIndex(name));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index,
-                                                      IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, deleteElement, JITTargetPlatform::EngineRegister,
-                         Reference(base), PointerToValue(index));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDeleteName(const QString &name, IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, deleteName, JITTargetPlatform::EngineRegister,
-                         StringToIndex(name));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDeleteValue(IR::Expr *result)
-{
-    _as->storeValue(JITAssembler::TargetPrimitive::fromBoolean(false), result);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinThrow(IR::Expr *arg)
-{
-    generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, throwException, JITTargetPlatform::EngineRegister,
-                         PointerToValue(arg));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinReThrow()
-{
-    _as->jumpToExceptionHandler();
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinUnwindException(IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, unwindException, JITTargetPlatform::EngineRegister);
-
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinPushCatchScope(const QString &exceptionName)
-{
-    generateRuntimeCall(_as, JITAssembler::Void, pushCatchScope, JITTargetPlatform::EngineRegister, StringToIndex(exceptionName));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result)
-{
-    Q_ASSERT(arg);
-    Q_ASSERT(result);
-
-    generateRuntimeCall(_as, result, foreachIterator, JITTargetPlatform::EngineRegister, PointerToValue(arg));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result)
-{
-    Q_ASSERT(arg);
-    Q_ASSERT(result);
-
-    generateRuntimeCall(_as, result, foreachNextPropertyName, Reference(arg));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinPushWithScope(IR::Expr *arg)
-{
-    Q_ASSERT(arg);
-
-    generateRuntimeCall(_as, JITAssembler::Void, pushWithScope, Reference(arg), JITTargetPlatform::EngineRegister);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinPopScope()
-{
-    generateRuntimeCall(_as, JITAssembler::Void, popScope, JITTargetPlatform::EngineRegister);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDeclareVar(bool deletable, const QString &name)
-{
-    generateRuntimeCall(_as, JITAssembler::Void, declareVar, JITTargetPlatform::EngineRegister,
-                         TrustedImm32(deletable), StringToIndex(name));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args)
-{
-    Q_ASSERT(result);
-
-    int length = prepareVariableArguments(args);
-    generateRuntimeCall(_as, result, arrayLiteral, JITTargetPlatform::EngineRegister,
-                         baseAddressForCallArguments(), TrustedImm32(length));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray)
-{
-    Q_ASSERT(result);
-
-    int argc = 0;
-
-    const int classId = registerJSClass(keyValuePairCount, keyValuePairs);
-
-    IR::ExprList *it = keyValuePairs;
-    for (int i = 0; i < keyValuePairCount; ++i, it = it->next) {
-        it = it->next;
-
-        bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
-
-        if (!isData) {
-            it = it->next;
-            _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
-        }
-    }
-
-    it = arrayEntries;
-    uint arrayValueCount = 0;
-    while (it) {
-        uint index = it->expr->asConst()->value;
-        it = it->next;
-
-        bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        if (!isData) {
-            it = it->next; // getter
-            it = it->next; // setter
-            continue;
-        }
-
-        ++arrayValueCount;
-
-        // Index
-        _as->storeValue(JITAssembler::TargetPrimitive::fromUInt32(index), _as->stackLayout().argumentAddressForCall(argc++), WriteBarrier::NoBarrier);
-
-        // Value
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
-        it = it->next;
-    }
-
-    it = arrayEntries;
-    uint arrayGetterSetterCount = 0;
-    while (it) {
-        uint index = it->expr->asConst()->value;
-        it = it->next;
-
-        bool isData = it->expr->asConst()->value;
-        it = it->next;
-
-        if (isData) {
-            it = it->next; // value
-            continue;
-        }
-
-        ++arrayGetterSetterCount;
-
-        // Index
-        _as->storeValue(JITAssembler::TargetPrimitive::fromUInt32(index), _as->stackLayout().argumentAddressForCall(argc++), WriteBarrier::NoBarrier);
-
-        // Getter
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
-        it = it->next;
-
-        // Setter
-        _as->copyValue(_as->stackLayout().argumentAddressForCall(argc++), it->expr, WriteBarrier::NoBarrier);
-        it = it->next;
-    }
-
-    generateRuntimeCall(_as, result, objectLiteral, JITTargetPlatform::EngineRegister,
-                         baseAddressForCallArguments(), TrustedImm32(classId),
-                         TrustedImm32(arrayValueCount), TrustedImm32(arrayGetterSetterCount | (needSparseArray << 30)));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinSetupArgumentObject(IR::Expr *result)
-{
-    generateRuntimeCall(_as, result, setupArgumentsObject, JITTargetPlatform::EngineRegister);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callBuiltinConvertThisToObject()
-{
-    generateRuntimeCall(_as, JITAssembler::Void, convertThisToObject, JITTargetPlatform::EngineRegister);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
-{
-    Q_ASSERT(value);
-
-    prepareCallData(args, 0);
-    if (value->asConst())
-        generateRuntimeCall(_as, result, callValue, JITTargetPlatform::EngineRegister,
-                             PointerToValue(value),
-                             baseAddressForCallData());
-    else
-        generateRuntimeCall(_as, result, callValue, JITTargetPlatform::EngineRegister,
-                             Reference(value),
-                             baseAddressForCallData());
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadThisObject(IR::Expr *temp)
-{
-    WriteBarrier::Type barrier;
-    Pointer addr = _as->loadAddressForWriting(JITTargetPlatform::ScratchRegister, temp, &barrier);
-    _as->loadPtr(Address(JITTargetPlatform::EngineRegister, JITAssembler::targetStructureOffset(offsetof(QV4::EngineBase, current))), JITTargetPlatform::ReturnValueRegister);
-    _as->loadPtr(Address(JITTargetPlatform::ReturnValueRegister,JITAssembler::targetStructureOffset(Heap::ExecutionContextData::baseOffset + offsetof(Heap::ExecutionContextData, callData))), JITTargetPlatform::ReturnValueRegister);
-    _as->copyValue(addr, Address(JITTargetPlatform::ReturnValueRegister, offsetof(CallData, thisObject)), barrier);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadQmlContext(IR::Expr *temp)
-{
-    generateRuntimeCall(_as, temp, getQmlContext, JITTargetPlatform::EngineRegister);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadQmlImportedScripts(IR::Expr *temp)
-{
-    generateRuntimeCall(_as, temp, getQmlImportedScripts, JITTargetPlatform::EngineRegister);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadQmlSingleton(const QString &name, IR::Expr *temp)
-{
-    generateRuntimeCall(_as, temp, getQmlSingleton, JITTargetPlatform::EngineRegister, StringToIndex(name));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadConst(IR::Const *sourceConst, IR::Expr *target)
-{
-    if (IR::Temp *targetTemp = target->asTemp()) {
-        if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-            if (targetTemp->type == IR::DoubleType) {
-                Q_ASSERT(sourceConst->type == IR::DoubleType);
-                _as->toDoubleRegister(sourceConst, (FPRegisterID) targetTemp->index);
-            } else if (targetTemp->type == IR::SInt32Type) {
-                Q_ASSERT(sourceConst->type == IR::SInt32Type);
-                _as->toInt32Register(sourceConst, (RegisterID) targetTemp->index);
-            } else if (targetTemp->type == IR::UInt32Type) {
-                Q_ASSERT(sourceConst->type == IR::UInt32Type);
-                _as->toUInt32Register(sourceConst, (RegisterID) targetTemp->index);
-            } else if (targetTemp->type == IR::BoolType) {
-                Q_ASSERT(sourceConst->type == IR::BoolType);
-                _as->move(TrustedImm32(convertToValue<Primitive>(sourceConst).int_32()),
-                          (RegisterID) targetTemp->index);
-            } else {
-                Q_UNREACHABLE();
-            }
-            return;
-        }
-    }
-
-    _as->storeValue(convertToValue<typename JITAssembler::TargetPrimitive>(sourceConst), target);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadString(const QString &str, IR::Expr *target)
-{
-    Pointer srcAddr = _as->loadStringAddress(JITTargetPlatform::ReturnValueRegister, str);
-    _as->loadPtr(srcAddr, JITTargetPlatform::ReturnValueRegister);
-    WriteBarrier::Type barrier;
-    Pointer destAddr = _as->loadAddressForWriting(JITTargetPlatform::ScratchRegister, target, &barrier);
-    JITAssembler::RegisterSizeDependentOps::loadManagedPointer(_as, JITTargetPlatform::ReturnValueRegister, destAddr, barrier);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target)
-{
-    int id = registerRegExp(sourceRegexp);
-    generateRuntimeCall(_as, target, regexpLiteral, JITTargetPlatform::EngineRegister, TrustedImm32(id));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::getActivationProperty(const IR::Name *name, IR::Expr *target)
-{
-    if (useFastLookups && name->global) {
-        uint index = registerGlobalGetterLookup(*name->id);
-        generateLookupCall(target, index, offsetof(QV4::Lookup, globalGetter), JITTargetPlatform::EngineRegister, JITAssembler::Void);
-        return;
-    }
-    generateRuntimeCall(_as, target, getActivationProperty, JITTargetPlatform::EngineRegister, StringToIndex(*name->id));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::setActivationProperty(IR::Expr *source, const QString &targetName)
-{
-    // ### should use a lookup call here
-    generateRuntimeCall(_as, JITAssembler::Void, setActivationProperty,
-                         JITTargetPlatform::EngineRegister, StringToIndex(targetName), PointerToValue(source));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::initClosure(IR::Closure *closure, IR::Expr *target)
-{
-    int id = closure->value;
-    generateRuntimeCall(_as, target, closure, JITTargetPlatform::EngineRegister, TrustedImm32(id));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::getProperty(IR::Expr *base, const QString &name, IR::Expr *target)
-{
-    if (useFastLookups) {
-        uint index = registerGetterLookup(name);
-        generateLookupCall(target, index, offsetof(QV4::Lookup, getter), JITTargetPlatform::EngineRegister, PointerToValue(base), JITAssembler::Void);
-    } else {
-        generateRuntimeCall(_as, target, getProperty, JITTargetPlatform::EngineRegister,
-                             PointerToValue(base), StringToIndex(name));
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::getQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject)
-        generateRuntimeCall(_as, target, getQmlScopeObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(index), TrustedImm32(captureRequired));
-    else if (kind == IR::Member::MemberOfQmlContextObject)
-        generateRuntimeCall(_as, target, getQmlContextObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(index), TrustedImm32(captureRequired));
-    else if (kind == IR::Member::MemberOfIdObjectsArray)
-        generateRuntimeCall(_as, target, getQmlIdObject, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(index));
-    else
-        Q_ASSERT(false);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingleton, int attachedPropertiesId, IR::Expr *target)
-{
-    if (attachedPropertiesId != 0)
-        generateRuntimeCall(_as, target, getQmlAttachedProperty, JITTargetPlatform::EngineRegister, TrustedImm32(attachedPropertiesId), TrustedImm32(propertyIndex));
-    else if (isSingleton)
-        generateRuntimeCall(_as, target, getQmlSingletonQObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(propertyIndex),
-                             TrustedImm32(captureRequired));
-    else
-        generateRuntimeCall(_as, target, getQmlQObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(base), TrustedImm32(propertyIndex),
-                             TrustedImm32(captureRequired));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::setProperty(IR::Expr *source, IR::Expr *targetBase,
-                                       const QString &targetName)
-{
-    if (useFastLookups) {
-        uint index = registerSetterLookup(targetName);
-        generateLookupCall(JITAssembler::Void, index, offsetof(QV4::Lookup, setter),
-                           JITTargetPlatform::EngineRegister,
-                           PointerToValue(targetBase),
-                           PointerToValue(source));
-    } else {
-        generateRuntimeCall(_as, JITAssembler::Void, setProperty, JITTargetPlatform::EngineRegister,
-                             PointerToValue(targetBase), StringToIndex(targetName),
-                             PointerToValue(source));
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex)
-{
-    if (kind == IR::Member::MemberOfQmlScopeObject)
-        generateRuntimeCall(_as, JITAssembler::Void, setQmlScopeObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(targetBase),
-                             TrustedImm32(propertyIndex), PointerToValue(source));
-    else if (kind == IR::Member::MemberOfQmlContextObject)
-        generateRuntimeCall(_as, JITAssembler::Void, setQmlContextObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(targetBase),
-                             TrustedImm32(propertyIndex), PointerToValue(source));
-    else
-        Q_ASSERT(false);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex)
-{
-    generateRuntimeCall(_as, JITAssembler::Void, setQmlQObjectProperty, JITTargetPlatform::EngineRegister, PointerToValue(targetBase),
-                         TrustedImm32(propertyIndex), PointerToValue(source));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target)
-{
-    if (0 && useFastLookups) {
-        uint lookup = registerIndexedGetterLookup();
-        generateLookupCall(target, lookup, offsetof(QV4::Lookup, indexedGetter),
-                           JITTargetPlatform::EngineRegister,
-                           PointerToValue(base),
-                           PointerToValue(index));
-        return;
-    }
-
-    generateRuntimeCall(_as, target, getElement, JITTargetPlatform::EngineRegister,
-                         PointerToValue(base), PointerToValue(index));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex)
-{
-    if (0 && useFastLookups) {
-        uint lookup = registerIndexedSetterLookup();
-        generateLookupCall(JITAssembler::Void, lookup, offsetof(QV4::Lookup, indexedSetter),
-                           JITTargetPlatform::EngineRegister,
-                           PointerToValue(targetBase), PointerToValue(targetIndex),
-                           PointerToValue(source));
-        return;
-    }
-    generateRuntimeCall(_as, JITAssembler::Void, setElement, JITTargetPlatform::EngineRegister,
-                         PointerToValue(targetBase), PointerToValue(targetIndex),
-                         PointerToValue(source));
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::copyValue(IR::Expr *source, IR::Expr *target)
-{
-    IR::Temp *sourceTemp = source->asTemp();
-    IR::Temp *targetTemp = target->asTemp();
-
-    if (sourceTemp && targetTemp && *sourceTemp == *targetTemp)
-        return;
-    if (IR::ArgLocal *sal = source->asArgLocal())
-        if (IR::ArgLocal *tal = target->asArgLocal())
-            if (*sal == *tal)
-                return;
-
-    if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-            if (sourceTemp->type == IR::DoubleType)
-                _as->moveDouble((FPRegisterID) sourceTemp->index,
-                                (FPRegisterID) targetTemp->index);
-            else
-                _as->move((RegisterID) sourceTemp->index,
-                          (RegisterID) targetTemp->index);
-            return;
-        } else {
-            switch (sourceTemp->type) {
-            case IR::DoubleType:
-                _as->storeDouble((FPRegisterID) sourceTemp->index, target);
-                break;
-            case IR::SInt32Type:
-                _as->storeInt32((RegisterID) sourceTemp->index, target);
-                break;
-            case IR::UInt32Type:
-                _as->storeUInt32((RegisterID) sourceTemp->index, target);
-                break;
-            case IR::BoolType:
-                _as->storeBool((RegisterID) sourceTemp->index, target);
-                break;
-            default:
-                Q_ASSERT(!"Unreachable");
-                break;
-            }
-            return;
-        }
-    } else if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-        switch (targetTemp->type) {
-        case IR::DoubleType:
-            Q_ASSERT(source->type == IR::DoubleType);
-            _as->toDoubleRegister(source, (FPRegisterID) targetTemp->index);
-            return;
-        case IR::BoolType:
-            Q_ASSERT(source->type == IR::BoolType);
-            _as->toInt32Register(source, (RegisterID) targetTemp->index);
-            return;
-        case IR::SInt32Type:
-            Q_ASSERT(source->type == IR::SInt32Type);
-            _as->toInt32Register(source, (RegisterID) targetTemp->index);
-            return;
-        case IR::UInt32Type:
-            Q_ASSERT(source->type == IR::UInt32Type);
-            _as->toUInt32Register(source, (RegisterID) targetTemp->index);
-            return;
-        default:
-            Q_ASSERT(!"Unreachable");
-            break;
-        }
-    }
-
-    WriteBarrier::Type barrier;
-    Pointer addr = _as->loadAddressForWriting(JITTargetPlatform::ReturnValueRegister, target, &barrier);
-    // The target is not a physical register, nor is the source. So we can do a memory-to-memory copy:
-    _as->memcopyValue(addr, source, JITTargetPlatform::ScratchRegister, barrier);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::swapValues(IR::Expr *source, IR::Expr *target)
-{
-    IR::Temp *sourceTemp = source->asTemp();
-    IR::Temp *targetTemp = target->asTemp();
-
-    if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister) {
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister) {
-            Q_ASSERT(sourceTemp->type == targetTemp->type);
-
-            if (sourceTemp->type == IR::DoubleType) {
-                _as->moveDouble((FPRegisterID) targetTemp->index, JITTargetPlatform::FPGpr0);
-                _as->moveDouble((FPRegisterID) sourceTemp->index,
-                                (FPRegisterID) targetTemp->index);
-                _as->moveDouble(JITTargetPlatform::FPGpr0, (FPRegisterID) sourceTemp->index);
-            } else {
-                _as->swap((RegisterID) sourceTemp->index,
-                          (RegisterID) targetTemp->index);
-            }
-            return;
-        }
-    } else if (!sourceTemp || sourceTemp->kind == IR::Temp::StackSlot) {
-        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            // Note: a swap for two stack-slots can involve different types.
-            WriteBarrier::Type barrierForSource, barrierForTarget;
-            Pointer sAddr = _as->loadAddressForWriting(JITTargetPlatform::ScratchRegister, source, &barrierForSource);
-            Pointer tAddr = _as->loadAddressForWriting(JITTargetPlatform::ReturnValueRegister, target, &barrierForTarget);
-            _as->loadRawValue(sAddr, JITTargetPlatform::FPGpr0);
-            _as->loadRawValue(tAddr, JITTargetPlatform::FPGpr1);
-            _as->storeRawValue(JITTargetPlatform::FPGpr1, sAddr, barrierForSource);
-            _as->storeRawValue(JITTargetPlatform::FPGpr0, tAddr, barrierForTarget);
-            return;
-        }
-    }
-
-    IR::Expr *memExpr = !sourceTemp || sourceTemp->kind == IR::Temp::StackSlot ? source : target;
-    IR::Temp *regTemp = sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister ? sourceTemp
-                                                                                     : targetTemp;
-    Q_ASSERT(memExpr);
-    Q_ASSERT(regTemp);
-
-    WriteBarrier::Type barrier;
-    Pointer addr = _as->loadAddressForWriting(JITTargetPlatform::ReturnValueRegister, memExpr, &barrier);
-    if (regTemp->type == IR::DoubleType) {
-        _as->loadDouble(addr, JITTargetPlatform::FPGpr0);
-        _as->storeDouble((FPRegisterID) regTemp->index, addr, barrier);
-        _as->moveDouble(JITTargetPlatform::FPGpr0, (FPRegisterID) regTemp->index);
-    } else if (regTemp->type == IR::UInt32Type) {
-        _as->toUInt32Register(addr, JITTargetPlatform::ScratchRegister);
-        _as->storeUInt32((RegisterID) regTemp->index, addr, barrier);
-        _as->move(JITTargetPlatform::ScratchRegister, (RegisterID) regTemp->index);
-    } else {
-        _as->load32(addr, JITTargetPlatform::ScratchRegister);
-        _as->store32((RegisterID) regTemp->index, addr);
-        if (regTemp->type != memExpr->type) {
-            addr.offset += 4;
-            quint32 tag;
-            switch (regTemp->type) {
-            case IR::BoolType:
-                tag = quint32(JITAssembler::ValueTypeInternal::Boolean);
-                break;
-            case IR::SInt32Type:
-                tag = quint32(JITAssembler::ValueTypeInternal::Integer);
-                break;
-            default:
-                tag = 31337; // bogus value
-                Q_UNREACHABLE();
-            }
-            _as->store32(TrustedImm32(tag), addr);
-            _as->emitWriteBarrier(addr, barrier);
-        }
-        _as->move(JITTargetPlatform::ScratchRegister, (RegisterID) regTemp->index);
-    }
-}
-
-#define setOp(op, opName, operation) \
-    do { \
-        op = typename JITAssembler::RuntimeCall(QV4::Runtime::operation); opName = "Runtime::" isel_stringIfy(operation); \
-        needsExceptionCheck = QV4::Runtime::Method_##operation##_NeedsExceptionCheck; \
-    } while (0)
-#define setOpContext(op, opName, operation) \
-    do { \
-        opContext = typename JITAssembler::RuntimeCall(QV4::Runtime::operation); opName = "Runtime::" isel_stringIfy(operation); \
-        needsExceptionCheck = QV4::Runtime::Method_##operation##_NeedsExceptionCheck; \
-    } while (0)
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::unop(IR::AluOp oper, IR::Expr *source, IR::Expr *target)
-{
-    QV4::JIT::Unop<JITAssembler> unop(_as, oper);
-    unop.generate(source, target);
-}
-
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target)
-{
-    QV4::JIT::Binop<JITAssembler> binop(_as, oper);
-    binop.generate(leftSource, rightSource, target);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result)
-{
-    prepareCallData(args, base);
-
-    if (kind == IR::Member::MemberOfQmlScopeObject)
-        generateRuntimeCall(_as, result, callQmlScopeObjectProperty,
-                             JITTargetPlatform::EngineRegister,
-                             TrustedImm32(propertyIndex),
-                             baseAddressForCallData());
-    else if (kind == IR::Member::MemberOfQmlContextObject)
-        generateRuntimeCall(_as, result, callQmlContextObjectProperty,
-                             JITTargetPlatform::EngineRegister,
-                             TrustedImm32(propertyIndex),
-                             baseAddressForCallData());
-    else
-        Q_ASSERT(false);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
-                                        IR::Expr *result)
-{
-    Q_ASSERT(base != 0);
-
-    prepareCallData(args, base);
-
-    if (useFastLookups) {
-        uint index = registerGetterLookup(name);
-        generateRuntimeCall(_as, result, callPropertyLookup,
-                             JITTargetPlatform::EngineRegister,
-                             TrustedImm32(index),
-                             baseAddressForCallData());
-    } else {
-        generateRuntimeCall(_as, result, callProperty, JITTargetPlatform::EngineRegister,
-                             StringToIndex(name),
-                             baseAddressForCallData());
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
-                                         IR::Expr *result)
-{
-    Q_ASSERT(base != 0);
-
-    prepareCallData(args, base);
-    generateRuntimeCall(_as, result, callElement, JITTargetPlatform::EngineRegister,
-                         PointerToValue(index),
-                         baseAddressForCallData());
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::convertType(IR::Expr *source, IR::Expr *target)
-{
-    switch (target->type) {
-    case IR::DoubleType:
-        convertTypeToDouble(source, target);
-        break;
-    case IR::BoolType:
-        convertTypeToBool(source, target);
-        break;
-    case IR::SInt32Type:
-        convertTypeToSInt32(source, target);
-        break;
-    case IR::UInt32Type:
-        convertTypeToUInt32(source, target);
-        break;
-    default:
-        convertTypeSlowPath(source, target);
-        break;
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::convertTypeSlowPath(IR::Expr *source, IR::Expr *target)
-{
-    Q_ASSERT(target->type != IR::BoolType);
-
-    if (target->type & IR::NumberType)
-        unop(IR::OpUPlus, source, target);
-    else
-        copyValue(source, target);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::convertTypeToDouble(IR::Expr *source, IR::Expr *target)
-{
-    switch (source->type) {
-    case IR::SInt32Type:
-    case IR::BoolType:
-    case IR::NullType:
-        convertIntToDouble(source, target);
-        break;
-    case IR::UInt32Type:
-        convertUIntToDouble(source, target);
-        break;
-    case IR::UndefinedType:
-        _as->loadDouble(_as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source), JITTargetPlatform::FPGpr0);
-        _as->storeDouble(JITTargetPlatform::FPGpr0, target);
-        break;
-    case IR::StringType:
-    case IR::VarType: {
-        // load the tag:
-        Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
-        tagAddr.offset += 4;
-        _as->load32(tagAddr, JITTargetPlatform::ScratchRegister);
-
-        // check if it's an int32:
-        Jump isNoInt = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
-                                     TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)));
-        convertIntToDouble(source, target);
-        Jump intDone = _as->jump();
-
-        // not an int, check if it's NOT a double:
-        isNoInt.link(_as);
-        Jump isDbl = _as->generateIsDoubleCheck(JITTargetPlatform::ScratchRegister);
-
-        generateRuntimeCall(_as, target, toDouble, PointerToValue(source));
-        Jump noDoubleDone = _as->jump();
-
-        // it is a double:
-        isDbl.link(_as);
-        Pointer addr2 = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
-        IR::Temp *targetTemp = target->asTemp();
-        if (!targetTemp || targetTemp->kind == IR::Temp::StackSlot) {
-            _as->memcopyValue(target, addr2, JITTargetPlatform::FPGpr0, JITTargetPlatform::ReturnValueRegister);
-        } else {
-            _as->loadDouble(addr2, (FPRegisterID) targetTemp->index);
-        }
-
-        noDoubleDone.link(_as);
-        intDone.link(_as);
-    } break;
-    default:
-        convertTypeSlowPath(source, target);
-        break;
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::convertTypeToBool(IR::Expr *source, IR::Expr *target)
-{
-    IR::Temp *sourceTemp = source->asTemp();
-    switch (source->type) {
-    case IR::SInt32Type:
-    case IR::UInt32Type:
-        convertIntToBool(source, target);
-        break;
-    case IR::DoubleType: {
-        // The source is in a register if the register allocator is used. If the register
-        // allocator was not used, then that means that we can use any register for to
-        // load the double into.
-        FPRegisterID reg;
-        if (sourceTemp && sourceTemp->kind == IR::Temp::PhysicalRegister)
-            reg = (FPRegisterID) sourceTemp->index;
-        else
-            reg = _as->toDoubleRegister(source, (FPRegisterID) 1);
-        Jump nonZero = _as->branchDoubleNonZero(reg, JITTargetPlatform::FPGpr0);
-
-        // it's 0, so false:
-        _as->storeBool(false, target);
-        Jump done = _as->jump();
-
-        // it's non-zero, so true:
-        nonZero.link(_as);
-        _as->storeBool(true, target);
-
-        // done:
-        done.link(_as);
-    } break;
-    case IR::UndefinedType:
-    case IR::NullType:
-        _as->storeBool(false, target);
-        break;
-    case IR::StringType:
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toBoolean,
-                            PointerToValue(source));
-        _as->storeBool(JITTargetPlatform::ReturnValueRegister, target);
-        Q_FALLTHROUGH();
-    case IR::VarType:
-    default:
-        Pointer addr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
-        Pointer tagAddr = addr;
-        tagAddr.offset += 4;
-        _as->load32(tagAddr, JITTargetPlatform::ReturnValueRegister);
-
-        // checkif it's a bool:
-        Jump notBool = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ReturnValueRegister,
-                                     TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Boolean)));
-        _as->load32(addr, JITTargetPlatform::ReturnValueRegister);
-        Jump boolDone = _as->jump();
-        // check if it's an int32:
-        notBool.link(_as);
-        Jump fallback = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ReturnValueRegister,
-                                      TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)));
-        _as->load32(addr, JITTargetPlatform::ReturnValueRegister);
-        Jump isZero = _as->branch32(RelationalCondition::Equal, JITTargetPlatform::ReturnValueRegister,
-                                               TrustedImm32(0));
-        _as->move(TrustedImm32(1), JITTargetPlatform::ReturnValueRegister);
-        Jump intDone = _as->jump();
-
-        // not an int:
-        fallback.link(_as);
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toBoolean,
-                            PointerToValue(source));
-
-        isZero.link(_as);
-        intDone.link(_as);
-        boolDone.link(_as);
-        _as->storeBool(JITTargetPlatform::ReturnValueRegister, target);
-
-        break;
-    }
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::convertTypeToSInt32(IR::Expr *source, IR::Expr *target)
-{
-    switch (source->type) {
-    case IR::VarType: {
-        JITAssembler::RegisterSizeDependentOps::convertVarToSInt32(_as, source, target);
-    } break;
-    case IR::DoubleType: {
-        Jump success =
-                _as->branchTruncateDoubleToInt32(_as->toDoubleRegister(source),
-                                                 JITTargetPlatform::ReturnValueRegister,
-                                                 BranchTruncateType::BranchIfTruncateSuccessful);
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, doubleToInt,
-                             PointerToValue(source));
-        success.link(_as);
-        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
-    } break;
-    case IR::UInt32Type:
-        _as->storeInt32(_as->toUInt32Register(source, JITTargetPlatform::ReturnValueRegister), target);
-        break;
-    case IR::NullType:
-    case IR::UndefinedType:
-        _as->move(TrustedImm32(0), JITTargetPlatform::ReturnValueRegister);
-        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
-        break;
-    case IR::BoolType:
-        _as->storeInt32(_as->toInt32Register(source, JITTargetPlatform::ReturnValueRegister), target);
-        break;
-    case IR::StringType:
-    default:
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toInt,
-                             _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source));
-        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
-        break;
-    } // switch (source->type)
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::convertTypeToUInt32(IR::Expr *source, IR::Expr *target)
-{
-    switch (source->type) {
-    case IR::VarType: {
-        // load the tag:
-        Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
-        tagAddr.offset += 4;
-        _as->load32(tagAddr, JITTargetPlatform::ScratchRegister);
-
-        // check if it's an int32:
-        Jump isNoInt = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
-                                     TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)));
-        Pointer addr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source);
-        _as->storeUInt32(_as->toInt32Register(addr, JITTargetPlatform::ScratchRegister), target);
-        Jump intDone = _as->jump();
-
-        // not an int:
-        isNoInt.link(_as);
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toUInt,
-                             _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, source));
-        _as->storeInt32(JITTargetPlatform::ReturnValueRegister, target);
-
-        intDone.link(_as);
-    } break;
-    case IR::DoubleType: {
-        FPRegisterID reg = _as->toDoubleRegister(source);
-        Jump success =
-                _as->branchTruncateDoubleToUint32(reg, JITTargetPlatform::ReturnValueRegister,
-                                                  BranchTruncateType::BranchIfTruncateSuccessful);
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, doubleToUInt,
-                             PointerToValue(source));
-        success.link(_as);
-        _as->storeUInt32(JITTargetPlatform::ReturnValueRegister, target);
-    } break;
-    case IR::NullType:
-    case IR::UndefinedType:
-        _as->move(TrustedImm32(0), JITTargetPlatform::ReturnValueRegister);
-        _as->storeUInt32(JITTargetPlatform::ReturnValueRegister, target);
-        break;
-    case IR::StringType:
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toUInt,
-                             PointerToValue(source));
-        _as->storeUInt32(JITTargetPlatform::ReturnValueRegister, target);
-        break;
-    case IR::SInt32Type:
-    case IR::BoolType:
-        _as->storeUInt32(_as->toInt32Register(source, JITTargetPlatform::ReturnValueRegister), target);
-        break;
-    default:
-        break;
-    } // switch (source->type)
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result)
-{
-    Q_ASSERT(func != 0);
-    prepareCallData(args, 0);
-
-    if (useFastLookups && func->global) {
-        uint index = registerGlobalGetterLookup(*func->id);
-        generateRuntimeCall(_as, result, constructGlobalLookup,
-                             JITTargetPlatform::EngineRegister,
-                             TrustedImm32(index), baseAddressForCallData());
-        return;
-    }
-
-    generateRuntimeCall(_as, result, constructActivationProperty,
-                         JITTargetPlatform::EngineRegister,
-                         StringToIndex(*func->id),
-                         baseAddressForCallData());
-}
-
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result)
-{
-    prepareCallData(args, base);
-    if (useFastLookups) {
-        uint index = registerGetterLookup(name);
-        generateRuntimeCall(_as, result, constructPropertyLookup,
-                             JITTargetPlatform::EngineRegister,
-                             TrustedImm32(index),
-                             baseAddressForCallData());
-        return;
-    }
-
-    generateRuntimeCall(_as, result, constructProperty, JITTargetPlatform::EngineRegister,
-                         StringToIndex(name),
-                         baseAddressForCallData());
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result)
-{
-    Q_ASSERT(value != 0);
-
-    prepareCallData(args, 0);
-    generateRuntimeCall(_as, result, constructValue,
-                         JITTargetPlatform::EngineRegister,
-                         Reference(value),
-                         baseAddressForCallData());
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::visitJump(IR::Jump *s)
-{
-    if (!_removableJumps.at(_block->index()))
-        _as->jumpToBlock(_block, s->target);
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::visitCJump(IR::CJump *s)
-{
-    IR::Temp *t = s->cond->asTemp();
-    if (t || s->cond->asArgLocal()) {
-        RegisterID reg;
-        if (t && t->kind == IR::Temp::PhysicalRegister) {
-            Q_ASSERT(t->type == IR::BoolType);
-            reg = (RegisterID) t->index;
-        } else if (t && t->kind == IR::Temp::StackSlot && t->type == IR::BoolType) {
-            reg = JITTargetPlatform::ReturnValueRegister;
-            _as->toInt32Register(t, reg);
-        } else {
-            Address temp = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, s->cond);
-            Address tag = temp;
-            tag.offset += QV4::Value::tagOffset();
-            Jump booleanConversion = _as->branch32(RelationalCondition::NotEqual, tag,
-                                                   TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Boolean)));
-
-            Address data = temp;
-            data.offset += QV4::Value::valueOffset();
-            _as->load32(data, JITTargetPlatform::ReturnValueRegister);
-            Jump testBoolean = _as->jump();
-
-            booleanConversion.link(_as);
-            reg = JITTargetPlatform::ReturnValueRegister;
-            generateRuntimeCall(_as, reg, toBoolean, Reference(s->cond));
-
-            testBoolean.link(_as);
-        }
-
-        _as->generateCJumpOnNonZero(reg, _block, s->iftrue, s->iffalse);
-        return;
-    } else if (IR::Const *c = s->cond->asConst()) {
-        // TODO: SSA optimization for constant condition evaluation should remove this.
-        // See also visitCJump() in RegAllocInfo.
-        generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, toBoolean,
-                             PointerToValue(c));
-        _as->generateCJumpOnNonZero(JITTargetPlatform::ReturnValueRegister, _block, s->iftrue, s->iffalse);
-        return;
-    } else if (IR::Binop *b = s->cond->asBinop()) {
-        if (b->left->type == IR::DoubleType && b->right->type == IR::DoubleType
-                && visitCJumpDouble(b->op, b->left, b->right, s->iftrue, s->iffalse))
-            return;
-
-        if (b->left->type == IR::SInt32Type && b->right->type == IR::SInt32Type
-                && visitCJumpSInt32(b->op, b->left, b->right, s->iftrue, s->iffalse))
-            return;
-
-        if (b->op == IR::OpStrictEqual || b->op == IR::OpStrictNotEqual) {
-            visitCJumpStrict(b, s->iftrue, s->iffalse);
-            return;
-        }
-        if (b->op == IR::OpEqual || b->op == IR::OpNotEqual) {
-            visitCJumpEqual(b, s->iftrue, s->iffalse);
-            return;
-        }
-
-        typename JITAssembler::RuntimeCall op;
-        typename JITAssembler::RuntimeCall opContext;
-        const char *opName = 0;
-        bool needsExceptionCheck;
-        switch (b->op) {
-        default: Q_UNREACHABLE(); Q_ASSERT(!"todo"); break;
-        case IR::OpGt: setOp(op, opName, compareGreaterThan); break;
-        case IR::OpLt: setOp(op, opName, compareLessThan); break;
-        case IR::OpGe: setOp(op, opName, compareGreaterEqual); break;
-        case IR::OpLe: setOp(op, opName, compareLessEqual); break;
-        case IR::OpEqual: setOp(op, opName, compareEqual); break;
-        case IR::OpNotEqual: setOp(op, opName, compareNotEqual); break;
-        case IR::OpStrictEqual: setOp(op, opName, compareStrictEqual); break;
-        case IR::OpStrictNotEqual: setOp(op, opName, compareStrictNotEqual); break;
-        case IR::OpInstanceof: setOpContext(op, opName, compareInstanceof); break;
-        case IR::OpIn: setOpContext(op, opName, compareIn); break;
-        } // switch
-
-        // TODO: in SSA optimization, do constant expression evaluation.
-        // The case here is, for example:
-        //   if (true === true) .....
-        // Of course, after folding the CJUMP to a JUMP, dead-code (dead-basic-block)
-        // elimination (which isn't there either) would remove the whole else block.
-        if (opContext.isValid())
-            _as->generateFunctionCallImp(needsExceptionCheck,
-                                         JITTargetPlatform::ReturnValueRegister, opName, opContext,
-                                         JITTargetPlatform::EngineRegister,
-                                         PointerToValue(b->left),
-                                         PointerToValue(b->right));
-        else
-            _as->generateFunctionCallImp(needsExceptionCheck,
-                                         JITTargetPlatform::ReturnValueRegister, opName, op,
-                                         PointerToValue(b->left),
-                                         PointerToValue(b->right));
-
-        _as->generateCJumpOnNonZero(JITTargetPlatform::ReturnValueRegister, _block, s->iftrue, s->iffalse);
-        return;
-    }
-    Q_UNREACHABLE();
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::visitRet(IR::Ret *s)
-{
-    _as->returnFromFunction(s, regularRegistersToSave, fpRegistersToSave);
-}
-
-template <typename JITAssembler>
-int InstructionSelection<JITAssembler>::prepareVariableArguments(IR::ExprList* args)
-{
-    int argc = 0;
-    for (IR::ExprList *it = args; it; it = it->next) {
-        ++argc;
-    }
-
-    int i = 0;
-    for (IR::ExprList *it = args; it; it = it->next, ++i) {
-        IR::Expr *arg = it->expr;
-        Q_ASSERT(arg != 0);
-        Pointer dst(_as->stackLayout().argumentAddressForCall(i));
-        if (arg->asTemp() && arg->asTemp()->kind != IR::Temp::PhysicalRegister)
-            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister, WriteBarrier::NoBarrier);
-        else
-            _as->copyValue(dst, arg, WriteBarrier::NoBarrier);
-    }
-
-    return argc;
-}
-
-template <typename JITAssembler>
-int InstructionSelection<JITAssembler>::prepareCallData(IR::ExprList* args, IR::Expr *thisObject)
-{
-    int argc = 0;
-    for (IR::ExprList *it = args; it; it = it->next) {
-        ++argc;
-    }
-
-    Pointer p = _as->stackLayout().callDataAddress(offsetof(CallData, tag));
-    _as->store32(TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Integer)), p);
-    p = _as->stackLayout().callDataAddress(offsetof(CallData, argc));
-    _as->store32(TrustedImm32(argc), p);
-    p = _as->stackLayout().callDataAddress(offsetof(CallData, thisObject));
-    if (!thisObject)
-        _as->storeValue(JITAssembler::TargetPrimitive::undefinedValue(), p, WriteBarrier::NoBarrier);
-    else
-        _as->copyValue(p, thisObject, WriteBarrier::NoBarrier);
-
-    int i = 0;
-    for (IR::ExprList *it = args; it; it = it->next, ++i) {
-        IR::Expr *arg = it->expr;
-        Q_ASSERT(arg != 0);
-        Pointer dst(_as->stackLayout().argumentAddressForCall(i));
-        if (arg->asTemp() && arg->asTemp()->kind != IR::Temp::PhysicalRegister)
-            _as->memcopyValue(dst, arg->asTemp(), JITTargetPlatform::ScratchRegister, WriteBarrier::NoBarrier);
-        else
-            _as->copyValue(dst, arg, WriteBarrier::NoBarrier);
-    }
-    return argc;
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::calculateRegistersToSave(const RegisterInformation &used)
-{
-    regularRegistersToSave.clear();
-    fpRegistersToSave.clear();
-
-    for (const RegisterInfo &ri : JITTargetPlatform::getRegisterInfo()) {
-        if (JITTargetPlatform::gotRegister != -1 && ri.isRegularRegister() && ri.reg<RegisterID>() == JITTargetPlatform::gotRegister) {
-            regularRegistersToSave.append(ri);
-            continue;
-        }
-        if (ri.isCallerSaved())
-            continue;
-        if (ri.isRegularRegister()) {
-            if (ri.isPredefined() || used.contains(ri))
-                regularRegistersToSave.append(ri);
-        } else {
-            Q_ASSERT(ri.isFloatingPoint());
-            if (ri.isPredefined() || used.contains(ri))
-                fpRegistersToSave.append(ri);
-        }
-    }
-}
-
-QT_BEGIN_NAMESPACE
-namespace QV4 {
-bool operator==(const Primitive &v1, const Primitive &v2)
-{
-    return v1.rawValue() == v2.rawValue();
-}
-} // QV4 namespace
-QT_END_NAMESPACE
-
-template <typename JITAssembler>
-bool InstructionSelection<JITAssembler>::visitCJumpDouble(IR::AluOp op, IR::Expr *left, IR::Expr *right,
-                                            IR::BasicBlock *iftrue, IR::BasicBlock *iffalse)
-{
-    if (_as->nextBlock() == iftrue) {
-        Jump target = _as->branchDouble(true, op, left, right);
-        _as->addPatch(iffalse, target);
-    } else {
-        Jump target = _as->branchDouble(false, op, left, right);
-        _as->addPatch(iftrue, target);
-        _as->jumpToBlock(_block, iffalse);
-    }
-    return true;
-}
-
-template <typename JITAssembler>
-bool InstructionSelection<JITAssembler>::visitCJumpSInt32(IR::AluOp op, IR::Expr *left, IR::Expr *right,
-                                            IR::BasicBlock *iftrue, IR::BasicBlock *iffalse)
-{
-    if (_as->nextBlock() == iftrue) {
-        Jump target = _as->branchInt32(true, op, left, right);
-        _as->addPatch(iffalse, target);
-    } else {
-        Jump target = _as->branchInt32(false, op, left, right);
-        _as->addPatch(iftrue, target);
-        _as->jumpToBlock(_block, iffalse);
-    }
-    return true;
-}
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::visitCJumpStrict(IR::Binop *binop, IR::BasicBlock *trueBlock,
-                                            IR::BasicBlock *falseBlock)
-{
-    Q_ASSERT(binop->op == IR::OpStrictEqual || binop->op == IR::OpStrictNotEqual);
-
-    if (visitCJumpStrictNull(binop, trueBlock, falseBlock))
-        return;
-    if (visitCJumpStrictUndefined(binop, trueBlock, falseBlock))
-        return;
-    if (visitCJumpStrictBool(binop, trueBlock, falseBlock))
-        return;
-
-    IR::Expr *left = binop->left;
-    IR::Expr *right = binop->right;
-
-    generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, compareStrictEqual,
-                                 PointerToValue(left), PointerToValue(right));
-    _as->generateCJumpOnCompare(binop->op == IR::OpStrictEqual ? RelationalCondition::NotEqual : RelationalCondition::Equal,
-                                JITTargetPlatform::ReturnValueRegister, TrustedImm32(0),
-                                _block, trueBlock, falseBlock);
-}
-
-// Only load the non-null temp.
-template <typename JITAssembler>
-bool InstructionSelection<JITAssembler>::visitCJumpStrictNull(IR::Binop *binop,
-                                                IR::BasicBlock *trueBlock,
-                                                IR::BasicBlock *falseBlock)
-{
-    IR::Expr *varSrc = 0;
-    if (binop->left->type == IR::VarType && binop->right->type == IR::NullType)
-        varSrc = binop->left;
-    else if (binop->left->type == IR::NullType && binop->right->type == IR::VarType)
-        varSrc = binop->right;
-    if (!varSrc)
-        return false;
-
-    if (varSrc->asTemp() && varSrc->asTemp()->kind == IR::Temp::PhysicalRegister) {
-        _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    if (IR::Const *c = varSrc->asConst()) {
-        if (c->type == IR::NullType)
-            _as->jumpToBlock(_block, trueBlock);
-        else
-            _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, varSrc);
-    tagAddr.offset += 4;
-    const RegisterID tagReg = JITTargetPlatform::ScratchRegister;
-    _as->load32(tagAddr, tagReg);
-
-    RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
-                                                                         : RelationalCondition::NotEqual;
-    const TrustedImm32 tag{quint32(JITAssembler::ValueTypeInternal::Null)};
-    _as->generateCJumpOnCompare(cond, tagReg, tag, _block, trueBlock, falseBlock);
-    return true;
-}
-
-template <typename JITAssembler>
-bool InstructionSelection<JITAssembler>::visitCJumpStrictUndefined(IR::Binop *binop,
-                                                     IR::BasicBlock *trueBlock,
-                                                     IR::BasicBlock *falseBlock)
-{
-    IR::Expr *varSrc = 0;
-    if (binop->left->type == IR::VarType && binop->right->type == IR::UndefinedType)
-        varSrc = binop->left;
-    else if (binop->left->type == IR::UndefinedType && binop->right->type == IR::VarType)
-        varSrc = binop->right;
-    if (!varSrc)
-        return false;
-
-    if (varSrc->asTemp() && varSrc->asTemp()->kind == IR::Temp::PhysicalRegister) {
-        _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    if (IR::Const *c = varSrc->asConst()) {
-        if (c->type == IR::UndefinedType)
-            _as->jumpToBlock(_block, trueBlock);
-        else
-            _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
-                                                                         : RelationalCondition::NotEqual;
-    const RegisterID tagReg = JITTargetPlatform::ReturnValueRegister;
-    _as->generateCJumpOnUndefined(cond, varSrc, JITTargetPlatform::ScratchRegister, tagReg, _block, trueBlock, falseBlock);
-    return true;
-}
-
-template <typename JITAssembler>
-bool InstructionSelection<JITAssembler>::visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock *trueBlock,
-                                                IR::BasicBlock *falseBlock)
-{
-    IR::Expr *boolSrc = 0, *otherSrc = 0;
-    if (binop->left->type == IR::BoolType) {
-        boolSrc = binop->left;
-        otherSrc = binop->right;
-    } else if (binop->right->type == IR::BoolType) {
-        boolSrc = binop->right;
-        otherSrc = binop->left;
-    } else {
-        // neither operands are statically typed as bool, so bail out.
-        return false;
-    }
-    if (otherSrc->type == IR::UnknownType) {
-        // Ok, we really need to call into the runtime.
-        // (This case doesn't happen when the optimizer ran, because everything will be typed (yes,
-        // possibly as "var" meaning anything), but it does happen for $0===true, which is generated
-        // for things where the optimizer didn't run (like functions with a try block).)
-        return false;
-    }
-
-    RelationalCondition cond = binop->op == IR::OpStrictEqual ? RelationalCondition::Equal
-                                                              : RelationalCondition::NotEqual;
-
-    if (otherSrc->type == IR::BoolType) { // both are boolean
-        RegisterID one = _as->toBoolRegister(boolSrc, JITTargetPlatform::ReturnValueRegister);
-        RegisterID two = _as->toBoolRegister(otherSrc, JITTargetPlatform::ScratchRegister);
-        _as->generateCJumpOnCompare(cond, one, two, _block, trueBlock, falseBlock);
-        return true;
-    }
-
-    if (otherSrc->type != IR::VarType) {
-        _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    Pointer otherAddr = _as->loadAddressForReading(JITTargetPlatform::ReturnValueRegister, otherSrc);
-    otherAddr.offset += 4; // tag address
-
-    // check if the tag of the var operand is indicates 'boolean'
-    _as->load32(otherAddr, JITTargetPlatform::ScratchRegister);
-    Jump noBool = _as->branch32(RelationalCondition::NotEqual, JITTargetPlatform::ScratchRegister,
-                                TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Boolean)));
-    if (binop->op == IR::OpStrictEqual)
-        _as->addPatch(falseBlock, noBool);
-    else
-        _as->addPatch(trueBlock, noBool);
-
-    // ok, both are boolean, so let's load them and compare them.
-    otherAddr.offset -= 4; // int_32 address
-    _as->load32(otherAddr, JITTargetPlatform::ReturnValueRegister);
-    RegisterID boolReg = _as->toBoolRegister(boolSrc, JITTargetPlatform::ScratchRegister);
-    _as->generateCJumpOnCompare(cond, boolReg, JITTargetPlatform::ReturnValueRegister, _block, trueBlock,
-                                falseBlock);
-    return true;
-}
-
-template <typename JITAssembler>
-bool InstructionSelection<JITAssembler>::visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Binop *binop,
-                                                         IR::BasicBlock *trueBlock,
-                                                         IR::BasicBlock *falseBlock)
-{
-    Q_ASSERT(nullOrUndef == IR::NullType || nullOrUndef == IR::UndefinedType);
-
-    IR::Expr *varSrc = 0;
-    if (binop->left->type == IR::VarType && binop->right->type == nullOrUndef)
-        varSrc = binop->left;
-    else if (binop->left->type == nullOrUndef && binop->right->type == IR::VarType)
-        varSrc = binop->right;
-    if (!varSrc)
-        return false;
-
-    if (varSrc->asTemp() && varSrc->asTemp()->kind == IR::Temp::PhysicalRegister) {
-        _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    if (IR::Const *c = varSrc->asConst()) {
-        if (c->type == nullOrUndef)
-            _as->jumpToBlock(_block, trueBlock);
-        else
-            _as->jumpToBlock(_block, falseBlock);
-        return true;
-    }
-
-    Pointer tagAddr = _as->loadAddressForReading(JITTargetPlatform::ScratchRegister, varSrc);
-    tagAddr.offset += 4;
-    const RegisterID tagReg = JITTargetPlatform::ReturnValueRegister;
-    _as->load32(tagAddr, tagReg);
-
-    if (binop->op == IR::OpNotEqual)
-        qSwap(trueBlock, falseBlock);
-    Jump isNull = _as->branch32(RelationalCondition::Equal, tagReg, TrustedImm32(quint32(JITAssembler::ValueTypeInternal::Null)));
-    Jump isNotUndefinedTag = _as->branch32(RelationalCondition::NotEqual, tagReg, TrustedImm32(int(QV4::Value::Managed_Type_Internal)));
-    tagAddr.offset -= 4;
-    _as->load32(tagAddr, tagReg);
-    Jump isNotUndefinedValue = _as->branch32(RelationalCondition::NotEqual, tagReg, TrustedImm32(0));
-    _as->addPatch(trueBlock, isNull);
-    _as->addPatch(falseBlock, isNotUndefinedTag);
-    _as->addPatch(falseBlock, isNotUndefinedValue);
-    _as->jumpToBlock(_block, trueBlock);
-
-    return true;
-}
-
-
-template <typename JITAssembler>
-void InstructionSelection<JITAssembler>::visitCJumpEqual(IR::Binop *binop, IR::BasicBlock *trueBlock,
-                                            IR::BasicBlock *falseBlock)
-{
-    Q_ASSERT(binop->op == IR::OpEqual || binop->op == IR::OpNotEqual);
-
-    if (visitCJumpNullUndefined(IR::NullType, binop, trueBlock, falseBlock))
-        return;
-
-    IR::Expr *left = binop->left;
-    IR::Expr *right = binop->right;
-
-    generateRuntimeCall(_as, JITTargetPlatform::ReturnValueRegister, compareEqual,
-                                 PointerToValue(left), PointerToValue(right));
-    _as->generateCJumpOnCompare(binop->op == IR::OpEqual ? RelationalCondition::NotEqual : RelationalCondition::Equal,
-                                JITTargetPlatform::ReturnValueRegister, TrustedImm32(0),
-                                _block, trueBlock, falseBlock);
-}
-
-template <typename JITAssembler>
-QQmlRefPointer<CompiledData::CompilationUnit> ISelFactory<JITAssembler>::createUnitForLoading()
-{
-    QQmlRefPointer<CompiledData::CompilationUnit> result;
-    result.adopt(new JIT::CompilationUnit);
-    return result;
-}
-
-#endif // ENABLE(ASSEMBLER)
-
-QT_BEGIN_NAMESPACE
-namespace QV4 { namespace JIT {
-#if ENABLE(ASSEMBLER)
-template class Q_QML_EXPORT InstructionSelection<>;
-template class Q_QML_EXPORT ISelFactory<>;
-#endif
-
-#if defined(V4_BOOTSTRAP)
-
-Q_QML_EXPORT QV4::EvalISelFactory *createISelForArchitecture(const QString &architecture)
-{
-#if ENABLE(ASSEMBLER)
-    using ARMv7CrossAssembler = QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>;
-    using ARM64CrossAssembler = QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>>;
-
-    if (architecture == QLatin1String("arm"))
-        return new ISelFactory<ARMv7CrossAssembler>;
-    else if (architecture == QLatin1String("arm64"))
-        return new ISelFactory<ARM64CrossAssembler>;
-
-    QString hostArch;
-#if CPU(ARM_THUMB2)
-    hostArch = QStringLiteral("arm");
-#elif CPU(MIPS)
-    hostArch = QStringLiteral("mips");
-#elif CPU(X86)
-    hostArch = QStringLiteral("i386");
-#elif CPU(X86_64)
-    hostArch = QStringLiteral("x86_64");
-#endif
-    if (!hostArch.isEmpty() && architecture == hostArch)
-        return new ISelFactory<>;
-#endif // ENABLE(ASSEMBLER)
-
-    return nullptr;
-}
-
-#endif
-} }
-QT_END_NAMESPACE
-
diff --git a/src/qml/jit/qv4isel_masm_p.h b/src/qml/jit/qv4isel_masm_p.h
deleted file mode 100644
index 7019a117a2..0000000000
--- a/src/qml/jit/qv4isel_masm_p.h
+++ /dev/null
@@ -1,319 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#ifndef QV4ISEL_MASM_P_H
-#define QV4ISEL_MASM_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "private/qv4global_p.h"
-#include "private/qv4jsir_p.h"
-#include "private/qv4isel_p.h"
-#include "private/qv4isel_util_p.h"
-#include "private/qv4util_p.h"
-#include "private/qv4value_p.h"
-#include "private/qv4lookup_p.h"
-
-#include <QtCore/QHash>
-#include <QtCore/QStack>
-#include <config.h>
-#include <wtf/Vector.h>
-
-#include "qv4assembler_p.h"
-
-#if ENABLE(ASSEMBLER)
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace JIT {
-
-template <typename JITAssembler = Assembler<DefaultAssemblerTargetConfiguration>>
-class Q_QML_EXPORT InstructionSelection:
-        protected IR::IRDecoder,
-        public EvalInstructionSelection
-{
-public:
-    InstructionSelection(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator, EvalISelFactory *iselFactory);
-    ~InstructionSelection();
-
-    void run(int functionIndex) override;
-
-protected:
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> backendCompileStep() override;
-
-    void callBuiltinInvalid(IR::Name *func, IR::ExprList *args, IR::Expr *result) override;
-    void callBuiltinTypeofQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::Expr *result) override;
-    void callBuiltinTypeofMember(IR::Expr *base, const QString &name, IR::Expr *result) override;
-    void callBuiltinTypeofSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result) override;
-    void callBuiltinTypeofName(const QString &name, IR::Expr *result) override;
-    void callBuiltinTypeofValue(IR::Expr *value, IR::Expr *result) override;
-    void callBuiltinDeleteMember(IR::Expr *base, const QString &name, IR::Expr *result) override;
-    void callBuiltinDeleteSubscript(IR::Expr *base, IR::Expr *index, IR::Expr *result) override;
-    void callBuiltinDeleteName(const QString &name, IR::Expr *result) override;
-    void callBuiltinDeleteValue(IR::Expr *result) override;
-    void callBuiltinThrow(IR::Expr *arg) override;
-    void callBuiltinReThrow() override;
-    void callBuiltinUnwindException(IR::Expr *) override;
-    void callBuiltinPushCatchScope(const QString &exceptionName) override;
-    void callBuiltinForeachIteratorObject(IR::Expr *arg, IR::Expr *result) override;
-    void callBuiltinForeachNextPropertyname(IR::Expr *arg, IR::Expr *result) override;
-    void callBuiltinPushWithScope(IR::Expr *arg) override;
-    void callBuiltinPopScope() override;
-    void callBuiltinDeclareVar(bool deletable, const QString &name) override;
-    void callBuiltinDefineArray(IR::Expr *result, IR::ExprList *args) override;
-    void callBuiltinDefineObjectLiteral(IR::Expr *result, int keyValuePairCount, IR::ExprList *keyValuePairs, IR::ExprList *arrayEntries, bool needSparseArray) override;
-    void callBuiltinSetupArgumentObject(IR::Expr *result) override;
-    void callBuiltinConvertThisToObject() override;
-    void callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) override;
-    void callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind kind, int propertyIndex, IR::ExprList *args, IR::Expr *result) override;
-    void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr *result) override;
-    void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args, IR::Expr *result) override;
-    void convertType(IR::Expr *source, IR::Expr *target) override;
-    void loadThisObject(IR::Expr *temp) override;
-    void loadQmlContext(IR::Expr *target) override;
-    void loadQmlImportedScripts(IR::Expr *target) override;
-    void loadQmlSingleton(const QString &name, IR::Expr *target) override;
-    void loadConst(IR::Const *sourceConst, IR::Expr *target) override;
-    void loadString(const QString &str, IR::Expr *target) override;
-    void loadRegexp(IR::RegExp *sourceRegexp, IR::Expr *target) override;
-    void getActivationProperty(const IR::Name *name, IR::Expr *target) override;
-    void setActivationProperty(IR::Expr *source, const QString &targetName) override;
-    void initClosure(IR::Closure *closure, IR::Expr *target) override;
-    void getProperty(IR::Expr *base, const QString &name, IR::Expr *target) override;
-    void getQmlContextProperty(IR::Expr *source, IR::Member::MemberKind kind, int index, bool captureRequired, IR::Expr *target) override;
-    void getQObjectProperty(IR::Expr *base, int propertyIndex, bool captureRequired, bool isSingleton, int attachedPropertiesId, IR::Expr *target) override;
-    void setProperty(IR::Expr *source, IR::Expr *targetBase, const QString &targetName) override;
-    void setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase, IR::Member::MemberKind kind, int propertyIndex) override;
-    void setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int propertyIndex) override;
-    void getElement(IR::Expr *base, IR::Expr *index, IR::Expr *target) override;
-    void setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex) override;
-    void copyValue(IR::Expr *source, IR::Expr *target) override;
-    void swapValues(IR::Expr *source, IR::Expr *target) override;
-    void unop(IR::AluOp oper, IR::Expr *sourceTemp, IR::Expr *target) override;
-    void binop(IR::AluOp oper, IR::Expr *leftSource, IR::Expr *rightSource, IR::Expr *target) override;
-
-    using Address = typename JITAssembler::Address;
-    using Pointer = typename JITAssembler::Pointer;
-    using PointerToValue = typename JITAssembler::PointerToValue;
-    using RegisterID = typename JITAssembler::RegisterID;
-    using FPRegisterID = typename JITAssembler::FPRegisterID;
-    using ResultCondition = typename JITAssembler::ResultCondition;
-    using TrustedImm32 = typename JITAssembler::TrustedImm32;
-    using TrustedImm64 = typename JITAssembler::TrustedImm64;
-    using Label = typename JITAssembler::Label;
-    using Jump = typename JITAssembler::Jump;
-    using StringToIndex = typename JITAssembler::StringToIndex;
-    using Reference = typename JITAssembler::Reference;
-    using RelationalCondition = typename JITAssembler::RelationalCondition;
-    using BranchTruncateType = typename JITAssembler::BranchTruncateType;
-    using RuntimeCall = typename JITAssembler::RuntimeCall;
-
-    using JITTargetPlatform = typename JITAssembler::JITTargetPlatform;
-
-    Address addressForArgument(int index) const
-    {
-        // FramePointerRegister points to its old value on the stack, and above
-        // it we have the return address, hence the need to step over two
-        // values before reaching the first argument.
-        return Address(JITTargetPlatform::FramePointerRegister, (index + 2) * JITTargetPlatform::RegisterSize);
-    }
-
-    Pointer baseAddressForCallArguments()
-    {
-        return _as->stackLayout().argumentAddressForCall(0);
-    }
-
-    Pointer baseAddressForCallData()
-    {
-        return _as->stackLayout().callDataAddress();
-    }
-
-    void constructActivationProperty(IR::Name *func, IR::ExprList *args, IR::Expr *result) override;
-    void constructProperty(IR::Expr *base, const QString &name, IR::ExprList *args, IR::Expr*result) override;
-    void constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) override;
-
-    void visitJump(IR::Jump *) override;
-    void visitCJump(IR::CJump *) override;
-    void visitRet(IR::Ret *) override;
-
-    bool visitCJumpDouble(IR::AluOp op, IR::Expr *left, IR::Expr *right,
-                          IR::BasicBlock *iftrue, IR::BasicBlock *iffalse);
-    bool visitCJumpSInt32(IR::AluOp op, IR::Expr *left, IR::Expr *right,
-                          IR::BasicBlock *iftrue, IR::BasicBlock *iffalse);
-    void visitCJumpStrict(IR::Binop *binop, IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-    bool visitCJumpStrictNull(IR::Binop *binop, IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-    bool visitCJumpStrictUndefined(IR::Binop *binop, IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-    bool visitCJumpStrictBool(IR::Binop *binop, IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-    bool visitCJumpNullUndefined(IR::Type nullOrUndef, IR::Binop *binop,
-                                 IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-    void visitCJumpEqual(IR::Binop *binop, IR::BasicBlock *trueBlock, IR::BasicBlock *falseBlock);
-
-private:
-    void convertTypeSlowPath(IR::Expr *source, IR::Expr *target);
-    void convertTypeToDouble(IR::Expr *source, IR::Expr *target);
-    void convertTypeToBool(IR::Expr *source, IR::Expr *target);
-    void convertTypeToSInt32(IR::Expr *source, IR::Expr *target);
-    void convertTypeToUInt32(IR::Expr *source, IR::Expr *target);
-
-    void convertIntToDouble(IR::Expr *source, IR::Expr *target)
-    {
-        if (IR::Temp *targetTemp = target->asTemp()) {
-            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-                if (IR::Temp *sourceTemp = source->asTemp()) {
-                    if (sourceTemp->kind == IR::Temp::PhysicalRegister) {
-                        _as->convertInt32ToDouble((RegisterID) sourceTemp->index,
-                                                  (FPRegisterID) targetTemp->index);
-                    } else {
-                        _as->convertInt32ToDouble(_as->loadAddressForReading(JITTargetPlatform::ReturnValueRegister, sourceTemp),
-                                                  (FPRegisterID) targetTemp->index);
-                    }
-                } else {
-                    _as->convertInt32ToDouble(_as->toInt32Register(source, JITTargetPlatform::ScratchRegister),
-                                              (FPRegisterID) targetTemp->index);
-                }
-
-                return;
-            }
-        }
-
-        _as->convertInt32ToDouble(_as->toInt32Register(source, JITTargetPlatform::ScratchRegister),
-                                  JITTargetPlatform::FPGpr0);
-        _as->storeDouble(JITTargetPlatform::FPGpr0, target);
-    }
-
-    void convertUIntToDouble(IR::Expr *source, IR::Expr *target)
-    {
-        RegisterID tmpReg = JITTargetPlatform::ScratchRegister;
-        RegisterID reg = _as->toInt32Register(source, tmpReg);
-
-        if (IR::Temp *targetTemp = target->asTemp()) {
-            if (targetTemp->kind == IR::Temp::PhysicalRegister) {
-                _as->convertUInt32ToDouble(reg, (FPRegisterID) targetTemp->index, tmpReg);
-                return;
-            }
-        }
-
-        _as->convertUInt32ToDouble(_as->toUInt32Register(source, tmpReg),
-                                   JITTargetPlatform::FPGpr0, tmpReg);
-        _as->storeDouble(JITTargetPlatform::FPGpr0, target);
-    }
-
-    void convertIntToBool(IR::Expr *source, IR::Expr *target)
-    {
-        RegisterID reg = JITTargetPlatform::ScratchRegister;
-
-        if (IR::Temp *targetTemp = target->asTemp())
-            if (targetTemp->kind == IR::Temp::PhysicalRegister)
-                reg = (RegisterID) targetTemp->index;
-        _as->move(_as->toInt32Register(source, reg), reg);
-        _as->compare32(RelationalCondition::NotEqual, reg, TrustedImm32(0), reg);
-        _as->storeBool(reg, target);
-    }
-
-    int prepareVariableArguments(IR::ExprList* args);
-    int prepareCallData(IR::ExprList* args, IR::Expr *thisObject);
-
-    void calculateRegistersToSave(const RegisterInformation &used);
-
-    template <typename Retval, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
-    void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4)
-    {
-        // Note: using the return value register is intentional: for ABIs where the first parameter
-        // goes into the same register as the return value (currently only ARM), the prepareCall
-        // will combine loading the looupAddr into the register and calculating the indirect call
-        // address.
-        Pointer lookupAddr(JITTargetPlatform::ReturnValueRegister, index * sizeof(QV4::Lookup));
-
-         _as->generateFunctionCallImp(true, retval, "lookup getter/setter",
-                                      typename JITAssembler::LookupCall(lookupAddr, getterSetterOffset), lookupAddr,
-                                      arg1, arg2, arg3, arg4);
-    }
-
-    template <typename Retval, typename Arg1, typename Arg2>
-    void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2)
-    {
-        generateLookupCall(retval, index, getterSetterOffset, arg1, arg2, typename JITAssembler::VoidType());
-    }
-
-    template <typename Retval, typename Arg1, typename Arg2, typename Arg3>
-    void generateLookupCall(Retval retval, uint index, uint getterSetterOffset, Arg1 arg1, Arg2 arg2, Arg3 arg3)
-    {
-        generateLookupCall(retval, index, getterSetterOffset, arg1, arg2, arg3, typename JITAssembler::VoidType());
-    }
-
-    IR::BasicBlock *_block;
-    BitVector _removableJumps;
-    JITAssembler* _as;
-
-    QScopedPointer<CompilationUnit> compilationUnit;
-    QQmlEnginePrivate *qmlEngine;
-    RegisterInformation regularRegistersToSave;
-    RegisterInformation fpRegistersToSave;
-};
-
-template <typename JITAssembler = Assembler<DefaultAssemblerTargetConfiguration>>
-class Q_QML_EXPORT ISelFactory: public EvalISelFactory
-{
-public:
-    ISelFactory() : EvalISelFactory(QStringLiteral("jit")) {}
-    virtual ~ISelFactory() {}
-    EvalInstructionSelection *create(QQmlEnginePrivate *qmlEngine, QV4::ExecutableAllocator *execAllocator, IR::Module *module, QV4::Compiler::JSUnitGenerator *jsGenerator) Q_DECL_OVERRIDE Q_DECL_FINAL
-    { return new InstructionSelection<JITAssembler>(qmlEngine, execAllocator, module, jsGenerator, this); }
-    bool jitCompileRegexps() const Q_DECL_OVERRIDE Q_DECL_FINAL
-    { return true; }
-    QQmlRefPointer<CompiledData::CompilationUnit> createUnitForLoading() Q_DECL_OVERRIDE Q_DECL_FINAL;
-};
-
-} // end of namespace JIT
-} // end of namespace QV4
-
-QT_END_NAMESPACE
-
-#endif // ENABLE(ASSEMBLER)
-
-#endif // QV4ISEL_MASM_P_H
diff --git a/src/qml/jit/qv4node.cpp b/src/qml/jit/qv4node.cpp
new file mode 100644
index 0000000000..e059e9fef6
--- /dev/null
+++ b/src/qml/jit/qv4node.cpp
@@ -0,0 +1,215 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4node_p.h"
+#include "qv4graph_p.h"
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace IR {
+
+Node *Node::create(Node::MemoryPool *pool, Node::Id id, const Operation *op, size_t nInputs,
+                   Node *const *inputs, bool inputsAreExtensible)
+{
+    size_t capacity = nInputs;
+    if (inputsAreExtensible)
+        capacity += 3;
+
+    Node *node = new (pool->allocate(sizeof(Node))) Node(pool, id, op, unsigned(nInputs),
+                                                         int(capacity));
+    for (uint i = 0; i < capacity; ++i)
+        new (&node->m_inputs[int(i)]) Use(node);
+    for (size_t i = 0; i < nInputs; ++i) {
+        Q_ASSERT(inputs[i] != nullptr);
+        node->replaceInput(unsigned(i), inputs[i]);
+    }
+
+    return node;
+}
+
+void Node::addInput(MemoryPool *pool, Node *in)
+{
+    Q_ASSERT(in);
+    ++m_nInputs;
+    if (m_nInputs >= unsigned(m_inputs.size())) {
+        QQmlJS::FixedPoolArray<Use> oldInputs = m_inputs;
+        m_inputs = QQmlJS::FixedPoolArray<Use>(pool, int(m_nInputs + 3));
+        for (Use &input : m_inputs)
+            new (&input) Use(this);
+        for (int i = 0, ei = oldInputs.size(); i != ei; ++i) {
+            Node *in = oldInputs[i].m_input;
+            oldInputs[i].set(nullptr);
+            m_inputs[i].set(in);
+        }
+    }
+    m_inputs.at(int(m_nInputs - 1)).set(in);
+}
+
+void Node::removeInput(unsigned index)
+{
+    Q_ASSERT(index < inputCount());
+    for (unsigned i = index, ei = inputCount(); i < ei - 1; ++i)
+        replaceInput(i, input(i + 1));
+    trimInputCount(inputCount() - 1);
+}
+
+void Node::removeInputs(unsigned start, unsigned count)
+{
+    for (unsigned idx = start; idx < start + count; ++idx)
+        m_inputs.at(int(idx)).set(nullptr);
+}
+
+void Node::removeAllInputs()
+{
+    removeInputs(0, inputCount());
+}
+
+void Node::trimInputCount(unsigned newCount)
+{
+    unsigned currentCount = inputCount();
+    if (newCount == currentCount)
+        return;
+    Q_ASSERT(newCount < currentCount);
+    removeInputs(newCount, currentCount - newCount);
+    m_nInputs = newCount;
+}
+
+void Node::removeExceptionHandlerUse()
+{
+    for (Use* use = m_firstUse; use; use = use->m_next) {
+        if (use->m_input->opcode() == Meta::OnException) {
+            use->set(nullptr);
+            break;
+        }
+    }
+}
+
+void Node::insertInput(Node::MemoryPool *pool, unsigned index, Node *newInput)
+{
+    Q_ASSERT(index < inputCount());
+    addInput(pool, input(inputCount() - 1));
+    for (unsigned i = inputCount() - 1; i > index; --i)
+        replaceInput(i, input(i - 1));
+    replaceInput(index, newInput);
+}
+
+void Node::replaceAllUsesWith(Node *replacement)
+{
+    for (Use *use = m_firstUse; use; ) {
+        Use *next = use->m_next;
+        const unsigned inIdx = use->inputIndex();
+        use->user()->replaceInput(inIdx, replacement);
+        use = next;
+    }
+}
+
+void Node::replaceUses(Node *newValueInput, Node *newEffectInput, Node *newControlInput)
+{
+    for (Use *use = m_firstUse; use; ) {
+        Use *next = use->m_next;
+        const Operation *inOp = use->user()->operation();
+        const unsigned inIdx = use->inputIndex();
+        if (inIdx < inOp->valueInputCount())
+            use->user()->replaceInput(inIdx, newValueInput);
+        else if (inIdx < inOp->indexOfFirstControl())
+            use->user()->replaceInput(inIdx, newEffectInput);
+        else
+            use->user()->replaceInput(inIdx, newControlInput);
+        use = next;
+    }
+}
+
+Node *Node::firstValueUse()
+{
+    for (auto it = uses().begin(), eit = uses().end(); it != eit; ++it) {
+        if (it.isUsedAsValue())
+            return *it;
+    }
+    return nullptr;
+}
+
+Node::Node(MemoryPool *pool, Node::Id id, const Operation *op, unsigned nInputs, int capacity)
+    : m_op(op)
+    , m_inputs(pool, capacity)
+    , m_nInputs(nInputs)
+    , m_id(id)
+{
+}
+
+NodeWorkList::NodeWorkList(const Graph *g)
+    : m_nodeState(g->nodeCount(), Unvisited)
+{ m_worklist.reserve(64); }
+
+void NodeWorkList::reset()
+{
+    std::fill(m_nodeState.begin(), m_nodeState.end(), Unvisited);
+    m_worklist.clear();
+    if (m_worklist.capacity() < 64)
+        m_worklist.reserve(64);
+}
+
+NodeCollector::NodeCollector(const Graph *g, bool collectUses, bool skipFramestate)
+{
+    markReachable(g->endNode());
+    for (size_t i = 0; i < m_reachable.size(); ++i) { // _reachable.size() is on purpose!
+        Node *n = m_reachable.at(i);
+        for (auto input : n->inputs()) {
+            if (input == nullptr)
+                continue;
+            if (isReachable(input->id()))
+                continue;
+            if (skipFramestate && input->opcode() == Meta::FrameState)
+                continue;
+            markReachable(input);
+        }
+
+        if (collectUses) {
+            for (Node *use : n->uses()) {
+                if (use && !isReachable(use->id()))
+                    markReachable(use);
+            }
+        }
+    }
+}
+
+} // IR namespace
+} // QV4 namespace
+QT_END_NAMESPACE
diff --git a/src/qml/jit/qv4node_p.h b/src/qml/jit/qv4node_p.h
new file mode 100644
index 0000000000..679a29764a
--- /dev/null
+++ b/src/qml/jit/qv4node_p.h
@@ -0,0 +1,642 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4NODE_P_H
+#define QV4NODE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmljsmemorypool_p.h>
+#include <private/qv4global_p.h>
+#include <private/qv4operation_p.h>
+#include "qv4util_p.h"
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace IR {
+
+class Use
+{
+    Q_DISABLE_COPY_MOVE(Use)
+
+public:
+    Use(Node *user)
+        : m_user(user)
+    {}
+
+    ~Use()
+    {
+        if (m_input)
+            removeFromList();
+    }
+
+    operator Node *() const { return m_input; }
+    Node *input() const { return m_input; }
+    Node *user() const { return m_user; }
+
+    inline void set(Node *newInput);
+
+    void validate() const
+    {
+        Q_ASSERT(m_user);
+        if (m_input) {
+            if (m_prev != nullptr)
+                Q_ASSERT(*m_prev == this);
+            if (m_next) {
+                Q_ASSERT(m_next->m_input == m_input);
+                Q_ASSERT(m_next->m_prev == &m_next);
+                m_next->validate();
+            }
+        }
+    }
+
+    inline int inputIndex() const;
+
+protected:
+    friend class Node;
+
+    void addToList(Use **list) {
+        validate();
+        m_next = *list;
+        if (m_next)
+            m_next->m_prev = &m_next;
+        m_prev = list;
+        *list = this;
+        validate();
+    }
+
+    void removeFromList() {
+        validate();
+        Use **newPrev = m_prev;
+        *newPrev = m_next;
+        m_prev = nullptr;
+        if (m_next)
+            m_next->m_prev = newPrev;
+        m_next = nullptr;
+        m_input = nullptr;
+        validate();
+    }
+
+private:
+    Node *m_input = nullptr;
+    Node *m_user = nullptr;
+    Use *m_next = nullptr;
+    Use **m_prev = nullptr;
+};
+
+// A node represents an calculation, action, or marker in the graph. Each node has an operation,
+// input dependencies and uses. The operation indicates what kind of node it is, e.g.: JSAdd,
+// Constant, Region, and so on. Two nodes can have the same operation, but different inputs.
+// For example, the expressions 1 + 2 and 3 + 4 will each have a node with an JSAdd operation
+// (which is exactly the same operation for both nodes), but the nodes have different inputs (1, and
+// 2 in the first expression, while the second operation has 3 and 4 as inputs).
+class Node final
+{
+    Q_DISABLE_COPY_MOVE(Node)
+
+public:
+    using Id = uint32_t;
+    using MemoryPool = QQmlJS::MemoryPool;
+    class Inputs;
+
+public:
+    static Node *create(MemoryPool *pool, Id id, const Operation *op, size_t nInputs,
+                        Node * const *inputs, bool inputsAreExtensible = false);
+    ~Node() = delete;
+
+    inline bool isDead() const;
+    inline void kill();
+
+    Id id() const { return m_id; }
+
+    const Operation *operation() const
+    { return m_op; }
+
+    void setOperation(const Operation *op)
+    { m_op = op; }
+
+    Operation::Kind opcode() const
+    { return operation()->kind(); }
+
+    inline Inputs inputs() const;
+    void addInput(MemoryPool *pool, Node *in);
+    void removeInput(unsigned index);
+    void removeInputs(unsigned start, unsigned count);
+    void removeAllInputs();
+    uint32_t inputCount() const
+    { return m_nInputs; }
+    void trimInputCount(unsigned newCount);
+
+    void removeExceptionHandlerUse();
+
+    Node *input(unsigned idx) const
+    {
+        Q_ASSERT(idx < inputCount());
+        return m_inputs.at(idx);
+    }
+
+    Node *effectInput(unsigned effectIndex = 0) const
+    {
+        if (operation()->effectInputCount() == 0)
+            return nullptr;
+        Q_ASSERT(effectIndex < operation()->effectInputCount());
+        return input(operation()->indexOfFirstEffect() + effectIndex);
+    }
+
+    Node *controlInput(unsigned controlIndex = 0) const
+    {
+        if (operation()->controlInputCount() == 0)
+            return nullptr;
+        Q_ASSERT(controlIndex < operation()->controlInputCount());
+        return input(operation()->indexOfFirstControl() + controlIndex);
+    }
+
+    Node *frameStateInput() const
+    {
+        if (operation()->hasFrameStateInput())
+            return input(operation()->indexOfFrameStateInput());
+        return nullptr;
+    }
+
+    void setFrameStateInput(Node *newFramestate)
+    {
+        if (operation()->hasFrameStateInput())
+            replaceInput(operation()->indexOfFrameStateInput(), newFramestate);
+    }
+
+    void insertInput(MemoryPool *pool, unsigned index, Node *newInput);
+
+    void replaceInput(Node *oldIn, Node *newIn)
+    {
+        for (unsigned i = 0, ei = inputCount(); i != ei; ++i) {
+            if (input(i) == oldIn)
+                replaceInput(i, newIn);
+        }
+    }
+
+    void replaceInput(unsigned idx, Node *newIn)
+    {
+        m_inputs[idx].set(newIn);
+    }
+
+    class Uses
+    {
+    public:
+        explicit Uses(Node *node)
+            : m_node(node)
+        {}
+
+        class const_iterator;
+        inline const_iterator begin() const;
+        inline const_iterator end() const;
+
+        bool isEmpty() const;
+
+    private:
+        Node *m_node;
+    };
+
+    Uses uses() { return Uses(this); }
+    bool hasUses() const { return m_firstUse != nullptr; }
+    unsigned useCount() const
+    {
+        unsigned cnt = 0;
+        for (Use *it = m_firstUse; it; it = it->m_next)
+            ++cnt;
+        return cnt;
+    }
+    void replaceAllUsesWith(Node *replacement);
+    void replaceUses(Node *newValueInput, Node *newEffectInput, Node *newControlInput);
+
+    Node *firstValueUse();
+
+private: // types and utility methods
+    friend class Use;
+    Node(MemoryPool *pool, Id id, const Operation *op, unsigned nInputs, int capacity);
+
+private: // fields
+    Use *m_firstUse = nullptr;
+    const Operation *m_op = nullptr;
+    QQmlJS::FixedPoolArray<Use> m_inputs;
+    unsigned m_nInputs = 0;
+    Id m_id = 0;
+};
+
+void Use::set(Node *newInput)
+{
+    if (m_input)
+        removeFromList();
+    m_input = newInput;
+    if (newInput)
+        addToList(&newInput->m_firstUse);
+}
+
+class Node::Inputs final
+{
+public:
+    using value_type = Node *;
+
+    class const_iterator;
+    inline const_iterator begin() const;
+    inline const_iterator end() const;
+
+    bool empty() const
+    { return m_nInputs == 0; }
+
+    unsigned count() const
+    { return m_nInputs; }
+
+    explicit Inputs(const Use *inputs, unsigned nInputs)
+        : m_inputs(inputs), m_nInputs(nInputs)
+    {}
+
+private:
+    const Use *m_inputs = nullptr;
+    unsigned m_nInputs = 0;
+};
+
+class Node::Inputs::const_iterator final
+{
+public:
+    using iterator_category = std::forward_iterator_tag;
+    using difference_type = std::ptrdiff_t;
+    using value_type = Node *;
+    using pointer = const value_type *;
+    using reference = value_type &;
+
+    Node *operator*() const
+    { return m_inputs->m_input; }
+
+    bool operator==(const const_iterator &other) const
+    { return m_inputs == other.m_inputs; }
+
+    bool operator!=(const const_iterator &other) const
+    { return !(*this == other); }
+
+    const_iterator &operator++()
+    { ++m_inputs; return *this; }
+
+    const_iterator& operator+=(difference_type offset)
+    { m_inputs += offset; return *this; }
+
+    const_iterator operator+(difference_type offset) const
+    { return const_iterator(m_inputs + offset); }
+
+    difference_type operator-(const const_iterator &other) const
+    { return m_inputs - other.m_inputs; }
+
+private:
+    friend class Node::Inputs;
+
+    explicit const_iterator(const Use *inputs)
+        : m_inputs(inputs)
+    {}
+
+    const Use *m_inputs;
+};
+
+Node::Inputs::const_iterator Node::Inputs::begin() const
+{ return const_iterator(m_inputs); }
+
+Node::Inputs::const_iterator Node::Inputs::end() const
+{ return const_iterator(m_inputs + m_nInputs); }
+
+Node::Inputs Node::inputs() const
+{
+    return Inputs(m_inputs.begin(), m_nInputs);
+}
+
+class Node::Uses::const_iterator final
+{
+public:
+    using iterator_category = std::forward_iterator_tag;
+    using difference_type = int;
+    using value_type = Node *;
+    using pointer = Node **;
+    using reference = Node *&;
+
+    Node *operator*() const
+    { return m_current->user(); }
+
+    bool operator==(const const_iterator &other) const
+    { return other.m_current == m_current; }
+
+    bool operator!=(const const_iterator &other) const
+    { return other.m_current != m_current; }
+
+    const_iterator &operator++()
+    { m_current = m_next; setNext(); return *this; }
+
+    unsigned inputIndex() const
+    { return m_current->inputIndex(); }
+
+    bool isUsedAsValue() const
+    { return inputIndex() < operator*()->operation()->valueInputCount(); }
+
+    bool isUsedAsControl() const
+    { return operator*()->operation()->indexOfFirstControl() <= inputIndex(); }
+
+private:
+    friend class Node::Uses;
+
+    const_iterator() = default;
+
+    explicit const_iterator(Node* node)
+        : m_current(node->m_firstUse)
+    { setNext(); }
+
+    void setNext()
+    {
+        if (m_current)
+            m_next = m_current->m_next;
+        else
+            m_next = nullptr;
+    }
+
+private:
+    Use *m_current = nullptr;
+    Use *m_next = nullptr;
+};
+
+Node::Uses::const_iterator Node::Uses::begin() const
+{ return const_iterator(this->m_node); }
+
+Node::Uses::const_iterator Node::Uses::end() const
+{ return const_iterator(); }
+
+int Use::inputIndex() const
+{
+    if (!m_user)
+        return -1;
+    return int(this - m_user->m_inputs.begin());
+}
+
+bool Node::isDead() const
+{
+    Inputs in = inputs();
+    return !in.empty() && *in.begin() == nullptr;
+}
+
+void Node::kill()
+{
+    removeAllInputs();
+}
+
+class NodeWorkList final
+{
+    enum State: uint8_t {
+        Unvisited = 0,
+        Queued,
+        Visited,
+    };
+
+public:
+    NodeWorkList(const Graph *g);
+
+    void reset();
+
+    bool enqueue(Node *n)
+    {
+        State &s = nodeState(n);
+        if (s == Queued || s == Visited)
+            return false;
+
+        m_worklist.push_back(n);
+        s = Queued;
+        return true;
+    }
+
+    void enqueue(const std::vector<Node *> &nodes)
+    {
+        m_worklist.insert(m_worklist.end(), nodes.begin(), nodes.end());
+        for (Node *n : nodes)
+            nodeState(n) = Queued;
+    }
+
+    void reEnqueue(Node *n)
+    {
+        if (!n)
+            return;
+        State &s = nodeState(n);
+        if (s == Queued)
+            return;
+        s = Queued;
+        m_worklist.push_back(n);
+    }
+
+    void reEnqueueLate(Node *n)
+    {
+        if (!n)
+            return;
+        State &s = nodeState(n);
+        if (s == Queued)
+            return;
+        s = Queued;
+        m_worklist.insert(m_worklist.begin(), n);
+    }
+
+    void enqueueAllInputs(Node *n)
+    {
+        for (Node *input : n->inputs())
+            enqueue(input);
+    }
+
+    void reEnqueueAllInputs(Node *n)
+    {
+        for (Node *input : n->inputs())
+            reEnqueue(input);
+    }
+
+    void enqueueValueInputs(Node *n)
+    {
+        for (unsigned i = 0, ei = n->operation()->valueInputCount(); i != ei; ++i)
+            enqueue(n->input(i));
+    }
+
+    void enqueueEffectInputs(Node *n)
+    {
+        for (unsigned i = n->operation()->indexOfFirstEffect(), ei = n->operation()->effectInputCount(); i != ei; ++i)
+            enqueue(n->input(i));
+    }
+
+    void enqueueAllUses(Node *n)
+    {
+        for (Node *use : n->uses())
+            enqueue(use);
+    }
+
+    Node *dequeueNextNodeForVisiting()
+    {
+        while (!m_worklist.empty()) {
+            Node *n = m_worklist.back();
+            m_worklist.pop_back();
+            State &s = nodeState(n);
+            if (s == Queued) {
+                s = Visited;
+                return n;
+            }
+            Q_UNREACHABLE();
+        }
+
+        return nullptr;
+    }
+
+    void markAsVisited(Node *n)
+    { nodeState(n) = Visited; }
+
+    bool isVisited(Node *n) const
+    { return nodeState(n) == Visited; }
+
+    bool isEmpty() const
+    { return m_worklist.empty(); }
+
+    QString status(Node *n) const
+    {
+        QString s = QStringLiteral("status for node %1: ").arg(n->id());
+        switch (nodeState(n)) {
+        case Queued: s += QLatin1String("queued"); break;
+        case Visited: s += QLatin1String("visited"); break;
+        case Unvisited: s += QLatin1String("unvisited"); break;
+        }
+        return s;
+    }
+
+private:
+    State &nodeState(Node *n)
+    {
+        const unsigned position(n->id());
+        if (position >= m_nodeState.size())
+            m_nodeState.resize(position + 1, Unvisited);
+
+        return m_nodeState[position];
+    }
+
+    State nodeState(Node *n) const
+    { return m_nodeState[unsigned(n->id())]; }
+
+private:
+    std::vector<Node *> m_worklist;
+    std::vector<State> m_nodeState;
+};
+
+class NodeInfo
+{
+public:
+    enum { NoInstructionOffset = -1 };
+
+public:
+    NodeInfo() = default;
+
+    Type type() const { return m_type; }
+    void setType(Type t) { m_type = t; }
+
+    int currentInstructionOffset() const
+    { return m_currentInstructionOffset; }
+
+    int nextInstructionOffset() const
+    { return m_nextInstructionOffset; }
+
+    void setBytecodeOffsets(int current, int next)
+    {
+        Q_ASSERT(current != NoInstructionOffset);
+        Q_ASSERT(next != NoInstructionOffset);
+        m_currentInstructionOffset = current;
+        m_nextInstructionOffset = next;
+    }
+
+private:
+    Type m_type;
+    int m_currentInstructionOffset = NoInstructionOffset;
+    int m_nextInstructionOffset = NoInstructionOffset;
+};
+
+class NodeCollector
+{
+public:
+    NodeCollector(const Graph *g, bool collectUses = false, bool skipFramestate = false);
+
+    const std::vector<Node *> &reachable() const
+    { return m_reachable; }
+
+    void sortById()
+    {
+        std::sort(m_reachable.begin(), m_reachable.end(), [](Node *n1, Node *n2) {
+            return n1->id() < n2->id();
+        });
+    }
+
+    bool isReachable(Node::Id nodeId) const
+    {
+        if (nodeId >= Node::Id(m_isReachable.size()))
+            return false;
+        return m_isReachable.at(int(nodeId));
+    }
+
+    void markReachable(Node *node)
+    {
+        auto nodeId = node->id();
+        m_reachable.push_back(node);
+        if (nodeId >= Node::Id(m_isReachable.size()))
+            m_isReachable.resize(int(nodeId + 1), false);
+        m_isReachable.setBit(int(nodeId));
+    }
+
+private:
+    std::vector<Node *> m_reachable;
+    BitVector m_isReachable;
+};
+
+} // namespace IR
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4NODE_P_H
diff --git a/src/qml/jit/qv4operation.cpp b/src/qml/jit/qv4operation.cpp
new file mode 100644
index 0000000000..8356a35098
--- /dev/null
+++ b/src/qml/jit/qv4operation.cpp
@@ -0,0 +1,782 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4operation_p.h"
+#include "qv4runtimesupport_p.h"
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace IR {
+
+OperationBuilder::OperationBuilder(QQmlJS::MemoryPool *graphPool)
+    : m_graphPool(graphPool)
+{}
+
+OperationBuilder *OperationBuilder::create(QQmlJS::MemoryPool *pool)
+{
+    return pool->New<OperationBuilder>(pool);
+}
+
+Operation *OperationBuilder::getConstant(Value v)
+{
+    Type t;
+    switch (v.type()) {
+    case Value::Undefined_Type: t = Type::undefinedType(); break;
+    case Value::Integer_Type: t = Type::int32Type(); break;
+    case Value::Boolean_Type: t = Type::booleanType(); break;
+    case Value::Null_Type: t = Type::nullType(); break;
+    case Value::Double_Type: t = Type::doubleType(); break;
+    case Value::Managed_Type: t = Type::objectType(); break;
+    default:
+        if (v.isEmpty())
+            t = Type::emptyType();
+        else
+            Q_UNREACHABLE();
+    }
+    return OperationWithPayload<ConstantPayload>::create(
+                m_graphPool, Meta::Constant, 0, 0, 0, 1, 0, 0, t, Operation::NoFlags,
+                ConstantPayload(v));
+}
+
+Operation *OperationBuilder::getParam(unsigned index, const Function::StringId name)
+{
+    return OperationWithPayload<ParameterPayload>::create(m_graphPool, Meta::Parameter,
+                                                          1, 0, 0,
+                                                          1, 0, 0,
+                                                          Type::anyType(), Operation::NoFlags,
+                                                          ParameterPayload(index, name));
+}
+
+Operation *OperationBuilder::getRegion(unsigned nControlInputs) //### cache common operands in the static pool
+{
+    return Operation::create(m_graphPool, Meta::Region,
+                             0, 0, uint16_t(nControlInputs),
+                             0, 0, 1,
+                             Type(), Operation::NoFlags);
+}
+
+Operation *OperationBuilder::getPhi(unsigned nValueInputs) //### cache common operands in the static pool
+{
+    return Operation::create(m_graphPool, Meta::Phi,
+                             uint16_t(nValueInputs), 0, 1,
+                             1, 0, 0,
+                             Type::anyType(), Operation::NoFlags);
+}
+
+Operation *OperationBuilder::getEffectPhi(unsigned nEffectInputs) //### cache common operands in the static pool
+{
+    return Operation::create(m_graphPool, Meta::EffectPhi,
+                             0, uint16_t(nEffectInputs), 1,
+                             0, 1, 0,
+                             Type(), Operation::NoFlags);
+}
+
+Operation *OperationBuilder::getUnwindDispatch(unsigned nContinuations, int unwindHandlerOffset,
+                                               int fallthroughSuccessor)
+{
+    return OperationWithPayload<UnwindDispatchPayload>::create(
+                m_graphPool, Meta::UnwindDispatch,
+                0, 1, 1, 0, nContinuations, nContinuations,
+                Type(), Operation::NoFlags,
+                UnwindDispatchPayload(unwindHandlerOffset,
+                                      fallthroughSuccessor));
+}
+
+Operation *OperationBuilder::getHandleUnwind(int unwindHandlerOffset)
+{
+    return OperationWithPayload<HandleUnwindPayload>::create(m_graphPool, Meta::HandleUnwind,
+                                                             0, 1, 1, 0, 1, 1,
+                                                             Type(), Operation::NoFlags,
+                                                             HandleUnwindPayload(unwindHandlerOffset));
+}
+
+Operation *OperationBuilder::getFrameState(uint16_t frameSize)
+{
+    if (m_opFrameState == nullptr)
+        m_opFrameState = Operation::create(m_graphPool, Meta::FrameState,
+                                          frameSize, 0, 0, 0, 0, 1,
+                                          Type(), Operation::NoFlags);
+    else
+        Q_ASSERT(frameSize == m_opFrameState->valueInputCount());
+
+    return m_opFrameState;
+}
+
+Operation *OperationBuilder::getStart(uint16_t outputCount)
+{
+    return Operation::create(m_graphPool, Meta::Start,
+                             0, 0, 0,
+                             outputCount, 1, 1,
+                             Type(), Operation::NoFlags);
+}
+
+Operation *OperationBuilder::getEnd(uint16_t controlInputCount)
+{
+    return Operation::create(m_graphPool, Meta::End,
+                             0, 0, controlInputCount,
+                             0, 0, 0,
+                             Type(), Operation::NoFlags);
+}
+
+inline Operation *createOperation(Operation::Kind kind, QQmlJS::MemoryPool *staticPool)
+{
+    auto get = [&](uint16_t inValueCount, uint16_t inEffectCount, uint16_t inControlCount,
+                   uint16_t outValueCount, uint16_t outEffectCount, uint16_t outControlCount,
+                   Type (*typeCreator)(), uint8_t flags) {
+        return Operation::create(staticPool, kind, inValueCount, inEffectCount, inControlCount,
+                                 outValueCount, outEffectCount, outControlCount, typeCreator(),
+                                 flags);
+    };
+
+    using K = Operation::Kind;
+    using F = Operation::Flags;
+    const auto none    = &Type::noneType;
+    const auto any     = &Type::anyType;
+    const auto number  = &Type::numberType;
+    const auto boolean = &Type::booleanType;
+
+    switch (kind) {
+    case K::Undefined:
+        return OperationWithPayload<ConstantPayload>::create(
+                staticPool, K::Undefined, 0, 0, 0, 1, 0, 0, Type::undefinedType(), F::NoFlags,
+                ConstantPayload(Primitive::undefinedValue()));
+    case K::Empty:
+        return OperationWithPayload<ConstantPayload>::create(
+                staticPool, K::Constant, 0, 0, 0, 1, 0, 0, Type::emptyType(), Operation::NoFlags,
+                ConstantPayload(Primitive::emptyValue()));
+    case K::Engine:                          return get(1, 0, 0, 1, 0, 0, none,    F::NoFlags);
+    case K::CppFrame:                        return get(1, 0, 0, 1, 0, 0, none,    F::NoFlags);
+    case K::Function:                        return get(1, 0, 0, 1, 0, 0, none,    F::NoFlags);
+    case K::Jump:                            return get(0, 0, 1, 0, 0, 1, none,    F::NoFlags);
+    case K::Return:                          return get(1, 1, 1, 0, 0, 1, none,    F::NoFlags);
+    case K::Branch:                          return get(1, 0, 1, 0, 0, 2, none,    F::HasFrameStateInput | F::NeedsBytecodeOffsets);
+    case K::IfTrue:                          return get(0, 0, 1, 0, 0, 1, none,    F::NoFlags);
+    case K::IfFalse:                         return get(0, 0, 1, 0, 0, 1, none,    F::NoFlags);
+    case K::SelectOutput:                    return get(3, 1, 1, 1, 1, 1, any,     F::NoFlags);
+    case K::Throw:                           return get(1, 1, 1, 0, 1, 1, any,     F::NeedsBytecodeOffsets);
+    case K::OnException:                     return get(0, 0, 1, 0, 0, 1, none,    F::NoFlags);
+    case K::ThrowReferenceError:             return get(1, 1, 1, 0, 1, 1, any,     F::NeedsBytecodeOffsets);
+    case K::UnwindToLabel:                   return get(2, 1, 1, 0, 1, 1, none,    F::NoFlags);
+    case K::LoadRegExp:                      return get(1, 0, 0, 1, 0, 0, any,     F::NoFlags);
+    case K::ScopedLoad:                      return get(2, 1, 0, 1, 1, 0, any,     F::NoFlags);
+    case K::ScopedStore:                     return get(3, 1, 0, 0, 1, 0, none,    F::NoFlags);
+    case K::JSLoadElement:                   return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSGetLookup:                     return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSLoadProperty:                  return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSStoreElement:                  return get(3, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSSetLookupStrict:               return get(3, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSSetLookupSloppy:               return get(3, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSStoreProperty:                 return get(3, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSLoadName:                      return get(1, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSLoadGlobalLookup:              return get(1, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSStoreNameSloppy:               return get(2, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSStoreNameStrict:               return get(2, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSLoadSuperProperty:             return get(1, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSStoreSuperProperty:            return get(2, 1, 1, 0, 1, 2, any,     F::CanThrow);
+    case K::JSLoadClosure:                   return get(1, 1, 0, 1, 1, 0, any,     F::Pure);
+    case K::JSGetIterator:                   return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+
+    // special case: see GraphBuilder::generate_IteratorNext
+    case K::JSIteratorNext:                  return get(2, 1, 1, 2, 1, 1, any,     F::NoFlags);
+
+    // special case: see GraphBuilder::generate_IteratorNext
+    case K::JSIteratorNextForYieldStar:      return get(3, 1, 1, 2, 1, 1, any,     F::NoFlags);
+
+    case K::JSIteratorClose:                 return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSDeleteProperty:                return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSDeleteName:                    return get(1, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSIn:                            return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSInstanceOf:                    return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::QMLLoadScopeObjectProperty:      return get(3, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::QMLStoreScopeObjectProperty:     return get(3, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::QMLLoadContextObjectProperty:    return get(3, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::QMLStoreContextObjectProperty:   return get(3, 1, 1, 1, 1, 2, none,    F::CanThrow);
+    case K::QMLLoadIdObject:                 return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+
+    case K::JSEqual:                         return get(2, 1, 1, 1, 1, 2, boolean, F::CanThrow);
+    case K::JSGreaterThan:                   return get(2, 1, 1, 1, 1, 2, boolean, F::CanThrow);
+    case K::JSGreaterEqual:                  return get(2, 1, 1, 1, 1, 2, boolean, F::CanThrow);
+    case K::JSLessThan:                      return get(2, 1, 1, 1, 1, 2, boolean, F::CanThrow);
+    case K::JSLessEqual:                     return get(2, 1, 1, 1, 1, 2, boolean, F::CanThrow);
+    case K::JSStrictEqual:                   return get(2, 1, 1, 1, 1, 2, boolean, F::CanThrow);
+
+    case K::JSAdd:                           return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSSubtract:                      return get(2, 1, 1, 1, 1, 2, number,  F::CanThrow);
+    case K::JSMultiply:                      return get(2, 1, 1, 1, 1, 2, number,  F::CanThrow);
+    case K::JSDivide:                        return get(2, 1, 1, 1, 1, 2, number,  F::CanThrow);
+    case K::JSModulo:                        return get(2, 1, 1, 1, 1, 2, number,  F::CanThrow);
+    case K::JSExponentiate:                  return get(2, 1, 1, 1, 1, 2, number,  F::CanThrow);
+
+    case K::JSBitAnd:                        return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSBitOr:                         return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSBitXor:                        return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSUnsignedShiftRight:            return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSShiftRight:                    return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSShiftLeft:                     return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+
+    case K::JSNegate:                        return get(1, 1, 1, 1, 1, 2, number,  F::CanThrow);
+    case K::JSToNumber:                      return get(1, 1, 1, 1, 1, 2, number,  F::CanThrow);
+    case K::Alloca:                          return get(1, 0, 0, 1, 0, 0, none,    F::NoFlags);
+
+    //### it is questionable if VAAlloc/VASeal need effect edges
+    case K::VAAlloc:                         return get(1, 1, 0, 1, 1, 0, none,    F::NoFlags);
+
+    case K::VAStore:                         return get(3, 0, 0, 1, 0, 0, none,    F::NoFlags);
+
+    case K::JSTypeofName:                    return get(1, 1, 0, 1, 1, 0, any,     F::NoFlags);
+    case K::JSTypeofValue:                   return get(1, 0, 0, 1, 0, 0, any,     F::Pure);
+    case K::JSDeclareVar:                    return get(2, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::JSDestructureRestElement:        return get(1, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::QMLLoadContext:                  return get(0, 0, 0, 1, 0, 0, any,     F::NoFlags);
+    case K::QMLLoadImportedScripts:          return get(0, 0, 0, 1, 0, 0, any,     F::NoFlags);
+
+    case K::JSCreateCallContext:             return get(0, 1, 1, 0, 1, 1, none,    F::NoFlags);
+    case K::JSCreateCatchContext:            return get(2, 1, 1, 1, 1, 1, none,    F::NoFlags);
+    case K::JSCreateWithContext:             return get(1, 1, 1, 1, 1, 1, any,     F::NoFlags);
+    case K::JSCreateBlockContext:            return get(1, 1, 1, 1, 1, 1, none,    F::NoFlags);
+    case K::JSCloneBlockContext:             return get(0, 1, 1, 0, 1, 1, none,    F::NoFlags);
+    case K::JSCreateScriptContext:           return get(1, 1, 1, 1, 1, 1, none,    F::NoFlags);
+    case K::JSPopScriptContext:              return get(0, 1, 1, 1, 1, 1, none,    F::NoFlags);
+    case K::PopContext:                      return get(0, 1, 1, 0, 1, 1, none,    F::NoFlags);
+
+    case K::JSThisToObject:                  return get(1, 1, 1, 0, 1, 2, any,     F::NoFlags);
+    case K::JSCreateMappedArgumentsObject:   return get(0, 1, 0, 1, 1, 0, any,     F::NoFlags);
+    case K::JSCreateUnmappedArgumentsObject: return get(0, 1, 0, 1, 1, 0, any,     F::NoFlags);
+    case K::JSCreateRestParameter:           return get(1, 0, 0, 1, 0, 0, any,     F::NoFlags);
+    case K::JSLoadSuperConstructor:          return get(1, 1, 1, 1, 1, 2, any,     F::NoFlags);
+    case K::JSThrowOnNullOrUndefined:        return get(1, 1, 1, 0, 1, 2, none,    F::CanThrow);
+    case K::JSGetTemplateObject:             return get(1, 0, 0, 1, 0, 0, any,     F::NoFlags);
+    case K::StoreThis:                       return get(1, 1, 0, 1, 1, 0, any,     F::NoFlags);
+
+    case K::GetException:                    return get(0, 1, 0, 1, 1, 0, any,     F::NoFlags);
+    case K::SetException:                    return get(1, 1, 0, 0, 1, 0, any,     F::NoFlags);
+
+    case K::ToObject:                        return get(1, 1, 1, 1, 1, 2, any,     F::CanThrow);
+    case K::ToBoolean:                       return get(1, 0, 0, 1, 0, 0, boolean, F::Pure);
+
+    case K::IsEmpty:                         return get(1, 0, 0, 1, 0, 0, boolean, F::Pure);
+
+    case K::BooleanNot:                      return get(1, 0, 0, 1, 0, 0, boolean, F::NoFlags);
+    case K::HasException:                    return get(1, 1, 0, 1, 1, 0, boolean, F::NoFlags);
+
+    case K::Swap:                            return get(0, 0, 0, 0, 0, 0, none,    F::NoFlags);
+    case K::Move:                            return get(1, 0, 0, 1, 0, 0, none,    F::NoFlags);
+
+    default: // Non-static operations:
+        return nullptr;
+    }
+}
+
+Operation *OperationBuilder::staticOperation(Operation::Kind kind)
+{
+    static QAtomicPointer<Operation *> ops;
+    if (Operation **staticOps = ops.load())
+        return staticOps[kind];
+
+    static QAtomicInt initializing = 0;
+    if (initializing.testAndSetOrdered(0, 1)) {
+        // This is safe now, because we can only run this piece of code once during the life time
+        // of the application as we can only change initializing from 0 to 1 once.
+        Operation **staticOps = new Operation *[Meta::KindsEnd];
+        static QQmlJS::MemoryPool pool;
+        for (int i = 0; i < Meta::KindsEnd; ++i)
+            staticOps[i] = createOperation(Operation::Kind(i), &pool);
+        bool success = ops.testAndSetOrdered(nullptr, staticOps);
+        Q_ASSERT(success);
+    } else {
+        // Unfortunately we need to busy wait now until the other thread finishes the static
+        // initialization;
+        while (!ops.load()) {}
+    }
+
+    return ops.load()[kind];
+}
+
+Operation *OperationBuilder::getJSVarArgsCall(Operation::Kind kind, uint16_t argc)
+{
+    return Operation::create(m_graphPool, kind,
+                             argc, 1, 1, 1, 1, 2,
+                             Type::anyType(), Operation::CanThrow);
+}
+
+Operation *OperationBuilder::getJSTailCall(uint16_t argc)
+{
+    return Operation::create(m_graphPool, Meta::JSTailCall,
+                             argc, 1, 1, 0, 0, 1,
+                             Type(), Operation::NoFlags);
+}
+
+Operation *OperationBuilder::getTailCall()
+{
+    // special varargs call, takes cppframe, engine, func, thisObject, argv, argc
+    return Operation::create(m_graphPool, Meta::TailCall,
+                             6, 1, 1, 0, 0, 1,
+                             Type(), Operation::NoFlags);
+}
+
+Operation *OperationBuilder::getCall(Operation::Kind callee)
+{
+    const bool canThrow = CallPayload::canThrow(callee);
+    const Type retTy = CallPayload::returnType(callee);
+    uint16_t nControlInputs = 0;
+    uint16_t nControlOutputs = 0;
+    if (canThrow) {
+        nControlInputs = 1;
+        nControlOutputs += 2;
+    }
+    if (CallPayload::changesContext(callee)) {
+        nControlInputs = 1;
+        nControlOutputs = std::max<uint16_t>(nControlInputs, 1);
+    }
+    if (callee == Meta::Throw || callee == Meta::ThrowReferenceError ||
+            callee == Meta::JSIteratorNext || callee == Meta::JSIteratorNextForYieldStar) {
+        nControlInputs = 1;
+        nControlOutputs = 1;
+    }
+    Operation::Flags flags = Operation::NoFlags;
+    if (canThrow)
+        flags = Operation::Flags(flags | Operation::CanThrow);
+    if (CallPayload::isPure(callee))
+        flags = Operation::Flags(flags | Operation::Pure);
+    const uint16_t nEffects = (flags & Operation::Pure) ? 0 : 1;
+    const uint16_t nValueOutputs = retTy.isNone() ? 0 : 1;
+    const uint16_t nValueInputs = CallPayload::argc(callee);
+
+    return OperationWithPayload<CallPayload>::create(
+                m_graphPool, Meta::Call,
+                nValueInputs, nEffects, nControlInputs,
+                nValueOutputs, nEffects, nControlOutputs,
+                retTy, flags,
+                CallPayload(callee));
+}
+
+Operation *OperationBuilder::getVASeal(uint16_t nElements)
+{
+    return Operation::create(m_graphPool, Meta::VASeal,
+                             nElements + 1, 1, 0, 1, 1, 0,
+                             Type::anyType(), Operation::NoFlags);
+}
+
+QString Operation::debugString() const
+{
+    switch (kind()) {
+
+    case Meta::Constant:
+        return QStringLiteral("Constant[%1]").arg(ConstantPayload::get(*this)->debugString());
+    case Meta::Parameter:
+        return QStringLiteral("Parameter[%1]").arg(ParameterPayload::get(*this)->debugString());
+    case Meta::Call:
+        return QStringLiteral("Call[%1]").arg(CallPayload::get(*this)->debugString());
+    case Meta::UnwindDispatch:
+        return QStringLiteral("UnwindDispatch[%1]").arg(UnwindDispatchPayload::get(*this)
+                                                                ->debugString());
+    case Meta::HandleUnwind:
+        return QStringLiteral("HandleUnwind[%1]").arg(HandleUnwindPayload::get(*this)
+                                                              ->debugString());
+
+    default:
+        return QString::fromLatin1(QMetaEnum::fromType<Meta::OpKind>().valueToKey(kind()));
+    }
+}
+
+QString ConstantPayload::debugString() const
+{
+    return debugString(m_value);
+}
+
+QString ConstantPayload::debugString(QV4::Value v)
+{
+    if (v.isManaged())
+        return QString().sprintf("Ptr: %p", v.heapObject());
+    if (v.isEmpty())
+        return QStringLiteral("empty");
+    return v.toQStringNoThrow();
+}
+
+QString ParameterPayload::debugString() const
+{
+    return QStringLiteral("%1").arg(m_index);
+}
+
+QString UnwindDispatchPayload::debugString() const
+{
+    return QStringLiteral("%1, %2").arg(QString::number(m_fallthroughSuccessor),
+                                    QString::number(m_unwindHandlerOffset));
+}
+
+QString HandleUnwindPayload::debugString() const
+{
+    return QStringLiteral("%1").arg(m_unwindHandlerOffset);
+}
+
+static Type translateType(RuntimeSupport::ArgumentType t)
+{
+    switch (t) {
+    case RuntimeSupport::ArgumentType::Int: return Type::int32Type();
+    case RuntimeSupport::ArgumentType::Bool: return Type::booleanType();
+    case RuntimeSupport::ArgumentType::Void: return Type();
+    case RuntimeSupport::ArgumentType::Engine: return Type::rawPointerType();
+    case RuntimeSupport::ArgumentType::ValueRef: return Type::anyType();
+    case RuntimeSupport::ArgumentType::ValueArray: return Type::anyType();
+    case RuntimeSupport::ArgumentType::ReturnedValue: return Type::anyType();
+    default: Q_UNREACHABLE();
+    }
+}
+
+template<template<typename Operation> class M /* MetaOperation */, typename ReturnValue>
+static ReturnValue operateOnRuntimeCall(Operation::Kind kind, bool abortOnMissingCall = true)
+{
+    using K = Operation::Kind;
+    using R = Runtime;
+
+    switch (kind) {
+    case K::Throw:                           return M<R::ThrowException>::doIt();
+    case K::ThrowReferenceError:             return M<R::ThrowReferenceError>::doIt();
+
+    case K::JSEqual:                         return M<R::CompareEqual>::doIt();
+    case K::JSGreaterThan:                   return M<R::CompareGreaterThan>::doIt();
+    case K::JSGreaterEqual:                  return M<R::CompareGreaterEqual>::doIt();
+    case K::JSLessThan:                      return M<R::CompareLessThan>::doIt();
+    case K::JSLessEqual:                     return M<R::CompareLessEqual>::doIt();
+    case K::JSStrictEqual:                   return M<R::CompareStrictEqual>::doIt();
+
+    case K::JSBitAnd:                        return M<R::BitAnd>::doIt();
+    case K::JSBitOr:                         return M<R::BitOr>::doIt();
+    case K::JSBitXor:                        return M<R::BitXor>::doIt();
+    case K::JSUnsignedShiftRight:            return M<R::UShr>::doIt();
+    case K::JSShiftRight:                    return M<R::Shr>::doIt();
+    case K::JSShiftLeft:                     return M<R::Shl>::doIt();
+
+    case K::JSAdd:                           return M<R::Add>::doIt();
+    case K::JSSubtract:                      return M<R::Sub>::doIt();
+    case K::JSMultiply:                      return M<R::Mul>::doIt();
+    case K::JSDivide:                        return M<R::Div>::doIt();
+    case K::JSModulo:                        return M<R::Mod>::doIt();
+    case K::JSExponentiate:                  return M<R::Exp>::doIt();
+
+    case K::ToBoolean:                       return M<R::ToBoolean>::doIt();
+    case K::ToObject:                        return M<R::ToObject>::doIt();
+
+    case K::JSNegate:                        return M<R::UMinus>::doIt();
+    case K::JSToNumber:                      return M<R::ToNumber>::doIt();
+
+    case K::JSLoadName:                      return M<R::LoadName>::doIt();
+    case K::JSLoadElement:                   return M<R::LoadElement>::doIt();
+    case K::JSStoreElement:                  return M<R::StoreElement>::doIt();
+    case K::JSGetLookup:                     return M<R::GetLookup>::doIt();
+    case K::JSSetLookupStrict:               return M<R::SetLookupStrict>::doIt();
+    case K::JSSetLookupSloppy:               return M<R::SetLookupSloppy>::doIt();
+    case K::JSLoadProperty:                  return M<R::LoadProperty>::doIt();
+    case K::JSStoreProperty:                 return M<R::StoreProperty>::doIt();
+    case K::JSLoadGlobalLookup:              return M<R::LoadGlobalLookup>::doIt();
+    case K::JSStoreNameSloppy:               return M<R::StoreNameSloppy>::doIt();
+    case K::JSStoreNameStrict:               return M<R::StoreNameStrict>::doIt();
+    case K::JSLoadSuperProperty:             return M<R::LoadSuperProperty>::doIt();
+    case K::JSStoreSuperProperty:            return M<R::StoreSuperProperty>::doIt();
+    case K::JSLoadClosure:                   return M<R::Closure>::doIt();
+    case K::JSGetIterator:                   return M<R::GetIterator>::doIt();
+    case K::JSIteratorNext:                  return M<R::IteratorNext>::doIt();
+    case K::JSIteratorNextForYieldStar:      return M<R::IteratorNextForYieldStar>::doIt();
+    case K::JSIteratorClose:                 return M<R::IteratorClose>::doIt();
+    case K::JSDeleteProperty:                return M<R::DeleteProperty>::doIt();
+    case K::JSDeleteName:                    return M<R::DeleteName>::doIt();
+    case K::JSIn:                            return M<R::In>::doIt();
+    case K::JSInstanceOf:                    return M<R::Instanceof>::doIt();
+    case K::QMLLoadScopeObjectProperty:      return M<R::LoadQmlScopeObjectProperty>::doIt();
+    case K::QMLStoreScopeObjectProperty:     return M<R::StoreQmlScopeObjectProperty>::doIt();
+    case K::QMLLoadContextObjectProperty:    return M<R::LoadQmlContextObjectProperty>::doIt();
+    case K::QMLStoreContextObjectProperty:   return M<R::StoreQmlContextObjectProperty>::doIt();
+    case K::QMLLoadIdObject:                 return M<R::LoadQmlIdObject>::doIt();
+
+    case K::JSTypeofName:                    return M<R::TypeofName>::doIt();
+    case K::JSTypeofValue:                   return M<R::TypeofValue>::doIt();
+    case K::JSDeclareVar:                    return M<R::DeclareVar>::doIt();
+    case K::JSDestructureRestElement:        return M<R::DestructureRestElement>::doIt();
+    case K::QMLLoadContext:                  return M<R::LoadQmlContext>::doIt();
+    case K::QMLLoadImportedScripts:          return M<R::LoadQmlImportedScripts>::doIt();
+    case K::JSThisToObject:                  return M<R::ConvertThisToObject>::doIt();
+    case K::JSCreateMappedArgumentsObject:   return M<R::CreateMappedArgumentsObject>::doIt();
+    case K::JSCreateUnmappedArgumentsObject: return M<R::CreateUnmappedArgumentsObject>::doIt();
+    case K::JSCreateRestParameter:           return M<R::CreateRestParameter>::doIt();
+    case K::JSLoadSuperConstructor:          return M<R::LoadSuperConstructor>::doIt();
+    case K::JSThrowOnNullOrUndefined:        return M<R::ThrowOnNullOrUndefined>::doIt();
+
+    case K::JSCreateCallContext:             return M<R::PushCallContext>::doIt();
+    case K::JSCreateCatchContext:            return M<R::PushCatchContext>::doIt();
+    case K::JSCreateWithContext:             return M<R::PushWithContext>::doIt();
+    case K::JSCreateBlockContext:            return M<R::PushBlockContext>::doIt();
+    case K::JSCloneBlockContext:             return M<R::CloneBlockContext>::doIt();
+    case K::JSCreateScriptContext:           return M<R::PushScriptContext>::doIt();
+    case K::JSPopScriptContext:              return M<R::PopScriptContext>::doIt();
+
+    case K::LoadRegExp:                      return M<R::RegexpLiteral>::doIt();
+    case K::JSGetTemplateObject:             return M<R::GetTemplateObject>::doIt();
+
+    case K::JSCallName:                      return M<R::CallName>::doIt();
+    case K::JSCallValue:                     return M<R::CallValue>::doIt();
+    case K::JSCallElement:                   return M<R::CallElement>::doIt();
+    case K::JSCallLookup:                    return M<R::CallPropertyLookup>::doIt();
+    case K::JSCallProperty:                  return M<R::CallProperty>::doIt();
+    case K::JSCallGlobalLookup:              return M<R::CallGlobalLookup>::doIt();
+    case K::JSCallPossiblyDirectEval:        return M<R::CallPossiblyDirectEval>::doIt();
+    case K::JSCallWithReceiver:              return M<R::CallWithReceiver>::doIt();
+    case K::JSDefineObjectLiteral:           return M<R::ObjectLiteral>::doIt();
+    case K::JSDefineArray:                   return M<R::ArrayLiteral>::doIt();
+    case K::JSCallWithSpread:                return M<R::CallWithSpread>::doIt();
+    case K::JSConstruct:                     return M<R::Construct>::doIt();
+    case K::JSConstructWithSpread:           return M<R::ConstructWithSpread>::doIt();
+    case K::JSTailCall:                      return M<R::TailCall>::doIt();
+    case K::JSCreateClass:                   return M<R::CreateClass>::doIt();
+    default:
+        if (abortOnMissingCall)
+            Q_UNREACHABLE();
+        else
+            return ReturnValue();
+    }
+}
+
+template<typename Method>
+struct IsRuntimeMethodOperation
+{
+    static constexpr bool doIt() { return true; }
+};
+
+bool CallPayload::isRuntimeCall(Operation::Kind m)
+{
+    return operateOnRuntimeCall<IsRuntimeMethodOperation, bool>(m, false);
+}
+
+QString CallPayload::debugString() const
+{
+    return QString::fromLatin1(QMetaEnum::fromType<Meta::OpKind>().valueToKey(m_callee));
+}
+
+template<typename Method>
+struct MethodArgcOperation
+{
+    static constexpr unsigned doIt() { return RuntimeSupport::argumentCount<Method>(); }
+};
+
+unsigned CallPayload::argc(Operation::Kind callee)
+{
+    return operateOnRuntimeCall<MethodArgcOperation, unsigned>(callee);
+}
+
+template<typename Method> struct MethodArg1TyOperation { static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::arg1Type<Method>(); } };
+template<typename Method> struct MethodArg2TyOperation { static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::arg2Type<Method>(); } };
+template<typename Method> struct MethodArg3TyOperation { static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::arg3Type<Method>(); } };
+template<typename Method> struct MethodArg4TyOperation { static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::arg4Type<Method>(); } };
+template<typename Method> struct MethodArg5TyOperation { static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::arg5Type<Method>(); } };
+template<typename Method> struct MethodArg6TyOperation { static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::arg6Type<Method>(); } };
+
+static RuntimeSupport::ArgumentType untranslatedArgumentType(Operation::Kind m, unsigned arg)
+{
+    if (m == Meta::JSTailCall) {
+        if (arg < 4)
+            return RuntimeSupport::ArgumentType::ValueRef;
+        else
+            return RuntimeSupport::ArgumentType::Invalid;
+    }
+
+    switch (arg) {
+    case 0: return operateOnRuntimeCall<MethodArg1TyOperation, RuntimeSupport::ArgumentType>(m);
+    case 1: return operateOnRuntimeCall<MethodArg2TyOperation, RuntimeSupport::ArgumentType>(m);
+    case 2: return operateOnRuntimeCall<MethodArg3TyOperation, RuntimeSupport::ArgumentType>(m);
+    case 3: return operateOnRuntimeCall<MethodArg4TyOperation, RuntimeSupport::ArgumentType>(m);
+    case 4: return operateOnRuntimeCall<MethodArg5TyOperation, RuntimeSupport::ArgumentType>(m);
+    case 5: return operateOnRuntimeCall<MethodArg6TyOperation, RuntimeSupport::ArgumentType>(m);
+    default: return RuntimeSupport::ArgumentType::Invalid;
+    }
+}
+
+bool CallPayload::needsStorageOnJSStack(Operation::Kind m, unsigned arg, const Operation *op,
+                                        Type nodeType)
+{
+    auto argTy = untranslatedArgumentType(m, arg);
+    if (argTy == RuntimeSupport::ArgumentType::ValueArray)
+        return true;
+    if (argTy != RuntimeSupport::ArgumentType::ValueRef)
+        return false;
+
+    if (op->kind() == Meta::Constant)
+        return true;
+
+    return !nodeType.isObject() && !nodeType.isRawPointer() && !nodeType.isAny();
+}
+
+template<typename Method>
+struct MethodRetTyOperation
+{
+    static constexpr RuntimeSupport::ArgumentType doIt() { return RuntimeSupport::retType<Method>(); }
+};
+
+Type CallPayload::returnType(Operation::Kind m)
+{
+    if (m == Meta::JSTailCall)
+        return Type();
+
+    auto t = operateOnRuntimeCall<MethodRetTyOperation, RuntimeSupport::ArgumentType>(m);
+    return translateType(t);
+}
+
+static int firstArgumentPositionForType(Operation::Kind m, RuntimeSupport::ArgumentType type)
+{
+    if (operateOnRuntimeCall<MethodArg1TyOperation, RuntimeSupport::ArgumentType>(m) == type)
+        return 1;
+    if (operateOnRuntimeCall<MethodArg2TyOperation, RuntimeSupport::ArgumentType>(m) == type)
+        return 2;
+    if (operateOnRuntimeCall<MethodArg3TyOperation, RuntimeSupport::ArgumentType>(m) == type)
+        return 3;
+    if (operateOnRuntimeCall<MethodArg4TyOperation, RuntimeSupport::ArgumentType>(m) == type)
+        return 4;
+    if (operateOnRuntimeCall<MethodArg5TyOperation, RuntimeSupport::ArgumentType>(m) == type)
+        return 5;
+    if (operateOnRuntimeCall<MethodArg6TyOperation, RuntimeSupport::ArgumentType>(m) == type)
+        return 6;
+    return -1;
+}
+
+unsigned CallPayload::varArgsStart(Operation::Kind m)
+{
+    if (m == Meta::JSTailCall)
+        return 4 - 1;
+
+    int pos = firstArgumentPositionForType(m, RuntimeSupport::ArgumentType::ValueArray) - 1;
+    Q_ASSERT(pos >= 0);
+    return pos;
+}
+
+bool CallPayload::isVarArgsCall(Operation::Kind m)
+{
+    if (m == Meta::JSTailCall)
+        return true;
+    if (lastArgumentIsOutputValue(m))
+        return false;
+    return firstArgumentPositionForType(m, RuntimeSupport::ArgumentType::ValueArray) != -1;
+}
+
+bool CallPayload::isVarArgsCall() const
+{
+    return isVarArgsCall(m_callee);
+}
+
+template<typename Method>
+struct MethodsLastArgumentIsOutputValue
+{
+    static constexpr bool doIt() { return Method::lastArgumentIsOutputValue; }
+};
+
+bool CallPayload::lastArgumentIsOutputValue(Operation::Kind m)
+{
+    return operateOnRuntimeCall<MethodsLastArgumentIsOutputValue, bool>(m);
+}
+
+template<typename Method>
+struct MethodChangesContext
+{
+    static constexpr bool doIt() { return Method::changesContext; }
+};
+
+bool CallPayload::changesContext(Operation::Kind m)
+{
+    return operateOnRuntimeCall<MethodChangesContext, bool>(m);
+}
+
+template<typename Method>
+struct MethodIsPure
+{
+    static constexpr bool doIt() { return Method::pure; }
+};
+
+bool CallPayload::isPure(Operation::Kind m)
+{
+    return operateOnRuntimeCall<MethodIsPure, bool>(m);
+}
+
+template<typename Method>
+struct MethodCanThrow
+{
+    static constexpr bool doIt() { return Method::throws; }
+};
+
+bool CallPayload::canThrow(Operation::Kind m)
+{
+    switch (m) {
+    case Meta::Throw: Q_FALLTHROUGH();
+    case Meta::ThrowReferenceError:
+        // the execution path following these instructions is already linked up to the exception handler
+        return false;
+    case Meta::JSIteratorNext: Q_FALLTHROUGH();
+    case Meta::JSIteratorNextForYieldStar:
+        // special case: see GraphBuilder::generate_IteratorNext
+        return false;
+    default:
+        return operateOnRuntimeCall<MethodCanThrow, bool>(m);
+    }
+}
+
+bool CallPayload::takesEngineAsArg(Operation::Kind m, int arg)
+{
+    return untranslatedArgumentType(m, arg) == RuntimeSupport::ArgumentType::Engine;
+}
+
+bool CallPayload::takesFunctionAsArg(Operation::Kind m, int arg)
+{
+    return untranslatedArgumentType(m, arg) == RuntimeSupport::ArgumentType::Function;
+}
+
+bool CallPayload::takesFrameAsArg(Operation::Kind m, int arg)
+{
+    return untranslatedArgumentType(m, arg) == RuntimeSupport::ArgumentType::Frame;
+}
+
+template<typename Method>
+struct GetMethodPtr
+{
+    static constexpr void *doIt() { return reinterpret_cast<void *>(&Method::call); }
+};
+
+void *CallPayload::getMethodPtr(Operation::Kind m)
+{
+    return operateOnRuntimeCall<GetMethodPtr, void *>(m);
+}
+
+} // IR namespace
+} // QV4 namespace
+QT_END_NAMESPACE
diff --git a/src/qml/jit/qv4operation_p.h b/src/qml/jit/qv4operation_p.h
new file mode 100644
index 0000000000..8b66e58d4b
--- /dev/null
+++ b/src/qml/jit/qv4operation_p.h
@@ -0,0 +1,574 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4OPERATION_P_H
+#define QV4OPERATION_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4ir_p.h>
+#include <private/qqmljsmemorypool_p.h>
+
+#include <QtCore/qatomic.h>
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace IR {
+
+namespace Meta {
+enum OpKind: uint16_t {
+    FrameState,
+    Start,
+    End,
+
+    Undefined,
+    Constant,
+    Parameter,
+    Empty,
+    Engine,
+    CppFrame,
+    Function,
+
+    Jump,
+    Return,
+    JSTailCall,
+    TailCall,
+    Branch,
+    IfTrue,
+    IfFalse,
+    Region,
+    OnException,
+    Phi,
+    EffectPhi,
+    SelectOutput,
+    UnwindDispatch,
+    UnwindToLabel,
+    HandleUnwind,
+    Throw,
+    ThrowReferenceError,
+
+    Call,
+
+    LoadRegExp,
+    ScopedLoad,
+    ScopedStore,
+
+    JSLoadElement,
+    JSStoreElement,
+    JSGetLookup,
+    JSSetLookupStrict,
+    JSSetLookupSloppy,
+    JSLoadProperty,
+    JSStoreProperty,
+    JSLoadName,
+    JSLoadGlobalLookup,
+    JSStoreNameSloppy,
+    JSStoreNameStrict,
+    JSLoadSuperProperty,
+    JSStoreSuperProperty,
+    JSLoadClosure,
+    JSGetIterator,
+    JSIteratorNext,
+    JSIteratorNextForYieldStar,
+    JSIteratorClose,
+    JSDeleteProperty,
+    JSDeleteName,
+    JSIn,
+    JSInstanceOf,
+    /* ok, these are qml object ops, but we don't care for now and treat them a s JS */
+    QMLLoadScopeObjectProperty,
+    QMLStoreScopeObjectProperty,
+    QMLLoadContextObjectProperty,
+    QMLStoreContextObjectProperty,
+    QMLLoadIdObject,
+
+    JSEqual,
+    JSGreaterThan,
+    JSGreaterEqual,
+    JSLessThan,
+    JSLessEqual,
+    JSStrictEqual,
+
+    JSAdd,
+    JSSubtract,
+    JSMultiply,
+    JSDivide,
+    JSModulo,
+    JSExponentiate,
+
+    JSBitAnd,
+    JSBitOr,
+    JSBitXor,
+    JSUnsignedShiftRight,
+    JSShiftRight,
+    JSShiftLeft,
+
+    JSNegate,
+    JSToNumber,
+
+    JSCallName,
+    JSCallValue,
+    JSCallElement,
+    JSCallProperty,
+    JSCallLookup,
+    JSCallGlobalLookup,
+    JSCallPossiblyDirectEval,
+    JSCallWithReceiver,
+    JSCallWithSpread,
+    JSDefineObjectLiteral,
+    JSDefineArray,
+    JSCreateClass,
+    JSConstruct,
+    JSConstructWithSpread,
+    /* ok, these are qml vararg calls, but we don't care for now and treat them as JS */
+    QMLCallScopeObjectProperty,
+    QMLCallContextObjectProperty,
+
+    JSTypeofName,
+    JSTypeofValue,
+    JSDeclareVar,
+    JSDestructureRestElement,
+    QMLLoadContext,
+    QMLLoadImportedScripts,
+    JSThisToObject,
+    JSCreateMappedArgumentsObject,
+    JSCreateUnmappedArgumentsObject,
+    JSCreateRestParameter,
+    JSLoadSuperConstructor,
+    JSThrowOnNullOrUndefined,
+    JSGetTemplateObject,
+    StoreThis,
+
+    JSCreateCallContext,
+    JSCreateCatchContext,
+    JSCreateWithContext,
+    JSCreateBlockContext,
+    JSCloneBlockContext,
+    JSCreateScriptContext,
+    JSPopScriptContext,
+    PopContext,
+
+    GetException,
+    SetException,
+
+    ToObject,
+    ToBoolean,
+
+    //### do we need this? Or should a later phase generate JumpIsEmpty?
+    IsEmpty,
+
+    Alloca,
+    VAAlloc,
+    VAStore,
+    VASeal,
+
+    BooleanNot,
+    HasException,
+
+    // Low level, used by the register allocator and stack allocator:
+    Swap,
+    Move,
+    KindsEnd
+};
+Q_NAMESPACE
+Q_ENUM_NS(OpKind)
+} // namespace Ops
+
+class Operation
+{
+    Q_DISABLE_COPY_MOVE(Operation)
+
+public:
+    using Kind = Meta::OpKind;
+
+    enum Flags: uint8_t {
+        NoFlags              = 0,
+        ThrowsFlag           = 1 << 0,
+        Pure                 = 1 << 1, // no read/write side effect, cannot throw, cannot deopt, and is idempotent
+        NeedsBytecodeOffsets = 1 << 2,
+
+        CanThrow             = ThrowsFlag | NeedsBytecodeOffsets,
+
+        HasFrameStateInput   = 1 << 3,
+    };
+
+public:
+    static Operation *create(QQmlJS::MemoryPool *pool, Kind kind, uint16_t  inValueCount,
+                             uint16_t inEffectCount, uint16_t  inControlCount,
+                             uint16_t outValueCount, uint16_t outEffectCount,
+                             uint16_t outControlCount, Type type, uint8_t flags)
+    {
+        return pool->New<Operation>(kind, inValueCount, inEffectCount, inControlCount,
+                                    outValueCount, outEffectCount, outControlCount,
+                                    type, Flags(flags));
+    }
+
+    Kind kind() const
+    { return m_kind; }
+
+    bool isConstant() const
+    {
+        switch (kind()) {
+        case Meta::Undefined: Q_FALLTHROUGH();
+        case Meta::Constant:
+        case Meta::Empty:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    QString debugString() const;
+
+    uint16_t valueInputCount() const { return m_inValueCount; }
+    uint16_t effectInputCount() const { return m_inEffectCount; }
+    uint16_t controlInputCount() const { return m_inControlCount; }
+    uint16_t valueOutputCount() const { return m_outValueCount; }
+    uint16_t effectOutputCount() const { return m_outEffectCount; }
+    uint16_t controlOutputCount() const { return m_outControlCount; }
+
+    unsigned indexOfFirstEffect() const { return m_inValueCount; }
+    unsigned indexOfFirstControl() const { return m_inValueCount + m_inEffectCount; }
+    unsigned indexOfFrameStateInput() const
+    {
+        return hasFrameStateInput() ? indexOfFirstControl() + m_inControlCount
+                                    : std::numeric_limits<unsigned>::max();
+    }
+
+    Type type() const
+    { return m_type; }
+
+    bool canThrow() const
+    { return m_flags & ThrowsFlag; }
+
+    bool isPure() const
+    { return m_flags & Pure; }
+
+    bool needsBytecodeOffsets() const
+    { return m_flags & NeedsBytecodeOffsets; }
+
+    bool hasFrameStateInput() const
+    { return m_flags & HasFrameStateInput; }
+
+    unsigned totalInputCount() const
+    {
+        return valueInputCount() + effectInputCount() + controlInputCount() +
+                (hasFrameStateInput() ? 1 : 0);
+    }
+    unsigned totalOutputCount() const { return valueOutputCount() + effectOutputCount() + controlOutputCount(); }
+
+protected:
+    friend class QQmlJS::MemoryPool;
+    Operation(Kind kind,
+              uint16_t  inValueCount, uint16_t  inEffectCount, uint16_t  inControlCount,
+              uint16_t outValueCount, uint16_t outEffectCount, uint16_t outControlCount,
+              Type type, uint8_t flags)
+        : m_kind(kind)
+        , m_inValueCount(inValueCount)
+        , m_inEffectCount(inEffectCount)
+        , m_inControlCount(inControlCount)
+        , m_outValueCount(outValueCount)
+        , m_outEffectCount(outEffectCount)
+        , m_outControlCount(outControlCount)
+        , m_type(type)
+        , m_flags(Flags(flags))
+    {
+    }
+
+    ~Operation() = default;
+
+private:
+    Kind m_kind;
+    uint16_t m_inValueCount;
+    uint16_t m_inEffectCount;
+    uint16_t m_inControlCount;
+    uint16_t m_outValueCount;
+    uint16_t m_outEffectCount;
+    uint16_t m_outControlCount;
+    Type m_type;
+    Flags m_flags;
+};
+
+template <typename Payload>
+class OperationWithPayload: public Operation
+{
+public:
+    static OperationWithPayload *create(QQmlJS::MemoryPool *pool, Kind kind,
+                                        uint16_t  inValueCount, uint16_t  inEffectCount, uint16_t  inControlCount,
+                                        uint16_t outValueCount, uint16_t outEffectCount, uint16_t outControlCount,
+                                        Type type, Flags flags, Payload payload)
+    {
+        return pool->New<OperationWithPayload>(kind, inValueCount, inEffectCount, inControlCount,
+                                               outValueCount, outEffectCount, outControlCount,
+                                               type, flags, payload);
+    }
+
+    const Payload &payload() const
+    { return m_payload; }
+
+protected:
+    friend class QQmlJS::MemoryPool;
+    OperationWithPayload(Kind kind,
+                         uint16_t  inValueCount, uint16_t  inEffectCount, uint16_t  inControlCount,
+                         uint16_t outValueCount, uint16_t outEffectCount, uint16_t outControlCount,
+                         Type type, Flags flags, Payload payload)
+        : Operation(kind,
+                    inValueCount, inEffectCount, inControlCount,
+                    outValueCount, outEffectCount, outControlCount,
+                    type, flags)
+        , m_payload(payload)
+    {}
+
+    ~OperationWithPayload() = default;
+
+private:
+    Payload m_payload;
+};
+
+class ConstantPayload
+{
+public:
+    explicit ConstantPayload(QV4::Value v)
+        : m_value(v)
+    {}
+
+    QV4::Value value() const
+    { return m_value; }
+
+    static const ConstantPayload *get(const Operation &op)
+    {
+        if (op.kind() != Meta::Constant)
+            return nullptr;
+
+        return &static_cast<const OperationWithPayload<ConstantPayload>&>(op).payload();
+    }
+
+    QString debugString() const;
+    static QString debugString(QV4::Value v);
+
+private:
+    QV4::Value m_value;
+};
+
+class ParameterPayload
+{
+public:
+    ParameterPayload(size_t index, Function::StringId stringId)
+        : m_index(index)
+        , m_stringId(stringId)
+    {}
+
+    size_t parameterIndex() const
+    { return m_index; }
+
+    Function::StringId stringId() const
+    { return m_stringId; }
+
+    static const ParameterPayload *get(const Operation &op)
+    {
+        if (op.kind() != Meta::Parameter)
+            return nullptr;
+
+        return &static_cast<const OperationWithPayload<ParameterPayload>&>(op).payload();
+    }
+
+    QString debugString() const;
+
+private:
+    size_t m_index;
+    Function::StringId m_stringId;
+};
+
+class CallPayload
+{
+public:
+    CallPayload(Operation::Kind callee)
+        : m_callee(callee)
+    {}
+
+    static const CallPayload *get(const Operation &op)
+    {
+        if (op.kind() != Meta::Call)
+            return nullptr;
+
+        return &static_cast<const OperationWithPayload<CallPayload>&>(op).payload();
+    }
+
+    static bool isRuntimeCall(Operation::Kind m);
+
+    Operation::Kind callee() const { return m_callee; }
+    QString debugString() const;
+
+    unsigned argc() const { return argc(m_callee); }
+    static unsigned argc(Operation::Kind callee);
+    static bool needsStorageOnJSStack(Operation::Kind m, unsigned arg, const Operation *op,
+                                      Type nodeType);
+    static Type returnType(Operation::Kind m);
+    static int engineArgumentPosition(Operation::Kind m);
+    static int functionArgumentPosition(Operation::Kind m);
+
+    static constexpr unsigned NoVarArgs = std::numeric_limits<unsigned>::max();
+    static unsigned varArgsStart(Operation::Kind m);
+    static bool isVarArgsCall(Operation::Kind m);
+    bool isVarArgsCall() const;
+    static bool lastArgumentIsOutputValue(Operation::Kind m);
+    static bool changesContext(Operation::Kind m);
+    static bool isPure(Operation::Kind m);
+    static bool canThrow(Operation::Kind m);
+    static bool takesEngineAsArg(Operation::Kind m, int arg);
+    static bool takesFunctionAsArg(Operation::Kind m, int arg);
+    static bool takesFrameAsArg(Operation::Kind m, int arg);
+    static void *getMethodPtr(Operation::Kind m);
+
+private:
+    Operation::Kind m_callee;
+};
+
+class UnwindDispatchPayload
+{
+public:
+    UnwindDispatchPayload(int unwindHandlerOffset, int fallthroughSuccessor)
+        : m_unwindHandlerOffset(unwindHandlerOffset)
+        , m_fallthroughSuccessor(fallthroughSuccessor)
+    {}
+
+    int unwindHandlerOffset() const
+    { return m_unwindHandlerOffset; }
+
+    int fallthroughSuccessor() const //### unused...
+    { return m_fallthroughSuccessor; }
+
+    static const UnwindDispatchPayload *get(const Operation &op)
+    {
+        if (op.kind() != Meta::UnwindDispatch)
+            return nullptr;
+
+        return &static_cast<const OperationWithPayload<UnwindDispatchPayload>&>(op).payload();
+    }
+
+    QString debugString() const;
+
+private:
+    int m_unwindHandlerOffset;
+    int m_fallthroughSuccessor;
+};
+
+class HandleUnwindPayload
+{
+public:
+    HandleUnwindPayload(int unwindHandlerOffset)
+        : m_unwindHandlerOffset(unwindHandlerOffset)
+    {}
+
+    int unwindHandlerOffset() const
+    { return m_unwindHandlerOffset; }
+
+    static const HandleUnwindPayload *get(const Operation &op)
+    {
+        if (op.kind() != Meta::HandleUnwind)
+            return nullptr;
+
+        return &static_cast<const OperationWithPayload<HandleUnwindPayload>&>(op).payload();
+    }
+
+    QString debugString() const;
+
+private:
+    int m_unwindHandlerOffset;
+};
+
+class OperationBuilder
+{
+    Q_DISABLE_COPY_MOVE(OperationBuilder)
+
+    friend class QQmlJS::MemoryPool;
+    OperationBuilder(QQmlJS::MemoryPool *graphPool);
+
+public:
+    static OperationBuilder *create(QQmlJS::MemoryPool *pool);
+    ~OperationBuilder() = delete;
+
+    Operation *getConstant(QV4::Value v);
+    Operation *getFrameState(uint16_t frameSize);
+    Operation *getStart(uint16_t outputCount);
+    Operation *getEnd(uint16_t controlInputCount);
+    Operation *getParam(unsigned index, Function::StringId name);
+    Operation *getRegion(unsigned nControlInputs);
+    Operation *getPhi(unsigned nValueInputs);
+    Operation *getEffectPhi(unsigned nEffectInputs);
+    Operation *getUnwindDispatch(unsigned nControlOutputs, int unwindHandlerOffset, int fallthroughSuccessor);
+    Operation *getHandleUnwind(int unwindHandlerOffset);
+
+    template<Operation::Kind kind>
+    Operation *get() {
+        return staticOperation(kind);
+    }
+
+    Operation *getVASeal(uint16_t nElements);
+
+    Operation *getJSVarArgsCall(Operation::Kind kind, uint16_t argc);
+    Operation *getJSTailCall(uint16_t argc);
+    Operation *getTailCall();
+
+    Operation *getCall(Operation::Kind callee);
+
+private:
+    QQmlJS::MemoryPool *m_graphPool; // used to store per-graph nodes
+    Operation *m_opFrameState = nullptr;
+    static Operation *staticOperation(Operation::Kind kind);
+};
+
+} // namespace IR
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4OPERATION_P_H
diff --git a/src/qml/jit/qv4regalloc.cpp b/src/qml/jit/qv4regalloc.cpp
deleted file mode 100644
index d418b050c4..0000000000
--- a/src/qml/jit/qv4regalloc.cpp
+++ /dev/null
@@ -1,1971 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the V4VM module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include <QtCore/QBuffer>
-#include <QtCore/QDebug>
-#include "qv4regalloc_p.h"
-#include "qv4alloca_p.h"
-#include <private/qv4value_p.h>
-
-#include <algorithm>
-#if defined(Q_CC_MINGW)
-#  include <malloc.h>
-#endif
-
-namespace {
-enum { DebugRegAlloc = 0 };
-
-struct Use {
-    enum RegisterFlag { MustHaveRegister = 0, CouldHaveRegister = 1 };
-    unsigned flag : 1;
-    unsigned pos  : 31;
-
-    Use(): flag(MustHaveRegister), pos(0) {}
-    Use(int position, RegisterFlag flag): flag(flag), pos(position)
-    { Q_ASSERT(position >= 0); }
-
-    bool mustHaveRegister() const { return flag == MustHaveRegister; }
-};
-}
-
-QT_BEGIN_NAMESPACE
-
-Q_DECLARE_TYPEINFO(Use, Q_MOVABLE_TYPE);
-
-using namespace QV4::IR;
-
-namespace QV4 {
-namespace JIT {
-
-namespace {
-class IRPrinterWithPositions: public IRPrinter
-{
-    LifeTimeIntervals::Ptr intervals;
-    const int positionSize;
-
-public:
-    IRPrinterWithPositions(QTextStream *out, const LifeTimeIntervals::Ptr &intervals)
-        : IRPrinter(out)
-        , intervals(intervals)
-        , positionSize(QString::number(intervals->lastPosition()).size())
-    {}
-
-protected:
-    void addStmtNr(Stmt *s) Q_DECL_OVERRIDE Q_DECL_FINAL
-    {
-        addJustifiedNr(intervals->positionForStatement(s));
-    }
-};
-
-class IRPrinterWithRegisters: public IRPrinterWithPositions
-{
-    const RegisterInformation &_registerInformation;
-    QHash<int, const RegisterInfo *> _infoForRegularRegister;
-    QHash<int, const RegisterInfo *> _infoForFPRegister;
-
-public:
-    IRPrinterWithRegisters(QTextStream *out, const LifeTimeIntervals::Ptr &intervals,
-                           const RegisterInformation &registerInformation)
-        : IRPrinterWithPositions(out, intervals)
-        , _registerInformation(registerInformation)
-    {
-        for (int i = 0, ei = _registerInformation.size(); i != ei; ++i)
-            if (_registerInformation.at(i).isRegularRegister())
-                _infoForRegularRegister.insert(_registerInformation.at(i).reg<int>(),
-                                               &_registerInformation.at(i));
-            else
-                _infoForFPRegister.insert(_registerInformation.at(i).reg<int>(),
-                                          &_registerInformation.at(i));
-    }
-
-protected:
-    void visitTemp(Temp *e) Q_DECL_OVERRIDE Q_DECL_FINAL
-    {
-        switch (e->kind) {
-        case Temp::PhysicalRegister: {
-            const RegisterInfo *ri = e->type == DoubleType ? _infoForFPRegister.value(e->index, 0)
-                                                           : _infoForRegularRegister.value(e->index, 0);
-            if (ri) {
-                *out << ri->prettyName();
-                break;
-            }
-            Q_FALLTHROUGH();
-        }
-        default:
-            IRPrinterWithPositions::visitTemp(e);
-        }
-    }
-};
-}
-
-class RegAllocInfo: public IRDecoder
-{
-public:
-    typedef QVarLengthArray<Temp, 4> Hints;
-
-private:
-    struct Def {
-        unsigned valid : 1;
-        unsigned canHaveReg : 1;
-        unsigned isPhiTarget : 1;
-
-        Def(): valid(0), canHaveReg(0), isPhiTarget(0) {}
-        Def(bool canHaveReg, bool isPhiTarget)
-            : valid(1), canHaveReg(canHaveReg), isPhiTarget(isPhiTarget)
-        {
-        }
-
-        bool isValid() const { return valid != 0; }
-    };
-
-    IR::LifeTimeIntervals::Ptr _lifeTimeIntervals;
-    BasicBlock *_currentBB;
-    Stmt *_currentStmt;
-    std::vector<Def> _defs;
-    std::vector<std::vector<Use> > _uses;
-    std::vector<int> _calls;
-    std::vector<Hints> _hints;
-
-    int usePosition(Stmt *s) const
-    {
-        int usePos = _lifeTimeIntervals->positionForStatement(s);
-        if (usePos == Stmt::InvalidId) // phi-node operand, so:
-            usePos = _lifeTimeIntervals->startPosition(_currentBB);
-        return usePos;
-    }
-
-public:
-    RegAllocInfo(): _currentBB(0), _currentStmt(0) {}
-
-    void collect(IR::Function *function, const IR::LifeTimeIntervals::Ptr &lifeTimeIntervals)
-    {
-        _lifeTimeIntervals = lifeTimeIntervals;
-        _defs.resize(function->tempCount);
-        _uses.resize(function->tempCount);
-        _calls.reserve(function->statementCount() / 3);
-        _hints.resize(function->tempCount);
-
-        for (BasicBlock *bb : function->basicBlocks()) {
-            _currentBB = bb;
-            for (Stmt *s : bb->statements()) {
-                _currentStmt = s;
-                visit(s);
-            }
-        }
-    }
-
-    const std::vector<Use> &uses(const Temp &t) const
-    {
-        return _uses.at(t.index);
-    }
-
-    bool canHaveRegister(const Temp &t) const {
-        Q_ASSERT(_defs[t.index].isValid());
-        return _defs[t.index].canHaveReg;
-    }
-    bool isPhiTarget(const Temp &t) const {
-        Q_ASSERT(_defs[t.index].isValid());
-        return _defs[t.index].isPhiTarget;
-    }
-
-    const std::vector<int> &calls() const { return _calls; }
-    const Hints &hints(const Temp &t) const { return _hints[t.index]; }
-    void addHint(const Temp &t, int physicalRegister)
-    { addHint(t, Temp::PhysicalRegister, physicalRegister); }
-
-    void addHint(const Temp &t, Temp::Kind kind, int hintedIndex)
-    {
-        Hints &hints = _hints[t.index];
-        for (Hints::iterator i = hints.begin(), ei = hints.end(); i != ei; ++i)
-            if (i->index == hintedIndex)
-                return;
-
-        Temp hint;
-        hint.init(kind, hintedIndex);
-        hints.append(hint);
-    }
-
-    void dump() const
-    {
-        if (!DebugRegAlloc)
-            return;
-
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream qout(&buf);
-        IRPrinterWithPositions printer(&qout, _lifeTimeIntervals);
-
-        qout << "RegAllocInfo:" << endl << "Defs/uses:" << endl;
-        for (unsigned t = 0; t < _defs.size(); ++t) {
-            const std::vector<Use> &uses = _uses[t];
-            if (uses.empty())
-                continue;
-            qout << "%" << t <<": "
-                 << " ("
-                 << (_defs[t].canHaveReg ? "can" : "can NOT")
-                 << " have a register, and "
-                 << (_defs[t].isPhiTarget ? "is" : "is NOT")
-                 << " defined by a phi node), uses at: ";
-            for (unsigned i = 0; i < uses.size(); ++i) {
-                if (i > 0) qout << ", ";
-                qout << uses[i].pos;
-                if (uses[i].mustHaveRegister()) qout << "(R)"; else qout << "(S)";
-            }
-            qout << endl;
-        }
-
-        qout << "Calls at: ";
-        for (unsigned i = 0; i < _calls.size(); ++i) {
-            if (i > 0) qout << ", ";
-            qout << _calls[i];
-        }
-        qout << endl;
-
-        qout << "Hints:" << endl;
-        for (unsigned t = 0; t < _hints.size(); ++t) {
-            if (_uses[t].empty())
-                continue;
-            qout << "\t%" << t << ": ";
-            const Hints &hints = _hints[t];
-            for (int i = 0; i < hints.size(); ++i) {
-                if (i > 0) qout << ", ";
-                printer.print(hints[i]);
-            }
-            qout << endl;
-        }
-        qDebug("%s", buf.data().constData());
-    }
-
-protected: // IRDecoder
-    void callBuiltinInvalid(IR::Name *, IR::ExprList *, IR::Expr *) override {}
-    void callBuiltinTypeofQmlContextProperty(IR::Expr *, IR::Member::MemberKind, int, IR::Expr *) override {}
-    void callBuiltinTypeofMember(IR::Expr *, const QString &, IR::Expr *) override {}
-    void callBuiltinTypeofSubscript(IR::Expr *, IR::Expr *, IR::Expr *) override {}
-    void callBuiltinTypeofName(const QString &, IR::Expr *) override {}
-    void callBuiltinTypeofValue(IR::Expr *, IR::Expr *) override {}
-    void callBuiltinDeleteMember(IR::Expr *, const QString &, IR::Expr *) override {}
-    void callBuiltinDeleteSubscript(IR::Expr *, IR::Expr *, IR::Expr *) override {}
-    void callBuiltinDeleteName(const QString &, IR::Expr *) override {}
-    void callBuiltinDeleteValue(IR::Expr *) override {}
-    void callBuiltinThrow(IR::Expr *) override {}
-    void callBuiltinReThrow() override {}
-    void callBuiltinUnwindException(IR::Expr *) override {}
-    void callBuiltinPushCatchScope(const QString &) override {};
-    void callBuiltinForeachIteratorObject(IR::Expr *, IR::Expr *) override {}
-    virtual void callBuiltinForeachNextProperty(IR::Temp *, IR::Temp *) {}
-    void callBuiltinForeachNextPropertyname(IR::Expr *, IR::Expr *) override {}
-    void callBuiltinPushWithScope(IR::Expr *) override {}
-    void callBuiltinPopScope() override {}
-    void callBuiltinDeclareVar(bool , const QString &) override {}
-    void callBuiltinDefineArray(IR::Expr *, IR::ExprList *) override {}
-    void callBuiltinDefineObjectLiteral(IR::Expr *, int, IR::ExprList *, IR::ExprList *, bool) override {}
-    void callBuiltinSetupArgumentObject(IR::Expr *) override {}
-    void callBuiltinConvertThisToObject() override {}
-
-    void callValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) override
-    {
-        addDef(result);
-        if (IR::Temp *tempValue = value->asTemp())
-            addUses(tempValue, Use::CouldHaveRegister);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void callQmlContextProperty(IR::Expr *base, IR::Member::MemberKind /*kind*/, int propertyIndex,
-                                        IR::ExprList *args, IR::Expr *result) override
-    {
-        Q_UNUSED(propertyIndex)
-
-        addDef(result);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void callProperty(IR::Expr *base, const QString &name, IR::ExprList *args,
-                      IR::Expr *result) override
-    {
-        Q_UNUSED(name)
-
-        addDef(result);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void callSubscript(IR::Expr *base, IR::Expr *index, IR::ExprList *args,
-                       IR::Expr *result) override
-    {
-        addDef(result);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addUses(index->asTemp(), Use::CouldHaveRegister);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void convertType(IR::Expr *source, IR::Expr *target) override
-    {
-        addDef(target);
-
-        bool needsCall = true;
-        Use::RegisterFlag sourceReg = Use::CouldHaveRegister;
-
-        switch (target->type) {
-        case DoubleType:
-            switch (source->type) {
-            case UInt32Type:
-            case SInt32Type:
-            case NullType:
-            case UndefinedType:
-            case BoolType:
-                needsCall = false;
-                break;
-            default:
-                break;
-            }
-            break;
-        case BoolType:
-            switch (source->type) {
-            case UInt32Type:
-                sourceReg = Use::MustHaveRegister;
-                needsCall = false;
-                break;
-            case DoubleType:
-            case UndefinedType:
-            case NullType:
-            case SInt32Type:
-                needsCall = false;
-                break;
-            default:
-                break;
-            }
-            break;
-        case SInt32Type:
-            switch (source->type) {
-            case UInt32Type:
-            case NullType:
-            case UndefinedType:
-            case BoolType:
-                needsCall = false;
-            default:
-                break;
-            }
-            break;
-        case UInt32Type:
-            switch (source->type) {
-            case SInt32Type:
-            case NullType:
-            case UndefinedType:
-            case BoolType:
-                needsCall = false;
-            default:
-                break;
-            }
-            break;
-        default:
-            break;
-        }
-
-        Temp *sourceTemp = source->asTemp();
-        if (sourceTemp)
-            addUses(sourceTemp, sourceReg);
-
-        if (needsCall)
-            addCall();
-        else if (target->asTemp())
-            addHint(target->asTemp(), sourceTemp);
-    }
-
-    void constructActivationProperty(IR::Name *, IR::ExprList *args, IR::Expr *result) override
-    {
-        addDef(result);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void constructProperty(IR::Expr *base, const QString &, IR::ExprList *args, IR::Expr *result) override
-    {
-        addDef(result);
-        addUses(base, Use::CouldHaveRegister);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void constructValue(IR::Expr *value, IR::ExprList *args, IR::Expr *result) override
-    {
-        addDef(result);
-        addUses(value, Use::CouldHaveRegister);
-        addUses(args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void loadThisObject(IR::Expr *temp) override
-    {
-        addDef(temp);
-    }
-
-    void loadQmlContext(IR::Expr *temp) override
-    {
-        addDef(temp);
-        addCall();
-    }
-
-    void loadQmlImportedScripts(IR::Expr *temp) override
-    {
-        addDef(temp);
-        addCall();
-    }
-
-    void loadQmlSingleton(const QString &/*name*/, Expr *temp) override
-    {
-        Q_UNUSED(temp);
-
-        addDef(temp);
-        addCall();
-    }
-
-    void loadConst(IR::Const *sourceConst, Expr *targetTemp) override
-    {
-        Q_UNUSED(sourceConst);
-
-        addDef(targetTemp);
-    }
-
-    void loadString(const QString &str, Expr *targetTemp) override
-    {
-        Q_UNUSED(str);
-
-        addDef(targetTemp);
-    }
-
-    void loadRegexp(IR::RegExp *sourceRegexp, Expr *targetTemp) override
-    {
-        Q_UNUSED(sourceRegexp);
-
-        addDef(targetTemp);
-        addCall();
-    }
-
-    void getActivationProperty(const IR::Name *, Expr *temp) override
-    {
-        addDef(temp);
-        addCall();
-    }
-
-    void setActivationProperty(IR::Expr *source, const QString &) override
-    {
-        addUses(source->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void initClosure(IR::Closure *closure, Expr *target) override
-    {
-        Q_UNUSED(closure);
-
-        addDef(target);
-        addCall();
-    }
-
-    void getProperty(IR::Expr *base, const QString &, Expr *target) override
-    {
-        addDef(target);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void setProperty(IR::Expr *source, IR::Expr *targetBase, const QString &) override
-    {
-        addUses(source->asTemp(), Use::CouldHaveRegister);
-        addUses(targetBase->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void setQmlContextProperty(IR::Expr *source, IR::Expr *targetBase,
-                               IR::Member::MemberKind /*kind*/, int /*propertyIndex*/) override
-    {
-        addUses(source->asTemp(), Use::CouldHaveRegister);
-        addUses(targetBase->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void setQObjectProperty(IR::Expr *source, IR::Expr *targetBase, int /*propertyIndex*/) override
-    {
-        addUses(source->asTemp(), Use::CouldHaveRegister);
-        addUses(targetBase->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void getQmlContextProperty(IR::Expr *base, IR::Member::MemberKind /*kind*/, int /*index*/,
-                               bool /*captureRequired*/, IR::Expr *target) override
-    {
-        addDef(target);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void getQObjectProperty(IR::Expr *base, int /*propertyIndex*/, bool /*captureRequired*/,
-                            bool /*isSingleton*/, int /*attachedPropertiesId*/, IR::Expr *target) override
-    {
-        addDef(target);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void getElement(IR::Expr *base, IR::Expr *index, Expr *target) override
-    {
-        addDef(target);
-        addUses(base->asTemp(), Use::CouldHaveRegister);
-        addUses(index->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void setElement(IR::Expr *source, IR::Expr *targetBase, IR::Expr *targetIndex) override
-    {
-        addUses(source->asTemp(), Use::CouldHaveRegister);
-        addUses(targetBase->asTemp(), Use::CouldHaveRegister);
-        addUses(targetIndex->asTemp(), Use::CouldHaveRegister);
-        addCall();
-    }
-
-    void copyValue(Expr *source, Expr *target) override
-    {
-        addDef(target);
-        Temp *sourceTemp = source->asTemp();
-        if (!sourceTemp)
-            return;
-        addUses(sourceTemp, Use::CouldHaveRegister);
-        Temp *targetTemp = target->asTemp();
-        if (targetTemp)
-            addHint(targetTemp, sourceTemp);
-    }
-
-    void swapValues(Expr *, Expr *) override
-    {
-        // Inserted by the register allocator, so it cannot occur here.
-        Q_UNREACHABLE();
-    }
-
-    void unop(AluOp oper, Expr *source, Expr *target) override
-    {
-        addDef(target);
-
-        bool needsCall = true;
-        if (oper == OpNot && source->type == IR::BoolType && target->type == IR::BoolType)
-            needsCall = false;
-
-#if 0 // TODO: change masm to generate code
-        switch (oper) {
-        case OpIfTrue:
-        case OpNot:
-        case OpUMinus:
-        case OpUPlus:
-        case OpCompl:
-            needsCall = sourceTemp->type & ~NumberType && sourceTemp->type != BoolType;
-            break;
-
-        case OpIncrement:
-        case OpDecrement:
-        default:
-            Q_UNREACHABLE();
-        }
-#endif
-
-        IR::Temp *sourceTemp = source->asTemp();
-        if (needsCall) {
-            if (sourceTemp)
-                addUses(sourceTemp, Use::CouldHaveRegister);
-            addCall();
-        } else {
-            if (sourceTemp)
-                addUses(sourceTemp, Use::MustHaveRegister);
-        }
-    }
-
-    void binop(AluOp oper, Expr *leftSource, Expr *rightSource, Expr *target) override
-    {
-        bool needsCall = true;
-
-        if (oper == OpStrictEqual || oper == OpStrictNotEqual) {
-            bool noCall = leftSource->type == NullType || rightSource->type == NullType
-                    || leftSource->type == UndefinedType || rightSource->type == UndefinedType
-                    || leftSource->type == BoolType || rightSource->type == BoolType;
-            needsCall = !noCall;
-        } else if (leftSource->type == DoubleType && rightSource->type == DoubleType) {
-            if (oper == OpMul || oper == OpAdd || oper == OpDiv || oper == OpSub
-                    || (oper >= OpGt && oper <= OpStrictNotEqual)) {
-                needsCall = false;
-            }
-        } else if (oper == OpBitAnd || oper == OpBitOr || oper == OpBitXor || oper == OpLShift || oper == OpRShift || oper == OpURShift) {
-            needsCall = false;
-        } else if (oper == OpAdd || oper == OpMul || oper == OpSub
-                   || (oper >= OpGt && oper <= OpStrictNotEqual)) {
-            if (leftSource->type == SInt32Type && rightSource->type == SInt32Type)
-                needsCall = false;
-        }
-
-        addDef(target);
-
-        if (needsCall) {
-            addUses(leftSource->asTemp(), Use::CouldHaveRegister);
-            addUses(rightSource->asTemp(), Use::CouldHaveRegister);
-            addCall();
-        } else {
-            addUses(leftSource->asTemp(), Use::MustHaveRegister);
-            addHint(target, leftSource->asTemp());
-            addHint(target, rightSource->asTemp());
-
-#if CPU(X86) || CPU(X86_64)
-            switch (oper) {
-                // The rhs operand can be a memory address
-            case OpAdd:
-            case OpSub:
-            case OpMul:
-            case OpDiv:
-#if CPU(X86_64)
-                if (leftSource->type == DoubleType || rightSource->type == DoubleType) {
-                    // well, on 64bit the doubles are mangled, so they must first be loaded in a register and demangled, so...:
-                    addUses(rightSource->asTemp(), Use::MustHaveRegister);
-                    break;
-                }
-                Q_FALLTHROUGH();
-#endif
-            case OpBitAnd:
-            case OpBitOr:
-            case OpBitXor:
-                addUses(rightSource->asTemp(), Use::CouldHaveRegister);
-                break;
-
-            default:
-                addUses(rightSource->asTemp(), Use::MustHaveRegister);
-                break;
-            }
-#else
-            addUses(rightSource->asTemp(), Use::MustHaveRegister);
-#endif
-        }
-    }
-
-    void visitJump(IR::Jump *) override {}
-    void visitCJump(IR::CJump *s) override
-    {
-        if (Temp *t = s->cond->asTemp()) {
-#if 0 // TODO: change masm to generate code
-            addUses(t, Use::MustHaveRegister);
-#else
-            addUses(t, Use::CouldHaveRegister);
-            addCall();
-#endif
-        } else if (Binop *b = s->cond->asBinop()) {
-            binop(b->op, b->left, b->right, 0);
-        } else if (s->cond->asConst()) {
-            // TODO: SSA optimization for constant condition evaluation should remove this.
-            // See also visitCJump() in masm.
-            addCall();
-        } else {
-            Q_UNREACHABLE();
-        }
-    }
-
-    void visitRet(IR::Ret *s) override
-    { addUses(s->expr->asTemp(), Use::CouldHaveRegister); }
-
-    void visitPhi(IR::Phi *s) override
-    {
-        addDef(s->targetTemp, true);
-        for (int i = 0, ei = s->incoming.size(); i < ei; ++i) {
-            Expr *e = s->incoming.at(i);
-            if (Temp *t = e->asTemp()) {
-                // The actual use of an incoming value in a phi node is right before the terminator
-                // of the other side of the incoming edge.
-                const int usePos = _lifeTimeIntervals->positionForStatement(_currentBB->in.at(i)->terminator()) - 1;
-                addUses(t, Use::CouldHaveRegister, usePos);
-                addHint(s->targetTemp, t);
-                addHint(t, s->targetTemp);
-            }
-        }
-    }
-
-protected:
-    void callBuiltin(IR::Call *c, IR::Expr *result) override
-    {
-        addDef(result);
-        addUses(c->base, Use::CouldHaveRegister);
-        addUses(c->args, Use::CouldHaveRegister);
-        addCall();
-    }
-
-private:
-    void addDef(Expr *e, bool isPhiTarget = false)
-    {
-        if (!e)
-            return;
-        Temp *t = e->asTemp();
-        if (!t)
-            return;
-        if (!t || t->kind != Temp::VirtualRegister)
-            return;
-        Q_ASSERT(!_defs[t->index].isValid());
-        bool canHaveReg = true;
-        switch (t->type) {
-        case QObjectType:
-        case VarType:
-        case StringType:
-        case UndefinedType:
-        case NullType:
-            canHaveReg = false;
-            break;
-        default:
-            break;
-        }
-
-        _defs[t->index] = Def(canHaveReg, isPhiTarget);
-    }
-
-    void addUses(Expr *e, Use::RegisterFlag flag)
-    {
-        const int usePos = usePosition(_currentStmt);
-        addUses(e, flag, usePos);
-    }
-
-    void addUses(Expr *e, Use::RegisterFlag flag, int usePos)
-    {
-        Q_ASSERT(usePos > 0);
-        if (!e)
-            return;
-        Temp *t = e->asTemp();
-        if (!t)
-            return;
-        if (t && t->kind == Temp::VirtualRegister)
-            _uses[t->index].push_back(Use(usePos, flag));
-    }
-
-    void addUses(ExprList *l, Use::RegisterFlag flag)
-    {
-        for (ExprList *it = l; it; it = it->next)
-            addUses(it->expr, flag);
-    }
-
-    void addCall()
-    {
-        _calls.push_back(usePosition(_currentStmt));
-    }
-
-    void addHint(Expr *hinted, Temp *hint1, Temp *hint2 = 0)
-    {
-        if (hinted)
-            if (Temp *hintedTemp = hinted->asTemp())
-                addHint(hintedTemp, hint1, hint2);
-    }
-
-    void addHint(Temp *hinted, Temp *hint1, Temp *hint2 = 0)
-    {
-        if (!hinted || hinted->kind != Temp::VirtualRegister)
-            return;
-        if (hint1 && hint1->kind == Temp::VirtualRegister && hinted->type == hint1->type)
-            addHint(*hinted, Temp::VirtualRegister, hint1->index);
-        if (hint2 && hint2->kind == Temp::VirtualRegister && hinted->type == hint2->type)
-            addHint(*hinted, Temp::VirtualRegister, hint2->index);
-    }
-};
-
-} // JIT namespace
-} // QV4 namespace
-QT_END_NAMESPACE
-
-QT_USE_NAMESPACE
-
-using namespace QT_PREPEND_NAMESPACE(QV4::JIT);
-using namespace QT_PREPEND_NAMESPACE(QV4::IR);
-using namespace QT_PREPEND_NAMESPACE(QV4);
-
-namespace {
-class ResolutionPhase
-{
-    Q_DISABLE_COPY(ResolutionPhase)
-
-    LifeTimeIntervals::Ptr _intervals;
-    QVector<LifeTimeInterval *> _unprocessedReverseOrder;
-    IR::Function *_function;
-    const std::vector<int> &_assignedSpillSlots;
-    std::vector<const LifeTimeInterval *> _liveIntervals;
-    const QVector<const RegisterInfo *> &_intRegs;
-    const QVector<const RegisterInfo *> &_fpRegs;
-
-    Stmt *_currentStmt;
-    std::vector<Move *> _loads;
-    std::vector<Move *> _stores;
-
-    std::vector<std::vector<const LifeTimeInterval *> > _liveAtStart;
-    std::vector<std::vector<const LifeTimeInterval *> > _liveAtEnd;
-
-public:
-    ResolutionPhase(QVector<LifeTimeInterval *> &&unprocessedReversedOrder,
-                    const LifeTimeIntervals::Ptr &intervals,
-                    IR::Function *function,
-                    const std::vector<int> &assignedSpillSlots,
-                    const QVector<const RegisterInfo *> &intRegs,
-                    const QVector<const RegisterInfo *> &fpRegs)
-        : _intervals(intervals)
-        , _unprocessedReverseOrder(unprocessedReversedOrder)
-        , _function(function)
-        , _assignedSpillSlots(assignedSpillSlots)
-        , _intRegs(intRegs)
-        , _fpRegs(fpRegs)
-        , _currentStmt(0)
-    {
-        _liveAtStart.resize(function->basicBlockCount());
-        _liveAtEnd.resize(function->basicBlockCount());
-    }
-
-    void run() {
-        renumber();
-        if (DebugRegAlloc) {
-            QBuffer buf;
-            buf.open(QIODevice::WriteOnly);
-            QTextStream qout(&buf);
-            IRPrinterWithPositions(&qout, _intervals).print(_function);
-            qDebug("%s", buf.data().constData());
-        }
-        resolve();
-    }
-
-private:
-    int defPosition(Stmt *s) const
-    {
-        return usePosition(s) + 1;
-    }
-
-    int usePosition(Stmt *s) const
-    {
-        return _intervals->positionForStatement(s);
-    }
-
-    void renumber()
-    {
-        QVector<Stmt *> newStatements;
-
-        for (BasicBlock *bb : _function->basicBlocks()) {
-            _currentStmt = 0;
-
-            QVector<Stmt *> statements = bb->statements();
-            newStatements.reserve(bb->statements().size() + 7);
-            newStatements.erase(newStatements.begin(), newStatements.end());
-
-            cleanOldIntervals(_intervals->startPosition(bb));
-            addNewIntervals(_intervals->startPosition(bb));
-            _liveAtStart[bb->index()] = _liveIntervals;
-
-            for (int i = 0, ei = statements.size(); i != ei; ++i) {
-                _currentStmt = statements.at(i);
-                _loads.clear();
-                _stores.clear();
-                if (_currentStmt->asTerminator())
-                    addNewIntervals(usePosition(_currentStmt));
-                else
-                    addNewIntervals(defPosition(_currentStmt));
-                visit(_currentStmt);
-                for (Move *load : _loads)
-                    newStatements.append(load);
-                if (_currentStmt->asPhi())
-                    newStatements.prepend(_currentStmt);
-                else
-                    newStatements.append(_currentStmt);
-                for (Move *store : _stores)
-                    newStatements.append(store);
-            }
-
-            cleanOldIntervals(_intervals->endPosition(bb));
-            _liveAtEnd[bb->index()] = _liveIntervals;
-
-            if (DebugRegAlloc) {
-                QBuffer buf;
-                buf.open(QIODevice::WriteOnly);
-                QTextStream os(&buf);
-                os << "Intervals live at the start of L" << bb->index() << ":" << endl;
-                if (_liveAtStart[bb->index()].empty())
-                    os << "\t(none)" << endl;
-                for (const LifeTimeInterval *i : _liveAtStart.at(bb->index())) {
-                    os << "\t";
-                    i->dump(os);
-                    os << endl;
-                }
-                os << "Intervals live at the end of L" << bb->index() << ":" << endl;
-                if (_liveAtEnd[bb->index()].empty())
-                    os << "\t(none)" << endl;
-                for (const LifeTimeInterval *i : _liveAtEnd.at(bb->index())) {
-                    os << "\t";
-                    i->dump(os);
-                    os << endl;
-                }
-                qDebug("%s", buf.data().constData());
-            }
-
-            bb->setStatements(newStatements);
-        }
-
-    }
-
-    const LifeTimeInterval *findLiveInterval(Temp *t) const
-    {
-        for (const LifeTimeInterval *lti : _liveIntervals) {
-            if (lti->temp() == *t)
-                return lti;
-        }
-
-        return nullptr;
-    }
-
-    void maybeGenerateSpill(Temp *t)
-    {
-        const LifeTimeInterval *i = findLiveInterval(t);
-        if (i->reg() == LifeTimeInterval::InvalidRegister)
-            return;
-
-        const RegisterInfo *pReg = platformRegister(*i);
-        Q_ASSERT(pReg);
-        int spillSlot = _assignedSpillSlots[i->temp().index];
-        if (spillSlot != RegisterAllocator::InvalidSpillSlot)
-            _stores.push_back(generateSpill(spillSlot, i->temp().type, pReg->reg<int>()));
-    }
-
-    void addNewIntervals(int position)
-    {
-        if (position == Stmt::InvalidId)
-            return;
-
-        while (!_unprocessedReverseOrder.isEmpty()) {
-            const LifeTimeInterval *i = _unprocessedReverseOrder.constLast();
-            if (i->start() > position)
-                break;
-
-            Q_ASSERT(!i->isFixedInterval());
-            auto it = _liveIntervals.begin();
-            for (; it != _liveIntervals.end(); ++it) {
-                if ((*it)->temp() == i->temp()) {
-                    *it = i;
-                    break;
-                }
-            }
-            if (it == _liveIntervals.end())
-                _liveIntervals.push_back(i);
-//            qDebug() << "-- Activating interval for temp" << i->temp().index;
-
-            _unprocessedReverseOrder.removeLast();
-        }
-    }
-
-    void cleanOldIntervals(int position)
-    {
-        for (size_t it = 0; it != _liveIntervals.size(); ) {
-            const LifeTimeInterval *lti = _liveIntervals.at(it);
-            if (lti->end() < position || lti->isFixedInterval())
-                _liveIntervals.erase(_liveIntervals.begin() + it);
-            else
-                ++it;
-        }
-    }
-
-    void resolve()
-    {
-        for (BasicBlock *bb : _function->basicBlocks()) {
-            for (BasicBlock *bbOut : bb->out)
-                resolveEdge(bb, bbOut);
-        }
-    }
-
-    Phi *findDefPhi(const Temp &t, BasicBlock *bb) const
-    {
-        for (Stmt *s : bb->statements()) {
-            Phi *phi = s->asPhi();
-            if (!phi)
-                return 0;
-
-            if (*phi->targetTemp == t)
-                return phi;
-        }
-
-        Q_UNREACHABLE();
-    }
-
-    void resolveEdge(BasicBlock *predecessor, BasicBlock *successor)
-    {
-        if (DebugRegAlloc) {
-            qDebug() << "Resolving edge" << predecessor->index() << "->" << successor->index();
-            QBuffer buf;
-            buf.open(QIODevice::WriteOnly);
-            QTextStream qout(&buf);
-            IRPrinterWithPositions printer(&qout, _intervals);
-            printer.print(predecessor);
-            printer.print(successor);
-            qDebug("%s", buf.data().constData());
-        }
-
-        MoveMapping mapping;
-
-        const int predecessorEnd = _intervals->endPosition(predecessor);
-        Q_ASSERT(predecessorEnd > 0);
-
-        int successorStart = _intervals->startPosition(successor);
-        Q_ASSERT(successorStart > 0);
-
-        for (const LifeTimeInterval *it : _liveAtStart.at(successor->index())) {
-            bool isPhiTarget = false;
-            Expr *moveFrom = 0;
-
-            if (it->start() == successorStart) {
-                if (Phi *phi = findDefPhi(it->temp(), successor)) {
-                    isPhiTarget = true;
-                    Expr *opd = phi->incoming[successor->in.indexOf(predecessor)];
-                    if (opd->asConst()) {
-                        moveFrom = opd;
-                    } else {
-                        Temp *t = opd->asTemp();
-                        Q_ASSERT(t);
-
-                        for (const LifeTimeInterval *it2 : _liveAtEnd.at(predecessor->index())) {
-                            if (it2->temp() == *t
-                                    && it2->reg() != LifeTimeInterval::InvalidRegister
-                                    && it2->covers(predecessorEnd)) {
-                                moveFrom = createPhysicalRegister(it2, t->type);
-                                break;
-                            }
-                        }
-                        if (!moveFrom)
-                            moveFrom = createTemp(Temp::StackSlot,
-                                                  _assignedSpillSlots[t->index],
-                                    t->type);
-                    }
-                }
-            } else {
-                for (const LifeTimeInterval *predIt : _liveAtEnd.at(predecessor->index())) {
-                    if (predIt->temp() == it->temp()) {
-                        if (predIt->reg() != LifeTimeInterval::InvalidRegister
-                                && predIt->covers(predecessorEnd)) {
-                            moveFrom = createPhysicalRegister(predIt, predIt->temp().type);
-                        } else {
-                            int spillSlot = _assignedSpillSlots[predIt->temp().index];
-                            if (spillSlot != -1)
-                                moveFrom = createTemp(Temp::StackSlot, spillSlot, predIt->temp().type);
-                        }
-                        break;
-                    }
-                }
-            }
-            if (!moveFrom) {
-#if !defined(QT_NO_DEBUG) && 0
-                bool lifeTimeHole = false;
-                if (it->ranges().first().start <= successorStart && it->ranges().last().end >= successorStart)
-                    lifeTimeHole = !it->covers(successorStart);
-
-                Q_ASSERT(!_info->isPhiTarget(it->temp()) || it->isSplitFromInterval() || lifeTimeHole);
-                if (_info->def(it->temp()) != successorStart && !it->isSplitFromInterval()) {
-                    const int successorEnd = successor->terminator()->id();
-                    const int idx = successor->in.indexOf(predecessor);
-                    for (const Use &use : _info->uses(it->temp)) {
-                        if (use.pos == static_cast<unsigned>(successorStart)) {
-                            // only check the current edge, not all other possible ones. This is
-                            // important for phi nodes: they have uses that are only valid when
-                            // coming in over a specific edge.
-                            for (Stmt *s : successor->statements()) {
-                                if (Phi *phi = s->asPhi()) {
-                                    Q_ASSERT(it->temp().index != phi->targetTemp->index);
-                                    Q_ASSERT(phi->d->incoming[idx]->asTemp() == 0
-                                             || it->temp().index != phi->d->incoming[idx]->asTemp()->index);
-                                } else {
-                                    // TODO: check that the first non-phi statement does not use
-                                    // the temp.
-                                    break;
-                                }
-                            }
-                        } else {
-                            Q_ASSERT(use.pos < static_cast<unsigned>(successorStart) ||
-                                     use.pos > static_cast<unsigned>(successorEnd));
-                        }
-                    }
-                }
-#endif
-
-                continue;
-            }
-
-            Temp *moveTo;
-            if (it->reg() == LifeTimeInterval::InvalidRegister || !it->covers(successorStart)) {
-                if (!isPhiTarget) // if it->temp() is a phi target, skip it.
-                    continue;
-                const int spillSlot = _assignedSpillSlots[it->temp().index];
-                if (spillSlot == RegisterAllocator::InvalidSpillSlot)
-                    continue; // it has a life-time hole here.
-                moveTo = createTemp(Temp::StackSlot, spillSlot, it->temp().type);
-            } else {
-                moveTo = createPhysicalRegister(it, it->temp().type);
-            }
-
-            // add move to mapping
-            mapping.add(moveFrom, moveTo);
-        }
-
-        if (DebugRegAlloc)
-            mapping.dump();
-        mapping.order();
-        if (DebugRegAlloc)
-            mapping.dump();
-
-        bool insertIntoPredecessor = successor->in.size() > 1;
-        mapping.insertMoves(insertIntoPredecessor ? predecessor : successor, _function,
-                            insertIntoPredecessor);
-
-        if (DebugRegAlloc) {
-            qDebug() << ".. done, result:";
-            QBuffer buf;
-            buf.open(QIODevice::WriteOnly);
-            QTextStream qout(&buf);
-            IRPrinterWithPositions printer(&qout, _intervals);
-            printer.print(predecessor);
-            printer.print(successor);
-            qDebug("%s", buf.data().constData());
-        }
-    }
-
-    Temp *createTemp(Temp::Kind kind, int index, Type type) const
-    {
-        Q_ASSERT(index >= 0);
-        Temp *t = _function->New<Temp>();
-        t->init(kind, index);
-        t->type = type;
-        return t;
-    }
-
-    Temp *createPhysicalRegister(const LifeTimeInterval *i, Type type) const
-    {
-        const RegisterInfo *ri = platformRegister(*i);
-        Q_ASSERT(ri);
-        return createTemp(Temp::PhysicalRegister, ri->reg<int>(), type);
-    }
-
-    const RegisterInfo *platformRegister(const LifeTimeInterval &i) const
-    {
-        if (i.isFP())
-            return _fpRegs.value(i.reg(), 0);
-        else
-            return _intRegs.value(i.reg(), 0);
-    }
-
-    Move *generateSpill(int spillSlot, Type type, int pReg) const
-    {
-        Q_ASSERT(spillSlot >= 0);
-
-        Move *store = _function->NewStmt<Move>();
-        store->init(createTemp(Temp::StackSlot, spillSlot, type),
-                    createTemp(Temp::PhysicalRegister, pReg, type));
-        return store;
-    }
-
-    Move *generateUnspill(const Temp &t, int pReg) const
-    {
-        Q_ASSERT(pReg >= 0);
-        int spillSlot = _assignedSpillSlots[t.index];
-        Q_ASSERT(spillSlot != -1);
-        Move *load = _function->NewStmt<Move>();
-        load->init(createTemp(Temp::PhysicalRegister, pReg, t.type),
-                   createTemp(Temp::StackSlot, spillSlot, t.type));
-        return load;
-    }
-
-private:
-    void visit(Expr *e)
-    {
-        switch (e->exprKind) {
-        case Expr::TempExpr:
-            visitTemp(e->asTemp());
-            break;
-        default:
-            EXPR_VISIT_ALL_KINDS(e);
-            break;
-        }
-    }
-
-    void visitTemp(Temp *t)
-    {
-        if (t->kind != Temp::VirtualRegister)
-            return;
-
-        const LifeTimeInterval *i = findLiveInterval(t);
-        Q_ASSERT(i->isValid());
-
-        if (_currentStmt != 0 && i->start() == usePosition(_currentStmt)) {
-            Q_ASSERT(i->isSplitFromInterval());
-            const RegisterInfo *pReg = platformRegister(*i);
-            Q_ASSERT(pReg);
-            _loads.push_back(generateUnspill(i->temp(), pReg->reg<int>()));
-        }
-
-        if (i->reg() != LifeTimeInterval::InvalidRegister &&
-                (i->covers(defPosition(_currentStmt)) ||
-                 i->covers(usePosition(_currentStmt)))) {
-            const RegisterInfo *pReg = platformRegister(*i);
-            Q_ASSERT(pReg);
-            t->kind = Temp::PhysicalRegister;
-            t->index = pReg->reg<unsigned>();
-        } else {
-            int stackSlot = _assignedSpillSlots[t->index];
-            Q_ASSERT(stackSlot >= 0);
-            t->kind = Temp::StackSlot;
-            t->index = stackSlot;
-        }
-    }
-
-    void visit(Stmt *s)
-    {
-        switch (s->stmtKind) {
-        case Stmt::MoveStmt: {
-            auto m = s->asMove();
-            if (Temp *t = m->target->asTemp())
-                maybeGenerateSpill(t);
-
-            visit(m->source);
-            visit(m->target);
-        } break;
-        case Stmt::PhiStmt: {
-            auto p = s->asPhi();
-            maybeGenerateSpill(p->targetTemp);
-        } break;
-        default:
-            STMT_VISIT_ALL_KINDS(s);
-            break;
-        }
-    }
-};
-} // anonymous namespace
-
-RegisterAllocator::RegisterAllocator(const QV4::JIT::RegisterInformation &registerInformation)
-    : _registerInformation(registerInformation)
-{
-    for (int i = 0, ei = registerInformation.size(); i != ei; ++i) {
-        const RegisterInfo &regInfo = registerInformation.at(i);
-        if (regInfo.useForRegAlloc()) {
-            if (regInfo.isRegularRegister())
-                _normalRegisters.append(&regInfo);
-            else
-                _fpRegisters.append(&regInfo);
-        }
-    }
-    Q_ASSERT(_normalRegisters.size() >= 2);
-    Q_ASSERT(_fpRegisters.size() >= 2);
-    _active.reserve((_normalRegisters.size() + _fpRegisters.size()) * 2);
-    _inactive.reserve(_active.size());
-
-    _regularRegsInUse.resize(_normalRegisters.size());
-    _fpRegsInUse.resize(_fpRegisters.size());
-}
-
-RegisterAllocator::~RegisterAllocator()
-{
-}
-
-void RegisterAllocator::run(IR::Function *function, const Optimizer &opt)
-{
-    _lastAssignedRegister.assign(function->tempCount, LifeTimeInterval::InvalidRegister);
-    _assignedSpillSlots.assign(function->tempCount, InvalidSpillSlot);
-    _activeSpillSlots.resize(function->tempCount);
-
-    if (DebugRegAlloc)
-        qDebug() << "*** Running regalloc for function" << (function->name ? qPrintable(*function->name) : "NO NAME") << "***";
-
-    _lifeTimeIntervals = opt.lifeTimeIntervals();
-
-    _unhandled = _lifeTimeIntervals->intervals();
-    _handled.reserve(_unhandled.size());
-
-    _info.reset(new RegAllocInfo);
-    _info->collect(function, _lifeTimeIntervals);
-
-    if (DebugRegAlloc) {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream qout(&buf);
-        qout << "Ranges:" << endl;
-        QVector<LifeTimeInterval *> intervals = _unhandled;
-        std::reverse(intervals.begin(), intervals.end());
-        for (const LifeTimeInterval *r : qAsConst(intervals)) {
-            r->dump(qout);
-            qout << endl;
-        }
-        qDebug("%s", buf.data().constData());
-        _info->dump();
-
-        qDebug() << "*** Before register allocation:";
-        buf.setData(QByteArray());
-        IRPrinterWithPositions(&qout, _lifeTimeIntervals).print(function);
-        qDebug("%s", buf.data().constData());
-    }
-    prepareRanges();
-
-    linearScan();
-
-    if (DebugRegAlloc)
-        dump(function);
-
-    // sort the ranges in reverse order, so the ResolutionPhase can take from the end (and thereby
-    // prevent the copy overhead that taking from the beginning would give).
-    std::sort(_handled.begin(), _handled.end(),
-              [](const LifeTimeInterval *r1, const LifeTimeInterval *r2) -> bool {
-        return LifeTimeInterval::lessThan(r2, r1);
-    });
-    ResolutionPhase(std::move(_handled), _lifeTimeIntervals, function, _assignedSpillSlots, _normalRegisters, _fpRegisters).run();
-
-    function->tempCount = *std::max_element(_assignedSpillSlots.begin(), _assignedSpillSlots.end()) + 1;
-
-    if (DebugRegAlloc)
-        qDebug() << "*** Finished regalloc , result:";
-
-    static const bool showCode = qEnvironmentVariableIsSet("QV4_SHOW_IR");
-    if (showCode) {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream qout(&buf);
-        IRPrinterWithRegisters(&qout, _lifeTimeIntervals, _registerInformation).print(function);
-        qDebug("%s", buf.data().constData());
-    }
-}
-
-RegisterInformation RegisterAllocator::usedRegisters() const
-{
-    RegisterInformation regInfo;
-
-    for (int i = 0, ei = _normalRegisters.size(); i != ei; ++i) {
-        if (_regularRegsInUse.testBit(i))
-            regInfo.append(*_normalRegisters.at(i));
-    }
-
-    for (int i = 0, ei = _fpRegisters.size(); i != ei; ++i) {
-        if (_fpRegsInUse.testBit(i))
-            regInfo.append(*_fpRegisters.at(i));
-    }
-
-    return regInfo;
-}
-
-void RegisterAllocator::markInUse(int reg, bool isFPReg)
-{
-    if (isFPReg)
-        _fpRegsInUse.setBit(reg);
-    else
-        _regularRegsInUse.setBit(reg);
-}
-
-static inline LifeTimeInterval createFixedInterval(int rangeCount)
-{
-    LifeTimeInterval i(rangeCount);
-    i.setReg(0);
-
-    Temp t;
-    t.init(Temp::PhysicalRegister, 0);
-    t.type = IR::SInt32Type;
-    i.setTemp(t);
-
-    return i;
-}
-
-LifeTimeInterval *RegisterAllocator::cloneFixedInterval(int reg, bool isFP, const LifeTimeInterval &original)
-{
-    LifeTimeInterval *lti = new LifeTimeInterval(original);
-    _lifeTimeIntervals->add(lti);
-    lti->setReg(reg);
-    lti->setFixedInterval(true);
-
-    Temp t;
-    t.init(Temp::PhysicalRegister, reg);
-    t.type = isFP ? IR::DoubleType : IR::SInt32Type;
-    lti->setTemp(t);
-
-    return lti;
-}
-
-// Creates the intervals with fixed ranges. See [Wimmer2]. Note that this only applies to callee-
-// saved registers.
-void RegisterAllocator::prepareRanges()
-{
-    LifeTimeInterval ltiWithCalls = createFixedInterval(int(_info->calls().size()));
-    for (int callPosition : _info->calls())
-        ltiWithCalls.addRange(callPosition, callPosition);
-
-    const int regCount = _normalRegisters.size();
-    _fixedRegisterRanges.resize(regCount);
-    for (int reg = 0; reg < regCount; ++reg) {
-        if (_normalRegisters.at(reg)->isCallerSaved()) {
-            LifeTimeInterval *lti = cloneFixedInterval(reg, false, ltiWithCalls);
-            if (lti->isValid()) {
-                _fixedRegisterRanges[reg] = lti;
-                _active.append(lti);
-            }
-        }
-    }
-
-    const int fpRegCount = _fpRegisters.size();
-    _fixedFPRegisterRanges.resize(fpRegCount);
-    for (int fpReg = 0; fpReg < fpRegCount; ++fpReg) {
-        if (_fpRegisters.at(fpReg)->isCallerSaved()) {
-            LifeTimeInterval *lti = cloneFixedInterval(fpReg, true, ltiWithCalls);
-            if (lti->isValid()) {
-                _fixedFPRegisterRanges[fpReg] = lti;
-                _active.append(lti);
-            }
-        }
-    }
-}
-
-void RegisterAllocator::linearScan()
-{
-    while (!_unhandled.isEmpty()) {
-        LifeTimeInterval *current = _unhandled.back();
-        _unhandled.pop_back();
-        const int position = current->start();
-
-        // check for intervals in active that are handled or inactive
-        for (int i = 0; i < _active.size(); ) {
-            LifeTimeInterval *it = _active.at(i);
-            if (it->end() < position) {
-                if (!it->isFixedInterval())
-                    _handled += it;
-                _active.remove(i);
-            } else if (!it->covers(position)) {
-                _inactive += it;
-                _active.remove(i);
-            } else {
-                ++i;
-            }
-        }
-
-        // check for intervals in inactive that are handled or active
-        for (int i = 0; i < _inactive.size(); ) {
-            LifeTimeInterval *it = _inactive.at(i);
-            if (it->end() < position) {
-                if (!it->isFixedInterval())
-                    _handled += it;
-                _inactive.remove(i);
-            } else if (it->covers(position)) {
-                if (it->reg() != LifeTimeInterval::InvalidRegister) {
-                    _active += it;
-                    _inactive.remove(i);
-                } else {
-                    // although this interval is now active, it has no register allocated (always
-                    // spilled), so leave it in inactive.
-                    ++i;
-                }
-            } else {
-                ++i;
-            }
-        }
-
-        Q_ASSERT(!current->isFixedInterval());
-
-#ifdef DEBUG_REGALLOC
-        qDebug() << "** Position" << position;
-#endif // DEBUG_REGALLOC
-
-        if (_info->canHaveRegister(current->temp())) {
-            tryAllocateFreeReg(*current);
-            if (current->reg() == LifeTimeInterval::InvalidRegister)
-                allocateBlockedReg(*current);
-            if (current->reg() != LifeTimeInterval::InvalidRegister)
-                _active += current;
-        } else {
-            assignSpillSlot(current->temp(), current->start(), current->end());
-            _inactive += current;
-            if (DebugRegAlloc)
-                qDebug() << "*** allocating stack slot" << _assignedSpillSlots[current->temp().index]
-                         << "for %" << current->temp().index << "as it cannot be loaded in a register";
-        }
-    }
-
-    for (LifeTimeInterval *r : qAsConst(_active))
-        if (!r->isFixedInterval())
-            _handled.append(r);
-    _active.clear();
-    for (LifeTimeInterval *r : qAsConst(_inactive))
-        if (!r->isFixedInterval())
-            _handled.append(r);
-    _inactive.clear();
-}
-
-static inline int indexOfRangeCoveringPosition(const LifeTimeInterval::Ranges &ranges, int position)
-{
-    for (int i = 0, ei = ranges.size(); i != ei; ++i) {
-        if (position <= ranges[i].end)
-            return i;
-    }
-    return -1;
-}
-
-static inline int intersectionPosition(const LifeTimeIntervalRange &one, const LifeTimeIntervalRange &two)
-{
-    if (one.covers(two.start))
-        return two.start;
-    if (two.covers(one.start))
-        return one.start;
-    return -1;
-}
-
-static inline bool isFP(const Temp &t)
-{ return t.type == DoubleType; }
-
-static inline bool candidateIsBetterFit(int bestSizeSoFar, int idealSize, int candidateSize)
-{
-    // If the candidateSize is larger than the current we take it only if the current size does not
-    // yet fit for the whole interval.
-    if (bestSizeSoFar < candidateSize && bestSizeSoFar < idealSize)
-        return true;
-
-    // If the candidateSize is smaller we only take it if it still fits the whole interval.
-    if (bestSizeSoFar > candidateSize && candidateSize >= idealSize)
-        return true;
-
-    // Other wise: no luck.
-    return false;
-}
-
-// Out of all available registers (with their next-uses), choose the one that fits the requested
-// duration best. This can return a register that is not free for the whole interval, but that's
-// fine: we just have to split the current interval.
-static void longestAvailableReg(int *nextUses, int nextUseCount, int &reg, int &freeUntilPos_reg, int lastUse)
-{
-    reg = LifeTimeInterval::InvalidRegister;
-    freeUntilPos_reg = 0;
-
-    for (int candidate = 0, candidateEnd = nextUseCount; candidate != candidateEnd; ++candidate) {
-        int fp = nextUses[candidate];
-        if (candidateIsBetterFit(freeUntilPos_reg, lastUse, fp)) {
-            reg = candidate;
-            freeUntilPos_reg = fp;
-        }
-    }
-}
-
-#define CALLOC_ON_STACK(ty, ptr, sz, val) \
-    Q_ASSERT(sz > 0); \
-    Q_ALLOCA_VAR(ty, ptr, sizeof(ty) * (sz)); \
-    for (ty *it = ptr, *eit = ptr + (sz); it != eit; ++it) \
-        *it = val;
-
-// Try to allocate a register that's currently free.
-void RegisterAllocator::tryAllocateFreeReg(LifeTimeInterval &current)
-{
-    Q_ASSERT(!current.isFixedInterval());
-    Q_ASSERT(current.reg() == LifeTimeInterval::InvalidRegister);
-
-    const bool needsFPReg = isFP(current.temp());
-    const int freeUntilPosCount = needsFPReg ? _fpRegisters.size() : _normalRegisters.size();
-    CALLOC_ON_STACK(int, freeUntilPos, freeUntilPosCount, INT_MAX);
-
-    for (Intervals::const_iterator i = _active.constBegin(), ei = _active.constEnd(); i != ei; ++i) {
-        const LifeTimeInterval *it = *i;
-        if (it->isFP() == needsFPReg)
-            freeUntilPos[it->reg()] = 0; // mark register as unavailable
-    }
-
-    for (Intervals::const_iterator i = _inactive.constBegin(), ei = _inactive.constEnd(); i != ei; ++i) {
-        const LifeTimeInterval *it = *i;
-        if (it->isFP() != needsFPReg)
-            continue; // different register type, so not applicable.
-        if (it->reg() == LifeTimeInterval::InvalidRegister)
-            continue; // this range does not block a register from being used, as it has no register assigned
-
-        if (current.isSplitFromInterval() || it->isFixedInterval()) {
-            const int intersectionPos = nextIntersection(current, *it);
-            if (intersectionPos != -1)
-                freeUntilPos[it->reg()] = qMin(freeUntilPos[it->reg()], intersectionPos);
-        }
-    }
-
-    int reg = LifeTimeInterval::InvalidRegister;
-    int freeUntilPos_reg = 0;
-
-    const RegAllocInfo::Hints &hints = _info->hints(current.temp());
-    for (RegAllocInfo::Hints::const_iterator i = hints.begin(), ei = hints.end(); i != ei; ++i) {
-        const Temp &hint = *i;
-        int candidate;
-        if (hint.kind == Temp::PhysicalRegister)
-            candidate = hint.index;
-        else
-            candidate = _lastAssignedRegister[hint.index];
-
-        const int end = current.end();
-        if (candidate == LifeTimeInterval::InvalidRegister)
-            continue; // the candidate has no register assigned, so it cannot be (re-)used
-        if (current.isFP() != isFP(hint))
-            continue;  // different register type, so not applicable.
-
-        const int fp = freeUntilPos[candidate];
-        if (candidateIsBetterFit(freeUntilPos_reg, end, fp)) {
-            reg = candidate;
-            freeUntilPos_reg = fp;
-        }
-    }
-
-    // None of the hinted registers could fit the interval, so try all registers next.
-    if (reg == LifeTimeInterval::InvalidRegister)
-        longestAvailableReg(freeUntilPos, freeUntilPosCount, reg, freeUntilPos_reg, current.end());
-
-    if (freeUntilPos_reg == 0) {
-        // no register available without spilling
-        if (DebugRegAlloc)
-            qDebug("*** no register available for %u", current.temp().index);
-        return;
-    } else if (current.end() < freeUntilPos_reg) {
-        // register available for the whole interval
-        if (DebugRegAlloc)
-            qDebug() << "*** allocating register" << reg << "for the whole interval of %" << current.temp().index;
-        current.setReg(reg);
-        _lastAssignedRegister[current.temp().index] = reg;
-        markInUse(reg, needsFPReg);
-    } else {
-        // register available for the first part of the interval
-
-        // TODO: this is slightly inefficient in the following case:
-        //   %1 = something
-        //   some_call(%1)
-        //   %2 = %1 + 1
-        // Now %1 will get a register assigned, and will be spilled to the stack immediately. It
-        // would be better to check if there are actually uses in the range before the split.
-
-        current.setReg(reg);
-        _lastAssignedRegister[current.temp().index] = reg;
-        if (DebugRegAlloc)
-            qDebug() << "*** allocating register" << reg << "for the first part of interval of %" << current.temp().index;
-        split(current, freeUntilPos_reg, true);
-        markInUse(reg, needsFPReg);
-    }
-}
-
-// This gets called when all registers are currently in use.
-void RegisterAllocator::allocateBlockedReg(LifeTimeInterval &current)
-{
-    Q_ASSERT(!current.isFixedInterval());
-    Q_ASSERT(current.reg() == LifeTimeInterval::InvalidRegister);
-    const int position = current.start();
-
-    const bool isPhiTarget = _info->isPhiTarget(current.temp());
-    if (isPhiTarget && !current.isSplitFromInterval()) {
-        // Special case: storing to a phi-node's target will result in a single move. So, if we
-        // would spill another interval to the stack (that's 1 store), and then do the move for the
-        // phi target (at least 1 move or a load), that would result in 2 instructions. Instead, we
-        // force the phi-node's target to go to the stack immediately, which is always a single
-        // store.
-        split(current, position + 1, true);
-        _inactive.append(&current);
-        return;
-    }
-
-    const bool needsFPReg = isFP(current.temp());
-    const int nextUsePosCount = needsFPReg ? _fpRegisters.size() : _normalRegisters.size();
-    CALLOC_ON_STACK(int, nextUsePos, nextUsePosCount, INT_MAX);
-    QVector<LifeTimeInterval *> nextUseRangeForReg(nextUsePosCount, 0);
-
-    for (Intervals::const_iterator i = _active.constBegin(), ei = _active.constEnd(); i != ei; ++i) {
-        LifeTimeInterval &it = **i;
-        if (it.isFP() != needsFPReg)
-            continue; // different register type, so not applicable.
-
-        const int nu = it.isFixedInterval() ? 0 : nextUse(it.temp(), current.start());
-        if (nu == position) {
-            nextUsePos[it.reg()] = 0;
-        } else if (nu != -1 && nu < nextUsePos[it.reg()]) {
-            nextUsePos[it.reg()] = nu;
-            nextUseRangeForReg[it.reg()] = &it;
-        } else if (nu == -1 && nextUsePos[it.reg()] == INT_MAX) {
-            // in a loop, the range can be active, but the result might only be used before the
-            // current position (e.g. the induction variable being used in the phi node in the loop
-            // header). So, we can use this register, but we need to remember to split the interval
-            // in order to have the edge-resolving generate a load at the edge going back to the
-            // loop header.
-            nextUseRangeForReg[it.reg()] = &it;
-        }
-    }
-
-    for (Intervals::const_iterator i = _inactive.constBegin(), ei = _inactive.constEnd(); i != ei; ++i) {
-        LifeTimeInterval &it = **i;
-        if (it.isFP() != needsFPReg)
-            continue; // different register type, so not applicable.
-        if (it.reg() == LifeTimeInterval::InvalidRegister)
-            continue; // this range does not block a register from being used, as it has no register assigned
-
-        if (current.isSplitFromInterval() || it.isFixedInterval()) {
-            if (nextIntersection(current, it) != -1) {
-                const int nu = nextUse(it.temp(), current.start());
-                if (nu != -1 && nu < nextUsePos[it.reg()]) {
-                    nextUsePos[it.reg()] = nu;
-                    nextUseRangeForReg[it.reg()] = &it;
-                }
-            }
-        }
-    }
-
-    int reg, nextUsePos_reg;
-    longestAvailableReg(nextUsePos, nextUsePosCount, reg, nextUsePos_reg, current.end());
-
-    Q_ASSERT(current.start() <= nextUsePos_reg);
-
-    // spill interval that currently block reg
-    if (DebugRegAlloc) {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream out(&buf);
-        out << "*** spilling intervals that block reg " <<reg<< " for interval ";
-        current.dump(out);
-        qDebug("%s", buf.data().constData());
-    }
-    current.setReg(reg);
-    _lastAssignedRegister[current.temp().index] = reg;
-    LifeTimeInterval *nextUse = nextUseRangeForReg[reg];
-    Q_ASSERT(nextUse);
-    Q_ASSERT(!nextUse->isFixedInterval());
-
-    split(*nextUse, position, /*skipOptionalRegisterUses =*/ true);
-
-    // We might have chosen a register that is used by a range that has a hole in its life time.
-    // If that's the case, check if the current interval completely fits in the hole. Or rephrased:
-    // check if the current interval will use the register after that hole ends (so that range, and
-    // if so, split that interval so that it gets a new register assigned when it needs one.
-    splitInactiveAtEndOfLifetimeHole(reg, needsFPReg, position);
-
-    // make sure that current does not intersect with the fixed interval for reg
-    const LifeTimeInterval *fixedRegRange = needsFPReg ? _fixedFPRegisterRanges.at(reg)
-                                                       : _fixedRegisterRanges.at(reg);
-    if (fixedRegRange) {
-        int ni = nextIntersection(current, *fixedRegRange);
-        if (ni != -1) {
-            if (DebugRegAlloc) {
-                qDebug("***-- current range intersects with a fixed reg use at %d, so splitting it.", ni);
-            }
-            // current does overlap with a fixed interval, so split current before that intersection.
-            split(current, ni, true);
-        }
-    }
-}
-
-int RegisterAllocator::nextIntersection(const LifeTimeInterval &current,
-                                        const LifeTimeInterval &another) const
-{
-    const LifeTimeInterval::Ranges &currentRanges = current.ranges();
-    int currentIt = 0;
-
-    const LifeTimeInterval::Ranges &anotherRanges = another.ranges();
-    const int anotherItStart = indexOfRangeCoveringPosition(anotherRanges, current.start());
-    if (anotherItStart == -1)
-        return -1;
-
-    for (int currentEnd = currentRanges.size(); currentIt < currentEnd; ++currentIt) {
-        const LifeTimeIntervalRange currentRange = currentRanges.at(currentIt);
-        for (int anotherIt = anotherItStart, anotherEnd = anotherRanges.size(); anotherIt < anotherEnd; ++anotherIt) {
-            const LifeTimeIntervalRange anotherRange = anotherRanges.at(anotherIt);
-            if (anotherRange.start > currentRange.end)
-                break;
-            int intersectPos = intersectionPosition(currentRange, anotherRange);
-            if (intersectPos != -1)
-                return intersectPos;
-        }
-    }
-
-    return -1;
-}
-
-/// Find the first use after the start position for the given temp.
-///
-/// This is only called when all registers are in use, and when one of them has to be spilled to the
-/// stack. So, uses where a register is optional can be ignored.
-int RegisterAllocator::nextUse(const Temp &t, int startPosition) const
-{
-    typedef std::vector<Use>::const_iterator ConstIt;
-
-    const std::vector<Use> &usePositions = _info->uses(t);
-    const ConstIt cend = usePositions.end();
-    for (ConstIt it = usePositions.begin(); it != cend; ++it) {
-        if (it->mustHaveRegister()) {
-            const int usePos = it->pos;
-            if (usePos >= startPosition)
-                return usePos;
-        }
-    }
-
-    return -1;
-}
-
-static inline void insertReverseSorted(QVector<LifeTimeInterval *> &intervals, LifeTimeInterval *newInterval)
-{
-    newInterval->validate();
-    for (int i = intervals.size(); i > 0;) {
-        if (LifeTimeInterval::lessThan(newInterval, intervals.at(--i))) {
-            intervals.insert(i + 1, newInterval);
-            return;
-        }
-    }
-    intervals.insert(0, newInterval);
-}
-
-void RegisterAllocator::split(LifeTimeInterval &current, int beforePosition,
-                              bool skipOptionalRegisterUses)
-{ // TODO: check if we can always skip the optional register uses
-    Q_ASSERT(!current.isFixedInterval());
-
-    if (DebugRegAlloc) {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream out(&buf);
-        out << "***** split request for range ";
-        current.dump(out);
-        out << " before position " << beforePosition
-            << " and skipOptionalRegisterUses = " << skipOptionalRegisterUses << endl;
-        qDebug("%s", buf.data().constData());
-    }
-
-    assignSpillSlot(current.temp(), current.start(), current.end());
-
-    const int firstPosition = current.start();
-    Q_ASSERT(beforePosition > firstPosition && "split before start");
-
-    int lastUse = firstPosition;
-    int nextUse = -1;
-    const std::vector<Use> &usePositions = _info->uses(current.temp());
-    for (size_t i = 0, ei = usePositions.size(); i != ei; ++i) {
-        const Use &usePosition = usePositions.at(i);
-        const int usePos = usePosition.pos;
-        if (lastUse < usePos && usePos < beforePosition) {
-            lastUse = usePos;
-        } else if (usePos >= beforePosition) {
-            if (!skipOptionalRegisterUses || usePosition.mustHaveRegister()) {
-                nextUse = usePos;
-                break;
-            }
-        }
-    }
-    Q_ASSERT(lastUse != -1);
-    Q_ASSERT(lastUse < beforePosition);
-
-    LifeTimeInterval newInterval = current.split(lastUse, nextUse);
-    if (DebugRegAlloc) {
-        QBuffer buf;
-        buf.open(QIODevice::WriteOnly);
-        QTextStream out(&buf);
-        out << "***** last use = " << lastUse << ", nextUse = " << nextUse << endl;
-        out << "***** new interval: ";
-        newInterval.dump(out);
-        out << endl;
-        out << "***** preceding interval: ";
-        current.dump(out);
-        out << endl;
-        qDebug("%s", buf.data().constData());
-    }
-    if (newInterval.isValid()) {
-        if (current.reg() != LifeTimeInterval::InvalidRegister)
-            _info->addHint(current.temp(), current.reg());
-        newInterval.setReg(LifeTimeInterval::InvalidRegister);
-        LifeTimeInterval *newIntervalPtr = new LifeTimeInterval(newInterval);
-        _lifeTimeIntervals->add(newIntervalPtr);
-        insertReverseSorted(_unhandled, newIntervalPtr);
-    }
-}
-
-void RegisterAllocator::splitInactiveAtEndOfLifetimeHole(int reg, bool isFPReg, int position)
-{
-    for (int i = 0, ei = _inactive.size(); i != ei; ++i) {
-        LifeTimeInterval &interval = *_inactive[i];
-        if (interval.isFixedInterval())
-            continue;
-        if (isFPReg == interval.isFP() && interval.reg() == reg) {
-            LifeTimeInterval::Ranges ranges = interval.ranges();
-            int endOfLifetimeHole = -1;
-            for (int j = 0, ej = ranges.size(); j != ej; ++j) {
-                if (position < ranges[j].start)
-                    endOfLifetimeHole = ranges[j].start;
-            }
-            if (endOfLifetimeHole != -1)
-                split(interval, endOfLifetimeHole);
-        }
-    }
-}
-
-void RegisterAllocator::assignSpillSlot(const Temp &t, int startPos, int endPos)
-{
-    if (_assignedSpillSlots[t.index] != InvalidSpillSlot)
-        return;
-
-    for (int i = 0, ei = _activeSpillSlots.size(); i != ei; ++i) {
-        if (_activeSpillSlots.at(i) < startPos) {
-            _activeSpillSlots[i] = endPos;
-            _assignedSpillSlots[t.index] = i;
-            return;
-        }
-    }
-
-    Q_UNREACHABLE();
-}
-
-void RegisterAllocator::dump(IR::Function *function) const
-{
-    QBuffer buf;
-    buf.open(QIODevice::WriteOnly);
-    QTextStream qout(&buf);
-    IRPrinterWithPositions printer(&qout, _lifeTimeIntervals);
-
-    qout << "Ranges:" << endl;
-    QVector<LifeTimeInterval *> handled = _handled;
-    std::sort(handled.begin(), handled.end(), LifeTimeInterval::lessThanForTemp);
-    for (const LifeTimeInterval *r : qAsConst(handled)) {
-        r->dump(qout);
-        qout << endl;
-    }
-
-    qout << "Spill slots:" << endl;
-    for (unsigned i = 0; i < _assignedSpillSlots.size(); ++i)
-        if (_assignedSpillSlots[i] != InvalidSpillSlot)
-            qout << "\t%" << i << " -> " << _assignedSpillSlots[i] << endl;
-
-    printer.print(function);
-    qDebug("%s", buf.data().constData());
-}
-
-// References:
-//  [Wimmer1] C. Wimmer and M. Franz. Linear Scan Register Allocation on SSA Form. In Proceedings of
-//            CGO'10, ACM Press, 2010
-//  [Wimmer2] C. Wimmer and H. Mossenbock. Optimized Interval Splitting in a Linear Scan Register
-//            Allocator. In Proceedings of the ACM/USENIX International Conference on Virtual
-//            Execution Environments, pages 132-141. ACM Press, 2005.
-//  [Traub]   Omri Traub, Glenn Holloway, and Michael D. Smith. Quality and Speed in Linear-scan
-//            Register Allocation. In Proceedings of the ACM SIGPLAN 1998 Conference on Programming
-//            Language Design and Implementation, pages 142-151, June 1998.
diff --git a/src/qml/jit/qv4regalloc_p.h b/src/qml/jit/qv4regalloc_p.h
deleted file mode 100644
index 4ee440b73e..0000000000
--- a/src/qml/jit/qv4regalloc_p.h
+++ /dev/null
@@ -1,140 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the V4VM module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#ifndef QV4REGALLOC_P_H
-#define QV4REGALLOC_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "qv4global_p.h"
-#include "qv4isel_p.h"
-#include "qv4ssa_p.h"
-#include "qv4registerinfo_p.h"
-
-#include <config.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace JIT {
-
-class RegAllocInfo;
-
-// This class implements a linear-scan register allocator, with a couple of tweaks:
-//  - Second-chance allocation is used when an interval becomes active after a spill, which results
-//    in fewer differences between edges, and hence fewer moves before jumps.
-//  - Use positions are flagged with either "must have" register or "could have" register. This is
-//    used to decide whether a register is really needed when a temporary is used after a spill
-//    occurred.
-//  - Fixed intervals are used to denotate IR positions where certain registers are needed in order
-//    to implement the operation, and cannot be used by a temporary on that position. An example is
-//    caller saved registers, where the call will use/clobber those registers.
-//  - Hints are used to indicate which registers could be used to generate more compact code. An
-//    example is an addition, where one (or both) operands' life-time ends at that instruction. In
-//    this case, re-using an operand register for the result will result in an in-place add.
-//  - SSA form properties are used:
-//      - to simplify life-times (two temporaries will never interfere as long as their intervals
-//        are not split), resulting in a slightly faster algorithm;
-//      - when a temporary needs to be spilled, it is done directly after calculating it, so that
-//        1 store is generated even if multiple spills/splits happen.
-//      - phi-node elimination (SSA form deconstruction) is done when resolving differences between
-//        CFG edges
-class RegisterAllocator
-{
-    typedef IR::LifeTimeInterval LifeTimeInterval;
-
-    const RegisterInformation &_registerInformation;
-    QVector<const RegisterInfo *> _normalRegisters;
-    QVector<const RegisterInfo *> _fpRegisters;
-    QScopedPointer<RegAllocInfo> _info;
-
-    QVector<LifeTimeInterval *> _fixedRegisterRanges, _fixedFPRegisterRanges;
-
-    IR::LifeTimeIntervals::Ptr _lifeTimeIntervals;
-    typedef QVector<LifeTimeInterval *> Intervals;
-    Intervals _unhandled, _active, _inactive, _handled;
-
-    std::vector<int> _lastAssignedRegister;
-    std::vector<int> _assignedSpillSlots;
-    QVector<int> _activeSpillSlots;
-
-    QBitArray _regularRegsInUse, _fpRegsInUse;
-
-    Q_DISABLE_COPY(RegisterAllocator)
-
-public:
-    enum { InvalidSpillSlot = -1 };
-
-    RegisterAllocator(const RegisterInformation &registerInformation);
-    ~RegisterAllocator();
-
-    void run(IR::Function *function, const IR::Optimizer &opt);
-    RegisterInformation usedRegisters() const;
-
-private:
-    void markInUse(int reg, bool isFPReg);
-    LifeTimeInterval *cloneFixedInterval(int reg, bool isFP, const LifeTimeInterval &original);
-    void prepareRanges();
-    void linearScan();
-    void tryAllocateFreeReg(LifeTimeInterval &current);
-    void allocateBlockedReg(LifeTimeInterval &current);
-    int nextIntersection(const LifeTimeInterval &current, const LifeTimeInterval &another) const;
-    int nextUse(const IR::Temp &t, int startPosition) const;
-    void split(LifeTimeInterval &current, int beforePosition, bool skipOptionalRegisterUses =false);
-    void splitInactiveAtEndOfLifetimeHole(int reg, bool isFPReg, int position);
-    void assignSpillSlot(const IR::Temp &t, int startPos, int endPos);
-    void resolve(IR::Function *function, const IR::Optimizer &opt);
-
-    void dump(IR::Function *function) const;
-};
-
-} // end of namespace JIT
-} // end of namespace QV4
-
-QT_END_NAMESPACE
-
-#endif // QV4REGALLOC_P_H
diff --git a/src/qml/jit/qv4runtimesupport_p.h b/src/qml/jit/qv4runtimesupport_p.h
new file mode 100644
index 0000000000..0dc6022331
--- /dev/null
+++ b/src/qml/jit/qv4runtimesupport_p.h
@@ -0,0 +1,255 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4RUNTIMESUPPORT_P_H
+#define QV4RUNTIMESUPPORT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <qv4runtimeapi_p.h>
+
+QT_REQUIRE_CONFIG(qml_tracing);
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+namespace IR {
+namespace RuntimeSupport {
+
+template <typename T>
+struct CountArguments {
+    static constexpr unsigned count = 0;
+};
+template <typename RetTy, typename... Args>
+struct CountArguments<RetTy (*)(Args... args)> {
+    static constexpr unsigned count = sizeof...(Args) ;
+};
+
+template<typename M>
+static constexpr unsigned argumentCount() {
+    using type = decltype(&M::call);
+    return CountArguments<type>::count;
+}
+
+enum class ArgumentType {
+    Invalid,
+    Engine,
+    Frame,
+    Function,
+    ValueRef,
+    ValueArray,
+    ReturnedValue,
+    Int,
+    Bool,
+    Void,
+};
+
+
+template <typename T>
+struct JavaScriptType
+{
+    // No default type. We want to make sure everything we do is actually recognized.
+};
+
+template <typename T>
+struct ReturnValue
+{
+    // No default type.
+};
+
+template <int I, typename T>
+struct Argument
+{
+    // For simplicity, we add a default here. Otherwise we would need to spell out more
+    // combinations of I and number of arguments of T.
+    static constexpr ArgumentType type = ArgumentType::Invalid;
+};
+
+template <typename RetTy, typename T, typename... Args>
+struct Argument<1, RetTy (*)(T, Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<T>::type;
+};
+
+template <typename RetTy, typename Arg1, typename T, typename... Args>
+struct Argument<2, RetTy (*)(Arg1, T, Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<T>::type;
+};
+
+template <typename RetTy, typename Arg1, typename Arg2, typename T,
+          typename... Args>
+struct Argument<3, RetTy (*)(Arg1, Arg2, T, Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<T>::type;
+};
+
+template <typename RetTy, typename Arg1, typename Arg2,
+          typename Arg3, typename T, typename... Args>
+struct Argument<4, RetTy (*)(Arg1, Arg2, Arg3, T, Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<T>::type;
+};
+
+template <typename RetTy, typename Arg1, typename Arg2,
+          typename Arg3, typename Arg4, typename T, typename... Args>
+struct Argument<5, RetTy (*)(Arg1, Arg2, Arg3, Arg4, T, Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<T>::type;
+};
+
+template <typename RetTy, typename Arg1, typename Arg2,
+          typename Arg3, typename Arg4, typename Arg5, typename T, typename... Args>
+struct Argument<6, RetTy (*)(Arg1, Arg2, Arg3, Arg4, Arg5, T, Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<T>::type;
+};
+
+template <typename RetTy, typename... Args>
+struct ReturnValue<RetTy (*)(Args... args)> {
+    static constexpr ArgumentType type = JavaScriptType<RetTy>::type;
+};
+
+template<>
+struct JavaScriptType<QV4::ExecutionEngine *>
+{
+    static constexpr ArgumentType type = ArgumentType::Engine;
+};
+
+template<>
+struct JavaScriptType<QV4::CppStackFrame *>
+{
+    static constexpr ArgumentType type = ArgumentType::Frame;
+};
+
+template<>
+struct JavaScriptType<QV4::Function *>
+{
+    static constexpr ArgumentType type = ArgumentType::Function;
+};
+
+template<>
+struct JavaScriptType<const QV4::Value &>
+{
+    static constexpr ArgumentType type = ArgumentType::ValueRef;
+};
+
+template<>
+// We need to pass Value * in order to match a parmeter Value[].
+struct JavaScriptType<QV4::Value *>
+{
+    static constexpr ArgumentType type = ArgumentType::ValueArray;
+};
+
+template<>
+struct JavaScriptType<int>
+{
+    static constexpr ArgumentType type = ArgumentType::Int;
+};
+
+template<>
+struct JavaScriptType<QV4::Bool>
+{
+    static constexpr ArgumentType type = ArgumentType::Bool;
+};
+
+template<>
+struct JavaScriptType<QV4::ReturnedValue>
+{
+    static constexpr ArgumentType type = ArgumentType::ReturnedValue;
+};
+
+template<>
+struct JavaScriptType<void>
+{
+    static constexpr ArgumentType type = ArgumentType::Void;
+};
+
+template<typename M>
+static constexpr ArgumentType retType() {
+    using Type = decltype(&M::call);
+    return ReturnValue<Type>::type;
+}
+
+template<typename M>
+static constexpr ArgumentType arg1Type() {
+    using Type = decltype(&M::call);
+    return Argument<1, Type>::type;
+}
+
+template<typename M>
+static constexpr ArgumentType arg2Type() {
+    using Type = decltype(&M::call);
+    return Argument<2, Type>::type;
+}
+
+template<typename M>
+static constexpr ArgumentType arg3Type() {
+    using Type = decltype(&M::call);
+    return Argument<3, Type>::type;
+}
+
+template<typename M>
+static constexpr ArgumentType arg4Type() {
+    using Type = decltype(&M::call);
+    return Argument<4, Type>::type;
+}
+
+template<typename M>
+static constexpr ArgumentType arg5Type() {
+    using Type = decltype(&M::call);
+    return Argument<5, Type>::type;
+}
+
+template<typename M>
+static constexpr ArgumentType arg6Type() {
+    using Type = decltype(&M::call);
+    return Argument<6, Type>::type;
+}
+
+} // namespace RuntimeSupport
+} // namespace IR
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4RUNTIMESUPPORT_P_H
diff --git a/src/qml/jit/qv4targetplatform_p.h b/src/qml/jit/qv4targetplatform_p.h
deleted file mode 100644
index 6d788f4a93..0000000000
--- a/src/qml/jit/qv4targetplatform_p.h
+++ /dev/null
@@ -1,707 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QV4TARGETPLATFORM_P_H
-#define QV4TARGETPLATFORM_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <config.h>
-
-#if ENABLE(ASSEMBLER)
-
-#include <private/qv4value_p.h>
-#include "qv4registerinfo_p.h"
-#include <assembler/MacroAssembler.h>
-
-QT_BEGIN_NAMESPACE
-
-namespace QV4 {
-namespace JIT {
-
-enum TargetOperatingSystemSpecialization {
-    NoOperatingSystemSpecialization,
-    WindowsSpecialization
-};
-
-// The TargetPlatform class describes how the stack and the registers work on a CPU+ABI combination.
-//
-// All combinations have a separate definition, guarded by #ifdefs. The exceptions are:
-//  - Linux/x86 and win32, which are the same, except that linux non-PIC/PIE code does not need to
-//    restore ebx (which holds the GOT ptr) before a call
-//  - All (supported) ARM platforms, where the only variety is the platform specific usage of r9,
-//    and the frame-pointer in Thumb/Thumb2 v.s. ARM mode.
-//
-// Specific handling of ebx when it holds the GOT:
-// In this case we can use it, but it needs to be restored when doing a call. So, the handling is as
-// follows: it is marked as caller saved, meaning the value in it won't survive a call. When
-// calculating the list of callee saved registers in getCalleeSavedRegisters (which is used to
-// generate push/pop instructions in the prelude/postlude), we add ebx too. Then when synthesizing
-// a call, we add a load it right before emitting the call instruction.
-//
-// NOTE: When adding new architecture, do not forget to whitelist it in qv4global_p.h!
-template <typename PlatformAssembler, TargetOperatingSystemSpecialization specialization = NoOperatingSystemSpecialization>
-class TargetPlatform
-{
-};
-
-#if CPU(X86) && (OS(LINUX) || OS(WINDOWS) || OS(QNX) || OS(FREEBSD) || defined(Q_OS_IOS))
-template <>
-class TargetPlatform<JSC::MacroAssemblerX86, NoOperatingSystemSpecialization>
-{
-public:
-    using PlatformAssembler = JSC::MacroAssemblerX86;
-    using RegisterID = PlatformAssembler::RegisterID;
-    using FPRegisterID = PlatformAssembler::FPRegisterID;
-    using TrustedImm32 = PlatformAssembler::TrustedImm32;
-
-    enum { RegAllocIsSupported = 1 };
-
-    static const RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
-    static const RegisterID StackPointerRegister = JSC::X86Registers::esp;
-    static const RegisterID LocalsRegister       = JSC::X86Registers::edi;
-    static const RegisterID EngineRegister      = JSC::X86Registers::esi;
-    static const RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
-    static const RegisterID ScratchRegister      = JSC::X86Registers::ecx;
-    static const FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
-    static const FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
-    static const RegisterID LowReturnValueRegister = JSC::X86Registers::eax;
-    static const RegisterID HighReturnValueRegister = JSC::X86Registers::edx;
-
-    static RegisterInformation getRegisterInfo()
-    {
-        typedef RegisterInfo RI;
-        static RegisterInformation info = RegisterInformation()
-                << RI(JSC::X86Registers::edx, QStringLiteral("edx"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::ebx, QStringLiteral("ebx"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::edi, QStringLiteral("edi"),   RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::esi, QStringLiteral("esi"),   RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::xmm2, QStringLiteral("xmm2"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm3, QStringLiteral("xmm3"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm4, QStringLiteral("xmm4"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm5, QStringLiteral("xmm5"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm6, QStringLiteral("xmm6"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm7, QStringLiteral("xmm7"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                   ;
-        return info;
-    }
-
-#  define HAVE_ALU_OPS_WITH_MEM_OPERAND 1
-    static const int RegisterSize = 4;
-
-    static const int RegisterArgumentCount = 0;
-    static RegisterID registerForArgument(int) { Q_UNREACHABLE(); }
-
-    static const int StackAlignment = 16;
-    static const int StackShadowSpace = 0;
-    static const int StackSpaceAllocatedUponFunctionEntry = RegisterSize; // Return address is pushed onto stack by the CPU.
-    static void platformEnterStandardStackFrame(PlatformAssembler *as) { as->push(FramePointerRegister); }
-    static void platformFinishEnteringStandardStackFrame(PlatformAssembler *) {}
-    static void platformLeaveStandardStackFrame(PlatformAssembler *as, int frameSize)
-    {
-        if (frameSize > 0)
-            as->add32(TrustedImm32(frameSize), StackPointerRegister);
-        as->pop(FramePointerRegister);
-    }
-
-#if OS(WINDOWS) || OS(QNX) || \
-    ((OS(LINUX) || OS(FREEBSD)) && (defined(__PIC__) || defined(__PIE__)))
-
-    static const int gotRegister = JSC::X86Registers::ebx;
-    static int savedGOTRegisterSlotOnStack() {
-        static int ebxIdx = -1;
-        if (ebxIdx == -1) {
-            int calleeSaves = 0;
-            const auto infos = getRegisterInfo();
-            for (const RegisterInfo &info : infos) {
-                if (info.reg<JSC::X86Registers::RegisterID>() == JSC::X86Registers::ebx) {
-                    ebxIdx = calleeSaves;
-                    break;
-                } else if (info.isCalleeSaved()) {
-                    ++calleeSaves;
-                }
-            }
-            Q_ASSERT(ebxIdx >= 0);
-            ebxIdx += 1;
-        }
-        return ebxIdx * -int(sizeof(void*));
-    }
-#else
-    static const int gotRegister = -1;
-    static int savedGOTRegisterSlotOnStack() { return -1; }
-#endif
-};
-#endif // x86
-
-#if CPU(X86_64) && (OS(LINUX) || OS(MAC_OS_X) || OS(FREEBSD) || OS(QNX) || defined(Q_OS_IOS))
-template <>
-class TargetPlatform<JSC::MacroAssemblerX86_64, NoOperatingSystemSpecialization>
-{
-public:
-    using PlatformAssembler = JSC::MacroAssemblerX86_64;
-    using RegisterID = PlatformAssembler::RegisterID;
-    using FPRegisterID = PlatformAssembler::FPRegisterID;
-    using TrustedImm32 = PlatformAssembler::TrustedImm32;
-
-    enum { RegAllocIsSupported = 1 };
-
-    static const RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
-    static const RegisterID StackPointerRegister = JSC::X86Registers::esp;
-    static const RegisterID LocalsRegister       = JSC::X86Registers::r12;
-    static const RegisterID EngineRegister      = JSC::X86Registers::r14;
-    static const RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
-    static const RegisterID ScratchRegister      = JSC::X86Registers::r10;
-    static const RegisterID DoubleMaskRegister   = JSC::X86Registers::r13;
-    static const FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
-    static const FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
-
-    static RegisterInformation getRegisterInfo()
-    {
-        typedef RegisterInfo RI;
-        static RegisterInformation info = RegisterInformation()
-                << RI(JSC::X86Registers::ebx,  QStringLiteral("rbx"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::edi,  QStringLiteral("rdi"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::esi,  QStringLiteral("rsi"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::edx,  QStringLiteral("rdx"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::r9,   QStringLiteral("r9"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::r8,   QStringLiteral("r8"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                   // r11 is used as scratch register by the macro assembler
-                << RI(JSC::X86Registers::r12,  QStringLiteral("r12"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::r13,  QStringLiteral("r13"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::r14,  QStringLiteral("r14"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::r15,  QStringLiteral("r15"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm2, QStringLiteral("xmm2"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm3, QStringLiteral("xmm3"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm4, QStringLiteral("xmm4"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm5, QStringLiteral("xmm5"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm6, QStringLiteral("xmm6"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm7, QStringLiteral("xmm7"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                   ;
-        return info;
-    }
-
-#define HAVE_ALU_OPS_WITH_MEM_OPERAND 1
-    static const int RegisterSize = 8;
-
-    static const int RegisterArgumentCount = 6;
-    static RegisterID registerForArgument(int index)
-    {
-        static RegisterID regs[RegisterArgumentCount] = {
-            JSC::X86Registers::edi,
-            JSC::X86Registers::esi,
-            JSC::X86Registers::edx,
-            JSC::X86Registers::ecx,
-            JSC::X86Registers::r8,
-            JSC::X86Registers::r9
-        };
-        Q_ASSERT(index >= 0 && index < RegisterArgumentCount);
-        return regs[index];
-    };
-
-    static const int StackAlignment = 16;
-    static const int StackShadowSpace = 0;
-    static const int StackSpaceAllocatedUponFunctionEntry = RegisterSize; // Return address is pushed onto stack by the CPU.
-    static void platformEnterStandardStackFrame(PlatformAssembler *as) { as->push(FramePointerRegister); }
-    static void platformFinishEnteringStandardStackFrame(PlatformAssembler *as)
-    {
-        as->move(PlatformAssembler::TrustedImm64(QV4::Value::NaNEncodeMask), DoubleMaskRegister);
-    }
-    static void platformLeaveStandardStackFrame(PlatformAssembler *as, int frameSize)
-    {
-        if (frameSize > 0)
-            as->add64(TrustedImm32(frameSize), StackPointerRegister);
-        as->pop(FramePointerRegister);
-    }
-
-    static const int gotRegister = -1;
-    static int savedGOTRegisterSlotOnStack() { return -1; }
-};
-#endif // Linux/MacOS on x86_64
-
-#if CPU(X86_64) && OS(WINDOWS)
-template <>
-class TargetPlatform<JSC::MacroAssemblerX86_64, WindowsSpecialization>
-{
-public:
-    using PlatformAssembler = JSC::MacroAssemblerX86_64;
-    using RegisterID = PlatformAssembler::RegisterID;
-    using FPRegisterID = PlatformAssembler::FPRegisterID;
-    using TrustedImm32 = PlatformAssembler::TrustedImm32;
-
-    enum { RegAllocIsSupported = 1 };
-
-    static const RegisterID FramePointerRegister   = JSC::X86Registers::ebp;
-    static const RegisterID StackPointerRegister = JSC::X86Registers::esp;
-    static const RegisterID LocalsRegister       = JSC::X86Registers::r12;
-    static const RegisterID EngineRegister      = JSC::X86Registers::r14;
-    static const RegisterID ReturnValueRegister  = JSC::X86Registers::eax;
-    static const RegisterID ScratchRegister      = JSC::X86Registers::r10;
-    static const RegisterID DoubleMaskRegister   = JSC::X86Registers::r13;
-    static const FPRegisterID FPGpr0             = JSC::X86Registers::xmm0;
-    static const FPRegisterID FPGpr1             = JSC::X86Registers::xmm1;
-
-    static RegisterInformation getRegisterInfo()
-    {
-        typedef RegisterInfo RI;
-        static RegisterInformation info = RegisterInformation()
-                << RI(JSC::X86Registers::ebx,  QStringLiteral("rbx"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::edi,  QStringLiteral("rdi"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::esi,  QStringLiteral("rsi"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::edx,  QStringLiteral("rdx"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::r8,   QStringLiteral("r8"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::r9,   QStringLiteral("r9"),   RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                   // r11 is used as scratch register by the macro assembler
-                << RI(JSC::X86Registers::r12,  QStringLiteral("r12"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::r13,  QStringLiteral("r13"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::r14,  QStringLiteral("r14"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::X86Registers::r15,  QStringLiteral("r15"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm2, QStringLiteral("xmm2"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm3, QStringLiteral("xmm3"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm4, QStringLiteral("xmm4"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm5, QStringLiteral("xmm5"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm6, QStringLiteral("xmm6"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::X86Registers::xmm7, QStringLiteral("xmm7"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                   ;
-        return info;
-    }
-
-#define HAVE_ALU_OPS_WITH_MEM_OPERAND 1
-    static const int RegisterSize = 8;
-
-    static const int RegisterArgumentCount = 4;
-    static RegisterID registerForArgument(int index)
-    {
-        static RegisterID regs[RegisterArgumentCount] = {
-            JSC::X86Registers::ecx,
-            JSC::X86Registers::edx,
-            JSC::X86Registers::r8,
-            JSC::X86Registers::r9
-        };
-        Q_ASSERT(index >= 0 && index < RegisterArgumentCount);
-        return regs[index];
-    }
-
-    static const int StackAlignment = 16;
-    static const int StackShadowSpace = 32;
-    static const int StackSpaceAllocatedUponFunctionEntry = RegisterSize; // Return address is pushed onto stack by the CPU.
-    static void platformEnterStandardStackFrame(PlatformAssembler *as) { as->push(FramePointerRegister); }
-    static void platformFinishEnteringStandardStackFrame(PlatformAssembler *as)
-    {
-        as->move(PlatformAssembler::TrustedImm64(QV4::Value::NaNEncodeMask), DoubleMaskRegister);
-    }
-    static void platformLeaveStandardStackFrame(PlatformAssembler *as, int frameSize)
-    {
-        if (frameSize > 0)
-            as->add64(TrustedImm32(frameSize), StackPointerRegister);
-        as->pop(FramePointerRegister);
-    }
-
-    static const int gotRegister = -1;
-    static int savedGOTRegisterSlotOnStack() { return -1; }
-};
-#endif // Windows on x86_64
-
-#if CPU(ARM) || defined(V4_BOOTSTRAP)
-template <>
-class TargetPlatform<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>
-{
-public:
-    using PlatformAssembler = JSC::MacroAssemblerARMv7;
-    using RegisterID = PlatformAssembler::RegisterID;
-    using FPRegisterID = PlatformAssembler::FPRegisterID;
-    using TrustedImm32 = PlatformAssembler::TrustedImm32;
-
-    enum { RegAllocIsSupported = 1 };
-
-    // The AAPCS specifies that the platform ABI has to define the usage of r9. Known are:
-    //  - The GNU/Linux ABI defines it as an additional callee-saved variable register (v6).
-    //  - iOS (for which we cannot JIT, but still...) defines it as having a special use, so we do
-    //    not touch it, nor use it.
-    //  - Any other platform has not been verified, so we conservatively assume we cannot use it.
-#if OS(LINUX)
-#define CAN_USE_R9
-#endif
-
-    // There are two designated frame-pointer registers on ARM, depending on which instruction set
-    // is used for the subroutine: r7 for Thumb or Thumb2, and r11 for ARM. We assign the constants
-    // accordingly, and assign the locals-register to the "other" register.
-#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
-    static const RegisterID FramePointerRegister = JSC::ARMRegisters::r7;
-    static const RegisterID LocalsRegister = JSC::ARMRegisters::r11;
-#else // Thumbs down
-    static const RegisterID FramePointerRegister = JSC::ARMRegisters::r11;
-    static const RegisterID LocalsRegister = JSC::ARMRegisters::r7;
-#endif
-    static const RegisterID StackPointerRegister = JSC::ARMRegisters::r13;
-    static const RegisterID ScratchRegister = JSC::ARMRegisters::r5;
-    static const RegisterID EngineRegister = JSC::ARMRegisters::r10;
-    static const RegisterID ReturnValueRegister = JSC::ARMRegisters::r0;
-    static const FPRegisterID FPGpr0 = JSC::ARMRegisters::d0;
-    static const FPRegisterID FPGpr1 = JSC::ARMRegisters::d1;
-    static const RegisterID LowReturnValueRegister = JSC::ARMRegisters::r0;
-    static const RegisterID HighReturnValueRegister = JSC::ARMRegisters::r1;
-
-    static RegisterInformation getRegisterInfo()
-    {
-        typedef RegisterInfo RI;
-        static RegisterInformation info = RegisterInformation()
-                << RI(JSC::ARMRegisters::r0,  QStringLiteral("r0"),  RI::RegularRegister,       RI::CallerSaved, RI::Predefined)
-                << RI(JSC::ARMRegisters::r1,  QStringLiteral("r1"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::r2,  QStringLiteral("r2"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::r3,  QStringLiteral("r3"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::r4,  QStringLiteral("r4"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::r5,  QStringLiteral("r5"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::ARMRegisters::r6,  QStringLiteral("r6"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-#if !CPU(ARM_THUMB2) && !defined(V4_BOOTSTRAP)
-                << RI(JSC::ARMRegisters::r7,  QStringLiteral("r7"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-#endif
-                << RI(JSC::ARMRegisters::r8,  QStringLiteral("r8"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-#ifdef CAN_USE_R9
-                << RI(JSC::ARMRegisters::r9,  QStringLiteral("r9"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-#endif
-                << RI(JSC::ARMRegisters::r10, QStringLiteral("r10"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-#if CPU(ARM_THUMB2) || defined(V4_BOOTSTRAP)
-                << RI(JSC::ARMRegisters::r11, QStringLiteral("r11"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-#endif
-                << RI(JSC::ARMRegisters::d2,  QStringLiteral("d2"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d3,  QStringLiteral("d3"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d4,  QStringLiteral("d4"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d5,  QStringLiteral("d5"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d6,  QStringLiteral("d6"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d8,  QStringLiteral("d8"),  RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d9,  QStringLiteral("d9"),  RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d10, QStringLiteral("d10"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d11, QStringLiteral("d11"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d12, QStringLiteral("d12"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d13, QStringLiteral("d13"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d14, QStringLiteral("d14"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARMRegisters::d15, QStringLiteral("d15"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                   ;
-        return info;
-    }
-
-#undef HAVE_ALU_OPS_WITH_MEM_OPERAND
-    static const int RegisterSize = 4;
-
-    static const int RegisterArgumentCount = 4;
-    static RegisterID registerForArgument(int index)
-    {
-        static RegisterID regs[RegisterArgumentCount] = {
-            JSC::ARMRegisters::r0,
-            JSC::ARMRegisters::r1,
-            JSC::ARMRegisters::r2,
-            JSC::ARMRegisters::r3
-        };
-
-        Q_ASSERT(index >= 0 && index < RegisterArgumentCount);
-        return regs[index];
-    };
-
-    static const int StackAlignment = 8; // Per AAPCS
-    static const int StackShadowSpace = 0;
-    static const int StackSpaceAllocatedUponFunctionEntry = 1 * RegisterSize; // Registers saved in platformEnterStandardStackFrame below.
-
-    static void platformEnterStandardStackFrame(PlatformAssembler *as)
-    {
-        as->push(JSC::ARMRegisters::lr);
-        as->push(FramePointerRegister);
-    }
-
-    static void platformFinishEnteringStandardStackFrame(PlatformAssembler *) {}
-
-    static void platformLeaveStandardStackFrame(PlatformAssembler *as, int frameSize)
-    {
-        if (frameSize > 0) {
-            // Work around bug in ARMv7Assembler.h where add32(imm, sp, sp) doesn't
-            // work well for large immediates.
-            as->move(TrustedImm32(frameSize), JSC::ARMRegisters::r3);
-            as->add32(JSC::ARMRegisters::r3, StackPointerRegister);
-        }
-        as->pop(FramePointerRegister);
-        as->pop(JSC::ARMRegisters::lr);
-    }
-
-    static const int gotRegister = -1;
-    static int savedGOTRegisterSlotOnStack() { return -1; }
-};
-#endif // ARM (32 bit)
-
-#if CPU(ARM64) || defined(V4_BOOTSTRAP)
-template <>
-class TargetPlatform<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>
-{
-public:
-    using PlatformAssembler = JSC::MacroAssemblerARM64;
-    using RegisterID = PlatformAssembler::RegisterID;
-    using FPRegisterID = PlatformAssembler::FPRegisterID;
-    using TrustedImm32 = PlatformAssembler::TrustedImm32;
-
-    enum { RegAllocIsSupported = 1 };
-
-    static const RegisterID FramePointerRegister = JSC::ARM64Registers::fp;
-    static const RegisterID LocalsRegister = JSC::ARM64Registers::x28;
-    static const RegisterID StackPointerRegister = JSC::ARM64Registers::sp;
-    static const RegisterID ScratchRegister = JSC::ARM64Registers::x9;
-    static const RegisterID EngineRegister = JSC::ARM64Registers::x27;
-    static const RegisterID ReturnValueRegister = JSC::ARM64Registers::x0;
-    static const RegisterID DoubleMaskRegister = JSC::ARM64Registers::x26;
-    static const FPRegisterID FPGpr0 = JSC::ARM64Registers::q0;
-    static const FPRegisterID FPGpr1 = JSC::ARM64Registers::q1;
-
-    static RegisterInformation getRegisterInfo()
-    {
-        typedef RegisterInfo RI;
-        static RegisterInformation info = RegisterInformation()
-                << RI(JSC::ARM64Registers::x0,  QStringLiteral("x0"),  RI::RegularRegister,       RI::CallerSaved, RI::Predefined)
-                << RI(JSC::ARM64Registers::x1,  QStringLiteral("x1"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x2,  QStringLiteral("x2"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x3,  QStringLiteral("x3"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x4,  QStringLiteral("x4"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x5,  QStringLiteral("x5"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x6,  QStringLiteral("x6"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x7,  QStringLiteral("x7"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x8,  QStringLiteral("x8"),  RI::RegularRegister,       RI::CallerSaved, RI::Predefined)
-                << RI(JSC::ARM64Registers::x9,  QStringLiteral("x9"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::ARM64Registers::x10, QStringLiteral("x10"), RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x11, QStringLiteral("x11"), RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x12, QStringLiteral("x12"), RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x13, QStringLiteral("x13"), RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x14, QStringLiteral("x14"), RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x15, QStringLiteral("x15"), RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x19, QStringLiteral("x19"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x20, QStringLiteral("x20"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x21, QStringLiteral("x21"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x22, QStringLiteral("x22"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x23, QStringLiteral("x23"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x24, QStringLiteral("x24"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x25, QStringLiteral("x25"), RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::x26, QStringLiteral("x26"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::ARM64Registers::x27, QStringLiteral("x27"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::ARM64Registers::x28, QStringLiteral("x28"), RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-
-                << RI(JSC::ARM64Registers::q2,  QStringLiteral("q2"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q3,  QStringLiteral("q3"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q4,  QStringLiteral("q4"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q5,  QStringLiteral("q5"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q6,  QStringLiteral("q6"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q8,  QStringLiteral("q8"),  RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q9,  QStringLiteral("q9"),  RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q10, QStringLiteral("q10"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q11, QStringLiteral("q11"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q12, QStringLiteral("q12"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q13, QStringLiteral("q13"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q14, QStringLiteral("q14"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q15, QStringLiteral("q15"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q16, QStringLiteral("q16"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q17, QStringLiteral("q17"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q18, QStringLiteral("q18"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q19, QStringLiteral("q19"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q20, QStringLiteral("q20"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q21, QStringLiteral("q21"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q22, QStringLiteral("q22"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q23, QStringLiteral("q23"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q24, QStringLiteral("q24"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q25, QStringLiteral("q25"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q26, QStringLiteral("q26"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q27, QStringLiteral("q27"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q28, QStringLiteral("q28"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q29, QStringLiteral("q29"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q30, QStringLiteral("q30"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::ARM64Registers::q31, QStringLiteral("q31"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                   ;
-        return info;
-    }
-
-#undef HAVE_ALU_OPS_WITH_MEM_OPERAND
-    static const int RegisterSize = 8;
-
-    static const int RegisterArgumentCount = 8;
-    static RegisterID registerForArgument(int index)
-    {
-        static RegisterID regs[RegisterArgumentCount] = {
-            JSC::ARM64Registers::x0,
-            JSC::ARM64Registers::x1,
-            JSC::ARM64Registers::x2,
-            JSC::ARM64Registers::x3,
-            JSC::ARM64Registers::x4,
-            JSC::ARM64Registers::x5,
-            JSC::ARM64Registers::x6,
-            JSC::ARM64Registers::x7
-        };
-
-        Q_ASSERT(index >= 0 && index < RegisterArgumentCount);
-        return regs[index];
-    };
-
-    static const int StackAlignment = 16;
-    static const int StackShadowSpace = 0;
-    static const int StackSpaceAllocatedUponFunctionEntry = 1 * RegisterSize; // Registers saved in platformEnterStandardStackFrame below.
-
-    static void platformEnterStandardStackFrame(PlatformAssembler *as)
-    {
-        as->pushPair(FramePointerRegister, JSC::ARM64Registers::lr);
-    }
-
-    static void platformFinishEnteringStandardStackFrame(PlatformAssembler *as)
-    {
-        as->move(PlatformAssembler::TrustedImm64(QV4::Value::NaNEncodeMask), DoubleMaskRegister);
-    }
-
-    static void platformLeaveStandardStackFrame(PlatformAssembler *as, int frameSize)
-    {
-        if (frameSize > 0)
-            as->add64(TrustedImm32(frameSize), StackPointerRegister);
-        as->popPair(FramePointerRegister, JSC::ARM64Registers::lr);
-    }
-
-    static const int gotRegister = -1;
-    static int savedGOTRegisterSlotOnStack() { return -1; }
-};
-#endif // ARM64
-
-#if defined(Q_PROCESSOR_MIPS_32) && defined(Q_OS_LINUX)
-template <>
-class TargetPlatform<JSC::MacroAssemblerMIPS, NoOperatingSystemSpecialization>
-{
-public:
-    using PlatformAssembler = JSC::MacroAssemblerMIPS;
-    using RegisterID = PlatformAssembler::RegisterID;
-    using FPRegisterID = PlatformAssembler::FPRegisterID;
-    using TrustedImm32 = PlatformAssembler::TrustedImm32;
-    enum { RegAllocIsSupported = 1 };
-
-    static const RegisterID FramePointerRegister = JSC::MIPSRegisters::fp;
-    static const RegisterID StackPointerRegister = JSC::MIPSRegisters::sp;
-    static const RegisterID LocalsRegister = JSC::MIPSRegisters::s0;
-    static const RegisterID EngineRegister = JSC::MIPSRegisters::s1;
-    static const RegisterID ReturnValueRegister = JSC::MIPSRegisters::v0;
-    static const RegisterID ScratchRegister = JSC::MIPSRegisters::s2;
-    static const FPRegisterID FPGpr0 = JSC::MIPSRegisters::f0;
-    static const FPRegisterID FPGpr1 = JSC::MIPSRegisters::f2;
-    static const RegisterID LowReturnValueRegister = JSC::MIPSRegisters::v0;
-    static const RegisterID HighReturnValueRegister = JSC::MIPSRegisters::v1;
-
-    static RegisterInformation getRegisterInfo()
-    {
-        typedef RegisterInfo RI;
-        static RegisterInformation info = RegisterInformation()
-                // Note: t0, t1, t2, t3 and f16 are already used by MacroAssemblerMIPS.
-                << RI(JSC::MIPSRegisters::t4,  QStringLiteral("t4"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::t5,  QStringLiteral("t5"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::t6,  QStringLiteral("t6"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::t7,  QStringLiteral("t7"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::t8,  QStringLiteral("t8"),  RI::RegularRegister,       RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::s0,  QStringLiteral("s0"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::MIPSRegisters::s1,  QStringLiteral("s1"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::MIPSRegisters::s2,  QStringLiteral("s2"),  RI::RegularRegister,       RI::CalleeSaved, RI::Predefined)
-                << RI(JSC::MIPSRegisters::s3,  QStringLiteral("s3"),  RI::RegularRegister,       RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f4,  QStringLiteral("f4"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f6,  QStringLiteral("f6"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f8,  QStringLiteral("f8"),  RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f10, QStringLiteral("f10"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f18, QStringLiteral("f18"), RI::FloatingPointRegister, RI::CallerSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f20, QStringLiteral("f20"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f22, QStringLiteral("f22"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f24, QStringLiteral("f24"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f26, QStringLiteral("f26"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                << RI(JSC::MIPSRegisters::f28, QStringLiteral("f28"), RI::FloatingPointRegister, RI::CalleeSaved, RI::RegAlloc)
-                   ;
-        return info;
-    }
-
-#undef HAVE_ALU_OPS_WITH_MEM_OPERAND
-    static const int RegisterSize = 4;
-
-    static const int RegisterArgumentCount = 4;
-    static RegisterID registerForArgument(int index)
-    {
-        static RegisterID regs[RegisterArgumentCount] = {
-            JSC::MIPSRegisters::a0,
-            JSC::MIPSRegisters::a1,
-            JSC::MIPSRegisters::a2,
-            JSC::MIPSRegisters::a3
-        };
-
-        Q_ASSERT(index >= 0 && index < RegisterArgumentCount);
-        return regs[index];
-    };
-
-    static const int StackAlignment = 8;
-    static const int StackShadowSpace = 4 * RegisterSize; // Stack space for 4 argument registers.
-    static const int StackSpaceAllocatedUponFunctionEntry = 1 * RegisterSize; // Registers saved in platformEnterStandardStackFrame below.
-
-    static void platformEnterStandardStackFrame(PlatformAssembler *as)
-    {
-        as->push(JSC::MIPSRegisters::ra);
-        as->push(FramePointerRegister);
-    }
-
-    static void platformFinishEnteringStandardStackFrame(PlatformAssembler *) {}
-
-    static void platformLeaveStandardStackFrame(PlatformAssembler *as, int frameSize)
-    {
-        if (frameSize > 0)
-            as->add32(TrustedImm32(frameSize), StackPointerRegister);
-        as->pop(FramePointerRegister);
-        as->pop(JSC::MIPSRegisters::ra);
-    }
-
-
-    static const int gotRegister = -1;
-    static int savedGOTRegisterSlotOnStack() { return -1; }
-};
-#endif // Linux on MIPS (32 bit)
-
-} // JIT namespace
-} // QV4 namespace
-
-QT_END_NAMESPACE
-
-#endif // ENABLE(ASSEMBLER)
-
-#endif // QV4TARGETPLATFORM_P_H
diff --git a/src/qml/jit/qv4tracingjit.cpp b/src/qml/jit/qv4tracingjit.cpp
new file mode 100644
index 0000000000..ded2488905
--- /dev/null
+++ b/src/qml/jit/qv4tracingjit.cpp
@@ -0,0 +1,79 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qloggingcategory.h>
+
+#include "qv4vme_moth_p.h"
+#include "qv4graphbuilder_p.h"
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcTracing, "qt.v4.tracing")
+
+namespace QV4 {
+
+// This is the entry point for the "tracing JIT". It uses the sea-of-nodes concept as described in
+// https://scholarship.rice.edu/bitstream/handle/1911/96451/TR95-252.pdf
+//
+// The minimal pipeline is as follows:
+//  - create the graph for the function
+//  - do generic lowering
+//  - schedule the nodes
+//  - run minimal stack slot allocation (no re-use of slots)
+//  - run the assembler
+//
+// This pipeline has no optimizations, and generates quite inefficient code. It does have the
+// advantage that no trace information is used, so it can be used for testing where it replaces
+// the baseline JIT. Any optimizations are additions to this pipeline.
+//
+// Note: generators (or resuming functions in general) are not supported by this JIT.
+void Moth::runTracingJit(QV4::Function *function)
+{
+    IR::Function irFunction(function);
+    qCDebug(lcTracing).noquote() << "runTracingJit called for" << irFunction.name() << "...";
+
+    qCDebug(lcTracing).noquote().nospace() << function->traceInfoToString();
+
+    IR::GraphBuilder::buildGraph(&irFunction);
+    irFunction.dump(QStringLiteral("initial IR"));
+    irFunction.verify();
+}
+
+} // QV4 namespace
+QT_END_NAMESPACE
diff --git a/src/qml/jit/qv4unop.cpp b/src/qml/jit/qv4unop.cpp
deleted file mode 100644
index 896be07ed5..0000000000
--- a/src/qml/jit/qv4unop.cpp
+++ /dev/null
@@ -1,157 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-#include <qv4unop_p.h>
-#include <qv4assembler_p.h>
-
-#if ENABLE(ASSEMBLER)
-
-using namespace QV4;
-using namespace JIT;
-
-#define stringIfyx(s) #s
-#define stringIfy(s) stringIfyx(s)
-#define setOp(operation) \
-    do { \
-        call = typename JITAssembler::RuntimeCall(QV4::Runtime::operation); name = "Runtime::" stringIfy(operation); \
-        needsExceptionCheck = Runtime::Method_##operation##_NeedsExceptionCheck; \
-    } while (0)
-
-template <typename JITAssembler>
-void Unop<JITAssembler>::generate(IR::Expr *source, IR::Expr *target)
-{
-    bool needsExceptionCheck;
-    typename JITAssembler::RuntimeCall call;
-    const char *name = 0;
-    switch (op) {
-    case IR::OpNot:
-        generateNot(source, target);
-        return;
-    case IR::OpUMinus:
-        generateUMinus(source, target);
-        return;
-    case IR::OpUPlus: setOp(uPlus); break;
-    case IR::OpCompl:
-        generateCompl(source, target);
-        return;
-    case IR::OpIncrement: setOp(increment); break;
-    case IR::OpDecrement: setOp(decrement); break;
-    default:
-        Q_UNREACHABLE();
-    } // switch
-
-    Q_ASSERT(call.isValid());
-    _as->generateFunctionCallImp(needsExceptionCheck, target, name, call, PointerToValue(source));
-}
-
-template <typename JITAssembler>
-void Unop<JITAssembler>::generateUMinus(IR::Expr *source, IR::Expr *target)
-{
-    IR::Temp *targetTemp = target->asTemp();
-    if (source->type == IR::SInt32Type) {
-        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
-        typename JITAssembler::RegisterID sReg = _as->toInt32Register(source, tReg);
-        _as->move(sReg, tReg);
-        _as->neg32(tReg);
-        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
-            _as->storeInt32(tReg, target);
-        return;
-    }
-
-    generateRuntimeCall(_as, target, uMinus, PointerToValue(source));
-}
-
-template <typename JITAssembler>
-void Unop<JITAssembler>::generateNot(IR::Expr *source, IR::Expr *target)
-{
-    IR::Temp *targetTemp = target->asTemp();
-    if (source->type == IR::BoolType) {
-        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
-        _as->xor32(TrustedImm32(0x1), _as->toInt32Register(source, tReg), tReg);
-        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
-            _as->storeBool(tReg, target);
-        return;
-    } else if (source->type == IR::SInt32Type) {
-        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
-        _as->compare32(RelationalCondition::Equal,
-                      _as->toInt32Register(source, JITAssembler::ScratchRegister), TrustedImm32(0),
-                      tReg);
-        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
-            _as->storeBool(tReg, target);
-        return;
-    } else if (source->type == IR::DoubleType) {
-        // ###
-    }
-    // ## generic implementation testing for int/bool
-
-    generateRuntimeCall(_as, target, uNot, PointerToValue(source));
-}
-
-template <typename JITAssembler>
-void Unop<JITAssembler>::generateCompl(IR::Expr *source, IR::Expr *target)
-{
-    IR::Temp *targetTemp = target->asTemp();
-    if (source->type == IR::SInt32Type) {
-        typename JITAssembler::RegisterID tReg = JITAssembler::ScratchRegister;
-        if (targetTemp && targetTemp->kind == IR::Temp::PhysicalRegister)
-            tReg = (typename JITAssembler::RegisterID) targetTemp->index;
-        _as->xor32(TrustedImm32(0xffffffff), _as->toInt32Register(source, tReg), tReg);
-        if (!targetTemp || targetTemp->kind != IR::Temp::PhysicalRegister)
-            _as->storeInt32(tReg, target);
-        return;
-    }
-    generateRuntimeCall(_as, target, complement, PointerToValue(source));
-}
-
-template struct QV4::JIT::Unop<QV4::JIT::Assembler<DefaultAssemblerTargetConfiguration>>;
-#if defined(V4_BOOTSTRAP)
-#if !CPU(ARM_THUMB2)
-template struct QV4::JIT::Unop<QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARMv7, NoOperatingSystemSpecialization>>>;
-#endif
-#if !CPU(ARM64)
-template struct QV4::JIT::Unop<QV4::JIT::Assembler<AssemblerTargetConfiguration<JSC::MacroAssemblerARM64, NoOperatingSystemSpecialization>>>;
-#endif
-#endif
-
-#endif
diff --git a/src/qml/jsapi/qjsengine.cpp b/src/qml/jsapi/qjsengine.cpp
index e4c150057a..aab72f8b2d 100644
--- a/src/qml/jsapi/qjsengine.cpp
+++ b/src/qml/jsapi/qjsengine.cpp
@@ -45,12 +45,15 @@
 
 #include "private/qv4engine_p.h"
 #include "private/qv4mm_p.h"
+#include "private/qv4errorobject_p.h"
 #include "private/qv4globalobject_p.h"
 #include "private/qv4script_p.h"
 #include "private/qv4runtime_p.h"
 #include <private/qqmlbuiltinfunctions_p.h>
 #include <private/qqmldebugconnector_p.h>
 #include <private/qv4qobjectwrapper_p.h>
+#include <private/qv4stackframe_p.h>
+#include <private/qv4module_p.h>
 
 #include <QtCore/qdatetime.h>
 #include <QtCore/qmetaobject.h>
@@ -113,6 +116,45 @@ Q_DECLARE_METATYPE(QList<int>)
   argument is a general-purpose string that is stored in the \c Error
   object for debugging purposes.
 
+  For larger pieces of functionality, you may want to encapsulate
+  your code and data into modules. A module is a file that contains
+  script code, variables, etc., and uses export statements to describe
+  its interface towards the rest of the application. With the help of
+  import statements, a module can refer to functionality from other modules.
+  This allows building a scripted application from smaller connected building blocks
+  in a safe way. In contrast, the approach of using evaluate() carries the risk
+  that internal variables or functions from one evaluate() call accidentally pollute the
+  global object and affect subsequent evaluations.
+
+  The following example provides a module that can add numbers:
+
+  \code
+  export function sum(left, right)
+  {
+      return left + right
+  }
+  \endcode
+
+  This module can be loaded with QJSEngine::import() if it is saved under
+  the name \c{math.mjs}:
+
+  \code
+  QJSvalue module = myEngine.importModule("./math.mjs");
+  QJSValue sumFunction = module.property("sum");
+  QJSValue result = sumFunction.call(args);
+  \endcode
+
+  Modules can also use functionality from other modules using import
+  statements:
+
+  \code
+  import { sum } from "./math.mjs";
+  export function addTwice(left, right)
+  {
+      return sum(left, right) * 2;
+  }
+  \endcode
+
   \section1 Engine Configuration
 
   The globalObject() function returns the \b {Global Object}
@@ -166,18 +208,37 @@ Q_DECLARE_METATYPE(QList<int>)
   properties of the proxy object. No binding code is needed because it
   is done dynamically using the Qt meta object system.
 
+  \snippet code/src_script_qjsengine.cpp 5
+
   Use newQMetaObject() to wrap a QMetaObject; this gives you a
   "script representation" of a QObject-based class. newQMetaObject()
   returns a proxy script object; enum values of the class are available
   as properties of the proxy object.
 
-  Constructors exposed to the meta-object system ( using Q_INVOKABLE ) can be
+  Constructors exposed to the meta-object system (using Q_INVOKABLE) can be
   called from the script to create a new QObject instance with
-  JavaScriptOwnership.
+  JavaScriptOwnership. For example, given the following class definition:
 
+  \snippet code/src_script_qjsengine.cpp 7
 
+  The \c staticMetaObject for the class can be exposed to JavaScript like so:
 
-  \snippet code/src_script_qjsengine.cpp 5
+  \snippet code/src_script_qjsengine.cpp 8
+
+  Instances of the class can then be created in JavaScript:
+
+  \snippet code/src_script_qjsengine.cpp 9
+
+  \note Currently only classes using the Q_OBJECT macro are supported; it is
+  not possible to expose the \c staticMetaObject of a Q_GADGET class to
+  JavaScript.
+
+  \section2 Dynamic QObject Properties
+
+  Dynamic QObject properties are not supported. For example, the following code
+  will not work:
+
+  \snippet code/src_script_qjsengine.cpp 6
 
   \section1 Extensions
 
@@ -285,8 +346,9 @@ QJSEngine::QJSEngine()
 
 QJSEngine::QJSEngine(QObject *parent)
     : QObject(*new QJSEnginePrivate, parent)
-    , d(new QV8Engine(this))
+    , m_v4Engine(new QV4::ExecutionEngine(this))
 {
+    m_v4Engine->v8Engine = new QV8Engine(m_v4Engine);
     checkForApplicationInstance();
 
     QJSEnginePrivate::addToDebugServer(this);
@@ -297,8 +359,9 @@ QJSEngine::QJSEngine(QObject *parent)
 */
 QJSEngine::QJSEngine(QJSEnginePrivate &dd, QObject *parent)
     : QObject(dd, parent)
-    , d(new QV8Engine(this))
+    , m_v4Engine(new QV4::ExecutionEngine(this))
 {
+    m_v4Engine->v8Engine = new QV8Engine(m_v4Engine);
     checkForApplicationInstance();
 }
 
@@ -312,11 +375,12 @@ QJSEngine::QJSEngine(QJSEnginePrivate &dd, QObject *parent)
 QJSEngine::~QJSEngine()
 {
     QJSEnginePrivate::removeFromDebugServer(this);
-    delete d;
+    delete m_v4Engine->v8Engine;
+    delete m_v4Engine;
 }
 
 /*!
-    \fn QV8Engine *QJSEngine::handle() const
+    \fn QV4::ExecutionEngine *QJSEngine::handle() const
     \internal
 */
 
@@ -333,7 +397,7 @@ QJSEngine::~QJSEngine()
 */
 void QJSEngine::collectGarbage()
 {
-    d->m_v4Engine->memoryManager->runGC();
+    m_v4Engine->memoryManager->runGC();
 }
 
 #if QT_DEPRECATED_SINCE(5, 6)
@@ -390,12 +454,12 @@ void QJSEngine::installTranslatorFunctions(const QJSValue &object)
 void QJSEngine::installExtensions(QJSEngine::Extensions extensions, const QJSValue &object)
 {
     QV4::ExecutionEngine *otherEngine = QJSValuePrivate::engine(&object);
-    if (otherEngine && otherEngine != d->m_v4Engine) {
+    if (otherEngine && otherEngine != m_v4Engine) {
         qWarning("QJSEngine: Trying to install extensions from a different engine");
         return;
     }
 
-    QV4::Scope scope(d->m_v4Engine);
+    QV4::Scope scope(m_v4Engine);
     QV4::ScopedObject obj(scope);
     QV4::Value *val = QJSValuePrivate::getValue(&object);
     if (val)
@@ -406,6 +470,17 @@ void QJSEngine::installExtensions(QJSEngine::Extensions extensions, const QJSVal
     QV4::GlobalExtensions::init(obj, extensions);
 }
 
+static QUrl urlForFileName(const QString &fileName)
+{
+    if (!fileName.startsWith(QLatin1Char(':')))
+        return QUrl::fromLocalFile(fileName);
+
+    QUrl url;
+    url.setPath(fileName.mid(1));
+    url.setScheme(QLatin1String("qrc"));
+    return url;
+}
+
 /*!
     Evaluates \a program, using \a lineNumber as the base line number,
     and returns the result of the evaluation.
@@ -436,17 +511,16 @@ void QJSEngine::installExtensions(QJSEngine::Extensions extensions, const QJSVal
 */
 QJSValue QJSEngine::evaluate(const QString& program, const QString& fileName, int lineNumber)
 {
-    QV4::ExecutionEngine *v4 = d->m_v4Engine;
+    QV4::ExecutionEngine *v4 = m_v4Engine;
     QV4::Scope scope(v4);
-    QV4::ExecutionContextSaver saver(scope);
-
-    QV4::ExecutionContext *ctx = v4->currentContext;
-    if (ctx->d() != v4->rootContext()->d())
-        ctx = v4->pushGlobalContext();
     QV4::ScopedValue result(scope);
 
-    QV4::Script script(ctx, program, fileName, lineNumber);
-    script.strictMode = ctx->d()->strictMode;
+    QV4::Script script(v4->rootContext(), QV4::Compiler::ContextType::Global, program, urlForFileName(fileName).toString(), lineNumber);
+    script.strictMode = false;
+    if (v4->currentStackFrame)
+        script.strictMode = v4->currentStackFrame->v4Function->isStrict();
+    else if (v4->globalCode)
+        script.strictMode = v4->globalCode->isStrict();
     script.inheritContext = true;
     script.parse();
     if (!scope.engine->hasException)
@@ -454,7 +528,44 @@ QJSValue QJSEngine::evaluate(const QString& program, const QString& fileName, in
     if (scope.engine->hasException)
         result = v4->catchException();
 
-    return QJSValue(v4, result->asReturnedValue());
+    QJSValue retval(v4, result->asReturnedValue());
+
+    return retval;
+}
+
+/*!
+    Imports the module located at \a fileName and returns a module namespace object that
+    contains all exported variables, constants and functions as properties.
+
+    If this is the first time the module is imported in the engine, the file is loaded
+    from the specified location in either the local file system or the Qt resource system
+    and evaluated as an ECMAScript module. The file is expected to be encoded in UTF-8 text.
+
+    Subsequent imports of the same module will return the previously imported instance. Modules
+    are singletons and remain around until the engine is destroyed.
+
+    The specified \a fileName will internally be normalized using \l QFileInfo::canonicalFilePath().
+    That means that multiple imports of the same file on disk using different relative paths will
+    load the file only once.
+
+    \note If an exception is thrown during the loading of the module, the return value
+    will be the exception (typically an \c{Error} object; see QJSValue::isError()).
+
+    \since 5.12
+ */
+QJSValue QJSEngine::importModule(const QString &fileName)
+{
+    const QUrl url = urlForFileName(QFileInfo(fileName).canonicalFilePath());
+    auto moduleUnit = m_v4Engine->loadModule(url);
+    if (m_v4Engine->hasException)
+        return QJSValue(m_v4Engine, m_v4Engine->catchException());
+
+    QV4::Scope scope(m_v4Engine);
+    QV4::Scoped<QV4::Module> moduleNamespace(scope, moduleUnit->instantiate(m_v4Engine));
+    if (m_v4Engine->hasException)
+        return QJSValue(m_v4Engine, m_v4Engine->catchException());
+    moduleUnit->evaluate();
+    return QJSValue(m_v4Engine, moduleNamespace->asReturnedValue());
 }
 
 /*!
@@ -467,9 +578,49 @@ QJSValue QJSEngine::evaluate(const QString& program, const QString& fileName, in
 */
 QJSValue QJSEngine::newObject()
 {
-    QV4::Scope scope(d->m_v4Engine);
-    QV4::ScopedValue v(scope, d->m_v4Engine->newObject());
-    return QJSValue(d->m_v4Engine, v->asReturnedValue());
+    QV4::Scope scope(m_v4Engine);
+    QV4::ScopedValue v(scope, m_v4Engine->newObject());
+    return QJSValue(m_v4Engine, v->asReturnedValue());
+}
+
+/*!
+  \since 5.12
+  Creates a JavaScript object of class Error.
+
+  The prototype of the created object will be \a errorType.
+
+  \sa newObject(), throwError(), QJSValue::isError()
+*/
+QJSValue QJSEngine::newErrorObject(QJSValue::ErrorType errorType, const QString &message)
+{
+    QV4::Scope scope(m_v4Engine);
+    QV4::ScopedObject error(scope);
+    switch (errorType) {
+    case QJSValue::RangeError:
+        error = m_v4Engine->newRangeErrorObject(message);
+        break;
+    case QJSValue::SyntaxError:
+        error = m_v4Engine->newSyntaxErrorObject(message);
+        break;
+    case QJSValue::TypeError:
+        error = m_v4Engine->newTypeErrorObject(message);
+        break;
+    case QJSValue::URIError:
+        error = m_v4Engine->newURIErrorObject(message);
+        break;
+    case QJSValue::ReferenceError:
+        error = m_v4Engine->newReferenceErrorObject(message);
+        break;
+    case QJSValue::EvalError:
+        error = m_v4Engine->newEvalErrorObject(message);
+        break;
+    case QJSValue::GenericError:
+        error = m_v4Engine->newErrorObject(message);
+        break;
+    case QJSValue::NoError:
+        return QJSValue::UndefinedValue;
+    }
+    return QJSValue(m_v4Engine, error->asReturnedValue());
 }
 
 /*!
@@ -479,12 +630,12 @@ QJSValue QJSEngine::newObject()
 */
 QJSValue QJSEngine::newArray(uint length)
 {
-    QV4::Scope scope(d->m_v4Engine);
-    QV4::ScopedArrayObject array(scope, d->m_v4Engine->newArrayObject());
+    QV4::Scope scope(m_v4Engine);
+    QV4::ScopedArrayObject array(scope, m_v4Engine->newArrayObject());
     if (length < 0x1000)
         array->arrayReserve(length);
     array->setArrayLengthUnchecked(length);
-    return QJSValue(d->m_v4Engine, array.asReturnedValue());
+    return QJSValue(m_v4Engine, array.asReturnedValue());
 }
 
 /*!
@@ -510,7 +661,7 @@ QJSValue QJSEngine::newArray(uint length)
 QJSValue QJSEngine::newQObject(QObject *object)
 {
     Q_D(QJSEngine);
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(d);
+    QV4::ExecutionEngine *v4 = m_v4Engine;
     QV4::Scope scope(v4);
     if (object) {
         QQmlData *ddata = QQmlData::get(object, true);
@@ -532,24 +683,24 @@ QJSValue QJSEngine::newQObject(QObject *object)
   When called as a constructor, a new instance of the class will be created.
   Only constructors exposed by Q_INVOKABLE will be visible from the script engine.
 
-  \sa newQObject()
+  \sa newQObject(), {QObject Integration}
 */
 
 QJSValue QJSEngine::newQMetaObject(const QMetaObject* metaObject) {
     Q_D(QJSEngine);
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(d);
+    QV4::ExecutionEngine *v4 = m_v4Engine;
     QV4::Scope scope(v4);
     QV4::ScopedValue v(scope, QV4::QMetaObjectWrapper::create(v4, metaObject));
     return QJSValue(v4, v->asReturnedValue());
 }
 
-/*! \fn QJSValue QJSEngine::newQMetaObject<T>()
+/*! \fn template <typename T> QJSValue QJSEngine::newQMetaObject()
 
   \since 5.8
   Creates a JavaScript object that wraps the static QMetaObject associated
   with class \c{T}.
 
-  \sa newQObject()
+  \sa newQObject(), {QObject Integration}
 */
 
 
@@ -565,10 +716,9 @@ QJSValue QJSEngine::newQMetaObject(const QMetaObject* metaObject) {
 */
 QJSValue QJSEngine::globalObject() const
 {
-    Q_D(const QJSEngine);
-    QV4::Scope scope(d->m_v4Engine);
-    QV4::ScopedValue v(scope, d->m_v4Engine->globalObject);
-    return QJSValue(d->m_v4Engine, v->asReturnedValue());
+    QV4::Scope scope(m_v4Engine);
+    QV4::ScopedValue v(scope, m_v4Engine->globalObject);
+    return QJSValue(m_v4Engine, v->asReturnedValue());
 }
 
 /*!
@@ -577,10 +727,9 @@ QJSValue QJSEngine::globalObject() const
  */
 QJSValue QJSEngine::create(int type, const void *ptr)
 {
-    Q_D(QJSEngine);
-    QV4::Scope scope(d->m_v4Engine);
+    QV4::Scope scope(m_v4Engine);
     QV4::ScopedValue v(scope, scope.engine->metaTypeToJS(type, ptr));
-    return QJSValue(d->m_v4Engine, v->asReturnedValue());
+    return QJSValue(m_v4Engine, v->asReturnedValue());
 }
 
 /*!
@@ -616,16 +765,16 @@ bool QJSEngine::convertV2(const QJSValue &value, int type, void *ptr)
             double d = QV4::RuntimeHelpers::stringToNumber(string);
             switch (type) {
             case QMetaType::Int:
-                *reinterpret_cast<int*>(ptr) = QV4::Primitive::toInt32(d);
+                *reinterpret_cast<int*>(ptr) = QV4::Value::toInt32(d);
                 return true;
             case QMetaType::UInt:
-                *reinterpret_cast<uint*>(ptr) = QV4::Primitive::toUInt32(d);
+                *reinterpret_cast<uint*>(ptr) = QV4::Value::toUInt32(d);
                 return true;
             case QMetaType::LongLong:
-                *reinterpret_cast<qlonglong*>(ptr) = QV4::Primitive::toInteger(d);
+                *reinterpret_cast<qlonglong*>(ptr) = QV4::Value::toInteger(d);
                 return true;
             case QMetaType::ULongLong:
-                *reinterpret_cast<qulonglong*>(ptr) = QV4::Primitive::toInteger(d);
+                *reinterpret_cast<qulonglong*>(ptr) = QV4::Value::toInteger(d);
                 return true;
             case QMetaType::Double:
                 *reinterpret_cast<double*>(ptr) = d;
@@ -634,19 +783,19 @@ bool QJSEngine::convertV2(const QJSValue &value, int type, void *ptr)
                 *reinterpret_cast<float*>(ptr) = d;
                 return true;
             case QMetaType::Short:
-                *reinterpret_cast<short*>(ptr) = QV4::Primitive::toInt32(d);
+                *reinterpret_cast<short*>(ptr) = QV4::Value::toInt32(d);
                 return true;
             case QMetaType::UShort:
-                *reinterpret_cast<unsigned short*>(ptr) = QV4::Primitive::toUInt32(d);
+                *reinterpret_cast<unsigned short*>(ptr) = QV4::Value::toUInt32(d);
                 return true;
             case QMetaType::Char:
-                *reinterpret_cast<char*>(ptr) = QV4::Primitive::toInt32(d);
+                *reinterpret_cast<char*>(ptr) = QV4::Value::toInt32(d);
                 return true;
             case QMetaType::UChar:
-                *reinterpret_cast<unsigned char*>(ptr) = QV4::Primitive::toUInt32(d);
+                *reinterpret_cast<unsigned char*>(ptr) = QV4::Value::toUInt32(d);
                 return true;
             case QMetaType::QChar:
-                *reinterpret_cast<QChar*>(ptr) = QV4::Primitive::toUInt32(d);
+                *reinterpret_cast<QChar*>(ptr) = QV4::Value::toUInt32(d);
                 return true;
             default:
                 return false;
@@ -703,32 +852,134 @@ bool QJSEngine::convertV2(const QJSValue &value, int type, void *ptr)
     }
 }
 
-/*! \fn QJSValue QJSEngine::toScriptValue(const T &value)
+/*! \fn template <typename T> QJSValue QJSEngine::toScriptValue(const T &value)
 
     Creates a QJSValue with the given \a value.
 
     \sa fromScriptValue()
 */
 
-/*! \fn T QJSEngine::fromScriptValue(const QJSValue &value)
+/*! \fn template <typename T> T QJSEngine::fromScriptValue(const QJSValue &value)
 
     Returns the given \a value converted to the template type \c{T}.
 
     \sa toScriptValue()
 */
 
+/*!
+    Throws a run-time error (exception) with the given \a message.
+
+    This method is the C++ counterpart of a \c throw() expression in
+    JavaScript. It enables C++ code to report run-time errors to QJSEngine.
+    Therefore it should only be called from C++ code that was invoked by a
+    JavaScript function through QJSEngine.
+
+    When returning from C++, the engine will interrupt the normal flow of
+    execution and call the the next pre-registered exception handler with
+    an error object that contains the given \a message. The error object
+    will point to the location of the top-most context on the JavaScript
+    caller stack; specifically, it will have properties \c lineNumber,
+    \c fileName and \c stack. These properties are described in
+    \l{Script Exceptions}.
+
+    In the following example a C++ method in \e FileAccess.cpp throws an error
+    in \e qmlFile.qml at the position where \c readFileAsText() is called:
+
+    \code
+    // qmlFile.qml
+    function someFunction() {
+      ...
+      var text = FileAccess.readFileAsText("/path/to/file.txt");
+    }
+    \endcode
+
+    \code
+    // FileAccess.cpp
+    // Assuming that FileAccess is a QObject-derived class that has been
+    // registered as a singleton type and provides an invokable method
+    // readFileAsText()
+
+    QJSValue FileAccess::readFileAsText(const QString & filePath) {
+      QFile file(filePath);
+
+      if (!file.open(QIODevice::ReadOnly)) {
+        jsEngine->throwError(file.errorString());
+        return QString();
+      }
+
+      ...
+      return content;
+    }
+    \endcode
+
+    It is also possible to catch the thrown error in JavaScript:
+    \code
+    // qmlFile.qml
+    function someFunction() {
+      ...
+      var text;
+      try {
+        text = FileAccess.readFileAsText("/path/to/file.txt");
+      } catch (error) {
+        console.warn("In " + error.fileName + ":" + "error.lineNumber" +
+                     ": " + error.message);
+      }
+    }
+    \endcode
+
+    If you need a more specific run-time error to describe an exception, you can use the
+    \l {QJSEngine::}{throwError(QJSValue::ErrorType errorType, const QString &message)}
+    overload.
+
+    \since Qt 5.12
+    \sa {Script Exceptions}
+*/
+void QJSEngine::throwError(const QString &message)
+{
+    m_v4Engine->throwError(message);
+}
+
+/*!
+    \overload throwError()
+
+    Throws a run-time error (exception) with the given \a errorType and
+    \a message.
+
+    \code
+    // Assuming that DataEntry is a QObject-derived class that has been
+    // registered as a singleton type and provides an invokable method
+    // setAge().
+
+    void DataEntry::setAge(int age) {
+      if (age < 0 || age > 200) {
+        jsEngine->throwError(QJSValue::RangeError,
+                             "Age must be between 0 and 200");
+      }
+      ...
+    }
+    \endcode
+
+    \since Qt 5.12
+    \sa {Script Exceptions}, newErrorObject()
+*/
+void QJSEngine::throwError(QJSValue::ErrorType errorType, const QString &message)
+{
+    QV4::Scope scope(m_v4Engine);
+    QJSValue error = newErrorObject(errorType, message);
+    QV4::ScopedObject e(scope, QJSValuePrivate::getValue(&error));
+    if (!e)
+        return;
+    m_v4Engine->throwError(e);
+}
 
 QJSEnginePrivate *QJSEnginePrivate::get(QV4::ExecutionEngine *e)
 {
-    return e->v8Engine->publicEngine()->d_func();
+    return e->jsEngine()->d_func();
 }
 
 QJSEnginePrivate::~QJSEnginePrivate()
 {
-    typedef QHash<const QMetaObject *, QQmlPropertyCache *>::Iterator PropertyCacheIt;
-
-    for (PropertyCacheIt iter = propertyCache.begin(), end = propertyCache.end(); iter != end; ++iter)
-        (*iter)->release();
+    QQmlMetaType::freeUnusedTypesAndCaches();
 }
 
 void QJSEnginePrivate::addToDebugServer(QJSEngine *q)
@@ -751,20 +1002,6 @@ void QJSEnginePrivate::removeFromDebugServer(QJSEngine *q)
         server->removeEngine(q);
 }
 
-QQmlPropertyCache *QJSEnginePrivate::createCache(const QMetaObject *mo)
-{
-    if (!mo->superClass()) {
-        QQmlPropertyCache *rv = new QQmlPropertyCache(QV8Engine::getV4(q_func()), mo);
-        propertyCache.insert(mo, rv);
-        return rv;
-    } else {
-        QQmlPropertyCache *super = cache(mo->superClass());
-        QQmlPropertyCache *rv = super->copyAndAppend(mo);
-        propertyCache.insert(mo, rv);
-        return rv;
-    }
-}
-
 /*!
    \since 5.5
    \relates QJSEngine
@@ -779,7 +1016,7 @@ QJSEngine *qjsEngine(const QObject *object)
 {
     QQmlData *data = QQmlData::get(object, false);
     if (!data || data->jsWrapper.isNullOrUndefined())
-        return 0;
+        return nullptr;
     return data->jsWrapper.engine()->jsEngine();
 }
 
diff --git a/src/qml/jsapi/qjsengine.h b/src/qml/jsapi/qjsengine.h
index 41c4b81270..6300842341 100644
--- a/src/qml/jsapi/qjsengine.h
+++ b/src/qml/jsapi/qjsengine.h
@@ -47,10 +47,10 @@
 #include <QtCore/qobject.h>
 #include <QtQml/qjsvalue.h>
 
-QT_BEGIN_NAMESPACE
+#include <QtQml/qqmldebug.h>
 
+QT_BEGIN_NAMESPACE
 
-class QV8Engine;
 
 template <typename T>
 inline T qjsvalue_cast(const QJSValue &);
@@ -63,12 +63,14 @@ class Q_QML_EXPORT QJSEngine
 public:
     QJSEngine();
     explicit QJSEngine(QObject *parent);
-    virtual ~QJSEngine();
+    ~QJSEngine() override;
 
     QJSValue globalObject() const;
 
     QJSValue evaluate(const QString &program, const QString &fileName = QString(), int lineNumber = 1);
 
+    QJSValue importModule(const QString &fileName);
+
     QJSValue newObject();
     QJSValue newArray(uint length = 0);
 
@@ -82,6 +84,8 @@ public:
         return newQMetaObject(&T::staticMetaObject);
     }
 
+    QJSValue newErrorObject(QJSValue::ErrorType errorType, const QString &message = QString());
+
     template <typename T>
     inline QJSValue toScriptValue(const T &value)
     {
@@ -109,7 +113,10 @@ public:
 
     void installExtensions(Extensions extensions, const QJSValue &object = QJSValue());
 
-    QV8Engine *handle() const { return d; }
+    QV4::ExecutionEngine *handle() const { return m_v4Engine; }
+
+    void throwError(const QString &message);
+    void throwError(QJSValue::ErrorType errorType, const QString &message = QString());
 
 private:
     QJSValue create(int type, const void *ptr);
@@ -119,13 +126,12 @@ private:
     friend inline bool qjsvalue_cast_helper(const QJSValue &, int, void *);
 
 protected:
-    QJSEngine(QJSEnginePrivate &dd, QObject *parent = Q_NULLPTR);
+    QJSEngine(QJSEnginePrivate &dd, QObject *parent = nullptr);
 
 private:
-    QV8Engine *d;
+    QV4::ExecutionEngine *m_v4Engine;
     Q_DISABLE_COPY(QJSEngine)
     Q_DECLARE_PRIVATE(QJSEngine)
-    friend class QV8Engine;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QJSEngine::Extensions)
diff --git a/src/qml/jsapi/qjsengine_p.h b/src/qml/jsapi/qjsengine_p.h
index 2b462451ed..a77d710cff 100644
--- a/src/qml/jsapi/qjsengine_p.h
+++ b/src/qml/jsapi/qjsengine_p.h
@@ -55,6 +55,7 @@
 #include <QtCore/qmutex.h>
 #include "qjsengine.h"
 #include "private/qtqmlglobal_p.h"
+#include <private/qqmlmetatype_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -74,7 +75,7 @@ public:
     static QJSEnginePrivate* get(QV4::ExecutionEngine *e);
 
     QJSEnginePrivate() : mutex(QMutex::Recursive) {}
-    ~QJSEnginePrivate();
+    ~QJSEnginePrivate() override;
 
     static void addToDebugServer(QJSEngine *q);
     static void removeFromDebugServer(QJSEngine *q);
@@ -108,16 +109,8 @@ public:
 
 
     // These methods may be called from the QML loader thread
-    inline QQmlPropertyCache *cache(QObject *obj);
-    inline QQmlPropertyCache *cache(const QMetaObject *);
-
-private:
-    // Must be called locked
-    QQmlPropertyCache *createCache(const QMetaObject *);
-
-    // These members must be protected by a QJSEnginePrivate::Locker as they are required by
-    // the threaded loader.  Only access them through their respective accessor methods.
-    QHash<const QMetaObject *, QQmlPropertyCache *> propertyCache;
+    inline QQmlPropertyCache *cache(QObject *obj, int minorVersion = -1);
+    inline QQmlPropertyCache *cache(const QMetaObject *, int minorVersion = -1);
 };
 
 QJSEnginePrivate::Locker::Locker(const QJSEngine *e)
@@ -167,16 +160,14 @@ and deleted before the loader thread has a chance to use or reference it.  This
 can't currently happen as the cache holds a reference to the
 QQmlPropertyCache until the QQmlEngine is destroyed.
 */
-QQmlPropertyCache *QJSEnginePrivate::cache(QObject *obj)
+QQmlPropertyCache *QJSEnginePrivate::cache(QObject *obj, int minorVersion)
 {
     if (!obj || QObjectPrivate::get(obj)->metaObject || QObjectPrivate::get(obj)->wasDeleted)
-        return 0;
+        return nullptr;
 
     Locker locker(this);
     const QMetaObject *mo = obj->metaObject();
-    QQmlPropertyCache *rv = propertyCache.value(mo);
-    if (!rv) rv = createCache(mo);
-    return rv;
+    return QQmlMetaType::propertyCache(mo, minorVersion);
 }
 
 /*!
@@ -188,14 +179,12 @@ exist for the lifetime of the QQmlEngine.
 
 The returned cache is not referenced, so if it is to be stored, call addref().
 */
-QQmlPropertyCache *QJSEnginePrivate::cache(const QMetaObject *metaObject)
+QQmlPropertyCache *QJSEnginePrivate::cache(const QMetaObject *metaObject, int minorVersion)
 {
     Q_ASSERT(metaObject);
 
     Locker locker(this);
-    QQmlPropertyCache *rv = propertyCache.value(metaObject);
-    if (!rv) rv = createCache(metaObject);
-    return rv;
+    return QQmlMetaType::propertyCache(metaObject, minorVersion);
 }
 
 
diff --git a/src/qml/jsapi/qjsvalue.cpp b/src/qml/jsapi/qjsvalue.cpp
index 3a3cf46ddb..e20317cff1 100644
--- a/src/qml/jsapi/qjsvalue.cpp
+++ b/src/qml/jsapi/qjsvalue.cpp
@@ -53,7 +53,7 @@
 #include "qv4errorobject_p.h"
 #include "private/qv8engine_p.h"
 #include <private/qv4mm_p.h>
-#include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 
 /*!
@@ -67,7 +67,7 @@
 
   QJSValue supports the types defined in the \l{ECMA-262}
   standard: The primitive types, which are Undefined, Null, Boolean,
-  Number, and String; and the Object type. Additionally, built-in
+  Number, and String; and the Object and Array types. Additionally, built-in
   support is provided for Qt/C++ types such as QVariant and QObject.
 
   For the object-based types (including Date and RegExp), use the
@@ -80,7 +80,7 @@
   used to test if a value is of a certain type. The methods named
   toT() (e.g. toBool(), toString()) can be used to convert a
   QJSValue to another type. You can also use the generic
-  QJSValue_cast() function.
+  qjsvalue_cast() function.
 
   Object values have zero or more properties which are themselves
   QJSValues. Use setProperty() to set a property of an object, and
@@ -108,6 +108,38 @@
   script code, or QJSValueIterator in C++.
 
   \sa QJSEngine, QJSValueIterator
+
+  \section1 Working With Arrays
+
+  To create an array using QJSValue, use \l QJSEngine::newArray():
+
+  \code
+  // Assumes that this class was declared in QML.
+  QJSValue jsArray = engine->newArray(3);
+  \endcode
+
+  To set individual elements in the array, use
+  the \l {QJSValue::}{setProperty(quint32 arrayIndex, const QJSValue &value)}
+  overload. For example, to fill the array above with integers:
+
+  \code
+  for (int i = 0; i < 3; ++i) {
+      jsArray.setProperty(i, QRandomGenerator::global().generate());
+  }
+  \endcode
+
+  To determine the length of the array, access the \c "length" property.
+  To access array elements, use the
+  \l {QJSValue::}{property(quint32 arrayIndex)} overload. The following code
+  reads the array we created above back into a list:
+
+  \code
+  QVector<int> integers;
+  const int length = jsArray.property("length").toInt();
+  for (int i = 0; i < length; ++i) {
+      integers.append(jsArray.property(i).toInt());
+  }
+  \endcode
 */
 
 /*!
@@ -120,6 +152,39 @@
     \value NullValue A null value.
 */
 
+/*!
+    \typedef QJSValueList
+    \relates QJSValue
+
+    This is a typedef for a QList<QJSValue>.
+*/
+
+/*!
+    \enum QJSValue::ErrorType
+    \since 5.12
+
+    Use this enum for JavaScript language-specific types of Error objects.
+
+    They may be useful when emulating language features in C++ requires the use
+    of specialized exception types. In addition, they may help to more clearly
+    communicate certain typical conditions, instead of throwing a generic
+    JavaScript exception. For example, code that deals with networking and
+    resource locators may find it useful to propagate errors related to
+    malformed locators using the URIError type.
+
+    \omitvalue NoError
+    \value GenericError A generic Error object, but not of a specific sub-type.
+    \omitvalue EvalError
+    \value RangeError A value did not match the expected set or range.
+    \value ReferenceError A non-existing variable referenced.
+    \value SyntaxError An invalid token or sequence of tokens was encountered
+    that does not conform with the syntax of the language.
+    \value TypeError An operand or argument is incompatible with the type
+    expected.
+    \value URIError A URI handling function was used incorrectly or the URI
+    provided is malformed.
+*/
+
 QT_BEGIN_NAMESPACE
 
 using namespace QV4;
@@ -225,7 +290,7 @@ QJSValue::QJSValue(const QJSValue& other)
 */
 
 /*!
-    \fn QJSValue &operator=(QJSValue && other)
+    \fn QJSValue &QJSValue::operator=(QJSValue && other)
 
     Move-assigns \a other to this QJSValue object.
 */
@@ -332,7 +397,7 @@ bool QJSValue::isUndefined() const
   Returns true if this QJSValue is an object of the Error class;
   otherwise returns false.
 
-  \sa {QJSEngine#Script Exceptions}{QJSEngine - Script Exceptions}
+  \sa errorType(), {QJSEngine#Script Exceptions}{QJSEngine - Script Exceptions}
 */
 bool QJSValue::isError() const
 {
@@ -343,6 +408,41 @@ bool QJSValue::isError() const
 }
 
 /*!
+  \since 5.12
+  Returns the error type this QJSValue represents if it is an Error object.
+  Otherwise, returns \c NoError."
+
+  \sa isError(), {QJSEngine#Script Exceptions}{QJSEngine - Script Exceptions}
+*/
+QJSValue::ErrorType QJSValue::errorType() const
+{
+    QV4::Value *val = QJSValuePrivate::getValue(this);
+    if (!val)
+        return NoError;
+    QV4::ErrorObject *error = val->as<ErrorObject>();
+    if (!error)
+        return NoError;
+    switch (error->d()->errorType) {
+    case QV4::Heap::ErrorObject::Error:
+        return GenericError;
+    case QV4::Heap::ErrorObject::EvalError:
+        return EvalError;
+    case QV4::Heap::ErrorObject::RangeError:
+        return RangeError;
+    case QV4::Heap::ErrorObject::ReferenceError:
+        return ReferenceError;
+    case QV4::Heap::ErrorObject::SyntaxError:
+        return SyntaxError;
+    case QV4::Heap::ErrorObject::TypeError:
+        return TypeError;
+    case QV4::Heap::ErrorObject::URIError:
+        return URIError;
+    }
+    Q_UNREACHABLE();
+    return NoError;
+}
+
+/*!
   Returns true if this QJSValue is an object of the Array class;
   otherwise returns false.
 
@@ -370,7 +470,7 @@ bool QJSValue::isObject() const
     QV4::Value *val = QJSValuePrivate::getValue(this);
     if (!val)
         return false;
-    return val->as<Object>();
+    return val->as<QV4::Object>();
 }
 
 /*!
@@ -530,7 +630,7 @@ qint32 QJSValue::toInt() const
     if (!val) {
         QVariant *variant = QJSValuePrivate::getVariant(this);
         if (variant->userType() == QMetaType::QString)
-            return QV4::Primitive::toInt32(RuntimeHelpers::stringToNumber(variant->toString()));
+            return QV4::Value::toInt32(RuntimeHelpers::stringToNumber(variant->toString()));
         else
             return variant->toInt();
     }
@@ -564,7 +664,7 @@ quint32 QJSValue::toUInt() const
     if (!val) {
         QVariant *variant = QJSValuePrivate::getVariant(this);
         if (variant->userType() == QMetaType::QString)
-            return QV4::Primitive::toUInt32(RuntimeHelpers::stringToNumber(variant->toString()));
+            return QV4::Value::toUInt32(RuntimeHelpers::stringToNumber(variant->toString()));
         else
             return variant->toUInt();
     }
@@ -610,7 +710,7 @@ QVariant QJSValue::toVariant() const
     QV4::Value *val = QJSValuePrivate::valueForData(this, &scratch);
     Q_ASSERT(val);
 
-    if (Object *o = val->as<Object>())
+    if (QV4::Object *o = val->as<QV4::Object>())
         return o->engine()->toVariant(*val, /*typeHint*/ -1, /*createJSValueForObjects*/ false);
 
     if (String *s = val->stringValue())
@@ -623,7 +723,7 @@ QVariant QJSValue::toVariant() const
         return QVariant(val->asDouble());
     }
     if (val->isNull())
-        return QVariant(QMetaType::Nullptr, 0);
+        return QVariant(QMetaType::Nullptr, nullptr);
     Q_ASSERT(val->isUndefined());
     return QVariant();
 }
@@ -657,21 +757,21 @@ QJSValue QJSValue::call(const QJSValueList &args)
     Q_ASSERT(engine);
 
     Scope scope(engine);
-    ScopedCallData callData(scope, args.length());
-    callData->thisObject = engine->globalObject;
+    JSCallData jsCallData(scope, args.length());
+    *jsCallData->thisObject = engine->globalObject;
     for (int i = 0; i < args.size(); ++i) {
         if (!QJSValuePrivate::checkEngine(engine, args.at(i))) {
             qWarning("QJSValue::call() failed: cannot call function with argument created in a different engine");
             return QJSValue();
         }
-        callData->args[i] = QJSValuePrivate::convertedToValue(engine, args.at(i));
+        jsCallData->args[i] = QJSValuePrivate::convertedToValue(engine, args.at(i));
     }
 
-    f->call(scope, callData);
+    ScopedValue result(scope, f->call(jsCallData));
     if (engine->hasException)
-        scope.result = engine->catchException();
+        result = engine->catchException();
 
-    return QJSValue(engine, scope.result.asReturnedValue());
+    return QJSValue(engine, result->asReturnedValue());
 }
 
 /*!
@@ -713,21 +813,21 @@ QJSValue QJSValue::callWithInstance(const QJSValue &instance, const QJSValueList
         return QJSValue();
     }
 
-    ScopedCallData callData(scope, args.size());
-    callData->thisObject = QJSValuePrivate::convertedToValue(engine, instance);
+    JSCallData jsCallData(scope, args.size());
+    *jsCallData->thisObject = QJSValuePrivate::convertedToValue(engine, instance);
     for (int i = 0; i < args.size(); ++i) {
         if (!QJSValuePrivate::checkEngine(engine, args.at(i))) {
             qWarning("QJSValue::call() failed: cannot call function with argument created in a different engine");
             return QJSValue();
         }
-        callData->args[i] = QJSValuePrivate::convertedToValue(engine, args.at(i));
+        jsCallData->args[i] = QJSValuePrivate::convertedToValue(engine, args.at(i));
     }
 
-    f->call(scope, callData);
+    ScopedValue result(scope, f->call(jsCallData));
     if (engine->hasException)
-        scope.result = engine->catchException();
+        result = engine->catchException();
 
-    return QJSValue(engine, scope.result.asReturnedValue());
+    return QJSValue(engine, result->asReturnedValue());
 }
 
 /*!
@@ -762,20 +862,20 @@ QJSValue QJSValue::callAsConstructor(const QJSValueList &args)
     Q_ASSERT(engine);
 
     Scope scope(engine);
-    ScopedCallData callData(scope, args.size());
+    JSCallData jsCallData(scope, args.size());
     for (int i = 0; i < args.size(); ++i) {
         if (!QJSValuePrivate::checkEngine(engine, args.at(i))) {
             qWarning("QJSValue::callAsConstructor() failed: cannot construct function with argument created in a different engine");
             return QJSValue();
         }
-        callData->args[i] = QJSValuePrivate::convertedToValue(engine, args.at(i));
+        jsCallData->args[i] = QJSValuePrivate::convertedToValue(engine, args.at(i));
     }
 
-    f->construct(scope, callData);
+    ScopedValue result(scope, f->callAsConstructor(jsCallData));
     if (engine->hasException)
-        scope.result = engine->catchException();
+        result = engine->catchException();
 
-    return QJSValue(engine, scope.result.asReturnedValue());
+    return QJSValue(engine, result->asReturnedValue());
 }
 
 #ifdef QT_DEPRECATED
@@ -792,7 +892,7 @@ QJSEngine* QJSValue::engine() const
     QV4::ExecutionEngine *engine = QJSValuePrivate::engine(this);
     if (engine)
         return engine->jsEngine();
-    return 0;
+    return nullptr;
 }
 
 #endif // QT_DEPRECATED
@@ -810,10 +910,10 @@ QJSValue QJSValue::prototype() const
     if (!engine)
         return QJSValue();
     QV4::Scope scope(engine);
-    ScopedObject o(scope, QJSValuePrivate::getValue(this)->as<Object>());
+    ScopedObject o(scope, QJSValuePrivate::getValue(this)->as<QV4::Object>());
     if (!o)
         return QJSValue();
-    ScopedObject p(scope, o->prototype());
+    ScopedObject p(scope, o->getPrototypeOf());
     if (!p)
         return QJSValue(NullValue);
     return QJSValue(o->internalClass()->engine, p.asReturnedValue());
@@ -845,7 +945,7 @@ void QJSValue::setPrototype(const QJSValue& prototype)
     if (!val)
         return;
     if (val->isNull()) {
-        o->setPrototype(0);
+        o->setPrototypeOf(nullptr);
         return;
     }
 
@@ -856,7 +956,7 @@ void QJSValue::setPrototype(const QJSValue& prototype)
         qWarning("QJSValue::setPrototype() failed: cannot set a prototype created in a different engine");
         return;
     }
-    if (!o->setPrototype(p))
+    if (!o->setPrototypeOf(p))
         qWarning("QJSValue::setPrototype() failed: cyclic prototype value");
 }
 
@@ -892,7 +992,7 @@ static bool js_equal(const QString &string, const QV4::Value &value)
         return RuntimeHelpers::stringToNumber(string) == value.asDouble();
     if (value.isBoolean())
         return RuntimeHelpers::stringToNumber(string) == double(value.booleanValue());
-    if (Object *o = value.objectValue()) {
+    if (QV4::Object *o = value.objectValue()) {
         Scope scope(o->engine());
         ScopedValue p(scope, RuntimeHelpers::toPrimitive(value, PREFERREDTYPE_HINT));
         return js_equal(string, p);
@@ -942,7 +1042,7 @@ bool QJSValue::equals(const QJSValue& other) const
     if (!ov)
         return other.equals(*this);
 
-    return Runtime::method_compareEqual(*v, *ov);
+    return Runtime::CompareEqual::call(*v, *ov);
 }
 
 /*!
@@ -1001,6 +1101,10 @@ bool QJSValue::strictlyEquals(const QJSValue& other) const
   occurred, property() returns the value that was thrown (typically
   an \c{Error} object).
 
+  To access array elements, use the
+  \l {QJSValue::}{setProperty(quint32 arrayIndex, const QJSValue &value)}
+  overload instead.
+
   \sa setProperty(), hasProperty(), QJSValueIterator
 */
 QJSValue QJSValue::property(const QString& name) const
@@ -1015,12 +1119,7 @@ QJSValue QJSValue::property(const QString& name) const
         return QJSValue();
 
     ScopedString s(scope, engine->newString(name));
-    uint idx = s->asArrayIndex();
-    if (idx < UINT_MAX)
-        return property(idx);
-
-    s->makeIdentifier();
-    QV4::ScopedValue result(scope, o->get(s));
+    QV4::ScopedValue result(scope, o->get(s->toPropertyKey()));
     if (engine->hasException)
         result = engine->catchException();
 
@@ -1032,8 +1131,25 @@ QJSValue QJSValue::property(const QString& name) const
 
   Returns the property at the given \a arrayIndex.
 
-  This function is provided for convenience and performance when
-  working with array objects.
+  It is possible to access elements in an array in two ways. The first is to
+  use the array index as the property name:
+
+  \code
+  qDebug() << jsValueArray.property(QLatin1String("4")).toString();
+  \endcode
+
+  The second is to use the overload that takes an index:
+
+  \code
+  qDebug() << jsValueArray.property(4).toString();
+  \endcode
+
+  Both of these approaches achieve the same result, except that the latter:
+
+  \list
+  \li Is easier to use (can use an integer directly)
+  \li Is faster (no conversion to integer)
+  \endlist
 
   If this QJSValue is not an Array object, this function behaves
   as if property() was called with the string representation of \a
@@ -1050,7 +1166,7 @@ QJSValue QJSValue::property(quint32 arrayIndex) const
     if (!o)
         return QJSValue();
 
-    QV4::ScopedValue result(scope, arrayIndex == UINT_MAX ? o->get(engine->id_uintMax()) : o->getIndexed(arrayIndex));
+    QV4::ScopedValue result(scope, arrayIndex == UINT_MAX ? o->get(engine->id_uintMax()) : o->get(arrayIndex));
     if (engine->hasException)
         engine->catchException();
     return QJSValue(engine, result->asReturnedValue());
@@ -1065,6 +1181,10 @@ QJSValue QJSValue::property(quint32 arrayIndex) const
   If this QJSValue does not already have a property with name \a name,
   a new property is created.
 
+  To modify array elements, use the
+  \l {QJSValue::}{setProperty(quint32 arrayIndex, const QJSValue &value)}
+  overload instead.
+
   \sa property(), deleteProperty()
 */
 void QJSValue::setProperty(const QString& name, const QJSValue& value)
@@ -1084,15 +1204,8 @@ void QJSValue::setProperty(const QString& name, const QJSValue& value)
     }
 
     ScopedString s(scope, engine->newString(name));
-    uint idx = s->asArrayIndex();
-    if (idx < UINT_MAX) {
-        setProperty(idx, value);
-        return;
-    }
-
-    s->makeIdentifier();
     QV4::ScopedValue v(scope, QJSValuePrivate::convertedToValue(engine, value));
-    o->put(s, v);
+    o->put(s->toPropertyKey(), v);
     if (engine->hasException)
         engine->catchException();
 }
@@ -1102,12 +1215,31 @@ void QJSValue::setProperty(const QString& name, const QJSValue& value)
 
   Sets the property at the given \a arrayIndex to the given \a value.
 
-  This function is provided for convenience and performance when
-  working with array objects.
+  It is possible to modify elements in an array in two ways. The first is to
+  use the array index as the property name:
+
+  \code
+  jsValueArray.setProperty(QLatin1String("4"), value);
+  \endcode
+
+  The second is to use the overload that takes an index:
+
+  \code
+  jsValueArray.setProperty(4, value);
+  \endcode
+
+  Both of these approaches achieve the same result, except that the latter:
+
+  \list
+  \li Is easier to use (can use an integer directly)
+  \li Is faster (no conversion to integer)
+  \endlist
 
   If this QJSValue is not an Array object, this function behaves
   as if setProperty() was called with the string representation of \a
   arrayIndex.
+
+  \sa {QJSValue::}{property(quint32 arrayIndex)}, {Working With Arrays}
 */
 void QJSValue::setProperty(quint32 arrayIndex, const QJSValue& value)
 {
@@ -1126,10 +1258,8 @@ void QJSValue::setProperty(quint32 arrayIndex, const QJSValue& value)
     }
 
     QV4::ScopedValue v(scope, QJSValuePrivate::convertedToValue(engine, value));
-    if (arrayIndex != UINT_MAX)
-        o->putIndexed(arrayIndex, v);
-    else
-        o->put(engine->id_uintMax(), v);
+    PropertyKey id = arrayIndex != UINT_MAX ? PropertyKey::fromArrayIndex(arrayIndex) : engine->id_uintMax()->propertyKey();
+    o->put(id, v);
     if (engine->hasException)
         engine->catchException();
 }
@@ -1166,10 +1296,7 @@ bool QJSValue::deleteProperty(const QString &name)
         return false;
 
     ScopedString s(scope, engine->newString(name));
-    bool b = o->deleteProperty(s);
-    if (engine->hasException)
-        engine->catchException();
-    return b;
+    return o->deleteProperty(s->toPropertyKey());
 }
 
 /*!
@@ -1189,8 +1316,8 @@ bool QJSValue::hasProperty(const QString &name) const
     if (!o)
         return false;
 
-    ScopedString s(scope, engine->newIdentifier(name));
-    return o->hasProperty(s);
+    ScopedString s(scope, engine->newString(name));
+    return o->hasProperty(s->toPropertyKey());
 }
 
 /*!
@@ -1211,16 +1338,16 @@ bool QJSValue::hasOwnProperty(const QString &name) const
         return false;
 
     ScopedString s(scope, engine->newIdentifier(name));
-    return o->hasOwnProperty(s);
+    return o->getOwnProperty(s->propertyKey()) != Attr_Invalid;
 }
 
 /*!
  * If this QJSValue is a QObject, returns the QObject pointer
- * that the QJSValue represents; otherwise, returns 0.
+ * that the QJSValue represents; otherwise, returns \nullptr.
  *
  * If the QObject that this QJSValue wraps has been deleted,
- * this function returns 0 (i.e. it is possible for toQObject()
- * to return 0 even when isQObject() returns true).
+ * this function returns \nullptr (i.e. it is possible for toQObject()
+ * to return \nullptr even when isQObject() returns true).
  *
  * \sa isQObject()
  */
@@ -1228,11 +1355,11 @@ QObject *QJSValue::toQObject() const
 {
     QV4::ExecutionEngine *engine = QJSValuePrivate::engine(this);
     if (!engine)
-        return 0;
+        return nullptr;
     QV4::Scope scope(engine);
     QV4::Scoped<QV4::QObjectWrapper> wrapper(scope, QJSValuePrivate::getValue(this));
     if (!wrapper)
-        return 0;
+        return nullptr;
 
     return wrapper->object();
 }
@@ -1249,11 +1376,11 @@ const QMetaObject *QJSValue::toQMetaObject() const
 {
     QV4::ExecutionEngine *engine = QJSValuePrivate::engine(this);
     if (!engine)
-        return 0;
+        return nullptr;
     QV4::Scope scope(engine);
     QV4::Scoped<QV4::QMetaObjectWrapper> wrapper(scope, QJSValuePrivate::getValue(this));
     if (!wrapper)
-        return 0;
+        return nullptr;
 
     return wrapper->metaObject();
 }
@@ -1309,7 +1436,7 @@ bool QJSValue::isRegExp() const
 bool QJSValue::isQObject() const
 {
     QV4::Value *val = QJSValuePrivate::getValue(this);
-    return val && val->as<QV4::QObjectWrapper>() != 0;
+    return val && val->as<QV4::QObjectWrapper>() != nullptr;
 }
 
 /*!
@@ -1323,7 +1450,7 @@ bool QJSValue::isQObject() const
 bool QJSValue::isQMetaObject() const
 {
     QV4::Value *val = QJSValuePrivate::getValue(this);
-    return val && val->as<QV4::QMetaObjectWrapper>() != 0;
+    return val && val->as<QV4::QMetaObjectWrapper>() != nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsapi/qjsvalue.h b/src/qml/jsapi/qjsvalue.h
index 56bd64eec1..2f95e0ff31 100644
--- a/src/qml/jsapi/qjsvalue.h
+++ b/src/qml/jsapi/qjsvalue.h
@@ -68,6 +68,17 @@ public:
         UndefinedValue
     };
 
+    enum ErrorType {
+        NoError,
+        GenericError,
+        EvalError,
+        RangeError,
+        ReferenceError,
+        SyntaxError,
+        TypeError,
+        URIError
+    };
+
 public:
     QJSValue(SpecialValue value = UndefinedValue);
     ~QJSValue();
@@ -137,6 +148,7 @@ public:
     QJSValue callWithInstance(const QJSValue &instance, const QJSValueList &args = QJSValueList()); // ### Qt6: Make const
     QJSValue callAsConstructor(const QJSValueList &args = QJSValueList()); // ### Qt6: Make const
 
+    ErrorType errorType() const;
 #ifdef QT_DEPRECATED
     QT_DEPRECATED QJSEngine *engine() const;
 #endif
diff --git a/src/qml/jsapi/qjsvalue_p.h b/src/qml/jsapi/qjsvalue_p.h
index c4761ad6ea..bcf0a9d12d 100644
--- a/src/qml/jsapi/qjsvalue_p.h
+++ b/src/qml/jsapi/qjsvalue_p.h
@@ -62,13 +62,13 @@
 
 QT_BEGIN_NAMESPACE
 
-class QJSValuePrivate
+class Q_AUTOTEST_EXPORT QJSValuePrivate
 {
 public:
     static inline QV4::Value *getValue(const QJSValue *jsval)
     {
         if (jsval->d & 3)
-            return 0;
+            return nullptr;
         return reinterpret_cast<QV4::Value *>(jsval->d);
     }
 
@@ -76,7 +76,7 @@ public:
     {
         if (jsval->d & 1)
             return reinterpret_cast<QVariant *>(jsval->d & ~3);
-        return 0;
+        return nullptr;
     }
 
     static inline void setVariant(QJSValue *jsval, const QVariant &v) {
@@ -153,14 +153,14 @@ public:
             *v = QV4::Encode(variant->toUInt());
             break;
         default:
-            return 0;
+            return nullptr;
         }
         return v;
     }
 
     static QV4::ExecutionEngine *engine(const QJSValue *jsval) {
         QV4::Value *v = getValue(jsval);
-        return v ? QV4::PersistentValueStorage::getEngine(v) : 0;
+        return v ? QV4::PersistentValueStorage::getEngine(v) : nullptr;
     }
 
     static inline bool checkEngine(QV4::ExecutionEngine *e, const QJSValue &jsval) {
diff --git a/src/qml/jsapi/qjsvalueiterator.cpp b/src/qml/jsapi/qjsvalueiterator.cpp
index ce472ce7e5..076b90c5f2 100644
--- a/src/qml/jsapi/qjsvalueiterator.cpp
+++ b/src/qml/jsapi/qjsvalueiterator.cpp
@@ -47,19 +47,50 @@
 QT_BEGIN_NAMESPACE
 
 QJSValueIteratorPrivate::QJSValueIteratorPrivate(const QJSValue &v)
-    : value(v)
-    , currentIndex(UINT_MAX)
-    , nextIndex(UINT_MAX)
 {
+    init(v);
+}
+
+void QJSValueIteratorPrivate::init(const QJSValue &v)
+{
+    engine = nullptr;
+
     QV4::ExecutionEngine *e = QJSValuePrivate::engine(&v);
     if (!e)
         return;
+    QV4::Object *o = QJSValuePrivate::getValue(&v)->objectValue();
+    if (!o)
+        return;
 
-    QV4::Scope scope(e);
-    QV4::ScopedObject o(scope, QJSValuePrivate::getValue(&v));
-    iterator.set(e, e->newForEachIteratorObject(o));
+    engine = e;
+    object = o;
+    iterator.reset(o->ownPropertyKeys(object.valueRef()));
+    next();
 }
 
+void QJSValueIteratorPrivate::next()
+{
+    QV4::Object *o = object.as<QV4::Object>();
+    if (!o || !iterator)
+        return;
+
+    QV4::PropertyKey key;
+    while (1) {
+        key = iterator->next(o);
+        if (!key.isSymbol())
+            break;
+    }
+    currentKey = nextKey;
+    nextKey.set(engine, key.id());
+}
+
+bool QJSValueIteratorPrivate::isValid() const
+{
+    if (!engine || !iterator)
+        return false;
+    QV4::Value *val = object.valueRef();
+    return (val && val->isObject());
+}
 
 /*!
     \class QJSValueIterator
@@ -98,17 +129,6 @@ QJSValueIteratorPrivate::QJSValueIteratorPrivate(const QJSValue &v)
 QJSValueIterator::QJSValueIterator(const QJSValue& object)
     : d_ptr(new QJSValueIteratorPrivate(object))
 {
-    QV4::ExecutionEngine *v4 = d_ptr->iterator.engine();
-    if (!v4)
-        return;
-    QV4::Scope scope(v4);
-    QV4::Scoped<QV4::ForEachIteratorObject> it(scope, d_ptr->iterator.value());
-    it->d()->it().flags =  QV4::ObjectIterator::NoFlags;
-    QV4::ScopedString nm(scope);
-    QV4::Property nextProperty;
-    QV4::PropertyAttributes nextAttributes;
-    it->d()->it().next(nm.getRef(), &d_ptr->nextIndex, &nextProperty, &nextAttributes);
-    d_ptr->nextName.set(v4, nm.asReturnedValue());
 }
 
 /*!
@@ -127,10 +147,9 @@ QJSValueIterator::~QJSValueIterator()
 */
 bool QJSValueIterator::hasNext() const
 {
-    QV4::Value *val = QJSValuePrivate::getValue(&d_ptr->value);
-    if (!val || !val->isObject())
+    if (!d_ptr->isValid())
         return false;
-    return d_ptr->nextName.as<QV4::String>() || d_ptr->nextIndex != UINT_MAX;
+    return QV4::PropertyKey::fromId(d_ptr->nextKey.value()).isValid();
 }
 
 /*!
@@ -143,23 +162,10 @@ bool QJSValueIterator::hasNext() const
 */
 bool QJSValueIterator::next()
 {
-    QV4::Value *val = QJSValuePrivate::getValue(&d_ptr->value);
-    if (!val || !val->isObject())
-        return false;
-    d_ptr->currentName = d_ptr->nextName;
-    d_ptr->currentIndex = d_ptr->nextIndex;
-
-    QV4::ExecutionEngine *v4 = d_ptr->iterator.engine();
-    if (!v4)
+    if (!d_ptr->isValid())
         return false;
-    QV4::Scope scope(v4);
-    QV4::Scoped<QV4::ForEachIteratorObject> it(scope, d_ptr->iterator.value());
-    QV4::ScopedString nm(scope);
-    QV4::Property nextProperty;
-    QV4::PropertyAttributes nextAttributes;
-    it->d()->it().next(nm.getRef(), &d_ptr->nextIndex, &nextProperty, &nextAttributes);
-    d_ptr->nextName.set(v4, nm.asReturnedValue());
-    return d_ptr->currentName.as<QV4::String>() || d_ptr->currentIndex != UINT_MAX;
+    d_ptr->next();
+    return QV4::PropertyKey::fromId(d_ptr->currentKey.value()).isValid();
 }
 
 /*!
@@ -170,14 +176,14 @@ bool QJSValueIterator::next()
 */
 QString QJSValueIterator::name() const
 {
-    QV4::Value *val = QJSValuePrivate::getValue(&d_ptr->value);
-    if (!val || !val->isObject())
+    if (!d_ptr->isValid())
+        return QString();
+    QV4::Scope scope(d_ptr->engine);
+    QV4::ScopedPropertyKey key(scope, QV4::PropertyKey::fromId(d_ptr->currentKey.value()));
+    if (!key->isValid())
         return QString();
-    if (QV4::String *s = d_ptr->currentName.as<QV4::String>())
-        return s->toQString();
-    if (d_ptr->currentIndex < UINT_MAX)
-        return QString::number(d_ptr->currentIndex);
-    return QString();
+    Q_ASSERT(!key->isSymbol());
+    return key->toStringOrSymbol(d_ptr->engine)->toQString();
 }
 
 
@@ -189,23 +195,21 @@ QString QJSValueIterator::name() const
 */
 QJSValue QJSValueIterator::value() const
 {
-    QV4::ExecutionEngine *engine = d_ptr->iterator.engine();
-    if (!engine)
+    if (!d_ptr->isValid())
         return QJSValue();
-    QV4::Scope scope(engine);
-    QV4::ScopedObject obj(scope, QJSValuePrivate::getValue(&d_ptr->value));
-    if (!obj)
+    QV4::Scope scope(d_ptr->engine);
+    QV4::ScopedPropertyKey key(scope, QV4::PropertyKey::fromId(d_ptr->currentKey.value()));
+    if (!key->isValid())
         return QJSValue();
 
-    if (!d_ptr->currentName.as<QV4::String>() && d_ptr->currentIndex == UINT_MAX)
-        return QJSValue();
+    QV4::ScopedObject obj(scope, d_ptr->object.asManaged());
+    QV4::ScopedValue val(scope, obj->get(key));
 
-    QV4::ScopedValue v(scope, d_ptr->currentIndex == UINT_MAX ? obj->get(d_ptr->currentName.as<QV4::String>()) : obj->getIndexed(d_ptr->currentIndex));
     if (scope.hasException()) {
-        engine->catchException();
+        scope.engine->catchException();
         return QJSValue();
     }
-    return QJSValue(engine, v->asReturnedValue());
+    return QJSValue(scope.engine, val->asReturnedValue());
 }
 
 
@@ -216,27 +220,7 @@ QJSValue QJSValueIterator::value() const
 */
 QJSValueIterator& QJSValueIterator::operator=(QJSValue& object)
 {
-    d_ptr->value = object;
-    d_ptr->currentIndex = UINT_MAX;
-    d_ptr->nextIndex = UINT_MAX;
-    d_ptr->currentName.clear();
-    d_ptr->nextName.clear();
-    QV4::ExecutionEngine *v4 = d_ptr->iterator.engine();
-    if (!v4) {
-        d_ptr->iterator.clear();
-        return *this;
-    }
-
-    QV4::Scope scope(v4);
-    QV4::ScopedObject o(scope, QJSValuePrivate::getValue(&object));
-    d_ptr->iterator.set(v4, v4->newForEachIteratorObject(o));
-    QV4::Scoped<QV4::ForEachIteratorObject> it(scope, d_ptr->iterator.value());
-    it->d()->it().flags =  QV4::ObjectIterator::NoFlags;
-    QV4::ScopedString nm(scope);
-    QV4::Property nextProperty;
-    QV4::PropertyAttributes nextAttributes;
-    it->d()->it().next(nm.getRef(), &d_ptr->nextIndex, &nextProperty, &nextAttributes);
-    d_ptr->nextName.set(v4, nm.asReturnedValue());
+    d_ptr->init(object);
     return *this;
 }
 
diff --git a/src/qml/jsapi/qjsvalueiterator_p.h b/src/qml/jsapi/qjsvalueiterator_p.h
index 474a98b9fa..a870850c11 100644
--- a/src/qml/jsapi/qjsvalueiterator_p.h
+++ b/src/qml/jsapi/qjsvalueiterator_p.h
@@ -61,12 +61,16 @@ class QJSValueIteratorPrivate
 public:
     QJSValueIteratorPrivate(const QJSValue &v);
 
-    QJSValue value;
-    QV4::PersistentValue iterator;
-    QV4::PersistentValue currentName;
-    uint currentIndex;
-    QV4::PersistentValue nextName;
-    uint nextIndex;
+    void init(const QJSValue &v);
+    bool isValid() const;
+
+    void next();
+
+    QV4::ExecutionEngine *engine = nullptr;
+    QV4::PersistentValue object;
+    QScopedPointer<QV4::OwnPropertyKeyIterator> iterator;
+    QV4::PersistentValue currentKey;
+    QV4::PersistentValue nextKey;
 };
 
 
diff --git a/src/qml/jsruntime/jsruntime.pri b/src/qml/jsruntime/jsruntime.pri
index 9938f60aea..a24ee0a188 100644
--- a/src/qml/jsruntime/jsruntime.pri
+++ b/src/qml/jsruntime/jsruntime.pri
@@ -3,7 +3,6 @@ INCLUDEPATH += $$OUT_PWD
 
 !qmldevtools_build {
 SOURCES += \
-    $$PWD/qv4engine.cpp \
     $$PWD/qv4context.cpp \
     $$PWD/qv4persistent.cpp \
     $$PWD/qv4lookup.cpp \
@@ -12,37 +11,55 @@ SOURCES += \
     $$PWD/qv4managed.cpp \
     $$PWD/qv4internalclass.cpp \
     $$PWD/qv4sparsearray.cpp \
+    $$PWD/qv4atomics.cpp \
     $$PWD/qv4arraydata.cpp \
     $$PWD/qv4arrayobject.cpp \
+    $$PWD/qv4arrayiterator.cpp \
     $$PWD/qv4argumentsobject.cpp \
     $$PWD/qv4booleanobject.cpp \
     $$PWD/qv4dateobject.cpp \
     $$PWD/qv4errorobject.cpp \
     $$PWD/qv4function.cpp \
     $$PWD/qv4functionobject.cpp \
+    $$PWD/qv4generatorobject.cpp \
     $$PWD/qv4globalobject.cpp \
+    $$PWD/qv4iterator.cpp \
     $$PWD/qv4jsonobject.cpp \
     $$PWD/qv4mathobject.cpp \
     $$PWD/qv4memberdata.cpp \
     $$PWD/qv4numberobject.cpp \
     $$PWD/qv4object.cpp \
     $$PWD/qv4objectproto.cpp \
+    $$PWD/qv4propertykey.cpp \
+    $$PWD/qv4proxy.cpp \
     $$PWD/qv4qmlcontext.cpp \
+    $$PWD/qv4reflect.cpp \
     $$PWD/qv4regexpobject.cpp \
+    $$PWD/qv4stackframe.cpp \
+    $$PWD/qv4stringiterator.cpp \
     $$PWD/qv4stringobject.cpp \
     $$PWD/qv4variantobject.cpp \
     $$PWD/qv4objectiterator.cpp \
     $$PWD/qv4regexp.cpp \
+    $$PWD/qv4runtimecodegen.cpp \
     $$PWD/qv4serialize.cpp \
     $$PWD/qv4script.cpp \
-    $$PWD/qv4sequenceobject.cpp \
+    $$PWD/qv4symbol.cpp \
+    $$PWD/qv4setobject.cpp \
+    $$PWD/qv4setiterator.cpp \
     $$PWD/qv4include.cpp \
     $$PWD/qv4qobjectwrapper.cpp \
     $$PWD/qv4arraybuffer.cpp \
     $$PWD/qv4typedarray.cpp \
-    $$PWD/qv4dataview.cpp
+    $$PWD/qv4dataview.cpp \
+    $$PWD/qv4vme_moth.cpp \
+    $$PWD/qv4mapobject.cpp \
+    $$PWD/qv4mapiterator.cpp \
+    $$PWD/qv4estable.cpp \
+    $$PWD/qv4module.cpp \
+    $$PWD/qv4promiseobject.cpp
 
-!contains(QT_CONFIG, no-qml-debug): SOURCES += $$PWD/qv4profiling.cpp
+qtConfig(qml-debug): SOURCES += $$PWD/qv4profiling.cpp
 
 HEADERS += \
     $$PWD/qv4global_p.h \
@@ -58,24 +75,35 @@ HEADERS += \
     $$PWD/qv4identifiertable_p.h \
     $$PWD/qv4managed_p.h \
     $$PWD/qv4internalclass_p.h \
+    $$PWD/qv4jscall_p.h \
     $$PWD/qv4sparsearray_p.h \
+    $$PWD/qv4atomics_p.h \
     $$PWD/qv4arraydata_p.h \
     $$PWD/qv4arrayobject_p.h \
+    $$PWD/qv4arrayiterator_p.h \
     $$PWD/qv4argumentsobject_p.h \
     $$PWD/qv4booleanobject_p.h \
     $$PWD/qv4dateobject_p.h \
     $$PWD/qv4errorobject_p.h \
     $$PWD/qv4function_p.h \
     $$PWD/qv4functionobject_p.h \
+    $$PWD/qv4generatorobject_p.h \
     $$PWD/qv4globalobject_p.h \
+    $$PWD/qv4iterator_p.h \
     $$PWD/qv4jsonobject_p.h \
     $$PWD/qv4mathobject_p.h \
     $$PWD/qv4memberdata_p.h \
     $$PWD/qv4numberobject_p.h \
     $$PWD/qv4object_p.h \
     $$PWD/qv4objectproto_p.h \
+    $$PWD/qv4propertykey_p.h \
+    $$PWD/qv4proxy_p.h \
     $$PWD/qv4qmlcontext_p.h \
+    $$PWD/qv4reflect_p.h \
     $$PWD/qv4regexpobject_p.h \
+    $$PWD/qv4runtimecodegen_p.h \
+    $$PWD/qv4stackframe_p.h \
+    $$PWD/qv4stringiterator_p.h \
     $$PWD/qv4stringobject_p.h \
     $$PWD/qv4variantobject_p.h \
     $$PWD/qv4property_p.h \
@@ -83,21 +111,31 @@ HEADERS += \
     $$PWD/qv4regexp_p.h \
     $$PWD/qv4serialize_p.h \
     $$PWD/qv4script_p.h \
+    $$PWD/qv4symbol_p.h \
+    $$PWD/qv4setobject_p.h \
+    $$PWD/qv4setiterator_p.h \
     $$PWD/qv4scopedvalue_p.h \
     $$PWD/qv4executableallocator_p.h \
-    $$PWD/qv4sequenceobject_p.h \
     $$PWD/qv4include_p.h \
     $$PWD/qv4qobjectwrapper_p.h \
     $$PWD/qv4profiling_p.h \
     $$PWD/qv4arraybuffer_p.h \
     $$PWD/qv4typedarray_p.h \
-    $$PWD/qv4dataview_p.h
+    $$PWD/qv4dataview_p.h \
+    $$PWD/qv4vme_moth_p.h \
+    $$PWD/qv4mapobject_p.h \
+    $$PWD/qv4mapiterator_p.h \
+    $$PWD/qv4estable_p.h \
+    $$PWD/qv4vtable_p.h \
+    $$PWD/qv4module_p.h \
+    $$PWD/qv4promiseobject_p.h
 
-qtConfig(qml-interpreter) {
+qtConfig(qml-sequence-object) {
     HEADERS += \
-        $$PWD/qv4vme_moth_p.h
+        $$PWD/qv4sequenceobject_p.h
+
     SOURCES += \
-        $$PWD/qv4vme_moth.cpp
+        $$PWD/qv4sequenceobject.cpp
 }
 
 }
@@ -109,14 +147,33 @@ HEADERS += \
     $$PWD/qv4value_p.h \
     $$PWD/qv4string_p.h \
     $$PWD/qv4util_p.h \
-    $$PWD/qv4value_p.h
+    $$PWD/qv4value_p.h \
+    $$PWD/qv4functiontable_p.h
 
 SOURCES += \
+    $$PWD/qv4engine.cpp \
     $$PWD/qv4runtime.cpp \
     $$PWD/qv4string.cpp \
     $$PWD/qv4value.cpp \
     $$PWD/qv4executableallocator.cpp
 
+qmldevtools_build {
+    SOURCES += \
+        $$PWD/qv4functiontable_noop.cpp
+} else:win32 {
+    !winrt:equals(QT_ARCH, x86_64) {
+        SOURCES += \
+            $$PWD/qv4functiontable_win64.cpp
+    } else {
+        SOURCES += \
+            $$PWD/qv4functiontable_noop.cpp
+    }
+} else {
+    SOURCES += \
+        $$PWD/qv4functiontable_unix.cpp
+}
+
+
 valgrind {
     DEFINES += V4_USE_VALGRIND
 }
diff --git a/src/qml/jsruntime/qv4alloca_p.h b/src/qml/jsruntime/qv4alloca_p.h
index 1e9f83a90e..65c3e4d65a 100644
--- a/src/qml/jsruntime/qv4alloca_p.h
+++ b/src/qml/jsruntime/qv4alloca_p.h
@@ -89,7 +89,7 @@ public:
     Qt_AllocaWrapper() { m_data = 0; }
     ~Qt_AllocaWrapper() { free(m_data); }
     void *data() { return m_data; }
-    void allocate(int size) { m_data = malloc(size); }
+    void allocate(int size) { m_data = malloc(size); memset(m_data, 0, size); }
 private:
     void *m_data;
 };
diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 0905c2828a..4a21f62cf2 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -37,209 +37,187 @@
 **
 ****************************************************************************/
 #include <qv4argumentsobject_p.h>
+#include <qv4arrayobject_p.h>
 #include <qv4alloca_p.h>
 #include <qv4scopedvalue_p.h>
 #include <qv4string_p.h>
 #include <qv4function_p.h>
+#include <qv4jscall_p.h>
+#include <qv4symbol_p.h>
 
 using namespace QV4;
 
 DEFINE_OBJECT_VTABLE(ArgumentsObject);
+DEFINE_OBJECT_VTABLE(StrictArgumentsObject);
+
+void Heap::StrictArgumentsObject::init(QV4::CppStackFrame *frame)
 
-void Heap::ArgumentsObject::init(QV4::CallContext *context)
 {
+    Q_ASSERT(vtable() == QV4::StrictArgumentsObject::staticVTable());
     ExecutionEngine *v4 = internalClass->engine;
 
     Object::init();
-    fullyCreated = false;
+
+    Q_ASSERT(internalClass->verifyIndex(v4->id_callee()->propertyKey(), CalleePropertyIndex));
+    Q_ASSERT(internalClass->findValueOrSetter(v4->id_callee()->propertyKey()).index == CalleeSetterPropertyIndex);
+    Q_ASSERT(internalClass->verifyIndex(v4->symbol_iterator()->propertyKey(), SymbolIteratorPropertyIndex));
+    setProperty(v4, SymbolIteratorPropertyIndex, *v4->arrayProtoValues());
+    setProperty(v4, CalleePropertyIndex, *v4->thrower());
+    setProperty(v4, CalleeSetterPropertyIndex, *v4->thrower());
+
+    Scope scope(v4);
+    Scoped<QV4::StrictArgumentsObject> args(scope, this);
+    args->arrayReserve(frame->originalArgumentsCount);
+    args->arrayPut(0, frame->originalArguments, frame->originalArgumentsCount);
+
+    Q_ASSERT(args->internalClass()->verifyIndex(v4->id_length()->propertyKey(), LengthPropertyIndex));
+    setProperty(v4, LengthPropertyIndex, Value::fromInt32(frame->originalArgumentsCount));
+}
+
+void Heap::ArgumentsObject::init(QV4::CppStackFrame *frame)
+{
+    ExecutionEngine *v4 = internalClass->engine;
+
+    QV4::CallContext *context = static_cast<QV4::CallContext *>(frame->context());
+
+    Object::init();
     this->context.set(v4, context->d());
     Q_ASSERT(vtable() == QV4::ArgumentsObject::staticVTable());
 
-    Scope scope(v4);
-    Scoped<QV4::ArgumentsObject> args(scope, this);
-
-    if (context->d()->strictMode) {
-        Q_ASSERT(CalleePropertyIndex == args->internalClass()->find(v4->id_callee()));
-        Q_ASSERT(CallerPropertyIndex == args->internalClass()->find(v4->id_caller()));
-        args->setProperty(CalleePropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
-        args->setProperty(CalleePropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
-        args->setProperty(CallerPropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
-        args->setProperty(CallerPropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
-
-        args->arrayReserve(context->argc());
-        args->arrayPut(0, context->args(), context->argc());
-        args->d()->fullyCreated = true;
-    } else {
-        Q_ASSERT(CalleePropertyIndex == args->internalClass()->find(v4->id_callee()));
-        args->setProperty(CalleePropertyIndex, context->d()->function);
-    }
-    Q_ASSERT(LengthPropertyIndex == args->internalClass()->find(v4->id_length()));
-    args->setProperty(LengthPropertyIndex, Primitive::fromInt32(context->d()->callData->argc));
+    Q_ASSERT(internalClass->verifyIndex(v4->id_callee()->propertyKey(), CalleePropertyIndex));
+    setProperty(v4, CalleePropertyIndex, context->d()->function);
+    Q_ASSERT(internalClass->verifyIndex(v4->id_length()->propertyKey(), LengthPropertyIndex));
+    setProperty(v4, LengthPropertyIndex, Value::fromInt32(context->argc()));
+    Q_ASSERT(internalClass->verifyIndex(v4->symbol_iterator()->propertyKey(), SymbolIteratorPropertyIndex));
+    setProperty(v4, SymbolIteratorPropertyIndex, *v4->arrayProtoValues());
+
+    fullyCreated = false;
+    argCount = frame->originalArgumentsCount;
+    uint nFormals = frame->v4Function->nFormals;
+    mapped = nFormals > 63 ? std::numeric_limits<quint64>::max() : (1ull << nFormals) - 1;
 }
 
 void ArgumentsObject::fullyCreate()
 {
-    if (fullyCreated())
+    if (d()->fullyCreated)
         return;
 
     Scope scope(engine());
 
-    uint argCount = context()->callData->argc;
-    uint numAccessors = qMin(context()->formalParameterCount(), argCount);
-    ArrayData::realloc(this, Heap::ArrayData::Sparse, argCount, true);
-    scope.engine->requireArgumentsAccessors(numAccessors);
-
-    Scoped<MemberData> md(scope, d()->mappedArguments);
-    if (numAccessors) {
-        d()->mappedArguments.set(scope.engine, md->allocate(scope.engine, numAccessors));
-        for (uint i = 0; i < numAccessors; ++i) {
-            d()->mappedArguments->values.set(scope.engine, i, context()->callData->args[i]);
-            arraySet(i, scope.engine->argumentsAccessors + i, Attr_Accessor);
-        }
-    }
-    arrayPut(numAccessors, context()->callData->args + numAccessors, argCount - numAccessors);
-    for (uint i = numAccessors; i < argCount; ++i)
-        setArrayAttributes(i, Attr_Data);
+    arrayReserve(d()->argCount);
+    arrayPut(0, context()->args(), d()->argCount);
+    // Use a sparse array, so that method_getElement() doesn't shortcut
+    initSparseArray();
 
     d()->fullyCreated = true;
 }
 
-bool ArgumentsObject::defineOwnProperty(ExecutionEngine *engine, uint index, const Property *desc, PropertyAttributes attrs)
+bool ArgumentsObject::virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *desc, PropertyAttributes attrs)
 {
-    fullyCreate();
-
-    Scope scope(engine);
-    ScopedProperty map(scope);
-    PropertyAttributes mapAttrs;
-    uint numAccessors = qMin(context()->formalParameterCount(), static_cast<uint>(context()->callData->argc));
-    bool isMapped = false;
-    if (arrayData() && index < numAccessors &&
-        arrayData()->attributes(index).isAccessor() &&
-        arrayData()->get(index) == scope.engine->argumentsAccessors[index].getter()->asReturnedValue())
-        isMapped = true;
-
-    if (isMapped) {
-        Q_ASSERT(arrayData());
-        mapAttrs = arrayData()->attributes(index);
-        arrayData()->getProperty(index, map, &mapAttrs);
-        setArrayAttributes(index, Attr_Data);
-        ArrayData::Index arrayIndex{ arrayData(), arrayData()->mappedIndex(index) };
-        arrayIndex.set(scope.engine, d()->mappedArguments->values[index]);
-    }
+    ArgumentsObject *args = static_cast<ArgumentsObject *>(m);
+    args->fullyCreate();
+    uint index = id.asArrayIndex();
+
+    if (!args->isMapped(index))
+        return Object::virtualDefineOwnProperty(m, id, desc, attrs);
+
+    Scope scope(args);
+    PropertyAttributes cAttrs = attrs;
+    ScopedProperty cDesc(scope);
+    cDesc->copy(desc, attrs);
 
-    bool strict = engine->current->strictMode;
-    engine->current->strictMode = false;
-    bool result = Object::defineOwnProperty2(scope.engine, index, desc, attrs);
-    engine->current->strictMode = strict;
-
-    if (isMapped && attrs.isData()) {
-        Q_ASSERT(arrayData());
-        ScopedFunctionObject setter(scope, map->setter());
-        ScopedCallData callData(scope, 1);
-        callData->thisObject = this->asReturnedValue();
-        callData->args[0] = desc->value;
-        setter->call(scope, callData);
-
-        if (attrs.isWritable()) {
-            setArrayAttributes(index, mapAttrs);
-            arrayData()->setProperty(engine, index, map);
-        }
+    if (attrs.isData() && desc->value.isEmpty() && attrs.hasWritable() && !attrs.isWritable()) {
+        cDesc->value = args->context()->args()[index];
+        cAttrs.setType(PropertyAttributes::Data);
     }
 
-    if (engine->current->strictMode && !result)
-        return engine->throwTypeError();
-    return result;
+    bool allowed = Object::virtualDefineOwnProperty(m, id, cDesc, cAttrs);
+    if (!allowed)
+        return false;
+
+    if (attrs.isAccessor()) {
+        args->removeMapping(index);
+    } else {
+        if (!desc->value.isEmpty())
+            args->context()->setArg(index, desc->value);
+        if (attrs.hasWritable() && !attrs.isWritable())
+            args->removeMapping(index);
+    }
+    return true;
 }
 
-ReturnedValue ArgumentsObject::getIndexed(const Managed *m, uint index, bool *hasProperty)
+ReturnedValue ArgumentsObject::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     const ArgumentsObject *args = static_cast<const ArgumentsObject *>(m);
-    if (args->fullyCreated())
-        return Object::getIndexed(m, index, hasProperty);
-
-    if (index < static_cast<uint>(args->context()->callData->argc)) {
+    uint index = id.asArrayIndex();
+    if (index < args->d()->argCount && !args->d()->fullyCreated) {
         if (hasProperty)
             *hasProperty = true;
-        return args->context()->callData->args[index].asReturnedValue();
+        return args->context()->args()[index].asReturnedValue();
     }
+
+    if (!args->isMapped(index))
+        return Object::virtualGet(m, id, receiver, hasProperty);
+    Q_ASSERT(index < static_cast<uint>(args->context()->function->formalParameterCount()));
     if (hasProperty)
-        *hasProperty = false;
-    return Encode::undefined();
+        *hasProperty = true;
+    return args->context()->args()[index].asReturnedValue();
 }
 
-bool ArgumentsObject::putIndexed(Managed *m, uint index, const Value &value)
+bool ArgumentsObject::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
     ArgumentsObject *args = static_cast<ArgumentsObject *>(m);
-    if (!args->fullyCreated() && index >= static_cast<uint>(args->context()->callData->argc))
-        args->fullyCreate();
+    uint index = id.asArrayIndex();
 
-    if (args->fullyCreated())
-        return Object::putIndexed(m, index, value);
+    if (args == receiver && index < args->d()->argCount && !args->d()->fullyCreated) {
+        args->context()->setArg(index, value);
+        return true;
+    }
 
-    args->context()->callData->args[index] = value;
-    return true;
+    bool isMapped = (args == receiver && args->isMapped(index));
+    if (isMapped)
+        args->context()->setArg(index, value);
+
+    return Object::virtualPut(m, id, value, receiver);
 }
 
-bool ArgumentsObject::deleteIndexedProperty(Managed *m, uint index)
+bool ArgumentsObject::virtualDeleteProperty(Managed *m, PropertyKey id)
 {
     ArgumentsObject *args = static_cast<ArgumentsObject *>(m);
-    if (!args->fullyCreated())
-        args->fullyCreate();
-    return Object::deleteIndexedProperty(m, index);
+    args->fullyCreate();
+    bool result = Object::virtualDeleteProperty(m, id);
+    if (result)
+        args->removeMapping(id.asArrayIndex());
+    return result;
 }
 
-PropertyAttributes ArgumentsObject::queryIndexed(const Managed *m, uint index)
+PropertyAttributes ArgumentsObject::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
 {
     const ArgumentsObject *args = static_cast<const ArgumentsObject *>(m);
-    if (args->fullyCreated())
-        return Object::queryIndexed(m, index);
-
-    uint numAccessors = qMin((int)args->context()->formalParameterCount(), args->context()->callData->argc);
-    uint argCount = args->context()->callData->argc;
-    if (index >= argCount)
-        return PropertyAttributes();
-    if (index >= numAccessors)
+    uint index = id.asArrayIndex();
+    if (index < args->d()->argCount && !args->d()->fullyCreated) {
+        p->value = args->context()->args()[index];
         return Attr_Data;
-    return Attr_Accessor;
-}
-
-DEFINE_OBJECT_VTABLE(ArgumentsGetterFunction);
-
-void ArgumentsGetterFunction::call(const Managed *getter, Scope &scope, CallData *callData)
-{
-    ExecutionEngine *v4 = static_cast<const ArgumentsGetterFunction *>(getter)->engine();
-    Scoped<ArgumentsGetterFunction> g(scope, static_cast<const ArgumentsGetterFunction *>(getter));
-    Scoped<ArgumentsObject> o(scope, callData->thisObject.as<ArgumentsObject>());
-    if (!o) {
-        scope.result = v4->throwTypeError();
-        return;
     }
 
-    Q_ASSERT(g->index() < static_cast<unsigned>(o->context()->callData->argc));
-    scope.result = o->context()->callData->args[g->index()];
-}
+    PropertyAttributes attrs = Object::virtualGetOwnProperty(m, id, p);
+    if (attrs.isEmpty() || !args->isMapped(index))
+        return attrs;
 
-DEFINE_OBJECT_VTABLE(ArgumentsSetterFunction);
+    Q_ASSERT(index < static_cast<uint>(args->context()->function->formalParameterCount()));
+    if (p)
+        p->value = args->context()->args()[index];
+    return attrs;
+}
 
-void ArgumentsSetterFunction::call(const Managed *setter, Scope &scope, CallData *callData)
+qint64 ArgumentsObject::virtualGetLength(const Managed *m)
 {
-    ExecutionEngine *v4 = static_cast<const ArgumentsSetterFunction *>(setter)->engine();
-    Scoped<ArgumentsSetterFunction> s(scope, static_cast<const ArgumentsSetterFunction *>(setter));
-    Scoped<ArgumentsObject> o(scope, callData->thisObject.as<ArgumentsObject>());
-    if (!o) {
-        scope.result = v4->throwTypeError();
-        return;
-    }
-
-    Q_ASSERT(s->index() < static_cast<unsigned>(o->context()->callData->argc));
-    o->context()->callData->args[s->index()] = callData->argc ? callData->args[0].asReturnedValue() : Encode::undefined();
-    scope.result = Encode::undefined();
+    const ArgumentsObject *a = static_cast<const ArgumentsObject *>(m);
+    return a->propertyData(Heap::ArgumentsObject::LengthPropertyIndex)->toLength();
 }
 
-uint ArgumentsObject::getLength(const Managed *m)
+OwnPropertyKeyIterator *ArgumentsObject::virtualOwnPropertyKeys(const Object *m, Value *target)
 {
-    const ArgumentsObject *a = static_cast<const ArgumentsObject *>(m);
-    if (a->propertyData(Heap::ArgumentsObject::LengthPropertyIndex)->isInteger())
-        return a->propertyData(Heap::ArgumentsObject::LengthPropertyIndex)->integerValue();
-    return Primitive::toUInt32(a->propertyData(Heap::ArgumentsObject::LengthPropertyIndex)->doubleValue());
+    static_cast<ArgumentsObject *>(const_cast<Object *>(m))->fullyCreate();
+    return Object::virtualOwnPropertyKeys(m, target);
 }
diff --git a/src/qml/jsruntime/qv4argumentsobject_p.h b/src/qml/jsruntime/qv4argumentsobject_p.h
index 46e1f884e8..f0e2192c7e 100644
--- a/src/qml/jsruntime/qv4argumentsobject_p.h
+++ b/src/qml/jsruntime/qv4argumentsobject_p.h
@@ -59,70 +59,36 @@ namespace QV4 {
 
 namespace Heap {
 
-#define ArgumentsGetterFunctionMembers(class, Member) \
-    Member(class, NoMark, uint, index)
-
-DECLARE_HEAP_OBJECT(ArgumentsGetterFunction, FunctionObject) {
-    DECLARE_MARK_TABLE(ArgumentsGetterFunction);
-    inline void init(QV4::ExecutionContext *scope, uint index);
-};
-
-#define ArgumentsSetterFunctionMembers(class, Member) \
-    Member(class, NoMark, uint, index)
-
-DECLARE_HEAP_OBJECT(ArgumentsSetterFunction, FunctionObject) {
-    DECLARE_MARK_TABLE(ArgumentsSetterFunction);
-    inline void init(QV4::ExecutionContext *scope, uint index);
-};
-
 #define ArgumentsObjectMembers(class, Member) \
     Member(class, Pointer, CallContext *, context) \
-    Member(class, Pointer, MemberData *, mappedArguments) \
-    Member(class, NoMark, bool, fullyCreated)
+    Member(class, NoMark, bool, fullyCreated) \
+    Member(class, NoMark, uint, argCount) \
+    Member(class, NoMark, quint64, mapped)
 
 DECLARE_HEAP_OBJECT(ArgumentsObject, Object) {
-    DECLARE_MARK_TABLE(ArgumentsObject);
+    DECLARE_MARKOBJECTS(ArgumentsObject);
     enum {
         LengthPropertyIndex = 0,
-        CalleePropertyIndex = 1,
-        CallerPropertyIndex = 3
+        SymbolIteratorPropertyIndex = 1,
+        CalleePropertyIndex = 2
     };
-    void init(QV4::CallContext *context);
+    void init(CppStackFrame *frame);
 };
 
-}
-
-struct ArgumentsGetterFunction: FunctionObject
-{
-    V4_OBJECT2(ArgumentsGetterFunction, FunctionObject)
-
-    uint index() const { return d()->index; }
-    static void call(const Managed *that, Scope &scope, CallData *d);
-};
-
-inline void
-Heap::ArgumentsGetterFunction::init(QV4::ExecutionContext *scope, uint index)
-{
-    Heap::FunctionObject::init(scope);
-    this->index = index;
-}
-
-struct ArgumentsSetterFunction: FunctionObject
-{
-    V4_OBJECT2(ArgumentsSetterFunction, FunctionObject)
+#define StrictArgumentsObjectMembers(class, Member)
 
-    uint index() const { return d()->index; }
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+DECLARE_HEAP_OBJECT(StrictArgumentsObject, Object) {
+    enum {
+        LengthPropertyIndex = 0,
+        SymbolIteratorPropertyIndex = 1,
+        CalleePropertyIndex = 2,
+        CalleeSetterPropertyIndex = 3
+    };
+    void init(CppStackFrame *frame);
 };
 
-inline void
-Heap::ArgumentsSetterFunction::init(QV4::ExecutionContext *scope, uint index)
-{
-    Heap::FunctionObject::init(scope);
-    this->index = index;
 }
 
-
 struct ArgumentsObject: Object {
     V4_OBJECT2(ArgumentsObject, Object)
     Q_MANAGED_TYPE(ArgumentsObject)
@@ -131,19 +97,35 @@ struct ArgumentsObject: Object {
     bool fullyCreated() const { return d()->fullyCreated; }
 
     static bool isNonStrictArgumentsObject(Managed *m) {
-        return m->d()->vtable()->type == Type_ArgumentsObject &&
-                !static_cast<ArgumentsObject *>(m)->context()->strictMode;
+        return m->vtable() == staticVTable();
     }
 
-    bool defineOwnProperty(ExecutionEngine *engine, uint index, const Property *desc, PropertyAttributes attrs);
-    static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
-    static bool putIndexed(Managed *m, uint index, const Value &value);
-    static bool deleteIndexedProperty(Managed *m, uint index);
-    static PropertyAttributes queryIndexed(const Managed *m, uint index);
-    static uint getLength(const Managed *m);
+    static bool virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *desc, PropertyAttributes attrs);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static bool virtualDeleteProperty(Managed *m, PropertyKey id);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static qint64 virtualGetLength(const Managed *m);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
 
     void fullyCreate();
 
+    // There's a slight hack here, as this limits the amount of mapped arguments to 64, but that should be
+    // more than enough for all practical uses of arguments
+    bool isMapped(uint arg) const {
+        return arg < 64 && (d()->mapped & (1ull << arg));
+    }
+
+    void removeMapping(uint arg) {
+        if (arg < 64)
+            (d()->mapped &= ~(1ull << arg));
+    }
+
+};
+
+struct StrictArgumentsObject : Object {
+    V4_OBJECT2(StrictArgumentsObject, Object)
+    Q_MANAGED_TYPE(ArgumentsObject)
 };
 
 }
diff --git a/src/qml/jsruntime/qv4arraybuffer.cpp b/src/qml/jsruntime/qv4arraybuffer.cpp
index ffe9aa846f..a99ec16943 100644
--- a/src/qml/jsruntime/qv4arraybuffer.cpp
+++ b/src/qml/jsruntime/qv4arraybuffer.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -40,86 +40,115 @@
 #include "qv4typedarray_p.h"
 #include "qv4dataview_p.h"
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
+#include "qv4symbol_p.h"
 
 using namespace QV4;
 
+DEFINE_OBJECT_VTABLE(SharedArrayBufferCtor);
 DEFINE_OBJECT_VTABLE(ArrayBufferCtor);
+DEFINE_OBJECT_VTABLE(SharedArrayBuffer);
 DEFINE_OBJECT_VTABLE(ArrayBuffer);
 
+void Heap::SharedArrayBufferCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("SharedArrayBuffer"));
+}
+
 void Heap::ArrayBufferCtor::init(QV4::ExecutionContext *scope)
 {
     Heap::FunctionObject::init(scope, QStringLiteral("ArrayBuffer"));
 }
 
-void ArrayBufferCtor::construct(const Managed *m, Scope &scope, CallData *callData)
+ReturnedValue SharedArrayBufferCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    Scope scope(f);
+    if (newTarget->isUndefined())
+        return scope.engine->throwTypeError();
+
+    qint64 len = argc ? argv[0].toIndex() : 0;
+    if (scope.engine->hasException)
+        return Encode::undefined();
+    if (len < 0 || len >= INT_MAX)
+        return scope.engine->throwRangeError(QStringLiteral("SharedArrayBuffer: Invalid length."));
+
+    Scoped<SharedArrayBuffer> a(scope, scope.engine->memoryManager->allocate<SharedArrayBuffer>(len));
+    if (scope.engine->hasException)
+        return Encode::undefined();
+
+    return a->asReturnedValue();
+}
+
+ReturnedValue SharedArrayBufferCtor::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
 {
-    ExecutionEngine *v4 = static_cast<const Object *>(m)->engine();
+    return f->engine()->throwTypeError();
+}
+
 
-    ScopedValue l(scope, callData->argument(0));
+ReturnedValue ArrayBufferCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    ExecutionEngine *v4 = f->engine();
+    Scope scope(v4);
+
+    ScopedValue l(scope, argc ? argv[0] : Value::undefinedValue());
     double dl = l->toInteger();
-    if (v4->hasException) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    if (v4->hasException)
+        return Encode::undefined();
     uint len = (uint)qBound(0., dl, (double)UINT_MAX);
-    if (len != dl) {
-        scope.result = v4->throwRangeError(QLatin1String("ArrayBuffer constructor: invalid length"));
-        return;
-    }
+    if (len != dl)
+        return v4->throwRangeError(QLatin1String("ArrayBuffer constructor: invalid length"));
 
     Scoped<ArrayBuffer> a(scope, v4->newArrayBuffer(len));
-    if (scope.engine->hasException) {
-        scope.result = Encode::undefined();
-    } else {
-        scope.result = a->asReturnedValue();
+    if (newTarget->heapObject() != f->heapObject() && newTarget->isFunctionObject()) {
+        const FunctionObject *nt = static_cast<const FunctionObject *>(newTarget);
+        ScopedObject o(scope, nt->protoProperty());
+        if (o)
+            a->setPrototypeOf(o);
     }
-}
+    if (scope.engine->hasException)
+        return Encode::undefined();
 
-
-void ArrayBufferCtor::call(const Managed *that, Scope &scope, CallData *callData)
-{
-    construct(that, scope, callData);
+    return a->asReturnedValue();
 }
 
-void ArrayBufferCtor::method_isView(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayBufferCtor::method_isView(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    QV4::Scoped<TypedArray> a(scope, callData->argument(0));
-    if (!!a) {
-        scope.result = Encode(true);
-        return;
-    }
-    QV4::Scoped<DataView> v(scope, callData->argument(0));
-    if (!!v) {
-        scope.result = Encode(true);
-        return;
-    }
-    scope.result = Encode(false);
+    if (argc < 1)
+        return Encode(false);
+
+    if (argv[0].as<TypedArray>() ||
+        argv[0].as<DataView>())
+        return Encode(true);
+
+    return Encode(false);
 }
 
 
-void Heap::ArrayBuffer::init(size_t length)
+void Heap::SharedArrayBuffer::init(size_t length)
 {
     Object::init();
-    data = QTypedArrayData<char>::allocate(length + 1);
+    if (length < UINT_MAX)
+        data = QTypedArrayData<char>::allocate(length + 1);
     if (!data) {
-        data = 0;
         internalClass->engine->throwRangeError(QStringLiteral("ArrayBuffer: out of memory"));
         return;
     }
     data->size = int(length);
     memset(data->data(), 0, length + 1);
+    isShared = true;
 }
 
-void Heap::ArrayBuffer::init(const QByteArray& array)
+void Heap::SharedArrayBuffer::init(const QByteArray& array)
 {
     Object::init();
     data = const_cast<QByteArray&>(array).data_ptr();
     data->ref.ref();
+    isShared = true;
 }
 
-void Heap::ArrayBuffer::destroy()
+void Heap::SharedArrayBuffer::destroy()
 {
-    if (!data->ref.deref())
+    if (data && !data->ref.deref())
         QTypedArrayData<char>::deallocate(data);
     Object::destroy();
 }
@@ -150,61 +179,105 @@ void ArrayBuffer::detach() {
 }
 
 
-void ArrayBufferPrototype::init(ExecutionEngine *engine, Object *ctor)
+void SharedArrayBufferPrototype::init(ExecutionEngine *engine, Object *ctor)
 {
     Scope scope(engine);
     ScopedObject o(scope);
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
-    ctor->defineDefaultProperty(QStringLiteral("isView"), ArrayBufferCtor::method_isView, 1);
+    ctor->addSymbolSpecies();
+
     defineDefaultProperty(engine->id_constructor(), (o = ctor));
-    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, 0);
+    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, nullptr);
     defineDefaultProperty(QStringLiteral("slice"), method_slice, 2);
-    defineDefaultProperty(QStringLiteral("toString"), method_toString, 0);
+    ScopedString name(scope, engine->newString(QStringLiteral("SharedArrayBuffer")));
+    defineReadonlyConfigurableProperty(scope.engine->symbol_toStringTag(), name);
 }
 
-void ArrayBufferPrototype::method_get_byteLength(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue SharedArrayBufferPrototype::method_get_byteLength(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<ArrayBuffer> v(scope, callData->thisObject);
-    if (!v)
-        THROW_TYPE_ERROR();
+    const SharedArrayBuffer *a = thisObject->as<SharedArrayBuffer>();
+    if (!a || a->isDetachedBuffer() || !a->isSharedArrayBuffer())
+        return b->engine()->throwTypeError();
 
-    scope.result = Encode(v->d()->data->size);
+    return Encode(a->d()->data->size);
 }
 
-void ArrayBufferPrototype::method_slice(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue SharedArrayBufferPrototype::method_slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<ArrayBuffer> a(scope, callData->thisObject);
-    if (!a)
-        THROW_TYPE_ERROR();
+    return slice(b, thisObject, argv, argc, true);
+}
+
+ReturnedValue SharedArrayBufferPrototype::slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc, bool shared)
+{
+    Scope scope(b);
+    const SharedArrayBuffer *a = thisObject->as<SharedArrayBuffer>();
+    if (!a || a->isDetachedBuffer() || (a->isSharedArrayBuffer() != shared))
+        return scope.engine->throwTypeError();
 
-    double start = callData->argc > 0 ? callData->args[0].toInteger() : 0;
-    double end = (callData->argc < 2 || callData->args[1].isUndefined()) ?
-                a->d()->data->size : callData->args[1].toInteger();
-    CHECK_EXCEPTION();
+    double start = argc > 0 ? argv[0].toInteger() : 0;
+    double end = (argc < 2 || argv[1].isUndefined()) ?
+                a->d()->data->size : argv[1].toInteger();
+    if (scope.hasException())
+        return QV4::Encode::undefined();
 
     double first = (start < 0) ? qMax(a->d()->data->size + start, 0.) : qMin(start, (double)a->d()->data->size);
     double final = (end < 0) ? qMax(a->d()->data->size + end, 0.) : qMin(end, (double)a->d()->data->size);
 
-    ScopedFunctionObject constructor(scope, a->get(scope.engine->id_constructor()));
+    const FunctionObject *constructor = a->speciesConstructor(scope, shared ? scope.engine->sharedArrayBufferCtor() : scope.engine->arrayBufferCtor());
     if (!constructor)
-        THROW_TYPE_ERROR();
+        return scope.engine->throwTypeError();
 
-    ScopedCallData cData(scope, 1);
     double newLen = qMax(final - first, 0.);
-    cData->args[0] = QV4::Encode(newLen);
-    constructor->construct(scope, cData);
-    QV4::Scoped<ArrayBuffer> newBuffer(scope, scope.result);
-    if (!newBuffer || newBuffer->d()->data->size < (int)newLen)
-        THROW_TYPE_ERROR();
+    ScopedValue argument(scope, QV4::Encode(newLen));
+    QV4::Scoped<SharedArrayBuffer> newBuffer(scope, constructor->callAsConstructor(argument, 1));
+    if (!newBuffer || newBuffer->d()->data->size < (int)newLen ||
+        newBuffer->isDetachedBuffer() || (newBuffer->isSharedArrayBuffer() != shared) ||
+        newBuffer->sameValue(*a) ||
+        a->isDetachedBuffer())
+        return scope.engine->throwTypeError();
 
     memcpy(newBuffer->d()->data->data(), a->d()->data->data() + (uint)first, newLen);
+    return newBuffer->asReturnedValue();
+}
+
+
+void ArrayBufferPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedObject o(scope);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
+    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
+    ctor->defineDefaultProperty(QStringLiteral("isView"), ArrayBufferCtor::method_isView, 1);
+    ctor->addSymbolSpecies();
+
+    defineDefaultProperty(engine->id_constructor(), (o = ctor));
+    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, nullptr);
+    defineDefaultProperty(QStringLiteral("slice"), method_slice, 2);
+    defineDefaultProperty(QStringLiteral("toString"), method_toString, 0);
+    ScopedString name(scope, engine->newString(QStringLiteral("ArrayBuffer")));
+    defineReadonlyConfigurableProperty(scope.engine->symbol_toStringTag(), name);
+}
+
+ReturnedValue ArrayBufferPrototype::method_get_byteLength(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    const ArrayBuffer *a = thisObject->as<ArrayBuffer>();
+    if (!a || a->isDetachedBuffer() || a->isSharedArrayBuffer())
+        return f->engine()->throwTypeError();
+
+    return Encode(a->d()->data->size);
+}
+
+ReturnedValue ArrayBufferPrototype::method_slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    return slice(b, thisObject, argv, argc, false);
 }
 
-void ArrayBufferPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayBufferPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<ArrayBuffer> a(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    const ArrayBuffer *a = thisObject->as<ArrayBuffer>();
     if (!a)
         RETURN_UNDEFINED();
-    scope.result = scope.engine->newString(QString::fromUtf8(a->asByteArray()));
+    return Encode(v4->newString(QString::fromUtf8(a->asByteArray())));
 }
diff --git a/src/qml/jsruntime/qv4arraybuffer_p.h b/src/qml/jsruntime/qv4arraybuffer_p.h
index 4f7926d3dc..8344fa2554 100644
--- a/src/qml/jsruntime/qv4arraybuffer_p.h
+++ b/src/qml/jsruntime/qv4arraybuffer_p.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -59,54 +59,113 @@ namespace QV4 {
 
 namespace Heap {
 
-struct ArrayBufferCtor : FunctionObject {
+struct SharedArrayBufferCtor : FunctionObject {
     void init(QV4::ExecutionContext *scope);
 };
 
-struct Q_QML_PRIVATE_EXPORT ArrayBuffer : Object {
+struct ArrayBufferCtor : SharedArrayBufferCtor {
+    void init(QV4::ExecutionContext *scope);
+};
+
+struct Q_QML_PRIVATE_EXPORT SharedArrayBuffer : Object {
     void init(size_t length);
     void init(const QByteArray& array);
     void destroy();
     QTypedArrayData<char> *data;
+    bool isShared;
+
+    uint byteLength() const { return data ? data->size : 0; }
+
+    bool isDetachedBuffer() const { return !data; }
+    bool isSharedArrayBuffer() const { return isShared; }
+};
 
-    uint byteLength() const { return data->size; }
+struct Q_QML_PRIVATE_EXPORT ArrayBuffer : SharedArrayBuffer {
+    void init(size_t length) {
+        SharedArrayBuffer::init(length);
+        isShared = false;
+    }
+    void init(const QByteArray& array) {
+        SharedArrayBuffer::init(array);
+        isShared = false;
+    }
+    void detachArrayBuffer() {
+        if (data && !data->ref.deref())
+            QTypedArrayData<char>::deallocate(data);
+        data = nullptr;
+    }
 };
 
+
 }
 
-struct ArrayBufferCtor: FunctionObject
+struct SharedArrayBufferCtor : FunctionObject
+{
+    V4_OBJECT2(SharedArrayBufferCtor, FunctionObject)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct ArrayBufferCtor : SharedArrayBufferCtor
 {
-    V4_OBJECT2(ArrayBufferCtor, FunctionObject)
+    V4_OBJECT2(ArrayBufferCtor, SharedArrayBufferCtor)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue method_isView(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct Q_QML_PRIVATE_EXPORT SharedArrayBuffer : Object
+{
+    V4_OBJECT2(SharedArrayBuffer, Object)
+    V4_NEEDS_DESTROY
+    V4_PROTOTYPE(sharedArrayBufferPrototype)
 
-    static void method_isView(const BuiltinFunction *, Scope &scope, CallData *callData);
+    QByteArray asByteArray() const;
+    uint byteLength() const { return d()->byteLength(); }
+    char *data() { Q_ASSERT(d()->data); return d()->data->data(); }
+    const char *constData() { Q_ASSERT(d()->data); return d()->data->data(); }
 
+    bool isShared() { return d()->data->ref.isShared(); }
+    bool isDetachedBuffer() const { return !d()->data; }
+    bool isSharedArrayBuffer() const { return d()->isShared; }
 };
 
-struct Q_QML_PRIVATE_EXPORT ArrayBuffer : Object
+struct Q_QML_PRIVATE_EXPORT ArrayBuffer : SharedArrayBuffer
 {
-    V4_OBJECT2(ArrayBuffer, Object)
+    V4_OBJECT2(ArrayBuffer, SharedArrayBuffer)
     V4_NEEDS_DESTROY
     V4_PROTOTYPE(arrayBufferPrototype)
 
     QByteArray asByteArray() const;
     uint byteLength() const { return d()->byteLength(); }
-    char *data() { detach(); return d()->data ? d()->data->data() : 0; }
-    const char *constData() { detach(); return d()->data ? d()->data->data() : 0; }
+    char *data() { detach(); return d()->data ? d()->data->data() : nullptr; }
+    // ### is that detach needed?
+    const char *constData() { detach(); return d()->data ? d()->data->data() : nullptr; }
 
-private:
+    bool isShared() { return d()->data && d()->data->ref.isShared(); }
     void detach();
+    void detachArrayBuffer() { d()->detachArrayBuffer(); }
+};
+
+struct SharedArrayBufferPrototype : Object
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_get_byteLength(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc, bool shared);
 };
 
-struct ArrayBufferPrototype: Object
+struct ArrayBufferPrototype : SharedArrayBufferPrototype
 {
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_get_byteLength(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_slice(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_get_byteLength(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 
diff --git a/src/qml/jsruntime/qv4arraydata.cpp b/src/qml/jsruntime/qv4arraydata.cpp
index df9884d84a..654d33b8d1 100644
--- a/src/qml/jsruntime/qv4arraydata.cpp
+++ b/src/qml/jsruntime/qv4arraydata.cpp
@@ -43,33 +43,15 @@
 #include "qv4runtime_p.h"
 #include "qv4argumentsobject_p.h"
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
 
 using namespace QV4;
 
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON
-
-const QV4::VTable QV4::ArrayData::static_vtbl = {
-    0,
-    0,
-    0,
-    0,
-    QV4::ArrayData::IsExecutionContext,
-    QV4::ArrayData::IsString,
-    QV4::ArrayData::IsObject,
-    QV4::ArrayData::IsFunctionObject,
-    QV4::ArrayData::IsErrorObject,
-    QV4::ArrayData::IsArrayData,
-    0,
-    QV4::ArrayData::MyType,
-    "ArrayData",
-    Q_VTABLE_FUNCTION(QV4::ArrayData, destroy),
-    0,
-    isEqualTo
-};
+DEFINE_MANAGED_VTABLE(ArrayData);
 
 const ArrayVTable SimpleArrayData::static_vtbl =
 {
-    DEFINE_MANAGED_VTABLE_INT(SimpleArrayData, 0),
+    DEFINE_MANAGED_VTABLE_INT(SimpleArrayData, nullptr),
     Heap::ArrayData::Simple,
     SimpleArrayData::reallocate,
     SimpleArrayData::get,
@@ -85,7 +67,7 @@ const ArrayVTable SimpleArrayData::static_vtbl =
 
 const ArrayVTable SparseArrayData::static_vtbl =
 {
-    DEFINE_MANAGED_VTABLE_INT(SparseArrayData, 0),
+    DEFINE_MANAGED_VTABLE_INT(SparseArrayData, nullptr),
     Heap::ArrayData::Sparse,
     SparseArrayData::reallocate,
     SparseArrayData::get,
@@ -99,18 +81,16 @@ const ArrayVTable SparseArrayData::static_vtbl =
     SparseArrayData::length
 };
 
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF
-
 Q_STATIC_ASSERT(sizeof(Heap::ArrayData) == sizeof(Heap::SimpleArrayData));
 Q_STATIC_ASSERT(sizeof(Heap::ArrayData) == sizeof(Heap::SparseArrayData));
 
-static Q_ALWAYS_INLINE void storeValue(ReturnedValue *target, uint value)
+void Heap::ArrayData::markObjects(Heap::Base *base, MarkStack *stack)
 {
-    Value v;
-    v.setEmpty(value);
-    *target = v.asReturnedValue();
+    ArrayData *a = static_cast<ArrayData *>(base);
+    a->values.mark(stack);
 }
 
+
 void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAttributes)
 {
     Scope scope(o->engine());
@@ -138,8 +118,6 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
         if (d->type() > newType)
             newType = d->type();
     }
-    if (enforceAttributes && newType == Heap::ArrayData::Simple)
-        newType = Heap::ArrayData::Complex;
 
     while (alloc < requested)
         alloc *= 2;
@@ -161,7 +139,7 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
     }
     newData->setAlloc(alloc);
     newData->setType(newType);
-    newData->setAttrs(enforceAttributes ? reinterpret_cast<PropertyAttributes *>(newData->d()->values.values + alloc) : 0);
+    newData->setAttrs(enforceAttributes ? reinterpret_cast<PropertyAttributes *>(newData->d()->values.values + alloc) : nullptr);
     o->setArrayData(newData);
 
     if (d) {
@@ -188,39 +166,38 @@ void ArrayData::realloc(Object *o, Type newType, uint requested, bool enforceAtt
 
     Heap::SparseArrayData *sparse = static_cast<Heap::SparseArrayData *>(newData->d());
 
-    ReturnedValue *lastFree;
+    Value *lastFree;
     if (d && d->type() == Heap::ArrayData::Sparse) {
         Heap::SparseArrayData *old = static_cast<Heap::SparseArrayData *>(d->d());
         sparse->sparse = old->sparse;
-        old->sparse = 0;
-        sparse->freeList = old->freeList;
-        lastFree = &sparse->freeList;
+        old->sparse = nullptr;
+        lastFree = &sparse->sparse->freeList;
     } else {
         sparse->sparse = new SparseArray;
-        lastFree = &sparse->freeList;
-        storeValue(lastFree, 0);
+        lastFree = &sparse->sparse->freeList;
+        *lastFree = Encode(0);
         for (uint i = 0; i < toCopy; ++i) {
             if (!sparse->values[i].isEmpty()) {
                 SparseArrayNode *n = sparse->sparse->insert(i);
                 n->value = i;
             } else {
-                storeValue(lastFree, i);
+                *lastFree = Encode(i);
                 sparse->values.values[i].setEmpty();
-                lastFree = &sparse->values.values[i].rawValueRef();
+                lastFree = &sparse->values.values[i];
             }
         }
     }
 
     if (toCopy < sparse->values.alloc) {
         for (uint i = toCopy; i < sparse->values.alloc; ++i) {
-            storeValue(lastFree, i);
+            *lastFree = Encode(i);
             sparse->values.values[i].setEmpty();
-            lastFree = &sparse->values.values[i].rawValueRef();
+            lastFree = &sparse->values.values[i];
         }
-        storeValue(lastFree, UINT_MAX);
     }
+    *lastFree = Encode(-1);
 
-    Q_ASSERT(Value::fromReturnedValue(sparse->freeList).isEmpty());
+    Q_ASSERT(sparse->sparse->freeList.isInteger());
     // ### Could explicitly free the old data
 }
 
@@ -242,7 +219,7 @@ ReturnedValue SimpleArrayData::get(const Heap::ArrayData *d, uint index)
 {
     const Heap::SimpleArrayData *dd = static_cast<const Heap::SimpleArrayData *>(d);
     if (index >= dd->values.size)
-        return Primitive::emptyValue().asReturnedValue();
+        return Value::emptyValue().asReturnedValue();
     return dd->data(index).asReturnedValue();
 }
 
@@ -267,7 +244,7 @@ bool SimpleArrayData::del(Object *o, uint index)
         return true;
 
     if (!dd->attrs || dd->attrs[index].isConfigurable()) {
-        dd->setData(o->engine(), index, Primitive::emptyValue());
+        dd->setData(o->engine(), index, Value::emptyValue());
         if (dd->attrs)
             dd->attrs[index] = Attr_Data;
         return true;
@@ -349,7 +326,7 @@ bool SimpleArrayData::putArray(Object *o, uint index, const Value *values, uint
     }
     QV4::ExecutionEngine *e = o->engine();
     for (uint i = dd->values.size; i < index; ++i)
-        dd->setData(e, i, Primitive::emptyValue());
+        dd->setData(e, i, Value::emptyValue());
     for (uint i = 0; i < n; ++i)
         dd->setData(e, index + i, values[i]);
     dd->values.size = qMax(dd->values.size, index + n);
@@ -362,12 +339,12 @@ void SparseArrayData::free(Heap::ArrayData *d, uint idx)
     Value *v = d->values.values + idx;
     if (d->attrs && d->attrs[idx].isAccessor()) {
         // double slot, free both. Order is important, so we have a double slot for allocation again afterwards.
-        v[1].setEmpty(Value::fromReturnedValue(d->freeList).emptyValue());
-        v[0].setEmpty(idx + 1);
+        v[1] = d->sparse->freeList;
+        v[0] = Encode(idx + 1);
     } else {
-        v->setEmpty(Value::fromReturnedValue(d->freeList).emptyValue());
+        *v = d->sparse->freeList;
     }
-    d->freeList = Primitive::emptyValue(idx).asReturnedValue();
+    d->sparse->freeList = Encode(idx);
     if (d->attrs)
         d->attrs[idx].clear();
 }
@@ -384,36 +361,34 @@ uint SparseArrayData::allocate(Object *o, bool doubleSlot)
     Q_ASSERT(o->d()->arrayData->type == Heap::ArrayData::Sparse);
     Heap::SimpleArrayData *dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
     if (doubleSlot) {
-        ReturnedValue *last = &dd->freeList;
+        Value *last = &dd->sparse->freeList;
         while (1) {
-            if (Value::fromReturnedValue(*last).value() == UINT_MAX) {
+            if (last->int_32() == -1) {
                 reallocate(o, dd->values.alloc + 2, true);
                 dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-                last = &dd->freeList;
-                Q_ASSERT(Value::fromReturnedValue(*last).value() != UINT_MAX);
+                last = &dd->sparse->freeList;
+                Q_ASSERT(last->int_32() != -1);
             }
 
-            Q_ASSERT(dd->values[Value::fromReturnedValue(*last).value()].value() != Value::fromReturnedValue(*last).value());
-            if (dd->values[Value::fromReturnedValue(*last).value()].value() == (Value::fromReturnedValue(*last).value() + 1)) {
+            Q_ASSERT(dd->values[static_cast<uint>(last->int_32())].int_32() != last->int_32());
+            if (dd->values[static_cast<uint>(last->int_32())].int_32() == last->int_32() + 1) {
                 // found two slots in a row
-                uint idx = Value::fromReturnedValue(*last).emptyValue();
-                Value lastV = Value::fromReturnedValue(*last);
-                lastV.setEmpty(dd->values[lastV.emptyValue() + 1].value());
-                *last = lastV.rawValue();
+                uint idx = static_cast<uint>(last->int_32());
+                *last = Encode(dd->values[static_cast<uint>(last->int_32()) + 1].int_32());
                 dd->attrs[idx] = Attr_Accessor;
                 return idx;
             }
-            last = &dd->values.values[Value::fromReturnedValue(*last).value()].rawValueRef();
+            last = &dd->values.values[last->int_32()];
         }
     } else {
-        if (Value::fromReturnedValue(dd->freeList).value() == UINT_MAX) {
+        if (dd->sparse->freeList.int_32() == -1) {
             reallocate(o, dd->values.alloc + 1, false);
             dd = o->d()->arrayData.cast<Heap::SimpleArrayData>();
         }
-        uint idx = Value::fromReturnedValue(dd->freeList).value();
-        Q_ASSERT(idx != UINT_MAX);
-        dd->freeList = dd->values[idx].asReturnedValue();
-        Q_ASSERT(Value::fromReturnedValue(dd->freeList).isEmpty());
+        Q_ASSERT(dd->sparse->freeList.int_32() != -1);
+        uint idx = static_cast<uint>(dd->sparse->freeList.int_32());
+        dd->sparse->freeList = dd->values[idx];
+        Q_ASSERT(dd->sparse->freeList.isInteger());
         if (dd->attrs)
             dd->attrs[idx] = Attr_Data;
         return idx;
@@ -425,7 +400,7 @@ ReturnedValue SparseArrayData::get(const Heap::ArrayData *d, uint index)
     const Heap::SparseArrayData *s = static_cast<const Heap::SparseArrayData *>(d);
     index = s->mappedIndex(index);
     if (index == UINT_MAX)
-        return Primitive::emptyValue().asReturnedValue();
+        return Value::emptyValue().asReturnedValue();
     return s->values[index].asReturnedValue();
 }
 
@@ -468,14 +443,14 @@ bool SparseArrayData::del(Object *o, uint index)
 
     if (isAccessor) {
         // free up both indices
-        dd->values.values[pidx + 1].setEmpty(Value::fromReturnedValue(dd->freeList).emptyValue());
-        dd->values.values[pidx].setEmpty(pidx + 1);
+        dd->values.values[pidx + 1] = dd->sparse->freeList;
+        dd->values.values[pidx] = Encode(pidx + 1);
     } else {
         Q_ASSERT(dd->type == Heap::ArrayData::Sparse);
-        dd->values.values[pidx].setEmpty(Value::fromReturnedValue(dd->freeList).emptyValue());
+        dd->values.values[pidx] = dd->sparse->freeList;
     }
 
-    dd->freeList = Primitive::emptyValue(pidx).asReturnedValue();
+    dd->sparse->freeList = Encode(pidx);
     dd->sparse->erase(n);
     return true;
 }
@@ -587,7 +562,7 @@ uint ArrayData::append(Object *obj, ArrayObject *otherObj, uint n)
     if (!other || ArgumentsObject::isNonStrictArgumentsObject(otherObj)) {
         ScopedValue v(scope);
         for (uint i = 0; i < n; ++i)
-            obj->arraySet(oldSize + i, (v = otherObj->getIndexed(i)));
+            obj->arraySet(oldSize + i, (v = otherObj->get(i)));
     } else if (other && other->isSparse()) {
         Heap::SparseArrayData *os = static_cast<Heap::SparseArrayData *>(other->d());
         if (other->hasAttributes()) {
@@ -607,7 +582,7 @@ uint ArrayData::append(Object *obj, ArrayObject *otherObj, uint n)
         uint toCopy = n;
         uint chunk = toCopy;
         if (chunk > os->values.alloc - os->offset)
-            chunk -= os->values.alloc - os->offset;
+            chunk = os->values.alloc - os->offset;
         obj->arrayPut(oldSize, os->values.data() + os->offset, chunk);
         toCopy -= chunk;
         if (toCopy)
@@ -629,7 +604,7 @@ void ArrayData::insert(Object *o, uint index, const Value *v, bool isAccessor)
             if (index >= d->values.size) {
                 // mark possible hole in the array
                 for (uint i = d->values.size; i < index; ++i)
-                    d->setData(o->engine(), i, Primitive::emptyValue());
+                    d->setData(o->engine(), i, Value::emptyValue());
                 d->values.size = index + 1;
             }
             d->setData(o->engine(), index, *v);
@@ -652,14 +627,13 @@ void ArrayData::insert(Object *o, uint index, const Value *v, bool isAccessor)
 class ArrayElementLessThan
 {
 public:
-    inline ArrayElementLessThan(ExecutionEngine *engine, Object *thisObject, const Value &comparefn)
-        : m_engine(engine), thisObject(thisObject), m_comparefn(comparefn) {}
+    inline ArrayElementLessThan(ExecutionEngine *engine, const Value &comparefn)
+        : m_engine(engine), m_comparefn(comparefn) {}
 
     bool operator()(Value v1, Value v2) const;
 
 private:
     ExecutionEngine *m_engine;
-    Object *thisObject;
     const Value &m_comparefn;
 };
 
@@ -672,15 +646,14 @@ bool ArrayElementLessThan::operator()(Value v1, Value v2) const
         return false;
     if (v2.isUndefined() || v2.isEmpty())
         return true;
-    ScopedObject o(scope, m_comparefn);
+    ScopedFunctionObject o(scope, m_comparefn);
     if (o) {
         Scope scope(o->engine());
         ScopedValue result(scope);
-        ScopedCallData callData(scope, 2);
-        callData->thisObject = Primitive::undefinedValue();
-        callData->args[0] = v1;
-        callData->args[1] = v2;
-        result = QV4::Runtime::method_callValue(scope.engine, m_comparefn, callData);
+        JSCallData jsCallData(scope, 2);
+        jsCallData->args[0] = v1;
+        jsCallData->args[1] = v2;
+        result = o->call(jsCallData);
 
         return result->toNumber() < 0;
     }
@@ -754,7 +727,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
     if (!arrayData || !arrayData->length())
         return;
 
-    if (!(comparefn.isUndefined() || comparefn.as<Object>())) {
+    if (!comparefn.isUndefined() && !comparefn.isFunctionObject()) {
         engine->throwTypeError();
         return;
     }
@@ -770,7 +743,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
         if (!sparse->sparse()->nEntries())
             return;
 
-        thisObject->setArrayData(0);
+        thisObject->setArrayData(nullptr);
         ArrayData::realloc(thisObject, Heap::ArrayData::Simple, sparse->sparse()->nEntries(), sparse->attrs() ? true : false);
         Heap::SimpleArrayData *d = thisObject->d()->arrayData.cast<Heap::SimpleArrayData>();
 
@@ -824,7 +797,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
                         break;
                 Q_ASSERT(!d->attrs || !d->attrs[len].isAccessor());
                 d->setData(engine, i, d->data(len));
-                d->setData(engine, len, Primitive::emptyValue());
+                d->setData(engine, len, Value::emptyValue());
             }
         }
 
@@ -833,7 +806,7 @@ void ArrayData::sort(ExecutionEngine *engine, Object *thisObject, const Value &c
     }
 
 
-    ArrayElementLessThan lessThan(engine, thisObject, comparefn);
+    ArrayElementLessThan lessThan(engine, static_cast<const FunctionObject &>(comparefn));
 
     Value *begin = thisObject->arrayData()->values.values;
     sortHelper(begin, begin + len, *begin, lessThan);
diff --git a/src/qml/jsruntime/qv4arraydata_p.h b/src/qml/jsruntime/qv4arraydata_p.h
index 1d895c90c5..64b2161ef5 100644
--- a/src/qml/jsruntime/qv4arraydata_p.h
+++ b/src/qml/jsruntime/qv4arraydata_p.h
@@ -91,62 +91,50 @@ struct ArrayVTable
 namespace Heap {
 
 #define ArrayDataMembers(class, Member) \
-    Member(class, NoMark, uint, type) \
+    Member(class, NoMark, ushort, type) \
+    Member(class, NoMark, ushort, unused) \
     Member(class, NoMark, uint, offset) \
     Member(class, NoMark, PropertyAttributes *, attrs) \
-    Member(class, NoMark, ReturnedValue, freeList) \
     Member(class, NoMark, SparseArray *, sparse) \
     Member(class, ValueArray, ValueArray, values)
 
 DECLARE_HEAP_OBJECT(ArrayData, Base) {
-    DECLARE_MARK_TABLE(ArrayData);
+    static void markObjects(Heap::Base *base, MarkStack *stack);
 
-    enum Type { Simple = 0, Complex = 1, Sparse = 2, Custom = 3 };
-
-    struct Index {
-        Heap::ArrayData *arrayData;
-        uint index;
-
-        void set(ExecutionEngine *e, Value newVal) {
-            arrayData->values.set(e, index, newVal);
-        }
-        const Value *operator->() const { return &arrayData->values[index]; }
-        const Value &operator*() const { return arrayData->values[index]; }
-        bool isNull() const { return !arrayData; }
-    };
+    enum Type { Simple = 0, Sparse = 1, Custom = 2 };
 
     bool isSparse() const { return type == Sparse; }
 
-    const ArrayVTable *vtable() const { return reinterpret_cast<const ArrayVTable *>(Base::vtable()); }
+    const ArrayVTable *vtable() const { return reinterpret_cast<const ArrayVTable *>(internalClass->vtable); }
 
     inline ReturnedValue get(uint i) const {
         return vtable()->get(this, i);
     }
     inline bool getProperty(uint index, Property *p, PropertyAttributes *attrs);
-    inline void setProperty(ExecutionEngine *e, uint index, const Property *p);
-    inline Index getValueOrSetter(uint index, PropertyAttributes *attrs);
+    inline void setProperty(EngineBase *e, uint index, const Property *p);
+    inline PropertyIndex getValueOrSetter(uint index, PropertyAttributes *attrs);
     inline PropertyAttributes attributes(uint i) const;
 
     bool isEmpty(uint i) const {
-        return get(i) == Primitive::emptyValue().asReturnedValue();
+        return get(i) == Value::emptyValue().asReturnedValue();
     }
 
     inline uint length() const {
         return vtable()->length(this);
     }
 
-    void setArrayData(ExecutionEngine *e, uint index, Value newVal) {
+    void setArrayData(EngineBase *e, uint index, Value newVal) {
         values.set(e, index, newVal);
     }
 
     uint mappedIndex(uint index) const;
 };
-V4_ASSERT_IS_TRIVIAL(ArrayData)
+Q_STATIC_ASSERT(std::is_trivial< ArrayData >::value);
 
 struct SimpleArrayData : public ArrayData {
-    uint mappedIndex(uint index) const { return (index + offset) % values.alloc; }
+    uint mappedIndex(uint index) const { index += offset; if (index >= values.alloc) index -= values.alloc; return index; }
     const Value &data(uint index) const { return values[mappedIndex(index)]; }
-    void setData(ExecutionEngine *e, uint index, Value newVal) {
+    void setData(EngineBase *e, uint index, Value newVal) {
         values.set(e, mappedIndex(index), newVal);
     }
 
@@ -154,7 +142,7 @@ struct SimpleArrayData : public ArrayData {
         return attrs ? attrs[i] : Attr_Data;
     }
 };
-V4_ASSERT_IS_TRIVIAL(SimpleArrayData)
+Q_STATIC_ASSERT(std::is_trivial< SimpleArrayData >::value);
 
 struct SparseArrayData : public ArrayData {
     void destroy() {
@@ -187,8 +175,6 @@ struct Q_QML_EXPORT ArrayData : public Managed
         IsArrayData = true
     };
 
-    typedef Heap::ArrayData::Index Index;
-
     uint alloc() const { return d()->values.alloc; }
     uint &alloc() { return d()->values.alloc; }
     void setAlloc(uint a) { d()->values.alloc = a; }
@@ -197,7 +183,7 @@ struct Q_QML_EXPORT ArrayData : public Managed
     PropertyAttributes *attrs() const { return d()->attrs; }
     void setAttrs(PropertyAttributes *a) { d()->attrs = a; }
     const Value *arrayData() const { return d()->values.data(); }
-    void setArrayData(ExecutionEngine *e, uint index, Value newVal) {
+    void setArrayData(EngineBase *e, uint index, Value newVal) {
         d()->setArrayData(e, index, newVal);
     }
 
@@ -261,8 +247,6 @@ struct Q_QML_EXPORT SparseArrayData : public ArrayData
     V4_INTERNALCLASS(SparseArrayData)
     V4_NEEDS_DESTROY
 
-    ReturnedValue &freeList() { return d()->freeList; }
-    ReturnedValue freeList() const { return d()->freeList; }
     SparseArray *sparse() const { return d()->sparse; }
     void setSparse(SparseArray *s) { d()->sparse = s; }
 
@@ -304,13 +288,15 @@ bool ArrayData::getProperty(uint index, Property *p, PropertyAttributes *attrs)
     }
 
     *attrs = attributes(index);
-    p->value = *(Index{ this, mapped });
-    if (attrs->isAccessor())
-        p->set = *(Index{ this, mapped + 1 /*Object::SetterOffset*/ });
+    if (p) {
+        p->value = *(PropertyIndex{ this, values.values + mapped });
+        if (attrs->isAccessor())
+            p->set = *(PropertyIndex{ this, values.values + mapped + 1 /*Object::SetterOffset*/ });
+    }
     return true;
 }
 
-void ArrayData::setProperty(QV4::ExecutionEngine *e, uint index, const Property *p)
+void ArrayData::setProperty(QV4::EngineBase *e, uint index, const Property *p)
 {
     uint mapped = mappedIndex(index);
     Q_ASSERT(mapped != UINT_MAX);
@@ -326,16 +312,18 @@ inline PropertyAttributes ArrayData::attributes(uint i) const
     return static_cast<const SimpleArrayData *>(this)->attributes(i);
 }
 
-ArrayData::Index ArrayData::getValueOrSetter(uint index, PropertyAttributes *attrs)
+PropertyIndex ArrayData::getValueOrSetter(uint index, PropertyAttributes *attrs)
 {
     uint idx = mappedIndex(index);
     if (idx == UINT_MAX) {
         *attrs = Attr_Invalid;
-        return { 0, 0 };
+        return { nullptr, nullptr };
     }
 
     *attrs = attributes(index);
-    return { this, attrs->isAccessor() ? idx + 1 /* QV4::Object::SetterOffset*/ : idx };
+    if (attrs->isAccessor())
+        ++idx;
+    return { this, values.values + idx };
 }
 
 
diff --git a/src/qml/jsruntime/qv4arrayiterator.cpp b/src/qml/jsruntime/qv4arrayiterator.cpp
new file mode 100644
index 0000000000..199b1a728a
--- /dev/null
+++ b/src/qml/jsruntime/qv4arrayiterator.cpp
@@ -0,0 +1,106 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Crimson AS <info@crimson.no>
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4iterator_p.h>
+#include <private/qv4arrayiterator_p.h>
+#include <private/qv4typedarray_p.h>
+#include <private/qv4symbol_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(ArrayIteratorObject);
+
+void ArrayIteratorPrototype::init(ExecutionEngine *e)
+{
+    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
+
+    Scope scope(e);
+    ScopedString val(scope, e->newString(QLatin1String("Array Iterator")));
+    defineReadonlyConfigurableProperty(e->symbol_toStringTag(), val);
+}
+
+ReturnedValue ArrayIteratorPrototype::method_next(const FunctionObject *b, const Value *that, const Value *, int)
+{
+    Scope scope(b);
+    const ArrayIteratorObject *thisObject = that->as<ArrayIteratorObject>();
+    if (!thisObject)
+        return scope.engine->throwTypeError(QLatin1String("Not an Array Iterator instance"));
+
+    ScopedObject a(scope, thisObject->d()->iteratedObject);
+    if (!a) {
+        QV4::Value undefined = Value::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+    }
+
+    quint32 index = thisObject->d()->nextIndex;
+    IteratorKind itemKind = thisObject->d()->iterationKind;
+
+    Scoped<TypedArray> ta(scope, a->as<TypedArray>());
+    quint32 len = a->getLength();
+
+    if (index >= len) {
+        thisObject->d()->iteratedObject.set(scope.engine, nullptr);
+        QV4::Value undefined = Value::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+    }
+
+    thisObject->d()->nextIndex = index + 1;
+    if (itemKind == KeyIteratorKind) {
+        return IteratorPrototype::createIterResultObject(scope.engine, Value::fromInt32(index), false);
+    }
+
+    ReturnedValue elementValue = a->get(index);
+    CHECK_EXCEPTION();
+
+    if (itemKind == ValueIteratorKind) {
+        return IteratorPrototype::createIterResultObject(scope.engine, Value::fromReturnedValue(elementValue), false);
+    } else {
+        Q_ASSERT(itemKind == KeyValueIteratorKind);
+
+        ScopedArrayObject resultArray(scope, scope.engine->newArrayObject());
+        resultArray->arrayReserve(2);
+        resultArray->arrayPut(0, Value::fromInt32(index));
+        resultArray->arrayPut(1, Value::fromReturnedValue(elementValue));
+        resultArray->setArrayLengthUnchecked(2);
+
+        return IteratorPrototype::createIterResultObject(scope.engine, resultArray, false);
+    }
+}
+
diff --git a/src/qml/jsruntime/qv4arrayiterator_p.h b/src/qml/jsruntime/qv4arrayiterator_p.h
new file mode 100644
index 0000000000..6d6bb466f1
--- /dev/null
+++ b/src/qml/jsruntime/qv4arrayiterator_p.h
@@ -0,0 +1,106 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Crimson AS <info@crimson.no>
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4ARRAYITERATOR_P_H
+#define QV4ARRAYITERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4iterator_p.h"
+#include "qv4arraydata_p.h"
+
+QT_BEGIN_NAMESPACE
+
+
+namespace QV4 {
+
+namespace Heap {
+
+#define ArrayIteratorObjectMembers(class, Member) \
+    Member(class, Pointer, Object *, iteratedObject) \
+    Member(class, NoMark, IteratorKind, iterationKind) \
+    Member(class, NoMark, quint32, nextIndex)
+
+DECLARE_HEAP_OBJECT(ArrayIteratorObject, Object) {
+    DECLARE_MARKOBJECTS(ArrayIteratorObject);
+    void init(Object *obj, QV4::ExecutionEngine *engine)
+    {
+        Object::init();
+        this->iteratedObject.set(engine, obj);
+        this->nextIndex = 0;
+    }
+};
+
+}
+
+struct ArrayIteratorPrototype : Object
+{
+    V4_PROTOTYPE(iteratorPrototype)
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_next(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct ArrayIteratorObject : Object
+{
+    V4_OBJECT2(ArrayIteratorObject, Object)
+    Q_MANAGED_TYPE(ArrayIteratorObject)
+    V4_PROTOTYPE(arrayIteratorPrototype)
+
+    void init(ExecutionEngine *engine);
+};
+
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4ARRAYITERATOR_P_H
+
diff --git a/src/qml/jsruntime/qv4arrayobject.cpp b/src/qml/jsruntime/qv4arrayobject.cpp
index a2c19e1f2d..b975d02d9d 100644
--- a/src/qml/jsruntime/qv4arrayobject.cpp
+++ b/src/qml/jsruntime/qv4arrayobject.cpp
@@ -1,5 +1,6 @@
 /****************************************************************************
 **
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -38,13 +39,17 @@
 ****************************************************************************/
 
 #include "qv4arrayobject_p.h"
+#include "qv4objectiterator_p.h"
+#include "qv4arrayiterator_p.h"
 #include "qv4sparsearray_p.h"
 #include "qv4objectproto_p.h"
-#include "qv4scopedvalue_p.h"
+#include "qv4jscall_p.h"
 #include "qv4argumentsobject_p.h"
 #include "qv4runtime_p.h"
 #include "qv4string_p.h"
+#include "qv4symbol_p.h"
 #include <QtCore/qscopedvaluerollback.h>
+#include "qv4proxy_p.h"
 
 using namespace QV4;
 
@@ -55,51 +60,77 @@ void Heap::ArrayCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("Array"));
 }
 
-void ArrayCtor::construct(const Managed *m, Scope &scope, CallData *callData)
+ReturnedValue ArrayCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ExecutionEngine *v4 = static_cast<const ArrayCtor *>(m)->engine();
+    ExecutionEngine *v4 = static_cast<const ArrayCtor *>(f)->engine();
+    Scope scope(v4);
     ScopedArrayObject a(scope, v4->newArrayObject());
+    if (newTarget)
+        a->setProtoFromNewTarget(newTarget);
     uint len;
-    if (callData->argc == 1 && callData->args[0].isNumber()) {
+    if (argc == 1 && argv[0].isNumber()) {
         bool ok;
-        len = callData->args[0].asArrayLength(&ok);
+        len = argv[0].asArrayLength(&ok);
 
-        if (!ok) {
-            scope.result = v4->throwRangeError(callData->args[0]);
-            return;
-        }
+        if (!ok)
+            return v4->throwRangeError(argv[0]);
 
         if (len < 0x1000)
             a->arrayReserve(len);
     } else {
-        len = callData->argc;
+        len = argc;
         a->arrayReserve(len);
-        a->arrayPut(0, callData->args, len);
+        a->arrayPut(0, argv, len);
     }
     a->setArrayLengthUnchecked(len);
 
-    scope.result = a.asReturnedValue();
+    return a.asReturnedValue();
 }
 
-void ArrayCtor::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue ArrayCtor::virtualCall(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    construct(that, scope, callData);
+    return virtualCallAsConstructor(f, argv, argc, f);
 }
 
 void ArrayPrototype::init(ExecutionEngine *engine, Object *ctor)
 {
     Scope scope(engine);
     ScopedObject o(scope);
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
     ctor->defineDefaultProperty(QStringLiteral("isArray"), method_isArray, 1);
+    ctor->defineDefaultProperty(QStringLiteral("of"), method_of, 0);
+    ctor->defineDefaultProperty(QStringLiteral("from"), method_from, 1);
+    ctor->addSymbolSpecies();
+
+    ScopedObject unscopables(scope, engine->newObject(engine->classes[EngineBase::Class_Empty]->changeVTable(QV4::Object::staticVTable())));
+    ScopedString name(scope);
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
     defineDefaultProperty(engine->id_toString(), method_toString, 0);
-    defineDefaultProperty(QStringLiteral("toLocaleString"), method_toLocaleString, 0);
+    defineDefaultProperty(engine->id_toLocaleString(), method_toLocaleString, 0);
     defineDefaultProperty(QStringLiteral("concat"), method_concat, 1);
-    defineDefaultProperty(QStringLiteral("find"), method_find, 1);
-    defineDefaultProperty(QStringLiteral("findIndex"), method_findIndex, 1);
+    name = engine->newIdentifier(QStringLiteral("copyWithin"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_copyWithin, 2);
+    name = engine->newIdentifier(QStringLiteral("entries"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_entries, 0);
+    name = engine->newIdentifier(QStringLiteral("fill"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_fill, 1);
+    name = engine->newIdentifier(QStringLiteral("find"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_find, 1);
+    name = engine->newIdentifier(QStringLiteral("findIndex"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_findIndex, 1);
+    name = engine->newIdentifier(QStringLiteral("includes"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_includes, 1);
     defineDefaultProperty(QStringLiteral("join"), method_join, 1);
+    name = engine->newIdentifier(QStringLiteral("keys"));
+    unscopables->put(name, Value::fromBoolean(true));
+    defineDefaultProperty(name, method_keys, 0);
     defineDefaultProperty(QStringLiteral("pop"), method_pop, 0);
     defineDefaultProperty(QStringLiteral("push"), method_push, 1);
     defineDefaultProperty(QStringLiteral("reverse"), method_reverse, 0);
@@ -117,149 +148,461 @@ void ArrayPrototype::init(ExecutionEngine *engine, Object *ctor)
     defineDefaultProperty(QStringLiteral("filter"), method_filter, 1);
     defineDefaultProperty(QStringLiteral("reduce"), method_reduce, 1);
     defineDefaultProperty(QStringLiteral("reduceRight"), method_reduceRight, 1);
+    ScopedString valuesString(scope, engine->newIdentifier(QStringLiteral("values")));
+    ScopedObject values(scope, FunctionObject::createBuiltinFunction(engine, valuesString, method_values, 0));
+    engine->jsObjects[ExecutionEngine::ArrayProtoValues] = values;
+    unscopables->put(valuesString, Value::fromBoolean(true));
+    defineDefaultProperty(valuesString, values);
+    defineDefaultProperty(engine->symbol_iterator(), values);
+
+    defineReadonlyConfigurableProperty(engine->symbol_unscopables(), unscopables);
+}
+
+ReturnedValue ArrayPrototype::method_isArray(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    if (!argc || !argv->objectValue())
+        return Encode(false);
+    return Encode(argv->objectValue()->isArray());
+}
+
+static ScopedObject createObjectFromCtorOrArray(Scope &scope, ScopedFunctionObject ctor, bool useLen, int len)
+{
+    ScopedObject a(scope, Value::undefinedValue());
+
+    if (ctor && ctor->isConstructor()) {
+        // this isn't completely kosher. for instance:
+        // Array.from.call(Object, []).constructor == Object
+        // is expected by the tests, but naturally, we get Number.
+        ScopedValue argument(scope, useLen ? QV4::Encode(len) : Value::undefinedValue());
+        a = ctor->callAsConstructor(argument, useLen ? 1 : 0);
+    } else {
+        a = scope.engine->newArrayObject(len);
+    }
+
+    return a;
 }
 
-void ArrayPrototype::method_isArray(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_from(const FunctionObject *builtin, const Value *thisObject, const Value *argv, int argc)
 {
-    bool isArray = callData->argc && callData->args[0].as<ArrayObject>();
-    scope.result = Encode(isArray);
+    Scope scope(builtin);
+    ScopedFunctionObject thatCtor(scope, thisObject);
+    ScopedObject itemsObject(scope, argv[0]);
+    bool usingIterator = false;
+
+    if (itemsObject) {
+        // If the object claims to support iterators, then let's try use them.
+        ScopedValue it(scope, itemsObject->get(scope.engine->symbol_iterator()));
+        if (!it->isNullOrUndefined()) {
+            ScopedFunctionObject itfunc(scope, it);
+            if (!itfunc)
+                return scope.engine->throwTypeError();
+            usingIterator = true;
+        }
+    }
+
+    ScopedFunctionObject mapfn(scope, Value::undefinedValue());
+    Value *mapArguments = nullptr;
+    if (argc > 1) {
+        mapfn = ScopedFunctionObject(scope, argv[1]);
+        if (!mapfn)
+            return scope.engine->throwTypeError(QString::fromLatin1("%1 is not a function").arg(argv[1].toQStringNoThrow()));
+        mapArguments = scope.alloc(2);
+    }
+
+    ScopedValue thisArg(scope);
+    if (argc > 2)
+        thisArg = argv[2];
+
+    if (usingIterator) {
+        // Item iteration supported, so let's go ahead and try use that.
+        ScopedObject a(createObjectFromCtorOrArray(scope, thatCtor, false, 0));
+        CHECK_EXCEPTION();
+        ScopedObject iterator(scope, Runtime::GetIterator::call(scope.engine, itemsObject, true));
+        CHECK_EXCEPTION(); // symbol_iterator threw; whoops.
+        if (!iterator) {
+            return scope.engine->throwTypeError(); // symbol_iterator wasn't an object.
+        }
+
+        qint64 k = 0;
+        ScopedValue mappedValue(scope);
+        Value *nextValue = scope.alloc(1);
+        ScopedValue done(scope);
+
+        // The loop below pulls out all the properties using the iterator, and
+        // sets them into the created array.
+        forever {
+            if (k > (static_cast<qint64>(1) << 53) - 1) {
+                ScopedValue falsey(scope, Encode(false));
+                ScopedValue error(scope, scope.engine->throwTypeError());
+                return Runtime::IteratorClose::call(scope.engine, iterator, falsey);
+            }
+
+            // Retrieve the next value. If the iteration ends, we're done here.
+            done = Value::fromReturnedValue(Runtime::IteratorNext::call(scope.engine, iterator, nextValue));
+            CHECK_EXCEPTION();
+            if (done->toBoolean()) {
+                if (ArrayObject *ao = a->as<ArrayObject>()) {
+                    ao->setArrayLengthUnchecked(k);
+                } else {
+                    a->set(scope.engine->id_length(), Value::fromDouble(k), QV4::Object::DoThrowOnRejection);
+                    CHECK_EXCEPTION();
+                }
+                return a.asReturnedValue();
+            }
+
+            if (mapfn) {
+                mapArguments[0] = *nextValue;
+                mapArguments[1] = Value::fromDouble(k);
+                mappedValue = mapfn->call(thisArg, mapArguments, 2);
+                if (scope.engine->hasException)
+                    return Runtime::IteratorClose::call(scope.engine, iterator, Value::fromBoolean(false));
+            } else {
+                mappedValue = *nextValue;
+            }
+
+            if (a->getOwnProperty(PropertyKey::fromArrayIndex(k)) == Attr_Invalid) {
+                a->arraySet(k, mappedValue);
+            } else {
+                // Don't return: we need to close the iterator.
+                scope.engine->throwTypeError(QString::fromLatin1("Cannot redefine property: %1").arg(k));
+            }
+
+            if (scope.engine->hasException) {
+                ScopedValue falsey(scope, Encode(false));
+                return Runtime::IteratorClose::call(scope.engine, iterator, falsey);
+            }
+
+            k++;
+        }
+
+        // the return is hidden up in the loop above, when iteration finishes.
+    } else {
+        // Array-like fallback. We request properties by index, and set them on
+        // the return object.
+        ScopedObject arrayLike(scope, argv[0].toObject(scope.engine));
+        if (!arrayLike)
+            return scope.engine->throwTypeError(QString::fromLatin1("Cannot convert %1 to object").arg(argv[0].toQStringNoThrow()));
+        qint64 len = arrayLike->getLength();
+        ScopedObject a(createObjectFromCtorOrArray(scope, thatCtor, true, len));
+        CHECK_EXCEPTION();
+
+        qint64 k = 0;
+        ScopedValue mappedValue(scope, Value::undefinedValue());
+        ScopedValue kValue(scope);
+        while (k < len) {
+            kValue = arrayLike->get(k);
+            CHECK_EXCEPTION();
+
+            if (mapfn) {
+                mapArguments[0] = kValue;
+                mapArguments[1] = Value::fromDouble(k);
+                mappedValue = mapfn->call(thisArg, mapArguments, 2);
+                CHECK_EXCEPTION();
+            } else {
+                mappedValue = kValue;
+            }
+
+            if (a->getOwnProperty(PropertyKey::fromArrayIndex(k)) != Attr_Invalid)
+                return scope.engine->throwTypeError(QString::fromLatin1("Cannot redefine property: %1").arg(k));
+
+            a->arraySet(k, mappedValue);
+            CHECK_EXCEPTION();
+
+            k++;
+        }
+
+        if (ArrayObject *ao = a->as<ArrayObject>()) {
+            ao->setArrayLengthUnchecked(k);
+        } else {
+            a->set(scope.engine->id_length(), Value::fromDouble(k), QV4::Object::DoThrowOnRejection);
+            CHECK_EXCEPTION();
+        }
+        return a.asReturnedValue();
+    }
+
 }
 
-void ArrayPrototype::method_toString(const BuiltinFunction *builtin, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_of(const FunctionObject *builtin, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->thisObject, ScopedObject::Convert);
+    Scope scope(builtin);
+    ScopedFunctionObject that(scope, thisObject);
+    ScopedObject a(createObjectFromCtorOrArray(scope, that, true, argc));
     CHECK_EXCEPTION();
-    ScopedString s(scope, scope.engine->newString(QStringLiteral("join")));
-    ScopedFunctionObject f(scope, o->get(s));
-    if (!!f) {
-        ScopedCallData d(scope, 0);
-        d->thisObject = callData->thisObject;
-        f->call(scope, d);
-        return;
+
+    int k = 0;
+    while (k < argc) {
+        if (a->getOwnProperty(PropertyKey::fromArrayIndex(k)) != Attr_Invalid) {
+            return scope.engine->throwTypeError(QString::fromLatin1("Cannot redefine property: %1").arg(k));
+        }
+        a->arraySet(k, argv[k]);
+        CHECK_EXCEPTION();
+
+        k++;
     }
-    ObjectPrototype::method_toString(builtin, scope, callData);
+
+    // ArrayObject updates its own length, and will throw if we try touch it.
+    if (!a->as<ArrayObject>()) {
+        a->set(scope.engine->id_length(), Value::fromDouble(argc), QV4::Object::DoThrowOnRejection);
+        CHECK_EXCEPTION();
+    }
+
+    return a.asReturnedValue();
 }
 
-void ArrayPrototype::method_toLocaleString(const BuiltinFunction *builtin, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_toString(const FunctionObject *builtin, const Value *thisObject, const Value *argv, int argc)
 {
-    return method_toString(builtin, scope, callData);
+    Scope scope(builtin);
+    ScopedObject that(scope, thisObject->toObject(scope.engine));
+    if (scope.hasException())
+        return QV4::Encode::undefined();
+
+    ScopedString string(scope, scope.engine->newString(QStringLiteral("join")));
+    ScopedFunctionObject f(scope, that->get(string));
+    if (f)
+        return f->call(that, argv, argc);
+    return ObjectPrototype::method_toString(builtin, that, argv, argc);
+}
+
+ReturnedValue ArrayPrototype::method_toLocaleString(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject);
+    if (!instance)
+        return scope.engine->throwTypeError();
+
+    uint len = instance->getLength();
+    const QString separator = QStringLiteral(",");
+
+    QString R;
+
+    ScopedValue v(scope);
+    ScopedString s(scope);
+
+    for (uint k = 0; k < len; ++k) {
+        if (k)
+            R += separator;
+
+        v = instance->get(k);
+        if (v->isNullOrUndefined())
+            continue;
+        v = Runtime::CallElement::call(scope.engine, v, *scope.engine->id_toLocaleString(), nullptr, 0);
+        s = v->toString(scope.engine);
+        if (scope.hasException())
+            return Encode::undefined();
+
+        R += s->toQString();
+    }
+    return scope.engine->newString(R)->asReturnedValue();
 }
 
-void ArrayPrototype::method_concat(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_concat(const FunctionObject *b, const Value *that, const Value *argv, int argc)
 {
-    ScopedObject thisObject(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject thisObject(scope, that->toObject(scope.engine));
     if (!thisObject)
         RETURN_UNDEFINED();
 
     ScopedArrayObject result(scope, scope.engine->newArrayObject());
 
-    if (thisObject->isArrayObject()) {
-        result->copyArrayData(thisObject);
-    } else {
-        result->arraySet(0, thisObject);
-    }
-
     ScopedArrayObject elt(scope);
     ScopedObject eltAsObj(scope);
     ScopedValue entry(scope);
-    for (int i = 0; i < callData->argc; ++i) {
-        eltAsObj = callData->args[i];
-        elt = callData->args[i];
+    for (int i = -1; i < argc; ++i) {
+        const Value *v = i == -1 ? thisObject.getPointer() : argv + i;
+        eltAsObj = *v;
+        elt = *v;
         if (elt) {
             uint n = elt->getLength();
             uint newLen = ArrayData::append(result, elt, n);
             result->setArrayLengthUnchecked(newLen);
+        } else if (eltAsObj && eltAsObj->isConcatSpreadable()) {
+            const uint startIndex = result->getLength();
+            const uint len = eltAsObj->getLength();
+            if (scope.engine->hasException)
+                return Encode::undefined();
+
+            for (uint i = 0; i < len; ++i) {
+                bool hasProperty = false;
+                entry = eltAsObj->get(i, &hasProperty);
+                if (hasProperty) {
+                    if (!result->put(startIndex + i, entry))
+                        return scope.engine->throwTypeError();
+                }
+            }
         } else if (eltAsObj && eltAsObj->isListType()) {
             const uint startIndex = result->getLength();
             for (int i = 0, len = eltAsObj->getLength(); i < len; ++i) {
-                entry = eltAsObj->getIndexed(i);
-                result->putIndexed(startIndex + i, entry);
+                entry = eltAsObj->get(i);
+                // spec says not to throw if this fails
+                result->put(startIndex + i, entry);
             }
         } else {
-            result->arraySet(result->getLength(), callData->args[i]);
+            result->arraySet(result->getLength(), *v);
         }
     }
 
-    scope.result = result;
+    return result.asReturnedValue();
+}
+
+ReturnedValue ArrayPrototype::method_copyWithin(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
+    if (!instance)
+        RETURN_UNDEFINED();
+
+    double len = instance->getLength();
+    double target = argv[0].toInteger();
+    double start = argc > 1 ? argv[1].toInteger() : 0;
+    double end = len;
+
+    if (argc > 2 && !argv[2].isUndefined()) {
+        end = argv[2].toInteger();
+    }
+
+    double relativeTarget = target;
+    double relativeStart = start;
+    double relativeEnd = end;
+    double from = 0;
+    double to = 0;
+
+    if (relativeTarget < 0) {
+        to = std::max(len+relativeTarget, 0.0);
+    } else {
+        to = std::min(relativeTarget, len);
+    }
+    if (relativeStart < 0) {
+        from = std::max(len+relativeStart, 0.0);
+    } else {
+        from = std::min(relativeStart, len);
+    }
+
+    double fin = 0;
+    if (relativeEnd < 0) {
+        fin = std::max(len+relativeEnd, 0.0);
+    } else {
+        fin = std::min(relativeEnd, len);
+    }
+    double count = std::min(fin-from, len-to);
+    double direction = 1;
+    if (from < to && to < from+count) {
+        direction = -1;
+        from = from + count - 1;
+        to = to + count - 1;
+    }
+
+    while (count > 0) {
+        bool fromPresent = false;
+        ScopedValue fromVal(scope, instance->get(from, &fromPresent));
+
+        if (fromPresent) {
+            instance->setIndexed(to, fromVal, QV4::Object::DoThrowOnRejection);
+            CHECK_EXCEPTION();
+        } else {
+            bool didDelete = instance->deleteProperty(PropertyKey::fromArrayIndex(to));
+            CHECK_EXCEPTION();
+            if (!didDelete) {
+                return scope.engine->throwTypeError();
+            }
+        }
+
+        from = from + direction;
+        to = to + direction;
+        count = count - 1;
+    }
+
+    return instance.asReturnedValue();
+}
+
+ReturnedValue ArrayPrototype::method_entries(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    ScopedObject O(scope, thisObject->toObject(scope.engine));
+    if (!O)
+        RETURN_UNDEFINED();
+
+    Scoped<ArrayIteratorObject> ao(scope, scope.engine->newArrayIteratorObject(O));
+    ao->d()->iterationKind = IteratorKind::KeyValueIteratorKind;
+    return ao->asReturnedValue();
 }
 
-void ArrayPrototype::method_find(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_find(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv[0].isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
-    ScopedCallData cData(scope, 3);
-    cData->thisObject = callData->argument(1);
-    cData->args[2] = instance;
+    ScopedValue result(scope);
+    Value *arguments = scope.alloc(3);
 
-    ScopedValue v(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
 
     for (uint k = 0; k < len; ++k) {
-        v = instance->getIndexed(k);
+        arguments[0] = instance->get(k);
         CHECK_EXCEPTION();
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        result = callback->call(that, arguments, 3);
 
         CHECK_EXCEPTION();
-        if (scope.result.toBoolean())
-            RETURN_RESULT(v);
+        if (result->toBoolean())
+            return arguments[0].asReturnedValue();
     }
 
     RETURN_UNDEFINED();
 }
 
-void ArrayPrototype::method_findIndex(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_findIndex(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv[0].isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
-    ScopedCallData cData(scope, 3);
-    cData->thisObject = callData->argument(1);
-    cData->args[2] = instance;
+    ScopedValue result(scope);
+    Value *arguments = scope.alloc(3);
 
-    ScopedValue v(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
 
     for (uint k = 0; k < len; ++k) {
-        v = instance->getIndexed(k);
+        arguments[0] = instance->get(k);
         CHECK_EXCEPTION();
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        result = callback->call(that, arguments, 3);
 
         CHECK_EXCEPTION();
-        if (scope.result.toBoolean())
-            RETURN_RESULT(Encode(k));
+        if (result->toBoolean())
+            return Encode(k);
     }
 
-    RETURN_RESULT(Encode(-1));
+    return Encode(-1);
 }
 
-void ArrayPrototype::method_join(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_join(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedValue arg(scope, callData->argument(0));
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
 
-    if (!instance) {
-        scope.result = scope.engine->newString();
-        return;
-    }
+    if (!instance)
+        return Encode(scope.engine->newString());
+
+    ScopedValue arg(scope, argc ? argv[0] : Value::undefinedValue());
 
     QString r4;
     if (arg->isUndefined())
@@ -270,10 +613,8 @@ void ArrayPrototype::method_join(const BuiltinFunction *, Scope &scope, CallData
     ScopedValue length(scope, instance->get(scope.engine->id_length()));
     const quint32 r2 = length->isUndefined() ? 0 : length->toUInt32();
 
-    if (!r2) {
-        scope.result = scope.engine->newString();
-        return;
-    }
+    if (!r2)
+        return Encode(scope.engine->newString());
 
     QString R;
 
@@ -284,7 +625,7 @@ void ArrayPrototype::method_join(const BuiltinFunction *, Scope &scope, CallData
             if (i)
                 R += r4;
 
-            e = a->getIndexed(i);
+            e = a->get(i);
             CHECK_EXCEPTION();
             if (!e->isNullOrUndefined())
                 R += e->toQString();
@@ -302,7 +643,7 @@ void ArrayPrototype::method_join(const BuiltinFunction *, Scope &scope, CallData
         for (quint32 k = 1; k < r2; ++k) {
             R += r4;
 
-            name = Primitive::fromDouble(k).toString(scope.engine);
+            name = Value::fromDouble(k).toString(scope.engine);
             r12 = instance->get(name);
             CHECK_EXCEPTION();
 
@@ -311,12 +652,13 @@ void ArrayPrototype::method_join(const BuiltinFunction *, Scope &scope, CallData
         }
     }
 
-    scope.result = scope.engine->newString(R);
+    return Encode(scope.engine->newString(R));
 }
 
-void ArrayPrototype::method_pop(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_pop(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
@@ -324,79 +666,90 @@ void ArrayPrototype::method_pop(const BuiltinFunction *, Scope &scope, CallData
 
     if (!len) {
         if (!instance->isArrayObject())
-            instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromInt32(0)));
+            instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromInt32(0)));
         RETURN_UNDEFINED();
     }
 
-    ScopedValue result(scope, instance->getIndexed(len - 1));
+    ScopedValue result(scope, instance->get(len - 1));
     CHECK_EXCEPTION();
 
-    instance->deleteIndexedProperty(len - 1);
-    CHECK_EXCEPTION();
+    if (!instance->deleteProperty(PropertyKey::fromArrayIndex(len - 1)))
+        return scope.engine->throwTypeError();
 
     if (instance->isArrayObject())
         instance->setArrayLength(len - 1);
-    else
-        instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromDouble(len - 1)));
-    scope.result = result;
+    else {
+        if (!instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromDouble(len - 1))))
+            return scope.engine->throwTypeError();
+    }
+    return result->asReturnedValue();
 }
 
-void ArrayPrototype::method_push(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_push(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     instance->arrayCreate();
     Q_ASSERT(instance->arrayData());
 
-    uint len = instance->getLength();
+    qint64 len = instance->getLength();
 
-    if (len + callData->argc < len) {
-        // ughh...
+    if (len + quint64(argc) >= UINT_MAX) {
+        // ughh... this goes beyond UINT_MAX
         double l = len;
         ScopedString s(scope);
-        for (int i = 0; i < callData->argc; ++i) {
-            s = Primitive::fromDouble(l + i).toString(scope.engine);
-            instance->put(s, callData->args[i]);
+        for (int i = 0, ei = argc; i < ei; ++i) {
+            s = Value::fromDouble(l + i).toString(scope.engine);
+            if (!instance->put(s, argv[i]))
+                return scope.engine->throwTypeError();
         }
-        double newLen = l + callData->argc;
-        if (!instance->isArrayObject())
-            instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromDouble(newLen)));
-        else {
+        double newLen = l + argc;
+        if (!instance->isArrayObject()) {
+            if (!instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromDouble(newLen))))
+                return scope.engine->throwTypeError();
+        } else {
             ScopedString str(scope, scope.engine->newString(QStringLiteral("Array.prototype.push: Overflow")));
-            scope.result = scope.engine->throwRangeError(str);
-            return;
+            return scope.engine->throwRangeError(str);
         }
-        scope.result = Encode(newLen);
-        return;
+        return Encode(newLen);
     }
 
-    if (!callData->argc)
+    if (!argc)
         ;
     else if (!instance->protoHasArray() && instance->arrayData()->length() <= len && instance->arrayData()->type == Heap::ArrayData::Simple) {
-        instance->arrayData()->vtable()->putArray(instance, len, callData->args, callData->argc);
+        instance->arrayData()->vtable()->putArray(instance, len, argv, argc);
         len = instance->arrayData()->length();
     } else {
-        for (int i = 0; i < callData->argc; ++i)
-            instance->putIndexed(len + i, callData->args[i]);
-        len += callData->argc;
+        for (int i = 0, ei = argc; i < ei; ++i) {
+            if (!instance->put(len + i, argv[i]))
+                return scope.engine->throwTypeError();
+        }
+        len += argc;
     }
     if (instance->isArrayObject())
         instance->setArrayLengthUnchecked(len);
-    else
-        instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromDouble(len)));
+    else {
+        if (!instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromDouble(len))))
+            return scope.engine->throwTypeError();
+    }
 
-    scope.result = Encode(len);
+    return Encode(uint(len));
 }
 
-void ArrayPrototype::method_reverse(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_reverse(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
-    uint length = instance->getLength();
+    qint64 length = instance->getLength();
+    // ### FIXME
+    if (length >= UINT_MAX)
+        return scope.engine->throwRangeError(QLatin1String("Array.prototype.reverse: Length out of range."));
 
     int lo = 0, hi = length - 1;
 
@@ -404,25 +757,30 @@ void ArrayPrototype::method_reverse(const BuiltinFunction *, Scope &scope, CallD
     ScopedValue hval(scope);
     for (; lo < hi; ++lo, --hi) {
         bool loExists, hiExists;
-        lval = instance->getIndexed(lo, &loExists);
-        hval = instance->getIndexed(hi, &hiExists);
+        lval = instance->get(lo, &loExists);
+        hval = instance->get(hi, &hiExists);
         CHECK_EXCEPTION();
+        bool ok;
         if (hiExists)
-            instance->putIndexed(lo, hval);
+            ok = instance->put(lo, hval);
         else
-            instance->deleteIndexedProperty(lo);
-        CHECK_EXCEPTION();
-        if (loExists)
-            instance->putIndexed(hi, lval);
-        else
-            instance->deleteIndexedProperty(hi);
+            ok = instance->deleteProperty(PropertyKey::fromArrayIndex(lo));
+        if (ok) {
+            if (loExists)
+                ok = instance->put(hi, lval);
+            else
+                ok = instance->deleteProperty(PropertyKey::fromArrayIndex(hi));
+        }
+        if (!ok)
+            return scope.engine->throwTypeError();
     }
-    scope.result = instance;
+    return instance->asReturnedValue();
 }
 
-void ArrayPrototype::method_shift(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_shift(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
@@ -433,46 +791,57 @@ void ArrayPrototype::method_shift(const BuiltinFunction *, Scope &scope, CallDat
 
     if (!len) {
         if (!instance->isArrayObject())
-            instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromInt32(0)));
+            if (!instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromInt32(0))))
+                return scope.engine->throwTypeError();
         RETURN_UNDEFINED();
     }
 
+    ScopedValue result(scope);
     if (!instance->protoHasArray() && !instance->arrayData()->attrs && instance->arrayData()->length() <= len && instance->arrayData()->type != Heap::ArrayData::Custom) {
-        scope.result = instance->arrayData()->vtable()->pop_front(instance);
+        result = instance->arrayData()->vtable()->pop_front(instance);
     } else {
-        scope.result = instance->getIndexed(0);
+        result = instance->get(uint(0));
         CHECK_EXCEPTION();
         ScopedValue v(scope);
         // do it the slow way
         for (uint k = 1; k < len; ++k) {
             bool exists;
-            v = instance->getIndexed(k, &exists);
+            v = instance->get(k, &exists);
             CHECK_EXCEPTION();
+            bool ok;
             if (exists)
-                instance->putIndexed(k - 1, v);
+                ok = instance->put(k - 1, v);
             else
-                instance->deleteIndexedProperty(k - 1);
-            CHECK_EXCEPTION();
+                ok = instance->deleteProperty(PropertyKey::fromArrayIndex(k - 1));
+            if (!ok)
+                return scope.engine->throwTypeError();
         }
-        instance->deleteIndexedProperty(len - 1);
-        CHECK_EXCEPTION();
+        bool ok = instance->deleteProperty(PropertyKey::fromArrayIndex(len - 1));
+        if (!ok)
+            return scope.engine->throwTypeError();
     }
 
     if (instance->isArrayObject())
         instance->setArrayLengthUnchecked(len - 1);
-    else
-        instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromDouble(len - 1)));
+    else {
+        bool ok = instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromDouble(len - 1)));
+        if (!ok)
+            return scope.engine->throwTypeError();
+    }
+
+    return result->asReturnedValue();
 }
 
-void ArrayPrototype::method_slice(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject o(scope, thisObject->toObject(scope.engine));
     if (!o)
         RETURN_UNDEFINED();
 
     ScopedArrayObject result(scope, scope.engine->newArrayObject());
     uint len = o->getLength();
-    double s = ScopedValue(scope, callData->argument(0))->toInteger();
+    double s = (argc ? argv[0] : Value::undefinedValue()).toInteger();
     uint start;
     if (s < 0)
         start = (uint)qMax(len + s, 0.);
@@ -481,8 +850,8 @@ void ArrayPrototype::method_slice(const BuiltinFunction *, Scope &scope, CallDat
     else
         start = (uint) s;
     uint end = len;
-    if (callData->argc > 1 && !callData->args[1].isUndefined()) {
-        double e = callData->args[1].toInteger();
+    if (argc > 1 && !argv[1].isUndefined()) {
+        double e = argv[1].toInteger();
         if (e < 0)
             end = (uint)qMax(len + e, 0.);
         else if (e > len)
@@ -495,106 +864,120 @@ void ArrayPrototype::method_slice(const BuiltinFunction *, Scope &scope, CallDat
     uint n = 0;
     for (uint i = start; i < end; ++i) {
         bool exists;
-        v = o->getIndexed(i, &exists);
+        v = o->get(i, &exists);
         CHECK_EXCEPTION();
         if (exists)
             result->arraySet(n, v);
         ++n;
     }
-    scope.result = result;
+    return result->asReturnedValue();
 }
 
-void ArrayPrototype::method_sort(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_sort(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedValue comparefn(scope, callData->argument(0));
+    ScopedValue comparefn(scope, argc ? argv[0] : Value::undefinedValue());
     ArrayData::sort(scope.engine, instance, comparefn, len);
-    scope.result = callData->thisObject;
+    return thisObject->asReturnedValue();
 }
 
-void ArrayPrototype::method_splice(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_splice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
-    uint len = instance->getLength();
-
-    ScopedArrayObject newArray(scope, scope.engine->newArrayObject());
+    qint64 len = instance->getLength();
 
-    double rs = ScopedValue(scope, callData->argument(0))->toInteger();
-    uint start;
+    double rs = (argc ? argv[0] : Value::undefinedValue()).toInteger();
+    qint64 start;
     if (rs < 0)
-        start = (uint) qMax(0., len + rs);
+        start = static_cast<qint64>(qMax(0., len + rs));
     else
-        start = (uint) qMin(rs, (double)len);
+        start = static_cast<qint64>(qMin(rs, static_cast<double>(len)));
+
+    qint64 deleteCount = 0;
+    qint64 itemCount = 0;
+    if (argc == 1) {
+        deleteCount = len - start;
+    } else if (argc > 1){
+        itemCount = argc - 2;
+        double dc = argv[1].toInteger();
+        deleteCount = static_cast<qint64>(qMin(qMax(dc, 0.), double(len - start)));
+    }
 
-    uint deleteCount = (uint)qMin(qMax(ScopedValue(scope, callData->argument(1))->toInteger(), 0.), (double)(len - start));
+    if (len + itemCount - deleteCount > /*(static_cast<qint64>(1) << 53) - 1*/ UINT_MAX - 1)
+        return scope.engine->throwTypeError();
+    if (deleteCount > /*(static_cast<qint64>(1) << 53) - 1*/ UINT_MAX - 1)
+        return scope.engine->throwRangeError(QString::fromLatin1("Array length out of range."));
 
+    ScopedArrayObject newArray(scope, scope.engine->newArrayObject());
     newArray->arrayReserve(deleteCount);
     ScopedValue v(scope);
     for (uint i = 0; i < deleteCount; ++i) {
         bool exists;
-        v = instance->getIndexed(start + i, &exists);
+        v = instance->get(start + i, &exists);
         CHECK_EXCEPTION();
         if (exists)
             newArray->arrayPut(i, v);
     }
     newArray->setArrayLengthUnchecked(deleteCount);
 
-    uint itemCount = callData->argc < 2 ? 0 : callData->argc - 2;
 
     if (itemCount < deleteCount) {
         for (uint k = start; k < len - deleteCount; ++k) {
             bool exists;
-            v = instance->getIndexed(k + deleteCount, &exists);
+            v = instance->get(k + deleteCount, &exists);
             CHECK_EXCEPTION();
+            bool ok;
             if (exists)
-                instance->putIndexed(k + itemCount, v);
+                ok = instance->put(k + itemCount, v);
             else
-                instance->deleteIndexedProperty(k + itemCount);
-            CHECK_EXCEPTION();
+                ok = instance->deleteProperty(PropertyKey::fromArrayIndex(k + itemCount));
+            if (!ok)
+                return scope.engine->throwTypeError();
         }
         for (uint k = len; k > len - deleteCount + itemCount; --k) {
-            instance->deleteIndexedProperty(k - 1);
-            CHECK_EXCEPTION();
+            if (!instance->deleteProperty(PropertyKey::fromArrayIndex(k - 1)))
+                return scope.engine->throwTypeError();
         }
     } else if (itemCount > deleteCount) {
         uint k = len - deleteCount;
         while (k > start) {
             bool exists;
-            v = instance->getIndexed(k + deleteCount - 1, &exists);
+            v = instance->get(k + deleteCount - 1, &exists);
             CHECK_EXCEPTION();
+            bool ok;
             if (exists)
-                instance->putIndexed(k + itemCount - 1, v);
+                ok = instance->put(k + itemCount - 1, v);
             else
-                instance->deleteIndexedProperty(k + itemCount - 1);
-            CHECK_EXCEPTION();
+                ok = instance->deleteProperty(PropertyKey::fromArrayIndex(k + itemCount - 1));
+            if (!ok)
+                return scope.engine->throwTypeError();
             --k;
         }
     }
 
-    for (uint i = 0; i < itemCount; ++i) {
-        instance->putIndexed(start + i, callData->args[i + 2]);
-        CHECK_EXCEPTION();
-    }
+    for (uint i = 0; i < itemCount; ++i)
+        instance->put(start + i, argv[i + 2]);
 
-    bool wasStrict = scope.engine->current->strictMode;
-    scope.engine->current->strictMode = true;
-    instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromDouble(len - deleteCount + itemCount)));
+    if (!instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromDouble(len - deleteCount + itemCount))))
+        return scope.engine->throwTypeError();
 
-    scope.result = newArray;
-    scope.engine->current->strictMode = wasStrict;
+    return newArray->asReturnedValue();
 }
 
-void ArrayPrototype::method_unshift(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_unshift(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
@@ -605,52 +988,95 @@ void ArrayPrototype::method_unshift(const BuiltinFunction *, Scope &scope, CallD
 
     if (!instance->protoHasArray() && !instance->arrayData()->attrs && instance->arrayData()->length() <= len &&
         instance->arrayData()->type != Heap::ArrayData::Custom) {
-        instance->arrayData()->vtable()->push_front(instance, callData->args, callData->argc);
+        instance->arrayData()->vtable()->push_front(instance, argv, argc);
     } else {
         ScopedValue v(scope);
         for (uint k = len; k > 0; --k) {
             bool exists;
-            v = instance->getIndexed(k - 1, &exists);
+            v = instance->get(k - 1, &exists);
+            bool ok;
             if (exists)
-                instance->putIndexed(k + callData->argc - 1, v);
+                ok = instance->put(k + argc - 1, v);
             else
-                instance->deleteIndexedProperty(k + callData->argc - 1);
+                ok = instance->deleteProperty(PropertyKey::fromArrayIndex(k + argc - 1));
+            if (!ok)
+                return scope.engine->throwTypeError();
+        }
+        for (int i = 0, ei = argc; i < ei; ++i) {
+            bool ok = instance->put(i, argv[i]);
+            if (!ok)
+                return scope.engine->throwTypeError();
         }
-        for (int i = 0; i < callData->argc; ++i)
-            instance->putIndexed(i, callData->args[i]);
     }
 
-    uint newLen = len + callData->argc;
+    uint newLen = len + argc;
     if (instance->isArrayObject())
         instance->setArrayLengthUnchecked(newLen);
-    else
-        instance->put(scope.engine->id_length(), ScopedValue(scope, Primitive::fromDouble(newLen)));
+    else {
+        if (!instance->put(scope.engine->id_length(), ScopedValue(scope, Value::fromDouble(newLen))))
+            return scope.engine->throwTypeError();
+    }
 
-    scope.result = Encode(newLen);
+    return Encode(newLen);
 }
 
-void ArrayPrototype::method_indexOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_includes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
-    uint len = instance->getLength();
-    if (!len) {
-        scope.result = Encode(-1);
-        return;
+    qint64 len = instance->getLength();
+    if (len == 0) {
+        return Encode(false);
+    }
+
+    double n = 0;
+    if (argc > 1 && !argv[1].isUndefined()) {
+        n = argv[1].toInteger();
+    }
+
+    double k = 0;
+    if (n >= 0) {
+        k = n;
+    } else {
+        k = len + n;
+        if (k < 0) {
+            k = 0;
+        }
     }
 
-    ScopedValue searchValue(scope, callData->argument(0));
+    while (k < len) {
+        ScopedValue val(scope, instance->get(k));
+        if (val->sameValueZero(argv[0])) {
+            return Encode(true);
+        }
+        k++;
+    }
+
+    return Encode(false);
+}
+
+ReturnedValue ArrayPrototype::method_indexOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
+    if (!instance)
+        RETURN_UNDEFINED();
+
+    uint len = instance->getLength();
+    if (!len)
+        return Encode(-1);
+
+    ScopedValue searchValue(scope, argc ? argv[0] : Value::undefinedValue());
     uint fromIndex = 0;
 
-    if (callData->argc >= 2) {
-        double f = callData->args[1].toInteger();
+    if (argc >= 2) {
+        double f = argv[1].toInteger();
         CHECK_EXCEPTION();
-        if (f >= len) {
-            scope.result = Encode(-1);
-            return;
-        }
+        if (f >= len)
+            return Encode(-1);
         if (f < 0)
             f = qMax(len + f, 0.);
         fromIndex = (uint) f;
@@ -660,14 +1086,11 @@ void ArrayPrototype::method_indexOf(const BuiltinFunction *, Scope &scope, CallD
         ScopedValue v(scope);
         for (uint k = fromIndex; k < len; ++k) {
             bool exists;
-            v = instance->getIndexed(k, &exists);
-            if (exists && RuntimeHelpers::strictEqual(v, searchValue)) {
-                scope.result = Encode(k);
-                return;
-            }
+            v = instance->get(k, &exists);
+            if (exists && RuntimeHelpers::strictEqual(v, searchValue))
+                return Encode(k);
         }
-        scope.result = Encode(-1);
-        return;
+        return Encode(-1);
     }
 
     ScopedValue value(scope);
@@ -677,18 +1100,15 @@ void ArrayPrototype::method_indexOf(const BuiltinFunction *, Scope &scope, CallD
         // lets be safe and slow
         for (uint i = fromIndex; i < len; ++i) {
             bool exists;
-            value = instance->getIndexed(i, &exists);
+            value = instance->get(i, &exists);
             CHECK_EXCEPTION();
-            if (exists && RuntimeHelpers::strictEqual(value, searchValue)) {
-                scope.result = Encode(i);
-                return;
-            }
+            if (exists && RuntimeHelpers::strictEqual(value, searchValue))
+                return Encode(i);
         }
     } else if (!instance->arrayData()) {
-        scope.result = Encode(-1);
-        return;
+        return Encode(-1);
     } else {
-        Q_ASSERT(instance->arrayType() == Heap::ArrayData::Simple || instance->arrayType() == Heap::ArrayData::Complex);
+        Q_ASSERT(instance->arrayType() == Heap::ArrayData::Simple);
         Heap::SimpleArrayData *sa = instance->d()->arrayData.cast<Heap::SimpleArrayData>();
         if (len > sa->values.size)
             len = sa->values.size;
@@ -696,47 +1116,54 @@ void ArrayPrototype::method_indexOf(const BuiltinFunction *, Scope &scope, CallD
         while (idx < len) {
             value = sa->data(idx);
             CHECK_EXCEPTION();
-            if (RuntimeHelpers::strictEqual(value, searchValue)) {
-                scope.result = Encode(idx);
-                return;
-            }
+            if (RuntimeHelpers::strictEqual(value, searchValue))
+                return Encode(idx);
             ++idx;
         }
     }
-    scope.result = Encode(-1);
+    return Encode(-1);
+}
+
+ReturnedValue ArrayPrototype::method_keys(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    ScopedObject O(scope, thisObject->toObject(scope.engine));
+    if (!O)
+        RETURN_UNDEFINED();
+
+    Scoped<ArrayIteratorObject> ao(scope, scope.engine->newArrayIteratorObject(O));
+    ao->d()->iterationKind = IteratorKind::KeyIteratorKind;
+    return ao->asReturnedValue();
 }
 
-void ArrayPrototype::method_lastIndexOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_lastIndexOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
-    if (!len) {
-        scope.result = Encode(-1);
-        return;
-    }
+    if (!len)
+        return Encode(-1);
 
     ScopedValue searchValue(scope);
     uint fromIndex = len;
 
-    if (callData->argc >= 1)
-        searchValue = callData->argument(0);
+    if (argc >= 1)
+        searchValue = argv[0];
     else
-        searchValue = Primitive::undefinedValue();
+        searchValue = Value::undefinedValue();
 
-    if (callData->argc >= 2) {
-        double f = callData->args[1].toInteger();
+    if (argc >= 2) {
+        double f = argv[1].toInteger();
         CHECK_EXCEPTION();
         if (f > 0)
             f = qMin(f, (double)(len - 1));
         else if (f < 0) {
             f = len + f;
-            if (f < 0) {
-                scope.result = Encode(-1);
-                return;
-            }
+            if (f < 0)
+                return Encode(-1);
         }
         fromIndex = (uint) f + 1;
     }
@@ -745,283 +1172,335 @@ void ArrayPrototype::method_lastIndexOf(const BuiltinFunction *, Scope &scope, C
     for (uint k = fromIndex; k > 0;) {
         --k;
         bool exists;
-        v = instance->getIndexed(k, &exists);
+        v = instance->get(k, &exists);
         CHECK_EXCEPTION();
-        if (exists && RuntimeHelpers::strictEqual(v, searchValue)) {
-            scope.result = Encode(k);
-            return;
-        }
+        if (exists && RuntimeHelpers::strictEqual(v, searchValue))
+            return Encode(k);
     }
-    scope.result = Encode(-1);
+    return Encode(-1);
 }
 
-void ArrayPrototype::method_every(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_every(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
-    ScopedCallData cData(scope, 3);
-    cData->args[2] = instance;
-    cData->thisObject = callData->argument(1);
-    ScopedValue v(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    ScopedValue r(scope);
+    Value *arguments = scope.alloc(3);
 
     bool ok = true;
     for (uint k = 0; ok && k < len; ++k) {
         bool exists;
-        v = instance->getIndexed(k, &exists);
+        arguments[0] = instance->get(k, &exists);
         if (!exists)
             continue;
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
-        ok = scope.result.toBoolean();
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        r = callback->call(that, arguments, 3);
+        ok = r->toBoolean();
     }
-    scope.result = Encode(ok);
+    return Encode(ok);
 }
 
-void ArrayPrototype::method_some(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_fill(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
+    int relativeStart = argc > 1 ? argv[1].toInteger() : 0;
+    int relativeEnd = len;
+    if (argc > 2 && !argv[2].isUndefined()) {
+        relativeEnd = argv[2].toInteger();
+    }
+    uint k = 0;
+    uint fin = 0;
+
+    if (relativeStart < 0) {
+        k = std::max(len+relativeStart, uint(0));
+    } else {
+        k = std::min(uint(relativeStart), len);
+    }
+
+    if (relativeEnd < 0) {
+        fin = std::max(len + relativeEnd, uint(0));
+    } else {
+        fin = std::min(uint(relativeEnd), len);
+    }
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    while (k < fin) {
+        instance->setIndexed(k, argv[0], QV4::Object::DoThrowOnRejection);
+        k++;
+    }
+
+    return instance.asReturnedValue();
+}
+
+ReturnedValue ArrayPrototype::method_some(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
+    if (!instance)
+        RETURN_UNDEFINED();
+
+    uint len = instance->getLength();
+
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
-    ScopedCallData cData(scope, 3);
-    cData->thisObject = callData->argument(1);
-    cData->args[2] = instance;
-    ScopedValue v(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    ScopedValue result(scope);
+    Value *arguments = scope.alloc(3);
 
     for (uint k = 0; k < len; ++k) {
         bool exists;
-        v = instance->getIndexed(k, &exists);
+        arguments[0] = instance->get(k, &exists);
         if (!exists)
             continue;
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
-        if (scope.result.toBoolean()) {
-            scope.result = Encode(true);
-            return;
-        }
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        result = callback->call(that, arguments, 3);
+        if (result->toBoolean())
+            return Encode(true);
     }
-    scope.result = Encode(false);
+    return Encode(false);
 }
 
-void ArrayPrototype::method_forEach(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_forEach(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
-    ScopedCallData cData(scope, 3);
-    cData->thisObject = callData->argument(1);
-    cData->args[2] = instance;
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Value *arguments = scope.alloc(3);
 
-    ScopedValue v(scope);
     for (uint k = 0; k < len; ++k) {
         bool exists;
-        v = instance->getIndexed(k, &exists);
+        arguments[0] = instance->get(k, &exists);
         if (!exists)
             continue;
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        callback->call(that, arguments, 3);
     }
     RETURN_UNDEFINED();
 }
 
-void ArrayPrototype::method_map(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_map(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
-    uint len = instance->getLength();
+    qint64 len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    if (len > UINT_MAX - 1)
+        return scope.engine->throwRangeError(QString::fromLatin1("Array length out of range."));
 
     ScopedArrayObject a(scope, scope.engine->newArrayObject());
     a->arrayReserve(len);
     a->setArrayLengthUnchecked(len);
 
-    ScopedCallData cData(scope, 3);
-    cData->thisObject = callData->argument(1);
-    cData->args[2] = instance;
-
     ScopedValue v(scope);
+    ScopedValue mapped(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Value *arguments = scope.alloc(3);
+
     for (uint k = 0; k < len; ++k) {
         bool exists;
-        v = instance->getIndexed(k, &exists);
+        arguments[0] = instance->get(k, &exists);
         if (!exists)
             continue;
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
-        a->arraySet(k, scope.result);
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        mapped = callback->call(that, arguments, 3);
+        a->arraySet(k, mapped);
     }
-    scope.result = a.asReturnedValue();
+    return a.asReturnedValue();
 }
 
-void ArrayPrototype::method_filter(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_filter(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
     ScopedArrayObject a(scope, scope.engine->newArrayObject());
     a->arrayReserve(len);
 
-    ScopedCallData cData(scope, 3);
-    cData->thisObject = callData->argument(1);
-    cData->args[2] = instance;
-
-    ScopedValue v(scope);
+    ScopedValue selected(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Value *arguments = scope.alloc(3);
 
     uint to = 0;
     for (uint k = 0; k < len; ++k) {
         bool exists;
-        v = instance->getIndexed(k, &exists);
+        arguments[0] = instance->get(k, &exists);
         if (!exists)
             continue;
 
-        cData->args[0] = v;
-        cData->args[1] = Primitive::fromDouble(k);
-        callback->call(scope, cData);
-        if (scope.result.toBoolean()) {
-            a->arraySet(to, v);
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        selected = callback->call(that, arguments, 3);
+        if (selected->toBoolean()) {
+            a->arraySet(to, arguments[0]);
             ++to;
         }
     }
-    scope.result = a.asReturnedValue();
+    return a.asReturnedValue();
 }
 
-void ArrayPrototype::method_reduce(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_reduce(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
     uint k = 0;
+    ScopedValue acc(scope);
     ScopedValue v(scope);
 
-    if (callData->argc > 1) {
-        scope.result = callData->argument(1);
+    if (argc > 1) {
+        acc = argv[1];
     } else {
         bool kPresent = false;
         while (k < len && !kPresent) {
-            v = instance->getIndexed(k, &kPresent);
+            v = instance->get(k, &kPresent);
             if (kPresent)
-                scope.result = v;
+                acc = v;
             ++k;
         }
         if (!kPresent)
             THROW_TYPE_ERROR();
     }
 
-    ScopedCallData cData(scope, 4);
-    cData->thisObject = Primitive::undefinedValue();
-    cData->args[0] = scope.result;
-    cData->args[3] = instance;
+    Value *arguments = scope.alloc(4);
 
     while (k < len) {
         bool kPresent;
-        v = instance->getIndexed(k, &kPresent);
+        v = instance->get(k, &kPresent);
         if (kPresent) {
-            cData->args[0] = scope.result;
-            cData->args[1] = v;
-            cData->args[2] = Primitive::fromDouble(k);
-            callback->call(scope, cData);
+            arguments[0] = acc;
+            arguments[1] = v;
+            arguments[2] = Value::fromDouble(k);
+            arguments[3] = instance;
+            acc = callback->call(nullptr, arguments, 4);
         }
         ++k;
     }
+    return acc->asReturnedValue();
 }
 
-void ArrayPrototype::method_reduceRight(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ArrayPrototype::method_reduceRight(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
 
     uint len = instance->getLength();
 
-    ScopedFunctionObject callback(scope, callData->argument(0));
-    if (!callback)
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
 
     if (len == 0) {
-        if (callData->argc == 1)
+        if (argc == 1)
             THROW_TYPE_ERROR();
-        scope.result = callData->argument(1);
-        return;
+        return argv[1].asReturnedValue();
     }
 
     uint k = len;
+    ScopedValue acc(scope);
     ScopedValue v(scope);
-    if (callData->argc > 1) {
-        scope.result = callData->argument(1);
+    if (argc > 1) {
+        acc = argv[1];
     } else {
         bool kPresent = false;
         while (k > 0 && !kPresent) {
-            v = instance->getIndexed(k - 1, &kPresent);
+            v = instance->get(k - 1, &kPresent);
             if (kPresent)
-                scope.result = v;
+                acc = v;
             --k;
         }
         if (!kPresent)
             THROW_TYPE_ERROR();
     }
 
-    ScopedCallData cData(scope, 4);
-    cData->thisObject = Primitive::undefinedValue();
-    cData->args[3] = instance;
+    Value *arguments = scope.alloc(4);
 
     while (k > 0) {
         bool kPresent;
-        v = instance->getIndexed(k - 1, &kPresent);
+        v = instance->get(k - 1, &kPresent);
         if (kPresent) {
-            cData->args[0] = scope.result;
-            cData->args[1] = v;
-            cData->args[2] = Primitive::fromDouble(k - 1);
-            callback->call(scope, cData);
+            arguments[0] = acc;
+            arguments[1] = v;
+            arguments[2] = Value::fromDouble(k - 1);
+            arguments[3] = instance;
+            acc = callback->call(nullptr, arguments, 4);
         }
         --k;
     }
-    scope.result = scope.result.asReturnedValue();
+    return acc->asReturnedValue();
+}
+
+ReturnedValue ArrayPrototype::method_values(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    ScopedObject O(scope, thisObject->toObject(scope.engine));
+    if (!O)
+        RETURN_UNDEFINED();
+
+    Scoped<ArrayIteratorObject> ao(scope, scope.engine->newArrayIteratorObject(O));
+    ao->d()->iterationKind = IteratorKind::ValueIteratorKind;
+    return ao->asReturnedValue();
+}
+
+ReturnedValue ArrayPrototype::method_get_species(const FunctionObject *, const Value *thisObject, const Value *, int)
+{
+    return thisObject->asReturnedValue();
 }
 
diff --git a/src/qml/jsruntime/qv4arrayobject_p.h b/src/qml/jsruntime/qv4arrayobject_p.h
index 689752433b..c959b71bc6 100644
--- a/src/qml/jsruntime/qv4arrayobject_p.h
+++ b/src/qml/jsruntime/qv4arrayobject_p.h
@@ -70,38 +70,50 @@ struct ArrayCtor: FunctionObject
 {
     V4_OBJECT2(ArrayCtor, FunctionObject)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct ArrayPrototype: ArrayObject
 {
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_isArray(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_toString(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_toLocaleString(const BuiltinFunction *builtin, Scope &, CallData *callData);
-    static void method_concat(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_find(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_findIndex(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_join(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_pop(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_push(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_reverse(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_shift(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_slice(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_sort(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_splice(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_unshift(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_indexOf(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_lastIndexOf(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_every(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_some(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_forEach(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_map(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_filter(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_reduce(const BuiltinFunction *, Scope &, CallData *callData);
-    static void method_reduceRight(const BuiltinFunction *, Scope &, CallData *callData);
+    static ReturnedValue method_isArray(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_from(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_of(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_concat(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_copyWithin(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_entries(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_find(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_findIndex(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_join(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_pop(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_push(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reverse(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_shift(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sort(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_splice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_unshift(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_includes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_indexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_keys(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_lastIndexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_every(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_fill(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_some(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_forEach(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_map(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_filter(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reduce(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reduceRight(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_values(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    // while this function is implemented here, it's the same for many other JS classes, so the corresponding JS function
+    // is instantiated in the engine, and it can be added to any JS object through Object::addSymbolSpecies()
+    static ReturnedValue method_get_species(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 
diff --git a/src/qml/jsruntime/qv4atomics.cpp b/src/qml/jsruntime/qv4atomics.cpp
new file mode 100644
index 0000000000..4299aef859
--- /dev/null
+++ b/src/qml/jsruntime/qv4atomics.cpp
@@ -0,0 +1,257 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "qv4arraybuffer_p.h"
+#include "qv4typedarray_p.h"
+#include "qv4atomics_p.h"
+#include "qv4symbol_p.h"
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(Atomics);
+
+void Heap::Atomics::init()
+{
+    Object::init();
+    Scope scope(internalClass->engine);
+    ScopedObject m(scope, this);
+
+    m->defineDefaultProperty(QStringLiteral("add"), QV4::Atomics::method_add, 3);
+    m->defineDefaultProperty(QStringLiteral("and"), QV4::Atomics::method_and, 3);
+    m->defineDefaultProperty(QStringLiteral("compareExchange"), QV4::Atomics::method_compareExchange, 4);
+    m->defineDefaultProperty(QStringLiteral("exchange"), QV4::Atomics::method_exchange, 3);
+    m->defineDefaultProperty(QStringLiteral("isLockFree"), QV4::Atomics::method_isLockFree, 1);
+    m->defineDefaultProperty(QStringLiteral("load"), QV4::Atomics::method_load, 2);
+    m->defineDefaultProperty(QStringLiteral("or"), QV4::Atomics::method_or, 3);
+    m->defineDefaultProperty(QStringLiteral("store"), QV4::Atomics::method_store, 3);
+    m->defineDefaultProperty(QStringLiteral("sub"), QV4::Atomics::method_sub, 3);
+    m->defineDefaultProperty(QStringLiteral("wait"), QV4::Atomics::method_wait, 4);
+    m->defineDefaultProperty(QStringLiteral("wake"), QV4::Atomics::method_wake, 3);
+    m->defineDefaultProperty(QStringLiteral("xor"), QV4::Atomics::method_xor, 3);
+
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("Atomics")));
+    m->defineReadonlyConfigurableProperty(scope.engine->symbol_toStringTag(), name);
+}
+
+static SharedArrayBuffer *validateSharedIntegerTypedArray(Scope &scope, const Value &typedArray, bool onlyInt32 = false)
+{
+    const TypedArray *a = typedArray.as<TypedArray>();
+    if (!a) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    TypedArrayType t(a->arrayType());
+    if (!a->d()->type->atomicLoad || (onlyInt32 && t != TypedArrayType::Int32Array)) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    Scoped<SharedArrayBuffer> buffer(scope, a->d()->buffer);
+    if (!buffer->isSharedArrayBuffer()) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    Q_ASSERT(!buffer->isDetachedBuffer());
+    return buffer;
+}
+
+static int validateAtomicAccess(Scope &scope, const TypedArray &typedArray, const Value &index)
+{
+    const TypedArray &a = static_cast<const TypedArray &>(typedArray);
+    qint64 idx = index.toIndex();
+    if (scope.hasException())
+        return -1;
+    if (idx < 0 || idx >= a.length()) {
+        scope.engine->throwRangeError(QStringLiteral("index out of range."));
+        return -1;
+    }
+    return static_cast<int>(idx);
+}
+
+ReturnedValue atomicReadModifyWrite(const FunctionObject *f, const Value *argv, int argc, AtomicModifyOps modify)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    SharedArrayBuffer *buffer = validateSharedIntegerTypedArray(scope, argv[0]);
+    if (!buffer)
+        return Encode::undefined();
+    const TypedArray &a = static_cast<const TypedArray &>(argv[0]);
+    int index = validateAtomicAccess(scope, a, argc > 1 ? argv[1] : Value::undefinedValue());
+    if (index < 0)
+        return Encode::undefined();
+
+    Value v = Value::fromReturnedValue((argc > 2 ? argv[2] : Value::undefinedValue()).convertedToNumber());
+    if (scope.hasException())
+        return Encode::undefined();
+
+    int bytesPerElement = a.d()->type->bytesPerElement;
+    int byteOffset = a.d()->byteOffset + index * bytesPerElement;
+
+    return a.d()->type->atomicModifyOps[modify](buffer->data() + byteOffset, v);
+}
+
+ReturnedValue Atomics::method_add(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return atomicReadModifyWrite(f, argv, argc, AtomicAdd);
+}
+
+ReturnedValue Atomics::method_and(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return atomicReadModifyWrite(f, argv, argc, AtomicAnd);
+}
+
+ReturnedValue Atomics::method_compareExchange(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    SharedArrayBuffer *buffer = validateSharedIntegerTypedArray(scope, argv[0]);
+    if (!buffer)
+        return Encode::undefined();
+    const TypedArray &a = static_cast<const TypedArray &>(argv[0]);
+    int index = validateAtomicAccess(scope, a, argc > 1 ? argv[1] : Value::undefinedValue());
+    if (index < 0)
+        return Encode::undefined();
+
+    Value expected = Value::fromReturnedValue((argc > 2 ? argv[2] : Value::undefinedValue()).convertedToNumber());
+    if (scope.hasException())
+        return Encode::undefined();
+    Value v = Value::fromReturnedValue((argc > 3 ? argv[3] : Value::undefinedValue()).convertedToNumber());
+    if (scope.hasException())
+        return Encode::undefined();
+
+    int bytesPerElement = a.d()->type->bytesPerElement;
+    int byteOffset = a.d()->byteOffset + index * bytesPerElement;
+
+    return a.d()->type->atomicCompareExchange(buffer->data() + byteOffset, expected, v);
+}
+
+ReturnedValue Atomics::method_exchange(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return atomicReadModifyWrite(f, argv, argc, AtomicExchange);
+}
+
+ReturnedValue Atomics::method_isLockFree(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    if (!argc)
+        return Encode(false);
+    double n = argv[0].toInteger();
+    if (n == 4.)
+        return Encode(true);
+    if (n == 2.)
+        return Encode(QAtomicOps<unsigned short>::isTestAndSetNative());
+#ifdef Q_ATOMIC_INT8_IS_SUPPORTED
+    if (n == 1.)
+        return Encode(QAtomicOps<unsigned char>::isTestAndSetNative());
+#endif
+    return Encode(false);
+}
+
+ReturnedValue Atomics::method_load(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    SharedArrayBuffer *buffer = validateSharedIntegerTypedArray(scope, argv[0]);
+    if (!buffer)
+        return Encode::undefined();
+    const TypedArray &a = static_cast<const TypedArray &>(argv[0]);
+    int index = validateAtomicAccess(scope, a, argc > 1 ? argv[1] : Value::undefinedValue());
+    if (index < 0)
+        return Encode::undefined();
+
+    int bytesPerElement = a.d()->type->bytesPerElement;
+    int byteOffset = a.d()->byteOffset + index * bytesPerElement;
+
+    return a.d()->type->atomicLoad(buffer->data() + byteOffset);
+}
+
+ReturnedValue Atomics::method_or(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return atomicReadModifyWrite(f, argv, argc, AtomicOr);
+}
+
+ReturnedValue Atomics::method_store(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    SharedArrayBuffer *buffer = validateSharedIntegerTypedArray(scope, argv[0]);
+    if (!buffer)
+        return Encode::undefined();
+    const TypedArray &a = static_cast<const TypedArray &>(argv[0]);
+    int index = validateAtomicAccess(scope, a, argc > 1 ? argv[1] : Value::undefinedValue());
+    if (index < 0)
+        return Encode::undefined();
+
+    Value v = Value::fromReturnedValue((argc > 2 ? argv[2] : Value::undefinedValue()).convertedToNumber());
+    if (scope.hasException())
+        return Encode::undefined();
+
+    int bytesPerElement = a.d()->type->bytesPerElement;
+    int byteOffset = a.d()->byteOffset + index * bytesPerElement;
+
+    return a.d()->type->atomicStore(buffer->data() + byteOffset, v);
+}
+
+ReturnedValue Atomics::method_sub(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return atomicReadModifyWrite(f, argv, argc, AtomicSub);
+}
+
+ReturnedValue Atomics::method_wait(const FunctionObject *f, const Value *, const Value *, int)
+{
+    return f->engine()->throwTypeError();
+}
+
+ReturnedValue Atomics::method_wake(const FunctionObject *f, const Value *, const Value *, int)
+{
+    return f->engine()->throwTypeError();
+}
+
+ReturnedValue Atomics::method_xor(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return atomicReadModifyWrite(f, argv, argc, AtomicXor);
+
+}
diff --git a/src/qml/jsruntime/qv4atomics_p.h b/src/qml/jsruntime/qv4atomics_p.h
new file mode 100644
index 0000000000..35b64bf4fe
--- /dev/null
+++ b/src/qml/jsruntime/qv4atomics_p.h
@@ -0,0 +1,91 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4ATOMICS_H
+#define QV4ATOMICS_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4functionobject_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Heap {
+
+struct Atomics : Object {
+    void init();
+};
+
+}
+
+struct Atomics : Object
+{
+    V4_OBJECT2(Atomics, Object)
+
+    static ReturnedValue method_add(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_and(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_compareExchange(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_exchange(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isLockFree(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_load(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_or(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_store(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sub(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_wait(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_wake(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_xor(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+
+} // namespace QV4
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/jsruntime/qv4booleanobject.cpp b/src/qml/jsruntime/qv4booleanobject.cpp
index c8e9ebb2dd..3e5f51c302 100644
--- a/src/qml/jsruntime/qv4booleanobject.cpp
+++ b/src/qml/jsruntime/qv4booleanobject.cpp
@@ -50,54 +50,70 @@ void Heap::BooleanCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("Boolean"));
 }
 
-void BooleanCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue BooleanCtor::virtualCallAsConstructor(const FunctionObject *that, const Value *argv, int argc, const Value *newTarget)
 {
-    bool n = callData->argc ? callData->args[0].toBoolean() : false;
-    scope.result = Encode(scope.engine->newBooleanObject(n));
+    auto v4 = that->engine();
+    bool n = argc ? argv[0].toBoolean() : false;
+
+    ReturnedValue o = Encode(v4->newBooleanObject(n));
+    if (!newTarget)
+        return o;
+    Scope scope(v4);
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
 }
 
-void BooleanCtor::call(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue BooleanCtor::virtualCall(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    bool value = callData->argc ? callData->args[0].toBoolean() : 0;
-    scope.result = Encode(value);
+    bool value = argc ? argv[0].toBoolean() : 0;
+    return Encode(value);
 }
 
 void BooleanPrototype::init(ExecutionEngine *engine, Object *ctor)
 {
     Scope scope(engine);
     ScopedObject o(scope);
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
     defineDefaultProperty(engine->id_toString(), method_toString);
     defineDefaultProperty(engine->id_valueOf(), method_valueOf);
 }
 
-void BooleanPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+static bool value(const Value *thisObject, bool *exception)
 {
-    bool result;
-    if (callData->thisObject.isBoolean()) {
-        result = callData->thisObject.booleanValue();
+    *exception = false;
+    if (thisObject->isBoolean()) {
+        return thisObject->booleanValue();
     } else {
-        const BooleanObject *thisObject = callData->thisObject.as<BooleanObject>();
-        if (!thisObject)
-            THROW_TYPE_ERROR();
-        result = thisObject->value();
+        const BooleanObject *that = thisObject->as<BooleanObject>();
+        if (that)
+            return that->value();
     }
+    *exception = true;
+    return false;
+}
 
-    scope.result = result ? scope.engine->id_true() : scope.engine->id_false();
+ReturnedValue BooleanPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    bool exception;
+    bool result = ::value(thisObject, &exception);
+    ExecutionEngine *v4 = b->engine();
+    if (exception)
+        return v4->throwTypeError();
+
+    return Encode(result ? v4->id_true() : v4->id_false());
 }
 
-void BooleanPrototype::method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue BooleanPrototype::method_valueOf(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    if (callData->thisObject.isBoolean()) {
-        scope.result = callData->thisObject.asReturnedValue();
-        return;
+    bool exception;
+    bool result = ::value(thisObject, &exception);
+    if (exception) {
+        ExecutionEngine *v4 = b->engine();
+        return v4->throwTypeError();
     }
 
-    const BooleanObject *thisObject = callData->thisObject.as<BooleanObject>();
-    if (!thisObject)
-        THROW_TYPE_ERROR();
-
-    scope.result = Encode(thisObject->value());
+    return Encode(result);
 }
diff --git a/src/qml/jsruntime/qv4booleanobject_p.h b/src/qml/jsruntime/qv4booleanobject_p.h
index ca2cf7d17a..276ec8393b 100644
--- a/src/qml/jsruntime/qv4booleanobject_p.h
+++ b/src/qml/jsruntime/qv4booleanobject_p.h
@@ -70,8 +70,8 @@ struct BooleanCtor: FunctionObject
 {
     V4_OBJECT2(BooleanCtor, FunctionObject)
 
-    static void construct(const Managed *, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct BooleanPrototype: BooleanObject
@@ -79,8 +79,8 @@ struct BooleanPrototype: BooleanObject
     V4_PROTOTYPE(objectPrototype)
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index ba72a9e43b..b3bcfe21d5 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -48,66 +48,103 @@
 #include "qv4errorobject_p.h"
 #include "qv4string_p.h"
 #include "qv4qmlcontext_p.h"
-#include "qv4profiling_p.h"
-#include <private/qqmljavascriptexpression_p.h>
+#include "qv4stackframe_p.h"
+#include "qv4symbol_p.h"
 
 using namespace QV4;
 
 DEFINE_MANAGED_VTABLE(ExecutionContext);
-DEFINE_MANAGED_VTABLE(SimpleCallContext);
 DEFINE_MANAGED_VTABLE(CallContext);
-DEFINE_MANAGED_VTABLE(WithContext);
-DEFINE_MANAGED_VTABLE(CatchContext);
-DEFINE_MANAGED_VTABLE(GlobalContext);
 
-Heap::CallContext *ExecutionContext::newCallContext(Function *function, CallData *callData)
+Heap::CallContext *ExecutionContext::newBlockContext(CppStackFrame *frame, int blockIndex)
 {
-    uint localsAndFormals = function->compiledFunction->nLocals + sizeof(CallData)/sizeof(Value) - 1 + qMax(static_cast<uint>(callData->argc), function->nFormals);
-    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * (localsAndFormals);
+    Function *function = frame->v4Function;
+
+    Heap::InternalClass *ic = function->compilationUnit->runtimeBlocks.at(blockIndex);
+    uint nLocals = ic->size;
+    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
+
+    ExecutionEngine *v4 = function->internalClass->engine;
+    Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(requiredMemory, ic);
+    c->init();
+    c->type = Heap::ExecutionContext::Type_BlockContext;
+
+    Heap::ExecutionContext *outer = static_cast<Heap::ExecutionContext *>(frame->context()->m());
+    c->outer.set(v4, outer);
+    c->function.set(v4, static_cast<Heap::FunctionObject *>(frame->jsFrame->function.m()));
+
+    c->locals.size = nLocals;
+    c->locals.alloc = nLocals;
 
-    ExecutionEngine *v4 = engine();
-    Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(requiredMemory);
-    c->init(Heap::ExecutionContext::Type_CallContext);
+    c->setupLocalTemporalDeadZone(function->compilationUnit->unitData()->blockAt(blockIndex));
 
-    c->v4Function = function;
+    return c;
+}
 
-    c->strictMode = function->isStrict();
-    c->outer.set(v4, this->d());
+Heap::CallContext *ExecutionContext::cloneBlockContext(ExecutionEngine *engine,
+                                                       Heap::CallContext *callContext)
+{
+    uint nLocals = callContext->locals.alloc;
+    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * nLocals;
 
-    c->compilationUnit = function->compilationUnit;
-    c->lookups = function->compilationUnit->runtimeLookups;
-    c->constantTable = function->compilationUnit->constants;
+    Heap::CallContext *c = engine->memoryManager->allocManaged<CallContext>(
+                requiredMemory, callContext->internalClass);
+    memcpy(c, callContext, requiredMemory);
+
+    return c;
+}
+
+Heap::CallContext *ExecutionContext::newCallContext(CppStackFrame *frame)
+{
+    Function *function = frame->v4Function;
+    Heap::ExecutionContext *outer = static_cast<Heap::ExecutionContext *>(frame->context()->m());
+
+    uint nFormals = qMax(static_cast<uint>(frame->originalArgumentsCount), function->nFormals);
+    uint localsAndFormals = function->compiledFunction->nLocals + nFormals;
+    size_t requiredMemory = sizeof(CallContext::Data) - sizeof(Value) + sizeof(Value) * (localsAndFormals);
+
+    ExecutionEngine *v4 = outer->internalClass->engine;
+    Heap::CallContext *c = v4->memoryManager->allocManaged<CallContext>(requiredMemory, function->internalClass);
+    c->init();
+
+    c->outer.set(v4, outer);
+    c->function.set(v4, static_cast<Heap::FunctionObject *>(frame->jsFrame->function.m()));
 
     const CompiledData::Function *compiledFunction = function->compiledFunction;
     uint nLocals = compiledFunction->nLocals;
     c->locals.size = nLocals;
     c->locals.alloc = localsAndFormals;
-#if QT_POINTER_SIZE == 8
-    // memory allocated from the JS heap is 0 initialized, so skip the std::fill() below
-    Q_ASSERT(Primitive::undefinedValue().asReturnedValue() == 0);
-#else
-    if (nLocals)
-        std::fill(c->locals.values, c->locals.values + nLocals, Primitive::undefinedValue());
-#endif
-
-    c->callData = reinterpret_cast<CallData *>(c->locals.values + nLocals);
-    ::memcpy(c->callData, callData, sizeof(CallData) - sizeof(Value) + static_cast<uint>(callData->argc) * sizeof(Value));
-    if (callData->argc < static_cast<int>(compiledFunction->nFormals))
-        std::fill(c->callData->args + c->callData->argc, c->callData->args + compiledFunction->nFormals, Primitive::undefinedValue());
+    // memory allocated from the JS heap is 0 initialized, so check if empty is 0
+    Q_ASSERT(Value::undefinedValue().asReturnedValue() == 0);
+
+    c->setupLocalTemporalDeadZone(compiledFunction);
+
+    Value *args = c->locals.values + nLocals;
+    ::memcpy(args, frame->originalArguments, frame->originalArgumentsCount * sizeof(Value));
+    c->nArgs = frame->originalArgumentsCount;
+    for (uint i = frame->originalArgumentsCount; i < function->nFormals; ++i)
+        args[i] = Encode::undefined();
 
     return c;
 }
 
-Heap::WithContext *ExecutionContext::newWithContext(Heap::Object *with)
+Heap::ExecutionContext *ExecutionContext::newWithContext(Heap::Object *with) const
 {
-    return engine()->memoryManager->alloc<WithContext>(d(), with);
+    Heap::ExecutionContext *c = engine()->memoryManager->alloc<ExecutionContext>(Heap::ExecutionContext::Type_WithContext);
+    c->outer.set(engine(), d());
+    c->activation.set(engine(), with);
+
+    return c;
 }
 
-Heap::CatchContext *ExecutionContext::newCatchContext(Heap::String *exceptionVarName, ReturnedValue exceptionValue)
+Heap::ExecutionContext *ExecutionContext::newCatchContext(CppStackFrame *frame, int blockIndex, Heap::String *exceptionVarName)
 {
-    Scope scope(this);
-    ScopedValue e(scope, exceptionValue);
-    return engine()->memoryManager->alloc<CatchContext>(d(), exceptionVarName, e);
+    Scope scope(frame->context());
+    ScopedString name(scope, exceptionVarName);
+    ScopedValue val(scope, scope.engine->catchException(nullptr));
+    ScopedContext ctx(scope, newBlockContext(frame, blockIndex));
+    ctx->setProperty(name, val);
+    return ctx->d();
 }
 
 void ExecutionContext::createMutableBinding(String *name, bool deletable)
@@ -120,136 +157,97 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
     while (ctx) {
         switch (ctx->d()->type) {
         case Heap::ExecutionContext::Type_CallContext:
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             if (!activation) {
+                Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
                 if (!c->activation)
                     c->activation.set(scope.engine, scope.engine->newObject());
                 activation = c->activation;
             }
             break;
-        }
         case Heap::ExecutionContext::Type_QmlContext: {
             // this is ugly, as it overrides the inner callcontext, but has to stay as long
             // as bindings still get their own callcontext
-            Heap::QmlContext *qml = static_cast<Heap::QmlContext *>(ctx->d());
-            activation = qml->qml;
+            activation = ctx->d()->activation;
             break;
         }
         case Heap::ExecutionContext::Type_GlobalContext: {
+            Q_ASSERT(scope.engine->globalObject->d() == ctx->d()->activation);
             if (!activation)
-                activation = scope.engine->globalObject;
+                activation = ctx->d()->activation;
             break;
         }
+        case Heap::ExecutionContext::Type_BlockContext:
+            // never create activation records on block contexts
         default:
             break;
         }
         ctx = ctx->d()->outer;
     }
 
-    if (activation->hasOwnProperty(name))
+    PropertyKey id = name->toPropertyKey();
+    if (activation->getOwnProperty(id) != Attr_Invalid)
         return;
     ScopedProperty desc(scope);
     PropertyAttributes attrs(Attr_Data);
     attrs.setConfigurable(deletable);
-    activation->__defineOwnProperty__(scope.engine, name, desc, attrs);
-}
-
-void Heap::GlobalContext::init(ExecutionEngine *eng)
-{
-    Heap::ExecutionContext::init(Heap::ExecutionContext::Type_GlobalContext);
-    global.set(eng, eng->globalObject->d());
-}
-
-void Heap::CatchContext::init(ExecutionContext *outerContext, String *exceptionVarName,
-                              const Value &exceptionValue)
-{
-    Heap::ExecutionContext::init(Heap::ExecutionContext::Type_CatchContext);
-    outer.set(internalClass->engine, outerContext);
-    strictMode = outer->strictMode;
-    callData = outer->callData;
-    lookups = outer->lookups;
-    constantTable = outer->constantTable;
-    compilationUnit = outer->compilationUnit;
-
-    this->exceptionVarName.set(internalClass->engine, exceptionVarName);
-    this->exceptionValue.set(internalClass->engine, exceptionValue);
-}
-
-void Heap::WithContext::init(ExecutionContext *outerContext, Object *with)
-{
-    Heap::ExecutionContext::init(Heap::ExecutionContext::Type_WithContext);
-    outer.set(internalClass->engine, outerContext);
-    callData = outer->callData;
-    lookups = outer->lookups;
-    constantTable = outer->constantTable;
-    compilationUnit = outer->compilationUnit;
-
-    withObject.set(internalClass->engine, with);
-}
-
-Identifier * const *SimpleCallContext::formals() const
-{
-    return d()->v4Function ? d()->v4Function->internalClass->nameMap.constData() : 0;
-}
-
-unsigned int SimpleCallContext::formalCount() const
-{
-    return d()->v4Function ? d()->v4Function->nFormals : 0;
+    if (!activation->defineOwnProperty(id, desc, attrs))
+        scope.engine->throwTypeError();
 }
 
-Identifier * const *SimpleCallContext::variables() const
+static bool unscopable(ExecutionEngine *engine, Heap::Object *withObject, PropertyKey id)
 {
-    return d()->v4Function ? d()->v4Function->internalClass->nameMap.constData() + d()->v4Function->nFormals : 0;
-}
-
-unsigned int SimpleCallContext::variableCount() const
-{
-    return d()->v4Function ? d()->v4Function->compiledFunction->nLocals : 0;
+    if (!withObject)
+        return false;
+    Scope scope(engine);
+    ScopedObject w(scope, withObject);
+    ScopedObject o(scope, w->get(scope.engine->symbol_unscopables()));
+    if (o) {
+        ScopedValue blocked(scope, o->get(id));
+        return blocked->toBoolean();
+    }
+    return false;
 }
 
-
-
 bool ExecutionContext::deleteProperty(String *name)
 {
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
+    PropertyKey id = name->toPropertyKey();
 
-    Scope scope(this);
-    ScopedContext ctx(scope, this);
-    for (; ctx; ctx = ctx->d()->outer) {
-        switch (ctx->d()->type) {
-        case Heap::ExecutionContext::Type_CatchContext: {
-            Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
-            if (c->exceptionVarName->isEqualTo(name->d()))
-                return false;
-            break;
-        }
-        case Heap::ExecutionContext::Type_WithContext: {
-            ScopedObject withObject(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
-            if (withObject->hasProperty(name))
-                return withObject->deleteProperty(name);
-            break;
-        }
-        case Heap::ExecutionContext::Type_GlobalContext: {
-            ScopedObject global(scope, static_cast<Heap::GlobalContext *>(ctx->d())->global);
-            if (global->hasProperty(name))
-                return global->deleteProperty(name);
-            break;
-        }
+    Heap::ExecutionContext *ctx = d();
+    ExecutionEngine *engine = ctx->internalClass->engine;
+
+    for (; ctx; ctx = ctx->outer) {
+        switch (ctx->type) {
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
-            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
-            uint index = c->v4Function->internalClass->find(id);
+            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
+            uint index = c->internalClass->indexOfValueOrGetter(id);
             if (index < UINT_MAX)
                 // ### throw in strict mode?
                 return false;
             Q_FALLTHROUGH();
         }
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
-            ScopedObject qml(scope, c->activation);
-            if (qml && qml->hasProperty(name))
-                return qml->deleteProperty(name);
+        case Heap::ExecutionContext::Type_WithContext: {
+            if (ctx->activation) {
+                Scope scope(this);
+                ScopedObject object(scope, ctx->activation);
+                if (object && object->hasProperty(id)) {
+                    bool u = ::unscopable(engine, ctx->activation, id);
+                    if (engine->hasException)
+                        return false;
+                    if (u)
+                        break;
+                    return object->deleteProperty(id);
+                }
+            }
+            break;
+        }
+        case Heap::ExecutionContext::Type_GlobalContext: {
+            if (ctx->activation) {
+                Scope scope(this);
+                ScopedObject object(scope, ctx->activation);
+                if (object && object->hasProperty(id))
+                    return object->deleteProperty(id);
+            }
             break;
         }
         case Heap::ExecutionContext::Type_QmlContext:
@@ -258,302 +256,180 @@ bool ExecutionContext::deleteProperty(String *name)
         }
     }
 
-    if (d()->strictMode)
-        engine()->throwSyntaxError(QStringLiteral("Can't delete property %1").arg(name->toQString()));
-    return true;
-}
-
-// Do a standard call with this execution context as the outer scope
-void ExecutionContext::call(Scope &scope, CallData *callData, Function *function, const FunctionObject *f)
-{
-    ExecutionContextSaver ctxSaver(scope);
-
-    Scoped<CallContext> ctx(scope, newCallContext(function, callData));
-    if (f)
-        ctx->d()->function.set(scope.engine, f->d());
-    scope.engine->pushContext(ctx);
-
-    scope.result = Q_V4_PROFILE(scope.engine, function);
-
-    if (function->hasQmlDependencies)
-        QQmlPropertyCapture::registerQmlDependencies(function->compiledFunction, scope);
-}
-
-// Do a simple, fast call with this execution context as the outer scope
-void QV4::ExecutionContext::simpleCall(Scope &scope, CallData *callData, Function *function)
-{
-    Q_ASSERT(function->canUseSimpleFunction());
-
-    ExecutionContextSaver ctxSaver(scope);
-
-    SimpleCallContext::Data *ctx = scope.engine->memoryManager->allocSimpleCallContext();
-
-    ctx->strictMode = function->isStrict();
-    ctx->callData = callData;
-    ctx->v4Function = function;
-    ctx->compilationUnit = function->compilationUnit;
-    ctx->lookups = function->compilationUnit->runtimeLookups;
-    ctx->constantTable = function->compilationUnit->constants;
-    ctx->outer.set(scope.engine, this->d());
-    for (int i = callData->argc; i < (int)function->nFormals; ++i)
-        callData->args[i] = Encode::undefined();
-
-    scope.engine->pushContext(ctx);
-    Q_ASSERT(scope.engine->current == ctx);
-
-    scope.result = Q_V4_PROFILE(scope.engine, function);
-
-    if (function->hasQmlDependencies)
-        QQmlPropertyCapture::registerQmlDependencies(function->compiledFunction, scope);
-    scope.engine->memoryManager->freeSimpleCallContext();
+    return !engine->currentStackFrame->v4Function->isStrict();
 }
 
-void ExecutionContext::setProperty(String *name, const Value &value)
+ExecutionContext::Error ExecutionContext::setProperty(String *name, const Value &value)
 {
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
+    PropertyKey id = name->toPropertyKey();
 
-    Scope scope(this);
-    ScopedContext ctx(scope, this);
-    ScopedObject activation(scope);
+    Heap::ExecutionContext *ctx = d();
+    QV4::ExecutionEngine *engine = ctx->internalClass->engine;
 
-    for (; ctx; ctx = ctx->d()->outer) {
-        activation = (Object *)0;
-        switch (ctx->d()->type) {
-        case Heap::ExecutionContext::Type_CatchContext: {
-            Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
-            if (c->exceptionVarName->isEqualTo(name->d())) {
-                    c->exceptionValue.set(scope.engine, value);
-                    return;
-            }
-            break;
-        }
+    for (; ctx; ctx = ctx->outer) {
+        switch (ctx->type) {
         case Heap::ExecutionContext::Type_WithContext: {
-            ScopedObject w(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
-            if (w->hasProperty(name)) {
-                w->put(name, value);
-                return;
+            Scope scope(engine);
+            ScopedObject w(scope, ctx->activation);
+            if (w->hasProperty(id)) {
+                bool u = ::unscopable(engine, ctx->activation, id);
+                if (engine->hasException)
+                    return TypeError;
+                if (u)
+                    break;
+                if (!w->put(name, value))
+                    return TypeError;
+                return NoError;
             }
             break;
         }
-        case Heap::ExecutionContext::Type_GlobalContext: {
-            activation = static_cast<Heap::GlobalContext *>(ctx->d())->global;
-            break;
+        case Heap::ExecutionContext::Type_BlockContext:
+        case Heap::ExecutionContext::Type_CallContext: {
+            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
+            uint index = c->internalClass->indexOfValueOrGetter(id);
+            if (index < UINT_MAX) {
+                static_cast<Heap::CallContext *>(c)->locals.set(engine, index, value);
+                return NoError;
+            }
         }
-        case Heap::ExecutionContext::Type_CallContext:
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
-            if (c->v4Function) {
-                uint index = c->v4Function->internalClass->find(id);
-                if (index < UINT_MAX) {
-                    if (index < c->v4Function->nFormals) {
-                        c->callData->args[c->v4Function->nFormals - index - 1] = value;
-                    } else {
-                        Q_ASSERT(c->type == Heap::ExecutionContext::Type_CallContext);
-                        index -= c->v4Function->nFormals;
-                        static_cast<Heap::CallContext *>(c)->locals.set(scope.engine, index, value);
-                    }
-                    return;
+            Q_FALLTHROUGH();
+        case Heap::ExecutionContext::Type_GlobalContext:
+            if (ctx->activation) {
+                auto member = ctx->activation->internalClass->findValueOrSetter(id);
+                if (member.index < UINT_MAX) {
+                    Scope scope(engine);
+                    ScopedObject a(scope, ctx->activation);
+                    if (!a->putValue(member.index, member.attrs, value))
+                        return TypeError;
+                    return NoError;
                 }
             }
-            activation = c->activation;
             break;
-        }
         case Heap::ExecutionContext::Type_QmlContext: {
-            activation = static_cast<Heap::QmlContext *>(ctx->d())->qml;
-            activation->put(name, value);
-            return;
+            Scope scope(engine);
+            ScopedObject activation(scope, ctx->activation);
+            if (!activation->put(name, value))
+                return TypeError;
+            return NoError;
         }
         }
 
-        if (activation) {
-            uint member = activation->internalClass()->find(id);
-            if (member < UINT_MAX) {
-                activation->putValue(member, value);
-                return;
-            }
-        }
     }
 
-    if (d()->strictMode || name->equals(engine()->id_this())) {
-        ScopedValue n(scope, name->asReturnedValue());
-        engine()->throwReferenceError(n);
-        return;
-    }
-    engine()->globalObject->put(name, value);
+    return RangeError;
 }
 
 ReturnedValue ExecutionContext::getProperty(String *name)
 {
-    Scope scope(this);
-    ScopedValue v(scope);
-    name->makeIdentifier();
+    PropertyKey id = name->toPropertyKey();
 
-    if (name->equals(engine()->id_this()))
-        return thisObject().asReturnedValue();
+    Heap::ExecutionContext *ctx = d();
+    QV4::ExecutionEngine *engine = ctx->internalClass->engine;
 
-    ScopedContext ctx(scope, this);
-    for (; ctx; ctx = ctx->d()->outer) {
-        switch (ctx->d()->type) {
-        case Heap::ExecutionContext::Type_CatchContext: {
-            Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
-            if (c->exceptionVarName->isEqualTo(name->d()))
-                return c->exceptionValue.asReturnedValue();
-            break;
-        }
-        case Heap::ExecutionContext::Type_WithContext: {
-            ScopedObject w(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
-            bool hasProperty = false;
-            v = w->get(name, &hasProperty);
-            if (hasProperty) {
-                return v->asReturnedValue();
-            }
-            break;
-        }
-        case Heap::ExecutionContext::Type_GlobalContext: {
-            ScopedObject global(scope, static_cast<Heap::GlobalContext *>(ctx->d())->global);
-            bool hasProperty = false;
-            v = global->get(name, &hasProperty);
-            if (hasProperty)
-                return v->asReturnedValue();
-            break;
-        }
+    for (; ctx; ctx = ctx->outer) {
+        switch (ctx->type) {
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
-            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
-            name->makeIdentifier();
-            Identifier *id = name->identifier();
+            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
 
-            uint index = c->v4Function->internalClass->find(id);
-            if (index < UINT_MAX) {
-                if (index < c->v4Function->nFormals)
-                    return c->callData->args[c->v4Function->nFormals - index - 1].asReturnedValue();
-                Q_ASSERT(c->type == Heap::ExecutionContext::Type_CallContext);
-                return c->locals[index - c->v4Function->nFormals].asReturnedValue();
-            }
-            if (c->v4Function->isNamedExpression()) {
-                if (c->function && name->equals(ScopedString(scope, c->v4Function->name())))
-                    return c->function->asReturnedValue();
-            }
+            uint index = c->internalClass->indexOfValueOrGetter(id);
+            if (index < UINT_MAX)
+                return c->locals[index].asReturnedValue();
             Q_FALLTHROUGH();
         }
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
-            ScopedObject activation(scope, c->activation);
-            if (activation) {
-                bool hasProperty = false;
-                v = activation->get(name, &hasProperty);
-                if (hasProperty)
-                    return v->asReturnedValue();
+        case Heap::ExecutionContext::Type_WithContext:
+            if (ctx->activation) {
+                Scope scope(this);
+                ScopedObject activation(scope, ctx->activation);
+                if (activation->hasProperty(id)) {
+                    bool u = ::unscopable(engine, ctx->activation, id);
+                    if (engine->hasException)
+                        return false;
+                    if (u)
+                        break;
+                    return activation->get(id);
+                }
             }
             break;
-        }
+        case Heap::ExecutionContext::Type_GlobalContext:
         case Heap::ExecutionContext::Type_QmlContext: {
-            ScopedObject qml(scope, static_cast<Heap::QmlContext *>(ctx->d())->qml);
-            bool hasProperty = false;
-            v = qml->get(name, &hasProperty);
-            if (hasProperty)
-                return v->asReturnedValue();
+            if (ctx->activation) {
+                Scope scope(this);
+                ScopedObject activation(scope, ctx->activation);
+                bool hasProperty = false;
+                ReturnedValue v = activation->get(id, nullptr, &hasProperty);
+                if (hasProperty)
+                    return v;
+            }
             break;
         }
         }
     }
-    ScopedValue n(scope, name);
-    return engine()->throwReferenceError(n);
+    return engine->throwReferenceError(*name);
 }
 
 ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Value *base)
 {
-    Scope scope(this);
-    ScopedValue v(scope);
-    base->setM(0);
-    name->makeIdentifier();
+    base->setM(nullptr);
+    PropertyKey id = name->toPropertyKey();
 
-    if (name->equals(engine()->id_this()))
-        return thisObject().asReturnedValue();
+    Heap::ExecutionContext *ctx = d();
+    QV4::ExecutionEngine *engine = ctx->internalClass->engine;
 
-    ScopedContext ctx(scope, this);
-    for (; ctx; ctx = ctx->d()->outer) {
-        switch (ctx->d()->type) {
-        case Heap::ExecutionContext::Type_CatchContext: {
-            Heap::CatchContext *c = static_cast<Heap::CatchContext *>(ctx->d());
-            if (c->exceptionVarName->isEqualTo(name->d()))
-                return c->exceptionValue.asReturnedValue();
-            break;
-        }
-        case Heap::ExecutionContext::Type_WithContext: {
-            ScopedObject w(scope, static_cast<Heap::WithContext *>(ctx->d())->withObject);
-            bool hasProperty = false;
-            v = w->get(name, &hasProperty);
-            if (hasProperty) {
-                base->setM(w->d());
-                return v->asReturnedValue();
-            }
-            break;
-        }
-        case Heap::ExecutionContext::Type_GlobalContext: {
-            ScopedObject global(scope, static_cast<Heap::GlobalContext *>(ctx->d())->global);
-            bool hasProperty = false;
-            v = global->get(name, &hasProperty);
-            if (hasProperty)
-                return v->asReturnedValue();
-            break;
-        }
+    for (; ctx; ctx = ctx->outer) {
+        switch (ctx->type) {
+        case Heap::ExecutionContext::Type_BlockContext:
         case Heap::ExecutionContext::Type_CallContext: {
-            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx->d());
-            name->makeIdentifier();
-            Identifier *id = name->identifier();
+            Heap::CallContext *c = static_cast<Heap::CallContext *>(ctx);
 
-            uint index = c->v4Function->internalClass->find(id);
-            if (index < UINT_MAX) {
-                if (index < c->v4Function->nFormals)
-                    return c->callData->args[c->v4Function->nFormals - index - 1].asReturnedValue();
-                return c->locals[index - c->v4Function->nFormals].asReturnedValue();
-            }
-            if (c->v4Function->isNamedExpression()) {
-                if (c->function && name->equals(ScopedString(scope, c->v4Function->name())))
-                    return c->function->asReturnedValue();
-            }
+            uint index = c->internalClass->indexOfValueOrGetter(id);
+            if (index < UINT_MAX)
+                return c->locals[index].asReturnedValue();
             Q_FALLTHROUGH();
         }
-        case Heap::ExecutionContext::Type_SimpleCallContext: {
-            Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
-            ScopedObject activation(scope, c->activation);
-            if (activation) {
+        case Heap::ExecutionContext::Type_GlobalContext: {
+            if (ctx->activation) {
+                Scope scope(this);
+                ScopedObject activation(scope, ctx->activation);
                 bool hasProperty = false;
-                v = activation->get(name, &hasProperty);
+                ReturnedValue v = activation->get(name, &hasProperty);
                 if (hasProperty)
-                    return v->asReturnedValue();
+                    return v;
             }
             break;
         }
+        case Heap::ExecutionContext::Type_WithContext:
+            if (ctx->activation) {
+                Scope scope(this);
+                ScopedObject activation(scope, ctx->activation);
+                if (activation->hasProperty(id)) {
+                    bool u = ::unscopable(engine, ctx->activation, id);
+                    if (engine->hasException)
+                        return false;
+                    if (u)
+                        break;
+                    base->setM(activation->d());
+                    return activation->get(id);
+                }
+            }
+            break;
         case Heap::ExecutionContext::Type_QmlContext: {
-            ScopedObject qml(scope, static_cast<Heap::QmlContext *>(ctx->d())->qml);
+            Scope scope(this);
+            ScopedObject o(scope, ctx->activation);
             bool hasProperty = false;
-            v = qml->get(name, &hasProperty);
+            ReturnedValue v = o->get(id, nullptr, &hasProperty);
             if (hasProperty) {
-                base->setM(qml->d());
-                return v->asReturnedValue();
+                base->setM(o->d());
+                return v;
             }
             break;
         }
         }
     }
-    ScopedValue n(scope, name);
-    return engine()->throwReferenceError(n);
+    return engine->throwReferenceError(*name);
 }
 
-Function *ExecutionContext::getFunction() const
+void Heap::CallContext::setArg(uint index, Value v)
 {
-    Scope scope(engine());
-    ScopedContext it(scope, this->d());
-    for (; it; it = it->d()->outer) {
-        if (const SimpleCallContext *callCtx = it->asSimpleCallContext())
-            return callCtx->d()->v4Function;
-        else if (it->asCatchContext() || it->asWithContext())
-            continue; // look in the parent context for a FunctionObject
-        else
-            break;
-    }
-
-    return 0;
+    locals.set(internalClass->engine, locals.size + index, v);
 }
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index a854c324d0..75fa2d08e6 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -55,72 +55,24 @@
 
 QT_BEGIN_NAMESPACE
 
-class QObject;
-class QQmlContextData;
-
 namespace QV4 {
 
-namespace CompiledData {
-struct CompilationUnitBase;
-struct Function;
-}
-
-struct Function;
-struct Identifier;
-struct CallContext;
-struct SimpleCallContext;
-struct CatchContext;
-struct WithContext;
-struct QmlContext;
-struct QQmlContextWrapper;
-
-// Attention: Make sure that this structure is the same size on 32-bit and 64-bit
-// architecture or you'll have to change the JIT code.
-struct CallData
-{
-    // below is to be compatible with Value. Initialize tag to 0
-#if Q_BYTE_ORDER != Q_LITTLE_ENDIAN
-    uint tag;
-#endif
-    int argc;
-#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
-    uint tag;
-#endif
-    inline ReturnedValue argument(int i) const {
-        return i < argc ? args[i].asReturnedValue() : Primitive::undefinedValue().asReturnedValue();
-    }
-
-    Value thisObject;
-    Value args[1];
-};
-
-Q_STATIC_ASSERT(std::is_standard_layout<CallData>::value);
-Q_STATIC_ASSERT(offsetof(CallData, thisObject) == 8);
-Q_STATIC_ASSERT(offsetof(CallData, args) == 16);
 
 namespace Heap {
 
-struct QmlContext;
-
 #define ExecutionContextMembers(class, Member) \
-    Member(class, NoMark, CallData *, callData)  \
     Member(class, Pointer, ExecutionContext *, outer) \
-    Member(class, NoMark, Lookup *, lookups) \
-    Member(class, NoMark, const QV4::Value *, constantTable) \
-    Member(class, NoMark, CompiledData::CompilationUnitBase *, compilationUnit) \
-    Member(class, NoMark, int, lineNumber) // as member of non-pointer size this has to come last to preserve the ability to
-                                           // translate offsetof of it between 64-bit and 32-bit.
+    Member(class, Pointer, Object *, activation)
 
 DECLARE_HEAP_OBJECT(ExecutionContext, Base) {
-    DECLARE_MARK_TABLE(ExecutionContext);
+    DECLARE_MARKOBJECTS(ExecutionContext);
 
     enum ContextType {
         Type_GlobalContext = 0x1,
-        Type_CatchContext = 0x2,
-        Type_WithContext = 0x3,
-        Type_QmlContext = 0x4,
-        Type_SimpleCallContext = 0x5,
-        Type_CallContext = 0x6
+        Type_WithContext = 0x2,
+        Type_QmlContext = 0x3,
+        Type_BlockContext = 0x4,
+        Type_CallContext = 0x5
     };
 
     void init(ContextType t)
@@ -128,104 +80,62 @@ DECLARE_HEAP_OBJECT(ExecutionContext, Base) {
         Base::init();
 
         type = t;
-        lineNumber = -1;
     }
 
-    quint8 type;
-    bool strictMode : 8;
+    const VTable *vtable() const {
+        return internalClass->vtable;
+    }
+
+    quint32 type : 8;
+    quint32 nArgs : 24;
 #if QT_POINTER_SIZE == 8
-    quint8 padding_[6];
-#else
-    quint8 padding_[2];
+    quint8 padding_[4];
 #endif
 };
-V4_ASSERT_IS_TRIVIAL(ExecutionContext)
+Q_STATIC_ASSERT(std::is_trivial< ExecutionContext >::value);
 Q_STATIC_ASSERT(sizeof(ExecutionContext) == sizeof(Base) + sizeof(ExecutionContextData) + QT_POINTER_SIZE);
 
 Q_STATIC_ASSERT(std::is_standard_layout<ExecutionContextData>::value);
-Q_STATIC_ASSERT(offsetof(ExecutionContextData, callData) == 0);
-Q_STATIC_ASSERT(offsetof(ExecutionContextData, outer) == offsetof(ExecutionContextData, callData) + QT_POINTER_SIZE);
-Q_STATIC_ASSERT(offsetof(ExecutionContextData, lookups) == offsetof(ExecutionContextData, outer) + QT_POINTER_SIZE);
-Q_STATIC_ASSERT(offsetof(ExecutionContextData, constantTable) == offsetof(ExecutionContextData, lookups) + QT_POINTER_SIZE);
-Q_STATIC_ASSERT(offsetof(ExecutionContextData, compilationUnit) == offsetof(ExecutionContextData, constantTable) + QT_POINTER_SIZE);
-Q_STATIC_ASSERT(offsetof(ExecutionContextData, lineNumber) == offsetof(ExecutionContextData, compilationUnit) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, outer) == 0);
+Q_STATIC_ASSERT(offsetof(ExecutionContextData, activation) == offsetof(ExecutionContextData, outer) + QT_POINTER_SIZE);
 
-#define SimpleCallContextMembers(class, Member) \
-    Member(class, Pointer, Object *, activation) \
-    Member(class, NoMark, QV4::Function *, v4Function)
+#define CallContextMembers(class, Member) \
+    Member(class, Pointer, FunctionObject *, function) \
+    Member(class, ValueArray, ValueArray, locals)
 
-DECLARE_HEAP_OBJECT(SimpleCallContext, ExecutionContext) {
-    DECLARE_MARK_TABLE(SimpleCallContext);
+DECLARE_HEAP_OBJECT(CallContext, ExecutionContext) {
+    DECLARE_MARKOBJECTS(CallContext);
 
-    void init(ContextType t = Type_SimpleCallContext)
+    void init()
     {
-        ExecutionContext::init(t);
+        ExecutionContext::init(Type_CallContext);
     }
 
-    inline unsigned int formalParameterCount() const;
-
-};
-V4_ASSERT_IS_TRIVIAL(SimpleCallContext)
-Q_STATIC_ASSERT(std::is_standard_layout<SimpleCallContextData>::value);
-Q_STATIC_ASSERT(offsetof(SimpleCallContextData, activation) == 0);
-Q_STATIC_ASSERT(offsetof(SimpleCallContextData, v4Function) == offsetof(SimpleCallContextData, activation) + QT_POINTER_SIZE);
-Q_STATIC_ASSERT(sizeof(SimpleCallContextData) == 2 * QT_POINTER_SIZE);
-Q_STATIC_ASSERT(sizeof(SimpleCallContext) == sizeof(ExecutionContext) + sizeof(SimpleCallContextData));
-
-#if QT_POINTER_SIZE == 8
-#define CallContextMembers(class, Member) \
-    Member(class, Pointer, FunctionObject *, function) \
-    Member(class, ValueArray, ValueArray, locals)
-#else
-#define CallContextMembers(class, Member) \
-    Member(class, Pointer, FunctionObject *, function) \
-    Member(class, NoMark, void *, padding) \
-    Member(class, ValueArray, ValueArray, locals)
-#endif
-
-DECLARE_HEAP_OBJECT(CallContext, SimpleCallContext) {
-    DECLARE_MARK_TABLE(CallContext);
+    int argc() const {
+        return static_cast<int>(nArgs);
+    }
+    const Value *args() const {
+        return locals.data() + locals.size;
+    }
+    void setArg(uint index, Value v);
 
-    using SimpleCallContext::formalParameterCount;
+    template <typename BlockOrFunction>
+    void setupLocalTemporalDeadZone(BlockOrFunction *bof) {
+        for (uint i = bof->nLocals - bof->sizeOfLocalTemporalDeadZone; i < bof->nLocals; ++i)
+            locals.values[i] = Value::emptyValue();
+    }
 };
-
+Q_STATIC_ASSERT(std::is_trivial< CallContext >::value);
 Q_STATIC_ASSERT(std::is_standard_layout<CallContextData>::value);
 Q_STATIC_ASSERT(offsetof(CallContextData, function) == 0);
-// IMPORTANT: we cannot do offsetof(CallContextData, locals) in the JIT as the offset does not scale with
-// the pointer size. On 32-bit ARM the offset of the ValueArray is aligned to 8 bytes, on 32-bit x86 for
-// example it is not. Therefore we have a padding in place and always have a distance of 8 bytes.
-Q_STATIC_ASSERT(offsetof(CallContextData, locals) == offsetof(CallContextData, function) + 8);
-
-#define GlobalContextMembers(class, Member) \
-    Member(class, Pointer, Object *, global)
-
-DECLARE_HEAP_OBJECT(GlobalContext, ExecutionContext) {
-    DECLARE_MARK_TABLE(GlobalContext);
+//### The following size check fails on Win8. With the ValueArray at the end of the
+// CallContextMembers, it doesn't look very useful.
+//#if defined(Q_PROCESSOR_ARM_32) && !defined(Q_OS_IOS)
+//Q_STATIC_ASSERT(sizeof(CallContext) == sizeof(ExecutionContext) + sizeof(CallContextData) + QT_POINTER_SIZE);
+//#else
+//Q_STATIC_ASSERT(sizeof(CallContext) == sizeof(ExecutionContext) + sizeof(CallContextData));
+//#endif
 
-    void init(ExecutionEngine *engine);
-};
-V4_ASSERT_IS_TRIVIAL(GlobalContext)
-
-#define CatchContextMembers(class, Member) \
-    Member(class, Pointer, String *, exceptionVarName) \
-    Member(class, HeapValue, HeapValue, exceptionValue)
-
-DECLARE_HEAP_OBJECT(CatchContext, ExecutionContext) {
-    DECLARE_MARK_TABLE(CatchContext);
-
-    void init(ExecutionContext *outerContext, String *exceptionVarName, const Value &exceptionValue);
-};
-V4_ASSERT_IS_TRIVIAL(CatchContext)
-
-#define WithContextMembers(class, Member) \
-    Member(class, Pointer, Object *, withObject)
-
-DECLARE_HEAP_OBJECT(WithContext, ExecutionContext) {
-    DECLARE_MARK_TABLE(WithContext);
-
-    void init(ExecutionContext *outerContext, Object *with);
-};
-V4_ASSERT_IS_TRIVIAL(WithContext)
 
 }
 
@@ -239,98 +149,58 @@ struct Q_QML_EXPORT ExecutionContext : public Managed
     Q_MANAGED_TYPE(ExecutionContext)
     V4_INTERNALCLASS(ExecutionContext)
 
-    Heap::CallContext *newCallContext(Function *f, CallData *callData);
-    Heap::WithContext *newWithContext(Heap::Object *with);
-    Heap::CatchContext *newCatchContext(Heap::String *exceptionVarName, ReturnedValue exceptionValue);
+    static Heap::CallContext *newBlockContext(QV4::CppStackFrame *frame, int blockIndex);
+    static Heap::CallContext *cloneBlockContext(ExecutionEngine *engine,
+                                                Heap::CallContext *callContext);
+    static Heap::CallContext *newCallContext(QV4::CppStackFrame *frame);
+    Heap::ExecutionContext *newWithContext(Heap::Object *with) const;
+    static Heap::ExecutionContext *newCatchContext(CppStackFrame *frame, int blockIndex, Heap::String *exceptionVarName);
 
     void createMutableBinding(String *name, bool deletable);
 
-    void setProperty(String *name, const Value &value);
+    enum Error {
+        NoError,
+        TypeError,
+        RangeError
+    };
+
+    Error setProperty(String *name, const Value &value);
+
     ReturnedValue getProperty(String *name);
     ReturnedValue getPropertyAndBase(String *name, Value *base);
     bool deleteProperty(String *name);
 
-    inline SimpleCallContext *asSimpleCallContext();
-    inline const SimpleCallContext *asSimpleCallContext() const;
-    inline const CatchContext *asCatchContext() const;
-    inline const WithContext *asWithContext() const;
-
-    Function *getFunction() const;
+    inline CallContext *asCallContext();
+    inline const CallContext *asCallContext() const;
 
-    Value &thisObject() const {
-        return d()->callData->thisObject;
-    }
-    int argc() const {
-        return d()->callData->argc;
+protected:
+    // vtable method required for compilation
+    static bool virtualDeleteProperty(Managed *, PropertyKey) {
+        Q_UNREACHABLE();
     }
-    const Value *args() const {
-        return d()->callData->args;
-    }
-    ReturnedValue argument(int i) const {
-        return d()->callData->argument(i);
-    }
-
-    void call(Scope &scope, CallData *callData, QV4::Function *function, const QV4::FunctionObject *f = 0);
-    void simpleCall(Scope &scope, CallData *callData, QV4::Function *function);
-};
-
-struct Q_QML_EXPORT SimpleCallContext : public ExecutionContext
-{
-    V4_MANAGED(SimpleCallContext, ExecutionContext)
-    V4_INTERNALCLASS(SimpleCallContext)
-
-    // formals are in reverse order
-    Identifier * const *formals() const;
-    unsigned int formalCount() const;
-    Identifier * const *variables() const;
-    unsigned int variableCount() const;
-
-    inline ReturnedValue argument(int i) const;
-};
-
-inline ReturnedValue SimpleCallContext::argument(int i) const {
-    return i < argc() ? args()[i].asReturnedValue() : Primitive::undefinedValue().asReturnedValue();
-}
-
-struct Q_QML_EXPORT CallContext : public SimpleCallContext
-{
-    V4_MANAGED(CallContext, SimpleCallContext)
-};
-
-struct GlobalContext : public ExecutionContext
-{
-    V4_MANAGED(GlobalContext, ExecutionContext)
-
 };
 
-struct CatchContext : public ExecutionContext
+struct Q_QML_EXPORT CallContext : public ExecutionContext
 {
-    V4_MANAGED(CatchContext, ExecutionContext)
-};
+    V4_MANAGED(CallContext, ExecutionContext)
+    V4_INTERNALCLASS(CallContext)
 
-struct WithContext : public ExecutionContext
-{
-    V4_MANAGED(WithContext, ExecutionContext)
+    int argc() const {
+        return d()->argc();
+    }
+    const Value *args() const {
+        return d()->args();
+    }
 };
 
-inline SimpleCallContext *ExecutionContext::asSimpleCallContext()
-{
-    return d()->type >= Heap::ExecutionContext::Type_SimpleCallContext ? static_cast<SimpleCallContext *>(this) : 0;
-}
-
-inline const SimpleCallContext *ExecutionContext::asSimpleCallContext() const
-{
-    return d()->type >= Heap::ExecutionContext::Type_SimpleCallContext ? static_cast<const SimpleCallContext *>(this) : 0;
-}
-
-inline const CatchContext *ExecutionContext::asCatchContext() const
+inline CallContext *ExecutionContext::asCallContext()
 {
-    return d()->type == Heap::ExecutionContext::Type_CatchContext ? static_cast<const CatchContext *>(this) : 0;
+    return d()->type == Heap::ExecutionContext::Type_CallContext ? static_cast<CallContext *>(this) : nullptr;
 }
 
-inline const WithContext *ExecutionContext::asWithContext() const
+inline const CallContext *ExecutionContext::asCallContext() const
 {
-    return d()->type == Heap::ExecutionContext::Type_WithContext ? static_cast<const WithContext *>(this) : 0;
+    return d()->type == Heap::ExecutionContext::Type_CallContext ? static_cast<const CallContext *>(this) : nullptr;
 }
 
 } // namespace QV4
diff --git a/src/qml/jsruntime/qv4dataview.cpp b/src/qml/jsruntime/qv4dataview.cpp
index f1405e08ee..5ab8cf2dcb 100644
--- a/src/qml/jsruntime/qv4dataview.cpp
+++ b/src/qml/jsruntime/qv4dataview.cpp
@@ -40,6 +40,7 @@
 #include "qv4dataview_p.h"
 #include "qv4arraybuffer_p.h"
 #include "qv4string_p.h"
+#include "qv4symbol_p.h"
 
 #include <QtCore/private/qnumeric_p.h>
 #include "qendian.h"
@@ -54,152 +55,195 @@ void Heap::DataViewCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("DataView"));
 }
 
-void DataViewCtor::construct(const Managed *, Scope &scope, CallData *callData)
+static uint toIndex(ExecutionEngine *e, const Value &v)
 {
-    Scoped<ArrayBuffer> buffer(scope, callData->argument(0));
-    if (!buffer) {
-        scope.result = scope.engine->throwTypeError();
-        return;
+    if (v.isUndefined())
+        return 0;
+    double index = v.toInteger();
+    if (index < 0) {
+        e->throwRangeError(QStringLiteral("index out of range"));
+        return 0;
     }
+    uint idx = static_cast<uint>(index);
+    if (idx != index) {
+        e->throwRangeError(QStringLiteral("index out of range"));
+        return 0;
+    }
+    return idx;
+}
+
+ReturnedValue DataViewCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    Scope scope(f->engine());
+    Scoped<SharedArrayBuffer> buffer(scope, argc ? argv[0] : Value::undefinedValue());
+    if (!newTarget || !buffer)
+        return scope.engine->throwTypeError();
+
+    uint offset = ::toIndex(scope.engine, argc > 1 ? argv[1]: Value::undefinedValue());
+    if (scope.hasException())
+        return Encode::undefined();
+    if (buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
 
-    double bo = callData->argc > 1 ? callData->args[1].toNumber() : 0;
-    uint byteOffset = (uint)bo;
     uint bufferLength = buffer->d()->data->size;
-    double bl = callData->argc < 3 || callData->args[2].isUndefined() ? (bufferLength - bo) : callData->args[2].toNumber();
-    uint byteLength = (uint)bl;
-    if (bo != byteOffset || bl != byteLength || byteOffset + byteLength > bufferLength) {
-        scope.result = scope.engine->throwRangeError(QStringLiteral("DataView: constructor arguments out of range"));
-        return;
-    }
+    if (offset > bufferLength)
+        return scope.engine->throwRangeError(QStringLiteral("DataView: constructor arguments out of range"));
+
+    uint byteLength = (argc < 3 || argv[2].isUndefined()) ? (bufferLength - offset) : ::toIndex(scope.engine, argv[2]);
+    if (scope.hasException())
+        return Encode::undefined();
+    if (offset + byteLength > bufferLength)
+        return scope.engine->throwRangeError(QStringLiteral("DataView: constructor arguments out of range"));
 
-    Scoped<DataView> a(scope, scope.engine->memoryManager->allocObject<DataView>());
+    Scoped<DataView> a(scope, scope.engine->memoryManager->allocate<DataView>());
     a->d()->buffer.set(scope.engine, buffer->d());
     a->d()->byteLength = byteLength;
-    a->d()->byteOffset = byteOffset;
-    scope.result = a.asReturnedValue();
+    a->d()->byteOffset = offset;
+    return a.asReturnedValue();
 }
 
-void DataViewCtor::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue DataViewCtor::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
 {
-    construct(that, scope, callData);
+    return f->engine()->throwTypeError();
 }
 
 void DataViewPrototype::init(ExecutionEngine *engine, Object *ctor)
 {
     Scope scope(engine);
     ScopedObject o(scope);
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(3));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
     defineDefaultProperty(engine->id_constructor(), (o = ctor));
-    defineAccessorProperty(QStringLiteral("buffer"), method_get_buffer, 0);
-    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, 0);
-    defineAccessorProperty(QStringLiteral("byteOffset"), method_get_byteOffset, 0);
-
-    defineDefaultProperty(QStringLiteral("getInt8"), method_getChar<signed char>, 0);
-    defineDefaultProperty(QStringLiteral("getUint8"), method_getChar<unsigned char>, 0);
-    defineDefaultProperty(QStringLiteral("getInt16"), method_get<short>, 0);
-    defineDefaultProperty(QStringLiteral("getUint16"), method_get<unsigned short>, 0);
-    defineDefaultProperty(QStringLiteral("getInt32"), method_get<int>, 0);
-    defineDefaultProperty(QStringLiteral("getUint32"), method_get<unsigned int>, 0);
-    defineDefaultProperty(QStringLiteral("getFloat32"), method_getFloat<float>, 0);
-    defineDefaultProperty(QStringLiteral("getFloat64"), method_getFloat<double>, 0);
-
-    defineDefaultProperty(QStringLiteral("setInt8"), method_setChar<signed char>, 0);
-    defineDefaultProperty(QStringLiteral("setUint8"), method_setChar<unsigned char>, 0);
-    defineDefaultProperty(QStringLiteral("setInt16"), method_set<short>, 0);
-    defineDefaultProperty(QStringLiteral("setUint16"), method_set<unsigned short>, 0);
-    defineDefaultProperty(QStringLiteral("setInt32"), method_set<int>, 0);
-    defineDefaultProperty(QStringLiteral("setUint32"), method_set<unsigned int>, 0);
-    defineDefaultProperty(QStringLiteral("setFloat32"), method_setFloat<float>, 0);
-    defineDefaultProperty(QStringLiteral("setFloat64"), method_setFloat<double>, 0);
+    defineAccessorProperty(QStringLiteral("buffer"), method_get_buffer, nullptr);
+    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, nullptr);
+    defineAccessorProperty(QStringLiteral("byteOffset"), method_get_byteOffset, nullptr);
+
+    defineDefaultProperty(QStringLiteral("getInt8"), method_getChar<signed char>, 1);
+    defineDefaultProperty(QStringLiteral("getUint8"), method_getChar<unsigned char>, 1);
+    defineDefaultProperty(QStringLiteral("getInt16"), method_get<short>, 1);
+    defineDefaultProperty(QStringLiteral("getUint16"), method_get<unsigned short>, 1);
+    defineDefaultProperty(QStringLiteral("getInt32"), method_get<int>, 1);
+    defineDefaultProperty(QStringLiteral("getUint32"), method_get<unsigned int>, 1);
+    defineDefaultProperty(QStringLiteral("getFloat32"), method_getFloat<float>, 1);
+    defineDefaultProperty(QStringLiteral("getFloat64"), method_getFloat<double>, 1);
+
+    defineDefaultProperty(QStringLiteral("setInt8"), method_setChar<signed char>, 2);
+    defineDefaultProperty(QStringLiteral("setUint8"), method_setChar<unsigned char>, 2);
+    defineDefaultProperty(QStringLiteral("setInt16"), method_set<short>, 2);
+    defineDefaultProperty(QStringLiteral("setUint16"), method_set<unsigned short>, 2);
+    defineDefaultProperty(QStringLiteral("setInt32"), method_set<int>, 2);
+    defineDefaultProperty(QStringLiteral("setUint32"), method_set<unsigned int>, 2);
+    defineDefaultProperty(QStringLiteral("setFloat32"), method_setFloat<float>, 2);
+    defineDefaultProperty(QStringLiteral("setFloat64"), method_setFloat<double>, 2);
+
+    ScopedString name(scope, engine->newString(QStringLiteral("DataView")));
+    defineReadonlyConfigurableProperty(scope.engine->symbol_toStringTag(), name);
 
     // For backword compatibility
-    defineDefaultProperty(QStringLiteral("getUInt8"), method_getChar<unsigned char>, 0);
-    defineDefaultProperty(QStringLiteral("getUInt16"), method_get<unsigned short>, 0);
-    defineDefaultProperty(QStringLiteral("getUInt32"), method_get<unsigned int>, 0);
-    defineDefaultProperty(QStringLiteral("setUInt8"), method_setChar<unsigned char>, 0);
-    defineDefaultProperty(QStringLiteral("setUInt16"), method_set<unsigned short>, 0);
-    defineDefaultProperty(QStringLiteral("setUInt32"), method_set<unsigned int>, 0);
+    defineDefaultProperty(QStringLiteral("getUInt8"), method_getChar<unsigned char>, 1);
+    defineDefaultProperty(QStringLiteral("getUInt16"), method_get<unsigned short>, 1);
+    defineDefaultProperty(QStringLiteral("getUInt32"), method_get<unsigned int>, 1);
+    defineDefaultProperty(QStringLiteral("setUInt8"), method_setChar<unsigned char>, 1);
+    defineDefaultProperty(QStringLiteral("setUInt16"), method_set<unsigned short>, 1);
+    defineDefaultProperty(QStringLiteral("setUInt32"), method_set<unsigned int>, 1);
 }
 
-void DataViewPrototype::method_get_buffer(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_get_buffer(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
+    const DataView *v = thisObject->as<DataView>();
     if (!v)
-        THROW_TYPE_ERROR();
+        return b->engine()->throwTypeError();
 
-    scope.result = v->d()->buffer;
+    return v->d()->buffer->asReturnedValue();
 }
 
-void DataViewPrototype::method_get_byteLength(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_get_byteLength(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
+    const DataView *v = thisObject->as<DataView>();
     if (!v)
-        THROW_TYPE_ERROR();
+        return b->engine()->throwTypeError();
 
-    scope.result = Encode(v->d()->byteLength);
+    if (v->d()->buffer->isDetachedBuffer())
+        return b->engine()->throwTypeError();
+
+    return Encode(v->d()->byteLength);
 }
 
-void DataViewPrototype::method_get_byteOffset(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_get_byteOffset(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
+    const DataView *v = thisObject->as<DataView>();
     if (!v)
-        THROW_TYPE_ERROR();
+        return b->engine()->throwTypeError();
+
+    if (v->d()->buffer->isDetachedBuffer())
+        return b->engine()->throwTypeError();
 
-    scope.result = Encode(v->d()->byteOffset);
+    return Encode(v->d()->byteOffset);
 }
 
 template <typename T>
-void DataViewPrototype::method_getChar(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_getChar(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
-    if (!v || callData->argc < 1)
-        THROW_TYPE_ERROR();
-    double l = callData->args[0].toNumber();
-    uint idx = (uint)l;
-    if (l != idx || idx + sizeof(T) > v->d()->byteLength)
-        THROW_TYPE_ERROR();
+    ExecutionEngine *e = b->engine();
+    const DataView *v = thisObject->as<DataView>();
+    if (!v)
+        return e->throwTypeError();
+    uint idx = ::toIndex(e, argc ? argv[0] : Value::undefinedValue());
+    if (e->hasException)
+        return Encode::undefined();
+    if (v->d()->buffer->isDetachedBuffer())
+        return e->throwTypeError();
+    if (idx + sizeof(T) > v->d()->byteLength)
+        return e->throwRangeError(QStringLiteral("index out of range"));
     idx += v->d()->byteOffset;
 
     T t = T(v->d()->buffer->data->data()[idx]);
 
-    scope.result = Encode((int)t);
+    return Encode((int)t);
 }
 
 template <typename T>
-void DataViewPrototype::method_get(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_get(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
-    if (!v || callData->argc < 1)
-        THROW_TYPE_ERROR();
-    double l = callData->args[0].toNumber();
-    uint idx = (uint)l;
-    if (l != idx || idx + sizeof(T) > v->d()->byteLength)
-        THROW_TYPE_ERROR();
+    ExecutionEngine *e = b->engine();
+    const DataView *v = thisObject->as<DataView>();
+    if (!v)
+        return e->throwTypeError();
+    uint idx = ::toIndex(e, argc ? argv[0] : Value::undefinedValue());
+    if (e->hasException)
+        return Encode::undefined();
+    if (v->d()->buffer->isDetachedBuffer())
+        return e->throwTypeError();
+    if (idx + sizeof(T) > v->d()->byteLength)
+        return e->throwRangeError(QStringLiteral("index out of range"));
     idx += v->d()->byteOffset;
 
-    bool littleEndian = callData->argc < 2 ? false : callData->args[1].toBoolean();
+    bool littleEndian = argc < 2 ? false : argv[1].toBoolean();
 
     T t = littleEndian
             ? qFromLittleEndian<T>((uchar *)v->d()->buffer->data->data() + idx)
             : qFromBigEndian<T>((uchar *)v->d()->buffer->data->data() + idx);
 
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
 template <typename T>
-void DataViewPrototype::method_getFloat(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_getFloat(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
-    if (!v || callData->argc < 1)
-        THROW_TYPE_ERROR();
-    double l = callData->args[0].toNumber();
-    uint idx = (uint)l;
-    if (l != idx || idx + sizeof(T) > v->d()->byteLength)
-        THROW_TYPE_ERROR();
+    ExecutionEngine *e = b->engine();
+    const DataView *v = thisObject->as<DataView>();
+    if (!v)
+        return e->throwTypeError();
+    uint idx = ::toIndex(e, argc ? argv[0] : Value::undefinedValue());
+    if (e->hasException)
+        return Encode::undefined();
+    if (v->d()->buffer->isDetachedBuffer())
+        return e->throwTypeError();
+    if (idx + sizeof(T) > v->d()->byteLength)
+        return e->throwRangeError(QStringLiteral("index out of range"));
     idx += v->d()->byteOffset;
 
-    bool littleEndian = callData->argc < 2 ? false : callData->args[1].toBoolean();
+    bool littleEndian = argc < 2 ? false : argv[1].toBoolean();
 
     if (sizeof(T) == 4) {
         // float
@@ -210,7 +254,7 @@ void DataViewPrototype::method_getFloat(const BuiltinFunction *, Scope &scope, C
         u.i = littleEndian
                 ? qFromLittleEndian<uint>((uchar *)v->d()->buffer->data->data() + idx)
                 : qFromBigEndian<uint>((uchar *)v->d()->buffer->data->data() + idx);
-        scope.result = Encode(u.f);
+        return Encode(u.f);
     } else {
         Q_ASSERT(sizeof(T) == 8);
         union {
@@ -220,43 +264,56 @@ void DataViewPrototype::method_getFloat(const BuiltinFunction *, Scope &scope, C
         u.i = littleEndian
                 ? qFromLittleEndian<quint64>((uchar *)v->d()->buffer->data->data() + idx)
                 : qFromBigEndian<quint64>((uchar *)v->d()->buffer->data->data() + idx);
-        scope.result = Encode(u.d);
+        return Encode(u.d);
     }
 }
 
 template <typename T>
-void DataViewPrototype::method_setChar(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_setChar(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
-    if (!v || callData->argc < 1)
-        THROW_TYPE_ERROR();
-    double l = callData->args[0].toNumber();
-    uint idx = (uint)l;
-    if (l != idx || idx + sizeof(T) > v->d()->byteLength)
-        THROW_TYPE_ERROR();
+    ExecutionEngine *e = b->engine();
+    const DataView *v = thisObject->as<DataView>();
+    if (!v)
+        return e->throwTypeError();
+    uint idx = ::toIndex(e, argc ? argv[0] : Value::undefinedValue());
+    if (e->hasException)
+        return Encode::undefined();
+
+    int val = argc >= 2 ? argv[1].toInt32() : 0;
+
+    if (v->d()->buffer->isDetachedBuffer())
+        return e->throwTypeError();
+
+    if (idx + sizeof(T) > v->d()->byteLength)
+        return e->throwRangeError(QStringLiteral("index out of range"));
     idx += v->d()->byteOffset;
 
-    int val = callData->argc >= 2 ? callData->args[1].toInt32() : 0;
     v->d()->buffer->data->data()[idx] = (char)val;
 
     RETURN_UNDEFINED();
 }
 
 template <typename T>
-void DataViewPrototype::method_set(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_set(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
-    if (!v || callData->argc < 1)
-        THROW_TYPE_ERROR();
-    double l = callData->args[0].toNumber();
-    uint idx = (uint)l;
-    if (l != idx || idx + sizeof(T) > v->d()->byteLength)
-        THROW_TYPE_ERROR();
-    idx += v->d()->byteOffset;
+    ExecutionEngine *e = b->engine();
+    const DataView *v = thisObject->as<DataView>();
+    if (!v)
+        return e->throwTypeError();
+    uint idx = ::toIndex(e, argc ? argv[0] : Value::undefinedValue());
+    if (e->hasException)
+        return Encode::undefined();
+
+    int val = argc >= 2 ? argv[1].toInt32() : 0;
+    bool littleEndian = argc < 3 ? false : argv[2].toBoolean();
 
-    int val = callData->argc >= 2 ? callData->args[1].toInt32() : 0;
+    if (v->d()->buffer->isDetachedBuffer())
+        return e->throwTypeError();
+
+    if (idx + sizeof(T) > v->d()->byteLength)
+        return e->throwRangeError(QStringLiteral("index out of range"));
+    idx += v->d()->byteOffset;
 
-    bool littleEndian = callData->argc < 3 ? false : callData->args[2].toBoolean();
 
     if (littleEndian)
         qToLittleEndian<T>(val, (uchar *)v->d()->buffer->data->data() + idx);
@@ -267,19 +324,25 @@ void DataViewPrototype::method_set(const BuiltinFunction *, Scope &scope, CallDa
 }
 
 template <typename T>
-void DataViewPrototype::method_setFloat(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DataViewPrototype::method_setFloat(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DataView> v(scope, callData->thisObject);
-    if (!v || callData->argc < 1)
-        THROW_TYPE_ERROR();
-    double l = callData->args[0].toNumber();
-    uint idx = (uint)l;
-    if (l != idx || idx + sizeof(T) > v->d()->byteLength)
-        THROW_TYPE_ERROR();
-    idx += v->d()->byteOffset;
+    ExecutionEngine *e = b->engine();
+    const DataView *v = thisObject->as<DataView>();
+    if (!v)
+        return e->throwTypeError();
+    uint idx = ::toIndex(e, argc ? argv[0] : Value::undefinedValue());
+    if (e->hasException)
+        return Encode::undefined();
 
-    double val = callData->argc >= 2 ? callData->args[1].toNumber() : qt_qnan();
-    bool littleEndian = callData->argc < 3 ? false : callData->args[2].toBoolean();
+    double val = argc >= 2 ? argv[1].toNumber() : qt_qnan();
+    bool littleEndian = argc < 3 ? false : argv[2].toBoolean();
+
+    if (v->d()->buffer->isDetachedBuffer())
+        return e->throwTypeError();
+
+    if (idx + sizeof(T) > v->d()->byteLength)
+        return e->throwRangeError(QStringLiteral("index out of range"));
+    idx += v->d()->byteOffset;
 
     if (sizeof(T) == 4) {
         // float
diff --git a/src/qml/jsruntime/qv4dataview_p.h b/src/qml/jsruntime/qv4dataview_p.h
index 5c50df4655..199a6f9f80 100644
--- a/src/qml/jsruntime/qv4dataview_p.h
+++ b/src/qml/jsruntime/qv4dataview_p.h
@@ -64,12 +64,12 @@ struct DataViewCtor : FunctionObject {
 };
 
 #define DataViewMembers(class, Member) \
-    Member(class, Pointer, ArrayBuffer *, buffer) \
+    Member(class, Pointer, SharedArrayBuffer *, buffer) \
     Member(class, NoMark, uint, byteLength) \
     Member(class, NoMark, uint, byteOffset)
 
 DECLARE_HEAP_OBJECT(DataView, Object) {
-    DECLARE_MARK_TABLE(DataView);
+    DECLARE_MARKOBJECTS(DataView);
     void init() { Object::init(); }
 };
 
@@ -79,8 +79,8 @@ struct DataViewCtor: FunctionObject
 {
     V4_OBJECT2(DataViewCtor, FunctionObject)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct DataView : Object
@@ -93,21 +93,21 @@ struct DataViewPrototype: Object
 {
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_get_buffer(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_byteLength(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_byteOffset(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_get_buffer(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_byteLength(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_byteOffset(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     template <typename T>
-    static void method_getChar(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_getChar(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     template <typename T>
-    static void method_get(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_get(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     template <typename T>
-    static void method_getFloat(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_getFloat(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     template <typename T>
-    static void method_setChar(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_setChar(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     template <typename T>
-    static void method_set(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_set(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     template <typename T>
-    static void method_setFloat(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_setFloat(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 
diff --git a/src/qml/jsruntime/qv4dateobject.cpp b/src/qml/jsruntime/qv4dateobject.cpp
index c56d007028..21c6a5d06b 100644
--- a/src/qml/jsruntime/qv4dateobject.cpp
+++ b/src/qml/jsruntime/qv4dateobject.cpp
@@ -43,6 +43,8 @@
 #include "qv4scopedvalue_p.h"
 #include "qv4runtime_p.h"
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
+#include "qv4symbol_p.h"
 
 #include <QtCore/QDebug>
 #include <QtCore/QDateTime>
@@ -54,16 +56,29 @@
 
 #include <wtf/MathExtras.h>
 
-#ifdef Q_OS_WIN
-#  include <windows.h>
+#if defined(Q_OS_LINUX) && QT_CONFIG(timezone)
+/*
+  See QTBUG-56899.  Although we don't (yet) have a proper way to reset the
+  system zone, the code below, that uses QTimeZone::systemTimeZone(), works
+  adequately on Linux, when the TZ environment variable is changed.
+ */
+#define USE_QTZ_SYSTEM_ZONE
+#endif
+
+#ifdef USE_QTZ_SYSTEM_ZONE
+#include <QtCore/QTimeZone>
 #else
-#  ifndef Q_OS_VXWORKS
-#    include <sys/time.h>
+#  ifdef Q_OS_WIN
+#    include <windows.h>
 #  else
-#    include "qplatformdefs.h"
+#    ifndef Q_OS_VXWORKS
+#      include <sys/time.h>
+#    else
+#      include "qplatformdefs.h"
+#    endif
+#    include <unistd.h> // for _POSIX_THREAD_SAFE_FUNCTIONS
 #  endif
-#  include <unistd.h> // for _POSIX_THREAD_SAFE_FUNCTIONS
-#endif
+#endif // USE_QTZ_SYSTEM_ZONE
 
 using namespace QV4;
 
@@ -75,8 +90,6 @@ static const double msPerMinute = 60000.0;
 static const double msPerHour = 3600000.0;
 static const double msPerDay = 86400000.0;
 
-static double LocalTZA = 0.0; // initialized at startup
-
 static inline double TimeWithinDay(double t)
 {
     double r = ::fmod(t, msPerDay);
@@ -209,7 +222,7 @@ static inline double MonthFromTime(double t)
 
 static inline double DateFromTime(double t)
 {
-    int m = (int) Primitive::toInteger(MonthFromTime(t));
+    int m = (int) QV4::Value::toInteger(MonthFromTime(t));
     double d = DayWithinYear(t);
     double l = InLeapYear(t);
 
@@ -240,6 +253,12 @@ static inline double WeekDay(double t)
 
 static inline double MakeTime(double hour, double min, double sec, double ms)
 {
+    if (!qIsFinite(hour) || !qIsFinite(min) || !qIsFinite(sec) || !qIsFinite(ms))
+        return qQNaN();
+    hour = QV4::Value::toInteger(hour);
+    min = QV4::Value::toInteger(min);
+    sec = QV4::Value::toInteger(sec);
+    ms = QV4::Value::toInteger(ms);
     return ((hour * MinutesPerHour + min) * SecondsPerMinute + sec) * msPerSecond + ms;
 }
 
@@ -265,6 +284,12 @@ static inline double DayFromMonth(double month, double leap)
 
 static double MakeDay(double year, double month, double day)
 {
+    if (!qIsFinite(year) || !qIsFinite(month) || !qIsFinite(day))
+        return qQNaN();
+    year = QV4::Value::toInteger(year);
+    month = QV4::Value::toInteger(month);
+    day = QV4::Value::toInteger(day);
+
     year += ::floor(month / 12.0);
 
     month = ::fmod(month, 12.0);
@@ -285,10 +310,35 @@ static inline double MakeDate(double day, double time)
     return day * msPerDay + time;
 }
 
-static inline double DaylightSavingTA(double t)
+#ifdef USE_QTZ_SYSTEM_ZONE
+/*
+  ECMAScript specifies use of a fixed (current, standard) time-zone offset,
+  LocalTZA; and LocalTZA + DaylightSavingTA(t) is taken to be (see LocalTime and
+  UTC, following) local time's offset from UTC at time t.  For simple zones,
+  DaylightSavingTA(t) is thus the DST offset applicable at date/time t; however,
+  if a zone has changed its standard offset, the only way to make LocalTime and
+  UTC (if implemented in accord with the spec) perform correct transformations
+  is to have DaylightSavingTA(t) correct for the zone's standard offset change
+  as well as its actual DST offset.
+
+  This means we have to treat any historical changes in the zone's standard
+  offset as DST perturbations, regardless of historical reality.  (This shall
+  mean a whole day of DST offset for some zones, that have crossed the
+  international date line.  This shall confuse client code.)  The bug report
+  against the ECMAScript spec is https://github.com/tc39/ecma262/issues/725
+*/
+
+static inline double DaylightSavingTA(double t, double localTZA) // t is a UTC time
+{
+    return QTimeZone::systemTimeZone().offsetFromUtc(
+        QDateTime::fromMSecsSinceEpoch(qint64(t), Qt::UTC)) * 1e3 - localTZA;
+}
+#else
+// This implementation fails to take account of past changes in standard offset.
+static inline double DaylightSavingTA(double t, double /*localTZA*/)
 {
     struct tm tmtm;
-#if defined(_MSC_VER) && _MSC_VER >= 1400
+#if defined(Q_CC_MSVC)
     __time64_t  tt = (__time64_t)(t / msPerSecond);
     // _localtime_64_s returns non-zero on failure
     if (_localtime64_s(&tmtm, &tt) != 0)
@@ -306,34 +356,26 @@ static inline double DaylightSavingTA(double t)
         return 0;
     return (tmtm.tm_isdst > 0) ? msPerHour : 0;
 }
+#endif // USE_QTZ_SYSTEM_ZONE
 
-static inline double LocalTime(double t)
+static inline double LocalTime(double t, double localTZA)
 {
-    return t + LocalTZA + DaylightSavingTA(t);
+    // Flawed, yet verbatim from the spec:
+    return t + localTZA + DaylightSavingTA(t, localTZA);
 }
 
-static inline double UTC(double t)
+// The spec does note [*] that UTC and LocalTime are not quite mutually inverse.
+// [*] http://www.ecma-international.org/ecma-262/7.0/index.html#sec-utc-t
+
+static inline double UTC(double t, double localTZA)
 {
-    return t - LocalTZA - DaylightSavingTA(t - LocalTZA);
+    // Flawed, yet verbatim from the spec:
+    return t - localTZA - DaylightSavingTA(t - localTZA, localTZA);
 }
 
 static inline double currentTime()
 {
-#ifndef Q_OS_WIN
-    struct timeval tv;
-
-    gettimeofday(&tv, 0);
-    return ::floor(tv.tv_sec * msPerSecond + (tv.tv_usec / 1000.0));
-#else
-    SYSTEMTIME st;
-    GetSystemTime(&st);
-    FILETIME ft;
-    SystemTimeToFileTime(&st, &ft);
-    LARGE_INTEGER li;
-    li.LowPart = ft.dwLowDateTime;
-    li.HighPart = ft.dwHighDateTime;
-    return double(li.QuadPart - Q_INT64_C(116444736000000000)) / 10000.0;
-#endif
+    return QDateTime::currentDateTimeUtc().toMSecsSinceEpoch();
 }
 
 static inline double TimeClip(double t)
@@ -342,18 +384,25 @@ static inline double TimeClip(double t)
         return qt_qnan();
 
     // +0 looks weird, but is correct. See ES6 20.3.1.15. We must not return -0.
-    return Primitive::toInteger(t) + 0;
+    return QV4::Value::toInteger(t) + 0;
 }
 
-static inline double ParseString(const QString &s)
+static inline double ParseString(const QString &s, double localTZA)
 {
-    // first try the format defined in 15.9.1.15, only if that fails fall back to
-    // QDateTime for parsing
+    /*
+      First, try the format defined in ECMA 262's "Date Time String Format";
+      only if that fails, fall back to QDateTime for parsing
 
-    // the define string format is YYYY-MM-DDTHH:mm:ss.sssZ
-    // It can be date or time only, and the second and later components
-    // of both fields are optional
-    // and extended syntax for negative and large positive years exists: +/-YYYYYY
+      The defined string format is YYYY-MM-DDTHH:mm:ss.sssZ; the time (T and all
+      after it) may be omitted; in each part, the second and later components
+      are optional; and there's an extended syntax for negative and large
+      positive years: +/-YYYYYY; the leading sign, even when +, isn't optional.
+      If month or day is omitted, it is 01; if minute or second is omitted, it's
+      00; if milliseconds are omitted, they're 000.
+
+      When the time zone offset is absent, date-only forms are interpreted as
+      indicating a UTC time and date-time forms are interpreted in local time.
+    */
 
     enum Format {
         Year,
@@ -386,6 +435,8 @@ static inline double ParseString(const QString &s)
     int msec = 0;
     int offsetSign = 1;
     int offset = 0;
+    bool seenT = false;
+    bool seenZ = false; // Have seen zone, i.e. +HH:mm or literal Z.
 
     bool error = false;
     if (*ch == '+' || *ch == '-') {
@@ -394,7 +445,7 @@ static inline double ParseString(const QString &s)
             yearSign = -1;
         ++ch;
     }
-    while (ch <= end) {
+    for (; ch <= end && !error && format != Done; ++ch) {
         if (*ch >= '0' && *ch <= '9') {
             current *= 10;
             current += ch->unicode() - '0';
@@ -422,7 +473,7 @@ static inline double ParseString(const QString &s)
                 break;
             case Minute:
                 minute = current;
-                error = (currentSize != 2) || minute > 60;
+                error = (currentSize != 2) || minute >= 60;
                 break;
             case Second:
                 second = current;
@@ -433,8 +484,10 @@ static inline double ParseString(const QString &s)
                 error = (currentSize != 3);
                 break;
             case TimezoneHour:
-                offset = current*60;
-                error = (currentSize != 2) || offset > 23*60;
+                Q_ASSERT(offset == 0 && !seenZ);
+                offset = current * 60;
+                error = (currentSize != 2) || current > 23;
+                seenZ = true;
                 break;
             case TimezoneMinute:
                 offset += current;
@@ -445,6 +498,7 @@ static inline double ParseString(const QString &s)
                 if (format >= Hour)
                     error = true;
                 format = Hour;
+                seenT = true;
             } else if (*ch == '-') {
                 if (format < Day)
                     ++format;
@@ -453,6 +507,7 @@ static inline double ParseString(const QString &s)
                 else if (format >= TimezoneHour)
                     error = true;
                 else {
+                    Q_ASSERT(offset == 0 && !seenZ);
                     offsetSign = -1;
                     format = TimezoneHour;
                 }
@@ -465,24 +520,32 @@ static inline double ParseString(const QString &s)
                     error = true;
                 ++format;
             } else if (*ch == '+') {
-                if (format < Minute || format >= TimezoneHour)
+                if (seenZ || format < Minute || format >= TimezoneHour)
                     error = true;
                 format = TimezoneHour;
-            } else if (*ch == 'Z' || ch->unicode() == 0) {
+            } else if (*ch == 'Z') {
+                if (seenZ || format < Minute || format >= TimezoneHour)
+                    error = true;
+                else
+                    Q_ASSERT(offset == 0);
+                format = Done;
+                seenZ = true;
+            } else if (ch->unicode() == 0) {
                 format = Done;
             }
             current = 0;
             currentSize = 0;
         }
-        if (error || format == Done)
-            break;
-        ++ch;
     }
 
     if (!error) {
         double t = MakeDate(MakeDay(year * yearSign, month, day), MakeTime(hour, minute, second, msec));
-        t -= offset * offsetSign * 60 * 1000;
-        return t;
+        if (seenZ)
+            t -= offset * offsetSign * 60 * 1000;
+        else if (seenT) // No zone specified, treat date-time as local time
+            t = UTC(t, localTZA);
+        // else: treat plain date as already in UTC
+        return TimeClip(t);
     }
 
     QDateTime dt = QDateTime::fromString(s, Qt::TextDate);
@@ -491,63 +554,68 @@ static inline double ParseString(const QString &s)
     if (!dt.isValid())
         dt = QDateTime::fromString(s, Qt::RFC2822Date);
     if (!dt.isValid()) {
-        QStringList formats;
-        formats << QStringLiteral("M/d/yyyy")
-                << QStringLiteral("M/d/yyyy hh:mm")
-                << QStringLiteral("M/d/yyyy hh:mm A")
-
-                << QStringLiteral("M/d/yyyy, hh:mm")
-                << QStringLiteral("M/d/yyyy, hh:mm A")
-
-                << QStringLiteral("MMM d yyyy")
-                << QStringLiteral("MMM d yyyy hh:mm")
-                << QStringLiteral("MMM d yyyy hh:mm:ss")
-                << QStringLiteral("MMM d yyyy, hh:mm")
-                << QStringLiteral("MMM d yyyy, hh:mm:ss")
-
-                << QStringLiteral("MMMM d yyyy")
-                << QStringLiteral("MMMM d yyyy hh:mm")
-                << QStringLiteral("MMMM d yyyy hh:mm:ss")
-                << QStringLiteral("MMMM d yyyy, hh:mm")
-                << QStringLiteral("MMMM d yyyy, hh:mm:ss")
-
-                << QStringLiteral("MMM d, yyyy")
-                << QStringLiteral("MMM d, yyyy hh:mm")
-                << QStringLiteral("MMM d, yyyy hh:mm:ss")
-
-                << QStringLiteral("MMMM d, yyyy")
-                << QStringLiteral("MMMM d, yyyy hh:mm")
-                << QStringLiteral("MMMM d, yyyy hh:mm:ss")
-
-                << QStringLiteral("d MMM yyyy")
-                << QStringLiteral("d MMM yyyy hh:mm")
-                << QStringLiteral("d MMM yyyy hh:mm:ss")
-                << QStringLiteral("d MMM yyyy, hh:mm")
-                << QStringLiteral("d MMM yyyy, hh:mm:ss")
-
-                << QStringLiteral("d MMMM yyyy")
-                << QStringLiteral("d MMMM yyyy hh:mm")
-                << QStringLiteral("d MMMM yyyy hh:mm:ss")
-                << QStringLiteral("d MMMM yyyy, hh:mm")
-                << QStringLiteral("d MMMM yyyy, hh:mm:ss")
-
-                << QStringLiteral("d MMM, yyyy")
-                << QStringLiteral("d MMM, yyyy hh:mm")
-                << QStringLiteral("d MMM, yyyy hh:mm:ss")
-
-                << QStringLiteral("d MMMM, yyyy")
-                << QStringLiteral("d MMMM, yyyy hh:mm")
-                << QStringLiteral("d MMMM, yyyy hh:mm:ss");
-
-        for (int i = 0; i < formats.size(); ++i) {
-            dt = QDateTime::fromString(s, formats.at(i));
+        const QString formats[] = {
+            QStringLiteral("M/d/yyyy"),
+            QStringLiteral("M/d/yyyy hh:mm"),
+            QStringLiteral("M/d/yyyy hh:mm A"),
+
+            QStringLiteral("M/d/yyyy, hh:mm"),
+            QStringLiteral("M/d/yyyy, hh:mm A"),
+
+            QStringLiteral("MMM d yyyy"),
+            QStringLiteral("MMM d yyyy hh:mm"),
+            QStringLiteral("MMM d yyyy hh:mm:ss"),
+            QStringLiteral("MMM d yyyy, hh:mm"),
+            QStringLiteral("MMM d yyyy, hh:mm:ss"),
+
+            QStringLiteral("MMMM d yyyy"),
+            QStringLiteral("MMMM d yyyy hh:mm"),
+            QStringLiteral("MMMM d yyyy hh:mm:ss"),
+            QStringLiteral("MMMM d yyyy, hh:mm"),
+            QStringLiteral("MMMM d yyyy, hh:mm:ss"),
+
+            QStringLiteral("MMM d, yyyy"),
+            QStringLiteral("MMM d, yyyy hh:mm"),
+            QStringLiteral("MMM d, yyyy hh:mm:ss"),
+
+            QStringLiteral("MMMM d, yyyy"),
+            QStringLiteral("MMMM d, yyyy hh:mm"),
+            QStringLiteral("MMMM d, yyyy hh:mm:ss"),
+
+            QStringLiteral("d MMM yyyy"),
+            QStringLiteral("d MMM yyyy hh:mm"),
+            QStringLiteral("d MMM yyyy hh:mm:ss"),
+            QStringLiteral("d MMM yyyy, hh:mm"),
+            QStringLiteral("d MMM yyyy, hh:mm:ss"),
+
+            QStringLiteral("d MMMM yyyy"),
+            QStringLiteral("d MMMM yyyy hh:mm"),
+            QStringLiteral("d MMMM yyyy hh:mm:ss"),
+            QStringLiteral("d MMMM yyyy, hh:mm"),
+            QStringLiteral("d MMMM yyyy, hh:mm:ss"),
+
+            QStringLiteral("d MMM, yyyy"),
+            QStringLiteral("d MMM, yyyy hh:mm"),
+            QStringLiteral("d MMM, yyyy hh:mm:ss"),
+
+            QStringLiteral("d MMMM, yyyy"),
+            QStringLiteral("d MMMM, yyyy hh:mm"),
+            QStringLiteral("d MMMM, yyyy hh:mm:ss"),
+        };
+
+        for (uint i = 0; i < sizeof(formats) / sizeof(formats[0]); ++i) {
+            const QString &format(formats[i]);
+            dt = format.indexOf(QLatin1String("hh:mm")) < 0
+                ? QDateTime(QDate::fromString(s, format),
+                            QTime(0, 0, 0), Qt::UTC)
+                : QDateTime::fromString(s, format); // as local time
             if (dt.isValid())
                 break;
         }
     }
     if (!dt.isValid())
         return qt_qnan();
-    return dt.toMSecsSinceEpoch();
+    return TimeClip(dt.toMSecsSinceEpoch());
 }
 
 /*!
@@ -560,15 +628,15 @@ static inline QDateTime ToDateTime(double t, Qt::TimeSpec spec)
 {
     if (std::isnan(t))
         return QDateTime();
-    return QDateTime::fromMSecsSinceEpoch(t, spec);
+    return QDateTime::fromMSecsSinceEpoch(t, Qt::UTC).toTimeSpec(spec);
 }
 
-static inline QString ToString(double t)
+static inline QString ToString(double t, double localTZA)
 {
     if (std::isnan(t))
         return QStringLiteral("Invalid Date");
     QString str = ToDateTime(t, Qt::LocalTime).toString() + QLatin1String(" GMT");
-    double tzoffset = LocalTZA + DaylightSavingTA(t);
+    double tzoffset = localTZA + DaylightSavingTA(t, localTZA);
     if (tzoffset) {
         int hours = static_cast<int>(::fabs(tzoffset) / 1000 / 60 / 60);
         int mins = int(::fabs(tzoffset) / 1000 / 60) % 60;
@@ -602,36 +670,44 @@ static inline QString ToTimeString(double t)
 
 static inline QString ToLocaleString(double t)
 {
-    return ToDateTime(t, Qt::LocalTime).toString(Qt::LocaleDate);
+    return ToDateTime(t, Qt::LocalTime).toString(Qt::DefaultLocaleShortDate);
 }
 
 static inline QString ToLocaleDateString(double t)
 {
-    return ToDateTime(t, Qt::LocalTime).date().toString(Qt::LocaleDate);
+    return ToDateTime(t, Qt::LocalTime).date().toString(Qt::DefaultLocaleShortDate);
 }
 
 static inline QString ToLocaleTimeString(double t)
 {
-    return ToDateTime(t, Qt::LocalTime).time().toString(Qt::LocaleDate);
+    return ToDateTime(t, Qt::LocalTime).time().toString(Qt::DefaultLocaleShortDate);
 }
 
 static double getLocalTZA()
 {
 #ifndef Q_OS_WIN
+    tzset();
+#endif
+#ifdef USE_QTZ_SYSTEM_ZONE
+    // TODO: QTimeZone::resetSystemTimeZone(), see QTBUG-56899 and comment above.
+    // Standard offset, with no daylight-savings adjustment, in ms:
+    return QTimeZone::systemTimeZone().standardTimeOffset(QDateTime::currentDateTime()) * 1e3;
+#else
+#  ifdef Q_OS_WIN
+    TIME_ZONE_INFORMATION tzInfo;
+    GetTimeZoneInformation(&tzInfo);
+    return -tzInfo.Bias * 60.0 * 1000.0;
+#  else
     struct tm t;
     time_t curr;
-    tzset();
     time(&curr);
-    localtime_r(&curr, &t);
+    localtime_r(&curr, &t); // Wrong: includes DST offset
     time_t locl = mktime(&t);
     gmtime_r(&curr, &t);
     time_t globl = mktime(&t);
     return (double(locl) - double(globl)) * 1000.0;
-#else
-    TIME_ZONE_INFORMATION tzInfo;
-    GetTimeZoneInformation(&tzInfo);
-    return -tzInfo.Bias * 60.0 * 1000.0;
-#endif
+#  endif
+#endif // USE_QTZ_SYSTEM_ZONE
 }
 
 DEFINE_OBJECT_VTABLE(DateObject);
@@ -639,7 +715,7 @@ DEFINE_OBJECT_VTABLE(DateObject);
 void Heap::DateObject::init(const QDateTime &date)
 {
     Object::init();
-    this->date = date.isValid() ? date.toMSecsSinceEpoch() : qt_qnan();
+    this->date = date.isValid() ? TimeClip(date.toMSecsSinceEpoch()) : qt_qnan();
 }
 
 void Heap::DateObject::init(const QTime &time)
@@ -650,19 +726,21 @@ void Heap::DateObject::init(const QTime &time)
         return;
     }
 
-    /* All programmers know that stuff starts at 0. Whatever that may mean in this context (and
-     * local timezone), it's before the epoch, so there is defenitely no DST problem. Specifically:
-     * you can't start with a date before the epoch, add some[*] hours, and end up with a date
-     * after. That's a problem for timezones where new year happens during DST, like
-     * Australia/Hobart, because we have to ignore DST before the epoch (but honor it after the
-     * epoch).
-     *
-     * [*] Well, when "some" is in the range 0-24. If you add something like 1M then this might
-     *     still happen.
+    /* We have to chose a date on which to instantiate this time.  All we really
+     * care about is that it round-trips back to the same time if we extract the
+     * time from it, which shall (via toQDateTime(), below) discard the date
+     * part.  We need a date for which time-zone data is likely to be sane (so
+     * MakeDay(0, 0, 0) was a bad choice; 2 BC, December 31st is before
+     * time-zones were standardized), with no transition nearby in date.  We
+     * ignore DST transitions before 1970, but even then zone transitions did
+     * happen.  Some do happen at new year, others on DST transitions in spring
+     * and autumn; so pick the three hundredth anniversary of the birth of
+     * Giovanni Domenico Cassini (1625-06-08), whose work first let us
+     * synchronize clocks tolerably accurately at distant locations.
      */
-    static const double d = MakeDay(0, 0, 0);
+    static const double d = MakeDay(1925, 5, 8);
     double t = MakeTime(time.hour(), time.minute(), time.second(), time.msec());
-    date = TimeClip(UTC(MakeDate(d, t)));
+    date = TimeClip(UTC(MakeDate(d, t), internalClass->engine->localTZA));
 }
 
 QDateTime DateObject::toQDateTime() const
@@ -677,48 +755,57 @@ void Heap::DateCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("Date"));
 }
 
-void DateCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue DateCtor::virtualCallAsConstructor(const FunctionObject *that, const Value *argv, int argc, const Value *newTarget)
 {
+    ExecutionEngine *v4 = that->engine();
     double t = 0;
 
-    if (callData->argc == 0)
+    if (argc == 0)
         t = currentTime();
 
-    else if (callData->argc == 1) {
-        ScopedValue arg(scope, callData->args[0]);
+    else if (argc == 1) {
+        Scope scope(v4);
+        ScopedValue arg(scope, argv[0]);
         if (DateObject *d = arg->as<DateObject>()) {
             t = d->date();
         } else {
             arg = RuntimeHelpers::toPrimitive(arg, PREFERREDTYPE_HINT);
 
             if (String *s = arg->stringValue())
-                t = ParseString(s->toQString());
+                t = ParseString(s->toQString(), v4->localTZA);
             else
                 t = TimeClip(arg->toNumber());
         }
     }
 
     else { // d.argc > 1
-        double year  = callData->args[0].toNumber();
-        double month = callData->args[1].toNumber();
-        double day  = callData->argc >= 3 ? callData->args[2].toNumber() : 1;
-        double hours = callData->argc >= 4 ? callData->args[3].toNumber() : 0;
-        double mins = callData->argc >= 5 ? callData->args[4].toNumber() : 0;
-        double secs = callData->argc >= 6 ? callData->args[5].toNumber() : 0;
-        double ms    = callData->argc >= 7 ? callData->args[6].toNumber() : 0;
+        double year  = argv[0].toNumber();
+        double month = argv[1].toNumber();
+        double day  = argc >= 3 ? argv[2].toNumber() : 1;
+        double hours = argc >= 4 ? argv[3].toNumber() : 0;
+        double mins = argc >= 5 ? argv[4].toNumber() : 0;
+        double secs = argc >= 6 ? argv[5].toNumber() : 0;
+        double ms    = argc >= 7 ? argv[6].toNumber() : 0;
         if (year >= 0 && year <= 99)
             year += 1900;
         t = MakeDate(MakeDay(year, month, day), MakeTime(hours, mins, secs, ms));
-        t = TimeClip(UTC(t));
+        t = TimeClip(UTC(t, v4->localTZA));
     }
 
-    scope.result = Encode(scope.engine->newDateObject(Primitive::fromDouble(t)));
+    ReturnedValue o = Encode(v4->newDateObject(Value::fromDouble(t)));
+    if (!newTarget)
+        return o;
+    Scope scope(v4);
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
 }
 
-void DateCtor::call(const Managed *m, Scope &scope, CallData *)
+ReturnedValue DateCtor::virtualCall(const FunctionObject *m, const Value *, const Value *, int)
 {
+    ExecutionEngine *e = m->engine();
     double t = currentTime();
-    scope.result = static_cast<const DateCtor *>(m)->engine()->newString(ToString(t));
+    return e->newString(ToString(t, e->localTZA))->asReturnedValue();
 }
 
 void DatePrototype::init(ExecutionEngine *engine, Object *ctor)
@@ -726,8 +813,8 @@ void DatePrototype::init(ExecutionEngine *engine, Object *ctor)
     Scope scope(engine);
     ScopedObject o(scope);
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
-    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Primitive::fromInt32(7));
-    LocalTZA = getLocalTZA();
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(7));
+    engine->localTZA = getLocalTZA();
 
     ctor->defineDefaultProperty(QStringLiteral("parse"), method_parse, 1);
     ctor->defineDefaultProperty(QStringLiteral("UTC"), method_UTC, 7);
@@ -737,7 +824,7 @@ void DatePrototype::init(ExecutionEngine *engine, Object *ctor)
     defineDefaultProperty(engine->id_toString(), method_toString, 0);
     defineDefaultProperty(QStringLiteral("toDateString"), method_toDateString, 0);
     defineDefaultProperty(QStringLiteral("toTimeString"), method_toTimeString, 0);
-    defineDefaultProperty(QStringLiteral("toLocaleString"), method_toLocaleString, 0);
+    defineDefaultProperty(engine->id_toLocaleString(), method_toLocaleString, 0);
     defineDefaultProperty(QStringLiteral("toLocaleDateString"), method_toLocaleDateString, 0);
     defineDefaultProperty(QStringLiteral("toLocaleTimeString"), method_toLocaleTimeString, 0);
     defineDefaultProperty(engine->id_valueOf(), method_valueOf, 0);
@@ -784,528 +871,608 @@ void DatePrototype::init(ExecutionEngine *engine, Object *ctor)
         QString toGmtString(QStringLiteral("toGMTString"));
         ScopedString us(scope, engine->newIdentifier(toUtcString));
         ScopedString gs(scope, engine->newIdentifier(toGmtString));
-        ExecutionContext *global = engine->rootContext();
-        ScopedFunctionObject toUtcGmtStringFn(scope, BuiltinFunction::create(global, us, method_toUTCString));
-        toUtcGmtStringFn->defineReadonlyConfigurableProperty(engine->id_length(), Primitive::fromInt32(0));
+        ScopedFunctionObject toUtcGmtStringFn(scope, FunctionObject::createBuiltinFunction(engine, us, method_toUTCString, 0));
         defineDefaultProperty(us, toUtcGmtStringFn);
         defineDefaultProperty(gs, toUtcGmtStringFn);
     }
 
     defineDefaultProperty(QStringLiteral("toISOString"), method_toISOString, 0);
     defineDefaultProperty(QStringLiteral("toJSON"), method_toJSON, 1);
+    defineDefaultProperty(engine->symbol_toPrimitive(), method_symbolToPrimitive, 1, Attr_ReadOnly_ButConfigurable);
 }
 
-double DatePrototype::getThisDate(Scope &scope, CallData *callData)
+double DatePrototype::getThisDate(ExecutionEngine *v4, const Value *thisObject)
 {
-    if (DateObject *thisObject = callData->thisObject.as<DateObject>())
-        return thisObject->date();
-    else {
-        scope.engine->throwTypeError();
-        return 0;
-    }
+    if (const DateObject *that = thisObject->as<DateObject>())
+        return that->date();
+    v4->throwTypeError();
+    return 0;
 }
 
-void DatePrototype::method_parse(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_parse(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc)
-        scope.result = Encode(qt_qnan());
+    if (!argc)
+        return Encode(qt_qnan());
     else
-        scope.result = Encode(ParseString(callData->args[0].toQString()));
+        return Encode(ParseString(argv[0].toQString(), f->engine()->localTZA));
 }
 
-void DatePrototype::method_UTC(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_UTC(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    const int numArgs = callData->argc;
-    if (numArgs >= 2) {
-        double year  = callData->args[0].toNumber();
-        double month = callData->args[1].toNumber();
-        double day   = numArgs >= 3 ? callData->args[2].toNumber() : 1;
-        double hours = numArgs >= 4 ? callData->args[3].toNumber() : 0;
-        double mins  = numArgs >= 5 ? callData->args[4].toNumber() : 0;
-        double secs  = numArgs >= 6 ? callData->args[5].toNumber() : 0;
-        double ms    = numArgs >= 7 ? callData->args[6].toNumber() : 0;
-        if (year >= 0 && year <= 99)
-            year += 1900;
-        double t = MakeDate(MakeDay(year, month, day),
-                            MakeTime(hours, mins, secs, ms));
-        scope.result = Encode(TimeClip(t));
-        return;
-    }
-    RETURN_UNDEFINED();
+    const int numArgs = argc;
+    if (numArgs < 1)
+        return Encode(qQNaN());
+    ExecutionEngine *e = f->engine();
+    double year  = argv[0].toNumber();
+    if (e->hasException)
+        return Encode::undefined();
+    double month = numArgs >= 2 ? argv[1].toNumber() : 0;
+    if (e->hasException)
+        return Encode::undefined();
+    double day   = numArgs >= 3 ? argv[2].toNumber() : 1;
+    if (e->hasException)
+        return Encode::undefined();
+    double hours = numArgs >= 4 ? argv[3].toNumber() : 0;
+    if (e->hasException)
+        return Encode::undefined();
+    double mins  = numArgs >= 5 ? argv[4].toNumber() : 0;
+    if (e->hasException)
+        return Encode::undefined();
+    double secs  = numArgs >= 6 ? argv[5].toNumber() : 0;
+    if (e->hasException)
+        return Encode::undefined();
+    double ms    = numArgs >= 7 ? argv[6].toNumber() : 0;
+    if (e->hasException)
+        return Encode::undefined();
+    double iyear = QV4::Value::toInteger(year);
+    if (!qIsNaN(year) && iyear >= 0 && iyear <= 99)
+        year = 1900 + iyear;
+    double t = MakeDate(MakeDay(year, month, day),
+                        MakeTime(hours, mins, secs, ms));
+    return Encode(TimeClip(t));
 }
 
-void DatePrototype::method_now(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_now(const FunctionObject *, const Value *, const Value *, int)
 {
-    Q_UNUSED(callData);
-    double t = currentTime();
-    scope.result = Encode(t);
+    return Encode(currentTime());
 }
 
-void DatePrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = scope.engine->newString(ToString(t));
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(v4->newString(ToString(t, v4->localTZA)));
 }
 
-void DatePrototype::method_toDateString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toDateString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = scope.engine->newString(ToDateString(t));
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(v4->newString(ToDateString(t)));
 }
 
-void DatePrototype::method_toTimeString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toTimeString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = scope.engine->newString(ToTimeString(t));
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(v4->newString(ToTimeString(t)));
 }
 
-void DatePrototype::method_toLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toLocaleString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = scope.engine->newString(ToLocaleString(t));
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(v4->newString(ToLocaleString(t)));
 }
 
-void DatePrototype::method_toLocaleDateString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toLocaleDateString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = scope.engine->newString(ToLocaleDateString(t));
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(v4->newString(ToLocaleDateString(t)));
 }
 
-void DatePrototype::method_toLocaleTimeString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toLocaleTimeString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = scope.engine->newString(ToLocaleTimeString(t));
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(v4->newString(ToLocaleTimeString(t)));
 }
 
-void DatePrototype::method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_valueOf(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = Encode(t);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(t);
 }
 
-void DatePrototype::method_getTime(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getTime(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
-    scope.result = Encode(t);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
+    return Encode(t);
 }
 
-void DatePrototype::method_getYear(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getYear(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = YearFromTime(LocalTime(t)) - 1900;
-    scope.result = Encode(t);
+        t = YearFromTime(LocalTime(t, v4->localTZA)) - 1900;
+    return Encode(t);
 }
 
-void DatePrototype::method_getFullYear(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getFullYear(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = YearFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = YearFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCFullYear(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCFullYear(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = YearFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getMonth(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getMonth(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = MonthFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = MonthFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCMonth(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCMonth(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = MonthFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getDate(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getDate(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = DateFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = DateFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCDate(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCDate(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = DateFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getDay(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getDay(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = WeekDay(LocalTime(t));
-    scope.result = Encode(t);
+        t = WeekDay(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCDay(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCDay(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = WeekDay(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getHours(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getHours(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = HourFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = HourFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCHours(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCHours(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = HourFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getMinutes(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getMinutes(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = MinFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = MinFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCMinutes(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCMinutes(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = MinFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getSeconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getSeconds(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = SecFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = SecFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCSeconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCSeconds(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = SecFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getMilliseconds(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = msFromTime(LocalTime(t));
-    scope.result = Encode(t);
+        t = msFromTime(LocalTime(t, v4->localTZA));
+    return Encode(t);
 }
 
-void DatePrototype::method_getUTCMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getUTCMilliseconds(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
         t = msFromTime(t);
-    scope.result = Encode(t);
+    return Encode(t);
 }
 
-void DatePrototype::method_getTimezoneOffset(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_getTimezoneOffset(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    double t = getThisDate(scope, callData);
+    ExecutionEngine *v4 = b->engine();
+    double t = getThisDate(v4, thisObject);
     if (!std::isnan(t))
-        t = (t - LocalTime(t)) / msPerMinute;
-    scope.result = Encode(t);
+        t = (t - LocalTime(t, v4->localTZA)) / msPerMinute;
+    return Encode(t);
 }
 
-void DatePrototype::method_setTime(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setTime(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DateObject> self(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
-    double t = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
+    double t = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
     self->setDate(TimeClip(t));
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setMilliseconds(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<DateObject> self(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
-    double ms = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    self->setDate(TimeClip(UTC(MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms)))));
-    scope.result = Encode(self->date());
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double ms = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    self->setDate(TimeClip(UTC(MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms)), v4->localTZA)));
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCMilliseconds(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    CHECK_EXCEPTION();
-    double ms = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double ms = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
     self->setDate(TimeClip(MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms))));
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setSeconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setSeconds(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
-
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
-    double sec = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    double ms = (callData->argc < 2) ? msFromTime(t) : callData->args[1].toNumber();
-    CHECK_EXCEPTION();
-    t = TimeClip(UTC(MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), sec, ms))));
+        return v4->throwTypeError();
+
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double sec = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double ms = (argc < 2) ? msFromTime(t) : argv[1].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    t = TimeClip(UTC(MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), sec, ms)), v4->localTZA));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCSeconds(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCSeconds(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    double sec = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    double ms = (callData->argc < 2) ? msFromTime(t) : callData->args[1].toNumber();
+    double sec = argc ? argv[0].toNumber() : qt_qnan();
+    double ms = (argc < 2) ? msFromTime(t) : argv[1].toNumber();
     t = TimeClip(MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), sec, ms)));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setMinutes(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setMinutes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
-
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
-    double min = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    double sec = (callData->argc < 2) ? SecFromTime(t) : callData->args[1].toNumber();
-    CHECK_EXCEPTION();
-    double ms = (callData->argc < 3) ? msFromTime(t) : callData->args[2].toNumber();
-    CHECK_EXCEPTION();
-    t = TimeClip(UTC(MakeDate(Day(t), MakeTime(HourFromTime(t), min, sec, ms))));
+        return v4->throwTypeError();
+
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double min = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double sec = (argc < 2) ? SecFromTime(t) : argv[1].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double ms = (argc < 3) ? msFromTime(t) : argv[2].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    t = TimeClip(UTC(MakeDate(Day(t), MakeTime(HourFromTime(t), min, sec, ms)), v4->localTZA));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCMinutes(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCMinutes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    double min = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    double sec = (callData->argc < 2) ? SecFromTime(t) : callData->args[1].toNumber();
-    double ms = (callData->argc < 3) ? msFromTime(t) : callData->args[2].toNumber();
+    double min = argc ? argv[0].toNumber() : qt_qnan();
+    double sec = (argc < 2) ? SecFromTime(t) : argv[1].toNumber();
+    double ms = (argc < 3) ? msFromTime(t) : argv[2].toNumber();
     t = TimeClip(MakeDate(Day(t), MakeTime(HourFromTime(t), min, sec, ms)));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setHours(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setHours(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
-
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
-    double hour = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    double min = (callData->argc < 2) ? MinFromTime(t) : callData->args[1].toNumber();
-    CHECK_EXCEPTION();
-    double sec = (callData->argc < 3) ? SecFromTime(t) : callData->args[2].toNumber();
-    CHECK_EXCEPTION();
-    double ms = (callData->argc < 4) ? msFromTime(t) : callData->args[3].toNumber();
-    CHECK_EXCEPTION();
-    t = TimeClip(UTC(MakeDate(Day(t), MakeTime(hour, min, sec, ms))));
+        return v4->throwTypeError();
+
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double hour = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double min = (argc < 2) ? MinFromTime(t) : argv[1].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double sec = (argc < 3) ? SecFromTime(t) : argv[2].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double ms = (argc < 4) ? msFromTime(t) : argv[3].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    t = TimeClip(UTC(MakeDate(Day(t), MakeTime(hour, min, sec, ms)), v4->localTZA));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCHours(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCHours(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    double hour = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    double min = (callData->argc < 2) ? MinFromTime(t) : callData->args[1].toNumber();
-    double sec = (callData->argc < 3) ? SecFromTime(t) : callData->args[2].toNumber();
-    double ms = (callData->argc < 4) ? msFromTime(t) : callData->args[3].toNumber();
+    double hour = argc ? argv[0].toNumber() : qt_qnan();
+    double min = (argc < 2) ? MinFromTime(t) : argv[1].toNumber();
+    double sec = (argc < 3) ? SecFromTime(t) : argv[2].toNumber();
+    double ms = (argc < 4) ? msFromTime(t) : argv[3].toNumber();
     t = TimeClip(MakeDate(Day(t), MakeTime(hour, min, sec, ms)));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setDate(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setDate(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
-
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
-    double date = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    t = TimeClip(UTC(MakeDate(MakeDay(YearFromTime(t), MonthFromTime(t), date), TimeWithinDay(t))));
+        return v4->throwTypeError();
+
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double date = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    t = TimeClip(UTC(MakeDate(MakeDay(YearFromTime(t), MonthFromTime(t), date), TimeWithinDay(t)), v4->localTZA));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCDate(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCDate(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    CHECK_EXCEPTION();
-    double date = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double date = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
     t = TimeClip(MakeDate(MakeDay(YearFromTime(t), MonthFromTime(t), date), TimeWithinDay(t)));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setMonth(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setMonth(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
-
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
-    double month = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    double date = (callData->argc < 2) ? DateFromTime(t) : callData->args[1].toNumber();
-    CHECK_EXCEPTION();
-    t = TimeClip(UTC(MakeDate(MakeDay(YearFromTime(t), month, date), TimeWithinDay(t))));
+        return v4->throwTypeError();
+
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double month = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double date = (argc < 2) ? DateFromTime(t) : argv[1].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    t = TimeClip(UTC(MakeDate(MakeDay(YearFromTime(t), month, date), TimeWithinDay(t)), v4->localTZA));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCMonth(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCMonth(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    double month = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    double date = (callData->argc < 2) ? DateFromTime(t) : callData->args[1].toNumber();
+    double month = argc ? argv[0].toNumber() : qt_qnan();
+    double date = (argc < 2) ? DateFromTime(t) : argv[1].toNumber();
     t = TimeClip(MakeDate(MakeDay(YearFromTime(t), month, date), TimeWithinDay(t)));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setYear(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setYear(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
     if (std::isnan(t))
         t = 0;
     else
-        t = LocalTime(t);
-    double year = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+        t = LocalTime(t, v4->localTZA);
+    double year = argc ? argv[0].toNumber() : qt_qnan();
     double r;
     if (std::isnan(year)) {
         r = qt_qnan();
     } else {
-        if ((Primitive::toInteger(year) >= 0) && (Primitive::toInteger(year) <= 99))
+        if ((QV4::Value::toInteger(year) >= 0) && (QV4::Value::toInteger(year) <= 99))
             year += 1900;
         r = MakeDay(year, MonthFromTime(t), DateFromTime(t));
-        r = UTC(MakeDate(r, TimeWithinDay(t)));
+        r = UTC(MakeDate(r, TimeWithinDay(t)), v4->localTZA);
         r = TimeClip(r);
     }
     self->setDate(r);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setUTCFullYear(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setUTCFullYear(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    double year = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    double month = (callData->argc < 2) ? MonthFromTime(t) : callData->args[1].toNumber();
-    double date = (callData->argc < 3) ? DateFromTime(t) : callData->args[2].toNumber();
+    double year = argc ? argv[0].toNumber() : qt_qnan();
+    double month = (argc < 2) ? MonthFromTime(t) : argv[1].toNumber();
+    double date = (argc < 3) ? DateFromTime(t) : argv[2].toNumber();
     t = TimeClip(MakeDate(MakeDay(year, month, date), TimeWithinDay(t)));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_setFullYear(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_setFullYear(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
-    double t = LocalTime(self->date());
-    CHECK_EXCEPTION();
+    double t = LocalTime(self->date(), v4->localTZA);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
     if (std::isnan(t))
         t = 0;
-    double year = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    CHECK_EXCEPTION();
-    double month = (callData->argc < 2) ? MonthFromTime(t) : callData->args[1].toNumber();
-    CHECK_EXCEPTION();
-    double date = (callData->argc < 3) ? DateFromTime(t) : callData->args[2].toNumber();
-    CHECK_EXCEPTION();
-    t = TimeClip(UTC(MakeDate(MakeDay(year, month, date), TimeWithinDay(t))));
+    double year = argc ? argv[0].toNumber() : qt_qnan();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double month = (argc < 2) ? MonthFromTime(t) : argv[1].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    double date = (argc < 3) ? DateFromTime(t) : argv[2].toNumber();
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    t = TimeClip(UTC(MakeDate(MakeDay(year, month, date), TimeWithinDay(t)), v4->localTZA));
     self->setDate(t);
-    scope.result = Encode(self->date());
+    return Encode(self->date());
 }
 
-void DatePrototype::method_toUTCString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toUTCString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
-    scope.result = scope.engine->newString(ToUTCString(t));
+    return Encode(v4->newString(ToUTCString(t)));
 }
 
 static void addZeroPrefixedInt(QString &str, int num, int nDigits)
@@ -1321,21 +1488,22 @@ static void addZeroPrefixedInt(QString &str, int num, int nDigits)
     }
 }
 
-void DatePrototype::method_toISOString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toISOString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    DateObject *self = callData->thisObject.as<DateObject>();
+    ExecutionEngine *v4 = b->engine();
+    DateObject *self = const_cast<DateObject *>(thisObject->as<DateObject>());
     if (!self)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
     double t = self->date();
     if (!std::isfinite(t))
-        RETURN_RESULT(scope.engine->throwRangeError(callData->thisObject));
+        RETURN_RESULT(v4->throwRangeError(*thisObject));
 
     QString result;
     int year = (int)YearFromTime(t);
     if (year < 0 || year > 9999) {
         if (qAbs(year) >= 1000000)
-            RETURN_RESULT(scope.engine->newString(QStringLiteral("Invalid Date")));
+            RETURN_RESULT(v4->throwRangeError(*thisObject));
         result += year < 0 ? QLatin1Char('-') : QLatin1Char('+');
         year = qAbs(year);
         addZeroPrefixedInt(result, year, 6);
@@ -1356,32 +1524,49 @@ void DatePrototype::method_toISOString(const BuiltinFunction *, Scope &scope, Ca
     addZeroPrefixedInt(result, msFromTime(t), 3);
     result += QLatin1Char('Z');
 
-    scope.result = scope.engine->newString(result);
+    return Encode(v4->newString(result));
 }
 
-void DatePrototype::method_toJSON(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue DatePrototype::method_toJSON(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    ScopedObject O(scope, callData->thisObject.toObject(scope.engine));
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    Scope scope(v4);
+    ScopedObject O(scope, thisObject->toObject(v4));
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     ScopedValue tv(scope, RuntimeHelpers::toPrimitive(O, NUMBER_HINT));
 
     if (tv->isNumber() && !std::isfinite(tv->toNumber()))
-        RETURN_RESULT(Encode::null());
+        return Encode::null();
 
-    ScopedString s(scope, scope.engine->newString(QStringLiteral("toISOString")));
+    ScopedString s(scope, v4->newString(QStringLiteral("toISOString")));
     ScopedValue v(scope, O->get(s));
     FunctionObject *toIso = v->as<FunctionObject>();
 
     if (!toIso)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
+
+    return toIso->call(O, nullptr, 0);
+}
+
+ReturnedValue DatePrototype::method_symbolToPrimitive(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *e = f->engine();
+    if (!thisObject->isObject() || !argc || !argv->isString())
+        return e->throwTypeError();
+
+    String *hint = argv->stringValue();
+    PropertyKey id = hint->toPropertyKey();
+    if (id == e->id_default()->propertyKey())
+        hint = e->id_string();
+    else if (id != e->id_string()->propertyKey() && id != e->id_number()->propertyKey())
+        return e->throwTypeError();
 
-    ScopedCallData cData(scope);
-    cData->thisObject = callData->thisObject;
-    toIso->call(scope, cData);
+    return RuntimeHelpers::ordinaryToPrimitive(e, static_cast<const Object *>(thisObject), hint);
 }
 
-void DatePrototype::timezoneUpdated()
+void DatePrototype::timezoneUpdated(ExecutionEngine *e)
 {
-    LocalTZA = getLocalTZA();
+    e->localTZA = getLocalTZA();
 }
diff --git a/src/qml/jsruntime/qv4dateobject_p.h b/src/qml/jsruntime/qv4dateobject_p.h
index b0373884dd..5b9934282c 100644
--- a/src/qml/jsruntime/qv4dateobject_p.h
+++ b/src/qml/jsruntime/qv4dateobject_p.h
@@ -101,15 +101,15 @@ struct DateObject: Object {
 
 template<>
 inline const DateObject *Value::as() const {
-    return isManaged() && m()->vtable()->type == Managed::Type_DateObject ? static_cast<const DateObject *>(this) : 0;
+    return isManaged() && m()->internalClass->vtable->type == Managed::Type_DateObject ? static_cast<const DateObject *>(this) : nullptr;
 }
 
 struct DateCtor: FunctionObject
 {
     V4_OBJECT2(DateCtor, FunctionObject)
 
-    static void construct(const Managed *, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int);
 };
 
 struct DatePrototype: Object
@@ -118,59 +118,60 @@ struct DatePrototype: Object
 
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static double getThisDate(Scope &scope, CallData *callData);
-
-    static void method_parse(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_UTC(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_now(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toDateString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toTimeString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleDateString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleTimeString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getTime(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getYear(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getFullYear(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCFullYear(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getMonth(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCMonth(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getDate(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCDate(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getDay(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCDay(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getHours(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCHours(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getMinutes(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCMinutes(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getSeconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCSeconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getUTCMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getTimezoneOffset(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setTime(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCMilliseconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setSeconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCSeconds(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setMinutes(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCMinutes(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setHours(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCHours(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setDate(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCDate(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setMonth(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCMonth(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setYear(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setFullYear(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_setUTCFullYear(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toUTCString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toISOString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toJSON(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void timezoneUpdated();
+    static double getThisDate(ExecutionEngine *v4, const Value *thisObject);
+
+    static ReturnedValue method_parse(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_UTC(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_now(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toDateString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toTimeString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleDateString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleTimeString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getTime(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getYear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getFullYear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCFullYear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getMonth(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCMonth(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getDate(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCDate(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getDay(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCDay(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getHours(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCHours(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getMinutes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCMinutes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getSeconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCSeconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getMilliseconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getUTCMilliseconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getTimezoneOffset(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setTime(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setMilliseconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCMilliseconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setSeconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCSeconds(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setMinutes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCMinutes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setHours(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCHours(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setDate(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCDate(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setMonth(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCMonth(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setYear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setFullYear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setUTCFullYear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toUTCString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toISOString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toJSON(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_symbolToPrimitive(const FunctionObject *f, const Value *thisObject, const Value *, int);
+
+    static void timezoneUpdated(ExecutionEngine *e);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4debugging_p.h b/src/qml/jsruntime/qv4debugging_p.h
index 8e2eec03d2..9b41bb6e7a 100644
--- a/src/qml/jsruntime/qv4debugging_p.h
+++ b/src/qml/jsruntime/qv4debugging_p.h
@@ -59,7 +59,7 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 namespace Debugging {
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 class Debugger
 {
@@ -78,7 +78,7 @@ class Q_QML_EXPORT Debugger : public QObject
     Q_OBJECT
 
 public:
-    virtual ~Debugger() {}
+    ~Debugger() override {}
     virtual bool pauseAtNextOpportunity() const = 0;
     virtual void maybeBreakAtInstruction() = 0;
     virtual void enteringFunction() = 0;
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 019936767a..c04617dac0 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -37,11 +37,34 @@
 **
 ****************************************************************************/
 #include <qv4engine_p.h>
+
+#include <private/qqmljslexer_p.h>
+#include <private/qqmljsparser_p.h>
+#include <private/qqmljsast_p.h>
+#include <private/qv4compileddata_p.h>
+#include <private/qv4compiler_p.h>
+#include <private/qv4compilercontext_p.h>
+#include <private/qv4codegen_p.h>
+
+#include <QtCore/QTextStream>
+#include <QDateTime>
+#include <QDir>
+#include <QFileInfo>
+#include <QLoggingCategory>
+#if QT_CONFIG(regularexpression)
+#include <QRegularExpression>
+#endif
+
+#ifndef V4_BOOTSTRAP
+
 #include <qv4qmlcontext_p.h>
 #include <qv4value_p.h>
 #include <qv4object_p.h>
 #include <qv4objectproto_p.h>
 #include <qv4objectiterator_p.h>
+#include <qv4setiterator_p.h>
+#include <qv4mapiterator_p.h>
+#include <qv4arrayiterator_p.h>
 #include <qv4arrayobject_p.h>
 #include <qv4booleanobject_p.h>
 #include <qv4globalobject_p.h>
@@ -52,6 +75,9 @@
 #include <qv4numberobject_p.h>
 #include <qv4regexpobject_p.h>
 #include <qv4regexp_p.h>
+#include "qv4symbol_p.h"
+#include "qv4setobject_p.h"
+#include "qv4mapobject_p.h"
 #include <qv4variantobject_p.h>
 #include <qv4runtime_p.h>
 #include <private/qv4mm_p.h>
@@ -63,11 +89,23 @@
 #include "qv4debugging_p.h"
 #include "qv4profiling_p.h"
 #include "qv4executableallocator_p.h"
+#include "qv4iterator_p.h"
+#include "qv4stringiterator_p.h"
+#include "qv4generatorobject_p.h"
+#include "qv4reflect_p.h"
+#include "qv4proxy_p.h"
+#include "qv4stackframe_p.h"
+#include "qv4atomics_p.h"
+
+#if QT_CONFIG(qml_sequence_object)
 #include "qv4sequenceobject_p.h"
+#endif
+
 #include "qv4qobjectwrapper_p.h"
 #include "qv4memberdata_p.h"
 #include "qv4arraybuffer_p.h"
 #include "qv4dataview_p.h"
+#include "qv4promiseobject_p.h"
 #include "qv4typedarray_p.h"
 #include <private/qv8engine_p.h>
 #include <private/qjsvalue_p.h>
@@ -76,18 +114,11 @@
 #include <private/qqmlvaluetype_p.h>
 #include <private/qqmllistwrapper_p.h>
 #include <private/qqmllist_p.h>
+#include <private/qqmltypeloader_p.h>
+#if QT_CONFIG(qml_locale)
 #include <private/qqmllocale_p.h>
-
-#include <QtCore/QTextStream>
-#include <QDateTime>
-
-#ifdef V4_ENABLE_JIT
-#include "qv4isel_masm_p.h"
-#endif // V4_ENABLE_JIT
-
-#if QT_CONFIG(qml_interpreter)
-#include "qv4isel_moth_p.h"
 #endif
+#include <qqmlfile.h>
 
 #if USE(PTHREADS)
 #  include <pthread.h>
@@ -103,48 +134,39 @@
 #include <valgrind/memcheck.h>
 #endif
 
-QT_BEGIN_NAMESPACE
+#endif // #ifndef V4_BOOTSTRAP
 
-using namespace QV4;
+QT_BEGIN_NAMESPACE
 
-static QBasicAtomicInt engineSerial = Q_BASIC_ATOMIC_INITIALIZER(1);
+Q_LOGGING_CATEGORY(lcTracingAll, "qt.v4.tracing.all")
 
-void throwTypeError(const BuiltinFunction *, Scope &scope, CallData *)
-{
-    scope.result = scope.engine->throwTypeError();
-}
+using namespace QV4;
 
+#ifndef V4_BOOTSTRAP
 
-#ifdef V4_BOOTSTRAP
-QJSEngine *ExecutionEngine::jsEngine() const
-{
-    return v8Engine->publicEngine();
-}
+static QBasicAtomicInt engineSerial = Q_BASIC_ATOMIC_INITIALIZER(1);
 
-QQmlEngine *ExecutionEngine::qmlEngine() const
+ReturnedValue throwTypeError(const FunctionObject *b, const QV4::Value *, const QV4::Value *, int)
 {
-    return v8Engine->engine();
+    return b->engine()->throwTypeError();
 }
-#endif // V4_BOOTSTRAP
 
 qint32 ExecutionEngine::maxCallDepth = -1;
 
-ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
+ExecutionEngine::ExecutionEngine(QJSEngine *jsEngine)
     : executableAllocator(new QV4::ExecutableAllocator)
     , regExpAllocator(new QV4::ExecutableAllocator)
     , bumperPointerAllocator(new WTF::BumpPointerAllocator)
     , jsStack(new WTF::PageAllocation)
     , gcStack(new WTF::PageAllocation)
-    , globalCode(0)
-    , v8Engine(0)
-    , argumentsAccessors(0)
-    , nArgumentsAccessors(0)
+    , globalCode(nullptr)
+    , v8Engine(nullptr)
+    , publicEngine(jsEngine)
     , m_engineId(engineSerial.fetchAndAddOrdered(1))
-    , regExpCache(0)
-    , m_multiplyWrappedQObjects(0)
-#ifndef QT_NO_QML_DEBUGGER
-    , m_debugger(0)
-    , m_profiler(0)
+    , regExpCache(nullptr)
+    , m_multiplyWrappedQObjects(nullptr)
+#if defined(V4_ENABLE_JIT) && !defined(V4_BOOTSTRAP)
+    , m_canAllocateExecutableMemory(OSAllocator::canAllocateExecutableMemory())
 #endif
 {
     memoryManager = new QV4::MemoryManager(this);
@@ -153,38 +175,15 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
         bool ok = false;
         maxCallDepth = qEnvironmentVariableIntValue("QV4_MAX_CALL_DEPTH", &ok);
         if (!ok || maxCallDepth <= 0) {
+#ifdef QT_NO_DEBUG
             maxCallDepth = 1234;
-        }
-    }
-    Q_ASSERT(maxCallDepth > 0);
-
-    if (!factory) {
-#if QT_CONFIG(qml_interpreter)
-        bool jitDisabled = true;
-
-#ifdef V4_ENABLE_JIT
-        static const bool forceMoth = !qEnvironmentVariableIsEmpty("QV4_FORCE_INTERPRETER") ||
-                                      !OSAllocator::canAllocateExecutableMemory();
-        if (forceMoth) {
-            factory = new Moth::ISelFactory;
-        } else {
-            factory = new JIT::ISelFactory<>;
-            jitDisabled = false;
-        }
-#else // !V4_ENABLE_JIT
-        factory = new Moth::ISelFactory;
-#endif // V4_ENABLE_JIT
-
-        if (jitDisabled) {
-            qWarning("JIT is disabled for QML. Property bindings and animations will be "
-                     "very slow. Visit https://wiki.qt.io/V4 to learn about possible "
-                     "solutions for your platform.");
-        }
 #else
-        factory = new JIT::ISelFactory<>;
+            // no (tail call) optimization is done, so there'll be a lot mare stack frames active
+            maxCallDepth = 200;
 #endif
+        }
     }
-    iselFactory.reset(factory);
+    Q_ASSERT(maxCallDepth > 0);
 
     // reserve space for the JS stack
     // we allow it to grow to a bit more than JSStackLimit, as we can overshoot due to ScopedValues
@@ -203,27 +202,54 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
                                              /* writable */ true, /* executable */ false,
                                              /* includesGuardPages */ true);
 
+    {
+        bool ok = false;
+        jitCallCountThreshold = qEnvironmentVariableIntValue("QV4_JIT_CALL_THRESHOLD", &ok);
+        if (!ok)
+            jitCallCountThreshold = 3;
+        if (qEnvironmentVariableIsSet("QV4_FORCE_INTERPRETER"))
+            jitCallCountThreshold = std::numeric_limits<int>::max();
+    }
+
     exceptionValue = jsAlloca(1);
+    *exceptionValue = Encode::undefined();
     globalObject = static_cast<Object *>(jsAlloca(1));
     jsObjects = jsAlloca(NJSObjects);
     typedArrayPrototype = static_cast<Object *>(jsAlloca(NTypedArrayTypes));
     typedArrayCtors = static_cast<FunctionObject *>(jsAlloca(NTypedArrayTypes));
     jsStrings = jsAlloca(NJSStrings);
+    jsSymbols = jsAlloca(NJSSymbols);
 
     // set up stack limits
     jsStackLimit = jsStackBase + JSStackLimit/sizeof(Value);
 
     identifierTable = new IdentifierTable(this);
 
-    classPool = new InternalClassPool;
+    memset(classes, 0, sizeof(classes));
+    classes[Class_Empty] = memoryManager->allocIC<InternalClass>();
+    classes[Class_Empty]->init(this);
 
-    internalClasses[Class_Empty] =  new (classPool) InternalClass(this);
-    internalClasses[Class_String] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::String::staticVTable());
-    internalClasses[Class_MemberData] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::MemberData::staticVTable());
-    internalClasses[Class_SimpleArrayData] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::SimpleArrayData::staticVTable());
-    internalClasses[Class_SparseArrayData] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::SparseArrayData::staticVTable());
-    internalClasses[Class_ExecutionContext] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::ExecutionContext::staticVTable());
-    internalClasses[Class_SimpleCallContext] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::CallContext::staticVTable());
+    classes[Class_MemberData] = classes[Class_Empty]->changeVTable(QV4::MemberData::staticVTable());
+    classes[Class_SimpleArrayData] = classes[Class_Empty]->changeVTable(QV4::SimpleArrayData::staticVTable());
+    classes[Class_SparseArrayData] = classes[Class_Empty]->changeVTable(QV4::SparseArrayData::staticVTable());
+    classes[Class_ExecutionContext] = classes[Class_Empty]->changeVTable(QV4::ExecutionContext::staticVTable());
+    classes[Class_CallContext] = classes[Class_Empty]->changeVTable(QV4::CallContext::staticVTable());
+    classes[Class_QmlContext] = classes[Class_Empty]->changeVTable(QV4::QmlContext::staticVTable());
+
+    Scope scope(this);
+    Scoped<InternalClass> ic(scope);
+    ic = classes[Class_Empty]->changeVTable(QV4::Object::staticVTable());
+    jsObjects[ObjectProto] = memoryManager->allocObject<ObjectPrototype>(ic->d());
+    classes[Class_Object] = ic->changePrototype(objectPrototype()->d());
+    classes[Class_QmlContextWrapper] = classes[Class_Object]->changeVTable(QV4::QQmlContextWrapper::staticVTable());
+
+    ic = newInternalClass(QV4::StringObject::staticVTable(), objectPrototype());
+    jsObjects[StringProto] = memoryManager->allocObject<StringPrototype>(ic->d(), /*init =*/ false);
+    classes[Class_String] = classes[Class_Empty]->changeVTable(QV4::String::staticVTable())->changePrototype(stringPrototype()->d());
+    Q_ASSERT(stringPrototype()->d() && classes[Class_String]->prototype);
+
+    jsObjects[SymbolProto] = memoryManager->allocate<SymbolPrototype>();
+    classes[Class_Symbol] = classes[EngineBase::Class_Empty]->changeVTable(QV4::Symbol::staticVTable())->changePrototype(symbolPrototype()->d());
 
     jsStrings[String_Empty] = newIdentifier(QString());
     jsStrings[String_undefined] = newIdentifier(QStringLiteral("undefined"));
@@ -233,6 +259,8 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     jsStrings[String_boolean] = newIdentifier(QStringLiteral("boolean"));
     jsStrings[String_number] = newIdentifier(QStringLiteral("number"));
     jsStrings[String_string] = newIdentifier(QStringLiteral("string"));
+    jsStrings[String_default] = newIdentifier(QStringLiteral("default"));
+    jsStrings[String_symbol] = newIdentifier(QStringLiteral("symbol"));
     jsStrings[String_object] = newIdentifier(QStringLiteral("object"));
     jsStrings[String_function] = newIdentifier(QStringLiteral("function"));
     jsStrings[String_length] = newIdentifier(QStringLiteral("length"));
@@ -255,146 +283,212 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     jsStrings[String_index] = newIdentifier(QStringLiteral("index"));
     jsStrings[String_input] = newIdentifier(QStringLiteral("input"));
     jsStrings[String_toString] = newIdentifier(QStringLiteral("toString"));
+    jsStrings[String_toLocaleString] = newIdentifier(QStringLiteral("toLocaleString"));
     jsStrings[String_destroy] = newIdentifier(QStringLiteral("destroy"));
     jsStrings[String_valueOf] = newIdentifier(QStringLiteral("valueOf"));
     jsStrings[String_byteLength] = newIdentifier(QStringLiteral("byteLength"));
     jsStrings[String_byteOffset] = newIdentifier(QStringLiteral("byteOffset"));
     jsStrings[String_buffer] = newIdentifier(QStringLiteral("buffer"));
     jsStrings[String_lastIndex] = newIdentifier(QStringLiteral("lastIndex"));
-
-    InternalClass *ic = internalClasses[Class_Empty]->changeVTable(QV4::Object::staticVTable());
-    jsObjects[ObjectProto] = memoryManager->allocObject<ObjectPrototype>(ic);
-    internalClasses[Class_Object] = ic->changePrototype(objectPrototype()->d());
+    jsStrings[String_next] = newIdentifier(QStringLiteral("next"));
+    jsStrings[String_done] = newIdentifier(QStringLiteral("done"));
+    jsStrings[String_return] = newIdentifier(QStringLiteral("return"));
+    jsStrings[String_throw] = newIdentifier(QStringLiteral("throw"));
+    jsStrings[String_global] = newIdentifier(QStringLiteral("global"));
+    jsStrings[String_ignoreCase] = newIdentifier(QStringLiteral("ignoreCase"));
+    jsStrings[String_multiline] = newIdentifier(QStringLiteral("multiline"));
+    jsStrings[String_unicode] = newIdentifier(QStringLiteral("unicode"));
+    jsStrings[String_sticky] = newIdentifier(QStringLiteral("sticky"));
+    jsStrings[String_source] = newIdentifier(QStringLiteral("source"));
+    jsStrings[String_flags] = newIdentifier(QStringLiteral("flags"));
+
+    jsSymbols[Symbol_hasInstance] = Symbol::create(this, QStringLiteral("@Symbol.hasInstance"));
+    jsSymbols[Symbol_isConcatSpreadable] = Symbol::create(this, QStringLiteral("@Symbol.isConcatSpreadable"));
+    jsSymbols[Symbol_iterator] = Symbol::create(this, QStringLiteral("@Symbol.iterator"));
+    jsSymbols[Symbol_match] = Symbol::create(this, QStringLiteral("@Symbol.match"));
+    jsSymbols[Symbol_replace] = Symbol::create(this, QStringLiteral("@Symbol.replace"));
+    jsSymbols[Symbol_search] = Symbol::create(this, QStringLiteral("@Symbol.search"));
+    jsSymbols[Symbol_species] = Symbol::create(this, QStringLiteral("@Symbol.species"));
+    jsSymbols[Symbol_split] = Symbol::create(this, QStringLiteral("@Symbol.split"));
+    jsSymbols[Symbol_toPrimitive] = Symbol::create(this, QStringLiteral("@Symbol.toPrimitive"));
+    jsSymbols[Symbol_toStringTag] = Symbol::create(this, QStringLiteral("@Symbol.toStringTag"));
+    jsSymbols[Symbol_unscopables] = Symbol::create(this, QStringLiteral("@Symbol.unscopables"));
+    jsSymbols[Symbol_revokableProxy] = Symbol::create(this, QStringLiteral("@Proxy.revokableProxy"));
 
     ic = newInternalClass(ArrayPrototype::staticVTable(), objectPrototype());
-    Q_ASSERT(ic->prototype);
-    ic = ic->addMember(id_length(), Attr_NotConfigurable|Attr_NotEnumerable);
-    Q_ASSERT(ic->prototype);
-    jsObjects[ArrayProto] = memoryManager->allocObject<ArrayPrototype>(ic, objectPrototype());
-    internalClasses[Class_ArrayObject] = ic->changePrototype(arrayPrototype()->d());
-    jsObjects[PropertyListProto] = memoryManager->allocObject<PropertyListPrototype>();
-
-    InternalClass *argsClass = newInternalClass(ArgumentsObject::staticVTable(), objectPrototype());
-    argsClass = argsClass->addMember(id_length(), Attr_NotEnumerable);
-    internalClasses[EngineBase::Class_ArgumentsObject] = argsClass->addMember(id_callee(), Attr_Data|Attr_NotEnumerable);
-    argsClass = argsClass->addMember(id_callee(), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
-    internalClasses[EngineBase::Class_StrictArgumentsObject] = argsClass->addMember(id_caller(), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
+    Q_ASSERT(ic->d()->prototype);
+    ic = ic->addMember(id_length()->propertyKey(), Attr_NotConfigurable|Attr_NotEnumerable);
+    Q_ASSERT(ic->d()->prototype);
+    jsObjects[ArrayProto] = memoryManager->allocObject<ArrayPrototype>(ic->d());
+    classes[Class_ArrayObject] = ic->changePrototype(arrayPrototype()->d());
+    jsObjects[PropertyListProto] = memoryManager->allocate<PropertyListPrototype>();
+
+    Scoped<InternalClass> argsClass(scope);
+    argsClass = newInternalClass(ArgumentsObject::staticVTable(), objectPrototype());
+    argsClass = argsClass->addMember(id_length()->propertyKey(), Attr_NotEnumerable);
+    argsClass = argsClass->addMember(symbol_iterator()->propertyKey(), Attr_Data|Attr_NotEnumerable);
+    classes[Class_ArgumentsObject] = argsClass->addMember(id_callee()->propertyKey(), Attr_Data|Attr_NotEnumerable);
+    argsClass = newInternalClass(StrictArgumentsObject::staticVTable(), objectPrototype());
+    argsClass = argsClass->addMember(id_length()->propertyKey(), Attr_NotEnumerable);
+    argsClass = argsClass->addMember(symbol_iterator()->propertyKey(), Attr_Data|Attr_NotEnumerable);
+    classes[Class_StrictArgumentsObject] = argsClass->addMember(id_callee()->propertyKey(), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
 
     *static_cast<Value *>(globalObject) = newObject();
     Q_ASSERT(globalObject->d()->vtable());
     initRootContext();
 
     ic = newInternalClass(QV4::StringObject::staticVTable(), objectPrototype());
-    ic = ic->addMember(id_length(), Attr_ReadOnly);
-    jsObjects[StringProto] = memoryManager->allocObject<StringPrototype>(ic);
-    internalClasses[Class_StringObject] = ic->changePrototype(stringPrototype()->d());
-    Q_ASSERT(internalClasses[EngineBase::Class_StringObject]->find(id_length()) == Heap::StringObject::LengthPropertyIndex);
+    ic = ic->addMember(id_length()->propertyKey(), Attr_ReadOnly);
+    classes[Class_StringObject] = ic->changePrototype(stringPrototype()->d());
+    Q_ASSERT(classes[Class_StringObject]->verifyIndex(id_length()->propertyKey(), Heap::StringObject::LengthPropertyIndex));
 
-    jsObjects[NumberProto] = memoryManager->allocObject<NumberPrototype>();
-    jsObjects[BooleanProto] = memoryManager->allocObject<BooleanPrototype>();
-    jsObjects[DateProto] = memoryManager->allocObject<DatePrototype>();
+    classes[Class_SymbolObject] = newInternalClass(QV4::SymbolObject::staticVTable(), symbolPrototype());
 
-    uint index;
+    jsObjects[NumberProto] = memoryManager->allocate<NumberPrototype>();
+    jsObjects[BooleanProto] = memoryManager->allocate<BooleanPrototype>();
+    jsObjects[DateProto] = memoryManager->allocate<DatePrototype>();
+
+#if defined(QT_NO_DEBUG) && !defined(QT_FORCE_ASSERTS)
+    InternalClassEntry *index = nullptr;
+#else
+    InternalClassEntry _index;
+    auto *index = &_index;
+#endif
     ic = newInternalClass(QV4::FunctionPrototype::staticVTable(), objectPrototype());
-    ic = ic->addMember(id_prototype(), Attr_NotEnumerable, &index);
-    Q_ASSERT(index == Heap::FunctionObject::Index_Prototype);
-    jsObjects[FunctionProto] = memoryManager->allocObject<FunctionPrototype>(ic, objectPrototype());
+    auto addProtoHasInstance = [&] {
+        // Add an invalid prototype slot, so that all function objects have the same layout
+        // This helps speed up instanceof operations and other things where we need to query
+        // prototype property (as we always know it's location)
+        ic = ic->addMember(id_prototype()->propertyKey(), Attr_Invalid, index);
+        Q_ASSERT(index->index == Heap::FunctionObject::Index_Prototype);
+        // add an invalid @hasInstance slot, so that we can quickly track whether the
+        // hasInstance method has been reimplemented. This is required for a fast
+        // instanceof implementation
+        ic = ic->addMember(symbol_hasInstance()->propertyKey(), Attr_Invalid, index);
+        Q_ASSERT(index->index == Heap::FunctionObject::Index_HasInstance);
+    };
+    addProtoHasInstance();
+    jsObjects[FunctionProto] = memoryManager->allocObject<FunctionPrototype>(ic->d());
     ic = newInternalClass(FunctionObject::staticVTable(), functionPrototype());
-    ic = ic->addMember(id_prototype(), Attr_NotEnumerable|Attr_NotConfigurable, &index);
-    Q_ASSERT(index == Heap::FunctionObject::Index_Prototype);
-    internalClasses[EngineBase::Class_FunctionObject] = ic;
-    ic = ic->addMember(id_name(), Attr_ReadOnly, &index);
-    Q_ASSERT(index == Heap::ScriptFunction::Index_Name);
+    addProtoHasInstance();
+    classes[Class_FunctionObject] = ic->d();
+    ic = ic->addMember(id_name()->propertyKey(), Attr_ReadOnly, index);
+    Q_ASSERT(index->index == Heap::ArrowFunction::Index_Name);
+    ic = ic->addMember(id_length()->propertyKey(), Attr_ReadOnly_ButConfigurable, index);
+    Q_ASSERT(index->index == Heap::ArrowFunction::Index_Length);
+    classes[Class_ArrowFunction] = ic->changeVTable(ArrowFunction::staticVTable());
+    ic = ic->changeVTable(MemberFunction::staticVTable());
+    classes[Class_MemberFunction] = ic->d();
+    ic = ic->changeVTable(GeneratorFunction::staticVTable());
+    classes[Class_GeneratorFunction] = ic->d();
+    ic = ic->changeVTable(MemberGeneratorFunction::staticVTable());
+    classes[Class_MemberGeneratorFunction] = ic->d();
+
+    ic = ic->changeMember(id_prototype()->propertyKey(), Attr_NotConfigurable|Attr_NotEnumerable);
     ic = ic->changeVTable(ScriptFunction::staticVTable());
-    internalClasses[EngineBase::Class_ScriptFunction] = ic->addMember(id_length(), Attr_ReadOnly, &index);
-    Q_ASSERT(index == Heap::ScriptFunction::Index_Length);
-    internalClasses[EngineBase::Class_BuiltinFunction] = ic->changeVTable(BuiltinFunction::staticVTable());
-    Q_ASSERT(index == Heap::ScriptFunction::Index_Length);
-    internalClasses[EngineBase::Class_ObjectProto] = internalClasses[Class_Object]->addMember(id_constructor(), Attr_NotEnumerable, &index);
-    Q_ASSERT(index == Heap::FunctionObject::Index_ProtoConstructor);
+    classes[Class_ScriptFunction] = ic->d();
+    ic = ic->changeVTable(ConstructorFunction::staticVTable());
+    classes[Class_ConstructorFunction] = ic->d();
+
+    classes[Class_ObjectProto] = classes[Class_Object]->addMember(id_constructor()->propertyKey(), Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == Heap::FunctionObject::Index_ProtoConstructor);
+
+    jsObjects[GeneratorProto] = memoryManager->allocObject<GeneratorPrototype>(classes[Class_Object]);
+    classes[Class_GeneratorObject] = newInternalClass(QV4::GeneratorObject::staticVTable(), generatorPrototype());
 
-    Scope scope(this);
     ScopedString str(scope);
-    internalClasses[Class_RegExp] = internalClasses[EngineBase::Class_Empty]->changeVTable(QV4::RegExp::staticVTable());
+    classes[Class_RegExp] = classes[Class_Empty]->changeVTable(QV4::RegExp::staticVTable());
     ic = newInternalClass(QV4::RegExpObject::staticVTable(), objectPrototype());
-    ic = ic->addMember(id_lastIndex(), Attr_NotEnumerable|Attr_NotConfigurable, &index);
-    Q_ASSERT(index == RegExpObject::Index_LastIndex);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("source"))), Attr_ReadOnly, &index);
-    Q_ASSERT(index == RegExpObject::Index_Source);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("global"))), Attr_ReadOnly, &index);
-    Q_ASSERT(index == RegExpObject::Index_Global);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("ignoreCase"))), Attr_ReadOnly, &index);
-    Q_ASSERT(index == RegExpObject::Index_IgnoreCase);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("multiline"))), Attr_ReadOnly, &index);
-    Q_ASSERT(index == RegExpObject::Index_Multiline);
-    jsObjects[RegExpProto] = memoryManager->allocObject<RegExpPrototype>(ic, objectPrototype());
-    internalClasses[Class_RegExpObject] = ic->changePrototype(regExpPrototype()->d());
-
-    ic = internalClasses[Class_ArrayObject]->addMember(id_index(), Attr_Data, &index);
-    Q_ASSERT(index == RegExpObject::Index_ArrayIndex);
-    internalClasses[EngineBase::Class_RegExpExecArray] = ic->addMember(id_input(), Attr_Data, &index);
-    Q_ASSERT(index == RegExpObject::Index_ArrayInput);
-
-    ic = newInternalClass(ErrorObject::staticVTable(), 0);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("stack"))), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable, &index);
-    Q_ASSERT(index == ErrorObject::Index_Stack);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("fileName"))), Attr_Data|Attr_NotEnumerable, &index);
-    Q_ASSERT(index == ErrorObject::Index_FileName);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("lineNumber"))), Attr_Data|Attr_NotEnumerable, &index);
-    internalClasses[EngineBase::Class_ErrorObject] = ic;
-    Q_ASSERT(index == ErrorObject::Index_LineNumber);
-    internalClasses[EngineBase::Class_ErrorObjectWithMessage] = ic->addMember((str = newIdentifier(QStringLiteral("message"))), Attr_Data|Attr_NotEnumerable, &index);
-    Q_ASSERT(index == ErrorObject::Index_Message);
-    ic = newInternalClass(ErrorObject::staticVTable(), objectPrototype());
-    ic = ic->addMember(id_constructor(), Attr_Data|Attr_NotEnumerable, &index);
-    Q_ASSERT(index == ErrorPrototype::Index_Constructor);
-    ic = ic->addMember((str = newIdentifier(QStringLiteral("message"))), Attr_Data|Attr_NotEnumerable, &index);
-    Q_ASSERT(index == ErrorPrototype::Index_Message);
-    internalClasses[EngineBase::Class_ErrorProto] = ic->addMember(id_name(), Attr_Data|Attr_NotEnumerable, &index);
-    Q_ASSERT(index == ErrorPrototype::Index_Name);
-
-    jsObjects[GetStack_Function] = BuiltinFunction::create(rootContext(), str = newIdentifier(QStringLiteral("stack")), ErrorObject::method_get_stack);
-    getStackFunction()->defineReadonlyProperty(id_length(), Primitive::fromInt32(0));
-
-    jsObjects[ErrorProto] = memoryManager->allocObject<ErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto], objectPrototype());
-    jsObjects[EvalErrorProto] = memoryManager->allocObject<EvalErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto]->changePrototype(errorPrototype()->d()), errorPrototype());
-    jsObjects[RangeErrorProto] = memoryManager->allocObject<RangeErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto]->changePrototype(errorPrototype()->d()), errorPrototype());
-    jsObjects[ReferenceErrorProto] = memoryManager->allocObject<ReferenceErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto]->changePrototype(errorPrototype()->d()), errorPrototype());
-    jsObjects[SyntaxErrorProto] = memoryManager->allocObject<SyntaxErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto]->changePrototype(errorPrototype()->d()), errorPrototype());
-    jsObjects[TypeErrorProto] = memoryManager->allocObject<TypeErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto]->changePrototype(errorPrototype()->d()), errorPrototype());
-    jsObjects[URIErrorProto] = memoryManager->allocObject<URIErrorPrototype>(internalClasses[EngineBase::Class_ErrorProto]->changePrototype(errorPrototype()->d()), errorPrototype());
-
-    jsObjects[VariantProto] = memoryManager->allocObject<VariantPrototype>();
-    Q_ASSERT(variantPrototype()->prototype() == objectPrototype()->d());
-
+    ic = ic->addMember(id_lastIndex()->propertyKey(), Attr_NotEnumerable|Attr_NotConfigurable, index);
+    Q_ASSERT(index->index == RegExpObject::Index_LastIndex);
+    jsObjects[RegExpProto] = memoryManager->allocObject<RegExpPrototype>(classes[Class_Object]);
+    classes[Class_RegExpObject] = ic->changePrototype(regExpPrototype()->d());
+
+    ic = classes[Class_ArrayObject]->addMember(id_index()->propertyKey(), Attr_Data, index);
+    Q_ASSERT(index->index == RegExpObject::Index_ArrayIndex);
+    classes[Class_RegExpExecArray] = ic->addMember(id_input()->propertyKey(), Attr_Data, index);
+    Q_ASSERT(index->index == RegExpObject::Index_ArrayInput);
+
+    ic = newInternalClass(ErrorObject::staticVTable(), nullptr);
+    ic = ic->addMember((str = newIdentifier(QStringLiteral("stack")))->propertyKey(), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == ErrorObject::Index_Stack);
+    Q_ASSERT(index->setterIndex == ErrorObject::Index_StackSetter);
+    ic = ic->addMember((str = newIdentifier(QStringLiteral("fileName")))->propertyKey(), Attr_Data|Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == ErrorObject::Index_FileName);
+    ic = ic->addMember((str = newIdentifier(QStringLiteral("lineNumber")))->propertyKey(), Attr_Data|Attr_NotEnumerable, index);
+    classes[Class_ErrorObject] = ic->d();
+    Q_ASSERT(index->index == ErrorObject::Index_LineNumber);
+    classes[Class_ErrorObjectWithMessage] = ic->addMember((str = newIdentifier(QStringLiteral("message")))->propertyKey(), Attr_Data|Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == ErrorObject::Index_Message);
+    ic = newInternalClass(Object::staticVTable(), objectPrototype());
+    ic = ic->addMember(id_constructor()->propertyKey(), Attr_Data|Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == ErrorPrototype::Index_Constructor);
+    ic = ic->addMember((str = newIdentifier(QStringLiteral("message")))->propertyKey(), Attr_Data|Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == ErrorPrototype::Index_Message);
+    classes[Class_ErrorProto] = ic->addMember(id_name()->propertyKey(), Attr_Data|Attr_NotEnumerable, index);
+    Q_ASSERT(index->index == ErrorPrototype::Index_Name);
+
+    classes[Class_ProxyObject] = classes[Class_Empty]->changeVTable(ProxyObject::staticVTable());
+    classes[Class_ProxyFunctionObject] = classes[Class_Empty]->changeVTable(ProxyFunctionObject::staticVTable());
+
+    jsObjects[GetStack_Function] = FunctionObject::createBuiltinFunction(this, str = newIdentifier(QStringLiteral("stack")), ErrorObject::method_get_stack, 0);
+
+    jsObjects[ErrorProto] = memoryManager->allocObject<ErrorPrototype>(classes[Class_ErrorProto]);
+    ic = classes[Class_ErrorProto]->changePrototype(errorPrototype()->d());
+    jsObjects[EvalErrorProto] = memoryManager->allocObject<EvalErrorPrototype>(ic->d());
+    jsObjects[RangeErrorProto] = memoryManager->allocObject<RangeErrorPrototype>(ic->d());
+    jsObjects[ReferenceErrorProto] = memoryManager->allocObject<ReferenceErrorPrototype>(ic->d());
+    jsObjects[SyntaxErrorProto] = memoryManager->allocObject<SyntaxErrorPrototype>(ic->d());
+    jsObjects[TypeErrorProto] = memoryManager->allocObject<TypeErrorPrototype>(ic->d());
+    jsObjects[URIErrorProto] = memoryManager->allocObject<URIErrorPrototype>(ic->d());
+
+    jsObjects[VariantProto] = memoryManager->allocate<VariantPrototype>();
+    Q_ASSERT(variantPrototype()->getPrototypeOf() == objectPrototype()->d());
+
+#if QT_CONFIG(qml_sequence_object)
     ic = newInternalClass(SequencePrototype::staticVTable(), SequencePrototype::defaultPrototype(this));
-    jsObjects[SequenceProto] = ScopedValue(scope, memoryManager->allocObject<SequencePrototype>(ic, SequencePrototype::defaultPrototype(this)));
+    jsObjects[SequenceProto] = ScopedValue(scope, memoryManager->allocObject<SequencePrototype>(ic->d()));
+#endif
 
     ExecutionContext *global = rootContext();
-    jsObjects[Object_Ctor] = memoryManager->allocObject<ObjectCtor>(global);
-    jsObjects[String_Ctor] = memoryManager->allocObject<StringCtor>(global);
-    jsObjects[Number_Ctor] = memoryManager->allocObject<NumberCtor>(global);
-    jsObjects[Boolean_Ctor] = memoryManager->allocObject<BooleanCtor>(global);
-    jsObjects[Array_Ctor] = memoryManager->allocObject<ArrayCtor>(global);
-    jsObjects[Function_Ctor] = memoryManager->allocObject<FunctionCtor>(global);
-    jsObjects[Date_Ctor] = memoryManager->allocObject<DateCtor>(global);
-    jsObjects[RegExp_Ctor] = memoryManager->allocObject<RegExpCtor>(global);
-    jsObjects[Error_Ctor] = memoryManager->allocObject<ErrorCtor>(global);
-    jsObjects[EvalError_Ctor] = memoryManager->allocObject<EvalErrorCtor>(global);
-    jsObjects[RangeError_Ctor] = memoryManager->allocObject<RangeErrorCtor>(global);
-    jsObjects[ReferenceError_Ctor] = memoryManager->allocObject<ReferenceErrorCtor>(global);
-    jsObjects[SyntaxError_Ctor] = memoryManager->allocObject<SyntaxErrorCtor>(global);
-    jsObjects[TypeError_Ctor] = memoryManager->allocObject<TypeErrorCtor>(global);
-    jsObjects[URIError_Ctor] = memoryManager->allocObject<URIErrorCtor>(global);
+
+    jsObjects[Object_Ctor] = memoryManager->allocate<ObjectCtor>(global);
+    jsObjects[String_Ctor] = memoryManager->allocate<StringCtor>(global);
+    jsObjects[Symbol_Ctor] = memoryManager->allocate<SymbolCtor>(global);
+    jsObjects[Number_Ctor] = memoryManager->allocate<NumberCtor>(global);
+    jsObjects[Boolean_Ctor] = memoryManager->allocate<BooleanCtor>(global);
+    jsObjects[Array_Ctor] = memoryManager->allocate<ArrayCtor>(global);
+    jsObjects[Function_Ctor] = memoryManager->allocate<FunctionCtor>(global);
+    jsObjects[GeneratorFunction_Ctor] = memoryManager->allocate<GeneratorFunctionCtor>(global);
+    jsObjects[Date_Ctor] = memoryManager->allocate<DateCtor>(global);
+    jsObjects[RegExp_Ctor] = memoryManager->allocate<RegExpCtor>(global);
+    jsObjects[Error_Ctor] = memoryManager->allocate<ErrorCtor>(global);
+    jsObjects[EvalError_Ctor] = memoryManager->allocate<EvalErrorCtor>(global);
+    jsObjects[RangeError_Ctor] = memoryManager->allocate<RangeErrorCtor>(global);
+    jsObjects[ReferenceError_Ctor] = memoryManager->allocate<ReferenceErrorCtor>(global);
+    jsObjects[SyntaxError_Ctor] = memoryManager->allocate<SyntaxErrorCtor>(global);
+    jsObjects[TypeError_Ctor] = memoryManager->allocate<TypeErrorCtor>(global);
+    jsObjects[URIError_Ctor] = memoryManager->allocate<URIErrorCtor>(global);
+    jsObjects[IteratorProto] = memoryManager->allocate<IteratorPrototype>();
+    jsObjects[ForInIteratorProto] = memoryManager->allocObject<ForInIteratorPrototype>(newInternalClass(ForInIteratorPrototype::staticVTable(), iteratorPrototype()));
+    jsObjects[MapIteratorProto] = memoryManager->allocObject<MapIteratorPrototype>(newInternalClass(SetIteratorPrototype::staticVTable(), iteratorPrototype()));
+    jsObjects[SetIteratorProto] = memoryManager->allocObject<SetIteratorPrototype>(newInternalClass(SetIteratorPrototype::staticVTable(), iteratorPrototype()));
+    jsObjects[ArrayIteratorProto] = memoryManager->allocObject<ArrayIteratorPrototype>(newInternalClass(ArrayIteratorPrototype::staticVTable(), iteratorPrototype()));
+    jsObjects[StringIteratorProto] = memoryManager->allocObject<StringIteratorPrototype>(newInternalClass(StringIteratorPrototype::staticVTable(), iteratorPrototype()));
+
+    str = newString(QStringLiteral("get [Symbol.species]"));
+    jsObjects[GetSymbolSpecies] = FunctionObject::createBuiltinFunction(this, str, ArrayPrototype::method_get_species, 0);
 
     static_cast<ObjectPrototype *>(objectPrototype())->init(this, objectCtor());
     static_cast<StringPrototype *>(stringPrototype())->init(this, stringCtor());
+    static_cast<SymbolPrototype *>(symbolPrototype())->init(this, symbolCtor());
     static_cast<NumberPrototype *>(numberPrototype())->init(this, numberCtor());
     static_cast<BooleanPrototype *>(booleanPrototype())->init(this, booleanCtor());
     static_cast<ArrayPrototype *>(arrayPrototype())->init(this, arrayCtor());
     static_cast<PropertyListPrototype *>(propertyListPrototype())->init(this);
     static_cast<DatePrototype *>(datePrototype())->init(this, dateCtor());
     static_cast<FunctionPrototype *>(functionPrototype())->init(this, functionCtor());
+    static_cast<GeneratorPrototype *>(generatorPrototype())->init(this, generatorFunctionCtor());
     static_cast<RegExpPrototype *>(regExpPrototype())->init(this, regExpCtor());
     static_cast<ErrorPrototype *>(errorPrototype())->init(this, errorCtor());
     static_cast<EvalErrorPrototype *>(evalErrorPrototype())->init(this, evalErrorCtor());
@@ -404,37 +498,79 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     static_cast<TypeErrorPrototype *>(typeErrorPrototype())->init(this, typeErrorCtor());
     static_cast<URIErrorPrototype *>(uRIErrorPrototype())->init(this, uRIErrorCtor());
 
+    static_cast<IteratorPrototype *>(iteratorPrototype())->init(this);
+    static_cast<ForInIteratorPrototype *>(forInIteratorPrototype())->init(this);
+    static_cast<MapIteratorPrototype *>(mapIteratorPrototype())->init(this);
+    static_cast<SetIteratorPrototype *>(setIteratorPrototype())->init(this);
+    static_cast<ArrayIteratorPrototype *>(arrayIteratorPrototype())->init(this);
+    static_cast<StringIteratorPrototype *>(stringIteratorPrototype())->init(this);
+
     static_cast<VariantPrototype *>(variantPrototype())->init();
+
+#if QT_CONFIG(qml_sequence_object)
     sequencePrototype()->cast<SequencePrototype>()->init();
+#endif
+
+    jsObjects[WeakMap_Ctor] = memoryManager->allocate<WeakMapCtor>(global);
+    jsObjects[WeakMapProto] = memoryManager->allocate<WeakMapPrototype>();
+    static_cast<WeakMapPrototype *>(weakMapPrototype())->init(this, weakMapCtor());
 
+    jsObjects[Map_Ctor] = memoryManager->allocate<MapCtor>(global);
+    jsObjects[MapProto] = memoryManager->allocate<MapPrototype>();
+    static_cast<MapPrototype *>(mapPrototype())->init(this, mapCtor());
+
+    jsObjects[WeakSet_Ctor] = memoryManager->allocate<WeakSetCtor>(global);
+    jsObjects[WeakSetProto] = memoryManager->allocate<WeakSetPrototype>();
+    static_cast<WeakSetPrototype *>(weakSetPrototype())->init(this, weakSetCtor());
+
+    jsObjects[Set_Ctor] = memoryManager->allocate<SetCtor>(global);
+    jsObjects[SetProto] = memoryManager->allocate<SetPrototype>();
+    static_cast<SetPrototype *>(setPrototype())->init(this, setCtor());
+
+    //
+    // promises
+    //
+
+    jsObjects[Promise_Ctor] = memoryManager->allocate<PromiseCtor>(global);
+    jsObjects[PromiseProto] = memoryManager->allocate<PromisePrototype>();
+    static_cast<PromisePrototype *>(promisePrototype())->init(this, promiseCtor());
 
     // typed arrays
 
-    jsObjects[ArrayBuffer_Ctor] = memoryManager->allocObject<ArrayBufferCtor>(global);
-    jsObjects[ArrayBufferProto] = memoryManager->allocObject<ArrayBufferPrototype>();
+    jsObjects[SharedArrayBuffer_Ctor] = memoryManager->allocate<SharedArrayBufferCtor>(global);
+    jsObjects[SharedArrayBufferProto] = memoryManager->allocate<SharedArrayBufferPrototype>();
+    static_cast<SharedArrayBufferPrototype *>(sharedArrayBufferPrototype())->init(this, sharedArrayBufferCtor());
+
+    jsObjects[ArrayBuffer_Ctor] = memoryManager->allocate<ArrayBufferCtor>(global);
+    jsObjects[ArrayBufferProto] = memoryManager->allocate<ArrayBufferPrototype>();
     static_cast<ArrayBufferPrototype *>(arrayBufferPrototype())->init(this, arrayBufferCtor());
 
-    jsObjects[DataView_Ctor] = memoryManager->allocObject<DataViewCtor>(global);
-    jsObjects[DataViewProto] = memoryManager->allocObject<DataViewPrototype>();
+    jsObjects[DataView_Ctor] = memoryManager->allocate<DataViewCtor>(global);
+    jsObjects[DataViewProto] = memoryManager->allocate<DataViewPrototype>();
     static_cast<DataViewPrototype *>(dataViewPrototype())->init(this, dataViewCtor());
-    jsObjects[ValueTypeProto] = (Heap::Base *) 0;
-    jsObjects[SignalHandlerProto] = (Heap::Base *) 0;
+    jsObjects[ValueTypeProto] = (Heap::Base *) nullptr;
+    jsObjects[SignalHandlerProto] = (Heap::Base *) nullptr;
+
+    jsObjects[IntrinsicTypedArray_Ctor] = memoryManager->allocate<IntrinsicTypedArrayCtor>(global);
+    jsObjects[IntrinsicTypedArrayProto] = memoryManager->allocate<IntrinsicTypedArrayPrototype>();
+    static_cast<IntrinsicTypedArrayPrototype *>(intrinsicTypedArrayPrototype())
+            ->init(this, static_cast<IntrinsicTypedArrayCtor *>(intrinsicTypedArrayCtor()));
 
-    for (int i = 0; i < Heap::TypedArray::NTypes; ++i) {
-        static_cast<Value &>(typedArrayCtors[i]) = memoryManager->allocObject<TypedArrayCtor>(global, Heap::TypedArray::Type(i));
-        static_cast<Value &>(typedArrayPrototype[i]) = memoryManager->allocObject<TypedArrayPrototype>(Heap::TypedArray::Type(i));
+    for (int i = 0; i < NTypedArrayTypes; ++i) {
+        static_cast<Value &>(typedArrayCtors[i]) = memoryManager->allocate<TypedArrayCtor>(global, Heap::TypedArray::Type(i));
+        static_cast<Value &>(typedArrayPrototype[i]) = memoryManager->allocate<TypedArrayPrototype>(Heap::TypedArray::Type(i));
         typedArrayPrototype[i].as<TypedArrayPrototype>()->init(this, static_cast<TypedArrayCtor *>(typedArrayCtors[i].as<Object>()));
     }
 
     //
     // set up the global object
     //
-    rootContext()->d()->global.set(scope.engine, globalObject->d());
-    rootContext()->d()->callData->thisObject = globalObject;
+    rootContext()->d()->activation.set(scope.engine, globalObject->d());
     Q_ASSERT(globalObject->d()->vtable());
 
     globalObject->defineDefaultProperty(QStringLiteral("Object"), *objectCtor());
     globalObject->defineDefaultProperty(QStringLiteral("String"), *stringCtor());
+    globalObject->defineDefaultProperty(QStringLiteral("Symbol"), *symbolCtor());
     FunctionObject *numberObject = numberCtor();
     globalObject->defineDefaultProperty(QStringLiteral("Number"), *numberObject);
     globalObject->defineDefaultProperty(QStringLiteral("Boolean"), *booleanCtor());
@@ -449,21 +585,31 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     globalObject->defineDefaultProperty(QStringLiteral("SyntaxError"), *syntaxErrorCtor());
     globalObject->defineDefaultProperty(QStringLiteral("TypeError"), *typeErrorCtor());
     globalObject->defineDefaultProperty(QStringLiteral("URIError"), *uRIErrorCtor());
+    globalObject->defineDefaultProperty(QStringLiteral("Promise"), *promiseCtor());
 
+    globalObject->defineDefaultProperty(QStringLiteral("SharedArrayBuffer"), *sharedArrayBufferCtor());
     globalObject->defineDefaultProperty(QStringLiteral("ArrayBuffer"), *arrayBufferCtor());
     globalObject->defineDefaultProperty(QStringLiteral("DataView"), *dataViewCtor());
-    for (int i = 0; i < Heap::TypedArray::NTypes; ++i)
-        globalObject->defineDefaultProperty((str = typedArrayCtors[i].as<FunctionObject>()->name())->toQString(), typedArrayCtors[i]);
+    globalObject->defineDefaultProperty(QStringLiteral("WeakSet"), *weakSetCtor());
+    globalObject->defineDefaultProperty(QStringLiteral("Set"), *setCtor());
+    globalObject->defineDefaultProperty(QStringLiteral("WeakMap"), *weakMapCtor());
+    globalObject->defineDefaultProperty(QStringLiteral("Map"), *mapCtor());
+
+    for (int i = 0; i < NTypedArrayTypes; ++i)
+        globalObject->defineDefaultProperty((str = typedArrayCtors[i].as<FunctionObject>()->name()), typedArrayCtors[i]);
     ScopedObject o(scope);
-    globalObject->defineDefaultProperty(QStringLiteral("Math"), (o = memoryManager->allocObject<MathObject>()));
-    globalObject->defineDefaultProperty(QStringLiteral("JSON"), (o = memoryManager->allocObject<JsonObject>()));
+    globalObject->defineDefaultProperty(QStringLiteral("Atomics"), (o = memoryManager->allocate<Atomics>()));
+    globalObject->defineDefaultProperty(QStringLiteral("Math"), (o = memoryManager->allocate<MathObject>()));
+    globalObject->defineDefaultProperty(QStringLiteral("JSON"), (o = memoryManager->allocate<JsonObject>()));
+    globalObject->defineDefaultProperty(QStringLiteral("Reflect"), (o = memoryManager->allocate<Reflect>()));
+    globalObject->defineDefaultProperty(QStringLiteral("Proxy"), (o = memoryManager->allocate<Proxy>(rootContext())));
 
-    globalObject->defineReadonlyProperty(QStringLiteral("undefined"), Primitive::undefinedValue());
-    globalObject->defineReadonlyProperty(QStringLiteral("NaN"), Primitive::fromDouble(std::numeric_limits<double>::quiet_NaN()));
-    globalObject->defineReadonlyProperty(QStringLiteral("Infinity"), Primitive::fromDouble(Q_INFINITY));
+    globalObject->defineReadonlyProperty(QStringLiteral("undefined"), Value::undefinedValue());
+    globalObject->defineReadonlyProperty(QStringLiteral("NaN"), Value::fromDouble(std::numeric_limits<double>::quiet_NaN()));
+    globalObject->defineReadonlyProperty(QStringLiteral("Infinity"), Value::fromDouble(Q_INFINITY));
 
 
-    jsObjects[Eval_Function] = memoryManager->allocObject<EvalFunction>(global);
+    jsObjects[Eval_Function] = memoryManager->allocate<EvalFunction>(global);
     globalObject->defineDefaultProperty(QStringLiteral("eval"), *evalFunction());
 
     // ES6: 20.1.2.12 &  20.1.2.13:
@@ -475,11 +621,8 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
         Scope scope(this);
         ScopedString pi(scope, newIdentifier(piString));
         ScopedString pf(scope, newIdentifier(pfString));
-        ExecutionContext *global = rootContext();
-        ScopedFunctionObject parseIntFn(scope, BuiltinFunction::create(global, pi, GlobalFunctions::method_parseInt));
-        ScopedFunctionObject parseFloatFn(scope, BuiltinFunction::create(global, pf, GlobalFunctions::method_parseFloat));
-        parseIntFn->defineReadonlyConfigurableProperty(id_length(), Primitive::fromInt32(2));
-        parseFloatFn->defineReadonlyConfigurableProperty(id_length(), Primitive::fromInt32(1));
+        ScopedFunctionObject parseIntFn(scope, FunctionObject::createBuiltinFunction(this, pi, GlobalFunctions::method_parseInt, 2));
+        ScopedFunctionObject parseFloatFn(scope, FunctionObject::createBuiltinFunction(this, pf, GlobalFunctions::method_parseFloat, 1));
         globalObject->defineDefaultProperty(piString, parseIntFn);
         globalObject->defineDefaultProperty(pfString, parseFloatFn);
         numberObject->defineDefaultProperty(piString, parseIntFn);
@@ -495,30 +638,36 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     globalObject->defineDefaultProperty(QStringLiteral("escape"), GlobalFunctions::method_escape, 1);
     globalObject->defineDefaultProperty(QStringLiteral("unescape"), GlobalFunctions::method_unescape, 1);
 
-    ScopedString name(scope, newString(QStringLiteral("thrower")));
-    jsObjects[ThrowerObject] = BuiltinFunction::create(global, name, ::throwTypeError);
+    ScopedFunctionObject t(scope, memoryManager->allocate<FunctionObject>(rootContext(), nullptr, ::throwTypeError));
+    t->defineReadonlyProperty(id_length(), Value::fromInt32(0));
+    t->setInternalClass(t->internalClass()->frozen());
+    jsObjects[ThrowerObject] = t;
+
+    ScopedProperty pd(scope);
+    pd->value = thrower();
+    pd->set = thrower();
+    functionPrototype()->insertMember(id_caller(), pd, Attr_Accessor|Attr_ReadOnly_ButConfigurable);
+    functionPrototype()->insertMember(id_arguments(), pd, Attr_Accessor|Attr_ReadOnly_ButConfigurable);
 }
 
 ExecutionEngine::~ExecutionEngine()
 {
-#ifndef QT_NO_QML_DEBUGGER
-    delete m_debugger;
-    m_debugger = 0;
-    delete m_profiler;
-    m_profiler = 0;
-#endif
+    if (Q_UNLIKELY(lcTracingAll().isDebugEnabled())) {
+        for (auto cu : compilationUnits) {
+            for (auto f : qAsConst(cu->runtimeFunctions))
+                qCDebug(lcTracingAll).noquote().nospace() << f->traceInfoToString();
+        }
+    }
+
+    modules.clear();
     delete m_multiplyWrappedQObjects;
-    m_multiplyWrappedQObjects = 0;
+    m_multiplyWrappedQObjects = nullptr;
     delete identifierTable;
     delete memoryManager;
 
-    QSet<QV4::CompiledData::CompilationUnit*> remainingUnits;
-    qSwap(compilationUnits, remainingUnits);
-    for (QV4::CompiledData::CompilationUnit *unit : qAsConst(remainingUnits))
-        unit->unlink();
+    while (!compilationUnits.isEmpty())
+        (*compilationUnits.begin())->unlink();
 
-    internalClasses[Class_Empty]->destroy();
-    delete classPool;
     delete bumperPointerAllocator;
     delete regExpCache;
     delete regExpAllocator;
@@ -527,99 +676,99 @@ ExecutionEngine::~ExecutionEngine()
     delete jsStack;
     gcStack->deallocate();
     delete gcStack;
-    delete [] argumentsAccessors;
 }
 
-#ifndef QT_NO_QML_DEBUGGER
+ExecutionContext *ExecutionEngine::currentContext() const
+{
+    return static_cast<ExecutionContext *>(&currentStackFrame->jsFrame->context);
+}
+
+#if QT_CONFIG(qml_debug)
 void ExecutionEngine::setDebugger(Debugging::Debugger *debugger)
 {
     Q_ASSERT(!m_debugger);
-    m_debugger = debugger;
+    m_debugger.reset(debugger);
 }
 
 void ExecutionEngine::setProfiler(Profiling::Profiler *profiler)
 {
     Q_ASSERT(!m_profiler);
-    m_profiler = profiler;
+    m_profiler.reset(profiler);
 }
-#endif // QT_NO_QML_DEBUGGER
+#endif // QT_CONFIG(qml_debug)
 
 void ExecutionEngine::initRootContext()
 {
     Scope scope(this);
-    Scoped<GlobalContext> r(scope, memoryManager->allocManaged<GlobalContext>(
-                                sizeof(GlobalContext::Data) + sizeof(CallData)));
-    r->d_unchecked()->init(this);
-    r->d()->callData = reinterpret_cast<CallData *>(r->d() + 1);
-    r->d()->callData->tag = quint32(Value::ValueTypeInternal::Integer);
-    r->d()->callData->argc = 0;
-    r->d()->callData->thisObject = globalObject;
-    r->d()->callData->args[0] = Encode::undefined();
+    Scoped<ExecutionContext> r(scope, memoryManager->allocManaged<ExecutionContext>(sizeof(ExecutionContext::Data)));
+    r->d_unchecked()->init(Heap::ExecutionContext::Type_GlobalContext);
+    r->d()->activation.set(this, globalObject->d());
     jsObjects[RootContext] = r;
+    jsObjects[ScriptContext] = r;
     jsObjects[IntegerNull] = Encode((int)0);
-
-    currentContext = static_cast<ExecutionContext *>(jsObjects + RootContext);
-    current = currentContext->d();
-}
-
-InternalClass *ExecutionEngine::newClass(const InternalClass &other)
-{
-    return new (classPool) InternalClass(other);
 }
 
-ExecutionContext *ExecutionEngine::pushGlobalContext()
+Heap::InternalClass *ExecutionEngine::newClass(Heap::InternalClass *other)
 {
-    pushContext(rootContext()->d());
-
-    Q_ASSERT(current == rootContext()->d());
-    return currentContext;
+    Heap::InternalClass *ic = memoryManager->allocIC<InternalClass>();
+    ic->init(other);
+    return ic;
 }
 
-InternalClass *ExecutionEngine::newInternalClass(const VTable *vtable, Object *prototype)
+Heap::InternalClass *ExecutionEngine::newInternalClass(const VTable *vtable, Object *prototype)
 {
-    return internalClasses[EngineBase::Class_Empty]->changeVTable(vtable)->changePrototype(prototype ? prototype->d() : 0);
+    Scope scope(this);
+    Scoped<InternalClass> ic(scope, internalClasses(Class_Empty)->changeVTable(vtable));
+    return ic->changePrototype(prototype ? prototype->d() : nullptr);
 }
 
 Heap::Object *ExecutionEngine::newObject()
 {
-    return memoryManager->allocObject<Object>();
+    return memoryManager->allocate<Object>();
 }
 
-Heap::Object *ExecutionEngine::newObject(InternalClass *internalClass, QV4::Object *prototype)
+Heap::Object *ExecutionEngine::newObject(Heap::InternalClass *internalClass)
 {
-    return memoryManager->allocObject<Object>(internalClass, prototype);
+    return memoryManager->allocObject<Object>(internalClass);
 }
 
 Heap::String *ExecutionEngine::newString(const QString &s)
 {
-    Scope scope(this);
-    return ScopedString(scope, memoryManager->allocWithStringData<String>(s.length() * sizeof(QChar), s))->d();
+    return memoryManager->allocWithStringData<String>(s.length() * sizeof(QChar), s);
 }
 
 Heap::String *ExecutionEngine::newIdentifier(const QString &text)
 {
-    return identifierTable->insertString(text);
+    Scope scope(this);
+    ScopedString s(scope, memoryManager->allocWithStringData<String>(text.length() * sizeof(QChar), text));
+    s->toPropertyKey();
+    return s->d();
 }
 
 Heap::Object *ExecutionEngine::newStringObject(const String *string)
 {
-    return memoryManager->allocObject<StringObject>(string);
+    return memoryManager->allocate<StringObject>(string);
+}
+
+Heap::Object *ExecutionEngine::newSymbolObject(const Symbol *symbol)
+{
+    return memoryManager->allocObject<SymbolObject>(classes[Class_SymbolObject], symbol);
 }
 
 Heap::Object *ExecutionEngine::newNumberObject(double value)
 {
-    return memoryManager->allocObject<NumberObject>(value);
+    return memoryManager->allocate<NumberObject>(value);
 }
 
 Heap::Object *ExecutionEngine::newBooleanObject(bool b)
 {
-    return memoryManager->allocObject<BooleanObject>(b);
+    return memoryManager->allocate<BooleanObject>(b);
 }
 
 Heap::ArrayObject *ExecutionEngine::newArrayObject(int count)
 {
     Scope scope(this);
-    ScopedArrayObject object(scope, memoryManager->allocObject<ArrayObject>());
+    ScopedArrayObject object(scope, memoryManager->allocate<ArrayObject>());
 
     if (count) {
         if (count < 0x1000)
@@ -632,7 +781,7 @@ Heap::ArrayObject *ExecutionEngine::newArrayObject(int count)
 Heap::ArrayObject *ExecutionEngine::newArrayObject(const Value *values, int length)
 {
     Scope scope(this);
-    ScopedArrayObject a(scope, memoryManager->allocObject<ArrayObject>());
+    ScopedArrayObject a(scope, memoryManager->allocate<ArrayObject>());
 
     if (length) {
         size_t size = sizeof(Heap::ArrayData) + (length-1)*sizeof(Value);
@@ -653,76 +802,76 @@ Heap::ArrayObject *ExecutionEngine::newArrayObject(const Value *values, int leng
 
 Heap::ArrayObject *ExecutionEngine::newArrayObject(const QStringList &list)
 {
-    Scope scope(this);
-    ScopedArrayObject object(scope, memoryManager->allocObject<ArrayObject>(list));
-    return object->d();
+    return memoryManager->allocate<ArrayObject>(list);
 }
 
-Heap::ArrayObject *ExecutionEngine::newArrayObject(InternalClass *internalClass, Object *prototype)
+Heap::ArrayObject *ExecutionEngine::newArrayObject(Heap::InternalClass *internalClass)
 {
-    Scope scope(this);
-    ScopedArrayObject object(scope, memoryManager->allocObject<ArrayObject>(internalClass, prototype));
-    return object->d();
+    return memoryManager->allocObject<ArrayObject>(internalClass);
 }
 
 Heap::ArrayBuffer *ExecutionEngine::newArrayBuffer(const QByteArray &array)
 {
-    return memoryManager->allocObject<ArrayBuffer>(array);
+    return memoryManager->allocate<ArrayBuffer>(array);
 }
 
 Heap::ArrayBuffer *ExecutionEngine::newArrayBuffer(size_t length)
 {
-    return memoryManager->allocObject<ArrayBuffer>(length);
+    return memoryManager->allocate<ArrayBuffer>(length);
 }
 
 
 Heap::DateObject *ExecutionEngine::newDateObject(const Value &value)
 {
-    return memoryManager->allocObject<DateObject>(value);
+    return memoryManager->allocate<DateObject>(value);
 }
 
 Heap::DateObject *ExecutionEngine::newDateObject(const QDateTime &dt)
 {
     Scope scope(this);
-    Scoped<DateObject> object(scope, memoryManager->allocObject<DateObject>(dt));
+    Scoped<DateObject> object(scope, memoryManager->allocate<DateObject>(dt));
     return object->d();
 }
 
 Heap::DateObject *ExecutionEngine::newDateObjectFromTime(const QTime &t)
 {
     Scope scope(this);
-    Scoped<DateObject> object(scope, memoryManager->allocObject<DateObject>(t));
+    Scoped<DateObject> object(scope, memoryManager->allocate<DateObject>(t));
     return object->d();
 }
 
 Heap::RegExpObject *ExecutionEngine::newRegExpObject(const QString &pattern, int flags)
 {
-    bool global = (flags & IR::RegExp::RegExp_Global);
-    bool ignoreCase = false;
-    bool multiline = false;
-    if (flags & IR::RegExp::RegExp_IgnoreCase)
-        ignoreCase = true;
-    if (flags & IR::RegExp::RegExp_Multiline)
-        multiline = true;
-
     Scope scope(this);
-    Scoped<RegExp> re(scope, RegExp::create(this, pattern, ignoreCase, multiline));
-    return newRegExpObject(re, global);
+    Scoped<RegExp> re(scope, RegExp::create(this, pattern, static_cast<CompiledData::RegExp::Flags>(flags)));
+    return newRegExpObject(re);
 }
 
-Heap::RegExpObject *ExecutionEngine::newRegExpObject(RegExp *re, bool global)
+Heap::RegExpObject *ExecutionEngine::newRegExpObject(RegExp *re)
 {
-    return memoryManager->allocObject<RegExpObject>(re, global);
+    return memoryManager->allocate<RegExpObject>(re);
 }
 
 Heap::RegExpObject *ExecutionEngine::newRegExpObject(const QRegExp &re)
 {
-    return memoryManager->allocObject<RegExpObject>(re);
+    return memoryManager->allocate<RegExpObject>(re);
 }
 
+#if QT_CONFIG(regularexpression)
+Heap::RegExpObject *ExecutionEngine::newRegExpObject(const QRegularExpression &re)
+{
+    return memoryManager->allocate<RegExpObject>(re);
+}
+#endif
+
 Heap::Object *ExecutionEngine::newErrorObject(const Value &value)
 {
-    return ErrorObject::create<ErrorObject>(this, value);
+    return ErrorObject::create<ErrorObject>(this, value, errorCtor());
+}
+
+Heap::Object *ExecutionEngine::newErrorObject(const QString &message)
+{
+    return ErrorObject::create<ErrorObject>(this, message);
 }
 
 Heap::Object *ExecutionEngine::newSyntaxErrorObject(const QString &message)
@@ -759,38 +908,93 @@ Heap::Object *ExecutionEngine::newRangeErrorObject(const QString &message)
 
 Heap::Object *ExecutionEngine::newURIErrorObject(const Value &message)
 {
+    return ErrorObject::create<URIErrorObject>(this, message, uRIErrorCtor());
+}
+
+Heap::PromiseObject *ExecutionEngine::newPromiseObject()
+{
+    if (!m_reactionHandler) {
+        m_reactionHandler.reset(new Promise::ReactionHandler);
+    }
+
+    Scope scope(this);
+    Scoped<PromiseObject> object(scope, memoryManager->allocate<PromiseObject>(this));
+    return object->d();
+}
+
+Heap::Object *ExecutionEngine::newPromiseObject(const QV4::FunctionObject *thisObject, const QV4::PromiseCapability *capability)
+{
+    if (!m_reactionHandler) {
+        m_reactionHandler.reset(new Promise::ReactionHandler);
+    }
+
+    Scope scope(this);
+    Scoped<CapabilitiesExecutorWrapper> executor(scope,  memoryManager->allocate<CapabilitiesExecutorWrapper>());
+    executor->d()->capabilities.set(this, capability->d());
+    executor->insertMember(id_length(), Primitive::fromInt32(2), Attr_NotWritable|Attr_NotEnumerable);
+
+    ScopedObject object(scope, thisObject->callAsConstructor(executor, 1));
+    return object->d();
+}
+
+Promise::ReactionHandler *ExecutionEngine::getPromiseReactionHandler()
+{
+    Q_ASSERT(m_reactionHandler);
+    return m_reactionHandler.data();
+}
+
+Heap::Object *ExecutionEngine::newURIErrorObject(const QString &message)
+{
     return ErrorObject::create<URIErrorObject>(this, message);
 }
 
+Heap::Object *ExecutionEngine::newEvalErrorObject(const QString &message)
+{
+    return ErrorObject::create<EvalErrorObject>(this, message);
+}
+
 Heap::Object *ExecutionEngine::newVariantObject(const QVariant &v)
 {
-    return memoryManager->allocObject<VariantObject>(v);
+    return memoryManager->allocate<VariantObject>(v);
 }
 
-Heap::Object *ExecutionEngine::newForEachIteratorObject(Object *o)
+Heap::Object *ExecutionEngine::newForInIteratorObject(Object *o)
 {
     Scope scope(this);
-    ScopedObject obj(scope, memoryManager->allocObject<ForEachIteratorObject>(o));
+    ScopedObject obj(scope, memoryManager->allocate<ForInIteratorObject>(o));
     return obj->d();
 }
 
-Heap::QmlContext *ExecutionEngine::qmlContext() const
+Heap::Object *ExecutionEngine::newMapIteratorObject(Object *o)
 {
-    Heap::ExecutionContext *ctx = current;
+    return memoryManager->allocate<MapIteratorObject>(o->d(), this);
+}
 
-    // get the correct context when we're within a builtin function
-    if (ctx->type == Heap::ExecutionContext::Type_SimpleCallContext && !ctx->outer)
-        ctx = parentContext(currentContext)->d();
+Heap::Object *ExecutionEngine::newSetIteratorObject(Object *o)
+{
+    return memoryManager->allocate<SetIteratorObject>(o->d(), this);
+}
+
+Heap::Object *ExecutionEngine::newArrayIteratorObject(Object *o)
+{
+    return memoryManager->allocate<ArrayIteratorObject>(o->d(), this);
+}
+
+Heap::QmlContext *ExecutionEngine::qmlContext() const
+{
+    if (!currentStackFrame)
+        return nullptr;
+    Heap::ExecutionContext *ctx = currentContext()->d();
 
     if (ctx->type != Heap::ExecutionContext::Type_QmlContext && !ctx->outer)
-        return 0;
+        return nullptr;
 
     while (ctx->outer && ctx->outer->type != Heap::ExecutionContext::Type_GlobalContext)
         ctx = ctx->outer;
 
     Q_ASSERT(ctx);
     if (ctx->type != Heap::ExecutionContext::Type_QmlContext)
-        return 0;
+        return nullptr;
 
     return static_cast<Heap::QmlContext *>(ctx);
 }
@@ -799,91 +1003,46 @@ QObject *ExecutionEngine::qmlScopeObject() const
 {
     Heap::QmlContext *ctx = qmlContext();
     if (!ctx)
-        return 0;
-
-    return ctx->qml->scopeObject;
-}
-
-ReturnedValue ExecutionEngine::qmlSingletonWrapper(String *name)
-{
-    QQmlContextData *ctx = callingQmlContext();
-    if (!ctx->imports)
-        return Encode::undefined();
-    // Search for attached properties, enums and imported scripts
-    QQmlTypeNameCache::Result r = ctx->imports->query(name);
-
-    Q_ASSERT(r.isValid());
-    Q_ASSERT(r.type);
-    Q_ASSERT(r.type->isSingleton());
-
-    QQmlType::SingletonInstanceInfo *siinfo = r.type->singletonInstanceInfo();
-    QQmlEngine *e = qmlEngine();
-    siinfo->init(e);
+        return nullptr;
 
-    if (QObject *qobjectSingleton = siinfo->qobjectApi(e))
-        return QV4::QObjectWrapper::wrap(this, qobjectSingleton);
-    return QJSValuePrivate::convertedToValue(this, siinfo->scriptApi(e));
+    return ctx->qml()->scopeObject;
 }
 
 QQmlContextData *ExecutionEngine::callingQmlContext() const
 {
     Heap::QmlContext *ctx = qmlContext();
     if (!ctx)
-        return 0;
+        return nullptr;
 
-    return ctx->qml->context->contextData();
+    return ctx->qml()->context->contextData();
 }
 
-QVector<StackFrame> ExecutionEngine::stackTrace(int frameLimit) const
+StackTrace ExecutionEngine::stackTrace(int frameLimit) const
 {
     Scope scope(const_cast<ExecutionEngine *>(this));
     ScopedString name(scope);
-    QVector<StackFrame> stack;
-
-    ExecutionContext *c = currentContext;
-    while (c && frameLimit) {
-        QV4::Function *function = c->getFunction();
-        if (function) {
-            StackFrame frame;
-            frame.source = function->sourceFile();
-            name = function->name();
-            frame.function = name->toQString();
-
-            // line numbers can be negative for places where you can't set a real breakpoint
-            frame.line = qAbs(c->d()->lineNumber);
-            frame.column = -1;
-
+    StackTrace stack;
+
+    CppStackFrame *f = currentStackFrame;
+    while (f && frameLimit) {
+        QV4::StackFrame frame;
+        frame.source = f->source();
+        frame.function = f->function();
+        frame.line = qAbs(f->lineNumber());
+        frame.column = -1;
+        stack.append(frame);
+        if (f->isTailCalling) {
+            QV4::StackFrame frame;
+            frame.function = QStringLiteral("[elided tail calls]");
             stack.append(frame);
-            --frameLimit;
         }
-        c = parentContext(c);
+        --frameLimit;
+        f = f->parent;
     }
 
-    if (frameLimit && globalCode) {
-        StackFrame frame;
-        frame.source = globalCode->sourceFile();
-        frame.function = globalCode->name()->toQString();
-        frame.line = rootContext()->d()->lineNumber;
-        frame.column = -1;
-
-        stack.append(frame);
-    }
     return stack;
 }
 
-StackFrame ExecutionEngine::currentStackFrame() const
-{
-    StackFrame frame;
-    frame.line = -1;
-    frame.column = -1;
-
-    QVector<StackFrame> trace = stackTrace(/*limit*/ 1);
-    if (!trace.isEmpty())
-        frame = trace.first();
-
-    return frame;
-}
-
 /* Helper and "C" linkage exported function to format a GDBMI stacktrace for
  * invocation by a debugger.
  * Sample GDB invocation: print qt_v4StackTrace((void*)0x7fffffffb290)
@@ -924,18 +1083,17 @@ QUrl ExecutionEngine::resolvedUrl(const QString &file)
         return src;
 
     QUrl base;
-    ExecutionContext *c = currentContext;
-    while (c) {
-        SimpleCallContext *callCtx = c->asSimpleCallContext();
-        if (callCtx && callCtx->d()->v4Function) {
-            base.setUrl(callCtx->d()->v4Function->sourceFile());
+    CppStackFrame *f = currentStackFrame;
+    while (f) {
+        if (f->v4Function) {
+            base = f->v4Function->finalUrl();
             break;
         }
-        c = parentContext(c);
+        f = f->parent;
     }
 
     if (base.isEmpty() && globalCode)
-        base.setUrl(globalCode->sourceFile());
+        base = globalCode->finalUrl();
 
     if (base.isEmpty())
         return src;
@@ -943,49 +1101,19 @@ QUrl ExecutionEngine::resolvedUrl(const QString &file)
     return base.resolved(src);
 }
 
-void ExecutionEngine::requireArgumentsAccessors(int n)
-{
-    if (n <= nArgumentsAccessors)
-        return;
-
-    Scope scope(this);
-    ScopedFunctionObject get(scope);
-    ScopedFunctionObject set(scope);
-
-    if (n >= nArgumentsAccessors) {
-        Property *oldAccessors = argumentsAccessors;
-        int oldSize = nArgumentsAccessors;
-        nArgumentsAccessors = qMax(8, n);
-        argumentsAccessors = new Property[nArgumentsAccessors];
-        if (oldAccessors) {
-            memcpy(argumentsAccessors, oldAccessors, oldSize*sizeof(Property));
-            delete [] oldAccessors;
-        }
-        ExecutionContext *global = rootContext();
-        for (int i = oldSize; i < nArgumentsAccessors; ++i) {
-            argumentsAccessors[i].value = ScopedValue(scope, memoryManager->allocObject<ArgumentsGetterFunction>(global, i));
-            argumentsAccessors[i].set = ScopedValue(scope, memoryManager->allocObject<ArgumentsSetterFunction>(global, i));
-        }
-    }
-}
-
 void ExecutionEngine::markObjects(MarkStack *markStack)
 {
-    identifierTable->mark(markStack);
+    for (int i = 0; i < NClasses; ++i)
+        if (classes[i])
+            classes[i]->mark(markStack);
+    markStack->drain();
 
-    for (int i = 0; i < nArgumentsAccessors; ++i) {
-        const Property &pd = argumentsAccessors[i];
-        if (Heap::FunctionObject *getter = pd.getter())
-            getter->mark(markStack);
-        if (Heap::FunctionObject *setter = pd.setter())
-            setter->mark(markStack);
-    }
+    identifierTable->markObjects(markStack);
 
-    classPool->markObjects(markStack);
-
-    for (QSet<CompiledData::CompilationUnit*>::ConstIterator it = compilationUnits.constBegin(), end = compilationUnits.constEnd();
-         it != end; ++it)
-        (*it)->markObjects(markStack);
+    for (auto compilationUnit: compilationUnits) {
+        compilationUnit->markObjects(markStack);
+        markStack->drain();
+    }
 }
 
 ReturnedValue ExecutionEngine::throwError(const Value &value)
@@ -1020,7 +1148,7 @@ ReturnedValue ExecutionEngine::catchException(StackTrace *trace)
     exceptionStackTrace.clear();
     hasException = false;
     ReturnedValue res = exceptionValue->asReturnedValue();
-    *exceptionValue = Primitive::emptyValue();
+    *exceptionValue = Value::emptyValue();
     return res;
 }
 
@@ -1123,12 +1251,7 @@ QQmlError ExecutionEngine::catchExceptionAsQmlError()
         error.setColumn(frame.column);
     }
     QV4::Scoped<QV4::ErrorObject> errorObj(scope, exception);
-    if (!!errorObj && errorObj->asSyntaxError()) {
-        QV4::ScopedString m(scope, newString(QStringLiteral("message")));
-        QV4::ScopedValue v(scope, errorObj->get(m));
-        error.setDescription(v->toQStringNoThrow());
-    } else
-        error.setDescription(exception->toQStringNoThrow());
+    error.setDescription(exception->toQStringNoThrow());
     return error;
 }
 
@@ -1137,11 +1260,12 @@ QQmlError ExecutionEngine::catchExceptionAsQmlError()
 typedef QSet<QV4::Heap::Object *> V4ObjectSet;
 static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int typeHint, bool createJSValueForObjects, V4ObjectSet *visitedObjects);
 static QObject *qtObjectFromJS(QV4::ExecutionEngine *engine, const QV4::Value &value);
-static QVariant objectToVariant(QV4::ExecutionEngine *e, const QV4::Object *o, V4ObjectSet *visitedObjects = 0);
+static QVariant objectToVariant(QV4::ExecutionEngine *e, const QV4::Object *o, V4ObjectSet *visitedObjects = nullptr);
 static bool convertToNativeQObject(QV4::ExecutionEngine *e, const QV4::Value &value,
                             const QByteArray &targetType,
                             void **result);
 static QV4::ReturnedValue variantListToJS(QV4::ExecutionEngine *v4, const QVariantList &lst);
+static QV4::ReturnedValue sequentialIterableToJS(QV4::ExecutionEngine *v4, const QSequentialIterable &lst);
 static QV4::ReturnedValue variantMapToJS(QV4::ExecutionEngine *v4, const QVariantMap &vmap);
 static QV4::ReturnedValue variantToJS(QV4::ExecutionEngine *v4, const QVariant &value)
 {
@@ -1151,7 +1275,7 @@ static QV4::ReturnedValue variantToJS(QV4::ExecutionEngine *v4, const QVariant &
 
 QVariant ExecutionEngine::toVariant(const Value &value, int typeHint, bool createJSValueForObjects)
 {
-    return ::toVariant(this, value, typeHint, createJSValueForObjects, 0);
+    return ::toVariant(this, value, typeHint, createJSValueForObjects, nullptr);
 }
 
 
@@ -1187,8 +1311,11 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
             return v->toVariant();
         } else if (QV4::QmlListWrapper *l = object->as<QV4::QmlListWrapper>()) {
             return l->toVariant();
-        } else if (object->isListType())
+#if QT_CONFIG(qml_sequence_object)
+        } else if (object->isListType()) {
             return QV4::SequencePrototype::toVariant(object);
+#endif
+        }
     }
 
     if (value.as<ArrayObject>()) {
@@ -1198,7 +1325,7 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
             uint length = a->getLength();
             QV4::Scoped<QV4::QObjectWrapper> qobjectWrapper(scope);
             for (uint ii = 0; ii < length; ++ii) {
-                qobjectWrapper = a->getIndexed(ii);
+                qobjectWrapper = a->get(ii);
                 if (!!qobjectWrapper) {
                     list << qobjectWrapper->object();
                 } else {
@@ -1211,10 +1338,12 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
             return QVariant::fromValue(QV4::JsonObject::toJsonArray(a));
         }
 
+#if QT_CONFIG(qml_sequence_object)
         bool succeeded = false;
         QVariant retn = QV4::SequencePrototype::toVariant(value, typeHint, &succeeded);
         if (succeeded)
             return retn;
+#endif
     }
 
     if (value.isUndefined())
@@ -1234,8 +1363,10 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
             return str.at(0);
         return str;
     }
+#if QT_CONFIG(qml_locale)
     if (const QV4::QQmlLocaleData *ld = value.as<QV4::QQmlLocaleData>())
         return *ld->d()->locale;
+#endif
     if (const QV4::DateObject *d = value.as<DateObject>())
         return d->toQDateTime();
     if (const ArrayBuffer *d = value.as<ArrayBuffer>())
@@ -1245,8 +1376,13 @@ static QVariant toVariant(QV4::ExecutionEngine *e, const QV4::Value &value, int
     QV4::ScopedObject o(scope, value);
     Q_ASSERT(o);
 
-    if (QV4::RegExpObject *re = o->as<QV4::RegExpObject>())
+    if (QV4::RegExpObject *re = o->as<QV4::RegExpObject>()) {
+#if QT_CONFIG(regularexpression)
+        if (typeHint != QMetaType::QRegExp)
+            return re->toQRegularExpression();
+#endif
         return re->toQRegExp();
+    }
 
     if (createJSValueForObjects)
         return QVariant::fromValue(QJSValue(scope.engine, o->asReturnedValue()));
@@ -1281,7 +1417,7 @@ static QVariant objectToVariant(QV4::ExecutionEngine *e, const QV4::Object *o, V
 
         int length = a->getLength();
         for (int ii = 0; ii < length; ++ii) {
-            v = a->getIndexed(ii);
+            v = a->get(ii);
             list << ::toVariant(e, v, -1, /*createJSValueForObjects*/false, visitedObjects);
         }
 
@@ -1308,38 +1444,6 @@ static QVariant objectToVariant(QV4::ExecutionEngine *e, const QV4::Object *o, V
     return result;
 }
 
-static QV4::ReturnedValue arrayFromVariantList(QV4::ExecutionEngine *e, const QVariantList &list)
-{
-    QV4::Scope scope(e);
-    QV4::ScopedArrayObject a(scope, e->newArrayObject());
-    int len = list.count();
-    a->arrayReserve(len);
-    QV4::ScopedValue v(scope);
-    for (int ii = 0; ii < len; ++ii)
-        a->arrayPut(ii, (v = scope.engine->fromVariant(list.at(ii))));
-
-    a->setArrayLengthUnchecked(len);
-    return a.asReturnedValue();
-}
-
-static QV4::ReturnedValue objectFromVariantMap(QV4::ExecutionEngine *e, const QVariantMap &map)
-{
-    QV4::Scope scope(e);
-    QV4::ScopedObject o(scope, e->newObject());
-    QV4::ScopedString s(scope);
-    QV4::ScopedValue v(scope);
-    for (QVariantMap::const_iterator iter = map.begin(), cend = map.end(); iter != cend; ++iter) {
-        s = e->newString(iter.key());
-        uint idx = s->asArrayIndex();
-        if (idx > 16 && (!o->arrayData() || idx > o->arrayData()->length() * 2))
-            o->initSparseArray();
-        o->put(s, (v = e->fromVariant(iter.value())));
-    }
-    return o.asReturnedValue();
-}
-
-Q_CORE_EXPORT QString qt_regexp_toCanonical(const QString &, QRegExp::PatternSyntax);
-
 QV4::ReturnedValue QV4::ExecutionEngine::fromVariant(const QVariant &variant)
 {
     int type = variant.userType();
@@ -1384,13 +1488,18 @@ QV4::ReturnedValue QV4::ExecutionEngine::fromVariant(const QVariant &variant)
             case QMetaType::QDateTime:
                 return QV4::Encode(newDateObject(*reinterpret_cast<const QDateTime *>(ptr)));
             case QMetaType::QDate:
-                return QV4::Encode(newDateObject(QDateTime(*reinterpret_cast<const QDate *>(ptr))));
+                return QV4::Encode(newDateObject(QDateTime(*reinterpret_cast<const QDate *>(ptr), QTime(0, 0, 0), Qt::UTC)));
             case QMetaType::QTime:
                 return QV4::Encode(newDateObjectFromTime(*reinterpret_cast<const QTime *>(ptr)));
             case QMetaType::QRegExp:
                 return QV4::Encode(newRegExpObject(*reinterpret_cast<const QRegExp *>(ptr)));
+#if QT_CONFIG(regularexpression)
+            case QMetaType::QRegularExpression:
+                return QV4::Encode(newRegExpObject(*reinterpret_cast<const QRegularExpression *>(ptr)));
+#endif
             case QMetaType::QObjectStar:
                 return QV4::QObjectWrapper::wrap(this, *reinterpret_cast<QObject* const *>(ptr));
+#if QT_CONFIG(qml_sequence_object)
             case QMetaType::QStringList:
                 {
                 bool succeeded = false;
@@ -1400,18 +1509,21 @@ QV4::ReturnedValue QV4::ExecutionEngine::fromVariant(const QVariant &variant)
                     return retn->asReturnedValue();
                 return QV4::Encode(newArrayObject(*reinterpret_cast<const QStringList *>(ptr)));
                 }
+#endif
             case QMetaType::QVariantList:
-                return arrayFromVariantList(this, *reinterpret_cast<const QVariantList *>(ptr));
+                return variantListToJS(this, *reinterpret_cast<const QVariantList *>(ptr));
             case QMetaType::QVariantMap:
-                return objectFromVariantMap(this, *reinterpret_cast<const QVariantMap *>(ptr));
+                return variantMapToJS(this, *reinterpret_cast<const QVariantMap *>(ptr));
             case QMetaType::QJsonValue:
                 return QV4::JsonObject::fromJsonValue(this, *reinterpret_cast<const QJsonValue *>(ptr));
             case QMetaType::QJsonObject:
                 return QV4::JsonObject::fromJsonObject(this, *reinterpret_cast<const QJsonObject *>(ptr));
             case QMetaType::QJsonArray:
                 return QV4::JsonObject::fromJsonArray(this, *reinterpret_cast<const QJsonArray *>(ptr));
+#if QT_CONFIG(qml_locale)
             case QMetaType::QLocale:
                 return QQmlLocale::wrap(this, *reinterpret_cast<const QLocale*>(ptr));
+#endif
             default:
                 break;
         }
@@ -1451,10 +1563,17 @@ QV4::ReturnedValue QV4::ExecutionEngine::fromVariant(const QVariant &variant)
         if (objOk)
             return QV4::QObjectWrapper::wrap(this, obj);
 
+#if QT_CONFIG(qml_sequence_object)
         bool succeeded = false;
         QV4::ScopedValue retn(scope, QV4::SequencePrototype::fromVariant(this, variant, &succeeded));
         if (succeeded)
             return retn->asReturnedValue();
+#endif
+
+        if (QMetaType::hasRegisteredConverterFunction(type, qMetaTypeId<QtMetaTypePrivate::QSequentialIterableImpl>())) {
+            QSequentialIterable lst = variant.value<QSequentialIterable>();
+            return sequentialIterableToJS(this, lst);
+        }
 
         if (const QMetaObject *vtmo = QQmlValueTypeFactory::metaObjectForMetaType(type))
             return QV4::QQmlValueTypeWrapper::create(this, variant, vtmo, type);
@@ -1489,6 +1608,22 @@ static QV4::ReturnedValue variantListToJS(QV4::ExecutionEngine *v4, const QVaria
     return a.asReturnedValue();
 }
 
+// Converts a QSequentialIterable to JS.
+// The result is a new Array object with length equal to the length
+// of the QSequentialIterable, and the elements being the QSequentialIterable's
+// elements converted to JS, recursively.
+static QV4::ReturnedValue sequentialIterableToJS(QV4::ExecutionEngine *v4, const QSequentialIterable &lst)
+{
+    QV4::Scope scope(v4);
+    QV4::ScopedArrayObject a(scope, v4->newArrayObject());
+    a->arrayReserve(lst.size());
+    QV4::ScopedValue v(scope);
+    for (int i = 0; i < lst.size(); i++)
+        a->arrayPut(i, (v = variantToJS(v4, lst.at(i))));
+    a->setArrayLengthUnchecked(lst.size());
+    return a.asReturnedValue();
+}
+
 // Converts a QVariantMap to JS.
 // The result is a new Object object with property names being
 // the keys of the QVariantMap, and values being the values of
@@ -1498,11 +1633,13 @@ static QV4::ReturnedValue variantMapToJS(QV4::ExecutionEngine *v4, const QVarian
     QV4::Scope scope(v4);
     QV4::ScopedObject o(scope, v4->newObject());
     QV4::ScopedString s(scope);
+    QV4::ScopedPropertyKey key(scope);
     QV4::ScopedValue v(scope);
     for (QVariantMap::const_iterator it = vmap.constBegin(), cend = vmap.constEnd(); it != cend; ++it) {
         s = v4->newIdentifier(it.key());
+        key = s->propertyKey();
         v = variantToJS(v4, it.value());
-        uint idx = s->asArrayIndex();
+        uint idx = key->asArrayIndex();
         if (idx < UINT_MAX)
             o->arraySet(idx, v);
         else
@@ -1515,97 +1652,142 @@ static QV4::ReturnedValue variantMapToJS(QV4::ExecutionEngine *v4, const QVarian
 // Returns the value if conversion succeeded, an empty handle otherwise.
 QV4::ReturnedValue ExecutionEngine::metaTypeToJS(int type, const void *data)
 {
-    Q_ASSERT(data != 0);
+    Q_ASSERT(data != nullptr);
 
-    // check if it's one of the types we know
-    switch (QMetaType::Type(type)) {
-    case QMetaType::UnknownType:
-    case QMetaType::Void:
-        return QV4::Encode::undefined();
-    case QMetaType::Nullptr:
-    case QMetaType::VoidStar:
-        return QV4::Encode::null();
-    case QMetaType::Bool:
-        return QV4::Encode(*reinterpret_cast<const bool*>(data));
-    case QMetaType::Int:
-        return QV4::Encode(*reinterpret_cast<const int*>(data));
-    case QMetaType::UInt:
-        return QV4::Encode(*reinterpret_cast<const uint*>(data));
-    case QMetaType::LongLong:
-        return QV4::Encode(double(*reinterpret_cast<const qlonglong*>(data)));
-    case QMetaType::ULongLong:
-#if defined(Q_OS_WIN) && defined(_MSC_FULL_VER) && _MSC_FULL_VER <= 12008804
-#pragma message("** NOTE: You need the Visual Studio Processor Pack to compile support for 64bit unsigned integers.")
-        return QV4::Encode(double((qlonglong)*reinterpret_cast<const qulonglong*>(data)));
-#elif defined(Q_CC_MSVC) && !defined(Q_CC_MSVC_NET)
-        return QV4::Encode(double((qlonglong)*reinterpret_cast<const qulonglong*>(data)));
-#else
-        return QV4::Encode(double(*reinterpret_cast<const qulonglong*>(data)));
-#endif
-    case QMetaType::Double:
-        return QV4::Encode(*reinterpret_cast<const double*>(data));
-    case QMetaType::QString:
-        return newString(*reinterpret_cast<const QString*>(data))->asReturnedValue();
-    case QMetaType::QByteArray:
-        return newArrayBuffer(*reinterpret_cast<const QByteArray*>(data))->asReturnedValue();
-    case QMetaType::Float:
-        return QV4::Encode(*reinterpret_cast<const float*>(data));
-    case QMetaType::Short:
-        return QV4::Encode((int)*reinterpret_cast<const short*>(data));
-    case QMetaType::UShort:
-        return QV4::Encode((int)*reinterpret_cast<const unsigned short*>(data));
-    case QMetaType::Char:
-        return QV4::Encode((int)*reinterpret_cast<const char*>(data));
-    case QMetaType::UChar:
-        return QV4::Encode((int)*reinterpret_cast<const unsigned char*>(data));
-    case QMetaType::QChar:
-        return QV4::Encode((int)(*reinterpret_cast<const QChar*>(data)).unicode());
-    case QMetaType::QStringList:
-        return QV4::Encode(newArrayObject(*reinterpret_cast<const QStringList *>(data)));
-    case QMetaType::QVariantList:
-        return variantListToJS(this, *reinterpret_cast<const QVariantList *>(data));
-    case QMetaType::QVariantMap:
-        return variantMapToJS(this, *reinterpret_cast<const QVariantMap *>(data));
-    case QMetaType::QDateTime:
-        return QV4::Encode(newDateObject(*reinterpret_cast<const QDateTime *>(data)));
-    case QMetaType::QDate:
-        return QV4::Encode(newDateObject(QDateTime(*reinterpret_cast<const QDate *>(data))));
-    case QMetaType::QRegExp:
-        return QV4::Encode(newRegExpObject(*reinterpret_cast<const QRegExp *>(data)));
-    case QMetaType::QObjectStar:
-        return QV4::QObjectWrapper::wrap(this, *reinterpret_cast<QObject* const *>(data));
-    case QMetaType::QVariant:
+    QVariant variant(type, data);
+    if (QMetaType::Type(variant.type()) == QMetaType::QVariant) {
+        // unwrap it: this is tested in QJSEngine, and makes the most sense for
+        // end-user code too.
         return variantToJS(this, *reinterpret_cast<const QVariant*>(data));
-    case QMetaType::QJsonValue:
-        return QV4::JsonObject::fromJsonValue(this, *reinterpret_cast<const QJsonValue *>(data));
-    case QMetaType::QJsonObject:
-        return QV4::JsonObject::fromJsonObject(this, *reinterpret_cast<const QJsonObject *>(data));
-    case QMetaType::QJsonArray:
-        return QV4::JsonObject::fromJsonArray(this, *reinterpret_cast<const QJsonArray *>(data));
-    default:
-        if (type == qMetaTypeId<QJSValue>()) {
-            return QJSValuePrivate::convertedToValue(this, *reinterpret_cast<const QJSValue*>(data));
+    }
+    return fromVariant(variant);
+}
+
+ReturnedValue ExecutionEngine::global()
+{
+    return globalObject->asReturnedValue();
+}
+
+QQmlRefPointer<CompiledData::CompilationUnit> ExecutionEngine::compileModule(const QUrl &url)
+{
+    QFile f(QQmlFile::urlToLocalFileOrQrc(url));
+    if (!f.open(QIODevice::ReadOnly)) {
+        throwError(QStringLiteral("Could not open module %1 for reading").arg(url.toString()));
+        return nullptr;
+    }
+
+    const QDateTime timeStamp = QFileInfo(f).lastModified();
+
+    const QString sourceCode = QString::fromUtf8(f.readAll());
+    f.close();
+
+    return compileModule(url, sourceCode, timeStamp);
+}
+
+
+QQmlRefPointer<CompiledData::CompilationUnit> ExecutionEngine::compileModule(const QUrl &url, const QString &sourceCode, const QDateTime &sourceTimeStamp)
+{
+    QList<QQmlJS::DiagnosticMessage> diagnostics;
+    auto unit = compileModule(/*debugMode*/debugger() != nullptr, url.toString(), sourceCode, sourceTimeStamp, &diagnostics);
+    for (const QQmlJS::DiagnosticMessage &m : diagnostics) {
+        if (m.isError()) {
+            throwSyntaxError(m.message, url.toString(), m.loc.startLine, m.loc.startColumn);
+            return nullptr;
         } else {
-            QByteArray typeName = QMetaType::typeName(type);
-            if (typeName.endsWith('*') && !*reinterpret_cast<void* const *>(data)) {
-                return QV4::Encode::null();
-            }
-            QMetaType mt(type);
-            if (mt.flags() & QMetaType::IsGadget) {
-                Q_ASSERT(mt.metaObject());
-                return QV4::QQmlValueTypeWrapper::create(this, QVariant(type, data), mt.metaObject(), type);
-            }
-            // Fall back to wrapping in a QVariant.
-            return QV4::Encode(newVariantObject(QVariant(type, data)));
+            qWarning() << url << ':' << m.loc.startLine << ':' << m.loc.startColumn
+                      << ": warning: " << m.message;
         }
     }
-    Q_UNREACHABLE();
-    return 0;
+    return unit;
+}
+
+#endif // ifndef V4_BOOTSTRAP
+
+QQmlRefPointer<CompiledData::CompilationUnit> ExecutionEngine::compileModule(bool debugMode, const QString &url, const QString &sourceCode,
+                                                                             const QDateTime &sourceTimeStamp, QList<QQmlJS::DiagnosticMessage> *diagnostics)
+{
+    QQmlJS::Engine ee;
+    QQmlJS::Lexer lexer(&ee);
+    lexer.setCode(sourceCode, /*line*/1, /*qml mode*/false);
+    QQmlJS::Parser parser(&ee);
+
+    const bool parsed = parser.parseModule();
+
+    if (diagnostics)
+        *diagnostics = parser.diagnosticMessages();
+
+    if (!parsed)
+        return nullptr;
+
+    QQmlJS::AST::ESModule *moduleNode = QQmlJS::AST::cast<QQmlJS::AST::ESModule*>(parser.rootNode());
+    if (!moduleNode) {
+        // if parsing was successful, and we have no module, then
+        // the file was empty.
+        if (diagnostics)
+            diagnostics->clear();
+        return nullptr;
+    }
+
+    using namespace QV4::Compiler;
+    Compiler::Module compilerModule(debugMode);
+    compilerModule.unitFlags |= CompiledData::Unit::IsESModule;
+    compilerModule.sourceTimeStamp = sourceTimeStamp;
+    JSUnitGenerator jsGenerator(&compilerModule);
+    Codegen cg(&jsGenerator, /*strictMode*/true);
+    cg.generateFromModule(url, url, sourceCode, moduleNode, &compilerModule);
+    auto errors = cg.errors();
+    if (diagnostics)
+        *diagnostics << errors;
+
+    if (!errors.isEmpty())
+        return nullptr;
+
+    return cg.generateCompilationUnit();
 }
 
-void ExecutionEngine::failStackLimitCheck(Scope &scope)
+#ifndef V4_BOOTSTRAP
+
+void ExecutionEngine::injectModule(const QQmlRefPointer<CompiledData::CompilationUnit> &moduleUnit)
 {
-    scope.result = throwRangeError(QStringLiteral("Maximum call stack size exceeded."));
+    // Injection can happen from the QML type loader thread for example, but instantiation and
+    // evaluation must be limited to the ExecutionEngine's thread.
+    QMutexLocker moduleGuard(&moduleMutex);
+    modules.insert(moduleUnit->finalUrl(), moduleUnit);
+}
+
+QQmlRefPointer<CompiledData::CompilationUnit> ExecutionEngine::moduleForUrl(const QUrl &_url, const CompiledData::CompilationUnit *referrer) const
+{
+    QUrl url = QQmlTypeLoader::normalize(_url);
+    if (referrer)
+        url = referrer->finalUrl().resolved(url);
+
+    QMutexLocker moduleGuard(&moduleMutex);
+    auto existingModule = modules.find(url);
+    if (existingModule == modules.end())
+        return nullptr;
+    return *existingModule;
+}
+
+QQmlRefPointer<CompiledData::CompilationUnit> ExecutionEngine::loadModule(const QUrl &_url, const CompiledData::CompilationUnit *referrer)
+{
+    QUrl url = QQmlTypeLoader::normalize(_url);
+    if (referrer)
+        url = referrer->finalUrl().resolved(url);
+
+    QMutexLocker moduleGuard(&moduleMutex);
+    auto existingModule = modules.find(url);
+    if (existingModule != modules.end())
+        return *existingModule;
+
+    moduleGuard.unlock();
+
+    auto newModule = compileModule(url);
+    if (newModule) {
+        moduleGuard.relock();
+        modules.insert(url, newModule);
+    }
+
+    return newModule;
 }
 
 // Converts a JS value to a meta-type.
@@ -1683,6 +1865,13 @@ bool ExecutionEngine::metaTypeFromJS(const Value *value, int type, void *data)
             *reinterpret_cast<QRegExp *>(data) = r->toQRegExp();
             return true;
         } break;
+#if QT_CONFIG(regularexpression)
+    case QMetaType::QRegularExpression:
+        if (const QV4::RegExpObject *r = value->as<QV4::RegExpObject>()) {
+            *reinterpret_cast<QRegularExpression *>(data) = r->toQRegularExpression();
+            return true;
+        } break;
+#endif
     case QMetaType::QObjectStar: {
         const QV4::QObjectWrapper *qobjectWrapper = value->as<QV4::QObjectWrapper>();
         if (qobjectWrapper || value->isNull()) {
@@ -1777,7 +1966,7 @@ bool ExecutionEngine::metaTypeFromJS(const Value *value, int type, void *data)
         } else if (Object *o = value->objectValue()) {
             // Look in the prototype chain.
             QV4::Scope scope(this);
-            QV4::ScopedObject proto(scope, o->prototype());
+            QV4::ScopedObject proto(scope, o->getPrototypeOf());
             while (proto) {
                 bool canCast = false;
                 if (QV4::VariantObject *vo = proto->as<QV4::VariantObject>()) {
@@ -1788,7 +1977,7 @@ bool ExecutionEngine::metaTypeFromJS(const Value *value, int type, void *data)
                     QByteArray className = name.left(name.size()-1);
                     QV4::ScopedObject p(scope, proto.getPointer());
                     if (QObject *qobject = qtObjectFromJS(this, p))
-                        canCast = qobject->qt_metacast(className) != 0;
+                        canCast = qobject->qt_metacast(className) != nullptr;
                 }
                 if (canCast) {
                     QByteArray varTypeName = QMetaType::typeName(var.userType());
@@ -1798,11 +1987,11 @@ bool ExecutionEngine::metaTypeFromJS(const Value *value, int type, void *data)
                         *reinterpret_cast<void* *>(data) = var.data();
                     return true;
                 }
-                proto = proto->prototype();
+                proto = proto->getPrototypeOf();
             }
         }
     } else if (value->isNull() && name.endsWith('*')) {
-        *reinterpret_cast<void* *>(data) = 0;
+        *reinterpret_cast<void* *>(data) = nullptr;
         return true;
     } else if (type == qMetaTypeId<QJSValue>()) {
         *reinterpret_cast<QJSValue*>(data) = QJSValue(this, value->asReturnedValue());
@@ -1830,7 +2019,7 @@ static bool convertToNativeQObject(QV4::ExecutionEngine *e, const QV4::Value &va
 static QObject *qtObjectFromJS(QV4::ExecutionEngine *engine, const QV4::Value &value)
 {
     if (!value.isObject())
-        return 0;
+        return nullptr;
 
     QV4::Scope scope(engine);
     QV4::Scoped<QV4::VariantObject> v(scope, value);
@@ -1843,9 +2032,10 @@ static QObject *qtObjectFromJS(QV4::ExecutionEngine *engine, const QV4::Value &v
     }
     QV4::Scoped<QV4::QObjectWrapper> wrapper(scope, value);
     if (!wrapper)
-        return 0;
+        return nullptr;
     return wrapper->object();
 }
 
+#endif // ifndef V4_BOOTSTRAP
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index 16a043dda5..3735c24601 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -51,14 +51,17 @@
 //
 
 #include "qv4global_p.h"
-#include "private/qv4isel_p.h"
 #include "qv4managed_p.h"
 #include "qv4context_p.h"
 #include <private/qintrusivelist_p.h>
 #include "qv4enginebase_p.h"
+#include <private/qqmlrefcount_p.h>
+#include <private/qqmljsengine_p.h>
 
 #ifndef V4_BOOTSTRAP
+#  include "qv4function_p.h"
 #  include <private/qv8engine_p.h>
+#  include <private/qv4compileddata_p.h>
 #endif
 
 namespace WTF {
@@ -85,8 +88,15 @@ namespace CompiledData {
 struct CompilationUnit;
 }
 
-struct InternalClass;
-struct InternalClassPool;
+namespace Heap {
+struct Module;
+};
+
+struct Function;
+
+namespace Promise {
+class ReactionHandler;
+};
 
 struct Q_QML_EXPORT ExecutionEngine : public EngineBase
 {
@@ -99,7 +109,6 @@ private:
 public:
     ExecutableAllocator *executableAllocator;
     ExecutableAllocator *regExpAllocator;
-    QScopedPointer<EvalISelFactory> iselFactory;
 
     WTF::BumpPointerAllocator *bumperPointerAllocator; // Used by Yarr Regex engine.
 
@@ -114,8 +123,6 @@ public:
     QML_NEARLY_ALWAYS_INLINE Value *jsAlloca(int nValues) {
         Value *ptr = jsStackTop;
         jsStackTop = ptr + nValues;
-        for (int i = 0; i < nValues; ++i)
-            ptr[i] = Primitive::undefinedValue();
         return ptr;
     }
 
@@ -125,22 +132,27 @@ public:
     QJSEngine *jsEngine() const;
     QQmlEngine *qmlEngine() const;
 #else // !V4_BOOTSTRAP
-    QJSEngine *jsEngine() const { return v8Engine->publicEngine(); }
+    QJSEngine *jsEngine() const { return publicEngine; }
     QQmlEngine *qmlEngine() const { return v8Engine ? v8Engine->engine() : nullptr; }
 #endif // V4_BOOTSTRAP
     QV8Engine *v8Engine;
+    QJSEngine *publicEngine;
 
     enum JSObjects {
         RootContext,
+        ScriptContext,
         IntegerNull, // Has to come after the RootContext to make the context stack safe
         ObjectProto,
+        SymbolProto,
         ArrayProto,
+        ArrayProtoValues,
         PropertyListProto,
         StringProto,
         NumberProto,
         BooleanProto,
         DateProto,
         FunctionProto,
+        GeneratorProto,
         RegExpProto,
         ErrorProto,
         EvalErrorProto,
@@ -149,19 +161,36 @@ public:
         SyntaxErrorProto,
         TypeErrorProto,
         URIErrorProto,
+        PromiseProto,
         VariantProto,
+#if QT_CONFIG(qml_sequence_object)
         SequenceProto,
+#endif
+        SharedArrayBufferProto,
         ArrayBufferProto,
         DataViewProto,
+        WeakSetProto,
+        SetProto,
+        WeakMapProto,
+        MapProto,
+        IntrinsicTypedArrayProto,
         ValueTypeProto,
         SignalHandlerProto,
+        IteratorProto,
+        ForInIteratorProto,
+        SetIteratorProto,
+        MapIteratorProto,
+        ArrayIteratorProto,
+        StringIteratorProto,
 
         Object_Ctor,
         String_Ctor,
+        Symbol_Ctor,
         Number_Ctor,
         Boolean_Ctor,
         Array_Ctor,
         Function_Ctor,
+        GeneratorFunction_Ctor,
         Date_Ctor,
         RegExp_Ctor,
         Error_Ctor,
@@ -171,8 +200,17 @@ public:
         SyntaxError_Ctor,
         TypeError_Ctor,
         URIError_Ctor,
+        SharedArrayBuffer_Ctor,
+        Promise_Ctor,
         ArrayBuffer_Ctor,
         DataView_Ctor,
+        WeakSet_Ctor,
+        Set_Ctor,
+        WeakMap_Ctor,
+        Map_Ctor,
+        IntrinsicTypedArray_Ctor,
+
+        GetSymbolSpecies,
 
         Eval_Function,
         GetStack_Function,
@@ -182,13 +220,17 @@ public:
     Value *jsObjects;
     enum { NTypedArrayTypes = 9 }; // == TypedArray::NValues, avoid header dependency
 
-    GlobalContext *rootContext() const { return reinterpret_cast<GlobalContext *>(jsObjects + RootContext); }
+    ExecutionContext *rootContext() const { return reinterpret_cast<ExecutionContext *>(jsObjects + RootContext); }
+    ExecutionContext *scriptContext() const { return reinterpret_cast<ExecutionContext *>(jsObjects + ScriptContext); }
+    void setScriptContext(ReturnedValue c) { jsObjects[ScriptContext] = c; }
     FunctionObject *objectCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Object_Ctor); }
     FunctionObject *stringCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + String_Ctor); }
+    FunctionObject *symbolCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Symbol_Ctor); }
     FunctionObject *numberCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Number_Ctor); }
     FunctionObject *booleanCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Boolean_Ctor); }
     FunctionObject *arrayCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Array_Ctor); }
     FunctionObject *functionCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Function_Ctor); }
+    FunctionObject *generatorFunctionCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + GeneratorFunction_Ctor); }
     FunctionObject *dateCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Date_Ctor); }
     FunctionObject *regExpCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + RegExp_Ctor); }
     FunctionObject *errorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Error_Ctor); }
@@ -198,18 +240,30 @@ public:
     FunctionObject *syntaxErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + SyntaxError_Ctor); }
     FunctionObject *typeErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + TypeError_Ctor); }
     FunctionObject *uRIErrorCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + URIError_Ctor); }
+    FunctionObject *sharedArrayBufferCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + SharedArrayBuffer_Ctor); }
+    FunctionObject *promiseCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Promise_Ctor); }
     FunctionObject *arrayBufferCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + ArrayBuffer_Ctor); }
     FunctionObject *dataViewCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + DataView_Ctor); }
+    FunctionObject *weakSetCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + WeakSet_Ctor); }
+    FunctionObject *setCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Set_Ctor); }
+    FunctionObject *weakMapCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + WeakMap_Ctor); }
+    FunctionObject *mapCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + Map_Ctor); }
+    FunctionObject *intrinsicTypedArrayCtor() const { return reinterpret_cast<FunctionObject *>(jsObjects + IntrinsicTypedArray_Ctor); }
     FunctionObject *typedArrayCtors;
 
+    FunctionObject *getSymbolSpecies() const { return reinterpret_cast<FunctionObject *>(jsObjects + GetSymbolSpecies); }
+
     Object *objectPrototype() const { return reinterpret_cast<Object *>(jsObjects + ObjectProto); }
+    Object *symbolPrototype() const { return reinterpret_cast<Object *>(jsObjects + SymbolProto); }
     Object *arrayPrototype() const { return reinterpret_cast<Object *>(jsObjects + ArrayProto); }
+    Object *arrayProtoValues() const { return reinterpret_cast<Object *>(jsObjects + ArrayProtoValues); }
     Object *propertyListPrototype() const { return reinterpret_cast<Object *>(jsObjects + PropertyListProto); }
     Object *stringPrototype() const { return reinterpret_cast<Object *>(jsObjects + StringProto); }
     Object *numberPrototype() const { return reinterpret_cast<Object *>(jsObjects + NumberProto); }
     Object *booleanPrototype() const { return reinterpret_cast<Object *>(jsObjects + BooleanProto); }
     Object *datePrototype() const { return reinterpret_cast<Object *>(jsObjects + DateProto); }
     Object *functionPrototype() const { return reinterpret_cast<Object *>(jsObjects + FunctionProto); }
+    Object *generatorPrototype() const { return reinterpret_cast<Object *>(jsObjects + GeneratorProto); }
     Object *regExpPrototype() const { return reinterpret_cast<Object *>(jsObjects + RegExpProto); }
     Object *errorPrototype() const { return reinterpret_cast<Object *>(jsObjects + ErrorProto); }
     Object *evalErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + EvalErrorProto); }
@@ -218,24 +272,35 @@ public:
     Object *syntaxErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + SyntaxErrorProto); }
     Object *typeErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + TypeErrorProto); }
     Object *uRIErrorPrototype() const { return reinterpret_cast<Object *>(jsObjects + URIErrorProto); }
+    Object *promisePrototype() const { return reinterpret_cast<Object *>(jsObjects + PromiseProto); }
     Object *variantPrototype() const { return reinterpret_cast<Object *>(jsObjects + VariantProto); }
+#if QT_CONFIG(qml_sequence_object)
     Object *sequencePrototype() const { return reinterpret_cast<Object *>(jsObjects + SequenceProto); }
+#endif
 
+    Object *sharedArrayBufferPrototype() const { return reinterpret_cast<Object *>(jsObjects + SharedArrayBufferProto); }
     Object *arrayBufferPrototype() const { return reinterpret_cast<Object *>(jsObjects + ArrayBufferProto); }
     Object *dataViewPrototype() const { return reinterpret_cast<Object *>(jsObjects + DataViewProto); }
+    Object *weakSetPrototype() const { return reinterpret_cast<Object *>(jsObjects + WeakSetProto); }
+    Object *setPrototype() const { return reinterpret_cast<Object *>(jsObjects + SetProto); }
+    Object *weakMapPrototype() const { return reinterpret_cast<Object *>(jsObjects + WeakMapProto); }
+    Object *mapPrototype() const { return reinterpret_cast<Object *>(jsObjects + MapProto); }
+    Object *intrinsicTypedArrayPrototype() const { return reinterpret_cast<Object *>(jsObjects + IntrinsicTypedArrayProto); }
     Object *typedArrayPrototype;
 
     Object *valueTypeWrapperPrototype() const { return reinterpret_cast<Object *>(jsObjects + ValueTypeProto); }
     Object *signalHandlerPrototype() const { return reinterpret_cast<Object *>(jsObjects + SignalHandlerProto); }
+    Object *iteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + IteratorProto); }
+    Object *forInIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + ForInIteratorProto); }
+    Object *setIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + SetIteratorProto); }
+    Object *mapIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + MapIteratorProto); }
+    Object *arrayIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + ArrayIteratorProto); }
+    Object *stringIteratorPrototype() const { return reinterpret_cast<Object *>(jsObjects + StringIteratorProto); }
 
-    InternalClassPool *classPool;
     EvalFunction *evalFunction() const { return reinterpret_cast<EvalFunction *>(jsObjects + Eval_Function); }
     FunctionObject *getStackFunction() const { return reinterpret_cast<FunctionObject *>(jsObjects + GetStack_Function); }
     FunctionObject *thrower() const { return reinterpret_cast<FunctionObject *>(jsObjects + ThrowerObject); }
 
-    Property *argumentsAccessors;
-    int nArgumentsAccessors;
-
     enum JSStrings {
         String_Empty,
         String_undefined,
@@ -245,6 +310,8 @@ public:
         String_boolean,
         String_number,
         String_string,
+        String_default,
+        String_symbol,
         String_object,
         String_function,
         String_length,
@@ -267,16 +334,46 @@ public:
         String_index,
         String_input,
         String_toString,
+        String_toLocaleString,
         String_destroy,
         String_valueOf,
         String_byteLength,
         String_byteOffset,
         String_buffer,
         String_lastIndex,
+        String_next,
+        String_done,
+        String_return,
+        String_throw,
+        String_global,
+        String_ignoreCase,
+        String_multiline,
+        String_unicode,
+        String_sticky,
+        String_source,
+        String_flags,
+
         NJSStrings
     };
     Value *jsStrings;
 
+    enum JSSymbols {
+        Symbol_hasInstance,
+        Symbol_isConcatSpreadable,
+        Symbol_iterator,
+        Symbol_match,
+        Symbol_replace,
+        Symbol_search,
+        Symbol_species,
+        Symbol_split,
+        Symbol_toPrimitive,
+        Symbol_toStringTag,
+        Symbol_unscopables,
+        Symbol_revokableProxy,
+        NJSSymbols
+    };
+    Value *jsSymbols;
+
     String *id_empty() const { return reinterpret_cast<String *>(jsStrings + String_Empty); }
     String *id_undefined() const { return reinterpret_cast<String *>(jsStrings + String_undefined); }
     String *id_null() const { return reinterpret_cast<String *>(jsStrings + String_null); }
@@ -285,6 +382,8 @@ public:
     String *id_boolean() const { return reinterpret_cast<String *>(jsStrings + String_boolean); }
     String *id_number() const { return reinterpret_cast<String *>(jsStrings + String_number); }
     String *id_string() const { return reinterpret_cast<String *>(jsStrings + String_string); }
+    String *id_default() const { return reinterpret_cast<String *>(jsStrings + String_default); }
+    String *id_symbol() const { return reinterpret_cast<String *>(jsStrings + String_symbol); }
     String *id_object() const { return reinterpret_cast<String *>(jsStrings + String_object); }
     String *id_function() const { return reinterpret_cast<String *>(jsStrings + String_function); }
     String *id_length() const { return reinterpret_cast<String *>(jsStrings + String_length); }
@@ -307,14 +406,41 @@ public:
     String *id_index() const { return reinterpret_cast<String *>(jsStrings + String_index); }
     String *id_input() const { return reinterpret_cast<String *>(jsStrings + String_input); }
     String *id_toString() const { return reinterpret_cast<String *>(jsStrings + String_toString); }
+    String *id_toLocaleString() const { return reinterpret_cast<String *>(jsStrings + String_toLocaleString); }
     String *id_destroy() const { return reinterpret_cast<String *>(jsStrings + String_destroy); }
     String *id_valueOf() const { return reinterpret_cast<String *>(jsStrings + String_valueOf); }
     String *id_byteLength() const { return reinterpret_cast<String *>(jsStrings + String_byteLength); }
     String *id_byteOffset() const { return reinterpret_cast<String *>(jsStrings + String_byteOffset); }
     String *id_buffer() const { return reinterpret_cast<String *>(jsStrings + String_buffer); }
     String *id_lastIndex() const { return reinterpret_cast<String *>(jsStrings + String_lastIndex); }
+    String *id_next() const { return reinterpret_cast<String *>(jsStrings + String_next); }
+    String *id_done() const { return reinterpret_cast<String *>(jsStrings + String_done); }
+    String *id_return() const { return reinterpret_cast<String *>(jsStrings + String_return); }
+    String *id_throw() const { return reinterpret_cast<String *>(jsStrings + String_throw); }
+    String *id_global() const { return reinterpret_cast<String *>(jsStrings + String_global); }
+    String *id_ignoreCase() const { return reinterpret_cast<String *>(jsStrings + String_ignoreCase); }
+    String *id_multiline() const { return reinterpret_cast<String *>(jsStrings + String_multiline); }
+    String *id_unicode() const { return reinterpret_cast<String *>(jsStrings + String_unicode); }
+    String *id_sticky() const { return reinterpret_cast<String *>(jsStrings + String_sticky); }
+    String *id_source() const { return reinterpret_cast<String *>(jsStrings + String_source); }
+    String *id_flags() const { return reinterpret_cast<String *>(jsStrings + String_flags); }
+
+    Symbol *symbol_hasInstance() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_hasInstance); }
+    Symbol *symbol_isConcatSpreadable() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_isConcatSpreadable); }
+    Symbol *symbol_iterator() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_iterator); }
+    Symbol *symbol_match() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_match); }
+    Symbol *symbol_replace() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_replace); }
+    Symbol *symbol_search() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_search); }
+    Symbol *symbol_species() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_species); }
+    Symbol *symbol_split() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_split); }
+    Symbol *symbol_toPrimitive() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_toPrimitive); }
+    Symbol *symbol_toStringTag() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_toStringTag); }
+    Symbol *symbol_unscopables() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_unscopables); }
+    Symbol *symbol_revokableProxy() const { return reinterpret_cast<Symbol *>(jsSymbols + Symbol_revokableProxy); }
 
-    QSet<CompiledData::CompilationUnit*> compilationUnits;
+#ifndef V4_BOOTSTRAP
+    QIntrusiveList<CompiledData::CompilationUnit, &CompiledData::CompilationUnit::nextCompilationUnit> compilationUnits;
+#endif
 
     quint32 m_engineId;
 
@@ -338,46 +464,51 @@ public:
     // but any time a QObject is wrapped a second time in another engine, we have to do
     // bookkeeping.
     MultiplyWrappedQObjectMap *m_multiplyWrappedQObjects;
+#if defined(V4_ENABLE_JIT) && !defined(V4_BOOTSTRAP)
+    const bool m_canAllocateExecutableMemory;
+#endif
+
+    quintptr protoIdCount = 1;
 
-    ExecutionEngine(EvalISelFactory *iselFactory = 0);
+    ExecutionEngine(QJSEngine *jsEngine = nullptr);
     ~ExecutionEngine();
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
     QV4::Debugging::Debugger *debugger() const { return nullptr; }
     QV4::Profiling::Profiler *profiler() const { return nullptr; }
 
     void setDebugger(Debugging::Debugger *) {}
     void setProfiler(Profiling::Profiler *) {}
 #else
-    QV4::Debugging::Debugger *debugger() const { return m_debugger; }
-    QV4::Profiling::Profiler *profiler() const { return m_profiler; }
+    QV4::Debugging::Debugger *debugger() const { return m_debugger.data(); }
+    QV4::Profiling::Profiler *profiler() const { return m_profiler.data(); }
 
     void setDebugger(Debugging::Debugger *debugger);
     void setProfiler(Profiling::Profiler *profiler);
-#endif // QT_NO_QML_DEBUGGER
+#endif // QT_CONFIG(qml_debug)
 
-    ExecutionContext *pushGlobalContext();
-    void pushContext(Heap::ExecutionContext *context);
-    void pushContext(ExecutionContext *context);
-    void popContext();
-    ExecutionContext *parentContext(ExecutionContext *context) const;
+    ExecutionContext *currentContext() const;
 
-    InternalClass *newInternalClass(const VTable *vtable, Object *prototype);
+    // ensure we always get odd prototype IDs. This helps make marking in QV4::Lookup fast
+    quintptr newProtoId() { return (protoIdCount += 2); }
+
+    Heap::InternalClass *newInternalClass(const VTable *vtable, Object *prototype);
 
     Heap::Object *newObject();
-    Heap::Object *newObject(InternalClass *internalClass, Object *prototype);
+    Heap::Object *newObject(Heap::InternalClass *internalClass);
 
     Heap::String *newString(const QString &s = QString());
     Heap::String *newIdentifier(const QString &text);
 
     Heap::Object *newStringObject(const String *string);
+    Heap::Object *newSymbolObject(const Symbol *symbol);
     Heap::Object *newNumberObject(double value);
     Heap::Object *newBooleanObject(bool b);
 
     Heap::ArrayObject *newArrayObject(int count = 0);
     Heap::ArrayObject *newArrayObject(const Value *values, int length);
     Heap::ArrayObject *newArrayObject(const QStringList &list);
-    Heap::ArrayObject *newArrayObject(InternalClass *ic, Object *prototype);
+    Heap::ArrayObject *newArrayObject(Heap::InternalClass *ic);
 
     Heap::ArrayBuffer *newArrayBuffer(const QByteArray &array);
     Heap::ArrayBuffer *newArrayBuffer(size_t length);
@@ -387,46 +518,53 @@ public:
     Heap::DateObject *newDateObjectFromTime(const QTime &t);
 
     Heap::RegExpObject *newRegExpObject(const QString &pattern, int flags);
-    Heap::RegExpObject *newRegExpObject(RegExp *re, bool global);
+    Heap::RegExpObject *newRegExpObject(RegExp *re);
     Heap::RegExpObject *newRegExpObject(const QRegExp &re);
+#if QT_CONFIG(regularexpression)
+    Heap::RegExpObject *newRegExpObject(const QRegularExpression &re);
+#endif
 
     Heap::Object *newErrorObject(const Value &value);
+    Heap::Object *newErrorObject(const QString &message);
     Heap::Object *newSyntaxErrorObject(const QString &message, const QString &fileName, int line, int column);
     Heap::Object *newSyntaxErrorObject(const QString &message);
     Heap::Object *newReferenceErrorObject(const QString &message);
     Heap::Object *newReferenceErrorObject(const QString &message, const QString &fileName, int line, int column);
     Heap::Object *newTypeErrorObject(const QString &message);
     Heap::Object *newRangeErrorObject(const QString &message);
+    Heap::Object *newURIErrorObject(const QString &message);
     Heap::Object *newURIErrorObject(const Value &message);
+    Heap::Object *newEvalErrorObject(const QString &message);
+
+    Heap::PromiseObject *newPromiseObject();
+    Heap::Object *newPromiseObject(const QV4::FunctionObject *thisObject, const QV4::PromiseCapability *capability);
+    Promise::ReactionHandler *getPromiseReactionHandler();
 
     Heap::Object *newVariantObject(const QVariant &v);
 
-    Heap::Object *newForEachIteratorObject(Object *o);
+    Heap::Object *newForInIteratorObject(Object *o);
+    Heap::Object *newSetIteratorObject(Object *o);
+    Heap::Object *newMapIteratorObject(Object *o);
+    Heap::Object *newArrayIteratorObject(Object *o);
 
     Heap::QmlContext *qmlContext() const;
     QObject *qmlScopeObject() const;
-    ReturnedValue qmlSingletonWrapper(String *name);
     QQmlContextData *callingQmlContext() const;
 
 
     StackTrace stackTrace(int frameLimit = -1) const;
-    StackFrame currentStackFrame() const;
     QUrl resolvedUrl(const QString &file);
 
-    void requireArgumentsAccessors(int n);
-
     void markObjects(MarkStack *markStack);
 
     void initRootContext();
 
-    InternalClass *newClass(const InternalClass &other);
+    Heap::InternalClass *newClass(Heap::InternalClass *other);
 
-    // Exception handling
-    Value *exceptionValue;
     StackTrace exceptionStackTrace;
 
     ReturnedValue throwError(const Value &value);
-    ReturnedValue catchException(StackTrace *trace = 0);
+    ReturnedValue catchException(StackTrace *trace = nullptr);
 
     ReturnedValue throwError(const QString &message);
     ReturnedValue throwSyntaxError(const QString &message);
@@ -452,93 +590,50 @@ public:
     bool metaTypeFromJS(const Value *value, int type, void *data);
     QV4::ReturnedValue metaTypeToJS(int type, const void *data);
 
-    bool checkStackLimits(Scope &scope);
+    bool checkStackLimits();
 
-private:
-    void failStackLimitCheck(Scope &scope);
-
-#ifndef QT_NO_QML_DEBUGGER
-    QV4::Debugging::Debugger *m_debugger;
-    QV4::Profiling::Profiler *m_profiler;
-#endif
-};
-
-// This is a trick to tell the code generators that functions taking a NoThrowContext won't
-// throw exceptions and therefore don't need a check after the call.
-#ifndef V4_BOOTSTRAP
-struct NoThrowEngine : public ExecutionEngine
-{
-};
+    bool canJIT(Function *f = nullptr)
+    {
+#if defined(V4_ENABLE_JIT) && !defined(V4_BOOTSTRAP)
+        if (!m_canAllocateExecutableMemory)
+            return false;
+        if (f)
+            return !f->isGenerator() && f->interpreterCallCount >= jitCallCountThreshold;
+        return true;
 #else
-struct NoThrowEngine;
+        Q_UNUSED(f);
+        return false;
 #endif
+    }
 
+    QV4::ReturnedValue global();
 
-inline void ExecutionEngine::pushContext(Heap::ExecutionContext *context)
-{
-    Q_ASSERT(currentContext && context);
-    Value *v = jsAlloca(2);
-    v[0] = Encode(context);
-    v[1] = Encode((int)(v - static_cast<Value *>(currentContext)));
-    currentContext = static_cast<ExecutionContext *>(v);
-    current = currentContext->d();
-}
-
-inline void ExecutionEngine::pushContext(ExecutionContext *context)
-{
-    pushContext(context->d());
-}
-
-
-inline void ExecutionEngine::popContext()
-{
-    Q_ASSERT(jsStackTop > currentContext);
-    QV4::Value *offset = (currentContext + 1);
-    Q_ASSERT(offset->isInteger());
-    int o = offset->integerValue();
-    Q_ASSERT(o);
-    currentContext -= o;
-    current = currentContext->d();
-}
+    double localTZA = 0.0; // local timezone, initialized at startup
 
-inline ExecutionContext *ExecutionEngine::parentContext(ExecutionContext *context) const
-{
-    Value *offset = static_cast<Value *>(context) + 1;
-    Q_ASSERT(offset->isInteger());
-    int o = offset->integerValue();
-    return o ? context - o : 0;
-}
-
-inline
-void Heap::Base::mark(QV4::MarkStack *markStack)
-{
-    Q_ASSERT(inUse());
-    const HeapItem *h = reinterpret_cast<const HeapItem *>(this);
-    Chunk *c = h->chunk();
-    size_t index = h - c->realBase();
-    Q_ASSERT(!Chunk::testBit(c->extendsBitmap, index));
-    quintptr *bitmap = c->blackBitmap + Chunk::bitmapIndex(index);
-    quintptr bit = Chunk::bitForIndex(index);
-    if (!(*bitmap & bit)) {
-        *bitmap |= bit;
-        markStack->push(this);
-    }
-}
+    static QQmlRefPointer<CompiledData::CompilationUnit> compileModule(bool debugMode, const QString &url, const QString &sourceCode, const QDateTime &sourceTimeStamp, QList<QQmlJS::DiagnosticMessage> *diagnostics);
+#ifndef V4_BOOTSTRAP
+    QQmlRefPointer<CompiledData::CompilationUnit> compileModule(const QUrl &url);
+    QQmlRefPointer<CompiledData::CompilationUnit> compileModule(const QUrl &url, const QString &sourceCode, const QDateTime &sourceTimeStamp);
+
+    mutable QMutex moduleMutex;
+    QHash<QUrl, QQmlRefPointer<CompiledData::CompilationUnit>> modules;
+    void injectModule(const QQmlRefPointer<CompiledData::CompilationUnit> &moduleUnit);
+    QQmlRefPointer<CompiledData::CompilationUnit> moduleForUrl(const QUrl &_url, const CompiledData::CompilationUnit *referrer = nullptr) const;
+    QQmlRefPointer<CompiledData::CompilationUnit> loadModule(const QUrl &_url, const CompiledData::CompilationUnit *referrer = nullptr);
+#endif
 
-inline void Value::mark(MarkStack *markStack)
-{
-    Heap::Base *o = heapObject();
-    if (o)
-        o->mark(markStack);
-}
+private:
+#if QT_CONFIG(qml_debug)
+    QScopedPointer<QV4::Debugging::Debugger> m_debugger;
+    QScopedPointer<QV4::Profiling::Profiler> m_profiler;
+#endif
+    int jitCallCountThreshold;
 
-inline void Managed::mark(MarkStack *markStack)
-{
-    Q_ASSERT(m());
-    m()->mark(markStack);
-}
+    // used by generated Promise objects to handle 'then' events
+    QScopedPointer<QV4::Promise::ReactionHandler> m_reactionHandler;
+};
 
-#define CHECK_STACK_LIMITS(v4, scope) if ((v4)->checkStackLimits(scope)) return; \
+#define CHECK_STACK_LIMITS(v4) if ((v4)->checkStackLimits()) return Encode::undefined(); \
     ExecutionEngineCallDepthRecorder _executionEngineCallDepthRecorder(v4);
 
 struct ExecutionEngineCallDepthRecorder
@@ -549,10 +644,10 @@ struct ExecutionEngineCallDepthRecorder
     ~ExecutionEngineCallDepthRecorder() { --ee->callDepth; }
 };
 
-inline bool ExecutionEngine::checkStackLimits(Scope &scope)
+inline bool ExecutionEngine::checkStackLimits()
 {
     if (Q_UNLIKELY((jsStackTop > jsStackLimit) || (callDepth >= maxCallDepth))) {
-        failStackLimitCheck(scope);
+        throwRangeError(QStringLiteral("Maximum call stack size exceeded."));
         return true;
     }
 
diff --git a/src/qml/jsruntime/qv4enginebase_p.h b/src/qml/jsruntime/qv4enginebase_p.h
index 88f9dfd85c..b5cfea8863 100644
--- a/src/qml/jsruntime/qv4enginebase_p.h
+++ b/src/qml/jsruntime/qv4enginebase_p.h
@@ -57,46 +57,57 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
+struct CppStackFrame;
+
 // Base class for the execution engine
 
 #if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
 #pragma pack(push, 1)
 #endif
-struct EngineBase {
-    Heap::ExecutionContext *current = 0;
+struct Q_QML_EXPORT EngineBase {
+
+    CppStackFrame *currentStackFrame = nullptr;
 
-    Value *jsStackTop = 0;
+    Value *jsStackTop = nullptr;
     quint8 hasException = false;
     quint8 writeBarrierActive = false;
     quint16 unused = 0;
-#if QT_POINTER_SIZE == 8
-    quint8 padding[4];
-#endif
-    MemoryManager *memoryManager = 0;
+    quint8 isExecutingInRegExpJIT = false;
+    quint8 padding[3];
+    MemoryManager *memoryManager = nullptr;
     Runtime runtime;
 
     qint32 callDepth = 0;
-    Value *jsStackLimit = 0;
-    Value *jsStackBase = 0;
+    Value *jsStackLimit = nullptr;
+    Value *jsStackBase = nullptr;
+
+    IdentifierTable *identifierTable = nullptr;
+    Object *globalObject = nullptr;
 
-    ExecutionContext *currentContext = 0;
-    IdentifierTable *identifierTable = 0;
-    Object *globalObject = 0;
+    // Exception handling
+    Value *exceptionValue = nullptr;
 
-    enum {
+    enum InternalClassType {
         Class_Empty,
         Class_String,
         Class_MemberData,
         Class_SimpleArrayData,
         Class_SparseArrayData,
         Class_ExecutionContext,
-        Class_SimpleCallContext,
+        Class_CallContext,
+        Class_QmlContext,
         Class_Object,
         Class_ArrayObject,
         Class_FunctionObject,
+        Class_ArrowFunction,
+        Class_GeneratorFunction,
+        Class_GeneratorObject,
         Class_StringObject,
+        Class_SymbolObject,
         Class_ScriptFunction,
-        Class_BuiltinFunction,
+        Class_ConstructorFunction,
+        Class_MemberFunction,
+        Class_MemberGeneratorFunction,
         Class_ObjectProto,
         Class_RegExp,
         Class_RegExpObject,
@@ -106,19 +117,24 @@ struct EngineBase {
         Class_ErrorObject,
         Class_ErrorObjectWithMessage,
         Class_ErrorProto,
+        Class_QmlContextWrapper,
+        Class_ProxyObject,
+        Class_ProxyFunctionObject,
+        Class_Symbol,
         NClasses
     };
-    InternalClass *internalClasses[NClasses];
+    Heap::InternalClass *classes[NClasses];
+    Heap::InternalClass *internalClasses(InternalClassType icType) { return classes[icType]; }
 };
 #if defined(Q_CC_MSVC) || defined(Q_CC_GNU)
 #pragma pack(pop)
 #endif
 
 Q_STATIC_ASSERT(std::is_standard_layout<EngineBase>::value);
-Q_STATIC_ASSERT(offsetof(EngineBase, current) == 0);
-Q_STATIC_ASSERT(offsetof(EngineBase, jsStackTop) == offsetof(EngineBase, current) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(EngineBase, currentStackFrame) == 0);
+Q_STATIC_ASSERT(offsetof(EngineBase, jsStackTop) == offsetof(EngineBase, currentStackFrame) + QT_POINTER_SIZE);
 Q_STATIC_ASSERT(offsetof(EngineBase, hasException) == offsetof(EngineBase, jsStackTop) + QT_POINTER_SIZE);
-Q_STATIC_ASSERT(offsetof(EngineBase, memoryManager) == offsetof(EngineBase, hasException) + QT_POINTER_SIZE);
+Q_STATIC_ASSERT(offsetof(EngineBase, memoryManager) == offsetof(EngineBase, hasException) + 8);
 Q_STATIC_ASSERT(offsetof(EngineBase, runtime) == offsetof(EngineBase, memoryManager) + QT_POINTER_SIZE);
 
 }
diff --git a/src/qml/jsruntime/qv4errorobject.cpp b/src/qml/jsruntime/qv4errorobject.cpp
index b3bd28e18b..c6d6c77d11 100644
--- a/src/qml/jsruntime/qv4errorobject.cpp
+++ b/src/qml/jsruntime/qv4errorobject.cpp
@@ -47,11 +47,6 @@
 
 #include "qv4string_p.h"
 #include <private/qv4mm_p.h>
-#include <private/qqmljsengine_p.h>
-#include <private/qqmljslexer_p.h>
-#include <private/qqmljsparser_p.h>
-#include <private/qqmljsast_p.h>
-#include <qv4jsir_p.h>
 #include <qv4codegen_p.h>
 
 #ifndef Q_OS_WIN
@@ -75,13 +70,13 @@ void Heap::ErrorObject::init()
     Scope scope(internalClass->engine);
     Scoped<QV4::ErrorObject> e(scope, this);
 
-    if (internalClass == scope.engine->internalClasses[EngineBase::Class_ErrorProto])
+    if (internalClass == scope.engine->internalClasses(EngineBase::Class_ErrorProto))
         return;
 
     setProperty(scope.engine, QV4::ErrorObject::Index_Stack, scope.engine->getStackFunction()->d());
-    setProperty(scope.engine, QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset, Primitive::undefinedValue());
-    setProperty(scope.engine, QV4::ErrorObject::Index_FileName, Primitive::undefinedValue());
-    setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Primitive::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_StackSetter, Value::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_FileName, Value::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Value::undefinedValue());
 }
 
 void Heap::ErrorObject::init(const Value &message, ErrorType t)
@@ -93,12 +88,12 @@ void Heap::ErrorObject::init(const Value &message, ErrorType t)
     Scoped<QV4::ErrorObject> e(scope, this);
 
     setProperty(scope.engine, QV4::ErrorObject::Index_Stack, scope.engine->getStackFunction()->d());
-    setProperty(scope.engine, QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset, Primitive::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_StackSetter, Value::undefinedValue());
 
     e->d()->stackTrace = new StackTrace(scope.engine->stackTrace());
     if (!e->d()->stackTrace->isEmpty()) {
         setProperty(scope.engine, QV4::ErrorObject::Index_FileName, scope.engine->newString(e->d()->stackTrace->at(0).source));
-        setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Primitive::fromInt32(e->d()->stackTrace->at(0).line));
+        setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Value::fromInt32(e->d()->stackTrace->at(0).line));
     }
 
     if (!message.isUndefined())
@@ -107,6 +102,7 @@ void Heap::ErrorObject::init(const Value &message, ErrorType t)
 
 void Heap::ErrorObject::init(const Value &message, const QString &fileName, int line, int column, ErrorObject::ErrorType t)
 {
+    Q_UNUSED(fileName); // ####
     Object::init();
     errorType = t;
 
@@ -114,7 +110,7 @@ void Heap::ErrorObject::init(const Value &message, const QString &fileName, int
     Scoped<QV4::ErrorObject> e(scope, this);
 
     setProperty(scope.engine, QV4::ErrorObject::Index_Stack, scope.engine->getStackFunction()->d());
-    setProperty(scope.engine, QV4::ErrorObject::Index_Stack + QV4::Object::SetterOffset, Primitive::undefinedValue());
+    setProperty(scope.engine, QV4::ErrorObject::Index_StackSetter, Value::undefinedValue());
 
     e->d()->stackTrace = new StackTrace(scope.engine->stackTrace());
     StackFrame frame;
@@ -123,10 +119,9 @@ void Heap::ErrorObject::init(const Value &message, const QString &fileName, int
     frame.column = column;
     e->d()->stackTrace->prepend(frame);
 
-    if (!e->d()->stackTrace->isEmpty()) {
-        setProperty(scope.engine, QV4::ErrorObject::Index_FileName, scope.engine->newString(e->d()->stackTrace->at(0).source));
-        setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Primitive::fromInt32(e->d()->stackTrace->at(0).line));
-    }
+    Q_ASSERT(!e->d()->stackTrace->isEmpty());
+    setProperty(scope.engine, QV4::ErrorObject::Index_FileName, scope.engine->newString(e->d()->stackTrace->at(0).source));
+    setProperty(scope.engine, QV4::ErrorObject::Index_LineNumber, Value::fromInt32(e->d()->stackTrace->at(0).line));
 
     if (!message.isUndefined())
         setProperty(scope.engine, QV4::ErrorObject::Index_Message, message);
@@ -153,11 +148,12 @@ const char *ErrorObject::className(Heap::ErrorObject::ErrorType t)
     Q_UNREACHABLE();
 }
 
-void ErrorObject::method_get_stack(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ErrorObject::method_get_stack(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<ErrorObject> This(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    const ErrorObject *This = thisObject->as<ErrorObject>();
     if (!This)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
     if (!This->d()->stack) {
         QString trace;
         for (int i = 0; i < This->d()->stackTrace->count(); ++i) {
@@ -168,9 +164,9 @@ void ErrorObject::method_get_stack(const BuiltinFunction *, Scope &scope, CallDa
             if (frame.line >= 0)
                 trace += QLatin1Char(':') + QString::number(frame.line);
         }
-        This->d()->stack.set(scope.engine, scope.engine->newString(trace));
+        This->d()->stack.set(v4, v4->newString(trace));
     }
-    scope.result = This->d()->stack;
+    return This->d()->stack->asReturnedValue();
 }
 
 DEFINE_OBJECT_VTABLE(ErrorObject);
@@ -233,81 +229,81 @@ void Heap::ErrorCtor::init(QV4::ExecutionContext *scope, const QString &name)
     Heap::FunctionObject::init(scope, name);
 }
 
-void ErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue ErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<ErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<ErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
-void ErrorCtor::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue ErrorCtor::virtualCall(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    static_cast<const Object *>(that)->construct(scope, callData);
+    return f->callAsConstructor(argv, argc);
 }
 
 void Heap::EvalErrorCtor::init(QV4::ExecutionContext *scope)
 {
-    Heap::ErrorCtor::init(scope, QStringLiteral("EvalError"));
+    Heap::FunctionObject::init(scope, QStringLiteral("EvalError"));
 }
 
-void EvalErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue EvalErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<EvalErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<EvalErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
 void Heap::RangeErrorCtor::init(QV4::ExecutionContext *scope)
 {
-    Heap::ErrorCtor::init(scope, QStringLiteral("RangeError"));
+    Heap::FunctionObject::init(scope, QStringLiteral("RangeError"));
 }
 
-void RangeErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue RangeErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<RangeErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<RangeErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
 void Heap::ReferenceErrorCtor::init(QV4::ExecutionContext *scope)
 {
-    Heap::ErrorCtor::init(scope, QStringLiteral("ReferenceError"));
+    Heap::FunctionObject::init(scope, QStringLiteral("ReferenceError"));
 }
 
-void ReferenceErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue ReferenceErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<ReferenceErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<ReferenceErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
 void Heap::SyntaxErrorCtor::init(QV4::ExecutionContext *scope)
 {
-    Heap::ErrorCtor::init(scope, QStringLiteral("SyntaxError"));
+    Heap::FunctionObject::init(scope, QStringLiteral("SyntaxError"));
 }
 
-void SyntaxErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue SyntaxErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<SyntaxErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<SyntaxErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
 void Heap::TypeErrorCtor::init(QV4::ExecutionContext *scope)
 {
-    Heap::ErrorCtor::init(scope, QStringLiteral("TypeError"));
+    Heap::FunctionObject::init(scope, QStringLiteral("TypeError"));
 }
 
-void TypeErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue TypeErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<TypeErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<TypeErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
 void Heap::URIErrorCtor::init(QV4::ExecutionContext *scope)
 {
-    Heap::ErrorCtor::init(scope, QStringLiteral("URIError"));
+    Heap::FunctionObject::init(scope, QStringLiteral("URIError"));
 }
 
-void URIErrorCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue URIErrorCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ScopedValue v(scope, callData->argument(0));
-    scope.result = ErrorObject::create<URIErrorObject>(scope.engine, v);
+    Value v = argc ? *argv : Value::undefinedValue();
+    return ErrorObject::create<URIErrorObject>(f->engine(), v, newTarget)->asReturnedValue();
 }
 
 void ErrorPrototype::init(ExecutionEngine *engine, Object *ctor, Object *obj, Heap::ErrorObject::ErrorType t)
@@ -316,19 +312,21 @@ void ErrorPrototype::init(ExecutionEngine *engine, Object *ctor, Object *obj, He
     ScopedString s(scope);
     ScopedObject o(scope);
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = obj));
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
     obj->setProperty(Index_Constructor, ctor->d());
     obj->setProperty(Index_Message, engine->id_empty()->d());
     obj->setProperty(Index_Name, engine->newString(QString::fromLatin1(ErrorObject::className(t))));
     obj->defineDefaultProperty(engine->id_toString(), method_toString, 0);
 }
 
-void ErrorPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ErrorPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Object *o = callData->thisObject.as<Object>();
+    ExecutionEngine *v4 = b->engine();
+    const Object *o = thisObject->as<Object>();
     if (!o)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
+    Scope scope(v4);
     ScopedValue name(scope, o->get(scope.engine->id_name()));
     QString qname;
     if (name->isUndefined())
@@ -351,5 +349,5 @@ void ErrorPrototype::method_toString(const BuiltinFunction *, Scope &scope, Call
         str = qname + QLatin1String(": ") + qmessage;
     }
 
-    scope.result = scope.engine->newString(str)->asReturnedValue();
+    return scope.engine->newString(str)->asReturnedValue();
 }
diff --git a/src/qml/jsruntime/qv4errorobject_p.h b/src/qml/jsruntime/qv4errorobject_p.h
index d556617b48..139bcc9754 100644
--- a/src/qml/jsruntime/qv4errorobject_p.h
+++ b/src/qml/jsruntime/qv4errorobject_p.h
@@ -67,7 +67,7 @@ namespace Heap {
     Member(class, Pointer, String *, stack)
 
 DECLARE_HEAP_OBJECT(ErrorObject, Object) {
-    DECLARE_MARK_TABLE(ErrorObject);
+    DECLARE_MARKOBJECTS(ErrorObject);
     enum ErrorType {
         Error,
         EvalError,
@@ -115,7 +115,7 @@ struct URIErrorObject : ErrorObject {
     void init(const Value &message);
 };
 
-struct ErrorCtor : Heap::FunctionObject {
+struct ErrorCtor : FunctionObject {
     void init(QV4::ExecutionContext *scope);
     void init(QV4::ExecutionContext *scope, const QString &name);
 };
@@ -153,6 +153,7 @@ struct ErrorObject: Object {
 
     enum {
         Index_Stack = 0, // Accessor Property
+        Index_StackSetter = 1, // Accessor Property
         Index_FileName = 2,
         Index_LineNumber = 3,
         Index_Message = 4
@@ -165,7 +166,7 @@ struct ErrorObject: Object {
     V4_NEEDS_DESTROY
 
     template <typename T>
-    static Heap::Object *create(ExecutionEngine *e, const Value &message);
+    static Heap::Object *create(ExecutionEngine *e, const Value &message, const Value *newTarget);
     template <typename T>
     static Heap::Object *create(ExecutionEngine *e, const QString &message);
     template <typename T>
@@ -175,12 +176,12 @@ struct ErrorObject: Object {
 
     static const char *className(Heap::ErrorObject::ErrorType t);
 
-    static void method_get_stack(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_get_stack(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 template<>
 inline const ErrorObject *Value::as() const {
-    return isManaged() && m()->vtable()->isErrorObject ? reinterpret_cast<const ErrorObject *>(this) : 0;
+    return isManaged() && m()->internalClass->vtable->isErrorObject ? reinterpret_cast<const ErrorObject *>(this) : nullptr;
 }
 
 struct EvalErrorObject: ErrorObject {
@@ -229,54 +230,60 @@ struct ErrorCtor: FunctionObject
 {
     V4_OBJECT2(ErrorCtor, FunctionObject)
 
-    static void construct(const Managed *, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct EvalErrorCtor: ErrorCtor
 {
-    V4_OBJECT2(EvalErrorCtor, ErrorCtor)
+    V4_OBJECT2(EvalErrorCtor, FunctionObject)
+    V4_PROTOTYPE(errorCtor)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 };
 
 struct RangeErrorCtor: ErrorCtor
 {
-    V4_OBJECT2(RangeErrorCtor, ErrorCtor)
+    V4_OBJECT2(RangeErrorCtor, FunctionObject)
+    V4_PROTOTYPE(errorCtor)
 
-    static void construct(const Managed *, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 };
 
 struct ReferenceErrorCtor: ErrorCtor
 {
-    V4_OBJECT2(ReferenceErrorCtor, ErrorCtor)
+    V4_OBJECT2(ReferenceErrorCtor, FunctionObject)
+    V4_PROTOTYPE(errorCtor)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 };
 
 struct SyntaxErrorCtor: ErrorCtor
 {
-    V4_OBJECT2(SyntaxErrorCtor, ErrorCtor)
+    V4_OBJECT2(SyntaxErrorCtor, FunctionObject)
+    V4_PROTOTYPE(errorCtor)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 };
 
 struct TypeErrorCtor: ErrorCtor
 {
-    V4_OBJECT2(TypeErrorCtor, ErrorCtor)
+    V4_OBJECT2(TypeErrorCtor, FunctionObject)
+    V4_PROTOTYPE(errorCtor)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 };
 
 struct URIErrorCtor: ErrorCtor
 {
-    V4_OBJECT2(URIErrorCtor, ErrorCtor)
+    V4_OBJECT2(URIErrorCtor, FunctionObject)
+    V4_PROTOTYPE(errorCtor)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
 };
 
 
-struct ErrorPrototype : ErrorObject
+struct ErrorPrototype : Object
 {
     enum {
         Index_Constructor = 0,
@@ -286,35 +293,35 @@ struct ErrorPrototype : ErrorObject
     void init(ExecutionEngine *engine, Object *ctor) { init(engine, ctor, this, Heap::ErrorObject::Error); }
 
     static void init(ExecutionEngine *engine, Object *ctor, Object *obj, Heap::ErrorObject::ErrorType t);
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
-struct EvalErrorPrototype : ErrorObject
+struct EvalErrorPrototype : Object
 {
     void init(ExecutionEngine *engine, Object *ctor) { ErrorPrototype::init(engine, ctor, this, Heap::ErrorObject::EvalError); }
 };
 
-struct RangeErrorPrototype : ErrorObject
+struct RangeErrorPrototype : Object
 {
     void init(ExecutionEngine *engine, Object *ctor) { ErrorPrototype::init(engine, ctor, this, Heap::ErrorObject::RangeError); }
 };
 
-struct ReferenceErrorPrototype : ErrorObject
+struct ReferenceErrorPrototype : Object
 {
     void init(ExecutionEngine *engine, Object *ctor) { ErrorPrototype::init(engine, ctor, this, Heap::ErrorObject::ReferenceError); }
 };
 
-struct SyntaxErrorPrototype : ErrorObject
+struct SyntaxErrorPrototype : Object
 {
     void init(ExecutionEngine *engine, Object *ctor) { ErrorPrototype::init(engine, ctor, this, Heap::ErrorObject::SyntaxError); }
 };
 
-struct TypeErrorPrototype : ErrorObject
+struct TypeErrorPrototype : Object
 {
     void init(ExecutionEngine *engine, Object *ctor) { ErrorPrototype::init(engine, ctor, this, Heap::ErrorObject::TypeError); }
 };
 
-struct URIErrorPrototype : ErrorObject
+struct URIErrorPrototype : Object
 {
     void init(ExecutionEngine *engine, Object *ctor) { ErrorPrototype::init(engine, ctor, this, Heap::ErrorObject::URIError); }
 };
@@ -322,31 +329,33 @@ struct URIErrorPrototype : ErrorObject
 
 inline SyntaxErrorObject *ErrorObject::asSyntaxError()
 {
-    return d()->errorType == QV4::Heap::ErrorObject::SyntaxError ? static_cast<SyntaxErrorObject *>(this) : 0;
+    return d()->errorType == QV4::Heap::ErrorObject::SyntaxError ? static_cast<SyntaxErrorObject *>(this) : nullptr;
 }
 
 
 template <typename T>
-Heap::Object *ErrorObject::create(ExecutionEngine *e, const Value &message) {
-    InternalClass *ic = e->internalClasses[message.isUndefined() ? EngineBase::Class_ErrorObject : EngineBase::Class_ErrorObjectWithMessage];
-    ic = ic->changePrototype(T::defaultPrototype(e)->d());
-    return e->memoryManager->allocObject<T>(ic, T::defaultPrototype(e), message);
+Heap::Object *ErrorObject::create(ExecutionEngine *e, const Value &message, const Value *newTarget) {
+    EngineBase::InternalClassType klass = message.isUndefined() ? EngineBase::Class_ErrorObject : EngineBase::Class_ErrorObjectWithMessage;
+    Scope scope(e);
+    ScopedObject proto(scope, static_cast<const Object *>(newTarget)->get(scope.engine->id_prototype()));
+    Scoped<InternalClass> ic(scope, e->internalClasses(klass)->changePrototype(proto->d()));
+    return e->memoryManager->allocObject<T>(ic->d(), message);
 }
 template <typename T>
 Heap::Object *ErrorObject::create(ExecutionEngine *e, const QString &message) {
     Scope scope(e);
     ScopedValue v(scope, message.isEmpty() ? Encode::undefined() : e->newString(message)->asReturnedValue());
-    InternalClass *ic = e->internalClasses[v->isUndefined() ? EngineBase::Class_ErrorObject : EngineBase::Class_ErrorObjectWithMessage];
-    ic = ic->changePrototype(T::defaultPrototype(e)->d());
-    return e->memoryManager->allocObject<T>(ic, T::defaultPrototype(e), v);
+    EngineBase::InternalClassType klass = v->isUndefined() ? EngineBase::Class_ErrorObject : EngineBase::Class_ErrorObjectWithMessage;
+    Scoped<InternalClass> ic(scope, e->internalClasses(klass)->changePrototype(T::defaultPrototype(e)->d()));
+    return e->memoryManager->allocObject<T>(ic->d(), v);
 }
 template <typename T>
 Heap::Object *ErrorObject::create(ExecutionEngine *e, const QString &message, const QString &filename, int line, int column) {
     Scope scope(e);
     ScopedValue v(scope, message.isEmpty() ? Encode::undefined() : e->newString(message)->asReturnedValue());
-    InternalClass *ic = e->internalClasses[v->isUndefined() ? EngineBase::Class_ErrorObject : EngineBase::Class_ErrorObjectWithMessage];
-    ic = ic->changePrototype(T::defaultPrototype(e)->d());
-    return e->memoryManager->allocObject<T>(ic, T::defaultPrototype(e), v, filename, line, column);
+    EngineBase::InternalClassType klass = v->isUndefined() ? EngineBase::Class_ErrorObject : EngineBase::Class_ErrorObjectWithMessage;
+    Scoped<InternalClass> ic(scope, e->internalClasses(klass)->changePrototype(T::defaultPrototype(e)->d()));
+    return e->memoryManager->allocObject<T>(ic->d(), v, filename, line, column);
 }
 
 
diff --git a/src/qml/jsruntime/qv4estable.cpp b/src/qml/jsruntime/qv4estable.cpp
new file mode 100644
index 0000000000..99f6bf6aa0
--- /dev/null
+++ b/src/qml/jsruntime/qv4estable.cpp
@@ -0,0 +1,199 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4estable_p.h"
+#include "qv4object_p.h"
+
+using namespace QV4;
+
+// The ES spec requires that Map/Set be implemented using a data structure that
+// is a little different from most; it requires nonlinear access, and must also
+// preserve the order of insertion of items in a deterministic way.
+//
+// This class implements those requirements, except for fast access: that
+// will be addressed in a followup patch.
+
+ESTable::ESTable()
+    : m_capacity(8)
+{
+    m_keys = (Value*)malloc(m_capacity * sizeof(Value));
+    m_values = (Value*)malloc(m_capacity * sizeof(Value));
+    memset(m_keys, 0, m_capacity);
+    memset(m_values, 0, m_capacity);
+}
+
+ESTable::~ESTable()
+{
+    free(m_keys);
+    free(m_values);
+    m_size = 0;
+    m_capacity = 0;
+    m_keys = nullptr;
+    m_values = nullptr;
+}
+
+void ESTable::markObjects(MarkStack *s, bool isWeakMap)
+{
+    for (uint i = 0; i < m_size; ++i) {
+        if (!isWeakMap)
+            m_keys[i].mark(s);
+        m_values[i].mark(s);
+    }
+}
+
+// Pretends that there's nothing in the table. Doesn't actually free memory, as
+// it will almost certainly be reused again anyway.
+void ESTable::clear()
+{
+    m_size = 0;
+}
+
+// Update the table to contain \a value for a given \a key. The key is
+// normalized, as required by the ES spec.
+void ESTable::set(const Value &key, const Value &value)
+{
+    for (uint i = 0; i < m_size; ++i) {
+        if (m_keys[i].sameValueZero(key)) {
+            m_values[i] = value;
+            return;
+        }
+    }
+
+    if (m_capacity == m_size) {
+        uint oldCap = m_capacity;
+        m_capacity *= 2;
+        m_keys = (Value*)realloc(m_keys, m_capacity * sizeof(Value));
+        m_values = (Value*)realloc(m_values, m_capacity * sizeof(Value));
+        memset(m_keys + oldCap, 0, m_capacity - oldCap);
+        memset(m_values + oldCap, 0, m_capacity - oldCap);
+    }
+
+    Value nk = key;
+    if (nk.isDouble()) {
+        if (nk.doubleValue() == 0 && std::signbit(nk.doubleValue()))
+            nk = Value::fromDouble(+0);
+    }
+
+    m_keys[m_size] = nk;
+    m_values[m_size] = value;
+
+    m_size++;
+}
+
+// Returns true if the table contains \a key, false otherwise.
+bool ESTable::has(const Value &key) const
+{
+    for (uint i = 0; i < m_size; ++i) {
+        if (m_keys[i].sameValueZero(key))
+            return true;
+    }
+
+    return false;
+}
+
+// Fetches the value for the given \a key, and if \a hasValue is passed in,
+// it is set depending on whether or not the given key was found.
+ReturnedValue ESTable::get(const Value &key, bool *hasValue) const
+{
+    for (uint i = 0; i < m_size; ++i) {
+        if (m_keys[i].sameValueZero(key)) {
+            if (hasValue)
+                *hasValue = true;
+            return m_values[i].asReturnedValue();
+        }
+    }
+
+    if (hasValue)
+        *hasValue = false;
+    return Encode::undefined();
+}
+
+// Removes the given \a key from the table
+bool ESTable::remove(const Value &key)
+{
+    bool found = false;
+    uint idx = 0;
+    for (; idx < m_size; ++idx) {
+        if (m_keys[idx].sameValueZero(key)) {
+            found = true;
+            break;
+        }
+    }
+
+    if (found == true) {
+        memmove(m_keys + idx, m_keys + idx + 1, (m_size - idx)*sizeof(Value));
+        memmove(m_values + idx, m_values + idx + 1, (m_size - idx)*sizeof(Value));
+        m_size--;
+    }
+    return found;
+}
+
+// Returns the size of the table. Note that the size may not match the underlying allocation.
+uint ESTable::size() const
+{
+    return m_size;
+}
+
+// Retrieves a key and value for a given \a idx, and places them in \a key and
+// \a value. They must be valid pointers.
+void ESTable::iterate(uint idx, Value *key, Value *value)
+{
+    Q_ASSERT(idx < m_size);
+    Q_ASSERT(key);
+    Q_ASSERT(value);
+    *key = m_keys[idx];
+    *value = m_values[idx];
+}
+
+void ESTable::removeUnmarkedKeys()
+{
+    uint idx = 0;
+    uint toIdx = 0;
+    for (; idx < m_size; ++idx) {
+        Q_ASSERT(m_keys[idx].isObject());
+        Object &o = static_cast<Object &>(m_keys[idx]);
+        if (o.d()->isMarked()) {
+            m_keys[toIdx] = m_keys[idx];
+            m_values[toIdx] = m_values[idx];
+            ++toIdx;
+        }
+    }
+    m_size = toIdx;
+}
+
diff --git a/src/qml/jsruntime/qv4estable_p.h b/src/qml/jsruntime/qv4estable_p.h
new file mode 100644
index 0000000000..f54fc37a7b
--- /dev/null
+++ b/src/qml/jsruntime/qv4estable_p.h
@@ -0,0 +1,89 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#ifndef QV4ESTABLE_P_H
+#define QV4ESTABLE_P_H
+
+#include "qv4value_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4
+{
+
+class ESTable
+{
+public:
+    ESTable();
+    ~ESTable();
+
+    void markObjects(MarkStack *s, bool isWeakMap);
+    void clear();
+    void set(const Value &k, const Value &v);
+    bool has(const Value &k) const;
+    ReturnedValue get(const Value &k, bool *hasValue = nullptr) const;
+    bool remove(const Value &k);
+    uint size() const;
+    void iterate(uint idx, Value *k, Value *v);
+
+    void removeUnmarkedKeys();
+
+private:
+    Value *m_keys = nullptr;
+    Value *m_values = nullptr;
+    uint m_size = 0;
+    uint m_capacity = 0;
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/jsruntime/qv4executableallocator.cpp b/src/qml/jsruntime/qv4executableallocator.cpp
index 64ac1267ce..c836d121e3 100644
--- a/src/qml/jsruntime/qv4executableallocator.cpp
+++ b/src/qml/jsruntime/qv4executableallocator.cpp
@@ -38,17 +38,23 @@
 ****************************************************************************/
 
 #include "qv4executableallocator_p.h"
+#include "qv4functiontable_p.h"
 
 #include <wtf/StdLibExtras.h>
 #include <wtf/PageAllocation.h>
 
 using namespace QV4;
 
-void *ExecutableAllocator::Allocation::start() const
+void *ExecutableAllocator::Allocation::exceptionHandler() const
 {
     return reinterpret_cast<void*>(addr);
 }
 
+void *ExecutableAllocator::Allocation::start() const
+{
+    return reinterpret_cast<void*>(addr + exceptionHandlerSize());
+}
+
 void ExecutableAllocator::Allocation::deallocate(ExecutableAllocator *allocator)
 {
     if (isValid())
@@ -159,10 +165,10 @@ ExecutableAllocator::~ExecutableAllocator()
 ExecutableAllocator::Allocation *ExecutableAllocator::allocate(size_t size)
 {
     QMutexLocker locker(&mutex);
-    Allocation *allocation = 0;
+    Allocation *allocation = nullptr;
 
     // Code is best aligned to 16-byte boundaries.
-    size = WTF::roundUpToMultipleOf(16, size);
+    size = WTF::roundUpToMultipleOf(16, size + exceptionHandlerSize());
 
     QMultiMap<size_t, Allocation*>::Iterator it = freeAllocations.lowerBound(size);
     if (it != freeAllocations.end()) {
@@ -217,7 +223,7 @@ void ExecutableAllocator::free(Allocation *allocation)
     if (!merged)
         freeAllocations.insert(allocation->size, allocation);
 
-    allocation = 0;
+    allocation = nullptr;
 
     if (!chunk->firstAllocation->next) {
         freeAllocations.remove(chunk->firstAllocation->size, chunk->firstAllocation);
@@ -235,7 +241,7 @@ ExecutableAllocator::ChunkOfPages *ExecutableAllocator::chunkForAllocation(Alloc
     if (it != chunks.begin())
         --it;
     if (it == chunks.end())
-        return 0;
+        return nullptr;
     return *it;
 }
 
diff --git a/src/qml/jsruntime/qv4executableallocator_p.h b/src/qml/jsruntime/qv4executableallocator_p.h
index 353a6eacff..013c6d7120 100644
--- a/src/qml/jsruntime/qv4executableallocator_p.h
+++ b/src/qml/jsruntime/qv4executableallocator_p.h
@@ -82,13 +82,11 @@ public:
     struct Allocation
     {
         Allocation()
-            : addr(0)
-            , size(0)
+            : size(0)
             , free(true)
-            , next(0)
-            , prev(0)
         {}
 
+        void *exceptionHandler() const;
         void *start() const;
         void invalidate() { addr = 0; }
         bool isValid() const { return addr != 0; }
@@ -103,11 +101,11 @@ public:
         bool mergeNext(ExecutableAllocator *allocator);
         bool mergePrevious(ExecutableAllocator *allocator);
 
-        quintptr addr;
+        quintptr addr = 0;
         uint size : 31; // More than 2GB of function code? nah :)
         uint free : 1;
-        Allocation *next;
-        Allocation *prev;
+        Allocation *next = nullptr;
+        Allocation *prev = nullptr;
     };
 
     // for debugging / unit-testing
@@ -117,13 +115,12 @@ public:
     struct ChunkOfPages
     {
         ChunkOfPages()
-            : pages(0)
-            , firstAllocation(0)
+
         {}
         ~ChunkOfPages();
 
-        WTF::PageAllocation *pages;
-        Allocation *firstAllocation;
+        WTF::PageAllocation *pages = nullptr;
+        Allocation *firstAllocation = nullptr;
 
         bool contains(Allocation *alloc) const;
     };
diff --git a/src/qml/jsruntime/qv4function.cpp b/src/qml/jsruntime/qv4function.cpp
index 4c8117527c..7702939e23 100644
--- a/src/qml/jsruntime/qv4function.cpp
+++ b/src/qml/jsruntime/qv4function.cpp
@@ -38,84 +38,173 @@
 ****************************************************************************/
 
 #include "qv4function_p.h"
+#include "qv4functionobject_p.h"
 #include "qv4managed_p.h"
 #include "qv4string_p.h"
 #include "qv4value_p.h"
 #include "qv4engine_p.h"
 #include "qv4lookup_p.h"
 #include <private/qv4mm_p.h>
+#include <private/qv4identifiertable_p.h>
+#include <private/qv4functiontable_p.h>
+#include <assembler/MacroAssemblerCodeRef.h>
+#include <private/qv4vme_moth_p.h>
+#include <private/qqmlglobal_p.h>
 
 QT_BEGIN_NAMESPACE
 
 using namespace QV4;
 
-Function::Function(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function,
-                   ReturnedValue (*codePtr)(ExecutionEngine *, const uchar *))
-        : compiledFunction(function)
-        , compilationUnit(unit)
-        , code(codePtr)
-        , codeData(0)
-        , hasQmlDependencies(function->hasQmlDependencies())
+ReturnedValue Function::call(const Value *thisObject, const Value *argv, int argc, const ExecutionContext *context) {
+    ExecutionEngine *engine = context->engine();
+    CppStackFrame frame;
+    frame.init(engine, this, argv, argc);
+    frame.setupJSFrame(engine->jsStackTop, Value::undefinedValue(), context->d(),
+                       thisObject ? *thisObject : Value::undefinedValue(),
+                       Value::undefinedValue());
+
+    frame.push();
+    engine->jsStackTop += frame.requiredJSStackFrameSize();
+
+    ReturnedValue result = Moth::VME::exec(&frame, engine);
+
+    frame.pop();
+
+    return result;
+}
+
+Function *Function::create(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function)
 {
-    Q_UNUSED(engine);
+    quint16 traceSlotCount = 0;
+#if QT_CONFIG(qml_tracing)
+        traceSlotCount = function->nTraceInfos == CompiledData::Function::NoTracing()
+                ? 1
+                : function->nTraceInfos;
+#endif
+    quint8 *storage = new quint8[sizeof(Function) + traceSlotCount];
+    return new(storage) Function(engine, unit, function);
+}
+
+void Function::destroy()
+{
+    delete[] reinterpret_cast<quint8 *>(this);
+}
 
-    internalClass = engine->internalClasses[EngineBase::Class_Empty];
-    const CompiledData::LEUInt32 *formalsIndices = compiledFunction->formalsTable();
-    // iterate backwards, so we get the right ordering for duplicate names
+Function::Function(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function)
+    : FunctionData(unit)
+    , compiledFunction(function)
+    , codeData(function->code())
+    , jittedCode(nullptr)
+    , codeRef(nullptr)
+    , hasQmlDependencies(function->hasQmlDependencies())
+{
     Scope scope(engine);
-    ScopedString arg(scope);
-    for (int i = static_cast<int>(compiledFunction->nFormals - 1); i >= 0; --i) {
-        arg = compilationUnit->runtimeStrings[formalsIndices[i]];
-        while (1) {
-            InternalClass *newClass = internalClass->addMember(arg, Attr_NotConfigurable);
-            if (newClass != internalClass) {
-                internalClass = newClass;
-                break;
-            }
-            // duplicate arguments, need some trick to store them
-            MemoryManager *mm = engine->memoryManager;
-            arg = mm->alloc<String>(arg->d(), engine->newString(QString(0xfffe)));
-        }
-    }
-    nFormals = compiledFunction->nFormals;
+    Scoped<InternalClass> ic(scope, engine->internalClasses(EngineBase::Class_CallContext));
 
-    const CompiledData::LEUInt32 *localsIndices = compiledFunction->localsTable();
+    // first locals
+    const quint32_le *localsIndices = compiledFunction->localsTable();
     for (quint32 i = 0; i < compiledFunction->nLocals; ++i)
-        internalClass = internalClass->addMember(compilationUnit->runtimeStrings[localsIndices[i]]->identifier, Attr_NotConfigurable);
+        ic = ic->addMember(engine->identifierTable->asPropertyKey(compilationUnit->runtimeStrings[localsIndices[i]]), Attr_NotConfigurable);
+
+    const quint32_le *formalsIndices = compiledFunction->formalsTable();
+    for (quint32 i = 0; i < compiledFunction->nFormals; ++i)
+        ic = ic->addMember(engine->identifierTable->asPropertyKey(compilationUnit->runtimeStrings[formalsIndices[i]]), Attr_NotConfigurable);
+    internalClass = ic->d();
 
-    canUseSimpleCall = compiledFunction->flags & CompiledData::Function::CanUseSimpleCall;
+    nFormals = compiledFunction->nFormals;
+
+#if QT_CONFIG(qml_tracing)
+    if (tracingEnabled()) {
+        for (uint i = 0; i < function->nTraceInfos; ++i)
+            *traceInfo(i) = 0;
+    }
+#endif
 }
 
 Function::~Function()
 {
+    if (codeRef) {
+        destroyFunctionTable(this, codeRef);
+        delete codeRef;
+    }
 }
 
 void Function::updateInternalClass(ExecutionEngine *engine, const QList<QByteArray> &parameters)
 {
-    internalClass = engine->internalClasses[EngineBase::Class_Empty];
+    QStringList parameterNames;
 
-    // iterate backwards, so we get the right ordering for duplicate names
-    Scope scope(engine);
-    ScopedString arg(scope);
-    for (int i = parameters.size() - 1; i >= 0; --i) {
-        arg = engine->newString(QString::fromUtf8(parameters.at(i)));
-        while (1) {
-            InternalClass *newClass = internalClass->addMember(arg, Attr_NotConfigurable);
-            if (newClass != internalClass) {
-                internalClass = newClass;
+    // Resolve duplicate parameter names:
+    for (int i = 0, ei = parameters.count(); i != ei; ++i) {
+        const QByteArray &param = parameters.at(i);
+        int duplicate = -1;
+
+        for (int j = i - 1; j >= 0; --j) {
+            const QByteArray &prevParam = parameters.at(j);
+            if (param == prevParam) {
+                duplicate = j;
                 break;
             }
-            // duplicate arguments, need some trick to store them
-            arg = engine->memoryManager->alloc<String>(arg->d(), engine->newString(QString(0xfffe)));
         }
+
+        if (duplicate == -1) {
+            parameterNames.append(QString::fromUtf8(param));
+        } else {
+            const QString &dup = parameterNames[duplicate];
+            parameterNames.append(dup);
+            parameterNames[duplicate] =
+                    QString(0xfffe) + QString::number(duplicate) + dup;
+        }
+
     }
-    nFormals = parameters.size();
 
-    const CompiledData::LEUInt32 *localsIndices = compiledFunction->localsTable();
+    internalClass = engine->internalClasses(EngineBase::Class_CallContext);
+
+    // first locals
+    const quint32_le *localsIndices = compiledFunction->localsTable();
     for (quint32 i = 0; i < compiledFunction->nLocals; ++i)
-        internalClass = internalClass->addMember(compilationUnit->runtimeStrings[localsIndices[i]]->identifier, Attr_NotConfigurable);
+        internalClass = internalClass->addMember(engine->identifierTable->asPropertyKey(compilationUnit->runtimeStrings[localsIndices[i]]), Attr_NotConfigurable);
 
-    canUseSimpleCall = false;
+    Scope scope(engine);
+    ScopedString arg(scope);
+    for (const QString &parameterName : parameterNames) {
+        arg = engine->newIdentifier(parameterName);
+        internalClass = internalClass->addMember(arg->propertyKey(), Attr_NotConfigurable);
+    }
+    nFormals = parameters.size();
+}
+
+QString Function::prettyName(const Function *function, const void *code)
+{
+    QString prettyName = function ? function->name()->toQString() : QString();
+    if (prettyName.isEmpty()) {
+        prettyName = QString::number(reinterpret_cast<quintptr>(code), 16);
+        prettyName.prepend(QLatin1String("QV4::Function(0x"));
+        prettyName.append(QLatin1Char(')'));
+    }
+    return prettyName;
+}
+
+QQmlSourceLocation Function::sourceLocation() const
+{
+    return QQmlSourceLocation(sourceFile(), compiledFunction->location.line, compiledFunction->location.column);
+}
+
+QString Function::traceInfoToString()
+{
+    QString info = QLatin1String("=== Trace information for ") + name()->toQString() + QLatin1Char(':');
+    if (!tracingEnabled())
+        return info + QStringLiteral(" disabled. Interpreter call count: %1\n").arg(interpreterCallCount);
+    if (compiledFunction->nTraceInfos == 0)
+        return info + QLatin1String(" none.\n");
+
+    info += QLatin1Char('\n');
+    for (uint i = 0, ei = compiledFunction->nTraceInfos; i < ei; ++i) {
+        auto bits = QString::number(*traceInfo(i), 2);
+        if (bits.size() < 8)
+            bits.prepend(QString(8 - bits.size(), '0'));
+        info += QStringLiteral("    %1: %2\n").arg(QString::number(i), bits);
+    }
+    return info;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4function_p.h b/src/qml/jsruntime/qv4function_p.h
index b11c8af94a..374e46b929 100644
--- a/src/qml/jsruntime/qv4function_p.h
+++ b/src/qml/jsruntime/qv4function_p.h
@@ -51,58 +51,105 @@
 //
 
 #include "qv4global_p.h"
-#include <private/qqmlglobal_p.h>
 #include <private/qv4compileddata_p.h>
 #include <private/qv4context_p.h>
 
+namespace JSC {
+class MacroAssemblerCodeRef;
+}
+
 QT_BEGIN_NAMESPACE
 
+struct QQmlSourceLocation;
+
 namespace QV4 {
 
-struct Q_QML_EXPORT Function {
-    const CompiledData::Function *compiledFunction;
+struct Q_QML_EXPORT FunctionData {
     CompiledData::CompilationUnit *compilationUnit;
 
-    ReturnedValue (*code)(ExecutionEngine *, const uchar *);
-    const uchar *codeData;
+    FunctionData(CompiledData::CompilationUnit *compilationUnit)
+        : compilationUnit(compilationUnit)
+    {}
+};
+// Make sure this class can be accessed through offsetof (done by the assemblers):
+Q_STATIC_ASSERT(std::is_standard_layout< FunctionData >::value);
+
+struct Q_QML_EXPORT Function : public FunctionData {
+private:
+    Function(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function);
+    ~Function();
+
+public:
+    const CompiledData::Function *compiledFunction;
+
+    ReturnedValue call(const Value *thisObject, const Value *argv, int argc, const ExecutionContext *context);
+
+    const char *codeData;
+
+    typedef ReturnedValue (*JittedCode)(CppStackFrame *, ExecutionEngine *);
+    JittedCode jittedCode;
+    JSC::MacroAssemblerCodeRef *codeRef;
 
     // first nArguments names in internalClass are the actual arguments
-    InternalClass *internalClass;
+    Heap::InternalClass *internalClass;
     uint nFormals;
+    int interpreterCallCount = 0;
     bool hasQmlDependencies;
-    bool canUseSimpleCall;
+    bool isEval = false;
 
-    Function(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function,
-             ReturnedValue (*codePtr)(ExecutionEngine *, const uchar *));
-    ~Function();
+    static Function *create(ExecutionEngine *engine, CompiledData::CompilationUnit *unit, const CompiledData::Function *function);
+    void destroy();
 
     // used when dynamically assigning signal handlers (QQmlConnection)
     void updateInternalClass(ExecutionEngine *engine, const QList<QByteArray> &parameters);
 
-    inline Heap::String *name() {
+    inline Heap::String *name() const {
         return compilationUnit->runtimeStrings[compiledFunction->nameIndex];
     }
+
+    static QString prettyName(const Function *function, const void *address);
+
     inline QString sourceFile() const { return compilationUnit->fileName(); }
+    inline QUrl finalUrl() const { return compilationUnit->finalUrl(); }
 
-    inline bool usesArgumentsObject() const { return compiledFunction->flags & CompiledData::Function::UsesArgumentsObject; }
     inline bool isStrict() const { return compiledFunction->flags & CompiledData::Function::IsStrict; }
-    inline bool isNamedExpression() const { return compiledFunction->flags & CompiledData::Function::IsNamedExpression; }
+    inline bool isArrowFunction() const { return compiledFunction->flags & CompiledData::Function::IsArrowFunction; }
+    inline bool isGenerator() const { return compiledFunction->flags & CompiledData::Function::IsGenerator; }
 
-    inline bool canUseSimpleFunction() const { return canUseSimpleCall; }
+    QQmlSourceLocation sourceLocation() const;
 
-    QQmlSourceLocation sourceLocation() const
+    Function *nestedFunction() const
     {
-        return QQmlSourceLocation(sourceFile(), compiledFunction->location.line, compiledFunction->location.column);
+        if (compiledFunction->nestedFunctionIndex == std::numeric_limits<uint32_t>::max())
+            return nullptr;
+        return compilationUnit->runtimeFunctions[compiledFunction->nestedFunctionIndex];
     }
 
-};
+    Q_NEVER_INLINE QString traceInfoToString();
 
+    quint8 *traceInfo(uint i)
+    {
+#if QT_CONFIG(qml_tracing)
+        Q_ASSERT((tracingEnabled() && i < traceInfoCount()) || (i == 0));
+        return reinterpret_cast<quint8 *>(this) + sizeof(Function) + i;
+#else
+        Q_UNUSED(i);
+        return nullptr;
+#endif
+    }
 
-inline unsigned int Heap::SimpleCallContext::formalParameterCount() const
-{
-    return v4Function ? v4Function->nFormals : 0;
-}
+    quint32 traceInfoCount() const
+    { return compiledFunction->nTraceInfos; }
 
+    bool tracingEnabled() const
+    {
+#if QT_CONFIG(qml_tracing)
+        return traceInfoCount() != CompiledData::Function::NoTracing();
+#else
+        return false;
+#endif
+    }
+};
 
 }
 
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index 45fdde98f7..41a21ba379 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -38,11 +38,10 @@
 ****************************************************************************/
 
 #include "qv4object_p.h"
-#include "qv4jsir_p.h"
-#include "qv4isel_p.h"
 #include "qv4objectproto_p.h"
 #include "qv4stringobject_p.h"
 #include "qv4function_p.h"
+#include "qv4symbol_p.h"
 #include <private/qv4mm_p.h>
 
 #include "qv4arrayobject_p.h"
@@ -55,9 +54,11 @@
 #include <private/qqmljsast_p.h>
 #include <private/qqmljavascriptexpression_p.h>
 #include <private/qqmlengine_p.h>
-#include <qv4codegen_p.h>
+#include <qv4runtimecodegen_p.h>
 #include "private/qlocale_tools_p.h"
 #include "private/qqmlbuiltinfunctions_p.h"
+#include <private/qv4jscall_p.h>
+#include <private/qv4vme_moth_p.h>
 
 #include <QtCore/QDebug>
 #include <algorithm>
@@ -69,47 +70,74 @@ using namespace QV4;
 
 DEFINE_OBJECT_VTABLE(FunctionObject);
 
-Q_STATIC_ASSERT((Heap::FunctionObject::markTable & Heap::Object::markTable) == Heap::Object::markTable);
-
-void Heap::FunctionObject::init(QV4::ExecutionContext *scope, QV4::String *name, bool createProto)
+void Heap::FunctionObject::init(QV4::ExecutionContext *scope, QV4::String *name, VTable::Call call)
 {
+    jsCall = call;
+    jsConstruct = nullptr;
+
     Object::init();
-    function = nullptr;
     this->scope.set(scope->engine(), scope->d());
     Scope s(scope->engine());
     ScopedFunctionObject f(s, this);
-    f->init(name, createProto);
+    if (name)
+        f->setName(name);
+}
+
+void Heap::FunctionObject::init(QV4::ExecutionContext *scope, QV4::String *name)
+{
+    ExecutionEngine *e = scope->engine();
+
+    jsCall = vtable()->call;
+    jsConstruct = vtable()->callAsConstructor;
+
+    Object::init();
+    this->scope.set(scope->engine(), scope->d());
+    Scope s(e);
+    ScopedFunctionObject f(s, this);
+    if (name)
+        f->setName(name);
 }
 
-void Heap::FunctionObject::init(QV4::ExecutionContext *scope, Function *function, bool createProto)
+
+
+void Heap::FunctionObject::init(QV4::ExecutionContext *scope, Function *function, QV4::String *n)
 {
+    jsCall = vtable()->call;
+    jsConstruct = vtable()->callAsConstructor;
+
     Object::init();
-    this->function = function;
-    function->compilationUnit->addref();
+    setFunction(function);
     this->scope.set(scope->engine(), scope->d());
     Scope s(scope->engine());
-    ScopedString name(s, function->name());
+    ScopedString name(s, n ? n->d() : function->name());
     ScopedFunctionObject f(s, this);
-    f->init(name, createProto);
+    if (name)
+        f->setName(name);
 }
 
-void Heap::FunctionObject::init(QV4::ExecutionContext *scope, const QString &name, bool createProto)
+void Heap::FunctionObject::init(QV4::ExecutionContext *scope, const QString &name)
 {
     Scope valueScope(scope);
     ScopedString s(valueScope, valueScope.engine->newString(name));
-    init(scope, s, createProto);
+    init(scope, s);
 }
 
 void Heap::FunctionObject::init()
 {
+    jsCall = vtable()->call;
+    jsConstruct = vtable()->callAsConstructor;
+
     Object::init();
-    function = nullptr;
     this->scope.set(internalClass->engine, internalClass->engine->rootContext()->d());
-    Q_ASSERT(internalClass && internalClass->find(internalClass->engine->id_prototype()) == Index_Prototype);
-    setProperty(internalClass->engine, Index_Prototype, Primitive::undefinedValue());
 }
 
-
+void Heap::FunctionObject::setFunction(Function *f)
+{
+    if (f) {
+        function = f;
+        function->compilationUnit->addref();
+    }
+}
 void Heap::FunctionObject::destroy()
 {
     if (function)
@@ -117,23 +145,15 @@ void Heap::FunctionObject::destroy()
     Object::destroy();
 }
 
-void FunctionObject::init(String *n, bool createProto)
+void FunctionObject::createDefaultPrototypeProperty(uint protoConstructorSlot)
 {
-    Scope s(internalClass()->engine);
-    ScopedValue protectThis(s, this);
+    Scope s(this);
 
-    Q_ASSERT(internalClass() && internalClass()->find(s.engine->id_prototype()) == Heap::FunctionObject::Index_Prototype);
-    if (createProto) {
-        ScopedObject proto(s, s.engine->newObject(s.engine->internalClasses[EngineBase::Class_ObjectProto], s.engine->objectPrototype()));
-        Q_ASSERT(s.engine->internalClasses[EngineBase::Class_ObjectProto]->find(s.engine->id_constructor()) == Heap::FunctionObject::Index_ProtoConstructor);
-        proto->setProperty(Heap::FunctionObject::Index_ProtoConstructor, d());
-        setProperty(Heap::FunctionObject::Index_Prototype, proto);
-    } else {
-        setProperty(Heap::FunctionObject::Index_Prototype, Primitive::undefinedValue());
-    }
+    Q_ASSERT(s.engine->internalClasses(EngineBase::Class_ObjectProto)->verifyIndex(s.engine->id_constructor()->propertyKey(), protoConstructorSlot));
 
-    if (n)
-        defineReadonlyConfigurableProperty(s.engine->id_name(), *n);
+    ScopedObject proto(s, s.engine->newObject(s.engine->internalClasses(EngineBase::Class_ObjectProto)));
+    proto->setProperty(protoConstructorSlot, d());
+    defineDefaultProperty(s.engine->id_prototype(), proto, Attr_NotEnumerable|Attr_NotConfigurable);
 }
 
 ReturnedValue FunctionObject::name() const
@@ -141,29 +161,59 @@ ReturnedValue FunctionObject::name() const
     return get(scope()->internalClass->engine->id_name());
 }
 
-void FunctionObject::construct(const Managed *that, Scope &scope, CallData *)
+ReturnedValue FunctionObject::virtualCall(const FunctionObject *, const Value *, const Value *, int)
 {
-    scope.result = static_cast<const FunctionObject *>(that)->engine()->throwTypeError();
+    return Encode::undefined();
 }
 
-void FunctionObject::call(const Managed *, Scope &scope, CallData *)
+Heap::FunctionObject *FunctionObject::createScriptFunction(ExecutionContext *scope, Function *function)
 {
-    scope.result = Encode::undefined();
+    if (function->isArrowFunction())
+        return scope->engine()->memoryManager->allocate<ArrowFunction>(scope, function);
+    return scope->engine()->memoryManager->allocate<ScriptFunction>(scope, function);
 }
 
-Heap::FunctionObject *FunctionObject::createScriptFunction(ExecutionContext *scope, Function *function)
+Heap::FunctionObject *FunctionObject::createConstructorFunction(ExecutionContext *scope, Function *function, Object *homeObject, bool isDerivedConstructor)
 {
-    return scope->engine()->memoryManager->allocObject<ScriptFunction>(scope, function);
+    if (!function) {
+        Heap::DefaultClassConstructorFunction *c = scope->engine()->memoryManager->allocate<DefaultClassConstructorFunction>(scope);
+        c->isDerivedConstructor = isDerivedConstructor;
+        return c;
+    }
+    Heap::ConstructorFunction *c = scope->engine()->memoryManager->allocate<ConstructorFunction>(scope, function);
+    c->homeObject.set(scope->engine(), homeObject->d());
+    c->isDerivedConstructor = isDerivedConstructor;
+    return c;
 }
 
-bool FunctionObject::isBinding() const
+Heap::FunctionObject *FunctionObject::createMemberFunction(ExecutionContext *scope, Function *function, Object *homeObject, QV4::String *name)
 {
-    return d()->vtable() == QQmlBindingFunction::staticVTable();
+    Heap::MemberFunction *m = scope->engine()->memoryManager->allocate<MemberFunction>(scope, function, name);
+    m->homeObject.set(scope->engine(), homeObject->d());
+    return m;
 }
 
-bool FunctionObject::isBoundFunction() const
+Heap::FunctionObject *FunctionObject::createBuiltinFunction(ExecutionEngine *engine, StringOrSymbol *nameOrSymbol, VTable::Call code, int argumentCount)
 {
-    return d()->vtable() == BoundFunction::staticVTable();
+    Scope scope(engine);
+    ScopedString name(scope, nameOrSymbol);
+    if (!name)
+        name = engine->newString(QChar::fromLatin1('[') + nameOrSymbol->toQString().midRef(1) + QChar::fromLatin1(']'));
+
+    ScopedFunctionObject function(scope, engine->memoryManager->allocate<FunctionObject>(engine->rootContext(), name, code));
+    function->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(argumentCount));
+    return function->d();
+}
+
+ReturnedValue FunctionObject::getHomeObject() const
+{
+    const MemberFunction *m = as<MemberFunction>();
+    if (m)
+        return m->d()->homeObject->asReturnedValue();
+    const ConstructorFunction *c = as<ConstructorFunction>();
+    if (c)
+        return c->d()->homeObject->asReturnedValue();
+    return Encode::undefined();
 }
 
 QQmlSourceLocation FunctionObject::sourceLocation() const
@@ -179,64 +229,77 @@ void Heap::FunctionCtor::init(QV4::ExecutionContext *scope)
 }
 
 // 15.3.2
-void FunctionCtor::construct(const Managed *that, Scope &scope, CallData *callData)
+QQmlRefPointer<CompiledData::CompilationUnit> FunctionCtor::parse(ExecutionEngine *engine, const Value *argv, int argc, Type t)
 {
-    Scoped<FunctionCtor> f(scope, static_cast<const FunctionCtor *>(that));
-
     QString arguments;
     QString body;
-    if (callData->argc > 0) {
-        for (int i = 0; i < callData->argc - 1; ++i) {
+    if (argc > 0) {
+        for (int i = 0, ei = argc - 1; i < ei; ++i) {
             if (i)
                 arguments += QLatin1String(", ");
-            arguments += callData->args[i].toQString();
+            arguments += argv[i].toQString();
         }
-        body = callData->args[callData->argc - 1].toQString();
-    }
-    if (scope.engine->hasException) {
-        scope.result = Encode::undefined();
-        return;
+        body = argv[argc - 1].toQString();
     }
+    if (engine->hasException)
+        return nullptr;
 
-    QString function = QLatin1String("function(") + arguments + QLatin1String("){") + body + QLatin1Char('}');
+    QString function = (t == Type_Function ? QLatin1String("function anonymous(") : QLatin1String("function* anonymous(")) + arguments + QLatin1String("\n){") + body + QLatin1String("\n}");
 
-    QQmlJS::Engine ee, *engine = &ee;
-    QQmlJS::Lexer lexer(engine);
+    QQmlJS::Engine ee;
+    QQmlJS::Lexer lexer(&ee);
     lexer.setCode(function, 1, false);
-    QQmlJS::Parser parser(engine);
+    QQmlJS::Parser parser(&ee);
 
     const bool parsed = parser.parseExpression();
 
     if (!parsed) {
-        scope.result = scope.engine->throwSyntaxError(QLatin1String("Parse error"));
-        return;
+        engine->throwSyntaxError(QLatin1String("Parse error"));
+        return nullptr;
     }
 
-    using namespace QQmlJS::AST;
-    FunctionExpression *fe = QQmlJS::AST::cast<FunctionExpression *>(parser.rootNode());
+    QQmlJS::AST::FunctionExpression *fe = QQmlJS::AST::cast<QQmlJS::AST::FunctionExpression *>(parser.rootNode());
     if (!fe) {
-        scope.result = scope.engine->throwSyntaxError(QLatin1String("Parse error"));
-        return;
+        engine->throwSyntaxError(QLatin1String("Parse error"));
+        return nullptr;
     }
 
-    IR::Module module(scope.engine->debugger() != 0);
+    Compiler::Module module(engine->debugger() != nullptr);
 
-    QQmlJS::RuntimeCodegen cg(scope.engine, f->strictMode());
+    Compiler::JSUnitGenerator jsGenerator(&module);
+    RuntimeCodegen cg(engine, &jsGenerator, false);
     cg.generateFromFunctionExpression(QString(), function, fe, &module);
 
-    Compiler::JSUnitGenerator jsGenerator(&module);
-    QScopedPointer<EvalInstructionSelection> isel(scope.engine->iselFactory->create(QQmlEnginePrivate::get(scope.engine), scope.engine->executableAllocator, &module, &jsGenerator));
-    QQmlRefPointer<CompiledData::CompilationUnit> compilationUnit = isel->compile();
-    Function *vmf = compilationUnit->linkToEngine(scope.engine);
+    if (engine->hasException)
+        return nullptr;
 
-    ExecutionContext *global = scope.engine->rootContext();
-    scope.result = FunctionObject::createScriptFunction(global, vmf);
+    return cg.generateCompilationUnit();
+}
+
+ReturnedValue FunctionCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    ExecutionEngine *engine = f->engine();
+
+    QQmlRefPointer<CompiledData::CompilationUnit> compilationUnit = parse(engine, argv, argc, Type_Function);
+    if (engine->hasException)
+        return Encode::undefined();
+
+    Function *vmf = compilationUnit->linkToEngine(engine);
+    ExecutionContext *global = engine->scriptContext();
+    ReturnedValue o = Encode(FunctionObject::createScriptFunction(global, vmf));
+
+    if (!newTarget)
+        return o;
+    Scope scope(engine);
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
 }
 
 // 15.3.1: This is equivalent to new Function(...)
-void FunctionCtor::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue FunctionCtor::virtualCall(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    construct(that, scope, callData);
+    return virtualCallAsConstructor(f, argv, argc, f);
 }
 
 DEFINE_OBJECT_VTABLE(FunctionPrototype);
@@ -251,253 +314,361 @@ void FunctionPrototype::init(ExecutionEngine *engine, Object *ctor)
     Scope scope(engine);
     ScopedObject o(scope);
 
-    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
 
-    defineReadonlyConfigurableProperty(engine->id_length(), Primitive::fromInt32(0));
+    defineReadonlyConfigurableProperty(engine->id_name(), *engine->id_empty());
+    defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
     defineDefaultProperty(engine->id_toString(), method_toString, 0);
     defineDefaultProperty(QStringLiteral("apply"), method_apply, 2);
     defineDefaultProperty(QStringLiteral("call"), method_call, 1);
     defineDefaultProperty(QStringLiteral("bind"), method_bind, 1);
-
+    defineDefaultProperty(engine->symbol_hasInstance(), method_hasInstance, 1, Attr_ReadOnly);
 }
 
-void FunctionPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue FunctionPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    FunctionObject *fun = callData->thisObject.as<FunctionObject>();
+    ExecutionEngine *v4 = b->engine();
+    const FunctionObject *fun = thisObject->as<FunctionObject>();
     if (!fun)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
-    scope.result = scope.engine->newString(QStringLiteral("function() { [code] }"));
-}
+    const Scope scope(fun->engine());
+    const ScopedString scopedFunctionName(scope, fun->name());
+    const QString functionName(scopedFunctionName ? scopedFunctionName->toQString() : QString());
+    QString functionAsString = QStringLiteral("function");
 
-void FunctionPrototype::method_apply(const BuiltinFunction *, Scope &scope, CallData *callData)
-{
-    FunctionObject *o = callData->thisObject.as<FunctionObject>();
-    if (!o)
-        THROW_TYPE_ERROR();
+    // If fun->name() is empty, then there is no function name
+    // to append because the function is anonymous.
+    if (!functionName.isEmpty())
+        functionAsString.append(QLatin1Char(' ') + functionName);
 
-    ScopedValue arg(scope, callData->argument(1));
+    functionAsString.append(QStringLiteral("() { [native code] }"));
 
-    ScopedObject arr(scope, arg);
+    return Encode(v4->newString(functionAsString));
+}
 
-    quint32 len;
-    if (!arr) {
-        len = 0;
-        if (!arg->isNullOrUndefined())
-            THROW_TYPE_ERROR();
-    } else {
-        len = arr->getLength();
-    }
+ReturnedValue FunctionPrototype::method_apply(const QV4::FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *v4 = b->engine();
+    const FunctionObject *f = thisObject->as<FunctionObject>();
+    if (!f)
+        return v4->throwTypeError();
+    thisObject = argc ? argv : nullptr;
+    if (argc < 2 || argv[1].isNullOrUndefined())
+        return f->call(thisObject, argv, 0);
+
+    Object *arr = argv[1].objectValue();
+    if (!arr)
+        return v4->throwTypeError();
 
-    ScopedCallData cData(scope, len);
+    uint len = arr->getLength();
 
+    Scope scope(v4);
+    Value *arguments = scope.alloc<Scope::Uninitialized>(len);
     if (len) {
         if (ArgumentsObject::isNonStrictArgumentsObject(arr) && !arr->cast<ArgumentsObject>()->fullyCreated()) {
             QV4::ArgumentsObject *a = arr->cast<ArgumentsObject>();
-            int l = qMin(len, (uint)a->d()->context->callData->argc);
-            memcpy(cData->args, a->d()->context->callData->args, l*sizeof(Value));
+            int l = qMin(len, (uint)a->d()->context->argc());
+            memcpy(arguments, a->d()->context->args(), l*sizeof(Value));
             for (quint32 i = l; i < len; ++i)
-                cData->args[i] = Primitive::undefinedValue();
+                arguments[i] = Value::undefinedValue();
         } else if (arr->arrayType() == Heap::ArrayData::Simple && !arr->protoHasArray()) {
             auto sad = static_cast<Heap::SimpleArrayData *>(arr->arrayData());
             uint alen = sad ? sad->values.size : 0;
             if (alen > len)
                 alen = len;
             for (uint i = 0; i < alen; ++i)
-                cData->args[i] = sad->data(i);
+                arguments[i] = sad->data(i);
             for (quint32 i = alen; i < len; ++i)
-                cData->args[i] = Primitive::undefinedValue();
+                arguments[i] = Value::undefinedValue();
         } else {
+            // need to init the arguments array, as the get() calls below can have side effects
+            memset(arguments, 0, len*sizeof(Value));
             for (quint32 i = 0; i < len; ++i)
-                cData->args[i] = arr->getIndexed(i);
+                arguments[i] = arr->get(i);
         }
     }
 
-    cData->thisObject = callData->argument(0);
-    o->call(scope, cData);
+    return f->call(thisObject, arguments, len);
 }
 
-void FunctionPrototype::method_call(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue FunctionPrototype::method_call(const QV4::FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    FunctionObject *o = callData->thisObject.as<FunctionObject>();
-    if (!o)
-        THROW_TYPE_ERROR();
+    if (!thisObject->isFunctionObject())
+        return b->engine()->throwTypeError();
 
-    ScopedCallData cData(scope, callData->argc ? callData->argc - 1 : 0);
-    if (callData->argc) {
-        for (int i = 1; i < callData->argc; ++i)
-            cData->args[i - 1] = callData->args[i];
+    const FunctionObject *f = static_cast<const FunctionObject *>(thisObject);
+
+    thisObject = argc ? argv : nullptr;
+    if (argc) {
+        ++argv;
+        --argc;
+    }
+    return f->call(thisObject, argv, argc);
+}
+
+ReturnedValue FunctionPrototype::method_bind(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    QV4::Scope scope(b);
+    ScopedFunctionObject target(scope, thisObject);
+    if (!target || target->isBinding())
+        return scope.engine->throwTypeError();
+
+    ScopedValue boundThis(scope, argc ? argv[0] : Value::undefinedValue());
+    Scoped<MemberData> boundArgs(scope, (Heap::MemberData *)nullptr);
+
+    int nArgs = (argc - 1 >= 0) ? argc - 1 : 0;
+    if (target->isBoundFunction()) {
+        BoundFunction *bound = static_cast<BoundFunction *>(target.getPointer());
+        Scoped<MemberData> oldArgs(scope, bound->boundArgs());
+        boundThis = bound->boundThis();
+        int oldSize = !oldArgs ? 0 : oldArgs->size();
+        if (oldSize + nArgs) {
+            boundArgs = MemberData::allocate(scope.engine, oldSize + nArgs);
+            boundArgs->d()->values.size = oldSize + nArgs;
+            for (uint i = 0; i < static_cast<uint>(oldSize); ++i)
+                boundArgs->set(scope.engine, i, oldArgs->data()[i]);
+            for (uint i = 0; i < static_cast<uint>(nArgs); ++i)
+                boundArgs->set(scope.engine, oldSize + i, argv[i + 1]);
+        }
+        target = bound->target();
+    } else if (nArgs) {
+        boundArgs = MemberData::allocate(scope.engine, nArgs);
+        boundArgs->d()->values.size = nArgs;
+        for (uint i = 0, ei = static_cast<uint>(nArgs); i < ei; ++i)
+            boundArgs->set(scope.engine, i, argv[i + 1]);
     }
-    cData->thisObject = callData->argument(0);
 
-    o->call(scope, cData);
+    ScopedContext ctx(scope, target->scope());
+    Heap::BoundFunction *bound = BoundFunction::create(ctx, target, boundThis, boundArgs);
+    bound->setFunction(target->function());
+    return bound->asReturnedValue();
 }
 
-void FunctionPrototype::method_bind(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue FunctionPrototype::method_hasInstance(const FunctionObject *, const Value *thisObject, const Value *argv, int argc)
 {
-    FunctionObject *target = callData->thisObject.as<FunctionObject>();
-    if (!target)
-        THROW_TYPE_ERROR();
-
-    ScopedValue boundThis(scope, callData->argument(0));
-    Scoped<MemberData> boundArgs(scope, (Heap::MemberData *)0);
-    if (callData->argc > 1) {
-        boundArgs = MemberData::allocate(scope.engine, callData->argc - 1);
-        boundArgs->d()->values.size = callData->argc - 1;
-        for (uint i = 0; i < static_cast<uint>(callData->argc - 1); ++i)
-            boundArgs->set(scope.engine, i, callData->args[i + 1]);
-    }
+    if (!argc)
+        return Encode(false);
+    const Object *o = thisObject->as<Object>();
+    if (!o)
+        return Encode(false);
 
-    ExecutionContext *global = scope.engine->rootContext();
-    scope.result = BoundFunction::create(global, target, boundThis, boundArgs);
+    return Object::virtualInstanceOf(o, argv[0]);
 }
 
 DEFINE_OBJECT_VTABLE(ScriptFunction);
 
-void ScriptFunction::construct(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue ScriptFunction::virtualCallAsConstructor(const FunctionObject *fo, const Value *argv, int argc, const Value *newTarget)
 {
-    ExecutionEngine *v4 = scope.engine;
-    if (Q_UNLIKELY(v4->hasException)) {
-        scope.result = Encode::undefined();
-        return;
-    }
-    CHECK_STACK_LIMITS(v4, scope);
+    ExecutionEngine *v4 = fo->engine();
+    const ScriptFunction *f = static_cast<const ScriptFunction *>(fo);
+    Q_ASSERT(newTarget->isFunctionObject());
+    const FunctionObject *nt = static_cast<const FunctionObject *>(newTarget);
 
-    ExecutionContextSaver ctxSaver(scope);
+    Scope scope(v4);
+    Scoped<InternalClass> ic(scope);
+    if (nt->d() == f->d()) {
+        ic = f->classForConstructor();
+    } else {
+        ScopedObject o(scope, nt->protoProperty());
+        ic = scope.engine->internalClasses(EngineBase::Class_Object);
+        if (o)
+            ic = ic->changePrototype(o->d());
+    }
+    ScopedValue thisObject(scope, v4->memoryManager->allocObject<Object>(ic));
 
-    Scoped<ScriptFunction> f(scope, static_cast<const ScriptFunction *>(that));
+    CppStackFrame frame;
+    frame.init(v4, f->function(), argv, argc);
+    frame.setupJSFrame(v4->jsStackTop, *f, f->scope(),
+                       thisObject,
+                       newTarget ? *newTarget : Value::undefinedValue());
 
-    InternalClass *ic = f->classForConstructor();
-    ScopedObject proto(scope, ic->prototype);
-    ScopedObject obj(scope, v4->newObject(ic, proto));
-    callData->thisObject = obj.asReturnedValue();
+    frame.push();
+    v4->jsStackTop += frame.requiredJSStackFrameSize();
 
-    QV4::Function *v4Function = f->function();
-    Q_ASSERT(v4Function);
+    ReturnedValue result = Moth::VME::exec(&frame, v4);
 
-    ScopedContext c(scope, f->scope());
-    if (v4Function->canUseSimpleCall)
-        c->simpleCall(scope, callData, v4Function);
-    else
-        c->call(scope, callData, v4Function, f);
+    frame.pop();
 
-    if (Q_UNLIKELY(v4->hasException)) {
-        scope.result = Encode::undefined();
-    } else if (!scope.result.isObject()) {
-        scope.result = obj.asReturnedValue();
-    }
+    if (Q_UNLIKELY(v4->hasException))
+        return Encode::undefined();
+    else if (!Value::fromReturnedValue(result).isObject())
+        return thisObject->asReturnedValue();
+    return result;
 }
 
-void ScriptFunction::call(const Managed *that, Scope &scope, CallData *callData)
+DEFINE_OBJECT_VTABLE(ArrowFunction);
+
+ReturnedValue ArrowFunction::virtualCall(const FunctionObject *fo, const Value *thisObject, const Value *argv, int argc)
 {
-    ExecutionEngine *v4 = scope.engine;
-    if (Q_UNLIKELY(v4->hasException)) {
-        scope.result = Encode::undefined();
-        return;
-    }
-    CHECK_STACK_LIMITS(v4, scope);
+    ExecutionEngine *engine = fo->engine();
+    CppStackFrame frame;
+    frame.init(engine, fo->function(), argv, argc, true);
+    frame.setupJSFrame(engine->jsStackTop, *fo, fo->scope(),
+                       thisObject ? *thisObject : Value::undefinedValue(),
+                       Value::undefinedValue());
 
-    Scoped<ScriptFunction> f(scope, static_cast<const ScriptFunction *>(that));
+    frame.push();
+    engine->jsStackTop += frame.requiredJSStackFrameSize();
 
-    QV4::Function *v4Function = f->function();
-    Q_ASSERT(v4Function);
+    ReturnedValue result;
 
-    ScopedContext c(scope, f->scope());
-    if (v4Function->canUseSimpleCall)
-        c->simpleCall(scope, callData, v4Function);
-    else
-        c->call(scope, callData, v4Function, f);
+    do {
+        frame.pendingTailCall = false;
+        result = Moth::VME::exec(&frame, engine);
+        frame.isTailCalling = true;
+    } while (frame.pendingTailCall);
+
+    frame.pop();
+
+    return result;
 }
 
-void Heap::ScriptFunction::init(QV4::ExecutionContext *scope, Function *function)
+void Heap::ArrowFunction::init(QV4::ExecutionContext *scope, Function *function, QV4::String *n)
 {
     FunctionObject::init();
     this->scope.set(scope->engine(), scope->d());
 
-    this->function = function;
-    function->compilationUnit->addref();
+    setFunction(function);
     Q_ASSERT(function);
-    Q_ASSERT(function->code);
 
     Scope s(scope);
     ScopedFunctionObject f(s, this);
 
-    ScopedString name(s, function->name());
-    f->init(name, true);
-    Q_ASSERT(internalClass && internalClass->find(s.engine->id_length()) == Index_Length);
-    setProperty(s.engine, Index_Length, Primitive::fromInt32(f->formalParameterCount()));
-
-    if (scope->d()->strictMode) {
-        ScopedProperty pd(s);
-        pd->value = s.engine->thrower();
-        pd->set = s.engine->thrower();
-        f->insertMember(s.engine->id_caller(), pd, Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
-        f->insertMember(s.engine->id_arguments(), pd, Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
-    }
+    ScopedString name(s, n ? n->d() : function->name());
+    if (name)
+        f->setName(name);
+
+    Q_ASSERT(internalClass && internalClass->verifyIndex(s.engine->id_length()->propertyKey(), Index_Length));
+    setProperty(s.engine, Index_Length, Value::fromInt32(int(function->compiledFunction->length)));
+    canBeTailCalled = true;
 }
 
-InternalClass *ScriptFunction::classForConstructor() const
+void Heap::ScriptFunction::init(QV4::ExecutionContext *scope, Function *function)
 {
-    const Object *o = d()->protoProperty();
-    InternalClass *ic = d()->cachedClassForConstructor;
-    if (ic && ic->prototype == o->d())
-        return ic;
+    ArrowFunction::init(scope, function);
+    Q_ASSERT(!function->isArrowFunction());
 
-    ic = engine()->internalClasses[EngineBase::Class_Object];
-    if (o)
-        ic = ic->changePrototype(o->d());
-    d()->cachedClassForConstructor = ic;
-
-    return ic;
+    Scope s(scope);
+    ScopedFunctionObject f(s, this);
+    f->createDefaultPrototypeProperty(Heap::FunctionObject::Index_ProtoConstructor);
 }
 
-DEFINE_OBJECT_VTABLE(BuiltinFunction);
-
-void Heap::BuiltinFunction::init(QV4::ExecutionContext *scope, QV4::String *name, void (*code)(const QV4::BuiltinFunction *, Scope &, CallData *))
+Heap::InternalClass *ScriptFunction::classForConstructor() const
 {
-    Heap::FunctionObject::init(scope, name);
-    this->code = code;
+    Scope scope(engine());
+    ScopedValue o(scope, protoProperty());
+    if (d()->cachedClassForConstructor && d()->cachedClassForConstructor->prototype == o->heapObject())
+        return d()->cachedClassForConstructor;
+
+    Scoped<InternalClass> ic(scope, engine()->internalClasses(EngineBase::Class_Object));
+    ScopedObject p(scope, o);
+    if (p)
+        ic = ic->changePrototype(p->d());
+    d()->cachedClassForConstructor.set(scope.engine, ic->d());
+
+    return ic->d();
 }
 
-void BuiltinFunction::construct(const Managed *f, Scope &scope, CallData *)
+DEFINE_OBJECT_VTABLE(ConstructorFunction);
+
+ReturnedValue ConstructorFunction::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    scope.result = static_cast<const BuiltinFunction *>(f)->internalClass()->engine->throwTypeError();
+    const ConstructorFunction *c = static_cast<const ConstructorFunction *>(f);
+    if (!c->d()->isDerivedConstructor)
+        return ScriptFunction::virtualCallAsConstructor(f, argv, argc, newTarget);
+
+    ExecutionEngine *v4 = f->engine();
+
+    CppStackFrame frame;
+    frame.init(v4, f->function(), argv, argc);
+    frame.setupJSFrame(v4->jsStackTop, *f, f->scope(),
+                       Value::emptyValue(),
+                       newTarget ? *newTarget : Value::undefinedValue());
+
+    frame.push();
+    v4->jsStackTop += frame.requiredJSStackFrameSize();
+
+    ReturnedValue result = Moth::VME::exec(&frame, v4);
+    ReturnedValue thisObject = frame.jsFrame->thisObject.asReturnedValue();
+
+    frame.pop();
+
+    if (Q_UNLIKELY(v4->hasException))
+        return Encode::undefined();
+    else if (Value::fromReturnedValue(result).isObject())
+        return result;
+    else if (!Value::fromReturnedValue(result).isUndefined())
+        return v4->throwTypeError();
+    else if (Value::fromReturnedValue(thisObject).isEmpty()) {
+        Scope scope(v4);
+        ScopedString s(scope, v4->newString(QStringLiteral("this")));
+        return v4->throwReferenceError(s);
+    }
+    return thisObject;
 }
 
-void BuiltinFunction::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue ConstructorFunction::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
 {
-    const BuiltinFunction *f = static_cast<const BuiltinFunction *>(that);
-    ExecutionEngine *v4 = scope.engine;
-    if (v4->hasException) {
-        scope.result = Encode::undefined();
-        return;
-    }
-    f->d()->code(f, scope, callData);
+    return f->engine()->throwTypeError(QStringLiteral("Cannot call a class constructor without |new|"));
 }
 
+DEFINE_OBJECT_VTABLE(MemberFunction);
 
-void IndexedBuiltinFunction::call(const Managed *that, Scope &scope, CallData *callData)
+DEFINE_OBJECT_VTABLE(DefaultClassConstructorFunction);
+
+ReturnedValue DefaultClassConstructorFunction::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    const IndexedBuiltinFunction *f = static_cast<const IndexedBuiltinFunction *>(that);
-    ExecutionEngine *v4 = scope.engine;
-    if (v4->hasException) {
-        scope.result = Encode::undefined();
-        return;
+    const DefaultClassConstructorFunction *c = static_cast<const DefaultClassConstructorFunction *>(f);
+    ExecutionEngine *v4 = f->engine();
+
+    Scope scope(v4);
+
+    if (!c->d()->isDerivedConstructor) {
+        ScopedObject proto(scope, static_cast<const Object *>(newTarget)->get(scope.engine->id_prototype()));
+        ScopedObject c(scope, scope.engine->newObject());
+        c->setPrototypeUnchecked(proto);
+        return c->asReturnedValue();
     }
-    CHECK_STACK_LIMITS(v4, scope);
 
-    ExecutionContextSaver ctxSaver(scope);
+    ScopedFunctionObject super(scope, f->getPrototypeOf());
+    Q_ASSERT(super->isFunctionObject());
+
+    CppStackFrame frame;
+    frame.init(v4, nullptr, argv, argc);
+    frame.setupJSFrame(v4->jsStackTop, *f, f->scope(),
+                       Value::undefinedValue(),
+                       newTarget ? *newTarget : Value::undefinedValue(), argc, argc);
+
+    frame.push();
+    v4->jsStackTop += frame.requiredJSStackFrameSize(argc);
+
+    // Do a super call
+    ReturnedValue result = super->callAsConstructor(argv, argc, newTarget);
+    ReturnedValue thisObject = frame.jsFrame->thisObject.asReturnedValue();
+
+    frame.pop();
+
+    if (Q_UNLIKELY(v4->hasException))
+        return Encode::undefined();
+    else if (Value::fromReturnedValue(result).isObject())
+        return result;
+    else if (!Value::fromReturnedValue(result).isUndefined())
+        return v4->throwTypeError();
+    else if (Value::fromReturnedValue(thisObject).isEmpty()) {
+        Scope scope(v4);
+        ScopedString s(scope, v4->newString(QStringLiteral("this")));
+        return v4->throwReferenceError(s);
+    }
 
-    SimpleCallContext::Data *ctx = v4->memoryManager->allocSimpleCallContext();
-    ctx->strictMode = f->scope()->strictMode; // ### needed? scope or parent context?
-    ctx->callData = callData;
-    v4->pushContext(ctx);
-    Q_ASSERT(v4->current == ctx);
+    return thisObject;
+}
 
-    scope.result = f->d()->code(static_cast<QV4::CallContext *>(v4->currentContext), f->d()->index);
-    v4->memoryManager->freeSimpleCallContext();
+ReturnedValue DefaultClassConstructorFunction::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
+{
+    return f->engine()->throwTypeError(QStringLiteral("Cannot call a class constructor without |new|"));
 }
 
 DEFINE_OBJECT_VTABLE(IndexedBuiltinFunction);
@@ -510,9 +681,12 @@ void Heap::BoundFunction::init(QV4::ExecutionContext *scope, QV4::FunctionObject
     Scope s(scope);
     Heap::FunctionObject::init(scope, QStringLiteral("__bound function__"));
     this->target.set(s.engine, target->d());
-    this->boundArgs.set(s.engine, boundArgs ? boundArgs->d() : 0);
+    this->boundArgs.set(s.engine, boundArgs ? boundArgs->d() : nullptr);
     this->boundThis.set(scope->engine(), boundThis);
 
+    if (!target->isConstructor())
+        jsConstruct = nullptr;
+
     ScopedObject f(s, this);
 
     ScopedValue l(s, target->get(s.engine->id_length()));
@@ -521,7 +695,7 @@ void Heap::BoundFunction::init(QV4::ExecutionContext *scope, QV4::FunctionObject
         len -= boundArgs->size();
     if (len < 0)
         len = 0;
-    f->defineReadonlyConfigurableProperty(s.engine->id_length(), Primitive::fromInt32(len));
+    f->defineReadonlyConfigurableProperty(s.engine->id_length(), Value::fromInt32(len));
 
     ScopedProperty pd(s);
     pd->value = s.engine->thrower();
@@ -530,43 +704,43 @@ void Heap::BoundFunction::init(QV4::ExecutionContext *scope, QV4::FunctionObject
     f->insertMember(s.engine->id_caller(), pd, Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
 }
 
-void BoundFunction::call(const Managed *that, Scope &scope, CallData *dd)
+ReturnedValue BoundFunction::virtualCall(const FunctionObject *fo, const Value *, const Value *argv, int argc)
 {
-    const BoundFunction *f = static_cast<const BoundFunction *>(that);
-    if (scope.hasException()) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    const BoundFunction *f = static_cast<const BoundFunction *>(fo);
+    Scope scope(f->engine());
+
+    if (scope.hasException())
+        return Encode::undefined();
 
     Scoped<MemberData> boundArgs(scope, f->boundArgs());
-    ScopedCallData callData(scope, (boundArgs ? boundArgs->size() : 0) + dd->argc);
-    callData->thisObject = f->boundThis();
-    Value *argp = callData->args;
+    ScopedFunctionObject target(scope, f->target());
+    JSCallData jsCallData(scope, (boundArgs ? boundArgs->size() : 0) + argc);
+    *jsCallData->thisObject = f->boundThis();
+    Value *argp = jsCallData->args;
     if (boundArgs) {
         memcpy(argp, boundArgs->data(), boundArgs->size()*sizeof(Value));
         argp += boundArgs->size();
     }
-    memcpy(argp, dd->args, dd->argc*sizeof(Value));
-    ScopedFunctionObject t(scope, f->target());
-    t->call(scope, callData);
+    memcpy(argp, argv, argc*sizeof(Value));
+    return target->call(jsCallData);
 }
 
-void BoundFunction::construct(const Managed *that, Scope &scope, CallData *dd)
+ReturnedValue BoundFunction::virtualCallAsConstructor(const FunctionObject *fo, const Value *argv, int argc, const Value *)
 {
-    const BoundFunction *f = static_cast<const BoundFunction *>(that);
-    if (scope.hasException()) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    const BoundFunction *f = static_cast<const BoundFunction *>(fo);
+    Scope scope(f->engine());
+
+    if (scope.hasException())
+        return Encode::undefined();
 
     Scoped<MemberData> boundArgs(scope, f->boundArgs());
-    ScopedCallData callData(scope, (boundArgs ? boundArgs->size() : 0) + dd->argc);
-    Value *argp = callData->args;
+    ScopedFunctionObject target(scope, f->target());
+    JSCallData jsCallData(scope, (boundArgs ? boundArgs->size() : 0) + argc);
+    Value *argp = jsCallData->args;
     if (boundArgs) {
         memcpy(argp, boundArgs->data(), boundArgs->size()*sizeof(Value));
         argp += boundArgs->size();
     }
-    memcpy(argp, dd->args, dd->argc*sizeof(Value));
-    ScopedFunctionObject t(scope, f->target());
-    t->construct(scope, callData);
+    memcpy(argp, argv, argc*sizeof(Value));
+    return target->callAsConstructor(jsCallData);
 }
diff --git a/src/qml/jsruntime/qv4functionobject_p.h b/src/qml/jsruntime/qv4functionobject_p.h
index 6ce5734b6d..e03d49c74d 100644
--- a/src/qml/jsruntime/qv4functionobject_p.h
+++ b/src/qml/jsruntime/qv4functionobject_p.h
@@ -61,31 +61,42 @@ struct QQmlSourceLocation;
 
 namespace QV4 {
 
-struct BuiltinFunction;
+struct IndexedBuiltinFunction;
+struct JSCallData;
 
 namespace Heap {
 
+
 #define FunctionObjectMembers(class, Member) \
     Member(class, Pointer, ExecutionContext *, scope) \
-    Member(class, NoMark, Function *, function)
+    Member(class, NoMark, Function *, function) \
+    Member(class, NoMark, VTable::Call, jsCall) \
+    Member(class, NoMark, VTable::CallAsConstructor, jsConstruct) \
+    Member(class, NoMark, bool, canBeTailCalled)
 
 DECLARE_HEAP_OBJECT(FunctionObject, Object) {
-    DECLARE_MARK_TABLE(FunctionObject);
+    DECLARE_MARKOBJECTS(FunctionObject);
     enum {
+        Index_ProtoConstructor = 0,
         Index_Prototype = 0,
-        Index_ProtoConstructor = 0
+        Index_HasInstance = 1,
     };
 
-    void init(QV4::ExecutionContext *scope, QV4::String *name = 0, bool createProto = false);
-    void init(QV4::ExecutionContext *scope, QV4::Function *function, bool createProto = false);
-    void init(QV4::ExecutionContext *scope, const QString &name, bool createProto = false);
+    bool isConstructor() const {
+        return jsConstruct != nullptr;
+    }
+
+    Q_QML_PRIVATE_EXPORT void init(QV4::ExecutionContext *scope, QV4::String *name, VTable::Call call);
+    void init(QV4::ExecutionContext *scope, QV4::String *name = nullptr);
+    void init(QV4::ExecutionContext *scope, QV4::Function *function, QV4::String *n = nullptr);
+    void init(QV4::ExecutionContext *scope, const QString &name);
     void init();
     void destroy();
 
+    void setFunction(Function *f);
+
     unsigned int formalParameterCount() { return function ? function->nFormals : 0; }
     unsigned int varCount() { return function ? function->compiledFunction->nLocals : 0; }
-
-    const QV4::Object *protoProperty() const { return propertyData(Index_Prototype)->as<QV4::Object>(); }
 };
 
 struct FunctionCtor : FunctionObject {
@@ -96,30 +107,49 @@ struct FunctionPrototype : FunctionObject {
     void init();
 };
 
-struct Q_QML_EXPORT OldBuiltinFunction : FunctionObject {
-    void init(QV4::ExecutionContext *scope, QV4::String *name, ReturnedValue (*code)(QV4::CallContext *));
-    ReturnedValue (*code)(QV4::CallContext *);
-};
-
-struct Q_QML_EXPORT BuiltinFunction : FunctionObject {
-    void init(QV4::ExecutionContext *scope, QV4::String *name, void (*code)(const QV4::BuiltinFunction *, Scope &, CallData *));
-    void (*code)(const QV4::BuiltinFunction *, Scope &, CallData *);
-};
-
 struct IndexedBuiltinFunction : FunctionObject {
-    inline void init(QV4::ExecutionContext *scope, uint index, ReturnedValue (*code)(QV4::CallContext *ctx, uint index));
-    ReturnedValue (*code)(QV4::CallContext *, uint index);
+    inline void init(QV4::ExecutionContext *scope, uint index, VTable::Call call);
     uint index;
 };
 
-struct ScriptFunction : FunctionObject {
+struct ArrowFunction : FunctionObject {
     enum {
-        Index_Name = FunctionObject::Index_Prototype + 1,
+        Index_Name = Index_HasInstance + 1,
         Index_Length
     };
+    void init(QV4::ExecutionContext *scope, Function *function, QV4::String *name = nullptr);
+};
+
+#define ScriptFunctionMembers(class, Member) \
+    Member(class, Pointer, InternalClass *, cachedClassForConstructor)
+
+DECLARE_HEAP_OBJECT(ScriptFunction, ArrowFunction) {
+    DECLARE_MARKOBJECTS(ScriptFunction)
     void init(QV4::ExecutionContext *scope, Function *function);
+};
 
-    QV4::InternalClass *cachedClassForConstructor;
+#define MemberFunctionMembers(class, Member) \
+    Member(class, Pointer, Object *, homeObject)
+
+DECLARE_HEAP_OBJECT(MemberFunction, ArrowFunction) {
+    DECLARE_MARKOBJECTS(MemberFunction)
+
+    void init(QV4::ExecutionContext *scope, Function *function, QV4::String *name = nullptr) {
+        ArrowFunction::init(scope, function, name);
+    }
+};
+
+#define ConstructorFunctionMembers(class, Member) \
+    Member(class, Pointer, Object *, homeObject)
+
+DECLARE_HEAP_OBJECT(ConstructorFunction, ScriptFunction) {
+    DECLARE_MARKOBJECTS(ConstructorFunction)
+    bool isDerivedConstructor;
+};
+
+struct DefaultClassConstructorFunction : FunctionObject
+{
+    bool isDerivedConstructor;
 };
 
 #define BoundFunctionMembers(class, Member) \
@@ -128,7 +158,7 @@ struct ScriptFunction : FunctionObject {
     Member(class, Pointer, MemberData *, boundArgs)
 
 DECLARE_HEAP_OBJECT(BoundFunction, FunctionObject) {
-    DECLARE_MARK_TABLE(BoundFunction);
+    DECLARE_MARKOBJECTS(BoundFunction);
 
     void init(QV4::ExecutionContext *scope, QV4::FunctionObject *target, const Value &boundThis, QV4::MemberData *boundArgs);
 };
@@ -144,7 +174,9 @@ struct Q_QML_EXPORT FunctionObject: Object {
     V4_INTERNALCLASS(FunctionObject)
     V4_PROTOTYPE(functionPrototype)
     V4_NEEDS_DESTROY
+    enum { NInlineProperties = 1 };
 
+    bool canBeTailCalled() const { return d()->canBeTailCalled; }
     Heap::ExecutionContext *scope() const { return d()->scope; }
     Function *function() const { return d()->function; }
 
@@ -152,25 +184,52 @@ struct Q_QML_EXPORT FunctionObject: Object {
     unsigned int formalParameterCount() const { return d()->formalParameterCount(); }
     unsigned int varCount() const { return d()->varCount(); }
 
-    void init(String *name, bool createProto);
+    void setName(String *name) {
+        defineReadonlyConfigurableProperty(engine()->id_name(), *name);
+    }
+    void createDefaultPrototypeProperty(uint protoConstructorSlot);
 
-    using Object::construct;
-    using Object::call;
-    static void construct(const Managed *that, Scope &scope, CallData *);
-    static void call(const Managed *that, Scope &scope, CallData *d);
+    inline ReturnedValue callAsConstructor(const JSCallData &data) const;
+    ReturnedValue callAsConstructor(const Value *argv, int argc, const Value *newTarget = nullptr) const {
+        if (!d()->jsConstruct)
+            return engine()->throwTypeError(QStringLiteral("Function is not a constructor."));
+        return d()->jsConstruct(this, argv, argc, newTarget ? newTarget : this);
+    }
+    inline ReturnedValue call(const JSCallData &data) const;
+    ReturnedValue call(const Value *thisObject, const Value *argv, int argc) const {
+        if (!d()->jsCall)
+            return engine()->throwTypeError(QStringLiteral("Function can only be called with |new|."));
+        return d()->jsCall(this, thisObject, argv, argc);
+    }
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 
     static Heap::FunctionObject *createScriptFunction(ExecutionContext *scope, Function *function);
+    static Heap::FunctionObject *createConstructorFunction(ExecutionContext *scope, Function *function, Object *homeObject, bool isDerivedConstructor);
+    static Heap::FunctionObject *createMemberFunction(ExecutionContext *scope, Function *function, Object *homeObject, String *name);
+    static Heap::FunctionObject *createBuiltinFunction(ExecutionEngine *engine, StringOrSymbol *nameOrSymbol, VTable::Call code, int argumentCount);
 
     bool strictMode() const { return d()->function ? d()->function->isStrict() : false; }
     bool isBinding() const;
     bool isBoundFunction() const;
+    bool isConstructor() const {
+        return d()->isConstructor();
+    }
+
+    ReturnedValue getHomeObject() const;
+
+    ReturnedValue protoProperty() const {
+        return getValueByIndex(Heap::FunctionObject::Index_Prototype);
+    }
+    bool hasHasInstanceProperty() const {
+        return !internalClass()->propertyData.at(Heap::FunctionObject::Index_HasInstance).isEmpty();
+    }
 
     QQmlSourceLocation sourceLocation() const;
 };
 
 template<>
 inline const FunctionObject *Value::as() const {
-    return isManaged() && m()->vtable()->isFunctionObject ? reinterpret_cast<const FunctionObject *>(this) : 0;
+    return isManaged() && m()->internalClass->vtable->isFunctionObject ? reinterpret_cast<const FunctionObject *>(this) : nullptr;
 }
 
 
@@ -178,8 +237,14 @@ struct FunctionCtor: FunctionObject
 {
     V4_OBJECT2(FunctionCtor, FunctionObject)
 
-    static void construct(const Managed *that, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+protected:
+    enum Type {
+        Type_Function,
+        Type_Generator
+    };
+    static QQmlRefPointer<CompiledData::CompilationUnit> parse(ExecutionEngine *engine, const Value *argv, int argc, Type t = Type_Function);
 };
 
 struct FunctionPrototype: FunctionObject
@@ -188,73 +253,82 @@ struct FunctionPrototype: FunctionObject
 
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_apply(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_call(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_bind(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_apply(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_call(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_bind(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_hasInstance(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
-struct Q_QML_EXPORT BuiltinFunction : FunctionObject {
-    V4_OBJECT2(BuiltinFunction, FunctionObject)
-    V4_INTERNALCLASS(BuiltinFunction)
-
-    static Heap::BuiltinFunction *create(ExecutionContext *scope, String *name, void (*code)(const BuiltinFunction *, Scope &, CallData *))
-    {
-        return scope->engine()->memoryManager->allocObject<BuiltinFunction>(scope, name, code);
-    }
-
-    static void construct(const Managed *, Scope &scope, CallData *);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
-};
-
-struct IndexedBuiltinFunction: FunctionObject
+struct IndexedBuiltinFunction : FunctionObject
 {
     V4_OBJECT2(IndexedBuiltinFunction, FunctionObject)
-
-    static void construct(const Managed *m, Scope &scope, CallData *)
-    {
-        scope.result = static_cast<const IndexedBuiltinFunction *>(m)->engine()->throwTypeError();
-    }
-
-    static void call(const Managed *that, Scope &scope, CallData *callData);
 };
 
-void Heap::IndexedBuiltinFunction::init(QV4::ExecutionContext *scope, uint index,
-                                        ReturnedValue (*code)(QV4::CallContext *ctx, uint index))
+void Heap::IndexedBuiltinFunction::init(QV4::ExecutionContext *scope, uint index, VTable::Call call)
 {
     Heap::FunctionObject::init(scope);
+    this->jsCall = call;
     this->index = index;
-    this->code = code;
 }
 
+struct ArrowFunction : FunctionObject {
+    V4_OBJECT2(ArrowFunction, FunctionObject)
+    V4_INTERNALCLASS(ArrowFunction)
+    enum { NInlineProperties = 3 };
+
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
 
-struct ScriptFunction : FunctionObject {
-    V4_OBJECT2(ScriptFunction, FunctionObject)
+struct ScriptFunction : ArrowFunction {
+    V4_OBJECT2(ScriptFunction, ArrowFunction)
     V4_INTERNALCLASS(ScriptFunction)
 
-    static void construct(const Managed *, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
 
-    InternalClass *classForConstructor() const;
+    Heap::InternalClass *classForConstructor() const;
 };
 
+struct MemberFunction : ArrowFunction {
+    V4_OBJECT2(MemberFunction, ArrowFunction)
+    V4_INTERNALCLASS(MemberFunction)
+};
+
+struct ConstructorFunction : ScriptFunction {
+    V4_OBJECT2(ConstructorFunction, ScriptFunction)
+    V4_INTERNALCLASS(ConstructorFunction)
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct DefaultClassConstructorFunction : FunctionObject {
+    V4_OBJECT2(DefaultClassConstructorFunction, FunctionObject)
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
 
 struct BoundFunction: FunctionObject {
     V4_OBJECT2(BoundFunction, FunctionObject)
 
     static Heap::BoundFunction *create(ExecutionContext *scope, FunctionObject *target, const Value &boundThis, QV4::MemberData *boundArgs)
     {
-        return scope->engine()->memoryManager->allocObject<BoundFunction>(scope, target, boundThis, boundArgs);
+        return scope->engine()->memoryManager->allocate<BoundFunction>(scope, target, boundThis, boundArgs);
     }
 
     Heap::FunctionObject *target() const { return d()->target; }
     Value boundThis() const { return d()->boundThis; }
     Heap::MemberData *boundArgs() const { return d()->boundArgs; }
 
-    static void construct(const Managed *, Scope &scope, CallData *d);
-    static void call(const Managed *that, Scope &scope, CallData *dd);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
+inline bool FunctionObject::isBoundFunction() const
+{
+    return d()->vtable() == BoundFunction::staticVTable();
+}
+
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4functiontable_noop.cpp b/src/qml/jsruntime/qv4functiontable_noop.cpp
new file mode 100644
index 0000000000..31c198eb00
--- /dev/null
+++ b/src/qml/jsruntime/qv4functiontable_noop.cpp
@@ -0,0 +1,65 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4functiontable_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+void generateFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef)
+{
+    Q_UNUSED(function);
+    Q_UNUSED(codeRef);
+}
+
+void destroyFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef)
+{
+    Q_UNUSED(function);
+    Q_UNUSED(codeRef);
+}
+
+size_t exceptionHandlerSize()
+{
+    return 0;
+}
+
+} // QV4
+
+QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4functiontable_p.h b/src/qml/jsruntime/qv4functiontable_p.h
new file mode 100644
index 0000000000..69e3d2bdd5
--- /dev/null
+++ b/src/qml/jsruntime/qv4functiontable_p.h
@@ -0,0 +1,75 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4FUNCTIONTABLE_P_H
+#define QV4FUNCTIONTABLE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4global_p.h"
+
+namespace JSC {
+class MacroAssemblerCodeRef;
+}
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+struct Function;
+
+void generateFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef);
+void destroyFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef);
+
+size_t exceptionHandlerSize();
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4FUNCTIONTABLE_P_H
diff --git a/src/qml/jsruntime/qv4functiontable_unix.cpp b/src/qml/jsruntime/qv4functiontable_unix.cpp
new file mode 100644
index 0000000000..25b5c27161
--- /dev/null
+++ b/src/qml/jsruntime/qv4functiontable_unix.cpp
@@ -0,0 +1,99 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4functiontable_p.h"
+#include "qv4function_p.h"
+
+#include <assembler/MacroAssemblerCodeRef.h>
+
+#include <QtCore/qfile.h>
+#include <QtCore/qcoreapplication.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+void generateFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef)
+{
+    // This implements writing of JIT'd addresses so that perf can find the
+    // symbol names.
+    //
+    // Perf expects the mapping to be in a certain place and have certain
+    // content, for more information, see:
+    // https://github.com/torvalds/linux/blob/master/tools/perf/Documentation/jit-interface.txt
+    static bool doProfile = !qEnvironmentVariableIsEmpty("QV4_PROFILE_WRITE_PERF_MAP");
+    if (Q_UNLIKELY(doProfile)) {
+        static QFile perfMapFile(QString::fromLatin1("/tmp/perf-%1.map")
+                                 .arg(QCoreApplication::applicationPid()));
+        static const bool isOpen = perfMapFile.open(QIODevice::WriteOnly);
+        if (!isOpen) {
+            qWarning("QV4::JIT::Assembler: Cannot write perf map file.");
+            doProfile = false;
+        } else {
+            const void *address = codeRef->code().executableAddress();
+            perfMapFile.write(QByteArray::number(reinterpret_cast<quintptr>(address), 16));
+            perfMapFile.putChar(' ');
+            perfMapFile.write(QByteArray::number(static_cast<qsizetype>(codeRef->size()), 16));
+            perfMapFile.putChar(' ');
+            perfMapFile.write(Function::prettyName(function, address).toUtf8());
+            perfMapFile.putChar('\n');
+            perfMapFile.flush();
+        }
+    }
+}
+
+void destroyFunctionTable(Function *function, JSC::MacroAssemblerCodeRef *codeRef)
+{
+    Q_UNUSED(function);
+    Q_UNUSED(codeRef);
+
+    // It's not advisable to remove things from the perf map file, as it's primarily used to analyze
+    // a trace after the application has terminated. We want to know about all functions that were
+    // ever jitted then. If the memory ranges overlap, we will have a problem when analyzing the
+    // trace. The JIT should try to avoid this.
+}
+
+size_t exceptionHandlerSize()
+{
+    return 0;
+}
+
+} // QV4
+
+QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4functiontable_win64.cpp b/src/qml/jsruntime/qv4functiontable_win64.cpp
new file mode 100644
index 0000000000..fc13dc2602
--- /dev/null
+++ b/src/qml/jsruntime/qv4functiontable_win64.cpp
@@ -0,0 +1,153 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4functiontable_p.h"
+
+#include <assembler/MacroAssemblerCodeRef.h>
+
+#include <QtCore/qdebug.h>
+
+#include <windows.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+enum UnwindOpcode: UINT8
+{
+    UWOP_PUSH_NONVOL = 0, /* info == register number */
+    UWOP_ALLOC_LARGE,     /* no info, alloc size in next 2 slots */
+    UWOP_ALLOC_SMALL,     /* info == size of allocation / 8 - 1 */
+    UWOP_SET_FPREG,       /* no info, FP = RSP + UNWIND_INFO.FPRegOffset*16 */
+    UWOP_SAVE_NONVOL,     /* info == register number, offset in next slot */
+    UWOP_SAVE_NONVOL_FAR, /* info == register number, offset in next 2 slots */
+    UWOP_SAVE_XMM128 = 8, /* info == XMM reg number, offset in next slot */
+    UWOP_SAVE_XMM128_FAR, /* info == XMM reg number, offset in next 2 slots */
+    UWOP_PUSH_MACHFRAME   /* info == 0: no error-code, 1: error-code */
+};
+
+enum Register : UINT8
+{
+    RAX = 0,
+    RCX,
+    RDX,
+    RBX,
+    RSP,
+    RBP,
+    RSI,
+    RDI,
+    NONE = 15
+};
+
+struct UnwindCode
+{
+    UnwindCode(UINT8 offset, UnwindOpcode operation, Register info)
+        : offset(offset), operation(operation), info(info)
+    {}
+
+    UINT8 offset;
+    UINT8 operation: 4;
+    UINT8 info:      4;
+};
+
+struct UnwindInfo
+{
+    UINT8 Version : 3;
+    UINT8 Flags : 5;
+    UINT8 SizeOfProlog;
+    UINT8 CountOfUnwindCodes;
+    UINT8 FrameRegister : 4;
+    UINT8 FrameRegisterOffset : 4;
+    UnwindCode UnwindCodes[2];
+};
+
+struct ExceptionHandlerRecord
+{
+    RUNTIME_FUNCTION handler;
+    UnwindInfo info;
+};
+
+void generateFunctionTable(Function *, JSC::MacroAssemblerCodeRef *codeRef)
+{
+    ExceptionHandlerRecord *record = reinterpret_cast<ExceptionHandlerRecord *>(
+                codeRef->executableMemory()->exceptionHandler());
+
+    record->info.Version             = 1;
+    record->info.Flags               = 0;
+    record->info.SizeOfProlog        = 4;
+    record->info.CountOfUnwindCodes  = 2;
+    record->info.FrameRegister       = RBP;
+    record->info.FrameRegisterOffset = 0;
+
+    // Push frame pointer
+    record->info.UnwindCodes[1] = UnwindCode(1, UWOP_PUSH_NONVOL,  RBP);
+    // Set frame pointer from stack pointer
+    record->info.UnwindCodes[0] = UnwindCode(4,   UWOP_SET_FPREG, NONE);
+
+    const quintptr codeStart = quintptr(codeRef->code().executableAddress());
+    const quintptr codeSize = codeRef->size();
+
+    record->handler.BeginAddress = DWORD(codeStart - quintptr(record));
+    record->handler.EndAddress   = DWORD(codeStart + codeSize - quintptr(record));
+    record->handler.UnwindData   = offsetof(ExceptionHandlerRecord, info);
+
+    if (!RtlAddFunctionTable(&record->handler, 1, DWORD64(record))) {
+        const unsigned int errorCode = GetLastError();
+        qWarning() << "Failed to install win64 unwind hook. Error code:" << errorCode;
+    }
+}
+
+void destroyFunctionTable(Function *, JSC::MacroAssemblerCodeRef *codeRef)
+{
+    ExceptionHandlerRecord *record = reinterpret_cast<ExceptionHandlerRecord *>(
+                codeRef->executableMemory()->exceptionHandler());
+    if (!RtlDeleteFunctionTable(&record->handler)) {
+        const unsigned int errorCode = GetLastError();
+        qWarning() << "Failed to remove win64 unwind hook. Error code:" << errorCode;
+    }
+}
+
+size_t exceptionHandlerSize()
+{
+    return sizeof(ExceptionHandlerRecord);
+}
+
+} // QV4
+
+QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4generatorobject.cpp b/src/qml/jsruntime/qv4generatorobject.cpp
new file mode 100644
index 0000000000..566db6fd4e
--- /dev/null
+++ b/src/qml/jsruntime/qv4generatorobject.cpp
@@ -0,0 +1,258 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qv4generatorobject_p.h>
+#include <qv4symbol_p.h>
+#include <qv4iterator_p.h>
+#include <qv4jscall_p.h>
+#include <qv4vme_moth_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(GeneratorFunctionCtor);
+DEFINE_OBJECT_VTABLE(GeneratorFunction);
+DEFINE_OBJECT_VTABLE(GeneratorObject);
+
+void Heap::GeneratorFunctionCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("GeneratorFunction"));
+}
+
+ReturnedValue GeneratorFunctionCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    ExecutionEngine *engine = f->engine();
+
+    QQmlRefPointer<CompiledData::CompilationUnit> compilationUnit = parse(engine, argv, argc, Type_Generator);
+    if (engine->hasException)
+        return Encode::undefined();
+
+    Function *vmf = compilationUnit->linkToEngine(engine);
+    ExecutionContext *global = engine->scriptContext();
+    ReturnedValue o = Encode(GeneratorFunction::create(global, vmf));
+
+    if (!newTarget)
+        return o;
+    Scope scope(engine);
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
+}
+
+// 15.3.1: This is equivalent to new Function(...)
+ReturnedValue GeneratorFunctionCtor::virtualCall(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return virtualCallAsConstructor(f, argv, argc, f);
+}
+
+Heap::FunctionObject *GeneratorFunction::create(ExecutionContext *context, Function *function)
+{
+    Scope scope(context);
+    Scoped<GeneratorFunction> g(scope, context->engine()->memoryManager->allocate<GeneratorFunction>(context, function));
+    ScopedObject proto(scope, scope.engine->newObject());
+    proto->setPrototypeOf(scope.engine->generatorPrototype());
+    g->defineDefaultProperty(scope.engine->id_prototype(), proto, Attr_NotConfigurable|Attr_NotEnumerable);
+    g->setPrototypeOf(ScopedObject(scope, scope.engine->generatorFunctionCtor()->get(scope.engine->id_prototype())));
+    return g->d();
+}
+
+ReturnedValue GeneratorFunction::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    const GeneratorFunction *gf = static_cast<const GeneratorFunction *>(f);
+    Function *function = gf->function();
+    ExecutionEngine *engine = gf->engine();
+
+    // We need to set up a separate stack for the generator, as it's being re-entered
+    uint stackSize = argc // space for the original arguments
+                   + CppStackFrame::requiredJSStackFrameSize(function); // space for the JS stack frame
+
+    size_t requiredMemory = sizeof(GeneratorObject::Data) - sizeof(Value) + sizeof(Value) * stackSize;
+
+    Scope scope(gf);
+    Scoped<GeneratorObject> g(scope, scope.engine->memoryManager->allocManaged<GeneratorObject>(requiredMemory, scope.engine->classes[EngineBase::Class_GeneratorObject]));
+    g->setPrototypeOf(ScopedObject(scope, gf->get(scope.engine->id_prototype())));
+
+    Heap::GeneratorObject *gp = g->d();
+    gp->stack.size = stackSize;
+    gp->stack.alloc = stackSize;
+
+    // copy original arguments
+    memcpy(gp->stack.values, argv, argc*sizeof(Value));
+    gp->cppFrame.init(engine, function, gp->stack.values, argc);
+    gp->cppFrame.setupJSFrame(&gp->stack.values[argc], *gf, gf->scope(),
+                              thisObject ? *thisObject : Value::undefinedValue(),
+                              Value::undefinedValue());
+
+    gp->cppFrame.push();
+
+    Moth::VME::interpret(&gp->cppFrame, engine, function->codeData);
+    gp->state = GeneratorState::SuspendedStart;
+
+    gp->cppFrame.pop();
+    return g->asReturnedValue();
+}
+
+
+void Heap::GeneratorPrototype::init()
+{
+    Heap::FunctionObject::init();
+}
+
+
+void GeneratorPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedValue v(scope);
+
+    ScopedObject ctorProto(scope, engine->newObject(engine->newInternalClass(Object::staticVTable(), engine->functionPrototype())));
+
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
+    ctor->defineReadonlyProperty(engine->id_prototype(), ctorProto);
+
+    ctorProto->defineDefaultProperty(QStringLiteral("constructor"), (v = ctor), Attr_ReadOnly_ButConfigurable);
+    ctorProto->defineDefaultProperty(engine->symbol_toStringTag(), (v = engine->newIdentifier(QStringLiteral("GeneratorFunction"))), Attr_ReadOnly_ButConfigurable);
+    ctorProto->defineDefaultProperty(engine->id_prototype(), (v = this), Attr_ReadOnly_ButConfigurable);
+
+    setPrototypeOf(engine->iteratorPrototype());
+    defineDefaultProperty(QStringLiteral("constructor"), ctorProto, Attr_ReadOnly_ButConfigurable);
+    defineDefaultProperty(QStringLiteral("next"), method_next, 1);
+    defineDefaultProperty(QStringLiteral("return"), method_return, 1);
+    defineDefaultProperty(QStringLiteral("throw"), method_throw, 1);
+    defineDefaultProperty(engine->symbol_toStringTag(), (v = engine->newString(QStringLiteral("Generator"))), Attr_ReadOnly_ButConfigurable);
+}
+
+ReturnedValue GeneratorPrototype::method_next(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *engine = f->engine();
+    const GeneratorObject *g = thisObject->as<GeneratorObject>();
+    if (!g || g->d()->state == GeneratorState::Executing)
+        return engine->throwTypeError();
+    Heap::GeneratorObject *gp = g->d();
+
+    if (gp->state == GeneratorState::Completed)
+        return IteratorPrototype::createIterResultObject(engine, Value::undefinedValue(), true);
+
+    return g->resume(engine, argc ? argv[0] : Value::undefinedValue());
+}
+
+ReturnedValue GeneratorPrototype::method_return(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *engine = f->engine();
+    const GeneratorObject *g = thisObject->as<GeneratorObject>();
+    if (!g || g->d()->state == GeneratorState::Executing)
+        return engine->throwTypeError();
+
+    Heap::GeneratorObject *gp = g->d();
+
+    if (gp->state == GeneratorState::SuspendedStart)
+        gp->state = GeneratorState::Completed;
+
+    if (gp->state == GeneratorState::Completed)
+        return IteratorPrototype::createIterResultObject(engine, argc ? argv[0] : Value::undefinedValue(), true);
+
+    // the bytecode interpreter interprets an exception with empty value as
+    // a yield called with return()
+    engine->throwError(Value::emptyValue());
+
+    return g->resume(engine, argc ? argv[0]: Value::undefinedValue());
+}
+
+ReturnedValue GeneratorPrototype::method_throw(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *engine = f->engine();
+    const GeneratorObject *g = thisObject->as<GeneratorObject>();
+    if (!g || g->d()->state == GeneratorState::Executing)
+        return engine->throwTypeError();
+
+    Heap::GeneratorObject *gp = g->d();
+
+    engine->throwError(argc ? argv[0]: Value::undefinedValue());
+
+    if (gp->state == GeneratorState::SuspendedStart || gp->state == GeneratorState::Completed) {
+        gp->state = GeneratorState::Completed;
+        return Encode::undefined();
+    }
+
+    return g->resume(engine, Value::undefinedValue());
+}
+
+ReturnedValue GeneratorObject::resume(ExecutionEngine *engine, const Value &arg) const
+{
+    Heap::GeneratorObject *gp = d();
+    gp->state = GeneratorState::Executing;
+    gp->cppFrame.parent = engine->currentStackFrame;
+    engine->currentStackFrame = &gp->cppFrame;
+
+    Q_ASSERT(gp->cppFrame.yield != nullptr);
+    const char *code = gp->cppFrame.yield;
+    gp->cppFrame.yield = nullptr;
+    gp->cppFrame.jsFrame->accumulator = arg;
+    gp->cppFrame.yieldIsIterator = false;
+
+    Scope scope(engine);
+    ScopedValue result(scope, Moth::VME::interpret(&gp->cppFrame, engine, code));
+
+    engine->currentStackFrame = gp->cppFrame.parent;
+
+    bool done = (gp->cppFrame.yield == nullptr);
+    gp->state = done ? GeneratorState::Completed : GeneratorState::SuspendedYield;
+    if (engine->hasException)
+        return Encode::undefined();
+    if (gp->cppFrame.yieldIsIterator)
+        return result->asReturnedValue();
+    return IteratorPrototype::createIterResultObject(engine, result, done);
+}
+
+DEFINE_OBJECT_VTABLE(MemberGeneratorFunction);
+
+Heap::FunctionObject *MemberGeneratorFunction::create(ExecutionContext *context, Function *function, Object *homeObject, String *name)
+{
+    Scope scope(context);
+    Scoped<MemberGeneratorFunction> g(scope, context->engine()->memoryManager->allocate<MemberGeneratorFunction>(context, function, name));
+    g->d()->homeObject.set(scope.engine, homeObject->d());
+    ScopedObject proto(scope, scope.engine->newObject());
+    proto->setPrototypeOf(scope.engine->generatorPrototype());
+    g->defineDefaultProperty(scope.engine->id_prototype(), proto, Attr_NotConfigurable|Attr_NotEnumerable);
+    g->setPrototypeOf(ScopedObject(scope, scope.engine->generatorFunctionCtor()->get(scope.engine->id_prototype())));
+    return g->d();
+}
+
+ReturnedValue MemberGeneratorFunction::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    return GeneratorFunction::virtualCall(f, thisObject, argv, argc);
+}
diff --git a/src/qml/jsruntime/qv4generatorobject_p.h b/src/qml/jsruntime/qv4generatorobject_p.h
new file mode 100644
index 0000000000..366319723d
--- /dev/null
+++ b/src/qml/jsruntime/qv4generatorobject_p.h
@@ -0,0 +1,151 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4GENERATOROBJECT_P_H
+#define QV4GENERATOROBJECT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4functionobject_p.h"
+#include "qv4stackframe_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+enum class GeneratorState {
+    Undefined,
+    SuspendedStart,
+    SuspendedYield,
+    Executing,
+    Completed
+};
+
+namespace Heap {
+
+struct GeneratorFunctionCtor : FunctionObject {
+    void init(QV4::ExecutionContext *scope);
+};
+
+struct GeneratorFunction : ArrowFunction {
+    void init(QV4::ExecutionContext *scope, Function *function, QV4::String *name = nullptr) {
+        ArrowFunction::init(scope, function, name);
+    }
+};
+
+struct MemberGeneratorFunction : MemberFunction {
+};
+
+struct GeneratorPrototype : FunctionObject {
+    void init();
+};
+
+#define GeneratorObjectMembers(class, Member) \
+    Member(class, Pointer, ExecutionContext *, context) \
+    Member(class, Pointer, GeneratorFunction *, function) \
+    Member(class, NoMark, GeneratorState, state) \
+    Member(class, NoMark, CppStackFrame, cppFrame) \
+    Member(class, ValueArray, ValueArray, stack)
+
+DECLARE_HEAP_OBJECT(GeneratorObject, Object) {
+    DECLARE_MARKOBJECTS(GeneratorObject);
+};
+
+}
+
+struct GeneratorFunctionCtor : FunctionCtor
+{
+    V4_OBJECT2(GeneratorFunctionCtor, FunctionCtor)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct GeneratorFunction : ArrowFunction
+{
+    V4_OBJECT2(GeneratorFunction, ArrowFunction)
+    V4_INTERNALCLASS(GeneratorFunction)
+
+    static Heap::FunctionObject *create(ExecutionContext *scope, Function *function);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct MemberGeneratorFunction : MemberFunction
+{
+    V4_OBJECT2(MemberGeneratorFunction, MemberFunction)
+    V4_INTERNALCLASS(MemberGeneratorFunction)
+
+    static Heap::FunctionObject *create(ExecutionContext *scope, Function *function, Object *homeObject, String *name);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct GeneratorPrototype : Object
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_next(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_return(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_throw(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+
+struct GeneratorObject : Object {
+    V4_OBJECT2(GeneratorObject, Object)
+    Q_MANAGED_TYPE(GeneratorObject)
+    V4_INTERNALCLASS(GeneratorObject)
+    V4_PROTOTYPE(generatorPrototype)
+
+    ReturnedValue resume(ExecutionEngine *engine, const Value &arg) const;
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4GENERATORFUNCTION_P_H
+
diff --git a/src/qml/jsruntime/qv4global_p.h b/src/qml/jsruntime/qv4global_p.h
index 8769519a59..44adac26cd 100644
--- a/src/qml/jsruntime/qv4global_p.h
+++ b/src/qml/jsruntime/qv4global_p.h
@@ -76,9 +76,6 @@ namespace std {
 inline bool isinf(double d) { return !_finite(d) && !_isnan(d); }
 inline bool isnan(double d) { return !!_isnan(d); }
 inline bool isfinite(double d) { return _finite(d); }
-#if _MSC_VER < 1800
-inline bool signbit(double d) { return _copysign(1.0, d) < 0; }
-#endif
 
 } // namespace std
 
@@ -91,11 +88,11 @@ inline double trunc(double d) { return d > 0 ? floor(d) : ceil(d); }
 //
 // NOTE: This should match the logic in qv4targetplatform_p.h!
 
-#if defined(Q_PROCESSOR_X86) && (QT_POINTER_SIZE == 4) \
+#if defined(Q_PROCESSOR_X86_32) && (QT_POINTER_SIZE == 4) \
     && (defined(Q_OS_WIN) || defined(Q_OS_LINUX) || defined(Q_OS_QNX) || defined(Q_OS_FREEBSD))
 #  define V4_ENABLE_JIT
 #elif defined(Q_PROCESSOR_X86_64) && (QT_POINTER_SIZE == 8) \
-    && (defined(Q_OS_WIN) || defined(Q_OS_LINUX) || defined(Q_OS_MAC) || defined(Q_OS_FREEBSD))
+    && (defined(Q_OS_WIN) || defined(Q_OS_LINUX) || defined(Q_OS_QNX) || defined(Q_OS_MAC) || defined(Q_OS_FREEBSD))
 #  define V4_ENABLE_JIT
 #elif defined(Q_PROCESSOR_ARM_32) && (QT_POINTER_SIZE == 4)
 #  if defined(thumb2) || defined(__thumb2__) || ((defined(__thumb) || defined(__thumb__)) && __TARGET_ARCH_THUMB-0 == 4)
@@ -104,11 +101,16 @@ inline double trunc(double d) { return d > 0 ? floor(d) : ceil(d); }
 #    define V4_ENABLE_JIT
 #  endif
 #elif defined(Q_PROCESSOR_ARM_64) && (QT_POINTER_SIZE == 8)
-#  if defined(Q_OS_LINUX)
+#  if defined(Q_OS_LINUX) || defined(Q_OS_QNX) || defined(Q_OS_INTEGRITY)
 #    define V4_ENABLE_JIT
 #  endif
-#elif defined(Q_PROCESSOR_MIPS_32) && defined(Q_OS_LINUX)
-#  define V4_ENABLE_JIT
+//#elif defined(Q_PROCESSOR_MIPS_32) && defined(Q_OS_LINUX)
+//#  define V4_ENABLE_JIT
+#endif
+
+// check FPU with double precision on ARM platform
+#if (defined(Q_PROCESSOR_ARM_64) || defined(Q_PROCESSOR_ARM_32)) && defined(V4_ENABLE_JIT) && defined(__ARM_FP) && (__ARM_FP <= 0x04)
+#  undef V4_ENABLE_JIT
 #endif
 
 // Black list some platforms
@@ -147,19 +149,33 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
+namespace Compiler {
+    struct Module;
+    struct Context;
+    struct JSUnitGenerator;
+    class Codegen;
+}
+
+namespace Moth {
+    class BytecodeGenerator;
+}
+
 namespace Heap {
     struct Base;
     struct MemberData;
     struct ArrayData;
 
+    struct StringOrSymbol;
     struct String;
+    struct Symbol;
     struct Object;
     struct ObjectPrototype;
 
     struct ExecutionContext;
-    struct GlobalContext;
     struct CallContext;
+    struct QmlContext;
     struct ScriptFunction;
+    struct InternalClass;
 
     struct BooleanObject;
     struct NumberObject;
@@ -174,21 +190,33 @@ namespace Heap {
     struct RegExp;
     struct EvalFunction;
 
+    struct SharedArrayBuffer;
     struct ArrayBuffer;
     struct DataView;
     struct TypedArray;
 
+    struct MapObject;
+    struct SetObject;
+
+    struct PromiseObject;
+    struct PromiseCapability;
+
     template <typename T, size_t> struct Pointer;
 }
 
+struct CppStackFrame;
 class MemoryManager;
+class ExecutableAllocator;
+struct PropertyKey;
+struct StringOrSymbol;
 struct String;
+struct Symbol;
 struct Object;
 struct ObjectPrototype;
 struct ObjectIterator;
 struct ExecutionContext;
-struct GlobalContext;
 struct CallContext;
+struct QmlContext;
 struct ScriptFunction;
 struct InternalClass;
 struct Property;
@@ -206,7 +234,6 @@ struct StringObject;
 struct ArrayObject;
 struct DateObject;
 struct FunctionObject;
-struct BuiltinFunction;
 struct ErrorObject;
 struct ArgumentsObject;
 struct Managed;
@@ -216,10 +243,17 @@ struct RegExpObject;
 struct RegExp;
 struct EvalFunction;
 
+struct SharedArrayBuffer;
 struct ArrayBuffer;
 struct DataView;
 struct TypedArray;
 
+struct MapObject;
+struct SetMapObject;
+
+struct PromiseObject;
+struct PromiseCapability;
+
 // ReturnedValue is used to return values from runtime methods
 // the type has to be a primitive type (no struct or union), so that the compiler
 // will return it in a register on all platforms.
@@ -230,6 +264,7 @@ struct Scope;
 struct ScopedValue;
 template<typename T> struct Scoped;
 typedef Scoped<String> ScopedString;
+typedef Scoped<StringOrSymbol> ScopedStringOrSymbol;
 typedef Scoped<Object> ScopedObject;
 typedef Scoped<ArrayObject> ScopedArrayObject;
 typedef Scoped<FunctionObject> ScopedFunctionObject;
@@ -238,16 +273,25 @@ typedef Scoped<ExecutionContext> ScopedContext;
 struct PersistentValueStorage;
 class PersistentValue;
 class WeakValue;
+struct MarkStack;
 
 struct IdentifierTable;
 class RegExpCache;
 class MultiplyWrappedQObjectMap;
 
-namespace Global {
-    enum {
-        ReservedArgumentCount = 6
-    };
-}
+enum class ObservedTraceValues : quint8 {
+    Integer = 1 << 0,
+    Boolean = 1 << 1,
+    Double  = 1 << 2,
+    Other   = 1 << 3,
+    TypeMask = Integer | Boolean | Double | Other,
+
+    TruePathTaken  = 1 << 0,
+    FalsePathTaken = 1 << 1,
+
+    ArrayWasAccessed          = 1 << 7,
+    ArrayAccessNeededFallback = 1 << 6,
+};
 
 enum PropertyFlag {
     Attr_Data = 0,
@@ -340,6 +384,7 @@ struct PropertyAttributes
     bool isEmpty() const { return !m_all; }
 
     uint flags() const { return m_flags; }
+    uint all() const { return m_all; }
 
     bool operator==(PropertyAttributes other) {
         return m_all == other.m_all;
@@ -349,15 +394,31 @@ struct PropertyAttributes
     }
 };
 
-struct StackFrame {
+struct Q_QML_EXPORT StackFrame {
     QString source;
     QString function;
-    int line;
-    int column;
+    int line = -1;
+    int column = -1;
 };
 typedef QVector<StackFrame> StackTrace;
 
-}
+enum class ObjectLiteralArgument {
+    Value,
+    Method,
+    Getter,
+    Setter
+};
+
+namespace JIT {
+
+enum class CallResultDestination {
+    Ignore,
+    InAccumulator,
+};
+
+} // JIT namespace
+
+} // QV4 namespace
 
 Q_DECLARE_TYPEINFO(QV4::PropertyAttributes, Q_PRIMITIVE_TYPE);
 
diff --git a/src/qml/jsruntime/qv4globalobject.cpp b/src/qml/jsruntime/qv4globalobject.cpp
index 0916e8e110..becdc3bc55 100644
--- a/src/qml/jsruntime/qv4globalobject.cpp
+++ b/src/qml/jsruntime/qv4globalobject.cpp
@@ -47,12 +47,12 @@
 #include "qv4script_p.h"
 #include "qv4scopedvalue_p.h"
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
 
 #include <private/qqmljsengine_p.h>
 #include <private/qqmljslexer_p.h>
 #include <private/qqmljsparser_p.h>
 #include <private/qqmljsast_p.h>
-#include <qv4jsir_p.h>
 #include <qv4codegen_p.h>
 #include "private/qlocale_tools_p.h"
 #include "private/qtools_p.h"
@@ -335,75 +335,60 @@ void Heap::EvalFunction::init(QV4::ExecutionContext *scope)
     Scope s(scope);
     Heap::FunctionObject::init(scope, s.engine->id_eval());
     ScopedFunctionObject f(s, this);
-    f->defineReadonlyProperty(s.engine->id_length(), Primitive::fromInt32(1));
+    f->defineReadonlyConfigurableProperty(s.engine->id_length(), Value::fromInt32(1));
 }
 
-void EvalFunction::evalCall(Scope &scope, CallData *callData, bool directCall) const
+ReturnedValue EvalFunction::evalCall(const Value *, const Value *argv, int argc, bool directCall) const
 {
-    if (callData->argc < 1) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    if (argc < 1)
+        return Encode::undefined();
 
     ExecutionEngine *v4 = engine();
-    ExecutionContextSaver ctxSaver(scope);
+    bool isStrict = v4->currentStackFrame->v4Function->isStrict();
 
-    ExecutionContext *currentContext = v4->currentContext;
-    ExecutionContext *ctx = currentContext;
+    Scope scope(v4);
+    ScopedContext ctx(scope, v4->currentContext());
 
     if (!directCall) {
-        // the context for eval should be the global scope, so we fake a root
-        // context
-        ctx = v4->pushGlobalContext();
+        // the context for eval should be the global scope
+        ctx = v4->scriptContext();
     }
 
-    String *scode = callData->args[0].stringValue();
-    if (!scode) {
-        scope.result = callData->args[0].asReturnedValue();
-        return;
-    }
+    String *scode = argv[0].stringValue();
+    if (!scode)
+        return argv[0].asReturnedValue();
 
     const QString code = scode->toQString();
-    bool inheritContext = !ctx->d()->strictMode;
+    bool inheritContext = !isStrict;
 
-    Script script(ctx, code, QStringLiteral("eval code"));
-    script.strictMode = (directCall && currentContext->d()->strictMode);
+    Script script(ctx, QV4::Compiler::ContextType::Eval, code, QStringLiteral("eval code"));
+    script.strictMode = (directCall && isStrict);
     script.inheritContext = inheritContext;
     script.parse();
-    if (v4->hasException) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    if (v4->hasException)
+        return Encode::undefined();
 
     Function *function = script.function();
-    if (!function) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    if (!function)
+        return Encode::undefined();
+    function->isEval = true;
 
-    if (function->isStrict() || (ctx->d()->strictMode)) {
+    if (function->isStrict() || isStrict) {
         ScopedFunctionObject e(scope, FunctionObject::createScriptFunction(ctx, function));
-        ScopedCallData callData(scope, 0);
-        callData->thisObject = ctx->thisObject();
-        e->call(scope, callData);
-        return;
+        ScopedValue thisObject(scope, directCall ? scope.engine->currentStackFrame->thisObject() : scope.engine->globalObject->asReturnedValue());
+        return e->call(thisObject, nullptr, 0);
     }
 
-    ContextStateSaver stateSaver(scope, ctx);
-
-    // set the correct strict mode flag on the context
-    ctx->d()->strictMode = false;
-    ctx->d()->compilationUnit = function->compilationUnit;
-    ctx->d()->constantTable = function->compilationUnit->constants;
+    ScopedValue thisObject(scope, scope.engine->currentStackFrame->thisObject());
 
-    scope.result = Q_V4_PROFILE(ctx->engine(), function);
+    return function->call(thisObject, nullptr, 0, ctx);
 }
 
 
-void EvalFunction::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue EvalFunction::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
 {
     // indirect call
-    static_cast<const EvalFunction *>(that)->evalCall(scope, callData, false);
+    return static_cast<const EvalFunction *>(f)->evalCall(thisObject, argv, argc, false);
 }
 
 
@@ -424,10 +409,11 @@ static inline int toInt(const QChar &qc, int R)
 }
 
 // parseInt [15.1.2.2]
-void GlobalFunctions::method_parseInt(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_parseInt(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedValue inputString(scope, callData->argument(0));
-    ScopedValue radix(scope, callData->argument(1));
+    Scope scope(b);
+    ScopedValue inputString(scope, argc ? argv[0] : Value::undefinedValue());
+    ScopedValue radix(scope, argc > 1 ? argv[1] : Value::undefinedValue());
     int R = radix->isUndefined() ? 0 : radix->toInt32();
 
     // [15.1.2.2] step by step:
@@ -504,10 +490,11 @@ void GlobalFunctions::method_parseInt(const BuiltinFunction *, Scope &scope, Cal
 }
 
 // parseFloat [15.1.2.3]
-void GlobalFunctions::method_parseFloat(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_parseFloat(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
+    Scope scope(b);
     // [15.1.2.3] step by step:
-    ScopedString inputString(scope, callData->argument(0), ScopedString::Convert);
+    ScopedString inputString(scope, argc ? argv[0] : Value::undefinedValue(), ScopedString::Convert);
     CHECK_EXCEPTION();
 
     QString trimmed = inputString->toQString().trimmed(); // 2
@@ -521,7 +508,7 @@ void GlobalFunctions::method_parseFloat(const BuiltinFunction *, Scope &scope, C
     QByteArray ba = trimmed.toLatin1();
     bool ok;
     const char *begin = ba.constData();
-    const char *end = 0;
+    const char *end = nullptr;
     double d = qstrtod(begin, &end, &ok);
     if (end - begin == 0)
         RETURN_RESULT(Encode(std::numeric_limits<double>::quiet_NaN())); // 3
@@ -530,115 +517,125 @@ void GlobalFunctions::method_parseFloat(const BuiltinFunction *, Scope &scope, C
 }
 
 /// isNaN [15.1.2.4]
-void GlobalFunctions::method_isNaN(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_isNaN(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc)
+    if (!argc)
         // undefined gets converted to NaN
         RETURN_RESULT(Encode(true));
 
-    if (callData->args[0].integerCompatible())
+    if (argv[0].integerCompatible())
         RETURN_RESULT(Encode(false));
 
-    double d = callData->args[0].toNumber();
+    double d = argv[0].toNumber();
     RETURN_RESULT(Encode((bool)std::isnan(d)));
 }
 
 /// isFinite [15.1.2.5]
-void GlobalFunctions::method_isFinite(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_isFinite(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc)
+    if (!argc)
         // undefined gets converted to NaN
         RETURN_RESULT(Encode(false));
 
-    if (callData->args[0].integerCompatible())
+    if (argv[0].integerCompatible())
         RETURN_RESULT(Encode(true));
 
-    double d = callData->args[0].toNumber();
+    double d = argv[0].toNumber();
     RETURN_RESULT(Encode((bool)std::isfinite(d)));
 }
 
 /// decodeURI [15.1.3.1]
-void GlobalFunctions::method_decodeURI(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_decodeURI(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    if (argc == 0)
         RETURN_UNDEFINED();
 
-    QString uriString = callData->args[0].toQString();
+    ExecutionEngine *v4 = b->engine();
+    QString uriString = argv[0].toQString();
     bool ok;
     QString out = decode(uriString, DecodeNonReserved, &ok);
     if (!ok) {
+        Scope scope(v4);
         ScopedString s(scope, scope.engine->newString(QStringLiteral("malformed URI sequence")));
         RETURN_RESULT(scope.engine->throwURIError(s));
     }
 
-    RETURN_RESULT(scope.engine->newString(out));
+    RETURN_RESULT(v4->newString(out));
 }
 
 /// decodeURIComponent [15.1.3.2]
-void GlobalFunctions::method_decodeURIComponent(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_decodeURIComponent(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    if (argc == 0)
         RETURN_UNDEFINED();
 
-    QString uriString = callData->args[0].toQString();
+    ExecutionEngine *v4 = b->engine();
+    QString uriString = argv[0].toQString();
     bool ok;
     QString out = decode(uriString, DecodeAll, &ok);
     if (!ok) {
+        Scope scope(v4);
         ScopedString s(scope, scope.engine->newString(QStringLiteral("malformed URI sequence")));
         RETURN_RESULT(scope.engine->throwURIError(s));
     }
 
-    RETURN_RESULT(scope.engine->newString(out));
+    RETURN_RESULT(v4->newString(out));
 }
 
 /// encodeURI [15.1.3.3]
-void GlobalFunctions::method_encodeURI(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_encodeURI(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    if (argc == 0)
         RETURN_UNDEFINED();
 
-    QString uriString = callData->args[0].toQString();
+    ExecutionEngine *v4 = b->engine();
+    QString uriString = argv[0].toQString();
     bool ok;
     QString out = encode(uriString, uriUnescapedReserved, &ok);
     if (!ok) {
+        Scope scope(v4);
         ScopedString s(scope, scope.engine->newString(QStringLiteral("malformed URI sequence")));
         RETURN_RESULT(scope.engine->throwURIError(s));
     }
 
-    RETURN_RESULT(scope.engine->newString(out));
+    RETURN_RESULT(v4->newString(out));
 }
 
 /// encodeURIComponent [15.1.3.4]
-void GlobalFunctions::method_encodeURIComponent(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_encodeURIComponent(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    if (argc == 0)
         RETURN_UNDEFINED();
 
-    QString uriString = callData->args[0].toQString();
+    ExecutionEngine *v4 = b->engine();
+    QString uriString = argv[0].toQString();
     bool ok;
     QString out = encode(uriString, uriUnescaped, &ok);
     if (!ok) {
+        Scope scope(v4);
         ScopedString s(scope, scope.engine->newString(QStringLiteral("malformed URI sequence")));
         RETURN_RESULT(scope.engine->throwURIError(s));
     }
 
-    RETURN_RESULT(scope.engine->newString(out));
+    RETURN_RESULT(v4->newString(out));
 }
 
-void GlobalFunctions::method_escape(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_escape(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc)
-        RETURN_RESULT(scope.engine->newString(QStringLiteral("undefined")));
+    ExecutionEngine *v4 = b->engine();
+    if (!argc)
+        RETURN_RESULT(v4->newString(QStringLiteral("undefined")));
 
-    QString str = callData->args[0].toQString();
-    RETURN_RESULT(scope.engine->newString(escape(str)));
+    QString str = argv[0].toQString();
+    RETURN_RESULT(v4->newString(escape(str)));
 }
 
-void GlobalFunctions::method_unescape(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalFunctions::method_unescape(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc)
-        RETURN_RESULT(scope.engine->newString(QStringLiteral("undefined")));
+    ExecutionEngine *v4 = b->engine();
+    if (!argc)
+        RETURN_RESULT(v4->newString(QStringLiteral("undefined")));
 
-    QString str = callData->args[0].toQString();
-    RETURN_RESULT(scope.engine->newString(unescape(str)));
+    QString str = argv[0].toQString();
+    RETURN_RESULT(v4->newString(unescape(str)));
 }
diff --git a/src/qml/jsruntime/qv4globalobject_p.h b/src/qml/jsruntime/qv4globalobject_p.h
index 273f1ba7ea..021b445955 100644
--- a/src/qml/jsruntime/qv4globalobject_p.h
+++ b/src/qml/jsruntime/qv4globalobject_p.h
@@ -69,23 +69,23 @@ struct Q_QML_EXPORT EvalFunction : FunctionObject
 {
     V4_OBJECT2(EvalFunction, FunctionObject)
 
-    void evalCall(Scope &scope, CallData *callData, bool directCall) const;
+    ReturnedValue evalCall(const Value *thisObject, const Value *argv, int argc, bool directCall) const;
 
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct GlobalFunctions
 {
-    static void method_parseInt(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_parseFloat(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isNaN(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isFinite(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_decodeURI(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_decodeURIComponent(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_encodeURI(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_encodeURIComponent(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_escape(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_unescape(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_parseInt(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_parseFloat(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isNaN(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isFinite(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_decodeURI(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_decodeURIComponent(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_encodeURI(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_encodeURIComponent(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_escape(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_unescape(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4identifier.cpp b/src/qml/jsruntime/qv4identifier.cpp
index 6260fd0cc8..5db5bd46ec 100644
--- a/src/qml/jsruntime/qv4identifier.cpp
+++ b/src/qml/jsruntime/qv4identifier.cpp
@@ -38,6 +38,7 @@
 ****************************************************************************/
 #include "qv4identifier_p.h"
 #include "qv4identifiertable_p.h"
+#include "qv4string_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -54,14 +55,16 @@ static inline int primeForNumBits(int numBits)
 }
 
 
-IdentifierHashData::IdentifierHashData(int numBits)
+IdentifierHashData::IdentifierHashData(IdentifierTable *table, int numBits)
     : size(0)
     , numBits(numBits)
+    , identifierTable(table)
 {
     refCount.store(1);
     alloc = primeForNumBits(numBits);
     entries = (IdentifierHashEntry *)malloc(alloc*sizeof(IdentifierHashEntry));
     memset(entries, 0, alloc*sizeof(IdentifierHashEntry));
+    identifierTable->addIdentifierHash(this);
 }
 
 IdentifierHashData::IdentifierHashData(IdentifierHashData *other)
@@ -73,15 +76,21 @@ IdentifierHashData::IdentifierHashData(IdentifierHashData *other)
     alloc = other->alloc;
     entries = (IdentifierHashEntry *)malloc(alloc*sizeof(IdentifierHashEntry));
     memcpy(entries, other->entries, alloc*sizeof(IdentifierHashEntry));
+    identifierTable->addIdentifierHash(this);
 }
 
-IdentifierHashBase::IdentifierHashBase(ExecutionEngine *engine)
+IdentifierHashData::~IdentifierHashData() {
+    free(entries);
+    if (identifierTable)
+        identifierTable->removeIdentifierHash(this);
+}
+
+IdentifierHash::IdentifierHash(ExecutionEngine *engine)
 {
-    d = new IdentifierHashData(3);
-    d->identifierTable = engine->identifierTable;
+    d = new IdentifierHashData(engine->identifierTable, 3);
 }
 
-void IdentifierHashBase::detach()
+void IdentifierHash::detach()
 {
     if (!d || d->refCount == 1)
         return;
@@ -92,8 +101,10 @@ void IdentifierHashBase::detach()
 }
 
 
-IdentifierHashEntry *IdentifierHashBase::addEntry(const Identifier *identifier)
+IdentifierHashEntry *IdentifierHash::addEntry(PropertyKey identifier)
 {
+    Q_ASSERT(identifier.isStringOrSymbol());
+
     // fill up to max 50%
     bool grow = (d->alloc <= d->size*2);
 
@@ -104,10 +115,10 @@ IdentifierHashEntry *IdentifierHashBase::addEntry(const Identifier *identifier)
         memset(newEntries, 0, newAlloc*sizeof(IdentifierHashEntry));
         for (int i = 0; i < d->alloc; ++i) {
             const IdentifierHashEntry &e = d->entries[i];
-            if (!e.identifier)
+            if (!e.identifier.isValid())
                 continue;
-            uint idx = e.identifier->hashValue % newAlloc;
-            while (newEntries[idx].identifier) {
+            uint idx = e.identifier.id() % newAlloc;
+            while (newEntries[idx].identifier.isValid()) {
                 ++idx;
                 idx %= newAlloc;
             }
@@ -118,8 +129,8 @@ IdentifierHashEntry *IdentifierHashBase::addEntry(const Identifier *identifier)
         d->alloc = newAlloc;
     }
 
-    uint idx = identifier->hashValue % d->alloc;
-    while (d->entries[idx].identifier) {
+    uint idx = identifier.id() % d->alloc;
+    while (d->entries[idx].identifier.isValid()) {
         Q_ASSERT(d->entries[idx].identifier != identifier);
         ++idx;
         idx %= d->alloc;
@@ -129,16 +140,16 @@ IdentifierHashEntry *IdentifierHashBase::addEntry(const Identifier *identifier)
     return d->entries + idx;
 }
 
-const IdentifierHashEntry *IdentifierHashBase::lookup(const Identifier *identifier) const
+const IdentifierHashEntry *IdentifierHash::lookup(PropertyKey identifier) const
 {
-    if (!d)
-        return 0;
+    if (!d || !identifier.isStringOrSymbol())
+        return nullptr;
     Q_ASSERT(d->entries);
 
-    uint idx = identifier->hashValue % d->alloc;
+    uint idx = identifier.id() % d->alloc;
     while (1) {
-        if (!d->entries[idx].identifier)
-            return 0;
+        if (!d->entries[idx].identifier.isValid())
+            return nullptr;
         if (d->entries[idx].identifier == identifier)
             return d->entries + idx;
         ++idx;
@@ -146,43 +157,58 @@ const IdentifierHashEntry *IdentifierHashBase::lookup(const Identifier *identifi
     }
 }
 
-const IdentifierHashEntry *IdentifierHashBase::lookup(const QString &str) const
+const IdentifierHashEntry *IdentifierHash::lookup(const QString &str) const
 {
     if (!d)
-        return 0;
-    Q_ASSERT(d->entries);
+        return nullptr;
 
-    uint hash = String::createHashValue(str.constData(), str.length(), Q_NULLPTR);
-    uint idx = hash % d->alloc;
-    while (1) {
-        if (!d->entries[idx].identifier)
-            return 0;
-        if (d->entries[idx].identifier->string == str)
-            return d->entries + idx;
-        ++idx;
-        idx %= d->alloc;
-    }
+    PropertyKey id = d->identifierTable->asPropertyKey(str);
+    return lookup(id);
 }
 
-const IdentifierHashEntry *IdentifierHashBase::lookup(String *str) const
+const IdentifierHashEntry *IdentifierHash::lookup(String *str) const
 {
     if (!d)
-        return 0;
-    if (str->d()->identifier)
-        return lookup(str->d()->identifier);
+        return nullptr;
+    PropertyKey id = d->identifierTable->asPropertyKey(str);
+    if (id.isValid())
+        return lookup(id);
     return lookup(str->toQString());
 }
 
-const Identifier *IdentifierHashBase::toIdentifier(const QString &str) const
+const PropertyKey IdentifierHash::toIdentifier(const QString &str) const
 {
     Q_ASSERT(d);
-    return d->identifierTable->identifier(str);
+    return d->identifierTable->asPropertyKey(str);
 }
 
-const Identifier *IdentifierHashBase::toIdentifier(Heap::String *str) const
+const PropertyKey IdentifierHash::toIdentifier(Heap::String *str) const
 {
     Q_ASSERT(d);
-    return d->identifierTable->identifier(str);
+    return d->identifierTable->asPropertyKey(str);
+}
+
+QString QV4::IdentifierHash::findId(int value) const
+{
+    IdentifierHashEntry *e = d->entries;
+    IdentifierHashEntry *end = e + d->alloc;
+    while (e < end) {
+        if (e->identifier.isValid() && e->value == value)
+            return e->identifier.toQString();
+        ++e;
+    }
+    return QString();
+}
+
+void IdentifierHashData::markObjects(MarkStack *markStack) const
+{
+    IdentifierHashEntry *e = entries;
+    IdentifierHashEntry *end = e + alloc;
+    while (e < end) {
+        if (Heap::Base *o = e->identifier.asStringOrSymbol())
+            o->mark(markStack);
+        ++e;
+    }
 }
 
 
diff --git a/src/qml/jsruntime/qv4identifier_p.h b/src/qml/jsruntime/qv4identifier_p.h
index 2695bbc875..32de8b7c8d 100644
--- a/src/qml/jsruntime/qv4identifier_p.h
+++ b/src/qml/jsruntime/qv4identifier_p.h
@@ -51,44 +51,24 @@
 //
 
 #include <qstring.h>
+#include <private/qv4global_p.h>
+#include <private/qv4propertykey_p.h>
 
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-namespace Heap {
-    struct String;
-}
-
-struct String;
-struct IdentifierTable;
-struct ExecutionEngine;
-
-struct Identifier
-{
-    QString string;
-    uint hashValue;
-};
-
-
 struct IdentifierHashEntry {
-    const Identifier *identifier;
-    union {
-        int value;
-        void *pointer;
-    };
-    static int get(const IdentifierHashEntry *This, int *) { return This ? This->value : -1; }
-    static bool get(const IdentifierHashEntry *This, bool *) { return This != 0; }
-    static void *get(const IdentifierHashEntry *This, void **) { return This ? This->pointer : 0; }
+    PropertyKey identifier;
+    int value;
 };
 
 struct IdentifierHashData
 {
-    IdentifierHashData(int numBits);
+    IdentifierHashData(IdentifierTable *table, int numBits);
     explicit IdentifierHashData(IdentifierHashData *other);
-    ~IdentifierHashData() {
-        free(entries);
-    }
+    ~IdentifierHashData();
+    void markObjects(MarkStack *markStack) const;
 
     QBasicAtomicInt refCount;
     int alloc;
@@ -98,73 +78,54 @@ struct IdentifierHashData
     IdentifierHashEntry *entries;
 };
 
-struct IdentifierHashBase
+struct IdentifierHash
 {
 
-    IdentifierHashData *d;
+    IdentifierHashData *d = nullptr;
 
-    IdentifierHashBase() : d(0) {}
-    IdentifierHashBase(ExecutionEngine *engine);
-    inline IdentifierHashBase(const IdentifierHashBase &other);
-    inline ~IdentifierHashBase();
-    inline IdentifierHashBase &operator=(const IdentifierHashBase &other);
+    IdentifierHash() {}
+    IdentifierHash(ExecutionEngine *engine);
+    inline IdentifierHash(const IdentifierHash &other);
+    inline ~IdentifierHash();
+    inline IdentifierHash &operator=(const IdentifierHash &other);
 
     bool isEmpty() const { return !d; }
 
     inline int count() const;
-    bool contains(const Identifier *i) const;
-    bool contains(const QString &str) const;
-    bool contains(String *str) const;
 
     void detach();
 
+    void add(const QString &str, int value);
+    void add(Heap::String *str, int value);
+
+    inline int value(const QString &str) const;
+    inline int value(String *str) const;
+    QString findId(int value) const;
+
 protected:
-    IdentifierHashEntry *addEntry(const Identifier *i);
-    const IdentifierHashEntry *lookup(const Identifier *identifier) const;
+    IdentifierHashEntry *addEntry(PropertyKey i);
+    const IdentifierHashEntry *lookup(PropertyKey identifier) const;
     const IdentifierHashEntry *lookup(const QString &str) const;
     const IdentifierHashEntry *lookup(String *str) const;
-    const Identifier *toIdentifier(const QString &str) const;
-    const Identifier *toIdentifier(Heap::String *str) const;
+    const PropertyKey toIdentifier(const QString &str) const;
+    const PropertyKey toIdentifier(Heap::String *str) const;
 };
 
 
-template<typename T>
-struct IdentifierHash : public IdentifierHashBase
-{
-    IdentifierHash()
-        : IdentifierHashBase() {}
-    IdentifierHash(ExecutionEngine *engine)
-        : IdentifierHashBase(engine) {}
-    inline IdentifierHash(const IdentifierHash<T> &other)
-        : IdentifierHashBase(other) {}
-    inline ~IdentifierHash() {}
-    inline IdentifierHash &operator=(const IdentifierHash<T> &other) {
-        IdentifierHashBase::operator =(other);
-        return *this;
-    }
-
-    void add(const QString &str, const T &value);
-    void add(Heap::String *str, const T &value);
-
-    inline T value(const QString &str) const;
-    inline T value(String *str) const;
-    QString findId(T value) const;
-};
-
-inline IdentifierHashBase::IdentifierHashBase(const IdentifierHashBase &other)
+inline IdentifierHash::IdentifierHash(const IdentifierHash &other)
 {
     d = other.d;
     if (d)
         d->refCount.ref();
 }
 
-inline IdentifierHashBase::~IdentifierHashBase()
+inline IdentifierHash::~IdentifierHash()
 {
     if (d && !d->refCount.deref())
         delete d;
 }
 
-IdentifierHashBase &IdentifierHashBase::operator=(const IdentifierHashBase &other)
+IdentifierHash &IdentifierHash::operator=(const IdentifierHash &other)
 {
     if (other.d)
         other.d->refCount.ref();
@@ -174,64 +135,35 @@ IdentifierHashBase &IdentifierHashBase::operator=(const IdentifierHashBase &othe
     return *this;
 }
 
-inline int IdentifierHashBase::count() const
+inline int IdentifierHash::count() const
 {
     return d ? d->size : 0;
 }
 
-inline bool IdentifierHashBase::contains(const Identifier *i) const
-{
-    return lookup(i) != 0;
-}
-
-inline bool IdentifierHashBase::contains(const QString &str) const
-{
-    return lookup(str) != 0;
-}
-
-inline bool IdentifierHashBase::contains(String *str) const
-{
-    return lookup(str) != 0;
-}
-
-template<typename T>
-void IdentifierHash<T>::add(const QString &str, const T &value)
+inline
+void IdentifierHash::add(const QString &str, int value)
 {
     IdentifierHashEntry *e = addEntry(toIdentifier(str));
     e->value = value;
 }
 
-template<typename T>
-void IdentifierHash<T>::add(Heap::String *str, const T &value)
+inline
+void IdentifierHash::add(Heap::String *str, int value)
 {
     IdentifierHashEntry *e = addEntry(toIdentifier(str));
     e->value = value;
 }
 
-template<typename T>
-inline T IdentifierHash<T>::value(const QString &str) const
-{
-    return IdentifierHashEntry::get(lookup(str), (T*)0);
-}
-
-template<typename T>
-inline T IdentifierHash<T>::value(String *str) const
+inline int IdentifierHash::value(const QString &str) const
 {
-    return IdentifierHashEntry::get(lookup(str), (T*)0);
+    const IdentifierHashEntry *e = lookup(str);
+    return e ? e->value : -1;
 }
 
-
-template<typename T>
-QString IdentifierHash<T>::findId(T value) const
+inline int IdentifierHash::value(String *str) const
 {
-    IdentifierHashEntry *e = d->entries;
-    IdentifierHashEntry *end = e + d->alloc;
-    while (e < end) {
-        if (e->identifier && IdentifierHashEntry::get(e, (T*)0) == value)
-            return e->identifier->string;
-        ++e;
-    }
-    return QString();
+    const IdentifierHashEntry *e = lookup(str);
+    return e ? e->value : -1;
 }
 
 }
diff --git a/src/qml/jsruntime/qv4identifiertable.cpp b/src/qml/jsruntime/qv4identifiertable.cpp
index 3def6defbf..e476baa886 100644
--- a/src/qml/jsruntime/qv4identifiertable.cpp
+++ b/src/qml/jsruntime/qv4identifiertable.cpp
@@ -37,6 +37,7 @@
 **
 ****************************************************************************/
 #include "qv4identifiertable_p.h"
+#include "qv4symbol_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -53,44 +54,44 @@ static inline int primeForNumBits(int numBits)
 }
 
 
-IdentifierTable::IdentifierTable(ExecutionEngine *engine)
+IdentifierTable::IdentifierTable(ExecutionEngine *engine, int numBits)
     : engine(engine)
     , size(0)
-    , numBits(8)
+    , numBits(numBits)
 {
     alloc = primeForNumBits(numBits);
-    entries = (Heap::String **)malloc(alloc*sizeof(Heap::String *));
-    memset(entries, 0, alloc*sizeof(Heap::String *));
+    entriesByHash = (Heap::StringOrSymbol **)malloc(alloc*sizeof(Heap::StringOrSymbol *));
+    entriesById = (Heap::StringOrSymbol **)malloc(alloc*sizeof(Heap::StringOrSymbol *));
+    memset(entriesByHash, 0, alloc*sizeof(Heap::String *));
+    memset(entriesById, 0, alloc*sizeof(Heap::String *));
 }
 
 IdentifierTable::~IdentifierTable()
 {
-    for (int i = 0; i < alloc; ++i)
-        if (entries[i])
-            delete entries[i]->identifier;
-    free(entries);
+    free(entriesByHash);
+    free(entriesById);
+    for (auto &h : idHashes)
+        h->identifierTable = nullptr;
 }
 
-void IdentifierTable::addEntry(Heap::String *str)
+void IdentifierTable::addEntry(Heap::StringOrSymbol *str)
 {
     uint hash = str->hashValue();
 
     if (str->subtype == Heap::String::StringType_ArrayIndex)
         return;
 
-    str->identifier = new Identifier;
-    str->identifier->string = str->toQString();
-    str->identifier->hashValue = hash;
+    str->identifier = PropertyKey::fromStringOrSymbol(str);
 
     bool grow = (alloc <= size*2);
 
     if (grow) {
         ++numBits;
         int newAlloc = primeForNumBits(numBits);
-        Heap::String **newEntries = (Heap::String **)malloc(newAlloc*sizeof(Heap::String *));
-        memset(newEntries, 0, newAlloc*sizeof(Heap::String *));
-        for (int i = 0; i < alloc; ++i) {
-            Heap::String *e = entries[i];
+        Heap::StringOrSymbol **newEntries = (Heap::StringOrSymbol **)malloc(newAlloc*sizeof(Heap::String *));
+        memset(newEntries, 0, newAlloc*sizeof(Heap::StringOrSymbol *));
+        for (uint i = 0; i < alloc; ++i) {
+            Heap::StringOrSymbol *e = entriesByHash[i];
             if (!e)
                 continue;
             uint idx = e->stringHash % newAlloc;
@@ -100,17 +101,42 @@ void IdentifierTable::addEntry(Heap::String *str)
             }
             newEntries[idx] = e;
         }
-        free(entries);
-        entries = newEntries;
+        free(entriesByHash);
+        entriesByHash = newEntries;
+
+        newEntries = (Heap::StringOrSymbol **)malloc(newAlloc*sizeof(Heap::String *));
+        memset(newEntries, 0, newAlloc*sizeof(Heap::StringOrSymbol *));
+        for (uint i = 0; i < alloc; ++i) {
+            Heap::StringOrSymbol *e = entriesById[i];
+            if (!e)
+                continue;
+            uint idx = e->identifier.id() % newAlloc;
+            while (newEntries[idx]) {
+                ++idx;
+                idx %= newAlloc;
+            }
+            newEntries[idx] = e;
+        }
+        free(entriesById);
+        entriesById = newEntries;
+
         alloc = newAlloc;
     }
 
     uint idx = hash % alloc;
-    while (entries[idx]) {
+    while (entriesByHash[idx]) {
+        ++idx;
+        idx %= alloc;
+    }
+    entriesByHash[idx] = str;
+
+    idx = str->identifier.id() % alloc;
+    while (entriesById[idx]) {
         ++idx;
         idx %= alloc;
     }
-    entries[idx] = str;
+    entriesById[idx] = str;
+
     ++size;
 }
 
@@ -120,10 +146,16 @@ Heap::String *IdentifierTable::insertString(const QString &s)
 {
     uint subtype;
     uint hash = String::createHashValue(s.constData(), s.length(), &subtype);
+    if (subtype == Heap::String::StringType_ArrayIndex) {
+        Heap::String *str = engine->newString(s);
+        str->stringHash = hash;
+        str->subtype = subtype;
+        return str;
+    }
     uint idx = hash % alloc;
-    while (Heap::String *e = entries[idx]) {
+    while (Heap::StringOrSymbol *e = entriesByHash[idx]) {
         if (e->stringHash == hash && e->toQString() == s)
-            return e;
+            return static_cast<Heap::String *>(e);
         ++idx;
         idx %= alloc;
     }
@@ -135,18 +167,42 @@ Heap::String *IdentifierTable::insertString(const QString &s)
     return str;
 }
 
+Heap::Symbol *IdentifierTable::insertSymbol(const QString &s)
+{
+    Q_ASSERT(s.at(0) == QLatin1Char('@'));
+
+    uint subtype;
+    uint hash = String::createHashValue(s.constData(), s.length(), &subtype);
+    uint idx = hash % alloc;
+    while (Heap::StringOrSymbol *e = entriesByHash[idx]) {
+        if (e->stringHash == hash && e->toQString() == s)
+            return static_cast<Heap::Symbol *>(e);
+        ++idx;
+        idx %= alloc;
+    }
+
+    Heap::Symbol *str = Symbol::create(engine, s);
+    str->stringHash = hash;
+    str->subtype = subtype;
+    addEntry(str);
+    return str;
+
+}
+
 
-Identifier *IdentifierTable::identifierImpl(const Heap::String *str)
+PropertyKey IdentifierTable::asPropertyKeyImpl(const Heap::String *str)
 {
-    if (str->identifier)
+    if (str->identifier.isValid())
         return str->identifier;
     uint hash = str->hashValue();
-    if (str->subtype == Heap::String::StringType_ArrayIndex)
-        return 0;
+    if (str->subtype == Heap::String::StringType_ArrayIndex) {
+        str->identifier = PropertyKey::fromArrayIndex(hash);
+        return str->identifier;
+    }
 
     uint idx = hash % alloc;
-    while (Heap::String *e = entries[idx]) {
-        if (e->stringHash == hash && e->isEqualTo(str)) {
+    while (Heap::StringOrSymbol *e = entriesByHash[idx]) {
+        if (e->stringHash == hash && e->toQString() == str->toQString()) {
             str->identifier = e->identifier;
             return e->identifier;
         }
@@ -158,37 +214,96 @@ Identifier *IdentifierTable::identifierImpl(const Heap::String *str)
     return str->identifier;
 }
 
-Heap::String *IdentifierTable::stringFromIdentifier(Identifier *i)
+Heap::StringOrSymbol *IdentifierTable::resolveId(PropertyKey i) const
 {
-    if (!i)
-        return 0;
+    uint arrayIdx = i.asArrayIndex();
+    if (arrayIdx < UINT_MAX)
+        return engine->newString(QString::number(arrayIdx));
+    if (!i.isValid())
+        return nullptr;
 
-    uint idx = i->hashValue % alloc;
+    uint idx = i.id() % alloc;
     while (1) {
-        Heap::String *e = entries[idx];
-        Q_ASSERT(e);
-        if (e->identifier == i)
+        Heap::StringOrSymbol *e = entriesById[idx];
+        if (!e || e->identifier == i)
             return e;
         ++idx;
         idx %= alloc;
     }
 }
 
-Identifier *IdentifierTable::identifier(const QString &s)
+Heap::String *IdentifierTable::stringForId(PropertyKey i) const
+{
+    Heap::StringOrSymbol *s = resolveId(i);
+    Q_ASSERT(s && s->internalClass->vtable->isString);
+    return static_cast<Heap::String *>(s);
+}
+
+Heap::Symbol *IdentifierTable::symbolForId(PropertyKey i) const
+{
+    Heap::StringOrSymbol *s = resolveId(i);
+    Q_ASSERT(!s || !s->internalClass->vtable->isString);
+    return static_cast<Heap::Symbol *>(s);
+}
+
+void IdentifierTable::markObjects(MarkStack *markStack)
+{
+    for (const auto &h : idHashes)
+        h->markObjects(markStack);
+}
+
+void IdentifierTable::sweep()
+{
+    int freed = 0;
+
+    Heap::StringOrSymbol **newTable = (Heap::StringOrSymbol **)malloc(alloc*sizeof(Heap::String *));
+    memset(newTable, 0, alloc*sizeof(Heap::StringOrSymbol *));
+    memset(entriesById, 0, alloc*sizeof(Heap::StringOrSymbol *));
+    for (uint i = 0; i < alloc; ++i) {
+        Heap::StringOrSymbol *e = entriesByHash[i];
+        if (!e)
+            continue;
+        if (!e->isMarked()) {
+            ++freed;
+            continue;
+        }
+        uint idx = e->hashValue() % alloc;
+        while (newTable[idx]) {
+            ++idx;
+            if (idx == alloc)
+                idx = 0;
+        }
+        newTable[idx] = e;
+
+        idx = e->identifier.id() % alloc;
+        while (entriesById[idx]) {
+            ++idx;
+            if (idx == alloc)
+                idx = 0;
+        }
+        entriesById[idx] = e;
+    }
+    free(entriesByHash);
+    entriesByHash = newTable;
+
+    size -= freed;
+}
+
+PropertyKey IdentifierTable::asPropertyKey(const QString &s)
 {
     return insertString(s)->identifier;
 }
 
-Identifier *IdentifierTable::identifier(const char *s, int len)
+PropertyKey IdentifierTable::asPropertyKey(const char *s, int len)
 {
     uint subtype;
     uint hash = String::createHashValue(s, len, &subtype);
     if (hash == UINT_MAX)
-        return identifier(QString::fromUtf8(s, len));
+        return asPropertyKey(QString::fromUtf8(s, len));
 
     QLatin1String latin(s, len);
     uint idx = hash % alloc;
-    while (Heap::String *e = entries[idx]) {
+    while (Heap::StringOrSymbol *e = entriesByHash[idx]) {
         if (e->stringHash == hash && e->toQString() == latin)
             return e->identifier;
         ++idx;
diff --git a/src/qml/jsruntime/qv4identifiertable_p.h b/src/qml/jsruntime/qv4identifiertable_p.h
index b0b08f1e54..78e2b6620e 100644
--- a/src/qml/jsruntime/qv4identifiertable_p.h
+++ b/src/qml/jsruntime/qv4identifiertable_p.h
@@ -53,55 +53,61 @@
 #include "qv4identifier_p.h"
 #include "qv4string_p.h"
 #include "qv4engine_p.h"
+#include <qset.h>
 #include <limits.h>
 
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-struct IdentifierTable
+struct Q_QML_PRIVATE_EXPORT IdentifierTable
 {
     ExecutionEngine *engine;
 
-    int alloc;
-    int size;
+    uint alloc;
+    uint size;
     int numBits;
-    Heap::String **entries;
+    Heap::StringOrSymbol **entriesByHash;
+    Heap::StringOrSymbol **entriesById;
 
-    void addEntry(Heap::String *str);
+    QSet<IdentifierHashData *> idHashes;
+
+    void addEntry(Heap::StringOrSymbol *str);
 
 public:
 
-    IdentifierTable(ExecutionEngine *engine);
+    IdentifierTable(ExecutionEngine *engine, int numBits = 8);
     ~IdentifierTable();
 
     Heap::String *insertString(const QString &s);
+    Heap::Symbol *insertSymbol(const QString &s);
 
-    Identifier *identifier(const Heap::String *str) {
-        if (str->identifier)
+    PropertyKey asPropertyKey(const Heap::String *str) {
+        if (str->identifier.isValid())
             return str->identifier;
-        return identifierImpl(str);
+        return asPropertyKeyImpl(str);
     }
-    Identifier *identifier(const QV4::String *str) {
-        return identifier(str->d());
+    PropertyKey asPropertyKey(const QV4::String *str) {
+        return asPropertyKey(str->d());
     }
 
-    Identifier *identifier(const QString &s);
-    Identifier *identifier(const char *s, int len);
+    PropertyKey asPropertyKey(const QString &s);
+    PropertyKey asPropertyKey(const char *s, int len);
+
+    PropertyKey asPropertyKeyImpl(const Heap::String *str);
 
-    Identifier *identifierImpl(const Heap::String *str);
+    Heap::StringOrSymbol *resolveId(PropertyKey i) const;
+    Heap::String *stringForId(PropertyKey i) const;
+    Heap::Symbol *symbolForId(PropertyKey i) const;
 
-    Heap::String *stringFromIdentifier(Identifier *i);
+    void markObjects(MarkStack *markStack);
+    void sweep();
 
-    void mark(MarkStack *markStack) {
-        for (int i = 0; i < alloc; ++i) {
-            Heap::String *entry = entries[i];
-            if (!entry || entry->isMarked())
-                continue;
-            entry->setMarkBit();
-            Q_ASSERT(entry->vtable()->markObjects);
-            entry->vtable()->markObjects(entry, markStack);
-        }
+    void addIdentifierHash(IdentifierHashData *h) {
+        idHashes.insert(h);
+    }
+    void removeIdentifierHash(IdentifierHashData *h) {
+        idHashes.remove(h);
     }
 };
 
diff --git a/src/qml/jsruntime/qv4include.cpp b/src/qml/jsruntime/qv4include.cpp
index 1edb7d3914..36569b0a60 100644
--- a/src/qml/jsruntime/qv4include.cpp
+++ b/src/qml/jsruntime/qv4include.cpp
@@ -39,6 +39,7 @@
 
 #include "qv4include_p.h"
 #include "qv4scopedvalue_p.h"
+#include "qv4jscall_p.h"
 
 #include <QtQml/qjsengine.h>
 #if QT_CONFIG(qml_network)
@@ -60,7 +61,7 @@ QV4Include::QV4Include(const QUrl &url, QV4::ExecutionEngine *engine,
                        QV4::QmlContext *qmlContext, const QV4::Value &callback)
     : v4(engine), m_url(url)
 #if QT_CONFIG(qml_network)
-    , m_redirectCount(0), m_network(0) , m_reply(0)
+    , m_redirectCount(0), m_network(nullptr) , m_reply(nullptr)
 #endif
 {
     if (qmlContext)
@@ -87,11 +88,12 @@ QV4Include::~QV4Include()
 {
 #if QT_CONFIG(qml_network)
     delete m_reply;
-    m_reply = 0;
+    m_reply = nullptr;
 #endif
 }
 
-QV4::ReturnedValue QV4Include::resultValue(QV4::ExecutionEngine *v4, Status status)
+QV4::ReturnedValue QV4Include::resultValue(QV4::ExecutionEngine *v4, Status status,
+                                           const QString &statusText)
 {
     QV4::Scope scope(v4);
 
@@ -99,11 +101,13 @@ QV4::ReturnedValue QV4Include::resultValue(QV4::ExecutionEngine *v4, Status stat
     QV4::ScopedObject o(scope, v4->newObject());
     QV4::ScopedString s(scope);
     QV4::ScopedValue v(scope);
-    o->put((s = v4->newString(QStringLiteral("OK"))), (v = QV4::Primitive::fromInt32(Ok)));
-    o->put((s = v4->newString(QStringLiteral("LOADING"))), (v = QV4::Primitive::fromInt32(Loading)));
-    o->put((s = v4->newString(QStringLiteral("NETWORK_ERROR"))), (v = QV4::Primitive::fromInt32(NetworkError)));
-    o->put((s = v4->newString(QStringLiteral("EXCEPTION"))), (v = QV4::Primitive::fromInt32(Exception)));
-    o->put((s = v4->newString(QStringLiteral("status"))), (v = QV4::Primitive::fromInt32(status)));
+    o->put((s = v4->newString(QStringLiteral("OK"))), (v = QV4::Value::fromInt32(Ok)));
+    o->put((s = v4->newString(QStringLiteral("LOADING"))), (v = QV4::Value::fromInt32(Loading)));
+    o->put((s = v4->newString(QStringLiteral("NETWORK_ERROR"))), (v = QV4::Value::fromInt32(NetworkError)));
+    o->put((s = v4->newString(QStringLiteral("EXCEPTION"))), (v = QV4::Value::fromInt32(Exception)));
+    o->put((s = v4->newString(QStringLiteral("status"))), (v = QV4::Value::fromInt32(status)));
+    if (!statusText.isEmpty())
+        o->put((s = v4->newString(QStringLiteral("statusText"))), (v = v4->newString(statusText)));
 
     return o.asReturnedValue();
 }
@@ -118,10 +122,10 @@ void QV4Include::callback(const QV4::Value &callback, const QV4::Value &status)
     if (!f)
         return;
 
-    QV4::ScopedCallData callData(scope, 1);
-    callData->thisObject = v4->globalObject->asReturnedValue();
-    callData->args[0] = status;
-    f->call(scope, callData);
+    QV4::JSCallData jsCallData(scope, 1);
+    *jsCallData->thisObject = v4->globalObject->asReturnedValue();
+    jsCallData->args[0] = status;
+    f->call(jsCallData);
     if (scope.hasException())
         scope.engine->catchException();
 }
@@ -162,27 +166,27 @@ void QV4Include::finished()
         QmlIR::Document::removeScriptPragmas(code);
 
         QV4::Scoped<QV4::QmlContext> qml(scope, m_qmlContext.value());
-        QV4::Script script(v4, qml, code, m_url.toString());
+        QV4::Script script(v4, qml, /*parse as QML binding*/false, code, m_url.toString());
 
         script.parse();
         if (!scope.engine->hasException)
             script.run();
         if (scope.engine->hasException) {
             QV4::ScopedValue ex(scope, scope.engine->catchException());
-            resultObj->put(status, QV4::ScopedValue(scope, QV4::Primitive::fromInt32(Exception)));
+            resultObj->put(status, QV4::ScopedValue(scope, QV4::Value::fromInt32(Exception)));
             QV4::ScopedString exception(scope, v4->newString(QStringLiteral("exception")));
             resultObj->put(exception, ex);
         } else {
-            resultObj->put(status, QV4::ScopedValue(scope, QV4::Primitive::fromInt32(Ok)));
+            resultObj->put(status, QV4::ScopedValue(scope, QV4::Value::fromInt32(Ok)));
         }
     } else {
-        resultObj->put(status, QV4::ScopedValue(scope, QV4::Primitive::fromInt32(NetworkError)));
+        resultObj->put(status, QV4::ScopedValue(scope, QV4::Value::fromInt32(NetworkError)));
     }
 #else
     QV4::Scope scope(v4);
     QV4::ScopedObject resultObj(scope, m_resultObject.value());
     QV4::ScopedString status(scope, v4->newString(QStringLiteral("status")));
-    resultObj->put(status, QV4::ScopedValue(scope, QV4::Primitive::fromInt32(NetworkError)));
+    resultObj->put(status, QV4::ScopedValue(scope, QV4::Value::fromInt32(NetworkError)));
 #endif // qml_network
 
     QV4::ScopedValue cb(scope, m_callbackFunction.value());
@@ -195,22 +199,23 @@ void QV4Include::finished()
 /*
     Documented in qv8engine.cpp
 */
-void QV4Include::method_include(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+QV4::ReturnedValue QV4Include::method_include(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *argv, int argc)
 {
-    if (!callData->argc)
+    QV4::Scope scope(b);
+    if (!argc)
         RETURN_UNDEFINED();
 
     QQmlContextData *context = scope.engine->callingQmlContext();
 
-    if (!context || !context->isJSContext)
+    if ((!context || !context->isJSContext) && scope.engine->qmlEngine())
         RETURN_RESULT(scope.engine->throwError(QString::fromUtf8("Qt.include(): Can only be called from JavaScript files")));
 
-    QV4::ScopedValue callbackFunction(scope, QV4::Primitive::undefinedValue());
-    if (callData->argc >= 2 && callData->args[1].as<QV4::FunctionObject>())
-        callbackFunction = callData->args[1];
+    QV4::ScopedValue callbackFunction(scope, QV4::Value::undefinedValue());
+    if (argc >= 2 && argv[1].as<QV4::FunctionObject>())
+        callbackFunction = argv[1];
 
 #if QT_CONFIG(qml_network)
-    QUrl url(scope.engine->resolvedUrl(callData->args[0].toQStringNoThrow()));
+    QUrl url(scope.engine->resolvedUrl(argv[0].toQStringNoThrow()));
     if (scope.engine->qmlEngine() && scope.engine->qmlEngine()->urlInterceptor())
         url = scope.engine->qmlEngine()->urlInterceptor()->intercept(url, QQmlAbstractUrlInterceptor::JavaScriptFile);
 
@@ -225,21 +230,8 @@ void QV4Include::method_include(const QV4::BuiltinFunction *, QV4::Scope &scope,
 
     } else {
         QScopedPointer<QV4::Script> script;
-
-        if (const QQmlPrivate::CachedQmlUnit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(url)) {
-            QV4::CompiledData::CompilationUnit *jsUnit = cachedUnit->createCompilationUnit();
-            script.reset(new QV4::Script(scope.engine, qmlcontext, jsUnit));
-        } else {
-            QFile f(localFile);
-
-            if (f.open(QIODevice::ReadOnly)) {
-                QByteArray data = f.readAll();
-                QString code = QString::fromUtf8(data);
-                QmlIR::Document::removeScriptPragmas(code);
-
-                script.reset(new QV4::Script(scope.engine, qmlcontext, code, url.toString()));
-            }
-        }
+        QString error;
+        script.reset(QV4::Script::createFromFileOrCache(scope.engine, qmlcontext, localFile, url, &error));
 
         if (!script.isNull()) {
             script->parse();
@@ -254,19 +246,19 @@ void QV4Include::method_include(const QV4::BuiltinFunction *, QV4::Scope &scope,
                 result = resultValue(scope.engine, Ok);
             }
         } else {
-            result = resultValue(scope.engine, NetworkError);
+            result = resultValue(scope.engine, NetworkError, error);
         }
 
         callback(callbackFunction, result);
     }
 
-    scope.result = result;
 #else
     QV4::ScopedValue result(scope);
     result = resultValue(scope.engine, NetworkError);
     callback(callbackFunction, result);
-    scope.result = result;
 #endif
+
+    return result->asReturnedValue();
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4include_p.h b/src/qml/jsruntime/qv4include_p.h
index 5908d6bfde..70ccfbf223 100644
--- a/src/qml/jsruntime/qv4include_p.h
+++ b/src/qml/jsruntime/qv4include_p.h
@@ -77,7 +77,7 @@ public:
         Exception = 3
     };
 
-    static void method_include(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue method_include(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 
 private Q_SLOTS:
     void finished();
@@ -88,7 +88,8 @@ private:
 
     QV4::ReturnedValue result();
 
-    static QV4::ReturnedValue resultValue(QV4::ExecutionEngine *v4, Status status = Loading);
+    static QV4::ReturnedValue resultValue(QV4::ExecutionEngine *v4, Status status = Loading,
+                                          const QString &statusText = QString());
     static void callback(const QV4::Value &callback, const QV4::Value &status);
 
     QV4::ExecutionEngine *v4;
diff --git a/src/qml/jsruntime/qv4internalclass.cpp b/src/qml/jsruntime/qv4internalclass.cpp
index 603da1df7b..ddb8542e07 100644
--- a/src/qml/jsruntime/qv4internalclass.cpp
+++ b/src/qml/jsruntime/qv4internalclass.cpp
@@ -47,7 +47,7 @@
 
 QT_BEGIN_NAMESPACE
 
-using namespace QV4;
+namespace QV4 {
 
 static const uchar prime_deltas[] = {
     0,  0,  1,  3,  1,  5,  3,  3,  1,  9,  7,  5,  3,  9, 25,  3,
@@ -74,27 +74,11 @@ void PropertyHash::addEntry(const PropertyHash::Entry &entry, int classSize)
     // fill up to max 50%
     bool grow = (d->alloc <= d->size*2);
 
-    if (classSize < d->size || grow) {
-        PropertyHashData *dd = new PropertyHashData(grow ? d->numBits + 1 : d->numBits);
-        for (int i = 0; i < d->alloc; ++i) {
-            const Entry &e = d->entries[i];
-            if (!e.identifier || e.index >= static_cast<unsigned>(classSize))
-                continue;
-            uint idx = e.identifier->hashValue % dd->alloc;
-            while (dd->entries[idx].identifier) {
-                ++idx;
-                idx %= dd->alloc;
-            }
-            dd->entries[idx] = e;
-        }
-        dd->size = classSize;
-        Q_ASSERT(d->refCount > 1);
-        --d->refCount;
-        d = dd;
-    }
+    if (classSize < d->size || grow)
+        detach(grow, classSize);
 
-    uint idx = entry.identifier->hashValue % d->alloc;
-    while (d->entries[idx].identifier) {
+    uint idx = entry.identifier.id() % d->alloc;
+    while (d->entries[idx].identifier.isValid()) {
         ++idx;
         idx %= d->alloc;
     }
@@ -102,69 +86,205 @@ void PropertyHash::addEntry(const PropertyHash::Entry &entry, int classSize)
     ++d->size;
 }
 
+int PropertyHash::removeIdentifier(PropertyKey identifier, int classSize)
+{
+    int val = -1;
+    PropertyHashData *dd = new PropertyHashData(d->numBits);
+    for (int i = 0; i < d->alloc; ++i) {
+        const Entry &e = d->entries[i];
+        if (!e.identifier.isValid() || e.index >= static_cast<unsigned>(classSize))
+            continue;
+        if (e.identifier == identifier) {
+            val = e.index;
+            continue;
+        }
+        uint idx = e.identifier.id() % dd->alloc;
+        while (dd->entries[idx].identifier.isValid()) {
+            ++idx;
+            idx %= dd->alloc;
+        }
+        dd->entries[idx] = e;
+    }
+    dd->size = classSize;
+    if (!--d->refCount)
+        delete d;
+    d = dd;
 
-InternalClass::InternalClass(ExecutionEngine *engine)
-    : engine(engine)
-    , vtable(0)
-    , prototype(0)
-    , m_sealed(0)
-    , m_frozen(0)
-    , size(0)
-    , extensible(true)
+    Q_ASSERT(val != -1);
+    return val;
+}
+
+void PropertyHash::detach(bool grow, int classSize)
 {
+    if (d->refCount == 1 && !grow)
+        return;
+
+    PropertyHashData *dd = new PropertyHashData(grow ? d->numBits + 1 : d->numBits);
+    for (int i = 0; i < d->alloc; ++i) {
+        const Entry &e = d->entries[i];
+        if (!e.identifier.isValid() || e.index >= static_cast<unsigned>(classSize))
+            continue;
+        uint idx = e.identifier.id() % dd->alloc;
+        while (dd->entries[idx].identifier.isValid()) {
+            ++idx;
+            idx %= dd->alloc;
+        }
+        dd->entries[idx] = e;
+    }
+    dd->size = classSize;
+    if (!--d->refCount)
+        delete d;
+    d = dd;
 }
 
 
-InternalClass::InternalClass(const QV4::InternalClass &other)
-    : QQmlJS::Managed()
-    , engine(other.engine)
-    , vtable(other.vtable)
-    , prototype(other.prototype)
-    , propertyTable(other.propertyTable)
-    , nameMap(other.nameMap)
-    , propertyData(other.propertyData)
-    , m_sealed(0)
-    , m_frozen(0)
-    , size(other.size)
-    , extensible(other.extensible)
+SharedInternalClassDataPrivate<PropertyKey>::SharedInternalClassDataPrivate(const SharedInternalClassDataPrivate<PropertyKey> &other)
+    : refcount(1),
+      engine(other.engine),
+      data(nullptr)
 {
-    Q_ASSERT(extensible);
+    if (other.alloc()) {
+        int s = other.size();
+        data = MemberData::allocate(engine, other.alloc(), other.data);
+        setSize(s);
+    }
 }
 
-static void insertHoleIntoPropertyData(Object *object, int idx)
+SharedInternalClassDataPrivate<PropertyKey>::SharedInternalClassDataPrivate(const SharedInternalClassDataPrivate<PropertyKey> &other,
+                                                                            uint pos, PropertyKey value)
+    : refcount(1),
+      engine(other.engine)
 {
-    Heap::Object *o = object->d();
-    ExecutionEngine *v4 = o->internalClass->engine;
-    int size = o->internalClass->size;
-    for (int i = size - 1; i > idx; --i)
-        o->setProperty(v4, i, *o->propertyData(i - 1));
+    data = MemberData::allocate(engine, other.alloc(), nullptr);
+    memcpy(data, other.data, sizeof(Heap::MemberData) - sizeof(Value) + pos*sizeof(Value));
+    data->values.size = pos + 1;
+    data->values.set(engine, pos, Value::fromReturnedValue(value.id()));
 }
 
-static void removeFromPropertyData(Object *object, int idx, bool accessor = false)
+void SharedInternalClassDataPrivate<PropertyKey>::grow()
 {
-    Heap::Object *o = object->d();
-    ExecutionEngine *v4 = o->internalClass->engine;
-    int size = o->internalClass->size;
-    for (int i = idx; i < size; ++i)
-        o->setProperty(v4, i, *o->propertyData(i + (accessor ? 2 : 1)));
+    uint a = alloc() * 2;
+    int s = size();
+    data = MemberData::allocate(engine, a, data);
+    setSize(s);
+    Q_ASSERT(alloc() >= a);
 }
 
-void InternalClass::changeMember(Object *object, String *string, PropertyAttributes data, uint *index)
+uint SharedInternalClassDataPrivate<PropertyKey>::alloc() const
 {
-    uint idx;
-    InternalClass *oldClass = object->internalClass();
-    InternalClass *newClass = oldClass->changeMember(string->identifier(), data, &idx);
-    if (index)
-        *index = idx;
+    return data ? data->values.alloc : 0;
+}
 
-    object->setInternalClass(newClass);
-    if (newClass->size > oldClass->size) {
-        Q_ASSERT(newClass->size == oldClass->size + 1);
-        insertHoleIntoPropertyData(object, idx);
-    } else if (newClass->size < oldClass->size) {
-        Q_ASSERT(newClass->size == oldClass->size - 1);
-        removeFromPropertyData(object, idx + 1);
+uint SharedInternalClassDataPrivate<PropertyKey>::size() const
+{
+    return data ? data->values.size : 0;
+}
+
+void SharedInternalClassDataPrivate<PropertyKey>::setSize(uint s)
+{
+    Q_ASSERT(data && s <= alloc());
+    data->values.size = s;
+}
+
+PropertyKey SharedInternalClassDataPrivate<PropertyKey>::at(uint i)
+{
+    Q_ASSERT(data && i < size());
+    return PropertyKey::fromId(data->values.values[i].rawValue());
+}
+
+void SharedInternalClassDataPrivate<PropertyKey>::set(uint i, PropertyKey t)
+{
+    Q_ASSERT(data && i < size());
+    data->values.values[i].rawValueRef() = t.id();
+}
+
+void SharedInternalClassDataPrivate<PropertyKey>::mark(MarkStack *s)
+{
+    if (data)
+        data->mark(s);
+}
+
+
+
+namespace Heap {
+
+void InternalClass::init(ExecutionEngine *engine)
+{
+    Base::init();
+    new (&propertyTable) PropertyHash();
+    new (&nameMap) SharedInternalClassData<PropertyKey>(engine);
+    new (&propertyData) SharedInternalClassData<PropertyAttributes>(engine);
+    new (&transitions) std::vector<Transition>();
+
+    this->engine = engine;
+    vtable = QV4::InternalClass::staticVTable();
+//    prototype = nullptr;
+//    parent = nullptr;
+//    size = 0;
+    extensible = true;
+    isFrozen = false;
+    isSealed = false;
+    isUsedAsProto = false;
+    protoId = engine->newProtoId();
+
+    // Also internal classes need an internal class pointer. Simply make it point to itself
+    internalClass.set(engine, this);
+}
+
+
+void InternalClass::init(Heap::InternalClass *other)
+{
+    Base::init();
+    Q_ASSERT(!other->isFrozen);
+    new (&propertyTable) PropertyHash(other->propertyTable);
+    new (&nameMap) SharedInternalClassData<PropertyKey>(other->nameMap);
+    new (&propertyData) SharedInternalClassData<PropertyAttributes>(other->propertyData);
+    new (&transitions) std::vector<Transition>();
+
+    engine = other->engine;
+    vtable = other->vtable;
+    prototype = other->prototype;
+    parent = other;
+    size = other->size;
+    extensible = other->extensible;
+    isSealed = other->isSealed;
+    isFrozen = other->isFrozen;
+    isUsedAsProto = other->isUsedAsProto;
+    protoId = engine->newProtoId();
+
+    internalClass.set(engine, other->internalClass);
+}
+
+void InternalClass::destroy()
+{
+#ifndef QT_NO_DEBUG
+    for (const auto &t : transitions) {
+        Q_ASSERT(!t.lookup || !t.lookup->isMarked());
     }
+#endif
+    if (parent && parent->engine && parent->isMarked())
+        parent->removeChildEntry(this);
+
+    propertyTable.~PropertyHash();
+    nameMap.~SharedInternalClassData<PropertyKey>();
+    propertyData.~SharedInternalClassData<PropertyAttributes>();
+    transitions.~vector<Transition>();
+    engine = nullptr;
+    Base::destroy();
+}
+
+QString InternalClass::keyAt(uint index) const
+{
+    return nameMap.at(index).toQString();
+}
+
+void InternalClass::changeMember(QV4::Object *object, PropertyKey id, PropertyAttributes data, InternalClassEntry *entry)
+{
+    Q_ASSERT(id.isStringOrSymbol());
+
+    Heap::InternalClass *oldClass = object->internalClass();
+    Heap::InternalClass *newClass = oldClass->changeMember(id, data, entry);
+    object->setInternalClass(newClass);
 }
 
 InternalClassTransition &InternalClass::lookupOrInsertTransition(const InternalClassTransition &t)
@@ -178,44 +298,66 @@ InternalClassTransition &InternalClass::lookupOrInsertTransition(const InternalC
     }
 }
 
-InternalClass *InternalClass::changeMember(Identifier *identifier, PropertyAttributes data, uint *index)
+static void addDummyEntry(InternalClass *newClass, PropertyHash::Entry e)
+{
+    // add a dummy entry, since we need two entries for accessors
+    newClass->propertyTable.addEntry(e, newClass->size);
+    newClass->nameMap.add(newClass->size, PropertyKey::invalid());
+    newClass->propertyData.add(newClass->size, PropertyAttributes());
+    ++newClass->size;
+}
+
+Heap::InternalClass *InternalClass::changeMember(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry)
 {
-    data.resolve();
-    uint idx = find(identifier);
+    if (!data.isEmpty())
+        data.resolve();
+    PropertyHash::Entry *e = findEntry(identifier);
+    Q_ASSERT(e && e->index != UINT_MAX);
+    uint idx = e->index;
     Q_ASSERT(idx != UINT_MAX);
 
-    if (index)
-        *index = idx;
+    if (entry) {
+        entry->index = idx;
+        entry->setterIndex = e->setterIndex;
+        entry->attributes = data;
+    }
 
     if (data == propertyData.at(idx))
-        return this;
+        return static_cast<Heap::InternalClass *>(this);
 
-    Transition temp = { { identifier }, nullptr, (int)data.flags() };
+    Transition temp = { { identifier }, nullptr, int(data.all()) };
     Transition &t = lookupOrInsertTransition(temp);
     if (t.lookup)
         return t.lookup;
 
     // create a new class and add it to the tree
-    InternalClass *newClass = engine->internalClasses[EngineBase::Class_Empty]->changeVTable(vtable);
-    newClass = newClass->changePrototype(prototype);
-    for (uint i = 0; i < size; ++i) {
-        if (i == idx) {
-            newClass = newClass->addMember(nameMap.at(i), data);
-        } else if (!propertyData.at(i).isEmpty()) {
-            newClass = newClass->addMember(nameMap.at(i), propertyData.at(i));
-        }
+    Heap::InternalClass *newClass = engine->newClass(this);
+    if (data.isAccessor() && e->setterIndex == UINT_MAX) {
+        Q_ASSERT(!propertyData.at(idx).isAccessor());
+
+        // add a dummy entry for the accessor
+        entry->setterIndex = newClass->size;
+        e->setterIndex = newClass->size;
+        addDummyEntry(newClass, *e);
     }
 
+    newClass->propertyData.set(idx, data);
+
     t.lookup = newClass;
     Q_ASSERT(t.lookup);
     return newClass;
 }
 
-InternalClass *InternalClass::changePrototypeImpl(Heap::Object *proto)
+Heap::InternalClass *InternalClass::changePrototypeImpl(Heap::Object *proto)
 {
+    Scope scope(engine);
+    ScopedValue protectThis(scope, this);
+    if (proto)
+        proto->setUsedAsProto();
     Q_ASSERT(prototype != proto);
+    Q_ASSERT(!proto || proto->internalClass->isUsedAsProto);
 
-    Transition temp = { { nullptr }, 0, Transition::PrototypeChange };
+    Transition temp = { { PropertyKey::invalid() }, nullptr, Transition::PrototypeChange };
     temp.prototype = proto;
 
     Transition &t = lookupOrInsertTransition(temp);
@@ -223,28 +365,19 @@ InternalClass *InternalClass::changePrototypeImpl(Heap::Object *proto)
         return t.lookup;
 
     // create a new class and add it to the tree
-    InternalClass *newClass;
-    if (!size && !prototype) {
-        newClass = engine->newClass(*this);
-        newClass->prototype = proto;
-    } else {
-        newClass = engine->internalClasses[EngineBase::Class_Empty]->changeVTable(vtable);
-        newClass = newClass->changePrototype(proto);
-        for (uint i = 0; i < size; ++i) {
-            if (!propertyData.at(i).isEmpty())
-                newClass = newClass->addMember(nameMap.at(i), propertyData.at(i));
-        }
-    }
+    Heap::InternalClass *newClass = engine->newClass(this);
+    newClass->prototype = proto;
 
     t.lookup = newClass;
+
     return newClass;
 }
 
-InternalClass *InternalClass::changeVTableImpl(const VTable *vt)
+Heap::InternalClass *InternalClass::changeVTableImpl(const VTable *vt)
 {
     Q_ASSERT(vtable != vt);
 
-    Transition temp = { { nullptr }, nullptr, Transition::VTableChange };
+    Transition temp = { { PropertyKey::invalid() }, nullptr, Transition::VTableChange };
     temp.vtable = vt;
 
     Transition &t = lookupOrInsertTransition(temp);
@@ -252,18 +385,8 @@ InternalClass *InternalClass::changeVTableImpl(const VTable *vt)
         return t.lookup;
 
     // create a new class and add it to the tree
-    InternalClass *newClass;
-    if (this == engine->internalClasses[EngineBase::Class_Empty]) {
-        newClass = engine->newClass(*this);
-        newClass->vtable = vt;
-    } else {
-        newClass = engine->internalClasses[EngineBase::Class_Empty]->changeVTable(vt);
-        newClass = newClass->changePrototype(prototype);
-        for (uint i = 0; i < size; ++i) {
-            if (!propertyData.at(i).isEmpty())
-                newClass = newClass->addMember(nameMap.at(i), propertyData.at(i));
-        }
-    }
+    Heap::InternalClass *newClass = engine->newClass(this);
+    newClass->vtable = vt;
 
     t.lookup = newClass;
     Q_ASSERT(t.lookup);
@@ -271,17 +394,17 @@ InternalClass *InternalClass::changeVTableImpl(const VTable *vt)
     return newClass;
 }
 
-InternalClass *InternalClass::nonExtensible()
+Heap::InternalClass *InternalClass::nonExtensible()
 {
     if (!extensible)
         return this;
 
-    Transition temp = { { nullptr }, nullptr, Transition::NotExtensible};
+    Transition temp = { { PropertyKey::invalid() }, nullptr, Transition::NotExtensible};
     Transition &t = lookupOrInsertTransition(temp);
     if (t.lookup)
         return t.lookup;
 
-    InternalClass *newClass = engine->newClass(*this);
+    Heap::InternalClass *newClass = engine->newClass(this);
     newClass->extensible = false;
 
     t.lookup = newClass;
@@ -289,214 +412,261 @@ InternalClass *InternalClass::nonExtensible()
     return newClass;
 }
 
-void InternalClass::addMember(Object *object, String *string, PropertyAttributes data, uint *index)
+void InternalClass::addMember(QV4::Object *object, PropertyKey id, PropertyAttributes data, InternalClassEntry *entry)
 {
-    data.resolve();
-    object->internalClass()->engine->identifierTable->identifier(string);
-    if (object->internalClass()->propertyTable.lookup(string->d()->identifier) < object->internalClass()->size) {
-        changeMember(object, string, data, index);
+    Q_ASSERT(id.isStringOrSymbol());
+    if (!data.isEmpty())
+        data.resolve();
+    PropertyHash::Entry *e = object->internalClass()->findEntry(id);
+    if (e) {
+        changeMember(object, id, data, entry);
         return;
     }
 
-    uint idx;
-    InternalClass *newClass = object->internalClass()->addMemberImpl(string->identifier(), data, &idx);
-    if (index)
-        *index = idx;
-
+    Heap::InternalClass *newClass = object->internalClass()->addMemberImpl(id, data, entry);
     object->setInternalClass(newClass);
 }
 
-InternalClass *InternalClass::addMember(String *string, PropertyAttributes data, uint *index)
+Heap::InternalClass *InternalClass::addMember(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry)
 {
-    engine->identifierTable->identifier(string);
-    return addMember(string->identifier(), data, index);
-}
+    Q_ASSERT(identifier.isStringOrSymbol());
+    if (!data.isEmpty())
+        data.resolve();
 
-InternalClass *InternalClass::addMember(Identifier *identifier, PropertyAttributes data, uint *index)
-{
-    data.resolve();
+    PropertyHash::Entry *e = findEntry(identifier);
+    if (e)
+        return changeMember(identifier, data, entry);
 
-    if (propertyTable.lookup(identifier) < size)
-        return changeMember(identifier, data, index);
-
-    return addMemberImpl(identifier, data, index);
+    return addMemberImpl(identifier, data, entry);
 }
 
-InternalClass *InternalClass::addMemberImpl(Identifier *identifier, PropertyAttributes data, uint *index)
+Heap::InternalClass *InternalClass::addMemberImpl(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry)
 {
     Transition temp = { { identifier }, nullptr, (int)data.flags() };
     Transition &t = lookupOrInsertTransition(temp);
 
-    if (index)
-        *index = size;
+    if (entry) {
+        entry->index = size;
+        entry->setterIndex = data.isAccessor() ? size + 1 : UINT_MAX;
+        entry->attributes = data;
+    }
 
     if (t.lookup)
         return t.lookup;
 
     // create a new class and add it to the tree
-    InternalClass *newClass = engine->newClass(*this);
-    PropertyHash::Entry e = { identifier, newClass->size };
+    Scope scope(engine);
+    Scoped<QV4::InternalClass> ic(scope, engine->newClass(this));
+    InternalClass *newClass = ic->d();
+    PropertyHash::Entry e = { identifier, newClass->size, data.isAccessor() ? newClass->size + 1 : UINT_MAX };
     newClass->propertyTable.addEntry(e, newClass->size);
 
     newClass->nameMap.add(newClass->size, identifier);
     newClass->propertyData.add(newClass->size, data);
     ++newClass->size;
-    if (data.isAccessor()) {
-        // add a dummy entry, since we need two entries for accessors
-        newClass->propertyTable.addEntry(e, newClass->size);
-        newClass->nameMap.add(newClass->size, 0);
-        newClass->propertyData.add(newClass->size, PropertyAttributes());
-        ++newClass->size;
-    }
+    if (data.isAccessor())
+        addDummyEntry(newClass, e);
 
     t.lookup = newClass;
     Q_ASSERT(t.lookup);
     return newClass;
 }
 
-void InternalClass::removeMember(Object *object, Identifier *id)
+void InternalClass::removeChildEntry(InternalClass *child)
 {
-    InternalClass *oldClass = object->internalClass();
-    uint propIdx = oldClass->propertyTable.lookup(id);
-    Q_ASSERT(propIdx < oldClass->size);
-
-    Transition temp = { { id }, nullptr, -1 };
-    Transition &t = object->internalClass()->lookupOrInsertTransition(temp);
-
-    bool accessor = oldClass->propertyData.at(propIdx).isAccessor();
-
-    if (t.lookup) {
-        object->setInternalClass(t.lookup);
-    } else {
-        // create a new class and add it to the tree
-        InternalClass *newClass = oldClass->engine->internalClasses[EngineBase::Class_Empty]->changeVTable(oldClass->vtable);
-        newClass = newClass->changePrototype(oldClass->prototype);
-        for (uint i = 0; i < oldClass->size; ++i) {
-            if (i == propIdx)
-                continue;
-            if (!oldClass->propertyData.at(i).isEmpty())
-                newClass = newClass->addMember(oldClass->nameMap.at(i), oldClass->propertyData.at(i));
+    Q_ASSERT(engine);
+    for (auto &t : transitions) {
+        if (t.lookup == child) {
+            t.lookup = nullptr;
+            return;
         }
-        object->setInternalClass(newClass);
     }
+    Q_UNREACHABLE();
 
-    Q_ASSERT(object->internalClass()->size == oldClass->size - (accessor ? 2 : 1));
-
-    // remove the entry in the property data
-    removeFromPropertyData(object, propIdx, accessor);
-
-    t.lookup = object->internalClass();
-    Q_ASSERT(t.lookup);
 }
 
-uint QV4::InternalClass::find(const String *string)
+void InternalClass::removeMember(QV4::Object *object, PropertyKey identifier)
 {
-    engine->identifierTable->identifier(string);
-    const Identifier *id = string->d()->identifier;
+#ifndef QT_NO_DEBUG
+    Heap::InternalClass *oldClass = object->internalClass();
+    Q_ASSERT(oldClass->findEntry(identifier) != nullptr);
+#endif
 
-    uint index = propertyTable.lookup(id);
-    if (index < size)
-        return index;
+    changeMember(object, identifier, Attr_Invalid);
 
-    return UINT_MAX;
+#ifndef QT_NO_DEBUG
+    // we didn't remove the data slot, just made it inaccessible
+    Q_ASSERT(object->internalClass()->size == oldClass->size);
+#endif
 }
 
-InternalClass *InternalClass::sealed()
+Heap::InternalClass *InternalClass::sealed()
 {
-    if (m_sealed)
-        return m_sealed;
+    if (isSealed)
+        return this;
+
+    bool alreadySealed = !extensible;
+    for (uint i = 0; i < size; ++i) {
+        PropertyAttributes attrs = propertyData.at(i);
+        if (attrs.isEmpty())
+            continue;
+        if (attrs.isConfigurable()) {
+            alreadySealed = false;
+            break;
+        }
+    }
+
+    if (alreadySealed) {
+        isSealed = true;
+        return this;
+    }
+
+    Transition temp = { { PropertyKey::invalid() }, nullptr, InternalClassTransition::Sealed };
+    Transition &t = lookupOrInsertTransition(temp);
+
+    if (t.lookup) {
+        Q_ASSERT(t.lookup && t.lookup->isSealed);
+        return t.lookup;
+    }
+
+    Scope scope(engine);
+    Scoped<QV4::InternalClass> ic(scope, engine->newClass(this));
+    Heap::InternalClass *s = ic->d();
 
-    m_sealed = engine->internalClasses[EngineBase::Class_Empty]->changeVTable(vtable);
-    m_sealed = m_sealed->changePrototype(prototype);
     for (uint i = 0; i < size; ++i) {
         PropertyAttributes attrs = propertyData.at(i);
         if (attrs.isEmpty())
             continue;
         attrs.setConfigurable(false);
-        m_sealed = m_sealed->addMember(nameMap.at(i), attrs);
+        s->propertyData.set(i, attrs);
     }
-    m_sealed = m_sealed->nonExtensible();
+    s->extensible = false;
+    s->isSealed = true;
 
-    m_sealed->m_sealed = m_sealed;
-    return m_sealed;
+    t.lookup = s;
+    return s;
 }
 
-InternalClass *InternalClass::frozen()
+Heap::InternalClass *InternalClass::frozen()
 {
-    if (m_frozen)
-        return m_frozen;
+    if (isFrozen)
+        return this;
+
+    bool alreadyFrozen = !extensible;
+    for (uint i = 0; i < size; ++i) {
+        PropertyAttributes attrs = propertyData.at(i);
+        if (attrs.isEmpty())
+            continue;
+        if ((attrs.isData() && attrs.isWritable()) || attrs.isConfigurable()) {
+            alreadyFrozen = false;
+            break;
+        }
+    }
+
+    if (alreadyFrozen) {
+        isSealed = true;
+        isFrozen = true;
+        return this;
+    }
 
-    m_frozen = propertiesFrozen();
-    m_frozen = m_frozen->nonExtensible();
+    Transition temp = { { PropertyKey::invalid() }, nullptr, InternalClassTransition::Frozen };
+    Transition &t = lookupOrInsertTransition(temp);
 
-    m_frozen->m_frozen = m_frozen;
-    m_frozen->m_sealed = m_frozen;
-    return m_frozen;
+    if (t.lookup) {
+        Q_ASSERT(t.lookup && t.lookup->isSealed && t.lookup->isFrozen);
+        return t.lookup;
+    }
+
+    Scope scope(engine);
+    Scoped<QV4::InternalClass> ic(scope, engine->newClass(this));
+    Heap::InternalClass *f = ic->d();
+
+    for (uint i = 0; i < size; ++i) {
+        PropertyAttributes attrs = propertyData.at(i);
+        if (attrs.isEmpty())
+            continue;
+        if (attrs.isData())
+            attrs.setWritable(false);
+        attrs.setConfigurable(false);
+        f->propertyData.set(i, attrs);
+    }
+    f->extensible = false;
+    f->isSealed = true;
+    f->isFrozen = true;
+
+    t.lookup = f;
+    return f;
 }
 
-InternalClass *InternalClass::propertiesFrozen() const
+Heap::InternalClass *InternalClass::propertiesFrozen() const
 {
-    InternalClass *frozen = engine->internalClasses[EngineBase::Class_Empty]->changeVTable(vtable);
+    Scope scope(engine);
+    Scoped<QV4::InternalClass> frozen(scope, engine->internalClasses(EngineBase::Class_Empty)->changeVTable(vtable));
     frozen = frozen->changePrototype(prototype);
     for (uint i = 0; i < size; ++i) {
         PropertyAttributes attrs = propertyData.at(i);
-        if (attrs.isEmpty())
+        if (!nameMap.at(i).isValid())
             continue;
-        attrs.setWritable(false);
-        attrs.setConfigurable(false);
+        if (!attrs.isEmpty()) {
+            attrs.setWritable(false);
+            attrs.setConfigurable(false);
+        }
         frozen = frozen->addMember(nameMap.at(i), attrs);
     }
-    return frozen;
+    return frozen->d();
 }
 
-void InternalClass::destroy()
+Heap::InternalClass *InternalClass::asProtoClass()
 {
-    std::vector<InternalClass *> destroyStack;
-    destroyStack.reserve(64);
-    destroyStack.push_back(this);
+    if (isUsedAsProto)
+        return this;
 
-    while (!destroyStack.empty()) {
-        InternalClass *next = destroyStack.back();
-        destroyStack.pop_back();
-        if (!next->engine)
-            continue;
-        next->engine = 0;
-        next->propertyTable.~PropertyHash();
-        next->nameMap.~SharedInternalClassData<Identifier *>();
-        next->propertyData.~SharedInternalClassData<PropertyAttributes>();
-        if (next->m_sealed)
-            destroyStack.push_back(next->m_sealed);
-        if (next->m_frozen)
-            destroyStack.push_back(next->m_frozen);
-
-        for (size_t i = 0; i < next->transitions.size(); ++i) {
-            Q_ASSERT(next->transitions.at(i).lookup);
-            destroyStack.push_back(next->transitions.at(i).lookup);
-        }
+    Transition temp = { { PropertyKey::invalid() }, nullptr, Transition::ProtoClass };
+    Transition &t = lookupOrInsertTransition(temp);
+    if (t.lookup)
+        return t.lookup;
+
+    Heap::InternalClass *newClass = engine->newClass(this);
+    newClass->isUsedAsProto = true;
 
-        next->transitions.~vector<Transition>();
+    t.lookup = newClass;
+    Q_ASSERT(t.lookup);
+    return newClass;
+}
+
+static void updateProtoUsage(Heap::Object *o, Heap::InternalClass *ic)
+{
+    if (ic->prototype == o)
+        ic->protoId = ic->engine->newProtoId();
+    for (auto &t : ic->transitions) {
+        if (t.lookup)
+            updateProtoUsage(o, t.lookup);
     }
 }
 
-void InternalClassPool::markObjects(MarkStack *markStack)
+
+void InternalClass::updateProtoUsage(Heap::Object *o)
 {
-    InternalClass *ic = markStack->engine->internalClasses[EngineBase::Class_Empty];
+    Q_ASSERT(isUsedAsProto);
+    Heap::InternalClass *ic = engine->internalClasses(EngineBase::Class_Empty);
     Q_ASSERT(!ic->prototype);
 
-    // only need to go two levels into the IC hierarchy, as prototype changes
-    // can only happen there
-    for (auto &t : ic->transitions) {
-        Q_ASSERT(t.lookup);
-        if (t.flags == InternalClassTransition::VTableChange) {
-            InternalClass *ic2 = t.lookup;
-            for (auto &t2 : ic2->transitions) {
-                if (t2.flags == InternalClassTransition::PrototypeChange)
-                    t2.lookup->prototype->mark(markStack);
-            }
-        } else if (t.flags == InternalClassTransition::PrototypeChange) {
-            t.lookup->prototype->mark(markStack);
-        }
-    }
+    Heap::updateProtoUsage(o, ic);
+}
+
+void InternalClass::markObjects(Heap::Base *b, MarkStack *stack)
+{
+    Heap::InternalClass *ic = static_cast<Heap::InternalClass *>(b);
+    if (ic->prototype)
+        ic->prototype->mark(stack);
+    if (ic->parent)
+        ic->parent->mark(stack);
+
+    ic->nameMap.mark(stack);
+}
+
+}
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4internalclass_p.h b/src/qml/jsruntime/qv4internalclass_p.h
index df17074e72..681cbda5f9 100644
--- a/src/qml/jsruntime/qv4internalclass_p.h
+++ b/src/qml/jsruntime/qv4internalclass_p.h
@@ -53,25 +53,30 @@
 #include "qv4global_p.h"
 
 #include <QHash>
-#include <private/qqmljsmemorypool_p.h>
-#include <private/qv4identifier_p.h>
+#include <private/qv4propertykey_p.h>
+#include <private/qv4heap_p.h>
 
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-struct String;
-struct Object;
-struct Identifier;
 struct VTable;
 struct MarkStack;
 
+struct InternalClassEntry {
+    uint index;
+    uint setterIndex;
+    PropertyAttributes attributes;
+    bool isValid() const { return !attributes.isEmpty(); }
+};
+
 struct PropertyHashData;
 struct PropertyHash
 {
     struct Entry {
-        const Identifier *identifier;
+        PropertyKey identifier;
         uint index;
+        uint setterIndex;
     };
 
     PropertyHashData *d;
@@ -79,12 +84,12 @@ struct PropertyHash
     inline PropertyHash();
     inline PropertyHash(const PropertyHash &other);
     inline ~PropertyHash();
+    PropertyHash &operator=(const PropertyHash &other);
 
     void addEntry(const Entry &entry, int classSize);
-    uint lookup(const Identifier *identifier) const;
-
-private:
-    PropertyHash &operator=(const PropertyHash &other);
+    Entry *lookup(PropertyKey identifier) const;
+    int removeIdentifier(PropertyKey identifier, int classSize);
+    void detach(bool grow, int classSize);
 };
 
 struct PropertyHashData
@@ -118,40 +123,121 @@ inline PropertyHash::~PropertyHash()
         delete d;
 }
 
-inline uint PropertyHash::lookup(const Identifier *identifier) const
+inline PropertyHash &PropertyHash::operator=(const PropertyHash &other)
+{
+    ++other.d->refCount;
+    if (!--d->refCount)
+        delete d;
+    d = other.d;
+    return *this;
+}
+
+
+
+inline PropertyHash::Entry *PropertyHash::lookup(PropertyKey identifier) const
 {
     Q_ASSERT(d->entries);
 
-    uint idx = identifier->hashValue % d->alloc;
+    uint idx = identifier.id() % d->alloc;
     while (1) {
         if (d->entries[idx].identifier == identifier)
-            return d->entries[idx].index;
-        if (!d->entries[idx].identifier)
-            return UINT_MAX;
+            return d->entries + idx;
+        if (!d->entries[idx].identifier.isValid())
+            return nullptr;
         ++idx;
         idx %= d->alloc;
     }
 }
 
+template<typename T>
+struct SharedInternalClassDataPrivate {
+    SharedInternalClassDataPrivate(ExecutionEngine *)
+        : refcount(1),
+          m_alloc(0),
+          m_size(0),
+          data(nullptr)
+    { }
+    SharedInternalClassDataPrivate(const SharedInternalClassDataPrivate &other)
+        : refcount(1),
+          m_alloc(other.m_alloc),
+          m_size(other.m_size)
+    {
+        if (m_alloc) {
+            data = new T[m_alloc];
+            memcpy(data, other.data, m_size*sizeof(T));
+        }
+    }
+    SharedInternalClassDataPrivate(const SharedInternalClassDataPrivate &other, uint pos, T value)
+        : refcount(1),
+          m_alloc(pos + 8),
+          m_size(pos + 1)
+    {
+        data = new T[m_alloc];
+        if (other.data)
+            memcpy(data, other.data, (m_size - 1)*sizeof(T));
+        data[pos] = value;
+    }
+    ~SharedInternalClassDataPrivate() { delete [] data; }
+
+
+    void grow() {
+        if (!m_alloc)
+            m_alloc = 4;
+        T *n = new T[m_alloc * 2];
+        if (data) {
+            memcpy(n, data, m_alloc*sizeof(T));
+            delete [] data;
+        }
+        data = n;
+        m_alloc *= 2;
+    }
+
+    uint alloc() const { return m_alloc; }
+    uint size() const { return m_size; }
+    void setSize(uint s) { m_size = s; }
+
+    T at(uint i) { Q_ASSERT(data && i < m_alloc); return data[i]; }
+    void set(uint i, T t) { Q_ASSERT(data && i < m_alloc); data[i] = t; }
+
+    void mark(MarkStack *) {}
+
+    int refcount = 1;
+private:
+    uint m_alloc;
+    uint m_size;
+    T *data;
+};
+
+template<>
+struct SharedInternalClassDataPrivate<PropertyKey> {
+    SharedInternalClassDataPrivate(ExecutionEngine *e) : refcount(1), engine(e), data(nullptr) {}
+    SharedInternalClassDataPrivate(const SharedInternalClassDataPrivate &other);
+    SharedInternalClassDataPrivate(const SharedInternalClassDataPrivate &other, uint pos, PropertyKey value);
+    ~SharedInternalClassDataPrivate() {}
+
+    void grow();
+    uint alloc() const;
+    uint size() const;
+    void setSize(uint s);
+
+    PropertyKey at(uint i);
+    void set(uint i, PropertyKey t);
+
+    void mark(MarkStack *s);
+
+    int refcount = 1;
+private:
+    ExecutionEngine *engine;
+    Heap::MemberData *data;
+};
+
 template <typename T>
 struct SharedInternalClassData {
-    struct Private {
-        Private(int alloc)
-            : refcount(1),
-              alloc(alloc),
-              size(0)
-        { data = new T  [alloc]; }
-        ~Private() { delete [] data; }
-
-        int refcount;
-        uint alloc;
-        uint size;
-        T *data;
-    };
+    using Private = SharedInternalClassDataPrivate<T>;
     Private *d;
 
-    inline SharedInternalClassData() {
-        d = new Private(8);
+    inline SharedInternalClassData(ExecutionEngine *e) {
+        d = new Private(e);
     }
 
     inline SharedInternalClassData(const SharedInternalClassData &other)
@@ -163,76 +249,72 @@ struct SharedInternalClassData {
         if (!--d->refcount)
             delete d;
     }
+    SharedInternalClassData &operator=(const SharedInternalClassData &other) {
+        ++other.d->refcount;
+        if (!--d->refcount)
+            delete d;
+        d = other.d;
+        return *this;
+    }
 
     void add(uint pos, T value) {
-        if (pos < d->size) {
+        if (pos < d->size()) {
             Q_ASSERT(d->refcount > 1);
             // need to detach
-            Private *dd = new Private(pos + 8);
-            memcpy(dd->data, d->data, pos*sizeof(T));
-            dd->size = pos + 1;
-            dd->data[pos] = value;
+            Private *dd = new Private(*d, pos, value);
             if (!--d->refcount)
                 delete d;
             d = dd;
             return;
         }
-        Q_ASSERT(pos == d->size);
-        if (pos == d->alloc) {
-            T *n = new T[d->alloc * 2];
-            memcpy(n, d->data, d->alloc*sizeof(T));
-            delete [] d->data;
-            d->data = n;
-            d->alloc *= 2;
-        }
-        d->data[pos] = value;
-        ++d->size;
+        Q_ASSERT(pos == d->size());
+        if (pos == d->alloc())
+            d->grow();
+        d->setSize(d->size() + 1);
+        d->set(pos, value);
     }
 
     void set(uint pos, T value) {
-        Q_ASSERT(pos < d->size);
+        Q_ASSERT(pos < d->size());
         if (d->refcount > 1) {
             // need to detach
-            Private *dd = new Private(d->alloc);
-            memcpy(dd->data, d->data, d->size*sizeof(T));
-            dd->size = d->size;
+            Private *dd = new Private(*d);
             if (!--d->refcount)
                 delete d;
             d = dd;
         }
-        d->data[pos] = value;
+        d->set(pos, value);
     }
 
-    T *constData() const {
-        return d->data;
-    }
     T at(uint i) const {
-        Q_ASSERT(i < d->size);
-        return d->data[i];
+        Q_ASSERT(i < d->size());
+        return d->at(i);
     }
     T operator[] (uint i) {
-        Q_ASSERT(i < d->size);
-        return d->data[i];
+        Q_ASSERT(i < d->size());
+        return d->at(i);
     }
 
-private:
-    SharedInternalClassData &operator=(const SharedInternalClassData &other);
+    void mark(MarkStack *s) { d->mark(s); }
 };
 
 struct InternalClassTransition
 {
     union {
-        Identifier *id;
+        PropertyKey id;
         const VTable *vtable;
         Heap::Object *prototype;
     };
-    InternalClass *lookup;
+    Heap::InternalClass *lookup;
     int flags;
     enum {
         // range 0-0xff is reserved for attribute changes
         NotExtensible = 0x100,
         VTableChange = 0x200,
-        PrototypeChange = 0x201
+        PrototypeChange = 0x201,
+        ProtoClass = 0x202,
+        Sealed = 0x203,
+        Frozen = 0x204
     };
 
     bool operator==(const InternalClassTransition &other) const
@@ -242,72 +324,168 @@ struct InternalClassTransition
     { return id < other.id || (id == other.id && flags < other.flags); }
 };
 
-struct InternalClass : public QQmlJS::Managed {
+namespace Heap {
+
+struct InternalClass : Base {
     ExecutionEngine *engine;
     const VTable *vtable;
+    quintptr protoId; // unique across the engine, gets changed whenever the proto chain changes
     Heap::Object *prototype;
+    InternalClass *parent;
 
     PropertyHash propertyTable; // id to valueIndex
-    SharedInternalClassData<Identifier *> nameMap;
+    SharedInternalClassData<PropertyKey> nameMap;
     SharedInternalClassData<PropertyAttributes> propertyData;
 
     typedef InternalClassTransition Transition;
     std::vector<Transition> transitions;
     InternalClassTransition &lookupOrInsertTransition(const InternalClassTransition &t);
 
-    InternalClass *m_sealed;
-    InternalClass *m_frozen;
-
     uint size;
     bool extensible;
+    bool isSealed;
+    bool isFrozen;
+    bool isUsedAsProto;
 
+    void init(ExecutionEngine *engine);
+    void init(InternalClass *other);
+    void destroy();
+
+    Q_QML_PRIVATE_EXPORT QString keyAt(uint index) const;
     Q_REQUIRED_RESULT InternalClass *nonExtensible();
-    Q_REQUIRED_RESULT InternalClass *changeVTable(const VTable *vt) {
-        if (vtable == vt)
-            return this;
-        return changeVTableImpl(vt);
+
+    static void addMember(QV4::Object *object, PropertyKey id, PropertyAttributes data, InternalClassEntry *entry);
+    Q_REQUIRED_RESULT InternalClass *addMember(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry = nullptr);
+    Q_REQUIRED_RESULT InternalClass *changeMember(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry = nullptr);
+    static void changeMember(QV4::Object *object, PropertyKey id, PropertyAttributes data, InternalClassEntry *entry = nullptr);
+    static void removeMember(QV4::Object *object, PropertyKey identifier);
+    PropertyHash::Entry *findEntry(const PropertyKey id)
+    {
+        Q_ASSERT(id.isStringOrSymbol());
+
+        PropertyHash::Entry *e = propertyTable.lookup(id);
+        if (e && e->index < size)
+            return e;
+
+        return nullptr;
     }
-    Q_REQUIRED_RESULT InternalClass *changePrototype(Heap::Object *proto) {
-        if (prototype == proto)
-            return this;
-        return changePrototypeImpl(proto);
+
+    InternalClassEntry find(const PropertyKey id)
+    {
+        Q_ASSERT(id.isStringOrSymbol());
+
+        PropertyHash::Entry *e = propertyTable.lookup(id);
+        if (e && e->index < size) {
+            PropertyAttributes a = propertyData.at(e->index);
+            if (!a.isEmpty())
+                return { e->index, e->setterIndex, a };
+        }
+
+        return { UINT_MAX, UINT_MAX, Attr_Invalid };
     }
 
-    static void addMember(Object *object, String *string, PropertyAttributes data, uint *index);
-    Q_REQUIRED_RESULT InternalClass *addMember(String *string, PropertyAttributes data, uint *index = 0);
-    Q_REQUIRED_RESULT InternalClass *addMember(Identifier *identifier, PropertyAttributes data, uint *index = 0);
-    Q_REQUIRED_RESULT InternalClass *changeMember(Identifier *identifier, PropertyAttributes data, uint *index = 0);
-    static void changeMember(Object *object, String *string, PropertyAttributes data, uint *index = 0);
-    static void removeMember(Object *object, Identifier *id);
-    uint find(const String *string);
-    uint find(const Identifier *id)
+    struct IndexAndAttribute {
+        uint index;
+        PropertyAttributes attrs;
+        bool isValid() const { return index != UINT_MAX; }
+    };
+
+    IndexAndAttribute findValueOrGetter(const PropertyKey id)
     {
-        uint index = propertyTable.lookup(id);
-        if (index < size)
-            return index;
+        Q_ASSERT(id.isStringOrSymbol());
+
+        PropertyHash::Entry *e = propertyTable.lookup(id);
+        if (e && e->index < size) {
+            PropertyAttributes a = propertyData.at(e->index);
+            if (!a.isEmpty())
+                return { e->index, a };
+        }
+
+        return { UINT_MAX, Attr_Invalid };
+    }
+
+    IndexAndAttribute findValueOrSetter(const PropertyKey id)
+    {
+        Q_ASSERT(id.isStringOrSymbol());
+
+        PropertyHash::Entry *e = propertyTable.lookup(id);
+        if (e && e->index < size) {
+            PropertyAttributes a = propertyData.at(e->index);
+            if (!a.isEmpty()) {
+                if (a.isAccessor()) {
+                    Q_ASSERT(e->setterIndex != UINT_MAX);
+                    return { e->setterIndex, a };
+                }
+                return { e->index, a };
+            }
+        }
+
+        return { UINT_MAX, Attr_Invalid };
+    }
+
+    uint indexOfValueOrGetter(const PropertyKey id)
+    {
+        Q_ASSERT(id.isStringOrSymbol());
+
+        PropertyHash::Entry *e = propertyTable.lookup(id);
+        if (e && e->index < size) {
+            Q_ASSERT(!propertyData.at(e->index).isEmpty());
+            return e->index;
+        }
 
         return UINT_MAX;
     }
 
+    bool verifyIndex(const PropertyKey id, uint index)
+    {
+        Q_ASSERT(id.isStringOrSymbol());
+
+        PropertyHash::Entry *e = propertyTable.lookup(id);
+        if (e && e->index < size) {
+            Q_ASSERT(!propertyData.at(e->index).isEmpty());
+            return e->index == index;
+        }
+
+        return false;
+    }
+
     Q_REQUIRED_RESULT InternalClass *sealed();
     Q_REQUIRED_RESULT InternalClass *frozen();
     Q_REQUIRED_RESULT InternalClass *propertiesFrozen() const;
 
-    void destroy();
+    Q_REQUIRED_RESULT InternalClass *asProtoClass();
+
+    Q_REQUIRED_RESULT InternalClass *changeVTable(const VTable *vt) {
+        if (vtable == vt)
+            return this;
+        return changeVTableImpl(vt);
+    }
+    Q_REQUIRED_RESULT InternalClass *changePrototype(Heap::Object *proto) {
+        if (prototype == proto)
+            return this;
+        return changePrototypeImpl(proto);
+    }
+
+    void updateProtoUsage(Heap::Object *o);
+
+    static void markObjects(Heap::Base *ic, MarkStack *stack);
 
 private:
     Q_QML_EXPORT InternalClass *changeVTableImpl(const VTable *vt);
     Q_QML_EXPORT InternalClass *changePrototypeImpl(Heap::Object *proto);
-    InternalClass *addMemberImpl(Identifier *identifier, PropertyAttributes data, uint *index);
+    InternalClass *addMemberImpl(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry);
+
+    void removeChildEntry(InternalClass *child);
     friend struct ExecutionEngine;
-    InternalClass(ExecutionEngine *engine);
-    InternalClass(const InternalClass &other);
 };
 
-struct InternalClassPool : public QQmlJS::MemoryPool
+inline
+void Base::markObjects(Base *b, MarkStack *stack)
 {
-    void markObjects(MarkStack *markStack);
-};
+    b->internalClass->mark(stack);
+}
+
+}
 
 }
 
diff --git a/src/qml/jsruntime/qv4iterator.cpp b/src/qml/jsruntime/qv4iterator.cpp
new file mode 100644
index 0000000000..a543565b37
--- /dev/null
+++ b/src/qml/jsruntime/qv4iterator.cpp
@@ -0,0 +1,64 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <qv4iterator_p.h>
+#include <qv4symbol_p.h>
+#include <qv4engine_p.h>
+
+using namespace QV4;
+
+void IteratorPrototype::init(ExecutionEngine *engine)
+{
+    defineDefaultProperty(engine->symbol_iterator(), method_iterator, 0);
+}
+
+ReturnedValue IteratorPrototype::method_iterator(const FunctionObject *, const Value *thisObject, const Value *, int)
+{
+    return thisObject->asReturnedValue();
+}
+
+
+ReturnedValue IteratorPrototype::createIterResultObject(ExecutionEngine *engine, const Value &value, bool done)
+{
+    Scope scope(engine);
+    ScopedObject obj(scope, engine->newObject());
+    obj->set(ScopedString(scope, engine->newString(QStringLiteral("value"))), value, Object::DoNotThrow);
+    obj->set(ScopedString(scope, engine->newString(QStringLiteral("done"))), Value::fromBoolean(done), Object::DoNotThrow);
+    return obj->asReturnedValue();
+}
+
diff --git a/src/qml/jsruntime/qv4iterator_p.h b/src/qml/jsruntime/qv4iterator_p.h
new file mode 100644
index 0000000000..28e337d21b
--- /dev/null
+++ b/src/qml/jsruntime/qv4iterator_p.h
@@ -0,0 +1,82 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4ITERATOR_P_H
+#define QV4ITERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4arraydata_p.h"
+
+QT_BEGIN_NAMESPACE
+
+
+namespace QV4 {
+
+enum IteratorKind {
+    KeyIteratorKind,
+    ValueIteratorKind,
+    KeyValueIteratorKind
+};
+
+struct IteratorPrototype : Object
+{
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_iterator(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue createIterResultObject(ExecutionEngine *engine, const Value &value, bool done);
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4ARRAYITERATOR_P_H
+
diff --git a/src/qml/jsruntime/qv4jscall_p.h b/src/qml/jsruntime/qv4jscall_p.h
new file mode 100644
index 0000000000..31689b1ba1
--- /dev/null
+++ b/src/qml/jsruntime/qv4jscall_p.h
@@ -0,0 +1,140 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4JSCALL_H
+#define QV4JSCALL_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4function_p.h"
+#include "qv4functionobject_p.h"
+#include "qv4context_p.h"
+#include "qv4scopedvalue_p.h"
+#include "qv4stackframe_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+struct JSCallData {
+    JSCallData(const Scope &scope, int argc = 0, const Value *argv = nullptr, const Value *thisObject = nullptr)
+        : scope(scope), argc(argc)
+    {
+        if (thisObject)
+            this->thisObject = const_cast<Value *>(thisObject);
+        else
+            this->thisObject = scope.alloc();
+        if (argv)
+            this->args = const_cast<Value *>(argv);
+        else
+            this->args = scope.alloc(argc);
+    }
+
+    JSCallData *operator->() {
+        return this;
+    }
+
+    CallData *callData(const FunctionObject *f = nullptr) const {
+        int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + argc;
+        CallData *ptr = reinterpret_cast<CallData *>(scope.alloc<Scope::Uninitialized>(size));
+        ptr->function = Encode::undefined();
+        ptr->context = Encode::undefined();
+        ptr->accumulator = Encode::undefined();
+        ptr->thisObject = thisObject->asReturnedValue();
+        ptr->newTarget = Encode::undefined();
+        ptr->setArgc(argc);
+        if (argc)
+            memcpy(ptr->args, args, argc*sizeof(Value));
+        if (f)
+            ptr->function = f->asReturnedValue();
+        return ptr;
+    }
+    const Scope &scope;
+    int argc;
+    Value *args;
+    Value *thisObject;
+};
+
+inline
+ReturnedValue FunctionObject::callAsConstructor(const JSCallData &data) const
+{
+    return callAsConstructor(data.args, data.argc, this);
+}
+
+inline
+ReturnedValue FunctionObject::call(const JSCallData &data) const
+{
+    return call(data.thisObject, data.args, data.argc);
+}
+
+
+struct ScopedStackFrame {
+    Scope &scope;
+    CppStackFrame frame;
+
+    ScopedStackFrame(Scope &scope, Heap::ExecutionContext *context)
+        : scope(scope)
+    {
+        frame.parent = scope.engine->currentStackFrame;
+        if (!context)
+            return;
+        frame.jsFrame = reinterpret_cast<CallData *>(scope.alloc(sizeof(CallData)/sizeof(Value)));
+        frame.jsFrame->context = context;
+        frame.v4Function = frame.parent ? frame.parent->v4Function : nullptr;
+        scope.engine->currentStackFrame = &frame;
+    }
+    ~ScopedStackFrame() {
+        scope.engine->currentStackFrame = frame.parent;
+    }
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4JSCALL_H
diff --git a/src/qml/jsruntime/qv4jsonobject.cpp b/src/qml/jsruntime/qv4jsonobject.cpp
index 0f021c8bd0..936c032fad 100644
--- a/src/qml/jsruntime/qv4jsonobject.cpp
+++ b/src/qml/jsruntime/qv4jsonobject.cpp
@@ -46,6 +46,8 @@
 #include <qv4runtime_p.h>
 #include <qv4variantobject_p.h>
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
+#include <qv4symbol_p.h>
 
 #include <qstack.h>
 #include <qstringlist.h>
@@ -259,11 +261,12 @@ bool JsonParser::parseMember(Object *o)
     if (!parseValue(val))
         return false;
 
-    ScopedString s(scope, engine->newIdentifier(key));
-    uint idx = s->asArrayIndex();
-    if (idx < UINT_MAX) {
-        o->putIndexed(idx, val);
+    ScopedString s(scope, engine->newString(key));
+    PropertyKey skey = s->toPropertyKey();
+    if (skey.isArrayIndex()) {
+        o->put(skey.asArrayIndex(), val);
     } else {
+        // avoid trouble with properties named __proto__
         o->insertMember(s, val);
     }
 
@@ -337,7 +340,7 @@ bool JsonParser::parseValue(Value *val)
         if (*json++ == 'u' &&
             *json++ == 'l' &&
             *json++ == 'l') {
-            *val = Primitive::nullValue();
+            *val = Value::nullValue();
             DEBUG << "value: null";
             END;
             return true;
@@ -352,7 +355,7 @@ bool JsonParser::parseValue(Value *val)
         if (*json++ == 'r' &&
             *json++ == 'u' &&
             *json++ == 'e') {
-            *val = Primitive::fromBoolean(true);
+            *val = Value::fromBoolean(true);
             DEBUG << "value: true";
             END;
             return true;
@@ -368,7 +371,7 @@ bool JsonParser::parseValue(Value *val)
             *json++ == 'l' &&
             *json++ == 's' &&
             *json++ == 'e') {
-            *val = Primitive::fromBoolean(false);
+            *val = Value::fromBoolean(false);
             DEBUG << "value: false";
             END;
             return true;
@@ -476,7 +479,7 @@ bool JsonParser::parseNumber(Value *val)
         bool ok;
         int n = number.toInt(&ok);
         if (ok && n < (1<<25) && n > -(1<<25)) {
-            *val = Primitive::fromInt32(n);
+            *val = Value::fromInt32(n);
             END;
             return true;
         }
@@ -491,7 +494,7 @@ bool JsonParser::parseNumber(Value *val)
         return false;
     }
 
-    * val = Primitive::fromDouble(d);
+    * val = Value::fromDouble(d);
 
     END;
     return true;
@@ -633,10 +636,10 @@ struct Stringify
         return false;
     }
 
-    Stringify(ExecutionEngine *e) : v4(e), replacerFunction(0), propertyList(0), propertyListSize(0) {}
+    Stringify(ExecutionEngine *e) : v4(e), replacerFunction(nullptr), propertyList(nullptr), propertyListSize(0) {}
 
     QString Str(const QString &key, const Value &v);
-    QString JA(ArrayObject *a);
+    QString JA(Object *a);
     QString JO(Object *o);
 
     QString makeMember(const QString &key, const Value &v);
@@ -689,61 +692,61 @@ static QString quote(const QString &str)
 QString Stringify::Str(const QString &key, const Value &v)
 {
     Scope scope(v4);
-    scope.result = v;
 
-    ScopedObject o(scope, scope.result);
+    ScopedValue value(scope, v);
+    ScopedObject o(scope, value);
     if (o) {
         ScopedString s(scope, v4->newString(QStringLiteral("toJSON")));
         ScopedFunctionObject toJSON(scope, o->get(s));
         if (!!toJSON) {
-            ScopedCallData callData(scope, 1);
-            callData->thisObject = scope.result;
-            callData->args[0] = v4->newString(key);
-            toJSON->call(scope, callData);
+            JSCallData jsCallData(scope, 1);
+            *jsCallData->thisObject = value;
+            jsCallData->args[0] = v4->newString(key);
+            value = toJSON->call(jsCallData);
         }
     }
 
     if (replacerFunction) {
         ScopedObject holder(scope, v4->newObject());
-        holder->put(scope.engine->id_empty(), scope.result);
-        ScopedCallData callData(scope, 2);
-        callData->args[0] = v4->newString(key);
-        callData->args[1] = scope.result;
-        callData->thisObject = holder;
-        replacerFunction->call(scope, callData);
+        holder->put(scope.engine->id_empty(), value);
+        JSCallData jsCallData(scope, 2);
+        jsCallData->args[0] = v4->newString(key);
+        jsCallData->args[1] = value;
+        *jsCallData->thisObject = holder;
+        value = replacerFunction->call(jsCallData);
     }
 
-    o = scope.result.asReturnedValue();
+    o = value->asReturnedValue();
     if (o) {
         if (NumberObject *n = o->as<NumberObject>())
-            scope.result = Encode(n->value());
+            value = Encode(n->value());
         else if (StringObject *so = o->as<StringObject>())
-            scope.result = so->d()->string;
+            value = so->d()->string;
         else if (BooleanObject *b = o->as<BooleanObject>())
-            scope.result = Encode(b->value());
+            value = Encode(b->value());
     }
 
-    if (scope.result.isNull())
+    if (value->isNull())
         return QStringLiteral("null");
-    if (scope.result.isBoolean())
-        return scope.result.booleanValue() ? QStringLiteral("true") : QStringLiteral("false");
-    if (String *s = scope.result.stringValue())
-        return quote(s->toQString());
-
-    if (scope.result.isNumber()) {
-        double d = scope.result.toNumber();
-        return std::isfinite(d) ? scope.result.toQString() : QStringLiteral("null");
+    if (value->isBoolean())
+        return value->booleanValue() ? QStringLiteral("true") : QStringLiteral("false");
+    if (value->isString())
+        return quote(value->stringValue()->toQString());
+
+    if (value->isNumber()) {
+        double d = value->toNumber();
+        return std::isfinite(d) ? value->toQString() : QStringLiteral("null");
     }
 
-    if (const QV4::VariantObject *v = scope.result.as<QV4::VariantObject>()) {
-        return v->d()->data().toString();
+    if (const QV4::VariantObject *v = value->as<QV4::VariantObject>()) {
+        return quote(v->d()->data().toString());
     }
 
-    o = scope.result.asReturnedValue();
+    o = value->asReturnedValue();
     if (o) {
         if (!o->as<FunctionObject>()) {
-            if (o->as<ArrayObject>()) {
-                return JA(static_cast<ArrayObject *>(o.getPointer()));
+            if (o->isArrayLike()) {
+                return JA(o.getPointer());
             } else {
                 return JO(o);
             }
@@ -826,7 +829,7 @@ QString Stringify::JO(Object *o)
     return result;
 }
 
-QString Stringify::JA(ArrayObject *a)
+QString Stringify::JA(Object *a)
 {
     if (stackContains(a)) {
         v4->throwTypeError();
@@ -845,7 +848,7 @@ QString Stringify::JA(ArrayObject *a)
     ScopedValue v(scope);
     for (uint i = 0; i < len; ++i) {
         bool exists;
-        v = a->getIndexed(i, &exists);
+        v = a->get(i, &exists);
         if (!exists) {
             partial += QStringLiteral("null");
             continue;
@@ -880,31 +883,36 @@ void Heap::JsonObject::init()
 
     o->defineDefaultProperty(QStringLiteral("parse"), QV4::JsonObject::method_parse, 2);
     o->defineDefaultProperty(QStringLiteral("stringify"), QV4::JsonObject::method_stringify, 3);
+    ScopedString json(scope, scope.engine->newString(QStringLiteral("JSON")));
+    o->defineReadonlyConfigurableProperty(scope.engine->symbol_toStringTag(), json);
 }
 
 
-void JsonObject::method_parse(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue JsonObject::method_parse(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedValue v(scope, callData->argument(0));
-    QString jtext = v->toQString();
+    ExecutionEngine *v4 = b->engine();
+    QString jtext;
+    if (argc > 0)
+        jtext = argv[0].toQString();
 
     DEBUG << "parsing source = " << jtext;
-    JsonParser parser(scope.engine, jtext.constData(), jtext.length());
+    JsonParser parser(v4, jtext.constData(), jtext.length());
     QJsonParseError error;
-    ScopedValue result(scope, parser.parse(&error));
+    ReturnedValue result = parser.parse(&error);
     if (error.error != QJsonParseError::NoError) {
         DEBUG << "parse error" << error.errorString();
-        RETURN_RESULT(scope.engine->throwSyntaxError(QStringLiteral("JSON.parse: Parse error")));
+        RETURN_RESULT(v4->throwSyntaxError(QStringLiteral("JSON.parse: Parse error")));
     }
 
-    scope.result = result;
+    return result;
 }
 
-void JsonObject::method_stringify(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue JsonObject::method_stringify(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
+    Scope scope(b);
     Stringify stringify(scope.engine);
 
-    ScopedObject o(scope, callData->argument(1));
+    ScopedObject o(scope, argc > 1 ? argv[1] : Value::undefinedValue());
     if (o) {
         stringify.replacerFunction = o->as<FunctionObject>();
         if (o->isArrayObject()) {
@@ -912,15 +920,15 @@ void JsonObject::method_stringify(const BuiltinFunction *, Scope &scope, CallDat
             stringify.propertyList = static_cast<QV4::String *>(scope.alloc(arrayLen));
             for (uint i = 0; i < arrayLen; ++i) {
                 Value *v = stringify.propertyList + i;
-                *v = o->getIndexed(i);
+                *v = o->get(i);
                 if (v->as<NumberObject>() || v->as<StringObject>() || v->isNumber())
                     *v = v->toString(scope.engine);
                 if (!v->isString()) {
-                    v->setM(0);
+                    v->setM(nullptr);
                 } else {
                     for (uint j = 0; j <i; ++j) {
                         if (stringify.propertyList[j].m() == v->m()) {
-                            v->setM(0);
+                            v->setM(nullptr);
                             break;
                         }
                     }
@@ -929,7 +937,7 @@ void JsonObject::method_stringify(const BuiltinFunction *, Scope &scope, CallDat
         }
     }
 
-    ScopedValue s(scope, callData->argument(2));
+    ScopedValue s(scope, argc > 2 ? argv[2] : Value::undefinedValue());
     if (NumberObject *n = s->as<NumberObject>())
         s = Encode(n->value());
     else if (StringObject *so = s->as<StringObject>())
@@ -942,11 +950,11 @@ void JsonObject::method_stringify(const BuiltinFunction *, Scope &scope, CallDat
     }
 
 
-    ScopedValue arg0(scope, callData->argument(0));
+    ScopedValue arg0(scope, argc ? argv[0] : Value::undefinedValue());
     QString result = stringify.Str(QString(), arg0);
     if (result.isEmpty() || scope.engine->hasException)
         RETURN_UNDEFINED();
-    scope.result = scope.engine->newString(result);
+    return Encode(scope.engine->newString(result));
 }
 
 
@@ -1074,7 +1082,7 @@ QJsonArray JsonObject::toJsonArray(const ArrayObject *a, V4ObjectSet &visitedObj
     ScopedValue v(scope);
     quint32 length = a->getLength();
     for (quint32 i = 0; i < length; ++i) {
-        v = a->getIndexed(i);
+        v = a->get(i);
         if (v->as<FunctionObject>())
             v = Encode::null();
         result.append(toJsonValue(v, visitedObjects));
diff --git a/src/qml/jsruntime/qv4jsonobject_p.h b/src/qml/jsruntime/qv4jsonobject_p.h
index a73ce1c74e..7d9f204910 100644
--- a/src/qml/jsruntime/qv4jsonobject_p.h
+++ b/src/qml/jsruntime/qv4jsonobject_p.h
@@ -88,8 +88,8 @@ private:
     typedef QSet<ObjectItem> V4ObjectSet;
 public:
 
-    static void method_parse(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_stringify(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_parse(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_stringify(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
     static ReturnedValue fromJsonValue(ExecutionEngine *engine, const QJsonValue &value);
     static ReturnedValue fromJsonObject(ExecutionEngine *engine, const QJsonObject &object);
diff --git a/src/qml/jsruntime/qv4lookup.cpp b/src/qml/jsruntime/qv4lookup.cpp
index d943ae1340..1b6cdcbd14 100644
--- a/src/qml/jsruntime/qv4lookup.cpp
+++ b/src/qml/jsruntime/qv4lookup.cpp
@@ -38,324 +38,178 @@
 ****************************************************************************/
 #include "qv4lookup_p.h"
 #include "qv4functionobject_p.h"
-#include "qv4scopedvalue_p.h"
+#include "qv4jscall_p.h"
 #include "qv4string_p.h"
+#include <private/qv4identifiertable_p.h>
 
 QT_BEGIN_NAMESPACE
 
 using namespace QV4;
 
 
-ReturnedValue Lookup::lookup(const Value &thisObject, Object *o, PropertyAttributes *attrs)
+void Lookup::resolveProtoGetter(PropertyKey name, const Heap::Object *proto)
 {
-    ExecutionEngine *engine = o->engine();
-    Identifier *name = engine->current->compilationUnit->runtimeStrings[nameIndex]->identifier;
-    int i = 0;
-    Heap::Object *obj = o->d();
-    while (i < Size && obj) {
-        classList[i] = obj->internalClass;
-
-        index = obj->internalClass->find(name);
-        if (index != UINT_MAX) {
-            level = i;
-            *attrs = obj->internalClass->propertyData.at(index);
-            const Value *v = obj->propertyData(index);
-            return !attrs->isAccessor() ? v->asReturnedValue() : Object::getValue(thisObject, *v, *attrs);
-        }
-
-        obj = obj->prototype();
-        ++i;
-    }
-    level = Size;
-
-    while (obj) {
-        index = obj->internalClass->find(name);
-        if (index != UINT_MAX) {
-            *attrs = obj->internalClass->propertyData.at(index);
-            const Value *v = obj->propertyData(index);
-            return !attrs->isAccessor() ? v->asReturnedValue() : Object::getValue(thisObject, *v, *attrs);
-        }
-
-        obj = obj->prototype();
-    }
-    return Primitive::emptyValue().asReturnedValue();
-}
-
-ReturnedValue Lookup::lookup(const Object *thisObject, PropertyAttributes *attrs)
-{
-    Heap::Object *obj = thisObject->d();
-    ExecutionEngine *engine = thisObject->engine();
-    Identifier *name = engine->current->compilationUnit->runtimeStrings[nameIndex]->identifier;
-    int i = 0;
-    while (i < Size && obj) {
-        classList[i] = obj->internalClass;
-
-        index = obj->internalClass->find(name);
-        if (index != UINT_MAX) {
-            level = i;
-            *attrs = obj->internalClass->propertyData.at(index);
-            const Value *v = obj->propertyData(index);
-            return !attrs->isAccessor() ? v->asReturnedValue() : thisObject->getValue(*v, *attrs);
-        }
-
-        obj = obj->prototype();
-        ++i;
-    }
-    level = Size;
-
-    while (obj) {
-        index = obj->internalClass->find(name);
-        if (index != UINT_MAX) {
-            *attrs = obj->internalClass->propertyData.at(index);
-            const Value *v = obj->propertyData(index);
-            return !attrs->isAccessor() ? v->asReturnedValue() : thisObject->getValue(*v, *attrs);
-        }
-
-        obj = obj->prototype();
-    }
-    return Primitive::emptyValue().asReturnedValue();
-}
-
-ReturnedValue Lookup::indexedGetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index)
-{
-    uint idx;
-    if (object.isObject() && index.asArrayIndex(idx)) {
-        l->indexedGetter = indexedGetterObjectInt;
-        return indexedGetterObjectInt(l, engine, object, index);
-    }
-    return indexedGetterFallback(l, engine, object, index);
-}
-
-ReturnedValue Lookup::indexedGetterFallback(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index)
-{
-    Q_UNUSED(l);
-    Scope scope(engine);
-    uint idx = 0;
-    bool isInt = index.asArrayIndex(idx);
-
-    ScopedObject o(scope, object);
-    if (!o) {
-        if (isInt) {
-            if (const String *str = object.as<String>()) {
-                if (idx >= (uint)str->toQString().length()) {
-                    return Encode::undefined();
-                }
-                const QString s = str->toQString().mid(idx, 1);
-                return scope.engine->newString(s)->asReturnedValue();
+    while (proto) {
+        auto index = proto->internalClass->findValueOrGetter(name);
+        if (index.isValid()) {
+            PropertyAttributes attrs = index.attrs;
+            protoLookup.data = proto->propertyData(index.index);
+            if (attrs.isData()) {
+                getter = getterProto;
+            } else {
+                getter = getterProtoAccessor;
             }
-        }
-
-        if (object.isNullOrUndefined()) {
-            QString message = QStringLiteral("Cannot read property '%1' of %2").arg(index.toQStringNoThrow()).arg(object.toQStringNoThrow());
-            return engine->throwTypeError(message);
-        }
-
-        o = RuntimeHelpers::convertToObject(scope.engine, object);
-        if (!o) // type error
-            return Encode::undefined();
-    }
-
-    if (isInt) {
-        if (o->d()->arrayData && !o->d()->arrayData->attrs) {
-            ScopedValue v(scope, Scoped<ArrayData>(scope, o->arrayData())->get(idx));
-            if (!v->isEmpty())
-                return v->asReturnedValue();
-        }
-
-        return o->getIndexed(idx);
-    }
-
-    ScopedString name(scope, index.toString(scope.engine));
-    if (scope.hasException())
-        return Encode::undefined();
-    return o->get(name);
-
-}
-
-
-ReturnedValue Lookup::indexedGetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index)
-{
-    uint idx;
-    if (index.asArrayIndex(idx)) {
-        if (Heap::Base *b = object.heapObject()) {
-            if (b->vtable()->isObject) {
-                Heap::Object *o = static_cast<Heap::Object *>(b);
-                if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
-                    Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
-                    if (idx < s->values.size)
-                        if (!s->data(idx).isEmpty())
-                            return s->data(idx).asReturnedValue();
-                }
-            }
-        }
-    }
-
-    return indexedGetterFallback(l, engine, object, index);
-}
-
-void Lookup::indexedSetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v)
-{
-    if (Object *o = object.objectValue()) {
-        uint idx;
-        if (o->d()->arrayData && o->d()->arrayData->type == Heap::ArrayData::Simple && index.asArrayIndex(idx)) {
-            l->indexedSetter = indexedSetterObjectInt;
-            indexedSetterObjectInt(l, engine, object, index, v);
             return;
         }
+        proto = proto->prototype();
     }
-    indexedSetterFallback(l, engine, object, index, v);
+    // ### put in a getterNotFound!
+    getter = getterFallback;
 }
 
-void Lookup::indexedSetterFallback(Lookup *, ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)
+ReturnedValue Lookup::resolveGetter(ExecutionEngine *engine, const Object *object)
 {
-    Scope scope(engine);
-    ScopedObject o(scope, object.toObject(scope.engine));
-    if (scope.engine->hasException)
-        return;
-
-    uint idx;
-    if (index.asArrayIndex(idx)) {
-        if (o->d()->arrayData && o->d()->arrayData->type == Heap::ArrayData::Simple) {
-            Heap::SimpleArrayData *s = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-            if (idx < s->values.size) {
-                s->setData(engine, idx, value);
-                return;
-            }
-        }
-        o->putIndexed(idx, value);
-        return;
+    Heap::Object *obj = object->d();
+    PropertyKey name = engine->identifierTable->asPropertyKey(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    if (name.isArrayIndex()) {
+        indexedLookup.index = name.asArrayIndex();
+        getter = getterIndexed;
+        return getter(this, engine, *object);
     }
 
-    ScopedString name(scope, index.toString(scope.engine));
-    o->put(name, value);
-}
-
-void Lookup::indexedSetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v)
-{
-    uint idx;
-    if (index.asArrayIndex(idx)) {
-        if (Heap::Base *b = object.heapObject()) {
-            if (b->vtable()->isObject) {
-                Heap::Object *o = static_cast<Heap::Object *>(b);
-                if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
-                    Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
-                    if (idx < s->values.size) {
-                        s->setData(engine, idx, v);
-                        return;
-                    }
-                }
+    auto index = obj->internalClass->findValueOrGetter(name);
+    if (index.isValid()) {
+        PropertyAttributes attrs = index.attrs;
+        uint nInline = obj->vtable()->nInlineProperties;
+        if (attrs.isData()) {
+            if (index.index < obj->vtable()->nInlineProperties) {
+                index.index += obj->vtable()->inlinePropertyOffset;
+                getter = getter0Inline;
+            } else {
+                index.index -= nInline;
+                getter = getter0MemberData;
             }
+        } else {
+            getter = getterAccessor;
         }
+        objectLookup.ic = obj->internalClass;
+        objectLookup.offset = index.index;
+        return getter(this, engine, *object);
     }
-    indexedSetterFallback(l, engine, object, index, v);
+
+    protoLookup.protoId = obj->internalClass->protoId;
+    resolveProtoGetter(name, obj->prototype());
+    return getter(this, engine, *object);
 }
 
-ReturnedValue Lookup::getterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::resolvePrimitiveGetter(ExecutionEngine *engine, const Value &object)
 {
-    if (const Object *o = object.as<Object>())
-        return o->getLookup(l);
-
-    Object *proto;
-    switch (object.type()) {
+    primitiveLookup.type = object.type();
+    switch (primitiveLookup.type) {
     case Value::Undefined_Type:
     case Value::Null_Type:
         return engine->throwTypeError();
     case Value::Boolean_Type:
-        proto = engine->booleanPrototype();
+        primitiveLookup.proto = engine->booleanPrototype()->d();
         break;
     case Value::Managed_Type: {
-        Q_ASSERT(object.isString());
-        proto = engine->stringPrototype();
+        // ### Should move this over to the Object path, as strings also have an internalClass
+        Q_ASSERT(object.isStringOrSymbol());
+        primitiveLookup.proto = static_cast<const Managed &>(object).internalClass()->prototype;
+        Q_ASSERT(primitiveLookup.proto);
         Scope scope(engine);
-        ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-        if (name->equals(engine->id_length())) {
+        ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+        if (object.isString() && name->equals(engine->id_length())) {
             // special case, as the property is on the object itself
-            l->getter = stringLengthGetter;
-            return stringLengthGetter(l, engine, object);
+            getter = stringLengthGetter;
+            return stringLengthGetter(this, engine, object);
         }
         break;
     }
     case Value::Integer_Type:
     default: // Number
-        proto = engine->numberPrototype();
+        primitiveLookup.proto = engine->numberPrototype()->d();
     }
 
-    PropertyAttributes attrs;
-    ReturnedValue v = l->lookup(object, proto, &attrs);
-    if (v != Primitive::emptyValue().asReturnedValue()) {
-        l->type = object.type();
-        l->proto = proto->d();
-        if (attrs.isData()) {
-            if (l->level == 0) {
-                uint nInline = l->proto->vtable()->nInlineProperties;
-                if (l->index < nInline)
-                    l->getter = Lookup::primitiveGetter0Inline;
-                else {
-                    l->index -= nInline;
-                    l->getter = Lookup::primitiveGetter0MemberData;
-                }
-            } else if (l->level == 1)
-                l->getter = Lookup::primitiveGetter1;
-            return v;
-        } else {
-            if (l->level == 0)
-                l->getter = Lookup::primitiveGetterAccessor0;
-            else if (l->level == 1)
-                l->getter = Lookup::primitiveGetterAccessor1;
-            return v;
-        }
+    PropertyKey name = engine->identifierTable->asPropertyKey(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    protoLookup.protoId = primitiveLookup.proto->internalClass->protoId;
+    resolveProtoGetter(name, primitiveLookup.proto);
+
+    if (getter == getterProto)
+        getter = primitiveGetterProto;
+    else if (getter == getterProtoAccessor)
+        getter = primitiveGetterAccessor;
+    return getter(this, engine, object);
+}
+
+ReturnedValue Lookup::resolveGlobalGetter(ExecutionEngine *engine)
+{
+    Object *o = engine->globalObject;
+    PropertyKey name = engine->identifierTable->asPropertyKey(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    protoLookup.protoId = o->internalClass()->protoId;
+    resolveProtoGetter(name, o->d());
+
+    if (getter == getterProto)
+        globalGetter = globalGetterProto;
+    else if (getter == getterProtoAccessor)
+        globalGetter = globalGetterProtoAccessor;
+    else {
+        globalGetter = globalGetterGeneric;
+        Scope scope(engine);
+        ScopedString n(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+        return engine->throwReferenceError(n);
     }
+    return globalGetter(this, engine);
+}
 
-    return Encode::undefined();
+ReturnedValue Lookup::getterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object)
+{
+    if (const Object *o = object.as<Object>())
+        return l->resolveGetter(engine, o);
+    return l->resolvePrimitiveGetter(engine, object);
 }
 
 ReturnedValue Lookup::getterTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
-    Lookup l1 = *l;
-
-    if (l1.getter == Lookup::getter0MemberData || l1.getter == Lookup::getter0Inline || l1.getter == Lookup::getter1) {
-        if (const Object *o = object.as<Object>()) {
-            ReturnedValue v = o->getLookup(l);
-            Lookup l2 = *l;
-
-            if (l2.index != UINT_MAX) {
-                if (l1.getter != Lookup::getter0Inline) {
-                    if (l2.getter == Lookup::getter0Inline ||
-                        (l1.getter != Lookup::getter0MemberData && l2.getter == Lookup::getter0MemberData))
-                        // sort the better getter first
-                        qSwap(l1, l2);
-                }
-
-                l->classList[0] = l1.classList[0];
-                l->classList[1] = l1.classList[1];
-                l->classList[2] = l2.classList[0];
-                l->classList[3] = l2.classList[1];
-                l->index = l1.index;
-                l->index2 = l2.index;
-
-                if (l1.getter == Lookup::getter0Inline) {
-                    if (l2.getter == Lookup::getter0Inline)
-                        l->getter = Lookup::getter0Inlinegetter0Inline;
-                    else if (l2.getter == Lookup::getter0MemberData)
-                        l->getter = Lookup::getter0Inlinegetter0MemberData;
-                    else if (l2.getter == Lookup::getter1)
-                        l->getter = Lookup::getter0Inlinegetter1;
-                    else
-                        Q_UNREACHABLE();
-                } else if (l1.getter == Lookup::getter0MemberData) {
-                    if (l2.getter == Lookup::getter0MemberData)
-                        l->getter = Lookup::getter0MemberDatagetter0MemberData;
-                    else if (l2.getter == Lookup::getter1)
-                        l->getter = Lookup::getter0MemberDatagetter1;
-                    else
-                        Q_UNREACHABLE();
-                } else {
-                    Q_ASSERT(l1.getter == Lookup::getter1 && l2.getter == Lookup::getter1);
-                    l->getter = Lookup::getter1getter1;
-                }
-                return v;
-            }
+    if (const Object *o = object.as<Object>()) {
+        Lookup first = *l;
+        Lookup second = *l;
+
+        ReturnedValue result = second.resolveGetter(engine, o);
+
+        if (first.getter == getter0Inline && (second.getter == getter0Inline || second.getter == getter0MemberData)) {
+            l->objectLookupTwoClasses.ic = first.objectLookup.ic;
+            l->objectLookupTwoClasses.ic2 = second.objectLookup.ic;
+            l->objectLookupTwoClasses.offset = first.objectLookup.offset;
+            l->objectLookupTwoClasses.offset2 = second.objectLookup.offset;
+            l->getter = second.getter == getter0Inline ? getter0Inlinegetter0Inline : getter0Inlinegetter0MemberData;
+            return result;
         }
+        if (first.getter == getter0MemberData && (second.getter == getter0Inline || second.getter == getter0MemberData)) {
+            l->objectLookupTwoClasses.ic = second.objectLookup.ic;
+            l->objectLookupTwoClasses.ic2 = first.objectLookup.ic;
+            l->objectLookupTwoClasses.offset = second.objectLookup.offset;
+            l->objectLookupTwoClasses.offset2 = first.objectLookup.offset;
+            l->getter = second.getter == getter0Inline ? getter0Inlinegetter0MemberData : getter0MemberDatagetter0MemberData;
+            return result;
+        }
+        if (first.getter == getterProto && second.getter == getterProto) {
+            l->protoLookupTwoClasses.protoId = first.protoLookup.protoId;
+            l->protoLookupTwoClasses.protoId2 = second.protoLookup.protoId;
+            l->protoLookupTwoClasses.data = first.protoLookup.data;
+            l->protoLookupTwoClasses.data2 = second.protoLookup.data;
+            l->getter = getterProtoTwoClasses;
+            return result;
+        }
+        if (first.getter == getterProtoAccessor && second.getter == getterProtoAccessor) {
+            l->protoLookupTwoClasses.protoId = first.protoLookup.protoId;
+            l->protoLookupTwoClasses.protoId2 = second.protoLookup.protoId;
+            l->protoLookupTwoClasses.data = first.protoLookup.data;
+            l->protoLookupTwoClasses.data2 = second.protoLookup.data;
+            l->getter = getterProtoAccessorTwoClasses;
+            return result;
+        }
+
     }
 
     l->getter = getterFallback;
@@ -368,7 +222,7 @@ ReturnedValue Lookup::getterFallback(Lookup *l, ExecutionEngine *engine, const V
     QV4::ScopedObject o(scope, object.toObject(scope.engine));
     if (!o)
         return Encode::undefined();
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
     return o->get(name);
 }
 
@@ -378,8 +232,8 @@ ReturnedValue Lookup::getter0MemberData(Lookup *l, ExecutionEngine *engine, cons
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->memberData->values.data()[l->index].asReturnedValue();
+        if (l->objectLookup.ic == o->internalClass)
+            return o->memberData->values.data()[l->objectLookup.offset].asReturnedValue();
     }
     return getterTwoClasses(l, engine, object);
 }
@@ -390,53 +244,37 @@ ReturnedValue Lookup::getter0Inline(Lookup *l, ExecutionEngine *engine, const Va
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->inlinePropertyData(l->index)->asReturnedValue();
+        if (l->objectLookup.ic == o->internalClass)
+            return o->inlinePropertyDataWithOffset(l->objectLookup.offset)->asReturnedValue();
     }
     return getterTwoClasses(l, engine, object);
 }
 
-ReturnedValue Lookup::getter1(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::getterProto(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
     // we can safely cast to a QV4::Object here. If object is actually a string,
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass && l->classList[1] == l->proto->internalClass)
-            return l->proto->propertyData(l->index)->asReturnedValue();
+        if (l->protoLookup.protoId == o->internalClass->protoId)
+            return l->protoLookup.data->asReturnedValue();
     }
     return getterTwoClasses(l, engine, object);
 }
 
-ReturnedValue Lookup::getter2(Lookup *l, ExecutionEngine *engine, const Value &object)
-{
-    // we can safely cast to a QV4::Object here. If object is actually a string,
-    // the internal class won't match
-    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
-    if (o) {
-        if (l->classList[0] == o->internalClass) {
-            Q_ASSERT(l->proto == o->prototype());
-            if (l->classList[1] == l->proto->internalClass) {
-                Heap::Object *p = l->proto->prototype();
-                if (l->classList[2] == p->internalClass)
-                    return p->propertyData(l->index)->asReturnedValue();
-            }
-        }
-    }
-    l->getter = getterFallback;
-    return getterFallback(l, engine, object);
-}
-
 ReturnedValue Lookup::getter0Inlinegetter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
     // we can safely cast to a QV4::Object here. If object is actually a string,
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->inlinePropertyData(l->index)->asReturnedValue();
-        if (l->classList[2] == o->internalClass)
-            return o->inlinePropertyData(l->index2)->asReturnedValue();
+        if (l->objectLookupTwoClasses.ic == o->internalClass)
+            return o->inlinePropertyDataWithOffset(l->objectLookupTwoClasses.offset)->asReturnedValue();
+        if (l->objectLookupTwoClasses.ic2 == o->internalClass)
+            return o->inlinePropertyDataWithOffset(l->objectLookupTwoClasses.offset2)->asReturnedValue();
+        Value obj = Value::fromHeapObject(o);
+        Value str = Value::fromHeapObject(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
+        return static_cast<Object &>(obj).get(&static_cast<String &>(str));
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
@@ -448,10 +286,13 @@ ReturnedValue Lookup::getter0Inlinegetter0MemberData(Lookup *l, ExecutionEngine
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->inlinePropertyData(l->index)->asReturnedValue();
-        if (l->classList[2] == o->internalClass)
-            return o->memberData->values.data()[l->index2].asReturnedValue();
+        if (l->objectLookupTwoClasses.ic == o->internalClass)
+            return o->inlinePropertyDataWithOffset(l->objectLookupTwoClasses.offset)->asReturnedValue();
+        if (l->objectLookupTwoClasses.ic2 == o->internalClass)
+            return o->memberData->values.data()[l->objectLookupTwoClasses.offset2].asReturnedValue();
+        Value obj = Value::fromHeapObject(o);
+        Value str = Value::fromHeapObject(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
+        return static_cast<Object &>(obj).get(&static_cast<String &>(str));
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
@@ -463,206 +304,130 @@ ReturnedValue Lookup::getter0MemberDatagetter0MemberData(Lookup *l, ExecutionEng
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->memberData->values.data()[l->index].asReturnedValue();
-        if (l->classList[2] == o->internalClass)
-            return o->memberData->values.data()[l->index2].asReturnedValue();
+        if (l->objectLookupTwoClasses.ic == o->internalClass)
+            return o->memberData->values.data()[l->objectLookupTwoClasses.offset].asReturnedValue();
+        if (l->objectLookupTwoClasses.ic2 == o->internalClass)
+            return o->memberData->values.data()[l->objectLookupTwoClasses.offset2].asReturnedValue();
+        Value obj = Value::fromHeapObject(o);
+        Value str = Value::fromHeapObject(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
+        return static_cast<Object &>(obj).get(&static_cast<String &>(str));
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
 }
 
-ReturnedValue Lookup::getter0Inlinegetter1(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::getterProtoTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
     // we can safely cast to a QV4::Object here. If object is actually a string,
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->inlinePropertyData(l->index)->asReturnedValue();
-        if (l->classList[2] == o->internalClass && l->classList[3] == o->prototype()->internalClass)
-            return o->prototype()->propertyData(l->index2)->asReturnedValue();
+        if (l->protoLookupTwoClasses.protoId == o->internalClass->protoId)
+            return l->protoLookupTwoClasses.data->asReturnedValue();
+        if (l->protoLookupTwoClasses.protoId2 == o->internalClass->protoId)
+            return l->protoLookupTwoClasses.data2->asReturnedValue();
+        Value obj = Value::fromHeapObject(o);
+        Value str = Value::fromHeapObject(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
+        return static_cast<Object &>(obj).get(&static_cast<String &>(str));
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
 }
 
-ReturnedValue Lookup::getter0MemberDatagetter1(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::getterAccessor(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
     // we can safely cast to a QV4::Object here. If object is actually a string,
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass)
-            return o->memberData->values.data()[l->index].asReturnedValue();
-        if (l->classList[2] == o->internalClass && l->classList[3] == o->prototype()->internalClass)
-            return o->prototype()->propertyData(l->index2)->asReturnedValue();
-    }
-    l->getter = getterFallback;
-    return getterFallback(l, engine, object);
-}
+        if (l->objectLookup.ic == o->internalClass) {
+            const Value *getter = o->propertyData(l->objectLookup.offset);
+            if (!getter->isFunctionObject()) // ### catch at resolve time
+                return Encode::undefined();
 
-ReturnedValue Lookup::getter1getter1(Lookup *l, ExecutionEngine *engine, const Value &object)
-{
-    // we can safely cast to a QV4::Object here. If object is actually a string,
-    // the internal class won't match
-    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
-    if (o) {
-        if (l->classList[0] == o->internalClass &&
-            l->classList[1] == o->prototype()->internalClass)
-            return o->prototype()->propertyData(l->index)->asReturnedValue();
-        if (l->classList[2] == o->internalClass &&
-            l->classList[3] == o->prototype()->internalClass)
-            return o->prototype()->propertyData(l->index2)->asReturnedValue();
-        return getterFallback(l, engine, object);
+            return static_cast<const FunctionObject *>(getter)->call(&object, nullptr, 0);
+        }
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
 }
 
-
-ReturnedValue Lookup::getterAccessor0(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::getterProtoAccessor(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
     // we can safely cast to a QV4::Object here. If object is actually a string,
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
-    if (o) {
-        if (l->classList[0] == o->internalClass) {
-            Scope scope(o->internalClass->engine);
-            ScopedFunctionObject getter(scope, o->propertyData(l->index + Object::GetterOffset));
-            if (!getter)
-                return Encode::undefined();
+    if (o && l->protoLookup.protoId == o->internalClass->protoId) {
+        const Value *getter = l->protoLookup.data;
+        if (!getter->isFunctionObject()) // ### catch at resolve time
+            return Encode::undefined();
 
-            ScopedCallData callData(scope, 0);
-            callData->thisObject = object;
-            getter->call(scope, callData);
-            return scope.result.asReturnedValue();
-        }
+        return static_cast<const FunctionObject *>(getter)->call(&object, nullptr, 0);
     }
-    l->getter = getterFallback;
-    return getterFallback(l, engine, object);
+    return getterTwoClasses(l, engine, object);
 }
 
-ReturnedValue Lookup::getterAccessor1(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::getterProtoAccessorTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
     // we can safely cast to a QV4::Object here. If object is actually a string,
     // the internal class won't match
     Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
     if (o) {
-        if (l->classList[0] == o->internalClass &&
-            l->classList[1] == l->proto->internalClass) {
-            Scope scope(o->internalClass->engine);
-            ScopedFunctionObject getter(scope, o->prototype()->propertyData(l->index + Object::GetterOffset));
-            if (!getter)
+        const Value *getter = nullptr;
+        if (l->protoLookupTwoClasses.protoId == o->internalClass->protoId)
+            getter = l->protoLookupTwoClasses.data;
+        else if (l->protoLookupTwoClasses.protoId2 == o->internalClass->protoId)
+            getter = l->protoLookupTwoClasses.data2;
+        if (getter) {
+            if (!getter->isFunctionObject()) // ### catch at resolve time
                 return Encode::undefined();
 
-            ScopedCallData callData(scope, 0);
-            callData->thisObject = object;
-            getter->call(scope, callData);
-            return scope.result.asReturnedValue();
+            return static_cast<const FunctionObject *>(getter)->call(&object, nullptr, 0);
         }
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
 }
 
-ReturnedValue Lookup::getterAccessor2(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::getterIndexed(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
-    // we can safely cast to a QV4::Object here. If object is actually a string,
-    // the internal class won't match
-    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
+    Object *o = object.objectValue();
     if (o) {
-        if (l->classList[0] == o->internalClass) {
-            Q_ASSERT(o->prototype() == l->proto);
-            if (l->classList[1] == l->proto->internalClass) {
-                o = l->proto->prototype();
-                if (l->classList[2] == o->internalClass) {
-                    Scope scope(o->internalClass->engine);
-                    ScopedFunctionObject getter(scope, o->propertyData(l->index + Object::GetterOffset));
-                    if (!getter)
-                        return Encode::undefined();
-
-                    ScopedCallData callData(scope, 0);
-                    callData->thisObject = object;
-                    getter->call(scope, callData);
-                    return scope.result.asReturnedValue();
-                }
-            }
+        Heap::Object *ho = o->d();
+        if (ho->arrayData && ho->arrayData->type == Heap::ArrayData::Simple) {
+            Heap::SimpleArrayData *s = ho->arrayData.cast<Heap::SimpleArrayData>();
+            if (l->indexedLookup.index < s->values.size)
+                if (!s->data(l->indexedLookup.index).isEmpty())
+                    return s->data(l->indexedLookup.index).asReturnedValue();
         }
+        return o->get(l->indexedLookup.index);
     }
     l->getter = getterFallback;
     return getterFallback(l, engine, object);
-}
 
-ReturnedValue Lookup::primitiveGetter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object)
-{
-    if (object.type() == l->type) {
-        Heap::Object *o = l->proto;
-        if (l->classList[0] == o->internalClass)
-            return o->inlinePropertyData(l->index)->asReturnedValue();
-    }
-    l->getter = getterGeneric;
-    return getterGeneric(l, engine, object);
-}
-
-ReturnedValue Lookup::primitiveGetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object)
-{
-    if (object.type() == l->type) {
-        Heap::Object *o = l->proto;
-        if (l->classList[0] == o->internalClass)
-            return o->memberData->values.data()[l->index].asReturnedValue();
-    }
-    l->getter = getterGeneric;
-    return getterGeneric(l, engine, object);
 }
 
-ReturnedValue Lookup::primitiveGetter1(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::primitiveGetterProto(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
-    if (object.type() == l->type) {
-        Heap::Object *o = l->proto;
-        if (l->classList[0] == o->internalClass &&
-            l->classList[1] == o->prototype()->internalClass)
-            return o->prototype()->propertyData(l->index)->asReturnedValue();
+    if (object.type() == l->primitiveLookup.type) {
+        Heap::Object *o = l->primitiveLookup.proto;
+        if (l->primitiveLookup.protoId == o->internalClass->protoId)
+            return l->primitiveLookup.data->asReturnedValue();
     }
     l->getter = getterGeneric;
     return getterGeneric(l, engine, object);
 }
 
-ReturnedValue Lookup::primitiveGetterAccessor0(Lookup *l, ExecutionEngine *engine, const Value &object)
+ReturnedValue Lookup::primitiveGetterAccessor(Lookup *l, ExecutionEngine *engine, const Value &object)
 {
-    if (object.type() == l->type) {
-        Heap::Object *o = l->proto;
-        if (l->classList[0] == o->internalClass) {
-            Scope scope(o->internalClass->engine);
-            ScopedFunctionObject getter(scope, o->propertyData(l->index + Object::GetterOffset));
-            if (!getter)
+    if (object.type() == l->primitiveLookup.type) {
+        Heap::Object *o = l->primitiveLookup.proto;
+        if (l->primitiveLookup.protoId == o->internalClass->protoId) {
+            const Value *getter = l->primitiveLookup.data;
+            if (!getter->isFunctionObject()) // ### catch at resolve time
                 return Encode::undefined();
 
-            ScopedCallData callData(scope, 0);
-            callData->thisObject = object;
-            getter->call(scope, callData);
-            return scope.result.asReturnedValue();
-        }
-    }
-    l->getter = getterGeneric;
-    return getterGeneric(l, engine, object);
-}
-
-ReturnedValue Lookup::primitiveGetterAccessor1(Lookup *l, ExecutionEngine *engine, const Value &object)
-{
-    if (object.type() == l->type) {
-        Heap::Object *o = l->proto;
-        if (l->classList[0] == o->internalClass &&
-            l->classList[1] == o->prototype()->internalClass) {
-            Scope scope(o->internalClass->engine);
-            ScopedFunctionObject getter(scope, o->prototype()->propertyData(l->index + Object::GetterOffset));
-            if (!getter)
-                return Encode::undefined();
-
-            ScopedCallData callData(scope, 0);
-            callData->thisObject = object;
-            getter->call(scope, callData);
-            return scope.result.asReturnedValue();
+            return static_cast<const FunctionObject *>(getter)->call(&object, nullptr, 0);
         }
     }
     l->getter = getterGeneric;
@@ -678,296 +443,206 @@ ReturnedValue Lookup::stringLengthGetter(Lookup *l, ExecutionEngine *engine, con
     return getterGeneric(l, engine, object);
 }
 
-ReturnedValue Lookup::arrayLengthGetter(Lookup *l, ExecutionEngine *engine, const Value &object)
-{
-    if (const ArrayObject *a = object.as<ArrayObject>())
-        return a->propertyData(Heap::ArrayObject::LengthPropertyIndex)->asReturnedValue();
-
-    l->getter = getterGeneric;
-    return getterGeneric(l, engine, object);
-}
-
-
 ReturnedValue Lookup::globalGetterGeneric(Lookup *l, ExecutionEngine *engine)
 {
-    Object *o = engine->globalObject;
-    PropertyAttributes attrs;
-    ReturnedValue v = l->lookup(o, &attrs);
-    if (v != Primitive::emptyValue().asReturnedValue()) {
-        if (attrs.isData()) {
-            if (l->level == 0) {
-                uint nInline = o->d()->vtable()->nInlineProperties;
-                if (l->index < nInline)
-                    l->globalGetter = globalGetter0Inline;
-                else {
-                    l->index -= nInline;
-                    l->globalGetter = globalGetter0MemberData;
-                }
-            } else if (l->level == 1)
-                l->globalGetter = globalGetter1;
-            else if (l->level == 2)
-                l->globalGetter = globalGetter2;
-            return v;
-        } else {
-            if (l->level == 0)
-                l->globalGetter = globalGetterAccessor0;
-            else if (l->level == 1)
-                l->globalGetter = globalGetterAccessor1;
-            else if (l->level == 2)
-                l->globalGetter = globalGetterAccessor2;
-            return v;
-        }
-    }
-    Scope scope(engine);
-    ScopedString n(scope, engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-    return engine->throwReferenceError(n);
-}
-
-ReturnedValue Lookup::globalGetter0Inline(Lookup *l, ExecutionEngine *engine)
-{
-    Object *o = engine->globalObject;
-    if (l->classList[0] == o->internalClass())
-        return o->d()->inlinePropertyData(l->index)->asReturnedValue();
-
-    l->globalGetter = globalGetterGeneric;
-    return globalGetterGeneric(l, engine);
+    return l->resolveGlobalGetter(engine);
 }
 
-ReturnedValue Lookup::globalGetter0MemberData(Lookup *l, ExecutionEngine *engine)
+ReturnedValue Lookup::globalGetterProto(Lookup *l, ExecutionEngine *engine)
 {
-    Object *o = engine->globalObject;
-    if (l->classList[0] == o->internalClass())
-        return o->d()->memberData->values.data()[l->index].asReturnedValue();
-
+    Heap::Object *o = engine->globalObject->d();
+    if (l->protoLookup.protoId == o->internalClass->protoId)
+        return l->protoLookup.data->asReturnedValue();
     l->globalGetter = globalGetterGeneric;
     return globalGetterGeneric(l, engine);
 }
 
-ReturnedValue Lookup::globalGetter1(Lookup *l, ExecutionEngine *engine)
+ReturnedValue Lookup::globalGetterProtoAccessor(Lookup *l, ExecutionEngine *engine)
 {
-    Object *o = engine->globalObject;
-    if (l->classList[0] == o->internalClass() &&
-        l->classList[1] == o->prototype()->internalClass)
-        return o->prototype()->propertyData(l->index)->asReturnedValue();
+    Heap::Object *o = engine->globalObject->d();
+    if (l->protoLookup.protoId == o->internalClass->protoId) {
+        const Value *getter = l->protoLookup.data;
+        if (!getter->isFunctionObject()) // ### catch at resolve time
+            return Encode::undefined();
 
+        return static_cast<const FunctionObject *>(getter)->call(engine->globalObject, nullptr, 0);
+    }
     l->globalGetter = globalGetterGeneric;
     return globalGetterGeneric(l, engine);
 }
 
-ReturnedValue Lookup::globalGetter2(Lookup *l, ExecutionEngine *engine)
+bool Lookup::resolveSetter(ExecutionEngine *engine, Object *object, const Value &value)
 {
-    Heap::Object *o = engine->globalObject->d();
-    if (l->classList[0] == o->internalClass) {
-        o = o->prototype();
-        if (l->classList[1] == o->internalClass) {
-            o = o->prototype();
-            if (l->classList[2] == o->internalClass) {
-                return o->prototype()->propertyData(l->index)->asReturnedValue();
+    Scope scope(engine);
+    ScopedString name(scope, scope.engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+
+    Heap::InternalClass *c = object->internalClass();
+    PropertyKey key = name->toPropertyKey();
+    auto idx = c->findValueOrSetter(key);
+    if (idx.isValid()) {
+        if (object->isArrayObject() && idx.index == Heap::ArrayObject::LengthPropertyIndex) {
+            Q_ASSERT(!idx.attrs.isAccessor());
+            setter = arrayLengthSetter;
+            return setter(this, engine, *object, value);
+        } else if (idx.attrs.isData() && idx.attrs.isWritable()) {
+            objectLookup.ic = object->internalClass();
+            objectLookup.index = idx.index;
+            const auto nInline = object->d()->vtable()->nInlineProperties;
+            if (idx.index < nInline) {
+                setter = Lookup::setter0Inline;
+                objectLookup.offset = idx.index + object->d()->vtable()->inlinePropertyOffset;
+            } else {
+                setter = Lookup::setter0MemberData;
+                objectLookup.offset = idx.index - nInline;
             }
+            return setter(this, engine, *object, value);
+        } else {
+            // ### handle setter
+            setter = setterFallback;
         }
+        return setter(this, engine, *object, value);
     }
-    l->globalGetter = globalGetterGeneric;
-    return globalGetterGeneric(l, engine);
-}
 
-ReturnedValue Lookup::globalGetterAccessor0(Lookup *l, ExecutionEngine *engine)
-{
-    Object *o = engine->globalObject;
-    if (l->classList[0] == o->internalClass()) {
-        Scope scope(o->engine());
-        ScopedFunctionObject getter(scope, o->propertyData(l->index + Object::GetterOffset));
-        if (!getter)
-            return Encode::undefined();
-
-        ScopedCallData callData(scope, 0);
-        callData->thisObject = Primitive::undefinedValue();
-        getter->call(scope, callData);
-        return scope.result.asReturnedValue();
+    insertionLookup.protoId = c->protoId;
+    if (!object->put(key, value)) {
+        setter = Lookup::setterFallback;
+        return false;
     }
-    l->globalGetter = globalGetterGeneric;
-    return globalGetterGeneric(l, engine);
-}
 
-ReturnedValue Lookup::globalGetterAccessor1(Lookup *l, ExecutionEngine *engine)
-{
-    Object *o = engine->globalObject;
-    if (l->classList[0] == o->internalClass() &&
-        l->classList[1] == o->prototype()->internalClass) {
-        Scope scope(o->engine());
-        ScopedFunctionObject getter(scope, o->prototype()->propertyData(l->index + Object::GetterOffset));
-        if (!getter)
-            return Encode::undefined();
-
-        ScopedCallData callData(scope, 0);
-        callData->thisObject = Primitive::undefinedValue();
-        getter->call(scope, callData);
-        return scope.result.asReturnedValue();
+    if (object->internalClass() == c) {
+        // ### setter in the prototype, should handle this
+        setter = setterFallback;
+        return true;
     }
-    l->globalGetter = globalGetterGeneric;
-    return globalGetterGeneric(l, engine);
-}
-
-ReturnedValue Lookup::globalGetterAccessor2(Lookup *l, ExecutionEngine *engine)
-{
-    Heap::Object *o = engine->globalObject->d();
-    if (l->classList[0] == o->internalClass) {
-        o = o->prototype();
-        if (l->classList[1] == o->internalClass) {
-            o = o->prototype();
-            if (l->classList[2] == o->internalClass) {
-                Scope scope(o->internalClass->engine);
-                ScopedFunctionObject getter(scope, o->propertyData(l->index + Object::GetterOffset));
-                if (!getter)
-                    return Encode::undefined();
-
-                ScopedCallData callData(scope, 0);
-                callData->thisObject = Primitive::undefinedValue();
-                getter->call(scope, callData);
-                return scope.result.asReturnedValue();
-            }
-        }
+    idx = object->internalClass()->findValueOrSetter(key);
+    if (!idx.isValid() || idx.attrs.isAccessor()) { // ### can this even happen?
+        setter = setterFallback;
+        return false;
     }
-    l->globalGetter = globalGetterGeneric;
-    return globalGetterGeneric(l, engine);
+    insertionLookup.newClass = object->internalClass();
+    insertionLookup.offset = idx.index;
+    setter = setterInsert;
+    return true;
 }
 
-void Lookup::setterGeneric(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setterGeneric(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
+    if (object.isObject())
+        return l->resolveSetter(engine, static_cast<Object *>(&object), value);
+
+    if (engine->currentStackFrame->v4Function->isStrict())
+        return false;
+
     Scope scope(engine);
-    ScopedObject o(scope, object);
-    if (!o) {
-        o = RuntimeHelpers::convertToObject(scope.engine, object);
-        if (!o) // type error
-            return;
-        ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-        o->put(name, value);
-        return;
-    }
-    o->setLookup(l, value);
+    ScopedObject o(scope, RuntimeHelpers::convertToObject(scope.engine, object));
+    if (!o) // type error
+        return false;
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
+    return o->put(name, value);
 }
 
-void Lookup::setterTwoClasses(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setterTwoClasses(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
-    Lookup l1 = *l;
+    Lookup first = *l;
+    Lookup second = *l;
 
-    if (Object *o = object.as<Object>()) {
-        o->setLookup(l, value);
+    if (object.isObject()) {
+        if (!l->resolveSetter(engine, static_cast<Object *>(&object), value)) {
+            l->setter = setterFallback;
+            return false;
+        }
 
-        if (l->setter == Lookup::setter0 || l->setter == Lookup::setter0Inline) {
+        if (l->setter == Lookup::setter0MemberData || l->setter == Lookup::setter0Inline) {
+            l->objectLookupTwoClasses.ic = first.objectLookup.ic;
+            l->objectLookupTwoClasses.ic2 = second.objectLookup.ic;
+            l->objectLookupTwoClasses.offset = first.objectLookup.index;
+            l->objectLookupTwoClasses.offset2 = second.objectLookup.index;
             l->setter = setter0setter0;
-            l->classList[1] = l1.classList[0];
-            l->index2 = l1.index;
-            return;
+            return true;
         }
     }
 
     l->setter = setterFallback;
-    setterFallback(l, engine, object, value);
+    return setterFallback(l, engine, object, value);
 }
 
-void Lookup::setterFallback(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setterFallback(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
     QV4::Scope scope(engine);
     QV4::ScopedObject o(scope, object.toObject(scope.engine));
-    if (o) {
-        ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-        o->put(name, value);
-    }
-}
-
-void Lookup::setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
-{
-    Object *o = static_cast<Object *>(object.managed());
-    if (o && o->internalClass() == l->classList[0]) {
-        o->setProperty(engine, l->index, value);
-        return;
-    }
+    if (!o)
+        return false;
 
-    setterTwoClasses(l, engine, object, value);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
+    return o->put(name, value);
 }
 
-void Lookup::setter0Inline(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setter0MemberData(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
-    Object *o = static_cast<Object *>(object.managed());
-    if (o && o->internalClass() == l->classList[0]) {
-        o->d()->setInlineProperty(engine, l->index, value);
-        return;
+    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
+    if (o && o->internalClass == l->objectLookup.ic) {
+        o->memberData->values.set(engine, l->objectLookup.offset, value);
+        return true;
     }
 
-    setterTwoClasses(l, engine, object, value);
+    return setterTwoClasses(l, engine, object, value);
 }
 
-void Lookup::setterInsert0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setter0Inline(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
-    Object *o = static_cast<Object *>(object.managed());
-    if (o && o->internalClass() == l->classList[0]) {
-        Q_ASSERT(!o->prototype());
-        o->setInternalClass(l->classList[3]);
-        o->setProperty(l->index, value);
-        return;
+    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
+    if (o && o->internalClass == l->objectLookup.ic) {
+        o->setInlinePropertyWithOffset(engine, l->objectLookup.offset, value);
+        return true;
     }
 
-    l->setter = setterFallback;
-    setterFallback(l, engine, object, value);
+    return setterTwoClasses(l, engine, object, value);
 }
 
-void Lookup::setterInsert1(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setter0setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
-    Object *o = static_cast<Object *>(object.managed());
-    if (o && o->internalClass() == l->classList[0]) {
-        Heap::Object *p = o->prototype();
-        Q_ASSERT(p);
-        if (p->internalClass == l->classList[1]) {
-            Q_ASSERT(!p->prototype());
-            o->setInternalClass(l->classList[3]);
-            o->setProperty(l->index, value);
-            return;
+    Heap::Object *o = static_cast<Heap::Object *>(object.heapObject());
+    if (o) {
+        if (o->internalClass == l->objectLookupTwoClasses.ic) {
+            o->setProperty(engine, l->objectLookupTwoClasses.offset, value);
+            return true;
+        }
+        if (o->internalClass == l->objectLookupTwoClasses.ic2) {
+            o->setProperty(engine, l->objectLookupTwoClasses.offset2, value);
+            return true;
         }
     }
 
     l->setter = setterFallback;
-    setterFallback(l, engine, object, value);
+    return setterFallback(l, engine, object, value);
 }
 
-void Lookup::setterInsert2(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::setterInsert(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
 {
     Object *o = static_cast<Object *>(object.managed());
-    if (o && o->internalClass() == l->classList[0]) {
-        Heap::Object *p = o->prototype();
-        Q_ASSERT(p);
-        if (p->internalClass == l->classList[1]) {
-            p = p->prototype();
-            Q_ASSERT(p);
-            if (p->internalClass == l->classList[2]) {
-                Q_ASSERT(!p->prototype());
-                o->setInternalClass(l->classList[3]);
-                o->setProperty(l->index, value);
-                return;
-            }
-        }
+    if (o && o->internalClass()->protoId == l->insertionLookup.protoId) {
+        o->setInternalClass(l->insertionLookup.newClass);
+        o->d()->setProperty(engine, l->insertionLookup.offset, value);
+        return true;
     }
 
     l->setter = setterFallback;
-    setterFallback(l, engine, object, value);
+    return setterFallback(l, engine, object, value);
 }
 
-void Lookup::setter0setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value)
+bool Lookup::arrayLengthSetter(Lookup *, ExecutionEngine *engine, Value &object, const Value &value)
 {
-    Object *o = static_cast<Object *>(object.managed());
-    if (o) {
-        if (o->internalClass() == l->classList[0]) {
-            o->setProperty(l->index, value);
-            return;
-        }
-        if (o->internalClass() == l->classList[1]) {
-            o->setProperty(l->index2, value);
-            return;
-        }
+    Q_ASSERT(object.isObject() && static_cast<Object &>(object).isArrayObject());
+    bool ok;
+    uint len = value.asArrayLength(&ok);
+    if (!ok) {
+        engine->throwRangeError(value);
+        return false;
     }
-
-    l->setter = setterFallback;
-    setterFallback(l, engine, object, value);
-
+    ok = static_cast<Object &>(object).setArrayLength(len);
+    if (!ok)
+        return false;
+    return true;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4lookup_p.h b/src/qml/jsruntime/qv4lookup_p.h
index ce5189a780..bfe2354427 100644
--- a/src/qml/jsruntime/qv4lookup_p.h
+++ b/src/qml/jsruntime/qv4lookup_p.h
@@ -65,38 +65,67 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 struct Lookup {
-    enum { Size = 4 };
     union {
-        ReturnedValue (*indexedGetter)(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
-        void (*indexedSetter)(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v);
         ReturnedValue (*getter)(Lookup *l, ExecutionEngine *engine, const Value &object);
         ReturnedValue (*globalGetter)(Lookup *l, ExecutionEngine *engine);
-        void (*setter)(Lookup *l, ExecutionEngine *engine, Value &object, const Value &v);
+        bool (*setter)(Lookup *l, ExecutionEngine *engine, Value &object, const Value &v);
     };
     union {
-        InternalClass *classList[Size];
         struct {
-            void *dummy0;
-            void *dummy1;
-            void *dummy2;
+            Heap::Base *h1;
+            Heap::Base *h2;
+            quintptr unused;
+            quintptr unused2;
+        } markDef;
+        struct {
+            Heap::InternalClass *ic;
+            quintptr unused;
+            uint index;
+            uint offset;
+        } objectLookup;
+        struct {
+            quintptr protoId;
+            quintptr _unused;
+            const Value *data;
+        } protoLookup;
+        struct {
+            Heap::InternalClass *ic;
+            Heap::InternalClass *ic2;
+            uint offset;
+            uint offset2;
+        } objectLookupTwoClasses;
+        struct {
+            quintptr protoId;
+            quintptr protoId2;
+            const Value *data;
+            const Value *data2;
+        } protoLookupTwoClasses;
+        struct {
+            // Make sure the next two values are in sync with protoLookup
+            quintptr protoId;
             Heap::Object *proto;
-        };
-    };
-    union {
-        int level;
-        uint index2;
-        unsigned type;
+            const Value *data;
+            quintptr type;
+        } primitiveLookup;
+        struct {
+            Heap::InternalClass *newClass;
+            quintptr protoId;
+            uint offset;
+            uint unused;
+        } insertionLookup;
+        struct {
+            quintptr _unused;
+            quintptr _unused2;
+            uint index;
+            uint unused;
+        } indexedLookup;
     };
-    uint index;
     uint nameIndex;
 
-    static ReturnedValue indexedGetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
-    static ReturnedValue indexedGetterFallback(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
-    static ReturnedValue indexedGetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index);
-
-    static void indexedSetterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v);
-    static void indexedSetterFallback(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &value);
-    static void indexedSetterObjectInt(Lookup *l, ExecutionEngine *engine, const Value &object, const Value &index, const Value &v);
+    ReturnedValue resolveGetter(ExecutionEngine *engine, const Object *object);
+    ReturnedValue resolvePrimitiveGetter(ExecutionEngine *engine, const Value &object);
+    ReturnedValue resolveGlobalGetter(ExecutionEngine *engine);
+    void resolveProtoGetter(PropertyKey name, const Heap::Object *proto);
 
     static ReturnedValue getterGeneric(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getterTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
@@ -104,54 +133,49 @@ struct Lookup {
 
     static ReturnedValue getter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter1(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter2(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getterProto(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter0Inlinegetter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter0Inlinegetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter0MemberDatagetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter0Inlinegetter1(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter0MemberDatagetter1(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter1getter1(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getterAccessor0(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getterAccessor1(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getterAccessor2(Lookup *l, ExecutionEngine *engine, const Value &object);
-
-    static ReturnedValue primitiveGetter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue primitiveGetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue primitiveGetter1(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue primitiveGetterAccessor0(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue primitiveGetterAccessor1(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getterProtoTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getterAccessor(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getterProtoAccessor(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getterProtoAccessorTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getterIndexed(Lookup *l, ExecutionEngine *engine, const Value &object);
+
+    static ReturnedValue primitiveGetterProto(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue primitiveGetterAccessor(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue stringLengthGetter(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue arrayLengthGetter(Lookup *l, ExecutionEngine *engine, const Value &object);
 
     static ReturnedValue globalGetterGeneric(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetter0Inline(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetter0MemberData(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetter1(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetter2(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetterAccessor0(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetterAccessor1(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetterAccessor2(Lookup *l, ExecutionEngine *engine);
-
-    static void setterGeneric(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setterTwoClasses(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setterFallback(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setter0Inline(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setterInsert0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setterInsert1(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setterInsert2(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-    static void setter0setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
-
-    ReturnedValue lookup(const Value &thisObject, Object *obj, PropertyAttributes *attrs);
-    ReturnedValue lookup(const Object *obj, PropertyAttributes *attrs);
-
+    static ReturnedValue globalGetterProto(Lookup *l, ExecutionEngine *engine);
+    static ReturnedValue globalGetterProtoAccessor(Lookup *l, ExecutionEngine *engine);
+
+    bool resolveSetter(ExecutionEngine *engine, Object *object, const Value &value);
+    static bool setterGeneric(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    Q_NEVER_INLINE static bool setterTwoClasses(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    static bool setterFallback(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    static bool setter0MemberData(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    static bool setter0Inline(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    static bool setter0setter0(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    static bool setterInsert(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+    static bool arrayLengthSetter(Lookup *l, ExecutionEngine *engine, Value &object, const Value &value);
+
+    void markObjects(MarkStack *stack) {
+        if (markDef.h1 && !(reinterpret_cast<quintptr>(markDef.h1) & 1))
+            markDef.h1->mark(stack);
+        if (markDef.h2 && !(reinterpret_cast<quintptr>(markDef.h2) & 1))
+            markDef.h2->mark(stack);
+    }
+
+    void clear() {
+        memset(&markDef, 0, sizeof(markDef));
+    }
 };
 
 Q_STATIC_ASSERT(std::is_standard_layout<Lookup>::value);
 // Ensure that these offsets are always at this point to keep generated code compatible
 // across 32-bit and 64-bit (matters when cross-compiling).
-Q_STATIC_ASSERT(offsetof(Lookup, indexedGetter) == 0);
 Q_STATIC_ASSERT(offsetof(Lookup, getter) == 0);
 
 }
diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index e00eaa0d9b..d51b03d90b 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -43,35 +43,23 @@
 
 using namespace QV4;
 
+DEFINE_MANAGED_VTABLE(Managed);
 
-const VTable Managed::static_vtbl =
-{
-    0,
-    0,
-    0,
-    0,
-    Managed::IsExecutionContext,
-    Managed::IsString,
-    Managed::IsObject,
-    Managed::IsFunctionObject,
-    Managed::IsErrorObject,
-    Managed::IsArrayData,
-    0,
-    Managed::MyType,
-    "Managed",
-    0,
-    0 /*markObjects*/,
-    isEqualTo
-};
+DEFINE_MANAGED_VTABLE(InternalClass);
 
 
 QString Managed::className() const
 {
-    const char *s = 0;
-    switch (Type(d()->vtable()->type)) {
+    const char *s = nullptr;
+    switch (Type(vtable()->type)) {
     case Type_Invalid:
-    case Type_String:
         return QString();
+    case Type_String:
+        s = "String";
+        break;
+    case Type_Symbol:
+        s = "Symbol";
+        break;
     case Type_Object:
         s = "Object";
         break;
@@ -81,6 +69,9 @@ QString Managed::className() const
     case Type_FunctionObject:
         s = "Function";
         break;
+    case Type_GeneratorObject:
+        s = "Generator";
+        break;
     case Type_BooleanObject:
         s = "Boolean";
         break;
@@ -90,6 +81,9 @@ QString Managed::className() const
     case Type_StringObject:
         s = "String";
         break;
+    case Type_SymbolObject:
+        s = "Symbol";
+        break;
     case Type_DateObject:
         s = "Date";
         break;
@@ -97,7 +91,7 @@ QString Managed::className() const
         s = "RegExp";
         break;
     case Type_ErrorObject:
-        s = ErrorObject::className(static_cast<Heap::ErrorObject *>(d())->errorType);
+        s = "Error";
         break;
     case Type_ArgumentsObject:
         s = "Arguments";
@@ -105,6 +99,9 @@ QString Managed::className() const
     case Type_JsonObject:
         s = "JSON";
         break;
+    case Type_ProxyObject:
+        s = "ProxyObject";
+        break;
     case Type_MathObject:
         s = "Math";
         break;
@@ -112,8 +109,23 @@ QString Managed::className() const
     case Type_ExecutionContext:
         s = "__ExecutionContext";
         break;
-    case Type_ForeachIteratorObject:
-        s = "__ForeachIterator";
+    case Type_MapIteratorObject:
+        s = "Map Iterator";
+        break;
+    case Type_SetIteratorObject:
+        s = "Set Iterator";
+        break;
+    case Type_ArrayIteratorObject:
+        s = "Array Iterator";
+        break;
+    case Type_StringIteratorObject:
+        s = "String Iterator";
+        break;
+    case Type_ForInIterator:
+        s = "__ForIn Iterator";
+        break;
+    case Type_InternalClass:
+        s = "__InternalClass";
         break;
     case Type_RegExp:
         s = "__RegExp";
@@ -126,7 +138,12 @@ QString Managed::className() const
     return QString::fromLatin1(s);
 }
 
-bool Managed::isEqualTo(Managed *, Managed *)
+bool Managed::virtualIsEqualTo(Managed *, Managed *)
 {
     return false;
 }
+
+
+OwnPropertyKeyIterator::~OwnPropertyKeyIterator()
+{
+}
diff --git a/src/qml/jsruntime/qv4managed_p.h b/src/qml/jsruntime/qv4managed_p.h
index 40dfc244ea..d85b30a056 100644
--- a/src/qml/jsruntime/qv4managed_p.h
+++ b/src/qml/jsruntime/qv4managed_p.h
@@ -55,6 +55,7 @@
 #include "qv4enginebase_p.h"
 #include <private/qv4heap_p.h>
 #include <private/qv4writebarrier_p.h>
+#include <private/qv4vtable_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -70,13 +71,9 @@ inline int qYouForgotTheQ_MANAGED_Macro(T, T) { return 0; }
 template <typename T1, typename T2>
 inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
 
-#ifdef Q_COMPILER_STATIC_ASSERT
-#define V4_MANAGED_SIZE_TEST void __dataTest() { Q_STATIC_ASSERT(sizeof(*this) == sizeof(Managed)); }
-#else
-#define V4_MANAGED_SIZE_TEST
-#endif
+#define V4_MANAGED_SIZE_TEST void __dataTest() { static_assert (sizeof(*this) == sizeof(Managed), "Classes derived from Managed can't have own data members."); }
 
-#define V4_NEEDS_DESTROY static void destroy(QV4::Heap::Base *b) { static_cast<Data *>(b)->destroy(); }
+#define V4_NEEDS_DESTROY static void virtualDestroy(QV4::Heap::Base *b) { static_cast<Data *>(b)->destroy(); }
 
 
 #define V4_MANAGED_ITSELF(DataClass, superClass) \
@@ -92,79 +89,30 @@ inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
             QV4::Heap::DataClass *dptr = d_unchecked(); \
             dptr->_checkIsInitialized(); \
             return dptr; \
-        } \
-        static Q_CONSTEXPR quint64 markTable = QV4::Heap::DataClass::markTable; \
-        V4_ASSERT_IS_TRIVIAL(QV4::Heap::DataClass)
+        }
 
 #define V4_MANAGED(DataClass, superClass) \
     private: \
         DataClass() Q_DECL_EQ_DELETE; \
         Q_DISABLE_COPY(DataClass) \
-        V4_MANAGED_ITSELF(DataClass, superClass)
+        V4_MANAGED_ITSELF(DataClass, superClass) \
+        Q_STATIC_ASSERT(std::is_trivial< QV4::Heap::DataClass >::value);
 
 #define Q_MANAGED_TYPE(type) \
     public: \
         enum { MyType = Type_##type };
 
-#define Q_VTABLE_FUNCTION(classname, func) \
-    (classname::func == QV4::Managed::func ? 0 : classname::func)
-
-// Q_VTABLE_FUNCTION triggers a bogus tautological-compare warning in GCC6+
-#if (defined(Q_CC_GNU) && Q_CC_GNU >= 600)
-#define QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON \
-    QT_WARNING_PUSH; \
-    QT_WARNING_DISABLE_GCC("-Wtautological-compare")
-
-#define QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF \
-    ;QT_WARNING_POP
-#elif defined(Q_CC_CLANG) && Q_CC_CLANG >= 306
-#define QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON \
-    QT_WARNING_PUSH; \
-    QT_WARNING_DISABLE_CLANG("-Wtautological-compare")
-
-#define QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF \
-    ;QT_WARNING_POP
-#else
-#define QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON
-#define QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF
-#endif
-
-#define DEFINE_MANAGED_VTABLE_INT(classname, parentVTable) \
-{     \
-    parentVTable, \
-    markTable, \
-    (sizeof(classname::Data) + sizeof(QV4::Value) - 1)/sizeof(QV4::Value), \
-    (sizeof(classname::Data) + (std::is_same<classname, Object>::value ? 2*sizeof(QV4::Value) : 0) + QV4::Chunk::SlotSize - 1)/QV4::Chunk::SlotSize*QV4::Chunk::SlotSize/sizeof(QV4::Value) \
-        - (sizeof(classname::Data) + sizeof(QV4::Value) - 1)/sizeof(QV4::Value), \
-    classname::IsExecutionContext,   \
-    classname::IsString,   \
-    classname::IsObject,   \
-    classname::IsFunctionObject,   \
-    classname::IsErrorObject,   \
-    classname::IsArrayData,   \
-    0,                                          \
-    classname::MyType,                          \
-    #classname, \
-    Q_VTABLE_FUNCTION(classname, destroy),                                    \
-    Q_VTABLE_FUNCTION(classname, markObjects),                                    \
-    isEqualTo                                  \
-}
-
-#define DEFINE_MANAGED_VTABLE(classname) \
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON \
-const QV4::VTable classname::static_vtbl = DEFINE_MANAGED_VTABLE_INT(classname, 0) \
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF
-
 #define V4_INTERNALCLASS(c) \
-    static QV4::InternalClass *defaultInternalClass(QV4::EngineBase *e) \
-        { return e->internalClasses[QV4::EngineBase::Class_##c]; }
+    static Heap::InternalClass *defaultInternalClass(QV4::EngineBase *e) \
+        { return e->internalClasses(QV4::EngineBase::Class_##c); }
 
-struct Q_QML_PRIVATE_EXPORT Managed : Value
+struct Q_QML_PRIVATE_EXPORT Managed : Value, VTableBase
 {
     V4_MANAGED_ITSELF(Base, Managed)
     enum {
         IsExecutionContext = false,
         IsString = false,
+        IsStringOrSymbol = false,
         IsObject = false,
         IsFunctionObject = false,
         IsErrorObject = false,
@@ -176,53 +124,61 @@ private:
     Q_DISABLE_COPY(Managed)
 
 public:
+    enum { NInlineProperties = 0 };
 
     enum Type {
         Type_Invalid,
         Type_String,
         Type_Object,
+        Type_Symbol,
         Type_ArrayObject,
         Type_FunctionObject,
+        Type_GeneratorObject,
         Type_BooleanObject,
         Type_NumberObject,
         Type_StringObject,
+        Type_SymbolObject,
         Type_DateObject,
         Type_RegExpObject,
         Type_ErrorObject,
         Type_ArgumentsObject,
         Type_JsonObject,
         Type_MathObject,
+        Type_ProxyObject,
 
         Type_ExecutionContext,
-        Type_ForeachIteratorObject,
+        Type_InternalClass,
+        Type_SetIteratorObject,
+        Type_MapIteratorObject,
+        Type_ArrayIteratorObject,
+        Type_StringIteratorObject,
+        Type_ForInIterator,
         Type_RegExp,
 
         Type_QmlSequence
     };
     Q_MANAGED_TYPE(Invalid)
 
-    InternalClass *internalClass() const { return d()->internalClass; }
+    Heap::InternalClass *internalClass() const { return d()->internalClass; }
+    const VTable *vtable() const { return d()->internalClass->vtable; }
     inline ExecutionEngine *engine() const { return internalClass()->engine; }
 
-    bool isListType() const { return d()->vtable()->type == Type_QmlSequence; }
+    bool isListType() const { return d()->internalClass->vtable->type == Type_QmlSequence; }
+    bool isArrayLike() const { return isArrayObject() || isListType(); }
 
-    bool isArrayObject() const { return d()->vtable()->type == Type_ArrayObject; }
-    bool isStringObject() const { return d()->vtable()->type == Type_StringObject; }
+    bool isArrayObject() const { return d()->internalClass->vtable->type == Type_ArrayObject; }
+    bool isStringObject() const { return d()->internalClass->vtable->type == Type_StringObject; }
+    bool isSymbolObject() const { return d()->internalClass->vtable->type == Type_SymbolObject; }
 
     QString className() const;
 
     bool isEqualTo(const Managed *other) const
-    { return d()->vtable()->isEqualTo(const_cast<Managed *>(this), const_cast<Managed *>(other)); }
-
-    static bool isEqualTo(Managed *m, Managed *other);
+    { return d()->internalClass->vtable->isEqualTo(const_cast<Managed *>(this), const_cast<Managed *>(other)); }
 
     bool inUse() const { return d()->inUse(); }
     bool markBit() const { return d()->isMarked(); }
     inline void mark(MarkStack *markStack);
 
-    static void destroy(Heap::Base *) {}
-    static void markObjects(Heap::Base *, MarkStack *) {}
-
     Q_ALWAYS_INLINE Heap::Base *heapObject() const {
         return m();
     }
@@ -234,12 +190,20 @@ public:
         return static_cast<const T *>(this);
     }
 
+protected:
+    static bool virtualIsEqualTo(Managed *m, Managed *other);
+
 private:
     friend class MemoryManager;
     friend struct Identifiers;
     friend struct ObjectIterator;
 };
 
+inline void Managed::mark(MarkStack *markStack)
+{
+    Q_ASSERT(m());
+    m()->mark(markStack);
+}
 
 template<>
 inline const Managed *Value::as() const {
@@ -251,6 +215,33 @@ inline const Object *Value::as() const {
     return objectValue();
 }
 
+
+struct InternalClass : Managed
+{
+    V4_MANAGED_ITSELF(InternalClass, Managed)
+    Q_MANAGED_TYPE(InternalClass)
+    V4_INTERNALCLASS(Empty)
+    V4_NEEDS_DESTROY
+
+    Q_REQUIRED_RESULT Heap::InternalClass *changeVTable(const VTable *vt) {
+        return d()->changeVTable(vt);
+    }
+    Q_REQUIRED_RESULT Heap::InternalClass *changePrototype(Heap::Object *proto) {
+        return d()->changePrototype(proto);
+    }
+    Q_REQUIRED_RESULT Heap::InternalClass *addMember(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry = nullptr) {
+        return d()->addMember(identifier, data, entry);
+    }
+
+    Q_REQUIRED_RESULT Heap::InternalClass *changeMember(PropertyKey identifier, PropertyAttributes data, InternalClassEntry *entry = nullptr) {
+        return d()->changeMember(identifier, data, entry);
+    }
+
+    void operator =(Heap::InternalClass *ic) {
+        Value::operator=(ic);
+    }
+};
+
 }
 
 
diff --git a/src/qml/jsruntime/qv4mapiterator.cpp b/src/qml/jsruntime/qv4mapiterator.cpp
new file mode 100644
index 0000000000..cd5fbb8e63
--- /dev/null
+++ b/src/qml/jsruntime/qv4mapiterator.cpp
@@ -0,0 +1,107 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4iterator_p.h>
+#include <private/qv4estable_p.h>
+#include <private/qv4mapiterator_p.h>
+#include <private/qv4mapobject_p.h>
+#include <private/qv4symbol_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(MapIteratorObject);
+
+void MapIteratorPrototype::init(ExecutionEngine *e)
+{
+    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
+
+    Scope scope(e);
+    ScopedString val(scope, e->newString(QLatin1String("Map Iterator")));
+    defineReadonlyConfigurableProperty(e->symbol_toStringTag(), val);
+}
+
+ReturnedValue MapIteratorPrototype::method_next(const FunctionObject *b, const Value *that, const Value *, int)
+{
+    Scope scope(b);
+    const MapIteratorObject *thisObject = that->as<MapIteratorObject>();
+    if (!thisObject)
+        return scope.engine->throwTypeError(QLatin1String("Not a Map Iterator instance"));
+
+    Scoped<MapObject> s(scope, thisObject->d()->iteratedMap);
+    uint index = thisObject->d()->mapNextIndex;
+    IteratorKind itemKind = thisObject->d()->iterationKind;
+
+    if (!s) {
+        QV4::Value undefined = Value::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+    }
+
+    Value *arguments = scope.alloc(2);
+
+    while (index < s->d()->esTable->size()) {
+        s->d()->esTable->iterate(index, &arguments[0], &arguments[1]);
+        thisObject->d()->mapNextIndex = index + 1;
+
+        ScopedValue result(scope);
+
+        if (itemKind == KeyIteratorKind) {
+            result = arguments[0];
+        } else if (itemKind == ValueIteratorKind) {
+            result = arguments[1];
+        } else {
+            Q_ASSERT(itemKind == KeyValueIteratorKind);
+
+            result = scope.engine->newArrayObject();
+
+            Scoped<ArrayObject> resultArray(scope, result);
+            resultArray->arrayReserve(2);
+            resultArray->arrayPut(0, arguments[0]);
+            resultArray->arrayPut(1, arguments[1]);
+            resultArray->setArrayLengthUnchecked(2);
+        }
+
+        return IteratorPrototype::createIterResultObject(scope.engine, result, false);
+    }
+
+    thisObject->d()->iteratedMap.set(scope.engine, nullptr);
+    QV4::Value undefined = Value::undefinedValue();
+    return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+}
+
+
diff --git a/src/qml/jsruntime/qv4mapiterator_p.h b/src/qml/jsruntime/qv4mapiterator_p.h
new file mode 100644
index 0000000000..836ba14663
--- /dev/null
+++ b/src/qml/jsruntime/qv4mapiterator_p.h
@@ -0,0 +1,104 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4MAPITERATOR_P_H
+#define QV4MAPITERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4iterator_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Heap {
+
+#define MapIteratorObjectMembers(class, Member) \
+    Member(class, Pointer, Object *, iteratedMap) \
+    Member(class, NoMark, IteratorKind, iterationKind) \
+    Member(class, NoMark, quint32, mapNextIndex)
+
+DECLARE_HEAP_OBJECT(MapIteratorObject, Object) {
+    DECLARE_MARKOBJECTS(MapIteratorObject);
+    void init(Object *obj, QV4::ExecutionEngine *engine)
+    {
+        Object::init();
+        this->iteratedMap.set(engine, obj);
+        this->mapNextIndex = 0;
+    }
+};
+
+}
+
+struct MapIteratorPrototype : Object
+{
+    V4_PROTOTYPE(iteratorPrototype)
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_next(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct MapIteratorObject : Object
+{
+    V4_OBJECT2(MapIteratorObject, Object)
+    Q_MANAGED_TYPE(MapIteratorObject)
+    V4_PROTOTYPE(mapIteratorPrototype)
+
+    void init(ExecutionEngine *engine);
+};
+
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4MAPITERATOR_P_H
+
+
diff --git a/src/qml/jsruntime/qv4mapobject.cpp b/src/qml/jsruntime/qv4mapobject.cpp
new file mode 100644
index 0000000000..90e1908a84
--- /dev/null
+++ b/src/qml/jsruntime/qv4mapobject.cpp
@@ -0,0 +1,382 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4setobject_p.h" // ### temporary
+#include "qv4mapobject_p.h"
+#include "qv4mapiterator_p.h"
+#include "qv4estable_p.h"
+#include "qv4symbol_p.h"
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(WeakMapCtor);
+DEFINE_OBJECT_VTABLE(MapCtor);
+DEFINE_OBJECT_VTABLE(MapObject);
+
+void Heap::WeakMapCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("WeakMap"));
+}
+
+void Heap::MapCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("Map"));
+}
+
+ReturnedValue WeakMapCtor::construct(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget, bool weakMap)
+{
+    Scope scope(f);
+    Scoped<MapObject> a(scope, scope.engine->memoryManager->allocate<MapObject>());
+    bool protoSet = false;
+    if (newTarget)
+        protoSet = a->setProtoFromNewTarget(newTarget);
+    if (!protoSet && weakMap) {
+        a->setPrototypeOf(scope.engine->weakMapPrototype());
+        scope.engine->memoryManager->registerWeakMap(a->d());
+    }
+    a->d()->isWeakMap = weakMap;
+
+    if (argc > 0) {
+        ScopedValue iterable(scope, argv[0]);
+
+        if (!iterable->isNullOrUndefined()) {
+            ScopedFunctionObject adder(scope, a->get(ScopedString(scope, scope.engine->newString(QString::fromLatin1("set")))));
+            if (!adder)
+                return scope.engine->throwTypeError();
+
+            ScopedObject iter(scope, Runtime::GetIterator::call(scope.engine, iterable, true));
+            if (scope.hasException())
+                return Encode::undefined();
+            Q_ASSERT(iter);
+
+            ScopedValue obj(scope);
+            Value *arguments = scope.alloc(2);
+            ScopedValue done(scope);
+            forever {
+                done = Runtime::IteratorNext::call(scope.engine, iter, obj);
+                if (scope.hasException())
+                    break;
+                if (done->toBoolean())
+                    return a->asReturnedValue();
+                const Object *o = obj->objectValue();
+                if (!o) {
+                    scope.engine->throwTypeError();
+                    break;
+                }
+
+                arguments[0] = o->get(PropertyKey::fromArrayIndex(0));
+                if (scope.hasException())
+                    break;
+                arguments[1] = o->get(PropertyKey::fromArrayIndex(1));
+                if (scope.hasException())
+                    break;
+
+                adder->call(a, arguments, 2);
+                if (scope.hasException())
+                    break;
+            }
+            ScopedValue falsey(scope, Encode(false));
+            return Runtime::IteratorClose::call(scope.engine, iter, falsey);
+        }
+    }
+    return a->asReturnedValue();
+
+}
+
+ReturnedValue WeakMapCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    return construct(f, argv, argc, newTarget, true);
+}
+
+ReturnedValue WeakMapCtor::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
+{
+    Scope scope(f);
+    return scope.engine->throwTypeError(QString::fromLatin1("(Weak)Map requires new"));
+}
+
+
+ReturnedValue MapCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    return construct(f, argv, argc, newTarget, false);
+}
+
+void WeakMapPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedObject o(scope);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
+    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
+    defineDefaultProperty(engine->id_constructor(), (o = ctor));
+
+    defineDefaultProperty(QStringLiteral("delete"), method_delete, 1);
+    defineDefaultProperty(QStringLiteral("get"), method_get, 1);
+    defineDefaultProperty(QStringLiteral("has"), method_has, 1);
+    defineDefaultProperty(QStringLiteral("set"), method_set, 2);
+
+    ScopedString val(scope, engine->newString(QLatin1String("WeakMap")));
+    defineReadonlyConfigurableProperty(engine->symbol_toStringTag(), val);
+}
+
+
+void MapPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedObject o(scope);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
+    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
+    ctor->addSymbolSpecies();
+    defineDefaultProperty(engine->id_constructor(), (o = ctor));
+
+    defineDefaultProperty(QStringLiteral("clear"), method_clear, 0);
+    defineDefaultProperty(QStringLiteral("delete"), method_delete, 1);
+    defineDefaultProperty(QStringLiteral("forEach"), method_forEach, 1);
+    defineDefaultProperty(QStringLiteral("get"), method_get, 1);
+    defineDefaultProperty(QStringLiteral("has"), method_has, 1);
+    defineDefaultProperty(QStringLiteral("keys"), method_keys, 0);
+    defineDefaultProperty(QStringLiteral("set"), method_set, 2);
+    defineAccessorProperty(QStringLiteral("size"), method_get_size, nullptr);
+    defineDefaultProperty(QStringLiteral("values"), method_values, 0);
+
+    // Per the spec, the value for entries/@@iterator is the same
+    ScopedString valString(scope, scope.engine->newIdentifier(QStringLiteral("entries")));
+    ScopedFunctionObject entriesFn(scope, FunctionObject::createBuiltinFunction(engine, valString, MapPrototype::method_entries, 0));
+    defineDefaultProperty(QStringLiteral("entries"), entriesFn);
+    defineDefaultProperty(engine->symbol_iterator(), entriesFn);
+
+    ScopedString val(scope, engine->newString(QLatin1String("Map")));
+    defineReadonlyConfigurableProperty(engine->symbol_toStringTag(), val);
+}
+
+void Heap::MapObject::init()
+{
+    Object::init();
+    esTable = new ESTable();
+}
+
+void Heap::MapObject::destroy()
+{
+    delete esTable;
+    esTable = nullptr;
+}
+
+void Heap::MapObject::removeUnmarkedKeys()
+{
+    esTable->removeUnmarkedKeys();
+}
+
+void Heap::MapObject::markObjects(Heap::Base *that, MarkStack *markStack)
+{
+    MapObject *m = static_cast<MapObject *>(that);
+    m->esTable->markObjects(markStack, m->isWeakMap);
+    Object::markObjects(that, markStack);
+}
+
+ReturnedValue WeakMapPrototype::method_delete(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || !that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+    if (!argc || !argv[0].isObject())
+        return Encode(false);
+
+    return Encode(that->d()->esTable->remove(argv[0]));
+
+}
+
+ReturnedValue WeakMapPrototype::method_get(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || !that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+    if (!argc || !argv[0].isObject())
+        return Encode::undefined();
+
+    return that->d()->esTable->get(argv[0]);
+}
+
+ReturnedValue WeakMapPrototype::method_has(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || !that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+    if (!argc || !argv[0].isObject())
+        return Encode(false);
+
+    return Encode(that->d()->esTable->has(argv[0]));
+}
+
+ReturnedValue WeakMapPrototype::method_set(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if ((!that || !that->d()->isWeakMap) ||
+        (!argc || !argv[0].isObject()))
+        return scope.engine->throwTypeError();
+
+    that->d()->esTable->set(argv[0], argc > 1 ? argv[1] : Value::undefinedValue());
+    return that.asReturnedValue();
+}
+
+
+ReturnedValue MapPrototype::method_clear(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    that->d()->esTable->clear();
+    return Encode::undefined();
+}
+
+ReturnedValue MapPrototype::method_delete(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    return Encode(that->d()->esTable->remove(argc ? argv[0] : Value::undefinedValue()));
+}
+
+ReturnedValue MapPrototype::method_entries(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    Scoped<MapIteratorObject> ao(scope, scope.engine->newMapIteratorObject(that));
+    ao->d()->iterationKind = IteratorKind::KeyValueIteratorKind;
+    return ao->asReturnedValue();
+}
+
+ReturnedValue MapPrototype::method_forEach(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    ScopedFunctionObject callbackfn(scope, argv[0]);
+    if (!callbackfn)
+        return scope.engine->throwTypeError();
+
+    ScopedValue thisArg(scope, Value::undefinedValue());
+    if (argc > 1)
+        thisArg = ScopedValue(scope, argv[1]);
+
+    Value *arguments = scope.alloc(3);
+    arguments[2] = that;
+    for (uint i = 0; i < that->d()->esTable->size(); ++i) {
+        that->d()->esTable->iterate(i, &arguments[1], &arguments[0]); // fill in key (0), value (1)
+
+        callbackfn->call(thisArg, arguments, 3);
+        CHECK_EXCEPTION();
+    }
+    return Encode::undefined();
+}
+
+ReturnedValue MapPrototype::method_get(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    return that->d()->esTable->get(argc ? argv[0] : Value::undefinedValue());
+}
+
+ReturnedValue MapPrototype::method_has(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    return Encode(that->d()->esTable->has(argc ? argv[0] : Value::undefinedValue()));
+}
+
+ReturnedValue MapPrototype::method_keys(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    Scoped<MapIteratorObject> ao(scope, scope.engine->newMapIteratorObject(that));
+    ao->d()->iterationKind = IteratorKind::KeyIteratorKind;
+    return ao->asReturnedValue();
+}
+
+ReturnedValue MapPrototype::method_set(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    that->d()->esTable->set(argc ? argv[0] : Value::undefinedValue(), argc > 1 ? argv[1] : Value::undefinedValue());
+    return that.asReturnedValue();
+}
+
+ReturnedValue MapPrototype::method_get_size(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    return Encode(that->d()->esTable->size());
+}
+
+ReturnedValue MapPrototype::method_values(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<MapObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakMap)
+        return scope.engine->throwTypeError();
+
+    Scoped<MapIteratorObject> ao(scope, scope.engine->newMapIteratorObject(that));
+    ao->d()->iterationKind = IteratorKind::ValueIteratorKind;
+    return ao->asReturnedValue();
+}
diff --git a/src/qml/jsruntime/qv4mapobject_p.h b/src/qml/jsruntime/qv4mapobject_p.h
new file mode 100644
index 0000000000..a0fae2a14a
--- /dev/null
+++ b/src/qml/jsruntime/qv4mapobject_p.h
@@ -0,0 +1,145 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4MAPOBJECT_P_H
+#define QV4MAPOBJECT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4objectproto_p.h"
+#include "qv4functionobject_p.h"
+#include "qv4string_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+class ESTable;
+
+namespace Heap {
+
+struct WeakMapCtor : FunctionObject {
+    void init(QV4::ExecutionContext *scope);
+};
+
+struct MapCtor : WeakMapCtor {
+    void init(QV4::ExecutionContext *scope);
+};
+
+struct MapObject : Object {
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
+    void init();
+    void destroy();
+    void removeUnmarkedKeys();
+
+    MapObject *nextWeakMap;
+    ESTable *esTable;
+    bool isWeakMap;
+};
+
+}
+
+struct WeakMapCtor: FunctionObject
+{
+    V4_OBJECT2(WeakMapCtor, FunctionObject)
+
+    static ReturnedValue construct(const FunctionObject *f, const Value *argv, int argc, const Value *, bool weakMap);
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct MapCtor : WeakMapCtor
+{
+    V4_OBJECT2(MapCtor, WeakMapCtor)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+};
+
+struct MapObject : Object
+{
+    V4_OBJECT2(MapObject, Object)
+    V4_PROTOTYPE(mapPrototype)
+    V4_NEEDS_DESTROY
+};
+
+struct WeakMapPrototype : Object
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_delete(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_has(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct MapPrototype : WeakMapPrototype
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_clear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_delete(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_entries(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_forEach(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_has(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_keys(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_size(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_values(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+
+} // namespace QV4
+
+
+QT_END_NAMESPACE
+
+#endif // QV4MAPOBJECT_P_H
+
diff --git a/src/qml/jsruntime/qv4math_p.h b/src/qml/jsruntime/qv4math_p.h
index 67c963622f..a60a49a811 100644
--- a/src/qml/jsruntime/qv4math_p.h
+++ b/src/qml/jsruntime/qv4math_p.h
@@ -66,28 +66,43 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-static inline QMLJS_READONLY ReturnedValue add_int32(int a, int b)
+static inline QMLJS_READONLY ReturnedValue add_int32(int a, int b, quint8 *traceInfo = nullptr)
 {
     int result;
-    if (Q_UNLIKELY(add_overflow(a, b, &result)))
-        return Primitive::fromDouble(static_cast<double>(a) + b).asReturnedValue();
-    return Primitive::fromInt32(result).asReturnedValue();
+    if (Q_UNLIKELY(add_overflow(a, b, &result))) {
+        if (traceInfo)
+            *traceInfo |= quint8(QV4::ObservedTraceValues::Double);
+        return Value::fromDouble(static_cast<double>(a) + b).asReturnedValue();
+    }
+    if (traceInfo)
+        *traceInfo |= quint8(QV4::ObservedTraceValues::Integer);
+    return Value::fromInt32(result).asReturnedValue();
 }
 
-static inline QMLJS_READONLY ReturnedValue sub_int32(int a, int b)
+static inline QMLJS_READONLY ReturnedValue sub_int32(int a, int b, quint8 *traceInfo = nullptr)
 {
     int result;
-    if (Q_UNLIKELY(sub_overflow(a, b, &result)))
-        return Primitive::fromDouble(static_cast<double>(a) - b).asReturnedValue();
-    return Primitive::fromInt32(result).asReturnedValue();
+    if (Q_UNLIKELY(sub_overflow(a, b, &result))) {
+        if (traceInfo)
+            *traceInfo |= quint8(QV4::ObservedTraceValues::Double);
+        return Value::fromDouble(static_cast<double>(a) - b).asReturnedValue();
+    }
+    if (traceInfo)
+        *traceInfo |= quint8(QV4::ObservedTraceValues::Integer);
+    return Value::fromInt32(result).asReturnedValue();
 }
 
-static inline QMLJS_READONLY ReturnedValue mul_int32(int a, int b)
+static inline QMLJS_READONLY ReturnedValue mul_int32(int a, int b, quint8 *traceInfo = nullptr)
 {
     int result;
-    if (Q_UNLIKELY(mul_overflow(a, b, &result)))
-        return Primitive::fromDouble(static_cast<double>(a) * b).asReturnedValue();
-    return Primitive::fromInt32(result).asReturnedValue();
+    if (Q_UNLIKELY(mul_overflow(a, b, &result))) {
+        if (traceInfo)
+            *traceInfo |= quint8(QV4::ObservedTraceValues::Double);
+        return Value::fromDouble(static_cast<double>(a) * b).asReturnedValue();
+    }
+    if (traceInfo)
+        *traceInfo |= quint8(QV4::ObservedTraceValues::Integer);
+    return Value::fromInt32(result).asReturnedValue();
 }
 
 }
diff --git a/src/qml/jsruntime/qv4mathobject.cpp b/src/qml/jsruntime/qv4mathobject.cpp
index 2d9d81c64b..07440047d4 100644
--- a/src/qml/jsruntime/qv4mathobject.cpp
+++ b/src/qml/jsruntime/qv4mathobject.cpp
@@ -39,12 +39,15 @@
 
 #include "qv4mathobject_p.h"
 #include "qv4objectproto_p.h"
+#include "qv4symbol_p.h"
 
 #include <QtCore/qdatetime.h>
 #include <QtCore/qmath.h>
+#include <QtCore/qrandom.h>
 #include <QtCore/private/qnumeric_p.h>
 #include <QtCore/qthreadstorage.h>
 
+#include <math.h>
 #include <cmath>
 
 using namespace QV4;
@@ -57,25 +60,38 @@ void Heap::MathObject::init()
     Scope scope(internalClass->engine);
     ScopedObject m(scope, this);
 
-    m->defineReadonlyProperty(QStringLiteral("E"), Primitive::fromDouble(M_E));
-    m->defineReadonlyProperty(QStringLiteral("LN2"), Primitive::fromDouble(M_LN2));
-    m->defineReadonlyProperty(QStringLiteral("LN10"), Primitive::fromDouble(M_LN10));
-    m->defineReadonlyProperty(QStringLiteral("LOG2E"), Primitive::fromDouble(M_LOG2E));
-    m->defineReadonlyProperty(QStringLiteral("LOG10E"), Primitive::fromDouble(M_LOG10E));
-    m->defineReadonlyProperty(QStringLiteral("PI"), Primitive::fromDouble(M_PI));
-    m->defineReadonlyProperty(QStringLiteral("SQRT1_2"), Primitive::fromDouble(M_SQRT1_2));
-    m->defineReadonlyProperty(QStringLiteral("SQRT2"), Primitive::fromDouble(M_SQRT2));
+    m->defineReadonlyProperty(QStringLiteral("E"), Value::fromDouble(M_E));
+    m->defineReadonlyProperty(QStringLiteral("LN2"), Value::fromDouble(M_LN2));
+    m->defineReadonlyProperty(QStringLiteral("LN10"), Value::fromDouble(M_LN10));
+    m->defineReadonlyProperty(QStringLiteral("LOG2E"), Value::fromDouble(M_LOG2E));
+    m->defineReadonlyProperty(QStringLiteral("LOG10E"), Value::fromDouble(M_LOG10E));
+    m->defineReadonlyProperty(QStringLiteral("PI"), Value::fromDouble(M_PI));
+    m->defineReadonlyProperty(QStringLiteral("SQRT1_2"), Value::fromDouble(M_SQRT1_2));
+    m->defineReadonlyProperty(QStringLiteral("SQRT2"), Value::fromDouble(M_SQRT2));
 
     m->defineDefaultProperty(QStringLiteral("abs"), QV4::MathObject::method_abs, 1);
     m->defineDefaultProperty(QStringLiteral("acos"), QV4::MathObject::method_acos, 1);
-    m->defineDefaultProperty(QStringLiteral("asin"), QV4::MathObject::method_asin, 0);
+    m->defineDefaultProperty(QStringLiteral("acosh"), QV4::MathObject::method_acosh, 1);
+    m->defineDefaultProperty(QStringLiteral("asin"), QV4::MathObject::method_asin, 1);
+    m->defineDefaultProperty(QStringLiteral("asinh"), QV4::MathObject::method_asinh, 1);
     m->defineDefaultProperty(QStringLiteral("atan"), QV4::MathObject::method_atan, 1);
+    m->defineDefaultProperty(QStringLiteral("atanh"), QV4::MathObject::method_atanh, 1);
     m->defineDefaultProperty(QStringLiteral("atan2"), QV4::MathObject::method_atan2, 2);
+    m->defineDefaultProperty(QStringLiteral("cbrt"), QV4::MathObject::method_cbrt, 1);
     m->defineDefaultProperty(QStringLiteral("ceil"), QV4::MathObject::method_ceil, 1);
+    m->defineDefaultProperty(QStringLiteral("clz32"), QV4::MathObject::method_clz32, 1);
     m->defineDefaultProperty(QStringLiteral("cos"), QV4::MathObject::method_cos, 1);
+    m->defineDefaultProperty(QStringLiteral("cosh"), QV4::MathObject::method_cosh, 1);
     m->defineDefaultProperty(QStringLiteral("exp"), QV4::MathObject::method_exp, 1);
+    m->defineDefaultProperty(QStringLiteral("expm1"), QV4::MathObject::method_expm1, 1);
     m->defineDefaultProperty(QStringLiteral("floor"), QV4::MathObject::method_floor, 1);
+    m->defineDefaultProperty(QStringLiteral("fround"), QV4::MathObject::method_fround, 1);
+    m->defineDefaultProperty(QStringLiteral("hypot"), QV4::MathObject::method_hypot, 2);
+    m->defineDefaultProperty(QStringLiteral("imul"), QV4::MathObject::method_imul, 2);
     m->defineDefaultProperty(QStringLiteral("log"), QV4::MathObject::method_log, 1);
+    m->defineDefaultProperty(QStringLiteral("log10"), QV4::MathObject::method_log10, 1);
+    m->defineDefaultProperty(QStringLiteral("log1p"), QV4::MathObject::method_log1p, 1);
+    m->defineDefaultProperty(QStringLiteral("log2"), QV4::MathObject::method_log2, 1);
     m->defineDefaultProperty(QStringLiteral("max"), QV4::MathObject::method_max, 2);
     m->defineDefaultProperty(QStringLiteral("min"), QV4::MathObject::method_min, 2);
     m->defineDefaultProperty(QStringLiteral("pow"), QV4::MathObject::method_pow, 2);
@@ -83,8 +99,14 @@ void Heap::MathObject::init()
     m->defineDefaultProperty(QStringLiteral("round"), QV4::MathObject::method_round, 1);
     m->defineDefaultProperty(QStringLiteral("sign"), QV4::MathObject::method_sign, 1);
     m->defineDefaultProperty(QStringLiteral("sin"), QV4::MathObject::method_sin, 1);
+    m->defineDefaultProperty(QStringLiteral("sinh"), QV4::MathObject::method_sinh, 1);
     m->defineDefaultProperty(QStringLiteral("sqrt"), QV4::MathObject::method_sqrt, 1);
     m->defineDefaultProperty(QStringLiteral("tan"), QV4::MathObject::method_tan, 1);
+    m->defineDefaultProperty(QStringLiteral("tanh"), QV4::MathObject::method_tanh, 1);
+    m->defineDefaultProperty(QStringLiteral("trunc"), QV4::MathObject::method_trunc, 1);
+
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("Math")));
+    m->defineReadonlyConfigurableProperty(scope.engine->symbol_toStringTag(), name);
 }
 
 static Q_ALWAYS_INLINE double copySign(double x, double y)
@@ -92,54 +114,99 @@ static Q_ALWAYS_INLINE double copySign(double x, double y)
     return ::copysign(x, y);
 }
 
-void MathObject::method_abs(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_abs(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc)
+    if (!argc)
         RETURN_RESULT(Encode(qt_qnan()));
 
-    if (callData->args[0].isInteger()) {
-        int i = callData->args[0].integerValue();
+    if (argv[0].isInteger()) {
+        int i = argv[0].integerValue();
         RETURN_RESULT(Encode(i < 0 ? - i : i));
     }
 
-    double v = callData->args[0].toNumber();
+    double v = argv[0].toNumber();
     if (v == 0) // 0 | -0
         RETURN_RESULT(Encode(0));
 
     RETURN_RESULT(Encode(v < 0 ? -v : v));
 }
 
-void MathObject::method_acos(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_acos(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : 2;
+    double v = argc ? argv[0].toNumber() : 2;
     if (v > 1)
         RETURN_RESULT(Encode(qt_qnan()));
 
     RETURN_RESULT(Encode(std::acos(v)));
 }
 
-void MathObject::method_asin(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_acosh(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : 2;
+    if (v < 1)
+        RETURN_RESULT(Encode(qt_qnan()));
+
+#ifdef Q_OS_ANDROID // incomplete std :-(
+    RETURN_RESULT(Encode(std::log(v +std::sqrt(v + 1) * std::sqrt(v - 1))));
+#else
+    RETURN_RESULT(Encode(std::acosh(v)));
+#endif
+}
+
+ReturnedValue MathObject::method_asin(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : 2;
+    double v = argc ? argv[0].toNumber() : 2;
     if (v > 1)
         RETURN_RESULT(Encode(qt_qnan()));
     else
         RETURN_RESULT(Encode(std::asin(v)));
 }
 
-void MathObject::method_atan(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_asinh(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : 2;
+    if (v == 0.0)
+        RETURN_RESULT(Encode(v));
+
+#ifdef Q_OS_ANDROID // incomplete std :-(
+    RETURN_RESULT(Encode(std::log(v +std::sqrt(1 + v * v))));
+#else
+    RETURN_RESULT(Encode(std::asinh(v)));
+#endif
+}
+
+ReturnedValue MathObject::method_atan(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     if (v == 0.0)
         RETURN_RESULT(Encode(v));
     else
         RETURN_RESULT(Encode(std::atan(v)));
 }
 
-void MathObject::method_atan2(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_atanh(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v == 0.0)
+        RETURN_RESULT(Encode(v));
+
+#ifdef Q_OS_ANDROID // incomplete std :-(
+    if (-1 < v && v < 1)
+        RETURN_RESULT(Encode(0.5 * (std::log(v + 1) - std::log(v - 1))));
+
+    if (v > 1 || v < -1)
+        RETURN_RESULT(Encode(qt_qnan()));
+
+    RETURN_RESULT(Encode(copySign(qt_inf(), v)));
+#else
+    RETURN_RESULT(Encode(std::atanh(v)));
+#endif
+}
+
+ReturnedValue MathObject::method_atan2(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v1 = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    double v2 = callData->argc > 1 ? callData->args[1].toNumber() : qt_qnan();
+    double v1 = argc ? argv[0].toNumber() : qt_qnan();
+    double v2 = argc > 1 ? argv[1].toNumber() : qt_qnan();
 
     if ((v1 < 0) && qt_is_finite(v1) && qt_is_inf(v2) && (copySign(1.0, v2) == 1.0))
         RETURN_RESULT(Encode(copySign(0, -1.0)));
@@ -154,24 +221,46 @@ void MathObject::method_atan2(const BuiltinFunction *, Scope &scope, CallData *c
     RETURN_RESULT(Encode(std::atan2(v1, v2)));
 }
 
-void MathObject::method_ceil(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_cbrt(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+#ifdef Q_OS_ANDROID // incomplete std :-(
+    RETURN_RESULT(Encode(copySign(std::exp(std::log(std::abs(v)) / 3), v)));
+#else
+    RETURN_RESULT(Encode(std::cbrt(v))); // cube root
+#endif
+}
+
+ReturnedValue MathObject::method_ceil(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     if (v < 0.0 && v > -1.0)
         RETURN_RESULT(Encode(copySign(0, -1.0)));
     else
         RETURN_RESULT(Encode(std::ceil(v)));
 }
 
-void MathObject::method_cos(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_clz32(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    quint32 v = argc ? argv[0].toUInt32() : 0;
+    RETURN_RESULT(Encode(qint32(qCountLeadingZeroBits(v))));
+}
+
+ReturnedValue MathObject::method_cos(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     RETURN_RESULT(Encode(std::cos(v)));
 }
 
-void MathObject::method_exp(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_cosh(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    RETURN_RESULT(Encode(std::cosh(v)));
+}
+
+ReturnedValue MathObject::method_exp(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     if (qt_is_inf(v)) {
         if (copySign(1.0, v) == -1.0)
             RETURN_RESULT(Encode(0));
@@ -182,49 +271,156 @@ void MathObject::method_exp(const BuiltinFunction *, Scope &scope, CallData *cal
     }
 }
 
-void MathObject::method_floor(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_expm1(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (std::isnan(v) || qIsNull(v)) {
+        RETURN_RESULT(Encode(v));
+    } else if (qt_is_inf(v)) {
+        if (copySign(1.0, v) == -1.0)
+            RETURN_RESULT(Encode(-1.0));
+        else
+            RETURN_RESULT(Encode(qt_inf()));
+    } else {
+#ifdef Q_OS_ANDROID // incomplete std :-(
+        RETURN_RESULT(Encode(std::exp(v) - 1));
+#else
+        RETURN_RESULT(Encode(std::expm1(v)));
+#endif
+    }
+}
+
+ReturnedValue MathObject::method_floor(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    Value result = Value::fromDouble(std::floor(v));
+    result.isInt32();
+    RETURN_RESULT(result);
+}
+
+ReturnedValue MathObject::method_fround(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (std::isnan(v) || qt_is_inf(v) || qIsNull(v))
+        RETURN_RESULT(Encode(v));
+    else // convert to 32-bit float using roundTiesToEven, then convert back to 64-bit double
+        RETURN_RESULT(Encode(double(float(v))));
+}
+
+ReturnedValue MathObject::method_hypot(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    // ES6 Math.hypot(v1, ..., vn) -> sqrt(sum(vi**2)) but "should take care to
+    // avoid the loss of precision from overflows and underflows" (as std::hypot does).
+    double v = argc ? argv[0].toNumber() : 0;
+    // Spec mandates +0 on no args; and says nothing about what to do if toNumber() signals ...
+#ifdef Q_OS_ANDROID // incomplete std :-(
+    bool big = qt_is_inf(v), bad = std::isnan(v);
+    v *= v;
+    for (int i = 1; !big && i < argc; i++) {
+        double u = argv[i].toNumber();
+        if (qt_is_inf(u))
+            big = true;
+        if (std::isnan(u))
+            bad = true;
+        v += u * u;
+    }
+    if (big)
+        RETURN_RESULT(Encode(qt_inf()));
+    if (bad)
+        RETURN_RESULT(Encode(qt_qnan()));
+    // Should actually check for {und,ov}erflow, but too fiddly !
+    RETURN_RESULT(Value::fromDouble(sqrt(v)));
+#else
+    for (int i = 1; i < argc; i++)
+        v = std::hypot(v, argv[i].toNumber());
+#endif
+    RETURN_RESULT(Value::fromDouble(v));
+}
+
+ReturnedValue MathObject::method_imul(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    RETURN_RESULT(Encode(std::floor(v)));
+    quint32 a = argc ? argv[0].toUInt32() : 0;
+    quint32 b = argc > 0 ? argv[1].toUInt32() : 0;
+    qint32 product = a * b;
+    RETURN_RESULT(Encode(product));
 }
 
-void MathObject::method_log(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_log(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     if (v < 0)
         RETURN_RESULT(Encode(qt_qnan()));
     else
         RETURN_RESULT(Encode(std::log(v)));
 }
 
-void MathObject::method_max(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_log10(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v < 0)
+        RETURN_RESULT(Encode(qt_qnan()));
+    else
+        RETURN_RESULT(Encode(std::log10(v)));
+}
+
+ReturnedValue MathObject::method_log1p(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+#if !defined(__ANDROID__)
+    using std::log1p;
+#endif
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v < -1)
+        RETURN_RESULT(Encode(qt_qnan()));
+    else
+        RETURN_RESULT(Encode(log1p(v)));
+}
+
+ReturnedValue MathObject::method_log2(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v < 0) {
+        RETURN_RESULT(Encode(qt_qnan()));
+    } else {
+#ifdef Q_OS_ANDROID // incomplete std :-(
+        // Android ndk r10e doesn't have std::log2, so fall back.
+        const double ln2 = std::log(2.0);
+        RETURN_RESULT(Encode(std::log(v) / ln2));
+#else
+        RETURN_RESULT(Encode(std::log2(v)));
+#endif
+    }
+}
+
+ReturnedValue MathObject::method_max(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
     double mx = -qt_inf();
-    for (int i = 0; i < callData->argc; ++i) {
-        double x = callData->args[i].toNumber();
-        if (x > mx || std::isnan(x))
+    for (int i = 0, ei = argc; i < ei; ++i) {
+        double x = argv[i].toNumber();
+        if ((x == 0 && mx == x && copySign(1.0, x) == 1.0)
+                || (x > mx) || std::isnan(x)) {
             mx = x;
+        }
     }
-    RETURN_RESULT(Encode(mx));
+    RETURN_RESULT(Encode::smallestNumber(mx));
 }
 
-void MathObject::method_min(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_min(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
     double mx = qt_inf();
-    for (int i = 0; i < callData->argc; ++i) {
-        double x = callData->args[i].toNumber();
+    for (int i = 0, ei = argc; i < ei; ++i) {
+        double x = argv[i].toNumber();
         if ((x == 0 && mx == x && copySign(1.0, x) == -1.0)
                 || (x < mx) || std::isnan(x)) {
             mx = x;
         }
     }
-    RETURN_RESULT(Encode(mx));
+    RETURN_RESULT(Encode::smallestNumber(mx));
 }
 
-void MathObject::method_pow(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_pow(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double x = callData->argc > 0 ? callData->args[0].toNumber() : qt_qnan();
-    double y = callData->argc > 1 ? callData->args[1].toNumber() : qt_qnan();
+    double x = argc > 0 ? argv[0].toNumber() : qt_qnan();
+    double y = argc > 1 ? argv[1].toNumber() : qt_qnan();
 
     if (std::isnan(y))
         RETURN_RESULT(Encode(qt_qnan()));
@@ -271,32 +467,24 @@ void MathObject::method_pow(const BuiltinFunction *, Scope &scope, CallData *cal
     RETURN_RESULT(Encode(qt_qnan()));
 }
 
-Q_GLOBAL_STATIC(QThreadStorage<bool *>, seedCreatedStorage);
-
-void MathObject::method_random(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue MathObject::method_random(const FunctionObject *, const Value *, const Value *, int)
 {
-    if (!seedCreatedStorage()->hasLocalData()) {
-        int msecs = QTime(0,0,0).msecsTo(QTime::currentTime());
-        Q_ASSERT(msecs >= 0);
-        qsrand(uint(uint(msecs) ^ reinterpret_cast<quintptr>(scope.engine)));
-        seedCreatedStorage()->setLocalData(new bool(true));
-    }
-    // rand()/qrand() return a value where the upperbound is RAND_MAX inclusive. So, instead of
-    // dividing by RAND_MAX (which would return 0..RAND_MAX inclusive), we divide by RAND_MAX + 1.
-    qint64 upperLimit = qint64(RAND_MAX) + 1;
-    RETURN_RESULT(Encode(qrand() / double(upperLimit)));
+    RETURN_RESULT(Encode(QRandomGenerator::global()->generateDouble()));
 }
 
-void MathObject::method_round(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_round(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    v = copySign(std::floor(v + 0.5), v);
-    RETURN_RESULT(Encode(v));
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (std::isnan(v) || qt_is_inf(v) || qIsNull(v))
+        RETURN_RESULT(Encode(v));
+
+     v = copySign(std::floor(v + 0.5), v);
+     RETURN_RESULT(Encode(v));
 }
 
-void MathObject::method_sign(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_sign(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : qt_qnan();
 
     if (std::isnan(v))
         RETURN_RESULT(Encode(qt_qnan()));
@@ -307,24 +495,58 @@ void MathObject::method_sign(const BuiltinFunction *, Scope &scope, CallData *ca
     RETURN_RESULT(Encode(std::signbit(v) ? -1 : 1));
 }
 
-void MathObject::method_sin(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_sin(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
-    RETURN_RESULT(Encode(std::sin(v)));
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v == 0.0)
+        RETURN_RESULT(Encode(v));
+    else
+        RETURN_RESULT(Encode(std::sin(v)));
 }
 
-void MathObject::method_sqrt(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_sinh(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v == 0.0)
+        RETURN_RESULT(Encode(v));
+    else
+        RETURN_RESULT(Encode(std::sinh(v)));
+}
+
+ReturnedValue MathObject::method_sqrt(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     RETURN_RESULT(Encode(std::sqrt(v)));
 }
 
-void MathObject::method_tan(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue MathObject::method_tan(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double v = callData->argc ? callData->args[0].toNumber() : qt_qnan();
+    double v = argc ? argv[0].toNumber() : qt_qnan();
     if (v == 0.0)
         RETURN_RESULT(Encode(v));
     else
         RETURN_RESULT(Encode(std::tan(v)));
 }
 
+ReturnedValue MathObject::method_tanh(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+    if (v == 0.0)
+        RETURN_RESULT(Encode(v));
+    else
+        RETURN_RESULT(Encode(std::tanh(v)));
+}
+
+ReturnedValue MathObject::method_trunc(const FunctionObject *, const Value *, const Value *argv, int argc)
+{
+    double v = argc ? argv[0].toNumber() : qt_qnan();
+#ifdef Q_OS_ANDROID // incomplete std :-(
+    if (std::isnan(v) || qt_is_inf(v) || qIsNull(v))
+        RETURN_RESULT(Encode(v));
+    // Nearest integer not greater in magnitude:
+    quint64 whole = std::abs(v);
+    RETURN_RESULT(Encode(copySign(whole, v)));
+#else
+    RETURN_RESULT(Encode(std::trunc(v)));
+#endif
+}
diff --git a/src/qml/jsruntime/qv4mathobject_p.h b/src/qml/jsruntime/qv4mathobject_p.h
index e617712905..2658e25438 100644
--- a/src/qml/jsruntime/qv4mathobject_p.h
+++ b/src/qml/jsruntime/qv4mathobject_p.h
@@ -69,25 +69,41 @@ struct MathObject: Object
     V4_OBJECT2(MathObject, Object)
     Q_MANAGED_TYPE(MathObject)
 
-    static void method_abs(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_acos(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_asin(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_atan(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_atan2(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_ceil(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_cos(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_exp(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_floor(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_log(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_max(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_min(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_pow(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_random(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_round(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_sign(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_sin(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_sqrt(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_tan(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_abs(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_acos(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_acosh(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_asin(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_asinh(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_atan(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_atanh(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_atan2(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_cbrt(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_ceil(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_clz32(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_cos(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_cosh(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_exp(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_expm1(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_floor(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_fround(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_hypot(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_imul(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_log(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_log10(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_log1p(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_log2(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_max(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_min(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_pow(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_random(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_round(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sign(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sin(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sinh(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sqrt(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_tan(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_tanh(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_trunc(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4memberdata.cpp b/src/qml/jsruntime/qv4memberdata.cpp
index 8f862d63e9..246f857643 100644
--- a/src/qml/jsruntime/qv4memberdata.cpp
+++ b/src/qml/jsruntime/qv4memberdata.cpp
@@ -45,12 +45,30 @@ using namespace QV4;
 
 DEFINE_MANAGED_VTABLE(MemberData);
 
+static size_t nextPowerOfTwo(size_t s)
+{
+    --s;
+    s |= s >> 1;
+    s |= s >> 2;
+    s |= s >> 4;
+    s |= s >> 8;
+    s |= s >> 16;
+#if (QT_POINTER_SIZE == 8)
+        s |= s >> 32;
+#endif
+    ++s;
+    return s;
+}
+
 Heap::MemberData *MemberData::allocate(ExecutionEngine *e, uint n, Heap::MemberData *old)
 {
-    Q_ASSERT(!old || old->values.size < n);
-    Q_ASSERT(n);
+    Q_ASSERT(!old || old->values.size <= n);
+    if (!n)
+        n = 4;
 
     size_t alloc = MemoryManager::align(sizeof(Heap::MemberData) + (n - 1)*sizeof(Value));
+    // round up to next power of two to avoid quadratic behaviour for very large objects
+    alloc = nextPowerOfTwo(alloc);
     Heap::MemberData *m = e->memoryManager->allocManaged<MemberData>(alloc);
     if (old)
         // no write barrier required here
diff --git a/src/qml/jsruntime/qv4memberdata_p.h b/src/qml/jsruntime/qv4memberdata_p.h
index 9d333011fc..186083b83a 100644
--- a/src/qml/jsruntime/qv4memberdata_p.h
+++ b/src/qml/jsruntime/qv4memberdata_p.h
@@ -63,9 +63,9 @@ namespace Heap {
     Member(class, ValueArray, ValueArray, values)
 
 DECLARE_HEAP_OBJECT(MemberData, Base) {
-    DECLARE_MARK_TABLE(MemberData);
+    DECLARE_MARKOBJECTS(MemberData);
 };
-V4_ASSERT_IS_TRIVIAL(MemberData)
+Q_STATIC_ASSERT(std::is_trivial< MemberData >::value);
 
 }
 
@@ -74,26 +74,14 @@ struct MemberData : Managed
     V4_MANAGED(MemberData, Managed)
     V4_INTERNALCLASS(MemberData)
 
-    struct Index {
-        Heap::Base *base;
-        Value *slot;
-
-        void set(EngineBase *e, Value newVal) {
-            WriteBarrier::write(e, base, slot, newVal);
-        }
-        const Value *operator->() const { return slot; }
-        const Value &operator*() const { return *slot; }
-        bool isNull() const { return !slot; }
-    };
-
     const Value &operator[] (uint idx) const { return d()->values[idx]; }
     const Value *data() const { return d()->values.data(); }
-    void set(ExecutionEngine *e, uint index, Value v) { d()->values.set(e, index, v); }
-    void set(ExecutionEngine *e, uint index, Heap::Base *b) { d()->values.set(e, index, b); }
+    void set(EngineBase *e, uint index, Value v) { d()->values.set(e, index, v); }
+    void set(EngineBase *e, uint index, Heap::Base *b) { d()->values.set(e, index, b); }
 
     inline uint size() const { return d()->values.size; }
 
-    static Heap::MemberData *allocate(QV4::ExecutionEngine *e, uint n, Heap::MemberData *old = 0);
+    static Heap::MemberData *allocate(QV4::ExecutionEngine *e, uint n, Heap::MemberData *old = nullptr);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4module.cpp b/src/qml/jsruntime/qv4module.cpp
new file mode 100644
index 0000000000..237ada8321
--- /dev/null
+++ b/src/qml/jsruntime/qv4module.cpp
@@ -0,0 +1,282 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include "qv4module_p.h"
+
+#include <private/qv4mm_p.h>
+#include <private/qv4vme_moth_p.h>
+#include <private/qv4context_p.h>
+#include <private/qv4symbol_p.h>
+#include <private/qv4identifiertable_p.h>
+
+#include <QScopeGuard>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(Module);
+
+void Heap::Module::init(ExecutionEngine *engine, CompiledData::CompilationUnit *moduleUnit)
+{
+    Object::init();
+
+    // This is a back pointer and there is no need to call addref() on the unit, because the unit
+    // owns this object instead.
+    unit = moduleUnit;
+    self.set(engine, this);
+
+    Function *moduleFunction = unit->runtimeFunctions[unit->unitData()->indexOfRootFunction];
+
+    const uint locals = moduleFunction->compiledFunction->nLocals;
+    const size_t requiredMemory = sizeof(QV4::CallContext::Data) - sizeof(Value) + sizeof(Value) * locals;
+    scope.set(engine, engine->memoryManager->allocManaged<QV4::CallContext>(requiredMemory, moduleFunction->internalClass));
+    scope->init();
+    scope->outer.set(engine, engine->rootContext()->d());
+    scope->locals.size = locals;
+    scope->locals.alloc = locals;
+    scope->nArgs = 0;
+
+    // Prepare the temporal dead zone
+    scope->setupLocalTemporalDeadZone(moduleFunction->compiledFunction);
+
+    Scope valueScope(engine);
+
+    // It's possible for example to re-export an import, for example:
+    //     import * as foo from "./bar.js"
+    //     export { foo }
+    // Since we don't add imports to the locals, it won't be found typically.
+    // Except now we add imports at the end of the internal class in the index
+    // space past the locals, so that resolveExport can find it.
+    {
+        Scoped<QV4::InternalClass> ic(valueScope, scope->internalClass);
+
+        for (uint i = 0; i < unit->data->importEntryTableSize; ++i) {
+            const CompiledData::ImportEntry &import = unit->data->importEntryTable()[i];
+            ic = ic->addMember(engine->identifierTable->asPropertyKey(unit->runtimeStrings[import.localName]), Attr_NotConfigurable);
+        }
+        scope->internalClass.set(engine, ic->d());
+    }
+
+
+    Scoped<QV4::Module> This(valueScope, this);
+    ScopedString name(valueScope, engine->newString(QStringLiteral("Module")));
+    This->insertMember(engine->symbol_toStringTag(), name, Attr_ReadOnly);
+    This->setPrototypeUnchecked(nullptr);
+}
+
+void Module::evaluate()
+{
+    if (d()->evaluated)
+        return;
+    d()->evaluated = true;
+
+    CompiledData::CompilationUnit *unit = d()->unit;
+
+    unit->evaluateModuleRequests();
+
+    ExecutionEngine *v4 = engine();
+    Function *moduleFunction = unit->runtimeFunctions[unit->data->indexOfRootFunction];
+    CppStackFrame frame;
+    frame.init(v4, moduleFunction, nullptr, 0);
+    frame.setupJSFrame(v4->jsStackTop, Value::undefinedValue(), d()->scope,
+                       Value::undefinedValue(), Value::undefinedValue());
+
+    frame.push();
+    v4->jsStackTop += frame.requiredJSStackFrameSize();
+    auto frameCleanup = qScopeGuard([&frame]() {
+        frame.pop();
+    });
+    Moth::VME::exec(&frame, v4);
+}
+
+const Value *Module::resolveExport(PropertyKey id) const
+{
+    if (d()->unit->isESModule()) {
+        if (!id.isString())
+            return nullptr;
+        Scope scope(engine());
+        ScopedString name(scope, id.asStringOrSymbol());
+        return d()->unit->resolveExport(name);
+    } else {
+        InternalClassEntry entry = d()->scope->internalClass->find(id);
+        if (entry.isValid())
+            return &d()->scope->locals[entry.index];
+        return nullptr;
+    }
+}
+
+ReturnedValue Module::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
+{
+    if (id.isSymbol())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+
+    const Module *module = static_cast<const Module *>(m);
+    const Value *v = module->resolveExport(id);
+    if (hasProperty)
+        *hasProperty = v != nullptr;
+    if (!v)
+        return Encode::undefined();
+    if (v->isEmpty()) {
+        Scope scope(m->engine());
+        ScopedValue propName(scope, id.toStringOrSymbol(scope.engine));
+        return scope.engine->throwReferenceError(propName);
+    }
+    return v->asReturnedValue();
+}
+
+PropertyAttributes Module::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
+{
+    if (id.isSymbol())
+        return Object::virtualGetOwnProperty(m, id, p);
+
+    const Module *module = static_cast<const Module *>(m);
+    const Value *v = module->resolveExport(id);
+    if (!v) {
+        if (p)
+            p->value = Encode::undefined();
+        return Attr_Invalid;
+    }
+    if (p)
+        p->value = v->isEmpty() ? Encode::undefined() : v->asReturnedValue();
+    if (v->isEmpty()) {
+        Scope scope(m->engine());
+        ScopedValue propName(scope, id.toStringOrSymbol(scope.engine));
+        scope.engine->throwReferenceError(propName);
+    }
+    return Attr_Data | Attr_NotConfigurable;
+}
+
+bool Module::virtualHasProperty(const Managed *m, PropertyKey id)
+{
+    if (id.isSymbol())
+        return Object::virtualHasProperty(m, id);
+
+    const Module *module = static_cast<const Module *>(m);
+    const Value *v = module->resolveExport(id);
+    return v != nullptr;
+}
+
+bool Module::virtualPreventExtensions(Managed *)
+{
+    return true;
+}
+
+bool Module::virtualDefineOwnProperty(Managed *, PropertyKey, const Property *, PropertyAttributes)
+{
+    return false;
+}
+
+bool Module::virtualPut(Managed *, PropertyKey, const Value &, Value *)
+{
+    return false;
+}
+
+bool Module::virtualDeleteProperty(Managed *m, PropertyKey id)
+{
+    if (id.isSymbol())
+        return Object::virtualDeleteProperty(m, id);
+    const Module *module = static_cast<const Module *>(m);
+    const Value *v = module->resolveExport(id);
+    if (v)
+        return false;
+    return true;
+}
+
+struct ModuleNamespaceIterator : ObjectOwnPropertyKeyIterator
+{
+    QStringList exportedNames;
+    int exportIndex = 0;
+    ModuleNamespaceIterator(const QStringList &names) : exportedNames(names) {}
+    ~ModuleNamespaceIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey ModuleNamespaceIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs)
+{
+    const Module *module = static_cast<const Module *>(o);
+    if (exportIndex < exportedNames.count()) {
+        if (attrs)
+            *attrs = Attr_Data;
+        Scope scope(module->engine());
+        ScopedString exportName(scope, scope.engine->newString(exportedNames.at(exportIndex)));
+        exportIndex++;
+        const Value *v = module->resolveExport(exportName->toPropertyKey());
+        if (pd) {
+            if (v->isEmpty())
+                scope.engine->throwReferenceError(exportName);
+            else
+                pd->value = *v;
+        }
+        return exportName->toPropertyKey();
+    }
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+OwnPropertyKeyIterator *Module::virtualOwnPropertyKeys(const Object *o, Value *target)
+{
+    const Module *module = static_cast<const Module *>(o);
+    *target = *o;
+
+    QStringList names;
+    if (module->d()->unit->isESModule()) {
+        names = module->d()->unit->exportedNames();
+    } else {
+        Heap::InternalClass *scopeClass = module->d()->scope->internalClass;
+        for (uint i = 0; i < scopeClass->size; ++i)
+            names << scopeClass->keyAt(i);
+    }
+
+    return new ModuleNamespaceIterator(names);
+}
+
+Heap::Object *Module::virtualGetPrototypeOf(const Managed *)
+{
+    return nullptr;
+}
+
+bool Module::virtualSetPrototypeOf(Managed *, const Object *proto)
+{
+    return proto == nullptr;
+}
+
+bool Module::virtualIsExtensible(const Managed *)
+{
+    return false;
+}
diff --git a/src/qml/jsruntime/qv4module_p.h b/src/qml/jsruntime/qv4module_p.h
new file mode 100644
index 0000000000..dca0678fe9
--- /dev/null
+++ b/src/qml/jsruntime/qv4module_p.h
@@ -0,0 +1,99 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4MODULE
+#define QV4MODULE
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4context_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Heap {
+
+#define ModuleMembers(class, Member) \
+    Member(class, NoMark, CompiledData::CompilationUnit *, unit) \
+    Member(class, Pointer, CallContext *, scope) \
+    Member(class, HeapValue, HeapValue, self) \
+    Member(class, NoMark, bool, evaluated)
+
+DECLARE_EXPORTED_HEAP_OBJECT(Module, Object) {
+    DECLARE_MARKOBJECTS(Module)
+
+    void init(ExecutionEngine *engine, CompiledData::CompilationUnit *moduleUnit);
+};
+
+}
+
+struct Q_QML_EXPORT Module : public Object {
+    V4_OBJECT2(Module, Object)
+
+    void evaluate();
+    const Value *resolveExport(PropertyKey key) const;
+
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static bool virtualHasProperty(const Managed *m, PropertyKey id);
+    static bool virtualPreventExtensions(Managed *);
+    static bool virtualDefineOwnProperty(Managed *, PropertyKey, const Property *, PropertyAttributes);
+    static bool virtualPut(Managed *, PropertyKey, const Value &, Value *);
+    static bool virtualDeleteProperty(Managed *m, PropertyKey id);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
+    static Heap::Object *virtualGetPrototypeOf(const Managed *);
+    static bool virtualSetPrototypeOf(Managed *, const Object *proto);
+    static bool virtualIsExtensible(const Managed *);
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4MODULE
diff --git a/src/qml/jsruntime/qv4numberobject.cpp b/src/qml/jsruntime/qv4numberobject.cpp
index 8cfa930888..13f6912371 100644
--- a/src/qml/jsruntime/qv4numberobject.cpp
+++ b/src/qml/jsruntime/qv4numberobject.cpp
@@ -78,16 +78,24 @@ void Heap::NumberCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("Number"));
 }
 
-void NumberCtor::construct(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue NumberCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    double dbl = callData->argc ? callData->args[0].toNumber() : 0.;
-    scope.result = Encode(scope.engine->newNumberObject(dbl));
+    auto v4 = f->engine();
+    double dbl = argc ? argv[0].toNumber() : 0.;
+
+    ReturnedValue o = Encode(f->engine()->newNumberObject(dbl));
+    if (!newTarget)
+        return o;
+    Scope scope(v4);
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
 }
 
-void NumberCtor::call(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue NumberCtor::virtualCall(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    double dbl = callData->argc ? callData->args[0].toNumber() : 0.;
-    scope.result = Encode(dbl);
+    double dbl = argc ? argv[0].toNumber() : 0.;
+    return Encode(dbl);
 }
 
 void NumberPrototype::init(ExecutionEngine *engine, Object *ctor)
@@ -95,19 +103,19 @@ void NumberPrototype::init(ExecutionEngine *engine, Object *ctor)
     Scope scope(engine);
     ScopedObject o(scope);
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
 
-    ctor->defineReadonlyProperty(QStringLiteral("NaN"), Primitive::fromDouble(qt_qnan()));
-    ctor->defineReadonlyProperty(QStringLiteral("NEGATIVE_INFINITY"), Primitive::fromDouble(-qInf()));
-    ctor->defineReadonlyProperty(QStringLiteral("POSITIVE_INFINITY"), Primitive::fromDouble(qInf()));
-    ctor->defineReadonlyProperty(QStringLiteral("MAX_VALUE"), Primitive::fromDouble(1.7976931348623158e+308));
-    ctor->defineReadonlyProperty(QStringLiteral("EPSILON"), Primitive::fromDouble(std::numeric_limits<double>::epsilon()));
-    ctor->defineReadonlyProperty(QStringLiteral("MAX_SAFE_INTEGER"), Primitive::fromDouble(9007199254740991));
-    ctor->defineReadonlyProperty(QStringLiteral("MIN_SAFE_INTEGER"), Primitive::fromDouble(-9007199254740991));
+    ctor->defineReadonlyProperty(QStringLiteral("NaN"), Value::fromDouble(qt_qnan()));
+    ctor->defineReadonlyProperty(QStringLiteral("NEGATIVE_INFINITY"), Value::fromDouble(-qInf()));
+    ctor->defineReadonlyProperty(QStringLiteral("POSITIVE_INFINITY"), Value::fromDouble(qInf()));
+    ctor->defineReadonlyProperty(QStringLiteral("MAX_VALUE"), Value::fromDouble(1.7976931348623158e+308));
+    ctor->defineReadonlyProperty(QStringLiteral("EPSILON"), Value::fromDouble(std::numeric_limits<double>::epsilon()));
+    ctor->defineReadonlyProperty(QStringLiteral("MAX_SAFE_INTEGER"), Value::fromDouble(9007199254740991));
+    ctor->defineReadonlyProperty(QStringLiteral("MIN_SAFE_INTEGER"), Value::fromDouble(-9007199254740991));
 
 QT_WARNING_PUSH
 QT_WARNING_DISABLE_INTEL(239)
-    ctor->defineReadonlyProperty(QStringLiteral("MIN_VALUE"), Primitive::fromDouble(5e-324));
+    ctor->defineReadonlyProperty(QStringLiteral("MIN_VALUE"), Value::fromDouble(5e-324));
 QT_WARNING_POP
 
     ctor->defineDefaultProperty(QStringLiteral("isFinite"), method_isFinite, 1);
@@ -117,190 +125,141 @@ QT_WARNING_POP
 
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
     defineDefaultProperty(engine->id_toString(), method_toString, 1);
-    defineDefaultProperty(QStringLiteral("toLocaleString"), method_toLocaleString);
+    defineDefaultProperty(engine->id_toLocaleString(), method_toLocaleString);
     defineDefaultProperty(engine->id_valueOf(), method_valueOf);
     defineDefaultProperty(QStringLiteral("toFixed"), method_toFixed, 1);
     defineDefaultProperty(QStringLiteral("toExponential"), method_toExponential, 1);
     defineDefaultProperty(QStringLiteral("toPrecision"), method_toPrecision, 1);
 }
 
-inline ReturnedValue thisNumberValue(Scope &scope, CallData *callData)
+inline ReturnedValue thisNumberValue(ExecutionEngine *v4, const Value *thisObject)
 {
-    if (callData->thisObject.isNumber())
-        return callData->thisObject.asReturnedValue();
-    NumberObject *n = callData->thisObject.as<NumberObject>();
+    if (thisObject->isNumber())
+        return thisObject->asReturnedValue();
+    const NumberObject *n = thisObject->as<NumberObject>();
     if (!n) {
-        scope.engine->throwTypeError();
+        v4->throwTypeError();
         return Encode::undefined();
     }
     return Encode(n->value());
 }
 
-inline double thisNumber(Scope &scope, CallData *callData)
+inline double thisNumber(ExecutionEngine *engine, const Value *thisObject)
 {
-    if (callData->thisObject.isNumber())
-        return callData->thisObject.asDouble();
-    NumberObject *n = callData->thisObject.as<NumberObject>();
+    if (thisObject->isNumber())
+        return thisObject->asDouble();
+    const NumberObject *n = thisObject->as<NumberObject>();
     if (!n) {
-        scope.engine->throwTypeError();
+        engine->throwTypeError();
         return 0;
     }
     return n->value();
 }
 
-void NumberPrototype::method_isFinite(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_isFinite(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (!argc || !argv[0].isNumber())
+        return Encode(false);
 
-    double v = callData->args[0].toNumber();
-    scope.result = Encode(!std::isnan(v) && !qt_is_inf(v));
+    double v = argv[0].toNumber();
+    return Encode(!std::isnan(v) && !qt_is_inf(v));
 }
 
-void NumberPrototype::method_isInteger(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_isInteger(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (!argc)
+        return Encode(false);
 
-    const Value &v = callData->args[0];
-    if (!v.isNumber()) {
-        scope.result = Encode(false);
-        return;
-    }
+    const Value &v = argv[0];
+    if (!v.isNumber())
+        return Encode(false);
 
     double dv = v.toNumber();
-    if (std::isnan(dv) || qt_is_inf(dv)) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (std::isnan(dv) || qt_is_inf(dv))
+        return Encode(false);
 
     double iv = v.toInteger();
-    scope.result = Encode(dv == iv);
+    return Encode(dv == iv);
 }
 
-void NumberPrototype::method_isSafeInteger(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_isSafeInteger(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (!argc)
+        return Encode(false);
 
-    const Value &v = callData->args[0];
-    if (!v.isNumber()) {
-        scope.result = Encode(false);
-        return;
-    }
+    const Value &v = argv[0];
+    if (!v.isNumber())
+        return Encode(false);
 
     double dv = v.toNumber();
-    if (std::isnan(dv) || qt_is_inf(dv)) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (std::isnan(dv) || qt_is_inf(dv))
+        return Encode(false);
 
     double iv = v.toInteger();
-    scope.result = Encode(dv == iv && std::fabs(iv) <= (2^53)-1);
+    return Encode(dv == iv && std::fabs(iv) <= (2^53)-1);
 }
 
-void NumberPrototype::method_isNaN(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_isNaN(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (!callData->argc) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (!argc || !argv[0].isNumber())
+        return Encode(false);
 
-    double v = callData->args[0].toNumber();
-    scope.result = Encode(std::isnan(v));
+    double v = argv[0].toNumber();
+    // cast to bool explicitly as std::isnan() may give us ::isnan(), which
+    // sometimes returns an int and we don't want the Encode(int) overload.
+    return Encode(bool(std::isnan(v)));
 }
 
-void NumberPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    double num = thisNumber(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    double num = thisNumber(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    if (callData->argc && !callData->args[0].isUndefined()) {
-        int radix = callData->args[0].toInt32();
+    if (argc && !argv[0].isUndefined()) {
+        int radix = argv[0].toInt32();
         if (radix < 2 || radix > 36) {
-            scope.result = scope.engine->throwError(QStringLiteral("Number.prototype.toString: %0 is not a valid radix")
-                            .arg(radix));
-            return;
-        }
-
-        if (std::isnan(num)) {
-            scope.result = scope.engine->newString(QStringLiteral("NaN"));
-            return;
-        } else if (qt_is_inf(num)) {
-            scope.result = scope.engine->newString(QLatin1String(num < 0 ? "-Infinity" : "Infinity"));
-            return;
+            return v4->throwError(QStringLiteral("Number.prototype.toString: %0 is not a valid radix").arg(radix));
         }
 
-        if (radix != 10) {
-            QString str;
-            bool negative = false;
-            if (num < 0) {
-                negative = true;
-                num = -num;
-            }
-            double frac = num - std::floor(num);
-            num = Primitive::toInteger(num);
-            do {
-                char c = (char)std::fmod(num, radix);
-                c = (c < 10) ? (c + '0') : (c - 10 + 'a');
-                str.prepend(QLatin1Char(c));
-                num = std::floor(num / radix);
-            } while (num != 0);
-            if (frac != 0) {
-                str.append(QLatin1Char('.'));
-                do {
-                    frac = frac * radix;
-                    char c = (char)std::floor(frac);
-                    c = (c < 10) ? (c + '0') : (c - 10 + 'a');
-                    str.append(QLatin1Char(c));
-                    frac = frac - std::floor(frac);
-                } while (frac != 0);
-            }
-            if (negative)
-                str.prepend(QLatin1Char('-'));
-            scope.result = scope.engine->newString(str);
-            return;
-        }
+        QString str;
+        RuntimeHelpers::numberToString(&str, num, radix);
+        return Encode(v4->newString(str));
     }
 
-    scope.result = Primitive::fromDouble(num).toString(scope.engine);
+    return Encode(Value::fromDouble(num).toString(v4));
 }
 
-void NumberPrototype::method_toLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_toLocaleString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    ScopedValue v(scope, thisNumberValue(scope, callData));
-    scope.result = v->toString(scope.engine);
-    CHECK_EXCEPTION();
+    Scope scope(b);
+    ScopedValue v(scope, thisNumberValue(b->engine(), thisObject));
+    return Encode(v->toString(scope.engine));
 }
 
-void NumberPrototype::method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_valueOf(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    scope.result = thisNumberValue(scope, callData);
+    return thisNumberValue(b->engine(), thisObject);
 }
 
-void NumberPrototype::method_toFixed(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_toFixed(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    double v = thisNumber(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    double v = thisNumber(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     double fdigits = 0;
 
-    if (callData->argc > 0)
-        fdigits = callData->args[0].toInteger();
+    if (argc > 0)
+        fdigits = argv[0].toInteger();
 
     if (std::isnan(fdigits))
         fdigits = 0;
 
-    if (fdigits < 0 || fdigits > 20) {
-        scope.result = scope.engine->throwRangeError(callData->thisObject);
-        return;
-    }
+    if (fdigits < 0 || fdigits > 100)
+        return v4->throwRangeError(*thisObject);
 
     QString str;
     if (std::isnan(v))
@@ -310,49 +269,65 @@ void NumberPrototype::method_toFixed(const BuiltinFunction *, Scope &scope, Call
     else if (v < 1.e21)
         str = NumberLocale::instance()->toString(v, 'f', int(fdigits));
     else {
-        scope.result = RuntimeHelpers::stringFromNumber(scope.engine, v);
-        return;
+        return Encode(RuntimeHelpers::stringFromNumber(v4, v));
     }
-    scope.result = scope.engine->newString(str);
+    return Encode(v4->newString(str));
 }
 
-void NumberPrototype::method_toExponential(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_toExponential(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    double d = thisNumber(scope, callData);
-    CHECK_EXCEPTION();
-
-    int fdigits = NumberLocale::instance()->defaultDoublePrecision;
-
-    if (callData->argc && !callData->args[0].isUndefined()) {
-        fdigits = callData->args[0].toInt32();
-        if (fdigits < 0 || fdigits > 20) {
-            ScopedString error(scope, scope.engine->newString(QStringLiteral("Number.prototype.toExponential: fractionDigits out of range")));
-            scope.result = scope.engine->throwRangeError(error);
-            return;
-        }
+    ExecutionEngine *v4 = b->engine();
+    double d = thisNumber(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+
+    bool defaultDigits = !argc || argv[0].isUndefined();
+    int fdigits = !defaultDigits ? argv[0].toInteger() : NumberLocale::instance()->defaultDoublePrecision;
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+
+    if (std::isnan(d))
+        return Encode(v4->newString(QLatin1String("NaN")));
+
+    if (qIsInf(d))
+        return Encode(v4->newString(QLatin1String(d < 0 ? "-Infinity" : "Infinity")));
+
+    if (!defaultDigits && (fdigits < 0 || fdigits > 100)) {
+        Scope scope(v4);
+        ScopedString error(scope, v4->newString(QStringLiteral("Number.prototype.toExponential: fractionDigits out of range")));
+        return v4->throwRangeError(error);
     }
 
     QString result = NumberLocale::instance()->toString(d, 'e', fdigits);
-    scope.result = scope.engine->newString(result);
+    return Encode(v4->newString(result));
 }
 
-void NumberPrototype::method_toPrecision(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue NumberPrototype::method_toPrecision(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedValue v(scope, thisNumberValue(scope, callData));
-    CHECK_EXCEPTION();
+    Scope scope(b);
+    ScopedValue v(scope, thisNumberValue(scope.engine, thisObject));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+    double d = v->asDouble();
 
-    if (!callData->argc || callData->args[0].isUndefined()) {
-        scope.result = v->toString(scope.engine);
-        return;
-    }
+    if (!argc || argv[0].isUndefined())
+        return Encode(v->toString(scope.engine));
+
+    int precision = argv[0].toInt32();
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    if (std::isnan(d))
+        return Encode(scope.engine->newString(QLatin1String("NaN")));
+
+    if (qIsInf(d))
+        return Encode(scope.engine->newString(QLatin1String(d < 0 ? "-Infinity" : "Infinity")));
 
-    int precision = callData->args[0].toInt32();
-    if (precision < 1 || precision > 21) {
+    if (precision < 1 || precision > 100) {
         ScopedString error(scope, scope.engine->newString(QStringLiteral("Number.prototype.toPrecision: precision out of range")));
-        scope.result = scope.engine->throwRangeError(error);
-        return;
+        return scope.engine->throwRangeError(error);
     }
 
-    QString result = NumberLocale::instance()->toString(v->asDouble(), 'g', precision);
-    scope.result = scope.engine->newString(result);
+    QString result = NumberLocale::instance()->toString(d, 'g', precision);
+    return Encode(scope.engine->newString(result));
 }
diff --git a/src/qml/jsruntime/qv4numberobject_p.h b/src/qml/jsruntime/qv4numberobject_p.h
index 0bc2cd8c65..576817cf36 100644
--- a/src/qml/jsruntime/qv4numberobject_p.h
+++ b/src/qml/jsruntime/qv4numberobject_p.h
@@ -79,8 +79,8 @@ struct NumberCtor: FunctionObject
 {
     V4_OBJECT2(NumberCtor, FunctionObject)
 
-    static void construct(const Managed *that, Scope &scope, CallData *callData);
-    static void call(const Managed *, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct NumberPrototype: NumberObject
@@ -88,16 +88,16 @@ struct NumberPrototype: NumberObject
     V4_PROTOTYPE(objectPrototype)
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_isFinite(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isInteger(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isSafeInteger(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isNaN(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toFixed(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toExponential(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toPrecision(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_isFinite(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isInteger(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isSafeInteger(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isNaN(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toFixed(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toExponential(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toPrecision(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index 94d5a74fe5..3d2d54f651 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -38,8 +38,6 @@
 ****************************************************************************/
 
 #include "qv4object_p.h"
-#include "qv4jsir_p.h"
-#include "qv4isel_p.h"
 #include "qv4objectproto_p.h"
 #include "qv4stringobject_p.h"
 #include "qv4argumentsobject_p.h"
@@ -51,6 +49,9 @@
 #include "qv4identifier_p.h"
 #include "qv4string_p.h"
 #include "qv4identifiertable_p.h"
+#include "qv4jscall_p.h"
+#include "qv4symbol_p.h"
+#include "qv4proxy_p.h"
 
 #include <stdint.h>
 
@@ -58,9 +59,11 @@ using namespace QV4;
 
 DEFINE_OBJECT_VTABLE(Object);
 
-void Object::setInternalClass(InternalClass *ic)
+void Object::setInternalClass(Heap::InternalClass *ic)
 {
-    d()->internalClass = ic;
+    d()->internalClass.set(engine(), ic);
+    if (ic->isUsedAsProto)
+        ic->updateProtoUsage(d());
     Q_ASSERT(ic && ic->vtable);
     uint nInline = d()->vtable()->nInlineProperties;
     if (ic->size <= nInline)
@@ -71,35 +74,26 @@ void Object::setInternalClass(InternalClass *ic)
         d()->memberData.set(ic->engine, MemberData::allocate(ic->engine, requiredSize, d()->memberData));
 }
 
-void Object::getProperty(uint index, Property *p, PropertyAttributes *attrs) const
+void Object::getProperty(const InternalClassEntry &entry, Property *p) const
 {
-    p->value = *propertyData(index);
-    *attrs = internalClass()->propertyData.at(index);
-    if (attrs->isAccessor())
-        p->set = *propertyData(index + SetterOffset);
+    p->value = *propertyData(entry.index);
+    if (entry.attributes.isAccessor())
+        p->set = *propertyData(entry.setterIndex);
 }
 
-void Object::setProperty(uint index, const Property *p)
+void Object::setProperty(const InternalClassEntry &entry, const Property *p)
 {
-    setProperty(index, p->value);
-    if (internalClass()->propertyData.at(index).isAccessor())
-        setProperty(index + SetterOffset, p->set);
+    setProperty(entry.index, p->value);
+    if (entry.attributes.isAccessor())
+        setProperty(entry.setterIndex, p->set);
 }
 
-bool Object::setPrototype(Object *proto)
+void Heap::Object::setUsedAsProto()
 {
-    Heap::Object *p = proto ? proto->d() : 0;
-    Heap::Object *pp = p;
-    while (pp) {
-        if (pp == d())
-            return false;
-        pp = pp->prototype();
-    }
-    setInternalClass(internalClass()->changePrototype(p));
-    return true;
+    internalClass.set(internalClass->engine, internalClass->asProtoClass());
 }
 
-ReturnedValue Object::getValue(const Value &thisObject, const Value &v, PropertyAttributes attrs)
+ReturnedValue Object::getValueAccessor(const Value &thisObject, const Value &v, PropertyAttributes attrs)
 {
     if (!attrs.isAccessor())
         return v.asReturnedValue();
@@ -108,77 +102,66 @@ ReturnedValue Object::getValue(const Value &thisObject, const Value &v, Property
         return Encode::undefined();
 
     Scope scope(f->engine());
-    ScopedCallData callData(scope);
-    callData->thisObject = thisObject;
-    f->call(scope, callData);
-    return scope.result.asReturnedValue();
+    JSCallData jsCallData(scope);
+    *jsCallData->thisObject = thisObject;
+    return f->call(jsCallData);
 }
 
-bool Object::putValue(uint memberIndex, const Value &value)
+bool Object::putValue(uint memberIndex, PropertyAttributes attrs, const Value &value)
 {
-    QV4::InternalClass *ic = internalClass();
+    Heap::InternalClass *ic = internalClass();
     if (ic->engine->hasException)
         return false;
 
-    PropertyAttributes attrs = ic->propertyData[memberIndex];
-
     if (attrs.isAccessor()) {
-        const FunctionObject *set = propertyData(memberIndex + SetterOffset)->as<FunctionObject>();
+        const FunctionObject *set = propertyData(memberIndex)->as<FunctionObject>();
         if (set) {
             Scope scope(ic->engine);
             ScopedFunctionObject setter(scope, set);
-            ScopedCallData callData(scope, 1);
-            callData->args[0] = value;
-            callData->thisObject = this;
-            setter->call(scope, callData);
+            JSCallData jsCallData(scope, 1);
+            jsCallData->args[0] = value;
+            *jsCallData->thisObject = this;
+            setter->call(jsCallData);
             return !ic->engine->hasException;
         }
-        goto reject;
+        return false;
     }
 
     if (!attrs.isWritable())
-        goto reject;
+        return false;
 
     setProperty(memberIndex, value);
     return true;
-
-  reject:
-    if (engine()->current->strictMode)
-        engine()->throwTypeError();
-    return false;
 }
 
-void Object::defineDefaultProperty(const QString &name, const Value &value)
+void Object::defineDefaultProperty(const QString &name, const Value &value, PropertyAttributes attributes)
 {
     ExecutionEngine *e = engine();
     Scope scope(e);
     ScopedString s(scope, e->newIdentifier(name));
-    defineDefaultProperty(s, value);
+    defineDefaultProperty(s, value, attributes);
 }
 
-void Object::defineDefaultProperty(const QString &name, void (*code)(const BuiltinFunction *, Scope &, CallData *), int argumentCount)
+void Object::defineDefaultProperty(const QString &name, VTable::Call code,
+                                   int argumentCount, PropertyAttributes attributes)
 {
     ExecutionEngine *e = engine();
     Scope scope(e);
     ScopedString s(scope, e->newIdentifier(name));
-    ExecutionContext *global = e->rootContext();
-    ScopedFunctionObject function(scope, BuiltinFunction::create(global, s, code));
-    function->defineReadonlyConfigurableProperty(e->id_length(), Primitive::fromInt32(argumentCount));
-    defineDefaultProperty(s, function);
+    ScopedFunctionObject function(scope, FunctionObject::createBuiltinFunction(e, s, code, argumentCount));
+    defineDefaultProperty(s, function, attributes);
 }
 
-void Object::defineDefaultProperty(String *name, void (*code)(const BuiltinFunction *, Scope &, CallData *), int argumentCount)
+void Object::defineDefaultProperty(StringOrSymbol *nameOrSymbol, VTable::Call code,
+                                   int argumentCount, PropertyAttributes attributes)
 {
     ExecutionEngine *e = engine();
     Scope scope(e);
-    ExecutionContext *global = e->rootContext();
-    ScopedFunctionObject function(scope, BuiltinFunction::create(global, name, code));
-    function->defineReadonlyConfigurableProperty(e->id_length(), Primitive::fromInt32(argumentCount));
-    defineDefaultProperty(name, function);
+    ScopedFunctionObject function(scope, FunctionObject::createBuiltinFunction(e, nameOrSymbol, code, argumentCount));
+    defineDefaultProperty(nameOrSymbol, function, attributes);
 }
 
-void Object::defineAccessorProperty(const QString &name, void (*getter)(const BuiltinFunction *, Scope &, CallData *),
-                                    void (*setter)(const BuiltinFunction *, Scope &, CallData *))
+void Object::defineAccessorProperty(const QString &name, VTable::Call getter, VTable::Call setter)
 {
     ExecutionEngine *e = engine();
     Scope scope(e);
@@ -186,18 +169,31 @@ void Object::defineAccessorProperty(const QString &name, void (*getter)(const Bu
     defineAccessorProperty(s, getter, setter);
 }
 
-void Object::defineAccessorProperty(String *name, void (*getter)(const BuiltinFunction *, Scope &, CallData *),
-                                    void (*setter)(const BuiltinFunction *, Scope &, CallData *))
+void Object::defineAccessorProperty(StringOrSymbol *name, VTable::Call getter, VTable::Call setter)
 {
     ExecutionEngine *v4 = engine();
     QV4::Scope scope(v4);
     ScopedProperty p(scope);
-    ExecutionContext *global = v4->rootContext();
-    p->setGetter(ScopedFunctionObject(scope, (getter ? BuiltinFunction::create(global, name, getter) : 0)));
-    p->setSetter(ScopedFunctionObject(scope, (setter ? BuiltinFunction::create(global, name, setter) : 0)));
-    insertMember(name, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
+    QString n = name->toQString();
+    if (n.at(0) == QLatin1Char('@'))
+        n = QChar::fromLatin1('[') + n.midRef(1) + QChar::fromLatin1(']');
+    if (getter) {
+        ScopedString getName(scope, v4->newString(QString::fromLatin1("get ") + n));
+        p->setGetter(ScopedFunctionObject(scope, FunctionObject::createBuiltinFunction(v4, getName, getter, 0)));
+    } else {
+        p->setGetter(nullptr);
+    }
+    if (setter) {
+        ScopedString setName(scope, v4->newString(QString::fromLatin1("set ") + n));
+        p->setSetter(ScopedFunctionObject(scope, FunctionObject::createBuiltinFunction(v4, setName, setter, 0)));
+    } else {
+        p->setSetter(nullptr);
+    }
+    insertMember(name, p, QV4::Attr_Accessor|QV4::Attr_NotEnumerable);
 }
 
+
+
 void Object::defineReadonlyProperty(const QString &name, const Value &value)
 {
     QV4::ExecutionEngine *e = engine();
@@ -219,14 +215,28 @@ void Object::defineReadonlyConfigurableProperty(const QString &name, const Value
     defineReadonlyConfigurableProperty(s, value);
 }
 
-void Object::defineReadonlyConfigurableProperty(String *name, const Value &value)
+void Object::defineReadonlyConfigurableProperty(StringOrSymbol *name, const Value &value)
 {
     insertMember(name, value, Attr_ReadOnly_ButConfigurable);
 }
 
-void Object::markObjects(Heap::Base *b, MarkStack *stack)
+void Object::addSymbolSpecies()
 {
-    Heap::Object *o = static_cast<Heap::Object *>(b);
+    Scope scope(engine());
+    ScopedProperty p(scope);
+    p->setGetter(scope.engine->getSymbolSpecies());
+    p->setSetter(nullptr);
+    insertMember(scope.engine->symbol_species(), p, QV4::Attr_Accessor|QV4::Attr_NotWritable|QV4::Attr_NotEnumerable);
+}
+
+void Heap::Object::markObjects(Heap::Base *b, MarkStack *stack)
+{
+    Base::markObjects(b, stack);
+    Object *o = static_cast<Object *>(b);
+    if (o->memberData)
+        o->memberData->mark(stack);
+    if (o->arrayData)
+        o->arrayData->mark(stack);
     uint nInline = o->vtable()->nInlineProperties;
     Value *v = reinterpret_cast<Value *>(o) + o->vtable()->inlinePropertyOffset;
     const Value *end = v + nInline;
@@ -236,460 +246,208 @@ void Object::markObjects(Heap::Base *b, MarkStack *stack)
     }
 }
 
-void Object::insertMember(String *s, const Property *p, PropertyAttributes attributes)
-{
-    uint idx;
-    InternalClass::addMember(this, s, attributes, &idx);
-
-    if (attributes.isAccessor()) {
-        setProperty(idx + GetterOffset, p->value);
-        setProperty(idx + SetterOffset, p->set);
-    } else {
-        setProperty(idx, p->value);
-    }
-}
-
-// Section 8.12.1
-void Object::getOwnProperty(String *name, PropertyAttributes *attrs, Property *p)
+void Object::insertMember(StringOrSymbol *s, const Property *p, PropertyAttributes attributes)
 {
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return getOwnProperty(idx, attrs, p);
-
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
-
-    uint member = internalClass()->find(id);
-    if (member < UINT_MAX) {
-        *attrs = internalClass()->propertyData[member];
-        if (p) {
-            p->value = *propertyData(member);
-            if (attrs->isAccessor())
-                p->set = *propertyData(member + SetterOffset);
-        }
-        return;
-    }
+    InternalClassEntry idx;
+    PropertyKey key = s->toPropertyKey();
+    Heap::InternalClass::addMember(this, key, attributes, &idx);
 
-    if (attrs)
-        *attrs = Attr_Invalid;
-    return;
+    setProperty(idx.index, p->value);
+    if (attributes.isAccessor())
+        setProperty(idx.setterIndex, p->set);
 }
 
-void Object::getOwnProperty(uint index, PropertyAttributes *attrs, Property *p)
+void Object::setPrototypeUnchecked(const Object *p)
 {
-    if (arrayData()) {
-        if (arrayData()->getProperty(index, p, attrs))
-            return;
-    }
-    if (isStringObject()) {
-        *attrs = Attr_NotConfigurable|Attr_NotWritable;
-        if (p)
-            p->value = static_cast<StringObject *>(this)->getIndex(index);
-        return;
-    }
-
-    if (attrs)
-        *attrs = Attr_Invalid;
-    return;
+    setInternalClass(internalClass()->changePrototype(p ? p->d() : nullptr));
 }
 
 // Section 8.12.2
-MemberData::Index Object::getValueOrSetter(String *name, PropertyAttributes *attrs)
-{
-    Q_ASSERT(name->asArrayIndex() == UINT_MAX);
-
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
-
-    Heap::Object *o = d();
-    while (o) {
-        uint idx = o->internalClass->find(id);
-        if (idx < UINT_MAX) {
-            *attrs = o->internalClass->propertyData[idx];
-            return o->writablePropertyData(attrs->isAccessor() ? idx + SetterOffset : idx );
-        }
-
-        o = o->prototype();
-    }
-    *attrs = Attr_Invalid;
-    return { 0, 0 };
-}
-
-ArrayData::Index Object::getValueOrSetter(uint index, PropertyAttributes *attrs)
+PropertyIndex Object::getValueOrSetter(PropertyKey id, PropertyAttributes *attrs)
 {
-    Heap::Object *o = d();
-    while (o) {
-        if (o->arrayData) {
-            uint idx = o->arrayData->mappedIndex(index);
-            if (idx != UINT_MAX) {
-                *attrs = o->arrayData->attributes(index);
-                return { o->arrayData , attrs->isAccessor() ? idx + SetterOffset : idx };
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+        Heap::Object *o = d();
+        while (o) {
+            if (o->arrayData) {
+                uint idx = o->arrayData->mappedIndex(index);
+                if (idx != UINT_MAX) {
+                    *attrs = o->arrayData->attributes(index);
+                    return { o->arrayData , o->arrayData->values.values + (attrs->isAccessor() ? idx + SetterOffset : idx) };
+                }
             }
+            if (o->vtable()->type == Type_StringObject) {
+                if (index < static_cast<const Heap::StringObject *>(o)->length()) {
+                    // this is an evil hack, but it works, as the method is only ever called from put,
+                    // where we don't use the returned pointer there for non writable attributes
+                    *attrs = (Attr_NotWritable|Attr_NotConfigurable);
+                    return { reinterpret_cast<Heap::ArrayData *>(0x1), nullptr };
+                }
+            }
+            o = o->prototype();
         }
-        if (o->vtable()->type == Type_StringObject) {
-            if (index < static_cast<const Heap::StringObject *>(o)->length()) {
-                // this is an evil hack, but it works, as the method is only ever called from putIndexed,
-                // where we don't use the returned pointer there for non writable attributes
-                *attrs = (Attr_NotWritable|Attr_NotConfigurable);
-                return { reinterpret_cast<Heap::ArrayData *>(0x1), 0 };
+    } else {
+        Heap::Object *o = d();
+        while (o) {
+            auto idx = o->internalClass->findValueOrSetter(id);
+            if (idx.isValid()) {
+                *attrs = idx.attrs;
+                return o->writablePropertyData(idx.index);
             }
+
+            o = o->prototype();
         }
-        o = o->prototype();
     }
     *attrs = Attr_Invalid;
-    return { 0, 0 };
-}
-
-bool Object::hasProperty(String *name) const
-{
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return hasProperty(idx);
-
-    Scope scope(engine());
-    ScopedObject o(scope, d());
-    while (o) {
-        if (o->hasOwnProperty(name))
-            return true;
-
-        o = o->prototype();
-    }
-
-    return false;
-}
-
-bool Object::hasProperty(uint index) const
-{
-    Scope scope(engine());
-    ScopedObject o(scope, d());
-    while (o) {
-        if (o->hasOwnProperty(index))
-                return true;
-
-        o = o->prototype();
-    }
-
-    return false;
-}
-
-bool Object::hasOwnProperty(String *name) const
-{
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return hasOwnProperty(idx);
-
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
-
-    if (internalClass()->find(id) < UINT_MAX)
-        return true;
-    if (!query(name).isEmpty())
-        return true;
-    return false;
-}
-
-bool Object::hasOwnProperty(uint index) const
-{
-    if (arrayData() && !arrayData()->isEmpty(index))
-        return true;
-
-    if (isStringObject()) {
-        if (index < static_cast<const StringObject *>(this)->length())
-            return true;
-    }
-    if (!queryIndexed(index).isEmpty())
-        return true;
-    return false;
-}
-
-void Object::construct(const Managed *m, Scope &scope, CallData *)
-{
-    scope.result = static_cast<const Object *>(m)->engine()->throwTypeError();
-}
-
-void Object::call(const Managed *m, Scope &scope, CallData *)
-{
-    scope.result = static_cast<const Object *>(m)->engine()->throwTypeError();
-}
-
-ReturnedValue Object::get(const Managed *m, String *name, bool *hasProperty)
-{
-    return static_cast<const Object *>(m)->internalGet(name, hasProperty);
-}
-
-ReturnedValue Object::getIndexed(const Managed *m, uint index, bool *hasProperty)
-{
-    return static_cast<const Object *>(m)->internalGetIndexed(index, hasProperty);
-}
-
-bool Object::put(Managed *m, String *name, const Value &value)
-{
-    return static_cast<Object *>(m)->internalPut(name, value);
-}
-
-bool Object::putIndexed(Managed *m, uint index, const Value &value)
-{
-    return static_cast<Object *>(m)->internalPutIndexed(index, value);
-}
-
-PropertyAttributes Object::query(const Managed *m, String *name)
-{
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return queryIndexed(m, idx);
-
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
-
-    const Object *o = static_cast<const Object *>(m);
-    idx = o->internalClass()->find(id);
-    if (idx < UINT_MAX)
-        return o->internalClass()->propertyData[idx];
-
-    return Attr_Invalid;
+    return { nullptr, nullptr };
 }
 
-PropertyAttributes Object::queryIndexed(const Managed *m, uint index)
+ReturnedValue Object::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
-    const Object *o = static_cast<const Object *>(m);
-    if (o->arrayData() && !o->arrayData()->isEmpty(index))
-        return o->arrayData()->attributes(index);
-
-    if (o->isStringObject()) {
-        if (index < static_cast<const StringObject *>(o)->length())
-            return (Attr_NotWritable|Attr_NotConfigurable);
-    }
-    return Attr_Invalid;
-}
-
-bool Object::deleteProperty(Managed *m, String *name)
-{
-    return static_cast<Object *>(m)->internalDeleteProperty(name);
+    return static_cast<const Object *>(m)->internalGet(id, receiver, hasProperty);
 }
 
-bool Object::deleteIndexedProperty(Managed *m, uint index)
+bool Object::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
-    return static_cast<Object *>(m)->internalDeleteIndexedProperty(index);
-}
-
-ReturnedValue Object::getLookup(const Managed *m, Lookup *l)
-{
-    const Object *o = static_cast<const Object *>(m);
-    PropertyAttributes attrs;
-    ReturnedValue v = l->lookup(o, &attrs);
-    if (v != Primitive::emptyValue().asReturnedValue()) {
-        l->proto = l->classList[0]->prototype;
-        if (attrs.isData()) {
-            Q_ASSERT(l->classList[0] == o->internalClass());
-            if (l->level == 0) {
-                uint nInline = o->d()->vtable()->nInlineProperties;
-                if (l->index < nInline)
-                    l->getter = Lookup::getter0Inline;
-                else {
-                    l->index -= nInline;
-                    l->getter = Lookup::getter0MemberData;
-                }
-                }
-            else if (l->level == 1)
-                l->getter = Lookup::getter1;
-            else if (l->level == 2)
-                l->getter = Lookup::getter2;
-            else
-                l->getter = Lookup::getterFallback;
-            return v;
-        } else {
-            if (l->level == 0)
-                l->getter = Lookup::getterAccessor0;
-            else if (l->level == 1)
-                l->getter = Lookup::getterAccessor1;
-            else if (l->level == 2)
-                l->getter = Lookup::getterAccessor2;
-            else
-                l->getter = Lookup::getterFallback;
-            return v;
-        }
-    }
-    return Encode::undefined();
+    return static_cast<Object *>(m)->internalPut(id, value, receiver);
 }
 
-void Object::setLookup(Managed *m, Lookup *l, const Value &value)
+bool Object::virtualDeleteProperty(Managed *m, PropertyKey id)
 {
-    Scope scope(static_cast<Object *>(m)->engine());
-    ScopedObject o(scope, static_cast<Object *>(m));
-    ScopedString name(scope, scope.engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-
-    InternalClass *c = o->internalClass();
-    uint idx = c->find(name);
-    if (!o->isArrayObject() || idx != Heap::ArrayObject::LengthPropertyIndex) {
-        if (idx != UINT_MAX && o->internalClass()->propertyData[idx].isData() && o->internalClass()->propertyData[idx].isWritable()) {
-            l->classList[0] = o->internalClass();
-            l->index = idx;
-            l->setter = idx < o->d()->vtable()->nInlineProperties ? Lookup::setter0Inline : Lookup::setter0;
-            o->setProperty(idx, value);
-            return;
-        }
-
-        if (idx != UINT_MAX) {
-            o->putValue(idx, value);
-            return;
-        }
-    }
-
-    o->put(name, value);
-
-    if (o->internalClass() == c)
-        return;
-    idx = o->internalClass()->find(name);
-    if (idx == UINT_MAX)
-        return;
-    l->classList[0] = c;
-    l->classList[3] = o->internalClass();
-    l->index = idx;
-    if (!o->prototype()) {
-        l->setter = Lookup::setterInsert0;
-        return;
-    }
-    o = o->prototype();
-    l->classList[1] = o->internalClass();
-    if (!o->prototype()) {
-        l->setter = Lookup::setterInsert1;
-        return;
-    }
-    o = o->prototype();
-    l->classList[2] = o->internalClass();
-    if (!o->prototype()) {
-        l->setter = Lookup::setterInsert2;
-        return;
-    }
-    l->setter = Lookup::setterGeneric;
+    return static_cast<Object *>(m)->internalDeleteProperty(id);
 }
 
-void Object::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *pd, PropertyAttributes *attrs)
+PropertyKey ObjectOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs)
 {
-    Object *o = static_cast<Object *>(m);
-    name->setM(0);
-    *index = UINT_MAX;
-
-    if (o->arrayData()) {
-        if (!it->arrayIndex)
-            it->arrayNode = o->sparseBegin();
+    if (arrayIndex != UINT_MAX && o->arrayData()) {
+        if (!arrayIndex)
+            arrayNode = o->sparseBegin();
 
         // sparse arrays
-        if (it->arrayNode) {
-            while (it->arrayNode != o->sparseEnd()) {
-                int k = it->arrayNode->key();
-                uint pidx = it->arrayNode->value;
+        if (arrayNode) {
+            while (arrayNode != o->sparseEnd()) {
+                uint k = arrayNode->key();
+                uint pidx = arrayNode->value;
                 Heap::SparseArrayData *sa = o->d()->arrayData.cast<Heap::SparseArrayData>();
                 const Property *p = reinterpret_cast<const Property *>(sa->values.data() + pidx);
-                it->arrayNode = it->arrayNode->nextNode();
+                arrayNode = arrayNode->nextNode();
                 PropertyAttributes a = sa->attrs ? sa->attrs[pidx] : Attr_Data;
-                if (!(it->flags & ObjectIterator::EnumerableOnly) || a.isEnumerable()) {
-                    it->arrayIndex = k + 1;
-                    *index = k;
-                    *attrs = a;
+                arrayIndex = k + 1;
+                if (pd)
                     pd->copy(p, a);
-                    return;
-                }
+                if (attrs)
+                    *attrs = a;
+                return PropertyKey::fromArrayIndex(k);
             }
-            it->arrayNode = 0;
-            it->arrayIndex = UINT_MAX;
+            arrayNode = nullptr;
+            arrayIndex = UINT_MAX;
         }
         // dense arrays
-        while (it->arrayIndex < o->d()->arrayData->values.size) {
+        while (arrayIndex < o->d()->arrayData->values.size) {
             Heap::SimpleArrayData *sa = o->d()->arrayData.cast<Heap::SimpleArrayData>();
-            const Value &val = sa->data(it->arrayIndex);
-            PropertyAttributes a = o->arrayData()->attributes(it->arrayIndex);
-            ++it->arrayIndex;
-            if (!val.isEmpty()
-                && (!(it->flags & ObjectIterator::EnumerableOnly) || a.isEnumerable())) {
-                *index = it->arrayIndex - 1;
-                *attrs = a;
-                pd->value = val;
-                return;
+            const Value &val = sa->data(arrayIndex);
+            PropertyAttributes a = o->arrayData()->attributes(arrayIndex);
+            int index = arrayIndex;
+            ++arrayIndex;
+            if (!val.isEmpty()) {
+                if (pd)
+                    pd->value = val;
+                if (attrs)
+                    *attrs = a;
+                return PropertyKey::fromArrayIndex(index);
             }
         }
+        arrayIndex = UINT_MAX;
     }
 
-    while (it->memberIndex < o->internalClass()->size) {
-        Identifier *n = o->internalClass()->nameMap.at(it->memberIndex);
-        if (!n) {
-            // accessor properties have a dummy entry with n == 0
-            ++it->memberIndex;
-            continue;
-        }
-
-        int idx = it->memberIndex;
-        PropertyAttributes a = o->internalClass()->propertyData[it->memberIndex];
-        ++it->memberIndex;
-        if (!(it->flags & ObjectIterator::EnumerableOnly) || a.isEnumerable()) {
-            name->setM(o->engine()->identifierTable->stringFromIdentifier(n));
-            *attrs = a;
-            pd->value = *o->propertyData(idx);
-            if (a.isAccessor())
-                pd->set = *o->propertyData(idx + SetterOffset);
-            return;
+    while (true) {
+        while (memberIndex < o->internalClass()->size) {
+            PropertyKey n = o->internalClass()->nameMap.at(memberIndex);
+            ++memberIndex;
+            if (!n.isStringOrSymbol())
+                // accessor properties have a dummy entry with n == 0
+                continue;
+            if (!iterateOverSymbols && n.isSymbol())
+                continue;
+            if (iterateOverSymbols && !n.isSymbol())
+                continue;
+
+            InternalClassEntry e = o->internalClass()->find(n);
+            if (!e.isValid())
+                continue;
+            if (pd) {
+                pd->value = *o->propertyData(e.index);
+                if (e.attributes.isAccessor())
+                    pd->set = *o->propertyData(e.setterIndex);
+            }
+            if (attrs)
+                *attrs = e.attributes;
+            return n;
         }
+        if (iterateOverSymbols)
+            break;
+        iterateOverSymbols = true;
+        memberIndex = 0;
     }
 
-    *attrs = PropertyAttributes();
+    return PropertyKey::invalid();
 }
 
-// Section 8.12.3
-ReturnedValue Object::internalGet(String *name, bool *hasProperty) const
+OwnPropertyKeyIterator *Object::virtualOwnPropertyKeys(const Object *o, Value *target)
 {
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return getIndexed(idx, hasProperty);
-
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
-
-    Scope scope(engine());
-    ScopedObject o(scope, this);
-    while (o) {
-        uint idx = o->internalClass()->find(id);
-        if (idx < UINT_MAX) {
-            if (hasProperty)
-                *hasProperty = true;
-            return getValue(*o->propertyData(idx), o->internalClass()->propertyData.at(idx));
-        }
-
-        o = o->prototype();
-    }
-
-    if (hasProperty)
-        *hasProperty = false;
-    return Encode::undefined();
+    *target = *o;
+    return new ObjectOwnPropertyKeyIterator;
 }
 
-ReturnedValue Object::internalGetIndexed(uint index, bool *hasProperty) const
+// Section 8.12.3
+ReturnedValue Object::internalGet(PropertyKey id, const Value *receiver, bool *hasProperty) const
 {
-    PropertyAttributes attrs;
-    Scope scope(engine());
-    ScopedObject o(scope, this);
-    ScopedProperty pd(scope);
-    bool exists = false;
-    while (o) {
-        if (o->arrayData() && o->arrayData()->getProperty(index, pd, &attrs)) {
-            exists = true;
-            break;
+    Heap::Object *o = d();
+
+    uint index = id.asArrayIndex();
+    if (index != UINT_MAX) {
+        Scope scope(this);
+        PropertyAttributes attrs;
+        ScopedProperty pd(scope);
+        while (1) {
+            if (o->arrayData && o->arrayData->getProperty(index, pd, &attrs)) {
+                if (hasProperty)
+                    *hasProperty = true;
+                return Object::getValue(*receiver, pd->value, attrs);
+            }
+            if (o->internalClass->vtable->type == Type_StringObject) {
+                ScopedString str(scope, static_cast<Heap::StringObject *>(o)->getIndex(index));
+                if (str) {
+                    attrs = (Attr_NotWritable|Attr_NotConfigurable);
+                    if (hasProperty)
+                        *hasProperty = true;
+                    return str.asReturnedValue();
+                }
+            }
+            o = o->prototype();
+            if (!o || o->internalClass->vtable->get != Object::virtualGet)
+                break;
         }
-        if (o->isStringObject()) {
-            ScopedString str(scope, static_cast<StringObject *>(o.getPointer())->getIndex(index));
-            if (str) {
-                attrs = (Attr_NotWritable|Attr_NotConfigurable);
+    } else {
+        Q_ASSERT(!id.isArrayIndex());
+
+        while (1) {
+            auto idx = o->internalClass->findValueOrGetter(id);
+            if (idx.isValid()) {
                 if (hasProperty)
                     *hasProperty = true;
-                return str.asReturnedValue();
+                return Object::getValue(*receiver, *o->propertyData(idx.index), idx.attrs);
             }
+            o = o->prototype();
+            if (!o || o->internalClass->vtable->get != Object::virtualGet)
+                break;
         }
-        o = o->prototype();
     }
 
-    if (exists) {
-        if (hasProperty)
-            *hasProperty = true;
-        return getValue(pd->value, attrs);
+    if (o) {
+        const Value v = Value::fromHeapObject(o);
+        const Object &obj = static_cast<const Object &>(v);
+        return obj.get(id, receiver, hasProperty);
     }
 
     if (hasProperty)
@@ -697,326 +455,141 @@ ReturnedValue Object::internalGetIndexed(uint index, bool *hasProperty) const
     return Encode::undefined();
 }
 
-
 // Section 8.12.5
-bool Object::internalPut(String *name, const Value &value)
+bool Object::internalPut(PropertyKey id, const Value &value, Value *receiver)
 {
-    ExecutionEngine *engine = this->engine();
-    if (engine->hasException)
+    Scope scope(this);
+    if (scope.engine->hasException)
         return false;
 
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return putIndexed(idx, value);
-
-    name->makeIdentifier();
-    Identifier *id = name->identifier();
-
-    MemberData::Index memberIndex{0, 0};
-    uint member = internalClass()->find(id);
-    PropertyAttributes attrs;
-    if (member < UINT_MAX) {
-        attrs = internalClass()->propertyData[member];
-        memberIndex = d()->writablePropertyData(attrs.isAccessor() ? member + SetterOffset : member);
-    }
-
-    // clause 1
-    if (!memberIndex.isNull()) {
-        if (attrs.isAccessor()) {
-            if (memberIndex->as<FunctionObject>())
-                goto cont;
-            goto reject;
-        } else if (!attrs.isWritable())
-            goto reject;
-        else if (isArrayObject() && name->equals(engine->id_length())) {
-            bool ok;
-            uint l = value.asArrayLength(&ok);
-            if (!ok) {
-                engine->throwRangeError(value);
-                return false;
+    Object *r = receiver->objectValue();
+    if (r && r->d() == d()) {
+        // receiver and this object are the same
+        if (d()->internalClass->vtable->getOwnProperty == Object::virtualGetOwnProperty) {
+            // This object standard methods in the vtable, so we can take a shortcut
+            // and avoid the calls to getOwnProperty and defineOwnProperty
+            uint index = id.asArrayIndex();
+
+            PropertyAttributes attrs;
+            PropertyIndex propertyIndex{nullptr, nullptr};
+
+            if (index != UINT_MAX) {
+                if (arrayData())
+                    propertyIndex = arrayData()->getValueOrSetter(index, &attrs);
+            } else {
+                auto member = internalClass()->findValueOrSetter(id);
+                if (member.isValid()) {
+                    attrs = member.attrs;
+                    propertyIndex = d()->writablePropertyData(member.index);
+                }
             }
-            ok = setArrayLength(l);
-            if (!ok)
-                goto reject;
-        } else {
-            memberIndex.set(engine, value);
-        }
-        return true;
-    } else if (!prototype()) {
-        if (!isExtensible())
-            goto reject;
-    } else {
-        // clause 4
-        Scope scope(engine);
-        memberIndex = ScopedObject(scope, prototype())->getValueOrSetter(name, &attrs);
-        if (!memberIndex.isNull()) {
-            if (attrs.isAccessor()) {
-                if (!memberIndex->as<FunctionObject>())
-                    goto reject;
-            } else if (!isExtensible() || !attrs.isWritable()) {
-                goto reject;
+
+            if (!propertyIndex.isNull() && !attrs.isAccessor()) {
+                if (!attrs.isWritable())
+                    return false;
+                else if (isArrayObject() && id == scope.engine->id_length()->propertyKey()) {
+                    bool ok;
+                    uint l = value.asArrayLength(&ok);
+                    if (!ok) {
+                        scope.engine->throwRangeError(value);
+                        return false;
+                    }
+                    ok = setArrayLength(l);
+                    if (!ok)
+                        return false;
+                } else {
+                    propertyIndex.set(scope.engine, value);
+                }
+                return true;
             }
-        } else if (!isExtensible()) {
-            goto reject;
         }
     }
 
-    cont:
-
-    // Clause 5
-    if (!memberIndex.isNull() && attrs.isAccessor()) {
-        Q_ASSERT(memberIndex->as<FunctionObject>());
-
-        Scope scope(engine);
-        ScopedFunctionObject setter(scope, *memberIndex);
-        ScopedCallData callData(scope, 1);
-        callData->args[0] = value;
-        callData->thisObject = this;
-        setter->call(scope, callData);
-        return !internalClass()->engine->hasException;
+    ScopedProperty p(scope);
+    PropertyAttributes attrs;
+    attrs = getOwnProperty(id, p);
+    if (attrs == Attr_Invalid) {
+        ScopedObject p(scope, getPrototypeOf());
+        if (p)
+            return p->put(id, value, receiver);
+        attrs = Attr_Data;
     }
 
-    insertMember(name, value);
-    return true;
-
-  reject:
-    // ### this should be removed once everything is ported to use Object::set()
-    if (engine->current->strictMode) {
-        QString message = QLatin1String("Cannot assign to read-only property \"") +
-                name->toQString() + QLatin1Char('\"');
-        engine->throwTypeError(message);
+    if (attrs.isAccessor()) {
+        ScopedFunctionObject setter(scope, p->setter());
+        if (!setter)
+            return false;
+        JSCallData jsCallData(scope, 1);
+        jsCallData->args[0] = value;
+        *jsCallData->thisObject = *receiver;
+        setter->call(jsCallData);
+        return !scope.engine->hasException;
     }
-    return false;
-}
 
-bool Object::internalPutIndexed(uint index, const Value &value)
-{
-    ExecutionEngine *engine = this->engine();
-    if (engine->hasException)
+    // Data property
+    if (!attrs.isWritable())
         return false;
+    if (!r)
+        return false;
+    attrs = r->getOwnProperty(id, p);
 
-    PropertyAttributes attrs;
-
-    ArrayData::Index arrayIndex = arrayData() ? arrayData()->getValueOrSetter(index, &attrs) : ArrayData::Index{ 0, 0 };
-
-    if (arrayIndex.isNull() && isStringObject()) {
-        if (index < static_cast<StringObject *>(this)->length())
-            // not writable
-            goto reject;
-    }
-
-    // clause 1
-    if (!arrayIndex.isNull()) {
-        if (attrs.isAccessor()) {
-            if (arrayIndex->as<FunctionObject>())
-                goto cont;
-            goto reject;
-        } else if (!attrs.isWritable())
-            goto reject;
-
-        arrayIndex.set(engine, value);
-        return true;
-    } else if (!prototype()) {
-        if (!isExtensible())
-            goto reject;
+    if (attrs != Attr_Invalid) {
+        if (attrs.isAccessor() || !attrs.isWritable())
+            return false;
     } else {
-        // clause 4
-        Scope scope(engine);
-        arrayIndex = ScopedObject(scope, prototype())->getValueOrSetter(index, &attrs);
-        if (!arrayIndex.isNull()) {
-            if (attrs.isAccessor()) {
-                if (!arrayIndex->as<FunctionObject>())
-                    goto reject;
-            } else if (!isExtensible() || !attrs.isWritable()) {
-                goto reject;
-            }
-        } else if (!isExtensible()) {
-            goto reject;
-        }
+        if (!r->isExtensible())
+            return false;
+        attrs = Attr_Data;
     }
 
-    cont:
-
-    // Clause 5
-    if (!arrayIndex.isNull() && attrs.isAccessor()) {
-        Q_ASSERT(arrayIndex->as<FunctionObject>());
-
-        Scope scope(engine);
-        ScopedFunctionObject setter(scope, *arrayIndex);
-        ScopedCallData callData(scope, 1);
-        callData->args[0] = value;
-        callData->thisObject = this;
-        setter->call(scope, callData);
-        return !internalClass()->engine->hasException;
+    if (r->internalClass()->vtable->defineOwnProperty == virtualDefineOwnProperty) {
+        // standard object, we can avoid some more checks
+        uint index = id.asArrayIndex();
+        if (index == UINT_MAX) {
+            ScopedStringOrSymbol s(scope, id.asStringOrSymbol());
+            r->insertMember(s, value);
+        } else {
+            r->arraySet(index, value);
+        }
+        return true;
     }
 
-    arraySet(index, value);
-    return true;
-
-  reject:
-    // ### this should be removed once everything is ported to use Object::setIndexed()
-    if (engine->current->strictMode)
-        engine->throwTypeError();
-    return false;
+    p->value = value;
+    return r->defineOwnProperty(id, p, attrs);
 }
 
 // Section 8.12.7
-bool Object::internalDeleteProperty(String *name)
+bool Object::internalDeleteProperty(PropertyKey id)
 {
     if (internalClass()->engine->hasException)
         return false;
 
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return deleteIndexedProperty(idx);
-
-    name->makeIdentifier();
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+        Scope scope(engine());
+        if (scope.engine->hasException)
+            return false;
 
-    uint memberIdx = internalClass()->find(name->identifier());
-    if (memberIdx != UINT_MAX) {
-        if (internalClass()->propertyData[memberIdx].isConfigurable()) {
-            InternalClass::removeMember(this, name->identifier());
+        Scoped<ArrayData> ad(scope, arrayData());
+        if (!ad || ad->vtable()->del(this, index))
             return true;
-        }
-        if (engine()->current->strictMode)
-            engine()->throwTypeError();
-        return false;
-    }
 
-    return true;
-}
-
-bool Object::internalDeleteIndexedProperty(uint index)
-{
-    Scope scope(engine());
-    if (scope.engine->hasException)
         return false;
-
-    Scoped<ArrayData> ad(scope, arrayData());
-    if (!ad || ad->vtable()->del(this, index))
-        return true;
-
-    if (engine()->current->strictMode)
-        engine()->throwTypeError();
-    return false;
-}
-
-// Section 8.12.9
-bool Object::__defineOwnProperty__(ExecutionEngine *engine, String *name, const Property *p, PropertyAttributes attrs)
-{
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return __defineOwnProperty__(engine, idx, p, attrs);
-
-    Scope scope(engine);
-    name->makeIdentifier();
-
-    uint memberIndex;
-
-    if (isArrayObject() && name->equals(engine->id_length())) {
-        Q_ASSERT(Heap::ArrayObject::LengthPropertyIndex == internalClass()->find(engine->id_length()));
-        ScopedProperty lp(scope);
-        PropertyAttributes cattrs;
-        getProperty(Heap::ArrayObject::LengthPropertyIndex, lp, &cattrs);
-        if (attrs.isEmpty() || p->isSubset(attrs, lp, cattrs))
-            return true;
-        if (!cattrs.isWritable() || attrs.type() == PropertyAttributes::Accessor || attrs.isConfigurable() || attrs.isEnumerable())
-            goto reject;
-        bool succeeded = true;
-        if (attrs.type() == PropertyAttributes::Data) {
-            bool ok;
-            uint l = p->value.asArrayLength(&ok);
-            if (!ok) {
-                ScopedValue v(scope, p->value);
-                engine->throwRangeError(v);
-                return false;
-            }
-            succeeded = setArrayLength(l);
-        }
-        if (attrs.hasWritable() && !attrs.isWritable()) {
-            cattrs.setWritable(false);
-            InternalClass::changeMember(this, engine->id_length(), cattrs);
-        }
-        if (!succeeded)
-            goto reject;
-        return true;
     }
 
-    // Clause 1
-    memberIndex = internalClass()->find(name->identifier());
-
-    if (memberIndex == UINT_MAX) {
-        // clause 3
-        if (!isExtensible())
-            goto reject;
-        // clause 4
-        ScopedProperty pd(scope);
-        pd->copy(p, attrs);
-        pd->fullyPopulated(&attrs);
-        insertMember(name, pd, attrs);
-        return true;
-    }
-
-    return __defineOwnProperty__(engine, memberIndex, name, p, attrs);
-reject:
-  if (engine->current->strictMode)
-      engine->throwTypeError();
-  return false;
-}
-
-bool Object::__defineOwnProperty__(ExecutionEngine *engine, uint index, const Property *p, PropertyAttributes attrs)
-{
-    // 15.4.5.1, 4b
-    if (isArrayObject() && index >= getLength() && !internalClass()->propertyData[Heap::ArrayObject::LengthPropertyIndex].isWritable())
-        goto reject;
-
-    if (ArgumentsObject::isNonStrictArgumentsObject(this))
-        return static_cast<ArgumentsObject *>(this)->defineOwnProperty(engine, index, p, attrs);
-
-    return defineOwnProperty2(engine, index, p, attrs);
-reject:
-  if (engine->current->strictMode)
-      engine->throwTypeError();
-  return false;
-}
-
-bool Object::defineOwnProperty2(ExecutionEngine *engine, uint index, const Property *p, PropertyAttributes attrs)
-{
-    bool hasProperty = 0;
-
-    // Clause 1
-    if (arrayData()) {
-        hasProperty = arrayData()->mappedIndex(index) != UINT_MAX;
-        if (!hasProperty && isStringObject())
-            hasProperty = (index < static_cast<StringObject *>(this)->length());
-    }
-
-    if (!hasProperty) {
-        // clause 3
-        if (!isExtensible())
-            goto reject;
-        // clause 4
-        Scope scope(engine);
-        ScopedProperty pp(scope);
-        pp->copy(p, attrs);
-        pp->fullyPopulated(&attrs);
-        if (attrs == Attr_Data) {
-            ScopedValue v(scope, pp->value);
-            arraySet(index, v);
-        } else {
-            arraySet(index, pp, attrs);
+    auto memberIdx = internalClass()->findValueOrGetter(id);
+    if (memberIdx.isValid()) {
+        if (memberIdx.attrs.isConfigurable()) {
+            Heap::InternalClass::removeMember(this, id);
+            return true;
         }
-        return true;
+        return false;
     }
 
-    return __defineOwnProperty__(engine, index, 0, p, attrs);
-reject:
-  if (engine->current->strictMode)
-      engine->throwTypeError();
-  return false;
+    return true;
 }
 
-bool Object::__defineOwnProperty__(ExecutionEngine *engine, uint index, String *member, const Property *p, PropertyAttributes attrs)
+bool Object::internalDefineOwnProperty(ExecutionEngine *engine, uint index, const InternalClassEntry *memberEntry, const Property *p, PropertyAttributes attrs)
 {
     // clause 5
     if (attrs.isEmpty())
@@ -1025,9 +598,9 @@ bool Object::__defineOwnProperty__(ExecutionEngine *engine, uint index, String *
     Scope scope(engine);
     ScopedProperty current(scope);
     PropertyAttributes cattrs;
-    if (member) {
-        getProperty(index, current, &cattrs);
-        cattrs = internalClass()->propertyData[index];
+    if (memberEntry) {
+        getProperty(*memberEntry, current);
+        cattrs = memberEntry->attributes;
     } else if (arrayData()) {
         arrayData()->getProperty(index, current, &cattrs);
         cattrs = arrayData()->attributes(index);
@@ -1040,9 +613,9 @@ bool Object::__defineOwnProperty__(ExecutionEngine *engine, uint index, String *
     // clause 7
     if (!cattrs.isConfigurable()) {
         if (attrs.isConfigurable())
-            goto reject;
+            return false;
         if (attrs.hasEnumerable() && attrs.isEnumerable() != cattrs.isEnumerable())
-            goto reject;
+            return false;
     }
 
     // clause 8
@@ -1053,70 +626,59 @@ bool Object::__defineOwnProperty__(ExecutionEngine *engine, uint index, String *
     if (cattrs.isData() != attrs.isData()) {
         // 9a
         if (!cattrs.isConfigurable())
-            goto reject;
+            return false;
         if (cattrs.isData()) {
             // 9b
             cattrs.setType(PropertyAttributes::Accessor);
             cattrs.clearWritable();
-            if (!member) {
+            if (!memberEntry) {
                 // need to convert the array and the slot
                 initSparseArray();
                 Q_ASSERT(arrayData());
                 setArrayAttributes(index, cattrs);
             }
-            current->setGetter(0);
-            current->setSetter(0);
+            current->setGetter(nullptr);
+            current->setSetter(nullptr);
         } else {
             // 9c
             cattrs.setType(PropertyAttributes::Data);
             cattrs.setWritable(false);
-            if (!member) {
+            if (!memberEntry) {
                 // need to convert the array and the slot
                 setArrayAttributes(index, cattrs);
             }
-            current->value = Primitive::undefinedValue();
+            current->value = Value::undefinedValue();
         }
     } else if (cattrs.isData() && attrs.isData()) { // clause 10
         if (!cattrs.isConfigurable() && !cattrs.isWritable()) {
             if (attrs.isWritable() || !current->value.sameValue(p->value))
-                goto reject;
+                return false;
         }
     } else { // clause 10
         Q_ASSERT(cattrs.isAccessor() && attrs.isAccessor());
         if (!cattrs.isConfigurable()) {
             if (!p->value.isEmpty() && current->value.rawValue() != p->value.rawValue())
-                goto reject;
+                return false;
             if (!p->set.isEmpty() && current->set.rawValue() != p->set.rawValue())
-                goto reject;
+                return false;
         }
     }
 
   accept:
 
     current->merge(cattrs, p, attrs);
-    if (member) {
-        InternalClass::changeMember(this, member, cattrs);
-        setProperty(index, current);
+    if (memberEntry) {
+        PropertyKey key = internalClass()->nameMap.at(memberEntry->index);
+        InternalClassEntry e;
+        Heap::InternalClass::changeMember(this, key, cattrs, &e);
+        setProperty(e, current);
     } else {
         setArrayAttributes(index, cattrs);
         arrayData()->setProperty(scope.engine, index, current);
     }
     return true;
-  reject:
-    if (engine->current->strictMode)
-        engine->throwTypeError();
-    return false;
-}
-
-
-bool Object::__defineOwnProperty__(ExecutionEngine *engine, const QString &name, const Property *p, PropertyAttributes attrs)
-{
-    Scope scope(engine);
-    ScopedString s(scope, engine->newString(name));
-    return __defineOwnProperty__(engine, s, p, attrs);
 }
 
-
 void Object::copyArrayData(Object *other)
 {
     Q_ASSERT(isArrayObject());
@@ -1129,7 +691,7 @@ void Object::copyArrayData(Object *other)
 
         ScopedValue v(scope);
         for (uint i = 0; i < len; ++i) {
-            arraySet(i, (v = other->getIndexed(i)));
+            arraySet(i, (v = other->get(i)));
         }
     } else if (!other->arrayData()) {
         ;
@@ -1141,7 +703,6 @@ void Object::copyArrayData(Object *other)
             Heap::ArrayData *od = other->d()->arrayData;
             Heap::ArrayData *dd = d()->arrayData;
             dd->sparse = new SparseArray(*od->sparse);
-            dd->freeList = od->freeList;
         } else {
             Heap::ArrayData *dd = d()->arrayData;
             dd->values.size = other->d()->arrayData->values.size;
@@ -1153,15 +714,15 @@ void Object::copyArrayData(Object *other)
     setArrayLengthUnchecked(other->getLength());
 }
 
-uint Object::getLength(const Managed *m)
+qint64 Object::virtualGetLength(const Managed *m)
 {
     Scope scope(static_cast<const Object *>(m)->engine());
     ScopedValue v(scope, static_cast<Object *>(const_cast<Managed *>(m))->get(scope.engine->id_length()));
-    return v->toUInt32();
+    return v->toLength();
 }
 
 // 'var' is 'V' in 15.3.5.3.
-ReturnedValue Object::instanceOf(const Object *typeObject, const Value &var)
+ReturnedValue Object::virtualInstanceOf(const Object *typeObject, const Value &var)
 {
     QV4::ExecutionEngine *engine = typeObject->internalClass()->engine;
 
@@ -1170,9 +731,16 @@ ReturnedValue Object::instanceOf(const Object *typeObject, const Value &var)
     if (!function)
         return engine->throwTypeError();
 
-    Heap::FunctionObject *f = function->d();
-    if (function->isBoundFunction())
-        f = function->cast<BoundFunction>()->target();
+    return checkedInstanceOf(engine, function, var);
+}
+
+ReturnedValue Object::checkedInstanceOf(ExecutionEngine *engine, const FunctionObject *f, const Value &var)
+{
+    Scope scope(engine);
+    if (f->isBoundFunction()) {
+        ScopedValue v(scope, static_cast<const BoundFunction *>(f)->target());
+        f = v->as<FunctionObject>();
+    }
 
     // 15.3.5.3, 1: HasInstance can only be used on an object
     const Object *lhs = var.as<Object>();
@@ -1180,9 +748,10 @@ ReturnedValue Object::instanceOf(const Object *typeObject, const Value &var)
         return Encode(false);
 
     // 15.3.5.3, 2
-    const Object *o = f->protoProperty();
+    Value p = Value::fromReturnedValue(f->protoProperty());
+    const Object *o = p.objectValue();
     if (!o) // 15.3.5.3, 3
-        return engine->throwTypeError();
+        return f->engine()->throwTypeError();
 
     Heap::Object *v = lhs->d();
 
@@ -1203,6 +772,142 @@ ReturnedValue Object::instanceOf(const Object *typeObject, const Value &var)
     return Encode(false);
 }
 
+bool Object::virtualHasProperty(const Managed *m, PropertyKey id)
+{
+    Scope scope(m->engine());
+    ScopedObject o(scope, m);
+    ScopedProperty p(scope);
+
+    if (o->getOwnProperty(id, p) != Attr_Invalid)
+        return true;
+
+    o = o->getPrototypeOf();
+    if (o)
+        return o->hasProperty(id);
+
+    return false;
+}
+
+PropertyAttributes Object::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
+{
+    PropertyAttributes attrs;
+    const Object *o = static_cast<const Object *>(m);
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+        if (o->arrayData()) {
+            if (o->arrayData()->getProperty(index, p, &attrs))
+                return attrs;
+        }
+    } else {
+        Q_ASSERT(id.asStringOrSymbol());
+
+        auto member = o->internalClass()->find(id);
+        if (member.isValid()) {
+            attrs = member.attributes;
+            if (p) {
+                p->value = *o->propertyData(member.index);
+                if (attrs.isAccessor())
+                    p->set = *o->propertyData(member.setterIndex);
+            }
+            return attrs;
+        }
+    }
+
+    return Attr_Invalid;
+}
+
+bool Object::virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs)
+{
+    Object *o = static_cast<Object *>(m);
+    Scope scope(o);
+
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+
+        bool hasProperty = false;
+
+        if (o->arrayData()) {
+            hasProperty = o->arrayData()->mappedIndex(index) != UINT_MAX;
+            if (!hasProperty && o->isStringObject())
+                hasProperty = (index < static_cast<StringObject *>(o)->length());
+        }
+
+        if (!hasProperty) {
+            if (!o->isExtensible())
+                return false;
+
+            ScopedProperty pp(scope);
+            pp->copy(p, attrs);
+            pp->fullyPopulated(&attrs);
+            if (attrs == Attr_Data) {
+                ScopedValue v(scope, pp->value);
+                o->arraySet(index, v);
+            } else {
+                o->arraySet(index, pp, attrs);
+            }
+            return true;
+        }
+
+        return o->internalDefineOwnProperty(scope.engine, index, nullptr, p, attrs);
+    }
+
+    auto memberIndex = o->internalClass()->find(id);
+
+    if (!memberIndex.isValid()) {
+        if (!o->isExtensible())
+            return false;
+
+        Scoped<StringOrSymbol> name(scope, id.asStringOrSymbol());
+        ScopedProperty pd(scope);
+        pd->copy(p, attrs);
+        pd->fullyPopulated(&attrs);
+        o->insertMember(name, pd, attrs);
+        return true;
+    }
+
+    return o->internalDefineOwnProperty(scope.engine, UINT_MAX, &memberIndex, p, attrs);
+}
+
+bool Object::virtualIsExtensible(const Managed *m)
+{
+    return m->d()->internalClass->extensible;
+}
+
+bool Object::virtualPreventExtensions(Managed *m)
+{
+    Q_ASSERT(m->isObject());
+    Object *o = static_cast<Object *>(m);
+    o->setInternalClass(o->internalClass()->nonExtensible());
+    return true;
+}
+
+Heap::Object *Object::virtualGetPrototypeOf(const Managed *m)
+{
+    return m->internalClass()->prototype;
+}
+
+bool Object::virtualSetPrototypeOf(Managed *m, const Object *proto)
+{
+    Q_ASSERT(m->isObject());
+    Object *o = static_cast<Object *>(m);
+    Heap::Object *current = o->internalClass()->prototype;
+    Heap::Object *protod = proto ? proto->d() : nullptr;
+    if (current == protod)
+        return true;
+    if (!o->internalClass()->extensible)
+        return false;
+    Heap::Object *p = protod;
+    while (p) {
+        if (p == o->d())
+            return false;
+        if (p->vtable()->getPrototypeOf != Object::staticVTable()->getPrototypeOf)
+            break;
+        p = p->prototype();
+    }
+    o->setInternalClass(o->internalClass()->changePrototype(protod));
+    return true;
+}
+
 bool Object::setArrayLength(uint newLen)
 {
     Q_ASSERT(isArrayObject());
@@ -1211,9 +916,7 @@ bool Object::setArrayLength(uint newLen)
     uint oldLen = getLength();
     bool ok = true;
     if (newLen < oldLen) {
-        if (!arrayData()) {
-            Q_ASSERT(!newLen);
-        } else {
+        if (arrayData()) {
             uint l = arrayData()->vtable()->truncate(this, newLen);
             if (l != newLen)
                 ok = false;
@@ -1235,6 +938,69 @@ void Object::initSparseArray()
     ArrayData::realloc(this, Heap::ArrayData::Sparse, 0, false);
 }
 
+bool Object::isConcatSpreadable() const
+{
+    Scope scope(this);
+    ScopedValue spreadable(scope, get(scope.engine->symbol_isConcatSpreadable()));
+    if (!spreadable->isUndefined())
+        return spreadable->toBoolean();
+    return isArray();
+}
+
+bool Object::isArray() const
+{
+    if (isArrayObject())
+        return true;
+    if (vtable() == ProxyObject::staticVTable()) {
+        const ProxyObject *p = static_cast<const ProxyObject *>(this);
+        Scope scope(this);
+        if (!p->d()->handler) {
+            scope.engine->throwTypeError();
+            return false;
+        }
+        ScopedObject o(scope, p->d()->target);
+        return o->isArray();
+    }
+    return false;
+}
+
+const FunctionObject *Object::speciesConstructor(Scope &scope, const FunctionObject *defaultConstructor) const
+{
+    ScopedValue C(scope, get(scope.engine->id_constructor()));
+    if (C->isUndefined())
+        return defaultConstructor;
+    const Object *c = C->objectValue();
+    if (!c) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    ScopedValue S(scope, c->get(scope.engine->symbol_species()));
+    if (S->isNullOrUndefined())
+        return defaultConstructor;
+    const FunctionObject *f = S->as<FunctionObject>();
+    if (!f || !f->isConstructor()) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    Q_ASSERT(f->isFunctionObject());
+    return static_cast<const FunctionObject *>(f);
+}
+
+bool Object::setProtoFromNewTarget(const Value *newTarget)
+{
+    if (!newTarget || newTarget->isUndefined())
+        return false;
+
+    Q_ASSERT(newTarget->isFunctionObject());
+    Scope scope(this);
+    ScopedObject proto(scope, static_cast<const FunctionObject *>(newTarget)->protoProperty());
+    if (proto) {
+        setPrototypeOf(proto);
+        return true;
+    }
+    return false;
+}
+
 
 DEFINE_OBJECT_VTABLE(ArrayObject);
 
@@ -1257,25 +1023,10 @@ void Heap::ArrayObject::init(const QStringList &list)
     a->setArrayLengthUnchecked(len);
 }
 
-ReturnedValue ArrayObject::getLookup(const Managed *m, Lookup *l)
-{
-    Scope scope(static_cast<const Object *>(m)->engine());
-    ScopedString name(scope, scope.engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-    if (name->equals(scope.engine->id_length())) {
-        // special case, as the property is on the object itself
-        l->getter = Lookup::arrayLengthGetter;
-        const ArrayObject *a = static_cast<const ArrayObject *>(m);
-        return a->propertyData(Heap::ArrayObject::LengthPropertyIndex)->asReturnedValue();
-    }
-    return Object::getLookup(m, l);
-}
-
-uint ArrayObject::getLength(const Managed *m)
+qint64 ArrayObject::virtualGetLength(const Managed *m)
 {
     const ArrayObject *a = static_cast<const ArrayObject *>(m);
-    if (a->propertyData(Heap::ArrayObject::LengthPropertyIndex)->isInteger())
-        return a->propertyData(Heap::ArrayObject::LengthPropertyIndex)->integerValue();
-    return Primitive::toUInt32(a->propertyData(Heap::ArrayObject::LengthPropertyIndex)->doubleValue());
+    return a->propertyData(Heap::ArrayObject::LengthPropertyIndex)->toLength();
 }
 
 QStringList ArrayObject::toQStringList() const
@@ -1288,8 +1039,62 @@ QStringList ArrayObject::toQStringList() const
 
     uint length = getLength();
     for (uint i = 0; i < length; ++i) {
-        v = const_cast<ArrayObject *>(this)->getIndexed(i);
+        v = const_cast<ArrayObject *>(this)->get(i);
         result.append(v->toQStringNoThrow());
     }
     return result;
 }
+
+bool ArrayObject::virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs)
+{
+    Q_ASSERT(m->isArrayObject());
+    ArrayObject *a = static_cast<ArrayObject *>(m);
+
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+        uint len = a->getLength();
+        if (index >= len && !a->internalClass()->propertyData[Heap::ArrayObject::LengthPropertyIndex].isWritable())
+            return false;
+
+        bool succeeded = Object::virtualDefineOwnProperty(m, id, p, attrs);
+        if (!succeeded)
+            return false;
+
+        if (index >= len)
+            a->setArrayLengthUnchecked(index + 1);
+
+        return true;
+    }
+
+    ExecutionEngine *engine = m->engine();
+    if (id == engine->id_length()->propertyKey()) {
+        Scope scope(engine);
+        Q_ASSERT(a->internalClass()->verifyIndex(engine->id_length()->propertyKey(), Heap::ArrayObject::LengthPropertyIndex));
+        ScopedProperty lp(scope);
+        InternalClassEntry e = a->internalClass()->find(scope.engine->id_length()->propertyKey());
+        a->getProperty(e, lp);
+        if (attrs.isEmpty() || p->isSubset(attrs, lp, e.attributes))
+            return true;
+        if (!e.attributes.isWritable() || attrs.type() == PropertyAttributes::Accessor || attrs.isConfigurable() || attrs.isEnumerable())
+            return false;
+        bool succeeded = true;
+        if (attrs.type() == PropertyAttributes::Data) {
+            bool ok;
+            uint l = p->value.asArrayLength(&ok);
+            if (!ok) {
+                ScopedValue v(scope, p->value);
+                engine->throwRangeError(v);
+                return false;
+            }
+            succeeded = a->setArrayLength(l);
+        }
+        if (attrs.hasWritable() && !attrs.isWritable()) {
+            e.attributes.setWritable(false);
+            Heap::InternalClass::changeMember(a, engine->id_length()->propertyKey(), e.attributes);
+        }
+        if (!succeeded)
+            return false;
+        return true;
+    }
+    return Object::virtualDefineOwnProperty(m, id, p, attrs);
+}
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 066a93cc61..72b6703554 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -57,46 +57,52 @@
 #include "qv4scopedvalue_p.h"
 #include "qv4value_p.h"
 #include "qv4internalclass_p.h"
+#include "qv4string_p.h"
 
 QT_BEGIN_NAMESPACE
 
 
 namespace QV4 {
 
-struct BuiltinFunction;
-
 namespace Heap {
 
 #define ObjectMembers(class, Member) \
     Member(class, Pointer, MemberData *, memberData) \
     Member(class, Pointer, ArrayData *, arrayData)
 
-DECLARE_HEAP_OBJECT(Object, Base) {
-    DECLARE_MARK_TABLE(Object);
+DECLARE_EXPORTED_HEAP_OBJECT(Object, Base) {
+    static void markObjects(Heap::Base *base, MarkStack *stack);
     void init() { Base::init(); }
-    void destroy() { Base::destroy(); }
 
+    const VTable *vtable() const {
+        return internalClass->vtable;
+    }
+
+    const Value *inlinePropertyDataWithOffset(uint indexWithOffset) const {
+        Q_ASSERT(indexWithOffset >= vtable()->inlinePropertyOffset && indexWithOffset < uint(vtable()->inlinePropertyOffset + vtable()->nInlineProperties));
+        return reinterpret_cast<const Value *>(this) + indexWithOffset;
+    }
     const Value *inlinePropertyData(uint index) const {
         Q_ASSERT(index < vtable()->nInlineProperties);
         return reinterpret_cast<const Value *>(this) + vtable()->inlinePropertyOffset + index;
     }
-    void setInlineProperty(ExecutionEngine *e, uint index, Value v) {
-        Q_ASSERT(index < vtable()->nInlineProperties);
-        Value *prop = reinterpret_cast<Value *>(this) + vtable()->inlinePropertyOffset + index;
-        WriteBarrier::write(e, this, prop, v);
+    void setInlinePropertyWithOffset(ExecutionEngine *e, uint indexWithOffset, Value v) {
+        Q_ASSERT(indexWithOffset >= vtable()->inlinePropertyOffset && indexWithOffset < uint(vtable()->inlinePropertyOffset + vtable()->nInlineProperties));
+        Value *prop = reinterpret_cast<Value *>(this) + indexWithOffset;
+        WriteBarrier::write(e, this, prop->data_ptr(), v.asReturnedValue());
     }
-    void setInlineProperty(ExecutionEngine *e, uint index, Heap::Base *b) {
-        Q_ASSERT(index < vtable()->nInlineProperties);
-        Value *prop = reinterpret_cast<Value *>(this) + vtable()->inlinePropertyOffset + index;
-        WriteBarrier::write(e, this, prop, b);
+    void setInlinePropertyWithOffset(ExecutionEngine *e, uint indexWithOffset, Heap::Base *b) {
+        Q_ASSERT(indexWithOffset >= vtable()->inlinePropertyOffset && indexWithOffset < uint(vtable()->inlinePropertyOffset + vtable()->nInlineProperties));
+        Value *prop = reinterpret_cast<Value *>(this) + indexWithOffset;
+        WriteBarrier::write(e, this, prop->data_ptr(), Value::fromHeapObject(b).asReturnedValue());
     }
 
-    QV4::MemberData::Index writablePropertyData(uint index) {
+    PropertyIndex writablePropertyData(uint index) {
         uint nInline = vtable()->nInlineProperties;
         if (index < nInline)
-            return { this, reinterpret_cast<Value *>(this) + vtable()->inlinePropertyOffset + index};
+            return PropertyIndex{ this, reinterpret_cast<Value *>(this) + vtable()->inlinePropertyOffset + index};
         index -= nInline;
-        return { memberData, memberData->values.values + index };
+        return PropertyIndex{ memberData, memberData->values.values + index };
     }
 
     const Value *propertyData(uint index) const {
@@ -109,7 +115,7 @@ DECLARE_HEAP_OBJECT(Object, Base) {
     void setProperty(ExecutionEngine *e, uint index, Value v) {
         uint nInline = vtable()->nInlineProperties;
         if (index < nInline) {
-            setInlineProperty(e, index, v);
+            setInlinePropertyWithOffset(e, index + vtable()->inlinePropertyOffset, v);
             return;
         }
         index -= nInline;
@@ -118,198 +124,120 @@ DECLARE_HEAP_OBJECT(Object, Base) {
     void setProperty(ExecutionEngine *e, uint index, Heap::Base *b) {
         uint nInline = vtable()->nInlineProperties;
         if (index < nInline) {
-            setInlineProperty(e, index, b);
+            setInlinePropertyWithOffset(e, index + vtable()->inlinePropertyOffset, b);
             return;
         }
         index -= nInline;
         memberData->values.set(e, index, b);
     }
 
-    Heap::Object *prototype() const { return internalClass->prototype; }
-};
-
-Q_STATIC_ASSERT(Object::markTable == ((2 << 2) | (2 << 4)));
-
-}
+    void setUsedAsProto();
 
-#define V4_OBJECT(superClass) \
-    public: \
-        Q_MANAGED_CHECK \
-        typedef superClass SuperClass; \
-        static const QV4::ObjectVTable static_vtbl; \
-        static inline const QV4::VTable *staticVTable() { return &static_vtbl.vTable; } \
-        V4_MANAGED_SIZE_TEST \
-        Data *d_unchecked() const { return static_cast<Data *>(m()); } \
-        Data *d() const { \
-            Data *dptr = d_unchecked(); \
-            dptr->_checkIsInitialized(); \
-            return dptr; \
-        } \
-        V4_ASSERT_IS_TRIVIAL(Data);
-
-#define V4_OBJECT2(DataClass, superClass) \
-    private: \
-        DataClass() Q_DECL_EQ_DELETE; \
-        Q_DISABLE_COPY(DataClass) \
-    public: \
-        Q_MANAGED_CHECK \
-        typedef QV4::Heap::DataClass Data; \
-        typedef superClass SuperClass; \
-        static const QV4::ObjectVTable static_vtbl; \
-        static inline const QV4::VTable *staticVTable() { return &static_vtbl.vTable; } \
-        V4_MANAGED_SIZE_TEST \
-        QV4::Heap::DataClass *d_unchecked() const { return static_cast<QV4::Heap::DataClass *>(m()); } \
-        QV4::Heap::DataClass *d() const { \
-            QV4::Heap::DataClass *dptr = d_unchecked(); \
-            dptr->_checkIsInitialized(); \
-            return dptr; \
-        } \
-        V4_ASSERT_IS_TRIVIAL(QV4::Heap::DataClass); \
-        static Q_CONSTEXPR quint64 markTable = QV4::Heap::DataClass::markTable;
-
-#define V4_PROTOTYPE(p) \
-    static QV4::Object *defaultPrototype(QV4::ExecutionEngine *e) \
-    { return e->p(); }
-
-struct ObjectVTable
-{
-    VTable vTable;
-    void (*call)(const Managed *, Scope &scope, CallData *data);
-    void (*construct)(const Managed *, Scope &scope, CallData *data);
-    ReturnedValue (*get)(const Managed *, String *name, bool *hasProperty);
-    ReturnedValue (*getIndexed)(const Managed *, uint index, bool *hasProperty);
-    bool (*put)(Managed *, String *name, const Value &value);
-    bool (*putIndexed)(Managed *, uint index, const Value &value);
-    PropertyAttributes (*query)(const Managed *, String *name);
-    PropertyAttributes (*queryIndexed)(const Managed *, uint index);
-    bool (*deleteProperty)(Managed *m, String *name);
-    bool (*deleteIndexedProperty)(Managed *m, uint index);
-    ReturnedValue (*getLookup)(const Managed *m, Lookup *l);
-    void (*setLookup)(Managed *m, Lookup *l, const Value &v);
-    uint (*getLength)(const Managed *m);
-    void (*advanceIterator)(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-    ReturnedValue (*instanceOf)(const Object *typeObject, const Value &var);
+    Heap::Object *prototype() const { return internalClass->prototype; }
 };
 
-#define DEFINE_OBJECT_VTABLE_BASE(classname) \
-const QV4::ObjectVTable classname::static_vtbl =    \
-{     \
-    DEFINE_MANAGED_VTABLE_INT(classname, (std::is_same<classname::SuperClass, Object>::value) ? nullptr : &classname::SuperClass::static_vtbl.vTable), \
-    call,                                       \
-    construct,                                  \
-    get,                                        \
-    getIndexed,                                 \
-    put,                                        \
-    putIndexed,                                 \
-    query,                                      \
-    queryIndexed,                               \
-    deleteProperty,                             \
-    deleteIndexedProperty,                      \
-    getLookup,                                  \
-    setLookup,                                  \
-    getLength,                                  \
-    advanceIterator,                            \
-    instanceOf                                  \
 }
 
-#define DEFINE_OBJECT_VTABLE(classname) \
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON \
-DEFINE_OBJECT_VTABLE_BASE(classname) \
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF
-
-#define DEFINE_OBJECT_TEMPLATE_VTABLE(classname) \
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_ON \
-template<> DEFINE_OBJECT_VTABLE_BASE(classname) \
-QT_WARNING_SUPPRESS_GCC_TAUTOLOGICAL_COMPARE_OFF
-
 struct Q_QML_EXPORT Object: Managed {
     V4_OBJECT2(Object, Object)
     Q_MANAGED_TYPE(Object)
     V4_INTERNALCLASS(Object)
     V4_PROTOTYPE(objectPrototype)
 
+    enum { NInlineProperties = 2 };
+
     enum {
         IsObject = true,
         GetterOffset = 0,
         SetterOffset = 1
     };
 
-    void setInternalClass(InternalClass *ic);
+    void setInternalClass(Heap::InternalClass *ic);
 
     const Value *propertyData(uint index) const { return d()->propertyData(index); }
 
     Heap::ArrayData *arrayData() const { return d()->arrayData; }
     void setArrayData(ArrayData *a) { d()->arrayData.set(engine(), a->d()); }
 
-    void getProperty(uint index, Property *p, PropertyAttributes *attrs) const;
-    void setProperty(uint index, const Property *p);
+    void getProperty(const InternalClassEntry &entry, Property *p) const;
+    void setProperty(const InternalClassEntry &entry, const Property *p);
     void setProperty(uint index, Value v) const { d()->setProperty(engine(), index, v); }
     void setProperty(uint index, Heap::Base *b) const { d()->setProperty(engine(), index, b); }
     void setProperty(ExecutionEngine *engine, uint index, Value v) const { d()->setProperty(engine, index, v); }
     void setProperty(ExecutionEngine *engine, uint index, Heap::Base *b) const { d()->setProperty(engine, index, b); }
 
-    const ObjectVTable *vtable() const { return reinterpret_cast<const ObjectVTable *>(d()->vtable()); }
-    Heap::Object *prototype() const { return d()->prototype(); }
-    bool setPrototype(Object *proto);
-
-    void getOwnProperty(String *name, PropertyAttributes *attrs, Property *p = 0);
-    void getOwnProperty(uint index, PropertyAttributes *attrs, Property *p = 0);
+    const VTable *vtable() const { return d()->vtable(); }
 
-    MemberData::Index getValueOrSetter(String *name, PropertyAttributes *attrs);
-    ArrayData::Index getValueOrSetter(uint index, PropertyAttributes *attrs);
+    PropertyAttributes getOwnProperty(PropertyKey id, Property *p = nullptr) const {
+        return vtable()->getOwnProperty(this, id, p);
+    }
 
-    bool hasProperty(String *name) const;
-    bool hasProperty(uint index) const;
+    PropertyIndex getValueOrSetter(PropertyKey id, PropertyAttributes *attrs);
 
-    bool hasOwnProperty(String *name) const;
-    bool hasOwnProperty(uint index) const;
+    bool hasProperty(PropertyKey id) const {
+        return vtable()->hasProperty(this, id);
+    }
 
-    bool __defineOwnProperty__(ExecutionEngine *engine, uint index, String *member, const Property *p, PropertyAttributes attrs);
-    bool __defineOwnProperty__(ExecutionEngine *engine, String *name, const Property *p, PropertyAttributes attrs);
-    bool __defineOwnProperty__(ExecutionEngine *engine, uint index, const Property *p, PropertyAttributes attrs);
-    bool __defineOwnProperty__(ExecutionEngine *engine, const QString &name, const Property *p, PropertyAttributes attrs);
-    bool defineOwnProperty2(ExecutionEngine *engine, uint index, const Property *p, PropertyAttributes attrs);
+    bool defineOwnProperty(PropertyKey id, const Property *p, PropertyAttributes attrs) {
+        return vtable()->defineOwnProperty(this, id, p, attrs);
+    }
 
     //
     // helpers
     //
-    static ReturnedValue getValue(const Value &thisObject, const Value &v, PropertyAttributes attrs);
+    static ReturnedValue getValue(const Value &thisObject, const Value &v, PropertyAttributes attrs) {
+        if (attrs.isData())
+            return v.asReturnedValue();
+        return getValueAccessor(thisObject, v, attrs);
+    }
     ReturnedValue getValue(const Value &v, PropertyAttributes attrs) const {
-        Scope scope(this->engine());
-        ScopedValue t(scope, const_cast<Object *>(this));
-        return getValue(t, v, attrs);
+        return getValue(*this, v, attrs);
+    }
+    ReturnedValue getValueByIndex(uint propertyIndex) const {
+        PropertyAttributes attrs = internalClass()->propertyData.at(propertyIndex);
+        const Value *v = propertyData(propertyIndex);
+        if (!attrs.isAccessor())
+            return v->asReturnedValue();
+        return getValueAccessor(*this, *v, attrs);
     }
+    static ReturnedValue getValueAccessor(const Value &thisObject, const Value &v, PropertyAttributes attrs);
 
-    bool putValue(uint memberIndex, const Value &value);
+    bool putValue(uint memberIndex, PropertyAttributes attrs, const Value &value);
 
     /* The spec default: Writable: true, Enumerable: false, Configurable: true */
-    void defineDefaultProperty(String *name, const Value &value) {
-        insertMember(name, value, Attr_Data|Attr_NotEnumerable);
-    }
-    void defineDefaultProperty(const QString &name, const Value &value);
-    void defineDefaultProperty(const QString &name, void (*code)(const BuiltinFunction *, Scope &, CallData *), int argumentCount = 0);
-    void defineDefaultProperty(String *name, void (*code)(const BuiltinFunction *, Scope &, CallData *), int argumentCount = 0);
-    void defineAccessorProperty(const QString &name, void (*getter)(const BuiltinFunction *, Scope &, CallData *),
-                                void (*setter)(const BuiltinFunction *, Scope &, CallData *));
-    void defineAccessorProperty(String *name, void (*getter)(const BuiltinFunction *, Scope &, CallData *),
-                                void (*setter)(const BuiltinFunction *, Scope &, CallData *));
+    void defineDefaultProperty(StringOrSymbol *name, const Value &value, PropertyAttributes attributes = Attr_Data|Attr_NotEnumerable) {
+        insertMember(name, value, attributes);
+    }
+    void defineDefaultProperty(const QString &name, const Value &value, PropertyAttributes attributes = Attr_Data|Attr_NotEnumerable);
+    void defineDefaultProperty(const QString &name, VTable::Call code,
+                               int argumentCount = 0, PropertyAttributes attributes = Attr_Data|Attr_NotEnumerable);
+    void defineDefaultProperty(StringOrSymbol *name, VTable::Call code,
+                               int argumentCount = 0, PropertyAttributes attributes = Attr_Data|Attr_NotEnumerable);
+    void defineAccessorProperty(const QString &name, VTable::Call getter, VTable::Call setter);
+    void defineAccessorProperty(StringOrSymbol *name, VTable::Call getter, VTable::Call setter);
     /* Fixed: Writable: false, Enumerable: false, Configurable: false */
     void defineReadonlyProperty(const QString &name, const Value &value);
     void defineReadonlyProperty(String *name, const Value &value);
 
     /* Fixed: Writable: false, Enumerable: false, Configurable: true */
     void defineReadonlyConfigurableProperty(const QString &name, const Value &value);
-    void defineReadonlyConfigurableProperty(String *name, const Value &value);
+    void defineReadonlyConfigurableProperty(StringOrSymbol *name, const Value &value);
+
+    void addSymbolSpecies();
 
-    void insertMember(String *s, const Value &v, PropertyAttributes attributes = Attr_Data) {
+    void insertMember(StringOrSymbol *s, const Value &v, PropertyAttributes attributes = Attr_Data) {
         Scope scope(engine());
         ScopedProperty p(scope);
         p->value = v;
         insertMember(s, p, attributes);
     }
-    void insertMember(String *s, const Property *p, PropertyAttributes attributes);
+    void insertMember(StringOrSymbol *s, const Property *p, PropertyAttributes attributes);
 
-    bool isExtensible() const { return d()->internalClass->extensible; }
+    bool isExtensible() const { return vtable()->isExtensible(this); }
+    bool preventExtensions() { return vtable()->preventExtensions(this); }
+    Heap::Object *getPrototypeOf() const { return vtable()->getPrototypeOf(this); }
+    bool setPrototypeOf(const Object *p) { return vtable()->setPrototypeOf(this, p); }
+    void setPrototypeUnchecked(const Object *p);
 
     // Array handling
 
@@ -362,117 +290,130 @@ public:
     }
 
     void initSparseArray();
-    SparseArrayNode *sparseBegin() { return arrayType() == Heap::ArrayData::Sparse ? d()->arrayData->sparse->begin() : 0; }
-    SparseArrayNode *sparseEnd() { return arrayType() == Heap::ArrayData::Sparse ? d()->arrayData->sparse->end() : 0; }
+    SparseArrayNode *sparseBegin() const { return arrayType() == Heap::ArrayData::Sparse ? d()->arrayData->sparse->begin() : nullptr; }
+    SparseArrayNode *sparseEnd() const { return arrayType() == Heap::ArrayData::Sparse ? d()->arrayData->sparse->end() : nullptr; }
 
     inline bool protoHasArray() {
         Scope scope(engine());
         ScopedObject p(scope, this);
 
-        while ((p = p->prototype()))
+        while ((p = p->getPrototypeOf()))
             if (p->arrayData())
                 return true;
 
         return false;
     }
 
-    inline ReturnedValue get(String *name, bool *hasProperty = 0) const
-    { return vtable()->get(this, name, hasProperty); }
-    inline ReturnedValue getIndexed(uint idx, bool *hasProperty = 0) const
-    { return vtable()->getIndexed(this, idx, hasProperty); }
+    inline ReturnedValue get(StringOrSymbol *name, bool *hasProperty = nullptr, const Value *receiver = nullptr) const
+    { if (!receiver) receiver = this; return vtable()->get(this, name->toPropertyKey(), receiver, hasProperty); }
+    inline ReturnedValue get(uint idx, bool *hasProperty = nullptr, const Value *receiver = nullptr) const
+    { if (!receiver) receiver = this; return vtable()->get(this, PropertyKey::fromArrayIndex(idx), receiver, hasProperty); }
+    QT_DEPRECATED inline ReturnedValue getIndexed(uint idx, bool *hasProperty = nullptr) const
+    { return get(idx, hasProperty); }
+    inline ReturnedValue get(PropertyKey id, const Value *receiver = nullptr, bool *hasProperty = nullptr) const
+    { if (!receiver) receiver = this; return vtable()->get(this, id, receiver, hasProperty); }
 
     // use the set variants instead, to customize throw behavior
-    inline bool put(String *name, const Value &v)
-    { return vtable()->put(this, name, v); }
-    inline bool putIndexed(uint idx, const Value &v)
-    { return vtable()->putIndexed(this, idx, v); }
+    inline bool put(StringOrSymbol *name, const Value &v, Value *receiver = nullptr)
+    { if (!receiver) receiver = this; return vtable()->put(this, name->toPropertyKey(), v, receiver); }
+    inline bool put(uint idx, const Value &v, Value *receiver = nullptr)
+    { if (!receiver) receiver = this; return vtable()->put(this, PropertyKey::fromArrayIndex(idx), v, receiver); }
+    QT_DEPRECATED inline bool putIndexed(uint idx, const Value &v)
+    { return put(idx, v); }
+    inline bool put(PropertyKey id, const Value &v, Value *receiver = nullptr)
+    { if (!receiver) receiver = this; return vtable()->put(this, id, v, receiver); }
 
     enum ThrowOnFailure {
         DoThrowOnRejection,
         DoNotThrow
     };
 
-    // ES6: 7.3.3 Set (O, P, V, Throw)
-    inline bool set(String *name, const Value &v, ThrowOnFailure shouldThrow)
+    // This is the same as set(), but it doesn't require creating a string key,
+    // which is much more efficient for the array case.
+    inline bool setIndexed(uint idx, const Value &v, ThrowOnFailure shouldThrow)
     {
-        bool ret = vtable()->put(this, name, v);
+        bool ret = vtable()->put(this, PropertyKey::fromArrayIndex(idx), v, this);
         // ES6: 7.3.3, 6: If success is false and Throw is true, throw a TypeError exception.
         if (!ret && shouldThrow == ThrowOnFailure::DoThrowOnRejection) {
             ExecutionEngine *e = engine();
             if (!e->hasException) { // allow a custom set impl to throw itself
                 QString message = QLatin1String("Cannot assign to read-only property \"") +
-                        name->toQString() + QLatin1Char('\"');
+                        QString::number(idx) + QLatin1Char('\"');
                 e->throwTypeError(message);
             }
         }
         return ret;
     }
 
-    inline bool setIndexed(uint idx, const Value &v, ThrowOnFailure shouldThrow)
+    // ES6: 7.3.3 Set (O, P, V, Throw)
+    inline bool set(StringOrSymbol *name, const Value &v, ThrowOnFailure shouldThrow)
     {
-        bool ret = vtable()->putIndexed(this, idx, v);
+        bool ret = vtable()->put(this, name->toPropertyKey(), v, this);
+        // ES6: 7.3.3, 6: If success is false and Throw is true, throw a TypeError exception.
         if (!ret && shouldThrow == ThrowOnFailure::DoThrowOnRejection) {
             ExecutionEngine *e = engine();
             if (!e->hasException) { // allow a custom set impl to throw itself
-                e->throwTypeError();
+                QString message = QLatin1String("Cannot assign to read-only property \"") +
+                        name->toQString() + QLatin1Char('\"');
+                e->throwTypeError(message);
             }
         }
         return ret;
     }
 
-
-    PropertyAttributes query(String *name) const
-    { return vtable()->query(this, name); }
-    PropertyAttributes queryIndexed(uint index) const
-    { return vtable()->queryIndexed(this, index); }
-    bool deleteProperty(String *name)
-    { return vtable()->deleteProperty(this, name); }
-    bool deleteIndexedProperty(uint index)
-    { return vtable()->deleteIndexedProperty(this, index); }
-    ReturnedValue getLookup(Lookup *l) const
-    { return vtable()->getLookup(this, l); }
-    void setLookup(Lookup *l, const Value &v)
-    { vtable()->setLookup(this, l, v); }
-    void advanceIterator(ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes)
-    { vtable()->advanceIterator(this, it, name, index, p, attributes); }
-    uint getLength() const { return vtable()->getLength(this); }
+    bool deleteProperty(PropertyKey id)
+    { return vtable()->deleteProperty(this, id); }
+    OwnPropertyKeyIterator *ownPropertyKeys(Value *target) const
+    { return vtable()->ownPropertyKeys(this, target); }
+    qint64 getLength() const { return vtable()->getLength(this); }
     ReturnedValue instanceOf(const Value &var) const
     { return vtable()->instanceOf(this, var); }
 
-    inline void construct(Scope &scope, CallData *d) const
-    { return vtable()->construct(this, scope, d); }
-    inline void call(Scope &scope, CallData *d) const
-    { vtable()->call(this, scope, d); }
+    bool isConcatSpreadable() const;
+    bool isArray() const;
+    const FunctionObject *speciesConstructor(Scope &scope, const FunctionObject *defaultConstructor) const;
+
+    bool setProtoFromNewTarget(const Value *newTarget);
+
 protected:
-    static void construct(const Managed *m, Scope &scope, CallData *);
-    static void call(const Managed *m, Scope &scope, CallData *);
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
-    static bool put(Managed *m, String *name, const Value &value);
-    static bool putIndexed(Managed *m, uint index, const Value &value);
-    static PropertyAttributes query(const Managed *m, String *name);
-    static PropertyAttributes queryIndexed(const Managed *m, uint index);
-    static bool deleteProperty(Managed *m, String *name);
-    static bool deleteIndexedProperty(Managed *m, uint index);
-    static ReturnedValue getLookup(const Managed *m, Lookup *l);
-    static void setLookup(Managed *m, Lookup *l, const Value &v);
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-    static uint getLength(const Managed *m);
-    static ReturnedValue instanceOf(const Object *typeObject, const Value &var);
-    static void markObjects(Heap::Base *, MarkStack *);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver,bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static bool virtualDeleteProperty(Managed *m, PropertyKey id);
+    static bool virtualHasProperty(const Managed *m, PropertyKey id);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static bool virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs);
+    static bool virtualIsExtensible(const Managed *m);
+    static bool virtualPreventExtensions(Managed *);
+    static Heap::Object *virtualGetPrototypeOf(const Managed *);
+    static bool virtualSetPrototypeOf(Managed *, const Object *);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
+    static qint64 virtualGetLength(const Managed *m);
+    static ReturnedValue virtualInstanceOf(const Object *typeObject, const Value &var);
+public:
+    // qv4runtime uses this directly
+    static ReturnedValue checkedInstanceOf(ExecutionEngine *engine, const FunctionObject *typeObject, const Value &var);
 
 private:
-    ReturnedValue internalGet(String *name, bool *hasProperty) const;
-    ReturnedValue internalGetIndexed(uint index, bool *hasProperty) const;
-    bool internalPut(String *name, const Value &value);
-    bool internalPutIndexed(uint index, const Value &value);
-    bool internalDeleteProperty(String *name);
-    bool internalDeleteIndexedProperty(uint index);
+    bool internalDefineOwnProperty(ExecutionEngine *engine, uint index, const InternalClassEntry *memberEntry, const Property *p, PropertyAttributes attrs);
+    ReturnedValue internalGet(PropertyKey id, const Value *receiver, bool *hasProperty) const;
+    bool internalPut(PropertyKey id, const Value &value, Value *receiver);
+    bool internalDeleteProperty(PropertyKey id);
 
     friend struct ObjectIterator;
     friend struct ObjectPrototype;
 };
 
+struct ObjectOwnPropertyKeyIterator : OwnPropertyKeyIterator
+{
+    uint arrayIndex = 0;
+    uint memberIndex = 0;
+    bool iterateOverSymbols = false;
+    SparseArrayNode *arrayNode = nullptr;
+    ~ObjectOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
 namespace Heap {
 
 struct BooleanObject : Object {
@@ -509,7 +450,7 @@ struct ArrayObject : Object {
 
 private:
     void commonInit()
-    { setProperty(internalClass->engine, LengthPropertyIndex, Primitive::fromInt32(0)); }
+    { setProperty(internalClass->engine, LengthPropertyIndex, Value::fromInt32(0)); }
 };
 
 }
@@ -539,17 +480,18 @@ struct ArrayObject: Object {
 
     void init(ExecutionEngine *engine);
 
-    static ReturnedValue getLookup(const Managed *m, Lookup *l);
-    using Object::getLength;
-    static uint getLength(const Managed *m);
+    static qint64 virtualGetLength(const Managed *m);
 
     QStringList toQStringList() const;
+protected:
+    static bool virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs);
+
 };
 
 inline void Object::setArrayLengthUnchecked(uint l)
 {
     if (isArrayObject())
-        setProperty(Heap::ArrayObject::LengthPropertyIndex, Primitive::fromUInt32(l));
+        setProperty(Heap::ArrayObject::LengthPropertyIndex, Value::fromUInt32(l));
 }
 
 inline void Object::push_back(const Value &v)
@@ -592,7 +534,7 @@ inline void Object::arraySet(uint index, const Value &value)
 
 template<>
 inline const ArrayObject *Value::as() const {
-    return isManaged() && m()->vtable()->type == Managed::Type_ArrayObject ? static_cast<const ArrayObject *>(this) : 0;
+    return isManaged() && m()->internalClass->vtable->type == Managed::Type_ArrayObject ? static_cast<const ArrayObject *>(this) : nullptr;
 }
 
 #ifndef V4_BOOTSTRAP
diff --git a/src/qml/jsruntime/qv4objectiterator.cpp b/src/qml/jsruntime/qv4objectiterator.cpp
index 3427ee89fe..e529b8e86b 100644
--- a/src/qml/jsruntime/qv4objectiterator.cpp
+++ b/src/qml/jsruntime/qv4objectiterator.cpp
@@ -42,145 +42,170 @@
 #include "qv4identifier_p.h"
 #include "qv4argumentsobject_p.h"
 #include "qv4string_p.h"
+#include "qv4iterator_p.h"
+#include "qv4propertykey_p.h"
 
 using namespace QV4;
 
-void ObjectIterator::init(const Object *o)
+void ForInIteratorPrototype::init(ExecutionEngine *)
 {
-    object->setM(o ? o->m() : 0);
-    current->setM(o ? o->m() : 0);
-
-    if (object->as<ArgumentsObject>()) {
-        Scope scope(engine);
-        Scoped<ArgumentsObject> (scope, object->asReturnedValue())->fullyCreate();
-    }
+    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
 }
 
-void ObjectIterator::next(Value *name, uint *index, Property *pd, PropertyAttributes *attrs)
+PropertyKey ObjectIterator::next(Property *pd, PropertyAttributes *attrs)
 {
-    name->setM(0);
-    *index = UINT_MAX;
+    if (!object || !iterator)
+        return PropertyKey::invalid();
 
-    if (!object->as<Object>()) {
-        *attrs = PropertyAttributes();
-        return;
-    }
     Scope scope(engine);
-    ScopedObject o(scope);
-    ScopedString n(scope);
+    ScopedPropertyKey key(scope);
 
     while (1) {
-        Object *co = current->objectValue();
-        if (!co)
-            break;
-
-        while (1) {
-            co->advanceIterator(this, name, index, pd, attrs);
-            if (attrs->isEmpty())
-                break;
-            // check the property is not already defined earlier in the proto chain
-            if (co->heapObject() != object->heapObject()) {
-                o = object->as<Object>();
-                n = *name;
-                bool shadowed = false;
-                while (o->d() != current->heapObject()) {
-                    if ((!!n && o->hasOwnProperty(n)) ||
-                        (*index != UINT_MAX && o->hasOwnProperty(*index))) {
-                        shadowed = true;
-                        break;
-                    }
-                    o = o->prototype();
-                }
-                if (shadowed)
-                    continue;
-            }
-            return;
+        key = iterator->next(object, pd, attrs);
+        if (!key->isValid()) {
+            object = nullptr;
+            return key;
         }
-
-        if (flags & WithProtoChain)
-            current->setM(co->prototype());
-        else
-            current->setM(0);
-
-        arrayIndex = 0;
-        memberIndex = 0;
+        if ((!(flags & WithSymbols) && key->isSymbol()) ||
+            ((flags & EnumerableOnly) && !attrs->isEnumerable()))
+            continue;
+        return key;
     }
-    *attrs = PropertyAttributes();
 }
 
 ReturnedValue ObjectIterator::nextPropertyName(Value *value)
 {
-    Object *o = object->objectValue();
-    if (!o)
+    if (!object)
         return Encode::null();
 
     PropertyAttributes attrs;
-    uint index;
     Scope scope(engine);
     ScopedProperty p(scope);
-    ScopedString name(scope);
-    next(name.getRef(), &index, p, &attrs);
-    if (attrs.isEmpty())
+    ScopedPropertyKey key(scope, next(p, &attrs));
+    if (!key->isValid())
         return Encode::null();
 
-    *value = o->getValue(p->value, attrs);
-
-    if (!!name)
-        return name->asReturnedValue();
-    Q_ASSERT(index < UINT_MAX);
-    return Encode(index);
+    *value = object->getValue(p->value, attrs);
+    if (key->isArrayIndex())
+        return Encode(key->asArrayIndex());
+    Q_ASSERT(key->isStringOrSymbol());
+    return key->asStringOrSymbol()->asReturnedValue();
 }
 
 ReturnedValue ObjectIterator::nextPropertyNameAsString(Value *value)
 {
-    Object *o = object->objectValue();
-    if (!o)
+    if (!object)
         return Encode::null();
 
     PropertyAttributes attrs;
-    uint index;
     Scope scope(engine);
     ScopedProperty p(scope);
-    ScopedString name(scope);
-    next(name.getRef(), &index, p, &attrs);
-    if (attrs.isEmpty())
+    ScopedPropertyKey key(scope, next(p, &attrs));
+    if (!key->isValid())
         return Encode::null();
 
-    *value = o->getValue(p->value, attrs);
+    *value = object->getValue(p->value, attrs);
 
-    if (!!name)
-        return name->asReturnedValue();
-    Q_ASSERT(index < UINT_MAX);
-    return Encode(engine->newString(QString::number(index)));
+    return key->toStringOrSymbol(engine)->asReturnedValue();
 }
 
 ReturnedValue ObjectIterator::nextPropertyNameAsString()
 {
-    if (!object->as<Object>())
+    if (!object)
         return Encode::null();
 
     PropertyAttributes attrs;
-    uint index;
     Scope scope(engine);
-    ScopedProperty p(scope);
-    ScopedString name(scope);
-    next(name.getRef(), &index, p, &attrs);
-    if (attrs.isEmpty())
+    ScopedPropertyKey key(scope, next(nullptr, &attrs));
+    if (!key->isValid())
         return Encode::null();
 
-    if (!!name)
-        return name->asReturnedValue();
-    Q_ASSERT(index < UINT_MAX);
-    return Encode(engine->newString(QString::number(index)));
+    return key->toStringOrSymbol(engine)->asReturnedValue();
 }
 
 
-DEFINE_OBJECT_VTABLE(ForEachIteratorObject);
+DEFINE_OBJECT_VTABLE(ForInIteratorObject);
 
-void ForEachIteratorObject::markObjects(Heap::Base *that, MarkStack *markStack)
+void Heap::ForInIteratorObject::markObjects(Heap::Base *that, MarkStack *markStack)
 {
-    ForEachIteratorObject::Data *o = static_cast<ForEachIteratorObject::Data *>(that);
+    ForInIteratorObject *o = static_cast<ForInIteratorObject *>(that);
+    if (o->object)
+        o->object->mark(markStack);
+    if (o->current)
+        o->current->mark(markStack);
     o->workArea[0].mark(markStack);
     o->workArea[1].mark(markStack);
     Object::markObjects(that, markStack);
 }
+
+void Heap::ForInIteratorObject::destroy()
+{
+    delete iterator;
+}
+
+ReturnedValue ForInIteratorPrototype::method_next(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    const ForInIteratorObject *forIn = static_cast<const ForInIteratorObject *>(thisObject);
+    Q_ASSERT(forIn);
+    Scope scope(b);
+
+    ScopedPropertyKey key(scope, forIn->nextProperty());
+    bool done = false;
+    if (!key->isValid())
+        done = true;
+    ScopedStringOrSymbol s(scope, key->toStringOrSymbol(scope.engine));
+    return IteratorPrototype::createIterResultObject(scope.engine, s, done);
+}
+
+
+PropertyKey ForInIteratorObject::nextProperty() const
+{
+    if (!d()->current)
+        return PropertyKey::invalid();
+
+    Scope scope(this);
+    ScopedObject c(scope, d()->current);
+    ScopedObject t(scope, d()->target);
+    ScopedObject o(scope);
+    ScopedProperty p(scope);
+    ScopedPropertyKey key(scope);
+    PropertyAttributes attrs;
+
+    while (1) {
+        while (1) {
+            key = d()->iterator->next(t, p, &attrs);
+            if (!key->isValid())
+                break;
+            if (!attrs.isEnumerable() || key->isSymbol())
+                continue;
+            // check the property is not already defined earlier in the proto chain
+            if (d()->current != d()->object) {
+                o = d()->object;
+                bool shadowed = false;
+                while (o->d() != c->heapObject()) {
+                    if (o->getOwnProperty(key) != Attr_Invalid) {
+                        shadowed = true;
+                        break;
+                    }
+                    o = o->getPrototypeOf();
+                }
+                if (shadowed)
+                    continue;
+            }
+            return key;
+        }
+
+        c = c->getPrototypeOf();
+        d()->current.set(scope.engine, c->d());
+        if (!c)
+            break;
+        delete d()->iterator;
+        d()->iterator = c->ownPropertyKeys(t.getRef());
+        d()->target.set(scope.engine, t->d());
+        if (!d()->iterator) {
+            scope.engine->throwTypeError();
+            return PropertyKey::invalid();
+        }
+    }
+    return PropertyKey::invalid();
+}
diff --git a/src/qml/jsruntime/qv4objectiterator_p.h b/src/qml/jsruntime/qv4objectiterator_p.h
index 6168d59914..a20ce9cb88 100644
--- a/src/qml/jsruntime/qv4objectiterator_p.h
+++ b/src/qml/jsruntime/qv4objectiterator_p.h
@@ -57,87 +57,86 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-struct Q_QML_EXPORT ObjectIteratorData
+struct Q_QML_EXPORT ObjectIterator
 {
     enum Flags {
         NoFlags = 0,
         EnumerableOnly = 0x1,
-        WithProtoChain = 0x2,
+        WithSymbols = 0x2
     };
 
     ExecutionEngine *engine;
-    Value *object;
-    Value *current;
-    SparseArrayNode *arrayNode;
-    uint arrayIndex;
-    uint memberIndex;
+    Object *object;
+    OwnPropertyKeyIterator *iterator = nullptr;
     uint flags;
-};
-V4_ASSERT_IS_TRIVIAL(ObjectIteratorData)
-
-struct Q_QML_EXPORT ObjectIterator: ObjectIteratorData
-{
-    ObjectIterator(ExecutionEngine *e, Value *scratch1, Value *scratch2, Object *o, uint flags)
-    {
-        engine = e;
-        object = scratch1;
-        current = scratch2;
-        arrayNode = nullptr;
-        arrayIndex = 0;
-        memberIndex = 0;
-        this->flags = flags;
-        init(o);
-    }
 
     ObjectIterator(Scope &scope, const Object *o, uint flags)
     {
         engine = scope.engine;
-        object = scope.alloc(1);
-        current = scope.alloc(1);
-        arrayNode = nullptr;
-        arrayIndex = 0;
-        memberIndex = 0;
+        object = static_cast<Object *>(scope.alloc());
         this->flags = flags;
-        init(o);
+        object->setM(o ? o->m() : nullptr);
+        if (o)
+            iterator = object->ownPropertyKeys(object);
+    }
+    ~ObjectIterator()
+    {
+        delete iterator;
     }
 
-    void next(Value *name, uint *index, Property *pd, PropertyAttributes *attributes = 0);
+    PropertyKey next(Property *pd = nullptr, PropertyAttributes *attributes = nullptr);
     ReturnedValue nextPropertyName(Value *value);
     ReturnedValue nextPropertyNameAsString(Value *value);
     ReturnedValue nextPropertyNameAsString();
-
-private:
-    void init(const Object *o);
 };
 
 namespace Heap {
-struct ForEachIteratorObject : Object {
+
+#define ForInIteratorObjectMembers(class, Member) \
+    Member(class, Pointer, Object *, object) \
+    Member(class, Pointer, Object *, current) \
+    Member(class, Pointer, Object *, target) \
+    Member(class, NoMark, OwnPropertyKeyIterator *, iterator)
+
+DECLARE_HEAP_OBJECT(ForInIteratorObject, Object) {
     void init(QV4::Object *o);
-    ObjectIterator &it() { return *reinterpret_cast<ObjectIterator*>(&itData); }
     Value workArea[2];
 
-private:
-    ObjectIteratorData itData;
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
+    void destroy();
 };
 
 }
 
-struct ForEachIteratorObject: Object {
-    V4_OBJECT2(ForEachIteratorObject, Object)
-    Q_MANAGED_TYPE(ForeachIteratorObject)
+struct ForInIteratorPrototype : Object
+{
+    V4_PROTOTYPE(iteratorPrototype)
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_next(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+};
 
-    ReturnedValue nextPropertyName() { return d()->it().nextPropertyNameAsString(); }
+struct ForInIteratorObject: Object {
+    V4_OBJECT2(ForInIteratorObject, Object)
+    Q_MANAGED_TYPE(ForInIterator)
+    V4_PROTOTYPE(forInIteratorPrototype)
+    V4_NEEDS_DESTROY
 
-protected:
-    static void markObjects(Heap::Base *that, MarkStack *markStack);
+    PropertyKey nextProperty() const;
 };
 
 inline
-void Heap::ForEachIteratorObject::init(QV4::Object *o)
+void Heap::ForInIteratorObject::init(QV4::Object *o)
 {
     Object::init();
-    it() = ObjectIterator(internalClass->engine, workArea, workArea + 1, o,
-                          ObjectIterator::EnumerableOnly | ObjectIterator::WithProtoChain);
+    if (!o)
+        return;
+    object.set(o->engine(), o->d());
+    current.set(o->engine(), o->d());
+    Scope scope(o);
+    ScopedObject obj(scope);
+    iterator = o->ownPropertyKeys(obj.getRef());
+    target.set(o->engine(), obj->d());
 }
 
 
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index 2e72c0f13f..6b4c3ba71a 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -46,6 +46,9 @@
 #include "qv4runtime_p.h"
 #include "qv4objectiterator_p.h"
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
+#include "qv4symbol_p.h"
+#include "qv4propertykey_p.h"
 
 #include <QtCore/QDateTime>
 #include <QtCore/QStringList>
@@ -60,27 +63,29 @@ void Heap::ObjectCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("Object"));
 }
 
-void ObjectCtor::construct(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue ObjectCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    const ObjectCtor *ctor = static_cast<const ObjectCtor *>(that);
-    if (!callData->argc || callData->args[0].isUndefined() || callData->args[0].isNull()) {
+    ExecutionEngine *v4 = f->engine();
+    const ObjectCtor *nt = static_cast<const ObjectCtor *>(newTarget);
+    if (!argc || argv[0].isUndefined() || argv[0].isNull()) {
+        Scope scope(v4);
         ScopedObject obj(scope, scope.engine->newObject());
-        ScopedObject proto(scope, ctor->get(scope.engine->id_prototype()));
+        ScopedObject proto(scope, nt->get(scope.engine->id_prototype()));
         if (!!proto)
-            obj->setPrototype(proto);
-        scope.result = obj.asReturnedValue();
+            obj->setPrototypeOf(proto);
+        return obj.asReturnedValue();
     } else {
-        scope.result = callData->args[0].toObject(scope.engine);
+        return argv[0].toObject(v4)->asReturnedValue();
     }
 }
 
-void ObjectCtor::call(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue ObjectCtor::virtualCall(const FunctionObject *m, const Value *, const Value *argv, int argc)
 {
-    ExecutionEngine *v4 = scope.engine;
-    if (!callData->argc || callData->args[0].isUndefined() || callData->args[0].isNull()) {
-        scope.result = v4->newObject()->asReturnedValue();
+    ExecutionEngine *v4 = m->engine();
+    if (!argc || argv[0].isUndefined() || argv[0].isNull()) {
+        return v4->newObject()->asReturnedValue();
     } else {
-        scope.result = callData->args[0].toObject(v4);
+        return argv[0].toObject(v4)->asReturnedValue();
     }
 }
 
@@ -90,25 +95,31 @@ void ObjectPrototype::init(ExecutionEngine *v4, Object *ctor)
     ScopedObject o(scope, this);
 
     ctor->defineReadonlyProperty(v4->id_prototype(), o);
-    ctor->defineReadonlyConfigurableProperty(v4->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyConfigurableProperty(v4->id_length(), Value::fromInt32(1));
     ctor->defineDefaultProperty(QStringLiteral("getPrototypeOf"), method_getPrototypeOf, 1);
     ctor->defineDefaultProperty(QStringLiteral("getOwnPropertyDescriptor"), method_getOwnPropertyDescriptor, 2);
+    ctor->defineDefaultProperty(QStringLiteral("getOwnPropertyDescriptors"), method_getOwnPropertyDescriptors, 1);
     ctor->defineDefaultProperty(QStringLiteral("getOwnPropertyNames"), method_getOwnPropertyNames, 1);
+    ctor->defineDefaultProperty(QStringLiteral("getOwnPropertySymbols"), method_getOwnPropertySymbols, 1);
     ctor->defineDefaultProperty(QStringLiteral("assign"), method_assign, 2);
     ctor->defineDefaultProperty(QStringLiteral("create"), method_create, 2);
     ctor->defineDefaultProperty(QStringLiteral("defineProperty"), method_defineProperty, 3);
     ctor->defineDefaultProperty(QStringLiteral("defineProperties"), method_defineProperties, 2);
+    ctor->defineDefaultProperty(QStringLiteral("entries"), method_entries, 1);
     ctor->defineDefaultProperty(QStringLiteral("seal"), method_seal, 1);
     ctor->defineDefaultProperty(QStringLiteral("freeze"), method_freeze, 1);
     ctor->defineDefaultProperty(QStringLiteral("preventExtensions"), method_preventExtensions, 1);
+    ctor->defineDefaultProperty(QStringLiteral("is"), method_is, 2);
     ctor->defineDefaultProperty(QStringLiteral("isSealed"), method_isSealed, 1);
     ctor->defineDefaultProperty(QStringLiteral("isFrozen"), method_isFrozen, 1);
     ctor->defineDefaultProperty(QStringLiteral("isExtensible"), method_isExtensible, 1);
     ctor->defineDefaultProperty(QStringLiteral("keys"), method_keys, 1);
+    ctor->defineDefaultProperty(QStringLiteral("setPrototypeOf"), method_setPrototypeOf, 2);
+    ctor->defineDefaultProperty(QStringLiteral("values"), method_values, 1);
 
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
     defineDefaultProperty(v4->id_toString(), method_toString, 0);
-    defineDefaultProperty(QStringLiteral("toLocaleString"), method_toLocaleString, 0);
+    defineDefaultProperty(v4->id_toLocaleString(), method_toLocaleString, 0);
     defineDefaultProperty(v4->id_valueOf(), method_valueOf, 0);
     defineDefaultProperty(QStringLiteral("hasOwnProperty"), method_hasOwnProperty, 1);
     defineDefaultProperty(QStringLiteral("isPrototypeOf"), method_isPrototypeOf, 1);
@@ -116,76 +127,154 @@ void ObjectPrototype::init(ExecutionEngine *v4, Object *ctor)
     defineDefaultProperty(QStringLiteral("__defineGetter__"), method_defineGetter, 2);
     defineDefaultProperty(QStringLiteral("__defineSetter__"), method_defineSetter, 2);
 
-    ExecutionContext *global = v4->rootContext();
-    ScopedProperty p(scope);
-    p->value = BuiltinFunction::create(global, v4->id___proto__(), method_get_proto);
-    p->set = BuiltinFunction::create(global, v4->id___proto__(), method_set_proto);
-    insertMember(v4->id___proto__(), p, Attr_Accessor|Attr_NotEnumerable);
+    defineAccessorProperty(v4->id___proto__(), method_get_proto, method_set_proto);
 }
 
-void ObjectPrototype::method_getPrototypeOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_getPrototypeOf(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->args[0].toObject(scope.engine));
-    CHECK_EXCEPTION();
+    Scope scope(b);
+    if (argc < 1)
+        return scope.engine->throwTypeError();
 
-    ScopedObject p(scope, o->prototype());
-    scope.result = !!p ? p->asReturnedValue() : Encode::null();
+    ScopedObject o(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    ScopedObject p(scope, o->getPrototypeOf());
+    return (!!p ? p->asReturnedValue() : Encode::null());
 }
 
-void ObjectPrototype::method_getOwnPropertyDescriptor(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_is(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    ScopedObject O(scope, callData->args[0].toObject(scope.engine));
-    CHECK_EXCEPTION();
+    if (!argc)
+        return Encode(true);
+    if (argc == 1)
+        return Encode((argv[0].isUndefined() ? true : false));
+    return Encode(argv[0].sameValue(argv[1]));
+}
+
+ReturnedValue ObjectPrototype::method_getOwnPropertyDescriptor(const FunctionObject *b, const Value *, const Value *argv, int argc)
+{
+    Scope scope(b);
+    if (argc < 1)
+        return scope.engine->throwTypeError();
+
+    ScopedObject O(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
     if (ArgumentsObject::isNonStrictArgumentsObject(O))
         static_cast<ArgumentsObject *>(O.getPointer())->fullyCreate();
 
-    ScopedValue v(scope, callData->argument(1));
-    ScopedString name(scope, v->toString(scope.engine));
-    CHECK_EXCEPTION();
+    ScopedValue v(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    ScopedPropertyKey name(scope, v->toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
-    PropertyAttributes attrs;
     ScopedProperty desc(scope);
-    O->getOwnProperty(name, &attrs, desc);
-    scope.result = fromPropertyDescriptor(scope.engine, desc, attrs);
+    PropertyAttributes attrs = O->getOwnProperty(name, desc);
+    return fromPropertyDescriptor(scope.engine, desc, attrs);
 }
 
-void ObjectPrototype::method_getOwnPropertyNames(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_getOwnPropertyDescriptors(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    ScopedObject O(scope, callData->args[0].toObject(scope.engine));
-    CHECK_EXCEPTION();
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return Encode::undefined();
+
+    ScopedObject descriptors(scope, scope.engine->newObject());
+
+    ObjectIterator it(scope, o, ObjectIterator::WithSymbols);
+    ScopedProperty pd(scope);
+    PropertyAttributes attrs;
+    ScopedPropertyKey key(scope);
+    ScopedObject entry(scope);
+    while (1) {
+        key = it.next(pd, &attrs);
+        if (!key->isValid())
+            break;
+        entry = fromPropertyDescriptor(scope.engine, pd, attrs);
+        descriptors->put(key, entry);
+    }
+
+    return descriptors.asReturnedValue();
 
-    scope.result = getOwnPropertyNames(scope.engine, callData->args[0]);
 }
 
-// 19.1.2.1
-void ObjectPrototype::method_assign(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_getOwnPropertyNames(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject to(scope, callData->args[0].toObject(scope.engine));
-    CHECK_EXCEPTION();
+    Scope scope(b);
+    if (argc < 1)
+        return scope.engine->throwTypeError();
 
-    if (callData->argc == 1) {
-        scope.result = to;
-        return;
+    ScopedObject O(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    return Encode(getOwnPropertyNames(scope.engine, argv[0]));
+}
+
+ReturnedValue ObjectPrototype::method_getOwnPropertySymbols(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject O(scope, argv[0].toObject(scope.engine));
+    if (!O)
+        return Encode::undefined();
+
+    ScopedArrayObject array(scope, scope.engine->newArrayObject());
+    if (O) {
+        ObjectIterator it(scope, O, ObjectIterator::WithSymbols);
+        ScopedValue name(scope);
+        while (1) {
+            name = it.nextPropertyNameAsString();
+            if (name->isNull())
+                break;
+            if (!name->isSymbol())
+                continue;
+            array->push_back(name);
+        }
     }
+    return array->asReturnedValue();
+}
+
+// 19.1.2.1
+ReturnedValue ObjectPrototype::method_assign(const FunctionObject *b, const Value *, const Value *argv, int argc)
+{
+    Scope scope(b);
+    if (argc < 1)
+        return scope.engine->throwTypeError();
 
-    for (int i = 1; i < callData->argc; ++i) {
-        if (callData->args[i].isUndefined() || callData->args[i].isNull())
+    ScopedObject to(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    if (argc == 1)
+        return to.asReturnedValue();
+
+    for (int i = 1, ei = argc; i < ei; ++i) {
+        if (argv[i].isUndefined() || argv[i].isNull())
             continue;
 
-        ScopedObject from(scope, callData->args[i].toObject(scope.engine));
-        CHECK_EXCEPTION();
+        ScopedObject from(scope, argv[i].toObject(scope.engine));
+        if (scope.engine->hasException)
+        return QV4::Encode::undefined();
         QV4::ScopedArrayObject keys(scope, QV4::ObjectPrototype::getOwnPropertyNames(scope.engine, from));
         quint32 length = keys->getLength();
 
         ScopedString nextKey(scope);
         ScopedValue propValue(scope);
         for (quint32 i = 0; i < length; ++i) {
-            nextKey = Value::fromReturnedValue(keys->getIndexed(i)).toString(scope.engine);
+            nextKey = Value::fromReturnedValue(keys->get(i)).toString(scope.engine);
 
-            PropertyAttributes attrs;
             ScopedProperty prop(scope);
-            from->getOwnProperty(nextKey, &attrs, prop);
+            PropertyAttributes attrs = from->getOwnProperty(nextKey->toPropertyKey(), prop);
 
             if (attrs == PropertyFlag::Attr_Invalid)
                 continue;
@@ -195,102 +284,144 @@ void ObjectPrototype::method_assign(const BuiltinFunction *, Scope &scope, CallD
 
             propValue = from->get(nextKey);
             to->set(nextKey, propValue, Object::DoThrowOnRejection);
-            CHECK_EXCEPTION();
+            if (scope.engine->hasException)
+        return QV4::Encode::undefined();
         }
     }
 
-    scope.result = to;
+    return to.asReturnedValue();
 }
 
-void ObjectPrototype::method_create(const BuiltinFunction *builtin, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_create(const FunctionObject *builtin, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedValue O(scope, callData->argument(0));
-    if (!O->isObject() && !O->isNull()) {
-        scope.result = scope.engine->throwTypeError();
-        return;
-    }
+    Scope scope(builtin);
+    if (!argc || (!argv[0].isObject() && !argv[0].isNull()))
+        return scope.engine->throwTypeError();
+
+    ScopedObject O(scope, argv[0]);
 
     ScopedObject newObject(scope, scope.engine->newObject());
-    newObject->setPrototype(O->as<Object>());
+    newObject->setPrototypeOf(O);
 
-    if (callData->argc > 1 && !callData->args[1].isUndefined()) {
-        callData->args[0] = newObject;
-        method_defineProperties(builtin, scope, callData);
-        return;
+
+    if (argc > 1 && !argv[1].isUndefined()) {
+        Value *arguments = scope.alloc(argc);
+        arguments[0] = newObject;
+        memcpy(arguments + 1, argv + 1, (argc - 1)*sizeof(Value));
+        return method_defineProperties(builtin, thisObject, arguments, argc);
     }
 
-    scope.result = newObject;
+    return newObject.asReturnedValue();
 }
 
-void ObjectPrototype::method_defineProperty(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_defineProperty(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject O(scope, callData->argument(0));
-    if (!O) {
-        scope.result = scope.engine->throwTypeError();
-        return;
-    }
+    Scope scope(b);
+    if (!argc || !argv[0].isObject())
+        return scope.engine->throwTypeError();
 
-    ScopedString name(scope, callData->argument(1), ScopedString::Convert);
-    CHECK_EXCEPTION();
+    ScopedObject O(scope, argv[0]);
+    ScopedPropertyKey name(scope, (argc > 1 ? argv[1] : Value::undefinedValue()).toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
-    ScopedValue attributes(scope, callData->argument(2));
+    ScopedValue attributes(scope, argc > 2 ? argv[2] : Value::undefinedValue());
     ScopedProperty pd(scope);
     PropertyAttributes attrs;
     toPropertyDescriptor(scope.engine, attributes, pd, &attrs);
-    CHECK_EXCEPTION();
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
-    if (!O->__defineOwnProperty__(scope.engine, name, pd, attrs))
+    if (!O->defineOwnProperty(name, pd, attrs))
         THROW_TYPE_ERROR();
 
-    scope.result = O;
+    return O.asReturnedValue();
 }
 
-void ObjectPrototype::method_defineProperties(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_defineProperties(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject O(scope, callData->argument(0));
-    if (!O)
-        THROW_TYPE_ERROR();
+    Scope scope(b);
+    if (argc < 2 || !argv[0].isObject())
+        return scope.engine->throwTypeError();
+
+    ScopedObject O(scope, argv[0]);
 
-    ScopedObject o(scope, callData->argument(1), ScopedObject::Convert);
-    CHECK_EXCEPTION();
+    ScopedObject o(scope, argv[1].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
     ScopedValue val(scope);
 
     ObjectIterator it(scope, o, ObjectIterator::EnumerableOnly);
-    ScopedString name(scope);
     ScopedProperty pd(scope);
     ScopedProperty n(scope);
+    ScopedPropertyKey key(scope);
     while (1) {
-        uint index;
         PropertyAttributes attrs;
-        it.next(name.getRef(), &index, pd, &attrs);
-        if (attrs.isEmpty())
+        key = it.next(pd, &attrs);
+        if (!key->isValid())
             break;
         PropertyAttributes nattrs;
         val = o->getValue(pd->value, attrs);
         toPropertyDescriptor(scope.engine, val, n, &nattrs);
-        CHECK_EXCEPTION();
-        bool ok;
-        if (name)
-            ok = O->__defineOwnProperty__(scope.engine, name, n, nattrs);
-        else
-            ok = O->__defineOwnProperty__(scope.engine, index, n, nattrs);
+        if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+        bool ok = O->defineOwnProperty(key, n, nattrs);
         if (!ok)
             THROW_TYPE_ERROR();
     }
 
-    scope.result = O;
+    return O.asReturnedValue();
 }
 
-void ObjectPrototype::method_seal(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_entries(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->argument(0));
-    if (!o) {
-        // 19.1.2.17, 1
-        scope.result = callData->argument(0);
-        return;
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return Encode::undefined();
+
+    ScopedArrayObject a(scope, scope.engine->newArrayObject());
+
+    ObjectIterator it(scope, o, ObjectIterator::EnumerableOnly);
+    ScopedString name(scope);
+    ScopedArrayObject entry(scope);
+    while (1) {
+        name = it.nextPropertyNameAsString();
+        if (!name)
+            break;
+        entry = scope.engine->newArrayObject();
+        entry->push_back(name);
+        a->push_back(entry);
+    }
+
+    // now add values, do this after the loop above as reading out the values can have side effects
+    uint len = a->getLength();
+    ScopedValue value(scope);
+    for (uint i = 0; i < len; ++i) {
+        entry = a->get(PropertyKey::fromArrayIndex(i));
+        name = entry->get(PropertyKey::fromArrayIndex(0));
+        value = o->get(name->toPropertyKey());
+        if (scope.engine->hasException)
+            return Encode::undefined();
+        entry->push_back(value);
     }
 
+    return a.asReturnedValue();
+}
+
+ReturnedValue ObjectPrototype::method_seal(const FunctionObject *b, const Value *, const Value *argv, int argc)
+{
+    const Value a = argc ? argv[0] : Value::undefinedValue();
+    if (!a.isObject())
+        // 19.1.2.17, 1
+        return a.asReturnedValue();
+
+    Scope scope(b);
+    ScopedObject o(scope, a);
     o->setInternalClass(o->internalClass()->sealed());
 
     if (o->arrayData()) {
@@ -301,17 +432,18 @@ void ObjectPrototype::method_seal(const BuiltinFunction *, Scope &scope, CallDat
         }
     }
 
-    scope.result = o;
+    return o.asReturnedValue();
 }
 
-void ObjectPrototype::method_freeze(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_freeze(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->argument(0));
-    if (!o) {
+    const Value a = argc ? argv[0] : Value::undefinedValue();
+    if (!a.isObject())
         // 19.1.2.5, 1
-        scope.result = callData->argument(0);
-        return;
-    }
+        return a.asReturnedValue();
+
+    Scope scope(b);
+    ScopedObject o(scope, a);
 
     if (ArgumentsObject::isNonStrictArgumentsObject(o))
         static_cast<ArgumentsObject *>(o.getPointer())->fullyCreate();
@@ -327,293 +459,349 @@ void ObjectPrototype::method_freeze(const BuiltinFunction *, Scope &scope, CallD
                 o->arrayData()->attrs[i].setWritable(false);
         }
     }
-    scope.result = o;
+    return o.asReturnedValue();
 }
 
-void ObjectPrototype::method_preventExtensions(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_preventExtensions(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->args[0].toObject(scope.engine));
-    if (!o) {
-        scope.result = callData->argument(0);
-        return;
-    }
+    Scope scope(b);
+    if (!argc)
+        return Encode::undefined();
+
+    ScopedObject o(scope, argv[0]);
+    if (!o)
+        return argv[0].asReturnedValue();
 
-    o->setInternalClass(o->internalClass()->nonExtensible());
-    scope.result = o;
+    o->preventExtensions();
+    return o.asReturnedValue();
 }
 
-void ObjectPrototype::method_isSealed(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_isSealed(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->args[0].toObject(scope.engine));
-    if (!o) {
-        scope.result = Encode(true);
-        return;
-    }
+    Scope scope(b);
+    if (!argc)
+        return Encode(true);
 
-    if (o->isExtensible()) {
-        scope.result = Encode(false);
-        return;
-    }
+    ScopedObject o(scope, argv[0]);
+    if (!o)
+        return Encode(true);
 
-    if (o->internalClass() != o->internalClass()->sealed()) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (o->isExtensible())
+        return  Encode(false);
 
-    if (!o->arrayData() || !o->arrayData()->length()) {
-        scope.result = Encode(true);
-        return;
-    }
+    if (o->internalClass() != o->internalClass()->sealed())
+        return Encode(false);
+
+    if (!o->arrayData() || !o->arrayData()->length())
+        return Encode(true);
 
     Q_ASSERT(o->arrayData() && o->arrayData()->length());
-    if (!o->arrayData()->attrs) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (!o->arrayData()->attrs)
+        return Encode(false);
 
     for (uint i = 0; i < o->arrayData()->values.alloc; ++i) {
         if (!o->arrayData()->isEmpty(i))
-            if (o->arrayData()->attributes(i).isConfigurable()) {
-                scope.result = Encode(false);
-                return;
-            }
+            if (o->arrayData()->attributes(i).isConfigurable())
+                return Encode(false);
     }
 
-    scope.result = Encode(true);
+    return Encode(true);
 }
 
-void ObjectPrototype::method_isFrozen(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_isFrozen(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->args[0].toObject(scope.engine));
-    if (!o) {
-        scope.result = Encode(true);
-        return;
-    }
+    Scope scope(b);
+    if (!argc)
+        return Encode(true);
 
-    if (o->isExtensible()) {
-        scope.result = Encode(false);
-        return;
-    }
+    ScopedObject o(scope, argv[0]);
+    if (!o)
+        return Encode(true);
 
-    if (o->internalClass() != o->internalClass()->frozen()) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (o->isExtensible())
+        return Encode(false);
 
-    if (!o->arrayData() || !o->arrayData()->length()) {
-        scope.result = Encode(true);
-        return;
-    }
+    if (o->internalClass() != o->internalClass()->frozen())
+        return Encode(false);
+
+    if (!o->arrayData() || !o->arrayData()->length())
+        return Encode(true);
 
     Q_ASSERT(o->arrayData() && o->arrayData()->length());
-    if (!o->arrayData()->attrs) {
-        scope.result = Encode(false);
-        return;
-    }
+    if (!o->arrayData()->attrs)
+        return Encode(false);
 
     for (uint i = 0; i < o->arrayData()->values.alloc; ++i) {
         if (!o->arrayData()->isEmpty(i))
-            if (o->arrayData()->attributes(i).isConfigurable() || o->arrayData()->attributes(i).isWritable()) {
-                scope.result = Encode(false);
-                return;
-            }
+            if (o->arrayData()->attributes(i).isConfigurable() || o->arrayData()->attributes(i).isWritable())
+                return Encode(false);
     }
 
-    scope.result = Encode(true);
+    return Encode(true);
 }
 
-void ObjectPrototype::method_isExtensible(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_isExtensible(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->args[0].toObject(scope.engine));
-    if (!o) {
-        scope.result = Encode(false);
-        return;
-    }
+    Scope scope(b);
+    if (!argc)
+        return Encode(false);
+
+    ScopedObject o(scope, argv[0]);
+    if (!o)
+        return Encode(false);
 
-    scope.result = Encode((bool)o->isExtensible());
+    return Encode((bool)o->isExtensible());
 }
 
-void ObjectPrototype::method_keys(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_keys(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->args[0].toObject(scope.engine));
-    CHECK_EXCEPTION();
+    Scope scope(b);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
     ScopedArrayObject a(scope, scope.engine->newArrayObject());
 
     ObjectIterator it(scope, o, ObjectIterator::EnumerableOnly);
     ScopedValue name(scope);
+    ScopedValue value(scope);
     while (1) {
-        name = it.nextPropertyNameAsString();
+        name = it.nextPropertyNameAsString(value);
         if (name->isNull())
             break;
         a->push_back(name);
     }
 
-    scope.result = a;
+    return a.asReturnedValue();
 }
 
-void ObjectPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_setPrototypeOf(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    if (callData->thisObject.isUndefined()) {
-        scope.result = scope.engine->newString(QStringLiteral("[object Undefined]"));
-    } else if (callData->thisObject.isNull()) {
-        scope.result = scope.engine->newString(QStringLiteral("[object Null]"));
-    } else {
-        ScopedObject obj(scope, callData->thisObject.toObject(scope.engine));
-        QString className = obj->className();
-        scope.result = scope.engine->newString(QStringLiteral("[object %1]").arg(className));
+    Scope scope(f->engine());
+    if (argc < 2 || argv[0].isNullOrUndefined() || !(argv[1].isObject() || argv[1].isNull()))
+        return scope.engine->throwTypeError();
+
+    if (!argv[0].isObject())
+        return argv[0].asReturnedValue();
+
+    ScopedObject o(scope, argv[0]);
+    const Object *p = argv[1].isNull() ? nullptr : static_cast<const Object *>(argv + 1);
+    bool ok = o->setPrototypeOf(p);
+    if (!ok)
+        return scope.engine->throwTypeError(QStringLiteral("Could not change prototype."));
+    return o->asReturnedValue();
+}
+
+ReturnedValue ObjectPrototype::method_values(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, argv[0].toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    ScopedArrayObject a(scope, scope.engine->newArrayObject());
+
+    ObjectIterator it(scope, o, ObjectIterator::EnumerableOnly);
+    ScopedPropertyKey key(scope);
+    ScopedProperty pd(scope);
+    ScopedValue value(scope);
+    PropertyAttributes attrs;
+    while (1) {
+        key = it.next(pd, &attrs);
+        if (!key->isValid())
+            break;
+        value = o->getValue(pd->value, attrs);
+        a->push_back(value);
     }
+
+    return a.asReturnedValue();
+}
+
+ReturnedValue ObjectPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    ExecutionEngine *v4 = b->engine();
+    QString string;
+    if (thisObject->isUndefined()) {
+        string = QStringLiteral("[object Undefined]");
+    } else if (thisObject->isNull()) {
+        string = QStringLiteral("[object Null]");
+    } else {
+        const Object *o = thisObject->as<Object>();
+        if (!o) {
+            // primitive, get the proper prototype
+            if (thisObject->isBoolean())
+                o = v4->booleanPrototype();
+            else if (thisObject->isNumber())
+                o = v4->numberPrototype();
+            else if (thisObject->isString())
+                o = v4->stringPrototype();
+            else if (thisObject->isSymbol())
+                o = v4->symbolPrototype();
+            Q_ASSERT(o);
+        }
+        QString name = o->className();
+        Scope scope(v4);
+        ScopedString toStringTag(scope, o->get(v4->symbol_toStringTag()));
+        if (toStringTag)
+            name = toStringTag->toQString();
+        string = QStringLiteral("[object %1]").arg(name);
+    }
+    return Encode(v4->newString(string));
 }
 
-void ObjectPrototype::method_toLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_toLocaleString(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject o(scope, thisObject->toObject(scope.engine));
     if (!o)
         RETURN_UNDEFINED();
 
     ScopedFunctionObject f(scope, o->get(scope.engine->id_toString()));
     if (!f)
         THROW_TYPE_ERROR();
-    ScopedCallData cData(scope);
-    cData->thisObject = o;
-    f->call(scope, callData);
+
+    return f->call(thisObject, argv, argc);
 }
 
-void ObjectPrototype::method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_valueOf(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    scope.result = callData->thisObject.toObject(scope.engine);
+    return Encode(thisObject->toObject(b->engine()));
 }
 
-void ObjectPrototype::method_hasOwnProperty(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_hasOwnProperty(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedString P(scope, callData->argument(0), ScopedString::Convert);
-    CHECK_EXCEPTION();
-    ScopedObject O(scope, callData->thisObject, ScopedObject::Convert);
-    CHECK_EXCEPTION();
-    bool r = O->hasOwnProperty(P);
-    if (!r)
-        r = !O->query(P).isEmpty();
-    scope.result = Encode(r);
+    Scope scope(b);
+    ScopedPropertyKey P(scope, (argc ? argv[0] : Value::undefinedValue()).toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+    ScopedObject O(scope, thisObject->toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+    bool r = O->getOwnProperty(P) != Attr_Invalid;
+    return Encode(r);
 }
 
-void ObjectPrototype::method_isPrototypeOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_isPrototypeOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject V(scope, callData->argument(0));
-    if (!V) {
-        scope.result = Encode(false);
-        return;
-    }
-
-    ScopedObject O(scope, callData->thisObject, ScopedObject::Convert);
-    CHECK_EXCEPTION();
-    ScopedObject proto(scope, V->prototype());
+    Scope scope(b);
+    if (!argc || !argv[0].isObject())
+        return Encode(false);
+
+    ScopedObject V(scope, argv[0]);
+    ScopedObject O(scope, thisObject->toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+    ScopedObject proto(scope, V->getPrototypeOf());
     while (proto) {
-        if (O->d() == proto->d()) {
-            scope.result = Encode(true);
-            return;
-        }
-        proto = proto->prototype();
+        if (O->d() == proto->d())
+            return Encode(true);
+        proto = proto->getPrototypeOf();
     }
-    scope.result = Encode(false);
+    return Encode(false);
 }
 
-void ObjectPrototype::method_propertyIsEnumerable(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_propertyIsEnumerable(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedString p(scope, callData->argument(0), ScopedString::Convert);
-    CHECK_EXCEPTION();
-
-    ScopedObject o(scope, callData->thisObject, ScopedObject::Convert);
-    CHECK_EXCEPTION();
-    PropertyAttributes attrs;
-    o->getOwnProperty(p, &attrs);
-    scope.result = Encode(attrs.isEnumerable());
+    Scope scope(b);
+    ScopedPropertyKey p(scope, (argc ? argv[0] : Value::undefinedValue()).toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    ScopedObject o(scope, thisObject->toObject(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+    PropertyAttributes attrs = o->getOwnProperty(p);
+    return Encode(attrs.isEnumerable());
 }
 
-void ObjectPrototype::method_defineGetter(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_defineGetter(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc < 2)
+    Scope scope(b);
+    if (argc < 2)
         THROW_TYPE_ERROR();
 
-    ScopedFunctionObject f(scope, callData->argument(1));
+    ScopedFunctionObject f(scope, argv[1]);
     if (!f)
         THROW_TYPE_ERROR();
 
-    ScopedString prop(scope, callData->argument(0), ScopedString::Convert);
-    CHECK_EXCEPTION();
+    ScopedString prop(scope, argv[0], ScopedString::Convert);
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
-    ScopedObject o(scope, callData->thisObject);
+    ScopedObject o(scope, thisObject);
     if (!o) {
-        if (!callData->thisObject.isUndefined())
+        if (!thisObject->isUndefined())
             RETURN_UNDEFINED();
         o = scope.engine->globalObject;
     }
 
     ScopedProperty pd(scope);
     pd->value = f;
-    pd->set = Primitive::emptyValue();
-    o->__defineOwnProperty__(scope.engine, prop, pd, Attr_Accessor);
+    pd->set = Value::emptyValue();
+    bool ok = o->defineOwnProperty(prop->toPropertyKey(), pd, Attr_Accessor);
+    if (!ok)
+        THROW_TYPE_ERROR();
     RETURN_UNDEFINED();
 }
 
-void ObjectPrototype::method_defineSetter(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_defineSetter(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc < 2)
+    Scope scope(b);
+    if (argc < 2)
         THROW_TYPE_ERROR();
 
-    ScopedFunctionObject f(scope, callData->argument(1));
+    ScopedFunctionObject f(scope, argv[1]);
     if (!f)
         THROW_TYPE_ERROR();
 
-    ScopedString prop(scope, callData->argument(0), ScopedString::Convert);
-    CHECK_EXCEPTION();
+    ScopedString prop(scope, argv[0], ScopedString::Convert);
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
-    ScopedObject o(scope, callData->thisObject);
+    ScopedObject o(scope, thisObject);
     if (!o) {
-        if (!callData->thisObject.isUndefined())
+        if (!thisObject->isUndefined())
             RETURN_UNDEFINED();
         o = scope.engine->globalObject;
     }
 
     ScopedProperty pd(scope);
-    pd->value = Primitive::emptyValue();
+    pd->value = Value::emptyValue();
     pd->set = f;
-    o->__defineOwnProperty__(scope.engine, prop, pd, Attr_Accessor);
+    bool ok = o->defineOwnProperty(prop->toPropertyKey(), pd, Attr_Accessor);
+    if (!ok)
+        THROW_TYPE_ERROR();
     RETURN_UNDEFINED();
 }
 
-void ObjectPrototype::method_get_proto(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_get_proto(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    ScopedObject o(scope, callData->thisObject.as<Object>());
+    Scope scope(b);
+    ScopedObject o(scope, thisObject->as<Object>());
     if (!o)
         THROW_TYPE_ERROR();
 
-    scope.result = o->prototype();
+    return Encode(o->getPrototypeOf());
 }
 
-void ObjectPrototype::method_set_proto(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ObjectPrototype::method_set_proto(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject o(scope, callData->thisObject);
-    if (!o || !callData->argc)
+    Scope scope(b);
+    ScopedObject o(scope, thisObject);
+    if (!o || !argc || (!argv[0].isObject() && !argv[0].isNull()))
         THROW_TYPE_ERROR();
 
-    if (callData->args[0].isNull()) {
-        o->setPrototype(0);
-        RETURN_UNDEFINED();
-    }
-
-    ScopedObject p(scope, callData->args[0]);
-    bool ok = false;
-    if (!!p) {
-        if (o->prototype() == p->d()) {
-            ok = true;
-        } else if (o->isExtensible()) {
-            ok = o->setPrototype(p);
-        }
-    }
-    if (!ok) {
-        scope.result = scope.engine->throwTypeError(QStringLiteral("Cyclic __proto__ value"));
-        return;
-    }
+    const Object *p = argv[0].isNull() ? nullptr : static_cast<const Object *>(argv);
+    bool ok = o->setPrototypeOf(p);
+    if (!ok)
+        return scope.engine->throwTypeError(QStringLiteral("Could not change prototype."));
+    return Encode::undefined();
     RETURN_UNDEFINED();
 }
 
@@ -627,17 +815,17 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionEngine *engine, const Value
     }
 
     attrs->clear();
-    desc->value = Primitive::emptyValue();
-    desc->set = Primitive::emptyValue();
+    desc->value = Value::emptyValue();
+    desc->set = Value::emptyValue();
     ScopedValue tmp(scope);
 
-    if (o->hasProperty(engine->id_enumerable()))
+    if (o->hasProperty(engine->id_enumerable()->toPropertyKey()))
         attrs->setEnumerable((tmp = o->get(engine->id_enumerable()))->toBoolean());
 
-    if (o->hasProperty(engine->id_configurable()))
+    if (o->hasProperty(engine->id_configurable()->toPropertyKey()))
         attrs->setConfigurable((tmp = o->get(engine->id_configurable()))->toBoolean());
 
-    if (o->hasProperty(engine->id_get())) {
+    if (o->hasProperty(engine->id_get()->toPropertyKey())) {
         ScopedValue get(scope, o->get(engine->id_get()));
         FunctionObject *f = get->as<FunctionObject>();
         if (f || get->isUndefined()) {
@@ -649,7 +837,7 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionEngine *engine, const Value
         attrs->setType(PropertyAttributes::Accessor);
     }
 
-    if (o->hasProperty(engine->id_set())) {
+    if (o->hasProperty(engine->id_set()->toPropertyKey())) {
         ScopedValue set(scope, o->get(engine->id_set()));
         FunctionObject *f = set->as<FunctionObject>();
         if (f || set->isUndefined()) {
@@ -661,17 +849,15 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionEngine *engine, const Value
         attrs->setType(PropertyAttributes::Accessor);
     }
 
-    if (o->hasProperty(engine->id_writable())) {
+    if (o->hasProperty(engine->id_writable()->toPropertyKey())) {
         if (attrs->isAccessor()) {
             engine->throwTypeError();
             return;
         }
         attrs->setWritable((tmp = o->get(engine->id_writable()))->toBoolean());
-        // writable forces it to be a data descriptor
-        desc->value = Primitive::undefinedValue();
     }
 
-    if (o->hasProperty(engine->id_value())) {
+    if (o->hasProperty(engine->id_value()->toPropertyKey())) {
         if (attrs->isAccessor()) {
             engine->throwTypeError();
             return;
@@ -681,7 +867,7 @@ void ObjectPrototype::toPropertyDescriptor(ExecutionEngine *engine, const Value
     }
 
     if (attrs->isGeneric())
-        desc->value = Primitive::emptyValue();
+        desc->value = Value::emptyValue();
 }
 
 
@@ -695,29 +881,28 @@ ReturnedValue ObjectPrototype::fromPropertyDescriptor(ExecutionEngine *engine, c
     // is the standard built-in constructor with that name.
     ScopedObject o(scope, engine->newObject());
     ScopedString s(scope);
+    ScopedValue v(scope);
 
-    ScopedProperty pd(scope);
     if (attrs.isData()) {
-        pd->value = desc->value;
         s = engine->newString(QStringLiteral("value"));
-        o->__defineOwnProperty__(scope.engine, s, pd, Attr_Data);
-        pd->value = Primitive::fromBoolean(attrs.isWritable());
+        o->put(s, desc->value);
+        v = Value::fromBoolean(attrs.isWritable());
         s = engine->newString(QStringLiteral("writable"));
-        o->__defineOwnProperty__(scope.engine, s, pd, Attr_Data);
+        o->put(s, v);
     } else {
-        pd->value = desc->getter() ? desc->getter()->asReturnedValue() : Encode::undefined();
+        v = desc->getter() ? desc->getter()->asReturnedValue() : Encode::undefined();
         s = engine->newString(QStringLiteral("get"));
-        o->__defineOwnProperty__(scope.engine, s, pd, Attr_Data);
-        pd->value = desc->setter() ? desc->setter()->asReturnedValue() : Encode::undefined();
+        o->put(s, v);
+        v = desc->setter() ? desc->setter()->asReturnedValue() : Encode::undefined();
         s = engine->newString(QStringLiteral("set"));
-        o->__defineOwnProperty__(scope.engine, s, pd, Attr_Data);
+        o->put(s, v);
     }
-    pd->value = Primitive::fromBoolean(attrs.isEnumerable());
+    v = Value::fromBoolean(attrs.isEnumerable());
     s = engine->newString(QStringLiteral("enumerable"));
-    o->__defineOwnProperty__(scope.engine, s, pd, Attr_Data);
-    pd->value = Primitive::fromBoolean(attrs.isConfigurable());
+    o->put(s, v);
+    v = Value::fromBoolean(attrs.isConfigurable());
     s = engine->newString(QStringLiteral("configurable"));
-    o->__defineOwnProperty__(scope.engine, s, pd, Attr_Data);
+    o->put(s, v);
 
     return o.asReturnedValue();
 }
@@ -735,6 +920,8 @@ Heap::ArrayObject *ObjectPrototype::getOwnPropertyNames(ExecutionEngine *v4, con
             name = it.nextPropertyNameAsString();
             if (name->isNull())
                 break;
+            if (name->isSymbol())
+                continue;
             array->push_back(name);
         }
     }
diff --git a/src/qml/jsruntime/qv4objectproto_p.h b/src/qml/jsruntime/qv4objectproto_p.h
index 44b54267f3..e9515b5b68 100644
--- a/src/qml/jsruntime/qv4objectproto_p.h
+++ b/src/qml/jsruntime/qv4objectproto_p.h
@@ -70,41 +70,47 @@ struct ObjectCtor: FunctionObject
 {
     V4_OBJECT2(ObjectCtor, FunctionObject)
 
-    static void construct(const Managed *that, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *m, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct ObjectPrototype: Object
 {
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_getPrototypeOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getOwnPropertyDescriptor(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_getOwnPropertyNames(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_assign(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_create(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_defineProperty(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_defineProperties(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_seal(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_freeze(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_preventExtensions(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isSealed(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isFrozen(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isExtensible(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_keys(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_hasOwnProperty(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_isPrototypeOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_propertyIsEnumerable(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_defineGetter(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_defineSetter(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_get_proto(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_set_proto(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_assign(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_create(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_defineProperties(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_defineProperty(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_entries(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_freeze(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getOwnPropertyDescriptor(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getOwnPropertyDescriptors(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getOwnPropertyNames(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getOwnPropertySymbols(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getPrototypeOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_is(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isExtensible(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isFrozen(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isSealed(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_keys(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_preventExtensions(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_seal(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setPrototypeOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_values(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_hasOwnProperty(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isPrototypeOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_propertyIsEnumerable(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_defineGetter(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_defineSetter(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_get_proto(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set_proto(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
     static void toPropertyDescriptor(ExecutionEngine *engine, const Value &v, Property *desc, PropertyAttributes *attrs);
     static ReturnedValue fromPropertyDescriptor(ExecutionEngine *engine, const Property *desc, PropertyAttributes attrs);
diff --git a/src/qml/jsruntime/qv4persistent.cpp b/src/qml/jsruntime/qv4persistent.cpp
index 0b31c971f9..79c372348f 100644
--- a/src/qml/jsruntime/qv4persistent.cpp
+++ b/src/qml/jsruntime/qv4persistent.cpp
@@ -68,6 +68,22 @@ Page *getPage(Value *val) {
    return reinterpret_cast<Page *>(reinterpret_cast<quintptr>(val) & ~((quintptr)(WTF::pageSize() - 1)));
 }
 
+QML_NEARLY_ALWAYS_INLINE void insertInFront(PersistentValueStorage *storage, Page *p)
+{
+    p->header.next = reinterpret_cast<Page *>(storage->firstPage);
+    p->header.prev = reinterpret_cast<Page **>(&storage->firstPage);
+    if (p->header.next)
+        p->header.next->header.prev = &p->header.next;
+    storage->firstPage = p;
+}
+
+QML_NEARLY_ALWAYS_INLINE void unlink(Page *p)
+{
+    if (p->header.prev)
+        *p->header.prev = p->header.next;
+    if (p->header.next)
+        p->header.next->header.prev = p->header.prev;
+}
 
 Page *allocatePage(PersistentValueStorage *storage)
 {
@@ -78,18 +94,13 @@ Page *allocatePage(PersistentValueStorage *storage)
 
     p->header.engine = storage->engine;
     p->header.alloc = page;
-    p->header.next = reinterpret_cast<Page *>(storage->firstPage);
-    p->header.prev = reinterpret_cast<Page **>(&storage->firstPage);
     p->header.refCount = 0;
     p->header.freeList = 0;
-    if (p->header.next)
-        p->header.next->header.prev = &p->header.next;
+    insertInFront(storage, p);
     for (int i = 0; i < kEntriesPerPage - 1; ++i) {
-        p->values[i].setEmpty(i + 1);
+        p->values[i] = Encode(i + 1);
     }
-    p->values[kEntriesPerPage - 1].setEmpty(-1);
-
-    storage->firstPage = p;
+    p->values[kEntriesPerPage - 1] = Encode(-1);
 
     return p;
 }
@@ -161,7 +172,7 @@ Value &PersistentValueStorage::Iterator::operator *()
 
 PersistentValueStorage::PersistentValueStorage(ExecutionEngine *engine)
     : engine(engine),
-      firstPage(0)
+      firstPage(nullptr)
 {
 }
 
@@ -174,9 +185,9 @@ PersistentValueStorage::~PersistentValueStorage()
                 p->values[i] = Encode::undefined();
         }
         Page *n = p->header.next;
-        p->header.engine = 0;
-        p->header.prev = 0;
-        p->header.next = 0;
+        p->header.engine = nullptr;
+        p->header.prev = nullptr;
+        p->header.next = nullptr;
         Q_ASSERT(p->header.refCount);
         p = n;
     }
@@ -195,6 +206,12 @@ Value *PersistentValueStorage::allocate()
 
     Value *v = p->values + p->header.freeList;
     p->header.freeList = v->int_32();
+
+    if (p->header.freeList != -1 && p != firstPage) {
+        unlink(p);
+        insertInFront(this, p);
+    }
+
     ++p->header.refCount;
 
     v->setRawValue(Encode::undefined());
@@ -209,7 +226,7 @@ void PersistentValueStorage::free(Value *v)
 
     Page *p = getPage(v);
 
-    v->setEmpty(p->header.freeList);
+    *v = Encode(p->header.freeList);
     p->header.freeList = v - p->values;
     if (!--p->header.refCount)
         freePage(p);
@@ -237,16 +254,13 @@ ExecutionEngine *PersistentValueStorage::getEngine(Value *v)
 void PersistentValueStorage::freePage(void *page)
 {
     Page *p = static_cast<Page *>(page);
-    if (p->header.prev)
-        *p->header.prev = p->header.next;
-    if (p->header.next)
-        p->header.next->header.prev = p->header.prev;
+    unlink(p);
     p->header.alloc.deallocate();
 }
 
 
 PersistentValue::PersistentValue(const PersistentValue &other)
-    : val(0)
+    : val(nullptr)
 {
     if (other.val) {
         val = other.engine()->memoryManager->m_persistentValues->allocate();
@@ -267,7 +281,7 @@ PersistentValue::PersistentValue(ExecutionEngine *engine, ReturnedValue value)
 }
 
 PersistentValue::PersistentValue(ExecutionEngine *engine, Object *object)
-    : val(0)
+    : val(nullptr)
 {
     if (!object)
         return;
@@ -288,6 +302,10 @@ PersistentValue &PersistentValue::operator=(const PersistentValue &other)
             return *this;
         val = other.engine()->memoryManager->m_persistentValues->allocate();
     }
+    if (!other.val) {
+        *val = Encode::undefined();
+        return *this;
+    }
 
     Q_ASSERT(engine() == other.engine());
 
@@ -302,6 +320,10 @@ PersistentValue &PersistentValue::operator=(const WeakValue &other)
             return *this;
         val = other.engine()->memoryManager->m_persistentValues->allocate();
     }
+    if (!other.valueRef()) {
+        *val = Encode::undefined();
+        return *this;
+    }
 
     Q_ASSERT(engine() == other.engine());
 
@@ -344,7 +366,7 @@ void PersistentValue::set(ExecutionEngine *engine, Heap::Base *obj)
 }
 
 WeakValue::WeakValue(const WeakValue &other)
-    : val(0)
+    : val(nullptr)
 {
     if (other.val) {
         allocVal(other.engine());
@@ -365,6 +387,10 @@ WeakValue &WeakValue::operator=(const WeakValue &other)
             return *this;
         allocVal(other.engine());
     }
+    if (!other.val) {
+        *val = Encode::undefined();
+        return *this;
+    }
 
     Q_ASSERT(engine() == other.engine());
 
@@ -404,6 +430,6 @@ void WeakValue::free()
         PersistentValueStorage::free(val);
     }
 
-    val = 0;
+    val = nullptr;
 }
 
diff --git a/src/qml/jsruntime/qv4persistent_p.h b/src/qml/jsruntime/qv4persistent_p.h
index 1f838f5531..55e8eefcb7 100644
--- a/src/qml/jsruntime/qv4persistent_p.h
+++ b/src/qml/jsruntime/qv4persistent_p.h
@@ -81,7 +81,7 @@ struct Q_QML_EXPORT PersistentValueStorage
         Value &operator *();
     };
     Iterator begin() { return Iterator(firstPage, 0); }
-    Iterator end() { return Iterator(0, 0); }
+    Iterator end() { return Iterator(nullptr, 0); }
 
     static ExecutionEngine *getEngine(Value *v);
 
@@ -94,7 +94,7 @@ private:
 class Q_QML_EXPORT PersistentValue
 {
 public:
-    PersistentValue() : val(0) {}
+    PersistentValue() {}
     PersistentValue(const PersistentValue &other);
     PersistentValue &operator=(const PersistentValue &other);
     PersistentValue &operator=(const WeakValue &other);
@@ -117,19 +117,19 @@ public:
     }
     Managed *asManaged() const {
         if (!val)
-            return 0;
+            return nullptr;
         return val->managed();
     }
     template<typename T>
     T *as() const {
         if (!val)
-            return 0;
+            return nullptr;
         return val->as<T>();
     }
 
     ExecutionEngine *engine() const {
         if (!val)
-            return 0;
+            return nullptr;
         return PersistentValueStorage::getEngine(val);
     }
 
@@ -137,18 +137,18 @@ public:
     bool isNullOrUndefined() const { return !val || val->isNullOrUndefined(); }
     void clear() {
         PersistentValueStorage::free(val);
-        val = 0;
+        val = nullptr;
     }
     bool isEmpty() { return !val; }
 
 private:
-    Value *val;
+    Value *val = nullptr;
 };
 
 class Q_QML_EXPORT WeakValue
 {
 public:
-    WeakValue() : val(0) {}
+    WeakValue() {}
     WeakValue(const WeakValue &other);
     WeakValue(ExecutionEngine *engine, const Value &value);
     WeakValue &operator=(const WeakValue &other);
@@ -183,19 +183,19 @@ public:
     }
     Managed *asManaged() const {
         if (!val)
-            return 0;
+            return nullptr;
         return val->managed();
     }
     template <typename T>
     T *as() const {
         if (!val)
-            return 0;
+            return nullptr;
         return val->as<T>();
     }
 
     ExecutionEngine *engine() const {
         if (!val)
-            return 0;
+            return nullptr;
         return PersistentValueStorage::getEngine(val);
     }
 
@@ -206,7 +206,7 @@ public:
     void markOnce(MarkStack *markStack);
 
 private:
-    Value *val;
+    Value *val = nullptr;
 
 private:
     Q_NEVER_INLINE void allocVal(ExecutionEngine *engine);
diff --git a/src/qml/jsruntime/qv4profiling.cpp b/src/qml/jsruntime/qv4profiling.cpp
index bedcb5b164..b337243204 100644
--- a/src/qml/jsruntime/qv4profiling.cpp
+++ b/src/qml/jsruntime/qv4profiling.cpp
@@ -78,7 +78,7 @@ Profiler::Profiler(QV4::ExecutionEngine *engine) : featuresEnabled(0), m_engine(
 void Profiler::stopProfiling()
 {
     featuresEnabled = 0;
-    reportData(true);
+    reportData();
     m_sentLocations.clear();
 }
 
@@ -89,7 +89,7 @@ bool operator<(const FunctionCall &call1, const FunctionCall &call2)
             (call1.m_end == call2.m_end && call1.m_function < call2.m_function)));
 }
 
-void Profiler::reportData(bool trackLocations)
+void Profiler::reportData()
 {
     std::sort(m_data.begin(), m_data.end());
     QVector<FunctionCallProperties> properties;
@@ -100,12 +100,11 @@ void Profiler::reportData(bool trackLocations)
         properties.append(call.properties());
         Function *function = call.function();
         SentMarker &marker = m_sentLocations[reinterpret_cast<quintptr>(function)];
-        if (!trackLocations || !marker.isValid()) {
+        if (!marker.isValid()) {
             FunctionLocation &location = locations[properties.constLast().id];
             if (!location.isValid())
                 location = call.resolveLocation();
-            if (trackLocations)
-                marker.setFunction(function);
+            marker.setFunction(function);
         }
     }
 
@@ -120,7 +119,8 @@ void Profiler::startProfiling(quint64 features)
         if (features & (1 << FeatureMemoryAllocation)) {
             qint64 timestamp = m_timer.nsecsElapsed();
             MemoryAllocationProperties heap = {timestamp,
-                                               (qint64)m_engine->memoryManager->getAllocatedMem(),
+                                               (qint64)m_engine->memoryManager->getAllocatedMem() -
+                                               (qint64)m_engine->memoryManager->getLargeItemsMem(),
                                                HeapPage};
             m_memory_data.append(heap);
             MemoryAllocationProperties small = {timestamp,
diff --git a/src/qml/jsruntime/qv4profiling_p.h b/src/qml/jsruntime/qv4profiling_p.h
index 9de597ad0e..8461384e9a 100644
--- a/src/qml/jsruntime/qv4profiling_p.h
+++ b/src/qml/jsruntime/qv4profiling_p.h
@@ -57,17 +57,20 @@
 
 #include <QElapsedTimer>
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
 
 #define Q_V4_PROFILE_ALLOC(engine, size, type) (!engine)
 #define Q_V4_PROFILE_DEALLOC(engine, size, type) (!engine)
-#define Q_V4_PROFILE(engine, function) (function->code(engine, function->codeData))
 
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 namespace Profiling {
 class Profiler {};
+class FunctionCallProfiler {
+public:
+    FunctionCallProfiler(ExecutionEngine *, Function *) {}
+};
 }
 }
 
@@ -85,12 +88,6 @@ QT_END_NAMESPACE
             (engine->profiler()->featuresEnabled & (1 << Profiling::FeatureMemoryAllocation)) ?\
         engine->profiler()->trackDealloc(size, type) : false)
 
-#define Q_V4_PROFILE(engine, function)\
-    (Q_UNLIKELY(engine->profiler()) &&\
-            (engine->profiler()->featuresEnabled & (1 << Profiling::FeatureFunctionCall)) ?\
-        Profiling::FunctionCallProfiler::profileCall(engine->profiler(), engine, function) :\
-        function->code(engine, function->codeData))
-
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
@@ -142,7 +139,7 @@ struct MemoryAllocationProperties {
 class FunctionCall {
 public:
 
-    FunctionCall() : m_function(0), m_start(0), m_end(0)
+    FunctionCall() : m_function(nullptr), m_start(0), m_end(0)
     { Q_ASSERT_X(false, Q_FUNC_INFO, "Cannot construct a function call without function"); }
 
     FunctionCall(Function *function, qint64 start, qint64 end) :
@@ -230,23 +227,31 @@ public:
 
     bool trackAlloc(size_t size, MemoryType type)
     {
-        MemoryAllocationProperties allocation = {m_timer.nsecsElapsed(), (qint64)size, type};
-        m_memory_data.append(allocation);
-        return true;
+        if (size) {
+            MemoryAllocationProperties allocation = {m_timer.nsecsElapsed(), (qint64)size, type};
+            m_memory_data.append(allocation);
+            return true;
+        } else {
+            return false;
+        }
     }
 
     bool trackDealloc(size_t size, MemoryType type)
     {
-        MemoryAllocationProperties allocation = {m_timer.nsecsElapsed(), -(qint64)size, type};
-        m_memory_data.append(allocation);
-        return true;
+        if (size) {
+            MemoryAllocationProperties allocation = {m_timer.nsecsElapsed(), -(qint64)size, type};
+            m_memory_data.append(allocation);
+            return true;
+        } else {
+            return false;
+        }
     }
 
     quint64 featuresEnabled;
 
     void stopProfiling();
     void startProfiling(quint64 features);
-    void reportData(bool trackLocations);
+    void reportData();
     void setTimer(const QElapsedTimer &timer) { m_timer = timer; }
 
 signals:
@@ -270,19 +275,21 @@ public:
 
     // It's enough to ref() the function in the destructor as it will probably not disappear while
     // it's executing ...
-    FunctionCallProfiler(Profiler *profiler, Function *function) :
-        profiler(profiler), function(function), startTime(profiler->m_timer.nsecsElapsed())
-    {}
-
-    ~FunctionCallProfiler()
+    FunctionCallProfiler(ExecutionEngine *engine, Function *f)
+        : profiler(nullptr)
     {
-        profiler->m_data.append(FunctionCall(function, startTime, profiler->m_timer.nsecsElapsed()));
+        Profiler *p = engine->profiler();
+        if (Q_UNLIKELY(p) && (p->featuresEnabled & (1 << Profiling::FeatureFunctionCall))) {
+            profiler = p;
+            function = f;
+            startTime = profiler->m_timer.nsecsElapsed();
+        }
     }
 
-    static ReturnedValue profileCall(Profiler *profiler, ExecutionEngine *engine, Function *function)
+    ~FunctionCallProfiler()
     {
-        FunctionCallProfiler callProfiler(profiler, function);
-        return function->code(engine, function->codeData);
+        if (profiler)
+            profiler->m_data.append(FunctionCall(function, startTime, profiler->m_timer.nsecsElapsed()));
     }
 
     Profiler *profiler;
@@ -305,6 +312,6 @@ Q_DECLARE_METATYPE(QV4::Profiling::FunctionLocationHash)
 Q_DECLARE_METATYPE(QVector<QV4::Profiling::FunctionCallProperties>)
 Q_DECLARE_METATYPE(QVector<QV4::Profiling::MemoryAllocationProperties>)
 
-#endif // QT_NO_QML_DEBUGGER
+#endif // QT_CONFIG(qml_debug)
 
 #endif // QV4PROFILING_H
diff --git a/src/qml/jsruntime/qv4promiseobject.cpp b/src/qml/jsruntime/qv4promiseobject.cpp
new file mode 100644
index 0000000000..b32e227b58
--- /dev/null
+++ b/src/qml/jsruntime/qv4promiseobject.cpp
@@ -0,0 +1,982 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <QCoreApplication>
+
+#include <private/qv4promiseobject_p.h>
+#include <private/qv4symbol_p.h>
+#include "qv4jscall_p.h"
+
+using namespace QV4;
+using namespace QV4::Promise;
+
+DEFINE_OBJECT_VTABLE(PromiseReaction);
+DEFINE_OBJECT_VTABLE(PromiseCtor);
+DEFINE_OBJECT_VTABLE(PromiseObject);
+DEFINE_OBJECT_VTABLE(PromiseCapability);
+DEFINE_OBJECT_VTABLE(PromiseExecutionState);
+
+DEFINE_OBJECT_VTABLE(CapabilitiesExecutorWrapper);
+DEFINE_OBJECT_VTABLE(ResolveElementWrapper);
+DEFINE_OBJECT_VTABLE(ResolveWrapper);
+DEFINE_OBJECT_VTABLE(RejectWrapper);
+
+
+namespace {
+
+bool isPromise(const Value &object)
+{
+    return object.as<PromiseObject>() != nullptr;
+}
+
+bool isCallable(const Value &object)
+{
+    return object.as<FunctionObject>() != nullptr;
+}
+
+void insertIdLengthTag(Scope& scope, Heap::FunctionObject* function)
+{
+    ScopedFunctionObject scopedFunction(scope, function);
+    scopedFunction->insertMember(scope.engine->id_length(), Primitive::fromInt32(1), Attr_NotWritable|Attr_NotEnumerable);
+}
+
+void dropException(QV4::ExecutionEngine* e)
+{
+    e->hasException = false;
+}
+}
+
+QT_BEGIN_NAMESPACE
+namespace QV4 {
+namespace Promise {
+
+const int PROMISE_REACTION_EVENT = QEvent::registerEventType();
+
+struct ReactionEvent : public QEvent
+{
+    ReactionEvent(ExecutionEngine *e, const Value *reaction_, const Value *resolution_)
+            : QEvent(QEvent::Type(PROMISE_REACTION_EVENT)),
+              reaction{e, *reaction_},
+              resolution{e, *resolution_}
+    {}
+
+    QV4::PersistentValue reaction;
+    QV4::PersistentValue resolution;
+};
+
+} // namespace Promise
+} // namespace QV4
+QT_END_NAMESPACE
+
+ReactionHandler::ReactionHandler(QObject *parent)
+    : QObject(parent)
+{}
+
+ReactionHandler::~ReactionHandler()
+{}
+
+void ReactionHandler::addReaction(ExecutionEngine *e, const Value *reaction, const Value *value)
+{
+    QCoreApplication::postEvent(this, new ReactionEvent(e, reaction, value));
+}
+
+void ReactionHandler::customEvent(QEvent *event)
+{
+    if (event)
+    {
+        const int type = event->type();
+        if (type == PROMISE_REACTION_EVENT)
+            executeReaction(static_cast<ReactionEvent*>(event));
+    }
+}
+
+void ReactionHandler::executeReaction(ReactionEvent *event)
+{
+    Scope scope(event->reaction.engine());
+
+    Scoped<QV4::PromiseReaction> ro(scope, event->reaction.as<QV4::PromiseReaction>());
+    Scoped<QV4::PromiseCapability> capability(scope, ro->d()->capability);
+
+    ScopedValue resolution(scope, event->resolution.value());
+    ScopedValue promise(scope, capability->d()->promise);
+
+    if (ro->d()->type == Heap::PromiseReaction::Function) {
+        ScopedFunctionObject handler(scope, ro->d()->handler.as<QV4::FunctionObject>());
+        ScopedValue result(scope, handler->call(promise, resolution, 1));
+
+        ScopedFunctionObject reaction(scope);
+        if (scope.hasException()) {
+            reaction = capability->d()->reject.as<QV4::FunctionObject>();
+        } else {
+            reaction = capability->d()->resolve.as<QV4::FunctionObject>();
+        }
+
+        reaction->call(promise, result, 1);
+    } else {
+        ScopedFunctionObject reaction(scope);
+        if (ro->d()->type == Heap::PromiseReaction::Identity) {
+            reaction = capability->d()->resolve.as<QV4::FunctionObject>();
+        } else {
+            reaction = capability->d()->reject.as<QV4::FunctionObject>();
+        }
+
+        reaction->call(promise, resolution, 1);
+    }
+}
+
+namespace {
+
+class FunctionBuilder {
+public:
+    static Heap::FunctionObject *makeResolveFunction(ExecutionEngine* e, QV4::Heap::PromiseObject *promise) {
+        Scope scope(e);
+        Scoped<QV4::ResolveWrapper> resolveWrapper(scope, e->memoryManager->allocate<QV4::ResolveWrapper>());
+
+        insertIdLengthTag(scope, resolveWrapper->d());
+        resolveWrapper->d()->promise.set(e, promise);
+
+        return resolveWrapper->d();
+    }
+
+    static Heap::FunctionObject *makeRejectFunction(ExecutionEngine* e, QV4::Heap::PromiseObject *promise) {
+        Scope scope(e);
+        Scoped<QV4::RejectWrapper> rejectWrapper(scope, e->memoryManager->allocate<QV4::RejectWrapper>());
+
+        insertIdLengthTag(scope, rejectWrapper->d());
+        rejectWrapper->d()->promise.set(e, promise);
+
+        return rejectWrapper->d();
+    }
+
+    static Heap::FunctionObject *makeResolveElementFunction(ExecutionEngine* e, uint index, Heap::PromiseExecutionState *executionState)
+    {
+        Scope scope(e);
+        Scoped<QV4::ResolveElementWrapper> resolveElementWrapper(scope, e->memoryManager->allocate<QV4::ResolveElementWrapper>());
+
+        resolveElementWrapper->d()->index = index;
+        resolveElementWrapper->d()->alreadyResolved = false;
+        resolveElementWrapper->d()->state.set(e, executionState);
+
+        insertIdLengthTag(scope, resolveElementWrapper->d());
+
+        return resolveElementWrapper->d();
+    }
+};
+
+}
+
+void Heap::PromiseObject::setState(PromiseObject::State state)
+{
+    this->state = state;
+}
+
+bool Heap::PromiseObject::isSettled() const
+{
+    return (state != Pending);
+}
+
+bool Heap::PromiseObject::isPending() const
+{
+    return (state == Pending);
+}
+
+bool Heap::PromiseObject::isFulfilled() const
+{
+    return (state == Fulfilled);
+}
+
+bool Heap::PromiseObject::isRejected() const
+{
+    return (state == Rejected);
+}
+
+void Heap::PromiseObject::triggerFullfillReactions(ExecutionEngine *e)
+{
+    Scope scope(e);
+    ScopedArrayObject a(scope, fulfillReactions);
+    if (a->arrayData()) {
+        Scoped<QV4::ArrayData> ad(scope, a->arrayData());
+        const uint sz = ad->length();
+        ScopedValue value(scope, resolution);
+        for (uint i = 0; i < sz; i++) {
+            Scoped<QV4::PromiseReaction> r(scope, ad->get(i));
+            r->d()->triggerWithValue(scope.engine, value);
+        }
+    }
+}
+
+void Heap::PromiseObject::triggerRejectReactions(ExecutionEngine *e)
+{
+    Scope scope(e);
+    ScopedArrayObject a(scope, rejectReactions);
+    if (a->arrayData()) {
+        Scoped<QV4::ArrayData> ad(scope, a->arrayData());
+        const uint sz = ad->d()->length();
+        ScopedValue value(scope, resolution);
+        for (uint i = 0; i < sz; i++) {
+            Scoped<QV4::PromiseReaction> r(scope, ad->d()->get(i));
+            r->d()->triggerWithValue(scope.engine, value);
+        }
+    }
+}
+
+Heap::PromiseReaction *Heap::PromiseReaction::createFulfillReaction(ExecutionEngine* e,
+    const QV4::PromiseCapability *capability, const QV4::FunctionObject *onFulfilled)
+{
+    Scope scope(e);
+    Scoped<QV4::PromiseReaction> fulfillReaction(scope, e->memoryManager->allocate<QV4::PromiseReaction>());
+    fulfillReaction->d()->capability.set(e, capability->d());
+
+    if (onFulfilled) {
+        QV4::ScopedFunctionObject scopedFullfillReaction(scope, onFulfilled);
+        if (!scopedFullfillReaction) {
+            fulfillReaction->d()->type = PromiseReaction::Identity;
+        } else {
+            fulfillReaction->d()->type = PromiseReaction::Function;
+            fulfillReaction->d()->handler.set(e, scopedFullfillReaction);
+        }
+    } else {
+        fulfillReaction->d()->type = PromiseReaction::Identity;
+    }
+
+    return fulfillReaction->d();
+}
+
+Heap::PromiseReaction *Heap::PromiseReaction::createRejectReaction(ExecutionEngine* e,
+    const QV4::PromiseCapability *capability, const QV4::FunctionObject *onRejected)
+{
+    Scope scope(e);
+    Scoped<QV4::PromiseReaction> rejectReaction(scope, e->memoryManager->allocate<QV4::PromiseReaction>());
+    rejectReaction->d()->capability.set(e, capability->d());
+
+    if (onRejected) {
+        ScopedFunctionObject scopedRejectReaction(scope, onRejected);
+        if (!scopedRejectReaction) {
+            rejectReaction->d()->type = PromiseReaction::Thrower;
+        } else {
+            rejectReaction->d()->type = PromiseReaction::Function;
+            rejectReaction->d()->handler.set(e, scopedRejectReaction);
+        }
+    } else {
+        rejectReaction->d()->type = PromiseReaction::Thrower;
+    }
+
+    return rejectReaction->d();
+}
+
+void Heap::PromiseReaction::triggerWithValue(ExecutionEngine *e, const Value *value)
+{
+    Scope scope(e);
+    auto handler =  e->getPromiseReactionHandler();
+    ScopedValue reaction(scope, Value::fromHeapObject(this));
+    handler->addReaction(e, reaction, value);
+}
+
+void Heap::PromiseCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("Promise"));
+}
+
+void Heap::PromiseObject::init(ExecutionEngine *e)
+{
+    Heap::Object::init();
+
+    {
+        Heap::ArrayObject* a = e->newArrayObject();
+        fulfillReactions.set(e, a);
+    }
+
+    {
+        Heap::ArrayObject* a = e->newArrayObject();
+        rejectReactions.set(e, a);
+    }
+}
+
+void Heap::CapabilitiesExecutorWrapper::init()
+{
+    Heap::FunctionObject::init();
+}
+
+void Heap::CapabilitiesExecutorWrapper::destroy()
+{
+    Heap::FunctionObject::destroy();
+}
+
+void Heap::PromiseExecutionState::init()
+{
+    index = 0;
+    remainingElementCount = 0;
+}
+
+void Heap::ResolveElementWrapper::init()
+{
+    index = 0;
+    alreadyResolved = false;
+
+    Heap::FunctionObject::init();
+}
+
+void Heap::ResolveWrapper::init()
+{
+    alreadyResolved = false;
+    Heap::FunctionObject::init();
+}
+
+void Heap::RejectWrapper::init()
+{
+    alreadyResolved = false;
+    Heap::FunctionObject::init();
+}
+
+
+ReturnedValue PromiseCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    Scope scope(f);
+
+    if (argc != 1)
+        THROW_TYPE_ERROR();
+
+    ScopedFunctionObject executor(scope, argv[0].as<const FunctionObject>());
+    if (!executor)
+        THROW_TYPE_ERROR();
+
+    Scoped<PromiseObject> a(scope, scope.engine->newPromiseObject());
+    if (scope.engine->hasException)
+        return Encode::undefined();
+
+    a->d()->state = Heap::PromiseObject::Pending;
+
+    ScopedFunctionObject resolve(scope, FunctionBuilder::makeResolveFunction(scope.engine, a->d()));
+    ScopedFunctionObject reject(scope, FunctionBuilder::makeRejectFunction(scope.engine, a->d()));
+
+    JSCallData jsCallData(scope, 2);
+    jsCallData->args[0] = resolve;
+    jsCallData->args[1] = reject;
+    jsCallData->thisObject = a;
+
+    executor->call(jsCallData);
+
+    if (scope.engine->hasException) {
+        a->d()->state = Heap::PromiseObject::Rejected;
+        a->d()->resolution.set(scope.engine, Value::fromReturnedValue(scope.engine->catchException()));
+    }
+
+    if (newTarget)
+        a->setProtoFromNewTarget(newTarget);
+
+    return a->asReturnedValue();
+}
+
+ReturnedValue PromiseCtor::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
+{
+    Scope scope(f);
+    THROW_TYPE_ERROR();
+}
+
+ReturnedValue PromiseCtor::method_resolve(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ExecutionEngine* e = scope.engine;
+    if (!thisObject || !thisObject->isObject())
+        THROW_TYPE_ERROR();
+
+    ScopedValue argument(scope);
+    if (argc < 1) {
+        argument = Encode::undefined();
+    } else {
+        argument = argv[0];
+    }
+
+    if (isPromise(argument) && argument->isObject()) {
+        ScopedObject so(scope, thisObject);
+        ScopedObject constructor(scope, argument->objectValue()->get(e->id_constructor()));
+        if (so->d() == constructor->d())
+            return argument->asReturnedValue();
+    }
+
+    Scoped<PromiseCapability> capability(scope, e->memoryManager->allocate<QV4::PromiseCapability>());
+
+    ScopedObject newPromise(scope, e->newPromiseObject(thisObject->as<const FunctionObject>(), capability));
+    if (!newPromise || !isCallable(capability->d()->resolve) || !isCallable(capability->d()->reject))
+        THROW_TYPE_ERROR();
+
+    ScopedValue undefined(scope, Value::undefinedValue());
+    ScopedFunctionObject resolve(scope, capability->d()->resolve);
+    resolve->call(undefined, argument, 1);
+
+    return newPromise.asReturnedValue();
+}
+
+ReturnedValue PromiseCtor::method_reject(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ExecutionEngine *e = scope.engine;
+
+    if (!thisObject || !thisObject->isObject())
+        THROW_TYPE_ERROR();
+
+    ScopedValue argument(scope);
+    if (argc < 1) {
+        argument = Encode::undefined();
+    } else {
+        argument = argv[0];
+    }
+
+    Scoped<PromiseCapability> capability(scope, e->memoryManager->allocate<QV4::PromiseCapability>());
+
+    ScopedObject newPromise(scope, e->newPromiseObject(thisObject->as<const FunctionObject>(), capability));
+    if (!newPromise || !isCallable(capability->d()->resolve) || !isCallable(capability->d()->reject))
+        THROW_TYPE_ERROR();
+
+    ScopedValue undefined(scope, Value::undefinedValue());
+    ScopedFunctionObject reject(scope, capability->d()->reject.as<const FunctionObject>());
+    reject->call(undefined, argument, 1);
+
+    return newPromise.asReturnedValue();
+}
+
+ReturnedValue PromiseCtor::method_all(const FunctionObject *f, const Value *thisObject, const Value *argv, int)
+{
+    Scope scope(f);
+    ExecutionEngine* e = scope.engine;
+
+    if (!thisObject || !thisObject->isObject())
+        THROW_TYPE_ERROR();
+
+    ScopedString resolveName(scope, e->newIdentifier(QStringLiteral("resolve")));
+    ScopedString thenName(scope, e->newIdentifier(QStringLiteral("then")));
+
+    Scoped<PromiseCapability> capability(scope, e->memoryManager->allocate<QV4::PromiseCapability>());
+
+    ScopedObject newPromise(scope, e->newPromiseObject(thisObject->as<FunctionObject>(), capability));
+    if (!newPromise || !isCallable(capability->d()->resolve) || !isCallable(capability->d()->reject)) {
+        if (scope.hasException()) {
+            return e->exceptionValue->asReturnedValue();
+        } else {
+            THROW_TYPE_ERROR();
+        }
+    }
+    capability->d()->promise.set(e, newPromise);
+
+    ScopedFunctionObject reject(scope, capability->d()->reject);
+
+    ScopedObject itemsObject(scope, argv);
+    ScopedObject iteratorObject(scope, Runtime::GetIterator::call(e, itemsObject, true));
+    if (!iteratorObject || scope.hasException()) {
+        ScopedObject error(scope);
+        if (scope.hasException()) {
+            error = e->exceptionValue;
+            dropException(e);
+        } else {
+            error = e->newTypeErrorObject(QStringLiteral("Type error"));
+        }
+        reject->call(newPromise, error, 1);
+        return newPromise.asReturnedValue();
+    }
+
+    Scoped<QV4::PromiseExecutionState> executionState(scope, e->memoryManager->allocate<QV4::PromiseExecutionState>());
+    executionState->d()->remainingElementCount = 1;
+    executionState->d()->capability.set(e, capability);
+
+    Scoped<QV4::ArrayObject> results(scope, e->newArrayObject(0));
+    executionState->d()->values.set(e, results);
+
+    ScopedValue doneValue(scope);
+    uint index = 0;
+    for (;;) {
+        Scope scope(e);
+        ScopedValue nextValue(scope);
+        doneValue = Value::fromReturnedValue(Runtime::IteratorNext::call(e, iteratorObject, nextValue));
+
+        if (doneValue->toBoolean())
+            break;
+
+        ScopedObject nextObject(scope);
+        if (nextValue->isObject()) {
+            nextObject = *nextValue;
+        } else if (nextValue->isBoolean()) {
+            nextObject = e->newBooleanObject(nextValue->toBoolean());
+        } else if (nextValue->isInteger() || nextValue->isDouble()) {
+            nextObject = e->newNumberObject(nextValue->toInteger());
+        } else if (nextValue->isString()) {
+            ScopedString scopedString(scope, nextValue->toString(scope.engine));
+            nextObject = e->newStringObject(scopedString);
+        }
+
+        ScopedFunctionObject resolve(scope, thisObject->as<Object>()->get(resolveName));
+        if (!resolve || scope.hasException()) {
+            ScopedValue completion(scope);
+            if (!scope.hasException()) {
+                completion = e->newTypeErrorObject(QStringLiteral("Type error"));
+            } else {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+
+            if (!doneValue->toBoolean())
+                completion = Runtime::IteratorClose::call(e, iteratorObject, doneValue);
+
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        ScopedObject nextPromise(scope, Value::fromReturnedValue(resolve->call(thisObject, nextValue, 1)));
+        if (!nextPromise || scope.hasException()) {
+            ScopedValue completion(scope, Runtime::IteratorClose::call(e, iteratorObject, doneValue));
+            if (scope.hasException()) {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        executionState->d()->remainingElementCount++;
+
+        ScopedFunctionObject then(scope, nextPromise->get(thenName));
+        if (!then || scope.hasException()) {
+            ScopedValue completion(scope);
+            if (!scope.hasException()) {
+                completion = e->newTypeErrorObject(QStringLiteral("Type error"));
+            } else {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+
+            if (!doneValue->toBoolean())
+                completion = Runtime::IteratorClose::call(scope.engine, iteratorObject, doneValue);
+
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        ScopedFunctionObject resolveElement(scope, FunctionBuilder::makeResolveElementFunction(e, index, executionState->d()));
+
+        JSCallData jsCallData(scope, 2);
+        jsCallData->args[0] = resolveElement;
+        jsCallData->args[1] = reject;
+        jsCallData->thisObject = nextPromise;
+
+        then->call(jsCallData);
+        if (scope.hasException()) {
+            ScopedValue completion(scope, e->exceptionValue->asReturnedValue());
+            dropException(e);
+
+            if (!doneValue->toBoolean())
+                completion = Runtime::IteratorClose::call(scope.engine, iteratorObject, doneValue);
+
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        index++;
+    }
+
+    // empty list
+    executionState->d()->remainingElementCount--;
+    if (executionState->d()->remainingElementCount == 0) {
+        const FunctionObject *resolve = capability->d()->resolve.as<FunctionObject>();
+        if (!resolve)
+            THROW_TYPE_ERROR();
+
+        ScopedValue values(scope, executionState->d()->values);
+        resolve->call(newPromise, values, 1);
+        if (scope.hasException()) {
+            dropException(e);
+            reject->call(newPromise, scope.engine->exceptionValue, 1);
+        }
+    }
+
+    return newPromise.asReturnedValue();
+}
+
+ReturnedValue PromiseCtor::method_race(const FunctionObject *f, const Value *thisObject, const Value *argv, int)
+{
+    Scope scope(f);
+    ExecutionEngine* e = scope.engine;
+
+    if (!thisObject || !thisObject->isObject())
+        THROW_TYPE_ERROR();
+
+    ScopedString resolveName(scope, e->newIdentifier(QStringLiteral("resolve")));
+    ScopedString thenName(scope, e->newIdentifier(QStringLiteral("then")));
+
+    Scoped<PromiseCapability> capability(scope, scope.engine->memoryManager->allocate<QV4::PromiseCapability>());
+
+    ScopedObject newPromise(scope, e->newPromiseObject(thisObject->as<FunctionObject>(), capability));
+    if (!newPromise || !isCallable(capability->d()->resolve) || !isCallable(capability->d()->reject))
+        THROW_TYPE_ERROR();
+    capability->d()->promise.set(scope.engine, newPromise);
+
+    ScopedFunctionObject reject(scope, capability->d()->reject);
+
+    ScopedObject itemsObject(scope, argv);
+    ScopedObject iteratorObject(scope, Runtime::GetIterator::call(e, itemsObject, true));
+    if (!iteratorObject) {
+        ScopedObject error(scope, e->newTypeErrorObject(QStringLiteral("Type error")));
+        reject->call(newPromise, error, 1);
+        return newPromise.asReturnedValue();
+    }
+
+    ScopedValue doneValue(scope);
+    for (;;) {
+        Scope scope(e);
+        ScopedValue nextValue(scope);
+        doneValue = Value::fromReturnedValue(Runtime::IteratorNext::call(e, iteratorObject, nextValue));
+
+        if (scope.hasException()) {
+            ScopedValue completion(scope, Runtime::IteratorClose::call(e, iteratorObject, doneValue));
+            if (scope.hasException()) {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        if (doneValue->toBoolean())
+            break;
+
+        ScopedObject nextObject(scope);
+        if (nextValue->isObject()) {
+            nextObject = *nextValue;
+        } else if (nextValue->isBoolean()) {
+            nextObject = scope.engine->newBooleanObject(nextValue->toBoolean());
+        } else if (nextValue->isInteger() || nextValue->isDouble()) {
+            nextObject = scope.engine->newNumberObject(nextValue->toInteger());
+        } else if (nextValue->isString()) {
+            ScopedString scopedString(scope, nextValue->toString(scope.engine));
+            nextObject = scope.engine->newStringObject(scopedString);
+        }
+
+       ScopedFunctionObject resolve(scope, thisObject->as<FunctionObject>()->get(resolveName));
+        if (!resolve || scope.hasException()) {
+            ScopedValue completion(scope);
+            if (!scope.hasException()) {
+                completion = e->newTypeErrorObject(QStringLiteral("Type error"));
+            } else {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+
+            if (!doneValue->toBoolean())
+                completion = Runtime::IteratorClose::call(e, iteratorObject, doneValue);
+
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        ScopedObject nextPromise(scope, Value::fromReturnedValue(resolve->call(thisObject, nextValue, 1)));
+        if (!nextPromise || scope.hasException()) {
+            ScopedValue completion(scope, Runtime::IteratorClose::call(e, iteratorObject, doneValue));
+            if (scope.hasException()) {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        ScopedFunctionObject then(scope, nextPromise->get(thenName));
+        if (!then || scope.hasException()) {
+            ScopedValue completion(scope);
+            if (!scope.hasException()) {
+                completion = e->newTypeErrorObject(QStringLiteral("Type error"));
+            } else {
+                completion = e->exceptionValue->asReturnedValue();
+                dropException(e);
+            }
+
+            if (!doneValue->toBoolean())
+                completion = Runtime::IteratorClose::call(e, iteratorObject, doneValue);
+
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+
+        ScopedFunctionObject resolveOriginalPromise(scope, capability->d()->resolve);
+
+        JSCallData jsCallData(scope, 2);
+        jsCallData->args[0] = resolveOriginalPromise;
+        jsCallData->args[1] = reject;
+        jsCallData->thisObject = nextPromise;
+
+        then->call(jsCallData);
+        if (scope.hasException()) {
+            ScopedValue completion(scope, e->exceptionValue->asReturnedValue());
+            dropException(e);
+
+            if (!doneValue->toBoolean())
+                completion = Runtime::IteratorClose::call(e, iteratorObject, doneValue);
+
+            reject->call(newPromise, completion, 1);
+            return newPromise.asReturnedValue();
+        }
+    }
+
+    return newPromise.asReturnedValue();
+}
+
+void PromisePrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedObject o(scope);
+
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Primitive::fromInt32(1));
+    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
+
+    ctor->defineDefaultProperty(QStringLiteral("resolve"), PromiseCtor::method_resolve, 1);
+    ctor->defineDefaultProperty(QStringLiteral("reject"), PromiseCtor::method_reject, 1);
+    ctor->defineDefaultProperty(QStringLiteral("all"), PromiseCtor::method_all, 1);
+    ctor->defineDefaultProperty(QStringLiteral("race"), PromiseCtor::method_race, 1);
+    ctor->addSymbolSpecies();
+
+    defineDefaultProperty(engine->id_constructor(), (o = ctor));
+
+    ScopedString val(scope, engine->newString(QLatin1String("Promise")));
+    defineReadonlyConfigurableProperty(engine->symbol_toStringTag(), val);
+
+    defineDefaultProperty(QStringLiteral("then"), method_then, 2);
+    defineDefaultProperty(QStringLiteral("catch"), method_catch, 1);
+}
+
+ReturnedValue PromisePrototype::method_then(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ExecutionEngine* e = scope.engine;
+
+    Scoped<QV4::PromiseObject> promise(scope, thisObject);
+    if (!promise)
+        THROW_TYPE_ERROR();
+
+    ScopedFunctionObject onFulfilled(scope);
+    if (argc >= 1) {
+        onFulfilled = argv[0];
+    } else {
+        onFulfilled = Encode::undefined();
+    }
+
+    ScopedFunctionObject onRejected(scope);
+    if (argc >= 2) {
+        onRejected = argv[1];
+    } else {
+        onRejected = Encode::undefined();
+    }
+
+    Scoped<PromiseCapability> capability(scope, e->memoryManager->allocate<PromiseCapability>());
+
+    ScopedFunctionObject constructor(scope, promise->get(e->id_constructor()));
+    if (!constructor || scope.hasException())
+        THROW_TYPE_ERROR();
+
+    ScopedObject nextPromise(scope, e->newPromiseObject(constructor, capability));
+    capability->d()->promise.set(scope.engine, nextPromise);
+
+    Scoped<PromiseReaction> fulfillReaction(scope, Heap::PromiseReaction::createFulfillReaction(scope.engine, capability, onFulfilled));
+    Scoped<PromiseReaction> rejectReaction(scope, Heap::PromiseReaction::createRejectReaction(scope.engine, capability, onRejected));
+
+    ScopedValue resolution(scope, promise->d()->resolution);
+    if (promise->d()->isPending()) {
+        {
+            ScopedArrayObject a(scope, promise->d()->fulfillReactions);
+            ScopedValue newValue(scope, fulfillReaction->d());
+            a->push_back(newValue);
+        }
+
+        {
+            ScopedArrayObject a(scope, promise->d()->rejectReactions);
+            ScopedValue newValue(scope, rejectReaction->d());
+            a->push_back(newValue);
+        }
+    } else if (promise->d()->isFulfilled()) {
+        fulfillReaction->as<QV4::PromiseReaction>()->d()->triggerWithValue(e, resolution);
+    } else if (promise->d()->isRejected()) {
+        rejectReaction->as<QV4::PromiseReaction>()->d()->triggerWithValue(e, resolution);
+    } else {
+        Q_ASSERT(false);
+        THROW_GENERIC_ERROR("Should never be thrown. Unknown promise state");
+    }
+
+    return nextPromise->asReturnedValue();
+}
+
+ReturnedValue PromisePrototype::method_catch(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    Scoped<Object> promise(scope);
+    if (thisObject->isObject()) {
+        promise.setPointer(thisObject->as<Object>());
+    } else if (thisObject->isBoolean()) {
+        promise = scope.engine->newBooleanObject(thisObject->toBoolean());
+    } else if (thisObject->isInteger() || thisObject->isDouble()) {
+        promise = scope.engine->newNumberObject(thisObject->toInteger());
+    } else if (thisObject->isString()) {
+        ScopedString scopedString(scope, thisObject->toString(scope.engine));
+        promise = scope.engine->newStringObject(scopedString);
+    } else {
+        THROW_TYPE_ERROR();
+    }
+
+    ScopedValue onRejected(scope);
+    if (argc < 1) {
+        onRejected = Encode::undefined();
+    } else {
+        onRejected = argv[0];
+    }
+
+    JSCallData jsCallData(scope, 2);
+    jsCallData->args[0] = Encode::undefined();
+    jsCallData->args[1] = onRejected;
+    jsCallData->thisObject = promise;
+
+    ScopedString thenName(scope, scope.engine->newIdentifier(QStringLiteral("then")));
+    ScopedFunctionObject then(scope, promise->get(thenName));
+    if (!then || scope.hasException())
+        THROW_TYPE_ERROR();
+
+    return then->call(jsCallData);
+}
+
+ReturnedValue CapabilitiesExecutorWrapper::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Q_UNUSED(thisObject);
+
+    Scope scope(f);
+    const CapabilitiesExecutorWrapper* self = static_cast<const CapabilitiesExecutorWrapper*>(f);
+    Heap::PromiseCapability *capabilities = self->d()->capabilities;
+
+    if (!capabilities->resolve.isUndefined() || !capabilities->reject.isUndefined())
+        THROW_TYPE_ERROR();
+
+    if (argc >= 1 && !argv[0].isUndefined())
+        capabilities->resolve.set(scope.engine, argv[0]);
+
+    if (argc >= 2 && !argv[1].isUndefined())
+        capabilities->reject.set(scope.engine, argv[1]);
+
+    // TODO: return?
+    return Encode::undefined();
+}
+
+ReturnedValue ResolveElementWrapper::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Q_UNUSED(thisObject);
+
+    Scope scope(f);
+    const ResolveElementWrapper* self = static_cast<const ResolveElementWrapper*>(f);
+
+    if (self->d()->alreadyResolved)
+        return Encode::undefined();
+
+    ScopedValue value(scope);
+    if (argc == 1) {
+        value = argv[0];
+    } else {
+        value = Encode::undefined();
+    }
+
+    Scoped<PromiseExecutionState> so(scope, self->d()->state);
+    self->d()->alreadyResolved = true;
+
+    ScopedObject values(scope, so->d()->values);
+    values->arraySet(self->d()->index, value);
+
+    so->d()->remainingElementCount--;
+    if (so->d()->remainingElementCount == 0) {
+        Scoped<PromiseCapability> capability(scope, so->d()->capability);
+        ScopedValue promise(scope, capability->d()->promise);
+        ScopedFunctionObject resolve(scope, capability->d()->resolve.as<QV4::FunctionObject>());
+        resolve->call(promise, values, 1);
+    }
+
+    return Encode::undefined();
+}
+
+ReturnedValue ResolveWrapper::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Q_UNUSED(thisObject);
+
+    Scope scope(f);
+    const ResolveWrapper *self = static_cast<const ResolveWrapper*>(f);
+
+    Scoped<PromiseObject> promise(scope, self->d()->promise);
+    if (self->d()->alreadyResolved || !promise->d()->isPending())
+        return Encode::undefined();
+
+    ScopedValue value(scope);
+    if (argc == 1) {
+        value = argv[0];
+    } else {
+        value = Encode::undefined();
+    }
+
+    self->d()->alreadyResolved = true;
+    promise->d()->setState(Heap::PromiseObject::Fulfilled);
+    promise->d()->resolution.set(scope.engine, value);
+
+    promise->d()->triggerFullfillReactions(scope.engine);
+
+    return Encode::undefined();
+}
+
+ReturnedValue RejectWrapper::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Q_UNUSED(thisObject);
+
+    Scope scope(f);
+    const RejectWrapper *self = static_cast<const RejectWrapper*>(f);
+
+    Scoped<PromiseObject> promise(scope, self->d()->promise);
+    if (self->d()->alreadyResolved || !promise->d()->isPending())
+        return Encode::undefined();
+
+    ScopedValue value(scope);
+    if (argc == 1) {
+        value = argv[0];
+    } else {
+        value = Encode::undefined();
+    }
+
+    self->d()->alreadyResolved = true;
+    promise->d()->setState(Heap::PromiseObject::Rejected);
+    promise->d()->resolution.set(scope.engine, value);
+
+    promise->d()->triggerRejectReactions(scope.engine);
+
+    return Encode::undefined();
+}
diff --git a/src/qml/jsruntime/qv4promiseobject_p.h b/src/qml/jsruntime/qv4promiseobject_p.h
new file mode 100644
index 0000000000..bce59b19a7
--- /dev/null
+++ b/src/qml/jsruntime/qv4promiseobject_p.h
@@ -0,0 +1,274 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4PROMISEOBJECT_H
+#define QV4PROMISEOBJECT_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4functionobject_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+struct PromiseCapability;
+
+namespace Promise {
+
+struct ReactionEvent;
+
+class ReactionHandler : public QObject
+{
+    Q_OBJECT
+
+public:
+    ReactionHandler(QObject *parent = nullptr);
+    virtual ~ReactionHandler();
+
+    void addReaction(ExecutionEngine *e, const Value *reaction, const Value *value);
+
+protected:
+    void customEvent(QEvent *event);
+    void executeReaction(ReactionEvent *event);
+};
+
+} // Promise
+
+namespace Heap {
+
+struct PromiseCtor : FunctionObject {
+    void init(QV4::ExecutionContext *scope);
+};
+
+#define PromiseObjectMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, resolution) \
+    Member(class, HeapValue, HeapValue, fulfillReactions) \
+    Member(class, HeapValue, HeapValue, rejectReactions)
+
+DECLARE_HEAP_OBJECT(PromiseObject, Object) {
+    DECLARE_MARKOBJECTS(PromiseObject)
+    void init(ExecutionEngine *e);
+
+    enum State {
+        Pending,
+        Fulfilled,
+        Rejected
+    };
+
+    void setState(State);
+    bool isSettled() const;
+    bool isPending() const;
+    bool isFulfilled() const;
+    bool isRejected() const;
+
+    State state;
+
+    void triggerFullfillReactions(ExecutionEngine *e);
+    void triggerRejectReactions(ExecutionEngine *e);
+};
+
+#define PromiseCapabilityMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, promise) \
+    Member(class, HeapValue, HeapValue, resolve) \
+    Member(class, HeapValue, HeapValue, reject)
+
+DECLARE_HEAP_OBJECT(PromiseCapability, Object) {
+    DECLARE_MARKOBJECTS(PromiseCapability)
+};
+
+#define PromiseReactionMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, handler) \
+    Member(class, Pointer, PromiseCapability*, capability)
+
+DECLARE_HEAP_OBJECT(PromiseReaction, Object) {
+    DECLARE_MARKOBJECTS(PromiseReaction)
+
+    static Heap::PromiseReaction *createFulfillReaction(ExecutionEngine* e, const QV4::PromiseCapability *capability, const QV4::FunctionObject *onFulfilled);
+    static Heap::PromiseReaction *createRejectReaction(ExecutionEngine* e, const QV4::PromiseCapability *capability, const QV4::FunctionObject *onRejected);
+
+    void triggerWithValue(ExecutionEngine *e, const Value *value);
+
+    enum Type {
+        Function,
+        Identity,
+        Thrower
+    };
+
+    Type type;
+
+    friend class ReactionHandler;
+};
+
+#define CapabilitiesExecutorWrapperMembers(class, Member) \
+    Member(class, Pointer, PromiseCapability*, capabilities)
+
+DECLARE_HEAP_OBJECT(CapabilitiesExecutorWrapper, FunctionObject) {
+    DECLARE_MARKOBJECTS(CapabilitiesExecutorWrapper)
+    void init();
+    void destroy();
+};
+
+#define PromiseExecutionStateMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, values) \
+    Member(class, HeapValue, HeapValue, capability)
+
+DECLARE_HEAP_OBJECT(PromiseExecutionState, FunctionObject) {
+    DECLARE_MARKOBJECTS(PromiseExecutionState)
+    void init();
+
+    uint index;
+    uint remainingElementCount;
+};
+
+#define ResolveElementWrapperMembers(class, Member) \
+    Member(class, HeapValue, HeapValue, state)
+
+DECLARE_HEAP_OBJECT(ResolveElementWrapper, FunctionObject) {
+    DECLARE_MARKOBJECTS(ResolveElementWrapper)
+    void init();
+
+    uint index;
+    bool alreadyResolved;
+};
+
+#define ResolveWrapperMembers(class, Member) \
+    Member(class, Pointer, PromiseObject*, promise)
+
+DECLARE_HEAP_OBJECT(ResolveWrapper, FunctionObject) {
+    DECLARE_MARKOBJECTS(ResolveWrapper)
+    void init();
+
+    bool alreadyResolved;
+};
+
+#define RejectWrapperMembers(class, Member) \
+    Member(class, Pointer, PromiseObject*, promise)
+
+DECLARE_HEAP_OBJECT(RejectWrapper, FunctionObject) {
+    DECLARE_MARKOBJECTS(RejectWrapper)
+    void init();
+
+    bool alreadyResolved;
+};
+
+} // Heap
+
+struct PromiseReaction : Object
+{
+    V4_OBJECT2(PromiseReaction, Object)
+};
+
+struct PromiseCapability : Object
+{
+    V4_OBJECT2(PromiseCapability, Object)
+};
+
+struct PromiseExecutionState : Object
+{
+    V4_OBJECT2(PromiseExecutionState, Object)
+};
+
+struct Q_QML_PRIVATE_EXPORT PromiseObject : Object
+{
+    V4_OBJECT2(PromiseObject, Object)
+    V4_NEEDS_DESTROY
+    V4_PROTOTYPE(promisePrototype)
+};
+
+struct PromiseCtor: FunctionObject
+{
+    V4_OBJECT2(PromiseCtor, FunctionObject)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_resolve(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reject(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_all(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_race(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct PromisePrototype : Object
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_then(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_catch(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct CapabilitiesExecutorWrapper: FunctionObject {
+    V4_OBJECT2(CapabilitiesExecutorWrapper, FunctionObject)
+
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct ResolveElementWrapper : FunctionObject {
+    V4_OBJECT2(ResolveElementWrapper, FunctionObject)
+
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct ResolveWrapper : FunctionObject {
+    V4_OBJECT2(ResolveWrapper, FunctionObject)
+
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct RejectWrapper : FunctionObject {
+    V4_OBJECT2(RejectWrapper, FunctionObject)
+
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+} // QV4
+
+QT_END_NAMESPACE
+
+#endif // QV4PROMISEOBJECT_H
diff --git a/src/qml/jsruntime/qv4property_p.h b/src/qml/jsruntime/qv4property_p.h
index 2a5b6f7f74..555f323737 100644
--- a/src/qml/jsruntime/qv4property_p.h
+++ b/src/qml/jsruntime/qv4property_p.h
@@ -66,25 +66,43 @@ struct Property {
     // Section 8.10
     inline void fullyPopulated(PropertyAttributes *attrs) {
         if (!attrs->hasType()) {
-            value = Primitive::undefinedValue();
+            value = Value::undefinedValue();
         }
         if (attrs->type() == PropertyAttributes::Accessor) {
             attrs->clearWritable();
             if (value.isEmpty())
-                value = Primitive::undefinedValue();
+                value = Value::undefinedValue();
             if (set.isEmpty())
-                set = Primitive::undefinedValue();
+                set = Value::undefinedValue();
         }
         attrs->resolve();
     }
 
+    // ES8: 6.2.5.6
+    void completed(PropertyAttributes *attrs) {
+        if (value.isEmpty())
+            value = Encode::undefined();
+        if (attrs->isGeneric() || attrs->isData()) {
+            attrs->setType(PropertyAttributes::Data);
+            if (!attrs->hasWritable())
+                attrs->setWritable(false);
+        } else {
+            if (set.isEmpty())
+                set = Encode::undefined();
+        }
+        if (!attrs->hasEnumerable())
+            attrs->setEnumerable(false);
+        if (!attrs->hasConfigurable())
+            attrs->setConfigurable(false);
+    }
+
     inline bool isSubset(const PropertyAttributes &attrs, const Property *other, PropertyAttributes otherAttrs) const;
     inline void merge(PropertyAttributes &attrs, const Property *other, PropertyAttributes otherAttrs);
 
     inline Heap::FunctionObject *getter() const { return reinterpret_cast<Heap::FunctionObject *>(value.heapObject()); }
     inline Heap::FunctionObject *setter() const { return reinterpret_cast<Heap::FunctionObject *>(set.heapObject()); }
     inline void setGetter(FunctionObject *g) { value = reinterpret_cast<Managed *>(g); }
-    inline void setSetter(FunctionObject *s) { set = (s ? reinterpret_cast<Managed *>(s) : 0); }
+    inline void setSetter(FunctionObject *s) { set = (s ? reinterpret_cast<Managed *>(s) : nullptr); }
 
     void copy(const Property *other, PropertyAttributes attrs) {
         value = other->value;
@@ -92,7 +110,41 @@ struct Property {
             set = other->set;
     }
 
-    explicit Property()  { value = Encode::undefined(); set = Value::fromHeapObject(0); }
+    // ES8, section 9.1.6.2/9,.1.6.3
+    bool isCompatible(PropertyAttributes &attrs, const Property *other, PropertyAttributes otherAttrs) const {
+        if (otherAttrs.isEmpty())
+            return true;
+        if (!attrs.isConfigurable()) {
+            if (otherAttrs.hasConfigurable() && otherAttrs.isConfigurable())
+                return false;
+            if (otherAttrs.hasEnumerable() && otherAttrs.isEnumerable() != attrs.isEnumerable())
+                return false;
+        }
+        if (otherAttrs.isGeneric())
+            return true;
+        if (attrs.isData() != otherAttrs.isData()) {
+            if (!attrs.isConfigurable())
+                return false;
+        } else if (attrs.isData() && otherAttrs.isData()) {
+            if (!attrs.isConfigurable() && !attrs.isWritable()) {
+                if (otherAttrs.hasWritable() && otherAttrs.isWritable())
+                    return false;
+                if (!other->value.isEmpty() && !value.sameValue(other->value))
+                    return false;
+            }
+        } else if (attrs.isAccessor() && otherAttrs.isAccessor()) {
+            if (!attrs.isConfigurable()) {
+                if (!other->value.isEmpty() && !value.sameValue(other->value))
+                    return false;
+                if (!other->set.isEmpty() && !set.sameValue(other->set))
+                    return false;
+            }
+        }
+        return true;
+    }
+
+
+    explicit Property()  { value = Encode::undefined(); set = Value::fromHeapObject(nullptr); }
     Property(Heap::FunctionObject *getter, Heap::FunctionObject *setter) {
         value.setM(reinterpret_cast<Heap::Base *>(getter));
         set.setM(reinterpret_cast<Heap::Base *>(setter));
@@ -142,6 +194,19 @@ inline void Property::merge(PropertyAttributes &attrs, const Property *other, Pr
     }
 }
 
+struct PropertyIndex {
+    Heap::Base *base;
+    Value *slot;
+
+    void set(EngineBase *e, Value newVal) {
+        WriteBarrier::write(e, base, slot->data_ptr(), newVal.asReturnedValue());
+    }
+    const Value *operator->() const { return slot; }
+    const Value &operator*() const { return *slot; }
+    bool isNull() const { return !slot; }
+};
+
+
 }
 
 Q_DECLARE_TYPEINFO(QV4::Property, Q_MOVABLE_TYPE);
diff --git a/src/qml/jsruntime/qv4propertykey.cpp b/src/qml/jsruntime/qv4propertykey.cpp
new file mode 100644
index 0000000000..064d030b83
--- /dev/null
+++ b/src/qml/jsruntime/qv4propertykey.cpp
@@ -0,0 +1,109 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4propertykey_p.h"
+
+#include <QtCore/qstring.h>
+#include <qv4string_p.h>
+#include <qv4engine_p.h>
+#include <qv4scopedvalue_p.h>
+
+QV4::Heap::StringOrSymbol *QV4::PropertyKey::toStringOrSymbol(QV4::ExecutionEngine *e)
+{
+    if (isArrayIndex())
+        return Value::fromUInt32(asArrayIndex()).toString(e);
+    return static_cast<Heap::StringOrSymbol *>(asStringOrSymbol());
+}
+
+bool QV4::PropertyKey::isString() const {
+    Heap::StringOrSymbol *s = asStringOrSymbol();
+    return s && s->internalClass->vtable->isString;
+}
+
+bool QV4::PropertyKey::isSymbol() const {
+    Heap::Base *s = asStringOrSymbol();
+    return s && !s->internalClass->vtable->isString && s->internalClass->vtable->isStringOrSymbol;
+}
+
+bool QV4::PropertyKey::isCanonicalNumericIndexString() const
+{
+    if (isArrayIndex())
+        return true;
+    if (isSymbol())
+        return false;
+    Heap::String *s = static_cast<Heap::String *>(asStringOrSymbol());
+    Scope scope(s->internalClass->engine);
+    ScopedString str(scope, s);
+    double d = str->toNumber();
+    if (d == 0. && std::signbit(d))
+        return true;
+    ScopedString converted(scope, Value::fromDouble(d).toString(scope.engine));
+    if (converted->equals(str))
+        return true;
+    return false;
+}
+
+QString QV4::PropertyKey::toQString() const
+{
+    if (isArrayIndex())
+        return QString::number(asArrayIndex());
+    Heap::StringOrSymbol *s = asStringOrSymbol();
+    Q_ASSERT(s->internalClass->vtable->isStringOrSymbol);
+    return s->toQString();
+}
+
+QV4::Heap::String *QV4::PropertyKey::asFunctionName(ExecutionEngine *engine, FunctionNamePrefix prefix) const
+{
+    QString n;
+    if (prefix == Getter)
+        n = QStringLiteral("get ");
+    else if (prefix == Setter)
+        n = QStringLiteral("set ");
+    if (isArrayIndex())
+        n += QString::number(asArrayIndex());
+    else {
+        Heap::StringOrSymbol *s = asStringOrSymbol();
+        QString str = s->toQString();
+        if (s->internalClass->vtable->isString)
+            n += s->toQString();
+        else if (str.length() > 1)
+            n += QChar::fromLatin1('[') + str.midRef(1) + QChar::fromLatin1(']');
+    }
+    return engine->newString(n);
+}
diff --git a/src/qml/jsruntime/qv4propertykey_p.h b/src/qml/jsruntime/qv4propertykey_p.h
new file mode 100644
index 0000000000..47867765db
--- /dev/null
+++ b/src/qml/jsruntime/qv4propertykey_p.h
@@ -0,0 +1,154 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4PROPERTYKEY_H
+#define QV4PROPERTYKEY_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4global_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QString;
+
+namespace QV4 {
+
+struct PropertyKey
+{
+private:
+    // Property keys are Strings, Symbols or unsigned integers.
+    // For convenience we derive them from Values, allowing us to store them
+    // on the JS stack
+    //
+    // They do however behave somewhat different than a Value:
+    // * If the key is a String, the pointer to the string is stored in the identifier
+    // table and thus unique.
+    // * If the key is a Symbol it simply points to the referenced symbol object
+    // * if the key is an array index (a uint < UINT_MAX), it's encoded as an
+    // integer value
+    quint64 val;
+
+    // Important: Always keep this in sync with the definitions for Integers and heap objects in Value
+    static const quint64 ArrayIndexMask = 0x3800000000000ull;
+    enum {
+        IsManagedOrUndefined_Shift = 64-15,
+    };
+    inline bool isManaged() const { return (val >> IsManagedOrUndefined_Shift) == 0; }
+    inline quint32 value() const { return val & quint64(~quint32(0)); }
+
+#if QT_POINTER_SIZE == 8
+    QML_NEARLY_ALWAYS_INLINE Heap::StringOrSymbol *m() const
+    {
+        Heap::StringOrSymbol *b;
+        memcpy(&b, &val, 8);
+        return b;
+    }
+    QML_NEARLY_ALWAYS_INLINE void setM(Heap::StringOrSymbol *b)
+    {
+        memcpy(&val, &b, 8);
+    }
+#elif QT_POINTER_SIZE == 4
+    QML_NEARLY_ALWAYS_INLINE Heap::StringOrSymbol *m() const
+    {
+        Q_STATIC_ASSERT(sizeof(Heap::StringOrSymbol*) == sizeof(quint32));
+        Heap::StringOrSymbol *b;
+        quint32 v = value();
+        memcpy(&b, &v, 4);
+        return b;
+    }
+    QML_NEARLY_ALWAYS_INLINE void setM(Heap::StringOrSymbol *b)
+    {
+        quint32 v;
+        memcpy(&v, &b, 4);
+        val = v;
+    }
+#endif
+
+public:
+    static PropertyKey invalid() { PropertyKey key; key.val = 0; return key; }
+    static PropertyKey fromArrayIndex(uint idx) { PropertyKey key; key.val = ArrayIndexMask | static_cast<quint64>(idx); return key; }
+    bool isStringOrSymbol() const { return isManaged() && val != 0; }
+    uint asArrayIndex() const { return (isManaged() || val == 0) ? std::numeric_limits<uint>::max() : static_cast<uint>(val & 0xffffffff); }
+    uint isArrayIndex() const { return !isManaged() && val != 0 && static_cast<uint>(val & 0xffffffff) != std::numeric_limits<uint>::max(); }
+    bool isValid() const { return val != 0; }
+    static PropertyKey fromStringOrSymbol(Heap::StringOrSymbol *b)
+    { PropertyKey key; key.setM(b); return key; }
+    Heap::StringOrSymbol *asStringOrSymbol() const {
+        if (!isManaged())
+            return nullptr;
+        return m();
+    }
+
+    bool isString() const;
+    bool isSymbol() const;
+    bool isCanonicalNumericIndexString() const;
+
+    Q_QML_EXPORT QString toQString() const;
+    Heap::StringOrSymbol *toStringOrSymbol(ExecutionEngine *e);
+    quint64 id() const { return val; }
+    static PropertyKey fromId(quint64 id) {
+        PropertyKey key; key.val = id; return key;
+    }
+
+    enum FunctionNamePrefix {
+        None,
+        Getter,
+        Setter
+    };
+    Heap::String *asFunctionName(ExecutionEngine *e, FunctionNamePrefix prefix) const;
+
+    bool operator ==(const PropertyKey &other) const { return val == other.val; }
+    bool operator !=(const PropertyKey &other) const { return val != other.val; }
+    bool operator <(const PropertyKey &other) const { return val < other.val; }
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/jsruntime/qv4proxy.cpp b/src/qml/jsruntime/qv4proxy.cpp
new file mode 100644
index 0000000000..9325e2e53b
--- /dev/null
+++ b/src/qml/jsruntime/qv4proxy.cpp
@@ -0,0 +1,782 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include "qv4proxy_p.h"
+#include "qv4symbol_p.h"
+#include "qv4jscall_p.h"
+#include "qv4objectproto_p.h"
+#include "qv4persistent_p.h"
+#include "qv4objectiterator_p.h"
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(ProxyObject);
+DEFINE_OBJECT_VTABLE(ProxyFunctionObject);
+
+void Heap::ProxyObject::init(const QV4::Object *target, const QV4::Object *handler)
+{
+    Object::init();
+    ExecutionEngine *e = internalClass->engine;
+    this->target.set(e, target->d());
+    this->handler.set(e, handler->d());
+}
+
+void Heap::ProxyFunctionObject::init(const QV4::FunctionObject *target, const QV4::Object *handler)
+{
+    ExecutionEngine *e = internalClass->engine;
+    FunctionObject::init(e->rootContext());
+    this->target.set(e, target->d());
+    this->handler.set(e, handler->d());
+
+    if (!target->isConstructor())
+        jsConstruct = nullptr;
+}
+
+
+ReturnedValue ProxyObject::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedValue trap(scope, handler->get(scope.engine->id_get()));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->get(id, receiver, hasProperty);
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+    if (hasProperty)
+        *hasProperty = true;
+
+    JSCallData cdata(scope, 3, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = id.toStringOrSymbol(scope.engine);
+    cdata.args[2] = *receiver;
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    ScopedProperty targetDesc(scope);
+    PropertyAttributes attributes = target->getOwnProperty(id, targetDesc);
+    if (attributes != Attr_Invalid && !attributes.isConfigurable()) {
+        if (attributes.isData() && !attributes.isWritable()) {
+            if (!trapResult->sameValue(targetDesc->value))
+                return scope.engine->throwTypeError();
+        }
+        if (attributes.isAccessor() && targetDesc->value.isUndefined()) {
+            if (!trapResult->isUndefined())
+                return scope.engine->throwTypeError();
+        }
+   }
+    return trapResult->asReturnedValue();
+}
+
+bool ProxyObject::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedValue trap(scope, handler->get(scope.engine->id_set()));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->put(id, value, receiver);
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    JSCallData cdata(scope, 4, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = id.toStringOrSymbol(scope.engine);
+    cdata.args[2] = value;
+    cdata.args[3] = *receiver;
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    if (!trapResult->toBoolean())
+        return false;
+    ScopedProperty targetDesc(scope);
+    PropertyAttributes attributes = target->getOwnProperty(id, targetDesc);
+    if (attributes != Attr_Invalid && !attributes.isConfigurable()) {
+        if (attributes.isData() && !attributes.isWritable()) {
+            if (!value.sameValue(targetDesc->value))
+                return scope.engine->throwTypeError();
+        }
+        if (attributes.isAccessor() && targetDesc->set.isUndefined())
+            return scope.engine->throwTypeError();
+    }
+    return true;
+}
+
+bool ProxyObject::virtualDeleteProperty(Managed *m, PropertyKey id)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString deleteProp(scope, scope.engine->newString(QStringLiteral("deleteProperty")));
+    ScopedValue trap(scope, handler->get(deleteProp));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->deleteProperty(id);
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    JSCallData cdata(scope, 3, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = id.toStringOrSymbol(scope.engine);
+    cdata.args[2] = o->d(); // ### fix receiver handling
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    if (!trapResult->toBoolean())
+        return false;
+    ScopedProperty targetDesc(scope);
+    PropertyAttributes attributes = target->getOwnProperty(id, targetDesc);
+    if (attributes == Attr_Invalid)
+        return true;
+    if (!attributes.isConfigurable())
+        return scope.engine->throwTypeError();
+    return true;
+}
+
+bool ProxyObject::virtualHasProperty(const Managed *m, PropertyKey id)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString hasProp(scope, scope.engine->newString(QStringLiteral("has")));
+    ScopedValue trap(scope, handler->get(hasProp));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->hasProperty(id);
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    JSCallData cdata(scope, 2, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = id.isArrayIndex() ? Value::fromUInt32(id.asArrayIndex()).toString(scope.engine) : id.asStringOrSymbol();
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    bool result = trapResult->toBoolean();
+    if (!result) {
+        ScopedProperty targetDesc(scope);
+        PropertyAttributes attributes = target->getOwnProperty(id, targetDesc);
+        if (attributes != Attr_Invalid) {
+            if (!attributes.isConfigurable() || !target->isExtensible())
+                return scope.engine->throwTypeError();
+        }
+    }
+    return result;
+}
+
+PropertyAttributes ProxyObject::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler) {
+        scope.engine->throwTypeError();
+        return Attr_Invalid;
+    }
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString deleteProp(scope, scope.engine->newString(QStringLiteral("getOwnPropertyDescriptor")));
+    ScopedValue trap(scope, handler->get(deleteProp));
+    if (scope.hasException())
+        return Attr_Invalid;
+    if (trap->isNullOrUndefined())
+        return target->getOwnProperty(id, p);
+    if (!trap->isFunctionObject()) {
+        scope.engine->throwTypeError();
+        return Attr_Invalid;
+    }
+
+    JSCallData cdata(scope, 2, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = id.isArrayIndex() ? Value::fromUInt32(id.asArrayIndex()).toString(scope.engine) : id.asStringOrSymbol();
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    if (!trapResult->isObject() && !trapResult->isUndefined()) {
+        scope.engine->throwTypeError();
+        return Attr_Invalid;
+    }
+
+    ScopedProperty targetDesc(scope);
+    PropertyAttributes targetAttributes = target->getOwnProperty(id, targetDesc);
+    if (trapResult->isUndefined()) {
+        p->value = Encode::undefined();
+        if (targetAttributes == Attr_Invalid) {
+            p->value = Encode::undefined();
+            return Attr_Invalid;
+        }
+        if (!targetAttributes.isConfigurable() || !target->isExtensible()) {
+            scope.engine->throwTypeError();
+            return Attr_Invalid;
+        }
+        return Attr_Invalid;
+    }
+
+    //bool extensibleTarget = target->isExtensible();
+    ScopedProperty resultDesc(scope);
+    PropertyAttributes resultAttributes;
+    ObjectPrototype::toPropertyDescriptor(scope.engine, trapResult, resultDesc, &resultAttributes);
+    resultDesc->completed(&resultAttributes);
+
+    if (!targetDesc->isCompatible(targetAttributes, resultDesc, resultAttributes)) {
+        scope.engine->throwTypeError();
+        return Attr_Invalid;
+    }
+
+    if (!resultAttributes.isConfigurable()) {
+        if (targetAttributes == Attr_Invalid || targetAttributes.isConfigurable()) {
+            scope.engine->throwTypeError();
+            return Attr_Invalid;
+        }
+    }
+
+    p->value = resultDesc->value;
+    p->set = resultDesc->set;
+    return resultAttributes;
+}
+
+bool ProxyObject::virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString prop(scope, scope.engine->newString(QStringLiteral("defineProperty")));
+    ScopedValue trap(scope, handler->get(prop));
+    if (scope.hasException())
+        return false;
+    if (trap->isNullOrUndefined())
+        return target->defineOwnProperty(id, p, attrs);
+    if (!trap->isFunctionObject()) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+
+    JSCallData cdata(scope, 3, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = id.isArrayIndex() ? Value::fromUInt32(id.asArrayIndex()).toString(scope.engine) : id.asStringOrSymbol();
+    cdata.args[2] = ObjectPrototype::fromPropertyDescriptor(scope.engine, p, attrs);
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    bool result = trapResult->toBoolean();
+    if (!result)
+        return false;
+
+    ScopedProperty targetDesc(scope);
+    PropertyAttributes targetAttributes = target->getOwnProperty(id, targetDesc);
+    bool extensibleTarget = target->isExtensible();
+    bool settingConfigFalse = attrs.hasConfigurable() && !attrs.isConfigurable();
+    if (targetAttributes == Attr_Invalid) {
+        if (!extensibleTarget || settingConfigFalse) {
+            scope.engine->throwTypeError();
+            return false;
+        }
+    } else {
+        if (!targetDesc->isCompatible(targetAttributes, p, attrs)) {
+            scope.engine->throwTypeError();
+            return false;
+        }
+        if (settingConfigFalse && targetAttributes.isConfigurable()) {
+            scope.engine->throwTypeError();
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool ProxyObject::virtualIsExtensible(const Managed *m)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString hasProp(scope, scope.engine->newString(QStringLiteral("isExtensible")));
+    ScopedValue trap(scope, handler->get(hasProp));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->isExtensible();
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    JSCallData cdata(scope, 1, nullptr, handler);
+    cdata.args[0] = target;
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    bool result = trapResult->toBoolean();
+    if (result != target->isExtensible()) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+    return result;
+}
+
+bool ProxyObject::virtualPreventExtensions(Managed *m)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString hasProp(scope, scope.engine->newString(QStringLiteral("preventExtensions")));
+    ScopedValue trap(scope, handler->get(hasProp));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->preventExtensions();
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    JSCallData cdata(scope, 1, nullptr, handler);
+    cdata.args[0] = target;
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    bool result = trapResult->toBoolean();
+    if (result && target->isExtensible()) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+    return result;
+}
+
+Heap::Object *ProxyObject::virtualGetPrototypeOf(const Managed *m)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("getPrototypeOf")));
+    ScopedValue trap(scope, handler->get(name));
+    if (scope.hasException())
+        return nullptr;
+    if (trap->isNullOrUndefined())
+        return target->getPrototypeOf();
+    if (!trap->isFunctionObject()) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    JSCallData cdata(scope, 1, nullptr, handler);
+    cdata.args[0] = target;
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    if (!trapResult->isNull() && !trapResult->isObject()) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    Heap::Object *proto = trapResult->isNull() ? nullptr : static_cast<Heap::Object *>(trapResult->heapObject());
+    if (!target->isExtensible()) {
+        Heap::Object *targetProto = target->getPrototypeOf();
+        if (proto != targetProto) {
+            scope.engine->throwTypeError();
+            return nullptr;
+        }
+    }
+    return proto;
+}
+
+bool ProxyObject::virtualSetPrototypeOf(Managed *m, const Object *p)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("setPrototypeOf")));
+    ScopedValue trap(scope, handler->get(name));
+    if (scope.hasException())
+        return false;
+    if (trap->isNullOrUndefined())
+        return target->setPrototypeOf(p);
+    if (!trap->isFunctionObject()) {
+        scope.engine->throwTypeError();
+        return false;
+    }
+
+    JSCallData cdata(scope, 2, nullptr, handler);
+    cdata.args[0] = target;
+    cdata.args[1] = p ? p->asReturnedValue() : Encode::null();
+
+    ScopedValue trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    bool result = trapResult->toBoolean();
+    if (!result)
+        return false;
+    if (!target->isExtensible()) {
+        Heap::Object *targetProto = target->getPrototypeOf();
+        if (p->d() != targetProto) {
+            scope.engine->throwTypeError();
+            return false;
+        }
+    }
+    return true;
+}
+
+struct ProxyObjectOwnPropertyKeyIterator : OwnPropertyKeyIterator
+{
+    PersistentValue ownKeys;
+    uint index = 0;
+    uint len = 0;
+
+    ProxyObjectOwnPropertyKeyIterator(ArrayObject *keys);
+    ~ProxyObjectOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+ProxyObjectOwnPropertyKeyIterator::ProxyObjectOwnPropertyKeyIterator(ArrayObject *keys)
+{
+    ownKeys = keys;
+    len = keys->getLength();
+}
+
+PropertyKey ProxyObjectOwnPropertyKeyIterator::next(const Object *m, Property *pd, PropertyAttributes *attrs)
+{
+    if (index >= len)
+        return PropertyKey::invalid();
+
+    Scope scope(m);
+    ScopedObject keys(scope, ownKeys.asManaged());
+    PropertyKey key = PropertyKey::fromId(keys->get(PropertyKey::fromArrayIndex(index)));
+    ++index;
+
+    if (pd || attrs) {
+        ScopedProperty p(scope);
+        PropertyAttributes a = const_cast<Object *>(m)->getOwnProperty(key, pd ? pd : p);
+        if (attrs)
+            *attrs = a;
+    }
+
+    return key;
+}
+
+static bool removeAllOccurrences(ArrayObject *target, ReturnedValue val) {
+    uint len = target->getLength();
+    bool found = false;
+    for (uint i = 0; i < len; ++i) {
+        ReturnedValue v = target->get(i);
+        if (v == val) {
+            found = true;
+            target->put(i, Value::undefinedValue());
+        }
+    }
+    return  found;
+}
+
+OwnPropertyKeyIterator *ProxyObject::virtualOwnPropertyKeys(const Object *m, Value *iteratorTarget)
+{
+    Scope scope(m);
+    const ProxyObject *o = static_cast<const ProxyObject *>(m);
+    if (!o->d()->handler) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    ScopedObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("ownKeys")));
+    ScopedValue trap(scope, handler->get(name));
+
+    if (scope.hasException())
+        return nullptr;
+    if (trap->isUndefined())
+        return target->ownPropertyKeys(iteratorTarget);
+    if (!trap->isFunctionObject()) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    JSCallData cdata(scope, 1, nullptr, handler);
+    cdata.args[0] = target;
+    ScopedObject trapResult(scope, static_cast<const FunctionObject *>(trap.ptr)->call(cdata));
+    if (!trapResult) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    uint len = trapResult->getLength();
+    ScopedArrayObject trapKeys(scope, scope.engine->newArrayObject());
+    ScopedStringOrSymbol key(scope);
+    for (uint i = 0; i < len; ++i) {
+        key = trapResult->get(i);
+        if (scope.engine->hasException)
+            return nullptr;
+        if (!key) {
+            scope.engine->throwTypeError();
+            return nullptr;
+        }
+        Value keyAsValue = Value::fromReturnedValue(key->toPropertyKey().id());
+        trapKeys->push_back(keyAsValue);
+    }
+
+    ScopedArrayObject targetConfigurableKeys(scope, scope.engine->newArrayObject());
+    ScopedArrayObject targetNonConfigurableKeys(scope, scope.engine->newArrayObject());
+    ObjectIterator it(scope, target, ObjectIterator::EnumerableOnly);
+    ScopedPropertyKey k(scope);
+    while (1) {
+        PropertyAttributes attrs;
+        k = it.next(nullptr, &attrs);
+        if (!k->isValid())
+            break;
+        Value keyAsValue = Value::fromReturnedValue(k->id());
+        if (attrs.isConfigurable())
+            targetConfigurableKeys->push_back(keyAsValue);
+        else
+            targetNonConfigurableKeys->push_back(keyAsValue);
+    }
+    if (target->isExtensible() && targetNonConfigurableKeys->getLength() == 0)
+        return new ProxyObjectOwnPropertyKeyIterator(trapKeys);
+
+    ScopedArrayObject uncheckedResultKeys(scope, scope.engine->newArrayObject());
+    uncheckedResultKeys->copyArrayData(trapKeys);
+
+    len = targetNonConfigurableKeys->getLength();
+    for (uint i = 0; i < len; ++i) {
+        k = PropertyKey::fromId(targetNonConfigurableKeys->get(i));
+        if (!removeAllOccurrences(uncheckedResultKeys, k->id())) {
+            scope.engine->throwTypeError();
+            return nullptr;
+        }
+    }
+
+    if (target->isExtensible())
+        return new ProxyObjectOwnPropertyKeyIterator(trapKeys);
+
+    len = targetConfigurableKeys->getLength();
+    for (uint i = 0; i < len; ++i) {
+        k = PropertyKey::fromId(targetConfigurableKeys->get(i));
+        if (!removeAllOccurrences(uncheckedResultKeys, k->id())) {
+            scope.engine->throwTypeError();
+            return nullptr;
+        }
+    }
+
+    len = uncheckedResultKeys->getLength();
+    for (uint i = 0; i < len; ++i) {
+        if (uncheckedResultKeys->get(i) != Encode::undefined()) {
+            scope.engine->throwTypeError();
+            return nullptr;
+        }
+    }
+
+    *iteratorTarget = *m;
+    return new ProxyObjectOwnPropertyKeyIterator(trapKeys);
+}
+
+
+ReturnedValue ProxyFunctionObject::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    Scope scope(f);
+    const ProxyObject *o = static_cast<const ProxyObject *>(f);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedFunctionObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("construct")));
+    ScopedValue trap(scope, handler->get(name));
+
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined()) {
+        Q_ASSERT(target->isConstructor());
+        return target->callAsConstructor(argv, argc, newTarget);
+    }
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    ScopedFunctionObject trapFunction(scope, trap);
+    Value *arguments = scope.alloc(3);
+    arguments[0] = target;
+    arguments[1] = scope.engine->newArrayObject(argv, argc);
+    arguments[2] = newTarget ? *newTarget : Value::undefinedValue();
+    ScopedObject result(scope, trapFunction->call(handler, arguments, 3));
+
+    if (!result)
+        return scope.engine->throwTypeError();
+    return result->asReturnedValue();
+}
+
+ReturnedValue ProxyFunctionObject::virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+
+    const ProxyObject *o = static_cast<const ProxyObject *>(f);
+    if (!o->d()->handler)
+        return scope.engine->throwTypeError();
+
+    ScopedFunctionObject target(scope, o->d()->target);
+    Q_ASSERT(target);
+    ScopedObject handler(scope, o->d()->handler);
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("apply")));
+    ScopedValue trap(scope, handler->get(name));
+
+    if (scope.hasException())
+        return Encode::undefined();
+    if (trap->isNullOrUndefined())
+        return target->call(thisObject, argv, argc);
+    if (!trap->isFunctionObject())
+        return scope.engine->throwTypeError();
+
+    ScopedFunctionObject trapFunction(scope, trap);
+    Value *arguments = scope.alloc(3);
+    arguments[0] = target;
+    arguments[1] = thisObject ? *thisObject : Value::undefinedValue();
+    arguments[2] = scope.engine->newArrayObject(argv, argc);
+    return trapFunction->call(handler, arguments, 3);
+}
+
+DEFINE_OBJECT_VTABLE(Proxy);
+
+void Heap::Proxy::init(QV4::ExecutionContext *ctx)
+{
+    Heap::FunctionObject::init(ctx, QStringLiteral("Proxy"));
+
+    Scope scope(ctx);
+    Scoped<QV4::Proxy> ctor(scope, this);
+    ctor->defineDefaultProperty(QStringLiteral("revocable"), QV4::Proxy::method_revocable, 2);
+    ctor->defineReadonlyConfigurableProperty(scope.engine->id_length(), Value::fromInt32(2));
+}
+
+ReturnedValue Proxy::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *)
+{
+    Scope scope(f);
+    if (argc < 2 || !argv[0].isObject() || !argv[1].isObject())
+        return scope.engine->throwTypeError();
+
+    const Object *target = static_cast<const Object *>(argv);
+    const Object *handler = static_cast<const Object *>(argv + 1);
+    if (const ProxyObject *ptarget = target->as<ProxyObject>())
+        if (!ptarget->d()->handler)
+            return scope.engine->throwTypeError();
+    if (const ProxyObject *phandler = handler->as<ProxyObject>())
+        if (!phandler->d()->handler)
+            return scope.engine->throwTypeError();
+
+    const FunctionObject *targetFunction = target->as<FunctionObject>();
+    if (targetFunction)
+        return scope.engine->memoryManager->allocate<ProxyFunctionObject>(targetFunction, handler)->asReturnedValue();
+    return scope.engine->memoryManager->allocate<ProxyObject>(target, handler)->asReturnedValue();
+}
+
+ReturnedValue Proxy::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
+{
+    return f->engine()->throwTypeError();
+}
+
+ReturnedValue Proxy::method_revocable(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ScopedObject proxy(scope, Proxy::virtualCallAsConstructor(f, argv, argc, f));
+    if (scope.hasException())
+        return Encode::undefined();
+    Q_ASSERT(proxy);
+
+    ScopedString revoke(scope, scope.engine->newString(QStringLiteral("revoke")));
+    ScopedFunctionObject revoker(scope, scope.engine->memoryManager->allocate<FunctionObject>(scope.engine->rootContext(), nullptr, method_revoke));
+    revoker->defineReadonlyConfigurableProperty(scope.engine->id_length(), Value::fromInt32(0));
+    revoker->defineDefaultProperty(scope.engine->symbol_revokableProxy(), proxy);
+
+    ScopedObject o(scope, scope.engine->newObject());
+    ScopedString p(scope, scope.engine->newString(QStringLiteral("proxy")));
+    o->defineDefaultProperty(p, proxy);
+    o->defineDefaultProperty(revoke, revoker);
+    return o->asReturnedValue();
+}
+
+ReturnedValue Proxy::method_revoke(const FunctionObject *f, const Value *, const Value *, int)
+{
+    Scope scope(f);
+    ScopedObject o(scope, f->get(scope.engine->symbol_revokableProxy()));
+    Q_ASSERT(o);
+    ProxyObject *proxy = o->cast<ProxyObject>();
+
+    proxy->d()->target.set(scope.engine, nullptr);
+    proxy->d()->handler.set(scope.engine, nullptr);
+    return Encode::undefined();
+}
diff --git a/src/qml/jsruntime/qv4proxy_p.h b/src/qml/jsruntime/qv4proxy_p.h
new file mode 100644
index 0000000000..2ccb50ece6
--- /dev/null
+++ b/src/qml/jsruntime/qv4proxy_p.h
@@ -0,0 +1,144 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4PROXY_P_H
+#define QV4PROXY_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4functionobject_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Heap {
+
+#define ProxyObjectMembers(class, Member) \
+    Member(class, Pointer, Object *, target) \
+    Member(class, Pointer, Object *, handler)
+
+DECLARE_HEAP_OBJECT(ProxyObject, FunctionObject) {
+    DECLARE_MARKOBJECTS(ProxyObject)
+
+    void init(const QV4::Object *target, const QV4::Object *handler);
+};
+
+struct ProxyFunctionObject : ProxyObject {
+    void init(const QV4::FunctionObject *target, const QV4::Object *handler);
+};
+
+#define ProxyMembers(class, Member) \
+    Member(class, Pointer, Symbol *, revokableProxySymbol) \
+
+DECLARE_HEAP_OBJECT(Proxy, FunctionObject) {
+    DECLARE_MARKOBJECTS(Proxy)
+
+    void init(QV4::ExecutionContext *ctx);
+};
+
+}
+
+/*
+ * The inheritance from FunctionObject is a hack. Regular proxy objects are no function objects.
+ * But this helps implement the proxy for function objects, where we need this and thus gives us
+ * all the virtual methods from ProxyObject without having to duplicate them.
+ *
+ * But it does require a few hacks to make sure we don't recognize regular proxy objects as function
+ * objects in the runtime.
+ */
+struct ProxyObject : FunctionObject {
+    V4_OBJECT2(ProxyObject, Object)
+    Q_MANAGED_TYPE(ProxyObject)
+    V4_INTERNALCLASS(ProxyObject)
+    enum {
+        IsFunctionObject = false
+    };
+
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static bool virtualDeleteProperty(Managed *m, PropertyKey id);
+    static bool virtualHasProperty(const Managed *m, PropertyKey id);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static bool virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs);
+    static bool virtualIsExtensible(const Managed *m);
+    static bool virtualPreventExtensions(Managed *);
+    static Heap::Object *virtualGetPrototypeOf(const Managed *);
+    static bool virtualSetPrototypeOf(Managed *, const Object *);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *iteratorTarget);
+};
+
+struct ProxyFunctionObject : ProxyObject {
+    V4_OBJECT2(ProxyFunctionObject, FunctionObject)
+    Q_MANAGED_TYPE(ProxyObject)
+    V4_INTERNALCLASS(ProxyFunctionObject)
+    enum {
+        IsFunctionObject = true
+    };
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct Proxy : FunctionObject
+{
+    V4_OBJECT2(Proxy, FunctionObject)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_revocable(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_revoke(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4ECMAOBJECTS_P_H
diff --git a/src/qml/jsruntime/qv4qmlcontext.cpp b/src/qml/jsruntime/qv4qmlcontext.cpp
index 61d785066f..88b0822f42 100644
--- a/src/qml/jsruntime/qv4qmlcontext.cpp
+++ b/src/qml/jsruntime/qv4qmlcontext.cpp
@@ -54,6 +54,7 @@
 #include <private/qqmljavascriptexpression_p.h>
 #include <private/qjsvalue_p.h>
 #include <private/qv4qobjectwrapper_p.h>
+#include <private/qv4module_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -62,57 +63,56 @@ using namespace QV4;
 DEFINE_OBJECT_VTABLE(QQmlContextWrapper);
 DEFINE_MANAGED_VTABLE(QmlContext);
 
-void Heap::QQmlContextWrapper::init(QQmlContextData *context, QObject *scopeObject, bool ownsContext)
+void Heap::QQmlContextWrapper::init(QQmlContextData *context, QObject *scopeObject)
 {
     Object::init();
-    readOnly = true;
-    this->ownsContext = ownsContext;
-    isNullWrapper = false;
-    this->context = new QQmlGuardedContextData(context);
+    this->context = new QQmlContextDataRef(context);
     this->scopeObject.init(scopeObject);
 }
 
 void Heap::QQmlContextWrapper::destroy()
 {
-    if (*context && ownsContext)
-        (*context)->destroy();
     delete context;
     scopeObject.destroy();
     Object::destroy();
 }
 
-ReturnedValue QQmlContextWrapper::get(const Managed *m, String *name, bool *hasProperty)
+ReturnedValue QQmlContextWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<QQmlContextWrapper>());
+
+    if (!id.isString())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+
     const QQmlContextWrapper *resource = static_cast<const QQmlContextWrapper *>(m);
     QV4::ExecutionEngine *v4 = resource->engine();
     QV4::Scope scope(v4);
 
-    // In V8 the JS global object would come _before_ the QML global object,
-    // so simulate that here.
-    bool hasProp;
-    QV4::ScopedValue result(scope, v4->globalObject->get(name, &hasProp));
-    if (hasProp) {
-        if (hasProperty)
-            *hasProperty = hasProp;
-        return result->asReturnedValue();
-    }
-
-    if (resource->d()->isNullWrapper)
-        return Object::get(m, name, hasProperty);
+    if (v4->callingQmlContext() != *resource->d()->context) {
+        if (resource->d()->module) {
+            Scoped<Module> module(scope, resource->d()->module);
+            bool hasProp = false;
+            ScopedValue value(scope, module->get(id, receiver, &hasProp));
+            if (hasProp) {
+                if (hasProperty)
+                    *hasProperty = hasProp;
+                return value->asReturnedValue();
+            }
+        }
 
-    if (v4->callingQmlContext() != *resource->d()->context)
-        return Object::get(m, name, hasProperty);
+        return Object::virtualGet(m, id, receiver, hasProperty);
+    }
 
-    result = Object::get(m, name, &hasProp);
+    bool hasProp = false;
+    ScopedValue result(scope, Object::virtualGet(m, id, receiver, &hasProp));
     if (hasProp) {
         if (hasProperty)
             *hasProperty = hasProp;
         return result->asReturnedValue();
     }
 
-    // Its possible we could delay the calculation of the "actual" context (in the case
-    // of sub contexts) until it is definately needed.
+    // It's possible we could delay the calculation of the "actual" context (in the case
+    // of sub contexts) until it is definitely needed.
     QQmlContextData *context = resource->getContext();
     QQmlContextData *expressionContext = context;
 
@@ -132,17 +132,51 @@ ReturnedValue QQmlContextWrapper::get(const Managed *m, String *name, bool *hasP
 
     QObject *scopeObject = resource->getScopeObject();
 
+    ScopedString name(scope, id.asStringOrSymbol());
+
+    const auto performGobalLookUp = [&result, v4, &name, hasProperty]() {
+        bool hasProp = false;
+        result = v4->globalObject->get(name, &hasProp);
+        if (hasProp) {
+            if (hasProperty)
+                *hasProperty = hasProp;
+            return true;
+        }
+        return false;
+    };
+
+    // If the scope object is a QAbstractDynamicMetaObject, then QMetaObject::indexOfProperty
+    // will call createProperty() on the QADMO and implicitly create the property. While that
+    // is questionable behavior, there are two use-cases that we support in the light of this:
+    //
+    //    (1) The implicit creation of properties is necessary because it will also result in
+    //        a recorded capture, which will allow a re-evaluation of bindings when the value
+    //        is populated later. See QTBUG-35233 and the test-case in tst_qqmlpropertymap.
+    //
+    //    (1) Looking up "console" in order to place a console.log() call for example must
+    //        find the console instead of creating a new property. Therefore we prioritize the
+    //        lookup in the global object here.
+    //
+    // Note: The scope object is only a QADMO for example when somebody registers a QQmlPropertyMap
+    // sub-class as QML type and then instantiates it in .qml.
+    if (scopeObject && QQmlPropertyCache::isDynamicMetaObject(scopeObject->metaObject())) {
+        if (performGobalLookUp())
+            return result->asReturnedValue();
+    }
+
     if (context->imports && name->startsWithUpper()) {
         // Search for attached properties, enums and imported scripts
-        QQmlTypeNameCache::Result r = context->imports->query(name);
+        QQmlTypeNameCache::Result r = context->imports->query(name, QQmlImport::AllowRecursion);
 
         if (r.isValid()) {
             if (hasProperty)
                 *hasProperty = true;
             if (r.scriptIndex != -1) {
                 QV4::ScopedObject scripts(scope, context->importedScripts.valueRef());
-                return scripts->getIndexed(r.scriptIndex);
-            } else if (r.type) {
+                if (scripts)
+                    return scripts->get(r.scriptIndex);
+                return QV4::Encode::null();
+            } else if (r.type.isValid()) {
                 return QQmlTypeWrapper::create(v4, scopeObject, r.type);
             } else if (r.importNamespace) {
                 return QQmlTypeWrapper::create(v4, scopeObject, context->imports, r.importNamespace);
@@ -157,7 +191,7 @@ ReturnedValue QQmlContextWrapper::get(const Managed *m, String *name, bool *hasP
 
     while (context) {
         // Search context properties
-        const QV4::IdentifierHash<int> &properties = context->propertyNames();
+        const QV4::IdentifierHash &properties = context->propertyNames();
         if (properties.count()) {
             int propertyIdx = properties.value(name);
 
@@ -203,7 +237,7 @@ ReturnedValue QQmlContextWrapper::get(const Managed *m, String *name, bool *hasP
                 return result->asReturnedValue();
             }
         }
-        scopeObject = 0;
+        scopeObject = nullptr;
 
 
         // Search context object
@@ -220,14 +254,23 @@ ReturnedValue QQmlContextWrapper::get(const Managed *m, String *name, bool *hasP
         context = context->parent;
     }
 
+    // Do a lookup in the global object here to avoid expressionContext->unresolvedNames becoming
+    // true if we access properties of the global object.
+    if (performGobalLookUp())
+        return result->asReturnedValue();
+
     expressionContext->unresolvedNames = true;
 
     return Encode::undefined();
 }
 
-bool QQmlContextWrapper::put(Managed *m, String *name, const Value &value)
+bool QQmlContextWrapper::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
     Q_ASSERT(m->as<QQmlContextWrapper>());
+
+    if (id.isSymbol() || id.isArrayIndex())
+        return Object::virtualPut(m, id, value, receiver);
+
     QQmlContextWrapper *resource = static_cast<QQmlContextWrapper *>(m);
     ExecutionEngine *v4 = resource->engine();
     QV4::Scope scope(v4);
@@ -235,24 +278,12 @@ bool QQmlContextWrapper::put(Managed *m, String *name, const Value &value)
         return false;
     QV4::Scoped<QQmlContextWrapper> wrapper(scope, resource);
 
-    uint member = wrapper->internalClass()->find(name);
-    if (member < UINT_MAX)
-        return wrapper->putValue(member, value);
-
-    if (wrapper->d()->isNullWrapper) {
-        if (wrapper && wrapper->d()->readOnly) {
-            QString error = QLatin1String("Invalid write to global property \"") + name->toQString() +
-                            QLatin1Char('"');
-            ScopedString e(scope, v4->newString(error));
-            v4->throwError(e);
-            return false;
-        }
+    auto member = wrapper->internalClass()->findValueOrSetter(id);
+    if (member.index < UINT_MAX)
+        return wrapper->putValue(member.index, member.attrs, value);
 
-        return Object::put(m, name, value);
-    }
-
-    // Its possible we could delay the calculation of the "actual" context (in the case
-    // of sub contexts) until it is definately needed.
+    // It's possible we could delay the calculation of the "actual" context (in the case
+    // of sub contexts) until it is definitely needed.
     QQmlContextData *context = wrapper->getContext();
     QQmlContextData *expressionContext = context;
 
@@ -262,9 +293,10 @@ bool QQmlContextWrapper::put(Managed *m, String *name, const Value &value)
     // See QV8ContextWrapper::Getter for resolution order
 
     QObject *scopeObject = wrapper->getScopeObject();
+    ScopedString name(scope, id.asStringOrSymbol());
 
     while (context) {
-        const QV4::IdentifierHash<int> &properties = context->propertyNames();
+        const QV4::IdentifierHash &properties = context->propertyNames();
         // Search context properties
         if (properties.count() && properties.value(name) != -1)
             return false;
@@ -273,7 +305,7 @@ bool QQmlContextWrapper::put(Managed *m, String *name, const Value &value)
         if (scopeObject &&
             QV4::QObjectWrapper::setQmlProperty(v4, context, scopeObject, name, QV4::QObjectWrapper::CheckRevision, value))
             return true;
-        scopeObject = 0;
+        scopeObject = nullptr;
 
         // Search context object
         if (context->contextObject &&
@@ -285,58 +317,25 @@ bool QQmlContextWrapper::put(Managed *m, String *name, const Value &value)
 
     expressionContext->unresolvedNames = true;
 
-    if (wrapper->d()->readOnly) {
-        QString error = QLatin1String("Invalid write to global property \"") + name->toQString() +
-                        QLatin1Char('"');
-        v4->throwError(error);
-        return false;
-    }
-
-    return Object::put(m, name, value);
+    QString error = QLatin1String("Invalid write to global property \"") + name->toQString() +
+            QLatin1Char('"');
+    v4->throwError(error);
+    return false;
 }
 
 void Heap::QmlContext::init(QV4::ExecutionContext *outerContext, QV4::QQmlContextWrapper *qml)
 {
     Heap::ExecutionContext::init(Heap::ExecutionContext::Type_QmlContext);
     outer.set(internalClass->engine, outerContext->d());
-    strictMode = false;
-    callData = outer->callData;
-    lookups = outer->lookups;
-    constantTable = outer->constantTable;
-    compilationUnit = outer->compilationUnit;
 
-    this->qml.set(internalClass->engine, qml->d());
-}
-
-Heap::QmlContext *QmlContext::createWorkerContext(ExecutionContext *parent, const QUrl &source, Value *sendFunction)
-{
-    Scope scope(parent);
-
-    QQmlContextData *context = new QQmlContextData;
-    context->baseUrl = source;
-    context->baseUrlString = source.toString();
-    context->isInternal = true;
-    context->isJSContext = true;
-
-    Scoped<QQmlContextWrapper> qml(scope, scope.engine->memoryManager->allocObject<QQmlContextWrapper>(context, (QObject*)0, true));
-    qml->d()->isNullWrapper = true;
-
-    qml->setReadOnly(false);
-    QV4::ScopedObject api(scope, scope.engine->newObject());
-    api->put(QV4::ScopedString(scope, scope.engine->newString(QStringLiteral("sendMessage"))), *sendFunction);
-    qml->QV4::Object::put(QV4::ScopedString(scope, scope.engine->newString(QStringLiteral("WorkerScript"))), api);
-    qml->setReadOnly(true);
-
-    Heap::QmlContext *c = scope.engine->memoryManager->alloc<QmlContext>(parent, qml);
-    Q_ASSERT(c->vtable() == staticVTable());
-    return c;
+    this->activation.set(internalClass->engine, qml->d());
 }
 
 Heap::QmlContext *QmlContext::create(ExecutionContext *parent, QQmlContextData *context, QObject *scopeObject)
 {
     Scope scope(parent);
 
-    Scoped<QQmlContextWrapper> qml(scope, scope.engine->memoryManager->allocObject<QQmlContextWrapper>(context, scopeObject));
+    Scoped<QQmlContextWrapper> qml(scope, scope.engine->memoryManager->allocate<QQmlContextWrapper>(context, scopeObject));
     Heap::QmlContext *c = scope.engine->memoryManager->alloc<QmlContext>(parent, qml);
     Q_ASSERT(c->vtable() == staticVTable());
     return c;
diff --git a/src/qml/jsruntime/qv4qmlcontext_p.h b/src/qml/jsruntime/qv4qmlcontext_p.h
index 2f1dbabaf2..dd6de3323d 100644
--- a/src/qml/jsruntime/qv4qmlcontext_p.h
+++ b/src/qml/jsruntime/qv4qmlcontext_p.h
@@ -66,23 +66,25 @@ struct QQmlContextWrapper;
 
 namespace Heap {
 
-struct QQmlContextWrapper : Object {
-    void init(QQmlContextData *context, QObject *scopeObject, bool ownsContext = false);
+#define QQmlContextWrapperMembers(class, Member) \
+    Member(class, Pointer, Module *, module)
+
+DECLARE_HEAP_OBJECT(QQmlContextWrapper, Object) {
+    DECLARE_MARKOBJECTS(QQmlContextWrapper);
+
+    void init(QQmlContextData *context, QObject *scopeObject);
     void destroy();
-    bool readOnly;
-    bool ownsContext;
-    bool isNullWrapper;
 
-    QQmlGuardedContextData *context;
+    QQmlContextDataRef *context;
     QQmlQPointer<QObject> scopeObject;
 };
 
-#define QmlContextMembers(class, Member) \
-    Member(class, Pointer, QQmlContextWrapper *, qml)
+#define QmlContextMembers(class, Member)
 
 DECLARE_HEAP_OBJECT(QmlContext, ExecutionContext) {
-    DECLARE_MARK_TABLE(QmlContext);
+    DECLARE_MARKOBJECTS(QmlContext);
 
+    QQmlContextWrapper *qml() { return static_cast<QQmlContextWrapper *>(activation.get()); }
     void init(QV4::ExecutionContext *outerContext, QV4::QQmlContextWrapper *qml);
 };
 
@@ -92,36 +94,27 @@ struct Q_QML_EXPORT QQmlContextWrapper : Object
 {
     V4_OBJECT2(QQmlContextWrapper, Object)
     V4_NEEDS_DESTROY
-
-    void takeContextOwnership() {
-        d()->ownsContext = true;
-    }
+    V4_INTERNALCLASS(QmlContextWrapper)
 
     inline QObject *getScopeObject() const { return d()->scopeObject; }
     inline QQmlContextData *getContext() const { return *d()->context; }
 
-    void setReadOnly(bool b) { d()->readOnly = b; }
-
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static bool put(Managed *m, String *name, const Value &value);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
 };
 
 struct Q_QML_EXPORT QmlContext : public ExecutionContext
 {
     V4_MANAGED(QmlContext, ExecutionContext)
+    V4_INTERNALCLASS(QmlContext)
 
-    static Heap::QmlContext *createWorkerContext(QV4::ExecutionContext *parent, const QUrl &source, Value *sendFunction);
     static Heap::QmlContext *create(QV4::ExecutionContext *parent, QQmlContextData *context, QObject *scopeObject);
 
     QObject *qmlScope() const {
-        return d()->qml->scopeObject;
+        return d()->qml()->scopeObject;
     }
     QQmlContextData *qmlContext() const {
-        return *d()->qml->context;
-    }
-
-    void takeContextOwnership() {
-        d()->qml->ownsContext = true;
+        return *d()->qml()->context;
     }
 };
 
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index 91650f16e2..15f064ba7a 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -39,7 +39,7 @@
 
 #include "qv4qobjectwrapper_p.h"
 
-#include <private/qqmlpropertycache_p.h>
+#include <private/qqmlstaticmetaobject_p.h>
 #include <private/qqmlengine_p.h>
 #include <private/qqmlvmemetaobject_p.h>
 #include <private/qqmlbinding_p.h>
@@ -56,12 +56,17 @@
 #include <private/qv4functionobject_p.h>
 #include <private/qv4runtime_p.h>
 #include <private/qv4variantobject_p.h>
+
+#if QT_CONFIG(qml_sequence_object)
 #include <private/qv4sequenceobject_p.h>
+#endif
+
 #include <private/qv4objectproto_p.h>
 #include <private/qv4jsonobject_p.h>
 #include <private/qv4regexpobject_p.h>
 #include <private/qv4dateobject_p.h>
 #include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 #include <private/qv4mm_p.h>
 #include <private/qqmlscriptstring_p.h>
 #include <private/qv4compileddata_p.h>
@@ -98,13 +103,13 @@ QPair<QObject *, int> QObjectMethod::extractQtMethod(const QV4::FunctionObject *
             return qMakePair(method->object(), method->methodIndex());
     }
 
-    return qMakePair((QObject *)0, -1);
+    return qMakePair((QObject *)nullptr, -1);
 }
 
-static QPair<QObject *, int> extractQtSignal(const Value &value)
+static QPair<QObject *, int> extractQtSignal(const QV4::Value &value)
 {
     if (value.isObject()) {
-        QV4::ExecutionEngine *v4 = value.as<Object>()->engine();
+        QV4::ExecutionEngine *v4 = value.as<QV4::Object>()->engine();
         QV4::Scope scope(v4);
         QV4::ScopedFunctionObject function(scope, value);
         if (function)
@@ -115,7 +120,7 @@ static QPair<QObject *, int> extractQtSignal(const Value &value)
             return qMakePair(handler->object(), handler->signalIndex());
     }
 
-    return qMakePair((QObject *)0, -1);
+    return qMakePair((QObject *)nullptr, -1);
 }
 
 static QV4::ReturnedValue loadProperty(QV4::ExecutionEngine *v4, QObject *object,
@@ -125,7 +130,7 @@ static QV4::ReturnedValue loadProperty(QV4::ExecutionEngine *v4, QObject *object
     QV4::Scope scope(v4);
 
     if (property.isQObject()) {
-        QObject *rv = 0;
+        QObject *rv = nullptr;
         property.readProperty(object, &rv);
         return QV4::QObjectWrapper::wrap(v4, rv);
     } else if (property.isQList()) {
@@ -180,11 +185,13 @@ static QV4::ReturnedValue loadProperty(QV4::ExecutionEngine *v4, QObject *object
         if (const QMetaObject *valueTypeMetaObject = QQmlValueTypeFactory::metaObjectForMetaType(property.propType()))
             return QV4::QQmlValueTypeWrapper::create(v4, object, property.coreIndex(), valueTypeMetaObject, property.propType());
     } else {
+#if QT_CONFIG(qml_sequence_object)
         // see if it's a sequence type
         bool succeeded = false;
-        QV4::ScopedValue retn(scope, QV4::SequencePrototype::newSequence(v4, property.propType(), object, property.coreIndex(), &succeeded));
+        QV4::ScopedValue retn(scope, QV4::SequencePrototype::newSequence(v4, property.propType(), object, property.coreIndex(), !property.isWritable(), &succeeded));
         if (succeeded)
             return retn->asReturnedValue();
+#endif
     }
 
     if (property.propType() == QMetaType::UnknownType) {
@@ -193,7 +200,7 @@ static QV4::ReturnedValue loadProperty(QV4::ExecutionEngine *v4, QObject *object
                  "'%s::%s'", p.typeName(), object->metaObject()->className(), p.name());
         return QV4::Encode::undefined();
     } else {
-        QVariant v(property.propType(), (void *)0);
+        QVariant v(property.propType(), (void *)nullptr);
         property.readProperty(object, v.data());
         return scope.engine->fromVariant(v);
     }
@@ -216,7 +223,7 @@ QQmlPropertyData *QObjectWrapper::findProperty(ExecutionEngine *engine, QObject
     Q_UNUSED(revisionMode);
 
     QQmlData *ddata = QQmlData::get(o, false);
-    QQmlPropertyData *result = 0;
+    QQmlPropertyData *result = nullptr;
     if (ddata && ddata->propertyCache)
         result = ddata->propertyCache->property(name, o, qmlContext);
     else
@@ -241,14 +248,14 @@ ReturnedValue QObjectWrapper::getProperty(ExecutionEngine *engine, QObject *obje
             return QV4::QObjectMethod::create(global, object, property->coreIndex());
         } else if (property->isSignalHandler()) {
             QmlSignalHandler::initProto(engine);
-            return engine->memoryManager->allocObject<QV4::QmlSignalHandler>(object, property->coreIndex())->asReturnedValue();
+            return engine->memoryManager->allocate<QV4::QmlSignalHandler>(object, property->coreIndex())->asReturnedValue();
         } else {
             ExecutionContext *global = engine->rootContext();
             return QV4::QObjectMethod::create(global, object, property->coreIndex());
         }
     }
 
-    QQmlEnginePrivate *ep = engine->qmlEngine() ? QQmlEnginePrivate::get(engine->qmlEngine()) : 0;
+    QQmlEnginePrivate *ep = engine->qmlEngine() ? QQmlEnginePrivate::get(engine->qmlEngine()) : nullptr;
 
     if (captureRequired && ep && ep->propertyCapture && !property->isConstant())
         ep->propertyCapture->captureProperty(object, property->coreIndex(), property->notifyIndex());
@@ -296,7 +303,7 @@ ReturnedValue QObjectWrapper::getQmlProperty(QQmlContextData *qmlContext, String
                 if (r.isValid()) {
                     if (r.scriptIndex != -1) {
                         return QV4::Encode::undefined();
-                    } else if (r.type) {
+                    } else if (r.type.isValid()) {
                         return QQmlTypeWrapper::create(v4, d()->object(),
                                                       r.type, Heap::QQmlTypeWrapper::ExcludeEnums);
                     } else if (r.importNamespace) {
@@ -307,7 +314,7 @@ ReturnedValue QObjectWrapper::getQmlProperty(QQmlContextData *qmlContext, String
                 }
             }
         }
-        return QV4::Object::get(this, name, hasProperty);
+        return QV4::Object::virtualGet(this, name->propertyKey(), this, hasProperty);
     }
 
     QQmlData *ddata = QQmlData::get(d()->object(), false);
@@ -334,6 +341,11 @@ ReturnedValue QObjectWrapper::getProperty(ExecutionEngine *engine, QObject *obje
     if (!ddata)
         return QV4::Encode::undefined();
 
+    if (Q_UNLIKELY(!ddata->propertyCache)) {
+        ddata->propertyCache = QQmlEnginePrivate::get(engine)->cache(object->metaObject());
+        ddata->propertyCache->addref();
+    }
+
     QQmlPropertyCache *cache = ddata->propertyCache;
     Q_ASSERT(cache);
     QQmlPropertyData *property = cache->property(propertyIndex);
@@ -433,7 +445,7 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP
         return;
     }
 
-    QQmlBinding *newBinding = 0;
+    QQmlBinding *newBinding = nullptr;
     QV4::Scope scope(engine);
     QV4::ScopedFunctionObject f(scope, value);
     if (f) {
@@ -454,9 +466,12 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP
 
             QV4::Scoped<QQmlBindingFunction> bindingFunction(scope, (const Value &)f);
 
+            QV4::ScopedFunctionObject f(scope, bindingFunction->bindingFunction());
             QV4::ScopedContext ctx(scope, bindingFunction->scope());
-            newBinding = QQmlBinding::create(property, bindingFunction->function(), object, callingQmlContext, ctx);
+            newBinding = QQmlBinding::create(property, f->function(), object, callingQmlContext, ctx);
             newBinding->setSourceLocation(bindingFunction->currentLocation());
+            if (f->isBoundFunction())
+                newBinding->setBoundFunction(static_cast<QV4::BoundFunction *>(f.getPointer()));
             newBinding->setTarget(object, *property, nullptr);
         }
     }
@@ -468,11 +483,11 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP
             if (auto binding = QQmlPropertyPrivate::binding(object, QQmlPropertyIndex(property->coreIndex()))) {
                 Q_ASSERT(!binding->isValueTypeProxy());
                 const auto qmlBinding = static_cast<const QQmlBinding*>(binding);
-                const auto stackFrame = engine->currentStackFrame();
+                const auto stackFrame = engine->currentStackFrame;
                 qCInfo(lcBindingRemoval,
                        "Overwriting binding on %s::%s at %s:%d that was initially bound at %s",
                        object->metaObject()->className(), qPrintable(property->name(object)),
-                       qPrintable(stackFrame.source), stackFrame.line,
+                       qPrintable(stackFrame->source()), stackFrame->lineNumber(),
                        qPrintable(qmlBinding->expressionIdentifier()));
             }
         }
@@ -495,9 +510,9 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP
     QMetaObject::metacall(object, QMetaObject::WriteProperty, property->coreIndex(), argv);
 
     if (value.isNull() && property->isQObject()) {
-        PROPERTY_STORE(QObject*, 0);
+        PROPERTY_STORE(QObject*, nullptr);
     } else if (value.isUndefined() && property->isResettable()) {
-        void *a[] = { 0 };
+        void *a[] = { nullptr };
         QMetaObject::metacall(object, QMetaObject::ResetProperty, property->coreIndex(), a);
     } else if (value.isUndefined() && property->propType() == qMetaTypeId<QVariant>()) {
         PROPERTY_STORE(QVariant, QVariant());
@@ -530,7 +545,7 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP
         Q_ASSERT(vmemo);
         vmemo->setVMEProperty(property->coreIndex(), value);
     } else if (property->propType() == qMetaTypeId<QQmlScriptString>() && (value.isUndefined() || value.isPrimitive())) {
-        QQmlScriptString ss(value.toQStringNoThrow(), 0 /* context */, object);
+        QQmlScriptString ss(value.toQStringNoThrow(), nullptr /* context */, object);
         if (value.isNumber()) {
             ss.d->numberValue = value.toNumber();
             ss.d->isNumberLiteral = true;
@@ -548,7 +563,7 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, QQmlP
 
         QQmlContextData *callingQmlContext = scope.engine->callingQmlContext();
         if (!QQmlPropertyPrivate::write(object, *property, v, callingQmlContext)) {
-            const char *valueType = 0;
+            const char *valueType = nullptr;
             if (v.userType() == QVariant::Invalid) valueType = "null";
             else valueType = QMetaType::typeName(v.userType());
 
@@ -589,7 +604,7 @@ ReturnedValue QObjectWrapper::wrap_slowPath(ExecutionEngine *engine, QObject *ob
     } else {
         // If this object is tainted, we have to check to see if it is in our
         // tainted object list
-        ScopedObject alternateWrapper(scope, (Object *)0);
+        ScopedObject alternateWrapper(scope, (Object *)nullptr);
         if (engine->m_multiplyWrappedQObjects && ddata->hasTaintedV4Object)
             alternateWrapper = engine->m_multiplyWrappedQObjects->value(object);
 
@@ -652,7 +667,7 @@ void QObjectWrapper::setProperty(ExecutionEngine *engine, QObject *object, int p
     return setProperty(engine, object, property, value);
 }
 
-bool QObjectWrapper::isEqualTo(Managed *a, Managed *b)
+bool QObjectWrapper::virtualIsEqualTo(Managed *a, Managed *b)
 {
     Q_ASSERT(a->as<QV4::QObjectWrapper>());
     QV4::QObjectWrapper *qobjectWrapper = static_cast<QV4::QObjectWrapper *>(a);
@@ -675,66 +690,92 @@ ReturnedValue QObjectWrapper::create(ExecutionEngine *engine, QObject *object)
                 return result;
         }
     }
-    return (engine->memoryManager->allocObject<QV4::QObjectWrapper>(object))->asReturnedValue();
+    return (engine->memoryManager->allocate<QV4::QObjectWrapper>(object))->asReturnedValue();
 }
 
-QV4::ReturnedValue QObjectWrapper::get(const Managed *m, String *name, bool *hasProperty)
+QV4::ReturnedValue QObjectWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
+    if (!id.isString())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+
     const QObjectWrapper *that = static_cast<const QObjectWrapper*>(m);
+    Scope scope(that);
+    ScopedString n(scope, id.asStringOrSymbol());
     QQmlContextData *qmlContext = that->engine()->callingQmlContext();
-    return that->getQmlProperty(qmlContext, name, IgnoreRevision, hasProperty, /*includeImports*/ true);
+    return that->getQmlProperty(qmlContext, n, IgnoreRevision, hasProperty, /*includeImports*/ true);
 }
 
-bool QObjectWrapper::put(Managed *m, String *name, const Value &value)
+bool QObjectWrapper::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
+    if (!id.isString())
+        return Object::virtualPut(m, id, value, receiver);
+
+    Scope scope(m);
     QObjectWrapper *that = static_cast<QObjectWrapper*>(m);
-    ExecutionEngine *v4 = that->engine();
+    ScopedString name(scope, id.asStringOrSymbol());
 
-    if (v4->hasException || QQmlData::wasDeleted(that->d()->object()))
+    if (scope.engine->hasException || QQmlData::wasDeleted(that->d()->object()))
         return false;
 
-    QQmlContextData *qmlContext = v4->callingQmlContext();
-    if (!setQmlProperty(v4, qmlContext, that->d()->object(), name, QV4::QObjectWrapper::IgnoreRevision, value)) {
+    QQmlContextData *qmlContext = scope.engine->callingQmlContext();
+    if (!setQmlProperty(scope.engine, qmlContext, that->d()->object(), name, QV4::QObjectWrapper::IgnoreRevision, value)) {
         QQmlData *ddata = QQmlData::get(that->d()->object());
         // Types created by QML are not extensible at run-time, but for other QObjects we can store them
         // as regular JavaScript properties, like on JavaScript objects.
         if (ddata && ddata->context) {
             QString error = QLatin1String("Cannot assign to non-existent property \"") +
                             name->toQString() + QLatin1Char('\"');
-            v4->throwError(error);
+            scope.engine->throwError(error);
             return false;
         } else {
-            return QV4::Object::put(m, name, value);
+            return QV4::Object::virtualPut(m, id, value, receiver);
         }
     }
 
     return true;
 }
 
-PropertyAttributes QObjectWrapper::query(const Managed *m, String *name)
+PropertyAttributes QObjectWrapper::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
 {
-    const QObjectWrapper *that = static_cast<const QObjectWrapper*>(m);
-    ExecutionEngine *engine = that->engine();
-    QQmlContextData *qmlContext = engine->callingQmlContext();
-    QQmlPropertyData local;
-    if (that->findProperty(engine, qmlContext, name, IgnoreRevision, &local)
-        || name->equals(engine->id_destroy()) || name->equals(engine->id_toString()))
-        return QV4::Attr_Data;
-    else
-        return QV4::Object::query(m, name);
+    if (id.isString()) {
+        const QObjectWrapper *that = static_cast<const QObjectWrapper*>(m);
+        const QObject *thatObject = that->d()->object();
+        if (!QQmlData::wasDeleted(thatObject)) {
+            Scope scope(m);
+            ScopedString n(scope, id.asStringOrSymbol());
+            QQmlContextData *qmlContext = scope.engine->callingQmlContext();
+            QQmlPropertyData local;
+            if (that->findProperty(scope.engine, qmlContext, n, IgnoreRevision, &local)
+                    || n->equals(scope.engine->id_destroy()) || n->equals(scope.engine->id_toString())) {
+                if (p) {
+                    // ### probably not the fastest implementation
+                    bool hasProperty;
+                    p->value = that->getQmlProperty(qmlContext, n, IgnoreRevision, &hasProperty, /*includeImports*/ true);
+                }
+                return QV4::Attr_Data;
+            }
+        }
+    }
+
+    return QV4::Object::virtualGetOwnProperty(m, id, p);
 }
 
-void QObjectWrapper::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes)
+struct QObjectWrapperOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
+{
+    int propertyIndex = 0;
+    ~QObjectWrapperOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const QV4::Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey QObjectWrapperOwnPropertyKeyIterator::next(const QV4::Object *o, Property *pd, PropertyAttributes *attrs)
 {
     // Used to block access to QObject::destroyed() and QObject::deleteLater() from QML
     static const int destroyedIdx1 = QObject::staticMetaObject.indexOfSignal("destroyed(QObject*)");
     static const int destroyedIdx2 = QObject::staticMetaObject.indexOfSignal("destroyed()");
     static const int deleteLaterIdx = QObject::staticMetaObject.indexOfSlot("deleteLater()");
 
-    name->setM(0);
-    *index = UINT_MAX;
-
-    QObjectWrapper *that = static_cast<QObjectWrapper*>(m);
+    const QObjectWrapper *that = static_cast<const QObjectWrapper*>(o);
 
     QObject *thatObject = that->d()->object();
     if (thatObject && !QQmlData::wasDeleted(thatObject)) {
@@ -742,40 +783,50 @@ void QObjectWrapper::advanceIterator(Managed *m, ObjectIterator *it, Value *name
         // These indices don't apply to gadgets, so don't block them.
         const bool preventDestruction = mo->superClass() || mo == &QObject::staticMetaObject;
         const int propertyCount = mo->propertyCount();
-        if (it->arrayIndex < static_cast<uint>(propertyCount)) {
+        if (propertyIndex < propertyCount) {
             ExecutionEngine *thatEngine = that->engine();
             Scope scope(thatEngine);
-            const QMetaProperty property = mo->property(it->arrayIndex);
+            const QMetaProperty property = mo->property(propertyIndex);
             ScopedString propName(scope, thatEngine->newString(QString::fromUtf8(property.name())));
-            name->setM(propName->d());
-            ++it->arrayIndex;
-            *attributes = QV4::Attr_Data;
-
-            QQmlPropertyData local;
-            local.load(property);
-            p->value = that->getProperty(thatEngine, thatObject, &local);
-            return;
+            ++propertyIndex;
+            if (attrs)
+                *attrs= QV4::Attr_Data;
+            if (pd) {
+                QQmlPropertyData local;
+                local.load(property);
+                pd->value = that->getProperty(thatEngine, thatObject, &local);
+            }
+            return propName->toPropertyKey();
         }
         const int methodCount = mo->methodCount();
-        while (it->arrayIndex < static_cast<uint>(propertyCount + methodCount)) {
-            const int index = it->arrayIndex - propertyCount;
+        while (propertyIndex < propertyCount + methodCount) {
+            Q_ASSERT(propertyIndex >= propertyCount);
+            int index = propertyIndex - propertyCount;
             const QMetaMethod method = mo->method(index);
-            ++it->arrayIndex;
+            ++propertyIndex;
             if (method.access() == QMetaMethod::Private || (preventDestruction && (index == deleteLaterIdx || index == destroyedIdx1 || index == destroyedIdx2)))
                 continue;
             ExecutionEngine *thatEngine = that->engine();
             Scope scope(thatEngine);
             ScopedString methodName(scope, thatEngine->newString(QString::fromUtf8(method.name())));
-            name->setM(methodName->d());
-            *attributes = QV4::Attr_Data;
-
-            QQmlPropertyData local;
-            local.load(method);
-            p->value = that->getProperty(thatEngine, thatObject, &local);
-            return;
+            if (attrs)
+                *attrs = QV4::Attr_Data;
+            if (pd) {
+                QQmlPropertyData local;
+                local.load(method);
+                pd->value = that->getProperty(thatEngine, thatObject, &local);
+            }
+            return methodName->toPropertyKey();
         }
     }
-    QV4::Object::advanceIterator(m, it, name, index, p, attributes);
+
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+OwnPropertyKeyIterator *QObjectWrapper::virtualOwnPropertyKeys(const Object *m, Value *target)
+{
+    *target = *m;
+    return new QObjectWrapperOwnPropertyKeyIterator;
 }
 
 namespace QV4 {
@@ -808,25 +859,25 @@ struct QObjectSlotDispatcher : public QtPrivate::QSlotObjectBase
                 break;
 
             QQmlMetaObject::ArgTypeStorage storage;
-            int *argsTypes = QQmlMetaObject(r).methodParameterTypes(This->signalIndex, &storage, 0);
+            int *argsTypes = QQmlMetaObject(r).methodParameterTypes(This->signalIndex, &storage, nullptr);
 
             int argCount = argsTypes ? argsTypes[0]:0;
 
             QV4::Scope scope(v4);
             QV4::ScopedFunctionObject f(scope, This->function.value());
 
-            QV4::ScopedCallData callData(scope, argCount);
-            callData->thisObject = This->thisObject.isUndefined() ? v4->globalObject->asReturnedValue() : This->thisObject.value();
+            QV4::JSCallData jsCallData(scope, argCount);
+            *jsCallData->thisObject = This->thisObject.isUndefined() ? v4->globalObject->asReturnedValue() : This->thisObject.value();
             for (int ii = 0; ii < argCount; ++ii) {
                 int type = argsTypes[ii + 1];
                 if (type == qMetaTypeId<QVariant>()) {
-                    callData->args[ii] = v4->fromVariant(*((QVariant *)metaArgs[ii + 1]));
+                    jsCallData->args[ii] = v4->fromVariant(*((QVariant *)metaArgs[ii + 1]));
                 } else {
-                    callData->args[ii] = v4->fromVariant(QVariant(type, metaArgs[ii + 1]));
+                    jsCallData->args[ii] = v4->fromVariant(QVariant(type, metaArgs[ii + 1]));
                 }
             }
 
-            f->call(scope, callData);
+            f->call(jsCallData);
             if (scope.hasException()) {
                 QQmlError error = v4->catchExceptionAsQmlError();
                 if (error.description().isEmpty()) {
@@ -837,7 +888,7 @@ struct QObjectSlotDispatcher : public QtPrivate::QSlotObjectBase
                     QQmlEnginePrivate::get(qmlEngine)->warning(error);
                 } else {
                     QMessageLogger(error.url().toString().toLatin1().constData(),
-                                   error.line(), 0).warning().noquote()
+                                   error.line(), nullptr).warning().noquote()
                             << error.toString();
                 }
             }
@@ -899,12 +950,14 @@ struct QObjectSlotDispatcher : public QtPrivate::QSlotObjectBase
 
 } // namespace QV4
 
-void QObjectWrapper::method_connect(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QObjectWrapper::method_connect(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    QV4::Scope scope(b);
+
+    if (argc == 0)
         THROW_GENERIC_ERROR("Function.prototype.connect: no arguments given");
 
-    QPair<QObject *, int> signalInfo = extractQtSignal(callData->thisObject);
+    QPair<QObject *, int> signalInfo = extractQtSignal(*thisObject);
     QObject *signalObject = signalInfo.first;
     int signalIndex = signalInfo.second; // in method range, not signal range!
 
@@ -918,25 +971,25 @@ void QObjectWrapper::method_connect(const BuiltinFunction *, Scope &scope, CallD
         THROW_GENERIC_ERROR("Function.prototype.connect: this object is not a signal");
 
     QV4::ScopedFunctionObject f(scope);
-    QV4::ScopedValue thisObject (scope, QV4::Encode::undefined());
+    QV4::ScopedValue object (scope, QV4::Encode::undefined());
 
-    if (callData->argc == 1) {
-        f = callData->args[0];
-    } else if (callData->argc >= 2) {
-        thisObject = callData->args[0];
-        f = callData->args[1];
+    if (argc == 1) {
+        f = argv[0];
+    } else if (argc >= 2) {
+        object = argv[0];
+        f = argv[1];
     }
 
     if (!f)
         THROW_GENERIC_ERROR("Function.prototype.connect: target is not a function");
 
-    if (!thisObject->isUndefined() && !thisObject->isObject())
+    if (!object->isUndefined() && !object->isObject())
         THROW_GENERIC_ERROR("Function.prototype.connect: target this is not an object");
 
     QV4::QObjectSlotDispatcher *slot = new QV4::QObjectSlotDispatcher;
     slot->signalIndex = signalIndex;
 
-    slot->thisObject.set(scope.engine, thisObject);
+    slot->thisObject.set(scope.engine, object);
     slot->function.set(scope.engine, f);
 
     if (QQmlData *ddata = QQmlData::get(signalObject)) {
@@ -949,12 +1002,14 @@ void QObjectWrapper::method_connect(const BuiltinFunction *, Scope &scope, CallD
     RETURN_UNDEFINED();
 }
 
-void QObjectWrapper::method_disconnect(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QObjectWrapper::method_disconnect(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    QV4::Scope scope(b);
+
+    if (argc == 0)
         THROW_GENERIC_ERROR("Function.prototype.disconnect: no arguments given");
 
-    QPair<QObject *, int> signalInfo = extractQtSignal(callData->thisObject);
+    QPair<QObject *, int> signalInfo = extractQtSignal(*thisObject);
     QObject *signalObject = signalInfo.first;
     int signalIndex = signalInfo.second;
 
@@ -970,11 +1025,11 @@ void QObjectWrapper::method_disconnect(const BuiltinFunction *, Scope &scope, Ca
     QV4::ScopedFunctionObject functionValue(scope);
     QV4::ScopedValue functionThisValue(scope, QV4::Encode::undefined());
 
-    if (callData->argc == 1) {
-        functionValue = callData->args[0];
-    } else if (callData->argc >= 2) {
-        functionThisValue = callData->args[0];
-        functionValue = callData->args[1];
+    if (argc == 1) {
+        functionValue = argv[0];
+    } else if (argc >= 2) {
+        functionThisValue = argv[0];
+        functionValue = argv[1];
     }
 
     if (!functionValue)
@@ -1010,9 +1065,9 @@ static void markChildQObjectsRecursively(QObject *parent, QV4::MarkStack *markSt
     }
 }
 
-void QObjectWrapper::markObjects(Heap::Base *that, QV4::MarkStack *markStack)
+void Heap::QObjectWrapper::markObjects(Heap::Base *that, QV4::MarkStack *markStack)
 {
-    QObjectWrapper::Data *This = static_cast<QObjectWrapper::Data *>(that);
+    QObjectWrapper *This = static_cast<QObjectWrapper *>(that);
 
     if (QObject *o = This->object()) {
         QQmlVMEMetaObject *vme = QQmlVMEMetaObject::get(o);
@@ -1027,7 +1082,7 @@ void QObjectWrapper::markObjects(Heap::Base *that, QV4::MarkStack *markStack)
             markChildQObjectsRecursively(o, markStack);
     }
 
-    QV4::Object::markObjects(that, markStack);
+    Object::markObjects(that, markStack);
 }
 
 void QObjectWrapper::destroyObject(bool lastCall)
@@ -1040,8 +1095,12 @@ void QObjectWrapper::destroyObject(bool lastCall)
         QQmlData *ddata = QQmlData::get(h->object(), false);
         if (ddata) {
             if (!h->object()->parent() && !ddata->indestructible) {
-                if (ddata && ddata->ownContext && ddata->context)
-                    ddata->context->emitDestruction();
+                if (ddata && ddata->ownContext) {
+                    Q_ASSERT(ddata->ownContext == ddata->context);
+                    ddata->ownContext->emitDestruction();
+                    ddata->ownContext = nullptr;
+                    ddata->context = nullptr;
+                }
                 // This object is notionally destroyed now
                 ddata->isQueuedForDeletion = true;
                 if (lastCall)
@@ -1085,7 +1144,7 @@ struct CallArgument {
     inline void *dataPtr();
 
     inline void initAsType(int type);
-    inline void fromValue(int type, ExecutionEngine *, const Value &);
+    inline bool fromValue(int type, ExecutionEngine *, const QV4::Value &);
     inline ReturnedValue toValue(ExecutionEngine *);
 
 private:
@@ -1145,8 +1204,24 @@ static QV4::ReturnedValue CallMethod(const QQmlObjectOrGadget &object, int index
         // Convert all arguments.
         QVarLengthArray<CallArgument, 9> args(argCount + 1);
         args[0].initAsType(returnType);
-        for (int ii = 0; ii < argCount; ++ii)
-            args[ii + 1].fromValue(argTypes[ii], engine, callArgs->args[ii]);
+        for (int ii = 0; ii < argCount; ++ii) {
+            if (!args[ii + 1].fromValue(argTypes[ii], engine, callArgs->args[ii])) {
+                qWarning() << QString::fromLatin1("Could not convert argument %1 at").arg(ii);
+                const StackTrace stack = engine->stackTrace();
+                for (const StackFrame &frame : stack) {
+                    qWarning() << "\t" << frame.function + QLatin1Char('@') + frame.source
+                                    + (frame.line > 0
+                                               ? (QLatin1Char(':') + QString::number(frame.line))
+                                               : QString());
+
+                }
+                qWarning() << QLatin1String("Passing incompatible arguments to C++ functions from "
+                                            "JavaScript is dangerous and deprecated.");
+                qWarning() << QLatin1String("This will throw a JavaScript TypeError in future "
+                                            "releases of Qt!");
+
+            }
+        }
         QVarLengthArray<void *, 9> argData(args.count());
         for (int ii = 0; ii < args.count(); ++ii)
             argData[ii] = args[ii].dataPtr();
@@ -1168,14 +1243,14 @@ static QV4::ReturnedValue CallMethod(const QQmlObjectOrGadget &object, int index
 
     } else {
 
-        void *args[] = { 0 };
+        void *args[] = { nullptr };
         object.metacall(callType, index, args);
         return Encode::undefined();
 
     }
 }
 
-/*!
+/*
     Returns the match score for converting \a actual to be of type \a conversionType.  A
     zero score means "perfect match" whereas a higher score is worse.
 
@@ -1242,6 +1317,9 @@ static int MatchScore(const QV4::Value &actual, int conversionType)
     } else if (actual.as<QV4::RegExpObject>()) {
         switch (conversionType) {
         case QMetaType::QRegExp:
+#if QT_CONFIG(regularexpression)
+        case QMetaType::QRegularExpression:
+#endif
             return 0;
         default:
             return 10;
@@ -1283,7 +1361,7 @@ static int MatchScore(const QV4::Value &actual, int conversionType)
                 return 10;
         }
         }
-    } else if (const Object *obj = actual.as<Object>()) {
+    } else if (const QV4::Object *obj = actual.as<QV4::Object>()) {
         if (obj->as<QV4::VariantObject>()) {
             if (conversionType == qMetaTypeId<QVariant>())
                 return 0;
@@ -1332,7 +1410,7 @@ static inline int QMetaObject_methods(const QMetaObject *metaObject)
     return reinterpret_cast<const Private *>(metaObject->d.data)->methodCount;
 }
 
-/*!
+/*
 Returns the next related method, if one, or 0.
 */
 static const QQmlPropertyData * RelatedMethod(const QQmlObjectOrGadget &object,
@@ -1341,7 +1419,7 @@ static const QQmlPropertyData * RelatedMethod(const QQmlObjectOrGadget &object,
                                               const QQmlPropertyCache *propertyCache)
 {
     if (!current->isOverload())
-        return 0;
+        return nullptr;
 
     Q_ASSERT(!current->overrideIndexIsProperty());
 
@@ -1359,7 +1437,7 @@ static const QQmlPropertyData * RelatedMethod(const QQmlObjectOrGadget &object,
         // If we've been called before with the same override index, then
         // we can't go any further...
         if (&dummy == current && dummy.coreIndex() == current->overrideIndex())
-            return 0;
+            return nullptr;
 
         QMetaMethod method = mo->method(current->overrideIndex());
         dummy.load(method);
@@ -1394,7 +1472,7 @@ static QV4::ReturnedValue CallPrecise(const QQmlObjectOrGadget &object, const QQ
 
     if (data.hasArguments()) {
 
-        int *args = 0;
+        int *args = nullptr;
         QQmlMetaObject::ArgTypeStorage storage;
 
         if (data.isConstructor())
@@ -1408,7 +1486,7 @@ static QV4::ReturnedValue CallPrecise(const QQmlObjectOrGadget &object, const QQ
                                       + QLatin1String(unknownTypeError));
         }
 
-        if (args[0] > callArgs->argc) {
+        if (args[0] > callArgs->argc()) {
             QString error = QLatin1String("Insufficient arguments");
             return engine->throwError(error);
         }
@@ -1417,12 +1495,12 @@ static QV4::ReturnedValue CallPrecise(const QQmlObjectOrGadget &object, const QQ
 
     } else {
 
-        return CallMethod(object, data.coreIndex(), returnType, 0, 0, engine, callArgs, callType);
+        return CallMethod(object, data.coreIndex(), returnType, 0, nullptr, engine, callArgs, callType);
 
     }
 }
 
-/*!
+/*
 Resolve the overloaded method to call.  The algorithm works conceptually like this:
     1.  Resolve the set of overloads it is *possible* to call.
         Impossible overloads include those that have too many parameters or have parameters
@@ -1439,7 +1517,7 @@ static QV4::ReturnedValue CallOverloaded(const QQmlObjectOrGadget &object, const
                                          QV4::ExecutionEngine *engine, QV4::CallData *callArgs, const QQmlPropertyCache *propertyCache,
                                          QMetaObject::Call callType = QMetaObject::InvokeMetaMethod)
 {
-    int argumentCount = callArgs->argc;
+    int argumentCount = callArgs->argc();
 
     QQmlPropertyData best;
     int bestParameterScore = INT_MAX;
@@ -1454,9 +1532,9 @@ static QV4::ReturnedValue CallOverloaded(const QQmlObjectOrGadget &object, const
     do {
         QQmlMetaObject::ArgTypeStorage storage;
         int methodArgumentCount = 0;
-        int *methodArgTypes = 0;
+        int *methodArgTypes = nullptr;
         if (attempt->hasArguments()) {
-            int *args = object.methodParameterTypes(attempt->coreIndex(), &storage, 0);
+            int *args = object.methodParameterTypes(attempt->coreIndex(), &storage, nullptr);
             if (!args) // Must be an unknown argument
                 continue;
 
@@ -1484,7 +1562,7 @@ static QV4::ReturnedValue CallOverloaded(const QQmlObjectOrGadget &object, const
         if (bestParameterScore == 0 && bestMatchScore == 0)
             break; // We can't get better than that
 
-    } while ((attempt = RelatedMethod(object, attempt, dummy, propertyCache)) != 0);
+    } while ((attempt = RelatedMethod(object, attempt, dummy, propertyCache)) != nullptr);
 
     if (best.isValid()) {
         return CallPrecise(object, best, engine, callArgs, callType);
@@ -1551,7 +1629,7 @@ void *CallArgument::dataPtr()
         return stdVectorQModelIndexPtr;
     else if (type != 0)
         return (void *)&allocData;
-    return 0;
+    return nullptr;
 }
 
 void CallArgument::initAsType(int callType)
@@ -1569,7 +1647,7 @@ void CallArgument::initAsType(int callType)
                callType == QMetaType::Float) {
         type = callType;
     } else if (callType == QMetaType::QObjectStar) {
-        qobjectPtr = 0;
+        qobjectPtr = nullptr;
         type = callType;
     } else if (callType == QMetaType::QString) {
         qstringPtr = new (&allocData) QString();
@@ -1594,10 +1672,11 @@ void CallArgument::initAsType(int callType)
         jsonValuePtr = new (&allocData) QJsonValue();
     } else {
         type = -1;
-        qvariantPtr = new (&allocData) QVariant(callType, (void *)0);
+        qvariantPtr = new (&allocData) QVariant(callType, (void *)nullptr);
     }
 }
 
+#if QT_CONFIG(qml_sequence_object)
 template <class T, class M>
 void CallArgument::fromContainerValue(const QV4::Object *object, int callType, M CallArgument::*member, bool &queryEngine)
 {
@@ -1610,8 +1689,9 @@ void CallArgument::fromContainerValue(const QV4::Object *object, int callType, M
     }
   }
 }
+#endif
 
-void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const QV4::Value &value)
+bool CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const QV4::Value &value)
 {
     if (type != 0) {
         cleanup();
@@ -1646,36 +1726,41 @@ void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
             qstringPtr = new (&allocData) QString(value.toQStringNoThrow());
         type = callType;
     } else if (callType == QMetaType::QObjectStar) {
-        qobjectPtr = 0;
+        qobjectPtr = nullptr;
+        type = callType;
         if (const QV4::QObjectWrapper *qobjectWrapper = value.as<QV4::QObjectWrapper>())
             qobjectPtr = qobjectWrapper->object();
         else if (const QV4::QQmlTypeWrapper *qmlTypeWrapper = value.as<QV4::QQmlTypeWrapper>())
             queryEngine = qmlTypeWrapper->isSingleton();
-        type = callType;
+        else if (!value.isNull() && !value.isUndefined()) // null and undefined are nullptr
+            return false;
     } else if (callType == qMetaTypeId<QVariant>()) {
         qvariantPtr = new (&allocData) QVariant(scope.engine->toVariant(value, -1));
         type = callType;
     } else if (callType == qMetaTypeId<QList<QObject*> >()) {
         qlistPtr = new (&allocData) QList<QObject *>();
+        type = callType;
         QV4::ScopedArrayObject array(scope, value);
         if (array) {
             Scoped<QV4::QObjectWrapper> qobjectWrapper(scope);
 
             uint length = array->getLength();
             for (uint ii = 0; ii < length; ++ii)  {
-                QObject *o = 0;
-                qobjectWrapper = array->getIndexed(ii);
+                QObject *o = nullptr;
+                qobjectWrapper = array->get(ii);
                 if (!!qobjectWrapper)
                     o = qobjectWrapper->object();
                 qlistPtr->append(o);
             }
         } else {
-            QObject *o = 0;
-            if (const QV4::QObjectWrapper *qobjectWrapper = value.as<QV4::QObjectWrapper>())
-                o = qobjectWrapper->object();
-            qlistPtr->append(o);
+            if (const QV4::QObjectWrapper *qobjectWrapper = value.as<QV4::QObjectWrapper>()) {
+                qlistPtr->append(qobjectWrapper->object());
+            } else {
+                qlistPtr->append(nullptr);
+                if (!value.isNull() && !value.isUndefined())
+                    return false;
+            }
         }
-        type = callType;
     } else if (callType == qMetaTypeId<QQmlV4Handle>()) {
         handlePtr = new (&allocData) QQmlV4Handle(value.asReturnedValue());
         type = callType;
@@ -1692,6 +1777,7 @@ void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
         type = callType;
     } else if (callType == QMetaType::Void) {
         *qvariantPtr = QVariant();
+#if QT_CONFIG(qml_sequence_object)
     } else if (callType == qMetaTypeId<std::vector<int>>()
                || callType == qMetaTypeId<std::vector<qreal>>()
                || callType == qMetaTypeId<std::vector<bool>>()
@@ -1699,7 +1785,7 @@ void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
                || callType == qMetaTypeId<std::vector<QUrl>>()
                || callType == qMetaTypeId<std::vector<QModelIndex>>()) {
         queryEngine = true;
-        const QV4::Object* object = value.as<Object>();
+        const QV4::Object* object = value.as<QV4::Object>();
         if (callType == qMetaTypeId<std::vector<int>>()) {
             stdVectorIntPtr = nullptr;
             fromContainerValue<std::vector<int>>(object, callType, &CallArgument::stdVectorIntPtr, queryEngine);
@@ -1719,6 +1805,16 @@ void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
             stdVectorQModelIndexPtr = nullptr;
             fromContainerValue<std::vector<QModelIndex>>(object, callType, &CallArgument::stdVectorQModelIndexPtr, queryEngine);
         }
+#endif
+    } else if (QMetaType::typeFlags(callType)
+               & (QMetaType::PointerToQObject | QMetaType::PointerToGadget)) {
+        // You can assign null or undefined to any pointer. The result is a nullptr.
+        if (value.isNull() || value.isUndefined()) {
+            qvariantPtr = new (&allocData) QVariant(callType, nullptr);
+            type = callType;
+        } else {
+            queryEngine = true;
+        }
     } else {
         queryEngine = true;
     }
@@ -1727,7 +1823,7 @@ void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
         qvariantPtr = new (&allocData) QVariant();
         type = -1;
 
-        QQmlEnginePrivate *ep = engine->qmlEngine() ? QQmlEnginePrivate::get(engine->qmlEngine()) : 0;
+        QQmlEnginePrivate *ep = engine->qmlEngine() ? QQmlEnginePrivate::get(engine->qmlEngine()) : nullptr;
         QVariant v = scope.engine->toVariant(value, callType);
 
         if (v.userType() == callType) {
@@ -1740,15 +1836,20 @@ void CallArgument::fromValue(int callType, QV4::ExecutionEngine *engine, const Q
             if (!mo.isNull()) {
                 QObject *obj = ep->toQObject(v);
 
-                if (obj != 0 && !QQmlMetaObject::canConvert(obj, mo))
-                    obj = 0;
+                if (obj != nullptr && !QQmlMetaObject::canConvert(obj, mo)) {
+                    *qvariantPtr = QVariant(callType, nullptr);
+                    return false;
+                }
 
                 *qvariantPtr = QVariant(callType, &obj);
-            } else {
-                *qvariantPtr = QVariant(callType, (void *)0);
+                return true;
             }
+
+            *qvariantPtr = QVariant(callType, (void *)nullptr);
+            return false;
         }
     }
+    return true;
 }
 
 QV4::ReturnedValue CallArgument::toValue(QV4::ExecutionEngine *engine)
@@ -1812,7 +1913,7 @@ QV4::ReturnedValue CallArgument::toValue(QV4::ExecutionEngine *engine)
 ReturnedValue QObjectMethod::create(ExecutionContext *scope, QObject *object, int index)
 {
     Scope valueScope(scope);
-    Scoped<QObjectMethod> method(valueScope, valueScope.engine->memoryManager->allocObject<QObjectMethod>(scope));
+    Scoped<QObjectMethod> method(valueScope, valueScope.engine->memoryManager->allocate<QObjectMethod>(scope));
     method->d()->setObject(object);
 
     if (QQmlData *ddata = QQmlData::get(object))
@@ -1825,7 +1926,7 @@ ReturnedValue QObjectMethod::create(ExecutionContext *scope, QObject *object, in
 ReturnedValue QObjectMethod::create(ExecutionContext *scope, const QQmlValueTypeWrapper *valueType, int index)
 {
     Scope valueScope(scope);
-    Scoped<QObjectMethod> method(valueScope, valueScope.engine->memoryManager->allocObject<QObjectMethod>(scope));
+    Scoped<QObjectMethod> method(valueScope, valueScope.engine->memoryManager->allocate<QObjectMethod>(scope));
     method->d()->setPropertyCache(valueType->d()->propertyCache());
     method->d()->index = index;
     method->d()->valueTypeWrapper.set(valueScope.engine, valueType->d());
@@ -1844,7 +1945,7 @@ const QMetaObject *Heap::QObjectMethod::metaObject()
     return object()->metaObject();
 }
 
-QV4::ReturnedValue QObjectMethod::method_toString(QV4::ExecutionContext *ctx) const
+QV4::ReturnedValue QObjectMethod::method_toString(QV4::ExecutionEngine *engine) const
 {
     QString result;
     if (const QMetaObject *metaObject = d()->metaObject()) {
@@ -1863,15 +1964,15 @@ QV4::ReturnedValue QObjectMethod::method_toString(QV4::ExecutionContext *ctx) co
         result = QLatin1String("null");
     }
 
-    return ctx->engine()->newString(result)->asReturnedValue();
+    return engine->newString(result)->asReturnedValue();
 }
 
-QV4::ReturnedValue QObjectMethod::method_destroy(QV4::ExecutionContext *ctx, const Value *args, int argc) const
+QV4::ReturnedValue QObjectMethod::method_destroy(QV4::ExecutionEngine *engine, const Value *args, int argc) const
 {
     if (!d()->object())
         return Encode::undefined();
     if (QQmlData::keepAliveDuringGarbageCollection(d()->object()))
-        return ctx->engine()->throwError(QStringLiteral("Invalid attempt to destroy() an indestructible object"));
+        return engine->throwError(QStringLiteral("Invalid attempt to destroy() an indestructible object"));
 
     int delay = 0;
     if (argc > 0)
@@ -1885,32 +1986,24 @@ QV4::ReturnedValue QObjectMethod::method_destroy(QV4::ExecutionContext *ctx, con
     return Encode::undefined();
 }
 
-void QObjectMethod::call(const Managed *m, Scope &scope, CallData *callData)
+ReturnedValue QObjectMethod::virtualCall(const FunctionObject *m, const Value *thisObject, const Value *argv, int argc)
 {
     const QObjectMethod *This = static_cast<const QObjectMethod*>(m);
-    This->callInternal(callData, scope);
+    return This->callInternal(thisObject, argv, argc);
 }
 
-void QObjectMethod::callInternal(CallData *callData, Scope &scope) const
+ReturnedValue QObjectMethod::callInternal(const Value *thisObject, const Value *argv, int argc) const
 {
     ExecutionEngine *v4 = engine();
-    ExecutionContext *context = v4->currentContext;
-    if (d()->index == DestroyMethod) {
-        scope.result = method_destroy(context, callData->args, callData->argc);
-        return;
-    }
-
-    else if (d()->index == ToStringMethod) {
-        scope.result = method_toString(context);
-        return;
-    }
+    if (d()->index == DestroyMethod)
+        return method_destroy(v4, argv, argc);
+    else if (d()->index == ToStringMethod)
+        return method_toString(v4);
 
     QQmlObjectOrGadget object(d()->object());
     if (!d()->object()) {
-        if (!d()->valueTypeWrapper) {
-            scope.result = Encode::undefined();
-            return;
-        }
+        if (!d()->valueTypeWrapper)
+            return Encode::undefined();
 
         object = QQmlObjectOrGadget(d()->propertyCache(), d()->valueTypeWrapper->gadgetPtr);
     }
@@ -1919,20 +2012,16 @@ void QObjectMethod::callInternal(CallData *callData, Scope &scope) const
 
     if (d()->propertyCache()) {
         QQmlPropertyData *data = d()->propertyCache()->method(d()->index);
-        if (!data) {
-            scope.result = QV4::Encode::undefined();
-            return;
-        }
+        if (!data)
+            return QV4::Encode::undefined();
         method = *data;
     } else {
         const QMetaObject *mo = d()->object()->metaObject();
         const QMetaMethod moMethod = mo->method(d()->index);
         method.load(moMethod);
 
-        if (method.coreIndex() == -1) {
-            scope.result = QV4::Encode::undefined();
-            return;
-        }
+        if (method.coreIndex() == -1)
+            return QV4::Encode::undefined();
 
         // Look for overloaded methods
         QByteArray methodName = moMethod.name();
@@ -1947,21 +2036,25 @@ void QObjectMethod::callInternal(CallData *callData, Scope &scope) const
         }
     }
 
+    Scope scope(v4);
+    JSCallData cData(scope, argc, argv, thisObject);
+    CallData *callData = cData.callData();
+
     if (method.isV4Function()) {
-        scope.result = QV4::Encode::undefined();
-        QQmlV4Function func(callData, &scope.result, v4);
+        QV4::ScopedValue rv(scope, QV4::Value::undefinedValue());
+        QQmlV4Function func(callData, rv, v4);
         QQmlV4Function *funcptr = &func;
 
-        void *args[] = { 0, &funcptr };
+        void *args[] = { nullptr, &funcptr };
         object.metacall(QMetaObject::InvokeMetaMethod, method.coreIndex(), args);
 
-        return;
+        return rv->asReturnedValue();
     }
 
     if (!method.isOverload()) {
-        scope.result = CallPrecise(object, method, v4, callData);
+        return CallPrecise(object, method, v4, callData);
     } else {
-        scope.result = CallOverloaded(object, method, v4, callData, d()->propertyCache());
+        return CallOverloaded(object, method, v4, callData, d()->propertyCache());
     }
 }
 
@@ -2006,7 +2099,7 @@ void Heap::QMetaObjectWrapper::ensureConstructorsCache() {
 ReturnedValue QMetaObjectWrapper::create(ExecutionEngine *engine, const QMetaObject* metaObject) {
 
      QV4::Scope scope(engine);
-     Scoped<QMetaObjectWrapper> mo(scope, engine->memoryManager->allocObject<QV4::QMetaObjectWrapper>(metaObject)->asReturnedValue());
+     Scoped<QMetaObjectWrapper> mo(scope, engine->memoryManager->allocate<QV4::QMetaObjectWrapper>(metaObject)->asReturnedValue());
      mo->init(engine);
      return mo->asReturnedValue();
 }
@@ -2019,18 +2112,19 @@ void QMetaObjectWrapper::init(ExecutionEngine *) {
         for (int k = 0; k < Enum.keyCount(); k++) {
             const char* key = Enum.key(k);
             const int value = Enum.value(k);
-            defineReadonlyProperty(QLatin1String(key), Primitive::fromInt32(value));
+            defineReadonlyProperty(QLatin1String(key), Value::fromInt32(value));
         }
     }
 }
 
-void QMetaObjectWrapper::construct(const Managed *m, Scope &scope, CallData *callData)
+ReturnedValue QMetaObjectWrapper::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *)
 {
-    const QMetaObjectWrapper *This = static_cast<const QMetaObjectWrapper*>(m);
-    scope.result = This->constructInternal(callData);
+    const QMetaObjectWrapper *This = static_cast<const QMetaObjectWrapper*>(f);
+    return This->constructInternal(argv, argc);
 }
 
-ReturnedValue QMetaObjectWrapper::constructInternal(CallData * callData) const {
+ReturnedValue QMetaObjectWrapper::constructInternal(const Value *argv, int argc) const
+{
 
     d()->ensureConstructorsCache();
 
@@ -2043,6 +2137,8 @@ ReturnedValue QMetaObjectWrapper::constructInternal(CallData * callData) const {
 
     Scope scope(v4);
     Scoped<QObjectWrapper> object(scope);
+    JSCallData cData(scope, argc, argv);
+    CallData *callData = cData.callData();
 
     if (d()->constructorCount == 1) {
         object = callConstructor(d()->constructors[0], v4, callData);
@@ -2052,7 +2148,7 @@ ReturnedValue QMetaObjectWrapper::constructInternal(CallData * callData) const {
     }
     Scoped<QMetaObjectWrapper> metaObject(scope, this);
     object->defineDefaultProperty(v4->id_constructor(), metaObject);
-    object->setPrototype(const_cast<QMetaObjectWrapper*>(this));
+    object->setPrototypeOf(const_cast<QMetaObjectWrapper*>(this));
     return object.asReturnedValue();
 
 }
@@ -2067,7 +2163,7 @@ ReturnedValue QMetaObjectWrapper::callConstructor(const QQmlPropertyData &data,
 
 ReturnedValue QMetaObjectWrapper::callOverloadedConstructor(QV4::ExecutionEngine *engine, QV4::CallData *callArgs) const {
     const int numberOfConstructors = d()->constructorCount;
-    const int argumentCount = callArgs->argc;
+    const int argumentCount = callArgs->argc();
     const QQmlStaticMetaObject object(d()->metaObject);
 
     QQmlPropertyData best;
@@ -2079,11 +2175,11 @@ ReturnedValue QMetaObjectWrapper::callOverloadedConstructor(QV4::ExecutionEngine
 
     for (int i = 0; i < numberOfConstructors; i++) {
         const QQmlPropertyData & attempt = d()->constructors[i];
+        QQmlMetaObject::ArgTypeStorage storage;
         int methodArgumentCount = 0;
-        int *methodArgTypes = 0;
+        int *methodArgTypes = nullptr;
         if (attempt.hasArguments()) {
-            QQmlMetaObject::ArgTypeStorage storage;
-            int *args = object.constructorParameterTypes(attempt.coreIndex(), &storage, 0);
+            int *args = object.constructorParameterTypes(attempt.coreIndex(), &storage, nullptr);
             if (!args) // Must be an unknown argument
                 continue;
 
@@ -2127,7 +2223,7 @@ ReturnedValue QMetaObjectWrapper::callOverloadedConstructor(QV4::ExecutionEngine
     }
 }
 
-bool QMetaObjectWrapper::isEqualTo(Managed *a, Managed *b)
+bool QMetaObjectWrapper::virtualIsEqualTo(Managed *a, Managed *b)
 {
     Q_ASSERT(a->as<QMetaObjectWrapper>());
     QMetaObjectWrapper *aMetaObject = a->as<QMetaObjectWrapper>();
@@ -2168,9 +2264,7 @@ void QmlSignalHandler::initProto(ExecutionEngine *engine)
 
 void MultiplyWrappedQObjectMap::insert(QObject *key, Heap::Object *value)
 {
-    QV4::WeakValue v;
-    v.set(value->internalClass->engine, value);
-    QHash<QObject*, QV4::WeakValue>::insert(key, v);
+    QHash<QObject*, QV4::WeakValue>::operator[](key).set(value->internalClass->engine, value);
     connect(key, SIGNAL(destroyed(QObject*)), this, SLOT(removeDestroyedObject(QObject*)));
 }
 
diff --git a/src/qml/jsruntime/qv4qobjectwrapper_p.h b/src/qml/jsruntime/qv4qobjectwrapper_p.h
index 018e444f7c..43a53ac673 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper_p.h
+++ b/src/qml/jsruntime/qv4qobjectwrapper_p.h
@@ -55,9 +55,7 @@
 #include <QtCore/qmetatype.h>
 #include <QtCore/qpair.h>
 #include <QtCore/qhash.h>
-#include <private/qhashedstring_p.h>
 #include <private/qqmldata_p.h>
-#include <private/qqmlpropertycache_p.h>
 #include <private/qintrusivelist_p.h>
 
 #include <private/qv4value_p.h>
@@ -90,6 +88,7 @@ struct Q_QML_EXPORT QObjectWrapper : Object {
     }
 
     QObject *object() const { return qObj.data(); }
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
 
 private:
     QQmlQPointer<QObject> qObj;
@@ -102,7 +101,7 @@ private:
     Member(class, NoMark, int, index)
 
 DECLARE_HEAP_OBJECT(QObjectMethod, FunctionObject) {
-    DECLARE_MARK_TABLE(QObjectMethod);
+    DECLARE_MARKOBJECTS(QObjectMethod);
 
     void init(QV4::ExecutionContext *scope);
     void destroy()
@@ -165,8 +164,8 @@ struct Q_QML_EXPORT QObjectWrapper : public Object
 
     QObject *object() const { return d()->object(); }
 
-    ReturnedValue getQmlProperty(QQmlContextData *qmlContext, String *name, RevisionMode revisionMode, bool *hasProperty = 0, bool includeImports = false) const;
-    static ReturnedValue getQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, bool *hasProperty = 0);
+    ReturnedValue getQmlProperty(QQmlContextData *qmlContext, String *name, RevisionMode revisionMode, bool *hasProperty = nullptr, bool includeImports = false) const;
+    static ReturnedValue getQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, bool *hasProperty = nullptr);
 
     static bool setQmlProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, QObject *object, String *name, RevisionMode revisionMode, const Value &value);
 
@@ -181,25 +180,23 @@ struct Q_QML_EXPORT QObjectWrapper : public Object
 
     void destroyObject(bool lastCall);
 
-protected:
-    static bool isEqualTo(Managed *that, Managed *o);
-
     static ReturnedValue getProperty(ExecutionEngine *engine, QObject *object, QQmlPropertyData *property, bool captureRequired = true);
+protected:
     static void setProperty(ExecutionEngine *engine, QObject *object, QQmlPropertyData *property, const Value &value);
 
+    static bool virtualIsEqualTo(Managed *that, Managed *o);
     static ReturnedValue create(ExecutionEngine *engine, QObject *object);
 
     static QQmlPropertyData *findProperty(ExecutionEngine *engine, QObject *o, QQmlContextData *qmlContext, String *name, RevisionMode revisionMode, QQmlPropertyData *local);
     QQmlPropertyData *findProperty(ExecutionEngine *engine, QQmlContextData *qmlContext, String *name, RevisionMode revisionMode, QQmlPropertyData *local) const;
 
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static bool put(Managed *m, String *name, const Value &value);
-    static PropertyAttributes query(const Managed *, String *name);
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-    static void markObjects(Heap::Base *that, QV4::MarkStack *markStack);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
 
-    static void method_connect(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_disconnect(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_connect(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_disconnect(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
 private:
     Q_NEVER_INLINE static ReturnedValue wrap_slowPath(ExecutionEngine *engine, QObject *object);
@@ -234,12 +231,12 @@ struct Q_QML_EXPORT QObjectMethod : public QV4::FunctionObject
     int methodIndex() const { return d()->index; }
     QObject *object() const { return d()->object(); }
 
-    QV4::ReturnedValue method_toString(QV4::ExecutionContext *ctx) const;
-    QV4::ReturnedValue method_destroy(QV4::ExecutionContext *ctx, const Value *args, int argc) const;
+    QV4::ReturnedValue method_toString(QV4::ExecutionEngine *engine) const;
+    QV4::ReturnedValue method_destroy(QV4::ExecutionEngine *ctx, const Value *args, int argc) const;
 
-    static void call(const Managed *, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCall(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
-    void callInternal(CallData *callData, Scope &scope) const;
+    ReturnedValue callInternal(const Value *thisObject, const Value *argv, int argc) const;
 
     static QPair<QObject *, int> extractQtMethod(const QV4::FunctionObject *function);
 };
@@ -251,14 +248,15 @@ struct Q_QML_EXPORT QMetaObjectWrapper : public QV4::FunctionObject
     V4_NEEDS_DESTROY
 
     static ReturnedValue create(ExecutionEngine *engine, const QMetaObject* metaObject);
-    static void construct(const Managed *, Scope &scope, CallData *callData);
-    static bool isEqualTo(Managed *a, Managed *b);
-
     const QMetaObject *metaObject() const { return d()->metaObject; }
 
+protected:
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *);
+    static bool virtualIsEqualTo(Managed *a, Managed *b);
+
 private:
     void init(ExecutionEngine *engine);
-    ReturnedValue constructInternal(CallData *callData) const;
+    ReturnedValue constructInternal(const Value *argv, int argc) const;
     ReturnedValue callConstructor(const QQmlPropertyData &data, QV4::ExecutionEngine *engine, QV4::CallData *callArgs) const;
     ReturnedValue callOverloadedConstructor(QV4::ExecutionEngine *engine, QV4::CallData *callArgs) const;
 
@@ -290,7 +288,14 @@ public:
     Iterator end() { return QHash<QObject*, QV4::WeakValue>::end(); }
 
     void insert(QObject *key, Heap::Object *value);
-    ReturnedValue value(QObject *key) const { return QHash<QObject*, QV4::WeakValue>::value(key).value(); }
+    ReturnedValue value(QObject *key) const
+    {
+        ConstIterator it = find(key);
+        return it == end()
+                ? QV4::WeakValue().value()
+                : it->value();
+    }
+
     Iterator erase(Iterator it);
     void remove(QObject *key);
     void mark(QObject *key, MarkStack *markStack);
diff --git a/src/qml/jsruntime/qv4reflect.cpp b/src/qml/jsruntime/qv4reflect.cpp
new file mode 100644
index 0000000000..0772770d63
--- /dev/null
+++ b/src/qml/jsruntime/qv4reflect.cpp
@@ -0,0 +1,285 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4reflect_p.h"
+#include "qv4symbol_p.h"
+#include "qv4runtimeapi_p.h"
+#include "qv4objectproto_p.h"
+#include "qv4propertykey_p.h"
+#include "qv4objectiterator_p.h"
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(Reflect);
+
+void Heap::Reflect::init()
+{
+    Object::init();
+    Scope scope(internalClass->engine);
+    ScopedObject r(scope, this);
+
+    r->defineDefaultProperty(QStringLiteral("apply"), QV4::Reflect::method_apply, 3);
+    r->defineDefaultProperty(QStringLiteral("construct"), QV4::Reflect::method_construct, 2);
+    r->defineDefaultProperty(QStringLiteral("defineProperty"), QV4::Reflect::method_defineProperty, 3);
+    r->defineDefaultProperty(QStringLiteral("deleteProperty"), QV4::Reflect::method_deleteProperty, 2);
+    r->defineDefaultProperty(QStringLiteral("get"), QV4::Reflect::method_get, 2);
+    r->defineDefaultProperty(QStringLiteral("getOwnPropertyDescriptor"), QV4::Reflect::method_getOwnPropertyDescriptor, 2);
+    r->defineDefaultProperty(QStringLiteral("getPrototypeOf"), QV4::Reflect::method_getPrototypeOf, 1);
+    r->defineDefaultProperty(QStringLiteral("has"), QV4::Reflect::method_has, 2);
+    r->defineDefaultProperty(QStringLiteral("isExtensible"), QV4::Reflect::method_isExtensible, 1);
+    r->defineDefaultProperty(QStringLiteral("ownKeys"), QV4::Reflect::method_ownKeys, 1);
+    r->defineDefaultProperty(QStringLiteral("preventExtensions"), QV4::Reflect::method_preventExtensions, 1);
+    r->defineDefaultProperty(QStringLiteral("set"), QV4::Reflect::method_set, 3);
+    r->defineDefaultProperty(QStringLiteral("setPrototypeOf"), QV4::Reflect::method_setPrototypeOf, 2);
+}
+
+struct CallArgs {
+    Value *argv;
+    int argc;
+};
+
+static CallArgs createListFromArrayLike(Scope &scope, const Object *o)
+{
+    int len = o->getLength();
+    Value *arguments = scope.alloc(len);
+
+    for (int i = 0; i < len; ++i) {
+        arguments[i] = o->get(i);
+        if (scope.hasException())
+            return { nullptr, 0 };
+    }
+    return { arguments, len };
+}
+
+ReturnedValue Reflect::method_apply(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (argc < 3 || !argv[0].isFunctionObject() || !argv[2].isObject())
+        return scope.engine->throwTypeError();
+
+    const Object *o = static_cast<const Object *>(argv + 2);
+    CallArgs arguments = createListFromArrayLike(scope, o);
+    if (scope.hasException())
+        return Encode::undefined();
+
+    return static_cast<const FunctionObject &>(argv[0]).call(&argv[1], arguments.argv, arguments.argc);
+}
+
+ReturnedValue Reflect::method_construct(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (argc < 2 || !argv[1].isObject())
+        return scope.engine->throwTypeError();
+    const FunctionObject *target = argv[0].as<FunctionObject>();
+    const FunctionObject *newTarget = argc == 3 ? argv[2].as<FunctionObject>() : target;
+    if (!target || !target->isConstructor() || !newTarget || !newTarget->isConstructor())
+        return scope.engine->throwTypeError();
+
+    const Object *o = static_cast<const Object *>(argv + 1);
+    CallArgs arguments = createListFromArrayLike(scope, o);
+    if (scope.hasException())
+        return Encode::undefined();
+
+    return target->callAsConstructor(arguments.argv, arguments.argc, newTarget);
+}
+
+ReturnedValue Reflect::method_defineProperty(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc || !argv[0].isObject())
+        return scope.engine->throwTypeError();
+
+    ScopedObject O(scope, argv[0]);
+    ScopedPropertyKey name(scope, (argc > 1 ? argv[1] : Value::undefinedValue()).toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    ScopedValue attributes(scope, argc > 2 ? argv[2] : Value::undefinedValue());
+    ScopedProperty pd(scope);
+    PropertyAttributes attrs;
+    ObjectPrototype::toPropertyDescriptor(scope.engine, attributes, pd, &attrs);
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
+
+    bool result = O->defineOwnProperty(name, pd, attrs);
+
+    return Encode(result);
+}
+
+ReturnedValue Reflect::method_deleteProperty(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    ExecutionEngine *e = f->engine();
+    if (!argc || !argv[0].isObject())
+        return e->throwTypeError();
+
+    bool result =  Runtime::DeleteProperty_NoThrow::call(e, argv[0], argc > 1 ? argv[1] : Value::undefinedValue());
+    return Encode(result);
+}
+
+ReturnedValue Reflect::method_get(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc || !argv[0].isObject())
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, static_cast<const Object *>(argv));
+    Value undef = Value::undefinedValue();
+    const Value *index = argc > 1 ? &argv[1] : &undef;
+    ScopedPropertyKey name(scope, index->toPropertyKey(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+    ScopedValue receiver(scope, argc > 2 ? argv[2] : *o);
+
+    return Encode(o->get(name, receiver));
+}
+
+ReturnedValue Reflect::method_getOwnPropertyDescriptor(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    if (!argc || !argv[0].isObject())
+        return f->engine()->throwTypeError();
+
+    return ObjectPrototype::method_getOwnPropertyDescriptor(f, thisObject, argv, argc);
+}
+
+ReturnedValue Reflect::method_getPrototypeOf(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    if (!argc || !argv[0].isObject())
+        return f->engine()->throwTypeError();
+
+    const Object *o = static_cast<const Object *>(argv);
+    Heap::Object *p = o->getPrototypeOf();
+    return (p ? p->asReturnedValue() : Encode::null());
+}
+
+ReturnedValue Reflect::method_has(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc || !argv[0].isObject())
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, static_cast<const Object *>(argv));
+    Value undef = Value::undefinedValue();
+    const Value *index = argc > 1 ? &argv[1] : &undef;
+
+    ScopedPropertyKey name(scope, index->toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return false;
+
+    return Encode(o->hasProperty(name));
+}
+
+ReturnedValue Reflect::method_isExtensible(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    if (!argc || !argv[0].isObject())
+        return f->engine()->throwTypeError();
+
+    const Object *o = static_cast<const Object *>(argv);
+    return Encode(o->isExtensible());
+}
+
+
+ReturnedValue Reflect::method_ownKeys(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    if (!argc || !argv[0].isObject())
+        return f->engine()->throwTypeError();
+
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject O(scope, argv[0].toObject(scope.engine));
+    if (!O)
+        return Encode::undefined();
+
+    ScopedArrayObject keys(scope, scope.engine->newArrayObject());
+
+    ObjectIterator it(scope, O, ObjectIterator::WithSymbols);
+    ScopedPropertyKey key(scope);
+    ScopedValue v(scope);
+    while (1) {
+        key = it.next();
+        if (!key->isValid())
+            break;
+        v = key->toStringOrSymbol(scope.engine);
+        keys->push_back(v);
+    }
+
+    return keys->asReturnedValue();
+
+}
+
+ReturnedValue Reflect::method_preventExtensions(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc || !argv[0].isObject())
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, static_cast<const Object *>(argv));
+    return Encode(o->preventExtensions());
+}
+
+ReturnedValue Reflect::method_set(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc || !argv[0].isObject())
+        return scope.engine->throwTypeError();
+
+    ScopedObject o(scope, static_cast<const Object *>(argv));
+    Value undef = Value::undefinedValue();
+    const Value *index = argc > 1 ? &argv[1] : &undef;
+    const Value &val = argc > 2 ? argv[2] : undef;
+    ScopedValue receiver(scope, argc >3 ? argv[3] : argv[0]);
+
+    ScopedPropertyKey propertyKey(scope, index->toPropertyKey(scope.engine));
+    if (scope.engine->hasException)
+        return false;
+    bool result = o->put(propertyKey, val, receiver);
+    return Encode(result);
+}
+
+ReturnedValue Reflect::method_setPrototypeOf(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    if (argc < 2 || !argv[0].isObject() || (!argv[1].isNull() && !argv[1].isObject()))
+        return f->engine()->throwTypeError();
+
+    Scope scope(f);
+    ScopedObject o(scope, static_cast<const Object *>(argv));
+    const Object *proto = argv[1].isNull() ? nullptr : static_cast<const Object *>(argv + 1);
+    return Encode(o->setPrototypeOf(proto));
+}
diff --git a/src/qml/jsruntime/qv4reflect_p.h b/src/qml/jsruntime/qv4reflect_p.h
new file mode 100644
index 0000000000..d480e1d914
--- /dev/null
+++ b/src/qml/jsruntime/qv4reflect_p.h
@@ -0,0 +1,89 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4REFLECT_H
+#define QV4REFLECT_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Heap {
+
+struct Reflect : Object {
+    void init();
+};
+
+}
+
+struct Reflect : Object {
+    V4_OBJECT2(Reflect, Object)
+
+    static ReturnedValue method_apply(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_construct(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_defineProperty(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_deleteProperty(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getOwnPropertyDescriptor(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getPrototypeOf(const FunctionObject *, const Value *, const Value *argv, int argc);
+    static ReturnedValue method_has(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_isExtensible(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_ownKeys(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_preventExtensions(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setPrototypeOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/jsruntime/qv4regexp.cpp b/src/qml/jsruntime/qv4regexp.cpp
index 6778145ff1..4ed1dbd5aa 100644
--- a/src/qml/jsruntime/qv4regexp.cpp
+++ b/src/qml/jsruntime/qv4regexp.cpp
@@ -41,14 +41,31 @@
 #include "qv4engine_p.h"
 #include "qv4scopedvalue_p.h"
 #include <private/qv4mm_p.h>
+#include <runtime/VM.h>
 
 using namespace QV4;
 
+static JSC::RegExpFlags jscFlags(uint flags)
+{
+    JSC::RegExpFlags jscFlags = JSC::NoFlags;
+    if (flags & CompiledData::RegExp::RegExp_Global)
+        jscFlags = static_cast<JSC::RegExpFlags>(flags | JSC::FlagGlobal);
+    if (flags & CompiledData::RegExp::RegExp_IgnoreCase)
+        jscFlags = static_cast<JSC::RegExpFlags>(flags | JSC::FlagIgnoreCase);
+    if (flags & CompiledData::RegExp::RegExp_Multiline)
+        jscFlags = static_cast<JSC::RegExpFlags>(flags | JSC::FlagMultiline);
+    if (flags & CompiledData::RegExp::RegExp_Unicode)
+        jscFlags = static_cast<JSC::RegExpFlags>(flags | JSC::FlagUnicode);
+    if (flags & CompiledData::RegExp::RegExp_Sticky)
+        jscFlags = static_cast<JSC::RegExpFlags>(flags | JSC::FlagSticky);
+    return jscFlags;
+}
+
 RegExpCache::~RegExpCache()
 {
     for (RegExpCache::Iterator it = begin(), e = end(); it != e; ++it) {
         if (RegExp *re = it.value().as<RegExp>())
-            re->d()->cache = 0;
+            re->d()->cache = nullptr;
     }
 }
 
@@ -56,22 +73,120 @@ DEFINE_MANAGED_VTABLE(RegExp);
 
 uint RegExp::match(const QString &string, int start, uint *matchOffsets)
 {
+    static const uint offsetJITFail = std::numeric_limits<unsigned>::max() - 1;
+
     if (!isValid())
         return JSC::Yarr::offsetNoMatch;
 
     WTF::String s(string);
 
 #if ENABLE(YARR_JIT)
-    if (!jitCode()->isFallBack() && jitCode()->has16BitCode())
-        return uint(jitCode()->execute(s.characters16(), start, s.length(), (int*)matchOffsets).start);
+    auto *priv = d();
+    if (priv->hasValidJITCode()) {
+        uint ret = JSC::Yarr::offsetNoMatch;
+#if ENABLE(YARR_JIT_ALL_PARENS_EXPRESSIONS)
+        char buffer[8192];
+        ret = uint(priv->jitCode->execute(s.characters16(), start, s.length(),
+                                          (int*)matchOffsets, buffer, 8192).start);
+#else
+        ret = uint(priv->jitCode->execute(s.characters16(), start, s.length(),
+                                          (int*)matchOffsets).start);
 #endif
+        if (ret != offsetJITFail)
+            return ret;
+
+        // JIT failed. We need byteCode to run the interpreter.
+        if (!priv->byteCode) {
+            JSC::Yarr::ErrorCode error = JSC::Yarr::ErrorCode::NoError;
+            JSC::Yarr::YarrPattern yarrPattern(WTF::String(*priv->pattern), jscFlags(priv->flags),
+                                               error);
+
+            // As we successfully parsed the pattern before, we should still be able to.
+            Q_ASSERT(error == JSC::Yarr::ErrorCode::NoError);
+
+            priv->byteCode = JSC::Yarr::byteCompile(
+                                     yarrPattern,
+                                     priv->internalClass->engine->bumperPointerAllocator).release();
+        }
+    }
+#endif // ENABLE(YARR_JIT)
 
     return JSC::Yarr::interpret(byteCode(), s.characters16(), string.length(), start, matchOffsets);
 }
 
-Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase, bool multiline)
+QString RegExp::getSubstitution(const QString &matched, const QString &str, int position, const Value *captures, int nCaptures, const QString &replacement)
 {
-    RegExpCacheKey key(pattern, ignoreCase, multiline);
+    QString result;
+
+    int matchedLength = matched.length();
+    Q_ASSERT(position >= 0 && position <= str.length());
+    int tailPos = position + matchedLength;
+    int seenDollar = -1;
+    for (int i = 0; i < replacement.length(); ++i) {
+        QChar ch = replacement.at(i);
+        if (seenDollar >= 0) {
+            if (ch.unicode() == '$') {
+                result += QLatin1Char('$');
+            } else if (ch.unicode() == '&') {
+                result += matched;
+            } else if (ch.unicode() == '`') {
+                result += str.left(position);
+            } else if (ch.unicode() == '\'') {
+                result += str.mid(tailPos);
+            } else if (ch.unicode() >= '0' && ch.unicode() <= '9') {
+                int n = ch.unicode() - '0';
+                if (i + 1 < replacement.length()) {
+                    ch = replacement.at(i + 1);
+                    if (ch.unicode() >= '0' && ch.unicode() <= '9') {
+                        n = n*10 + (ch.unicode() - '0');
+                        ++i;
+                    }
+                }
+                if (n > 0 && n <= nCaptures) {
+                    String *s = captures[n].stringValue();
+                    if (s)
+                        result += s->toQString();
+                } else {
+                    for (int j = seenDollar; j <= i; ++j)
+                        result += replacement.at(j);
+                }
+            } else {
+                result += QLatin1Char('$');
+                result += ch;
+            }
+            seenDollar = -1;
+        } else {
+            if (ch == QLatin1Char('$')) {
+                seenDollar = i;
+                continue;
+            }
+            result += ch;
+        }
+    }
+    if (seenDollar >= 0)
+        result += QLatin1Char('$');
+    return result;
+}
+
+QString Heap::RegExp::flagsAsString() const
+{
+    QString result;
+    if (flags & CompiledData::RegExp::RegExp_Global)
+        result += QLatin1Char('g');
+    if (flags & CompiledData::RegExp::RegExp_IgnoreCase)
+        result += QLatin1Char('i');
+    if (flags & CompiledData::RegExp::RegExp_Multiline)
+        result += QLatin1Char('m');
+    if (flags & CompiledData::RegExp::RegExp_Unicode)
+        result += QLatin1Char('u');
+    if (flags & CompiledData::RegExp::RegExp_Sticky)
+        result += QLatin1Char('y');
+    return result;
+}
+
+Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, uint flags)
+{
+    RegExpCacheKey key(pattern, flags);
 
     RegExpCache *cache = engine->regExpCache;
     if (!cache)
@@ -82,7 +197,7 @@ Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bo
         return result->d();
 
     Scope scope(engine);
-    Scoped<RegExp> result(scope, engine->memoryManager->alloc<RegExp>(engine, pattern, ignoreCase, multiline));
+    Scoped<RegExp> result(scope, engine->memoryManager->alloc<RegExp>(engine, pattern, flags));
 
     result->d()->cache = cache;
     cachedValue.set(engine, result);
@@ -90,27 +205,35 @@ Heap::RegExp *RegExp::create(ExecutionEngine* engine, const QString& pattern, bo
     return result->d();
 }
 
-void Heap::RegExp::init(ExecutionEngine* engine, const QString &pattern, bool ignoreCase, bool multiline)
+void Heap::RegExp::init(ExecutionEngine *engine, const QString &pattern, uint flags)
 {
     Base::init();
     this->pattern = new QString(pattern);
-    this->ignoreCase = ignoreCase;
-    this->multiLine = multiline;
+    this->flags = flags;
 
-    const char* error = 0;
-    JSC::Yarr::YarrPattern yarrPattern(WTF::String(pattern), ignoreCase, multiline, &error);
-    if (error)
+    valid = false;
+
+    JSC::Yarr::ErrorCode error = JSC::Yarr::ErrorCode::NoError;
+    JSC::Yarr::YarrPattern yarrPattern(WTF::String(pattern), jscFlags(flags), error);
+    if (error != JSC::Yarr::ErrorCode::NoError)
         return;
     subPatternCount = yarrPattern.m_numSubpatterns;
-    OwnPtr<JSC::Yarr::BytecodePattern> p = JSC::Yarr::byteCompile(yarrPattern, engine->bumperPointerAllocator);
-    byteCode = p.take();
 #if ENABLE(YARR_JIT)
-    jitCode = new JSC::Yarr::YarrCodeBlock;
-    if (!yarrPattern.m_containsBackreferences && engine->iselFactory->jitCompileRegexps()) {
-        JSC::JSGlobalData dummy(engine->regExpAllocator);
-        JSC::Yarr::jitCompile(yarrPattern, JSC::Yarr::Char16, &dummy, *jitCode);
+    if (!yarrPattern.m_containsBackreferences && engine->canJIT()) {
+        jitCode = new JSC::Yarr::YarrCodeBlock;
+        JSC::VM *vm = static_cast<JSC::VM *>(engine);
+        JSC::Yarr::jitCompile(yarrPattern, JSC::Yarr::Char16, vm, *jitCode);
     }
+#else
+    Q_UNUSED(engine)
 #endif
+    if (hasValidJITCode()) {
+        valid = true;
+        return;
+    }
+    byteCode = JSC::Yarr::byteCompile(yarrPattern, internalClass->engine->bumperPointerAllocator).release();
+    if (byteCode)
+        valid = true;
 }
 
 void Heap::RegExp::destroy()
diff --git a/src/qml/jsruntime/qv4regexp_p.h b/src/qml/jsruntime/qv4regexp_p.h
index 7ab12fe245..6afb10ea95 100644
--- a/src/qml/jsruntime/qv4regexp_p.h
+++ b/src/qml/jsruntime/qv4regexp_p.h
@@ -76,7 +76,7 @@ struct RegExpCacheKey;
 namespace Heap {
 
 struct RegExp : Base {
-    void init(ExecutionEngine* engine, const QString& pattern, bool ignoreCase, bool multiline);
+    void init(ExecutionEngine *engine, const QString& pattern, uint flags);
     void destroy();
 
     QString *pattern;
@@ -84,14 +84,29 @@ struct RegExp : Base {
 #if ENABLE(YARR_JIT)
     JSC::Yarr::YarrCodeBlock *jitCode;
 #endif
+    bool hasValidJITCode() const {
+#if ENABLE(YARR_JIT)
+        return jitCode && !jitCode->failureReason().has_value() && jitCode->has16BitCode();
+#else
+        return false;
+#endif
+    }
+
+    bool ignoreCase() const { return flags & CompiledData::RegExp::RegExp_IgnoreCase; }
+    bool multiLine() const { return flags & CompiledData::RegExp::RegExp_Multiline; }
+    bool global() const { return flags & CompiledData::RegExp::RegExp_Global; }
+    bool unicode() const { return flags & CompiledData::RegExp::RegExp_Unicode; }
+    bool sticky() const { return flags & CompiledData::RegExp::RegExp_Sticky; }
+
     RegExpCache *cache;
     int subPatternCount;
-    bool ignoreCase;
-    bool multiLine;
+    uint flags;
+    bool valid;
 
+    QString flagsAsString() const;
     int captureCount() const { return subPatternCount + 1; }
 };
-V4_ASSERT_IS_TRIVIAL(RegExp)
+Q_STATIC_ASSERT(std::is_trivial< RegExp >::value);
 
 }
 
@@ -109,43 +124,44 @@ struct RegExp : public Managed
 #endif
     RegExpCache *cache() const { return d()->cache; }
     int subPatternCount() const { return d()->subPatternCount; }
-    bool ignoreCase() const { return d()->ignoreCase; }
-    bool multiLine() const { return d()->multiLine; }
+    bool ignoreCase() const { return d()->ignoreCase(); }
+    bool multiLine() const { return d()->multiLine(); }
+    bool global() const { return d()->global(); }
+    bool unicode() const { return d()->unicode(); }
+    bool sticky() const { return d()->sticky(); }
 
-    static Heap::RegExp *create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase = false, bool multiline = false);
+    static Heap::RegExp *create(ExecutionEngine* engine, const QString& pattern, uint flags = CompiledData::RegExp::RegExp_NoFlags);
 
-    bool isValid() const { return d()->byteCode; }
+    bool isValid() const { return d()->valid; }
 
     uint match(const QString& string, int start, uint *matchOffsets);
 
     int captureCount() const { return subPatternCount() + 1; }
 
+    static QString getSubstitution(const QString &matched, const QString &str, int position, const Value *captures, int nCaptures, const QString &replacement);
+
     friend class RegExpCache;
 };
 
 struct RegExpCacheKey
 {
-    RegExpCacheKey(const QString &pattern, bool ignoreCase, bool multiLine)
-        : pattern(pattern)
-        , ignoreCase(ignoreCase)
-        , multiLine(multiLine)
+    RegExpCacheKey(const QString &pattern, uint flags)
+        : pattern(pattern), flags(flags)
     { }
     explicit inline RegExpCacheKey(const RegExp::Data *re);
 
     bool operator==(const RegExpCacheKey &other) const
-    { return pattern == other.pattern && ignoreCase == other.ignoreCase && multiLine == other.multiLine; }
+    { return pattern == other.pattern && flags == other.flags;; }
     bool operator!=(const RegExpCacheKey &other) const
     { return !operator==(other); }
 
     QString pattern;
-    uint ignoreCase : 1;
-    uint multiLine : 1;
+    uint flags;
 };
 
 inline RegExpCacheKey::RegExpCacheKey(const RegExp::Data *re)
     : pattern(*re->pattern)
-    , ignoreCase(re->ignoreCase)
-    , multiLine(re->multiLine)
+    , flags(re->flags)
 {}
 
 inline uint qHash(const RegExpCacheKey& key, uint seed = 0) Q_DECL_NOTHROW
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index 735951e085..5bd25dcbec 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -38,24 +38,21 @@
 ****************************************************************************/
 
 #include "qv4regexpobject_p.h"
-#include "qv4jsir_p.h"
-#include "qv4isel_p.h"
 #include "qv4objectproto_p.h"
 #include "qv4regexp_p.h"
 #include "qv4stringobject_p.h"
 #include <private/qv4mm_p.h>
 #include "qv4scopedvalue_p.h"
+#include "qv4jscall_p.h"
+#include "qv4symbol_p.h"
 
-#include <private/qqmljsengine_p.h>
-#include <private/qqmljslexer_p.h>
-#include <private/qqmljsparser_p.h>
-#include <private/qqmljsast_p.h>
-#include <qv4jsir_p.h>
-#include <qv4codegen_p.h>
 #include "private/qlocale_tools_p.h"
 
 #include <QtCore/QDebug>
 #include <QtCore/qregexp.h>
+#if QT_CONFIG(regularexpression)
+#include <QtCore/qregularexpression.h>
+#endif
 #include <cassert>
 #include <typeinfo>
 #include <iostream>
@@ -74,16 +71,14 @@ void Heap::RegExpObject::init()
     Object::init();
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
-    value.set(scope.engine, QV4::RegExp::create(scope.engine, QString(), false, false));
-    global = false;
+    value.set(scope.engine, QV4::RegExp::create(scope.engine, QString(), CompiledData::RegExp::RegExp_NoFlags));
     o->initProperties();
 }
 
-void Heap::RegExpObject::init(QV4::RegExp *value, bool global)
+void Heap::RegExpObject::init(QV4::RegExp *value)
 {
     Object::init();
     Scope scope(internalClass->engine);
-    this->global = global;
     this->value.set(scope.engine, value->d());
     Scoped<QV4::RegExpObject> o(scope, this);
     o->initProperties();
@@ -95,7 +90,6 @@ void Heap::RegExpObject::init(QV4::RegExp *value, bool global)
 void Heap::RegExpObject::init(const QRegExp &re)
 {
     Object::init();
-    global = false;
 
     // Convert the pattern to a ECMAScript pattern.
     QString pattern = QT_PREPEND_NAMESPACE(qt_regexp_toCanonical)(re.pattern(), re.patternSyntax());
@@ -137,30 +131,36 @@ void Heap::RegExpObject::init(const QRegExp &re)
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
 
-    o->d()->value.set(scope.engine,
-                        QV4::RegExp::create(scope.engine, pattern, re.caseSensitivity() == Qt::CaseInsensitive, false));
+    uint flags = (re.caseSensitivity() == Qt::CaseInsensitive ? CompiledData::RegExp::RegExp_IgnoreCase : CompiledData::RegExp::RegExp_NoFlags);
+    o->d()->value.set(scope.engine, QV4::RegExp::create(scope.engine, pattern, flags));
 
     o->initProperties();
 }
 
-void RegExpObject::initProperties()
+#if QT_CONFIG(regularexpression)
+// Converts a QRegularExpression to a JS RegExp.
+// The conversion is not 100% exact since ECMA regexp and QRegularExpression
+// have different semantics/flags, but we try to do our best.
+void Heap::RegExpObject::init(const QRegularExpression &re)
 {
-    setProperty(Index_LastIndex, Primitive::fromInt32(0));
+    Object::init();
 
-    Q_ASSERT(value());
+    Scope scope(internalClass->engine);
+    Scoped<QV4::RegExpObject> o(scope, this);
 
-    QString p = *value()->pattern;
-    if (p.isEmpty()) {
-        p = QStringLiteral("(?:)");
-    } else {
-        // escape certain parts, see ch. 15.10.4
-        p.replace('/', QLatin1String("\\/"));
-    }
+    const uint flags = (re.patternOptions() & QRegularExpression::CaseInsensitiveOption)
+            ? CompiledData::RegExp::RegExp_IgnoreCase
+            : CompiledData::RegExp::RegExp_NoFlags;
+    o->d()->value.set(scope.engine, QV4::RegExp::create(scope.engine, re.pattern(), flags));
+    o->initProperties();
+}
+#endif
 
-    setProperty(Index_Source, engine()->newString(p));
-    setProperty(Index_Global, Primitive::fromBoolean(global()));
-    setProperty(Index_IgnoreCase, Primitive::fromBoolean(value()->ignoreCase));
-    setProperty(Index_Multiline, Primitive::fromBoolean(value()->multiLine));
+void RegExpObject::initProperties()
+{
+    setProperty(Index_LastIndex, Value::fromInt32(0));
+
+    Q_ASSERT(value());
 }
 
 // Converts a JS RegExp to a QRegExp.
@@ -168,40 +168,96 @@ void RegExpObject::initProperties()
 // have different semantics/flags, but we try to do our best.
 QRegExp RegExpObject::toQRegExp() const
 {
-    Qt::CaseSensitivity caseSensitivity = value()->ignoreCase ? Qt::CaseInsensitive : Qt::CaseSensitive;
+    Qt::CaseSensitivity caseSensitivity = (value()->flags & CompiledData::RegExp::RegExp_IgnoreCase) ? Qt::CaseInsensitive : Qt::CaseSensitive;
     return QRegExp(*value()->pattern, caseSensitivity, QRegExp::RegExp2);
 }
 
+#if QT_CONFIG(regularexpression)
+// Converts a JS RegExp to a QRegularExpression.
+// The conversion is not 100% exact since ECMA regexp and QRegularExpression
+// have different semantics/flags, but we try to do our best.
+QRegularExpression RegExpObject::toQRegularExpression() const
+{
+    QRegularExpression::PatternOptions caseSensitivity
+            = (value()->flags & CompiledData::RegExp::RegExp_IgnoreCase)
+            ? QRegularExpression::CaseInsensitiveOption
+            : QRegularExpression::NoPatternOption;
+    return QRegularExpression(*value()->pattern, caseSensitivity);
+}
+#endif
+
 QString RegExpObject::toString() const
 {
-    QString result = QLatin1Char('/') + source() + QLatin1Char('/');
-    if (global())
-        result += QLatin1Char('g');
-    if (value()->ignoreCase)
-        result += QLatin1Char('i');
-    if (value()->multiLine)
-        result += QLatin1Char('m');
-    return result;
+    QString p = *value()->pattern;
+    if (p.isEmpty()) {
+        p = QStringLiteral("(?:)");
+    } else {
+        // escape certain parts, see ch. 15.10.4
+        p.replace('/', QLatin1String("\\/"));
+    }
+    return p;
 }
 
 QString RegExpObject::source() const
 {
     Scope scope(engine());
-    ScopedString source(scope, scope.engine->newIdentifier(QStringLiteral("source")));
-    ScopedValue s(scope, const_cast<RegExpObject *>(this)->get(source));
+    ScopedValue s(scope, get(scope.engine->id_source()));
     return s->toQString();
 }
 
-uint RegExpObject::flags() const
+ReturnedValue RegExpObject::builtinExec(ExecutionEngine *engine, const String *str)
 {
-    uint f = 0;
-    if (global())
-        f |= QV4::RegExpObject::RegExp_Global;
-    if (value()->ignoreCase)
-        f |= QV4::RegExpObject::RegExp_IgnoreCase;
-    if (value()->multiLine)
-        f |= QV4::RegExpObject::RegExp_Multiline;
-    return f;
+    QString s = str->toQString();
+
+    Scope scope(engine);
+    int offset = (global() || sticky()) ? lastIndex() : 0;
+    if (offset < 0 || offset > s.length()) {
+        setLastIndex(0);
+        RETURN_RESULT(Encode::null());
+    }
+
+    Q_ALLOCA_VAR(uint, matchOffsets, value()->captureCount() * 2 * sizeof(uint));
+    const uint result = Scoped<RegExp>(scope, value())->match(s, offset, matchOffsets);
+
+    RegExpCtor *regExpCtor = static_cast<RegExpCtor *>(scope.engine->regExpCtor());
+    regExpCtor->d()->clearLastMatch();
+
+    if (result == JSC::Yarr::offsetNoMatch) {
+        if (global() || sticky())
+            setLastIndex(0);
+        RETURN_RESULT(Encode::null());
+    }
+
+    Q_ASSERT(result <= uint(std::numeric_limits<int>::max()));
+
+    // fill in result data
+    ScopedArrayObject array(scope, scope.engine->newArrayObject(scope.engine->internalClasses(EngineBase::Class_RegExpExecArray)));
+    int len = value()->captureCount();
+    array->arrayReserve(len);
+    ScopedValue v(scope);
+    int strlen = s.length();
+    for (int i = 0; i < len; ++i) {
+        int start = matchOffsets[i * 2];
+        int end = matchOffsets[i * 2 + 1];
+        if (end > strlen)
+            end = strlen;
+        v = (start != -1) ? scope.engine->memoryManager->alloc<ComplexString>(str->d(), start, end - start)->asReturnedValue() : Encode::undefined();
+        array->arrayPut(i, v);
+    }
+    array->setArrayLengthUnchecked(len);
+    array->setProperty(Index_ArrayIndex, Value::fromInt32(int(result)));
+    array->setProperty(Index_ArrayInput, *str);
+
+    RegExpCtor::Data *dd = regExpCtor->d();
+    dd->lastMatch.set(scope.engine, array);
+    dd->lastInput.set(scope.engine, str->d());
+    dd->lastMatchStart = matchOffsets[0];
+    dd->lastMatchEnd = matchOffsets[1];
+
+    if (global() || sticky())
+        setLastIndex(matchOffsets[1]);
+
+    return array.asReturnedValue();
 }
 
 DEFINE_OBJECT_VTABLE(RegExpCtor);
@@ -214,79 +270,118 @@ void Heap::RegExpCtor::init(QV4::ExecutionContext *scope)
 
 void Heap::RegExpCtor::clearLastMatch()
 {
-    lastMatch.set(internalClass->engine, Primitive::nullValue());
+    lastMatch.set(internalClass->engine, Value::nullValue());
     lastInput.set(internalClass->engine, internalClass->engine->id_empty()->d());
     lastMatchStart = 0;
     lastMatchEnd = 0;
 }
 
-void RegExpCtor::construct(const Managed *, Scope &scope, CallData *callData)
+static bool isRegExp(ExecutionEngine *e, const QV4::Value *arg)
 {
-    ScopedValue r(scope, callData->argument(0));
-    ScopedValue f(scope, callData->argument(1));
-    Scoped<RegExpObject> re(scope, r);
-    if (re) {
-        if (!f->isUndefined()) {
-            scope.result = scope.engine->throwTypeError();
-            return;
-        }
-
-        Scoped<RegExp> regexp(scope, re->value());
-        scope.result = Encode(scope.engine->newRegExpObject(regexp, re->global()));
-        return;
-    }
-
-    QString pattern;
-    if (!r->isUndefined())
-        pattern = r->toQString();
-    if (scope.hasException()) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    const QV4::Object *o = arg->objectValue();
+    if (!o)
+        return false;
+
+    QV4::Value isRegExp = QV4::Value::fromReturnedValue(o->get(e->symbol_match()));
+    if (!isRegExp.isUndefined())
+        return isRegExp.toBoolean();
+    const RegExpObject *re = o->as<RegExpObject>();
+    return re ? true : false;
+}
 
-    bool global = false;
-    bool ignoreCase = false;
-    bool multiLine = false;
+uint parseFlags(Scope &scope, const QV4::Value *f)
+{
+    uint flags = CompiledData::RegExp::RegExp_NoFlags;
     if (!f->isUndefined()) {
         ScopedString s(scope, f->toString(scope.engine));
-        if (scope.hasException()) {
-            scope.result = Encode::undefined();
-            return;
-        }
+        if (scope.hasException())
+            return flags;
         QString str = s->toQString();
         for (int i = 0; i < str.length(); ++i) {
-            if (str.at(i) == QLatin1Char('g') && !global) {
-                global = true;
-            } else if (str.at(i) == QLatin1Char('i') && !ignoreCase) {
-                ignoreCase = true;
-            } else if (str.at(i) == QLatin1Char('m') && !multiLine) {
-                multiLine = true;
+            if (str.at(i) == QLatin1Char('g') && !(flags & CompiledData::RegExp::RegExp_Global)) {
+                flags |= CompiledData::RegExp::RegExp_Global;
+            } else if (str.at(i) == QLatin1Char('i') && !(flags & CompiledData::RegExp::RegExp_IgnoreCase)) {
+                flags |= CompiledData::RegExp::RegExp_IgnoreCase;
+            } else if (str.at(i) == QLatin1Char('m') && !(flags & CompiledData::RegExp::RegExp_Multiline)) {
+                flags |= CompiledData::RegExp::RegExp_Multiline;
+            } else if (str.at(i) == QLatin1Char('u') && !(flags & CompiledData::RegExp::RegExp_Unicode)) {
+                flags |= CompiledData::RegExp::RegExp_Unicode;
+            } else if (str.at(i) == QLatin1Char('y') && !(flags & CompiledData::RegExp::RegExp_Sticky)) {
+                flags |= CompiledData::RegExp::RegExp_Sticky;
             } else {
-                scope.result = scope.engine->throwSyntaxError(QStringLiteral("Invalid flags supplied to RegExp constructor"));
-                return;
+                scope.engine->throwSyntaxError(QStringLiteral("Invalid flags supplied to RegExp constructor"));
+                return flags;
             }
         }
     }
+    return flags;
+}
 
-    Scoped<RegExp> regexp(scope, RegExp::create(scope.engine, pattern, ignoreCase, multiLine));
-    if (!regexp->isValid()) {
-        scope.result = scope.engine->throwSyntaxError(QStringLiteral("Invalid regular expression"));
-        return;
+ReturnedValue RegExpCtor::virtualCallAsConstructor(const FunctionObject *fo, const Value *argv, int argc, const Value *newTarget)
+{
+    Scope scope(fo);
+
+    bool patternIsRegExp = argc ? ::isRegExp(scope.engine, argv) : false;
+
+    if (newTarget == fo) {
+        if (patternIsRegExp && (argc < 2 || argv[1].isUndefined())) {
+            const Object *pattern = static_cast<const Object *>(argv);
+            ScopedValue patternConstructor(scope, pattern->get(scope.engine->id_constructor()));
+            if (patternConstructor->sameValue(*newTarget))
+                return pattern->asReturnedValue();
+        }
     }
 
-    scope.result = Encode(scope.engine->newRegExpObject(regexp, global));
-}
+    ScopedValue p(scope, argc ? argv[0] : Value::undefinedValue());
+    ScopedValue f(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Scoped<RegExpObject> re(scope, p);
+    QString pattern;
+    uint flags = CompiledData::RegExp::RegExp_NoFlags;
 
-void RegExpCtor::call(const Managed *that, Scope &scope, CallData *callData)
-{
-    if (callData->argc > 0 && callData->args[0].as<RegExpObject>()) {
-        if (callData->argc == 1 || callData->args[1].isUndefined()) {
-            scope.result = callData->args[0];
-            return;
+    if (re) {
+        if (f->isUndefined()) {
+            Scoped<RegExp> regexp(scope, re->value());
+            return Encode(scope.engine->newRegExpObject(regexp));
         }
+        pattern = *re->value()->pattern;
+        flags = parseFlags(scope, f);
+    } else if (patternIsRegExp) {
+        const Object *po = static_cast<const Object *>(argv);
+        p = po->get(scope.engine->id_source());
+        if (!p->isUndefined())
+            pattern = p->toQString();
+        if (scope.hasException())
+            return Encode::undefined();
+        if (f->isUndefined())
+            f = po->get(scope.engine->id_flags());
+        flags = parseFlags(scope, f);
+    } else {
+        if (!p->isUndefined())
+            pattern = p->toQString();
+        if (scope.hasException())
+            return Encode::undefined();
+        flags = parseFlags(scope, f);
+    }
+    if (scope.hasException())
+        return Encode::undefined();
+
+    Scoped<RegExp> regexp(scope, RegExp::create(scope.engine, pattern, flags));
+    if (!regexp->isValid()) {
+        return scope.engine->throwSyntaxError(QStringLiteral("Invalid regular expression"));
     }
 
-    construct(that, scope, callData);
+    ReturnedValue o = Encode(scope.engine->newRegExpObject(regexp));
+
+    if (!newTarget)
+        return o;
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
+}
+
+ReturnedValue RegExpCtor::virtualCall(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    return virtualCallAsConstructor(f, argv, argc, f);
 }
 
 void RegExpPrototype::init(ExecutionEngine *engine, Object *constructor)
@@ -296,49 +391,62 @@ void RegExpPrototype::init(ExecutionEngine *engine, Object *constructor)
     ScopedObject ctor(scope, constructor);
 
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(2));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(2));
+    ctor->addSymbolSpecies();
 
     // Properties deprecated in the spec but required by "the web" :(
-    ctor->defineAccessorProperty(QStringLiteral("lastMatch"), method_get_lastMatch_n<0>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$&"), method_get_lastMatch_n<0>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$1"), method_get_lastMatch_n<1>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$2"), method_get_lastMatch_n<2>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$3"), method_get_lastMatch_n<3>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$4"), method_get_lastMatch_n<4>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$5"), method_get_lastMatch_n<5>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$6"), method_get_lastMatch_n<6>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$7"), method_get_lastMatch_n<7>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$8"), method_get_lastMatch_n<8>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$9"), method_get_lastMatch_n<9>, 0);
-    ctor->defineAccessorProperty(QStringLiteral("lastParen"), method_get_lastParen, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$+"), method_get_lastParen, 0);
-    ctor->defineAccessorProperty(QStringLiteral("input"), method_get_input, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$_"), method_get_input, 0);
-    ctor->defineAccessorProperty(QStringLiteral("leftContext"), method_get_leftContext, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$`"), method_get_leftContext, 0);
-    ctor->defineAccessorProperty(QStringLiteral("rightContext"), method_get_rightContext, 0);
-    ctor->defineAccessorProperty(QStringLiteral("$'"), method_get_rightContext, 0);
+    ctor->defineAccessorProperty(QStringLiteral("lastMatch"), method_get_lastMatch_n<0>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$&"), method_get_lastMatch_n<0>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$1"), method_get_lastMatch_n<1>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$2"), method_get_lastMatch_n<2>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$3"), method_get_lastMatch_n<3>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$4"), method_get_lastMatch_n<4>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$5"), method_get_lastMatch_n<5>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$6"), method_get_lastMatch_n<6>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$7"), method_get_lastMatch_n<7>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$8"), method_get_lastMatch_n<8>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$9"), method_get_lastMatch_n<9>, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("lastParen"), method_get_lastParen, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$+"), method_get_lastParen, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("input"), method_get_input, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$_"), method_get_input, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("leftContext"), method_get_leftContext, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$`"), method_get_leftContext, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("rightContext"), method_get_rightContext, nullptr);
+    ctor->defineAccessorProperty(QStringLiteral("$'"), method_get_rightContext, nullptr);
 
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
+    defineAccessorProperty(scope.engine->id_flags(), method_get_flags, nullptr);
+    defineAccessorProperty(scope.engine->id_global(), method_get_global, nullptr);
+    defineAccessorProperty(scope.engine->id_ignoreCase(), method_get_ignoreCase, nullptr);
     defineDefaultProperty(QStringLiteral("exec"), method_exec, 1);
+    defineDefaultProperty(engine->symbol_match(), method_match, 1);
+    defineAccessorProperty(scope.engine->id_multiline(), method_get_multiline, nullptr);
+    defineDefaultProperty(engine->symbol_replace(), method_replace, 2);
+    defineDefaultProperty(engine->symbol_search(), method_search, 1);
+    defineAccessorProperty(scope.engine->id_source(), method_get_source, nullptr);
+    defineDefaultProperty(engine->symbol_split(), method_split, 2);
+    defineAccessorProperty(scope.engine->id_sticky(), method_get_sticky, nullptr);
     defineDefaultProperty(QStringLiteral("test"), method_test, 1);
     defineDefaultProperty(engine->id_toString(), method_toString, 0);
+    defineAccessorProperty(scope.engine->id_unicode(), method_get_unicode, nullptr);
+
+    // another web extension
     defineDefaultProperty(QStringLiteral("compile"), method_compile, 2);
 }
 
-void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallData *callData)
+/* used by String.match */
+ReturnedValue RegExpPrototype::execFirstMatch(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<RegExpObject> r(scope, callData->thisObject.as<RegExpObject>());
-    if (!r)
-        THROW_TYPE_ERROR();
+    Scope scope(b);
+    Scoped<RegExpObject> r(scope, thisObject->as<RegExpObject>());
+    Q_ASSERT(r && r->global());
 
-    ScopedValue arg(scope, callData->argument(0));
-    ScopedString str(scope, arg->toString(scope.engine));
-    if (scope.hasException())
-        RETURN_UNDEFINED();
+    ScopedString str(scope, argc ? argv[0] : Value::undefinedValue());
+    Q_ASSERT(str);
     QString s = str->toQString();
 
-    int offset = r->global() ? r->lastIndex() : 0;
+    int offset = r->lastIndex();
     if (offset < 0 || offset > s.length()) {
         r->setLastIndex(0);
         RETURN_RESULT(Encode::null());
@@ -347,7 +455,7 @@ void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallDat
     Q_ALLOCA_VAR(uint, matchOffsets, r->value()->captureCount() * 2 * sizeof(uint));
     const int result = Scoped<RegExp>(scope, r->value())->match(s, offset, matchOffsets);
 
-    Scoped<RegExpCtor> regExpCtor(scope, scope.engine->regExpCtor());
+    RegExpCtor *regExpCtor = static_cast<RegExpCtor *>(scope.engine->regExpCtor());
     regExpCtor->d()->clearLastMatch();
 
     if (result == -1) {
@@ -355,99 +463,556 @@ void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallDat
         RETURN_RESULT(Encode::null());
     }
 
-    // fill in result data
-    ScopedArrayObject array(scope, scope.engine->newArrayObject(scope.engine->internalClasses[EngineBase::Class_RegExpExecArray], scope.engine->arrayPrototype()));
-    int len = r->value()->captureCount();
-    array->arrayReserve(len);
-    ScopedValue v(scope);
-    for (int i = 0; i < len; ++i) {
-        int start = matchOffsets[i * 2];
-        int end = matchOffsets[i * 2 + 1];
-        v = (start != -1) ? scope.engine->newString(s.mid(start, end - start))->asReturnedValue() : Encode::undefined();
-        array->arrayPut(i, v);
+    ReturnedValue retVal = Encode::undefined();
+    // return first match
+    if (r->value()->captureCount()) {
+        int start = matchOffsets[0];
+        int end = matchOffsets[1];
+        retVal = (start != -1) ? scope.engine->memoryManager->alloc<ComplexString>(str->d(), start, end - start)->asReturnedValue() : Encode::undefined();
     }
-    array->setArrayLengthUnchecked(len);
-    array->setProperty(Index_ArrayIndex, Primitive::fromInt32(result));
-    array->setProperty(Index_ArrayInput, str);
 
     RegExpCtor::Data *dd = regExpCtor->d();
-    dd->lastMatch.set(scope.engine, array);
     dd->lastInput.set(scope.engine, str->d());
     dd->lastMatchStart = matchOffsets[0];
     dd->lastMatchEnd = matchOffsets[1];
 
-    if (r->global())
-        r->setLastIndex(matchOffsets[1]);
+    r->setLastIndex(matchOffsets[1]);
 
-    scope.result = array;
+    return retVal;
 }
 
-void RegExpPrototype::method_test(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue RegExpPrototype::exec(ExecutionEngine *engine, const Object *o, const String *s)
 {
-    method_exec(b, scope, callData);
-    scope.result = Encode(!scope.result.isNull());
+    Scope scope(engine);
+    ScopedString key(scope, scope.engine->newString(QStringLiteral("exec")));
+    ScopedFunctionObject exec(scope, o->get(key));
+    if (exec) {
+        ScopedValue result(scope, exec->call(o, s, 1));
+        if (!result->isNull() && !result->isObject())
+            return scope.engine->throwTypeError();
+        return result->asReturnedValue();
+    }
+    Scoped<RegExpObject> re(scope, o);
+    if (!re)
+        return scope.engine->throwTypeError();
+    return re->builtinExec(engine, s);
 }
 
-void RegExpPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue RegExpPrototype::method_exec(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<RegExpObject> r(scope, callData->thisObject.as<RegExpObject>());
+    Scope scope(b);
+    Scoped<RegExpObject> r(scope, thisObject->as<RegExpObject>());
     if (!r)
-        THROW_TYPE_ERROR();
+        return scope.engine->throwTypeError();
+
+    ScopedValue arg(scope, argc ? argv[0]: Value::undefinedValue());
+    ScopedString str(scope, arg->toString(scope.engine));
+    if (scope.hasException())
+        RETURN_UNDEFINED();
+
+    return  r->builtinExec(scope.engine, str);
+}
+
+ReturnedValue RegExpPrototype::method_get_flags(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    ScopedObject o(scope, thisObject);
+    if (!o)
+        return scope.engine->throwTypeError();
+
+    QString result;
+    ScopedValue v(scope);
+    v = o->get(scope.engine->id_global());
+    if (scope.hasException())
+        return Encode::undefined();
+    if (v->toBoolean())
+        result += QLatin1Char('g');
+    v = o->get(scope.engine->id_ignoreCase());
+    if (scope.hasException())
+        return Encode::undefined();
+    if (v->toBoolean())
+        result += QLatin1Char('i');
+    v = o->get(scope.engine->id_multiline());
+    if (scope.hasException())
+        return Encode::undefined();
+    if (v->toBoolean())
+        result += QLatin1Char('m');
+    v = o->get(scope.engine->id_unicode());
+    if (scope.hasException())
+        return Encode::undefined();
+    if (v->toBoolean())
+        result += QLatin1Char('u');
+    v = o->get(scope.engine->id_sticky());
+    if (scope.hasException())
+        return Encode::undefined();
+    if (v->toBoolean())
+        result += QLatin1Char('y');
+    return scope.engine->newString(result)->asReturnedValue();
+}
+
+ReturnedValue RegExpPrototype::method_get_global(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<RegExpObject> re(scope, thisObject);
+    if (!re) {
+        if (thisObject->sameValue(*scope.engine->regExpPrototype()))
+            return Encode::undefined();
+        return scope.engine->throwTypeError();
+    }
 
-    scope.result = scope.engine->newString(r->toString());
+    bool b = re->value()->flags & CompiledData::RegExp::RegExp_Global;
+    return Encode(b);
 }
 
-void RegExpPrototype::method_compile(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue RegExpPrototype::method_get_ignoreCase(const FunctionObject *f, const Value *thisObject, const Value *, int)
 {
-    Scoped<RegExpObject> r(scope, callData->thisObject.as<RegExpObject>());
+    Scope scope(f);
+    Scoped<RegExpObject> re(scope, thisObject);
+    if (!re) {
+        if (thisObject->sameValue(*scope.engine->regExpPrototype()))
+            return Encode::undefined();
+        return scope.engine->throwTypeError();
+    }
+
+    bool b = re->value()->flags & CompiledData::RegExp::RegExp_IgnoreCase;
+    return Encode(b);
+}
+
+static int advanceStringIndex(int index, const QString &str, bool unicode)
+{
+    if (unicode) {
+        if (index < str.length() - 1 &&
+            str.at(index).isHighSurrogate() &&
+            str.at(index + 1).isLowSurrogate())
+            ++index;
+    }
+    ++index;
+    return index;
+}
+
+static void advanceLastIndexOnEmptyMatch(ExecutionEngine *e, bool unicode, QV4::Object *rx, const String *matchString, const QString &str)
+{
+    Scope scope(e);
+    if (matchString->d()->length() == 0) {
+        QV4::ScopedValue v(scope, rx->get(scope.engine->id_lastIndex()));
+        int lastIndex = advanceStringIndex(v->toLength(), str, unicode);
+        if (!rx->put(scope.engine->id_lastIndex(), QV4::Value::fromInt32(lastIndex)))
+            scope.engine->throwTypeError();
+    }
+}
+
+ReturnedValue RegExpPrototype::method_match(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ScopedObject rx(scope, thisObject);
+    if (!rx)
+        return scope.engine->throwTypeError();
+    ScopedString s(scope, (argc ? argv[0] : Value::undefinedValue()).toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+    bool global = ScopedValue(scope, rx->get(scope.engine->id_global()))->toBoolean();
+
+    if (!global)
+        return exec(scope.engine, rx, s);
+
+    bool unicode = ScopedValue(scope, rx->get(scope.engine->id_unicode()))->toBoolean();
+
+    rx->put(scope.engine->id_lastIndex(), Value::fromInt32(0));
+    ScopedArrayObject a(scope, scope.engine->newArrayObject());
+    uint n = 0;
+
+    ScopedValue result(scope);
+    ScopedValue match(scope);
+    ScopedString matchString(scope);
+    ScopedValue v(scope);
+    while (1) {
+        result = exec(scope.engine, rx, s);
+        if (scope.hasException())
+            return Encode::undefined();
+        if (result->isNull()) {
+            if (!n)
+                return Encode::null();
+            return a->asReturnedValue();
+        }
+        Q_ASSERT(result->isObject());
+        match = static_cast<Object &>(*result).get(PropertyKey::fromArrayIndex(0));
+        matchString = match->toString(scope.engine);
+        if (scope.hasException())
+            return Encode::undefined();
+        a->push_back(matchString);
+        advanceLastIndexOnEmptyMatch(scope.engine, unicode, rx, matchString, s->toQString());
+        ++n;
+    }
+}
+
+ReturnedValue RegExpPrototype::method_get_multiline(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<RegExpObject> re(scope, thisObject);
+    if (!re) {
+        if (thisObject->sameValue(*scope.engine->regExpPrototype()))
+            return Encode::undefined();
+        return scope.engine->throwTypeError();
+    }
+
+    bool b = re->value()->flags & CompiledData::RegExp::RegExp_Multiline;
+    return Encode(b);
+}
+
+ReturnedValue RegExpPrototype::method_replace(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ScopedObject rx(scope, thisObject);
+    if (!rx)
+        return scope.engine->throwTypeError();
+
+    ScopedString s(scope, (argc ? argv[0] : Value::undefinedValue()).toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    int lengthS = s->toQString().length();
+
+    ScopedString replaceValue(scope);
+    ScopedFunctionObject replaceFunction(scope, (argc > 1 ? argv[1] : Value::undefinedValue()));
+    bool functionalReplace = !!replaceFunction;
+    if (!functionalReplace)
+        replaceValue = (argc > 1 ? argv[1] : Value::undefinedValue()).toString(scope.engine);
+
+    ScopedValue v(scope);
+    bool global = (v = rx->get(scope.engine->id_global()))->toBoolean();
+    bool unicode = false;
+    if (global) {
+        unicode = (v = rx->get(scope.engine->id_unicode()))->toBoolean();
+        if (!rx->put(scope.engine->id_lastIndex(), Value::fromInt32(0)))
+            return scope.engine->throwTypeError();
+    }
+
+    ScopedArrayObject results(scope, scope.engine->newArrayObject());
+    ScopedValue result(scope);
+    ScopedValue match(scope);
+    ScopedString matchString(scope);
+    while (1) {
+        result = exec(scope.engine, rx, s);
+        if (scope.hasException())
+            return Encode::undefined();
+        if (result->isNull())
+            break;
+        results->push_back(result);
+        if (!global)
+            break;
+        match = static_cast<Object &>(*result).get(PropertyKey::fromArrayIndex(0));
+        matchString = match->toString(scope.engine);
+        if (scope.hasException())
+            return Encode::undefined();
+        advanceLastIndexOnEmptyMatch(scope.engine, unicode, rx, matchString, s->toQString());
+    }
+    QString accumulatedResult;
+    int nextSourcePosition = 0;
+    int resultsLength = results->getLength();
+    ScopedObject resultObject(scope);
+    for (int i = 0; i < resultsLength; ++i) {
+        resultObject = results->get(PropertyKey::fromArrayIndex(i));
+        if (scope.hasException())
+            return Encode::undefined();
+
+        int nCaptures = resultObject->getLength();
+        nCaptures = qMax(nCaptures - 1, 0);
+        match = resultObject->get(PropertyKey::fromArrayIndex(0));
+        matchString = match->toString(scope.engine);
+        if (scope.hasException())
+            return Encode::undefined();
+        QString m = matchString->toQString();
+        int matchLength = m.length();
+        v = resultObject->get(scope.engine->id_index());
+        int position = v->toInt32();
+        position = qMax(qMin(position, lengthS), 0);
+        if (scope.hasException())
+            return Encode::undefined();
+
+        int n = 1;
+        Scope innerScope(scope.engine);
+        JSCallData cData(scope, nCaptures + 3);
+        while (n <= nCaptures) {
+            v = resultObject->get(PropertyKey::fromArrayIndex(n));
+            if (!v->isUndefined())
+                cData->args[n] = v->toString(scope.engine);
+            ++n;
+        }
+        QString replacement;
+        if (functionalReplace) {
+            cData->args[0] = matchString;
+            cData->args[nCaptures + 1] = Encode(position);
+            cData->args[nCaptures + 2] = s;
+            ScopedValue replValue(scope, replaceFunction->call(cData));
+            replacement = replValue->toQString();
+        } else {
+            replacement = RegExp::getSubstitution(matchString->toQString(), s->toQString(), position, cData.args, nCaptures, replaceValue->toQString());
+        }
+        if (scope.hasException())
+            return Encode::undefined();
+        if (position >= nextSourcePosition) {
+            accumulatedResult += s->toQString().midRef(nextSourcePosition, position - nextSourcePosition) + replacement;
+            nextSourcePosition = position + matchLength;
+        }
+    }
+    if (nextSourcePosition < lengthS) {
+        accumulatedResult += s->toQString().midRef(nextSourcePosition);
+    }
+    return scope.engine->newString(accumulatedResult)->asReturnedValue();
+}
+
+ReturnedValue RegExpPrototype::method_search(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ScopedObject rx(scope, thisObject);
+    if (!rx)
+        return scope.engine->throwTypeError();
+
+    ScopedString s(scope, (argc ? argv[0] : Value::undefinedValue()).toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    ScopedValue previousLastIndex(scope, rx->get(scope.engine->id_lastIndex()));
+    if (previousLastIndex->toNumber() != 0) {
+        if (!rx->put(scope.engine->id_lastIndex(), Value::fromInt32(0)))
+            return scope.engine->throwTypeError();
+    }
+
+    ScopedValue result(scope, exec(scope.engine, rx, s));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    ScopedValue currentLastIndex(scope, rx->get(scope.engine->id_lastIndex()));
+    if (!currentLastIndex->sameValue(previousLastIndex)) {
+        if (!rx->put(scope.engine->id_lastIndex(), previousLastIndex))
+            return scope.engine->throwTypeError();
+    }
+
+    if (result->isNull())
+        return Encode(-1);
+    ScopedObject o(scope, result);
+    Q_ASSERT(o);
+    return o->get(scope.engine->id_index());
+}
+
+
+ReturnedValue RegExpPrototype::method_get_source(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<RegExpObject> re(scope, thisObject);
+    if (!re) {
+        if (thisObject->sameValue(*scope.engine->regExpPrototype()))
+            return scope.engine->newString(QStringLiteral("(?:)"))->asReturnedValue();
+        return scope.engine->throwTypeError();
+    }
+
+    return scope.engine->newString(re->toString())->asReturnedValue();
+}
+
+ReturnedValue RegExpPrototype::method_split(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ScopedObject rx(scope, thisObject);
+    if (!rx)
+        return scope.engine->throwTypeError();
+
+    ScopedString s(scope, (argc ? argv[0] : Value::undefinedValue()).toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    ScopedValue flagsValue(scope, rx->get(scope.engine->id_flags()));
+    ScopedString flags(scope, flagsValue->toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+    QString flagsString = flags->toQString();
+    if (!flagsString.contains(QLatin1Char('y')))
+        flags = scope.engine->newString(flagsString + QLatin1Char('y'));
+    bool unicodeMatching = flagsString.contains(QLatin1Char('u'));
+
+    const FunctionObject *C = rx->speciesConstructor(scope, scope.engine->regExpCtor());
+    if (!C)
+        return Encode::undefined();
+
+    Value *args = scope.alloc(2);
+    args[0] = rx;
+    args[1] = flags;
+    ScopedObject splitter(scope, C->callAsConstructor(args, 2, f));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    ScopedArrayObject A(scope, scope.engine->newArrayObject());
+    uint lengthA = 0;
+    uint limit = argc < 2 ? UINT_MAX : argv[1].toUInt32();
+    if (limit == 0)
+        return A->asReturnedValue();
+
+    QString S = s->toQString();
+    int size = S.length();
+    if (size == 0) {
+        ScopedValue z(scope, exec(scope.engine, splitter, s));
+        if (z->isNull())
+            A->push_back(s);
+        return A->asReturnedValue();
+    }
+
+    int p = 0;
+    int q = 0;
+    ScopedValue v(scope);
+    ScopedValue z(scope);
+    ScopedObject zz(scope);
+    ScopedString t(scope);
+    while (q < size) {
+        Value qq = Value::fromInt32(q);
+        if (!splitter->put(scope.engine->id_lastIndex(), qq))
+            return scope.engine->throwTypeError();
+        z = exec(scope.engine, splitter, s);
+        if (scope.hasException())
+            return Encode::undefined();
+
+        if (z->isNull()) {
+            q = advanceStringIndex(q, S, unicodeMatching);
+            continue;
+        }
+
+        v = splitter->get(scope.engine->id_lastIndex());
+        int e = qMin(v->toInt32(), size);
+        if (e == p) {
+            q = advanceStringIndex(q, S, unicodeMatching);
+            continue;
+        }
+        QString T = S.mid(p, q - p);
+        t = scope.engine->newString(T);
+        A->push_back(t);
+        ++lengthA;
+        if (lengthA == limit)
+            return A->asReturnedValue();
+        p = e;
+        zz = *z;
+        uint numberOfCaptures = qMax(zz->getLength() - 1, 0ll);
+        for (uint i = 1; i <= numberOfCaptures; ++i) {
+            v = zz->get(PropertyKey::fromArrayIndex(i));
+            A->push_back(v);
+            ++lengthA;
+            if (lengthA == limit)
+                return A->asReturnedValue();
+        }
+        q = p;
+    }
+
+    QString T = S.mid(p);
+    t = scope.engine->newString(T);
+    A->push_back(t);
+    return A->asReturnedValue();
+}
+
+ReturnedValue RegExpPrototype::method_get_sticky(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<RegExpObject> re(scope, thisObject);
+    if (!re) {
+        if (thisObject->sameValue(*scope.engine->regExpPrototype()))
+            return Encode::undefined();
+        return scope.engine->throwTypeError();
+    }
+
+    bool b = re->value()->flags & CompiledData::RegExp::RegExp_Sticky;
+    return Encode(b);
+}
+
+ReturnedValue RegExpPrototype::method_test(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Value res = Value::fromReturnedValue(method_exec(b, thisObject, argv, argc));
+    return Encode(!res.isNull());
+}
+
+ReturnedValue RegExpPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    const Object *r = thisObject->as<Object>();
     if (!r)
-        THROW_TYPE_ERROR();
+        return scope.engine->throwTypeError();
+
+    ScopedValue v(scope);
+    v = r->get(scope.engine->id_source());
+    ScopedString source(scope, v->toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+    v = r->get(scope.engine->id_flags());
+    ScopedString flags(scope, v->toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    QString result = QLatin1Char('/') + source->toQString() + QLatin1Char('/') + flags->toQString();
+    return Encode(scope.engine->newString(result));
+}
 
-    ScopedCallData cData(scope, callData->argc);
-    memcpy(cData->args, callData->args, callData->argc*sizeof(Value));
+ReturnedValue RegExpPrototype::method_get_unicode(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<RegExpObject> re(scope, thisObject);
+    if (!re) {
+        if (thisObject->sameValue(*scope.engine->regExpPrototype()))
+            return Encode::undefined();
+        return scope.engine->throwTypeError();
+    }
+
+    bool b = re->value()->flags & CompiledData::RegExp::RegExp_Unicode;
+    return Encode(b);
+}
+
+ReturnedValue RegExpPrototype::method_compile(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<RegExpObject> r(scope, thisObject->as<RegExpObject>());
+    if (!r)
+        return scope.engine->throwTypeError();
 
-    scope.engine->regExpCtor()->as<FunctionObject>()->construct(scope, cData);
-    Scoped<RegExpObject> re(scope, scope.result.asReturnedValue());
+    Scoped<RegExpObject> re(scope, scope.engine->regExpCtor()->callAsConstructor(argv, argc));
 
     r->d()->value.set(scope.engine, re->value());
-    r->d()->global = re->global();
-    RETURN_UNDEFINED();
+    return Encode::undefined();
 }
 
-template <int index>
-void RegExpPrototype::method_get_lastMatch_n(const BuiltinFunction *, Scope &scope, CallData *)
+template <uint index>
+ReturnedValue RegExpPrototype::method_get_lastMatch_n(const FunctionObject *b, const Value *, const Value *, int)
 {
+    Scope scope(b);
     ScopedArrayObject lastMatch(scope, static_cast<RegExpCtor*>(scope.engine->regExpCtor())->lastMatch());
-    scope.result = lastMatch ? lastMatch->getIndexed(index) : Encode::undefined();
-    if (scope.result.isUndefined())
-        scope.result = scope.engine->newString();
+    ScopedValue res(scope, lastMatch ? lastMatch->get(index) : Encode::undefined());
+    if (res->isUndefined())
+        res = scope.engine->newString();
+    return res->asReturnedValue();
 }
 
-void RegExpPrototype::method_get_lastParen(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue RegExpPrototype::method_get_lastParen(const FunctionObject *b, const Value *, const Value *, int)
 {
+    Scope scope(b);
     ScopedArrayObject lastMatch(scope, static_cast<RegExpCtor*>(scope.engine->regExpCtor())->lastMatch());
-    scope.result = lastMatch ? lastMatch->getIndexed(lastMatch->getLength() - 1) : Encode::undefined();
-    if (scope.result.isUndefined())
-        scope.result = scope.engine->newString();
+    ScopedValue res(scope, lastMatch ? lastMatch->get(lastMatch->getLength() - 1) : Encode::undefined());
+    if (res->isUndefined())
+        res = scope.engine->newString();
+    return res->asReturnedValue();
 }
 
-void RegExpPrototype::method_get_input(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue RegExpPrototype::method_get_input(const FunctionObject *b, const Value *, const Value *, int)
 {
-    scope.result = static_cast<RegExpCtor*>(scope.engine->regExpCtor())->lastInput();
+    return static_cast<RegExpCtor*>(b->engine()->regExpCtor())->lastInput()->asReturnedValue();
 }
 
-void RegExpPrototype::method_get_leftContext(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue  RegExpPrototype::method_get_leftContext(const FunctionObject *b, const Value *, const Value *, int)
 {
+    Scope scope(b);
     Scoped<RegExpCtor> regExpCtor(scope, scope.engine->regExpCtor());
     QString lastInput = regExpCtor->lastInput()->toQString();
-    scope.result = scope.engine->newString(lastInput.left(regExpCtor->lastMatchStart()));
+    return Encode(scope.engine->newString(lastInput.left(regExpCtor->lastMatchStart())));
 }
 
-void RegExpPrototype::method_get_rightContext(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue  RegExpPrototype::method_get_rightContext(const FunctionObject *b, const Value *, const Value *, int)
 {
+    Scope scope(b);
     Scoped<RegExpCtor> regExpCtor(scope, scope.engine->regExpCtor());
     QString lastInput = regExpCtor->lastInput()->toQString();
-    scope.result = scope.engine->newString(lastInput.mid(regExpCtor->lastMatchEnd()));
+    return Encode(scope.engine->newString(lastInput.mid(regExpCtor->lastMatchEnd())));
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4regexpobject_p.h b/src/qml/jsruntime/qv4regexpobject_p.h
index 6f54a4ab92..04b533e49d 100644
--- a/src/qml/jsruntime/qv4regexpobject_p.h
+++ b/src/qml/jsruntime/qv4regexpobject_p.h
@@ -55,11 +55,10 @@
 #include "qv4context_p.h"
 #include "qv4functionobject_p.h"
 #include "qv4string_p.h"
-#include "qv4codegen_p.h"
-#include "qv4isel_p.h"
 #include "qv4managed_p.h"
 #include "qv4property_p.h"
 #include "qv4objectiterator_p.h"
+#include "qv4regexp_p.h"
 
 #include <QtCore/QString>
 #include <QtCore/QHash>
@@ -74,15 +73,17 @@ namespace QV4 {
 namespace Heap {
 
 #define RegExpObjectMembers(class, Member) \
-    Member(class, Pointer, RegExp *, value) \
-    Member(class, NoMark, bool, global)
+    Member(class, Pointer, RegExp *, value)
 
 DECLARE_HEAP_OBJECT(RegExpObject, Object) {
-    DECLARE_MARK_TABLE(RegExpObject);
+    DECLARE_MARKOBJECTS(RegExpObject)
 
     void init();
-    void init(QV4::RegExp *value, bool global);
+    void init(QV4::RegExp *value);
     void init(const QRegExp &re);
+#if QT_CONFIG(regularexpression)
+    void init(const QRegularExpression &re);
+#endif
 };
 
 #define RegExpCtorMembers(class, Member) \
@@ -92,7 +93,7 @@ DECLARE_HEAP_OBJECT(RegExpObject, Object) {
     Member(class, NoMark, int, lastMatchEnd)
 
 DECLARE_HEAP_OBJECT(RegExpCtor, FunctionObject) {
-    DECLARE_MARK_TABLE(RegExpCtor);
+    DECLARE_MARKOBJECTS(RegExpCtor);
 
     void init(QV4::ExecutionContext *scope);
     void clearLastMatch();
@@ -106,41 +107,53 @@ struct RegExpObject: Object {
     V4_INTERNALCLASS(RegExpObject)
     V4_PROTOTYPE(regExpPrototype)
 
-    // needs to be compatible with the flags in qv4jsir_p.h
+    // needs to be compatible with the flags in qv4compileddata_p.h
     enum Flags {
         RegExp_Global     = 0x01,
         RegExp_IgnoreCase = 0x02,
-        RegExp_Multiline  = 0x04
+        RegExp_Multiline  = 0x04,
+        RegExp_Unicode    = 0x08,
+        RegExp_Sticky     = 0x10
     };
 
     enum {
         Index_LastIndex = 0,
-        Index_Source = 1,
-        Index_Global = 2,
-        Index_IgnoreCase = 3,
-        Index_Multiline = 4,
         Index_ArrayIndex = Heap::ArrayObject::LengthPropertyIndex + 1,
         Index_ArrayInput = Index_ArrayIndex + 1
     };
 
-    Heap::RegExp *value() const { return d()->value; }
-    bool global() const { return d()->global; }
+    enum { NInlineProperties = 5 };
+
 
     void initProperties();
 
     int lastIndex() const {
-        Q_ASSERT(Index_LastIndex == internalClass()->find(engine()->id_lastIndex()));
+        Q_ASSERT(internalClass()->verifyIndex(engine()->id_lastIndex()->propertyKey(), Index_LastIndex));
         return propertyData(Index_LastIndex)->toInt32();
     }
     void setLastIndex(int index) {
-        Q_ASSERT(Index_LastIndex == internalClass()->find(engine()->id_lastIndex()));
-        return setProperty(Index_LastIndex, Primitive::fromInt32(index));
+        Q_ASSERT(internalClass()->verifyIndex(engine()->id_lastIndex()->propertyKey(), Index_LastIndex));
+        if (!internalClass()->propertyData[Index_LastIndex].isWritable()) {
+            engine()->throwTypeError();
+            return;
+        }
+        return setProperty(Index_LastIndex, Value::fromInt32(index));
     }
 
     QRegExp toQRegExp() const;
+#if QT_CONFIG(regularexpression)
+    QRegularExpression toQRegularExpression() const;
+#endif
     QString toString() const;
     QString source() const;
-    uint flags() const;
+
+    Heap::RegExp *value() const { return d()->value; }
+    uint flags() const { return d()->value->flags; }
+    bool global() const { return d()->value->global(); }
+    bool sticky() const { return d()->value->sticky(); }
+    bool unicode() const { return d()->value->unicode(); }
+
+    ReturnedValue builtinExec(ExecutionEngine *engine, const String *s);
 };
 
 struct RegExpCtor: FunctionObject
@@ -152,25 +165,43 @@ struct RegExpCtor: FunctionObject
     int lastMatchStart() { return d()->lastMatchStart; }
     int lastMatchEnd() { return d()->lastMatchEnd; }
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
-struct RegExpPrototype: RegExpObject
+struct RegExpPrototype: Object
 {
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_exec(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_test(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_compile(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    template <int index>
-    static void method_get_lastMatch_n(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_lastParen(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_input(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_leftContext(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_rightContext(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_exec(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_flags(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_global(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_ignoreCase(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_match(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_multiline(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_replace(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_search(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_source(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_split(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_sticky(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_test(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_unicode(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    // Web extension
+    static ReturnedValue method_compile(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    // properties on the constructor, web extensions
+    template <uint index>
+    static ReturnedValue method_get_lastMatch_n(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_lastParen(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_input(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_leftContext(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_rightContext(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue execFirstMatch(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue exec(ExecutionEngine *engine, const Object *o, const String *s);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index df2af9de40..9753ee4b1d 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -51,13 +51,18 @@
 #include "qv4lookup_p.h"
 #include "qv4function_p.h"
 #include "qv4numberobject_p.h"
+#include "qv4regexp_p.h"
+#include "qv4regexpobject_p.h"
 #include "private/qlocale_tools_p.h"
 #include "qv4scopedvalue_p.h"
+#include "qv4jscall_p.h"
 #include <private/qv4qmlcontext_p.h>
 #include <private/qqmltypewrapper_p.h>
 #include <private/qqmlengine_p.h>
 #include <private/qqmljavascriptexpression_p.h>
 #include "qv4qobjectwrapper_p.h"
+#include "qv4symbol_p.h"
+#include "qv4generatorobject_p.h"
 #include <private/qv8engine_p.h>
 #endif
 
@@ -220,13 +225,6 @@ void RuntimeCounters::count(const char *func, uint tag1, uint tag2)
 
 #ifndef V4_BOOTSTRAP
 
-Runtime::Runtime()
-{
-#define INIT_METHOD(returnvalue, name, args) runtimeMethods[name] = reinterpret_cast<void*>(&method_##name);
-FOR_EACH_RUNTIME_METHOD(INIT_METHOD)
-#undef INIT_METHOD
-}
-
 void RuntimeHelpers::numberToString(QString *result, double num, int radix)
 {
     Q_ASSERT(result);
@@ -282,7 +280,7 @@ void RuntimeHelpers::numberToString(QString *result, double num, int radix)
     }
 
     double frac = num - ::floor(num);
-    num = Primitive::toInteger(num);
+    num = Value::toInteger(num);
 
     do {
         char c = (char)::fmod(num, radix);
@@ -293,82 +291,113 @@ void RuntimeHelpers::numberToString(QString *result, double num, int radix)
 
     if (frac != 0) {
         result->append(QLatin1Char('.'));
+        double magnitude = 1;
+        double next = frac;
         do {
-            frac = frac * radix;
-            char c = (char)::floor(frac);
+            next *= radix;
+            const int floored = ::floor(next);
+            char c = char(floored);
             c = (c < 10) ? (c + '0') : (c - 10 + 'a');
             result->append(QLatin1Char(c));
-            frac = frac - ::floor(frac);
-        } while (frac != 0);
+            magnitude /= radix;
+            frac -= double(floored) * magnitude;
+            next -= double(floored);
+
+            // The next digit still makes a difference
+            // if a value of "radix" for it would change frac.
+            // Otherwise we've reached the limit of numerical precision.
+        } while (frac > 0 && frac - magnitude != frac);
     }
 
     if (negative)
         result->prepend(QLatin1Char('-'));
 }
 
-ReturnedValue Runtime::method_closure(ExecutionEngine *engine, int functionId)
+ReturnedValue Runtime::Closure::call(ExecutionEngine *engine, int functionId)
 {
-    QV4::Function *clos = static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeFunctions[functionId];
+    QV4::Function *clos = static_cast<CompiledData::CompilationUnit*>(engine->currentStackFrame->v4Function->compilationUnit)->runtimeFunctions[functionId];
     Q_ASSERT(clos);
-    return FunctionObject::createScriptFunction(engine->currentContext, clos)->asReturnedValue();
+    ExecutionContext *current = static_cast<ExecutionContext *>(&engine->currentStackFrame->jsFrame->context);
+    if (clos->isGenerator())
+        return GeneratorFunction::create(current, clos)->asReturnedValue();
+    return FunctionObject::createScriptFunction(current, clos)->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_deleteElement(ExecutionEngine *engine, const Value &base, const Value &index)
+Bool Runtime::DeleteProperty_NoThrow::call(ExecutionEngine *engine, const Value &base, const Value &index)
 {
     Scope scope(engine);
-    ScopedObject o(scope, base);
-    if (o) {
-        uint n = index.asArrayIndex();
-        if (n < UINT_MAX) {
-            return Encode((bool)o->deleteIndexedProperty(n));
-        }
-    }
+    ScopedObject o(scope, base.toObject(engine));
+    if (scope.engine->hasException)
+        return Encode::undefined();
+    Q_ASSERT(o);
 
-    ScopedString name(scope, index.toString(engine));
-    return method_deleteMemberString(engine, base, name);
+    ScopedPropertyKey key(scope, index.toPropertyKey(engine));
+    if (engine->hasException)
+        return false;
+    return o->deleteProperty(key);
 }
 
-ReturnedValue Runtime::method_deleteMember(ExecutionEngine *engine, const Value &base, int nameIndex)
+ReturnedValue Runtime::DeleteProperty::call(ExecutionEngine *engine, QV4::Function *function, const QV4::Value &base, const QV4::Value &index)
 {
-    Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    return method_deleteMemberString(engine, base, name);
+    if (!Runtime::DeleteProperty_NoThrow::call(engine, base, index)) {
+        if (function->isStrict())
+            engine->throwTypeError();
+        return Encode(false);
+    } else {
+        return Encode(true);
+    }
 }
 
-ReturnedValue Runtime::method_deleteMemberString(ExecutionEngine *engine, const Value &base, String *name)
+Bool Runtime::DeleteName_NoThrow::call(ExecutionEngine *engine, int nameIndex)
 {
     Scope scope(engine);
-    ScopedObject obj(scope, base.toObject(engine));
-    if (scope.engine->hasException)
-        return Encode::undefined();
-    return Encode(obj->deleteProperty(name));
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    return static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).deleteProperty(name);
 }
 
-ReturnedValue Runtime::method_deleteName(ExecutionEngine *engine, int nameIndex)
+ReturnedValue Runtime::DeleteName::call(ExecutionEngine *engine, Function *function, int name)
 {
-    Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    return Encode(engine->currentContext->deleteProperty(name));
+    if (!Runtime::DeleteName_NoThrow::call(engine, name)) {
+        if (function->isStrict())
+            engine->throwTypeError();
+        return Encode(false);
+    } else {
+        return Encode(true);
+    }
 }
 
-QV4::ReturnedValue Runtime::method_instanceof(ExecutionEngine *engine, const Value &lval, const Value &rval)
+QV4::ReturnedValue Runtime::Instanceof::call(ExecutionEngine *engine, const Value &lval, const Value &rval)
 {
     // 11.8.6, 5: rval must be an Object
     const Object *rhs = rval.as<Object>();
     if (!rhs)
        return engine->throwTypeError();
 
-    // 11.8.6, 7: call "HasInstance", which we term instanceOf, and return the result.
-    return rhs->instanceOf(lval);
+    const FunctionObject *f = rhs->as<FunctionObject>();
+    // shortcut hasInstance evaluation. In this case we know that we are calling the regular hasInstance()
+    // method of the FunctionPrototype
+    if (f && f->d()->prototype() == engine->functionPrototype()->d() && !f->hasHasInstanceProperty())
+        return Object::checkedInstanceOf(engine, f, lval);
+
+    Scope scope(engine);
+    ScopedValue hasInstance(scope, rhs->get(engine->symbol_hasInstance()));
+    if (hasInstance->isUndefined())
+        return rhs->instanceOf(lval);
+    FunctionObject *fHasInstance = hasInstance->as<FunctionObject>();
+    if (!fHasInstance)
+        return engine->throwTypeError();
+
+    ScopedValue result(scope, fHasInstance->call(&rval, &lval, 1));
+    return Encode(result->toBoolean());
 }
 
-QV4::ReturnedValue Runtime::method_in(ExecutionEngine *engine, const Value &left, const Value &right)
+QV4::ReturnedValue Runtime::In::call(ExecutionEngine *engine, const Value &left, const Value &right)
 {
     Object *ro = right.objectValue();
     if (!ro)
         return engine->throwTypeError();
     Scope scope(engine);
-    ScopedString s(scope, left.toString(engine));
+    ScopedPropertyKey s(scope, left.toPropertyKey(engine));
     if (scope.hasException())
         return Encode::undefined();
     bool r = ro->hasProperty(s);
@@ -378,12 +407,27 @@ QV4::ReturnedValue Runtime::method_in(ExecutionEngine *engine, const Value &left
 double RuntimeHelpers::stringToNumber(const QString &string)
 {
     const QStringRef s = QStringRef(&string).trimmed();
-    if (s.startsWith(QLatin1String("0x")) || s.startsWith(QLatin1String("0X")))
-        return s.toLong(0, 16);
-    bool ok;
+    if (s.startsWith(QLatin1Char('0'))) {
+        int base = -1;
+        if (s.startsWith(QLatin1String("0x")) || s.startsWith(QLatin1String("0X")))
+            base = 16;
+        else if (s.startsWith(QLatin1String("0o")) || s.startsWith(QLatin1String("0O")))
+            base = 8;
+        else if (s.startsWith(QLatin1String("0b")) || s.startsWith(QLatin1String("0B")))
+            base = 2;
+        if (base > 0) {
+            bool ok = true;
+            qlonglong num;
+            num = s.mid(2).toLongLong(&ok, base);
+            if (!ok)
+                return qQNaN();
+            return num;
+        }
+    }
+    bool ok = false;
     QByteArray ba = s.toLatin1();
     const char *begin = ba.constData();
-    const char *end = 0;
+    const char *end = nullptr;
     double d = qstrtod(begin, &end, &ok);
     if (end - begin != ba.size()) {
         if (ba == "Infinity" || ba == "+Infinity")
@@ -405,32 +449,63 @@ Heap::String *RuntimeHelpers::stringFromNumber(ExecutionEngine *engine, double n
 
 ReturnedValue RuntimeHelpers::objectDefaultValue(const Object *object, int typeHint)
 {
-    if (typeHint == PREFERREDTYPE_HINT) {
-        if (object->as<DateObject>())
-            typeHint = STRING_HINT;
-        else
-            typeHint = NUMBER_HINT;
+    ExecutionEngine *engine = object->internalClass()->engine;
+    if (engine->hasException)
+        return Encode::undefined();
+
+    String *hint;
+    switch (typeHint) {
+    case STRING_HINT:
+        hint = engine->id_string();
+        break;
+    case NUMBER_HINT:
+        hint = engine->id_number();
+        break;
+    default:
+        hint = engine->id_default();
+        break;
     }
 
-    ExecutionEngine *engine = object->internalClass()->engine;
+    Scope scope(engine);
+    ScopedFunctionObject toPrimitive(scope, object->get(engine->symbol_toPrimitive()));
     if (engine->hasException)
         return Encode::undefined();
+    if (toPrimitive) {
+        ScopedValue result(scope, toPrimitive->call(object, hint, 1));
+        if (engine->hasException)
+            return Encode::undefined();
+        if (!result->isPrimitive())
+            return engine->throwTypeError();
+        return result->asReturnedValue();
+    }
+
+    if (hint == engine->id_default())
+        hint = engine->id_number();
+    return ordinaryToPrimitive(engine, object, hint);
+}
+
+
+ReturnedValue RuntimeHelpers::ordinaryToPrimitive(ExecutionEngine *engine, const Object *object, String *typeHint)
+{
+    Q_ASSERT(!engine->hasException);
 
     String *meth1 = engine->id_toString();
     String *meth2 = engine->id_valueOf();
 
-    if (typeHint == NUMBER_HINT)
+    if (typeHint->propertyKey() == engine->id_number()->propertyKey()) {
         qSwap(meth1, meth2);
+    } else {
+        Q_ASSERT(typeHint->propertyKey() == engine->id_string()->propertyKey());
+    }
 
     Scope scope(engine);
-    ScopedCallData callData(scope, 0);
-    callData->thisObject = *object;
+    ScopedValue result(scope);
 
     ScopedValue conv(scope, object->get(meth1));
     if (FunctionObject *o = conv->as<FunctionObject>()) {
-        o->call(scope, callData);
-        if (scope.result.isPrimitive())
-            return scope.result.asReturnedValue();
+        result = o->call(object, nullptr, 0);
+        if (result->isPrimitive())
+            return result->asReturnedValue();
     }
 
     if (engine->hasException)
@@ -438,28 +513,31 @@ ReturnedValue RuntimeHelpers::objectDefaultValue(const Object *object, int typeH
 
     conv = object->get(meth2);
     if (FunctionObject *o = conv->as<FunctionObject>()) {
-        o->call(scope, callData);
-        if (scope.result.isPrimitive())
-            return scope.result.asReturnedValue();
+        result = o->call(object, nullptr, 0);
+        if (result->isPrimitive())
+            return result->asReturnedValue();
     }
 
     return engine->throwTypeError();
 }
 
 
-
 Heap::Object *RuntimeHelpers::convertToObject(ExecutionEngine *engine, const Value &value)
 {
     Q_ASSERT(!value.isObject());
     switch (value.type()) {
     case Value::Undefined_Type:
+        engine->throwTypeError(QLatin1String("Value is undefined and could not be converted to an object"));
+        return nullptr;
     case Value::Null_Type:
-        engine->throwTypeError();
-        return 0;
+        engine->throwTypeError(QLatin1String("Value is null and could not be converted to an object"));
+        return nullptr;
     case Value::Boolean_Type:
         return engine->newBooleanObject(value.booleanValue());
     case Value::Managed_Type:
-        Q_ASSERT(value.isString());
+        Q_ASSERT(value.isStringOrSymbol());
+        if (!value.isString())
+            return engine->newSymbolObject(value.symbolValue());
         return engine->newStringObject(value.stringValue());
     case Value::Integer_Type:
     default: // double
@@ -467,8 +545,9 @@ Heap::Object *RuntimeHelpers::convertToObject(ExecutionEngine *engine, const Val
     }
 }
 
-Heap::String *RuntimeHelpers::convertToString(ExecutionEngine *engine, const Value &value)
+Heap::String *RuntimeHelpers::convertToString(ExecutionEngine *engine, Value value, TypeHint hint)
 {
+  redo:
     switch (value.type()) {
     case Value::Empty_Type:
         Q_ASSERT(!"empty Value encountered");
@@ -482,15 +561,19 @@ Heap::String *RuntimeHelpers::convertToString(ExecutionEngine *engine, const Val
             return engine->id_true()->d();
         else
             return engine->id_false()->d();
-    case Value::Managed_Type:
-        if (String *s = value.stringValue())
-            return s->d();
-        {
-            Scope scope(engine);
-            ScopedValue prim(scope, RuntimeHelpers::toPrimitive(value, STRING_HINT));
-            Q_ASSERT(!prim->isManaged() || prim->isString());
-            return RuntimeHelpers::convertToString(engine, prim);
+    case Value::Managed_Type: {
+        if (value.isString())
+            return static_cast<const String &>(value).d();
+        if (value.isSymbol()) {
+            engine->throwTypeError(QLatin1String("Cannot convert a symbol to a string."));
+            return  nullptr;
         }
+        value = Value::fromReturnedValue(RuntimeHelpers::toPrimitive(value, hint));
+        Q_ASSERT(value.isPrimitive());
+        if (value.isString())
+            return static_cast<const String &>(value).d();
+        goto redo;
+    }
     case Value::Integer_Type:
         return RuntimeHelpers::stringFromNumber(engine, value.int_32());
     default: // double
@@ -500,34 +583,9 @@ Heap::String *RuntimeHelpers::convertToString(ExecutionEngine *engine, const Val
 
 // This is slightly different from the method above, as
 // the + operator requires a slightly different conversion
-static Heap::String *convert_to_string_add(ExecutionEngine *engine, const Value &value)
+static Heap::String *convert_to_string_add(ExecutionEngine *engine, Value value)
 {
-    switch (value.type()) {
-    case Value::Empty_Type:
-        Q_ASSERT(!"empty Value encountered");
-        Q_UNREACHABLE();
-    case Value::Undefined_Type:
-        return engine->id_undefined()->d();
-    case Value::Null_Type:
-        return engine->id_null()->d();
-    case Value::Boolean_Type:
-        if (value.booleanValue())
-            return engine->id_true()->d();
-        else
-            return engine->id_false()->d();
-    case Value::Managed_Type:
-        if (String *s = value.stringValue())
-            return s->d();
-        {
-            Scope scope(engine);
-            ScopedValue prim(scope, RuntimeHelpers::toPrimitive(value, PREFERREDTYPE_HINT));
-            return RuntimeHelpers::convertToString(engine, prim);
-        }
-    case Value::Integer_Type:
-        return RuntimeHelpers::stringFromNumber(engine, value.int_32());
-    default: // double
-        return RuntimeHelpers::stringFromNumber(engine, value.doubleValue());
-    } // switch
+    return RuntimeHelpers::convertToString(engine, value, PREFERREDTYPE_HINT);
 }
 
 QV4::ReturnedValue RuntimeHelpers::addHelper(ExecutionEngine *engine, const Value &left, const Value &right)
@@ -547,56 +605,40 @@ QV4::ReturnedValue RuntimeHelpers::addHelper(ExecutionEngine *engine, const Valu
             pright = convert_to_string_add(engine, pright);
             sright = static_cast<String *>(pright.ptr);
         }
-        if (scope.engine->hasException)
+        if (engine->hasException)
             return Encode::undefined();
         if (!sleft->d()->length())
             return sright->asReturnedValue();
         if (!sright->d()->length())
             return sleft->asReturnedValue();
         MemoryManager *mm = engine->memoryManager;
-        return (mm->alloc<String>(sleft->d(), sright->d()))->asReturnedValue();
+        return (mm->alloc<ComplexString>(sleft->d(), sright->d()))->asReturnedValue();
     }
     double x = RuntimeHelpers::toNumber(pleft);
     double y = RuntimeHelpers::toNumber(pright);
     return Encode(x + y);
 }
 
-QV4::ReturnedValue Runtime::method_addString(ExecutionEngine *engine, const Value &left, const Value &right)
+ReturnedValue Runtime::GetTemplateObject::call(Function *function, int index)
 {
-    Q_ASSERT(left.isString() || right.isString());
-
-    Scope scope(engine);
-    ScopedValue pleft(scope, left);
-    ScopedValue pright(scope, right);
-    String *sleft = pleft->stringValue();
-    String *sright = pright->stringValue();
-
-    if (!sleft) {
-        pleft = convert_to_string_add(engine, pleft);
-        sleft = static_cast<String *>(pleft.ptr);
-    }
-    if (!sright) {
-        pright = convert_to_string_add(engine, pright);
-        sright = static_cast<String *>(pright.ptr);
-    }
-    if (scope.engine->hasException)
-        return Encode::undefined();
-    if (!sleft->d()->length())
-        return pright->asReturnedValue();
-    if (!sright->d()->length())
-        return pleft->asReturnedValue();
-    MemoryManager *mm = engine->memoryManager;
-    return (mm->alloc<String>(sleft->d(), sright->d()))->asReturnedValue();
+    return function->compilationUnit->templateObjectAt(index)->asReturnedValue();
 }
 
-void Runtime::method_setProperty(ExecutionEngine *engine, const Value &object, int nameIndex, const Value &value)
+void Runtime::StoreProperty::call(ExecutionEngine *engine, const Value &object, int nameIndex, const Value &value)
 {
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    ScopedObject o(scope, object.toObject(engine));
-    if (!o)
-        return;
-    o->put(name, value);
+    QV4::Function *v4Function = engine->currentStackFrame->v4Function;
+    ScopedString name(scope, v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    ScopedObject o(scope, object);
+    if (!o) {
+        if (v4Function->isStrict()) {
+            engine->throwTypeError();
+            return;
+        }
+        o = object.toObject(engine);
+    }
+    if ((!o || !o->put(name, value)) && v4Function->isStrict())
+        engine->throwTypeError();
 }
 
 static Q_NEVER_INLINE ReturnedValue getElementIntFallback(ExecutionEngine *engine, const Value &object, uint idx)
@@ -629,12 +671,13 @@ static Q_NEVER_INLINE ReturnedValue getElementIntFallback(ExecutionEngine *engin
             return v->asReturnedValue();
     }
 
-    return o->getIndexed(idx);
+    return o->get(idx);
 }
 
 static Q_NEVER_INLINE ReturnedValue getElementFallback(ExecutionEngine *engine, const Value &object, const Value &index)
 {
-    Q_ASSERT(index.asArrayIndex() == UINT_MAX);
+    Q_ASSERT(!index.isPositiveInt());
+
     Scope scope(engine);
 
     ScopedObject o(scope, object);
@@ -648,18 +691,40 @@ static Q_NEVER_INLINE ReturnedValue getElementFallback(ExecutionEngine *engine,
         Q_ASSERT(!!o); // can't fail as null/undefined is covered above
     }
 
-    ScopedString name(scope, index.toString(engine));
+    ScopedPropertyKey name(scope, index.toPropertyKey(engine));
     if (scope.hasException())
         return Encode::undefined();
     return o->get(name);
 }
 
-ReturnedValue Runtime::method_getElement(ExecutionEngine *engine, const Value &object, const Value &index)
+ReturnedValue Runtime::LoadElement::call(ExecutionEngine *engine, const Value &object, const Value &index)
+{
+    if (index.isPositiveInt()) {
+        uint idx = static_cast<uint>(index.int_32());
+        if (Heap::Base *b = object.heapObject()) {
+            if (b->internalClass->vtable->isObject) {
+                Heap::Object *o = static_cast<Heap::Object *>(b);
+                if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
+                    Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
+                    if (idx < s->values.size)
+                        if (!s->data(idx).isEmpty())
+                            return s->data(idx).asReturnedValue();
+                }
+            }
+        }
+        return getElementIntFallback(engine, object, idx);
+    }
+
+    return getElementFallback(engine, object, index);
+}
+
+ReturnedValue Runtime::LoadElement_Traced::call(ExecutionEngine *engine, const Value &object, const Value &index, quint8 *traceSlot)
 {
-    uint idx;
-    if (index.asArrayIndex(idx)) {
+    *traceSlot |= quint8(ObservedTraceValues::ArrayWasAccessed);
+    if (index.isPositiveInt()) {
+        uint idx = static_cast<uint>(index.int_32());
         if (Heap::Base *b = object.heapObject()) {
-            if (b->vtable()->isObject) {
+            if (b->internalClass->vtable->isObject) {
                 Heap::Object *o = static_cast<Heap::Object *>(b);
                 if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
                     Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
@@ -669,42 +734,76 @@ ReturnedValue Runtime::method_getElement(ExecutionEngine *engine, const Value &o
                 }
             }
         }
+        *traceSlot |= quint8(ObservedTraceValues::ArrayAccessNeededFallback);
         return getElementIntFallback(engine, object, idx);
     }
 
+    *traceSlot |= quint8(ObservedTraceValues::ArrayAccessNeededFallback);
     return getElementFallback(engine, object, index);
 }
 
-static Q_NEVER_INLINE void setElementFallback(ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)
+static Q_NEVER_INLINE bool setElementFallback(ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)
 {
     Scope scope(engine);
-    ScopedObject o(scope, object.toObject(engine));
+    ScopedObject o(scope, object);
+    if (!o) {
+        if (engine->currentStackFrame->v4Function->isStrict()) {
+            engine->throwTypeError();
+            return false;
+        }
+
+        o = object.toObject(engine);
+    }
     if (engine->hasException)
-        return;
+        return false;
 
-    uint idx;
-    if (index.asArrayIndex(idx)) {
+    if (index.isPositiveInt()) {
+        uint idx = static_cast<uint>(index.int_32());
         if (o->d()->arrayData && o->d()->arrayData->type == Heap::ArrayData::Simple) {
             Heap::SimpleArrayData *s = o->d()->arrayData.cast<Heap::SimpleArrayData>();
             if (idx < s->values.size) {
                 s->setData(engine, idx, value);
-                return;
+                return true;
+            }
+        }
+        return o->put(idx, value);
+    }
+
+    ScopedPropertyKey name(scope, index.toPropertyKey(engine));
+    if (engine->hasException)
+        return false;
+    return o->put(name, value);
+}
+
+void Runtime::StoreElement::call(ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)
+{
+    if (index.isPositiveInt()) {
+        uint idx = static_cast<uint>(index.int_32());
+        if (Heap::Base *b = object.heapObject()) {
+            if (b->internalClass->vtable->isObject) {
+                Heap::Object *o = static_cast<Heap::Object *>(b);
+                if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
+                    Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
+                    if (idx < s->values.size) {
+                        s->setData(engine, idx, value);
+                        return;
+                    }
+                }
             }
         }
-        o->putIndexed(idx, value);
-        return;
     }
 
-    ScopedString name(scope, index.toString(engine));
-    o->put(name, value);
+    if (!setElementFallback(engine, object, index, value) && engine->currentStackFrame->v4Function->isStrict())
+        engine->throwTypeError();
 }
 
-void Runtime::method_setElement(ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)
+void Runtime::StoreElement_traced::call(ExecutionEngine *engine, const Value &object, const Value &index, const Value &value, quint8 *traceSlot)
 {
-    uint idx;
-    if (index.asArrayIndex(idx)) {
+    *traceSlot |= quint8(ObservedTraceValues::ArrayWasAccessed);
+    if (index.isPositiveInt()) {
+        uint idx = static_cast<uint>(index.int_32());
         if (Heap::Base *b = object.heapObject()) {
-            if (b->vtable()->isObject) {
+            if (b->internalClass->vtable->isObject) {
                 Heap::Object *o = static_cast<Heap::Object *>(b);
                 if (o->arrayData && o->arrayData->type == Heap::ArrayData::Simple) {
                     Heap::SimpleArrayData *s = o->arrayData.cast<Heap::SimpleArrayData>();
@@ -717,40 +816,229 @@ void Runtime::method_setElement(ExecutionEngine *engine, const Value &object, co
         }
     }
 
-    return setElementFallback(engine, object, index, value);
+    *traceSlot |= quint8(ObservedTraceValues::ArrayAccessNeededFallback);
+    if (!setElementFallback(engine, object, index, value) && engine->currentStackFrame->v4Function->isStrict())
+        engine->throwTypeError();
 }
 
-ReturnedValue Runtime::method_foreachIterator(ExecutionEngine *engine, const Value &in)
+ReturnedValue Runtime::GetIterator::call(ExecutionEngine *engine, const Value &in, int iterator)
 {
     Scope scope(engine);
-    ScopedObject o(scope, (Object *)0);
+    ScopedObject o(scope, (Object *)nullptr);
     if (!in.isNullOrUndefined())
         o = in.toObject(engine);
-    return engine->newForEachIteratorObject(o)->asReturnedValue();
+    if (engine->hasException)
+        return Encode::undefined();
+    if (iterator == static_cast<int>(QQmlJS::AST::ForEachType::Of)) {
+        if (!o)
+            return engine->throwTypeError();
+        ScopedFunctionObject f(scope, o->get(engine->symbol_iterator()));
+        if (!f)
+            return engine->throwTypeError();
+        JSCallData cData(scope, 0, nullptr, o);
+        ScopedObject it(scope, f->call(cData));
+        if (!it)
+            return engine->throwTypeError();
+        return it->asReturnedValue();
+    }
+    return engine->newForInIteratorObject(o)->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_foreachNextPropertyName(const Value &foreach_iterator)
+ReturnedValue Runtime::IteratorNext::call(ExecutionEngine *engine, const Value &iterator, Value *value)
 {
-    Q_ASSERT(foreach_iterator.isObject());
+    // if we throw an exception from here, return true, not undefined. This is to ensure iteratorDone is set to true
+    // and the stack unwinding won't close the iterator
+    Q_ASSERT(iterator.isObject());
 
-    ForEachIteratorObject *it = static_cast<ForEachIteratorObject *>(foreach_iterator.objectValue());
-    Q_ASSERT(it->as<ForEachIteratorObject>());
+    Scope scope(engine);
+    ScopedFunctionObject f(scope, static_cast<const Object &>(iterator).get(engine->id_next()));
+    if (!f) {
+        engine->throwTypeError();
+        return Encode(true);
+    }
+    JSCallData cData(scope, 0, nullptr, &iterator);
+    ScopedObject o(scope, f->call(cData));
+    if (scope.hasException())
+        return Encode(true);
+    if (!o) {
+        engine->throwTypeError();
+        return Encode(true);
+    }
+
+    ScopedValue d(scope, o->get(engine->id_done()));
+    if (scope.hasException())
+        return Encode(true);
+    bool done = d->toBoolean();
+    if (done) {
+        *value = Encode::undefined();
+        return Encode(true);
+    }
 
-    return it->nextPropertyName();
+    *value = o->get(engine->id_value());
+    if (scope.hasException())
+        return Encode(true);
+    return Encode(false);
 }
 
+ReturnedValue Runtime::IteratorNextForYieldStar::call(ExecutionEngine *engine, const Value &received, const Value &iterator, Value *object)
+{
+    // the return value encodes how to continue the yield* iteration.
+    // true implies iteration is done, false for iteration to continue
+    // a return value of undefines is a special marker, that the iterator has been invoked with return()
+
+    Scope scope(engine);
+    Q_ASSERT(iterator.isObject());
+
+    const Value *arg = &received;
+    bool returnCalled = false;
+    FunctionObject *f = nullptr;
+    if (engine->hasException) {
+        if (engine->exceptionValue->isEmpty()) {
+            // generator called with return()
+            *engine->exceptionValue = Encode::undefined();
+            engine->hasException = false;
+
+            ScopedValue ret(scope, static_cast<const Object &>(iterator).get(engine->id_return()));
+            if (ret->isUndefined()) {
+                // propagate return()
+                return Encode::undefined();
+            }
+            returnCalled = true;
+            f = ret->as<FunctionObject>();
+        } else {
+            // generator called with throw
+            ScopedValue exceptionValue(scope, *engine->exceptionValue);
+            *engine->exceptionValue = Encode::undefined();
+            engine->hasException = false;
+
+            ScopedValue t(scope, static_cast<const Object &>(iterator).get(engine->id_throw()));
+            if (engine->hasException)
+                return Encode::undefined();
+            if (t->isUndefined()) {
+                // no throw method on the iterator
+                ScopedValue done(scope, Encode(false));
+                IteratorClose::call(engine, iterator, done);
+                if (engine->hasException)
+                    return Encode::undefined();
+                return engine->throwTypeError();
+            }
+            f = t->as<FunctionObject>();
+            arg = exceptionValue;
+        }
+    } else {
+        // generator called with next()
+        ScopedFunctionObject next(scope, static_cast<const Object &>(iterator).get(engine->id_next()));
+        f = next->as<FunctionObject>();
+    }
+
+    if (!f)
+        return engine->throwTypeError();
 
-void Runtime::method_setActivationProperty(ExecutionEngine *engine, int nameIndex, const Value &value)
+    ScopedObject o(scope, f->call(&iterator, arg, 1));
+    if (scope.hasException())
+        return Encode(true);
+    if (!o)
+        return engine->throwTypeError();
+
+    ScopedValue d(scope, o->get(engine->id_done()));
+    if (scope.hasException())
+        return Encode(true);
+    bool done = d->toBoolean();
+    if (done) {
+        *object = o->get(engine->id_value());
+        return returnCalled ? Encode::undefined() : Encode(true);
+    }
+    *object = o;
+    return Encode(false);
+}
+
+ReturnedValue Runtime::IteratorClose::call(ExecutionEngine *engine, const Value &iterator, const Value &done)
+{
+    Q_ASSERT(iterator.isObject());
+    Q_ASSERT(done.isBoolean());
+    if (done.booleanValue())
+        return Encode::undefined();
+
+    Scope scope(engine);
+    ScopedValue e(scope);
+    bool hadException = engine->hasException;
+    if (hadException) {
+        e = *engine->exceptionValue;
+        engine->hasException = false;
+    }
+
+    auto originalCompletion = [=]() {
+        if (hadException) {
+            *engine->exceptionValue = e;
+            engine->hasException = hadException;
+        }
+        return Encode::undefined();
+    };
+
+    ScopedValue ret(scope, static_cast<const Object &>(iterator).get(engine->id_return()));
+    ScopedObject o(scope);
+    if (!ret->isUndefined()) {
+        FunctionObject *f = ret->as<FunctionObject>();
+        o = f->call(&iterator, nullptr, 0);
+        if (engine->hasException && !hadException)
+            return Encode::undefined();
+    }
+    if (hadException || ret->isUndefined())
+        return originalCompletion();
+
+    if (!o)
+        return engine->throwTypeError();
+
+    return originalCompletion();
+}
+
+ReturnedValue Runtime::DestructureRestElement::call(ExecutionEngine *engine, const Value &iterator)
 {
+    Q_ASSERT(iterator.isObject());
+
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    engine->currentContext->setProperty(name, value);
+    ScopedArrayObject array(scope, engine->newArrayObject());
+    array->arrayCreate();
+    uint index = 0;
+    while (1) {
+        ScopedValue n(scope);
+        ScopedValue done(scope, IteratorNext::call(engine, iterator, n));
+        if (engine->hasException)
+            return Encode::undefined();
+        Q_ASSERT(done->isBoolean());
+        if (done->booleanValue())
+            break;
+        array->arraySet(index, n);
+        ++index;
+    }
+    return array->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_getProperty(ExecutionEngine *engine, const Value &object, int nameIndex)
+void Runtime::StoreNameSloppy::call(ExecutionEngine *engine, int nameIndex, const Value &value)
 {
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    ExecutionContext::Error e = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).setProperty(name, value);
+
+    if (e == ExecutionContext::RangeError)
+        engine->globalObject->put(name, value);
+}
+
+void Runtime::StoreNameStrict::call(ExecutionEngine *engine, int nameIndex, const Value &value)
+{
+    Scope scope(engine);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    ExecutionContext::Error e = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).setProperty(name, value);
+    if (e == ExecutionContext::TypeError)
+        engine->throwTypeError();
+    else if (e == ExecutionContext::RangeError)
+        engine->throwReferenceError(name);
+}
+
+ReturnedValue Runtime::LoadProperty::call(ExecutionEngine *engine, const Value &object, int nameIndex)
+{
+    Scope scope(engine);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
 
     ScopedObject o(scope, object);
     if (o)
@@ -767,11 +1055,114 @@ ReturnedValue Runtime::method_getProperty(ExecutionEngine *engine, const Value &
     return o->get(name);
 }
 
-ReturnedValue Runtime::method_getActivationProperty(ExecutionEngine *engine, int nameIndex)
+ReturnedValue Runtime::LoadName::call(ExecutionEngine *engine, int nameIndex)
+{
+    Scope scope(engine);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    return static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).getProperty(name);
+}
+
+static Object *getSuperBase(Scope &scope)
+{
+    if (scope.engine->currentStackFrame->jsFrame->thisObject.isEmpty()) {
+        scope.engine->throwReferenceError(QStringLiteral("Missing call to super()."), QString(), 0, 0);
+        return nullptr;
+    }
+
+    ScopedFunctionObject f(scope, scope.engine->currentStackFrame->jsFrame->function);
+    ScopedObject homeObject(scope, f->getHomeObject());
+    if (!homeObject) {
+        ScopedContext ctx(scope, static_cast<ExecutionContext *>(&scope.engine->currentStackFrame->jsFrame->context));
+        Q_ASSERT(ctx);
+        while (ctx) {
+            if (CallContext *c = ctx->asCallContext()) {
+                f = c->d()->function;
+                QV4::Function *fn = f->function();
+                if (fn && !fn->isArrowFunction() && !fn->isEval)
+                    break;
+            }
+            ctx = ctx->d()->outer;
+        }
+        homeObject = f->getHomeObject();
+    }
+    if (!homeObject) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    Q_ASSERT(homeObject);
+    ScopedObject proto(scope, homeObject->getPrototypeOf());
+    if (!proto) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    return proto;
+}
+
+ReturnedValue Runtime::LoadSuperProperty::call(ExecutionEngine *engine, const Value &property)
+{
+    Scope scope(engine);
+    Object *base = getSuperBase(scope);
+    if (!base)
+        return Encode::undefined();
+    ScopedPropertyKey key(scope, property.toPropertyKey(engine));
+    if (engine->hasException)
+        return Encode::undefined();
+    return base->get(key, &engine->currentStackFrame->jsFrame->thisObject);
+}
+
+void Runtime::StoreSuperProperty::call(ExecutionEngine *engine, const Value &property, const Value &value)
 {
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    return engine->currentContext->getProperty(name);
+    Object *base = getSuperBase(scope);
+    if (!base)
+        return;
+    ScopedPropertyKey key(scope, property.toPropertyKey(engine));
+    if (engine->hasException)
+        return;
+    bool result = base->put(key, value, &engine->currentStackFrame->jsFrame->thisObject);
+    if (!result && engine->currentStackFrame->v4Function->isStrict())
+        engine->throwTypeError();
+}
+
+ReturnedValue Runtime::LoadGlobalLookup::call(ExecutionEngine *engine, Function *f, int index)
+{
+    Lookup *l = f->compilationUnit->runtimeLookups + index;
+    return l->globalGetter(l, engine);
+}
+
+ReturnedValue Runtime::GetLookup::call(ExecutionEngine *engine, Function *f, const Value &base, int index)
+{
+    Lookup *l = f->compilationUnit->runtimeLookups + index;
+    return l->getter(l, engine, base);
+}
+
+void Runtime::SetLookupSloppy::call(Function *f, const Value &base, int index, const Value &value)
+{
+    ExecutionEngine *engine = f->internalClass->engine;
+    QV4::Lookup *l = f->compilationUnit->runtimeLookups + index;
+    l->setter(l, engine, const_cast<Value &>(base), value);
+}
+
+void Runtime::SetLookupStrict::call(Function *f, const Value &base, int index, const Value &value)
+{
+    ExecutionEngine *engine = f->internalClass->engine;
+    QV4::Lookup *l = f->compilationUnit->runtimeLookups + index;
+    if (!l->setter(l, engine, const_cast<Value &>(base), value))
+        engine->throwTypeError();
+}
+
+ReturnedValue Runtime::LoadSuperConstructor::call(ExecutionEngine *engine, const Value &t)
+{
+    if (engine->currentStackFrame->thisObject() != Value::emptyValue().asReturnedValue()) {
+        return engine->throwReferenceError(QStringLiteral("super() already called."), QString(), 0, 0); // ### fix line number
+    }
+    const FunctionObject *f = t.as<FunctionObject>();
+    if (!f)
+        return engine->throwTypeError();
+    Heap::Object *c = static_cast<const Object &>(t).getPrototypeOf();
+    if (!c->vtable()->isFunctionObject || !static_cast<Heap::FunctionObject *>(c)->isConstructor())
+        return engine->throwTypeError();
+    return c->asReturnedValue();
 }
 
 #endif // V4_BOOTSTRAP
@@ -793,9 +1184,9 @@ uint RuntimeHelpers::equalHelper(const Value &x, const Value &y)
         double dx = RuntimeHelpers::toNumber(x);
         return dx == y.asDouble();
     } else if (x.isBoolean()) {
-        return Runtime::method_compareEqual(Primitive::fromDouble((double) x.booleanValue()), y);
+        return Runtime::CompareEqual::call(Value::fromDouble((double) x.booleanValue()), y);
     } else if (y.isBoolean()) {
-        return Runtime::method_compareEqual(x, Primitive::fromDouble((double) y.booleanValue()));
+        return Runtime::CompareEqual::call(x, Value::fromDouble((double) y.booleanValue()));
     } else {
 #ifdef V4_BOOTSTRAP
         Q_UNIMPLEMENTED();
@@ -805,11 +1196,11 @@ uint RuntimeHelpers::equalHelper(const Value &x, const Value &y)
         if (yo && (x.isNumber() || x.isString())) {
             Scope scope(yo->engine());
             ScopedValue py(scope, RuntimeHelpers::objectDefaultValue(yo, PREFERREDTYPE_HINT));
-            return Runtime::method_compareEqual(x, py);
+            return Runtime::CompareEqual::call(x, py);
         } else if (xo && (y.isNumber() || y.isString())) {
             Scope scope(xo->engine());
             ScopedValue px(scope, RuntimeHelpers::objectDefaultValue(xo, PREFERREDTYPE_HINT));
-            return Runtime::method_compareEqual(px, y);
+            return Runtime::CompareEqual::call(px, y);
         }
 #endif
     }
@@ -832,7 +1223,7 @@ Bool RuntimeHelpers::strictEqual(const Value &x, const Value &y)
     return false;
 }
 
-QV4::Bool Runtime::method_compareGreaterThan(const Value &l, const Value &r)
+QV4::Bool Runtime::CompareGreaterThan::call(const Value &l, const Value &r)
 {
     TRACE2(l, r);
     if (l.isInteger() && r.isInteger())
@@ -846,7 +1237,7 @@ QV4::Bool Runtime::method_compareGreaterThan(const Value &l, const Value &r)
         Q_UNIMPLEMENTED();
         return false;
 #else
-        return sr->compare(sl);
+        return sr->lessThan(sl);
 #endif
     }
 
@@ -860,7 +1251,7 @@ QV4::Bool Runtime::method_compareGreaterThan(const Value &l, const Value &r)
         QV4::Scope scope(e);
         QV4::ScopedValue pl(scope, lo ? RuntimeHelpers::objectDefaultValue(lo, QV4::NUMBER_HINT) : l.asReturnedValue());
         QV4::ScopedValue pr(scope, ro ? RuntimeHelpers::objectDefaultValue(ro, QV4::NUMBER_HINT) : r.asReturnedValue());
-        return Runtime::method_compareGreaterThan(pl, pr);
+        return Runtime::CompareGreaterThan::call(pl, pr);
 #endif
     }
 
@@ -869,7 +1260,7 @@ QV4::Bool Runtime::method_compareGreaterThan(const Value &l, const Value &r)
     return dl > dr;
 }
 
-QV4::Bool Runtime::method_compareLessThan(const Value &l, const Value &r)
+QV4::Bool Runtime::CompareLessThan::call(const Value &l, const Value &r)
 {
     TRACE2(l, r);
     if (l.isInteger() && r.isInteger())
@@ -883,7 +1274,7 @@ QV4::Bool Runtime::method_compareLessThan(const Value &l, const Value &r)
         Q_UNIMPLEMENTED();
         return false;
 #else
-        return sl->compare(sr);
+        return sl->lessThan(sr);
 #endif
     }
 
@@ -897,7 +1288,7 @@ QV4::Bool Runtime::method_compareLessThan(const Value &l, const Value &r)
         QV4::Scope scope(e);
         QV4::ScopedValue pl(scope, lo ? RuntimeHelpers::objectDefaultValue(lo, QV4::NUMBER_HINT) : l.asReturnedValue());
         QV4::ScopedValue pr(scope, ro ? RuntimeHelpers::objectDefaultValue(ro, QV4::NUMBER_HINT) : r.asReturnedValue());
-        return Runtime::method_compareLessThan(pl, pr);
+        return Runtime::CompareLessThan::call(pl, pr);
 #endif
     }
 
@@ -906,7 +1297,7 @@ QV4::Bool Runtime::method_compareLessThan(const Value &l, const Value &r)
     return dl < dr;
 }
 
-QV4::Bool Runtime::method_compareGreaterEqual(const Value &l, const Value &r)
+QV4::Bool Runtime::CompareGreaterEqual::call(const Value &l, const Value &r)
 {
     TRACE2(l, r);
     if (l.isInteger() && r.isInteger())
@@ -920,7 +1311,7 @@ QV4::Bool Runtime::method_compareGreaterEqual(const Value &l, const Value &r)
         Q_UNIMPLEMENTED();
         return false;
 #else
-        return !sl->compare(sr);
+        return !sl->lessThan(sr);
 #endif
     }
 
@@ -934,7 +1325,7 @@ QV4::Bool Runtime::method_compareGreaterEqual(const Value &l, const Value &r)
         QV4::Scope scope(e);
         QV4::ScopedValue pl(scope, lo ? RuntimeHelpers::objectDefaultValue(lo, QV4::NUMBER_HINT) : l.asReturnedValue());
         QV4::ScopedValue pr(scope, ro ? RuntimeHelpers::objectDefaultValue(ro, QV4::NUMBER_HINT) : r.asReturnedValue());
-        return Runtime::method_compareGreaterEqual(pl, pr);
+        return Runtime::CompareGreaterEqual::call(pl, pr);
 #endif
     }
 
@@ -943,7 +1334,7 @@ QV4::Bool Runtime::method_compareGreaterEqual(const Value &l, const Value &r)
     return dl >= dr;
 }
 
-QV4::Bool Runtime::method_compareLessEqual(const Value &l, const Value &r)
+QV4::Bool Runtime::CompareLessEqual::call(const Value &l, const Value &r)
 {
     TRACE2(l, r);
     if (l.isInteger() && r.isInteger())
@@ -957,7 +1348,7 @@ QV4::Bool Runtime::method_compareLessEqual(const Value &l, const Value &r)
         Q_UNIMPLEMENTED();
         return false;
 #else
-        return !sr->compare(sl);
+        return !sr->lessThan(sl);
 #endif
     }
 
@@ -971,7 +1362,7 @@ QV4::Bool Runtime::method_compareLessEqual(const Value &l, const Value &r)
         QV4::Scope scope(e);
         QV4::ScopedValue pl(scope, lo ? RuntimeHelpers::objectDefaultValue(lo, QV4::NUMBER_HINT) : l.asReturnedValue());
         QV4::ScopedValue pr(scope, ro ? RuntimeHelpers::objectDefaultValue(ro, QV4::NUMBER_HINT) : r.asReturnedValue());
-        return Runtime::method_compareLessEqual(pl, pr);
+        return Runtime::CompareLessEqual::call(pl, pr);
 #endif
     }
 
@@ -981,259 +1372,317 @@ QV4::Bool Runtime::method_compareLessEqual(const Value &l, const Value &r)
 }
 
 #ifndef V4_BOOTSTRAP
-Bool Runtime::method_compareInstanceof(ExecutionEngine *engine, const Value &left, const Value &right)
+Bool Runtime::CompareInstanceof::call(ExecutionEngine *engine, const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
     Scope scope(engine);
-    ScopedValue v(scope, method_instanceof(engine, left, right));
+    ScopedValue v(scope, Instanceof::call(engine, left, right));
     return v->booleanValue();
 }
 
-uint Runtime::method_compareIn(ExecutionEngine *engine, const Value &left, const Value &right)
+uint Runtime::CompareIn::call(ExecutionEngine *engine, const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
     Scope scope(engine);
-    ScopedValue v(scope, method_in(engine, left, right));
+    ScopedValue v(scope, In::call(engine, left, right));
     return v->booleanValue();
 }
 
 
-ReturnedValue Runtime::method_callGlobalLookup(ExecutionEngine *engine, uint index, CallData *callData)
+ReturnedValue Runtime::CallGlobalLookup::call(ExecutionEngine *engine, uint index, Value argv[], int argc)
 {
-    Scope scope(engine);
-    Q_ASSERT(callData->thisObject.isUndefined());
-
-    Lookup *l = engine->current->lookups + index;
-    ScopedFunctionObject o(scope, l->globalGetter(l, engine));
-    if (!o)
+    Lookup *l = engine->currentStackFrame->v4Function->compilationUnit->runtimeLookups + index;
+    Value function = Value::fromReturnedValue(l->globalGetter(l, engine));
+    if (!function.isFunctionObject())
         return engine->throwTypeError();
 
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[l->nameIndex]);
-    if (o->d() == scope.engine->evalFunction()->d() && name->equals(scope.engine->id_eval())) {
-        static_cast<EvalFunction *>(o.getPointer())->evalCall(scope, callData, true);
-    } else {
-        o->call(scope, callData);
-    }
-
-    return scope.result.asReturnedValue();
+    Value thisObject = Value::undefinedValue();
+    return static_cast<FunctionObject &>(function).call(&thisObject, argv, argc);
 }
 
-
-ReturnedValue Runtime::method_callActivationProperty(ExecutionEngine *engine, int nameIndex, CallData *callData)
+ReturnedValue Runtime::CallPossiblyDirectEval::call(ExecutionEngine *engine, Value *argv, int argc)
 {
-    Q_ASSERT(callData->thisObject.isUndefined());
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
+    ScopedValue thisObject(scope);
 
-    ScopedObject base(scope);
-    ScopedValue func(scope, engine->currentContext->getPropertyAndBase(name, base.getRef()));
-    if (scope.engine->hasException)
+    ExecutionContext &ctx = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context);
+    ScopedFunctionObject function(scope, ctx.getPropertyAndBase(engine->id_eval(), thisObject));
+    if (engine->hasException)
         return Encode::undefined();
 
-    if (base)
-        callData->thisObject = base;
-
-    FunctionObject *o = func->as<FunctionObject>();
-    if (!o) {
+    if (!function) {
         QString objectAsString = QStringLiteral("[null]");
-        if (base)
-            objectAsString = ScopedValue(scope, base.asReturnedValue())->toQStringNoThrow();
-        QString msg = QStringLiteral("Property '%1' of object %2 is not a function").arg(name->toQString()).arg(objectAsString);
+        if (!thisObject->isUndefined())
+            objectAsString = thisObject->toQStringNoThrow();
+        QString msg = QStringLiteral("Property 'eval' of object %2 is not a function").arg(objectAsString);
         return engine->throwTypeError(msg);
     }
 
-    if (o->d() == scope.engine->evalFunction()->d() && name->equals(scope.engine->id_eval())) {
-        static_cast<EvalFunction *>(o)->evalCall(scope, callData, true);
-    } else {
-        o->call(scope, callData);
-    }
+    if (function->d() == engine->evalFunction()->d())
+        return static_cast<EvalFunction *>(function.getPointer())->evalCall(thisObject, argv, argc, true);
 
-    return scope.result.asReturnedValue();
+    return function->call(thisObject, argv, argc);
 }
 
-ReturnedValue Runtime::method_callQmlScopeObjectProperty(ExecutionEngine *engine, int propertyIndex, CallData *callData)
+ReturnedValue Runtime::CallName::call(ExecutionEngine *engine, int nameIndex, Value *argv, int argc)
 {
     Scope scope(engine);
-    ScopedFunctionObject o(scope, method_getQmlScopeObjectProperty(engine, callData->thisObject, propertyIndex, /*captureRequired*/true));
-    if (!o) {
-        QString error = QStringLiteral("Property '%1' of scope object is not a function").arg(propertyIndex);
-        return engine->throwTypeError(error);
-    }
+    ScopedValue thisObject(scope);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
 
-    o->call(scope, callData);
-    return scope.result.asReturnedValue();
-}
+    ExecutionContext &ctx = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context);
+    ScopedFunctionObject f(scope, ctx.getPropertyAndBase(name, thisObject));
+    if (engine->hasException)
+        return Encode::undefined();
 
-ReturnedValue Runtime::method_callQmlContextObjectProperty(ExecutionEngine *engine, int propertyIndex, CallData *callData)
-{
-    Scope scope(engine);
-    ScopedFunctionObject o(scope, method_getQmlContextObjectProperty(engine, callData->thisObject, propertyIndex, /*captureRequired*/true));
-    if (!o) {
-        QString error = QStringLiteral("Property '%1' of context object is not a function").arg(propertyIndex);
-        return engine->throwTypeError(error);
+    if (!f) {
+        QString objectAsString = QStringLiteral("[null]");
+        if (!thisObject->isUndefined())
+            objectAsString = thisObject->toQStringNoThrow();
+        QString msg = QStringLiteral("Property '%1' of object %2 is not a function")
+                .arg(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]->toQString(),
+                     objectAsString);
+        return engine->throwTypeError(msg);
     }
 
-    o->call(scope, callData);
-    return scope.result.asReturnedValue();
+    return f->call(thisObject, argv, argc);
 }
 
-ReturnedValue Runtime::method_callProperty(ExecutionEngine *engine, int nameIndex, CallData *callData)
+ReturnedValue Runtime::CallProperty::call(ExecutionEngine *engine, const Value &baseRef, int nameIndex, Value *argv, int argc)
 {
+    const Value *base = &baseRef;
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    ScopedObject baseObject(scope, callData->thisObject);
-    if (!baseObject) {
-        Q_ASSERT(!callData->thisObject.isEmpty());
-        if (callData->thisObject.isNullOrUndefined()) {
-            QString message = QStringLiteral("Cannot call method '%1' of %2").arg(name->toQString()).arg(callData->thisObject.toQStringNoThrow());
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    ScopedObject lookupObject(scope, base);
+
+    if (!lookupObject) {
+        Q_ASSERT(!base->isEmpty());
+        if (base->isNullOrUndefined()) {
+            QString message = QStringLiteral("Cannot call method '%1' of %2")
+                    .arg(name->toQString(), base->toQStringNoThrow());
             return engine->throwTypeError(message);
         }
 
-        baseObject = RuntimeHelpers::convertToObject(scope.engine, callData->thisObject);
-        if (!baseObject) // type error
-            return Encode::undefined();
-        callData->thisObject = baseObject.asReturnedValue();
+        if (base->isManaged()) {
+            const Managed *m = static_cast<const Managed *>(base);
+            lookupObject = m->internalClass()->prototype;
+            Q_ASSERT(m->internalClass()->prototype);
+        } else {
+            lookupObject = RuntimeHelpers::convertToObject(engine, *base);
+            if (engine->hasException) // type error
+                return Encode::undefined();
+            if (!engine->currentStackFrame->v4Function->isStrict())
+                base = lookupObject;
+        }
     }
 
-    ScopedFunctionObject o(scope, baseObject->get(name));
-    if (o) {
-        o->call(scope, callData);
-        return scope.result.asReturnedValue();
-    } else {
-        QString error = QStringLiteral("Property '%1' of object %2 is not a function").arg(name->toQString(), callData->thisObject.toQStringNoThrow());
+    ScopedFunctionObject f(scope, static_cast<Object *>(lookupObject)->get(name));
+
+    if (!f) {
+        QString error = QStringLiteral("Property '%1' of object %2 is not a function")
+                .arg(engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]->toQString(),
+                     base->toQStringNoThrow());
         return engine->throwTypeError(error);
     }
 
+    return f->call(base, argv, argc);
 }
 
-ReturnedValue Runtime::method_callPropertyLookup(ExecutionEngine *engine, uint index, CallData *callData)
+ReturnedValue Runtime::CallPropertyLookup::call(ExecutionEngine *engine, const Value &base, uint index, Value *argv, int argc)
 {
-    Lookup *l = engine->current->lookups + index;
-    Value v;
-    v = l->getter(l, engine, callData->thisObject);
-    Object *o = v.objectValue();
-    if (Q_LIKELY(o)) {
-        Scope scope(engine);
-        o->call(scope, callData);
-        return scope.result.asReturnedValue();
-    }
-    return engine->throwTypeError();
+    Lookup *l = engine->currentStackFrame->v4Function->compilationUnit->runtimeLookups + index;
+    // ok to have the value on the stack here
+    Value f = Value::fromReturnedValue(l->getter(l, engine, base));
+
+    if (!f.isFunctionObject())
+        return engine->throwTypeError();
+
+    return static_cast<FunctionObject &>(f).call(&base, argv, argc);
 }
 
-ReturnedValue Runtime::method_callElement(ExecutionEngine *engine, const Value &index, CallData *callData)
+ReturnedValue Runtime::CallElement::call(ExecutionEngine *engine, const Value &baseRef, const Value &index, Value *argv, int argc)
 {
+    const Value *base = &baseRef;
     Scope scope(engine);
-    ScopedObject baseObject(scope, callData->thisObject.toObject(engine));
-    ScopedString s(scope, index.toString(engine));
+    ScopedValue thisObject(scope, base->toObject(engine));
+    base = thisObject;
 
-    if (scope.engine->hasException)
+    ScopedPropertyKey str(scope, index.toPropertyKey(engine));
+    if (engine->hasException)
         return Encode::undefined();
-    callData->thisObject = baseObject;
 
-    ScopedObject o(scope, baseObject->get(s));
-    if (!o)
+    ScopedFunctionObject f(scope, static_cast<const Object *>(base)->get(str));
+    if (!f)
         return engine->throwTypeError();
 
-    o->call(scope, callData);
-    return scope.result.asReturnedValue();
+    return f->call(base, argv, argc);
 }
 
-ReturnedValue Runtime::method_callValue(ExecutionEngine *engine, const Value &func, CallData *callData)
+ReturnedValue Runtime::CallValue::call(ExecutionEngine *engine, const Value &func, Value *argv, int argc)
 {
-    if (Object *o = func.objectValue()) {
-        Scope scope(engine);
-        o->call(scope, callData);
-        return scope.result.asReturnedValue();
-    }
-    return engine->throwTypeError(QStringLiteral("%1 is not a function").arg(func.toQStringNoThrow()));
+    if (!func.isFunctionObject())
+        return engine->throwTypeError(QStringLiteral("%1 is not a function").arg(func.toQStringNoThrow()));
+    Value undef = Value::undefinedValue();
+    return static_cast<const FunctionObject &>(func).call(&undef, argv, argc);
 }
 
+ReturnedValue Runtime::CallWithReceiver::call(ExecutionEngine *engine, const Value &func,
+                                               const Value &thisObject, Value argv[], int argc)
+{
+    if (!func.isFunctionObject())
+        return engine->throwTypeError(QStringLiteral("%1 is not a function").arg(func.toQStringNoThrow()));
+    return static_cast<const FunctionObject &>(func).call(&thisObject, argv, argc);
+}
 
-ReturnedValue Runtime::method_constructGlobalLookup(ExecutionEngine *engine, uint index, CallData *callData)
+ReturnedValue Runtime::CallQmlScopeObjectProperty::call(ExecutionEngine *engine, const Value &base,
+                                                         int propertyIndex, Value argv[], int argc)
 {
     Scope scope(engine);
-    Q_ASSERT(callData->thisObject.isUndefined());
+    ScopedFunctionObject fo(scope, LoadQmlScopeObjectProperty::call(engine, base, propertyIndex,
+                                                                    /*captureRequired*/true));
+    if (!fo) {
+        QString error = QStringLiteral("Property '%1' of scope object is not a function").arg(propertyIndex);
+        return engine->throwTypeError(error);
+    }
 
-    Lookup *l = engine->current->lookups + index;
-    ScopedObject f(scope, l->globalGetter(l, engine));
-    if (f) {
-        f->construct(scope, callData);
-        return scope.result.asReturnedValue();
-    } else {
-        return engine->throwTypeError();
+    QObject *qmlScopeObj = static_cast<const QmlContext *>(&base)->d()->qml()->scopeObject;
+    ScopedValue qmlScopeValue(scope, QObjectWrapper::wrap(engine, qmlScopeObj));
+    return fo->call(qmlScopeValue, argv, argc);
+}
+
+ReturnedValue Runtime::CallQmlContextObjectProperty::call(ExecutionEngine *engine,
+                                                           const Value &base,
+                                                           int propertyIndex,
+                                                           Value argv[],
+                                                           int argc)
+{
+    Scope scope(engine);
+    ScopedFunctionObject fo(scope, LoadQmlContextObjectProperty::call(engine, base, propertyIndex,
+                                                                      /*captureRequired*/true));
+    if (!fo) {
+        QString error = QStringLiteral("Property '%1' of context object is not a function").arg(propertyIndex);
+        return engine->throwTypeError(error);
     }
+
+    QObject *qmlContextObj = static_cast<const QmlContext *>(&base)->d()->qml()->context->contextData()->contextObject;
+    ScopedValue qmlContextValue(scope, QObjectWrapper::wrap(engine, qmlContextObj));
+    return fo->call(qmlContextValue, argv, argc);
 }
 
+struct CallArgs {
+    Value *argv;
+    int argc;
+};
 
-ReturnedValue Runtime::method_constructActivationProperty(ExecutionEngine *engine, int nameIndex, CallData *callData)
+static CallArgs createSpreadArguments(Scope &scope, Value *argv, int argc)
 {
-    Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    ScopedValue func(scope, engine->currentContext->getProperty(name));
-    if (scope.engine->hasException)
-        return Encode::undefined();
+    ScopedValue it(scope);
+    ScopedValue done(scope);
 
-    Object *f = func->as<Object>();
-    if (!f)
-        return engine->throwTypeError();
+    int argCount = 0;
 
-    f->construct(scope, callData);
-    return scope.result.asReturnedValue();
+    Value *v = scope.alloc<Scope::Uninitialized>();
+    Value *arguments = v;
+    for (int i = 0; i < argc; ++i) {
+        if (!argv[i].isEmpty()) {
+            *v = argv[i];
+            ++argCount;
+            v = scope.alloc<Scope::Uninitialized>();
+            continue;
+        }
+        // spread element
+        ++i;
+        it = Runtime::GetIterator::call(scope.engine, argv[i], /* ForInIterator */ 1);
+        if (scope.engine->hasException)
+            return { nullptr, 0 };
+        while (1) {
+            done = Runtime::IteratorNext::call(scope.engine, it, v);
+            if (scope.engine->hasException)
+                return { nullptr, 0 };
+            Q_ASSERT(done->isBoolean());
+            if (done->booleanValue())
+                break;
+            ++argCount;
+            v = scope.alloc<Scope::Uninitialized>();
+        }
+    }
+    return { arguments, argCount };
 }
 
-ReturnedValue Runtime::method_constructValue(ExecutionEngine *engine, const Value &func, CallData *callData)
+ReturnedValue Runtime::CallWithSpread::call(ExecutionEngine *engine, const Value &function, const Value &thisObject, Value *argv, int argc)
 {
-    const Object *f = func.as<Object>();
-    if (!f)
+    Q_ASSERT(argc >= 1);
+    if (!function.isFunctionObject())
         return engine->throwTypeError();
 
     Scope scope(engine);
-    f->construct(scope, callData);
-    return scope.result.asReturnedValue();
+    CallArgs arguments = createSpreadArguments(scope, argv, argc);
+    if (engine->hasException)
+        return Encode::undefined();
+
+    return static_cast<const FunctionObject &>(function).call(&thisObject, arguments.argv, arguments.argc);
+}
+
+ReturnedValue Runtime::Construct::call(ExecutionEngine *engine, const Value &function, const Value &newTarget, Value *argv, int argc)
+{
+    if (!function.isFunctionObject())
+        return engine->throwTypeError();
+
+    return static_cast<const FunctionObject &>(function).callAsConstructor(argv, argc, &newTarget);
 }
 
-ReturnedValue Runtime::method_constructProperty(ExecutionEngine *engine, int nameIndex, CallData *callData)
+ReturnedValue Runtime::ConstructWithSpread::call(ExecutionEngine *engine, const Value &function, const Value &newTarget, Value *argv, int argc)
 {
+    if (!function.isFunctionObject())
+        return engine->throwTypeError();
+
     Scope scope(engine);
-    ScopedObject thisObject(scope, callData->thisObject.toObject(engine));
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    if (scope.engine->hasException)
+    CallArgs arguments = createSpreadArguments(scope, argv, argc);
+    if (engine->hasException)
         return Encode::undefined();
 
-    ScopedObject f(scope, thisObject->get(name));
-    if (f) {
-        Scope scope(engine);
-        f->construct(scope, callData);
-        return scope.result.asReturnedValue();
-    } else {
-        return engine->throwTypeError();
-    }
+    return static_cast<const FunctionObject &>(function).callAsConstructor(arguments.argv, arguments.argc, &newTarget);
 }
 
-ReturnedValue Runtime::method_constructPropertyLookup(ExecutionEngine *engine, uint index, CallData *callData)
+ReturnedValue Runtime::TailCall::call(CppStackFrame *frame, ExecutionEngine *engine)
 {
-    Lookup *l = engine->current->lookups + index;
-    Value v;
-    v = l->getter(l, engine, callData->thisObject);
-    Object *o = v.objectValue();
-    if (Q_LIKELY(o)) {
-        Scope scope(engine);
-        o->construct(scope, callData);
-        return scope.result.asReturnedValue();
+    // IMPORTANT! The JIT assumes that this method has the same amount (or less) arguments than
+    // the jitted function, so it can safely do a tail call.
+
+    Value *tos = engine->jsStackTop;
+    const Value &function = tos[StackOffsets::tailCall_function];
+    const Value &thisObject = tos[StackOffsets::tailCall_thisObject];
+    Value *argv = reinterpret_cast<Value *>(frame->jsFrame) + tos[StackOffsets::tailCall_argv].int_32();
+    int argc = tos[StackOffsets::tailCall_argc].int_32();
+    Q_ASSERT(argc >= 0);
+
+    if (!function.isFunctionObject())
+        return engine->throwTypeError();
+
+    const FunctionObject &fo = static_cast<const FunctionObject &>(function);
+    if (!frame->callerCanHandleTailCall || !fo.canBeTailCalled() || engine->debugger()
+            || unsigned(argc) > fo.formalParameterCount()) {
+        // Cannot tailcall, do a normal call:
+        return fo.call(&thisObject, argv, argc);
     }
-    return engine->throwTypeError();
-}
 
+    memcpy(frame->jsFrame->args, argv, argc * sizeof(Value));
+    frame->init(engine, fo.function(), frame->jsFrame->args, argc, frame->callerCanHandleTailCall);
+    frame->setupJSFrame(frame->savedStackTop, fo, fo.scope(), thisObject, Primitive::undefinedValue());
+    engine->jsStackTop = frame->savedStackTop + frame->requiredJSStackFrameSize();
+    frame->pendingTailCall = true;
+    return Encode::undefined();
+}
 
-void Runtime::method_throwException(ExecutionEngine *engine, const Value &value)
+void Runtime::ThrowException::call(ExecutionEngine *engine, const Value &value)
 {
     if (!value.isEmpty())
         engine->throwError(value);
 }
 
-ReturnedValue Runtime::method_typeofValue(ExecutionEngine *engine, const Value &value)
+ReturnedValue Runtime::TypeofValue::call(ExecutionEngine *engine, const Value &value)
 {
     Scope scope(engine);
     ScopedString res(scope);
@@ -1250,6 +1699,8 @@ ReturnedValue Runtime::method_typeofValue(ExecutionEngine *engine, const Value &
     case Value::Managed_Type:
         if (value.isString())
             res = engine->id_string();
+        else if (value.isSymbol())
+            res = engine->id_symbol();
         else if (value.objectValue()->as<FunctionObject>())
             res = engine->id_function();
         else
@@ -1262,307 +1713,359 @@ ReturnedValue Runtime::method_typeofValue(ExecutionEngine *engine, const Value &
     return res.asReturnedValue();
 }
 
-QV4::ReturnedValue Runtime::method_typeofName(ExecutionEngine *engine, int nameIndex)
+QV4::ReturnedValue Runtime::TypeofName::call(ExecutionEngine *engine, int nameIndex)
 {
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    ScopedValue prop(scope, engine->currentContext->getProperty(name));
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    ScopedValue prop(scope, static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).getProperty(name));
     // typeof doesn't throw. clear any possible exception
     scope.engine->hasException = false;
-    return method_typeofValue(engine, prop);
+    return TypeofValue::call(engine, prop);
 }
 
-#ifndef V4_BOOTSTRAP
-ReturnedValue Runtime::method_typeofScopeObjectProperty(ExecutionEngine *engine, const Value &context, int propertyIndex)
+void Runtime::PushCallContext::call(CppStackFrame *frame)
 {
-    Scope scope(engine);
-    ScopedValue prop(scope, method_getQmlScopeObjectProperty(engine, context, propertyIndex, /*captureRequired*/true));
-    if (scope.engine->hasException)
-        return Encode::undefined();
-    return method_typeofValue(engine, prop);
+    frame->jsFrame->context = ExecutionContext::newCallContext(frame)->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_typeofContextObjectProperty(ExecutionEngine *engine, const Value &context, int propertyIndex)
+ReturnedValue Runtime::PushWithContext::call(ExecutionEngine *engine, const Value &acc)
 {
-    Scope scope(engine);
-    ScopedValue prop(scope, method_getQmlContextObjectProperty(engine, context, propertyIndex, /*captureRequired*/true));
-    if (scope.engine->hasException)
-        return Encode::undefined();
-    return method_typeofValue(engine, prop);
+    CallData *jsFrame = engine->currentStackFrame->jsFrame;
+    Value &newAcc = jsFrame->accumulator;
+    newAcc = Value::fromHeapObject(acc.toObject(engine));
+    if (!engine->hasException) {
+        Q_ASSERT(newAcc.isObject());
+        const Object &obj = static_cast<const Object &>(newAcc);
+        Value &context = jsFrame->context;
+        auto ec = static_cast<const ExecutionContext *>(&context);
+        context = ec->newWithContext(obj.d())->asReturnedValue();
+    }
+    return newAcc.asReturnedValue();
 }
-#endif // V4_BOOTSTRAP
 
-QV4::ReturnedValue Runtime::method_typeofMember(ExecutionEngine *engine, const Value &base, int nameIndex)
+void Runtime::PushCatchContext::call(ExecutionEngine *engine, int blockIndex, int exceptionVarNameIndex)
 {
-    Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    ScopedObject obj(scope, base.toObject(engine));
-    if (scope.engine->hasException)
-        return Encode::undefined();
-    ScopedValue prop(scope, obj->get(name));
-    return method_typeofValue(engine, prop);
+    auto name = engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[exceptionVarNameIndex];
+    engine->currentStackFrame->jsFrame->context = ExecutionContext::newCatchContext(engine->currentStackFrame, blockIndex, name)->asReturnedValue();
 }
 
-QV4::ReturnedValue Runtime::method_typeofElement(ExecutionEngine *engine, const Value &base, const Value &index)
+void Runtime::PushBlockContext::call(ExecutionEngine *engine, int index)
 {
-    Scope scope(engine);
-    ScopedString name(scope, index.toString(engine));
-    ScopedObject obj(scope, base.toObject(engine));
-    if (scope.engine->hasException)
-        return Encode::undefined();
-    ScopedValue prop(scope, obj->get(name));
-    return method_typeofValue(engine, prop);
+    engine->currentStackFrame->jsFrame->context = ExecutionContext::newBlockContext(engine->currentStackFrame, index)->asReturnedValue();
+}
+
+void Runtime::CloneBlockContext::call(ExecutionEngine *engine)
+{
+    auto frame = engine->currentStackFrame;
+    auto context = static_cast<Heap::CallContext *>(frame->jsFrame->context.m());
+    frame->jsFrame->context =
+            ExecutionContext::cloneBlockContext(engine, context)->asReturnedValue();
+}
+
+void Runtime::PushScriptContext::call(ExecutionEngine *engine, int index)
+{
+    Q_ASSERT(engine->currentStackFrame->context()->d()->type == Heap::ExecutionContext::Type_GlobalContext ||
+             engine->currentStackFrame->context()->d()->type == Heap::ExecutionContext::Type_QmlContext);
+    ReturnedValue c = ExecutionContext::newBlockContext(engine->currentStackFrame, index)->asReturnedValue();
+    engine->setScriptContext(c);
+    engine->currentStackFrame->jsFrame->context = c;
 }
 
-ReturnedValue Runtime::method_unwindException(ExecutionEngine *engine)
+void Runtime::PopScriptContext::call(ExecutionEngine *engine)
 {
-    if (!engine->hasException)
-        return Primitive::emptyValue().asReturnedValue();
-    return engine->catchException(0);
+    ReturnedValue root = engine->rootContext()->asReturnedValue();
+    engine->setScriptContext(root);
+    engine->currentStackFrame->jsFrame->context = root;
 }
 
-/* The next three methods are a bit tricky. They can't open up a Scope, as that
- * would mess up the pushing of the context.
- *
- * Instead the push/pop pair acts as a non local scope.
- */
-void Runtime::method_pushWithScope(const Value &o, NoThrowEngine *engine)
+void Runtime::ThrowReferenceError::call(ExecutionEngine *engine, int nameIndex)
 {
-    QV4::Value *v = engine->jsAlloca(1);
-    Heap::Object *withObject = o.toObject(engine);
-    *v = withObject;
-    engine->pushContext(engine->currentContext->newWithContext(withObject));
-    Q_ASSERT(engine->jsStackTop == engine->currentContext + 2);
+    Scope scope(engine);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    engine->throwReferenceError(name);
 }
 
-void Runtime::method_pushCatchScope(NoThrowEngine *engine, int exceptionVarNameIndex)
+void Runtime::ThrowOnNullOrUndefined::call(ExecutionEngine *engine, const Value &v)
 {
-    engine->jsAlloca(1); // keep this symmetric with pushWithScope
-    ExecutionContext *c = engine->currentContext;
-    engine->pushContext(c->newCatchContext(c->d()->compilationUnit->runtimeStrings[exceptionVarNameIndex], engine->catchException(0)));
-    Q_ASSERT(engine->jsStackTop == engine->currentContext + 2);
+    if (v.isNullOrUndefined())
+        engine->throwTypeError();
 }
 
-void Runtime::method_popScope(NoThrowEngine *engine)
+ReturnedValue Runtime::ConvertThisToObject::call(ExecutionEngine *engine, const Value &t)
 {
-    Q_ASSERT(engine->jsStackTop == engine->currentContext + 2);
-    engine->popContext();
-    engine->jsStackTop -= 3;
+    if (!t.isObject()) {
+        if (t.isNullOrUndefined()) {
+            return engine->globalObject->asReturnedValue();
+        } else {
+            return t.toObject(engine)->asReturnedValue();
+        }
+    }
+    return t.asReturnedValue();
 }
 
-void Runtime::method_declareVar(ExecutionEngine *engine, bool deletable, int nameIndex)
+void Runtime::DeclareVar::call(ExecutionEngine *engine, Bool deletable, int nameIndex)
 {
     Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    engine->currentContext->createMutableBinding(name, deletable);
+    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
+    static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).createMutableBinding(name, deletable);
 }
 
-ReturnedValue Runtime::method_arrayLiteral(ExecutionEngine *engine, Value *values, uint length)
+ReturnedValue Runtime::ArrayLiteral::call(ExecutionEngine *engine, Value *values, uint length)
 {
     return engine->newArrayObject(values, length)->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_objectLiteral(ExecutionEngine *engine, const QV4::Value *args, int classId, int arrayValueCount, int arrayGetterSetterCountAndFlags)
+ReturnedValue Runtime::ObjectLiteral::call(ExecutionEngine *engine, int classId, QV4::Value args[], int argc)
 {
     Scope scope(engine);
-    QV4::InternalClass *klass = static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeClasses[classId];
-    ScopedObject o(scope, engine->newObject(klass, engine->objectPrototype()));
+    Scoped<InternalClass> klass(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeClasses[classId]);
+    ScopedObject o(scope, engine->newObject(klass->d()));
 
-    {
-        bool needSparseArray = arrayGetterSetterCountAndFlags >> 30;
-        if (needSparseArray)
-            o->initSparseArray();
-    }
+    Q_ASSERT(uint(argc) >= klass->d()->size);
 
-    for (uint i = 0; i < klass->size; ++i)
+    for (uint i = 0; i < klass->d()->size; ++i)
         o->setProperty(i, *args++);
 
-    if (arrayValueCount > 0) {
-        ScopedValue entry(scope);
-        for (int i = 0; i < arrayValueCount; ++i) {
-            uint idx = args->toUInt32();
-            ++args;
-            entry = *args++;
-            o->arraySet(idx, entry);
+    Q_ASSERT((argc - klass->d()->size) % 3 == 0);
+    int additionalArgs = (argc - int(klass->d()->size))/3;
+
+    if (!additionalArgs)
+        return o->asReturnedValue();
+
+    ScopedPropertyKey name(scope);
+    ScopedProperty pd(scope);
+    ScopedFunctionObject fn(scope);
+    ScopedString fnName(scope);
+    ScopedValue value(scope);
+    for (int i = 0; i < additionalArgs; ++i) {
+        Q_ASSERT(args->isInteger());
+        ObjectLiteralArgument arg = ObjectLiteralArgument(args->integerValue());
+        name = args[1].toPropertyKey(engine);
+        value = args[2];
+        if (engine->hasException)
+            return Encode::undefined();
+        if (arg != ObjectLiteralArgument::Value) {
+            Q_ASSERT(args[2].isInteger());
+            int functionId = args[2].integerValue();
+            QV4::Function *clos = static_cast<CompiledData::CompilationUnit*>(engine->currentStackFrame->v4Function->compilationUnit)->runtimeFunctions[functionId];
+            Q_ASSERT(clos);
+
+            PropertyKey::FunctionNamePrefix prefix = PropertyKey::None;
+            if (arg == ObjectLiteralArgument::Getter)
+                prefix = PropertyKey::Getter;
+            else if (arg == ObjectLiteralArgument::Setter)
+                prefix = PropertyKey::Setter;
+            else
+                arg = ObjectLiteralArgument::Value;
+            fnName = name->asFunctionName(engine, prefix);
+
+            ExecutionContext *current = static_cast<ExecutionContext *>(&engine->currentStackFrame->jsFrame->context);
+            if (clos->isGenerator())
+                value = MemberGeneratorFunction::create(current, clos, o, fnName)->asReturnedValue();
+            else
+                value = FunctionObject::createMemberFunction(current, clos, o, fnName)->asReturnedValue();
+        } else if (args[2].isFunctionObject()) {
+            fn = static_cast<const FunctionObject &>(args[2]);
+
+            fnName = name->asFunctionName(engine, PropertyKey::None);
+            fn->setName(fnName);
         }
-    }
-
-    uint arrayGetterSetterCount = arrayGetterSetterCountAndFlags & ((1 << 30) - 1);
-    if (arrayGetterSetterCount > 0) {
-        ScopedProperty pd(scope);
-        for (uint i = 0; i < arrayGetterSetterCount; ++i) {
-            uint idx = args->toUInt32();
-            ++args;
-            pd->value = *args;
-            ++args;
-            pd->set = *args;
-            ++args;
-            o->arraySet(idx, pd, Attr_Accessor);
+        Q_ASSERT(arg != ObjectLiteralArgument::Method);
+        Q_ASSERT(arg == ObjectLiteralArgument::Value || value->isFunctionObject());
+        if (arg == ObjectLiteralArgument::Value || arg == ObjectLiteralArgument::Getter) {
+            pd->value = value;
+            pd->set = Value::emptyValue();
+        } else {
+            pd->value = Value::emptyValue();
+            pd->set = value;
         }
-    }
+        bool ok = o->defineOwnProperty(name, pd, (arg == ObjectLiteralArgument::Value ? Attr_Data : Attr_Accessor));
+        if (!ok)
+            return engine->throwTypeError();
 
+        args += 3;
+    }
     return o.asReturnedValue();
 }
 
-QV4::ReturnedValue Runtime::method_setupArgumentsObject(ExecutionEngine *engine)
-{
-    Q_ASSERT(engine->current->type == Heap::ExecutionContext::Type_CallContext);
-    QV4::CallContext *c = static_cast<QV4::CallContext *>(engine->currentContext);
-    QV4::InternalClass *ic = engine->internalClasses[c->d()->strictMode ? EngineBase::Class_StrictArgumentsObject : EngineBase::Class_ArgumentsObject];
-    return engine->memoryManager->allocObject<ArgumentsObject>(ic, engine->objectPrototype(), c)->asReturnedValue();
-}
-
-#endif // V4_BOOTSTRAP
-
-QV4::ReturnedValue Runtime::method_increment(const Value &value)
+ReturnedValue Runtime::CreateClass::call(ExecutionEngine *engine, int classIndex,
+                                          const Value &superClass, Value computedNames[])
 {
-    TRACE1(value);
+    const CompiledData::CompilationUnit *unit = engine->currentStackFrame->v4Function->compilationUnit;
+    const QV4::CompiledData::Class *cls = unit->unitData()->classAt(classIndex);
 
-    if (value.isInteger() && value.integerValue() < INT_MAX)
-        return Encode(value.integerValue() + 1);
-    else {
-        double d = value.toNumber();
-        return Encode(d + 1.);
+    Scope scope(engine);
+    ScopedObject protoParent(scope, engine->objectPrototype());
+    ScopedObject constructorParent(scope, engine->functionPrototype());
+    if (!superClass.isEmpty()) {
+        if (superClass.isNull()) {
+            protoParent = Encode::null();
+        } else {
+            const FunctionObject *superFunction = superClass.as<FunctionObject>();
+            // ### check that the heritage object is a constructor
+            if (!superFunction || !superFunction->isConstructor())
+                return engine->throwTypeError(QStringLiteral("The superclass is not a function object."));
+            const FunctionObject *s = static_cast<const FunctionObject *>(&superClass);
+            ScopedValue result(scope, s->get(scope.engine->id_prototype()));
+            if (!result->isObject() && !result->isNull())
+                return engine->throwTypeError(QStringLiteral("The value of the superclass's prototype property is not an object."));
+            protoParent = *result;
+            constructorParent = superClass;
+        }
     }
-}
-
-QV4::ReturnedValue Runtime::method_decrement(const Value &value)
-{
-    TRACE1(value);
 
-    if (value.isInteger() && value.integerValue() > INT_MIN)
-        return Encode(value.integerValue() - 1);
-    else {
-        double d = value.toNumber();
-        return Encode(d - 1.);
+    ScopedObject proto(scope, engine->newObject());
+    proto->setPrototypeUnchecked(protoParent);
+    ExecutionContext *current = static_cast<ExecutionContext *>(&engine->currentStackFrame->jsFrame->context);
+
+    ScopedFunctionObject constructor(scope);
+    QV4::Function *f = cls->constructorFunction != UINT_MAX ? unit->runtimeFunctions[cls->constructorFunction] : nullptr;
+    constructor = FunctionObject::createConstructorFunction(current, f, proto, !superClass.isEmpty())->asReturnedValue();
+    constructor->setPrototypeUnchecked(constructorParent);
+    Value argCount = Value::fromInt32(f ? f->nFormals : 0);
+    constructor->defineReadonlyConfigurableProperty(scope.engine->id_length(), argCount);
+    constructor->defineReadonlyConfigurableProperty(engine->id_prototype(), proto);
+    proto->defineDefaultProperty(engine->id_constructor(), constructor);
+
+    ScopedString name(scope);
+    if (cls->nameIndex != UINT_MAX) {
+        name = unit->runtimeStrings[cls->nameIndex];
+        constructor->defineReadonlyConfigurableProperty(engine->id_name(), name);
     }
-}
 
-ReturnedValue Runtime::method_toDouble(const Value &value)
-{
-    TRACE1(value);
-    return Encode(value.toNumber());
-}
-
-int Runtime::method_toInt(const Value &value)
-{
-    TRACE1(value);
-    return value.toInt32();
-}
+    ScopedObject receiver(scope, *constructor);
+    ScopedPropertyKey propertyName(scope);
+    ScopedFunctionObject function(scope);
+    ScopedProperty property(scope);
+    const CompiledData::Method *methods = cls->methodTable();
+    for (uint i = 0; i < cls->nStaticMethods + cls->nMethods; ++i) {
+        if (i == cls->nStaticMethods)
+            receiver = proto;
+        if (methods[i].name == UINT_MAX) {
+            propertyName = computedNames->toPropertyKey(engine);
+            if (propertyName == scope.engine->id_prototype()->propertyKey() && receiver->d() == constructor->d())
+                return engine->throwTypeError(QStringLiteral("Cannot declare a static method named 'prototype'."));
+            if (engine->hasException)
+                return Encode::undefined();
+            ++computedNames;
+        } else {
+            name = unit->runtimeStrings[methods[i].name];
+            propertyName = name->toPropertyKey();
+        }
+        QV4::Function *f = unit->runtimeFunctions[methods[i].function];
+        Q_ASSERT(f);
+        PropertyKey::FunctionNamePrefix prefix = PropertyKey::None;
+        if (methods[i].type == CompiledData::Method::Getter)
+            prefix = PropertyKey::Getter;
+        else if (methods[i].type == CompiledData::Method::Setter)
+            prefix = PropertyKey::Setter;
+
+        name = propertyName->asFunctionName(engine, prefix);
+
+        if (f->isGenerator())
+            function = MemberGeneratorFunction::create(current, f, receiver, name);
+        else
+            function = FunctionObject::createMemberFunction(current, f, receiver, name);
+        Q_ASSERT(function);
+        PropertyAttributes attributes;
+        switch (methods[i].type) {
+        case CompiledData::Method::Getter:
+            property->setGetter(function);
+            property->set = Value::emptyValue();
+            attributes = Attr_Accessor|Attr_NotEnumerable;
+            break;
+        case CompiledData::Method::Setter:
+            property->value = Value::emptyValue();
+            property->setSetter(function);
+            attributes = Attr_Accessor|Attr_NotEnumerable;
+            break;
+        default: // Regular
+            property->value = function;
+            property->set = Value::emptyValue();
+            attributes = Attr_Data|Attr_NotEnumerable;
+            break;
+        }
+        receiver->defineOwnProperty(propertyName, property, attributes);
+    }
 
-int Runtime::method_doubleToInt(const double &d)
-{
-    TRACE0();
-    return Primitive::toInt32(d);
+    return constructor->asReturnedValue();
 }
 
-unsigned Runtime::method_toUInt(const Value &value)
+QV4::ReturnedValue Runtime::CreateMappedArgumentsObject::call(ExecutionEngine *engine)
 {
-    TRACE1(value);
-    return value.toUInt32();
+    Q_ASSERT(engine->currentContext()->d()->type == Heap::ExecutionContext::Type_CallContext);
+    Heap::InternalClass *ic = engine->internalClasses(EngineBase::Class_ArgumentsObject);
+    return engine->memoryManager->allocObject<ArgumentsObject>(ic, engine->currentStackFrame)->asReturnedValue();
 }
 
-unsigned Runtime::method_doubleToUInt(const double &d)
+QV4::ReturnedValue Runtime::CreateUnmappedArgumentsObject::call(ExecutionEngine *engine)
 {
-    TRACE0();
-    return Primitive::toUInt32(d);
+    Heap::InternalClass *ic = engine->internalClasses(EngineBase::Class_StrictArgumentsObject);
+    return engine->memoryManager->allocObject<StrictArgumentsObject>(ic, engine->currentStackFrame)->asReturnedValue();
 }
 
-#ifndef V4_BOOTSTRAP
-
-ReturnedValue Runtime::method_getQmlContext(NoThrowEngine *engine)
+QV4::ReturnedValue Runtime::CreateRestParameter::call(ExecutionEngine *engine, int argIndex)
 {
-    return engine->qmlContext()->asReturnedValue();
+    const Value *values = engine->currentStackFrame->originalArguments + argIndex;
+    int nValues = engine->currentStackFrame->originalArgumentsCount - argIndex;
+    if (nValues <= 0)
+        return engine->newArrayObject(0)->asReturnedValue();
+    return engine->newArrayObject(values, nValues)->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_regexpLiteral(ExecutionEngine *engine, int id)
-{
-    return static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeRegularExpressions[id].asReturnedValue();
-}
 
-ReturnedValue Runtime::method_getQmlQObjectProperty(ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)
+ReturnedValue Runtime::LoadQmlContext::call(ExecutionEngine *engine)
 {
-    Scope scope(engine);
-    QV4::Scoped<QObjectWrapper> wrapper(scope, object);
-    if (!wrapper) {
-        engine->throwTypeError(QStringLiteral("Cannot read property of null"));
-        return Encode::undefined();
-    }
-    return QV4::QObjectWrapper::getProperty(scope.engine, wrapper->object(), propertyIndex, captureRequired);
+    Heap::QmlContext *ctx = engine->qmlContext();
+    Q_ASSERT(ctx);
+    return ctx->asReturnedValue();
 }
 
-QV4::ReturnedValue Runtime::method_getQmlAttachedProperty(ExecutionEngine *engine, int attachedPropertiesId, int propertyIndex)
+ReturnedValue Runtime::RegexpLiteral::call(ExecutionEngine *engine, int id)
 {
-    QObject *scopeObject = engine->qmlScopeObject();
-    QObject *attachedObject = qmlAttachedPropertiesObjectById(attachedPropertiesId, scopeObject);
-
-    QJSEngine *jsEngine = engine->jsEngine();
-    QQmlData::ensurePropertyCache(jsEngine, attachedObject);
-    return QV4::QObjectWrapper::getProperty(engine, attachedObject, propertyIndex, /*captureRequired*/true);
+    Heap::RegExpObject *ro = engine->newRegExpObject(engine->currentStackFrame->v4Function->compilationUnit->runtimeRegularExpressions[id].as<RegExp>());
+    return ro->asReturnedValue();
 }
 
-ReturnedValue Runtime::method_getQmlScopeObjectProperty(ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)
+ReturnedValue Runtime::LoadQmlScopeObjectProperty::call(ExecutionEngine *engine, const Value &context, int propertyIndex, Bool captureRequired)
 {
     const QmlContext &c = static_cast<const QmlContext &>(context);
-    return QV4::QObjectWrapper::getProperty(engine, c.d()->qml->scopeObject, propertyIndex, captureRequired);
+    return QV4::QObjectWrapper::getProperty(engine, c.d()->qml()->scopeObject, propertyIndex, captureRequired);
 }
 
-ReturnedValue Runtime::method_getQmlContextObjectProperty(ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)
+ReturnedValue Runtime::LoadQmlContextObjectProperty::call(ExecutionEngine *engine, const Value &context, int propertyIndex, Bool captureRequired)
 {
     const QmlContext &c = static_cast<const QmlContext &>(context);
-    return QV4::QObjectWrapper::getProperty(engine, (*c.d()->qml->context)->contextObject, propertyIndex, captureRequired);
-}
-
-ReturnedValue Runtime::method_getQmlSingletonQObjectProperty(ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)
-{
-    Scope scope(engine);
-    QV4::Scoped<QQmlTypeWrapper> wrapper(scope, object);
-    if (!wrapper) {
-        scope.engine->throwTypeError(QStringLiteral("Cannot read property of null"));
-        return Encode::undefined();
-    }
-    return QV4::QObjectWrapper::getProperty(scope.engine, wrapper->singletonObject(), propertyIndex, captureRequired);
+    return QV4::QObjectWrapper::getProperty(engine, (*c.d()->qml()->context)->contextObject, propertyIndex, captureRequired);
 }
 
-ReturnedValue Runtime::method_getQmlIdObject(ExecutionEngine *engine, const Value &c, uint index)
+ReturnedValue Runtime::LoadQmlIdObject::call(ExecutionEngine *engine, const Value &c, uint index)
 {
-    Scope scope(engine);
     const QmlContext &qmlContext = static_cast<const QmlContext &>(c);
-    QQmlContextData *context = *qmlContext.d()->qml->context;
+    QQmlContextData *context = *qmlContext.d()->qml()->context;
     if (!context || index >= (uint)context->idValueCount)
         return Encode::undefined();
 
-    QQmlEnginePrivate *ep = engine->qmlEngine() ? QQmlEnginePrivate::get(engine->qmlEngine()) : 0;
+    QQmlEnginePrivate *ep = engine->qmlEngine() ? QQmlEnginePrivate::get(engine->qmlEngine()) : nullptr;
     if (ep && ep->propertyCapture)
         ep->propertyCapture->captureProperty(&context->idValues[index].bindings);
 
     return QObjectWrapper::wrap(engine, context->idValues[index].data());
 }
 
-void Runtime::method_setQmlScopeObjectProperty(ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)
+void Runtime::StoreQmlScopeObjectProperty::call(ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)
 {
     const QmlContext &c = static_cast<const QmlContext &>(context);
-    return QV4::QObjectWrapper::setProperty(engine, c.d()->qml->scopeObject, propertyIndex, value);
+    return QV4::QObjectWrapper::setProperty(engine, c.d()->qml()->scopeObject, propertyIndex, value);
 }
 
-void Runtime::method_setQmlContextObjectProperty(ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)
+void Runtime::StoreQmlContextObjectProperty::call(ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)
 {
     const QmlContext &c = static_cast<const QmlContext &>(context);
-    return QV4::QObjectWrapper::setProperty(engine, (*c.d()->qml->context)->contextObject, propertyIndex, value);
-}
-
-void Runtime::method_setQmlQObjectProperty(ExecutionEngine *engine, const Value &object, int propertyIndex, const Value &value)
-{
-    Scope scope(engine);
-    QV4::Scoped<QObjectWrapper> wrapper(scope, object);
-    if (!wrapper) {
-        engine->throwTypeError(QStringLiteral("Cannot write property of null"));
-        return;
-    }
-    wrapper->setProperty(engine, propertyIndex, value);
+    return QV4::QObjectWrapper::setProperty(engine, (*c.d()->qml()->context)->contextObject, propertyIndex, value);
 }
 
-ReturnedValue Runtime::method_getQmlImportedScripts(NoThrowEngine *engine)
+ReturnedValue Runtime::LoadQmlImportedScripts::call(ExecutionEngine *engine)
 {
     QQmlContextData *context = engine->callingQmlContext();
     if (!context)
@@ -1570,44 +2073,32 @@ ReturnedValue Runtime::method_getQmlImportedScripts(NoThrowEngine *engine)
     return context->importedScripts.value();
 }
 
-QV4::ReturnedValue Runtime::method_getQmlSingleton(QV4::NoThrowEngine *engine, int nameIndex)
+ReturnedValue Runtime::ToObject::call(ExecutionEngine *engine, const Value &obj)
 {
-    Scope scope(engine);
-    ScopedString name(scope, engine->current->compilationUnit->runtimeStrings[nameIndex]);
-    return engine->qmlSingletonWrapper(name);
+    if (obj.isObject())
+        return obj.asReturnedValue();
+
+    return obj.toObject(engine)->asReturnedValue();
 }
 
-void Runtime::method_convertThisToObject(ExecutionEngine *engine)
+Bool Runtime::ToBoolean::call(const Value &obj)
 {
-    Value *t = &engine->current->callData->thisObject;
-    if (t->isObject())
-        return;
-    if (t->isNullOrUndefined()) {
-        *t = engine->globalObject->asReturnedValue();
-    } else {
-        *t = t->toObject(engine)->asReturnedValue();
-    }
+    return obj.toBoolean();
 }
 
-ReturnedValue Runtime::method_uPlus(const Value &value)
+ReturnedValue Runtime::ToNumber::call(ExecutionEngine *, const Value &v)
 {
-    TRACE1(value);
-
-    if (value.isNumber())
-        return value.asReturnedValue();
-    if (value.integerCompatible())
-        return Encode(value.int_32());
-
-    double n = value.toNumberImpl();
-    return Encode(n);
+    return Encode(v.toNumber());
 }
+#endif // V4_BOOTSTRAP
 
-ReturnedValue Runtime::method_uMinus(const Value &value)
+ReturnedValue Runtime::UMinus::call(const Value &value)
 {
     TRACE1(value);
 
     // +0 != -0, so we need to convert to double when negating 0
-    if (value.isInteger() && value.integerValue())
+    if (value.isInteger() && value.integerValue() &&
+            value.integerValue() != std::numeric_limits<int>::min())
         return Encode(-value.integerValue());
     else {
         double n = RuntimeHelpers::toNumber(value);
@@ -1615,98 +2106,57 @@ ReturnedValue Runtime::method_uMinus(const Value &value)
     }
 }
 
-ReturnedValue Runtime::method_complement(const Value &value)
-{
-    TRACE1(value);
-
-    int n = value.toInt32();
-    return Encode((int)~n);
-}
-
-ReturnedValue Runtime::method_uNot(const Value &value)
-{
-    TRACE1(value);
-
-    bool b = value.toBoolean();
-    return Encode(!b);
-}
-
 // binary operators
-ReturnedValue Runtime::method_bitOr(const Value &left, const Value &right)
-{
-    TRACE2(left, right);
-
-    int lval = left.toInt32();
-    int rval = right.toInt32();
-    return Encode(lval | rval);
-}
-
-ReturnedValue Runtime::method_bitXor(const Value &left, const Value &right)
-{
-    TRACE2(left, right);
-
-    int lval = left.toInt32();
-    int rval = right.toInt32();
-    return Encode(lval ^ rval);
-}
-
-ReturnedValue Runtime::method_bitAnd(const Value &left, const Value &right)
-{
-    TRACE2(left, right);
-
-    int lval = left.toInt32();
-    int rval = right.toInt32();
-    return Encode(lval & rval);
-}
 
 #ifndef V4_BOOTSTRAP
-ReturnedValue Runtime::method_add(ExecutionEngine *engine, const Value &left, const Value &right)
+ReturnedValue Runtime::Add::call(ExecutionEngine *engine, const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    if (Q_LIKELY(left.isInteger() && right.isInteger()))
+    if (Q_LIKELY(left.integerCompatible() && right.integerCompatible()))
         return add_int32(left.integerValue(), right.integerValue());
     if (left.isNumber() && right.isNumber())
-        return Primitive::fromDouble(left.asDouble() + right.asDouble()).asReturnedValue();
+        return Value::fromDouble(left.asDouble() + right.asDouble()).asReturnedValue();
 
     return RuntimeHelpers::addHelper(engine, left, right);
 }
-#endif // V4_BOOTSTRAP
 
-ReturnedValue Runtime::method_sub(const Value &left, const Value &right)
+ReturnedValue Runtime::Sub::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    if (Q_LIKELY(left.isInteger() && right.isInteger()))
+    if (Q_LIKELY(left.integerCompatible() && right.integerCompatible()))
         return sub_int32(left.integerValue(), right.integerValue());
 
     double lval = left.isNumber() ? left.asDouble() : left.toNumberImpl();
     double rval = right.isNumber() ? right.asDouble() : right.toNumberImpl();
 
-    return Primitive::fromDouble(lval - rval).asReturnedValue();
+    return Value::fromDouble(lval - rval).asReturnedValue();
 }
 
-ReturnedValue Runtime::method_mul(const Value &left, const Value &right)
+ReturnedValue Runtime::Mul::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    if (Q_LIKELY(left.isInteger() && right.isInteger()))
+    if (Q_LIKELY(left.integerCompatible() && right.integerCompatible()))
         return mul_int32(left.integerValue(), right.integerValue());
 
     double lval = left.isNumber() ? left.asDouble() : left.toNumberImpl();
     double rval = right.isNumber() ? right.asDouble() : right.toNumberImpl();
 
-    return Primitive::fromDouble(lval * rval).asReturnedValue();
+    return Value::fromDouble(lval * rval).asReturnedValue();
 }
 
-ReturnedValue Runtime::method_div(const Value &left, const Value &right)
+ReturnedValue Runtime::Div::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
     if (Value::integerCompatible(left, right)) {
         int lval = left.integerValue();
         int rval = right.integerValue();
-        if (rval != 0 && (lval % rval == 0))
+        if (rval != 0 // division by zero should result in a NaN
+                && (lval % rval == 0)  // fractions can't be stored in an int
+                && !(lval == 0 && rval < 0)) // 0 / -something results in -0.0
             return Encode(int(lval / rval));
         else
             return Encode(double(lval) / rval);
@@ -1714,17 +2164,20 @@ ReturnedValue Runtime::method_div(const Value &left, const Value &right)
 
     double lval = left.toNumber();
     double rval = right.toNumber();
-    return Primitive::fromDouble(lval / rval).asReturnedValue();
+    return Value::fromDouble(lval / rval).asReturnedValue();
 }
 
-ReturnedValue Runtime::method_mod(const Value &left, const Value &right)
+ReturnedValue Runtime::Mod::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    if (Value::integerCompatible(left, right) && right.integerValue() != 0) {
-        int intRes = left.integerValue() % right.integerValue();
-        if (intRes != 0 || left.integerValue() >= 0)
-            return Encode(intRes);
+    if (Value::integerCompatible(left, right) && left.integerValue() >= 0 && right.integerValue() > 0) {
+        // special cases are handled by fmod, among them:
+        //  - arithmic execeptions for ints in c++, eg: INT_MIN % -1
+        //  - undefined behavior in c++, e.g.: anything % 0
+        //  - uncommon cases which would complicate the condition, e.g.: negative integers
+        //    (this makes sure that -1 % 1 == -0 by passing it to fmod)
+        return Encode(left.integerValue() % right.integerValue());
     }
 
     double lval = RuntimeHelpers::toNumber(left);
@@ -1732,10 +2185,46 @@ ReturnedValue Runtime::method_mod(const Value &left, const Value &right)
 #ifdef fmod
 #  undef fmod
 #endif
-    return Primitive::fromDouble(std::fmod(lval, rval)).asReturnedValue();
+    return Value::fromDouble(std::fmod(lval, rval)).asReturnedValue();
+}
+
+ReturnedValue Runtime::Exp::call(const Value &base, const Value &exp)
+{
+    double b = base.toNumber();
+    double e = exp.toNumber();
+    if (qt_is_inf(e) && (b == 1 || b == -1))
+        return Encode(qt_snan());
+    return Encode(pow(b,e));
+}
+
+ReturnedValue Runtime::BitAnd::call(const Value &left, const Value &right)
+{
+    TRACE2(left, right);
+
+    int lval = left.toInt32();
+    int rval = right.toInt32();
+    return Encode((int)(lval & rval));
+}
+
+ReturnedValue Runtime::BitOr::call(const Value &left, const Value &right)
+{
+    TRACE2(left, right);
+
+    int lval = left.toInt32();
+    int rval = right.toInt32();
+    return Encode((int)(lval | rval));
+}
+
+ReturnedValue Runtime::BitXor::call(const Value &left, const Value &right)
+{
+    TRACE2(left, right);
+
+    int lval = left.toInt32();
+    int rval = right.toInt32();
+    return Encode((int)(lval ^ rval));
 }
 
-ReturnedValue Runtime::method_shl(const Value &left, const Value &right)
+ReturnedValue Runtime::Shl::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
@@ -1744,7 +2233,7 @@ ReturnedValue Runtime::method_shl(const Value &left, const Value &right)
     return Encode((int)(lval << rval));
 }
 
-ReturnedValue Runtime::method_shr(const Value &left, const Value &right)
+ReturnedValue Runtime::Shr::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
@@ -1753,7 +2242,7 @@ ReturnedValue Runtime::method_shr(const Value &left, const Value &right)
     return Encode((int)(lval >> rval));
 }
 
-ReturnedValue Runtime::method_ushr(const Value &left, const Value &right)
+ReturnedValue Runtime::UShr::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
@@ -1766,75 +2255,184 @@ ReturnedValue Runtime::method_ushr(const Value &left, const Value &right)
 
 #endif // V4_BOOTSTRAP
 
-ReturnedValue Runtime::method_greaterThan(const Value &left, const Value &right)
+ReturnedValue Runtime::GreaterThan::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    bool r = method_compareGreaterThan(left, right);
+    bool r = CompareGreaterThan::call(left, right);
     return Encode(r);
 }
 
-ReturnedValue Runtime::method_lessThan(const Value &left, const Value &right)
+ReturnedValue Runtime::LessThan::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    bool r = method_compareLessThan(left, right);
+    bool r = CompareLessThan::call(left, right);
     return Encode(r);
 }
 
-ReturnedValue Runtime::method_greaterEqual(const Value &left, const Value &right)
+ReturnedValue Runtime::GreaterEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    bool r = method_compareGreaterEqual(left, right);
+    bool r = CompareGreaterEqual::call(left, right);
     return Encode(r);
 }
 
-ReturnedValue Runtime::method_lessEqual(const Value &left, const Value &right)
+ReturnedValue Runtime::LessEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    bool r = method_compareLessEqual(left, right);
+    bool r = CompareLessEqual::call(left, right);
     return Encode(r);
 }
 
-Bool Runtime::method_compareEqual(const Value &left, const Value &right)
+struct LazyScope
+{
+    ExecutionEngine *engine = nullptr;
+    Value *stackMark = nullptr;
+    ~LazyScope() {
+        if (engine)
+            engine->jsStackTop = stackMark;
+    }
+    template <typename T>
+    void set(Value **scopedValue, T value, ExecutionEngine *e) {
+        if (!engine) {
+            engine = e;
+            stackMark = engine->jsStackTop;
+        }
+        if (!*scopedValue)
+            *scopedValue = e->jsAlloca(1);
+        **scopedValue = value;
+    }
+};
+
+Bool Runtime::CompareEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    if (left.rawValue() == right.rawValue())
-        // NaN != NaN
-        return !left.isNaN();
+    Value lhs = left;
+    Value rhs = right;
 
-    if (left.type() == right.type()) {
-        if (left.isDouble() && left.doubleValue() == 0 && right.doubleValue() == 0)
-            return true; // this takes care of -0 == +0 (which obviously have different raw values)
-        if (!left.isManaged())
-            return false;
-        if (left.isString() == right.isString())
-            return left.cast<Managed>()->isEqualTo(right.cast<Managed>());
+#ifndef V4_BOOTSTRAP
+    LazyScope scope;
+    Value *lhsGuard = nullptr;
+    Value *rhsGuard = nullptr;
+#endif
+
+  redo:
+    if (lhs.asReturnedValue() == rhs.asReturnedValue())
+        return !lhs.isNaN();
+
+    int lt = lhs.quickType();
+    int rt = rhs.quickType();
+    if (rt < lt) {
+        qSwap(lhs, rhs);
+        qSwap(lt, rt);
     }
 
-    return RuntimeHelpers::equalHelper(left, right);
+    switch (lt) {
+    case QV4::Value::QT_ManagedOrUndefined:
+        if (lhs.isUndefined())
+            return rhs.isNullOrUndefined();
+        Q_FALLTHROUGH();
+    case QV4::Value::QT_ManagedOrUndefined1:
+    case QV4::Value::QT_ManagedOrUndefined2:
+    case QV4::Value::QT_ManagedOrUndefined3:
+        // LHS: Managed
+        switch (rt) {
+        case QV4::Value::QT_ManagedOrUndefined:
+            if (rhs.isUndefined())
+                return false;
+            Q_FALLTHROUGH();
+        case QV4::Value::QT_ManagedOrUndefined1:
+        case QV4::Value::QT_ManagedOrUndefined2:
+        case QV4::Value::QT_ManagedOrUndefined3: {
+#ifndef V4_BOOTSTRAP
+            // RHS: Managed
+            Heap::Base *l = lhs.m();
+            Heap::Base *r = rhs.m();
+            Q_ASSERT(l);
+            Q_ASSERT(r);
+            if (l->internalClass->vtable->isStringOrSymbol == r->internalClass->vtable->isStringOrSymbol)
+                return static_cast<QV4::Managed &>(lhs).isEqualTo(&static_cast<QV4::Managed &>(rhs));
+            if (l->internalClass->vtable->isStringOrSymbol) {
+                scope.set(&rhsGuard, RuntimeHelpers::objectDefaultValue(&static_cast<QV4::Object &>(rhs), PREFERREDTYPE_HINT), r->internalClass->engine);
+                rhs = rhsGuard->asReturnedValue();
+                break;
+            } else {
+                Q_ASSERT(r->internalClass->vtable->isStringOrSymbol);
+                scope.set(&lhsGuard, RuntimeHelpers::objectDefaultValue(&static_cast<QV4::Object &>(lhs), PREFERREDTYPE_HINT), l->internalClass->engine);
+                lhs = lhsGuard->asReturnedValue();
+                break;
+            }
+#endif
+            return false;
+        }
+        case QV4::Value::QT_Empty:
+            Q_UNREACHABLE();
+        case QV4::Value::QT_Null:
+            return false;
+        case QV4::Value::QT_Bool:
+        case QV4::Value::QT_Int:
+            rhs = Value::fromDouble(rhs.int_32());
+            // fall through
+        default: // double
+#ifndef V4_BOOTSTRAP
+            if (lhs.m()->internalClass->vtable->isStringOrSymbol) {
+                return lhs.m()->internalClass->vtable->isString ? (RuntimeHelpers::toNumber(lhs) == rhs.doubleValue()) : false;
+            } else {
+                scope.set(&lhsGuard, RuntimeHelpers::objectDefaultValue(&static_cast<QV4::Object &>(lhs), PREFERREDTYPE_HINT), lhs.m()->internalClass->engine);
+                lhs = lhsGuard->asReturnedValue();
+            }
+#else
+            Q_UNIMPLEMENTED();
+#endif
+        }
+        goto redo;
+    case QV4::Value::QT_Empty:
+        Q_UNREACHABLE();
+    case QV4::Value::QT_Null:
+        return rhs.isNull();
+    case QV4::Value::QT_Bool:
+    case QV4::Value::QT_Int:
+        switch (rt) {
+        case QV4::Value::QT_ManagedOrUndefined:
+        case QV4::Value::QT_ManagedOrUndefined1:
+        case QV4::Value::QT_ManagedOrUndefined2:
+        case QV4::Value::QT_ManagedOrUndefined3:
+        case QV4::Value::QT_Empty:
+        case QV4::Value::QT_Null:
+            Q_UNREACHABLE();
+        case QV4::Value::QT_Bool:
+        case QV4::Value::QT_Int:
+            return lhs.int_32() == rhs.int_32();
+        default: // double
+            return lhs.int_32() == rhs.doubleValue();
+        }
+    default: // double
+        Q_ASSERT(rhs.isDouble());
+        return lhs.doubleValue() == rhs.doubleValue();
+    }
 }
 
-ReturnedValue Runtime::method_equal(const Value &left, const Value &right)
+ReturnedValue Runtime::Equal::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    bool r = method_compareEqual(left, right);
+    bool r = CompareEqual::call(left, right);
     return Encode(r);
 }
 
-ReturnedValue Runtime::method_notEqual(const Value &left, const Value &right)
+ReturnedValue Runtime::NotEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    bool r = !method_compareEqual(left, right);
+    bool r = !CompareEqual::call(left, right);
     return Encode(r);
 }
 
-ReturnedValue Runtime::method_strictEqual(const Value &left, const Value &right)
+ReturnedValue Runtime::StrictEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
@@ -1842,7 +2440,7 @@ ReturnedValue Runtime::method_strictEqual(const Value &left, const Value &right)
     return Encode(r);
 }
 
-ReturnedValue Runtime::method_strictNotEqual(const Value &left, const Value &right)
+ReturnedValue Runtime::StrictNotEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
@@ -1850,32 +2448,27 @@ ReturnedValue Runtime::method_strictNotEqual(const Value &left, const Value &rig
     return Encode(r);
 }
 
-Bool Runtime::method_compareNotEqual(const Value &left, const Value &right)
+Bool Runtime::CompareNotEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
-    return !Runtime::method_compareEqual(left, right);
+    return !Runtime::CompareEqual::call(left, right);
 }
 
-Bool Runtime::method_compareStrictEqual(const Value &left, const Value &right)
+Bool Runtime::CompareStrictEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
     return RuntimeHelpers::strictEqual(left, right);
 }
 
-Bool Runtime::method_compareStrictNotEqual(const Value &left, const Value &right)
+Bool Runtime::CompareStrictNotEqual::call(const Value &left, const Value &right)
 {
     TRACE2(left, right);
 
     return ! RuntimeHelpers::strictEqual(left, right);
 }
 
-Bool Runtime::method_toBoolean(const Value &value)
-{
-    return value.toBoolean();
-}
-
 } // namespace QV4
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4runtime_p.h b/src/qml/jsruntime/qv4runtime_p.h
index 0d787714cf..72af90d1dc 100644
--- a/src/qml/jsruntime/qv4runtime_p.h
+++ b/src/qml/jsruntime/qv4runtime_p.h
@@ -83,8 +83,8 @@ private:
 };
 
 #  define TRACE0() RuntimeCounters::instance->count(Q_FUNC_INFO);
-#  define TRACE1(x) RuntimeCounters::instance->count(Q_FUNC_INFO, x->type());
-#  define TRACE2(x, y) RuntimeCounters::instance->count(Q_FUNC_INFO, x->type(), y->type());
+#  define TRACE1(x) RuntimeCounters::instance->count(Q_FUNC_INFO, x.type());
+#  define TRACE2(x, y) RuntimeCounters::instance->count(Q_FUNC_INFO, x.type(), y.type());
 #else
 #  define TRACE0()
 #  define TRACE1(x)
@@ -99,14 +99,15 @@ enum TypeHint {
 
 struct Q_QML_PRIVATE_EXPORT RuntimeHelpers {
     static ReturnedValue objectDefaultValue(const Object *object, int typeHint);
-    static ReturnedValue toPrimitive(const Value &value, int typeHint);
+    static ReturnedValue toPrimitive(const Value &value, TypeHint typeHint);
+    static ReturnedValue ordinaryToPrimitive(ExecutionEngine *engine, const Object *object, String *typeHint);
 
     static double stringToNumber(const QString &s);
     static Heap::String *stringFromNumber(ExecutionEngine *engine, double number);
     static double toNumber(const Value &value);
     static void numberToString(QString *result, double num, int radix = 10);
 
-    static Heap::String *convertToString(ExecutionEngine *engine, const Value &value);
+    static Heap::String *convertToString(ExecutionEngine *engine, Value value, TypeHint = STRING_HINT);
     static Heap::Object *convertToObject(ExecutionEngine *engine, const Value &value);
 
     static Bool equalHelper(const Value &x, const Value &y);
@@ -118,12 +119,11 @@ struct Q_QML_PRIVATE_EXPORT RuntimeHelpers {
 
 // type conversion and testing
 #ifndef V4_BOOTSTRAP
-inline ReturnedValue RuntimeHelpers::toPrimitive(const Value &value, int typeHint)
+inline ReturnedValue RuntimeHelpers::toPrimitive(const Value &value, TypeHint typeHint)
 {
-    const Object *o = value.as<Object>();
-    if (!o)
+    if (!value.isObject())
         return value.asReturnedValue();
-    return RuntimeHelpers::objectDefaultValue(o, typeHint);
+    return RuntimeHelpers::objectDefaultValue(&reinterpret_cast<const Object &>(value), typeHint);
 }
 #endif
 
diff --git a/src/qml/jsruntime/qv4runtimeapi_p.h b/src/qml/jsruntime/qv4runtimeapi_p.h
index 302facba06..0312522d90 100644
--- a/src/qml/jsruntime/qv4runtimeapi_p.h
+++ b/src/qml/jsruntime/qv4runtimeapi_p.h
@@ -57,202 +57,492 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 typedef uint Bool;
-struct NoThrowEngine;
 
-namespace {
-template <typename T>
-struct ExceptionCheck {
-    enum { NeedsCheck = 1 };
-};
-// push_catch and pop context methods shouldn't check for exceptions
-template <>
-struct ExceptionCheck<void (*)(QV4::NoThrowEngine *)> {
-    enum { NeedsCheck = 0 };
-};
-template <typename A>
-struct ExceptionCheck<void (*)(A, QV4::NoThrowEngine)> {
-    enum { NeedsCheck = 0 };
-};
-template <>
-struct ExceptionCheck<QV4::ReturnedValue (*)(QV4::NoThrowEngine *)> {
-    enum { NeedsCheck = 0 };
-};
-template <typename A>
-struct ExceptionCheck<QV4::ReturnedValue (*)(QV4::NoThrowEngine *, A)> {
-    enum { NeedsCheck = 0 };
-};
-template <typename A, typename B>
-struct ExceptionCheck<QV4::ReturnedValue (*)(QV4::NoThrowEngine *, A, B)> {
-    enum { NeedsCheck = 0 };
-};
-template <typename A, typename B, typename C>
-struct ExceptionCheck<void (*)(QV4::NoThrowEngine *, A, B, C)> {
-    enum { NeedsCheck = 0 };
-};
-} // anonymous namespace
-
-#define FOR_EACH_RUNTIME_METHOD(F) \
-    /* call */ \
-    F(ReturnedValue, callGlobalLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
-    F(ReturnedValue, callActivationProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
-    F(ReturnedValue, callQmlScopeObjectProperty, (ExecutionEngine *engine, int propertyIndex, CallData *callData)) \
-    F(ReturnedValue, callQmlContextObjectProperty, (ExecutionEngine *engine, int propertyIndex, CallData *callData)) \
-    F(ReturnedValue, callProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
-    F(ReturnedValue, callPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
-    F(ReturnedValue, callElement, (ExecutionEngine *engine, const Value &index, CallData *callData)) \
-    F(ReturnedValue, callValue, (ExecutionEngine *engine, const Value &func, CallData *callData)) \
-    \
-    /* construct */ \
-    F(ReturnedValue, constructGlobalLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
-    F(ReturnedValue, constructActivationProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
-    F(ReturnedValue, constructProperty, (ExecutionEngine *engine, int nameIndex, CallData *callData)) \
-    F(ReturnedValue, constructPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
-    F(ReturnedValue, constructValue, (ExecutionEngine *engine, const Value &func, CallData *callData)) \
-    \
-    /* set & get */ \
-    F(void, setActivationProperty, (ExecutionEngine *engine, int nameIndex, const Value &value)) \
-    F(void, setProperty, (ExecutionEngine *engine, const Value &object, int nameIndex, const Value &value)) \
-    F(void, setElement, (ExecutionEngine *engine, const Value &object, const Value &index, const Value &value)) \
-    F(ReturnedValue, getProperty, (ExecutionEngine *engine, const Value &object, int nameIndex)) \
-    F(ReturnedValue, getActivationProperty, (ExecutionEngine *engine, int nameIndex)) \
-    F(ReturnedValue, getElement, (ExecutionEngine *engine, const Value &object, const Value &index)) \
-    \
-    /* typeof */  \
-    F(ReturnedValue, typeofValue, (ExecutionEngine *engine, const Value &val)) \
-    F(ReturnedValue, typeofName, (ExecutionEngine *engine, int nameIndex)) \
-    F(ReturnedValue, typeofScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex)) \
-    F(ReturnedValue, typeofContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex)) \
-    F(ReturnedValue, typeofMember, (ExecutionEngine *engine, const Value &base, int nameIndex)) \
-    F(ReturnedValue, typeofElement, (ExecutionEngine *engine, const Value &base, const Value &index)) \
-    \
-    /* delete */ \
-    F(ReturnedValue, deleteElement, (ExecutionEngine *engine, const Value &base, const Value &index)) \
-    F(ReturnedValue, deleteMember, (ExecutionEngine *engine, const Value &base, int nameIndex)) \
-    F(ReturnedValue, deleteMemberString, (ExecutionEngine *engine, const Value &base, String *name)) \
-    F(ReturnedValue, deleteName, (ExecutionEngine *engine, int nameIndex)) \
-    \
-    /* exceptions & scopes */ \
-    F(void, throwException, (ExecutionEngine *engine, const Value &value)) \
-    F(ReturnedValue, unwindException, (ExecutionEngine *engine)) \
-    F(void, pushWithScope, (const Value &o, NoThrowEngine *engine)) \
-    F(void, pushCatchScope, (NoThrowEngine *engine, int exceptionVarNameIndex)) \
-    F(void, popScope, (NoThrowEngine *engine)) \
-    \
-    /* closures */ \
-    F(ReturnedValue, closure, (ExecutionEngine *engine, int functionId)) \
-    \
-    /* function header */ \
-    F(void, declareVar, (ExecutionEngine *engine, bool deletable, int nameIndex)) \
-    F(ReturnedValue, setupArgumentsObject, (ExecutionEngine *engine)) \
-    F(void, convertThisToObject, (ExecutionEngine *engine)) \
-    \
-    /* literals */ \
-    F(ReturnedValue, arrayLiteral, (ExecutionEngine *engine, Value *values, uint length)) \
-    F(ReturnedValue, objectLiteral, (ExecutionEngine *engine, const Value *args, int classId, int arrayValueCount, int arrayGetterSetterCountAndFlags)) \
-    F(ReturnedValue, regexpLiteral, (ExecutionEngine *engine, int id)) \
-    \
-    /* foreach */ \
-    F(ReturnedValue, foreachIterator, (ExecutionEngine *engine, const Value &in)) \
-    F(ReturnedValue, foreachNextPropertyName, (const Value &foreach_iterator)) \
-    \
-    /* unary operators */ \
-    F(ReturnedValue, uPlus, (const Value &value)) \
-    F(ReturnedValue, uMinus, (const Value &value)) \
-    F(ReturnedValue, uNot, (const Value &value)) \
-    F(ReturnedValue, complement, (const Value &value)) \
-    F(ReturnedValue, increment, (const Value &value)) \
-    F(ReturnedValue, decrement, (const Value &value)) \
-    \
-    /* binary operators */ \
-    F(ReturnedValue, instanceof, (ExecutionEngine *engine, const Value &left, const Value &right)) \
-    F(ReturnedValue, in, (ExecutionEngine *engine, const Value &left, const Value &right)) \
-    F(ReturnedValue, add, (ExecutionEngine *engine, const Value &left, const Value &right)) \
-    F(ReturnedValue, addString, (ExecutionEngine *engine, const Value &left, const Value &right)) \
-    F(ReturnedValue, bitOr, (const Value &left, const Value &right)) \
-    F(ReturnedValue, bitXor, (const Value &left, const Value &right)) \
-    F(ReturnedValue, bitAnd, (const Value &left, const Value &right)) \
-    F(ReturnedValue, sub, (const Value &left, const Value &right)) \
-    F(ReturnedValue, mul, (const Value &left, const Value &right)) \
-    F(ReturnedValue, div, (const Value &left, const Value &right)) \
-    F(ReturnedValue, mod, (const Value &left, const Value &right)) \
-    F(ReturnedValue, shl, (const Value &left, const Value &right)) \
-    F(ReturnedValue, shr, (const Value &left, const Value &right)) \
-    F(ReturnedValue, ushr, (const Value &left, const Value &right)) \
-    F(ReturnedValue, greaterThan, (const Value &left, const Value &right)) \
-    F(ReturnedValue, lessThan, (const Value &left, const Value &right)) \
-    F(ReturnedValue, greaterEqual, (const Value &left, const Value &right)) \
-    F(ReturnedValue, lessEqual, (const Value &left, const Value &right)) \
-    F(ReturnedValue, equal, (const Value &left, const Value &right)) \
-    F(ReturnedValue, notEqual, (const Value &left, const Value &right)) \
-    F(ReturnedValue, strictEqual, (const Value &left, const Value &right)) \
-    F(ReturnedValue, strictNotEqual, (const Value &left, const Value &right)) \
-    \
-    /* comparisons */ \
-    F(Bool, compareGreaterThan, (const Value &l, const Value &r)) \
-    F(Bool, compareLessThan, (const Value &l, const Value &r)) \
-    F(Bool, compareGreaterEqual, (const Value &l, const Value &r)) \
-    F(Bool, compareLessEqual, (const Value &l, const Value &r)) \
-    F(Bool, compareEqual, (const Value &left, const Value &right)) \
-    F(Bool, compareNotEqual, (const Value &left, const Value &right)) \
-    F(Bool, compareStrictEqual, (const Value &left, const Value &right)) \
-    F(Bool, compareStrictNotEqual, (const Value &left, const Value &right)) \
-    \
-    F(Bool, compareInstanceof, (ExecutionEngine *engine, const Value &left, const Value &right)) \
-    F(Bool, compareIn, (ExecutionEngine *engine, const Value &left, const Value &right)) \
-    \
-    /* conversions */ \
-    F(Bool, toBoolean, (const Value &value)) \
-    F(ReturnedValue, toDouble, (const Value &value)) \
-    F(int, toInt, (const Value &value)) \
-    F(int, doubleToInt, (const double &d)) \
-    F(unsigned, toUInt, (const Value &value)) \
-    F(unsigned, doubleToUInt, (const double &d)) \
-    \
-    /* qml */ \
-    F(ReturnedValue, getQmlContext, (NoThrowEngine *engine)) \
-    F(ReturnedValue, getQmlImportedScripts, (NoThrowEngine *engine)) \
-    F(ReturnedValue, getQmlSingleton, (NoThrowEngine *engine, int nameIndex)) \
-    F(ReturnedValue, getQmlAttachedProperty, (ExecutionEngine *engine, int attachedPropertiesId, int propertyIndex)) \
-    F(ReturnedValue, getQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)) \
-    F(ReturnedValue, getQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, bool captureRequired)) \
-    F(ReturnedValue, getQmlQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)) \
-    F(ReturnedValue, getQmlSingletonQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, bool captureRequired)) \
-    F(ReturnedValue, getQmlIdObject, (ExecutionEngine *engine, const Value &context, uint index)) \
-    \
-    F(void, setQmlScopeObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)) \
-    F(void, setQmlContextObjectProperty, (ExecutionEngine *engine, const Value &context, int propertyIndex, const Value &value)) \
-    F(void, setQmlQObjectProperty, (ExecutionEngine *engine, const Value &object, int propertyIndex, const Value &value))
 
 struct Q_QML_PRIVATE_EXPORT Runtime {
-    Runtime();
-
     typedef ReturnedValue (*UnaryOperation)(const Value &value);
     typedef ReturnedValue (*BinaryOperation)(const Value &left, const Value &right);
-    typedef ReturnedValue (*BinaryOperationContext)(ExecutionEngine *engine, const Value &left, const Value &right);
+    typedef ReturnedValue (*BinaryOperationContext)(ExecutionEngine *, const Value &left, const Value &right);
+
+    enum class Throws { No, Yes };
+    enum class ChangesContext { No, Yes };
+    enum class Pure { No, Yes };
+    enum class LastArgumentIsOutputValue { No, Yes };
+
+    template<Throws t, ChangesContext c = ChangesContext::No, Pure p = Pure::No,
+             LastArgumentIsOutputValue out = LastArgumentIsOutputValue::No>
+    struct Method
+    {
+        static constexpr bool throws = t == Throws::Yes;
+        static constexpr bool changesContext = c == ChangesContext::Yes;
+        static constexpr bool pure = p == Pure::Yes;
+        static constexpr bool lastArgumentIsOutputValue = out == LastArgumentIsOutputValue::Yes;
+    };
+    using PureMethod = Method<Throws::No, ChangesContext::No, Pure::Yes>;
+    using IteratorMethod = Method<Throws::Yes, ChangesContext::No, Pure::No,
+                                  LastArgumentIsOutputValue::Yes>;
+
+    /* call */
+    struct Q_QML_PRIVATE_EXPORT CallGlobalLookup : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, uint, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallName : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, int, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallPropertyLookup : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, uint, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallElement : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallValue : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallWithReceiver : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallPossiblyDirectEval : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallWithSpread : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT TailCall : Method<Throws::Yes>
+    {
+        static ReturnedValue call(CppStackFrame *, ExecutionEngine *);
+    };
+
+    /* construct */
+    struct Q_QML_PRIVATE_EXPORT Construct : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT ConstructWithSpread : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, Value[], int);
+    };
+
+    /* load & store */
+    struct Q_QML_PRIVATE_EXPORT StoreNameStrict : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, int, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StoreNameSloppy : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, int, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StoreProperty : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &, int, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StoreElement : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StoreElement_traced : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &, const Value &, const Value &, quint8 *);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadName : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadElement : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadElement_Traced : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, quint8 *);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadSuperProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StoreSuperProperty : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadSuperConstructor : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadGlobalLookup : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, Function *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT GetLookup : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, Function *, const Value &, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT SetLookupStrict : Method<Throws::Yes>
+    {
+        static void call(Function *, const Value &, int, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT SetLookupSloppy : Method<Throws::Yes>
+    {
+        static void call(Function *, const Value &, int, const Value &);
+    };
+
+    /* typeof */
+    struct Q_QML_PRIVATE_EXPORT TypeofValue : PureMethod
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT TypeofName : Method<Throws::No>
+    {
+        static ReturnedValue call(ExecutionEngine *, int);
+    };
+
+    /* delete */
+    struct Q_QML_PRIVATE_EXPORT DeleteProperty_NoThrow : Method<Throws::No>
+    {
+        static Bool call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT DeleteProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, Function *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT DeleteName_NoThrow : Method<Throws::No>
+    {
+        static Bool call(ExecutionEngine *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT DeleteName : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, Function *, int);
+    };
+
+    /* exceptions & scopes */
+    struct Q_QML_PRIVATE_EXPORT ThrowException : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT PushCallContext : Method<Throws::No, ChangesContext::Yes>
+    {
+        static void call(CppStackFrame *);
+    };
+    struct Q_QML_PRIVATE_EXPORT PushWithContext : Method<Throws::Yes, ChangesContext::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT PushCatchContext : Method<Throws::No, ChangesContext::Yes>
+    {
+        static void call(ExecutionEngine *, int, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT PushBlockContext : Method<Throws::No, ChangesContext::Yes>
+    {
+        static void call(ExecutionEngine *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CloneBlockContext : Method<Throws::No, ChangesContext::Yes>
+    {
+        static void call(ExecutionEngine *);
+    };
+    struct Q_QML_PRIVATE_EXPORT PushScriptContext : Method<Throws::No, ChangesContext::Yes>
+    {
+        static void call(ExecutionEngine *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT PopScriptContext : Method<Throws::No, ChangesContext::Yes>
+    {
+        static void call(ExecutionEngine *);
+    };
+    struct Q_QML_PRIVATE_EXPORT ThrowReferenceError : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT ThrowOnNullOrUndefined : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &);
+    };
+
+    /* closures */
+    struct Q_QML_PRIVATE_EXPORT Closure : Method<Throws::No>
+    {
+        static ReturnedValue call(ExecutionEngine *, int);
+    };
+
+    /* Function header */
+    struct Q_QML_PRIVATE_EXPORT ConvertThisToObject : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT DeclareVar : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, Bool, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CreateMappedArgumentsObject : Method<Throws::No>
+    {
+        static ReturnedValue call(ExecutionEngine *);
+    };
+    struct Q_QML_PRIVATE_EXPORT CreateUnmappedArgumentsObject : Method<Throws::No>
+    {
+        static ReturnedValue call(ExecutionEngine *);
+    };
+    struct Q_QML_PRIVATE_EXPORT CreateRestParameter : PureMethod
+    {
+        static ReturnedValue call(ExecutionEngine *, int);
+    };
 
-#define DEFINE_RUNTIME_METHOD_ENUM(returnvalue, name, args) name,
-    enum RuntimeMethods {
-        FOR_EACH_RUNTIME_METHOD(DEFINE_RUNTIME_METHOD_ENUM)
-        RuntimeMethodCount,
-        InvalidRuntimeMethod = RuntimeMethodCount
+    /* literals */
+    struct Q_QML_PRIVATE_EXPORT ArrayLiteral : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, Value[], uint);
+    };
+    struct Q_QML_PRIVATE_EXPORT ObjectLiteral : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, int, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CreateClass : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, int, const Value &, Value[]);
     };
-#undef DEFINE_RUNTIME_METHOD_ENUM
 
-    void *runtimeMethods[RuntimeMethodCount];
+    /* for-in, for-of and array destructuring */
+    struct Q_QML_PRIVATE_EXPORT GetIterator : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT IteratorNext : IteratorMethod
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, Value *);
+    };
+    struct Q_QML_PRIVATE_EXPORT IteratorNextForYieldStar : IteratorMethod
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &, Value *);
+    };
+    struct Q_QML_PRIVATE_EXPORT IteratorClose : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT DestructureRestElement : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
 
-    static uint runtimeMethodOffset(RuntimeMethods method) { return method*QT_POINTER_SIZE; }
+    /* conversions */
+    struct Q_QML_PRIVATE_EXPORT ToObject : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT ToBoolean : PureMethod
+    {
+        static Bool call(const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT ToNumber : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &);
+    };
+    /* unary operators */
+    struct Q_QML_PRIVATE_EXPORT UMinus : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &);
+    };
 
-#define RUNTIME_METHOD(returnvalue, name, args) \
-    typedef returnvalue (*Method_##name)args; \
-    enum { Method_##name##_NeedsExceptionCheck = ExceptionCheck<Method_##name>::NeedsCheck }; \
-    static returnvalue method_##name args;
-    FOR_EACH_RUNTIME_METHOD(RUNTIME_METHOD)
-#undef RUNTIME_METHOD
+    /* binary operators */
+    struct Q_QML_PRIVATE_EXPORT Instanceof : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT In : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Add : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Sub : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Mul : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Div : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Mod : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Exp : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT BitAnd : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT BitOr : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT BitXor : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Shl : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Shr : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT UShr : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT GreaterThan : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT LessThan : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT GreaterEqual : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT LessEqual : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT Equal : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT NotEqual : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StrictEqual : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StrictNotEqual : Method<Throws::Yes>
+    {
+        static ReturnedValue call(const Value &, const Value &);
+    };
+
+    /* comparisons */
+    struct Q_QML_PRIVATE_EXPORT CompareGreaterThan : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareLessThan : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareGreaterEqual : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareLessEqual : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareEqual : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareNotEqual : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareStrictEqual : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareStrictNotEqual : Method<Throws::Yes>
+    {
+        static Bool call(const Value &, const Value &);
+    };
+
+    struct Q_QML_PRIVATE_EXPORT CompareInstanceof : Method<Throws::Yes>
+    {
+        static Bool call(ExecutionEngine *, const Value &, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT CompareIn : Method<Throws::Yes>
+    {
+        static Bool call(ExecutionEngine *, const Value &, const Value &);
+    };
+
+    struct Q_QML_PRIVATE_EXPORT RegexpLiteral : PureMethod
+    {
+        static ReturnedValue call(ExecutionEngine *, int);
+    };
+    struct Q_QML_PRIVATE_EXPORT GetTemplateObject : PureMethod
+    {
+        static ReturnedValue call(Function *, int);
+    };
+
+    /* qml */
+    struct Q_QML_PRIVATE_EXPORT LoadQmlContext : Method<Throws::No>
+    {
+        static ReturnedValue call(ExecutionEngine *);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadQmlImportedScripts : Method<Throws::No>
+    {
+        static ReturnedValue call(ExecutionEngine *);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadQmlScopeObjectProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int, Bool);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadQmlContextObjectProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int, Bool);
+    };
+    struct Q_QML_PRIVATE_EXPORT LoadQmlIdObject : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, uint);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallQmlScopeObjectProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int, Value[], int);
+    };
+    struct Q_QML_PRIVATE_EXPORT CallQmlContextObjectProperty : Method<Throws::Yes>
+    {
+        static ReturnedValue call(ExecutionEngine *, const Value &, int, Value[], int);
+    };
 
+    struct Q_QML_PRIVATE_EXPORT StoreQmlScopeObjectProperty : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &, int, const Value &);
+    };
+    struct Q_QML_PRIVATE_EXPORT StoreQmlContextObjectProperty : Method<Throws::Yes>
+    {
+        static void call(ExecutionEngine *, const Value &, int, const Value &);
+    };
+
+    struct StackOffsets {
+        static const int tailCall_function   = -1;
+        static const int tailCall_thisObject = -2;
+        static const int tailCall_argv       = -3;
+        static const int tailCall_argc       = -4;
+    };
 };
 
 static_assert(std::is_standard_layout<Runtime>::value, "Runtime needs to be standard layout in order for us to be able to use offsetof");
-static_assert(offsetof(Runtime, runtimeMethods) == 0, "JIT expects this to be the first member");
 static_assert(sizeof(Runtime::BinaryOperation) == sizeof(void*), "JIT expects a function pointer to fit into a regular pointer, for cross-compilation offset translation");
 
 } // namespace QV4
diff --git a/src/qml/jsruntime/qv4runtimecodegen.cpp b/src/qml/jsruntime/qv4runtimecodegen.cpp
new file mode 100644
index 0000000000..9866966936
--- /dev/null
+++ b/src/qml/jsruntime/qv4runtimecodegen.cpp
@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4runtimecodegen_p.h"
+#include "qv4compilerscanfunctions_p.h"
+
+using namespace QV4;
+
+void RuntimeCodegen::generateFromFunctionExpression(const QString &fileName,
+                                                    const QString &sourceCode,
+                                                    AST::FunctionExpression *ast,
+                                                    Compiler::Module *module)
+{
+    _module = module;
+    _module->fileName = fileName;
+    _module->finalUrl = fileName;
+    _context = nullptr;
+
+    Compiler::ScanFunctions scan(this, sourceCode, Compiler::ContextType::Global);
+    // fake a global environment
+    scan.enterEnvironment(nullptr, Compiler::ContextType::Function, QString());
+    scan(ast);
+    scan.leaveEnvironment();
+
+    if (hasError)
+        return;
+
+    int index = defineFunction(ast->name.toString(), ast, ast->formals, ast->body);
+    _module->rootContext = _module->functions.at(index);
+}
+
+void RuntimeCodegen::throwSyntaxError(const AST::SourceLocation &loc, const QString &detail)
+{
+    if (hasError)
+        return;
+    hasError = true;
+    engine->throwSyntaxError(detail, _module->fileName, loc.startLine, loc.startColumn);
+}
+
+void RuntimeCodegen::throwReferenceError(const AST::SourceLocation &loc, const QString &detail)
+{
+    if (hasError)
+        return;
+    hasError = true;
+    engine->throwReferenceError(detail, _module->fileName, loc.startLine, loc.startColumn);
+}
+
diff --git a/src/qml/jit/qv4unop_p.h b/src/qml/jsruntime/qv4runtimecodegen_p.h
index fb68f80eec..be66dc57ca 100644
--- a/src/qml/jit/qv4unop_p.h
+++ b/src/qml/jsruntime/qv4runtimecodegen_p.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -36,8 +36,8 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-#ifndef QV4UNOP_P_H
-#define QV4UNOP_P_H
+#ifndef QV4RUNTIMECODEGEN_P_H
+#define QV4RUNTIMECODEGEN_P_H
 
 //
 //  W A R N I N G
@@ -50,43 +50,33 @@
 // We mean it.
 //
 
-#include <qv4jsir_p.h>
-#include <qv4isel_masm_p.h>
+#include <private/qv4codegen_p.h>
 
 QT_BEGIN_NAMESPACE
 
-#if ENABLE(ASSEMBLER)
-
 namespace QV4 {
-namespace JIT {
 
-template <typename JITAssembler>
-struct Unop {
-    Unop(JITAssembler *assembler, IR::AluOp operation)
-        : _as(assembler)
-        , op(operation)
+class RuntimeCodegen : public Compiler::Codegen
+{
+public:
+    RuntimeCodegen(ExecutionEngine *engine, Compiler::JSUnitGenerator *jsUnitGenerator, bool strict)
+        : Codegen(jsUnitGenerator, strict)
+        , engine(engine)
     {}
 
-    using RelationalCondition = typename JITAssembler::RelationalCondition;
-    using PointerToValue = typename JITAssembler::PointerToValue;
-    using RuntimeCall = typename JITAssembler::RuntimeCall;
-    using TrustedImm32 = typename JITAssembler::TrustedImm32;
-
-    void generate(IR::Expr *source, IR::Expr *target);
-
-    void generateUMinus(IR::Expr *source, IR::Expr *target);
-    void generateNot(IR::Expr *source, IR::Expr *target);
-    void generateCompl(IR::Expr *source, IR::Expr *target);
+    void generateFromFunctionExpression(const QString &fileName,
+                                        const QString &sourceCode,
+                                        AST::FunctionExpression *ast,
+                                        Compiler::Module *module);
 
-    JITAssembler *_as;
-    IR::AluOp op;
+    void throwSyntaxError(const AST::SourceLocation &loc, const QString &detail) override;
+    void throwReferenceError(const AST::SourceLocation &loc, const QString &detail) override;
+private:
+    ExecutionEngine *engine;
 };
 
 }
-}
-
-#endif
 
 QT_END_NAMESPACE
 
-#endif
+#endif // QV4CODEGEN_P_H
diff --git a/src/qml/jsruntime/qv4scopedvalue_p.h b/src/qml/jsruntime/qv4scopedvalue_p.h
index 04a0c74133..e4aceef3ee 100644
--- a/src/qml/jsruntime/qv4scopedvalue_p.h
+++ b/src/qml/jsruntime/qv4scopedvalue_p.h
@@ -52,8 +52,8 @@
 
 #include "qv4engine_p.h"
 #include "qv4value_p.h"
-#include "qv4persistent_p.h"
 #include "qv4property_p.h"
+#include "qv4propertykey_p.h"
 
 #ifdef V4_USE_VALGRIND
 #include <valgrind/memcheck.h>
@@ -71,56 +71,45 @@ struct ScopedValue;
 #define CHECK_EXCEPTION() \
     do { \
         if (scope.hasException()) { \
-            scope.result = QV4::Encode::undefined(); \
-            return; \
+            return QV4::Encode::undefined(); \
         } \
     } while (false)
 
 #define RETURN_UNDEFINED() \
-    do { \
-        scope.result = QV4::Encode::undefined(); \
-        return; \
-    } while (false)
+    return QV4::Encode::undefined()
 
 #define RETURN_RESULT(r) \
-    do { \
-        scope.result = r; \
-        return; \
-    } while (false)
+    return QV4::Encode(r)
 
 #define THROW_TYPE_ERROR() \
-    do { \
-        scope.result = scope.engine->throwTypeError(); \
-        return; \
-    } while (false)
+    return scope.engine->throwTypeError()
 
 #define THROW_GENERIC_ERROR(str) \
-    do { \
-        scope.result = scope.engine->throwError(QString::fromUtf8(str)); \
-        return; \
-    } while (false)
+    return scope.engine->throwError(QString::fromUtf8(str))
 
 struct Scope {
-    inline Scope(ExecutionContext *ctx)
+    explicit Scope(ExecutionContext *ctx)
         : engine(ctx->engine())
         , mark(engine->jsStackTop)
-        , result(*engine->jsAlloca(1))
     {
-        result = Encode::undefined();
     }
 
     explicit Scope(ExecutionEngine *e)
         : engine(e)
         , mark(engine->jsStackTop)
-        , result(*engine->jsAlloca(1))
     {
-        result = Encode::undefined();
+    }
+
+    explicit Scope(const Managed *m)
+        : engine(m->engine())
+        , mark(engine->jsStackTop)
+    {
     }
 
     ~Scope() {
 #ifndef QT_NO_DEBUG
         Q_ASSERT(engine->jsStackTop >= mark);
-        Q_ASSERT(engine->currentContext < mark);
+//        Q_ASSERT(engine->currentContext < mark);
         memset(mark, 0, (engine->jsStackTop - mark)*sizeof(Value));
 #endif
 #ifdef V4_USE_VALGRIND
@@ -129,8 +118,45 @@ struct Scope {
         engine->jsStackTop = mark;
     }
 
-    QML_NEARLY_ALWAYS_INLINE Value *alloc(int nValues) const {
-        return engine->jsAlloca(nValues);
+    enum AllocMode {
+        Undefined,
+        Empty,
+        /* Be careful when using Uninitialized, the stack has to be fully initialized before calling into the memory manager again */
+        Uninitialized
+    };
+    template <AllocMode mode = Undefined>
+    QML_NEARLY_ALWAYS_INLINE Value *alloc(int nValues) const
+    {
+        Value *ptr = engine->jsAlloca(nValues);
+        switch (mode) {
+        case Undefined:
+            for (int i = 0; i < nValues; ++i)
+                ptr[i] = Value::undefinedValue();
+            break;
+        case Empty:
+            for (int i = 0; i < nValues; ++i)
+                ptr[i] = Value::emptyValue();
+            break;
+        case Uninitialized:
+            break;
+        }
+        return ptr;
+    }
+    template <AllocMode mode = Undefined>
+    QML_NEARLY_ALWAYS_INLINE Value *alloc() const
+    {
+        Value *ptr = engine->jsAlloca(1);
+        switch (mode) {
+        case Undefined:
+            *ptr = Value::undefinedValue();
+            break;
+        case Empty:
+            *ptr = Value::emptyValue();
+            break;
+        case Uninitialized:
+            break;
+        }
+        return ptr;
     }
 
     bool hasException() const {
@@ -139,7 +165,6 @@ struct Scope {
 
     ExecutionEngine *engine;
     Value *mark;
-    Value &result;
 
 private:
     Q_DISABLE_COPY(Scope)
@@ -149,31 +174,31 @@ struct ScopedValue
 {
     ScopedValue(const Scope &scope)
     {
-        ptr = scope.engine->jsStackTop++;
+        ptr = scope.alloc<Scope::Uninitialized>();
         ptr->setRawValue(0);
     }
 
     ScopedValue(const Scope &scope, const Value &v)
     {
-        ptr = scope.engine->jsStackTop++;
+        ptr = scope.alloc<Scope::Uninitialized>();
         *ptr = v;
     }
 
     ScopedValue(const Scope &scope, Heap::Base *o)
     {
-        ptr = scope.engine->jsStackTop++;
+        ptr = scope.alloc<Scope::Uninitialized>();
         ptr->setM(o);
     }
 
     ScopedValue(const Scope &scope, Managed *m)
     {
-        ptr = scope.engine->jsStackTop++;
+        ptr = scope.alloc<Scope::Uninitialized>();
         ptr->setRawValue(m->asReturnedValue());
     }
 
     ScopedValue(const Scope &scope, const ReturnedValue &v)
     {
-        ptr = scope.engine->jsStackTop++;
+        ptr = scope.alloc<Scope::Uninitialized>();
         ptr->setRawValue(v);
     }
 
@@ -216,77 +241,121 @@ struct ScopedValue
     Value *ptr;
 };
 
+
+struct ScopedPropertyKey
+{
+    ScopedPropertyKey(const Scope &scope)
+    {
+        ptr = reinterpret_cast<PropertyKey *>(scope.alloc<Scope::Uninitialized>());
+        *ptr = PropertyKey::invalid();
+    }
+
+    ScopedPropertyKey(const Scope &scope, const PropertyKey &v)
+    {
+        ptr = reinterpret_cast<PropertyKey *>(scope.alloc<Scope::Uninitialized>());
+        *ptr = v;
+    }
+
+    ScopedPropertyKey &operator=(const PropertyKey &other) {
+        *ptr = other;
+        return *this;
+    }
+
+    PropertyKey *operator->() {
+        return ptr;
+    }
+    operator PropertyKey() const {
+        return *ptr;
+    }
+
+    bool operator==(const PropertyKey &other) const {
+        return *ptr == other;
+    }
+    bool operator==(const ScopedPropertyKey &other) const {
+        return *ptr == *other.ptr;
+    }
+    bool operator!=(const PropertyKey &other) const {
+        return *ptr != other;
+    }
+    bool operator!=(const ScopedPropertyKey &other) const {
+        return *ptr != *other.ptr;
+    }
+
+    PropertyKey *ptr;
+};
+
+
 template<typename T>
 struct Scoped
 {
     enum ConvertType { Convert };
 
     QML_NEARLY_ALWAYS_INLINE void setPointer(const Managed *p) {
-        ptr->setM(p ? p->m() : 0);
+        ptr->setM(p ? p->m() : nullptr);
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Undefined>();
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const Value &v)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         setPointer(v.as<T>());
     }
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, Heap::Base *o)
     {
         Value v;
         v = o;
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         setPointer(v.as<T>());
     }
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const ScopedValue &v)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         setPointer(v.ptr->as<T>());
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const Value &v, ConvertType)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         ptr->setRawValue(value_convert<T>(scope.engine, v));
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const Value *v)
     {
-        ptr = scope.engine->jsAlloca(1);
-        setPointer(v ? v->as<T>() : 0);
+        ptr = scope.alloc<Scope::Uninitialized>();
+        setPointer(v ? v->as<T>() : nullptr);
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, T *t)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         setPointer(t);
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const T *t)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         setPointer(t);
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, typename T::Data *t)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         *ptr = t;
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const ReturnedValue &v)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         setPointer(QV4::Value::fromReturnedValue(v).as<T>());
     }
 
     QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const ReturnedValue &v, ConvertType)
     {
-        ptr = scope.engine->jsAlloca(1);
+        ptr = scope.alloc<Scope::Uninitialized>();
         ptr->setRawValue(value_convert<T>(scope.engine, QV4::Value::fromReturnedValue(v)));
     }
 
@@ -303,7 +372,7 @@ struct Scoped
         return *this;
     }
     Scoped<T> &operator=(Value *v) {
-        setPointer(v ? v->as<T>() : 0);
+        setPointer(v ? v->as<T>() : nullptr);
         return *this;
     }
 
@@ -337,10 +406,7 @@ struct Scoped
         return getPointer();
     }
 
-    bool operator!() const {
-        return !ptr->m();
-    }
-    operator void *() const {
+    explicit operator bool() const {
         return ptr->m();
     }
 
@@ -363,27 +429,6 @@ struct Scoped
     Value *ptr;
 };
 
-struct ScopedCallData {
-    ScopedCallData(const Scope &scope, int argc = 0)
-    {
-        int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + qMax(argc , int(QV4::Global::ReservedArgumentCount));
-        ptr = reinterpret_cast<CallData *>(scope.alloc(size));
-        ptr->tag = quint32(QV4::Value::ValueTypeInternal::Integer);
-        ptr->argc = argc;
-    }
-
-    CallData *operator->() {
-        return ptr;
-    }
-
-    operator CallData *() const {
-        return ptr;
-    }
-
-    CallData *ptr;
-};
-
-
 inline Value &Value::operator =(const ScopedValue &v)
 {
     _val = v.ptr->rawValue();
@@ -411,25 +456,6 @@ struct ScopedProperty
     Property *property;
 };
 
-struct ExecutionContextSaver
-{
-    Scope scope; // this makes sure that a reference to context on the JS stack goes out of scope as soon as the context is not used anymore.
-    ExecutionContext *savedContext;
-
-    ExecutionContextSaver(const Scope &scope)
-        : scope(scope.engine)
-    {
-        savedContext = scope.engine->currentContext;
-    }
-    ~ExecutionContextSaver()
-    {
-        Q_ASSERT(scope.engine->jsStackTop > scope.engine->currentContext);
-        scope.engine->currentContext = savedContext;
-        scope.engine->current = savedContext->d();
-    }
-};
-
-
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4script.cpp b/src/qml/jsruntime/qv4script.cpp
index 62145f36cc..7bbef3335e 100644
--- a/src/qml/jsruntime/qv4script.cpp
+++ b/src/qml/jsruntime/qv4script.cpp
@@ -45,6 +45,7 @@
 #include "qv4debugging_p.h"
 #include "qv4profiling_p.h"
 #include "qv4scopedvalue_p.h"
+#include "qv4jscall_p.h"
 
 #include <private/qqmljsengine_p.h>
 #include <private/qqmljslexer_p.h>
@@ -52,24 +53,24 @@
 #include <private/qqmljsast_p.h>
 #include <private/qqmlengine_p.h>
 #include <private/qv4profiling_p.h>
-#include <qv4jsir_p.h>
-#include <qv4codegen_p.h>
+#include <qv4runtimecodegen_p.h>
 
 #include <QtCore/QDebug>
 #include <QtCore/QString>
+#include <QScopedValueRollback>
 
 using namespace QV4;
 
-Script::Script(ExecutionEngine *v4, QmlContext *qml, CompiledData::CompilationUnit *compilationUnit)
-    : line(0), column(0), scope(v4->rootContext()), strictMode(false), inheritContext(true), parsed(false)
-    , compilationUnit(compilationUnit), vmFunction(0), parseAsBinding(true)
+Script::Script(ExecutionEngine *v4, QmlContext *qml, const QQmlRefPointer<CompiledData::CompilationUnit> &compilationUnit)
+    : line(1), column(0), context(v4->rootContext()), strictMode(false), inheritContext(true), parsed(false)
+    , compilationUnit(compilationUnit), vmFunction(nullptr), parseAsBinding(true)
 {
     if (qml)
         qmlContext.set(v4, *qml);
 
     parsed = true;
 
-    vmFunction = compilationUnit ? compilationUnit->linkToEngine(v4) : 0;
+    vmFunction = compilationUnit ? compilationUnit->linkToEngine(v4) : nullptr;
 }
 
 Script::~Script()
@@ -81,16 +82,23 @@ void Script::parse()
     if (parsed)
         return;
 
-    using namespace QQmlJS;
+    using namespace QV4::Compiler;
 
     parsed = true;
 
-    ExecutionEngine *v4 = scope->engine();
+    ExecutionEngine *v4 = context->engine();
     Scope valueScope(v4);
 
-    IR::Module module(v4->debugger() != 0);
+    Module module(v4->debugger() != nullptr);
 
-    QQmlJS::Engine ee, *engine = &ee;
+    if (sourceCode.startsWith(QLatin1String("function("))) {
+        static const int snippetLength = 70;
+        qWarning() << "Warning: Using function expressions as statements in scripts is not compliant with the ECMAScript specification:\n"
+                   << (sourceCode.leftRef(snippetLength) + QLatin1String("..."))
+                   << "\nThis will throw a syntax error in Qt 5.12. If you want a function expression, surround it by parentheses.";
+    }
+
+    Engine ee, *engine = &ee;
     Lexer lexer(engine);
     lexer.setCode(sourceCode, line, parseAsBinding);
     Parser parser(engine);
@@ -98,7 +106,7 @@ void Script::parse()
     const bool parsed = parser.parseProgram();
 
     const auto diagnosticMessages = parser.diagnosticMessages();
-    for (const QQmlJS::DiagnosticMessage &m : diagnosticMessages) {
+    for (const DiagnosticMessage &m : diagnosticMessages) {
         if (m.isError()) {
             valueScope.engine->throwSyntaxError(m.message, sourceFile, m.loc.startLine, m.loc.startColumn);
             return;
@@ -117,25 +125,15 @@ void Script::parse()
             return;
         }
 
-        QStringList inheritedLocals;
-        if (inheritContext) {
-            Scoped<CallContext> ctx(valueScope, scope);
-            if (ctx) {
-                for (Identifier * const *i = ctx->variables(), * const *ei = i + ctx->variableCount(); i < ei; ++i)
-                    inheritedLocals.append(*i ? (*i)->string : QString());
-            }
-        }
-
-        RuntimeCodegen cg(v4, strictMode);
-        cg.generateFromProgram(sourceFile, sourceCode, program, &module, QQmlJS::Codegen::EvalCode, inheritedLocals);
+        QV4::Compiler::JSUnitGenerator jsGenerator(&module);
+        RuntimeCodegen cg(v4, &jsGenerator, strictMode);
+        if (inheritContext)
+            cg.setUseFastLookups(false);
+        cg.generateFromProgram(sourceFile, sourceFile, sourceCode, program, &module, contextType);
         if (v4->hasException)
             return;
 
-        QV4::Compiler::JSUnitGenerator jsGenerator(&module);
-        QScopedPointer<EvalInstructionSelection> isel(v4->iselFactory->create(QQmlEnginePrivate::get(v4), v4->executableAllocator, &module, &jsGenerator));
-        if (inheritContext)
-            isel->setUseFastLookups(false);
-        compilationUnit = isel->compile();
+        compilationUnit = cg.generateCompilationUnit();
         vmFunction = compilationUnit->linkToEngine(v4);
     }
 
@@ -146,36 +144,24 @@ void Script::parse()
     }
 }
 
-ReturnedValue Script::run()
+ReturnedValue Script::run(const QV4::Value *thisObject)
 {
     if (!parsed)
         parse();
     if (!vmFunction)
         return Encode::undefined();
 
-    QV4::ExecutionEngine *engine = scope->engine();
+    QV4::ExecutionEngine *engine = context->engine();
     QV4::Scope valueScope(engine);
 
     if (qmlContext.isUndefined()) {
-        TemporaryAssignment<Function*> savedGlobalCode(engine->globalCode, vmFunction);
-
-        ExecutionContextSaver ctxSaver(valueScope);
-        ContextStateSaver stateSaver(valueScope, scope);
-        scope->d()->strictMode = vmFunction->isStrict();
-        scope->d()->lookups = vmFunction->compilationUnit->runtimeLookups;
-        scope->d()->constantTable = vmFunction->compilationUnit->constants;
-        scope->d()->compilationUnit = vmFunction->compilationUnit;
+        QScopedValueRollback<Function*> savedGlobalCode(engine->globalCode, vmFunction);
 
-        return Q_V4_PROFILE(engine, vmFunction);
+        return vmFunction->call(thisObject ? thisObject : engine->globalObject, nullptr, 0,
+                                context);
     } else {
         Scoped<QmlContext> qml(valueScope, qmlContext.value());
-        ScopedCallData callData(valueScope);
-        callData->thisObject = Primitive::undefinedValue();
-        if (vmFunction->canUseSimpleFunction())
-            qml->simpleCall(valueScope, callData, vmFunction);
-        else
-            qml->call(valueScope, callData, vmFunction);
-        return valueScope.result.asReturnedValue();
+        return vmFunction->call(thisObject, nullptr, 0, qml);
     }
 }
 
@@ -186,76 +172,76 @@ Function *Script::function()
     return vmFunction;
 }
 
-QQmlRefPointer<QV4::CompiledData::CompilationUnit> Script::precompile(IR::Module *module, Compiler::JSUnitGenerator *unitGenerator, ExecutionEngine *engine, const QUrl &url, const QString &source, QList<QQmlError> *reportedErrors, QQmlJS::Directives *directivesCollector)
+QQmlRefPointer<QV4::CompiledData::CompilationUnit> Script::precompile(QV4::Compiler::Module *module, QQmlJS::Engine *jsEngine, Compiler::JSUnitGenerator *unitGenerator,
+                                                                      const QString &fileName, const QString &finalUrl, const QString &source,
+                                                                      QList<QQmlError> *reportedErrors,
+                                                                      QV4::Compiler::ContextType contextType)
 {
-    using namespace QQmlJS;
+    using namespace QV4::Compiler;
     using namespace QQmlJS::AST;
 
-    QQmlJS::Engine ee;
-    if (directivesCollector)
-        ee.setDirectives(directivesCollector);
-    QQmlJS::Lexer lexer(&ee);
+    Lexer lexer(jsEngine);
     lexer.setCode(source, /*line*/1, /*qml mode*/false);
-    QQmlJS::Parser parser(&ee);
+    Parser parser(jsEngine);
 
     parser.parseProgram();
 
-    QList<QQmlError> errors;
-
-    const auto diagnosticMessages = parser.diagnosticMessages();
-    for (const QQmlJS::DiagnosticMessage &m : diagnosticMessages) {
-        if (m.isWarning()) {
-            qWarning("%s:%d : %s", qPrintable(url.toString()), m.loc.startLine, qPrintable(m.message));
-            continue;
-        }
-
-        QQmlError error;
-        error.setUrl(url);
-        error.setDescription(m.message);
-        error.setLine(m.loc.startLine);
-        error.setColumn(m.loc.startColumn);
-        errors << error;
-    }
-
+    QList<QQmlError> errors = QQmlEnginePrivate::qmlErrorFromDiagnostics(fileName, parser.diagnosticMessages());
     if (!errors.isEmpty()) {
         if (reportedErrors)
             *reportedErrors << errors;
-        return 0;
+        return nullptr;
     }
 
     Program *program = AST::cast<Program *>(parser.rootNode());
     if (!program) {
         // if parsing was successful, and we have no program, then
         // we're done...:
-        return 0;
+        return nullptr;
     }
 
-    QQmlJS::Codegen cg(/*strict mode*/false);
-    cg.generateFromProgram(url.toString(), source, program, module, QQmlJS::Codegen::EvalCode);
+    Codegen cg(unitGenerator, /*strict mode*/false);
+    cg.setUseFastLookups(false);
+    cg.generateFromProgram(fileName, finalUrl, source, program, module, contextType);
     errors = cg.qmlErrors();
     if (!errors.isEmpty()) {
         if (reportedErrors)
             *reportedErrors << errors;
-        return 0;
+        return nullptr;
     }
 
-    QScopedPointer<EvalInstructionSelection> isel(engine->iselFactory->create(QQmlEnginePrivate::get(engine), engine->executableAllocator, module, unitGenerator));
-    isel->setUseFastLookups(false);
-    return isel->compile(/*generate unit data*/false);
+    return cg.generateCompilationUnit(/*generate unit data*/false);
 }
 
-QV4::ReturnedValue Script::evaluate(ExecutionEngine *engine, const QString &script, QmlContext *qmlContext)
+Script *Script::createFromFileOrCache(ExecutionEngine *engine, QmlContext *qmlContext, const QString &fileName, const QUrl &originalUrl, QString *error)
 {
-    QV4::Scope scope(engine);
-    QV4::Script qmlScript(engine, qmlContext, script, QString());
-
-    qmlScript.parse();
-    QV4::ScopedValue result(scope);
-    if (!scope.engine->hasException)
-        result = qmlScript.run();
-    if (scope.engine->hasException) {
-        scope.engine->catchException();
-        return Encode::undefined();
+    if (error)
+        error->clear();
+
+    QQmlMetaType::CachedUnitLookupError cacheError = QQmlMetaType::CachedUnitLookupError::NoError;
+    if (const QV4::CompiledData::Unit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(originalUrl, &cacheError)) {
+        QQmlRefPointer<QV4::CompiledData::CompilationUnit> jsUnit;
+        jsUnit.adopt(new QV4::CompiledData::CompilationUnit(cachedUnit));
+        return new QV4::Script(engine, qmlContext, jsUnit);
     }
-    return result->asReturnedValue();
+
+    QFile f(fileName);
+    if (!f.open(QIODevice::ReadOnly)) {
+        if (error) {
+            if (cacheError == QQmlMetaType::CachedUnitLookupError::VersionMismatch)
+                *error = originalUrl.toString() + QString::fromUtf8(" was compiled ahead of time with an incompatible version of Qt and the original source code cannot be found. Please recompile");
+            else
+                *error = QString::fromUtf8("Error opening source file %1: %2").arg(originalUrl.toString()).arg(f.errorString());
+        }
+        return nullptr;
+    }
+
+    QByteArray data = f.readAll();
+    QString sourceCode = QString::fromUtf8(data);
+    QmlIR::Document::removeScriptPragmas(sourceCode);
+
+    auto result = new QV4::Script(engine, qmlContext, /*parseAsBinding*/false, sourceCode, originalUrl.toString());
+    result->contextType = QV4::Compiler::ContextType::ScriptImportedByQML;
+    result->parse();
+    return result;
 }
diff --git a/src/qml/jsruntime/qv4script_p.h b/src/qml/jsruntime/qv4script_p.h
index 4ebe2dd609..a1e9b83a8b 100644
--- a/src/qml/jsruntime/qv4script_p.h
+++ b/src/qml/jsruntime/qv4script_p.h
@@ -54,6 +54,7 @@
 #include "qv4engine_p.h"
 #include "qv4functionobject_p.h"
 #include "qv4qmlcontext_p.h"
+#include "private/qv4compilercontext_p.h"
 
 #include <QQmlError>
 
@@ -62,87 +63,49 @@ QT_BEGIN_NAMESPACE
 class QQmlContextData;
 
 namespace QQmlJS {
-class Directives;
+class Engine;
 }
 
 namespace QV4 {
 
-struct ContextStateSaver {
-    Value *savedContext;
-    bool strictMode;
-    Lookup *lookups;
-    const QV4::Value *constantTable;
-    CompiledData::CompilationUnitBase *compilationUnit;
-    int lineNumber;
-
-    ContextStateSaver(const Scope &scope, ExecutionContext *context)
-        : savedContext(scope.alloc(1))
-        , strictMode(context->d()->strictMode)
-        , lookups(context->d()->lookups)
-        , constantTable(context->d()->constantTable)
-        , compilationUnit(context->d()->compilationUnit)
-        , lineNumber(context->d()->lineNumber)
-    {
-        savedContext->setM(context->d());
-    }
-    ContextStateSaver(const Scope &scope, Heap::ExecutionContext *context)
-        : savedContext(scope.alloc(1))
-        , strictMode(context->strictMode)
-        , lookups(context->lookups)
-        , constantTable(context->constantTable)
-        , compilationUnit(context->compilationUnit)
-        , lineNumber(context->lineNumber)
-    {
-        savedContext->setM(context);
-    }
-
-    ~ContextStateSaver()
-    {
-        Heap::ExecutionContext *ctx = static_cast<Heap::ExecutionContext *>(savedContext->m());
-        ctx->strictMode = strictMode;
-        ctx->lookups = lookups;
-        ctx->constantTable = constantTable;
-        ctx->compilationUnit = compilationUnit;
-        ctx->lineNumber = lineNumber;
-    }
-};
-
 struct Q_QML_EXPORT Script {
-    Script(ExecutionContext *scope, const QString &sourceCode, const QString &source = QString(), int line = 1, int column = 0)
+    Script(ExecutionContext *scope, QV4::Compiler::ContextType mode, const QString &sourceCode, const QString &source = QString(), int line = 1, int column = 0)
         : sourceFile(source), line(line), column(column), sourceCode(sourceCode)
-        , scope(scope), strictMode(false), inheritContext(false), parsed(false)
-        , vmFunction(0), parseAsBinding(false) {}
-    Script(ExecutionEngine *engine, QmlContext *qml, const QString &sourceCode, const QString &source = QString(), int line = 1, int column = 0)
+        , context(scope), strictMode(false), inheritContext(false), parsed(false), contextType(mode)
+        , vmFunction(nullptr), parseAsBinding(false) {}
+    Script(ExecutionEngine *engine, QmlContext *qml, bool parseAsBinding, const QString &sourceCode, const QString &source = QString(), int line = 1, int column = 0)
         : sourceFile(source), line(line), column(column), sourceCode(sourceCode)
-        , scope(engine->rootContext()), strictMode(false), inheritContext(true), parsed(false)
-        , vmFunction(0), parseAsBinding(true) {
+        , context(engine->rootContext()), strictMode(false), inheritContext(true), parsed(false)
+        , vmFunction(nullptr), parseAsBinding(parseAsBinding) {
         if (qml)
             qmlContext.set(engine, *qml);
     }
-    Script(ExecutionEngine *engine, QmlContext *qml, CompiledData::CompilationUnit *compilationUnit);
+    Script(ExecutionEngine *engine, QmlContext *qml, const QQmlRefPointer<CompiledData::CompilationUnit> &compilationUnit);
     ~Script();
     QString sourceFile;
     int line;
     int column;
     QString sourceCode;
-    ExecutionContext *scope;
+    ExecutionContext *context;
     bool strictMode;
     bool inheritContext;
     bool parsed;
+    QV4::Compiler::ContextType contextType = QV4::Compiler::ContextType::Eval;
     QV4::PersistentValue qmlContext;
     QQmlRefPointer<CompiledData::CompilationUnit> compilationUnit;
     Function *vmFunction;
     bool parseAsBinding;
 
     void parse();
-    ReturnedValue run();
+    ReturnedValue run(const QV4::Value *thisObject = nullptr);
 
     Function *function();
 
-    static QQmlRefPointer<CompiledData::CompilationUnit> precompile(IR::Module *module, Compiler::JSUnitGenerator *unitGenerator, ExecutionEngine *engine, const QUrl &url, const QString &source,
-                                                                    QList<QQmlError> *reportedErrors = 0, QQmlJS::Directives *directivesCollector = 0);
-
-    static ReturnedValue evaluate(ExecutionEngine *engine, const QString &script, QmlContext *qmlContext);
+    static QQmlRefPointer<CompiledData::CompilationUnit> precompile(QV4::Compiler::Module *module, QQmlJS::Engine *jsEngine, Compiler::JSUnitGenerator *unitGenerator,
+            const QString &fileName, const QString &finalUrl, const QString &source,
+            QList<QQmlError> *reportedErrors = nullptr,
+            QV4::Compiler::ContextType contextType = QV4::Compiler::ContextType::Global);
+    static Script *createFromFileOrCache(ExecutionEngine *engine, QmlContext *qmlContext, const QString &fileName, const QUrl &originalUrl, QString *error);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4sequenceobject.cpp b/src/qml/jsruntime/qv4sequenceobject.cpp
index 8afc672aa2..1eef12a491 100644
--- a/src/qml/jsruntime/qv4sequenceobject.cpp
+++ b/src/qml/jsruntime/qv4sequenceobject.cpp
@@ -45,6 +45,7 @@
 #include <private/qv4arrayobject_p.h>
 #include <private/qqmlengine_p.h>
 #include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 #include "qv4runtime_p.h"
 #include "qv4objectiterator_p.h"
 #include <private/qqmlvaluetypewrapper_p.h>
@@ -66,10 +67,10 @@ static void generateWarning(QV4::ExecutionEngine *v4, const QString& description
     QQmlError retn;
     retn.setDescription(description);
 
-    QV4::StackFrame frame = v4->currentStackFrame();
+    QV4::CppStackFrame *stackFrame = v4->currentStackFrame;
 
-    retn.setLine(frame.line);
-    retn.setUrl(QUrl(frame.source));
+    retn.setLine(stackFrame->lineNumber());
+    retn.setUrl(QUrl(stackFrame->source()));
     QQmlEnginePrivate::warning(engine, retn);
 }
 
@@ -226,7 +227,7 @@ namespace Heap {
 template <typename Container>
 struct QQmlSequence : Object {
     void init(const Container &container);
-    void init(QObject *object, int propertyIndex);
+    void init(QObject *object, int propertyIndex, bool readOnly);
     void destroy() {
         delete container;
         object.destroy();
@@ -236,7 +237,8 @@ struct QQmlSequence : Object {
     mutable Container *container;
     QQmlQPointer<QObject> object;
     int propertyIndex;
-    bool isReference;
+    bool isReference : 1;
+    bool isReadOnly : 1;
 };
 
 }
@@ -293,6 +295,9 @@ public:
             return false;
         }
 
+        if (d()->isReadOnly)
+            return false;
+
         if (d()->isReference) {
             if (!d()->object)
                 return false;
@@ -337,27 +342,37 @@ public:
         return (index < size_t(d()->container->size())) ? QV4::Attr_Data : QV4::Attr_Invalid;
     }
 
-    void containerAdvanceIterator(ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attrs)
+    struct OwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
     {
-        name->setM(0);
-        *index = UINT_MAX;
+        ~OwnPropertyKeyIterator() override = default;
+        PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override
+        {
+            const QQmlSequence *s = static_cast<const QQmlSequence *>(o);
 
-        if (d()->isReference) {
-            if (!d()->object) {
-                QV4::Object::advanceIterator(this, it, name, index, p, attrs);
-                return;
+            if (s->d()->isReference) {
+                if (!s->d()->object)
+                    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+                s->loadReference();
             }
-            loadReference();
-        }
 
-        if (it->arrayIndex < static_cast<uint>(d()->container->size())) {
-            *index = it->arrayIndex;
-            ++it->arrayIndex;
-            *attrs = QV4::Attr_Data;
-            p->value = convertElementToValue(engine(), d()->container->at(*index));
-            return;
+            if (arrayIndex < static_cast<uint>(s->d()->container->size())) {
+                uint index = arrayIndex;
+                ++arrayIndex;
+                if (attrs)
+                    *attrs = QV4::Attr_Data;
+                if (pd)
+                    pd->value = convertElementToValue(s->engine(), s->d()->container->at(index));
+                return PropertyKey::fromArrayIndex(index);
+            }
+
+            return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
         }
-        QV4::Object::advanceIterator(this, it, name, index, p, attrs);
+    };
+
+    static OwnPropertyKeyIterator *containerOwnPropertyKeys(const Object *m, Value *target)
+    {
+        *target = *m;
+        return new OwnPropertyKeyIterator;
     }
 
     bool containerDeleteIndexedProperty(uint index)
@@ -365,6 +380,8 @@ public:
         /* Qt containers have int (rather than uint) allowable indexes. */
         if (index > INT_MAX)
             return false;
+        if (d()->isReadOnly)
+            return false;
         if (d()->isReference) {
             if (!d()->object)
                 return false;
@@ -416,13 +433,14 @@ public:
         bool operator()(typename Container::value_type lhs, typename Container::value_type rhs)
         {
             QV4::Scope scope(m_v4);
-            ScopedObject compare(scope, m_compareFn);
-            ScopedCallData callData(scope, 2);
-            callData->args[0] = convertElementToValue(m_v4, lhs);
-            callData->args[1] = convertElementToValue(m_v4, rhs);
-            callData->thisObject = m_v4->globalObject;
-            compare->call(scope, callData);
-            return scope.result.toNumber() < 0;
+            ScopedFunctionObject compare(scope, m_compareFn);
+            if (!compare)
+                return m_v4->throwTypeError();
+            Value *argv = scope.alloc(2);
+            argv[0] = convertElementToValue(m_v4, lhs);
+            argv[1] = convertElementToValue(m_v4, rhs);
+            QV4::ScopedValue result(scope, compare->call(m_v4->globalObject, argv, 2));
+            return result->toNumber() < 0;
         }
 
     private:
@@ -430,16 +448,18 @@ public:
         const QV4::Value *m_compareFn;
     };
 
-    void sort(const BuiltinFunction *, Scope &scope, CallData *callData)
+    bool sort(const FunctionObject *f, const Value *, const Value *argv, int argc)
     {
+        if (d()->isReadOnly)
+            return false;
         if (d()->isReference) {
             if (!d()->object)
-                return;
+                return false;
             loadReference();
         }
 
-        if (callData->argc == 1 && callData->args[0].as<FunctionObject>()) {
-            CompareFunctor cf(scope.engine, callData->args[0]);
+        if (argc == 1 && argv[0].as<FunctionObject>()) {
+            CompareFunctor cf(f->engine(), argv[0]);
             std::sort(d()->container->begin(), d()->container->end(), cf);
         } else {
             DefaultCompareFunctor cf;
@@ -448,11 +468,14 @@ public:
 
         if (d()->isReference)
             storeReference();
+
+        return true;
     }
 
-    static void method_get_length(const BuiltinFunction *, Scope &scope, CallData *callData)
+    static QV4::ReturnedValue method_get_length(const FunctionObject *b, const Value *thisObject, const Value *, int)
     {
-        QV4::Scoped<QQmlSequence<Container> > This(scope, callData->thisObject.as<QQmlSequence<Container> >());
+        QV4::Scope scope(b);
+        QV4::Scoped<QQmlSequence<Container>> This(scope, thisObject->as<QQmlSequence<Container> >());
         if (!This)
             THROW_TYPE_ERROR();
 
@@ -464,18 +487,23 @@ public:
         RETURN_RESULT(Encode(qint32(This->d()->container->size())));
     }
 
-    static void method_set_length(const BuiltinFunction *, Scope &scope, CallData *callData)
+    static QV4::ReturnedValue method_set_length(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
     {
-        QV4::Scoped<QQmlSequence<Container> > This(scope, callData->thisObject.as<QQmlSequence<Container> >());
+        QV4::Scope scope(f);
+        QV4::Scoped<QQmlSequence<Container>> This(scope, thisObject->as<QQmlSequence<Container> >());
         if (!This)
             THROW_TYPE_ERROR();
 
-        quint32 newLength = callData->args[0].toUInt32();
+        quint32 newLength = argc ? argv[0].toUInt32() : 0;
         /* Qt containers have int (rather than uint) allowable indexes. */
         if (newLength > INT_MAX) {
             generateWarning(scope.engine, QLatin1String("Index out of range during length set"));
             RETURN_UNDEFINED();
         }
+
+        if (This->d()->isReadOnly)
+            THROW_TYPE_ERROR();
+
         /* Read the sequence from the QObject property if we're a reference */
         if (This->d()->isReference) {
             if (!This->d()->object)
@@ -520,7 +548,7 @@ public:
         quint32 length = array->getLength();
         QV4::ScopedValue v(scope);
         for (quint32 i = 0; i < length; ++i)
-            result.push_back(convertValueToElement<typename Container::value_type>((v = array->getIndexed(i))));
+            result.push_back(convertValueToElement<typename Container::value_type>((v = array->get(i))));
         return QVariant::fromValue(result);
     }
 
@@ -531,7 +559,7 @@ public:
     {
         Q_ASSERT(d()->object);
         Q_ASSERT(d()->isReference);
-        void *a[] = { d()->container, 0 };
+        void *a[] = { d()->container, nullptr };
         QMetaObject::metacall(d()->object, QMetaObject::ReadProperty, d()->propertyIndex, a);
     }
 
@@ -541,22 +569,36 @@ public:
         Q_ASSERT(d()->isReference);
         int status = -1;
         QQmlPropertyData::WriteFlags flags = QQmlPropertyData::DontRemoveBinding;
-        void *a[] = { d()->container, 0, &status, &flags };
+        void *a[] = { d()->container, nullptr, &status, &flags };
         QMetaObject::metacall(d()->object, QMetaObject::WriteProperty, d()->propertyIndex, a);
     }
 
-    static QV4::ReturnedValue getIndexed(const QV4::Managed *that, uint index, bool *hasProperty)
-    { return static_cast<const QQmlSequence<Container> *>(that)->containerGetIndexed(index, hasProperty); }
-    static bool putIndexed(Managed *that, uint index, const QV4::Value &value)
-    { return static_cast<QQmlSequence<Container> *>(that)->containerPutIndexed(index, value); }
+    static QV4::ReturnedValue virtualGet(const QV4::Managed *that, PropertyKey id, const Value *receiver, bool *hasProperty)
+    {
+        if (!id.isArrayIndex())
+            return Object::virtualGet(that, id, receiver, hasProperty);
+        return static_cast<const QQmlSequence<Container> *>(that)->containerGetIndexed(id.asArrayIndex(), hasProperty);
+    }
+    static bool virtualPut(Managed *that, PropertyKey id, const QV4::Value &value, Value *receiver)
+    {
+        if (id.isArrayIndex())
+            return static_cast<QQmlSequence<Container> *>(that)->containerPutIndexed(id.asArrayIndex(), value);
+        return Object::virtualPut(that, id, value, receiver);
+    }
     static QV4::PropertyAttributes queryIndexed(const QV4::Managed *that, uint index)
     { return static_cast<const QQmlSequence<Container> *>(that)->containerQueryIndexed(index); }
-    static bool deleteIndexedProperty(QV4::Managed *that, uint index)
-    { return static_cast<QQmlSequence<Container> *>(that)->containerDeleteIndexedProperty(index); }
-    static bool isEqualTo(Managed *that, Managed *other)
+    static bool virtualDeleteProperty(QV4::Managed *that, PropertyKey id)
+    {
+        if (id.isArrayIndex()) {
+            uint index = id.asArrayIndex();
+            return static_cast<QQmlSequence<Container> *>(that)->containerDeleteIndexedProperty(index);
+        }
+        return Object::virtualDeleteProperty(that, id);
+    }
+    static bool virtualIsEqualTo(Managed *that, Managed *other)
     { return static_cast<QQmlSequence<Container> *>(that)->containerIsEqualTo(other); }
-    static void advanceIterator(Managed *that, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attrs)
-    { return static_cast<QQmlSequence<Container> *>(that)->containerAdvanceIterator(it, name, index, p, attrs); }
+    static QV4::OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target)
+    { return static_cast<const QQmlSequence<Container> *>(m)->containerOwnPropertyKeys(m, target);}
 
 };
 
@@ -568,6 +610,7 @@ void Heap::QQmlSequence<Container>::init(const Container &container)
     this->container = new Container(container);
     propertyIndex = -1;
     isReference = false;
+    isReadOnly = false;
     object.init();
 
     QV4::Scope scope(internalClass->engine);
@@ -577,12 +620,13 @@ void Heap::QQmlSequence<Container>::init(const Container &container)
 }
 
 template <typename Container>
-void Heap::QQmlSequence<Container>::init(QObject *object, int propertyIndex)
+void Heap::QQmlSequence<Container>::init(QObject *object, int propertyIndex, bool readOnly)
 {
     Object::init();
     this->container = new Container;
     this->propertyIndex = propertyIndex;
     isReference = true;
+    this->isReadOnly = readOnly;
     this->object.init(object);
     QV4::Scope scope(internalClass->engine);
     QV4::Scoped<QV4::QQmlSequence<Container> > o(scope, this);
@@ -647,25 +691,32 @@ void SequencePrototype::init()
 }
 #undef REGISTER_QML_SEQUENCE_METATYPE
 
-void SequencePrototype::method_sort(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue SequencePrototype::method_valueOf(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    return Encode(thisObject->toString(f->engine()));
+}
+
+ReturnedValue SequencePrototype::method_sort(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QV4::ScopedObject o(scope, callData->thisObject);
+    Scope scope(b);
+    QV4::ScopedObject o(scope, thisObject);
     if (!o || !o->isListType())
         THROW_TYPE_ERROR();
 
-    if (callData->argc >= 2)
-        RETURN_RESULT(o);
+    if (argc >= 2)
+        return o.asReturnedValue();
 
 #define CALL_SORT(SequenceElementType, SequenceElementTypeName, SequenceType, DefaultValue) \
         if (QQml##SequenceElementTypeName##List *s = o->as<QQml##SequenceElementTypeName##List>()) { \
-            s->sort(b, scope, callData); \
+            if (!s->sort(b, thisObject, argv, argc)) \
+                THROW_TYPE_ERROR(); \
         } else
 
         FOREACH_QML_SEQUENCE_TYPE(CALL_SORT)
 
 #undef CALL_SORT
         {}
-    RETURN_RESULT(o);
+    return o.asReturnedValue();
 }
 
 #define IS_SEQUENCE(unused1, unused2, SequenceType, unused3) \
@@ -681,11 +732,11 @@ bool SequencePrototype::isSequenceType(int sequenceTypeId)
 
 #define NEW_REFERENCE_SEQUENCE(ElementType, ElementTypeName, SequenceType, unused) \
     if (sequenceType == qMetaTypeId<SequenceType>()) { \
-        QV4::ScopedObject obj(scope, engine->memoryManager->allocObject<QQml##ElementTypeName##List>(object, propertyIndex)); \
+        QV4::ScopedObject obj(scope, engine->memoryManager->allocate<QQml##ElementTypeName##List>(object, propertyIndex, readOnly)); \
         return obj.asReturnedValue(); \
     } else
 
-ReturnedValue SequencePrototype::newSequence(QV4::ExecutionEngine *engine, int sequenceType, QObject *object, int propertyIndex, bool *succeeded)
+ReturnedValue SequencePrototype::newSequence(QV4::ExecutionEngine *engine, int sequenceType, QObject *object, int propertyIndex, bool readOnly, bool *succeeded)
 {
     QV4::Scope scope(engine);
     // This function is called when the property is a QObject Q_PROPERTY of
@@ -699,7 +750,7 @@ ReturnedValue SequencePrototype::newSequence(QV4::ExecutionEngine *engine, int s
 
 #define NEW_COPY_SEQUENCE(ElementType, ElementTypeName, SequenceType, unused) \
     if (sequenceType == qMetaTypeId<SequenceType>()) { \
-        QV4::ScopedObject obj(scope, engine->memoryManager->allocObject<QQml##ElementTypeName##List>(v.value<SequenceType >())); \
+        QV4::ScopedObject obj(scope, engine->memoryManager->allocate<QQml##ElementTypeName##List>(v.value<SequenceType >())); \
         return obj.asReturnedValue(); \
     } else
 
diff --git a/src/qml/jsruntime/qv4sequenceobject_p.h b/src/qml/jsruntime/qv4sequenceobject_p.h
index 2b8d1ea716..da71215bed 100644
--- a/src/qml/jsruntime/qv4sequenceobject_p.h
+++ b/src/qml/jsruntime/qv4sequenceobject_p.h
@@ -59,6 +59,8 @@
 #include "qv4context_p.h"
 #include "qv4string_p.h"
 
+QT_REQUIRE_CONFIG(qml_sequence_object);
+
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
@@ -68,15 +70,11 @@ struct SequencePrototype : public QV4::Object
     V4_PROTOTYPE(arrayPrototype)
     void init();
 
-    static void method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData)
-    {
-        scope.result = callData->thisObject.toString(scope.engine);
-    }
-
-    static void method_sort(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_sort(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
     static bool isSequenceType(int sequenceTypeId);
-    static ReturnedValue newSequence(QV4::ExecutionEngine *engine, int sequenceTypeId, QObject *object, int propertyIndex, bool *succeeded);
+    static ReturnedValue newSequence(QV4::ExecutionEngine *engine, int sequenceTypeId, QObject *object, int propertyIndex, bool readOnly, bool *succeeded);
     static ReturnedValue fromVariant(QV4::ExecutionEngine *engine, const QVariant& v, bool *succeeded);
     static int metaTypeForSequence(const Object *object);
     static QVariant toVariant(Object *object);
diff --git a/src/qml/jsruntime/qv4serialize.cpp b/src/qml/jsruntime/qv4serialize.cpp
index 14def49d0a..50871a4d87 100644
--- a/src/qml/jsruntime/qv4serialize.cpp
+++ b/src/qml/jsruntime/qv4serialize.cpp
@@ -40,13 +40,17 @@
 #include "qv4serialize_p.h"
 
 #include <private/qv8engine_p.h>
+#if QT_CONFIG(qml_list_model)
 #include <private/qqmllistmodel_p.h>
 #include <private/qqmllistmodelworkeragent_p.h>
+#endif
 
 #include <private/qv4value_p.h>
 #include <private/qv4dateobject_p.h>
 #include <private/qv4regexpobject_p.h>
+#if QT_CONFIG(qml_sequence_object)
 #include <private/qv4sequenceobject_p.h>
+#endif
 #include <private/qv4objectproto_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 
@@ -82,8 +86,12 @@ enum Type {
     WorkerNumber,
     WorkerDate,
     WorkerRegexp,
+#if QT_CONFIG(qml_list_model)
     WorkerListModel,
+#endif
+#if QT_CONFIG(qml_sequence_object)
     WorkerSequence
+#endif
 };
 
 static inline quint32 valueheader(Type type, quint32 size = 0)
@@ -189,7 +197,7 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, ExecutionEngine
         push(data, valueheader(WorkerArray, length));
         ScopedValue val(scope);
         for (uint ii = 0; ii < length; ++ii)
-            serialize(data, (val = array->getIndexed(ii)), engine);
+            serialize(data, (val = array->get(ii)), engine);
     } else if (v.isInteger()) {
         reserve(data, 2 * sizeof(quint32));
         push(data, valueheader(WorkerInt32));
@@ -228,6 +236,7 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, ExecutionEngine
     } else if (const QObjectWrapper *qobjectWrapper = v.as<QV4::QObjectWrapper>()) {
         // XXX TODO: Generalize passing objects between the main thread and worker scripts so
         // that others can trivially plug in their elements.
+#if QT_CONFIG(qml_list_model)
         QQmlListModel *lm = qobject_cast<QQmlListModel *>(qobjectWrapper->object());
         if (lm && lm->agent()) {
             QQmlListModelWorkerAgent *agent = lm->agent();
@@ -236,9 +245,13 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, ExecutionEngine
             push(data, (void *)agent);
             return;
         }
+#else
+        Q_UNUSED(qobjectWrapper);
+#endif
         // No other QObject's are allowed to be sent
         push(data, valueheader(WorkerUndefined));
     } else if (const Object *o = v.as<Object>()) {
+#if QT_CONFIG(qml_sequence_object)
         if (o->isListType()) {
             // valid sequence.  we generate a length (sequence length + 1 for the sequence type)
             uint seqLength = ScopedValue(scope, o->get(engine->id_length()))->toUInt32();
@@ -249,13 +262,14 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, ExecutionEngine
             }
             reserve(data, sizeof(quint32) + length * sizeof(quint32));
             push(data, valueheader(WorkerSequence, length));
-            serialize(data, QV4::Primitive::fromInt32(QV4::SequencePrototype::metaTypeForSequence(o)), engine); // sequence type
+            serialize(data, QV4::Value::fromInt32(QV4::SequencePrototype::metaTypeForSequence(o)), engine); // sequence type
             ScopedValue val(scope);
             for (uint ii = 0; ii < seqLength; ++ii)
-                serialize(data, (val = o->getIndexed(ii)), engine); // sequence elements
+                serialize(data, (val = o->get(ii)), engine); // sequence elements
 
             return;
         }
+#endif
 
         // regular object
         QV4::ScopedValue val(scope, v);
@@ -269,7 +283,7 @@ void Serialize::serialize(QByteArray &data, const QV4::Value &v, ExecutionEngine
 
         QV4::ScopedValue s(scope);
         for (quint32 ii = 0; ii < length; ++ii) {
-            s = properties->getIndexed(ii);
+            s = properties->get(ii);
             serialize(data, s, engine);
 
             QV4::String *str = s->as<String>();
@@ -318,7 +332,7 @@ ReturnedValue Serialize::deserialize(const char *&data, ExecutionEngine *engine)
         ScopedValue v(scope);
         for (quint32 ii = 0; ii < size; ++ii) {
             v = deserialize(data, engine);
-            a->putIndexed(ii, v);
+            a->put(ii, v);
         }
         return a.asReturnedValue();
     }
@@ -344,7 +358,7 @@ ReturnedValue Serialize::deserialize(const char *&data, ExecutionEngine *engine)
     case WorkerNumber:
         return QV4::Encode(popDouble(data));
     case WorkerDate:
-        return QV4::Encode(engine->newDateObject(QV4::Primitive::fromDouble(popDouble(data))));
+        return QV4::Encode(engine->newDateObject(QV4::Value::fromDouble(popDouble(data))));
     case WorkerRegexp:
     {
         quint32 flags = headersize(header);
@@ -353,6 +367,7 @@ ReturnedValue Serialize::deserialize(const char *&data, ExecutionEngine *engine)
         data += ALIGN(length * sizeof(quint16));
         return Encode(engine->newRegExpObject(pattern, flags));
     }
+#if QT_CONFIG(qml_list_model)
     case WorkerListModel:
     {
         void *ptr = popPtr(data);
@@ -369,6 +384,8 @@ ReturnedValue Serialize::deserialize(const char *&data, ExecutionEngine *engine)
         agent->setEngine(engine);
         return rv->asReturnedValue();
     }
+#endif
+#if QT_CONFIG(qml_sequence_object)
     case WorkerSequence:
     {
         ScopedValue value(scope);
@@ -387,6 +404,7 @@ ReturnedValue Serialize::deserialize(const char *&data, ExecutionEngine *engine)
         QVariant seqVariant = QV4::SequencePrototype::toVariant(array, sequenceType, &succeeded);
         return QV4::SequencePrototype::fromVariant(engine, seqVariant, &succeeded);
     }
+#endif
     }
     Q_ASSERT(!"Unreachable");
     return QV4::Encode::undefined();
diff --git a/src/qml/jsruntime/qv4setiterator.cpp b/src/qml/jsruntime/qv4setiterator.cpp
new file mode 100644
index 0000000000..d32e2079a0
--- /dev/null
+++ b/src/qml/jsruntime/qv4setiterator.cpp
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4iterator_p.h>
+#include <private/qv4estable_p.h>
+#include <private/qv4setiterator_p.h>
+#include <private/qv4setobject_p.h>
+#include <private/qv4symbol_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(SetIteratorObject);
+
+void SetIteratorPrototype::init(ExecutionEngine *e)
+{
+    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
+
+    Scope scope(e);
+    ScopedString val(scope, e->newString(QLatin1String("Set Iterator")));
+    defineReadonlyConfigurableProperty(e->symbol_toStringTag(), val);
+}
+
+ReturnedValue SetIteratorPrototype::method_next(const FunctionObject *b, const Value *that, const Value *, int)
+{
+    Scope scope(b);
+    const SetIteratorObject *thisObject = that->as<SetIteratorObject>();
+    if (!thisObject)
+        return scope.engine->throwTypeError(QLatin1String("Not a Set Iterator instance"));
+
+    Scoped<SetObject> s(scope, thisObject->d()->iteratedSet);
+    uint index = thisObject->d()->setNextIndex;
+    IteratorKind itemKind = thisObject->d()->iterationKind;
+
+    if (!s) {
+        QV4::Value undefined = Value::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+    }
+
+    Value *arguments = scope.alloc(2);
+
+    while (index < s->d()->esTable->size()) {
+        s->d()->esTable->iterate(index, &arguments[0], &arguments[1]);
+        thisObject->d()->setNextIndex = index + 1;
+
+        if (itemKind == KeyValueIteratorKind) {
+            ScopedArrayObject resultArray(scope, scope.engine->newArrayObject());
+            resultArray->arrayReserve(2);
+            resultArray->arrayPut(0, arguments[0]);
+            resultArray->arrayPut(1, arguments[0]); // yes, the key is repeated.
+            resultArray->setArrayLengthUnchecked(2);
+
+            return IteratorPrototype::createIterResultObject(scope.engine, resultArray, false);
+        }
+
+        return IteratorPrototype::createIterResultObject(scope.engine, arguments[0], false);
+    }
+
+    thisObject->d()->iteratedSet.set(scope.engine, nullptr);
+    QV4::Value undefined = Value::undefinedValue();
+    return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+}
+
diff --git a/src/qml/jsruntime/qv4setiterator_p.h b/src/qml/jsruntime/qv4setiterator_p.h
new file mode 100644
index 0000000000..78eda6d57b
--- /dev/null
+++ b/src/qml/jsruntime/qv4setiterator_p.h
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4SETITERATOR_P_H
+#define QV4SETITERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4iterator_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+namespace Heap {
+
+#define SetIteratorObjectMembers(class, Member) \
+    Member(class, Pointer, Object *, iteratedSet) \
+    Member(class, NoMark, IteratorKind, iterationKind) \
+    Member(class, NoMark, quint32, setNextIndex)
+
+DECLARE_HEAP_OBJECT(SetIteratorObject, Object) {
+    DECLARE_MARKOBJECTS(SetIteratorObject);
+    void init(Object *obj, QV4::ExecutionEngine *engine)
+    {
+        Object::init();
+        this->iteratedSet.set(engine, obj);
+        this->setNextIndex = 0;
+    }
+};
+
+}
+
+struct SetIteratorPrototype : Object
+{
+    V4_PROTOTYPE(iteratorPrototype)
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_next(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct SetIteratorObject : Object
+{
+    V4_OBJECT2(SetIteratorObject, Object)
+    Q_MANAGED_TYPE(SetIteratorObject)
+    V4_PROTOTYPE(setIteratorPrototype)
+
+    void init(ExecutionEngine *engine);
+};
+
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4SETITERATOR_P_H
+
diff --git a/src/qml/jsruntime/qv4setobject.cpp b/src/qml/jsruntime/qv4setobject.cpp
new file mode 100644
index 0000000000..1664d1bd71
--- /dev/null
+++ b/src/qml/jsruntime/qv4setobject.cpp
@@ -0,0 +1,326 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include "qv4setobject_p.h"
+#include "qv4setiterator_p.h"
+#include "qv4estable_p.h"
+#include "qv4symbol_p.h"
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(SetCtor);
+DEFINE_OBJECT_VTABLE(WeakSetCtor);
+DEFINE_OBJECT_VTABLE(SetObject);
+
+void Heap::WeakSetCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("WeakSet"));
+}
+
+void Heap::SetCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("Set"));
+}
+
+ReturnedValue WeakSetCtor::construct(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget, bool isWeak)
+{
+    Scope scope(f);
+    Scoped<SetObject> a(scope, scope.engine->memoryManager->allocate<SetObject>());
+    bool protoSet = false;
+    if (newTarget)
+        protoSet = a->setProtoFromNewTarget(newTarget);
+    if (!protoSet && isWeak)
+        a->setPrototypeOf(scope.engine->weakSetPrototype());
+    a->d()->isWeakSet = isWeak;
+
+    if (argc > 0) {
+        ScopedValue iterable(scope, argv[0]);
+        if (!iterable->isUndefined() && !iterable->isNull()) {
+            ScopedFunctionObject adder(scope, a->get(ScopedString(scope, scope.engine->newString(QString::fromLatin1("add")))));
+            if (!adder)
+                return scope.engine->throwTypeError();
+            ScopedObject iter(scope, Runtime::GetIterator::call(scope.engine, iterable, true));
+            CHECK_EXCEPTION();
+            if (!iter)
+                return a.asReturnedValue();
+
+            Value *nextValue = scope.alloc(1);
+            ScopedValue done(scope);
+            forever {
+                done = Runtime::IteratorNext::call(scope.engine, iter, nextValue);
+                CHECK_EXCEPTION();
+                if (done->toBoolean())
+                    return a.asReturnedValue();
+
+                adder->call(a, nextValue, 1);
+                if (scope.engine->hasException) {
+                    ScopedValue falsey(scope, Encode(false));
+                    return Runtime::IteratorClose::call(scope.engine, iter, falsey);
+                }
+            }
+        }
+    }
+
+    return a.asReturnedValue();
+}
+
+ReturnedValue WeakSetCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    return construct(f, argv, argc, newTarget, true);
+}
+
+ReturnedValue WeakSetCtor::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
+{
+    Scope scope(f);
+    return scope.engine->throwTypeError(QString::fromLatin1("Set requires new"));
+}
+
+ReturnedValue SetCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
+{
+    return construct(f, argv, argc, newTarget, false);
+}
+
+void WeakSetPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedObject o(scope);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
+    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
+    defineDefaultProperty(engine->id_constructor(), (o = ctor));
+
+    defineDefaultProperty(QStringLiteral("add"), method_add, 1);
+    defineDefaultProperty(QStringLiteral("delete"), method_delete, 1);
+    defineDefaultProperty(QStringLiteral("has"), method_has, 1);
+
+    ScopedString val(scope, engine->newString(QLatin1String("WeakSet")));
+    defineReadonlyConfigurableProperty(engine->symbol_toStringTag(), val);
+}
+
+ReturnedValue WeakSetPrototype::method_add(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if ((!that || !that->d()->isWeakSet) ||
+        (!argc || !argv[0].isObject()))
+        return scope.engine->throwTypeError();
+
+    that->d()->esTable->set(argv[0], Value::undefinedValue());
+    return that.asReturnedValue();
+}
+
+ReturnedValue WeakSetPrototype::method_delete(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || !that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+    if (!argc || !argv[0].isObject())
+        return Encode(false);
+
+    return Encode(that->d()->esTable->remove(argv[0]));
+}
+
+ReturnedValue WeakSetPrototype::method_has(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || !that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+    if (!argc || !argv[0].isObject())
+        return Encode(false);
+
+    return Encode(that->d()->esTable->has(argv[0]));
+}
+
+void SetPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedObject o(scope);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
+    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
+    ctor->addSymbolSpecies();
+    defineDefaultProperty(engine->id_constructor(), (o = ctor));
+
+    defineDefaultProperty(QStringLiteral("add"), method_add, 1);
+    defineDefaultProperty(QStringLiteral("clear"), method_clear, 0);
+    defineDefaultProperty(QStringLiteral("delete"), method_delete, 1);
+    defineDefaultProperty(QStringLiteral("entries"), method_entries, 0);
+    defineDefaultProperty(QStringLiteral("forEach"), method_forEach, 1);
+    defineDefaultProperty(QStringLiteral("has"), method_has, 1);
+    defineAccessorProperty(QStringLiteral("size"), method_get_size, nullptr);
+
+    // Per the spec, the value for 'keys' is the same as 'values'.
+    ScopedString valString(scope, scope.engine->newIdentifier(QStringLiteral("values")));
+    ScopedFunctionObject valuesFn(scope, FunctionObject::createBuiltinFunction(engine, valString, SetPrototype::method_values, 0));
+    defineDefaultProperty(QStringLiteral("keys"), valuesFn);
+    defineDefaultProperty(QStringLiteral("values"), valuesFn);
+
+    defineDefaultProperty(engine->symbol_iterator(), valuesFn);
+
+    ScopedString val(scope, engine->newString(QLatin1String("Set")));
+    defineReadonlyConfigurableProperty(engine->symbol_toStringTag(), val);
+}
+
+void Heap::SetObject::init()
+{
+    Object::init();
+    esTable = new ESTable();
+}
+
+void Heap::SetObject::destroy()
+{
+    delete esTable;
+    esTable = 0;
+}
+
+void Heap::SetObject::removeUnmarkedKeys()
+{
+    esTable->removeUnmarkedKeys();
+}
+
+void Heap::SetObject::markObjects(Heap::Base *that, MarkStack *markStack)
+{
+    SetObject *s = static_cast<SetObject *>(that);
+    s->esTable->markObjects(markStack, s->isWeakSet);
+    Object::markObjects(that, markStack);
+}
+
+ReturnedValue SetPrototype::method_add(const FunctionObject *b, const Value *thisObject, const Value *argv, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    that->d()->esTable->set(argv[0], Value::undefinedValue());
+    return that.asReturnedValue();
+}
+
+ReturnedValue SetPrototype::method_clear(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    that->d()->esTable->clear();
+    return Encode::undefined();
+}
+
+ReturnedValue SetPrototype::method_delete(const FunctionObject *b, const Value *thisObject, const Value *argv, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    return Encode(that->d()->esTable->remove(argv[0]));
+}
+
+ReturnedValue SetPrototype::method_entries(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    Scoped<SetIteratorObject> ao(scope, scope.engine->newSetIteratorObject(that));
+    ao->d()->iterationKind = IteratorKind::KeyValueIteratorKind;
+    return ao->asReturnedValue();
+}
+
+ReturnedValue SetPrototype::method_forEach(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    ScopedFunctionObject callbackfn(scope, argv[0]);
+    if (!callbackfn)
+        return scope.engine->throwTypeError();
+
+    ScopedValue thisArg(scope, Value::undefinedValue());
+    if (argc > 1)
+        thisArg = ScopedValue(scope, argv[1]);
+
+    Value *arguments = scope.alloc(3);
+    for (uint i = 0; i < that->d()->esTable->size(); ++i) {
+        that->d()->esTable->iterate(i, &arguments[0], &arguments[1]); // fill in key (0), value (1)
+        arguments[1] = arguments[0]; // but for set, we want to return the key twice; value is always undefined.
+
+        arguments[2] = that;
+        callbackfn->call(thisArg, arguments, 3);
+        CHECK_EXCEPTION();
+    }
+    return Encode::undefined();
+}
+
+ReturnedValue SetPrototype::method_has(const FunctionObject *b, const Value *thisObject, const Value *argv, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    return Encode(that->d()->esTable->has(argv[0]));
+}
+
+ReturnedValue SetPrototype::method_get_size(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    return Encode(that->d()->esTable->size());
+}
+
+ReturnedValue SetPrototype::method_values(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<SetObject> that(scope, thisObject);
+    if (!that || that->d()->isWeakSet)
+        return scope.engine->throwTypeError();
+
+    Scoped<SetIteratorObject> ao(scope, scope.engine->newSetIteratorObject(that));
+    ao->d()->iterationKind = IteratorKind::ValueIteratorKind;
+    return ao->asReturnedValue();
+}
diff --git a/src/qml/jsruntime/qv4setobject_p.h b/src/qml/jsruntime/qv4setobject_p.h
new file mode 100644
index 0000000000..21584e2132
--- /dev/null
+++ b/src/qml/jsruntime/qv4setobject_p.h
@@ -0,0 +1,144 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Crimson AS <info@crimson.no>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4SETOBJECT_P_H
+#define QV4SETOBJECT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4objectproto_p.h"
+#include "qv4functionobject_p.h"
+#include "qv4string_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+class ESTable;
+
+namespace Heap {
+
+struct WeakSetCtor : FunctionObject {
+    void init(QV4::ExecutionContext *scope);
+};
+
+
+struct SetCtor : WeakSetCtor {
+    void init(QV4::ExecutionContext *scope);
+};
+
+struct SetObject : Object {
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
+    void init();
+    void destroy();
+    void removeUnmarkedKeys();
+
+    ESTable *esTable;
+    SetObject *nextWeakSet;
+    bool isWeakSet;
+};
+
+}
+
+
+struct WeakSetCtor: FunctionObject
+{
+    V4_OBJECT2(WeakSetCtor, FunctionObject)
+
+    static ReturnedValue construct(const FunctionObject *f, const Value *argv, int argc, const Value *, bool weakSet);
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct SetCtor : WeakSetCtor
+{
+    V4_OBJECT2(SetCtor, WeakSetCtor)
+
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+};
+
+struct SetObject : Object
+{
+    V4_OBJECT2(SetObject, Object)
+    V4_PROTOTYPE(setPrototype)
+    V4_NEEDS_DESTROY
+};
+
+struct WeakSetPrototype : Object
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_add(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_delete(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_has(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+
+struct SetPrototype : WeakSetPrototype
+{
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_add(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_clear(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_delete(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_entries(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_forEach(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_has(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_size(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_values(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+
+} // namespace QV4
+
+
+QT_END_NAMESPACE
+
+#endif // QV4SETOBJECT_P_H
diff --git a/src/qml/jsruntime/qv4sparsearray.cpp b/src/qml/jsruntime/qv4sparsearray.cpp
index 8f6aa6723c..8930c9a94d 100644
--- a/src/qml/jsruntime/qv4sparsearray.cpp
+++ b/src/qml/jsruntime/qv4sparsearray.cpp
@@ -89,20 +89,20 @@ const SparseArrayNode *SparseArrayNode::previousNode() const
 
 SparseArrayNode *SparseArrayNode::copy(SparseArray *d) const
 {
-    SparseArrayNode *n = d->createNode(size_left, 0, false);
+    SparseArrayNode *n = d->createNode(size_left, nullptr, false);
     n->value = value;
     n->setColor(color());
     if (left) {
         n->left = left->copy(d);
         n->left->setParent(n);
     } else {
-        n->left = 0;
+        n->left = nullptr;
     }
     if (right) {
         n->right = right->copy(d);
         n->right->setParent(n);
     } else {
-        n->right = 0;
+        n->right = nullptr;
     }
     return n;
 }
@@ -119,7 +119,7 @@ void SparseArray::rotateLeft(SparseArrayNode *x)
     SparseArrayNode *&root = header.left;
     SparseArrayNode *y = x->right;
     x->right = y->left;
-    if (y->left != 0)
+    if (y->left != nullptr)
         y->left->setParent(x);
     y->setParent(x->parent());
     if (x == root)
@@ -146,7 +146,7 @@ void SparseArray::rotateRight(SparseArrayNode *x)
     SparseArrayNode *&root = header.left;
     SparseArrayNode *y = x->left;
     x->left = y->right;
-    if (y->right != 0)
+    if (y->right != nullptr)
         y->right->setParent(x);
     y->setParent(x->parent());
     if (x == root)
@@ -209,7 +209,7 @@ void SparseArray::deleteNode(SparseArrayNode *z)
     SparseArrayNode *y = z;
     SparseArrayNode *x;
     SparseArrayNode *x_parent;
-    if (y->left == 0) {
+    if (y->left == nullptr) {
         x = y->right;
         if (y == mostLeftNode) {
             if (x)
@@ -217,11 +217,11 @@ void SparseArray::deleteNode(SparseArrayNode *z)
             else
                 mostLeftNode = y->parent();
         }
-    } else if (y->right == 0) {
+    } else if (y->right == nullptr) {
             x = y->left;
     } else {
         y = y->right;
-        while (y->left != 0)
+        while (y->left != nullptr)
             y = y->left;
         x = y->right;
     }
@@ -261,7 +261,7 @@ void SparseArray::deleteNode(SparseArrayNode *z)
         y->size_left = 0;
     }
     if (y->color() != SparseArrayNode::Red) {
-        while (x != root && (x == 0 || x->color() == SparseArrayNode::Black)) {
+        while (x != root && (x == nullptr || x->color() == SparseArrayNode::Black)) {
             if (x == x_parent->left) {
                 SparseArrayNode *w = x_parent->right;
                 if (w->color() == SparseArrayNode::Red) {
@@ -270,13 +270,13 @@ void SparseArray::deleteNode(SparseArrayNode *z)
                     rotateLeft(x_parent);
                     w = x_parent->right;
                 }
-                if ((w->left == 0 || w->left->color() == SparseArrayNode::Black) &&
-                    (w->right == 0 || w->right->color() == SparseArrayNode::Black)) {
+                if ((w->left == nullptr || w->left->color() == SparseArrayNode::Black) &&
+                    (w->right == nullptr || w->right->color() == SparseArrayNode::Black)) {
                     w->setColor(SparseArrayNode::Red);
                     x = x_parent;
                     x_parent = x_parent->parent();
                 } else {
-                    if (w->right == 0 || w->right->color() == SparseArrayNode::Black) {
+                    if (w->right == nullptr || w->right->color() == SparseArrayNode::Black) {
                         if (w->left)
                             w->left->setColor(SparseArrayNode::Black);
                         w->setColor(SparseArrayNode::Red);
@@ -298,13 +298,13 @@ void SparseArray::deleteNode(SparseArrayNode *z)
                 rotateRight(x_parent);
                 w = x_parent->left;
             }
-            if ((w->right == 0 || w->right->color() == SparseArrayNode::Black) &&
-                (w->left == 0 || w->left->color() == SparseArrayNode::Black)) {
+            if ((w->right == nullptr || w->right->color() == SparseArrayNode::Black) &&
+                (w->left == nullptr || w->left->color() == SparseArrayNode::Black)) {
                 w->setColor(SparseArrayNode::Red);
                 x = x_parent;
                 x_parent = x_parent->parent();
             } else {
-                if (w->left == 0 || w->left->color() == SparseArrayNode::Black) {
+                if (w->left == nullptr || w->left->color() == SparseArrayNode::Black) {
                     if (w->right)
                         w->right->setColor(SparseArrayNode::Black);
                     w->setColor(SparseArrayNode::Red);
@@ -363,8 +363,8 @@ SparseArrayNode *SparseArray::createNode(uint sl, SparseArrayNode *parent, bool
     Q_CHECK_PTR(node);
 
     node->p = (quintptr)parent;
-    node->left = 0;
-    node->right = 0;
+    node->left = nullptr;
+    node->right = nullptr;
     node->size_left = sl;
     node->value = UINT_MAX;
     ++numEntries;
@@ -395,21 +395,23 @@ void SparseArray::freeTree(SparseArrayNode *root, int alignment)
 SparseArray::SparseArray()
     : numEntries(0)
 {
+    freeList = Encode(-1);
     header.p = 0;
-    header.left = 0;
-    header.right = 0;
+    header.left = nullptr;
+    header.right = nullptr;
     mostLeftNode = &header;
 }
 
 SparseArray::SparseArray(const SparseArray &other)
 {
     header.p = 0;
-    header.right = 0;
+    header.right = nullptr;
     if (other.header.left) {
         header.left = other.header.left->copy(this);
         header.left->setParent(&header);
         recalcMostLeftNode();
     }
+    freeList = other.freeList;
 }
 
 SparseArrayNode *SparseArray::insert(uint akey)
diff --git a/src/qml/jsruntime/qv4sparsearray_p.h b/src/qml/jsruntime/qv4sparsearray_p.h
index 2e4ac883f2..c1e50c8dcf 100644
--- a/src/qml/jsruntime/qv4sparsearray_p.h
+++ b/src/qml/jsruntime/qv4sparsearray_p.h
@@ -52,6 +52,7 @@
 //
 
 #include "qv4global_p.h"
+#include "qv4value_p.h"
 #include <QtCore/qlist.h>
 
 //#define Q_MAP_DEBUG
@@ -109,7 +110,7 @@ struct SparseArrayNode
 inline SparseArrayNode *SparseArrayNode::lowerBound(uint akey)
 {
     SparseArrayNode *n = this;
-    SparseArrayNode *last = 0;
+    SparseArrayNode *last = nullptr;
     while (n) {
         if (akey <= n->size_left) {
             last = n;
@@ -126,7 +127,7 @@ inline SparseArrayNode *SparseArrayNode::lowerBound(uint akey)
 inline SparseArrayNode *SparseArrayNode::upperBound(uint akey)
 {
     SparseArrayNode *n = this;
-    SparseArrayNode *last = 0;
+    SparseArrayNode *last = nullptr;
     while (n) {
         if (akey < n->size_left) {
             last = n;
@@ -150,6 +151,8 @@ struct Q_QML_EXPORT SparseArray
     }
 
     SparseArray(const SparseArray &other);
+
+    Value freeList;
 private:
     SparseArray &operator=(const SparseArray &other);
 
@@ -221,7 +224,7 @@ inline SparseArrayNode *SparseArray::findNode(uint akey) const
         }
     }
 
-    return 0;
+    return nullptr;
 }
 
 inline uint SparseArray::pop_front()
diff --git a/src/qml/jsruntime/qv4stackframe.cpp b/src/qml/jsruntime/qv4stackframe.cpp
new file mode 100644
index 0000000000..a716c53aea
--- /dev/null
+++ b/src/qml/jsruntime/qv4stackframe.cpp
@@ -0,0 +1,74 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "qv4stackframe_p.h"
+#include <QtCore/qstring.h>
+
+using namespace  QV4;
+
+QString CppStackFrame::source() const
+{
+    return v4Function ? v4Function->sourceFile() : QString();
+}
+
+QString CppStackFrame::function() const
+{
+    return v4Function ? v4Function->name()->toQString() : QString();
+}
+
+int CppStackFrame::lineNumber() const
+{
+    if (!v4Function)
+        return -1;
+
+    auto findLine = [](const CompiledData::CodeOffsetToLine &entry, uint offset) {
+        return entry.codeOffset < offset;
+    };
+
+    const QV4::CompiledData::Function *cf = v4Function->compiledFunction;
+    uint offset = instructionPointer;
+    const CompiledData::CodeOffsetToLine *lineNumbers = cf->lineNumberTable();
+    uint nLineNumbers = cf->nLineNumbers;
+    const CompiledData::CodeOffsetToLine *line = std::lower_bound(lineNumbers, lineNumbers + nLineNumbers, offset, findLine) - 1;
+    return line->line;
+}
+
+ReturnedValue CppStackFrame::thisObject() const {
+    return jsFrame->thisObject.asReturnedValue();
+}
+
diff --git a/src/qml/jsruntime/qv4stackframe_p.h b/src/qml/jsruntime/qv4stackframe_p.h
new file mode 100644
index 0000000000..44cfef9173
--- /dev/null
+++ b/src/qml/jsruntime/qv4stackframe_p.h
@@ -0,0 +1,223 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4STACKFRAME_H
+#define QV4STACKFRAME_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qv4context_p.h>
+#include <private/qv4enginebase_p.h>
+#ifndef V4_BOOTSTRAP
+#include <private/qv4function_p.h>
+#endif
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+struct CallData
+{
+    enum Offsets {
+        Function = 0,
+        Context = 1,
+        Accumulator = 2,
+        This = 3,
+        NewTarget = 4,
+        Argc = 5,
+
+        LastOffset = Argc,
+        OffsetCount = LastOffset + 1
+    };
+
+    Value function;
+    Value context;
+    Value accumulator;
+    Value thisObject;
+    Value newTarget;
+    Value _argc;
+
+    int argc() const {
+        Q_ASSERT(_argc.isInteger());
+        return _argc.int_32();
+    }
+
+    void setArgc(int argc) {
+        Q_ASSERT(argc >= 0);
+        _argc.setInt_32(argc);
+    }
+
+    inline ReturnedValue argument(int i) const {
+        return i < argc() ? args[i].asReturnedValue() : Value::undefinedValue().asReturnedValue();
+    }
+
+    Value args[1];
+
+    static Q_DECL_CONSTEXPR int HeaderSize() { return offsetof(CallData, args) / sizeof(QV4::Value); }
+};
+
+Q_STATIC_ASSERT(std::is_standard_layout<CallData>::value);
+Q_STATIC_ASSERT(offsetof(CallData, function   ) == CallData::Function    * sizeof(Value));
+Q_STATIC_ASSERT(offsetof(CallData, context    ) == CallData::Context     * sizeof(Value));
+Q_STATIC_ASSERT(offsetof(CallData, accumulator) == CallData::Accumulator * sizeof(Value));
+Q_STATIC_ASSERT(offsetof(CallData, thisObject ) == CallData::This        * sizeof(Value));
+Q_STATIC_ASSERT(offsetof(CallData, newTarget  ) == CallData::NewTarget   * sizeof(Value));
+Q_STATIC_ASSERT(offsetof(CallData, _argc      ) == CallData::Argc        * sizeof(Value));
+Q_STATIC_ASSERT(offsetof(CallData, args       ) == 6 * sizeof(Value));
+
+struct Q_QML_EXPORT CppStackFrame {
+    EngineBase *engine;
+    Value *savedStackTop;
+    CppStackFrame *parent;
+    Function *v4Function;
+    CallData *jsFrame;
+    const Value *originalArguments;
+    int originalArgumentsCount;
+    int instructionPointer;
+    const char *yield;
+    const char *unwindHandler;
+    const char *unwindLabel;
+    int unwindLevel;
+    bool yieldIsIterator;
+    bool callerCanHandleTailCall;
+    bool pendingTailCall;
+    bool isTailCalling;
+
+    void init(EngineBase *engine, Function *v4Function, const Value *argv, int argc, bool callerCanHandleTailCall = false) {
+        this->engine = engine;
+
+        this->v4Function = v4Function;
+        originalArguments = argv;
+        originalArgumentsCount = argc;
+        instructionPointer = 0;
+        yield = nullptr;
+        unwindHandler = nullptr;
+        unwindLabel = nullptr;
+        unwindLevel = 0;
+        yieldIsIterator = false;
+        this->callerCanHandleTailCall = callerCanHandleTailCall;
+        pendingTailCall = false;
+        isTailCalling = false;
+    }
+
+    void push() {
+        parent = engine->currentStackFrame;
+        engine->currentStackFrame = this;
+        savedStackTop = engine->jsStackTop;
+    }
+
+    void pop() {
+        engine->currentStackFrame = parent;
+        engine->jsStackTop = savedStackTop;
+    }
+
+#ifndef V4_BOOTSTRAP
+    static uint requiredJSStackFrameSize(uint nRegisters) {
+        return CallData::HeaderSize() + nRegisters;
+    }
+    static uint requiredJSStackFrameSize(Function *v4Function) {
+        return CallData::HeaderSize() + v4Function->compiledFunction->nRegisters;
+    }
+    uint requiredJSStackFrameSize() const {
+        return requiredJSStackFrameSize(v4Function);
+    }
+    void setupJSFrame(Value *stackSpace, const Value &function, const Heap::ExecutionContext *scope,
+                      const Value &thisObject, const Value &newTarget = Value::undefinedValue()) {
+        setupJSFrame(stackSpace, function, scope, thisObject, newTarget,
+                     v4Function->nFormals, v4Function->compiledFunction->nRegisters);
+    }
+    void setupJSFrame(Value *stackSpace, const Value &function, const Heap::ExecutionContext *scope,
+                      const Value &thisObject, const Value &newTarget, uint nFormals, uint nRegisters)
+    {
+        jsFrame = reinterpret_cast<CallData *>(stackSpace);
+        jsFrame->function = function;
+        jsFrame->context = scope->asReturnedValue();
+        jsFrame->accumulator = Encode::undefined();
+        jsFrame->thisObject = thisObject;
+        jsFrame->newTarget = newTarget;
+
+        uint argc = uint(originalArgumentsCount);
+        if (argc > nFormals)
+            argc = nFormals;
+        jsFrame->setArgc(argc);
+
+        memcpy(jsFrame->args, originalArguments, argc*sizeof(Value));
+        Q_STATIC_ASSERT(Encode::undefined() == 0);
+        memset(jsFrame->args + argc, 0, (nRegisters - argc)*sizeof(Value));
+
+        if (v4Function && v4Function->compiledFunction) {
+            const int firstDeadZoneRegister = v4Function->compiledFunction->firstTemporalDeadZoneRegister;
+            const int registerDeadZoneSize = v4Function->compiledFunction->sizeOfRegisterTemporalDeadZone;
+
+            const Value * tdzEnd = stackSpace + firstDeadZoneRegister + registerDeadZoneSize;
+            for (Value *v = stackSpace + firstDeadZoneRegister; v < tdzEnd; ++v)
+                *v = Value::emptyValue().asReturnedValue();
+        }
+    }
+#endif
+
+    QString source() const;
+    QString function() const;
+    inline QV4::ExecutionContext *context() const {
+        return static_cast<ExecutionContext *>(&jsFrame->context);
+    }
+    int lineNumber() const;
+
+    inline QV4::Heap::CallContext *callContext() const {
+        Heap::ExecutionContext *ctx = static_cast<ExecutionContext &>(jsFrame->context).d();\
+        while (ctx->type != Heap::ExecutionContext::Type_CallContext)
+            ctx = ctx->outer;
+        return static_cast<Heap::CallContext *>(ctx);
+    }
+    ReturnedValue thisObject() const;
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index c0183a46a7..68d65f2e24 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -52,23 +52,41 @@ using namespace QV4;
 
 #ifndef V4_BOOTSTRAP
 
-DEFINE_MANAGED_VTABLE(String);
+void Heap::StringOrSymbol::markObjects(Heap::Base *that, MarkStack *markStack)
+{
+    StringOrSymbol *s = static_cast<StringOrSymbol *>(that);
+    Heap::StringOrSymbol *id = s->identifier.asStringOrSymbol();
+    if (id)
+        id->mark(markStack);
+}
 
-void String::markObjects(Heap::Base *that, MarkStack *markStack)
+void Heap::String::markObjects(Heap::Base *that, MarkStack *markStack)
 {
-    String::Data *s = static_cast<String::Data *>(that);
-    if (s->largestSubLength) {
-        s->left->mark(markStack);
-        s->right->mark(markStack);
+    StringOrSymbol::markObjects(that, markStack);
+    String *s = static_cast<String *>(that);
+    if (s->subtype < StringType_Complex)
+        return;
+
+    ComplexString *cs = static_cast<ComplexString *>(s);
+    if (cs->subtype == StringType_AddedString) {
+        cs->left->mark(markStack);
+        cs->right->mark(markStack);
+    } else {
+        Q_ASSERT(cs->subtype == StringType_SubString);
+        cs->left->mark(markStack);
     }
 }
 
-bool String::isEqualTo(Managed *t, Managed *o)
+DEFINE_MANAGED_VTABLE(StringOrSymbol);
+DEFINE_MANAGED_VTABLE(String);
+
+
+bool String::virtualIsEqualTo(Managed *t, Managed *o)
 {
     if (t == o)
         return true;
 
-    if (!o->d()->vtable()->isString)
+    if (!o->vtable()->isString)
         return false;
 
     return static_cast<String *>(t)->isEqualTo(static_cast<String *>(o));
@@ -83,37 +101,46 @@ void Heap::String::init(const QString &t)
 
     text = const_cast<QString &>(t).data_ptr();
     text->ref.ref();
-    identifier = 0;
-    stringHash = UINT_MAX;
-    largestSubLength = 0;
-    len = text->size;
 }
 
-void Heap::String::init(String *l, String *r)
+void Heap::ComplexString::init(String *l, String *r)
 {
     Base::init();
 
-    subtype = String::StringType_Unknown;
+    subtype = String::StringType_AddedString;
 
     left = l;
     right = r;
-    stringHash = UINT_MAX;
-    largestSubLength = qMax(l->largestSubLength, r->largestSubLength);
-    len = l->len + r->len;
-    Q_ASSERT(largestSubLength <= len);
-
-    if (!l->largestSubLength && l->len > largestSubLength)
-        largestSubLength = l->len;
-    if (!r->largestSubLength && r->len > largestSubLength)
-        largestSubLength = r->len;
+    len = left->length() + right->length();
+    if (left->subtype >= StringType_Complex)
+        largestSubLength = static_cast<ComplexString *>(left)->largestSubLength;
+    else
+        largestSubLength = left->length();
+    if (right->subtype >= StringType_Complex)
+        largestSubLength = qMax(largestSubLength, static_cast<ComplexString *>(right)->largestSubLength);
+    else
+        largestSubLength = qMax(largestSubLength, right->length());
 
     // make sure we don't get excessive depth in our strings
     if (len > 256 && len >= 2*largestSubLength)
         simplifyString();
 }
 
-void Heap::String::destroy() {
-    if (!largestSubLength) {
+void Heap::ComplexString::init(Heap::String *ref, int from, int len)
+{
+    Q_ASSERT(ref->length() >= from + len);
+    Base::init();
+
+    subtype = String::StringType_SubString;
+
+    left = ref;
+    this->from = from;
+    this->len = len;
+}
+
+void Heap::StringOrSymbol::destroy()
+{
+    if (text) {
         internalClass->engine->memoryManager->changeUnmanagedHeapSizeUsage(qptrdiff(-text->size) * (int)sizeof(QChar));
         if (!text->ref.deref())
             QStringData::deallocate(text);
@@ -125,7 +152,7 @@ uint String::toUInt(bool *ok) const
 {
     *ok = true;
 
-    if (subtype() == Heap::String::StringType_Unknown)
+    if (subtype() >= Heap::String::StringType_Unknown)
         d()->createHashValue();
     if (subtype() == Heap::String::StringType_ArrayIndex)
         return d()->stringHash;
@@ -139,17 +166,17 @@ uint String::toUInt(bool *ok) const
     return UINT_MAX;
 }
 
-void String::makeIdentifierImpl() const
+void String::createPropertyKeyImpl() const
 {
-    if (d()->largestSubLength)
+    if (!d()->text)
         d()->simplifyString();
-    Q_ASSERT(!d()->largestSubLength);
-    engine()->identifierTable->identifier(this);
+    Q_ASSERT(d()->text);
+    engine()->identifierTable->asPropertyKey(this);
 }
 
 void Heap::String::simplifyString() const
 {
-    Q_ASSERT(largestSubLength);
+    Q_ASSERT(!text);
 
     int l = length();
     QString result(l, Qt::Uninitialized);
@@ -157,9 +184,33 @@ void Heap::String::simplifyString() const
     append(this, ch);
     text = result.data_ptr();
     text->ref.ref();
-    identifier = 0;
-    largestSubLength = 0;
+    const ComplexString *cs = static_cast<const ComplexString *>(this);
+    identifier = PropertyKey::invalid();
+    cs->left = cs->right = nullptr;
+
     internalClass->engine->memoryManager->changeUnmanagedHeapSizeUsage(qptrdiff(text->size) * (qptrdiff)sizeof(QChar));
+    subtype = StringType_Unknown;
+}
+
+bool Heap::String::startsWithUpper() const
+{
+    if (subtype == StringType_AddedString)
+        return static_cast<const Heap::ComplexString *>(this)->left->startsWithUpper();
+
+    const Heap::String *str = this;
+    int offset = 0;
+    if (subtype == StringType_SubString) {
+        const ComplexString *cs = static_cast<const Heap::ComplexString *>(this);
+        if (!cs->len)
+            return false;
+        // simplification here is not ideal, but hopefully not a common case.
+        if (cs->left->subtype >= Heap::String::StringType_Complex)
+            cs->left->simplifyString();
+        str = cs->left;
+        offset = cs->from;
+    }
+    Q_ASSERT(str->subtype < Heap::String::StringType_Complex);
+    return str->text->size > offset && QChar::isUpper(str->text->data()[offset]);
 }
 
 void Heap::String::append(const String *data, QChar *ch)
@@ -172,27 +223,34 @@ void Heap::String::append(const String *data, QChar *ch)
         const String *item = worklist.back();
         worklist.pop_back();
 
-        if (item->largestSubLength) {
-            worklist.push_back(item->right);
-            worklist.push_back(item->left);
+        if (item->subtype == StringType_AddedString) {
+            const ComplexString *cs = static_cast<const ComplexString *>(item);
+            worklist.push_back(cs->right);
+            worklist.push_back(cs->left);
+        } else if (item->subtype == StringType_SubString) {
+            const ComplexString *cs = static_cast<const ComplexString *>(item);
+            memcpy(ch, cs->left->toQString().constData() + cs->from, cs->len*sizeof(QChar));
+            ch += cs->len;
         } else {
-            memcpy(ch, item->text->data(), item->text->size * sizeof(QChar));
+            memcpy(static_cast<void *>(ch), static_cast<const void *>(item->text->data()), item->text->size * sizeof(QChar));
             ch += item->text->size;
         }
     }
 }
 
-void Heap::String::createHashValue() const
+void Heap::StringOrSymbol::createHashValue() const
 {
-    if (largestSubLength)
-        simplifyString();
-    Q_ASSERT(!largestSubLength);
+    if (!text) {
+        Q_ASSERT(internalClass->vtable->isString);
+        static_cast<const Heap::String *>(this)->simplifyString();
+    }
+    Q_ASSERT(text);
     const QChar *ch = reinterpret_cast<const QChar *>(text->data());
     const QChar *end = ch + text->size;
     stringHash = QV4::String::calculateHashValue(ch, end, &subtype);
 }
 
-uint String::getLength(const Managed *m)
+qint64 String::virtualGetLength(const Managed *m)
 {
     return static_cast<const String *>(m)->d()->length();
 }
@@ -203,4 +261,3 @@ uint String::toArrayIndex(const QString &str)
 {
     return QV4::String::toArrayIndex(str.constData(), str.constData() + str.length());
 }
-
diff --git a/src/qml/jsruntime/qv4string_p.h b/src/qml/jsruntime/qv4string_p.h
index 2f34dd6139..fbd4f5f550 100644
--- a/src/qml/jsruntime/qv4string_p.h
+++ b/src/qml/jsruntime/qv4string_p.h
@@ -60,41 +60,63 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 struct ExecutionEngine;
-struct Identifier;
+struct PropertyKey;
 
 namespace Heap {
 
-struct Q_QML_PRIVATE_EXPORT String : Base {
+struct Q_QML_PRIVATE_EXPORT StringOrSymbol : Base
+{
     enum StringType {
-        StringType_Unknown,
+        StringType_Symbol,
         StringType_Regular,
-        StringType_ArrayIndex
+        StringType_ArrayIndex,
+        StringType_Unknown,
+        StringType_AddedString,
+        StringType_SubString,
+        StringType_Complex = StringType_AddedString
     };
 
-#ifndef V4_BOOTSTRAP
-    void init(const QString &text);
-    void init(String *l, String *n);
+    mutable QStringData *text;
+    mutable PropertyKey identifier;
+    mutable uint subtype;
+    mutable uint stringHash;
+
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
     void destroy();
-    void simplifyString() const;
-    int length() const {
-        Q_ASSERT((largestSubLength &&
-                  (len == left->len + right->len)) ||
-                 len == (uint)text->size);
-        return len;
-    }
-    std::size_t retainedTextSize() const {
-        return largestSubLength ? 0 : (std::size_t(text->size) * sizeof(QChar));
+
+    inline QString toQString() const {
+        if (!text)
+            return QString();
+        QStringDataPtr ptr = { text };
+        text->ref.ref();
+        return QString(ptr);
     }
     void createHashValue() const;
     inline unsigned hashValue() const {
-        if (subtype == StringType_Unknown)
+        if (subtype >= StringType_Unknown)
             createHashValue();
-        Q_ASSERT(!largestSubLength);
+        Q_ASSERT(subtype < StringType_Complex);
 
         return stringHash;
     }
+};
+
+struct Q_QML_PRIVATE_EXPORT String : StringOrSymbol {
+    static void markObjects(Heap::Base *that, MarkStack *markStack);
+
+#ifndef V4_BOOTSTRAP
+    const VTable *vtable() const {
+        return internalClass->vtable;
+    }
+
+    void init(const QString &text);
+    void simplifyString() const;
+    int length() const;
+    std::size_t retainedTextSize() const {
+        return subtype >= StringType_Complex ? 0 : (std::size_t(text->size) * sizeof(QChar));
+    }
     inline QString toQString() const {
-        if (largestSubLength)
+        if (subtype >= StringType_Complex)
             simplifyString();
         QStringDataPtr ptr = { text };
         text->ref.ref();
@@ -105,8 +127,8 @@ struct Q_QML_PRIVATE_EXPORT String : Base {
             return true;
         if (hashValue() != other->hashValue())
             return false;
-        Q_ASSERT(!largestSubLength);
-        if (identifier && identifier == other->identifier)
+        Q_ASSERT(subtype < StringType_Complex);
+        if (identifier.isValid() && identifier == other->identifier)
             return true;
         if (subtype == Heap::String::StringType_ArrayIndex && other->subtype == Heap::String::StringType_ArrayIndex)
             return true;
@@ -114,32 +136,62 @@ struct Q_QML_PRIVATE_EXPORT String : Base {
         return toQString() == other->toQString();
     }
 
-    union {
-        mutable QStringData *text;
-        mutable String *left;
-    };
-    union {
-        mutable Identifier *identifier;
-        mutable String *right;
-    };
-    mutable uint subtype;
-    mutable uint stringHash;
-    mutable uint largestSubLength;
-    uint len;
+    bool startsWithUpper() const;
+
 private:
     static void append(const String *data, QChar *ch);
 #endif
 };
-V4_ASSERT_IS_TRIVIAL(String)
+Q_STATIC_ASSERT(std::is_trivial< String >::value);
+
+#ifndef V4_BOOTSTRAP
+struct ComplexString : String {
+    void init(String *l, String *n);
+    void init(String *ref, int from, int len);
+    mutable String *left;
+    mutable String *right;
+    union {
+        mutable int largestSubLength;
+        int from;
+    };
+    int len;
+};
+Q_STATIC_ASSERT(std::is_trivial< ComplexString >::value);
+
+inline
+int String::length() const {
+    return text ? text->size : static_cast<const ComplexString *>(this)->len;
+}
+#endif
 
 }
 
-struct Q_QML_PRIVATE_EXPORT String : public Managed {
+struct Q_QML_PRIVATE_EXPORT StringOrSymbol : public Managed {
+#ifndef V4_BOOTSTRAP
+    V4_MANAGED(StringOrSymbol, Managed)
+    V4_NEEDS_DESTROY
+    enum {
+        IsStringOrSymbol = true
+    };
+
+private:
+    inline void createPropertyKey() const;
+public:
+    PropertyKey propertyKey() const { Q_ASSERT(d()->identifier.isValid()); return d()->identifier; }
+    PropertyKey toPropertyKey() const;
+
+
+    inline QString toQString() const {
+        return d()->toQString();
+    }
+#endif
+};
+
+struct Q_QML_PRIVATE_EXPORT String : public StringOrSymbol {
 #ifndef V4_BOOTSTRAP
-    V4_MANAGED(String, Managed)
+    V4_MANAGED(String, StringOrSymbol)
     Q_MANAGED_TYPE(String)
     V4_INTERNALCLASS(String)
-    V4_NEEDS_DESTROY
     enum {
         IsString = true
     };
@@ -154,7 +206,7 @@ struct Q_QML_PRIVATE_EXPORT String : public Managed {
         return d()->isEqualTo(other->d());
     }
 
-    inline bool compare(const String *other) {
+    inline bool lessThan(const String *other) {
         return toQString() < other->toQString();
     }
 
@@ -165,23 +217,10 @@ struct Q_QML_PRIVATE_EXPORT String : public Managed {
     inline unsigned hashValue() const {
         return d()->hashValue();
     }
-    uint asArrayIndex() const {
-        if (subtype() == Heap::String::StringType_Unknown)
-            d()->createHashValue();
-        Q_ASSERT(!d()->largestSubLength);
-        if (subtype() == Heap::String::StringType_ArrayIndex)
-            return d()->stringHash;
-        return UINT_MAX;
-    }
     uint toUInt(bool *ok) const;
 
-    void makeIdentifier() const {
-        if (d()->identifier)
-            return;
-        makeIdentifierImpl();
-    }
-
-    void makeIdentifierImpl() const;
+    // slow path
+    Q_NEVER_INLINE void createPropertyKeyImpl() const;
 
     static uint createHashValue(const QChar *ch, int length, uint *subtype)
     {
@@ -195,19 +234,11 @@ struct Q_QML_PRIVATE_EXPORT String : public Managed {
         return calculateHashValue(ch, end, subtype);
     }
 
-    bool startsWithUpper() const {
-        const String::Data *l = d();
-        while (l->largestSubLength)
-            l = l->left;
-        return l->text->size && QChar::isUpper(l->text->data()[0]);
-    }
-
-    Identifier *identifier() const { return d()->identifier; }
+    bool startsWithUpper() const { return d()->startsWithUpper(); }
 
 protected:
-    static void markObjects(Heap::Base *that, MarkStack *markStack);
-    static bool isEqualTo(Managed *that, Managed *o);
-    static uint getLength(const Managed *m);
+    static bool virtualIsEqualTo(Managed *that, Managed *o);
+    static qint64 virtualGetLength(const Managed *m);
 #endif
 
 public:
@@ -215,7 +246,7 @@ public:
 
 private:
     static inline uint toUInt(const QChar *ch) { return ch->unicode(); }
-    static inline uint toUInt(const char *ch) { return *ch; }
+    static inline uint toUInt(const char *ch) { return static_cast<unsigned char>(*ch); }
 
     template <typename T>
     static inline uint toArrayIndex(const T *ch, const T *end)
@@ -247,7 +278,7 @@ public:
         uint h = toArrayIndex(ch, end);
         if (h != UINT_MAX) {
             if (subtype)
-                *subtype = Heap::String::StringType_ArrayIndex;
+                *subtype = Heap::StringOrSymbol::StringType_ArrayIndex;
             return h;
         }
 
@@ -257,17 +288,45 @@ public:
         }
 
         if (subtype)
-            *subtype = Heap::String::StringType_Regular;
+            *subtype = (toUInt(ch) == '@') ? Heap::StringOrSymbol::StringType_Symbol : Heap::StringOrSymbol::StringType_Regular;
         return h;
     }
 };
 
+#ifndef V4_BOOTSTRAP
+struct ComplexString : String {
+    typedef QV4::Heap::ComplexString Data;
+    QV4::Heap::ComplexString *d_unchecked() const { return static_cast<QV4::Heap::ComplexString *>(m()); }
+    QV4::Heap::ComplexString *d() const {
+        QV4::Heap::ComplexString *dptr = d_unchecked();
+        dptr->_checkIsInitialized();
+        return dptr;
+    }
+};
+
+inline
+void StringOrSymbol::createPropertyKey() const {
+    Q_ASSERT(!d()->identifier.isValid());
+    Q_ASSERT(isString());
+    static_cast<const String *>(this)->createPropertyKeyImpl();
+}
+
+inline PropertyKey StringOrSymbol::toPropertyKey() const {
+    if (!d()->identifier.isValid())
+        createPropertyKey();
+    return d()->identifier;
+}
+
+template<>
+inline const StringOrSymbol *Value::as() const {
+    return isManaged() && m()->internalClass->vtable->isStringOrSymbol ? static_cast<const String *>(this) : nullptr;
+}
+
 template<>
 inline const String *Value::as() const {
-    return isManaged() && m()->vtable()->isString ? static_cast<const String *>(this) : 0;
+    return isManaged() && m()->internalClass->vtable->isString ? static_cast<const String *>(this) : nullptr;
 }
 
-#ifndef V4_BOOTSTRAP
 template<>
 inline ReturnedValue value_convert<String>(ExecutionEngine *e, const Value &v)
 {
diff --git a/src/qml/jsruntime/qv4stringiterator.cpp b/src/qml/jsruntime/qv4stringiterator.cpp
new file mode 100644
index 0000000000..62db83ff26
--- /dev/null
+++ b/src/qml/jsruntime/qv4stringiterator.cpp
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Crimson AS <info@crimson.no>
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <private/qv4iterator_p.h>
+#include <private/qv4stringiterator_p.h>
+#include <private/qv4symbol_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(StringIteratorObject);
+
+void StringIteratorPrototype::init(ExecutionEngine *e)
+{
+    defineDefaultProperty(QStringLiteral("next"), method_next, 0);
+
+    Scope scope(e);
+    ScopedString val(scope, e->newString(QLatin1String("String Iterator")));
+    defineReadonlyConfigurableProperty(e->symbol_toStringTag(), val);
+}
+
+ReturnedValue StringIteratorPrototype::method_next(const FunctionObject *b, const Value *that, const Value *, int)
+{
+    Scope scope(b);
+    const StringIteratorObject *thisObject = that->as<StringIteratorObject>();
+    if (!thisObject)
+        return scope.engine->throwTypeError(QLatin1String("Not an String Iterator instance"));
+
+    ScopedString s(scope, thisObject->d()->iteratedString);
+    if (!s) {
+        QV4::Value undefined = Value::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+    }
+
+    quint32 index = thisObject->d()->nextIndex;
+
+    QString str = s->toQString();
+    quint32 len = str.length();
+
+    if (index >= len) {
+        thisObject->d()->iteratedString.set(scope.engine, nullptr);
+        QV4::Value undefined = Value::undefinedValue();
+        return IteratorPrototype::createIterResultObject(scope.engine, undefined, true);
+    }
+
+    QChar ch = str.at(index);
+    int num = 1;
+    if (ch.unicode() >= 0xd800 && ch.unicode() <= 0xdbff && index + 1 != len) {
+        ch = str.at(index + 1);
+        if (ch.unicode() >= 0xdc00 && ch.unicode() <= 0xdfff)
+            num = 2;
+    }
+
+    thisObject->d()->nextIndex += num;
+
+    ScopedString resultString(scope, scope.engine->newString(s->toQString().mid(index, num)));
+    return IteratorPrototype::createIterResultObject(scope.engine, resultString, false);
+}
+
diff --git a/src/qml/jsruntime/qv4stringiterator_p.h b/src/qml/jsruntime/qv4stringiterator_p.h
new file mode 100644
index 0000000000..672ccc9963
--- /dev/null
+++ b/src/qml/jsruntime/qv4stringiterator_p.h
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QV4STRINGITERATOR_P_H
+#define QV4STRINGITERATOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4object_p.h"
+#include "qv4string_p.h"
+
+QT_BEGIN_NAMESPACE
+
+
+namespace QV4 {
+
+namespace Heap {
+
+#define StringIteratorObjectMembers(class, Member) \
+    Member(class, Pointer, String *, iteratedString) \
+    Member(class, NoMark, quint32, nextIndex)
+
+DECLARE_HEAP_OBJECT(StringIteratorObject, Object) {
+    DECLARE_MARKOBJECTS(StringIteratorObject);
+    void init(String *str, QV4::ExecutionEngine *engine)
+    {
+        Object::init();
+        this->iteratedString.set(engine, str);
+        this->nextIndex = 0;
+    }
+};
+
+}
+
+struct StringIteratorPrototype : Object
+{
+    V4_PROTOTYPE(iteratorPrototype)
+    void init(ExecutionEngine *engine);
+
+    static ReturnedValue method_next(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct StringIteratorObject : Object
+{
+    V4_OBJECT2(StringIteratorObject, Object)
+    Q_MANAGED_TYPE(StringIteratorObject)
+    V4_PROTOTYPE(stringIteratorPrototype)
+
+    void init(ExecutionEngine *engine);
+};
+
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QV4ARRAYITERATOR_P_H
+
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index 81f5c3566c..8186153ba4 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -44,18 +44,14 @@
 #include "qv4objectproto_p.h"
 #include <private/qv4mm_p.h>
 #include "qv4scopedvalue_p.h"
+#include "qv4symbol_p.h"
 #include "qv4alloca_p.h"
+#include "qv4jscall_p.h"
+#include "qv4stringiterator_p.h"
 #include <QtCore/QDateTime>
 #include <QtCore/QDebug>
 #include <QtCore/QStringList>
 
-#include <private/qqmljsengine_p.h>
-#include <private/qqmljslexer_p.h>
-#include <private/qqmljsparser_p.h>
-#include <private/qqmljsast_p.h>
-#include <qv4jsir_p.h>
-#include <qv4codegen_p.h>
-
 #include <cassert>
 
 #ifndef Q_OS_WIN
@@ -78,71 +74,93 @@ void Heap::StringObject::init()
     Object::init();
     Q_ASSERT(vtable() == QV4::StringObject::staticVTable());
     string.set(internalClass->engine, internalClass->engine->id_empty()->d());
-    setProperty(internalClass->engine, LengthPropertyIndex, Primitive::fromInt32(0));
+    setProperty(internalClass->engine, LengthPropertyIndex, Value::fromInt32(0));
 }
 
 void Heap::StringObject::init(const QV4::String *str)
 {
     Object::init();
     string.set(internalClass->engine, str->d());
-    setProperty(internalClass->engine, LengthPropertyIndex, Primitive::fromInt32(length()));
+    setProperty(internalClass->engine, LengthPropertyIndex, Value::fromInt32(length()));
 }
 
 Heap::String *Heap::StringObject::getIndex(uint index) const
 {
     QString str = string->toQString();
     if (index >= (uint)str.length())
-        return 0;
+        return nullptr;
     return internalClass->engine->newString(str.mid(index, 1));
 }
 
 uint Heap::StringObject::length() const
 {
-    return string->len;
+    return string->length();
 }
 
-bool StringObject::deleteIndexedProperty(Managed *m, uint index)
+bool StringObject::virtualDeleteProperty(Managed *m, PropertyKey id)
 {
-    ExecutionEngine *v4 = static_cast<StringObject *>(m)->engine();
-    Scope scope(v4);
-    Scoped<StringObject> o(scope, m->as<StringObject>());
-    Q_ASSERT(!!o);
-
-    if (index < static_cast<uint>(o->d()->string->toQString().length())) {
-        if (v4->current->strictMode)
-            v4->throwTypeError();
-        return false;
+    Q_ASSERT(m->as<StringObject>());
+    if (id.isArrayIndex()) {
+        StringObject *o = static_cast<StringObject *>(m);
+        uint index = id.asArrayIndex();
+        if (index < static_cast<uint>(o->d()->string->toQString().length()))
+            return false;
     }
-    return true;
+    return Object::virtualDeleteProperty(m, id);
 }
 
-void StringObject::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attrs)
+struct StringObjectOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
+{
+    ~StringObjectOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const QV4::Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey StringObjectOwnPropertyKeyIterator::next(const QV4::Object *o, Property *pd, PropertyAttributes *attrs)
 {
-    name->setM(0);
-    StringObject *s = static_cast<StringObject *>(m);
+    const StringObject *s = static_cast<const StringObject *>(o);
     uint slen = s->d()->string->toQString().length();
-    if (it->arrayIndex <= slen) {
-        while (it->arrayIndex < slen) {
-            *index = it->arrayIndex;
-            ++it->arrayIndex;
-            PropertyAttributes a;
-            Property pd;
-            s->getOwnProperty(*index, &a, &pd);
-            if (!(it->flags & ObjectIterator::EnumerableOnly) || a.isEnumerable()) {
-                *attrs = a;
-                p->copy(&pd, a);
-                return;
-            }
-        }
+    if (arrayIndex < slen) {
+        uint index = arrayIndex;
+        ++arrayIndex;
+        if (attrs)
+            *attrs = Attr_NotConfigurable|Attr_NotWritable;
+        if (pd)
+            pd->value = s->getIndex(index);
+        return PropertyKey::fromArrayIndex(index);
+    } else if (arrayIndex == slen) {
         if (s->arrayData()) {
-            it->arrayNode = s->sparseBegin();
+            arrayNode = s->sparseBegin();
             // iterate until we're past the end of the string
-            while (it->arrayNode && it->arrayNode->key() < slen)
-                it->arrayNode = it->arrayNode->nextNode();
+            while (arrayNode && arrayNode->key() < slen)
+                arrayNode = arrayNode->nextNode();
         }
     }
 
-    return Object::advanceIterator(m, it, name, index, p, attrs);
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+OwnPropertyKeyIterator *StringObject::virtualOwnPropertyKeys(const Object *m, Value *target)
+{
+    *target = *m;
+    return new StringObjectOwnPropertyKeyIterator;
+}
+
+PropertyAttributes StringObject::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
+{
+    PropertyAttributes attributes = Object::virtualGetOwnProperty(m, id, p);
+    if (attributes != Attr_Invalid)
+        return attributes;
+
+    const StringObject *s = static_cast<const StringObject *>(m);
+    uint slen = s->d()->string->toQString().length();
+    uint index = id.asArrayIndex();
+    if (index < slen) {
+        if (p)
+            p->value = s->getIndex(index);
+        return Attr_NotConfigurable|Attr_NotWritable;
+    }
+    return Object::virtualGetOwnProperty(m, id, p);
 }
 
 DEFINE_OBJECT_VTABLE(StringCtor);
@@ -152,24 +170,114 @@ void Heap::StringCtor::init(QV4::ExecutionContext *scope)
     Heap::FunctionObject::init(scope, QStringLiteral("String"));
 }
 
-void StringCtor::construct(const Managed *m, Scope &scope, CallData *callData)
+ReturnedValue StringCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    ExecutionEngine *v4 = static_cast<const Object *>(m)->engine();
+    ExecutionEngine *v4 = static_cast<const Object *>(f)->engine();
+    Scope scope(v4);
     ScopedString value(scope);
-    if (callData->argc)
-        value = callData->args[0].toString(v4);
+    if (argc)
+        value = argv[0].toString(v4);
     else
         value = v4->newString();
-    scope.result = Encode(v4->newStringObject(value));
+    CHECK_EXCEPTION();
+    ReturnedValue o = Encode(v4->newStringObject(value));
+
+    if (!newTarget)
+        return o;
+    ScopedObject obj(scope, o);
+    obj->setProtoFromNewTarget(newTarget);
+    return obj->asReturnedValue();
 }
 
-void StringCtor::call(const Managed *, Scope &scope, CallData *callData)
+ReturnedValue StringCtor::virtualCall(const FunctionObject *m, const Value *, const Value *argv, int argc)
 {
-    ExecutionEngine *v4 = scope.engine;
-    if (callData->argc)
-        scope.result = callData->args[0].toString(v4);
-    else
-        scope.result = v4->newString();
+    ExecutionEngine *v4 = m->engine();
+    if (!argc)
+        return v4->newString()->asReturnedValue();
+    if (argv[0].isSymbol())
+        return v4->newString(argv[0].symbolValue()->descriptiveString())->asReturnedValue();
+    return argv[0].toString(v4)->asReturnedValue();
+}
+
+ReturnedValue StringCtor::method_fromCharCode(const FunctionObject *b, const Value *, const Value *argv, int argc)
+{
+    QString str(argc, Qt::Uninitialized);
+    QChar *ch = str.data();
+    for (int i = 0, ei = argc; i < ei; ++i) {
+        *ch = QChar(argv[i].toUInt16());
+        ++ch;
+    }
+    *ch = 0;
+    return Encode(b->engine()->newString(str));
+}
+
+
+
+ReturnedValue StringCtor::method_fromCodePoint(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    ExecutionEngine *e = f->engine();
+    QString result(argc*2, Qt::Uninitialized); // assume worst case
+    QChar *ch = result.data();
+    for (int i = 0; i < argc; ++i) {
+        double num = argv[i].toNumber();
+        if (e->hasException)
+            return Encode::undefined();
+        int cp = static_cast<int>(num);
+        if (cp != num || cp < 0 || cp > 0x10ffff)
+            return e->throwRangeError(QStringLiteral("String.fromCodePoint: argument out of range."));
+        if (cp > 0xffff) {
+            *ch = QChar::highSurrogate(cp);
+            ++ch;
+            *ch = QChar::lowSurrogate(cp);
+        } else {
+            *ch = cp;
+        }
+        ++ch;
+    }
+    *ch = 0;
+    result.truncate(ch - result.constData());
+    return e->newString(result)->asReturnedValue();
+}
+
+ReturnedValue StringCtor::method_raw(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    ScopedObject cooked(scope, argv[0].toObject(scope.engine));
+    if (!cooked)
+        return scope.engine->throwTypeError();
+    ScopedString rawString(scope, scope.engine->newIdentifier(QStringLiteral("raw")));
+    ScopedValue rawValue(scope, cooked->get(rawString));
+    ScopedObject raw(scope, rawValue->toObject(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+
+    ++argv;
+    --argc;
+
+    QString result;
+    uint literalSegments = raw->getLength();
+    if (!literalSegments)
+        return scope.engine->id_empty()->asReturnedValue();
+
+    uint nextIndex = 0;
+    ScopedValue val(scope);
+    while (1) {
+        val = raw->get(nextIndex);
+        result += val->toQString();
+        if (scope.engine->hasException)
+            return Encode::undefined();
+        if (nextIndex + 1 == literalSegments)
+            return scope.engine->newString(result)->asReturnedValue();
+
+        if (nextIndex < static_cast<uint>(argc))
+            result += argv[nextIndex].toQString();
+        if (scope.engine->hasException)
+            return Encode::undefined();
+        ++nextIndex;
+    }
 }
 
 void StringPrototype::init(ExecutionEngine *engine, Object *ctor)
@@ -177,15 +285,24 @@ void StringPrototype::init(ExecutionEngine *engine, Object *ctor)
     Scope scope(engine);
     ScopedObject o(scope);
 
+    // need to set this once again, as these were not fully defined when creating the string proto
+    Heap::InternalClass *ic = scope.engine->classes[ExecutionEngine::Class_StringObject]->changePrototype(scope.engine->objectPrototype()->d());
+    d()->internalClass.set(scope.engine, ic);
+    d()->string.set(scope.engine, scope.engine->id_empty()->d());
+    setProperty(scope.engine, Heap::StringObject::LengthPropertyIndex, Value::fromInt32(0));
+
     ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(1));
-    ctor->defineDefaultProperty(QStringLiteral("fromCharCode"), method_fromCharCode, 1);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(1));
+    ctor->defineDefaultProperty(QStringLiteral("fromCharCode"), StringCtor::method_fromCharCode, 1);
+    ctor->defineDefaultProperty(QStringLiteral("fromCodePoint"), StringCtor::method_fromCodePoint, 1);
+    ctor->defineDefaultProperty(QStringLiteral("raw"), StringCtor::method_raw, 1);
 
     defineDefaultProperty(QStringLiteral("constructor"), (o = ctor));
     defineDefaultProperty(engine->id_toString(), method_toString);
     defineDefaultProperty(engine->id_valueOf(), method_toString); // valueOf and toString are identical
     defineDefaultProperty(QStringLiteral("charAt"), method_charAt, 1);
     defineDefaultProperty(QStringLiteral("charCodeAt"), method_charCodeAt, 1);
+    defineDefaultProperty(QStringLiteral("codePointAt"), method_codePointAt, 1);
     defineDefaultProperty(QStringLiteral("concat"), method_concat, 1);
     defineDefaultProperty(QStringLiteral("endsWith"), method_endsWith, 1);
     defineDefaultProperty(QStringLiteral("indexOf"), method_indexOf, 1);
@@ -193,6 +310,9 @@ void StringPrototype::init(ExecutionEngine *engine, Object *ctor)
     defineDefaultProperty(QStringLiteral("lastIndexOf"), method_lastIndexOf, 1);
     defineDefaultProperty(QStringLiteral("localeCompare"), method_localeCompare, 1);
     defineDefaultProperty(QStringLiteral("match"), method_match, 1);
+    defineDefaultProperty(QStringLiteral("normalize"), method_normalize, 0);
+    defineDefaultProperty(QStringLiteral("padEnd"), method_padEnd, 1);
+    defineDefaultProperty(QStringLiteral("padStart"), method_padStart, 1);
     defineDefaultProperty(QStringLiteral("repeat"), method_repeat, 1);
     defineDefaultProperty(QStringLiteral("replace"), method_replace, 2);
     defineDefaultProperty(QStringLiteral("search"), method_search, 1);
@@ -206,142 +326,187 @@ void StringPrototype::init(ExecutionEngine *engine, Object *ctor)
     defineDefaultProperty(QStringLiteral("toUpperCase"), method_toUpperCase);
     defineDefaultProperty(QStringLiteral("toLocaleUpperCase"), method_toLocaleUpperCase);
     defineDefaultProperty(QStringLiteral("trim"), method_trim);
+    defineDefaultProperty(engine->symbol_iterator(), method_iterator);
 }
 
-static QString getThisString(Scope &scope, CallData *callData)
+static Heap::String *thisAsString(ExecutionEngine *v4, const QV4::Value *thisObject)
 {
-    ScopedValue t(scope, callData->thisObject);
-    if (String *s = t->stringValue())
+    if (String *s = thisObject->stringValue())
+        return s->d();
+    if (const StringObject *thisString = thisObject->as<StringObject>())
+        return thisString->d()->string;
+    return thisObject->toString(v4);
+}
+
+static QString getThisString(ExecutionEngine *v4, const QV4::Value *thisObject)
+{
+    if (String *s = thisObject->stringValue())
         return s->toQString();
-    if (StringObject *thisString = t->as<StringObject>())
+    if (const StringObject *thisString = thisObject->as<StringObject>())
         return thisString->d()->string->toQString();
-    if (t->isUndefined() || t->isNull()) {
-        scope.engine->throwTypeError();
+    if (thisObject->isUndefined() || thisObject->isNull()) {
+        v4->throwTypeError();
         return QString();
     }
-    return t->toQString();
+    return thisObject->toQString();
 }
 
-void StringPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    if (callData->thisObject.isString())
-        RETURN_RESULT(callData->thisObject);
+    if (thisObject->isString())
+        return thisObject->asReturnedValue();
 
-    StringObject *o = callData->thisObject.as<StringObject>();
+    ExecutionEngine *v4 = b->engine();
+    const StringObject *o = thisObject->as<StringObject>();
     if (!o)
-        THROW_TYPE_ERROR();
-    scope.result = o->d()->string;
+        return v4->throwTypeError();
+    return o->d()->string->asReturnedValue();
 }
 
-void StringPrototype::method_charAt(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_charAt(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    const QString str = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString str = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     int pos = 0;
-    if (callData->argc > 0)
-        pos = (int) callData->args[0].toInteger();
+    if (argc > 0)
+        pos = (int) argv[0].toInteger();
 
     QString result;
     if (pos >= 0 && pos < str.length())
         result += str.at(pos);
 
-    scope.result = scope.engine->newString(result);
+    return Encode(v4->newString(result));
 }
 
-void StringPrototype::method_charCodeAt(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_charCodeAt(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    const QString str = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString str = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     int pos = 0;
-    if (callData->argc > 0)
-        pos = (int) callData->args[0].toInteger();
+    if (argc > 0)
+        pos = (int) argv[0].toInteger();
 
 
     if (pos >= 0 && pos < str.length())
         RETURN_RESULT(Encode(str.at(pos).unicode()));
 
-    scope.result = Encode(qt_qnan());
+    return Encode(qt_qnan());
 }
 
-void StringPrototype::method_concat(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_codePointAt(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = f->engine();
+    QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+
+    int index = argc ? argv[0].toInteger() : 0;
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+
+    if (index < 0 || index >= value.size())
+        return Encode::undefined();
+
+    uint first = value.at(index).unicode();
+    if (QChar::isHighSurrogate(first) && index + 1 < value.size()) {
+        uint second = value.at(index + 1).unicode();
+        if (QChar::isLowSurrogate(second))
+            return Encode(QChar::surrogateToUcs4(first, second));
+    }
+    return Encode(first);
+}
+
+ReturnedValue StringPrototype::method_concat(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *v4 = b->engine();
+    QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
+    Scope scope(v4);
     ScopedString s(scope);
-    for (int i = 0; i < callData->argc; ++i) {
-        s = callData->args[i].toString(scope.engine);
-        CHECK_EXCEPTION();
+    for (int i = 0; i < argc; ++i) {
+        s = argv[i].toString(scope.engine);
+        if (v4->hasException)
+            return QV4::Encode::undefined();
 
         Q_ASSERT(s->isString());
         value += s->toQString();
     }
 
-    scope.result = scope.engine->newString(value);
+    return Encode(v4->newString(value));
 }
 
-void StringPrototype::method_endsWith(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_endsWith(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    QString searchString;
-    if (callData->argc) {
-        if (callData->args[0].as<RegExpObject>())
-            THROW_TYPE_ERROR();
-        searchString = callData->args[0].toQString();
-    }
+    if (argc && argv[0].as<RegExpObject>())
+        return v4->throwTypeError();
+    QString searchString = (argc ? argv[0] : Value::undefinedValue()).toQString();
+    if (v4->hasException)
+        return Encode::undefined();
 
     int pos = value.length();
-    if (callData->argc > 1)
-        pos = (int) callData->args[1].toInteger();
+    if (argc > 1)
+        pos = (int) argv[1].toInteger();
 
     if (pos == value.length())
         RETURN_RESULT(Encode(value.endsWith(searchString)));
 
     QStringRef stringToSearch = value.leftRef(pos);
-    scope.result = Encode(stringToSearch.endsWith(searchString));
+    return Encode(stringToSearch.endsWith(searchString));
 }
 
-void StringPrototype::method_indexOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_indexOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    QString searchString;
-    if (callData->argc)
-        searchString = callData->args[0].toQString();
+    QString searchString = (argc ? argv[0] : Value::undefinedValue()).toQString();
+    if (v4->hasException)
+        return Encode::undefined();
 
     int pos = 0;
-    if (callData->argc > 1)
-        pos = (int) callData->args[1].toInteger();
+    if (argc > 1)
+        pos = (int) argv[1].toInteger();
 
     int index = -1;
     if (! value.isEmpty())
         index = value.indexOf(searchString, qMin(qMax(pos, 0), value.length()));
 
-    scope.result = Encode(index);
+    return Encode(index);
 }
 
-void StringPrototype::method_includes(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_includes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    QString searchString;
-    if (callData->argc) {
-        if (callData->args[0].as<RegExpObject>())
-            THROW_TYPE_ERROR();
-        searchString = callData->args[0].toQString();
-    }
+    if (argc && argv[0].as<RegExpObject>())
+        return v4->throwTypeError();
+    QString searchString = (argc ? argv[0] : Value::undefinedValue()).toQString();
+    if (v4->hasException)
+        return Encode::undefined();
 
     int pos = 0;
-    if (callData->argc > 1) {
-        ScopedValue posArg(scope, callData->argument(1));
-        pos = (int) posArg->toInteger();
-        if (!posArg->isInteger() && posArg->isNumber() && qIsInf(posArg->toNumber()))
+    if (argc > 1) {
+        const Value &posArg = argv[1];
+        pos = (int) posArg.toInteger();
+        if (!posArg.isInteger() && posArg.isNumber() && qIsInf(posArg.toNumber()))
             pos = value.length();
     }
 
@@ -349,20 +514,21 @@ void StringPrototype::method_includes(const BuiltinFunction *, Scope &scope, Cal
         RETURN_RESULT(Encode(value.contains(searchString)));
 
     QStringRef stringToSearch = value.midRef(pos);
-    scope.result = Encode(stringToSearch.contains(searchString));
+    return Encode(stringToSearch.contains(searchString));
 }
 
-void StringPrototype::method_lastIndexOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_lastIndexOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    const QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    QString searchString;
-    if (callData->argc)
-        searchString = callData->args[0].toQString();
+    QString searchString = (argc ? argv[0] : Value::undefinedValue()).toQString();
+    if (v4->hasException)
+        return Encode::undefined();
 
-    ScopedValue posArg(scope, callData->argument(1));
-    double position = RuntimeHelpers::toNumber(posArg);
+    double position = argc > 1 ? RuntimeHelpers::toNumber(argv[1]) : +qInf();
     if (std::isnan(position))
         position = +qInf();
     else
@@ -374,97 +540,181 @@ void StringPrototype::method_lastIndexOf(const BuiltinFunction *, Scope &scope,
     if (searchString.isNull() && pos == 0)
         RETURN_RESULT(Encode(-1));
     int index = value.lastIndexOf(searchString, pos);
-    scope.result = Encode(index);
+    return Encode(index);
 }
 
-void StringPrototype::method_localeCompare(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_localeCompare(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    const QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    ScopedValue v(scope, callData->argument(0));
-    const QString that = v->toQString();
-    scope.result = Encode(QString::localeAwareCompare(value, that));
+    const QString that = (argc ? argv[0] : Value::undefinedValue()).toQString();
+    return Encode(QString::localeAwareCompare(value, that));
 }
 
-void StringPrototype::method_match(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_match(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->thisObject.isUndefined() || callData->thisObject.isNull())
-        THROW_TYPE_ERROR();
+    ExecutionEngine *v4 = b->engine();
+    if (thisObject->isNullOrUndefined())
+        return v4->throwTypeError();
+
+    Scope scope(v4);
+    if (argc && !argv[0].isNullOrUndefined()) {
+        ScopedObject r(scope, argv[0].toObject(scope.engine));
+        if (scope.hasException())
+            return Encode::undefined();
+        ScopedValue f(scope, r->get(scope.engine->symbol_match()));
+        if (!f->isNullOrUndefined()) {
+            ScopedFunctionObject fo(scope, f);
+            if (!fo)
+                return scope.engine->throwTypeError();
+            return fo->call(r, thisObject, 1);
+        }
+    }
 
-    ScopedString s(scope, callData->thisObject.toString(scope.engine));
+    ScopedString s(scope, thisObject->toString(v4));
+    if (v4->hasException)
+        return Encode::undefined();
 
-    ScopedValue regexp(scope, callData->argument(0));
-    Scoped<RegExpObject> rx(scope, regexp);
-    if (!rx) {
-        ScopedCallData callData(scope, 1);
-        callData->args[0] = regexp;
-        scope.engine->regExpCtor()->construct(scope, callData);
-        rx = scope.result.asReturnedValue();
+    Scoped<RegExpObject> that(scope, argc ? argv[0] : Value::undefinedValue());
+    if (!that) {
+        // convert args[0] to a regexp
+        that = RegExpCtor::virtualCallAsConstructor(b, argv, argc, b);
+        if (v4->hasException)
+            return Encode::undefined();
     }
+    Q_ASSERT(!!that);
 
-    if (!rx)
-        // ### CHECK
-        THROW_TYPE_ERROR();
+    ScopedFunctionObject match(scope, that->get(scope.engine->symbol_match()));
+    if (!match)
+        return scope.engine->throwTypeError();
+    return match->call(that, s, 1);
+}
 
-    bool global = rx->global();
+ReturnedValue StringPrototype::method_normalize(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *v4 = f->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return Encode::undefined();
+
+    QString::NormalizationForm form = QString::NormalizationForm_C;
+    if (argc >= 1 && !argv[0].isUndefined()) {
+        QString f = argv[0].toQString();
+        if (v4->hasException)
+            return Encode::undefined();
+        if (f == QLatin1String("NFC"))
+            form = QString::NormalizationForm_C;
+        else if (f == QLatin1String("NFD"))
+            form = QString::NormalizationForm_D;
+        else if (f == QLatin1String("NFKC"))
+            form = QString::NormalizationForm_KC;
+        else if (f == QLatin1String("NFKD"))
+            form = QString::NormalizationForm_KD;
+        else
+            return v4->throwRangeError(QLatin1String("String.prototype.normalize: Invalid normalization form."));
+    }
+    QString normalized = value.normalized(form);
+    return v4->newString(normalized)->asReturnedValue();
+}
 
-    // ### use the standard builtin function, not the one that might be redefined in the proto
-    ScopedString execString(scope, scope.engine->newString(QStringLiteral("exec")));
-    ScopedFunctionObject exec(scope, scope.engine->regExpPrototype()->get(execString));
+ReturnedValue StringPrototype::method_padEnd(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *v4 = f->engine();
+    if (thisObject->isNullOrUndefined())
+        return v4->throwTypeError();
 
-    ScopedCallData cData(scope, 1);
-    cData->thisObject = rx;
-    cData->args[0] = s;
-    if (!global) {
-        exec->call(scope, cData);
-        return;
+    Scope scope(v4);
+    ScopedString s(scope, thisAsString(v4, thisObject));
+    if (v4->hasException)
+        return Encode::undefined();
+    if (!argc)
+        return s->asReturnedValue();
+
+    int maxLen = argv[0].toInteger();
+    if (maxLen <= s->d()->length())
+        return s->asReturnedValue();
+    QString fillString = (argc > 1 && !argv[1].isUndefined()) ? argv[1].toQString() : QString::fromLatin1(" ");
+    if (v4->hasException)
+        return Encode::undefined();
+
+    if (fillString.isEmpty())
+        return s->asReturnedValue();
+
+    QString padded = s->toQString();
+    int oldLength = padded.length();
+    int toFill = maxLen - oldLength;
+    padded.resize(maxLen);
+    QChar *ch = padded.data() + oldLength;
+    while (toFill) {
+        int copy = qMin(fillString.length(), toFill);
+        memcpy(ch, fillString.constData(), copy*sizeof(QChar));
+        toFill -= copy;
+        ch += copy;
     }
+    *ch = 0;
+
+    return v4->newString(padded)->asReturnedValue();
+}
 
-    ScopedString lastIndex(scope, scope.engine->newString(QStringLiteral("lastIndex")));
-    rx->put(lastIndex, ScopedValue(scope, Primitive::fromInt32(0)));
-    ScopedArrayObject a(scope, scope.engine->newArrayObject());
+ReturnedValue StringPrototype::method_padStart(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    ExecutionEngine *v4 = f->engine();
+    if (thisObject->isNullOrUndefined())
+        return v4->throwTypeError();
 
-    double previousLastIndex = 0;
-    uint n = 0;
-    ScopedValue matchStr(scope);
-    ScopedValue index(scope);
-    while (1) {
-        exec->call(scope, cData);
-        if (scope.result.isNull())
-            break;
-        assert(scope.result.isObject());
-        index = rx->get(lastIndex, 0);
-        double thisIndex = index->toInteger();
-        if (previousLastIndex == thisIndex) {
-            previousLastIndex = thisIndex + 1;
-            rx->put(lastIndex, ScopedValue(scope, Primitive::fromDouble(previousLastIndex)));
-        } else {
-            previousLastIndex = thisIndex;
-        }
-        matchStr = scope.result.objectValue()->getIndexed(0);
-        a->arraySet(n, matchStr);
-        ++n;
+    Scope scope(v4);
+    ScopedString s(scope, thisAsString(v4, thisObject));
+    if (v4->hasException)
+        return Encode::undefined();
+    if (!argc)
+        return s->asReturnedValue();
+
+    int maxLen = argv[0].toInteger();
+    if (maxLen <= s->d()->length())
+        return s->asReturnedValue();
+    QString fillString = (argc > 1 && !argv[1].isUndefined()) ? argv[1].toQString() : QString::fromLatin1(" ");
+    if (v4->hasException)
+        return Encode::undefined();
+
+    if (fillString.isEmpty())
+        return s->asReturnedValue();
+
+    QString original = s->toQString();
+    int oldLength = original.length();
+    int toFill = maxLen - oldLength;
+    QString padded;
+    padded.resize(maxLen);
+    QChar *ch = padded.data();
+    while (toFill) {
+        int copy = qMin(fillString.length(), toFill);
+        memcpy(ch, fillString.constData(), copy*sizeof(QChar));
+        toFill -= copy;
+        ch += copy;
     }
-    if (!n)
-        scope.result = Encode::null();
-    else
-        scope.result = a;
+    memcpy(ch, original.constData(), oldLength*sizeof(QChar));
+    ch += oldLength;
+    *ch = 0;
+
+    return v4->newString(padded)->asReturnedValue();
 }
 
-void StringPrototype::method_repeat(const BuiltinFunction *, Scope &scope, CallData *callData)
+
+ReturnedValue StringPrototype::method_repeat(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    double repeats = callData->args[0].toInteger();
+    double repeats = (argc ? argv[0] : Value::undefinedValue()).toInteger();
 
-    if (repeats < 0 || qIsInf(repeats)) {
-        scope.result = scope.engine->throwRangeError(QLatin1String("Invalid count value"));
-        return;
-    }
+    if (repeats < 0 || qIsInf(repeats))
+        return v4->throwRangeError(QLatin1String("Invalid count value"));
 
-    scope.result = scope.engine->newString(value.repeated(int(repeats)));
+    return Encode(v4->newString(value.repeated(int(repeats))));
 }
 
 static void appendReplacementString(QString *result, const QString &input, const QString& replaceValue, uint* matchOffsets, int captureCount)
@@ -472,54 +722,65 @@ static void appendReplacementString(QString *result, const QString &input, const
     result->reserve(result->length() + replaceValue.length());
     for (int i = 0; i < replaceValue.length(); ++i) {
         if (replaceValue.at(i) == QLatin1Char('$') && i < replaceValue.length() - 1) {
-            ushort ch = replaceValue.at(++i).unicode();
+            ushort ch = replaceValue.at(i + 1).unicode();
             uint substStart = JSC::Yarr::offsetNoMatch;
             uint substEnd = JSC::Yarr::offsetNoMatch;
+            int skip = 0;
             if (ch == '$') {
                 *result += QChar(ch);
+                ++i;
                 continue;
             } else if (ch == '&') {
                 substStart = matchOffsets[0];
                 substEnd = matchOffsets[1];
+                skip = 1;
             } else if (ch == '`') {
                 substStart = 0;
                 substEnd = matchOffsets[0];
+                skip = 1;
             } else if (ch == '\'') {
                 substStart = matchOffsets[1];
                 substEnd = input.length();
-            } else if (ch >= '1' && ch <= '9') {
+                skip = 1;
+            } else if (ch >= '0' && ch <= '9') {
                 uint capture = ch - '0';
-                Q_ASSERT(capture > 0);
-                if (capture < static_cast<uint>(captureCount)) {
+                skip = 1;
+                if (i < replaceValue.length() - 2) {
+                    ch = replaceValue.at(i + 2).unicode();
+                    if (ch >= '0' && ch <= '9') {
+                        uint c = capture*10 + ch - '0';
+                        if (c < static_cast<uint>(captureCount)) {
+                            capture = c;
+                            skip = 2;
+                        }
+                    }
+                }
+                if (capture > 0 && capture < static_cast<uint>(captureCount)) {
                     substStart = matchOffsets[capture * 2];
                     substEnd = matchOffsets[capture * 2 + 1];
-                }
-            } else if (ch == '0' && i < replaceValue.length() - 1) {
-                int capture = (ch - '0') * 10;
-                ch = replaceValue.at(++i).unicode();
-                if (ch >= '0' && ch <= '9') {
-                    capture += ch - '0';
-                    if (capture > 0 && capture < captureCount) {
-                        substStart = matchOffsets[capture * 2];
-                        substEnd = matchOffsets[capture * 2 + 1];
-                    }
+                } else {
+                    skip = 0;
                 }
             }
+            i += skip;
             if (substStart != JSC::Yarr::offsetNoMatch && substEnd != JSC::Yarr::offsetNoMatch)
                 *result += input.midRef(substStart, substEnd - substStart);
+            else {
+                *result += replaceValue.at(i);
+            }
         } else {
             *result += replaceValue.at(i);
         }
     }
 }
 
-void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_replace(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
     QString string;
-    if (StringObject *thisString = callData->thisObject.as<StringObject>())
+    if (const StringObject *thisString = thisObject->as<StringObject>())
         string = thisString->d()->string->toQString();
     else
-        string = callData->thisObject.toQString();
+        string = thisObject->toQString();
 
     int numCaptures = 0;
     int numStringMatches = 0;
@@ -528,7 +789,8 @@ void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, Call
     uint _matchOffsets[64];
     uint *matchOffsets = _matchOffsets;
 
-    ScopedValue searchValue(scope, callData->argument(0));
+    Scope scope(b);
+    ScopedValue searchValue(scope, argc ? argv[0] : Value::undefinedValue());
     Scoped<RegExpObject> regExp(scope, searchValue);
     if (regExp) {
         uint offset = 0;
@@ -551,12 +813,15 @@ void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, Call
                 break;
             }
             nMatchOffsets += re->captureCount() * 2;
-            if (!regExp->d()->global)
+            if (!regExp->global())
                 break;
             offset = qMax(offset + 1, matchOffsets[oldSize + 1]);
         }
-        if (regExp->global())
+        if (regExp->global()) {
             regExp->setLastIndex(0);
+            if (scope.hasException())
+                return Encode::undefined();
+        }
         numStringMatches = nMatchOffsets / (regExp->value()->captureCount() * 2);
         numCaptures = regExp->value()->captureCount();
     } else {
@@ -571,33 +836,34 @@ void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, Call
     }
 
     QString result;
-    ScopedValue replaceValue(scope, callData->argument(1));
+    ScopedValue replacement(scope);
+    ScopedValue replaceValue(scope, argc > 1 ? argv[1] : Value::undefinedValue());
     ScopedFunctionObject searchCallback(scope, replaceValue);
     if (!!searchCallback) {
         result.reserve(string.length() + 10*numStringMatches);
-        ScopedCallData callData(scope, numCaptures + 2);
-        callData->thisObject = Primitive::undefinedValue();
-        int lastEnd = 0;
         ScopedValue entry(scope);
+        Value *arguments = scope.alloc(numCaptures + 2);
+        int lastEnd = 0;
         for (int i = 0; i < numStringMatches; ++i) {
             for (int k = 0; k < numCaptures; ++k) {
                 int idx = (i * numCaptures + k) * 2;
                 uint start = matchOffsets[idx];
                 uint end = matchOffsets[idx + 1];
-                entry = Primitive::undefinedValue();
+                entry = Value::undefinedValue();
                 if (start != JSC::Yarr::offsetNoMatch && end != JSC::Yarr::offsetNoMatch)
                     entry = scope.engine->newString(string.mid(start, end - start));
-                callData->args[k] = entry;
+                arguments[k] = entry;
             }
             uint matchStart = matchOffsets[i * numCaptures * 2];
             Q_ASSERT(matchStart >= static_cast<uint>(lastEnd));
             uint matchEnd = matchOffsets[i * numCaptures * 2 + 1];
-            callData->args[numCaptures] = Primitive::fromUInt32(matchStart);
-            callData->args[numCaptures + 1] = scope.engine->newString(string);
+            arguments[numCaptures] = Value::fromUInt32(matchStart);
+            arguments[numCaptures + 1] = scope.engine->newString(string);
 
-            searchCallback->call(scope, callData);
+            Value that = Value::undefinedValue();
+            replacement = searchCallback->call(&that, arguments, numCaptures + 2);
             result += string.midRef(lastEnd, matchStart - lastEnd);
-            result += scope.result.toQString();
+            result += replacement->toQString();
             lastEnd = matchEnd;
         }
         result += string.midRef(lastEnd);
@@ -623,44 +889,47 @@ void StringPrototype::method_replace(const BuiltinFunction *, Scope &scope, Call
     if (matchOffsets != _matchOffsets)
         free(matchOffsets);
 
-    scope.result = scope.engine->newString(result);
+    return Encode(scope.engine->newString(result));
 }
 
-void StringPrototype::method_search(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_search(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString string = getThisString(scope, callData);
-    scope.result = callData->argument(0);
-    CHECK_EXCEPTION();
+    Scope scope(b);
+    QString string = getThisString(scope.engine, thisObject);
+    if (scope.engine->hasException)
+        return QV4::Encode::undefined();
 
-    Scoped<RegExpObject> regExp(scope, scope.result.as<RegExpObject>());
+    Scoped<RegExpObject> regExp(scope, argc ? argv[0] : Value::undefinedValue());
     if (!regExp) {
-        ScopedCallData callData(scope, 1);
-        callData->args[0] = scope.result;
-        scope.engine->regExpCtor()->construct(scope, callData);
-        CHECK_EXCEPTION();
+        regExp = scope.engine->regExpCtor()->callAsConstructor(argv, 1);
+        if (scope.engine->hasException)
+            return QV4::Encode::undefined();
 
-        regExp = scope.result.as<RegExpObject>();
         Q_ASSERT(regExp);
     }
     Scoped<RegExp> re(scope, regExp->value());
     Q_ALLOCA_VAR(uint, matchOffsets, regExp->value()->captureCount() * 2 * sizeof(uint));
     uint result = re->match(string, /*offset*/0, matchOffsets);
     if (result == JSC::Yarr::offsetNoMatch)
-        scope.result = Encode(-1);
+        return Encode(-1);
     else
-        scope.result = Encode(result);
+        return Encode(result);
 }
 
-void StringPrototype::method_slice(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    const QString text = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    Scope scope(v4);
+    ScopedString s(scope, thisAsString(v4, thisObject));
+    if (v4->hasException)
+        return QV4::Encode::undefined();
+    Q_ASSERT(s);
 
-    const double length = text.length();
+    const double length = s->d()->length();
 
-    double start = callData->argc ? callData->args[0].toInteger() : 0;
-    double end = (callData->argc < 2 || callData->args[1].isUndefined())
-            ? length : callData->args[1].toInteger();
+    double start = argc ? argv[0].toInteger() : 0;
+    double end = (argc < 2 || argv[1].isUndefined())
+            ? length : argv[1].toInteger();
 
     if (start < 0)
         start = qMax(length + start, 0.);
@@ -676,16 +945,19 @@ void StringPrototype::method_slice(const BuiltinFunction *, Scope &scope, CallDa
     const int intEnd = int(end);
 
     int count = qMax(0, intEnd - intStart);
-    scope.result = scope.engine->newString(text.mid(intStart, count));
+    return Encode(v4->memoryManager->alloc<ComplexString>(s->d(), intStart, count));
 }
 
-void StringPrototype::method_split(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_split(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString text = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    QString text = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    ScopedValue separatorValue(scope, callData->argument(0));
-    ScopedValue limitValue(scope, callData->argument(1));
+    Scope scope(v4);
+    ScopedValue separatorValue(scope, argc ? argv[0] : Value::undefinedValue());
+    ScopedValue limitValue(scope, argc > 1 ? argv[1] : Value::undefinedValue());
 
     ScopedArrayObject array(scope, scope.engine->newArrayObject());
 
@@ -693,7 +965,7 @@ void StringPrototype::method_split(const BuiltinFunction *, Scope &scope, CallDa
         if (limitValue->isUndefined()) {
             ScopedString s(scope, scope.engine->newString(text));
             array->push_back(s);
-            RETURN_RESULT(array);
+            return array.asReturnedValue();
         }
         RETURN_RESULT(scope.engine->newString(text.left(limitValue->toInteger())));
     }
@@ -701,12 +973,12 @@ void StringPrototype::method_split(const BuiltinFunction *, Scope &scope, CallDa
     uint limit = limitValue->isUndefined() ? UINT_MAX : limitValue->toUInt32();
 
     if (limit == 0)
-        RETURN_RESULT(array);
+        return array.asReturnedValue();
 
     Scoped<RegExpObject> re(scope, separatorValue);
     if (re) {
         if (re->value()->pattern->isEmpty()) {
-            re = (RegExpObject *)0;
+            re = (RegExpObject *)nullptr;
             separatorValue = scope.engine->newString();
         }
     }
@@ -742,7 +1014,7 @@ void StringPrototype::method_split(const BuiltinFunction *, Scope &scope, CallDa
         if (separator.isEmpty()) {
             for (uint i = 0; i < qMin(limit, uint(text.length())); ++i)
                 array->push_back((s = scope.engine->newString(text.mid(i, 1))));
-            RETURN_RESULT(array);
+            return array.asReturnedValue();
         }
 
         int start = 0;
@@ -756,44 +1028,47 @@ void StringPrototype::method_split(const BuiltinFunction *, Scope &scope, CallDa
         if (array->getLength() < limit && start != -1)
             array->push_back((s = scope.engine->newString(text.mid(start))));
     }
-    RETURN_RESULT(array);
+    return array.asReturnedValue();
 }
 
-void StringPrototype::method_startsWith(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_startsWith(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    QString searchString;
-    if (callData->argc) {
-        if (callData->args[0].as<RegExpObject>())
-            THROW_TYPE_ERROR();
-        searchString = callData->args[0].toQString();
-    }
+    if (argc && argv[0].as<RegExpObject>())
+        return v4->throwTypeError();
+    QString searchString = (argc ? argv[0] : Value::undefinedValue()).toQString();
+    if (v4->hasException)
+        return Encode::undefined();
 
     int pos = 0;
-    if (callData->argc > 1)
-        pos = (int) callData->args[1].toInteger();
+    if (argc > 1)
+        pos = (int) argv[1].toInteger();
 
     if (pos == 0)
-        RETURN_RESULT(Encode(value.startsWith(searchString)));
+        return Encode(value.startsWith(searchString));
 
     QStringRef stringToSearch = value.midRef(pos);
     RETURN_RESULT(Encode(stringToSearch.startsWith(searchString)));
 }
 
-void StringPrototype::method_substr(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_substr(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    const QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     double start = 0;
-    if (callData->argc > 0)
-        start = callData->args[0].toInteger();
+    if (argc > 0)
+        start = argv[0].toInteger();
 
     double length = +qInf();
-    if (callData->argc > 1)
-        length = callData->args[1].toInteger();
+    if (argc > 1)
+        length = argv[1].toInteger();
 
     double count = value.length();
     if (start < 0)
@@ -801,27 +1076,28 @@ void StringPrototype::method_substr(const BuiltinFunction *, Scope &scope, CallD
 
     length = qMin(qMax(length, 0.0), count - start);
 
-    qint32 x = Primitive::toInt32(start);
-    qint32 y = Primitive::toInt32(length);
-    scope.result = scope.engine->newString(value.mid(x, y));
+    qint32 x = Value::toInt32(start);
+    qint32 y = Value::toInt32(length);
+    return Encode(v4->newString(value.mid(x, y)));
 }
 
-void StringPrototype::method_substring(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_substring(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     int length = value.length();
 
     double start = 0;
     double end = length;
 
-    if (callData->argc > 0)
-        start = callData->args[0].toInteger();
+    if (argc > 0)
+        start = argv[0].toInteger();
 
-    ScopedValue endValue(scope, callData->argument(1));
-    if (!endValue->isUndefined())
-        end = endValue->toInteger();
+    if (argc > 1 && !argv[1].isUndefined())
+        end = argv[1].toInteger();
 
     if (std::isnan(start) || start < 0)
         start = 0;
@@ -843,50 +1119,45 @@ void StringPrototype::method_substring(const BuiltinFunction *, Scope &scope, Ca
 
     qint32 x = (int)start;
     qint32 y = (int)(end - start);
-    scope.result = scope.engine->newString(value.mid(x, y));
+    return Encode(v4->newString(value.mid(x, y)));
 }
 
-void StringPrototype::method_toLowerCase(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_toLowerCase(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-    scope.result = scope.engine->newString(value.toLower());
+    return Encode(v4->newString(value.toLower()));
 }
 
-void StringPrototype::method_toLocaleLowerCase(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_toLocaleLowerCase(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    method_toLowerCase(b, scope, callData);
+    return method_toLowerCase(b, thisObject, argv, argc);
 }
 
-void StringPrototype::method_toUpperCase(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_toUpperCase(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QString value = getThisString(scope, callData);
-    CHECK_EXCEPTION();
-
-    scope.result = scope.engine->newString(value.toUpper());
-}
+    ExecutionEngine *v4 = b->engine();
+    const QString value = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
-void StringPrototype::method_toLocaleUpperCase(const BuiltinFunction *b, Scope &scope, CallData *callData)
-{
-    return method_toUpperCase(b, scope, callData);
+    return Encode(v4->newString(value.toUpper()));
 }
 
-void StringPrototype::method_fromCharCode(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_toLocaleUpperCase(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QString str(callData->argc, Qt::Uninitialized);
-    QChar *ch = str.data();
-    for (int i = 0; i < callData->argc; ++i) {
-        *ch = QChar(callData->args[i].toUInt16());
-        ++ch;
-    }
-    scope.result = scope.engine->newString(str);
+    return method_toUpperCase(b, thisObject, argv, argc);
 }
 
-void StringPrototype::method_trim(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue StringPrototype::method_trim(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QString s = getThisString(scope, callData);
-    CHECK_EXCEPTION();
+    ExecutionEngine *v4 = b->engine();
+    QString s = getThisString(v4, thisObject);
+    if (v4->hasException)
+        return QV4::Encode::undefined();
 
     const QChar *chars = s.constData();
     int start, end;
@@ -899,5 +1170,18 @@ void StringPrototype::method_trim(const BuiltinFunction *, Scope &scope, CallDat
             break;
     }
 
-    scope.result = scope.engine->newString(QString(chars + start, end - start + 1));
+    return Encode(v4->newString(QString(chars + start, end - start + 1)));
+}
+
+
+
+ReturnedValue StringPrototype::method_iterator(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    ScopedString s(scope, thisObject->toString(scope.engine));
+    if (!s || thisObject->isNullOrUndefined())
+        return scope.engine->throwTypeError();
+
+    Scoped<StringIteratorObject> si(scope, scope.engine->memoryManager->allocate<StringIteratorObject>(s->d(), scope.engine));
+    return si->asReturnedValue();
 }
diff --git a/src/qml/jsruntime/qv4stringobject_p.h b/src/qml/jsruntime/qv4stringobject_p.h
index ce046f4844..794ee91575 100644
--- a/src/qml/jsruntime/qv4stringobject_p.h
+++ b/src/qml/jsruntime/qv4stringobject_p.h
@@ -64,12 +64,14 @@ namespace Heap {
     Member(class, Pointer, String *, string)
 
 DECLARE_HEAP_OBJECT(StringObject, Object) {
-    DECLARE_MARK_TABLE(StringObject);
+    DECLARE_MARKOBJECTS(StringObject);
 
     enum {
         LengthPropertyIndex = 0
     };
 
+    void init(bool /*don't init*/)
+    { Object::init(); }
     void init();
     void init(const QV4::String *string);
 
@@ -96,18 +98,23 @@ struct StringObject: Object {
         return d()->length();
     }
 
-    static bool deleteIndexedProperty(Managed *m, uint index);
-
+    using Object::getOwnProperty;
 protected:
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attrs);
+    static bool virtualDeleteProperty(Managed *m, PropertyKey id);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
 };
 
 struct StringCtor: FunctionObject
 {
     V4_OBJECT2(StringCtor, FunctionObject)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
-    static void call(const Managed *, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_fromCharCode(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_fromCodePoint(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_raw(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct StringPrototype: StringObject
@@ -115,30 +122,34 @@ struct StringPrototype: StringObject
     V4_PROTOTYPE(objectPrototype)
     void init(ExecutionEngine *engine, Object *ctor);
 
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_charAt(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_charCodeAt(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_concat(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_endsWith(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_indexOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_includes(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_lastIndexOf(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_localeCompare(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_match(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_repeat(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_replace(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_search(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_slice(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_split(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_startsWith(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_substr(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_substring(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLowerCase(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleLowerCase(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toUpperCase(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toLocaleUpperCase(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_fromCharCode(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_trim(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_charAt(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_charCodeAt(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_codePointAt(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_concat(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_endsWith(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_indexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_includes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_lastIndexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_localeCompare(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_match(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_normalize(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_padEnd(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_padStart(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_repeat(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_replace(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_search(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_split(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_startsWith(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_substr(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_substring(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLowerCase(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleLowerCase(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toUpperCase(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleUpperCase(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_trim(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_iterator(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4symbol.cpp b/src/qml/jsruntime/qv4symbol.cpp
new file mode 100644
index 0000000000..004a9938e2
--- /dev/null
+++ b/src/qml/jsruntime/qv4symbol.cpp
@@ -0,0 +1,187 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qv4symbol_p.h>
+#include <qv4functionobject_p.h>
+#include <qv4identifiertable_p.h>
+
+using namespace QV4;
+
+DEFINE_OBJECT_VTABLE(SymbolCtor);
+DEFINE_MANAGED_VTABLE(Symbol);
+DEFINE_OBJECT_VTABLE(SymbolObject);
+
+void Heap::Symbol::init(const QString &s)
+{
+    Q_ASSERT(s.at(0) == QLatin1Char('@'));
+    identifier = PropertyKey::fromStringOrSymbol(this);
+    QString desc(s);
+    text = desc.data_ptr();
+    text->ref.ref();
+}
+
+void Heap::SymbolCtor::init(QV4::ExecutionContext *scope)
+{
+    Heap::FunctionObject::init(scope, QStringLiteral("Symbol"));
+}
+
+void Heap::SymbolObject::init(const QV4::Symbol *s)
+{
+    Object::init();
+    symbol.set(internalClass->engine, s->d());
+}
+
+ReturnedValue QV4::SymbolCtor::virtualCall(const QV4::FunctionObject *f, const QV4::Value *, const QV4::Value *argv, int argc)
+{
+    Scope scope(f);
+    QString desc = QChar::fromLatin1('@');
+    if (argc && !argv[0].isUndefined()) {
+        ScopedString s(scope, argv[0].toString(scope.engine));
+        if (scope.hasException())
+            return Encode::undefined();
+        desc += s->toQString();
+    }
+    return Symbol::create(scope.engine, desc)->asReturnedValue();
+}
+
+ReturnedValue SymbolCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *, int, const Value *)
+{
+    return f->engine()->throwTypeError(QStringLiteral("Symbol can't be used together with |new|."));
+}
+
+ReturnedValue SymbolCtor::method_for(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    Scope scope(f);
+    ScopedValue k(scope, argc ? argv[0]: Value::undefinedValue());
+    ScopedString key(scope, k->toString(scope.engine));
+    if (scope.hasException())
+        return Encode::undefined();
+    QString desc = QLatin1Char('@') + key->toQString();
+    return scope.engine->identifierTable->insertSymbol(desc)->asReturnedValue();
+}
+
+ReturnedValue SymbolCtor::method_keyFor(const FunctionObject *f, const Value *, const Value *argv, int argc)
+{
+    ExecutionEngine *e = f->engine();
+    if (!argc || !argv[0].isSymbol())
+        return e->throwTypeError(QLatin1String("Symbol.keyFor: Argument is not a symbol."));
+    const Symbol &arg = static_cast<const Symbol &>(argv[0]);
+    Heap::Symbol *s = e->identifierTable->symbolForId(arg.propertyKey());
+    Q_ASSERT(!s || s == arg.d());
+    if (s)
+        return e->newString(arg.toQString().mid((1)))->asReturnedValue();
+    return Encode::undefined();
+}
+
+void SymbolPrototype::init(ExecutionEngine *engine, Object *ctor)
+{
+    Scope scope(engine);
+    ScopedValue v(scope);
+    ctor->defineReadonlyProperty(engine->id_prototype(), (v = this));
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
+
+    ctor->defineDefaultProperty(QStringLiteral("for"), SymbolCtor::method_for, 1);
+    ctor->defineDefaultProperty(QStringLiteral("keyFor"), SymbolCtor::method_keyFor, 1);
+    ctor->defineReadonlyProperty(QStringLiteral("hasInstance"), *engine->symbol_hasInstance());
+    ctor->defineReadonlyProperty(QStringLiteral("isConcatSpreadable"), *engine->symbol_isConcatSpreadable());
+    ctor->defineReadonlyProperty(QStringLiteral("iterator"), *engine->symbol_iterator());
+    ctor->defineReadonlyProperty(QStringLiteral("match"), *engine->symbol_match());
+    ctor->defineReadonlyProperty(QStringLiteral("replace"), *engine->symbol_replace());
+    ctor->defineReadonlyProperty(QStringLiteral("search"), *engine->symbol_search());
+    ctor->defineReadonlyProperty(QStringLiteral("species"), *engine->symbol_species());
+    ctor->defineReadonlyProperty(QStringLiteral("split"), *engine->symbol_split());
+    ctor->defineReadonlyProperty(QStringLiteral("toPrimitive"), *engine->symbol_toPrimitive());
+    ctor->defineReadonlyProperty(QStringLiteral("toStringTag"), *engine->symbol_toStringTag());
+    ctor->defineReadonlyProperty(QStringLiteral("unscopables"), *engine->symbol_unscopables());
+
+    defineDefaultProperty(QStringLiteral("constructor"), (v = ctor));
+    defineDefaultProperty(QStringLiteral("toString"), method_toString);
+    defineDefaultProperty(QStringLiteral("valueOf"), method_valueOf);
+    defineDefaultProperty(engine->symbol_toPrimitive(), method_symbolToPrimitive, 1, Attr_ReadOnly_ButConfigurable);
+
+    v = engine->newString(QStringLiteral("Symbol"));
+    defineReadonlyConfigurableProperty(engine->symbol_toStringTag(), v);
+
+}
+
+ReturnedValue SymbolPrototype::method_toString(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<Symbol> s(scope, thisObject->as<Symbol>());
+    if (!s) {
+        if (const SymbolObject *o = thisObject->as<SymbolObject>())
+            s = o->d()->symbol;
+        else
+            return scope.engine->throwTypeError();
+    }
+    return scope.engine->newString(s->descriptiveString())->asReturnedValue();
+}
+
+ReturnedValue SymbolPrototype::method_valueOf(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    Scope scope(f);
+    Scoped<Symbol> s(scope, thisObject->as<Symbol>());
+    if (!s) {
+        if (const SymbolObject *o = thisObject->as<SymbolObject>())
+            s = o->d()->symbol;
+        else
+            return scope.engine->throwTypeError();
+    }
+    return s->asReturnedValue();
+}
+
+ReturnedValue SymbolPrototype::method_symbolToPrimitive(const FunctionObject *f, const Value *thisObject, const Value *, int)
+{
+    if (thisObject->isSymbol())
+        return thisObject->asReturnedValue();
+    if (const SymbolObject *o = thisObject->as<SymbolObject>())
+        return o->d()->symbol->asReturnedValue();
+    return f->engine()->throwTypeError();
+}
+
+Heap::Symbol *Symbol::create(ExecutionEngine *e, const QString &s)
+{
+    Q_ASSERT(s.at(0) == QLatin1Char('@'));
+    return e->memoryManager->alloc<Symbol>(s);
+}
+
+QString Symbol::descriptiveString() const
+{
+    return QLatin1String("Symbol(") + toQString().midRef(1) + QLatin1String(")");
+}
diff --git a/src/qml/jsruntime/qv4symbol_p.h b/src/qml/jsruntime/qv4symbol_p.h
new file mode 100644
index 0000000000..c7e12b512b
--- /dev/null
+++ b/src/qml/jsruntime/qv4symbol_p.h
@@ -0,0 +1,126 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4_SYMBOL_H
+#define QV4_SYMBOL_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4string_p.h"
+#include "qv4functionobject_p.h"
+
+QT_BEGIN_NAMESPACE
+
+
+namespace QV4 {
+
+namespace Heap {
+
+struct SymbolCtor : FunctionObject {
+    void init(QV4::ExecutionContext *scope);
+};
+
+struct Symbol : StringOrSymbol {
+    void init(const QString &s);
+};
+
+#define SymbolObjectMembers(class, Member) \
+    Member(class, Pointer, Symbol *, symbol)
+
+DECLARE_HEAP_OBJECT(SymbolObject, Object) {
+    DECLARE_MARKOBJECTS(SymbolObject);
+    void init(const QV4::Symbol *s);
+};
+
+}
+
+struct SymbolCtor : FunctionObject
+{
+    V4_OBJECT2(SymbolCtor, FunctionObject)
+
+    static ReturnedValue virtualCall(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *, const Value *argv, int argc, const Value *newTarget);
+    static ReturnedValue method_for(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_keyFor(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct SymbolPrototype : Object
+{
+    V4_PROTOTYPE(objectPrototype)
+    void init(ExecutionEngine *engine, Object *ctor);
+
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_symbolToPrimitive(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+};
+
+struct Symbol : StringOrSymbol
+{
+    V4_MANAGED(Symbol, StringOrSymbol)
+    Q_MANAGED_TYPE(Symbol)
+    V4_INTERNALCLASS(Symbol)
+    V4_NEEDS_DESTROY
+
+    static Heap::Symbol *create(ExecutionEngine *e, const QString &s);
+
+    QString descriptiveString() const;
+};
+
+struct SymbolObject : Object
+{
+    V4_OBJECT2(SymbolObject, Object)
+    Q_MANAGED_TYPE(SymbolObject)
+    V4_INTERNALCLASS(SymbolObject)
+    V4_PROTOTYPE(symbolPrototype)
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/jsruntime/qv4typedarray.cpp b/src/qml/jsruntime/qv4typedarray.cpp
index fe27d7c2d2..d83f021450 100644
--- a/src/qml/jsruntime/qv4typedarray.cpp
+++ b/src/qml/jsruntime/qv4typedarray.cpp
@@ -36,169 +36,241 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
+
 #include "qv4typedarray_p.h"
+#include "qv4arrayiterator_p.h"
 #include "qv4arraybuffer_p.h"
 #include "qv4string_p.h"
+#include "qv4jscall_p.h"
+#include "qv4symbol_p.h"
+#include "qv4runtime_p.h"
+#include <QtCore/qatomic.h>
 
 #include <cmath>
 
 using namespace QV4;
 
+DEFINE_OBJECT_VTABLE(IntrinsicTypedArrayCtor);
+DEFINE_OBJECT_VTABLE(IntrinsicTypedArrayPrototype);
 DEFINE_OBJECT_VTABLE(TypedArrayCtor);
 DEFINE_OBJECT_VTABLE(TypedArrayPrototype);
 DEFINE_OBJECT_VTABLE(TypedArray);
 
-Q_STATIC_ASSERT((int)ExecutionEngine::NTypedArrayTypes == (int)Heap::TypedArray::NTypes);
+Q_STATIC_ASSERT((int)ExecutionEngine::NTypedArrayTypes == (int)NTypedArrayTypes);
 
-ReturnedValue Int8ArrayRead(const char *data, int index)
+static inline int toInt32(Value v)
 {
-    return Encode((int)(signed char)data[index]);
+    Q_ASSERT(v.isNumber());
+    if (v.isInteger())
+        return v.integerValue();
+    return Double::toInt32(v.doubleValue());
 }
 
-void Int8ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+static inline double toDouble(Value v)
 {
-    signed char v = (signed char)value.toUInt32();
-    if (e->hasException)
-        return;
-    data[index] = v;
+    Q_ASSERT(v.isNumber());
+    if (v.isInteger())
+        return v.integerValue();
+    return v.doubleValue();
 }
 
-ReturnedValue UInt8ArrayRead(const char *data, int index)
-{
-    return Encode((int)(unsigned char)data[index]);
+struct ClampedUInt8 {
+    quint8 c;
+};
+
+template <typename T>
+ReturnedValue typeToValue(T t) {
+    return Encode(t);
+}
+
+template <>
+ReturnedValue typeToValue(ClampedUInt8 t) {
+    return Encode(t.c);
 }
 
-void UInt8ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <typename T>
+T valueToType(Value value)
 {
-    unsigned char v = (unsigned char)value.toUInt32();
-    if (e->hasException)
-        return;
-    data[index] = v;
+    Q_ASSERT(value.isNumber());
+    int n = toInt32(value);
+    return static_cast<T>(n);
 }
 
-void UInt8ClampedArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <>
+ClampedUInt8 valueToType(Value value)
 {
-    if (value.isInteger()) {
-        data[index] = (char)(unsigned char)qBound(0, value.integerValue(), 255);
-        return;
-    }
-    double d = value.toNumber();
-    if (e->hasException)
-        return;
+    Q_ASSERT(value.isNumber());
+    if (value.isInteger())
+        return { static_cast<quint8>(qBound(0, value.integerValue(), 255)) };
+    Q_ASSERT(value.isDouble());
+    double d = value.doubleValue();
     // ### is there a way to optimise this?
-    if (d <= 0 || std::isnan(d)) {
-        data[index] = 0;
-        return;
-    }
-    if (d >= 255) {
-        data[index] = (char)(255);
-        return;
-    }
+    if (d <= 0 || std::isnan(d))
+        return { 0 };
+    if (d >= 255)
+        return { 255 };
     double f = std::floor(d);
-    if (f + 0.5 < d) {
-        data[index] = (unsigned char)(f + 1);
-        return;
-    }
-    if (d < f + 0.5) {
-        data[index] = (unsigned char)(f);
-        return;
-    }
-    if (int(f) % 2) {
+    if (f + 0.5 < d)
+        return { (quint8)(f + 1) };
+    if (d < f + 0.5)
+        return { (quint8)(f) };
+    if (int(f) % 2)
         // odd number
-        data[index] = (unsigned char)(f + 1);
-        return;
-    }
-    data[index] = (unsigned char)(f);
+        return { (quint8)(f + 1) };
+    return { (quint8)(f) };
+}
+
+template <>
+float valueToType(Value value)
+{
+    Q_ASSERT(value.isNumber());
+    double d = toDouble(value);
+    return static_cast<float>(d);
+}
+
+template <>
+double valueToType(Value value)
+{
+    Q_ASSERT(value.isNumber());
+    return toDouble(value);
 }
 
-ReturnedValue Int16ArrayRead(const char *data, int index)
+template <typename T>
+ReturnedValue read(const char *data) {
+    return typeToValue(*reinterpret_cast<const T *>(data));
+}
+template <typename T>
+void write(char *data, Value value)
 {
-    return Encode((int)*(const short *)(data + index));
+    *reinterpret_cast<T *>(data) = valueToType<T>(value);
 }
 
-void Int16ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <typename T>
+ReturnedValue atomicAdd(char *data, Value v)
 {
-    short v = (short)value.toInt32();
-    if (e->hasException)
-        return;
-    *(short *)(data + index) = v;
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    value = QAtomicOps<T>::fetchAndAddOrdered(*mem, value);
+    return typeToValue(value);
 }
 
-ReturnedValue UInt16ArrayRead(const char *data, int index)
+template <typename T>
+ReturnedValue atomicAnd(char *data, Value v)
 {
-    return Encode((int)*(const unsigned short *)(data + index));
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    value = QAtomicOps<T>::fetchAndAndOrdered(*mem, value);
+    return typeToValue(value);
 }
 
-void UInt16ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <typename T>
+ReturnedValue atomicExchange(char *data, Value v)
 {
-    unsigned short v = (unsigned short)value.toInt32();
-    if (e->hasException)
-        return;
-    *(unsigned short *)(data + index) = v;
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    value = QAtomicOps<T>::fetchAndStoreOrdered(*mem, value);
+    return typeToValue(value);
 }
 
-ReturnedValue Int32ArrayRead(const char *data, int index)
+template <typename T>
+ReturnedValue atomicOr(char *data, Value v)
 {
-    return Encode(*(const int *)(data + index));
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    value = QAtomicOps<T>::fetchAndOrOrdered(*mem, value);
+    return typeToValue(value);
 }
 
-void Int32ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <typename T>
+ReturnedValue atomicSub(char *data, Value v)
 {
-    int v = (int)value.toInt32();
-    if (e->hasException)
-        return;
-    *(int *)(data + index) = v;
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    value = QAtomicOps<T>::fetchAndSubOrdered(*mem, value);
+    return typeToValue(value);
 }
 
-ReturnedValue UInt32ArrayRead(const char *data, int index)
+template <typename T>
+ReturnedValue atomicXor(char *data, Value v)
 {
-    return Encode(*(const unsigned int *)(data + index));
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    value = QAtomicOps<T>::fetchAndXorOrdered(*mem, value);
+    return typeToValue(value);
 }
 
-void UInt32ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <typename T>
+ReturnedValue atomicCompareExchange(char *data, Value expected, Value v)
 {
-    unsigned int v = (unsigned int)value.toUInt32();
-    if (e->hasException)
-        return;
-    *(unsigned int *)(data + index) = v;
+    T value = valueToType<T>(v);
+    T exp = valueToType<T>(expected);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    T old;
+    QAtomicOps<T>::testAndSetOrdered(*mem, exp, value, &old);
+    return typeToValue(old);
 }
 
-ReturnedValue Float32ArrayRead(const char *data, int index)
+template <typename T>
+ReturnedValue atomicLoad(char *data)
 {
-    return Encode(*(const float *)(data + index));
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    T val = QAtomicOps<T>::load(*mem);
+    return typeToValue(val);
 }
 
-void Float32ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template <typename T>
+ReturnedValue atomicStore(char *data, Value v)
 {
-    float v = value.toNumber();
-    if (e->hasException)
-        return;
-    *(float *)(data + index) = v;
+    T value = valueToType<T>(v);
+    typename QAtomicOps<T>::Type *mem = reinterpret_cast<typename QAtomicOps<T>::Type *>(data);
+    QAtomicOps<T>::store(*mem, value);
+    return typeToValue(value);
 }
 
-ReturnedValue Float64ArrayRead(const char *data, int index)
+
+template<typename T>
+constexpr TypedArrayOperations TypedArrayOperations::create(const char *name)
 {
-    return Encode(*(const double *)(data + index));
+    return { sizeof(T),
+             name,
+             ::read<T>,
+             ::write<T>,
+             { nullptr, nullptr, nullptr, nullptr, nullptr, nullptr },
+             nullptr,
+             nullptr,
+             nullptr
+    };
 }
 
-void Float64ArrayWrite(ExecutionEngine *e, char *data, int index, const Value &value)
+template<typename T>
+constexpr TypedArrayOperations TypedArrayOperations::createWithAtomics(const char *name)
 {
-    double v = value.toNumber();
-    if (e->hasException)
-        return;
-    *(double *)(data + index) = v;
+    return { sizeof(T),
+             name,
+             ::read<T>,
+             ::write<T>,
+             { ::atomicAdd<T>, ::atomicAnd<T>, ::atomicExchange<T>, ::atomicOr<T>, ::atomicSub<T>, ::atomicXor<T> },
+             ::atomicCompareExchange<T>,
+             ::atomicLoad<T>,
+             ::atomicStore<T>
+    };
 }
 
-const TypedArrayOperations operations[Heap::TypedArray::NTypes] = {
-    { 1, "Int8Array", Int8ArrayRead, Int8ArrayWrite },
-    { 1, "Uint8Array", UInt8ArrayRead, UInt8ArrayWrite },
-    { 1, "Uint8ClampedArray", UInt8ArrayRead, UInt8ClampedArrayWrite },
-    { 2, "Int16Array", Int16ArrayRead, Int16ArrayWrite },
-    { 2, "Uint16Array", UInt16ArrayRead, UInt16ArrayWrite },
-    { 4, "Int32Array", Int32ArrayRead, Int32ArrayWrite },
-    { 4, "Uint32Array", UInt32ArrayRead, UInt32ArrayWrite },
-    { 4, "Float32Array", Float32ArrayRead, Float32ArrayWrite },
-    { 8, "Float64Array", Float64ArrayRead, Float64ArrayWrite },
+const TypedArrayOperations operations[NTypedArrayTypes] = {
+#ifdef Q_ATOMIC_INT8_IS_SUPPORTED
+    TypedArrayOperations::createWithAtomics<qint8>("Int8Array"),
+    TypedArrayOperations::createWithAtomics<quint8>("Uint8Array"),
+#else
+    TypedArrayOperations::create<qint8>("Int8Array"),
+    TypedArrayOperations::create<quint8>("Uint8Array"),
+#endif
+    TypedArrayOperations::createWithAtomics<qint16>("Int16Array"),
+    TypedArrayOperations::createWithAtomics<quint16>("Uint16Array"),
+    TypedArrayOperations::createWithAtomics<qint32>("Int32Array"),
+    TypedArrayOperations::createWithAtomics<quint32>("Uint32Array"),
+    TypedArrayOperations::create<ClampedUInt8>("Uint8ClampedArray"),
+    TypedArrayOperations::create<float>("Float32Array"),
+    TypedArrayOperations::create<double>("Float64Array")
 };
 
 
@@ -208,49 +280,58 @@ void Heap::TypedArrayCtor::init(QV4::ExecutionContext *scope, TypedArray::Type t
     type = t;
 }
 
-void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callData)
+ReturnedValue TypedArrayCtor::virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *newTarget)
 {
-    Scoped<TypedArrayCtor> that(scope, static_cast<const TypedArrayCtor *>(m));
+    Scope scope(f->engine());
+    const TypedArrayCtor *that = static_cast<const TypedArrayCtor *>(f);
+
+    auto updateProto = [=](Scope &scope, Scoped<TypedArray> &a) {
+        if (newTarget->heapObject() != f->heapObject() && newTarget->isFunctionObject()) {
+            const FunctionObject *nt = static_cast<const FunctionObject *>(newTarget);
+            ScopedObject o(scope, nt->protoProperty());
+            if (o)
+                a->setPrototypeOf(o);
+        }
+    };
 
-    if (!callData->argc || !callData->args[0].isObject()) {
+    if (!argc || !argv[0].isObject()) {
         // ECMA 6 22.2.1.1
-        double l = callData->argc ? callData->args[0].toNumber() : 0;
-        if (scope.engine->hasException) {
-            scope.result = Encode::undefined();
-            return;
-        }
+        qint64 l = argc ? argv[0].toIndex() : 0;
+        if (scope.engine->hasException)
+            return Encode::undefined();
+        // ### lift UINT_MAX restriction
+        if (l < 0 || l > UINT_MAX)
+            return scope.engine->throwRangeError(QLatin1String("Index out of range."));
         uint len = (uint)l;
         if (l != len)
             scope.engine->throwRangeError(QStringLiteral("Non integer length for typed array."));
         uint byteLength = len * operations[that->d()->type].bytesPerElement;
         Scoped<ArrayBuffer> buffer(scope, scope.engine->newArrayBuffer(byteLength));
-        if (scope.engine->hasException) {
-            scope.result = Encode::undefined();
-            return;
-        }
+        if (scope.engine->hasException)
+            return Encode::undefined();
 
         Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
         array->d()->buffer.set(scope.engine, buffer->d());
         array->d()->byteLength = byteLength;
         array->d()->byteOffset = 0;
 
-        scope.result = array.asReturnedValue();
-        return;
+        updateProto(scope, array);
+        return array.asReturnedValue();
     }
-    Scoped<TypedArray> typedArray(scope, callData->argument(0));
+    Scoped<TypedArray> typedArray(scope, argc ? argv[0] : Value::undefinedValue());
     if (!!typedArray) {
         // ECMA 6 22.2.1.2
         Scoped<ArrayBuffer> buffer(scope, typedArray->d()->buffer);
+        if (!buffer || buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
         uint srcElementSize = typedArray->d()->type->bytesPerElement;
         uint destElementSize = operations[that->d()->type].bytesPerElement;
         uint byteLength = typedArray->d()->byteLength;
         uint destByteLength = byteLength*destElementSize/srcElementSize;
 
         Scoped<ArrayBuffer> newBuffer(scope, scope.engine->newArrayBuffer(destByteLength));
-        if (scope.engine->hasException) {
-            scope.result = Encode::undefined();
-            return;
-        }
+        if (scope.engine->hasException)
+            return Encode::undefined();
 
         Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
         array->d()->buffer.set(scope.engine, newBuffer->d());
@@ -266,48 +347,46 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
         } else {
             // not same size, we need to loop
             uint l = typedArray->length();
-            TypedArrayRead read = typedArray->d()->type->read;
-            TypedArrayWrite write =array->d()->type->write;
+            TypedArrayOperations::Read read = typedArray->d()->type->read;
+            TypedArrayOperations::Write write =array->d()->type->write;
             for (uint i = 0; i < l; ++i) {
-                Primitive val;
-                val.setRawValue(read(src, i*srcElementSize));
-                write(scope.engine, dest, i*destElementSize, val);
+                Value val;
+                val.setRawValue(read(src + i*srcElementSize));
+                write(dest + i*destElementSize, val);
             }
         }
 
-        scope.result =  array.asReturnedValue();
-        return;
+        updateProto(scope, array);
+        return array.asReturnedValue();
     }
-    Scoped<ArrayBuffer> buffer(scope, callData->argument(0));
+    Scoped<ArrayBuffer> buffer(scope, argc ? argv[0] : Value::undefinedValue());
     if (!!buffer) {
         // ECMA 6 22.2.1.4
 
-        double dbyteOffset = callData->argc > 1 ? callData->args[1].toInteger() : 0;
+        double dbyteOffset = argc > 1 ? argv[1].toInteger() : 0;
+
+        if (buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+
         uint byteOffset = (uint)dbyteOffset;
         uint elementSize = operations[that->d()->type].bytesPerElement;
-        if (dbyteOffset < 0 || (byteOffset % elementSize) || dbyteOffset > buffer->byteLength()) {
-            scope.result = scope.engine->throwRangeError(QStringLiteral("new TypedArray: invalid byteOffset"));
-            return;
-        }
+        if (dbyteOffset < 0 || (byteOffset % elementSize) || dbyteOffset > buffer->byteLength())
+            return scope.engine->throwRangeError(QStringLiteral("new TypedArray: invalid byteOffset"));
 
         uint byteLength;
-        if (callData->argc < 3 || callData->args[2].isUndefined()) {
+        if (argc < 3 || argv[2].isUndefined()) {
             byteLength = buffer->byteLength() - byteOffset;
-            if (buffer->byteLength() < byteOffset || byteLength % elementSize) {
-                scope.result = scope.engine->throwRangeError(QStringLiteral("new TypedArray: invalid length"));
-                return;
-            }
+            if (buffer->byteLength() < byteOffset || byteLength % elementSize)
+                return scope.engine->throwRangeError(QStringLiteral("new TypedArray: invalid length"));
         } else {
-            double l = qBound(0., callData->args[2].toInteger(), (double)UINT_MAX);
-            if (scope.engine->hasException) {
-                scope.result = Encode::undefined();
-                return;
-            }
+            double l = qBound(0., argv[2].toInteger(), (double)UINT_MAX);
+            if (scope.engine->hasException)
+                return Encode::undefined();
+            if (buffer->isDetachedBuffer())
+                return scope.engine->throwTypeError();
             l *= elementSize;
-            if (buffer->byteLength() - byteOffset < l) {
-                scope.result = scope.engine->throwRangeError(QStringLiteral("new TypedArray: invalid length"));
-                return;
-            }
+            if (buffer->byteLength() - byteOffset < l)
+                return scope.engine->throwRangeError(QStringLiteral("new TypedArray: invalid length"));
             byteLength = (uint)l;
         }
 
@@ -315,25 +394,25 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
         array->d()->buffer.set(scope.engine, buffer->d());
         array->d()->byteLength = byteLength;
         array->d()->byteOffset = byteOffset;
-        scope.result = array.asReturnedValue();
-        return;
+
+        updateProto(scope, array);
+        return array.asReturnedValue();
     }
 
     // ECMA 6 22.2.1.3
 
-    ScopedObject o(scope, callData->argument(0));
+    ScopedObject o(scope, argc ? argv[0] : Value::undefinedValue());
     uint l = (uint) qBound(0., ScopedValue(scope, o->get(scope.engine->id_length()))->toInteger(), (double)UINT_MAX);
-    if (scope.engine->hasException) {
-        scope.result = scope.engine->throwTypeError();
-        return;
-    }
+    if (scope.engine->hasException)
+        return scope.engine->throwTypeError();
 
     uint elementSize = operations[that->d()->type].bytesPerElement;
-    Scoped<ArrayBuffer> newBuffer(scope, scope.engine->newArrayBuffer(l * elementSize));
-    if (scope.engine->hasException) {
-        scope.result = Encode::undefined();
-        return;
-    }
+    size_t bufferSize;
+    if (mul_overflow(size_t(l), size_t(elementSize), &bufferSize))
+        return scope.engine->throwRangeError(QLatin1String("new TypedArray: invalid length"));
+    Scoped<ArrayBuffer> newBuffer(scope, scope.engine->newArrayBuffer(bufferSize));
+    if (scope.engine->hasException)
+        return Encode::undefined();
 
     Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
     array->d()->buffer.set(scope.engine, newBuffer->d());
@@ -344,172 +423,1017 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
     char *b = newBuffer->d()->data->data();
     ScopedValue val(scope);
     while (idx < l) {
-        val = o->getIndexed(idx);
-        array->d()->type->write(scope.engine, b, 0, val);
-        if (scope.engine->hasException) {
-            scope.result = Encode::undefined();
-            return;
-        }
+        val = o->get(idx);
+        val = val->convertedToNumber();
+        if (scope.engine->hasException)
+            return Encode::undefined();
+        array->d()->type->write(b, val);
+        if (scope.engine->hasException)
+            return Encode::undefined();
         ++idx;
         b += elementSize;
     }
 
-
-    scope.result = array.asReturnedValue();
+    updateProto(scope, array);
+    return array.asReturnedValue();
 }
 
-void TypedArrayCtor::call(const Managed *that, Scope &scope, CallData *callData)
+ReturnedValue TypedArrayCtor::virtualCall(const FunctionObject *f, const Value *, const Value *, int)
 {
-    construct(that, scope, callData);
+    return f->engine()->throwTypeError(QStringLiteral("calling a TypedArray constructor without new is invalid"));
 }
 
 void Heap::TypedArray::init(Type t)
 {
     Object::init();
-    type = operations + t;
-    arrayType = t;
+    type = operations + static_cast<int>(t);
+    arrayType = static_cast<int>(t);
 }
 
 Heap::TypedArray *TypedArray::create(ExecutionEngine *e, Heap::TypedArray::Type t)
 {
-    QV4::InternalClass *ic = e->internalClasses[EngineBase::Class_Empty]->changeVTable(staticVTable());
-    ic = ic->changePrototype(e->typedArrayPrototype[t].d());
-    return e->memoryManager->allocObject<TypedArray>(ic, e->typedArrayPrototype + t, t);
+    Scope scope(e);
+    Scoped<InternalClass> ic(scope, e->newInternalClass(staticVTable(), e->typedArrayPrototype + static_cast<int>(t)));
+    return e->memoryManager->allocObject<TypedArray>(ic->d(), t);
 }
 
-ReturnedValue TypedArray::getIndexed(const Managed *m, uint index, bool *hasProperty)
+ReturnedValue TypedArray::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
+    uint index = id.asArrayIndex();
+    if (index == UINT_MAX && !id.isCanonicalNumericIndexString())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+    // fall through, with index == UINT_MAX it'll do the right thing.
+
     Scope scope(static_cast<const Object *>(m)->engine());
     Scoped<TypedArray> a(scope, static_cast<const TypedArray *>(m));
+    if (a->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
 
-    uint bytesPerElement = a->d()->type->bytesPerElement;
-    uint byteOffset = a->d()->byteOffset + index * bytesPerElement;
-    if (byteOffset + bytesPerElement > (uint)a->d()->buffer->byteLength()) {
+    if (index >= a->length()) {
         if (hasProperty)
             *hasProperty = false;
         return Encode::undefined();
     }
+
+    uint bytesPerElement = a->d()->type->bytesPerElement;
+    uint byteOffset = a->d()->byteOffset + index * bytesPerElement;
+    Q_ASSERT(byteOffset + bytesPerElement <= (uint)a->d()->buffer->byteLength());
+
     if (hasProperty)
         *hasProperty = true;
-    return a->d()->type->read(a->d()->buffer->data->data(), byteOffset);
+    return a->d()->type->read(a->d()->buffer->data->data() + byteOffset);
+}
+
+bool TypedArray::virtualHasProperty(const Managed *m, PropertyKey id)
+{
+    uint index = id.asArrayIndex();
+    if (index == UINT_MAX && !id.isCanonicalNumericIndexString())
+        return Object::virtualHasProperty(m, id);
+    // fall through, with index == UINT_MAX it'll do the right thing.
+
+    const TypedArray *a = static_cast<const TypedArray *>(m);
+    if (a->d()->buffer->isDetachedBuffer()) {
+        a->engine()->throwTypeError();
+        return false;
+    }
+    if (index >= a->length())
+        return false;
+    return true;
 }
 
-bool TypedArray::putIndexed(Managed *m, uint index, const Value &value)
+PropertyAttributes TypedArray::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
 {
+    uint index = id.asArrayIndex();
+    if (index == UINT_MAX && !id.isCanonicalNumericIndexString())
+        return Object::virtualGetOwnProperty(m, id, p);
+    // fall through, with index == UINT_MAX it'll do the right thing.
+
+    bool hasProperty = false;
+    ReturnedValue v = virtualGet(m, id, m, &hasProperty);
+    if (p)
+        p->value = v;
+    return hasProperty ? Attr_NotConfigurable : PropertyAttributes();
+}
+
+bool TypedArray::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
+{
+    uint index = id.asArrayIndex();
+    if (index == UINT_MAX && !id.isCanonicalNumericIndexString())
+        return Object::virtualPut(m, id, value, receiver);
+    // fall through, with index == UINT_MAX it'll do the right thing.
+
     ExecutionEngine *v4 = static_cast<Object *>(m)->engine();
     if (v4->hasException)
         return false;
 
     Scope scope(v4);
     Scoped<TypedArray> a(scope, static_cast<TypedArray *>(m));
+    if (a->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    if (index >= a->length())
+        return false;
 
     uint bytesPerElement = a->d()->type->bytesPerElement;
     uint byteOffset = a->d()->byteOffset + index * bytesPerElement;
-    if (byteOffset + bytesPerElement > (uint)a->d()->buffer->byteLength())
-        goto reject;
+    Q_ASSERT(byteOffset + bytesPerElement <= (uint)a->d()->buffer->byteLength());
 
-    a->d()->type->write(scope.engine, a->d()->buffer->data->data(), byteOffset, value);
+    Value v = Value::fromReturnedValue(value.convertedToNumber());
+    if (scope.hasException() || a->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+    a->d()->type->write(a->d()->buffer->data->data() + byteOffset, v);
     return true;
+}
 
-reject:
-  if (scope.engine->current->strictMode)
-      scope.engine->throwTypeError();
-  return false;
+bool TypedArray::virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs)
+{
+    uint index = id.asArrayIndex();
+    if (index == UINT_MAX && !id.isCanonicalNumericIndexString())
+        return Object::virtualDefineOwnProperty(m, id, p, attrs);
+    // fall through, with index == UINT_MAX it'll do the right thing.
+
+    TypedArray *a = static_cast<TypedArray *>(m);
+    if (index >= a->length() || attrs.isAccessor())
+        return false;
+
+    if (attrs.hasConfigurable() && attrs.isConfigurable())
+        return false;
+    if (attrs.hasEnumerable() && !attrs.isEnumerable())
+        return false;
+    if (attrs.hasWritable() && !attrs.isWritable())
+        return false;
+    if (!p->value.isEmpty()) {
+        ExecutionEngine *engine = a->engine();
+
+        Value v = Value::fromReturnedValue(p->value.convertedToNumber());
+        if (engine->hasException || a->d()->buffer->isDetachedBuffer())
+            return engine->throwTypeError();
+        uint bytesPerElement = a->d()->type->bytesPerElement;
+        uint byteOffset = a->d()->byteOffset + index * bytesPerElement;
+        Q_ASSERT(byteOffset + bytesPerElement <= (uint)a->d()->buffer->byteLength());
+        a->d()->type->write(a->d()->buffer->data->data() + byteOffset, v);
+    }
+    return true;
+}
+
+struct TypedArrayOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
+{
+    ~TypedArrayOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey TypedArrayOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs)
+{
+    const TypedArray *a = static_cast<const TypedArray *>(o);
+    if (arrayIndex < a->length()) {
+        if (attrs)
+            *attrs = Attr_NotConfigurable;
+        PropertyKey id = PropertyKey::fromArrayIndex(arrayIndex);
+        if (pd) {
+            bool hasProperty = false;
+            pd->value = TypedArray::virtualGet(a, id, a, &hasProperty);
+        }
+        ++arrayIndex;
+        return id;
+    }
+
+    arrayIndex = UINT_MAX;
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+OwnPropertyKeyIterator *TypedArray::virtualOwnPropertyKeys(const Object *m, Value *target)
+{
+    *target = *m;
+    return new TypedArrayOwnPropertyKeyIterator();
 }
 
 void TypedArrayPrototype::init(ExecutionEngine *engine, TypedArrayCtor *ctor)
 {
     Scope scope(engine);
     ScopedObject o(scope);
-    ctor->defineReadonlyProperty(engine->id_length(), Primitive::fromInt32(3));
-    ctor->defineReadonlyProperty(engine->id_prototype(), (o = this));
-    ctor->defineReadonlyProperty(QStringLiteral("BYTES_PER_ELEMENT"), Primitive::fromInt32(operations[ctor->d()->type].bytesPerElement));
+
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(3));
+    ctor->defineReadonlyProperty(engine->id_prototype(), *this);
+    ctor->defineReadonlyProperty(QStringLiteral("BYTES_PER_ELEMENT"), Value::fromInt32(operations[static_cast<int>(ctor->d()->type)].bytesPerElement));
+    ctor->setPrototypeOf(engine->intrinsicTypedArrayCtor());
+
+    setPrototypeOf(engine->intrinsicTypedArrayPrototype());
     defineDefaultProperty(engine->id_constructor(), (o = ctor));
-    defineAccessorProperty(QStringLiteral("buffer"), method_get_buffer, 0);
-    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, 0);
-    defineAccessorProperty(QStringLiteral("byteOffset"), method_get_byteOffset, 0);
-    defineAccessorProperty(QStringLiteral("length"), method_get_length, 0);
-    defineReadonlyProperty(QStringLiteral("BYTES_PER_ELEMENT"), Primitive::fromInt32(operations[ctor->d()->type].bytesPerElement));
+    defineReadonlyProperty(QStringLiteral("BYTES_PER_ELEMENT"), Value::fromInt32(operations[static_cast<int>(ctor->d()->type)].bytesPerElement));
+}
 
-    defineDefaultProperty(QStringLiteral("set"), method_set, 1);
-    defineDefaultProperty(QStringLiteral("subarray"), method_subarray, 0);
+ReturnedValue IntrinsicTypedArrayPrototype::method_get_buffer(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    ExecutionEngine *v4 = b->engine();
+    const TypedArray *v = thisObject->as<TypedArray>();
+    if (!v)
+        return v4->throwTypeError();
+
+    return v->d()->buffer->asReturnedValue();
 }
 
-void TypedArrayPrototype::method_get_buffer(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue IntrinsicTypedArrayPrototype::method_get_byteLength(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<TypedArray> v(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    const TypedArray *v = thisObject->as<TypedArray>();
     if (!v)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
+
+    if (v->d()->buffer->isDetachedBuffer())
+        return Encode(0);
 
-    scope.result = v->d()->buffer;
+    return Encode(v->d()->byteLength);
 }
 
-void TypedArrayPrototype::method_get_byteLength(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue IntrinsicTypedArrayPrototype::method_get_byteOffset(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<TypedArray> v(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    const TypedArray *v = thisObject->as<TypedArray>();
     if (!v)
-        THROW_TYPE_ERROR();
+        return v4->throwTypeError();
 
-    scope.result = Encode(v->d()->byteLength);
+    if (v->d()->buffer->isDetachedBuffer())
+        return Encode(0);
+
+    return Encode(v->d()->byteOffset);
 }
 
-void TypedArrayPrototype::method_get_byteOffset(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue IntrinsicTypedArrayPrototype::method_get_length(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<TypedArray> v(scope, callData->thisObject);
+    ExecutionEngine *v4 = b->engine();
+    const TypedArray *v = thisObject->as<TypedArray>();
     if (!v)
+        return v4->throwTypeError();
+
+    if (v->d()->buffer->isDetachedBuffer())
+        return Encode(0);
+
+    return Encode(v->d()->byteLength/v->d()->type->bytesPerElement);
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_copyWithin(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    Scoped<TypedArray> O(scope, thisObject);
+    if (!O || O->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    if (!argc)
+        return O->asReturnedValue();
+
+    qint64 len = static_cast<uint>(O->length());
+
+    qint64 to = static_cast<qint64>(argv[0].toInteger());
+    if (to < 0)
+        to = qMax(len + to, 0ll);
+    else
+        to = qMin(to, len);
+
+    qint64 from = (argc > 1) ? static_cast<qint64>(argv[1].toInteger()) : 0ll;
+    if (from < 0)
+        from = qMax(len + from, 0ll);
+    else
+        from = qMin(from, len);
+
+    double fend = argv[2].toInteger();
+    if (fend > len)
+        fend = len;
+    qint64 end = (argc > 2 && !argv[2].isUndefined()) ? static_cast<qint64>(fend) : len;
+    if (end < 0)
+        end = qMax(len + end, 0ll);
+    else
+        end = qMin(end, len);
+
+    qint64 count = qMin(end - from, len - to);
+
+    if (count <= 0)
+        return O->asReturnedValue();
+
+    if (O->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    if (from != to) {
+        int elementSize = O->d()->type->bytesPerElement;
+        char *data = O->d()->buffer->data->data() + O->d()->byteOffset;
+        memmove(data + to*elementSize, data + from*elementSize, count*elementSize);
+    }
+
+    return O->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_entries(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    Scoped<ArrayIteratorObject> ao(scope, scope.engine->newArrayIteratorObject(v));
+    ao->d()->iterationKind = IteratorKind::KeyValueIteratorKind;
+    return ao->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_every(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    ScopedValue r(scope);
+    Value *arguments = scope.alloc(3);
 
-    scope.result = Encode(v->d()->byteOffset);
+    const char *data = v->d()->buffer->data->data();
+    uint bytesPerElement = v->d()->type->bytesPerElement;
+    uint byteOffset = v->d()->byteOffset;
+
+    bool ok = true;
+    for (uint k = 0; ok && k < len; ++k) {
+        if (v->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+
+        arguments[0] = v->d()->type->read(data + byteOffset + k * bytesPerElement);
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = v;
+        r = callback->call(that, arguments, 3);
+        ok = r->toBoolean();
+    }
+    return Encode(ok);
 }
 
-void TypedArrayPrototype::method_get_length(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue IntrinsicTypedArrayPrototype::method_fill(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<TypedArray> v(scope, callData->thisObject);
-    if (!v)
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+    double dlen = len;
+    double relativeStart = argc > 1 ? argv[1].toInteger() : 0.;
+    double relativeEnd = len;
+    if (argc > 2 && !argv[2].isUndefined())
+        relativeEnd = argv[2].toInteger();
+
+    uint k = 0;
+    uint fin = 0;
+
+    if (relativeStart < 0) {
+        k = static_cast<uint>(std::max(len+relativeStart, 0.));
+    } else {
+        k = static_cast<uint>(std::min(relativeStart, dlen));
+    }
+
+    if (relativeEnd < 0) {
+        fin = static_cast<uint>(std::max(len + relativeEnd, 0.));
+    } else {
+        fin = static_cast<uint>(std::min(relativeEnd, dlen));
+    }
+
+    double val = argc ? argv[0].toNumber() : std::numeric_limits<double>::quiet_NaN();
+    Value value = Value::fromDouble(val);
+    if (scope.hasException() || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    char *data = v->d()->buffer->data->data();
+    uint bytesPerElement = v->d()->type->bytesPerElement;
+    uint byteOffset = v->d()->byteOffset;
+
+    while (k < fin) {
+        v->d()->type->write(data + byteOffset + k * bytesPerElement, value);
+        k++;
+    }
+
+    return v.asReturnedValue();
+}
+
+static TypedArray *typedArraySpeciesCreate(Scope &scope, const TypedArray *instance, uint len)
+{
+    const FunctionObject *constructor = instance->speciesConstructor(scope, scope.engine->typedArrayCtors + instance->d()->arrayType);
+    if (!constructor) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+
+    Value *arguments = scope.alloc(1);
+    arguments[0] = Encode(len);
+    Scoped<TypedArray> a(scope, constructor->callAsConstructor(arguments, 1));
+    if (!a || a->d()->buffer->isDetachedBuffer() || a->length() < len) {
+        scope.engine->throwTypeError();
+        return nullptr;
+    }
+    return a;
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_filter(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    ScopedValue selected(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Value *arguments = scope.alloc(3);
+    Value *list = arguments;
+
+    uint to = 0;
+    for (uint k = 0; k < len; ++k) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        bool exists;
+        arguments[0] = instance->get(k, &exists);
+        if (!exists)
+            continue;
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        selected = callback->call(that, arguments, 3);
+        if (selected->toBoolean()) {
+            ++arguments;
+            scope.alloc(1);
+            ++to;
+        }
+    }
+
+    TypedArray *a = typedArraySpeciesCreate(scope, instance, to);
+    if (!a)
+        return Encode::undefined();
 
-    scope.result = Encode(v->d()->byteLength/v->d()->type->bytesPerElement);
+    for (uint i = 0; i < to; ++i)
+        a->put(i, list[i]);
+
+    return a->asReturnedValue();
 }
 
-void TypedArrayPrototype::method_set(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue IntrinsicTypedArrayPrototype::method_find(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<TypedArray> a(scope, callData->thisObject);
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+
+    if (!argc || !argv[0].isFunctionObject())
+        THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    ScopedValue result(scope);
+    Value *arguments = scope.alloc(3);
+
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+
+    for (uint k = 0; k < len; ++k) {
+        if (v->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        arguments[0] = v->get(k);
+        CHECK_EXCEPTION();
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = v;
+        result = callback->call(that, arguments, 3);
+
+        CHECK_EXCEPTION();
+        if (result->toBoolean())
+            return arguments[0].asReturnedValue();
+    }
+
+    RETURN_UNDEFINED();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_findIndex(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+
+    if (!argc || !argv[0].isFunctionObject())
+        THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    ScopedValue result(scope);
+    Value *arguments = scope.alloc(3);
+
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+
+    for (uint k = 0; k < len; ++k) {
+        if (v->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        arguments[0] = v->get(k);
+        CHECK_EXCEPTION();
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = v;
+        result = callback->call(that, arguments, 3);
+
+        CHECK_EXCEPTION();
+        if (result->toBoolean())
+            return Encode(k);
+    }
+
+    return Encode(-1);
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_forEach(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+
+    if (!argc || !argv->isFunctionObject())
+        THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Value *arguments = scope.alloc(3);
+
+    for (uint k = 0; k < len; ++k) {
+        if (v->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        bool exists;
+        arguments[0] = v->get(k, &exists);
+        if (!exists)
+            continue;
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = v;
+        callback->call(that, arguments, 3);
+    }
+    RETURN_UNDEFINED();
+}
+
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_includes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+    if (len == 0) {
+        return Encode(false);
+    }
+
+    double n = 0;
+    if (argc > 1 && !argv[1].isUndefined()) {
+        n = argv[1].toInteger();
+    }
+
+    double k = 0;
+    if (n >= 0) {
+        k = n;
+    } else {
+        k = len + n;
+        if (k < 0) {
+            k = 0;
+        }
+    }
+
+    while (k < len) {
+        ScopedValue val(scope, v->get(k));
+        if (val->sameValueZero(argv[0])) {
+            return Encode(true);
+        }
+        k++;
+    }
+
+    return Encode(false);
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_indexOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+    if (!len)
+        return Encode(-1);
+
+    ScopedValue searchValue(scope, argc ? argv[0] : Value::undefinedValue());
+    uint fromIndex = 0;
+
+    if (argc >= 2) {
+        double f = argv[1].toInteger();
+        CHECK_EXCEPTION();
+        if (f >= len)
+            return Encode(-1);
+        if (f < 0)
+            f = qMax(len + f, 0.);
+        fromIndex = (uint) f;
+    }
+
+    if (v->isStringObject()) {
+        ScopedValue value(scope);
+        for (uint k = fromIndex; k < len; ++k) {
+            bool exists;
+            value = v->get(k, &exists);
+            if (exists && RuntimeHelpers::strictEqual(value, searchValue))
+                return Encode(k);
+        }
+        return Encode(-1);
+    }
+
+    ScopedValue value(scope);
+
+    for (uint i = fromIndex; i < len; ++i) {
+        bool exists;
+        value = v->get(i, &exists);
+        CHECK_EXCEPTION();
+        if (exists && RuntimeHelpers::strictEqual(value, searchValue))
+            return Encode(i);
+    }
+    return Encode(-1);
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_join(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = v->length();
+
+    ScopedValue arg(scope, argc ? argv[0] : Value::undefinedValue());
+
+    QString r4;
+    if (arg->isUndefined())
+        r4 = QStringLiteral(",");
+    else
+        r4 = arg->toQString();
+
+    const quint32 r2 = len;
+
+    if (!r2)
+        return Encode(scope.engine->newString());
+
+    QString R;
+
+    //
+    // crazy!
+    //
+    ScopedString name(scope, scope.engine->newString(QStringLiteral("0")));
+    ScopedValue r6(scope, v->get(name));
+    if (!r6->isNullOrUndefined())
+        R = r6->toQString();
+
+    ScopedValue r12(scope);
+    for (quint32 k = 1; k < r2; ++k) {
+        R += r4;
+
+        name = Value::fromDouble(k).toString(scope.engine);
+        r12 = v->get(name);
+        CHECK_EXCEPTION();
+
+        if (!r12->isNullOrUndefined())
+            R += r12->toQString();
+    }
+
+    return Encode(scope.engine->newString(R));
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_keys(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    Scoped<ArrayIteratorObject> ao(scope, scope.engine->newArrayIteratorObject(v));
+    ao->d()->iterationKind = IteratorKind::KeyIteratorKind;
+    return ao->asReturnedValue();
+}
+
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_lastIndexOf(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+    if (!len)
+        return Encode(-1);
+
+    ScopedValue searchValue(scope);
+    uint fromIndex = len;
+
+    if (argc >= 1)
+        searchValue = argv[0];
+    else
+        searchValue = Value::undefinedValue();
+
+    if (argc >= 2) {
+        double f = argv[1].toInteger();
+        CHECK_EXCEPTION();
+        if (f > 0)
+            f = qMin(f, (double)(len - 1));
+        else if (f < 0) {
+            f = len + f;
+            if (f < 0)
+                return Encode(-1);
+        }
+        fromIndex = (uint) f + 1;
+    }
+
+    ScopedValue value(scope);
+    for (uint k = fromIndex; k > 0;) {
+        --k;
+        bool exists;
+        value = instance->get(k, &exists);
+        if (exists && RuntimeHelpers::strictEqual(value, searchValue))
+            return Encode(k);
+    }
+    return Encode(-1);
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_map(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+
+    if (!argc || !argv->isFunctionObject())
+        THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    TypedArray *a = typedArraySpeciesCreate(scope, instance, len);
     if (!a)
+        return Encode::undefined();
+
+    ScopedValue v(scope);
+    ScopedValue mapped(scope);
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    Value *arguments = scope.alloc(3);
+
+    for (uint k = 0; k < len; ++k) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        arguments[0] = instance->get(k);
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        mapped = callback->call(that, arguments, 3);
+        a->put(k, mapped);
+    }
+    return a->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_reduce(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+
+    if (!argc || !argv->isFunctionObject())
+        THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    uint k = 0;
+    ScopedValue acc(scope);
+    ScopedValue v(scope);
+
+    if (argc > 1) {
+        acc = argv[1];
+    } else {
+        bool kPresent = false;
+        while (k < len && !kPresent) {
+            v = instance->get(k, &kPresent);
+            if (kPresent)
+                acc = v;
+            ++k;
+        }
+        if (!kPresent)
+            THROW_TYPE_ERROR();
+    }
+
+    Value *arguments = scope.alloc(4);
+
+    while (k < len) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        bool kPresent;
+        v = instance->get(k, &kPresent);
+        if (kPresent) {
+            arguments[0] = acc;
+            arguments[1] = v;
+            arguments[2] = Value::fromDouble(k);
+            arguments[3] = instance;
+            acc = callback->call(nullptr, arguments, 4);
+        }
+        ++k;
+    }
+    return acc->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_reduceRight(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+
+    if (!argc || !argv->isFunctionObject())
         THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    if (len == 0) {
+        if (argc == 1)
+            THROW_TYPE_ERROR();
+        return argv[1].asReturnedValue();
+    }
+
+    uint k = len;
+    ScopedValue acc(scope);
+    ScopedValue v(scope);
+    if (argc > 1) {
+        acc = argv[1];
+    } else {
+        bool kPresent = false;
+        while (k > 0 && !kPresent) {
+            v = instance->get(k - 1, &kPresent);
+            if (kPresent)
+                acc = v;
+            --k;
+        }
+        if (!kPresent)
+            THROW_TYPE_ERROR();
+    }
+
+    Value *arguments = scope.alloc(4);
+
+    while (k > 0) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        bool kPresent;
+        v = instance->get(k - 1, &kPresent);
+        if (kPresent) {
+            arguments[0] = acc;
+            arguments[1] = v;
+            arguments[2] = Value::fromDouble(k - 1);
+            arguments[3] = instance;
+            acc = callback->call(nullptr, arguments, 4);
+        }
+        --k;
+    }
+    return acc->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_reverse(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint length = instance->length();
+
+    int lo = 0, hi = length - 1;
+
+    ScopedValue lval(scope);
+    ScopedValue hval(scope);
+    for (; lo < hi; ++lo, --hi) {
+        bool loExists, hiExists;
+        lval = instance->get(lo, &loExists);
+        hval = instance->get(hi, &hiExists);
+        Q_ASSERT(hiExists && loExists);
+        bool ok;
+        ok = instance->put(lo, hval);
+        Q_ASSERT(ok);
+        ok = instance->put(hi, lval);
+        Q_ASSERT(ok);
+    }
+    return instance->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_some(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+
+    if (!argc || !argv->isFunctionObject())
+        THROW_TYPE_ERROR();
+    const FunctionObject *callback = static_cast<const FunctionObject *>(argv);
+
+    ScopedValue that(scope, argc > 1 ? argv[1] : Value::undefinedValue());
+    ScopedValue result(scope);
+    Value *arguments = scope.alloc(3);
+
+    for (uint k = 0; k < len; ++k) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        bool exists;
+        arguments[0] = instance->get(k, &exists);
+        if (!exists)
+            continue;
+
+        arguments[1] = Value::fromDouble(k);
+        arguments[2] = instance;
+        result = callback->call(that, arguments, 3);
+        if (result->toBoolean())
+            return Encode(true);
+    }
+    return Encode(false);
+}
+
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_values(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<TypedArray> v(scope, thisObject);
+    if (!v || v->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    Scoped<ArrayIteratorObject> ao(scope, scope.engine->newArrayIteratorObject(v));
+    ao->d()->iterationKind = IteratorKind::ValueIteratorKind;
+    return ao->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_set(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    Scoped<TypedArray> a(scope, *thisObject);
+    if (!a)
+        return scope.engine->throwTypeError();
     Scoped<ArrayBuffer> buffer(scope, a->d()->buffer);
-    if (!buffer)
-        scope.engine->throwTypeError();
 
-    double doffset = callData->argc >= 2 ? callData->args[1].toInteger() : 0;
+    double doffset = argc >= 2 ? argv[1].toInteger() : 0;
     if (scope.engine->hasException)
         RETURN_UNDEFINED();
+    if (!buffer || buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
 
     if (doffset < 0 || doffset >= UINT_MAX)
         RETURN_RESULT(scope.engine->throwRangeError(QStringLiteral("TypedArray.set: out of range")));
     uint offset = (uint)doffset;
     uint elementSize = a->d()->type->bytesPerElement;
 
-    Scoped<TypedArray> srcTypedArray(scope, callData->args[0]);
+    Scoped<TypedArray> srcTypedArray(scope, argv[0]);
     if (!srcTypedArray) {
         // src is a regular object
-        ScopedObject o(scope, callData->args[0].toObject(scope.engine));
+        ScopedObject o(scope, argv[0].toObject(scope.engine));
         if (scope.engine->hasException || !o)
-            THROW_TYPE_ERROR();
+            return scope.engine->throwTypeError();
 
         double len = ScopedValue(scope, o->get(scope.engine->id_length()))->toNumber();
         uint l = (uint)len;
         if (scope.engine->hasException || l != len)
-            THROW_TYPE_ERROR();
+            return scope.engine->throwTypeError();
 
         if (offset + l > a->length())
             RETURN_RESULT(scope.engine->throwRangeError(QStringLiteral("TypedArray.set: out of range")));
 
         uint idx = 0;
+        if (buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
         char *b = buffer->d()->data->data() + a->d()->byteOffset + offset*elementSize;
         ScopedValue val(scope);
         while (idx < l) {
-            val = o->getIndexed(idx);
-            a->d()->type->write(scope.engine, b, 0, val);
+            val = o->get(idx);
+            if (scope.hasException())
+                return Encode::undefined();
+            val = val->convertedToNumber();
+            if (scope.hasException() || buffer->isDetachedBuffer())
+                return scope.engine->throwTypeError();
+            a->d()->type->write(b, val);
             if (scope.engine->hasException)
                 RETURN_UNDEFINED();
             ++idx;
@@ -520,8 +1444,8 @@ void TypedArrayPrototype::method_set(const BuiltinFunction *, Scope &scope, Call
 
     // src is a typed array
     Scoped<ArrayBuffer> srcBuffer(scope, srcTypedArray->d()->buffer);
-    if (!srcBuffer)
-        THROW_TYPE_ERROR();
+    if (!srcBuffer || srcBuffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
 
     uint l = srcTypedArray->length();
     if (offset + l > a->length())
@@ -535,7 +1459,7 @@ void TypedArrayPrototype::method_set(const BuiltinFunction *, Scope &scope, Call
         RETURN_UNDEFINED();
     }
 
-    char *srcCopy = 0;
+    char *srcCopy = nullptr;
     if (buffer->d() == srcBuffer->d()) {
         // same buffer, need to take a temporary copy, to not run into problems
         srcCopy = new char[srcTypedArray->d()->byteLength];
@@ -545,12 +1469,12 @@ void TypedArrayPrototype::method_set(const BuiltinFunction *, Scope &scope, Call
 
     // typed arrays of different kind, need to manually loop
     uint srcElementSize = srcTypedArray->d()->type->bytesPerElement;
-    TypedArrayRead read = srcTypedArray->d()->type->read;
-    TypedArrayWrite write = a->d()->type->write;
+    TypedArrayOperations::Read read = srcTypedArray->d()->type->read;
+    TypedArrayOperations::Write write = a->d()->type->write;
     for (uint i = 0; i < l; ++i) {
-        Primitive val;
-        val.setRawValue(read(src, i*srcElementSize));
-        write(scope.engine, dest, i*elementSize, val);
+        Value val;
+        val.setRawValue(read(src + i*srcElementSize));
+        write(dest + i*elementSize, val);
     }
 
     if (srcCopy)
@@ -559,24 +1483,71 @@ void TypedArrayPrototype::method_set(const BuiltinFunction *, Scope &scope, Call
     RETURN_UNDEFINED();
 }
 
-void TypedArrayPrototype::method_subarray(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue IntrinsicTypedArrayPrototype::method_slice(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<TypedArray> a(scope, callData->thisObject);
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+
+    double s = (argc ? argv[0] : Value::undefinedValue()).toInteger();
+    uint start;
+    if (s < 0)
+        start = (uint)qMax(len + s, 0.);
+    else if (s > len)
+        start = len;
+    else
+        start = (uint) s;
+    uint end = len;
+    if (argc > 1 && !argv[1].isUndefined()) {
+        double e = argv[1].toInteger();
+        if (e < 0)
+            end = (uint)qMax(len + e, 0.);
+        else if (e > len)
+            end = len;
+        else
+            end = (uint) e;
+    }
+    uint count = start > end ? 0 : end - start;
 
+    TypedArray *a = typedArraySpeciesCreate(scope, instance, count);
     if (!a)
-        THROW_TYPE_ERROR();
+        return Encode::undefined();
+
+    ScopedValue v(scope);
+    uint n = 0;
+    for (uint i = start; i < end; ++i) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        v = instance->get(i);
+        if (a->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        a->put(n, v);
+        ++n;
+    }
+    return a->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_subarray(const FunctionObject *builtin, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(builtin);
+    Scoped<TypedArray> a(scope, *thisObject);
+
+    if (!a)
+        return scope.engine->throwTypeError();
 
     Scoped<ArrayBuffer> buffer(scope, a->d()->buffer);
-    if (!buffer)
-        THROW_TYPE_ERROR();
+    Q_ASSERT(buffer);
 
     int len = a->length();
-    double b = callData->argc > 0 ? callData->args[0].toInteger() : 0;
+    double b = argc > 0 ? argv[0].toInteger() : 0;
     if (b < 0)
         b = len + b;
     uint begin = (uint)qBound(0., b, (double)len);
 
-    double e = callData->argc < 2 || callData->args[1].isUndefined() ? len : callData->args[1].toInteger();
+    double e = argc < 2 || argv[1].isUndefined() ? len : argv[1].toInteger();
     if (e < 0)
         e = len + e;
     uint end = (uint)qBound(0., e, (double)len);
@@ -588,13 +1559,142 @@ void TypedArrayPrototype::method_subarray(const BuiltinFunction *, Scope &scope,
 
     int newLen = end - begin;
 
-    ScopedFunctionObject constructor(scope, a->get(scope.engine->id_constructor()));
+    ScopedFunctionObject constructor(scope, a->speciesConstructor(scope, scope.engine->typedArrayCtors + a->d()->arrayType));
     if (!constructor)
-        THROW_TYPE_ERROR();
+        return scope.engine->throwTypeError();
+
+    Value *arguments = scope.alloc(3);
+    arguments[0] = buffer;
+    arguments[1] = Encode(a->d()->byteOffset + begin*a->d()->type->bytesPerElement);
+    arguments[2] = Encode(newLen);
+    a = constructor->callAsConstructor(arguments, 3);
+    if (!a || a->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+    return a->asReturnedValue();
+}
 
-    ScopedCallData cData(scope, 3);
-    cData->args[0] = buffer;
-    cData->args[1] = Encode(a->d()->byteOffset + begin*a->d()->type->bytesPerElement);
-    cData->args[2] = Encode(newLen);
-    constructor->construct(scope, cData);
+ReturnedValue IntrinsicTypedArrayPrototype::method_toLocaleString(const FunctionObject *b, const Value *thisObject, const Value *, int)
+{
+    Scope scope(b);
+    Scoped<TypedArray> instance(scope, thisObject);
+    if (!instance || instance->d()->buffer->isDetachedBuffer())
+        return scope.engine->throwTypeError();
+
+    uint len = instance->length();
+    const QString separator = QStringLiteral(",");
+
+    QString R;
+
+    ScopedValue v(scope);
+    ScopedString s(scope);
+
+    for (uint k = 0; k < len; ++k) {
+        if (instance->d()->buffer->isDetachedBuffer())
+            return scope.engine->throwTypeError();
+        if (k)
+            R += separator;
+
+        v = instance->get(k);
+        v = Runtime::CallElement::call(scope.engine, v, *scope.engine->id_toLocaleString(), nullptr, 0);
+        s = v->toString(scope.engine);
+        if (scope.hasException())
+            return Encode::undefined();
+
+        R += s->toQString();
+    }
+    return scope.engine->newString(R)->asReturnedValue();
+}
+
+ReturnedValue IntrinsicTypedArrayPrototype::method_get_toStringTag(const FunctionObject *, const Value *thisObject, const Value *, int)
+{
+    const TypedArray *a = thisObject->as<TypedArray>();
+    if (!a)
+        return Encode::undefined();
+
+    return a->engine()->newString(QString::fromLatin1(a->d()->type->name))->asReturnedValue();
+}
+
+static bool validateTypedArray(const Object *o)
+{
+    const TypedArray *a = o->as<TypedArray>();
+    if (!a)
+        return false;
+    if (a->d()->buffer->isDetachedBuffer())
+        return false;
+    return true;
+}
+
+ReturnedValue IntrinsicTypedArrayCtor::method_of(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(f);
+    int len = argc;
+    const Value *items = argv;
+    const FunctionObject *C = thisObject->as<FunctionObject>();
+    if (!C || !C->isConstructor())
+        return scope.engine->throwTypeError();
+
+    Value lenValue = Value::fromInt32(len);
+    ScopedObject newObj(scope, C->callAsConstructor(&lenValue, 1));
+    if (scope.hasException())
+        return Encode::undefined();
+    if (!::validateTypedArray(newObj))
+        return scope.engine->throwTypeError();
+    TypedArray *a = newObj->as<TypedArray>();
+    Q_ASSERT(a);
+    if (a->length() < static_cast<uint>(len))
+        return scope.engine->throwTypeError();
+
+    for (int k = 0; k < len; ++k) {
+        newObj->put(PropertyKey::fromArrayIndex(k), items[k]);
+    }
+    return newObj->asReturnedValue();
+}
+
+void IntrinsicTypedArrayPrototype::init(ExecutionEngine *engine, IntrinsicTypedArrayCtor *ctor)
+{
+    Scope scope(engine);
+    ctor->defineReadonlyProperty(engine->id_prototype(), *this);
+    ctor->defineReadonlyConfigurableProperty(engine->id_length(), Value::fromInt32(0));
+    ScopedString s(scope, engine->newString(QStringLiteral("TypedArray")));
+    ctor->defineReadonlyConfigurableProperty(engine->id_name(), s);
+    s = scope.engine->newString(QStringLiteral("of"));
+    ctor->defineDefaultProperty(s, IntrinsicTypedArrayCtor::method_of);
+    ctor->addSymbolSpecies();
+
+    defineAccessorProperty(QStringLiteral("buffer"), method_get_buffer, nullptr);
+    defineAccessorProperty(QStringLiteral("byteLength"), method_get_byteLength, nullptr);
+    defineAccessorProperty(QStringLiteral("byteOffset"), method_get_byteOffset, nullptr);
+    defineAccessorProperty(QStringLiteral("length"), method_get_length, nullptr);
+
+    defineDefaultProperty(QStringLiteral("copyWithin"), method_copyWithin, 2);
+    defineDefaultProperty(QStringLiteral("entries"), method_entries, 0);
+    defineDefaultProperty(QStringLiteral("every"), method_every, 1);
+    defineDefaultProperty(QStringLiteral("fill"), method_fill, 1);
+    defineDefaultProperty(QStringLiteral("filter"), method_filter, 1);
+    defineDefaultProperty(QStringLiteral("find"), method_find, 1);
+    defineDefaultProperty(QStringLiteral("findIndex"), method_findIndex, 1);
+    defineDefaultProperty(QStringLiteral("forEach"), method_forEach, 1);
+    defineDefaultProperty(QStringLiteral("includes"), method_includes, 1);
+    defineDefaultProperty(QStringLiteral("indexOf"), method_indexOf, 1);
+    defineDefaultProperty(QStringLiteral("join"), method_join, 1);
+    defineDefaultProperty(QStringLiteral("keys"), method_keys, 0);
+    defineDefaultProperty(QStringLiteral("lastIndexOf"), method_lastIndexOf, 1);
+    defineDefaultProperty(QStringLiteral("map"), method_map, 1);
+    defineDefaultProperty(QStringLiteral("reduce"), method_reduce, 1);
+    defineDefaultProperty(QStringLiteral("reduceRight"), method_reduceRight, 1);
+    defineDefaultProperty(QStringLiteral("reverse"), method_reverse, 0);
+    defineDefaultProperty(QStringLiteral("some"), method_some, 1);
+    defineDefaultProperty(QStringLiteral("set"), method_set, 1);
+    defineDefaultProperty(QStringLiteral("slice"), method_slice, 2);
+    defineDefaultProperty(QStringLiteral("subarray"), method_subarray, 2);
+    defineDefaultProperty(engine->id_toLocaleString(), method_toLocaleString, 0);
+    ScopedObject f(scope, engine->arrayPrototype()->get(engine->id_toString()));
+    defineDefaultProperty(engine->id_toString(), f);
+
+    ScopedString valuesString(scope, engine->newIdentifier(QStringLiteral("values")));
+    ScopedObject values(scope, FunctionObject::createBuiltinFunction(engine, valuesString, method_values, 0));
+    defineDefaultProperty(QStringLiteral("values"), values);
+    defineDefaultProperty(engine->symbol_iterator(), values);
+
+    defineAccessorProperty(engine->symbol_toStringTag(), method_get_toStringTag, nullptr);
 }
diff --git a/src/qml/jsruntime/qv4typedarray_p.h b/src/qml/jsruntime/qv4typedarray_p.h
index a472dfa607..64792f23a2 100644
--- a/src/qml/jsruntime/qv4typedarray_p.h
+++ b/src/qml/jsruntime/qv4typedarray_p.h
@@ -60,14 +60,50 @@ namespace QV4 {
 
 struct ArrayBuffer;
 
-typedef ReturnedValue (*TypedArrayRead)(const char *data, int index);
-typedef void (*TypedArrayWrite)(ExecutionEngine *engine, char *data, int index, const Value &value);
+enum TypedArrayType {
+    Int8Array,
+    UInt8Array,
+    Int16Array,
+    UInt16Array,
+    Int32Array,
+    UInt32Array,
+    UInt8ClampedArray,
+    Float32Array,
+    Float64Array,
+    NTypedArrayTypes
+};
+
+enum AtomicModifyOps {
+    AtomicAdd,
+    AtomicAnd,
+    AtomicExchange,
+    AtomicOr,
+    AtomicSub,
+    AtomicXor,
+    NAtomicModifyOps
+};
 
 struct TypedArrayOperations {
+    typedef ReturnedValue (*Read)(const char *data);
+    typedef void (*Write)(char *data, Value value);
+    typedef ReturnedValue (*AtomicModify)(char *data, Value value);
+    typedef ReturnedValue (*AtomicCompareExchange)(char *data, Value expected, Value v);
+    typedef ReturnedValue (*AtomicLoad)(char *data);
+    typedef ReturnedValue (*AtomicStore)(char *data, Value value);
+
+    template<typename T>
+    static constexpr TypedArrayOperations create(const char *name);
+    template<typename T>
+    static constexpr TypedArrayOperations createWithAtomics(const char *name);
+
     int bytesPerElement;
     const char *name;
-    TypedArrayRead read;
-    TypedArrayWrite write;
+    Read read;
+    Write write;
+    AtomicModify atomicModifyOps[AtomicModifyOps::NAtomicModifyOps];
+    AtomicCompareExchange atomicCompareExchange;
+    AtomicLoad atomicLoad;
+    AtomicStore atomicStore;
 };
 
 namespace Heap {
@@ -80,29 +116,24 @@ namespace Heap {
     Member(class, NoMark, uint, arrayType)
 
 DECLARE_HEAP_OBJECT(TypedArray, Object) {
-    DECLARE_MARK_TABLE(TypedArray);
-    enum Type {
-        Int8Array,
-        UInt8Array,
-        UInt8ClampedArray,
-        Int16Array,
-        UInt16Array,
-        Int32Array,
-        UInt32Array,
-        Float32Array,
-        Float64Array,
-        NTypes
-    };
+    DECLARE_MARKOBJECTS(TypedArray);
+    using Type = TypedArrayType;
 
     void init(Type t);
 };
 
+struct IntrinsicTypedArrayCtor : FunctionObject {
+};
+
 struct TypedArrayCtor : FunctionObject {
     void init(QV4::ExecutionContext *scope, TypedArray::Type t);
 
     TypedArray::Type type;
 };
 
+struct IntrinsicTypedArrayPrototype : Object {
+};
+
 struct TypedArrayPrototype : Object {
     inline void init(TypedArray::Type t);
     TypedArray::Type type;
@@ -132,19 +163,73 @@ struct Q_QML_PRIVATE_EXPORT TypedArray : Object
     Heap::TypedArray::Type arrayType() const {
         return static_cast<Heap::TypedArray::Type>(d()->arrayType);
     }
+    using Object::get;
+
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualHasProperty(const Managed *m, PropertyKey id);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static bool virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
 
-    static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
-    static bool putIndexed(Managed *m, uint index, const Value &value);
+};
+
+struct IntrinsicTypedArrayCtor: FunctionObject
+{
+    V4_OBJECT2(IntrinsicTypedArrayCtor, FunctionObject)
+
+    static constexpr VTable::Call virtualCall = nullptr;
+
+    static ReturnedValue method_of(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 struct TypedArrayCtor: FunctionObject
 {
     V4_OBJECT2(TypedArrayCtor, FunctionObject)
 
-    static void construct(const Managed *m, Scope &scope, CallData *callData);
-    static void call(const Managed *that, Scope &scope, CallData *callData);
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *argv, int argc, const Value *);
+    static ReturnedValue virtualCall(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
 };
 
+struct IntrinsicTypedArrayPrototype : Object
+{
+    V4_OBJECT2(IntrinsicTypedArrayPrototype, Object)
+    V4_PROTOTYPE(objectPrototype)
+
+    void init(ExecutionEngine *engine, IntrinsicTypedArrayCtor *ctor);
+
+    static ReturnedValue method_get_buffer(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_byteLength(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_byteOffset(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_length(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_copyWithin(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_entries(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_every(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_fill(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_filter(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_find(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_findIndex(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_forEach(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_includes(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_indexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_join(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_keys(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_lastIndexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_map(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reduce(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reduceRight(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_reverse(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_some(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_values(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_slice(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_subarray(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toLocaleString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_get_toStringTag(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+
+};
 
 struct TypedArrayPrototype : Object
 {
@@ -152,14 +237,6 @@ struct TypedArrayPrototype : Object
     V4_PROTOTYPE(objectPrototype)
 
     void init(ExecutionEngine *engine, TypedArrayCtor *ctor);
-
-    static void method_get_buffer(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_byteLength(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_byteOffset(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_length(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_set(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_subarray(const BuiltinFunction *, Scope &scope, CallData *callData);
 };
 
 inline void
diff --git a/src/qml/jsruntime/qv4util_p.h b/src/qml/jsruntime/qv4util_p.h
index 2669a3e4bf..073832937d 100644
--- a/src/qml/jsruntime/qv4util_p.h
+++ b/src/qml/jsruntime/qv4util_p.h
@@ -59,26 +59,6 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-template <typename T>
-struct TemporaryAssignment
-{
-    TemporaryAssignment(T &var, const T& temporaryValue)
-        : variable(var)
-        , savedValue(var)
-    {
-        variable = temporaryValue;
-    }
-    ~TemporaryAssignment()
-    {
-        variable = savedValue;
-    }
-    T &variable;
-    T savedValue;
-private:
-    TemporaryAssignment(const TemporaryAssignment<T>&);
-    TemporaryAssignment operator=(const TemporaryAssignment<T>&);
-};
-
 #if !defined(BROKEN_STD_VECTOR_BOOL_OR_BROKEN_STD_FIND)
 // Sanity:
 class BitVector
diff --git a/src/qml/jsruntime/qv4value.cpp b/src/qml/jsruntime/qv4value.cpp
index f41442df7a..cbc153bb86 100644
--- a/src/qml/jsruntime/qv4value.cpp
+++ b/src/qml/jsruntime/qv4value.cpp
@@ -39,7 +39,9 @@
 #include <qv4engine_p.h>
 #include <qv4runtime_p.h>
 #include <qv4string_p.h>
+#include <qv4propertykey_p.h>
 #ifndef V4_BOOTSTRAP
+#include <qv4symbol_p.h>
 #include <qv4object_p.h>
 #include <qv4objectproto_p.h>
 #include <private/qv4mm_p.h>
@@ -75,39 +77,29 @@ int Value::toUInt16() const
     return (unsigned short)number;
 }
 
-bool Value::toBoolean() const
+bool Value::toBooleanImpl(Value val)
 {
-    if (isInteger() || isBoolean())
-        return static_cast<bool>(int_32());
-
-    if (isUndefined() || isNull())
-        return false;
-
-    if (isManaged()) {
+    if (val.isManagedOrUndefined()) {
+        Heap::Base *b = val.m();
+        if (!b)
+            return false;
 #ifdef V4_BOOTSTRAP
         Q_UNIMPLEMENTED();
 #else
-        if (String *s = stringValue())
-            return s->toQString().length() > 0;
+        if (b->internalClass->vtable->isString)
+            return static_cast<Heap::String *>(b)->length() > 0;
 #endif
         return true;
     }
 
     // double
-    return doubleValue() && !std::isnan(doubleValue());
-}
-
-double Value::toInteger() const
-{
-    if (integerCompatible())
-        return int_32();
-
-    return Primitive::toInteger(toNumber());
+    double d = val.doubleValue();
+    return d && !std::isnan(d);
 }
 
-double Value::toNumberImpl() const
+double Value::toNumberImpl(Value val)
 {
-    switch (type()) {
+    switch (val.type()) {
     case QV4::Value::Undefined_Type:
         return std::numeric_limits<double>::quiet_NaN();
     case QV4::Value::Managed_Type:
@@ -115,12 +107,18 @@ double Value::toNumberImpl() const
         Q_UNIMPLEMENTED();
         Q_FALLTHROUGH();
 #else
-        if (String *s = stringValue())
+        if (String *s = val.stringValue())
             return RuntimeHelpers::stringToNumber(s->toQString());
+        if (val.isSymbol()) {
+            Managed &m = static_cast<Managed &>(val);
+            m.engine()->throwTypeError();
+            return 0;
+        }
     {
-        Q_ASSERT(isObject());
-        Scope scope(objectValue()->engine());
-        ScopedValue prim(scope, RuntimeHelpers::toPrimitive(*this, NUMBER_HINT));
+        Q_ASSERT(val.isObject());
+        Scope scope(val.objectValue()->engine());
+        ScopedValue protectThis(scope, val);
+        ScopedValue prim(scope, RuntimeHelpers::toPrimitive(val, NUMBER_HINT));
             if (scope.engine->hasException)
                 return 0;
             return prim->toNumber();
@@ -129,7 +127,7 @@ double Value::toNumberImpl() const
     case QV4::Value::Null_Type:
     case QV4::Value::Boolean_Type:
     case QV4::Value::Integer_Type:
-        return int_32();
+        return val.int_32();
     default: // double
         Q_UNREACHABLE();
     }
@@ -154,6 +152,8 @@ QString Value::toQStringNoThrow() const
     case Value::Managed_Type:
         if (String *s = stringValue())
             return s->toQString();
+        if (Symbol *s = symbolValue())
+            return s->descriptiveString();
         {
             Q_ASSERT(isObject());
             Scope scope(objectValue()->engine());
@@ -206,9 +206,12 @@ QString Value::toQString() const
         else
             return QStringLiteral("false");
     case Value::Managed_Type:
-        if (String *s = stringValue())
+        if (String *s = stringValue()) {
             return s->toQString();
-        {
+        } else if (isSymbol()) {
+            static_cast<const Managed *>(this)->engine()->throwTypeError();
+            return QString();
+        } else {
             Q_ASSERT(isObject());
             Scope scope(objectValue()->engine());
             ScopedValue prim(scope, RuntimeHelpers::toPrimitive(*this, STRING_HINT));
@@ -226,6 +229,25 @@ QString Value::toQString() const
     }
     } // switch
 }
+
+QV4::PropertyKey Value::toPropertyKey(ExecutionEngine *e) const
+{
+    if (isInteger() && int_32() >= 0)
+        return PropertyKey::fromArrayIndex(static_cast<uint>(int_32()));
+    if (isStringOrSymbol()) {
+        Scope scope(e);
+        ScopedStringOrSymbol s(scope, this);
+        return s->toPropertyKey();
+    }
+    Scope scope(e);
+    ScopedValue v(scope, RuntimeHelpers::toPrimitive(*this, STRING_HINT));
+    if (!v->isStringOrSymbol())
+        v = v->toString(e);
+    if (e->hasException)
+        return PropertyKey::invalid();
+    ScopedStringOrSymbol s(scope, v);
+    return s->toPropertyKey();
+}
 #endif // V4_BOOTSTRAP
 
 bool Value::sameValue(Value other) const {
@@ -236,83 +258,42 @@ bool Value::sameValue(Value other) const {
     if (s && os)
         return s->isEqualTo(os);
     if (isInteger() && other.isDouble())
-        return int_32() ? (double(int_32()) == other.doubleValue()) : (other._val == 0);
+        return int_32() ? (double(int_32()) == other.doubleValue())
+                        : (other.doubleValue() == 0 && !std::signbit(other.doubleValue()));
     if (isDouble() && other.isInteger())
-        return other.int_32() ? (doubleValue() == double(other.int_32())) : (_val == 0);
+        return other.int_32() ? (doubleValue() == double(other.int_32()))
+                              : (doubleValue() == 0 && !std::signbit(doubleValue()));
     return false;
 }
 
-
-int Primitive::toInt32(double number)
-{
-    const double D32 = 4294967296.0;
-    const double D31 = D32 / 2.0;
-
-    if ((number >= -D31 && number < D31))
-        return static_cast<int>(number);
-
-
-    if (!std::isfinite(number))
-        return 0;
-
-    double d = ::floor(::fabs(number));
-    if (std::signbit(number))
-        d = -d;
-
-    number = ::fmod(d , D32);
-
-    if (number < -D31)
-        number += D32;
-    else if (number >= D31)
-        number -= D32;
-
-    return int(number);
-}
-
-unsigned int Primitive::toUInt32(double number)
-{
-    const double D32 = 4294967296.0;
-    if ((number >= 0 && number < D32))
-        return static_cast<uint>(number);
-
-    if (!std::isfinite(number))
-        return +0;
-
-    double d = ::floor(::fabs(number));
-    if (std::signbit(number))
-        d = -d;
-
-    number = ::fmod(d , D32);
-
-    if (number < 0)
-        number += D32;
-
-    return unsigned(number);
-}
-
-double Primitive::toInteger(double number)
-{
-    if (std::isnan(number))
-        return +0;
-    else if (! number || std::isinf(number))
-        return number;
-    const double v = floor(fabs(number));
-    return std::signbit(number) ? -v : v;
+bool Value::sameValueZero(Value other) const {
+    if (_val == other._val)
+        return true;
+    String *s = stringValue();
+    String *os = other.stringValue();
+    if (s && os)
+        return s->isEqualTo(os);
+    if (isInteger() && other.isDouble())
+        return double(int_32()) == other.doubleValue();
+    if (isDouble() && other.isInteger())
+        return other.int_32() == doubleValue();
+    if (isDouble() && other.isDouble()) {
+        if (doubleValue() == 0 && other.doubleValue() == 0) {
+            return true;
+        }
+    }
+    return false;
 }
 
 #ifndef V4_BOOTSTRAP
-Heap::String *Value::toString(ExecutionEngine *e) const
+Heap::String *Value::toString(ExecutionEngine *e, Value val)
 {
-    if (String *s = stringValue())
-        return s->d();
-    return RuntimeHelpers::convertToString(e, *this);
+    return RuntimeHelpers::convertToString(e, val);
 }
 
-Heap::Object *Value::toObject(ExecutionEngine *e) const
+Heap::Object *Value::toObject(ExecutionEngine *e, Value val)
 {
-    if (Object *o = objectValue())
-        return o->d();
-    return RuntimeHelpers::convertToObject(e, *this);
+    return RuntimeHelpers::convertToObject(e, val);
 }
 
 uint Value::asArrayLength(bool *ok) const
diff --git a/src/qml/jsruntime/qv4value_p.h b/src/qml/jsruntime/qv4value_p.h
index 50cecb6598..b1cae8796f 100644
--- a/src/qml/jsruntime/qv4value_p.h
+++ b/src/qml/jsruntime/qv4value_p.h
@@ -51,14 +51,14 @@
 //
 
 #include <limits.h>
+#include <cmath>
 
 #include <QtCore/QString>
 #include "qv4global_p.h"
 #include <private/qv4heap_p.h>
+#include <private/qv4internalclass_p.h>
 
-#if QT_POINTER_SIZE == 8
-#define QV4_USE_64_BIT_VALUE_ENCODING
-#endif
+#include <private/qnumeric_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -70,11 +70,8 @@ namespace Heap {
 
 struct Q_QML_PRIVATE_EXPORT Value
 {
-private:
     /*
-        We use two different ways of encoding JS values. One for 32bit and one for 64bit systems.
-
-        In both cases, we use 8 bytes for a value and a different variant of NaN boxing. A Double
+        We use 8 bytes for a value and a different variant of NaN boxing. A Double
         NaN (actually -qNaN) is indicated by a number that has the top 13 bits set, and for a
         signalling NaN it is the top 14 bits. The other values are usually set to 0 by the
         processor, and are thus free for us to store other data. We keep pointers in there for
@@ -83,18 +80,14 @@ private:
         only have 48 bits of addressable memory. (Note: we do leave the lower 49 bits available for
         pointers.)
 
-        On 32bit, we store doubles as doubles. All other values, have the high 32bits set to a value
-        that will make the number a NaN. The Masks below are used for encoding the other types.
-
-        On 64 bit, we xor Doubles with (0xffff8000 << 32). That has the effect that no doubles will
+        We xor Doubles with (0xffff8000 << 32). That has the effect that no doubles will
         get encoded with bits 63-49 all set to 0. We then use bit 48 to distinguish between
         managed/undefined (0), or Null/Int/Bool/Empty (1). So, storing a 49 bit pointer will leave
         the top 15 bits 0, which is exactly the 'natural' representation of pointers. If bit 49 is
         set, bit 48 indicates Empty (0) or integer-convertible (1). Then the 3 bit below that are
         used to encode Null/Int/Bool.
 
-        On both 32bit and 64bit, Undefined is encoded as a managed pointer with value 0. This is
-        the same as a nullptr.
+        Undefined is encoded as a managed pointer with value 0. This is the same as a nullptr.
 
         Specific bit-sequences:
         0 = always 0
@@ -102,8 +95,6 @@ private:
         x = stored value
         a,b,c,d = specific bit values, see notes
 
-        64bit:
-
         32109876 54321098 76543210 98765432 10987654 32109876 54321098 76543210 |
         66665555 55555544 44444444 33333333 33222222 22221111 11111100 00000000 | JS Value
         ------------------------------------------------------------------------+--------------
@@ -112,9 +103,9 @@ private:
         a0000000 0000bc00 00000000 00000000 00000000 00000000 00000000 00000000 | NaN/Inf
         dddddddd ddddddxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx | double
         00000000 00000010 00000000 00000000 00000000 00000000 00000000 00000000 | empty (non-sparse array hole)
-        00000000 00000011 10000000 00000000 00000000 00000000 00000000 00000000 | Null
-        00000000 00000011 01000000 00000000 00000000 00000000 00000000 0000000x | Bool
-        00000000 00000011 00100000 00000000 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx | Int
+        00000000 00000010 10000000 00000000 00000000 00000000 00000000 00000000 | Null
+        00000000 00000011 00000000 00000000 00000000 00000000 00000000 0000000x | Bool
+        00000000 00000011 10000000 00000000 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx | Int
 
         Notes:
         - a: xor-ed signbit, always 1 for NaN
@@ -128,39 +119,15 @@ private:
         - Null, Bool, and Int have bit 48 set, indicating integer-convertible
         - xoring _val with NaNEncodeMask will convert to a double in "natural" representation, where
           any non double results in a NaN
-
-        32bit:
-
-        32109876 54321098 76543210 98765432 10987654 32109876 54321098 76543210 |
-        66665555 55555544 44444444 33333333 33222222 22221111 11111100 00000000 | JS Value
-        ------------------------------------------------------------------------+--------------
-        01111111 11111100 00000000 00000000 00000000 00000000 00000000 00000000 | Undefined
-        01111111 11111100 00000000 00000000 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx | Managed (heap pointer)
-        a1111111 1111bc00 00000000 00000000 00000000 00000000 00000000 00000000 | NaN/Inf
-        xddddddd ddddddxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx | double
-        01111111 11111110 00000000 00000000 00000000 00000000 00000000 00000000 | empty (non-sparse array hole)
-        01111111 11111111 10000000 00000000 00000000 00000000 00000000 00000000 | Null
-        01111111 11111111 01000000 00000000 00000000 00000000 00000000 0000000x | Bool
-        01111111 11111111 00100000 00000000 xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx | Int
-
-        Notes:
-        - the upper 32 bits are the tag, the lower 32 bits the value
-        - Undefined has a nullptr in the value, Managed has a non-nullptr stored in the value
-        - a: sign bit, always 0 for NaN
-        - b,c: 00=inf, 01 = sNaN, 10 = qNaN, 11 = boxed value
-        - d: stored double value, as long as not *all* of them are 1, because that's a boxed value
-          (see above)
-        - empty, Null, Bool, and Int have bit 63 set to 0, bits 62-50 set to 1 (same as undefined
-          and managed), and bit 49 set to 1 (where undefined and managed have it set to 0)
-        - Null, Bool, and Int have bit 48 set, indicating integer-convertible
+        - on 32bit we can use the fact that addresses are 32bits wide, so the tag part (bits 32 to
+          63) are zero. No need to shift.
     */
 
     quint64 _val;
 
-public:
-    QML_NEARLY_ALWAYS_INLINE quint64 &rawValueRef() { return _val; }
-    QML_NEARLY_ALWAYS_INLINE quint64 rawValue() const { return _val; }
-    QML_NEARLY_ALWAYS_INLINE void setRawValue(quint64 raw) { _val = raw; }
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR quint64 &rawValueRef() { return _val; }
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR quint64 rawValue() const { return _val; }
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR void setRawValue(quint64 raw) { _val = raw; }
 
 #if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
     static inline int valueOffset() { return 0; }
@@ -169,11 +136,13 @@ public:
     static inline int valueOffset() { return 4; }
     static inline int tagOffset() { return 0; }
 #endif
-    QML_NEARLY_ALWAYS_INLINE void setTagValue(quint32 tag, quint32 value) { _val = quint64(tag) << 32 | value; }
-    QML_NEARLY_ALWAYS_INLINE quint32 value() const { return _val & quint64(~quint32(0)); }
-    QML_NEARLY_ALWAYS_INLINE quint32 tag() const { return _val >> 32; }
+    static inline constexpr quint64 tagValue(quint32 tag, quint32 value) { return quint64(tag) << 32 | value; }
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR void setTagValue(quint32 tag, quint32 value) { _val = quint64(tag) << 32 | value; }
+    QML_NEARLY_ALWAYS_INLINE constexpr quint32 value() const { return _val & quint64(~quint32(0)); }
+    QML_NEARLY_ALWAYS_INLINE constexpr quint32 tag() const { return _val >> 32; }
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR void setTag(quint32 tag) { setTagValue(tag, value()); }
 
-#if defined(QV4_USE_64_BIT_VALUE_ENCODING)
+#if QT_POINTER_SIZE == 8
     QML_NEARLY_ALWAYS_INLINE Heap::Base *m() const
     {
         Heap::Base *b;
@@ -184,7 +153,7 @@ public:
     {
         memcpy(&_val, &b, 8);
     }
-#else // !QV4_USE_64_BIT_VALUE_ENCODING
+#elif QT_POINTER_SIZE == 4
     QML_NEARLY_ALWAYS_INLINE Heap::Base *m() const
     {
         Q_STATIC_ASSERT(sizeof(Heap::Base*) == sizeof(quint32));
@@ -199,57 +168,56 @@ public:
         memcpy(&v, &b, 4);
         setTagValue(Managed_Type_Internal, v);
     }
+#else
+#  error "unsupported pointer size"
 #endif
 
-    QML_NEARLY_ALWAYS_INLINE int int_32() const
+    QML_NEARLY_ALWAYS_INLINE constexpr int int_32() const
     {
         return int(value());
     }
-    QML_NEARLY_ALWAYS_INLINE void setInt_32(int i)
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR void setInt_32(int i)
     {
         setTagValue(quint32(ValueTypeInternal::Integer), quint32(i));
     }
     QML_NEARLY_ALWAYS_INLINE uint uint_32() const { return value(); }
 
-    QML_NEARLY_ALWAYS_INLINE void setEmpty()
+    QML_NEARLY_ALWAYS_INLINE Q_DECL_RELAXED_CONSTEXPR void setEmpty()
     {
-        setTagValue(quint32(ValueTypeInternal::Empty), value());
-    }
-
-    QML_NEARLY_ALWAYS_INLINE void setEmpty(int i)
-    {
-        setTagValue(quint32(ValueTypeInternal::Empty), quint32(i));
-    }
-
-    QML_NEARLY_ALWAYS_INLINE void setEmpty(quint32 i)
-    {
-        setTagValue(quint32(ValueTypeInternal::Empty), i);
-    }
-
-    QML_NEARLY_ALWAYS_INLINE quint32 emptyValue()
-    {
-        Q_ASSERT(isEmpty());
-        return quint32(value());
-    }
+        setTagValue(quint32(ValueTypeInternal::Empty), 0);
+    }
+
+    // ### Fix for 32 bit (easiest solution is to set highest bit to 1 for mananged/undefined/integercompatible
+    // and use negative numbers here
+    enum QuickType {
+        QT_ManagedOrUndefined = 0,
+        QT_ManagedOrUndefined1 = 1,
+        QT_ManagedOrUndefined2 = 2,
+        QT_ManagedOrUndefined3 = 3,
+        QT_Empty = 4,
+        QT_Null = 5,
+        QT_Bool = 6,
+        QT_Int = 7
+        // all other values are doubles
+    };
 
     enum Type {
-        Undefined_Type,
-        Managed_Type,
-        Empty_Type,
-        Integer_Type,
-        Boolean_Type,
-        Null_Type,
-        Double_Type
+        Undefined_Type = 0,
+        Managed_Type = 1,
+        Empty_Type = 4,
+        Null_Type = 5,
+        Boolean_Type = 6,
+        Integer_Type = 7,
+        Double_Type = 8
     };
 
     inline Type type() const {
-        if (isUndefined()) return Undefined_Type;
-        if (isManaged()) return Managed_Type;
-        if (isEmpty()) return Empty_Type;
-        if (isInteger()) return Integer_Type;
-        if (isBoolean()) return Boolean_Type;
-        if (isNull()) return Null_Type;
-        Q_ASSERT(isDouble()); return Double_Type;
+        int t = quickType();
+        if (t < QT_Empty)
+            return _val ? Managed_Type : Undefined_Type;
+        if (t > QT_Int)
+            return Double_Type;
+        return static_cast<Type>(t);
     }
 
     // Shared between 32-bit and 64-bit encoding
@@ -258,23 +226,23 @@ public:
     };
 
     // Used only by 64-bit encoding
-    static const quint64 NaNEncodeMask  = 0xfffc000000000000ll;
+    static const quint64 NaNEncodeMask = 0xfffc000000000000ull;
     enum {
         IsDouble_Shift = 64-14,
         IsManagedOrUndefined_Shift = 64-15,
-        IsIntegerConvertible_Shift = 64-16,
-        IsDoubleTag_Shift = IsDouble_Shift - Tag_Shift,
-        Managed_Type_Internal_64 = 0
+        IsIntegerConvertible_Shift = 64-15,
+        IsIntegerOrBool_Shift = 64-16,
+        QuickType_Shift = 64 - 17,
+        IsPositiveIntShift = 31
     };
 
     static const quint64 Immediate_Mask_64 = 0x00020000u; // bit 49
 
     enum class ValueTypeInternal_64 {
-        Empty            = Immediate_Mask_64| 0,
-        ConvertibleToInt = Immediate_Mask_64| 0x10000u, // bit 48
-        Null             = ConvertibleToInt | 0x08000u,
-        Boolean          = ConvertibleToInt | 0x04000u,
-        Integer          = ConvertibleToInt | 0x02000u
+        Empty            = Immediate_Mask_64 | 0,
+        Null             = Immediate_Mask_64 | 0x08000u,
+        Boolean          = Immediate_Mask_64 | 0x10000u,
+        Integer          = Immediate_Mask_64 | 0x18000u
     };
 
     // Used only by 32-bit encoding
@@ -285,50 +253,58 @@ public:
     static const quint64 Immediate_Mask_32 = NotDouble_Mask | 0x00020000u | SilentNaNBit;
 
     enum class ValueTypeInternal_32 {
-        Empty            = Immediate_Mask_32| 0,
-        ConvertibleToInt = Immediate_Mask_32| 0x10000u, // bit 48
-        Null             = ConvertibleToInt | 0x08000u,
-        Boolean          = ConvertibleToInt | 0x04000u,
-        Integer          = ConvertibleToInt | 0x02000u
+        Empty            = Immediate_Mask_32 | 0,
+        Null             = Immediate_Mask_32 | 0x08000u,
+        Boolean          = Immediate_Mask_32 | 0x10000u,
+        Integer          = Immediate_Mask_32 | 0x18000u
     };
 
     enum {
-        Managed_Type_Internal_32  = NotDouble_Mask
+        Managed_Type_Internal = 0
     };
 
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    enum {
-        Managed_Type_Internal  = Managed_Type_Internal_64
-    };
-    static const quint64 Immediate_Mask = Immediate_Mask_64;
     using ValueTypeInternal = ValueTypeInternal_64;
-#else
-    enum {
-        Managed_Type_Internal  = Managed_Type_Internal_32
-    };
-    static const quint64 Immediate_Mask = Immediate_Mask_32;
-    using ValueTypeInternal = ValueTypeInternal_32;
-#endif
+
     enum {
         NaN_Mask = 0x7ff80000,
     };
 
+    inline quint64 quickType() const { return (_val >> QuickType_Shift); }
+
     // used internally in property
     inline bool isEmpty() const { return tag() == quint32(ValueTypeInternal::Empty); }
     inline bool isNull() const { return tag() == quint32(ValueTypeInternal::Null); }
     inline bool isBoolean() const { return tag() == quint32(ValueTypeInternal::Boolean); }
     inline bool isInteger() const { return tag() == quint32(ValueTypeInternal::Integer); }
     inline bool isNullOrUndefined() const { return isNull() || isUndefined(); }
-    inline bool isNumber() const { return isDouble() || isInteger(); }
+    inline bool isNumber() const { return quickType() >= QT_Int; }
 
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
     inline bool isUndefined() const { return _val == 0; }
     inline bool isDouble() const { return (_val >> IsDouble_Shift); }
-    inline bool isManaged() const { return !isUndefined() && ((_val >> IsManagedOrUndefined_Shift) == 0); }
-    inline bool isManagedOrUndefined() const { return ((_val >> IsManagedOrUndefined_Shift) == 0); }
+    inline bool isManaged() const
+    {
+#if QT_POINTER_SIZE == 4
+        return value() && tag() == Managed_Type_Internal;
+#else
+        return _val && ((_val >> IsManagedOrUndefined_Shift) == 0);
+#endif
+    }
+    inline bool isManagedOrUndefined() const
+    {
+#if QT_POINTER_SIZE == 4
+        return tag() == Managed_Type_Internal;
+#else
+        return ((_val >> IsManagedOrUndefined_Shift) == 0);
+#endif
+    }
+
+    inline bool isIntOrBool() const {
+        return (_val >> IsIntegerOrBool_Shift) == 3;
+    }
 
     inline bool integerCompatible() const {
-        return (_val >> IsIntegerConvertible_Shift) == 3;
+        Q_ASSERT(!isEmpty());
+        return (_val >> IsIntegerConvertible_Shift) == 1;
     }
     static inline bool integerCompatible(Value a, Value b) {
         return a.integerCompatible() && b.integerCompatible();
@@ -337,52 +313,51 @@ public:
         return a.isDouble() && b.isDouble();
     }
     inline bool isNaN() const { return (tag() & 0x7ffc0000  ) == 0x00040000; }
+
+    inline bool isPositiveInt() const {
+#if QT_POINTER_SIZE == 4
+        return isInteger() && int_32() >= 0;
 #else
-    inline bool isUndefined() const { return tag() == Managed_Type_Internal && value() == 0; }
-    inline bool isDouble() const { return (tag() & NotDouble_Mask) != NotDouble_Mask; }
-    inline bool isManaged() const { return tag() == Managed_Type_Internal && !isUndefined(); }
-    inline bool isManagedOrUndefined() const { return tag() == Managed_Type_Internal; }
-    inline bool integerCompatible() const { return (tag() & quint32(ValueTypeInternal::ConvertibleToInt)) == quint32(ValueTypeInternal::ConvertibleToInt); }
-    static inline bool integerCompatible(Value a, Value b) {
-        return ((a.tag() & b.tag()) & quint32(ValueTypeInternal::ConvertibleToInt)) == quint32(ValueTypeInternal::ConvertibleToInt);
-    }
-    static inline bool bothDouble(Value a, Value b) {
-        return ((a.tag() | b.tag()) & NotDouble_Mask) != NotDouble_Mask;
-    }
-    inline bool isNaN() const { return (tag() & QV4::Value::NotDouble_Mask) == QV4::Value::NaN_Mask; }
+        return (_val >> IsPositiveIntShift) == (quint64(ValueTypeInternal::Integer) << 1);
 #endif
+    }
+
     QML_NEARLY_ALWAYS_INLINE double doubleValue() const {
         Q_ASSERT(isDouble());
         double d;
-        quint64 v = _val;
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-        v ^= NaNEncodeMask;
-#endif
-        memcpy(&d, &v, 8);
+        Value v = *this;
+        v._val ^= NaNEncodeMask;
+        memcpy(&d, &v._val, 8);
         return d;
     }
     QML_NEARLY_ALWAYS_INLINE void setDouble(double d) {
+        if (qt_is_nan(d))
+            d = qt_qnan();
         memcpy(&_val, &d, 8);
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
         _val ^= NaNEncodeMask;
-#endif
         Q_ASSERT(isDouble());
     }
     inline bool isString() const;
+    inline bool isStringOrSymbol() const;
+    inline bool isSymbol() const;
     inline bool isObject() const;
+    inline bool isFunctionObject() const;
     inline bool isInt32() {
         if (tag() == quint32(ValueTypeInternal::Integer))
             return true;
         if (isDouble()) {
             double d = doubleValue();
-            int i = (int)d;
-            if (i == d) {
-                setInt_32(i);
+            if (isInt32(d)) {
+                setInt_32(int(d));
                 return true;
             }
         }
         return false;
     }
+    QML_NEARLY_ALWAYS_INLINE static bool isInt32(double d) {
+        int i = int(d);
+        return (i == d && !(d == 0 && std::signbit(d)));
+    }
     double asDouble() const {
         if (tag() == quint32(ValueTypeInternal::Integer))
             return int_32();
@@ -399,7 +374,17 @@ public:
     QML_NEARLY_ALWAYS_INLINE String *stringValue() const {
         if (!isString())
             return nullptr;
-        return reinterpret_cast<String*>(const_cast<Value *>(this));
+        return reinterpret_cast<String *>(const_cast<Value *>(this));
+    }
+    QML_NEARLY_ALWAYS_INLINE StringOrSymbol *stringOrSymbolValue() const {
+        if (!isStringOrSymbol())
+            return nullptr;
+        return reinterpret_cast<StringOrSymbol *>(const_cast<Value *>(this));
+    }
+    QML_NEARLY_ALWAYS_INLINE Symbol *symbolValue() const {
+        if (!isSymbol())
+            return nullptr;
+        return reinterpret_cast<Symbol *>(const_cast<Value *>(this));
     }
     QML_NEARLY_ALWAYS_INLINE Object *objectValue() const {
         if (!isObject())
@@ -425,15 +410,37 @@ public:
     int toUInt16() const;
     inline int toInt32() const;
     inline unsigned int toUInt32() const;
+    qint64 toLength() const;
+    inline qint64 toIndex() const;
+
+    bool toBoolean() const {
+        if (integerCompatible())
+            return static_cast<bool>(int_32());
 
-    bool toBoolean() const;
+        return toBooleanImpl(*this);
+    }
+    static bool toBooleanImpl(Value val);
     double toInteger() const;
+    inline ReturnedValue convertedToNumber() const;
     inline double toNumber() const;
-    double toNumberImpl() const;
+    static double toNumberImpl(Value v);
+    double toNumberImpl() const { return toNumberImpl(*this); }
     QString toQStringNoThrow() const;
     QString toQString() const;
-    Heap::String *toString(ExecutionEngine *e) const;
-    Heap::Object *toObject(ExecutionEngine *e) const;
+    Heap::String *toString(ExecutionEngine *e) const {
+        if (isString())
+            return reinterpret_cast<Heap::String *>(m());
+        return toString(e, *this);
+    }
+    QV4::PropertyKey toPropertyKey(ExecutionEngine *e) const;
+
+    static Heap::String *toString(ExecutionEngine *e, Value val);
+    Heap::Object *toObject(ExecutionEngine *e) const {
+        if (isObject())
+            return reinterpret_cast<Heap::Object *>(m());
+        return toObject(e, *this);
+    }
+    static Heap::Object *toObject(ExecutionEngine *e, Value val);
 
     inline bool isPrimitive() const;
     inline bool tryIntegerConversion() {
@@ -446,19 +453,19 @@ public:
     template <typename T>
     const T *as() const {
         if (!isManaged())
-            return 0;
+            return nullptr;
 
-        Q_ASSERT(m()->vtable());
+        Q_ASSERT(m()->internalClass->vtable);
 #if !defined(QT_NO_QOBJECT_CHECK)
         static_cast<const T *>(this)->qt_check_for_QMANAGED_macro(static_cast<const T *>(this));
 #endif
-        const VTable *vt = m()->vtable();
+        const VTable *vt = m()->internalClass->vtable;
         while (vt) {
             if (vt == T::staticVTable())
                 return static_cast<const T *>(this);
             vt = vt->parent;
         }
-        return 0;
+        return nullptr;
     }
     template <typename T>
     T *as() {
@@ -475,25 +482,37 @@ public:
         return static_cast<const T *>(managed());
     }
 
-    inline uint asArrayIndex() const;
-    inline bool asArrayIndex(uint &idx) const;
 #ifndef V4_BOOTSTRAP
     uint asArrayLength(bool *ok) const;
 #endif
 
-    ReturnedValue asReturnedValue() const { return _val; }
+    ReturnedValue *data_ptr() { return &_val; }
+    constexpr ReturnedValue asReturnedValue() const { return _val; }
     static Value fromReturnedValue(ReturnedValue val) { Value v; v._val = val; return v; }
 
-    // Section 9.12
+    // As per ES specs
     bool sameValue(Value other) const;
+    bool sameValueZero(Value other) const;
 
     inline void mark(MarkStack *markStack);
 
+    inline static constexpr Value emptyValue() { return { tagValue(quint32(ValueTypeInternal::Empty), 0) }; }
+    static inline constexpr Value fromBoolean(bool b) { return { tagValue(quint32(ValueTypeInternal::Boolean), b) }; }
+    static inline constexpr Value fromInt32(int i) { return { tagValue(quint32(ValueTypeInternal::Integer), quint32(i)) }; }
+    inline static constexpr Value undefinedValue() { return { 0 }; }
+    static inline constexpr Value nullValue() { return { tagValue(quint32(ValueTypeInternal::Null), 0) }; }
+    static inline Value fromDouble(double d);
+    static inline Value fromUInt32(uint i);
+
+    static double toInteger(double d);
+    static int toInt32(double d);
+    static unsigned int toUInt32(double d);
+
     Value &operator =(const ScopedValue &v);
     Value &operator=(ReturnedValue v) { _val = v; return *this; }
     Value &operator=(Managed *m) {
         if (!m) {
-            setM(0);
+            setM(nullptr);
         } else {
             _val = reinterpret_cast<Value *>(m)->_val;
         }
@@ -507,17 +526,44 @@ public:
     template<typename T>
     Value &operator=(const Scoped<T> &t);
 };
-V4_ASSERT_IS_TRIVIAL(Value)
+Q_STATIC_ASSERT(std::is_trivial< Value >::value);
+
+inline void Value::mark(MarkStack *markStack)
+{
+    Heap::Base *o = heapObject();
+    if (o)
+        o->mark(markStack);
+}
 
 inline bool Value::isString() const
 {
     Heap::Base *b = heapObject();
-    return b && b->vtable()->isString;
+    return b && b->internalClass->vtable->isString;
+}
+
+bool Value::isStringOrSymbol() const
+{
+    Heap::Base *b = heapObject();
+    return b && b->internalClass->vtable->isStringOrSymbol;
+}
+
+bool Value::isSymbol() const
+{
+    Heap::Base *b = heapObject();
+    return b && b->internalClass->vtable->isStringOrSymbol && !b->internalClass->vtable->isString;
 }
+
 inline bool Value::isObject() const
+
 {
     Heap::Base *b = heapObject();
-    return b && b->vtable()->isObject;
+    return b && b->internalClass->vtable->isObject;
+}
+
+inline bool Value::isFunctionObject() const
+{
+    Heap::Base *b = heapObject();
+    return b && b->internalClass->vtable->isFunctionObject;
 }
 
 inline bool Value::isPrimitive() const
@@ -534,42 +580,14 @@ inline double Value::toNumber() const
     return toNumberImpl();
 }
 
-
-#ifndef V4_BOOTSTRAP
-inline uint Value::asArrayIndex() const
+inline ReturnedValue Value::convertedToNumber() const
 {
-#ifdef QV4_USE_64_BIT_VALUE_ENCODING
-    if (!isNumber())
-        return UINT_MAX;
-    if (isInteger())
-        return int_32() >= 0 ? (uint)int_32() : UINT_MAX;
-#else
-    if (isInteger() && int_32() >= 0)
-        return (uint)int_32();
-    if (!isDouble())
-        return UINT_MAX;
-#endif
-    double d = doubleValue();
-    uint idx = (uint)d;
-    if (idx != d)
-        return UINT_MAX;
-    return idx;
-}
-
-inline bool Value::asArrayIndex(uint &idx) const
-{
-    if (!isDouble()) {
-        if (isInteger() && int_32() >= 0) {
-            idx = (uint)int_32();
-            return true;
-        }
-        return false;
-    }
-    double d = doubleValue();
-    idx = (uint)d;
-    return (idx == d && idx != UINT_MAX);
+    if (isInteger() || isDouble())
+        return asReturnedValue();
+    Value v;
+    v.setDouble(toNumberImpl());
+    return v.asReturnedValue();
 }
-#endif
 
 inline
 ReturnedValue Heap::Base::asReturnedValue() const
@@ -577,122 +595,146 @@ ReturnedValue Heap::Base::asReturnedValue() const
     return Value::fromHeapObject(const_cast<Heap::Base *>(this)).asReturnedValue();
 }
 
-
-
-struct Q_QML_PRIVATE_EXPORT Primitive : public Value
+inline Value Value::fromDouble(double d)
 {
-    inline static Primitive emptyValue();
-    inline static Primitive emptyValue(uint v);
-    static inline Primitive fromBoolean(bool b);
-    static inline Primitive fromInt32(int i);
-    inline static Primitive undefinedValue();
-    static inline Primitive nullValue();
-    static inline Primitive fromDouble(double d);
-    static inline Primitive fromUInt32(uint i);
-
-    using Value::toInt32;
-    using Value::toUInt32;
-
-    static double toInteger(double fromNumber);
-    static int toInt32(double value);
-    static unsigned int toUInt32(double value);
-};
-
-inline Primitive Primitive::undefinedValue()
-{
-    Primitive v;
-    v.setM(Q_NULLPTR);
+    Value v;
+    v.setDouble(d);
     return v;
 }
 
-inline Primitive Primitive::emptyValue()
+inline Value Value::fromUInt32(uint i)
 {
-    Primitive v;
-    v.setEmpty(0);
+    Value v;
+    if (i < INT_MAX) {
+        v.setTagValue(quint32(ValueTypeInternal::Integer), i);
+    } else {
+        v.setDouble(i);
+    }
     return v;
 }
 
-inline Primitive Primitive::emptyValue(uint e)
-{
-    Primitive v;
-    v.setEmpty(e);
-    return v;
-}
+struct Double {
+    quint64 d;
 
-inline Primitive Primitive::nullValue()
-{
-    Primitive v;
-    v.setTagValue(quint32(ValueTypeInternal::Null), 0);
-    return v;
-}
+    Double(double dbl) {
+        memcpy(&d, &dbl, sizeof(double));
+    }
 
-inline Primitive Primitive::fromBoolean(bool b)
-{
-    Primitive v;
-    v.setTagValue(quint32(ValueTypeInternal::Boolean), b);
-    return v;
-}
+    int sign() const {
+        return (d >> 63) ? -1 : 1;
+    }
+
+    bool isDenormal() const {
+        return static_cast<int>((d << 1) >> 53) == 0;
+    }
+
+    int exponent() const {
+        return static_cast<int>((d << 1) >> 53) - 1023;
+    }
+
+    quint64 significant() const {
+        quint64 m = (d << 12) >> 12;
+        if (!isDenormal())
+            m |= (static_cast<quint64>(1) << 52);
+        return m;
+    }
 
-inline Primitive Primitive::fromDouble(double d)
+    static int toInt32(double d) {
+        int i = static_cast<int>(d);
+        if (i == d)
+                return i;
+        return Double(d).toInt32();
+    }
+
+    int toInt32() {
+        int e = exponent() - 52;
+        if (e < 0) {
+            if (e <= -53)
+                return 0;
+            return sign() * static_cast<int>(significant() >> -e);
+        } else {
+            if (e > 31)
+                return 0;
+            return sign() * (static_cast<int>(significant()) << e);
+        }
+    }
+};
+
+inline double Value::toInteger(double d)
 {
-    Primitive v;
-    v.setDouble(d);
-    return v;
+    if (std::isnan(d))
+        return +0;
+    else if (!d || std::isinf(d))
+        return d;
+    return d >= 0 ? std::floor(d) : std::ceil(d);
 }
 
-inline Primitive Primitive::fromInt32(int i)
+inline int Value::toInt32(double value)
 {
-    Primitive v;
-    v.setInt_32(i);
-    return v;
+    return Double::toInt32(value);
 }
 
-inline Primitive Primitive::fromUInt32(uint i)
+inline unsigned int Value::toUInt32(double d)
 {
-    Primitive v;
-    if (i < INT_MAX) {
-        v.setTagValue(quint32(ValueTypeInternal::Integer), i);
-    } else {
-        v.setDouble(i);
-    }
-    return v;
+    return static_cast<uint>(toInt32(d));
 }
 
+// For source compat with older code in other modules
+using Primitive = Value;
+
 struct Encode {
-    static ReturnedValue undefined() {
-        return Primitive::undefinedValue().rawValue();
+    static constexpr ReturnedValue undefined() {
+        return Value::undefinedValue().asReturnedValue();
     }
-    static ReturnedValue null() {
-        return Primitive::nullValue().rawValue();
+    static constexpr ReturnedValue null() {
+        return Value::nullValue().asReturnedValue();
     }
 
-    Encode(bool b) {
-        val = Primitive::fromBoolean(b).rawValue();
+    explicit constexpr Encode(bool b)
+        : val(Value::fromBoolean(b).asReturnedValue())
+    {
     }
-    Encode(double d) {
-        val = Primitive::fromDouble(d).rawValue();
+    explicit Encode(double d) {
+        val = Value::fromDouble(d).asReturnedValue();
     }
-    Encode(int i) {
-        val = Primitive::fromInt32(i).rawValue();
+    explicit constexpr Encode(int i)
+        : val(Value::fromInt32(i).asReturnedValue())
+    {
+    }
+    explicit Encode(uint i) {
+        val = Value::fromUInt32(i).asReturnedValue();
     }
-    Encode(uint i) {
-        val = Primitive::fromUInt32(i).rawValue();
+    explicit constexpr Encode(ReturnedValue v)
+        : val(v)
+    {
     }
-    Encode(ReturnedValue v) {
-        val = v;
+    constexpr Encode(Value v)
+        : val(v.asReturnedValue())
+    {
     }
 
-    Encode(Heap::Base *o) {
-        Q_ASSERT(o);
+    explicit Encode(Heap::Base *o) {
         val = Value::fromHeapObject(o).asReturnedValue();
     }
 
-    operator ReturnedValue() const {
+    explicit Encode(Value *o) {
+        Q_ASSERT(o);
+        val = o->asReturnedValue();
+    }
+
+    static ReturnedValue smallestNumber(double d) {
+        if (Value::isInt32(d))
+            return Encode(static_cast<int>(d));
+        else
+            return Encode(d);
+    }
+
+    constexpr operator ReturnedValue() const {
         return val;
     }
     quint64 val;
 private:
-    Encode(void *);
+    explicit Encode(void *);
 };
 
 template<typename T>
@@ -700,24 +742,141 @@ ReturnedValue value_convert(ExecutionEngine *e, const Value &v);
 
 inline int Value::toInt32() const
 {
-    if (isInteger())
+    if (Q_LIKELY(integerCompatible()))
         return int_32();
-    double d = isNumber() ? doubleValue() : toNumberImpl();
-
-    const double D32 = 4294967296.0;
-    const double D31 = D32 / 2.0;
 
-    if ((d >= -D31 && d < D31))
-        return static_cast<int>(d);
+    if (Q_LIKELY(isDouble()))
+        return Double::toInt32(doubleValue());
 
-    return Primitive::toInt32(d);
+    return Double::toInt32(toNumberImpl());
 }
 
 inline unsigned int Value::toUInt32() const
 {
-    return (unsigned int)toInt32();
+    return static_cast<unsigned int>(toInt32());
 }
 
+inline qint64 Value::toLength() const
+{
+    if (Q_LIKELY(integerCompatible()))
+        return int_32() < 0 ? 0 : int_32();
+    double i = Value::toInteger(isDouble() ? doubleValue() : toNumberImpl());
+    if (i <= 0)
+        return 0;
+    if (i > (static_cast<qint64>(1) << 53) - 1)
+        return (static_cast<qint64>(1) << 53) - 1;
+    return static_cast<qint64>(i);
+}
+
+inline qint64 Value::toIndex() const
+{
+    qint64 idx;
+    if (Q_LIKELY(integerCompatible())) {
+        idx = int_32();
+    } else {
+        idx = static_cast<qint64>(Value::toInteger(isDouble() ? doubleValue() : toNumberImpl()));
+    }
+    if (idx > (static_cast<qint64>(1) << 53) - 1)
+        idx = -1;
+    return idx;
+}
+
+inline double Value::toInteger() const
+{
+    if (integerCompatible())
+        return int_32();
+
+    return Value::toInteger(isDouble() ? doubleValue() : toNumberImpl());
+}
+
+
+template <size_t o>
+struct HeapValue : Value {
+    static Q_CONSTEXPR size_t offset = o;
+    Heap::Base *base() {
+        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
+        Q_ASSERT(base->inUse());
+        return base;
+    }
+
+    void set(EngineBase *e, const Value &newVal) {
+        WriteBarrier::write(e, base(), data_ptr(), newVal.asReturnedValue());
+    }
+    void set(EngineBase *e, Heap::Base *b) {
+        WriteBarrier::write(e, base(), data_ptr(), b->asReturnedValue());
+    }
+};
+
+template <size_t o>
+struct ValueArray {
+    static Q_CONSTEXPR size_t offset = o;
+    uint size;
+    uint alloc;
+    Value values[1];
+
+    Heap::Base *base() {
+        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
+        Q_ASSERT(base->inUse());
+        return base;
+    }
+
+    void set(EngineBase *e, uint index, Value v) {
+        WriteBarrier::write(e, base(), values[index].data_ptr(), v.asReturnedValue());
+    }
+    void set(EngineBase *e, uint index, Heap::Base *b) {
+        WriteBarrier::write(e, base(), values[index].data_ptr(), Value::fromHeapObject(b).asReturnedValue());
+    }
+    inline const Value &operator[] (uint index) const {
+        Q_ASSERT(index < alloc);
+        return values[index];
+    }
+    inline const Value *data() const {
+        return values;
+    }
+
+    void insertData(EngineBase *e, uint index, Value v) {
+        for (uint i = size - 1; i > index; --i) {
+            values[i] = values[i - 1];
+        }
+        set(e, index, v);
+    }
+    void removeData(EngineBase *e, uint index, int n = 1) {
+        Q_UNUSED(e);
+        for (uint i = index; i < size - n; ++i) {
+            values[i] = values[i + n];
+        }
+    }
+
+    void mark(MarkStack *markStack) {
+        Value *v = values;
+        const Value *end = v + alloc;
+        if (alloc > 32*1024) {
+            // drain from time to time to avoid overflows in the js stack
+            Heap::Base **currentBase = markStack->top;
+            while (v < end) {
+                v->mark(markStack);
+                ++v;
+                if (markStack->top >= currentBase + 32*1024) {
+                    Heap::Base **oldBase = markStack->base;
+                    markStack->base = currentBase;
+                    markStack->drain();
+                    markStack->base = oldBase;
+                }
+            }
+        } else {
+            while (v < end) {
+                v->mark(markStack);
+                ++v;
+            }
+        }
+    }
+};
+
+// It's really important that the offset of values in this structure is
+// constant across all architecture,  otherwise JIT cross-compiled code will
+// have wrong offsets between host and target.
+Q_STATIC_ASSERT(offsetof(ValueArray<0>, values) == 8);
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4variantobject.cpp b/src/qml/jsruntime/qv4variantobject.cpp
index f2ff5d307e..e4d8bcaafc 100644
--- a/src/qml/jsruntime/qv4variantobject.cpp
+++ b/src/qml/jsruntime/qv4variantobject.cpp
@@ -70,7 +70,7 @@ bool VariantObject::Data::isScarce() const
     return t == QVariant::Pixmap || t == QVariant::Image;
 }
 
-bool VariantObject::isEqualTo(Managed *m, Managed *other)
+bool VariantObject::virtualIsEqualTo(Managed *m, Managed *other)
 {
     Q_ASSERT(m->as<QV4::VariantObject>());
     QV4::VariantObject *lv = static_cast<QV4::VariantObject *>(m);
@@ -113,17 +113,17 @@ void VariantPrototype::init()
     defineDefaultProperty(engine()->id_toString(), method_toString, 0);
 }
 
-void VariantPrototype::method_preserve(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue VariantPrototype::method_preserve(const FunctionObject *, const Value *thisObject, const Value *, int)
 {
-    Scoped<VariantObject> o(scope, callData->thisObject.as<QV4::VariantObject>());
+    const VariantObject *o = thisObject->as<QV4::VariantObject>();
     if (o && o->d()->isScarce())
         o->d()->addVmePropertyReference();
     RETURN_UNDEFINED();
 }
 
-void VariantPrototype::method_destroy(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue VariantPrototype::method_destroy(const FunctionObject *, const Value *thisObject, const Value *, int)
 {
-    Scoped<VariantObject> o(scope, callData->thisObject.as<QV4::VariantObject>());
+    const VariantObject *o = thisObject->as<QV4::VariantObject>();
     if (o) {
         if (o->d()->isScarce())
             o->d()->addVmePropertyReference();
@@ -132,49 +132,48 @@ void VariantPrototype::method_destroy(const BuiltinFunction *, Scope &scope, Cal
     RETURN_UNDEFINED();
 }
 
-void VariantPrototype::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue VariantPrototype::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<VariantObject> o(scope, callData->thisObject.as<QV4::VariantObject>());
+    ExecutionEngine *v4 = b->engine();
+    const VariantObject *o = thisObject->as<QV4::VariantObject>();
     if (!o)
         RETURN_UNDEFINED();
-    QString result = o->d()->data().toString();
-    if (result.isEmpty() && !o->d()->data().canConvert(QVariant::String)) {
-        result = QLatin1String("QVariant(")
-                 + QLatin1String(o->d()->data().typeName())
-                 + QLatin1Char(')');
+    const QVariant variant = o->d()->data();
+    QString result = variant.toString();
+    if (result.isEmpty() && !variant.canConvert(QVariant::String)) {
+        QDebug dbg(&result);
+        dbg << variant;
+        // QDebug appends a space, we're not interested in continuing the stream so we chop it off.
+        // Can't use nospace() because it would affect the debug-stream operator of the variant.
+        result.chop(1);
     }
-    scope.result = scope.engine->newString(result);
+    return Encode(v4->newString(result));
 }
 
-void VariantPrototype::method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue VariantPrototype::method_valueOf(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<VariantObject> o(scope, callData->thisObject.as<QV4::VariantObject>());
+    const VariantObject *o = thisObject->as<QV4::VariantObject>();
     if (o) {
         QVariant v = o->d()->data();
         switch (v.type()) {
         case QVariant::Invalid:
-            scope.result = Encode::undefined();
-            return;
+            return Encode::undefined();
         case QVariant::String:
-            scope.result = scope.engine->newString(v.toString());
-            return;
+            return Encode(b->engine()->newString(v.toString()));
         case QVariant::Int:
-            scope.result = Encode(v.toInt());
-            return;
+            return Encode(v.toInt());
         case QVariant::Double:
         case QVariant::UInt:
-            scope.result = Encode(v.toDouble());
-            return;
+            return Encode(v.toDouble());
         case QVariant::Bool:
-            scope.result = Encode(v.toBool());
-            return;
+            return Encode(v.toBool());
         default:
             if (QMetaType::typeFlags(v.userType()) & QMetaType::IsEnumeration)
                 RETURN_RESULT(Encode(v.toInt()));
             break;
         }
     }
-    scope.result = callData->thisObject;
+    return thisObject->asReturnedValue();
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4variantobject_p.h b/src/qml/jsruntime/qv4variantobject_p.h
index a7c6fa320c..78e0a5373a 100644
--- a/src/qml/jsruntime/qv4variantobject_p.h
+++ b/src/qml/jsruntime/qv4variantobject_p.h
@@ -99,7 +99,8 @@ struct VariantObject : Object
     void addVmePropertyReference() const;
     void removeVmePropertyReference() const;
 
-    static bool isEqualTo(Managed *m, Managed *other);
+protected:
+    static bool virtualIsEqualTo(Managed *m, Managed *other);
 };
 
 struct VariantPrototype : VariantObject
@@ -108,10 +109,10 @@ public:
     V4_PROTOTYPE(objectPrototype)
     void init();
 
-    static void method_preserve(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_destroy(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_valueOf(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_preserve(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_destroy(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_toString(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_valueOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 }
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 7293630924..3098837e1c 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -50,20 +50,22 @@
 #include <private/qv4math_p.h>
 #include <private/qv4scopedvalue_p.h>
 #include <private/qv4lookup_p.h>
+#include <private/qv4regexp_p.h>
+#include <private/qv4regexpobject_p.h>
 #include <private/qv4string_p.h>
+#include <private/qv4profiling_p.h>
+#include <private/qv4jscall_p.h>
+#include <private/qv4generatorobject_p.h>
+#include <private/qqmljavascriptexpression_p.h>
 #include <iostream>
 
 #include "qv4alloca_p.h"
 
-#undef DO_TRACE_INSTR // define to enable instruction tracing
+#include <private/qv4baselinejit_p.h>
 
-#ifdef DO_TRACE_INSTR
-#  define TRACE_INSTR(I) qDebug("executing a %s\n", #I);
-#  define TRACE(n, str, ...) { char buf[4096]; snprintf(buf, 4096, str, __VA_ARGS__); qDebug("    %s : %s", #n, buf); }
-#else
-#  define TRACE_INSTR(I)
-#  define TRACE(n, str, ...)
-#endif // DO_TRACE_INSTR
+#undef COUNT_INSTRUCTIONS
+
+enum { ShowWhenDeoptimiationHappens = 0 };
 
 extern "C" {
 
@@ -142,9 +144,9 @@ Q_QML_EXPORT int qt_v4DebuggerHook(const char *json);
 
 } // extern "C"
 
-#ifndef QT_NO_QML_DEBUGGER
+#if QT_CONFIG(qml_debug)
 static int qt_v4BreakpointCount = 0;
-static bool qt_v4IsDebugging = true;
+static bool qt_v4IsDebugging = false;
 static bool qt_v4IsStepping = false;
 
 class Breakpoint
@@ -167,14 +169,6 @@ public:
 static QVector<Breakpoint> qt_v4Breakpoints;
 static Breakpoint qt_v4LastStop;
 
-static QV4::Function *qt_v4ExtractFunction(QV4::ExecutionContext *context)
-{
-    if (QV4::Function *function = context->getFunction())
-        return function;
-    else
-        return context->engine()->globalCode;
-}
-
 static void qt_v4TriggerBreakpoint(const Breakpoint &bp, QV4::Function *function)
 {
     qt_v4LastStop = bp;
@@ -221,6 +215,7 @@ int qt_v4DebuggerHook(const char *json)
         bp.fullName = ob.value(QLatin1String("fullName")).toString();
         bp.condition = ob.value(QLatin1String("condition")).toString();
         qt_v4Breakpoints.append(bp);
+        qt_v4IsDebugging = true;
         return bp.bpNumber;
     }
 
@@ -229,6 +224,7 @@ int qt_v4DebuggerHook(const char *json)
         QString fullName = ob.value(QLatin1String("fullName")).toString();
         if (qt_v4Breakpoints.last().matches(fullName, lineNumber)) {
             qt_v4Breakpoints.removeLast();
+            qt_v4IsDebugging = !qt_v4Breakpoints.isEmpty();
             return Success;
         }
         for (int i = 0; i + 1 < qt_v4Breakpoints.size(); ++i) {
@@ -249,13 +245,13 @@ int qt_v4DebuggerHook(const char *json)
     return -NoSuchCommand; // Failure.
 }
 
-static void qt_v4CheckForBreak(QV4::ExecutionContext *context)
+Q_NEVER_INLINE static void qt_v4CheckForBreak(QV4::CppStackFrame *frame)
 {
     if (!qt_v4IsStepping && !qt_v4Breakpoints.size())
         return;
 
-    const int lineNumber = context->d()->lineNumber;
-    QV4::Function *function = qt_v4ExtractFunction(context);
+    const int lineNumber = frame->lineNumber();
+    QV4::Function *function = frame->v4Function;
     QString engineName = function->sourceFile();
 
     if (engineName.isEmpty())
@@ -285,691 +281,1242 @@ static void qt_v4CheckForBreak(QV4::ExecutionContext *context)
     }
 }
 
-#endif // QT_NO_QML_DEBUGGER
+Q_NEVER_INLINE static void debug_slowPath(QV4::ExecutionEngine *engine)
+{
+    QV4::Debugging::Debugger *debugger = engine->debugger();
+    if (debugger && debugger->pauseAtNextOpportunity())
+        debugger->maybeBreakAtInstruction();
+    if (qt_v4IsDebugging)
+        qt_v4CheckForBreak(engine->currentStackFrame);
+}
+
+#endif // QT_CONFIG(qml_debug)
 // End of debugger interface
 
 using namespace QV4;
 using namespace QV4::Moth;
 
-#define MOTH_BEGIN_INSTR_COMMON(I) { \
-    const InstrMeta<(int)Instr::I>::DataType &instr = InstrMeta<(int)Instr::I>::data(*genericInstr); \
-    code += InstrMeta<(int)Instr::I>::Size; \
-    Q_UNUSED(instr); \
-    TRACE_INSTR(I)
-
-#ifdef MOTH_THREADED_INTERPRETER
+#ifdef COUNT_INSTRUCTIONS
+static struct InstrCount {
+    InstrCount() {
+        fprintf(stderr, "Counting instructions...\n");
+        for (int i = 0; i < MOTH_NUM_INSTRUCTIONS(); ++i)
+            hits[i] = 0;
+    }
+    ~InstrCount() {
+        fprintf(stderr, "Instruction count:\n");
+#define BLAH(I) \
+        fprintf(stderr, "%llu : %s\n", hits[int(Instr::Type::I)], #I);
+        FOR_EACH_MOTH_INSTR(BLAH)
+        #undef BLAH
+    }
+    quint64 hits[MOTH_NUM_INSTRUCTIONS()];
+    void hit(Instr::Type i) { hits[int(i)]++; }
+} instrCount;
+#endif // COUNT_INSTRUCTIONS
+
+#define MOTH_BEGIN_INSTR_COMMON(instr) \
+    { \
+        INSTR_##instr(MOTH_DECODE)
+
+#ifdef COUNT_INSTRUCTIONS
+#  define MOTH_BEGIN_INSTR(instr) \
+    MOTH_BEGIN_INSTR_COMMON(instr) \
+    instrCount.hit(Instr::Type::instr);
+#else // !COUNT_INSTRUCTIONS
+#  define MOTH_BEGIN_INSTR(instr) \
+    MOTH_BEGIN_INSTR_COMMON(instr)
+#endif // COUNT_INSTRUCTIONS
+
+#ifdef MOTH_COMPUTED_GOTO
+#define MOTH_END_INSTR(instr) \
+        MOTH_DISPATCH_SINGLE() \
+    }
+#else // !MOTH_COMPUTED_GOTO
+#define MOTH_END_INSTR(instr) \
+        continue; \
+    }
+#endif
 
-#  define MOTH_BEGIN_INSTR(I) op_##I: \
-    MOTH_BEGIN_INSTR_COMMON(I)
+#define STACK_VALUE(temp) stack[temp]
 
-#  define MOTH_END_INSTR(I) } \
-    genericInstr = reinterpret_cast<const Instr *>(code); \
-    goto *jumpTable[genericInstr->common.instructionType]; \
+// qv4scopedvalue_p.h also defines a CHECK_EXCEPTION macro
+#ifdef CHECK_EXCEPTION
+#undef CHECK_EXCEPTION
+#endif
+#define CHECK_EXCEPTION \
+    if (engine->hasException) \
+        goto handleUnwind
 
+static inline void traceJumpTakesTruePath(bool truePathTaken, Function *f, int slot)
+{
+#if QT_CONFIG(qml_tracing)
+    quint8 *traceInfo = f->traceInfo(slot);
+    Q_ASSERT(traceInfo);
+    *traceInfo |= truePathTaken ? quint8(ObservedTraceValues::TruePathTaken)
+                                : quint8(ObservedTraceValues::FalsePathTaken);
 #else
-
-#  define MOTH_BEGIN_INSTR(I) \
-    case Instr::I: \
-    MOTH_BEGIN_INSTR_COMMON(I)
-
-#  define MOTH_END_INSTR(I) } \
-    continue;
-
+    Q_UNUSED(truePathTaken);
+    Q_UNUSED(f);
+    Q_UNUSED(slot);
 #endif
+}
 
-#ifdef DO_TRACE_INSTR
-Param traceParam(const Param &param)
+static inline void traceValue(ReturnedValue acc, Function *f, int slot)
 {
-    if (param.isConstant()) {
-        qDebug("    constant\n");
-    } else if (param.isArgument()) {
-        qDebug("    argument %d@%d\n", param.index, param.scope);
-    } else if (param.isLocal()) {
-        qDebug("    local %d\n", param.index);
-    } else if (param.isTemp()) {
-        qDebug("    temp %d\n", param.index);
-    } else if (param.isScopedLocal()) {
-        qDebug("    temp %d@%d\n", param.index, param.scope);
-    } else {
-        Q_ASSERT(!"INVALID");
+#if QT_CONFIG(qml_tracing)
+    quint8 *traceInfo = f->traceInfo(slot);
+    Q_ASSERT(traceInfo);
+    switch (Primitive::fromReturnedValue(acc).type()) {
+    case QV4::Value::Integer_Type:
+        *traceInfo |= quint8(ObservedTraceValues::Integer);
+        break;
+    case QV4::Value::Boolean_Type:
+        *traceInfo |= quint8(ObservedTraceValues::Boolean);
+        break;
+    case QV4::Value::Double_Type:
+        *traceInfo |= quint8(ObservedTraceValues::Double);
+        break;
+    default:
+        *traceInfo |= quint8(ObservedTraceValues::Other);
+        break;
     }
-    return param;
-}
-# define VALUE(param) (*VALUEPTR(param))
-# define VALUEPTR(param) (scopes[traceParam(param).scope].values + param.index)
 #else
-# define VALUE(param) (*VALUEPTR(param))
-# define VALUEPTR(param) (scopes[param.scope].values + param.index)
+    Q_UNUSED(acc);
+    Q_UNUSED(f);
+    Q_UNUSED(slot);
 #endif
-
-// ### add write barrier here
-#define STOREVALUE(param, value) { \
-    QV4::ReturnedValue tmp = (value); \
-    if (engine->hasException) \
-        goto catchException; \
-    if (Q_LIKELY(!engine->writeBarrierActive || !scopes[param.scope].base)) { \
-        VALUE(param) = tmp; \
-    } else { \
-        QV4::WriteBarrier::write(engine, scopes[param.scope].base, VALUEPTR(param), QV4::Value::fromReturnedValue(tmp)); \
-    } \
 }
 
-// qv4scopedvalue_p.h also defines a CHECK_EXCEPTION macro
-#ifdef CHECK_EXCEPTION
-#undef CHECK_EXCEPTION
+static inline void traceDoubleValue(Function *f, int slot)
+{
+#if QT_CONFIG(qml_tracing)
+    quint8 *traceInfo = f->traceInfo(slot);
+    Q_ASSERT(traceInfo);
+    *traceInfo |= quint8(ObservedTraceValues::Double);
+#else
+    Q_UNUSED(f);
+    Q_UNUSED(slot);
 #endif
-#define CHECK_EXCEPTION \
-    if (engine->hasException) \
-        goto catchException
+}
 
-QV4::ReturnedValue VME::run(ExecutionEngine *engine, const uchar *code)
+static inline void traceOtherValue(Function *f, int slot)
 {
-#ifdef DO_TRACE_INSTR
-    qDebug("Starting VME with context=%p and code=%p", context, code);
-#endif // DO_TRACE_INSTR
-
-    qt_v4ResolvePendingBreakpointsHook();
-
-#ifdef MOTH_THREADED_INTERPRETER
-#define MOTH_INSTR_ADDR(I, FMT) &&op_##I,
-    static void *jumpTable[] = {
-        FOR_EACH_MOTH_INSTR(MOTH_INSTR_ADDR)
-    };
-#undef MOTH_INSTR_ADDR
+#if QT_CONFIG(qml_tracing)
+    quint8 *traceInfo = f->traceInfo(slot);
+    Q_ASSERT(traceInfo);
+    *traceInfo |= quint8(ObservedTraceValues::Other);
+#else
+    Q_UNUSED(f);
+    Q_UNUSED(slot);
 #endif
+}
+
+static inline Heap::CallContext *getScope(QV4::Value *stack, int level)
+{
+    Heap::ExecutionContext *scope = static_cast<ExecutionContext &>(stack[CallData::Context]).d();
+    while (level > 0) {
+        --level;
+        scope = scope->outer;
+    }
+    Q_ASSERT(scope);
+    return static_cast<Heap::CallContext *>(scope);
+}
 
-    QV4::Value *stack = 0;
-    unsigned stackSize = 0;
+static inline const QV4::Value &constant(Function *function, int index)
+{
+    return function->compilationUnit->constants[index];
+}
 
-    const uchar *exceptionHandler = 0;
+static bool compareEqualInt(QV4::Value &accumulator, QV4::Value lhs, int rhs)
+{
+  redo:
+    switch (lhs.quickType()) {
+    case QV4::Value::QT_ManagedOrUndefined:
+        if (lhs.isUndefined())
+            return false;
+        Q_FALLTHROUGH();
+    case QV4::Value::QT_ManagedOrUndefined1:
+    case QV4::Value::QT_ManagedOrUndefined2:
+    case QV4::Value::QT_ManagedOrUndefined3:
+        // LHS: Managed
+        if (lhs.m()->internalClass->vtable->isString)
+            return RuntimeHelpers::stringToNumber(static_cast<String &>(lhs).toQString()) == rhs;
+        accumulator = lhs;
+        lhs = QV4::Value::fromReturnedValue(RuntimeHelpers::objectDefaultValue(&static_cast<QV4::Object &>(accumulator), PREFERREDTYPE_HINT));
+        goto redo;
+    case QV4::Value::QT_Empty:
+        Q_UNREACHABLE();
+    case QV4::Value::QT_Null:
+        return false;
+    case QV4::Value::QT_Bool:
+    case QV4::Value::QT_Int:
+        return lhs.int_32() == rhs;
+    default: // double
+        return lhs.doubleValue() == rhs;
+    }
+}
 
-    QV4::Scope scope(engine);
-    engine->current->lineNumber = -1;
+#define STORE_IP() frame->instructionPointer = int(code - function->codeData);
+#define STORE_ACC() accumulator = acc;
+#define ACC Value::fromReturnedValue(acc)
+#define VALUE_TO_INT(i, val) \
+    int i; \
+    do { \
+        if (Q_LIKELY(val.integerCompatible())) { \
+            i = val.int_32(); \
+        } else { \
+            double d; \
+            if (val.isDouble()) \
+                d = val.doubleValue(); \
+            else { \
+                STORE_ACC(); \
+                d = val.toNumberImpl(); \
+                CHECK_EXCEPTION; \
+            } \
+            i = Double::toInt32(d); \
+        } \
+    } while (false)
+
+ReturnedValue VME::exec(CppStackFrame *frame, ExecutionEngine *engine)
+{
+    qt_v4ResolvePendingBreakpointsHook();
+    CHECK_STACK_LIMITS(engine);
 
-#ifdef DO_TRACE_INSTR
-    qDebug("Starting VME with context=%p and code=%p", context, code);
-#endif // DO_TRACE_INSTR
+    Function *function = frame->v4Function;
+    Profiling::FunctionCallProfiler profiler(engine, function); // start execution profiling
+    QV4::Debugging::Debugger *debugger = engine->debugger();
 
-    // setup lookup scopes
-    int scopeDepth = 0;
-    {
-        QV4::Heap::ExecutionContext *scope = engine->current;
-        while (scope) {
-            ++scopeDepth;
-            scope = scope->outer;
+#ifdef V4_ENABLE_JIT
+    if (debugger == nullptr) {
+        if (function->jittedCode == nullptr) {
+            if (engine->canJIT(function)) {
+#if QT_CONFIG(qml_tracing)
+                if (function->tracingEnabled())
+                    runTracingJit(function);
+                else
+#endif
+                    QV4::JIT::BaselineJIT(function).generate();
+            } else {
+                ++function->interpreterCallCount;
+            }
         }
     }
+#endif // V4_ENABLE_JIT
 
-    struct Scopes {
-        QV4::Value *values;
-        QV4::Heap::Base *base; // non 0 if a write barrier is required
-    };
-    Q_ALLOCA_VAR(Scopes, scopes, sizeof(Scopes)*(2 + 2*scopeDepth));
-    {
-        scopes[0] = { const_cast<QV4::Value *>(static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->constants), 0 };
-        // stack gets setup in push instruction
-        scopes[1] = { 0, 0 };
-        QV4::Heap::ExecutionContext *scope = engine->current;
-        int i = 0;
-        while (scope) {
-            if (scope->type == QV4::Heap::ExecutionContext::Type_SimpleCallContext) {
-                QV4::Heap::SimpleCallContext *cc = static_cast<QV4::Heap::SimpleCallContext *>(scope);
-                scopes[2*i + 2] = { cc->callData->args, 0 };
-                scopes[2*i + 3] = { 0, 0 };
-            } else if (scope->type == QV4::Heap::ExecutionContext::Type_CallContext) {
-                QV4::Heap::CallContext *cc = static_cast<QV4::Heap::CallContext *>(scope);
-                scopes[2*i + 2] = { cc->callData->args, cc };
-                scopes[2*i + 3] = { cc->locals.values, cc };
-            } else {
-                scopes[2*i + 2] = { 0, 0 };
-                scopes[2*i + 3] = { 0, 0 };
+    // interpreter
+    if (debugger)
+        debugger->enteringFunction();
+
+    ReturnedValue result;
+    if (function->jittedCode != nullptr && debugger == nullptr) {
+        result = function->jittedCode(frame, engine);
+        if (QV4::Value::fromReturnedValue(result).isEmpty()) { // de-optimize!
+            if (ShowWhenDeoptimiationHappens) {
+                // This is debug code, which is disabled by default, and completely removed by the
+                // compiler.
+                fprintf(stderr, "*********************** DEOPT! %s ***********************\n"
+                                "*** deopt IP: %d, line: %d\n",
+                        function->name()->toQString().toUtf8().constData(),
+                        frame->instructionPointer,
+                        frame->lineNumber());
             }
-            ++i;
-            scope = scope->outer;
+            delete function->codeRef;
+            function->codeRef = nullptr;
+            function->jittedCode = nullptr;
+            function->interpreterCallCount = 0; // reset to restart tracing: apparently we didn't have enough info before
+            result = interpret(frame, engine, function->codeData + frame->instructionPointer);
         }
+    } else {
+        // interpreter
+        result = interpret(frame, engine, function->codeData);
     }
 
+    if (debugger)
+        debugger->leavingFunction(result);
+
+    return result;
+}
+
+QV4::ReturnedValue VME::interpret(CppStackFrame *frame, ExecutionEngine *engine, const char *code)
+{
+    QV4::Function *function = frame->v4Function;
+    QV4::Value &accumulator = frame->jsFrame->accumulator;
+    QV4::ReturnedValue acc = accumulator.asReturnedValue();
+    Value *stack = reinterpret_cast<Value *>(frame->jsFrame);
+
+    if (function->tracingEnabled()) {
+        for (int i = 0; i < int(function->nFormals); ++i)
+            traceValue(frame->jsFrame->argument(i), function, i);
+    }
+
+    MOTH_JUMP_TABLE;
 
     for (;;) {
-        const Instr *genericInstr = reinterpret_cast<const Instr *>(code);
-#ifdef MOTH_THREADED_INTERPRETER
-        goto *jumpTable[genericInstr->common.instructionType];
-#else
-        switch (genericInstr->common.instructionType) {
-#endif
+    MOTH_DISPATCH()
+    Q_UNREACHABLE(); // only reached when the dispatch doesn't jump somewhere
+
+    MOTH_BEGIN_INSTR(LoadConst)
+        acc = constant(function, index).asReturnedValue();
+    MOTH_END_INSTR(LoadConst)
+
+    MOTH_BEGIN_INSTR(LoadNull)
+        acc = Encode::null();
+    MOTH_END_INSTR(LoadNull)
+
+    MOTH_BEGIN_INSTR(LoadZero)
+        acc = Encode(static_cast<int>(0));
+    MOTH_END_INSTR(LoadZero)
 
-    MOTH_BEGIN_INSTR(Move)
-        VALUE(instr.result) = VALUE(instr.source);
-    MOTH_END_INSTR(Move)
+    MOTH_BEGIN_INSTR(LoadTrue)
+        acc = Encode(true);
+    MOTH_END_INSTR(LoadTrue)
+
+    MOTH_BEGIN_INSTR(LoadFalse)
+        acc = Encode(false);
+    MOTH_END_INSTR(LoadFalse)
+
+    MOTH_BEGIN_INSTR(LoadUndefined)
+        acc = Encode::undefined();
+    MOTH_END_INSTR(LoadUndefined)
+
+    MOTH_BEGIN_INSTR(LoadInt)
+        acc = Encode(value);
+    MOTH_END_INSTR(LoadInt)
 
     MOTH_BEGIN_INSTR(MoveConst)
-        VALUE(instr.result) = instr.source;
+        STACK_VALUE(destTemp) = constant(function, constIndex);
     MOTH_END_INSTR(MoveConst)
 
-    MOTH_BEGIN_INSTR(SwapTemps)
-        qSwap(VALUE(instr.left),  VALUE(instr.right));
-    MOTH_END_INSTR(MoveTemp)
+    MOTH_BEGIN_INSTR(LoadReg)
+        acc = STACK_VALUE(reg).asReturnedValue();
+    MOTH_END_INSTR(LoadReg)
+
+    MOTH_BEGIN_INSTR(StoreReg)
+        STACK_VALUE(reg) = acc;
+    MOTH_END_INSTR(StoreReg)
+
+    MOTH_BEGIN_INSTR(MoveReg)
+        STACK_VALUE(destReg) = STACK_VALUE(srcReg);
+    MOTH_END_INSTR(MoveReg)
+
+    MOTH_BEGIN_INSTR(LoadImport)
+        acc = function->compilationUnit->imports[index]->asReturnedValue();
+    MOTH_END_INSTR(LoadImport)
+
+    MOTH_BEGIN_INSTR(LoadLocal)
+        auto cc = static_cast<Heap::CallContext *>(stack[CallData::Context].m());
+        Q_ASSERT(cc->type != QV4::Heap::CallContext::Type_GlobalContext);
+        acc = cc->locals[index].asReturnedValue();
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(LoadLocal)
+
+    MOTH_BEGIN_INSTR(StoreLocal)
+        CHECK_EXCEPTION;
+        auto cc = static_cast<Heap::CallContext *>(stack[CallData::Context].m());
+        Q_ASSERT(cc->type != QV4::Heap::CallContext::Type_GlobalContext);
+        QV4::WriteBarrier::write(engine, cc, cc->locals.values[index].data_ptr(), acc);
+    MOTH_END_INSTR(StoreLocal)
+
+    MOTH_BEGIN_INSTR(LoadScopedLocal)
+        auto cc = getScope(stack, scope);
+        acc = cc->locals[index].asReturnedValue();
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(LoadScopedLocal)
+
+    MOTH_BEGIN_INSTR(StoreScopedLocal)
+        CHECK_EXCEPTION;
+        auto cc = getScope(stack, scope);
+        QV4::WriteBarrier::write(engine, cc, cc->locals.values[index].data_ptr(), acc);
+    MOTH_END_INSTR(StoreScopedLocal)
 
     MOTH_BEGIN_INSTR(LoadRuntimeString)
-//        TRACE(value, "%s", instr.value.toString(context)->toQString().toUtf8().constData());
-        VALUE(instr.result) = engine->current->compilationUnit->runtimeStrings[instr.stringId];
+        acc = function->compilationUnit->runtimeStrings[stringId]->asReturnedValue();
     MOTH_END_INSTR(LoadRuntimeString)
 
-    MOTH_BEGIN_INSTR(LoadRegExp)
-//        TRACE(value, "%s", instr.value.toString(context)->toQString().toUtf8().constData());
-        VALUE(instr.result) = static_cast<CompiledData::CompilationUnit*>(engine->current->compilationUnit)->runtimeRegularExpressions[instr.regExpId];
-    MOTH_END_INSTR(LoadRegExp)
+    MOTH_BEGIN_INSTR(MoveRegExp)
+        STACK_VALUE(destReg) = Runtime::RegexpLiteral::call(engine, regExpId);
+    MOTH_END_INSTR(MoveRegExp)
 
     MOTH_BEGIN_INSTR(LoadClosure)
-        STOREVALUE(instr.result, Runtime::method_closure(engine, instr.value));
+        acc = Runtime::Closure::call(engine, value);
     MOTH_END_INSTR(LoadClosure)
 
     MOTH_BEGIN_INSTR(LoadName)
-        TRACE(inline, "property name = %s", runtimeStrings[instr.name]->toQString().toUtf8().constData());
-        STOREVALUE(instr.result, Runtime::method_getActivationProperty(engine, instr.name));
+        STORE_IP();
+        acc = Runtime::LoadName::call(engine, name);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(LoadName)
 
-    MOTH_BEGIN_INSTR(GetGlobalLookup)
-        QV4::Lookup *l = engine->current->lookups + instr.index;
-        STOREVALUE(instr.result, l->globalGetter(l, engine));
-    MOTH_END_INSTR(GetGlobalLookup)
+    MOTH_BEGIN_INSTR(LoadGlobalLookup)
+        STORE_IP();
+        QV4::Lookup *l = function->compilationUnit->runtimeLookups + index;
+        acc = l->globalGetter(l, engine);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(LoadGlobalLookup)
+
+    MOTH_BEGIN_INSTR(StoreNameStrict)
+        STORE_IP();
+        STORE_ACC();
+        Runtime::StoreNameStrict::call(engine, name, accumulator);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(StoreNameStrict)
 
-    MOTH_BEGIN_INSTR(StoreName)
-        TRACE(inline, "property name = %s", runtimeStrings[instr.name]->toQString().toUtf8().constData());
-        Runtime::method_setActivationProperty(engine, instr.name, VALUE(instr.source));
+    MOTH_BEGIN_INSTR(StoreNameSloppy)
+        STORE_IP();
+        STORE_ACC();
+        Runtime::StoreNameSloppy::call(engine, name, accumulator);
         CHECK_EXCEPTION;
-    MOTH_END_INSTR(StoreName)
+    MOTH_END_INSTR(StoreNameSloppy)
 
     MOTH_BEGIN_INSTR(LoadElement)
-        STOREVALUE(instr.result, Runtime::method_getElement(engine, VALUE(instr.base), VALUE(instr.index)));
+        STORE_IP();
+        STORE_ACC();
+#if QT_CONFIG(qml_tracing)
+        acc = Runtime::LoadElement_Traced::call(engine, STACK_VALUE(base), accumulator, function->traceInfo(traceSlot));
+        traceValue(acc, function, traceSlot);
+#else
+        Q_UNUSED(traceSlot);
+        acc = Runtime::LoadElement::call(engine, STACK_VALUE(base), accumulator);
+#endif
+        CHECK_EXCEPTION;
     MOTH_END_INSTR(LoadElement)
 
-    MOTH_BEGIN_INSTR(LoadElementLookup)
-        QV4::Lookup *l = engine->current->lookups + instr.lookup;
-        STOREVALUE(instr.result, l->indexedGetter(l, engine, VALUE(instr.base), VALUE(instr.index)));
-    MOTH_END_INSTR(LoadElementLookup)
-
     MOTH_BEGIN_INSTR(StoreElement)
-        Runtime::method_setElement(engine, VALUE(instr.base), VALUE(instr.index), VALUE(instr.source));
+        STORE_IP();
+        STORE_ACC();
+#if QT_CONFIG(qml_tracing)
+        Runtime::StoreElement_traced::call(engine, STACK_VALUE(base), STACK_VALUE(index), accumulator, function->traceInfo(traceSlot));
+#else
+        Q_UNUSED(traceSlot);
+        Runtime::StoreElement::call(engine, STACK_VALUE(base), STACK_VALUE(index), accumulator);
+#endif
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreElement)
 
-    MOTH_BEGIN_INSTR(StoreElementLookup)
-        QV4::Lookup *l = engine->current->lookups + instr.lookup;
-        l->indexedSetter(l, engine, VALUE(instr.base), VALUE(instr.index), VALUE(instr.source));
-        CHECK_EXCEPTION;
-    MOTH_END_INSTR(StoreElementLookup)
-
     MOTH_BEGIN_INSTR(LoadProperty)
-        STOREVALUE(instr.result, Runtime::method_getProperty(engine, VALUE(instr.base), instr.name));
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::LoadProperty::call(engine, accumulator, name);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(LoadProperty)
 
     MOTH_BEGIN_INSTR(GetLookup)
-        QV4::Lookup *l = engine->current->lookups + instr.index;
-        STOREVALUE(instr.result, l->getter(l, engine, VALUE(instr.base)));
+        STORE_IP();
+        STORE_ACC();
+        QV4::Lookup *l = function->compilationUnit->runtimeLookups + index;
+        acc = l->getter(l, engine, accumulator);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(GetLookup)
 
     MOTH_BEGIN_INSTR(StoreProperty)
-        Runtime::method_setProperty(engine, VALUE(instr.base), instr.name, VALUE(instr.source));
+        STORE_IP();
+        STORE_ACC();
+        Runtime::StoreProperty::call(engine, STACK_VALUE(base), name, accumulator);
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreProperty)
 
     MOTH_BEGIN_INSTR(SetLookup)
-        QV4::Lookup *l = engine->current->lookups + instr.index;
-        l->setter(l, engine, VALUE(instr.base), VALUE(instr.source));
+        STORE_IP();
+        STORE_ACC();
+        QV4::Lookup *l = function->compilationUnit->runtimeLookups + index;
+        if (!l->setter(l, engine, STACK_VALUE(base), accumulator) && function->isStrict())
+            engine->throwTypeError();
         CHECK_EXCEPTION;
     MOTH_END_INSTR(SetLookup)
 
-    MOTH_BEGIN_INSTR(StoreQObjectProperty)
-        Runtime::method_setQmlQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
+    MOTH_BEGIN_INSTR(LoadSuperProperty)
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::LoadSuperProperty::call(engine, STACK_VALUE(property));
         CHECK_EXCEPTION;
-    MOTH_END_INSTR(StoreQObjectProperty)
+    MOTH_END_INSTR(LoadSuperProperty)
 
-    MOTH_BEGIN_INSTR(LoadQObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_getQmlQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
-    MOTH_END_INSTR(LoadQObjectProperty)
+    MOTH_BEGIN_INSTR(StoreSuperProperty)
+        STORE_IP();
+        STORE_ACC();
+        Runtime::StoreSuperProperty::call(engine, STACK_VALUE(property), accumulator);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(StoreSuperProperty)
 
     MOTH_BEGIN_INSTR(StoreScopeObjectProperty)
-        Runtime::method_setQmlScopeObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
+        STORE_ACC();
+        Runtime::StoreQmlScopeObjectProperty::call(engine, STACK_VALUE(base), propertyIndex, accumulator);
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreScopeObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadScopeObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_getQmlScopeObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
+        STORE_IP();
+        acc = Runtime::LoadQmlScopeObjectProperty::call(engine, STACK_VALUE(base), propertyIndex, captureRequired);
+        CHECK_EXCEPTION;
     MOTH_END_INSTR(LoadScopeObjectProperty)
 
     MOTH_BEGIN_INSTR(StoreContextObjectProperty)
-        Runtime::method_setQmlContextObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, VALUE(instr.source));
+        STORE_IP();
+        STORE_ACC();
+        Runtime::StoreQmlContextObjectProperty::call(engine, STACK_VALUE(base), propertyIndex, accumulator);
         CHECK_EXCEPTION;
     MOTH_END_INSTR(StoreContextObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadContextObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_getQmlContextObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
+        STORE_IP();
+        acc = Runtime::LoadQmlContextObjectProperty::call(engine, STACK_VALUE(base), propertyIndex, captureRequired);
+        CHECK_EXCEPTION;
     MOTH_END_INSTR(LoadContextObjectProperty)
 
     MOTH_BEGIN_INSTR(LoadIdObject)
-        STOREVALUE(instr.result, Runtime::method_getQmlIdObject(engine, VALUE(instr.base), instr.index));
+        STORE_IP();
+        acc = Runtime::LoadQmlIdObject::call(engine, STACK_VALUE(base), index);
+        CHECK_EXCEPTION;
     MOTH_END_INSTR(LoadIdObject)
 
-    MOTH_BEGIN_INSTR(LoadAttachedQObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_getQmlAttachedProperty(engine, instr.attachedPropertiesId, instr.propertyIndex));
-    MOTH_END_INSTR(LoadAttachedQObjectProperty)
-
-    MOTH_BEGIN_INSTR(LoadSingletonQObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_getQmlSingletonQObjectProperty(engine, VALUE(instr.base), instr.propertyIndex, instr.captureRequired));
-    MOTH_END_INSTR(LoadSingletonQObjectProperty)
+    MOTH_BEGIN_INSTR(Yield)
+        frame->yield = code;
+        frame->yieldIsIterator = false;
+        return acc;
+    MOTH_END_INSTR(Yield)
+
+    MOTH_BEGIN_INSTR(YieldStar)
+        frame->yield = code;
+        frame->yieldIsIterator = true;
+        return acc;
+    MOTH_END_INSTR(YieldStar)
+
+    MOTH_BEGIN_INSTR(Resume)
+        // check exception, in case the generator was called with throw() or return()
+        if (engine->hasException) {
+            // an empty value indicates that the generator was called with return()
+            if (engine->exceptionValue->asReturnedValue() != Value::emptyValue().asReturnedValue())
+                goto handleUnwind;
+            engine->hasException = false;
+            *engine->exceptionValue = Value::undefinedValue();
+        } else {
+            code += offset;
+        }
+    MOTH_END_INSTR(Resume)
 
-    MOTH_BEGIN_INSTR(Push)
-        TRACE(inline, "stack size: %u", instr.value);
-        stackSize = instr.value;
-        stack = scope.alloc(stackSize);
-        scopes[1].values = stack;
-    MOTH_END_INSTR(Push)
+    MOTH_BEGIN_INSTR(IteratorNextForYieldStar)
+        STORE_ACC();
+        acc = Runtime::IteratorNextForYieldStar::call(engine, accumulator, STACK_VALUE(iterator), &STACK_VALUE(object));
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(IteratorNextForYieldStar)
 
     MOTH_BEGIN_INSTR(CallValue)
-#if 0 //def DO_TRACE_INSTR
-        if (Debugging::Debugger *debugger = context->engine()->debugger) {
-            if (QV4::FunctionObject *o = (VALUE(instr.dest)).asFunctionObject()) {
-                if (Debugging::FunctionDebugInfo *info = debugger->debugInfo(o)) {
-                    QString n = debugger->name(o);
-                    std::cerr << "*** Call to \"" << (n.isNull() ? "<no name>" : qPrintable(n)) << "\" defined @" << info->startLine << ":" << info->startColumn << std::endl;
-                }
-            }
+        STORE_IP();
+        Value func = STACK_VALUE(name);
+        if (Q_UNLIKELY(!func.isFunctionObject())) {
+            acc = engine->throwTypeError(QStringLiteral("%1 is not a function").arg(func.toQStringNoThrow()));
+            goto handleUnwind;
         }
-#endif // DO_TRACE_INSTR
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, Runtime::method_callValue(engine, VALUE(instr.dest), callData));
+        Value undef = Value::undefinedValue();
+        acc = static_cast<const FunctionObject &>(func).call(&undef, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(CallValue)
 
+    MOTH_BEGIN_INSTR(CallWithReceiver)
+        STORE_IP();
+        Value func = STACK_VALUE(name);
+        if (Q_UNLIKELY(!func.isFunctionObject())) {
+            acc = engine->throwTypeError(QStringLiteral("%1 is not a function").arg(func.toQStringNoThrow()));
+            goto handleUnwind;
+        }
+        acc = static_cast<const FunctionObject &>(func).call(stack + thisObject, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(CallWithReceiver)
+
     MOTH_BEGIN_INSTR(CallProperty)
-        TRACE(property name, "%s, args=%u, argc=%u, this=%s", qPrintable(runtimeStrings[instr.name]->toQString()), instr.callData, instr.argc, (VALUE(instr.base)).toString(engine)->toQString().toUtf8().constData());
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_callProperty(engine, instr.name, callData));
+        STORE_IP();
+        acc = Runtime::CallProperty::call(engine, stack[base], name, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(CallProperty)
 
     MOTH_BEGIN_INSTR(CallPropertyLookup)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_callPropertyLookup(engine, instr.lookupIndex, callData));
+        STORE_IP();
+        Lookup *l = function->compilationUnit->runtimeLookups + lookupIndex;
+        // ok to have the value on the stack here
+        Value f = Value::fromReturnedValue(l->getter(l, engine, stack[base]));
+
+        if (Q_UNLIKELY(!f.isFunctionObject())) {
+            acc = engine->throwTypeError();
+            goto handleUnwind;
+        }
+
+        acc = static_cast<FunctionObject &>(f).call(stack + base, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(CallPropertyLookup)
 
+    MOTH_BEGIN_INSTR(CallElement)
+        STORE_IP();
+        acc = Runtime::CallElement::call(engine, stack[base], STACK_VALUE(index), stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(CallElement)
+
+    MOTH_BEGIN_INSTR(CallName)
+        STORE_IP();
+        acc = Runtime::CallName::call(engine, name, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(CallName)
+
+    MOTH_BEGIN_INSTR(CallPossiblyDirectEval)
+        STORE_IP();
+        acc = Runtime::CallPossiblyDirectEval::call(engine, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(CallPossiblyDirectEval)
+
+    MOTH_BEGIN_INSTR(CallGlobalLookup)
+        STORE_IP();
+        acc = Runtime::CallGlobalLookup::call(engine, index, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(CallGlobalLookup)
+
     MOTH_BEGIN_INSTR(CallScopeObjectProperty)
-        TRACE(property name, "%s, args=%u, argc=%u, this=%s", qPrintable(runtimeStrings[instr.name]->toQString()), instr.callData, instr.argc, (VALUE(instr.base)).toString(engine)->toQString().toUtf8().constData());
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_callQmlScopeObjectProperty(engine, instr.index, callData));
+        STORE_IP();
+        acc = Runtime::CallQmlScopeObjectProperty::call(engine, stack[base], name, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(CallScopeObjectProperty)
 
     MOTH_BEGIN_INSTR(CallContextObjectProperty)
-        TRACE(property name, "%s, args=%u, argc=%u, this=%s", qPrintable(runtimeStrings[instr.name]->toQString()), instr.callData, instr.argc, (VALUE(instr.base)).toString(engine)->toQString().toUtf8().constData());
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_callQmlContextObjectProperty(engine, instr.index, callData));
+        STORE_IP();
+        acc = Runtime::CallQmlContextObjectProperty::call(engine, stack[base], name, stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
     MOTH_END_INSTR(CallContextObjectProperty)
 
-    MOTH_BEGIN_INSTR(CallElement)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_callElement(engine, VALUE(instr.index), callData));
-    MOTH_END_INSTR(CallElement)
+    MOTH_BEGIN_INSTR(CallWithSpread)
+        STORE_IP();
+        acc = Runtime::CallWithSpread::call(engine, STACK_VALUE(func), STACK_VALUE(thisObject), stack + argv, argc);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(CallWithSpread)
+
+    MOTH_BEGIN_INSTR(TailCall)
+        STORE_IP();
+        *engine->jsAlloca(1) = Primitive::fromInt32(argc);
+        *engine->jsAlloca(1) = Primitive::fromInt32(argv);
+        *engine->jsAlloca(1) = STACK_VALUE(thisObject);
+        *engine->jsAlloca(1) = STACK_VALUE(func);
+        return Runtime::TailCall::call(frame, engine);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(TailCall)
 
-    MOTH_BEGIN_INSTR(CallActivationProperty)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, Runtime::method_callActivationProperty(engine, instr.name, callData));
-    MOTH_END_INSTR(CallActivationProperty)
+    MOTH_BEGIN_INSTR(Construct)
+        STORE_IP();
+        acc = Runtime::Construct::call(engine, STACK_VALUE(func), ACC, stack + argv, argc);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(Construct)
 
-    MOTH_BEGIN_INSTR(CallGlobalLookup)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, Runtime::method_callGlobalLookup(engine, instr.index, callData));
-    MOTH_END_INSTR(CallGlobalLookup)
+    MOTH_BEGIN_INSTR(ConstructWithSpread)
+        STORE_IP();
+        acc = Runtime::ConstructWithSpread::call(engine, STACK_VALUE(func), ACC, stack + argv, argc);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(ConstructWithSpread)
 
-    MOTH_BEGIN_INSTR(SetExceptionHandler)
-        exceptionHandler = instr.offset ? ((const uchar *)&instr.offset) + instr.offset : 0;
-    MOTH_END_INSTR(SetExceptionHandler)
+    MOTH_BEGIN_INSTR(SetUnwindHandler)
+        frame->unwindHandler = offset ? code + offset : nullptr;
+    MOTH_END_INSTR(SetUnwindHandler)
 
-    MOTH_BEGIN_INSTR(CallBuiltinThrow)
-        Runtime::method_throwException(engine, VALUE(instr.arg));
+    MOTH_BEGIN_INSTR(UnwindDispatch)
         CHECK_EXCEPTION;
-    MOTH_END_INSTR(CallBuiltinThrow)
+        if (frame->unwindLevel) {
+            --frame->unwindLevel;
+            if (frame->unwindLevel)
+                goto handleUnwind;
+            code = frame->unwindLabel;
+        }
+    MOTH_END_INSTR(UnwindDispatch)
+
+    MOTH_BEGIN_INSTR(UnwindToLabel)
+        frame->unwindLevel = level;
+        frame->unwindLabel = code + offset;
+        goto handleUnwind;
+    MOTH_END_INSTR(UnwindToLabel)
+
+    MOTH_BEGIN_INSTR(DeadTemporalZoneCheck)
+        if (ACC.isEmpty()) {
+            STORE_IP();
+            STORE_ACC();
+            Runtime::ThrowReferenceError::call(engine, name);
+            goto handleUnwind;
+        }
+    MOTH_END_INSTR(DeadTemporalZoneCheck)
+
+    MOTH_BEGIN_INSTR(ThrowException)
+        STORE_IP();
+        STORE_ACC();
+        Runtime::ThrowException::call(engine, accumulator);
+        goto handleUnwind;
+    MOTH_END_INSTR(ThrowException)
+
+    MOTH_BEGIN_INSTR(GetException)
+        acc = engine->hasException ? engine->exceptionValue->asReturnedValue()
+                                   : Value::emptyValue().asReturnedValue();
+        engine->hasException = false;
+    MOTH_END_INSTR(HasException)
+
+    MOTH_BEGIN_INSTR(SetException)
+        if (acc != Value::emptyValue().asReturnedValue()) {
+            *engine->exceptionValue = acc;
+            engine->hasException = true;
+        }
+    MOTH_END_INSTR(SetException)
 
-    MOTH_BEGIN_INSTR(CallBuiltinUnwindException)
-        STOREVALUE(instr.result, Runtime::method_unwindException(engine));
-    MOTH_END_INSTR(CallBuiltinUnwindException)
+    MOTH_BEGIN_INSTR(PushCatchContext)
+        Runtime::PushCatchContext::call(engine, index, name);
+    MOTH_END_INSTR(PushCatchContext)
 
-    MOTH_BEGIN_INSTR(CallBuiltinPushCatchScope)
-        Runtime::method_pushCatchScope(static_cast<QV4::NoThrowEngine*>(engine), instr.name);
-    MOTH_END_INSTR(CallBuiltinPushCatchScope)
-
-    MOTH_BEGIN_INSTR(CallBuiltinPushScope)
-        Runtime::method_pushWithScope(VALUE(instr.arg), static_cast<QV4::NoThrowEngine*>(engine));
-        CHECK_EXCEPTION;
-    MOTH_END_INSTR(CallBuiltinPushScope)
-
-    MOTH_BEGIN_INSTR(CallBuiltinPopScope)
-        Runtime::method_popScope(static_cast<QV4::NoThrowEngine*>(engine));
-    MOTH_END_INSTR(CallBuiltinPopScope)
-
-    MOTH_BEGIN_INSTR(CallBuiltinForeachIteratorObject)
-        STOREVALUE(instr.result, Runtime::method_foreachIterator(engine, VALUE(instr.arg)));
-    MOTH_END_INSTR(CallBuiltinForeachIteratorObject)
-
-    MOTH_BEGIN_INSTR(CallBuiltinForeachNextPropertyName)
-        STOREVALUE(instr.result, Runtime::method_foreachNextPropertyName(VALUE(instr.arg)));
-    MOTH_END_INSTR(CallBuiltinForeachNextPropertyName)
-
-    MOTH_BEGIN_INSTR(CallBuiltinDeleteMember)
-        STOREVALUE(instr.result, Runtime::method_deleteMember(engine, VALUE(instr.base), instr.member));
-    MOTH_END_INSTR(CallBuiltinDeleteMember)
-
-    MOTH_BEGIN_INSTR(CallBuiltinDeleteSubscript)
-        STOREVALUE(instr.result, Runtime::method_deleteElement(engine, VALUE(instr.base), VALUE(instr.index)));
-    MOTH_END_INSTR(CallBuiltinDeleteSubscript)
-
-    MOTH_BEGIN_INSTR(CallBuiltinDeleteName)
-        STOREVALUE(instr.result, Runtime::method_deleteName(engine, instr.name));
-    MOTH_END_INSTR(CallBuiltinDeleteName)
-
-    MOTH_BEGIN_INSTR(CallBuiltinTypeofScopeObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_typeofScopeObjectProperty(engine, VALUE(instr.base), instr.index));
-    MOTH_END_INSTR(CallBuiltinTypeofMember)
-
-    MOTH_BEGIN_INSTR(CallBuiltinTypeofContextObjectProperty)
-        STOREVALUE(instr.result, Runtime::method_typeofContextObjectProperty(engine, VALUE(instr.base), instr.index));
-    MOTH_END_INSTR(CallBuiltinTypeofMember)
-
-    MOTH_BEGIN_INSTR(CallBuiltinTypeofMember)
-        STOREVALUE(instr.result, Runtime::method_typeofMember(engine, VALUE(instr.base), instr.member));
-    MOTH_END_INSTR(CallBuiltinTypeofMember)
-
-    MOTH_BEGIN_INSTR(CallBuiltinTypeofSubscript)
-        STOREVALUE(instr.result, Runtime::method_typeofElement(engine, VALUE(instr.base), VALUE(instr.index)));
-    MOTH_END_INSTR(CallBuiltinTypeofSubscript)
-
-    MOTH_BEGIN_INSTR(CallBuiltinTypeofName)
-        STOREVALUE(instr.result, Runtime::method_typeofName(engine, instr.name));
-    MOTH_END_INSTR(CallBuiltinTypeofName)
-
-    MOTH_BEGIN_INSTR(CallBuiltinTypeofValue)
-        STOREVALUE(instr.result, Runtime::method_typeofValue(engine, VALUE(instr.value)));
-    MOTH_END_INSTR(CallBuiltinTypeofValue)
-
-    MOTH_BEGIN_INSTR(CallBuiltinDeclareVar)
-        Runtime::method_declareVar(engine, instr.isDeletable, instr.varName);
-    MOTH_END_INSTR(CallBuiltinDeclareVar)
-
-    MOTH_BEGIN_INSTR(CallBuiltinDefineArray)
-        Q_ASSERT(instr.args + instr.argc <= stackSize);
-        QV4::Value *args = stack + instr.args;
-        STOREVALUE(instr.result, Runtime::method_arrayLiteral(engine, args, instr.argc));
-    MOTH_END_INSTR(CallBuiltinDefineArray)
-
-    MOTH_BEGIN_INSTR(CallBuiltinDefineObjectLiteral)
-        QV4::Value *args = stack + instr.args;
-    STOREVALUE(instr.result, Runtime::method_objectLiteral(engine, args, instr.internalClassId, instr.arrayValueCount, instr.arrayGetterSetterCountAndFlags));
-    MOTH_END_INSTR(CallBuiltinDefineObjectLiteral)
-
-    MOTH_BEGIN_INSTR(CallBuiltinSetupArgumentsObject)
-        STOREVALUE(instr.result, Runtime::method_setupArgumentsObject(engine));
-    MOTH_END_INSTR(CallBuiltinSetupArgumentsObject)
-
-    MOTH_BEGIN_INSTR(CallBuiltinConvertThisToObject)
-        Runtime::method_convertThisToObject(engine);
-        CHECK_EXCEPTION;
-    MOTH_END_INSTR(CallBuiltinConvertThisToObject)
-
-    MOTH_BEGIN_INSTR(CreateValue)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, Runtime::method_constructValue(engine, VALUE(instr.func), callData));
-    MOTH_END_INSTR(CreateValue)
-
-    MOTH_BEGIN_INSTR(CreateProperty)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_constructProperty(engine, instr.name, callData));
-    MOTH_END_INSTR(CreateProperty)
-
-    MOTH_BEGIN_INSTR(ConstructPropertyLookup)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = VALUE(instr.base);
-        STOREVALUE(instr.result, Runtime::method_constructPropertyLookup(engine, instr.index, callData));
-    MOTH_END_INSTR(ConstructPropertyLookup)
-
-    MOTH_BEGIN_INSTR(CreateActivationProperty)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, Runtime::method_constructActivationProperty(engine, instr.name, callData));
-    MOTH_END_INSTR(CreateActivationProperty)
-
-    MOTH_BEGIN_INSTR(ConstructGlobalLookup)
-        Q_ASSERT(instr.callData + instr.argc + offsetof(QV4::CallData, args)/sizeof(QV4::Value) <= stackSize);
-        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData);
-        callData->tag = quint32(Value::ValueTypeInternal::Integer);
-        callData->argc = instr.argc;
-        callData->thisObject = QV4::Primitive::undefinedValue();
-        STOREVALUE(instr.result, Runtime::method_constructGlobalLookup(engine, instr.index, callData));
-    MOTH_END_INSTR(ConstructGlobalLookup)
+    MOTH_BEGIN_INSTR(CreateCallContext)
+        Runtime::PushCallContext::call(frame);
+    MOTH_END_INSTR(CreateCallContext)
+
+    MOTH_BEGIN_INSTR(PushWithContext)
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::PushWithContext::call(engine, stack[CallData::Accumulator]);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(PushWithContext)
+
+    MOTH_BEGIN_INSTR(PushBlockContext)
+        STORE_ACC();
+        Runtime::PushBlockContext::call(engine, index);
+    MOTH_END_INSTR(PushBlockContext)
+
+    MOTH_BEGIN_INSTR(CloneBlockContext)
+        STORE_ACC();
+        Runtime::CloneBlockContext::call(engine);
+    MOTH_END_INSTR(CloneBlockContext)
+
+    MOTH_BEGIN_INSTR(PushScriptContext)
+        Runtime::PushScriptContext::call(engine, index);
+    MOTH_END_INSTR(PushScriptContext)
+
+    MOTH_BEGIN_INSTR(PopScriptContext)
+        Runtime::PopScriptContext::call(engine);
+    MOTH_END_INSTR(PopScriptContext)
+
+    MOTH_BEGIN_INSTR(PopContext)
+        ExecutionContext *c = static_cast<ExecutionContext *>(stack + CallData::Context);
+        STACK_VALUE(CallData::Context) = c->d()->outer;
+    MOTH_END_INSTR(PopContext)
+
+    MOTH_BEGIN_INSTR(GetIterator)
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::GetIterator::call(engine, accumulator, iterator);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(GetIterator)
+
+    MOTH_BEGIN_INSTR(IteratorNext)
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::IteratorNext::call(engine, accumulator, &STACK_VALUE(value));
+        STACK_VALUE(done) = acc;
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(IteratorNext)
+
+    MOTH_BEGIN_INSTR(IteratorClose)
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::IteratorClose::call(engine, accumulator, STACK_VALUE(done));
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(IteratorClose)
+
+    MOTH_BEGIN_INSTR(DestructureRestElement)
+        STORE_IP();
+        STORE_ACC();
+        acc = Runtime::DestructureRestElement::call(engine, ACC);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(DestructureRestElement)
+
+    MOTH_BEGIN_INSTR(DeleteProperty)
+        acc = Runtime::DeleteProperty::call(engine, function, STACK_VALUE(base), STACK_VALUE(index));
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(DeleteProperty)
+
+    MOTH_BEGIN_INSTR(DeleteName)
+        acc = Runtime::DeleteName::call(engine, function, name);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(DeleteName)
+
+    MOTH_BEGIN_INSTR(TypeofName)
+        acc = Runtime::TypeofName::call(engine, name);
+    MOTH_END_INSTR(TypeofName)
+
+    MOTH_BEGIN_INSTR(TypeofValue)
+        STORE_ACC();
+        acc = Runtime::TypeofValue::call(engine, accumulator);
+    MOTH_END_INSTR(TypeofValue)
+
+    MOTH_BEGIN_INSTR(DeclareVar)
+        Runtime::DeclareVar::call(engine, isDeletable, varName);
+    MOTH_END_INSTR(DeclareVar)
+
+    MOTH_BEGIN_INSTR(DefineArray)
+        QV4::Value *arguments = stack + args;
+        acc = Runtime::ArrayLiteral::call(engine, arguments, argc);
+    MOTH_END_INSTR(DefineArray)
+
+    MOTH_BEGIN_INSTR(DefineObjectLiteral)
+        QV4::Value *arguments = stack + args;
+        acc = Runtime::ObjectLiteral::call(engine, internalClassId, arguments, argc);
+    MOTH_END_INSTR(DefineObjectLiteral)
+
+    MOTH_BEGIN_INSTR(CreateClass)
+        acc = Runtime::CreateClass::call(engine, classIndex, STACK_VALUE(heritage), stack + computedNames);
+    MOTH_END_INSTR(CreateClass)
+
+    MOTH_BEGIN_INSTR(CreateMappedArgumentsObject)
+        acc = Runtime::CreateMappedArgumentsObject::call(engine);
+    MOTH_END_INSTR(CreateMappedArgumentsObject)
+
+    MOTH_BEGIN_INSTR(CreateUnmappedArgumentsObject)
+        acc = Runtime::CreateUnmappedArgumentsObject::call(engine);
+    MOTH_END_INSTR(CreateUnmappedArgumentsObject)
+
+    MOTH_BEGIN_INSTR(CreateRestParameter)
+        acc = Runtime::CreateRestParameter::call(engine, argIndex);
+    MOTH_END_INSTR(CreateRestParameter)
+
+    MOTH_BEGIN_INSTR(ConvertThisToObject)
+        stack[CallData::This] = Runtime::ConvertThisToObject::call(engine, stack[CallData::This]);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(ConvertThisToObject)
+
+    MOTH_BEGIN_INSTR(LoadSuperConstructor)
+        acc = Runtime::LoadSuperConstructor::call(engine, stack[CallData::Function]);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(LoadSuperConstructor)
+
+    MOTH_BEGIN_INSTR(ToObject)
+        acc = ACC.toObject(engine)->asReturnedValue();
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(ToObject)
 
     MOTH_BEGIN_INSTR(Jump)
-        code = ((const uchar *)&instr.offset) + instr.offset;
+        code += offset;
     MOTH_END_INSTR(Jump)
 
-    MOTH_BEGIN_INSTR(JumpEq)
-        bool cond = VALUEPTR(instr.condition)->toBoolean();
-        TRACE(condition, "%s", cond ? "TRUE" : "FALSE");
-        if (cond)
-            code = ((const uchar *)&instr.offset) + instr.offset;
-    MOTH_END_INSTR(JumpEq)
+    MOTH_BEGIN_INSTR(JumpTrue)
+        bool takeJump;
+        if (Q_LIKELY(ACC.integerCompatible()))
+            takeJump = ACC.int_32();
+        else
+            takeJump = ACC.toBoolean();
+        traceJumpTakesTruePath(takeJump, function, traceSlot);
+        if (takeJump)
+            code += offset;
+    MOTH_END_INSTR(JumpTrue)
+
+    MOTH_BEGIN_INSTR(JumpFalse)
+        bool takeJump;
+        if (Q_LIKELY(ACC.integerCompatible()))
+            takeJump = !ACC.int_32();
+        else
+            takeJump = !ACC.toBoolean();
+        traceJumpTakesTruePath(!takeJump, function, traceSlot);
+        if (takeJump)
+            code += offset;
+    MOTH_END_INSTR(JumpFalse)
+
+    MOTH_BEGIN_INSTR(JumpNoException)
+        if (!engine->hasException)
+            code += offset;
+    MOTH_END_INSTR(JumpNoException)
+
+    MOTH_BEGIN_INSTR(JumpNotUndefined)
+        if (Q_LIKELY(acc != QV4::Encode::undefined()))
+            code += offset;
+    MOTH_END_INSTR(JumpNotUndefined)
+
+    MOTH_BEGIN_INSTR(CmpEqNull)
+        acc = Encode(ACC.isNullOrUndefined());
+    MOTH_END_INSTR(CmpEqNull)
+
+    MOTH_BEGIN_INSTR(CmpNeNull)
+        acc = Encode(!ACC.isNullOrUndefined());
+    MOTH_END_INSTR(CmpNeNull)
+
+    MOTH_BEGIN_INSTR(CmpEqInt)
+        if (ACC.isIntOrBool()) {
+            acc = Encode(ACC.int_32() == lhs);
+        } else {
+            STORE_ACC();
+            acc = Encode(compareEqualInt(accumulator, ACC, lhs));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpEqInt)
+
+    MOTH_BEGIN_INSTR(CmpNeInt)
+        if (ACC.isIntOrBool()) {
+            acc = Encode(bool(ACC.int_32() != lhs));
+        } else {
+            STORE_ACC();
+            acc = Encode(!compareEqualInt(accumulator, ACC, lhs));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpNeInt)
+
+    MOTH_BEGIN_INSTR(CmpEq)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(left.asReturnedValue() == ACC.asReturnedValue())) {
+            acc = Encode(!ACC.isNaN());
+        } else if (Q_LIKELY(left.isInteger() && ACC.isInteger())) {
+            acc = Encode(left.int_32() == ACC.int_32());
+        } else {
+            STORE_ACC();
+            acc = Encode(bool(Runtime::CompareEqual::call(left, accumulator)));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpEq)
+
+    MOTH_BEGIN_INSTR(CmpNe)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(left.isInteger() && ACC.isInteger())) {
+            acc = Encode(bool(left.int_32() != ACC.int_32()));
+        } else {
+            STORE_ACC();
+            acc = Encode(bool(!Runtime::CompareEqual::call(left, accumulator)));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpNe)
+
+    MOTH_BEGIN_INSTR(CmpGt)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(left.isInteger() && ACC.isInteger())) {
+            acc = Encode(left.int_32() > ACC.int_32());
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() > ACC.asDouble());
+        } else {
+            STORE_ACC();
+            acc = Encode(bool(Runtime::CompareGreaterThan::call(left, accumulator)));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpGt)
+
+    MOTH_BEGIN_INSTR(CmpGe)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(left.isInteger() && ACC.isInteger())) {
+            acc = Encode(left.int_32() >= ACC.int_32());
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() >= ACC.asDouble());
+        } else {
+            STORE_ACC();
+            acc = Encode(bool(Runtime::CompareGreaterEqual::call(left, accumulator)));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpGe)
+
+    MOTH_BEGIN_INSTR(CmpLt)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(left.isInteger() && ACC.isInteger())) {
+            acc = Encode(left.int_32() < ACC.int_32());
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() < ACC.asDouble());
+        } else {
+            STORE_ACC();
+            acc = Encode(bool(Runtime::CompareLessThan::call(left, accumulator)));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpLt)
+
+    MOTH_BEGIN_INSTR(CmpLe)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(left.isInteger() && ACC.isInteger())) {
+            acc = Encode(left.int_32() <= ACC.int_32());
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() <= ACC.asDouble());
+        } else {
+            STORE_ACC();
+            acc = Encode(bool(Runtime::CompareLessEqual::call(left, accumulator)));
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpLe)
+
+    MOTH_BEGIN_INSTR(CmpStrictEqual)
+        if (STACK_VALUE(lhs).rawValue() == ACC.rawValue() && !ACC.isNaN()) {
+            acc = Encode(true);
+        } else {
+            STORE_ACC();
+            acc = Runtime::StrictEqual::call(STACK_VALUE(lhs), accumulator);
+            CHECK_EXCEPTION;
+        }
+    MOTH_END_INSTR(CmpStrictEqual)
+
+    MOTH_BEGIN_INSTR(CmpStrictNotEqual)
+        if (STACK_VALUE(lhs).rawValue() != ACC.rawValue() || ACC.isNaN()) {
+            STORE_ACC();
+            acc = Runtime::StrictNotEqual::call(STACK_VALUE(lhs), accumulator);
+            CHECK_EXCEPTION;
+        } else {
+            acc = Encode(false);
+        }
+    MOTH_END_INSTR(CmpStrictNotEqual)
+
+    MOTH_BEGIN_INSTR(CmpIn)
+        STORE_ACC();
+        acc = Runtime::In::call(engine, STACK_VALUE(lhs), accumulator);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(CmpIn)
 
-    MOTH_BEGIN_INSTR(JumpNe)
-        bool cond = VALUEPTR(instr.condition)->toBoolean();
-        TRACE(condition, "%s", cond ? "TRUE" : "FALSE");
-        if (!cond)
-            code = ((const uchar *)&instr.offset) + instr.offset;
-    MOTH_END_INSTR(JumpNe)
+    MOTH_BEGIN_INSTR(CmpInstanceOf)
+        STORE_ACC();
+        acc = Runtime::Instanceof::call(engine, STACK_VALUE(lhs), ACC);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(CmpInstanceOf)
 
     MOTH_BEGIN_INSTR(UNot)
-        STOREVALUE(instr.result, Runtime::method_uNot(VALUE(instr.source)));
+        if (ACC.integerCompatible()) {
+            acc = Encode(!static_cast<bool>(ACC.int_32()));
+        } else {
+            acc = Encode(!Value::toBooleanImpl(ACC));
+        }
     MOTH_END_INSTR(UNot)
 
-    MOTH_BEGIN_INSTR(UNotBool)
-        bool b = VALUE(instr.source).booleanValue();
-        VALUE(instr.result) = QV4::Encode(!b);
-    MOTH_END_INSTR(UNotBool)
-
     MOTH_BEGIN_INSTR(UPlus)
-        STOREVALUE(instr.result, Runtime::method_uPlus(VALUE(instr.source)));
+        if (Q_UNLIKELY(!ACC.isNumber())) {
+            acc = Encode(ACC.toNumberImpl());
+            CHECK_EXCEPTION;
+        }
     MOTH_END_INSTR(UPlus)
 
     MOTH_BEGIN_INSTR(UMinus)
-        STOREVALUE(instr.result, Runtime::method_uMinus(VALUE(instr.source)));
+        if (Q_LIKELY(ACC.integerCompatible())) {
+            int a = ACC.int_32();
+            if (a == 0 || a == std::numeric_limits<int>::min()) {
+                acc = Encode(-static_cast<double>(a));
+                traceDoubleValue(function, traceSlot);
+            } else {
+                acc = sub_int32(0, ACC.int_32(), function->traceInfo(traceSlot));
+            }
+        } else if (ACC.isDouble()) {
+            acc ^= (1ull << 63); // simply flip sign bit
+            traceDoubleValue(function, traceSlot);
+        } else {
+            acc = Encode(-ACC.toNumberImpl());
+            CHECK_EXCEPTION;
+            traceOtherValue(function, traceSlot);
+        }
     MOTH_END_INSTR(UMinus)
 
     MOTH_BEGIN_INSTR(UCompl)
-        STOREVALUE(instr.result, Runtime::method_complement(VALUE(instr.source)));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(~a);
     MOTH_END_INSTR(UCompl)
 
-    MOTH_BEGIN_INSTR(UComplInt)
-        VALUE(instr.result) = QV4::Encode((int)~VALUE(instr.source).integerValue());
-    MOTH_END_INSTR(UComplInt)
-
     MOTH_BEGIN_INSTR(Increment)
-        STOREVALUE(instr.result, Runtime::method_increment(VALUE(instr.source)));
+        if (Q_LIKELY(ACC.integerCompatible())) {
+            acc = add_int32(ACC.int_32(), 1, function->traceInfo(traceSlot));
+        } else if (ACC.isDouble()) {
+            acc = QV4::Encode(ACC.doubleValue() + 1.);
+            traceDoubleValue(function, traceSlot);
+        } else {
+            acc = Encode(ACC.toNumberImpl() + 1.);
+            CHECK_EXCEPTION;
+            traceDoubleValue(function, traceSlot);
+        }
     MOTH_END_INSTR(Increment)
 
     MOTH_BEGIN_INSTR(Decrement)
-        STOREVALUE(instr.result, Runtime::method_decrement(VALUE(instr.source)));
+        if (Q_LIKELY(ACC.integerCompatible())) {
+            acc = sub_int32(ACC.int_32(), 1, function->traceInfo(traceSlot));
+        } else if (ACC.isDouble()) {
+            acc = QV4::Encode(ACC.doubleValue() - 1.);
+            traceDoubleValue(function, traceSlot);
+        } else {
+            acc = Encode(ACC.toNumberImpl() - 1.);
+            CHECK_EXCEPTION;
+            traceDoubleValue(function, traceSlot);
+        }
     MOTH_END_INSTR(Decrement)
 
-    MOTH_BEGIN_INSTR(Binop)
-        QV4::Runtime::BinaryOperation op = *reinterpret_cast<QV4::Runtime::BinaryOperation *>(reinterpret_cast<char *>(&engine->runtime.runtimeMethods[instr.alu]));
-        STOREVALUE(instr.result, op(VALUE(instr.lhs), VALUE(instr.rhs)));
-    MOTH_END_INSTR(Binop)
-
     MOTH_BEGIN_INSTR(Add)
-        STOREVALUE(instr.result, Runtime::method_add(engine, VALUE(instr.lhs), VALUE(instr.rhs)));
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(Value::integerCompatible(left, ACC))) {
+            acc = add_int32(left.int_32(), ACC.int_32(), function->traceInfo(traceSlot));
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() + ACC.asDouble());
+            traceDoubleValue(function, traceSlot);
+        } else {
+            STORE_ACC();
+            acc = Runtime::Add::call(engine, left, accumulator);
+            CHECK_EXCEPTION;
+            traceOtherValue(function, traceSlot);
+        }
     MOTH_END_INSTR(Add)
 
+    MOTH_BEGIN_INSTR(Sub)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(Value::integerCompatible(left, ACC))) {
+            acc = sub_int32(left.int_32(), ACC.int_32(), function->traceInfo(traceSlot));
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() - ACC.asDouble());
+            traceDoubleValue(function, traceSlot);
+        } else {
+            STORE_ACC();
+            acc = Runtime::Sub::call(left, accumulator);
+            CHECK_EXCEPTION;
+            traceOtherValue(function, traceSlot);
+        }
+    MOTH_END_INSTR(Sub)
+
+    MOTH_BEGIN_INSTR(Exp)
+        const Value left = STACK_VALUE(lhs);
+        double base = left.toNumber();
+        double exp = ACC.toNumber();
+        if (qIsInf(exp) && (base == 1 || base == -1))
+            acc = Encode(qSNaN());
+        else
+            acc = Encode(pow(base,exp));
+    MOTH_END_INSTR(Exp)
+
+    MOTH_BEGIN_INSTR(Mul)
+        const Value left = STACK_VALUE(lhs);
+        if (Q_LIKELY(Value::integerCompatible(left, ACC))) {
+            acc = mul_int32(left.int_32(), ACC.int_32(), function->traceInfo(traceSlot));
+        } else if (left.isNumber() && ACC.isNumber()) {
+            acc = Encode(left.asDouble() * ACC.asDouble());
+            traceDoubleValue(function, traceSlot);
+        } else {
+            STORE_ACC();
+            acc = Runtime::Mul::call(left, accumulator);
+            CHECK_EXCEPTION;
+            traceOtherValue(function, traceSlot);
+        }
+    MOTH_END_INSTR(Mul)
+
+    MOTH_BEGIN_INSTR(Div)
+        STORE_ACC();
+        acc = Runtime::Div::call(STACK_VALUE(lhs), accumulator);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(Div)
+
+    MOTH_BEGIN_INSTR(Mod)
+        STORE_ACC();
+        acc = Runtime::Mod::call(STACK_VALUE(lhs), accumulator);
+        CHECK_EXCEPTION;
+        traceValue(acc, function, traceSlot);
+    MOTH_END_INSTR(Mod)
+
     MOTH_BEGIN_INSTR(BitAnd)
-        STOREVALUE(instr.result, Runtime::method_bitAnd(VALUE(instr.lhs), VALUE(instr.rhs)));
+        VALUE_TO_INT(l, STACK_VALUE(lhs));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(l & a);
     MOTH_END_INSTR(BitAnd)
 
     MOTH_BEGIN_INSTR(BitOr)
-        STOREVALUE(instr.result, Runtime::method_bitOr(VALUE(instr.lhs), VALUE(instr.rhs)));
+        VALUE_TO_INT(l, STACK_VALUE(lhs));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(l | a);
     MOTH_END_INSTR(BitOr)
 
     MOTH_BEGIN_INSTR(BitXor)
-        STOREVALUE(instr.result, Runtime::method_bitXor(VALUE(instr.lhs), VALUE(instr.rhs)));
+        VALUE_TO_INT(l, STACK_VALUE(lhs));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(l ^ a);
     MOTH_END_INSTR(BitXor)
 
+    MOTH_BEGIN_INSTR(UShr)
+        VALUE_TO_INT(l, STACK_VALUE(lhs));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(static_cast<uint>(l) >> uint(a & 0x1f));
+    MOTH_END_INSTR(UShr)
+
     MOTH_BEGIN_INSTR(Shr)
-        STOREVALUE(instr.result, QV4::Encode((int)(VALUEPTR(instr.lhs)->toInt32() >> (VALUEPTR(instr.rhs)->toInt32() & 0x1f))));
+        VALUE_TO_INT(l, STACK_VALUE(lhs));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(l >> (a & 0x1f));
     MOTH_END_INSTR(Shr)
 
     MOTH_BEGIN_INSTR(Shl)
-        STOREVALUE(instr.result, QV4::Encode((int)(VALUEPTR(instr.lhs)->toInt32() << (VALUEPTR(instr.rhs)->toInt32() & 0x1f))));
+        VALUE_TO_INT(l, STACK_VALUE(lhs));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(l << (a & 0x1f));
     MOTH_END_INSTR(Shl)
 
     MOTH_BEGIN_INSTR(BitAndConst)
-        int lhs = VALUEPTR(instr.lhs)->toInt32();
-        STOREVALUE(instr.result, QV4::Encode((int)(lhs & instr.rhs)));
-    MOTH_END_INSTR(BitAnd)
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(a & rhs);
+        CHECK_EXCEPTION;
+    MOTH_END_INSTR(BitAndConst)
 
     MOTH_BEGIN_INSTR(BitOrConst)
-        int lhs = VALUEPTR(instr.lhs)->toInt32();
-        STOREVALUE(instr.result, QV4::Encode((int)(lhs | instr.rhs)));
-    MOTH_END_INSTR(BitOr)
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(a | rhs);
+    MOTH_END_INSTR(BitOrConst)
 
     MOTH_BEGIN_INSTR(BitXorConst)
-        int lhs = VALUEPTR(instr.lhs)->toInt32();
-        STOREVALUE(instr.result, QV4::Encode((int)(lhs ^ instr.rhs)));
-    MOTH_END_INSTR(BitXor)
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(a ^ rhs);
+    MOTH_END_INSTR(BitXorConst)
+
+    MOTH_BEGIN_INSTR(UShrConst)
+        acc = Encode(ACC.toUInt32() >> uint(rhs));
+    MOTH_END_INSTR(UShrConst)
 
     MOTH_BEGIN_INSTR(ShrConst)
-        STOREVALUE(instr.result, QV4::Encode((int)(VALUEPTR(instr.lhs)->toInt32() >> instr.rhs)));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(a >> rhs);
     MOTH_END_INSTR(ShrConst)
 
     MOTH_BEGIN_INSTR(ShlConst)
-        STOREVALUE(instr.result, QV4::Encode((int)(VALUEPTR(instr.lhs)->toInt32() << instr.rhs)));
+        VALUE_TO_INT(a, ACC);
+        acc = Encode(a << rhs);
     MOTH_END_INSTR(ShlConst)
 
-    MOTH_BEGIN_INSTR(Mul)
-        STOREVALUE(instr.result, Runtime::method_mul(VALUE(instr.lhs), VALUE(instr.rhs)));
-    MOTH_END_INSTR(Mul)
+    MOTH_BEGIN_INSTR(Ret)
+        return acc;
+    MOTH_END_INSTR(Ret)
 
-    MOTH_BEGIN_INSTR(Sub)
-        STOREVALUE(instr.result, Runtime::method_sub(VALUE(instr.lhs), VALUE(instr.rhs)));
-    MOTH_END_INSTR(Sub)
+    MOTH_BEGIN_INSTR(InitializeBlockDeadTemporalZone)
+        acc = Encode(Value::emptyValue());
+        for (int i = firstReg, end = firstReg + count; i < end; ++i)
+            STACK_VALUE(i) = acc;
+    MOTH_END_INSTR(InitializeBlockDeadTemporalZone)
 
-    MOTH_BEGIN_INSTR(BinopContext)
-        QV4::Runtime::BinaryOperationContext op = *reinterpret_cast<QV4::Runtime::BinaryOperationContext *>(reinterpret_cast<char *>(&engine->runtime.runtimeMethods[instr.alu]));
-        STOREVALUE(instr.result, op(engine, VALUE(instr.lhs), VALUE(instr.rhs)));
-    MOTH_END_INSTR(BinopContext)
+    MOTH_BEGIN_INSTR(ThrowOnNullOrUndefined)
+        if (Value::fromReturnedValue(acc).isNullOrUndefined()) {
+            engine->throwTypeError();
+            goto handleUnwind;
+        }
+    MOTH_END_INSTR(ThrowOnNullOrUndefined)
 
-    MOTH_BEGIN_INSTR(Ret)
-//        TRACE(Ret, "returning value %s", result.toString(context)->toQString().toUtf8().constData());
-        return VALUE(instr.result).asReturnedValue();
-    MOTH_END_INSTR(Ret)
+    MOTH_BEGIN_INSTR(GetTemplateObject)
+        acc = Runtime::GetTemplateObject::call(function, index);
+    MOTH_END_INSTR(GetTemplateObject)
 
-#ifndef QT_NO_QML_DEBUGGER
     MOTH_BEGIN_INSTR(Debug)
-        engine->current->lineNumber = instr.lineNumber;
-        QV4::Debugging::Debugger *debugger = engine->debugger();
-        if (debugger && debugger->pauseAtNextOpportunity())
-            debugger->maybeBreakAtInstruction();
-        if (qt_v4IsDebugging)
-            qt_v4CheckForBreak(engine->currentContext);
+#if QT_CONFIG(qml_debug)
+        STORE_IP();
+        debug_slowPath(engine);
+#endif // QT_CONFIG(qml_debug)
     MOTH_END_INSTR(Debug)
 
-    MOTH_BEGIN_INSTR(Line)
-        engine->current->lineNumber = instr.lineNumber;
-        if (qt_v4IsDebugging)
-            qt_v4CheckForBreak(engine->currentContext);
-    MOTH_END_INSTR(Line)
-#endif // QT_NO_QML_DEBUGGER
-
-    MOTH_BEGIN_INSTR(LoadThis)
-        VALUE(instr.result) = engine->currentContext->thisObject();
-    MOTH_END_INSTR(LoadThis)
-
     MOTH_BEGIN_INSTR(LoadQmlContext)
-        VALUE(instr.result) = Runtime::method_getQmlContext(static_cast<QV4::NoThrowEngine*>(engine));
+        STACK_VALUE(result) = Runtime::LoadQmlContext::call(engine);
     MOTH_END_INSTR(LoadQmlContext)
 
     MOTH_BEGIN_INSTR(LoadQmlImportedScripts)
-        VALUE(instr.result) = Runtime::method_getQmlImportedScripts(static_cast<QV4::NoThrowEngine*>(engine));
+        STACK_VALUE(result) = Runtime::LoadQmlImportedScripts::call(engine);
     MOTH_END_INSTR(LoadQmlImportedScripts)
 
-    MOTH_BEGIN_INSTR(LoadQmlSingleton)
-        VALUE(instr.result) = Runtime::method_getQmlSingleton(static_cast<QV4::NoThrowEngine*>(engine), instr.name);
-    MOTH_END_INSTR(LoadQmlSingleton)
-
-#ifdef MOTH_THREADED_INTERPRETER
-    // nothing to do
-#else
-        default:
-            qFatal("QQmlJS::Moth::VME: Internal error - unknown instruction %d", genericInstr->common.instructionType);
-            break;
+    handleUnwind:
+        Q_ASSERT(engine->hasException || frame->unwindLevel);
+        if (!frame->unwindHandler) {
+            acc = Encode::undefined();
+            return acc;
         }
-#endif
-
-        Q_ASSERT(false);
-    catchException:
-        Q_ASSERT(engine->hasException);
-        if (!exceptionHandler)
-            return QV4::Encode::undefined();
-        code = exceptionHandler;
+        code = frame->unwindHandler;
     }
 }
-
-QV4::ReturnedValue VME::exec(ExecutionEngine *engine, const uchar *code)
-{
-    VME vme;
-    QV4::Debugging::Debugger *debugger = engine->debugger();
-    if (debugger)
-        debugger->enteringFunction();
-    QV4::ReturnedValue retVal = vme.run(engine, code);
-    if (debugger)
-        debugger->leavingFunction(retVal);
-    return retVal;
-}
diff --git a/src/qml/jsruntime/qv4vme_moth_p.h b/src/qml/jsruntime/qv4vme_moth_p.h
index 8d46207f2b..4ac7120d36 100644
--- a/src/qml/jsruntime/qv4vme_moth_p.h
+++ b/src/qml/jsruntime/qv4vme_moth_p.h
@@ -52,23 +52,23 @@
 //
 
 #include <private/qv4global_p.h>
-#include <private/qv4runtime_p.h>
-#include <private/qv4instr_moth_p.h>
-
-QT_REQUIRE_CONFIG(qml_interpreter);
 
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 namespace Moth {
 
+void runTracingJit(QV4::Function *function);
+
 class VME
 {
 public:
-    static QV4::ReturnedValue exec(QV4::ExecutionEngine *, const uchar *);
-
-private:
-    QV4::ReturnedValue run(QV4::ExecutionEngine *, const uchar *code);
+    struct ExecData {
+        QV4::Function *function;
+        const QV4::ExecutionContext *scope;
+    };
+    static QV4::ReturnedValue exec(CppStackFrame *frame, ExecutionEngine *engine);
+    static QV4::ReturnedValue interpret(CppStackFrame *frame, ExecutionEngine *engine, const char *codeEntry);
 };
 
 } // namespace Moth
diff --git a/src/qml/jsruntime/qv4vtable_p.h b/src/qml/jsruntime/qv4vtable_p.h
new file mode 100644
index 0000000000..00dcb962d3
--- /dev/null
+++ b/src/qml/jsruntime/qv4vtable_p.h
@@ -0,0 +1,226 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QV4VTABLE_P_H
+#define QV4VTABLE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qv4global_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QV4 {
+
+struct OwnPropertyKeyIterator {
+    virtual ~OwnPropertyKeyIterator() = 0;
+    virtual PropertyKey next(const Object *o, Property *p = nullptr, PropertyAttributes *attrs = nullptr) = 0;
+};
+
+struct VTable
+{
+    typedef void (*Destroy)(Heap::Base *);
+    typedef void (*MarkObjects)(Heap::Base *, MarkStack *markStack);
+    typedef bool (*IsEqualTo)(Managed *m, Managed *other);
+
+    typedef ReturnedValue (*Get)(const Managed *, PropertyKey id, const Value *receiver, bool *hasProperty);
+    typedef bool (*Put)(Managed *, PropertyKey id, const Value &value, Value *receiver);
+    typedef bool (*DeleteProperty)(Managed *m, PropertyKey id);
+    typedef bool (*HasProperty)(const Managed *m, PropertyKey id);
+    typedef PropertyAttributes (*GetOwnProperty)(const Managed *m, PropertyKey id, Property *p);
+    typedef bool (*DefineOwnProperty)(Managed *m, PropertyKey id, const Property *p, PropertyAttributes attrs);
+    typedef bool (*IsExtensible)(const Managed *);
+    typedef bool (*PreventExtensions)(Managed *);
+    typedef Heap::Object *(*GetPrototypeOf)(const Managed *);
+    typedef bool (*SetPrototypeOf)(Managed *, const Object *);
+    typedef qint64 (*GetLength)(const Managed *m);
+    typedef OwnPropertyKeyIterator *(*OwnPropertyKeys)(const Object *m, Value *target);
+    typedef ReturnedValue (*InstanceOf)(const Object *typeObject, const Value &var);
+
+    typedef ReturnedValue (*Call)(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    typedef ReturnedValue (*CallAsConstructor)(const FunctionObject *, const Value *argv, int argc, const Value *newTarget);
+
+    const VTable * const parent;
+    quint16 inlinePropertyOffset;
+    quint16 nInlineProperties;
+    quint8 isExecutionContext;
+    quint8 isString;
+    quint8 isObject;
+    quint8 isFunctionObject;
+    quint8 isErrorObject;
+    quint8 isArrayData;
+    quint8 isStringOrSymbol;
+    quint8 type;
+    quint8 unused[4];
+    const char *className;
+
+    Destroy destroy;
+    MarkObjects markObjects;
+    IsEqualTo isEqualTo;
+
+    Get get;
+    Put put;
+    DeleteProperty deleteProperty;
+    HasProperty hasProperty;
+    GetOwnProperty getOwnProperty;
+    DefineOwnProperty defineOwnProperty;
+    IsExtensible isExtensible;
+    PreventExtensions preventExtensions;
+    GetPrototypeOf getPrototypeOf;
+    SetPrototypeOf setPrototypeOf;
+    GetLength getLength;
+    OwnPropertyKeys ownPropertyKeys;
+    InstanceOf instanceOf;
+
+    Call call;
+    CallAsConstructor callAsConstructor;
+};
+
+
+struct VTableBase {
+protected:
+    static constexpr VTable::Destroy virtualDestroy = nullptr;
+    static constexpr VTable::IsEqualTo virtualIsEqualTo = nullptr;
+
+    static constexpr VTable::Get virtualGet = nullptr;
+    static constexpr VTable::Put virtualPut = nullptr;
+    static constexpr VTable::DeleteProperty virtualDeleteProperty = nullptr;
+    static constexpr VTable::HasProperty virtualHasProperty = nullptr;
+    static constexpr VTable::GetOwnProperty virtualGetOwnProperty = nullptr;
+    static constexpr VTable::DefineOwnProperty virtualDefineOwnProperty = nullptr;
+    static constexpr VTable::IsExtensible virtualIsExtensible = nullptr;
+    static constexpr VTable::PreventExtensions virtualPreventExtensions = nullptr;
+    static constexpr VTable::GetPrototypeOf virtualGetPrototypeOf = nullptr;
+    static constexpr VTable::SetPrototypeOf virtualSetPrototypeOf = nullptr;
+    static constexpr VTable::GetLength virtualGetLength = nullptr;
+    static constexpr VTable::OwnPropertyKeys virtualOwnPropertyKeys = nullptr;
+    static constexpr VTable::InstanceOf virtualInstanceOf = nullptr;
+
+    static constexpr VTable::Call virtualCall = nullptr;
+    static constexpr VTable::CallAsConstructor virtualCallAsConstructor = nullptr;
+};
+
+#define DEFINE_MANAGED_VTABLE_INT(classname, parentVTable) \
+{     \
+    parentVTable, \
+    (sizeof(classname::Data) + sizeof(QV4::Value) - 1)/sizeof(QV4::Value), \
+    (sizeof(classname::Data) + (classname::NInlineProperties*sizeof(QV4::Value)) + QV4::Chunk::SlotSize - 1)/QV4::Chunk::SlotSize*QV4::Chunk::SlotSize/sizeof(QV4::Value) \
+        - (sizeof(classname::Data) + sizeof(QV4::Value) - 1)/sizeof(QV4::Value), \
+    classname::IsExecutionContext,          \
+    classname::IsString,                    \
+    classname::IsObject,                    \
+    classname::IsFunctionObject,            \
+    classname::IsErrorObject,               \
+    classname::IsArrayData,                 \
+    classname::IsStringOrSymbol,            \
+    classname::MyType,                      \
+    { 0, 0, 0, 0 },                         \
+    #classname, \
+    \
+    classname::virtualDestroy,              \
+    classname::Data::markObjects,           \
+    classname::virtualIsEqualTo,            \
+    \
+    classname::virtualGet,                  \
+    classname::virtualPut,                  \
+    classname::virtualDeleteProperty,       \
+    classname::virtualHasProperty,          \
+    classname::virtualGetOwnProperty,       \
+    classname::virtualDefineOwnProperty,    \
+    classname::virtualIsExtensible,         \
+    classname::virtualPreventExtensions,    \
+    classname::virtualGetPrototypeOf,       \
+    classname::virtualSetPrototypeOf,       \
+    classname::virtualGetLength,            \
+    classname::virtualOwnPropertyKeys,      \
+    classname::virtualInstanceOf,           \
+    \
+    classname::virtualCall,                 \
+    classname::virtualCallAsConstructor,    \
+}
+
+#define DEFINE_MANAGED_VTABLE(classname) \
+const QV4::VTable classname::static_vtbl = DEFINE_MANAGED_VTABLE_INT(classname, 0)
+
+#define V4_OBJECT2(DataClass, superClass) \
+    private: \
+        DataClass() Q_DECL_EQ_DELETE; \
+        Q_DISABLE_COPY(DataClass) \
+    public: \
+        Q_MANAGED_CHECK \
+        typedef QV4::Heap::DataClass Data; \
+        typedef superClass SuperClass; \
+        static const QV4::VTable static_vtbl; \
+        static inline const QV4::VTable *staticVTable() { return &static_vtbl; } \
+        V4_MANAGED_SIZE_TEST \
+        QV4::Heap::DataClass *d_unchecked() const { return static_cast<QV4::Heap::DataClass *>(m()); } \
+        QV4::Heap::DataClass *d() const { \
+            QV4::Heap::DataClass *dptr = d_unchecked(); \
+            dptr->_checkIsInitialized(); \
+            return dptr; \
+        } \
+        Q_STATIC_ASSERT(std::is_trivial< QV4::Heap::DataClass >::value);
+
+#define V4_PROTOTYPE(p) \
+    static QV4::Object *defaultPrototype(QV4::ExecutionEngine *e) \
+    { return e->p(); }
+
+
+#define DEFINE_OBJECT_VTABLE_BASE(classname) \
+    const QV4::VTable classname::static_vtbl = DEFINE_MANAGED_VTABLE_INT(classname, (std::is_same<classname::SuperClass, Object>::value) ? nullptr : &classname::SuperClass::static_vtbl)
+
+#define DEFINE_OBJECT_VTABLE(classname) \
+DEFINE_OBJECT_VTABLE_BASE(classname)
+
+#define DEFINE_OBJECT_TEMPLATE_VTABLE(classname) \
+template<> DEFINE_OBJECT_VTABLE_BASE(classname)
+
+}
+
+QT_END_NAMESPACE
+
+#endif
diff --git a/src/qml/memory/qv4heap_p.h b/src/qml/memory/qv4heap_p.h
index f00ce4283c..07af5a6f7a 100644
--- a/src/qml/memory/qv4heap_p.h
+++ b/src/qml/memory/qv4heap_p.h
@@ -53,58 +53,55 @@
 #include <QtCore/QString>
 #include <private/qv4global_p.h>
 #include <private/qv4mmdefs_p.h>
-#include <private/qv4internalclass_p.h>
+#include <private/qv4writebarrier_p.h>
+#include <private/qv4vtable_p.h>
 #include <QSharedPointer>
 
 // To check if Heap::Base::init is called (meaning, all subclasses did their init and called their
 // parent's init all up the inheritance chain), define QML_CHECK_INIT_DESTROY_CALLS below.
 #undef QML_CHECK_INIT_DESTROY_CALLS
 
-#if defined(_MSC_VER) && (_MSC_VER < 1900) // broken compilers:
-#  define V4_ASSERT_IS_TRIVIAL(x)
-#else // working compilers:
-#  define V4_ASSERT_IS_TRIVIAL(x) Q_STATIC_ASSERT(std::is_trivial< x >::value);
-#endif
-
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-struct InternalClass;
+namespace Heap {
 
-struct VTable
-{
-    const VTable * const parent;
-    const quint64 markTable;
-    uint inlinePropertyOffset : 16;
-    uint nInlineProperties : 16;
-    uint isExecutionContext : 1;
-    uint isString : 1;
-    uint isObject : 1;
-    uint isFunctionObject : 1;
-    uint isErrorObject : 1;
-    uint isArrayData : 1;
-    uint unused : 18;
-    uint type : 8;
-    const char *className;
-    void (*destroy)(Heap::Base *);
-    void (*markObjects)(Heap::Base *, MarkStack *markStack);
-    bool (*isEqualTo)(Managed *m, Managed *other);
-};
+template <typename T, size_t o>
+struct Pointer {
+    static Q_CONSTEXPR size_t offset = o;
+    T operator->() const { return get(); }
+    operator T () const { return get(); }
 
-namespace Heap {
+    Base *base();
+
+    void set(EngineBase *e, T newVal) {
+        WriteBarrier::write(e, base(), &ptr, reinterpret_cast<Base *>(newVal));
+    }
+
+    T get() const { return reinterpret_cast<T>(ptr); }
+
+    template <typename Type>
+    Type *cast() { return static_cast<Type *>(ptr); }
+
+    Base *heapObject() const { return ptr; }
+
+private:
+    Base *ptr;
+};
+typedef Pointer<char *, 0> V4PointerCheck;
+Q_STATIC_ASSERT(std::is_trivial< V4PointerCheck >::value);
 
 struct Q_QML_EXPORT Base {
     void *operator new(size_t) = delete;
 
-    static Q_CONSTEXPR quint64 markTable = 0;
+    static void markObjects(Base *, MarkStack *);
 
-    InternalClass *internalClass;
+    Pointer<InternalClass *, 0> internalClass;
 
     inline ReturnedValue asReturnedValue() const;
     inline void mark(QV4::MarkStack *markStack);
 
-    const VTable *vtable() const { return internalClass->vtable; }
     inline bool isMarked() const {
         const HeapItem *h = reinterpret_cast<const HeapItem *>(this);
         Chunk *c = h->chunk();
@@ -131,11 +128,9 @@ struct Q_QML_EXPORT Base {
         return Chunk::testBit(c->objectBitmap, h - c->realBase());
     }
 
-    inline void markChildren(MarkStack *markStack);
-
     void *operator new(size_t, Managed *m) { return m; }
-    void *operator new(size_t, Heap::Base *m) { return m; }
-    void operator delete(void *, Heap::Base *) {}
+    void *operator new(size_t, Base *m) { return m; }
+    void operator delete(void *, Base *) {}
 
     void init() { _setInitialized(); }
     void destroy() { _setDestroyed(); }
@@ -174,7 +169,7 @@ struct Q_QML_EXPORT Base {
     Q_ALWAYS_INLINE void _setDestroyed() {}
 #endif
 };
-V4_ASSERT_IS_TRIVIAL(Base)
+Q_STATIC_ASSERT(std::is_trivial< Base >::value);
 // This class needs to consist only of pointer sized members to allow
 // for a size/offset translation when cross-compiling between 32- and
 // 64-bit.
@@ -182,6 +177,29 @@ Q_STATIC_ASSERT(std::is_standard_layout<Base>::value);
 Q_STATIC_ASSERT(offsetof(Base, internalClass) == 0);
 Q_STATIC_ASSERT(sizeof(Base) == QT_POINTER_SIZE);
 
+inline
+void Base::mark(QV4::MarkStack *markStack)
+{
+    Q_ASSERT(inUse());
+    const HeapItem *h = reinterpret_cast<const HeapItem *>(this);
+    Chunk *c = h->chunk();
+    size_t index = h - c->realBase();
+    Q_ASSERT(!Chunk::testBit(c->extendsBitmap, index));
+    quintptr *bitmap = c->blackBitmap + Chunk::bitmapIndex(index);
+    quintptr bit = Chunk::bitForIndex(index);
+    if (!(*bitmap & bit)) {
+        *bitmap |= bit;
+        markStack->push(this);
+    }
+}
+
+template<typename T, size_t o>
+Base *Pointer<T, o>::base() {
+    Base *base = reinterpret_cast<Base *>(this) - (offset/sizeof(Base *));
+    Q_ASSERT(base->inUse());
+    return base;
+}
+
 }
 
 #ifdef QT_NO_QOBJECT
@@ -236,7 +254,7 @@ private:
     QtSharedPointer::ExternalRefCountData *d;
     QObject *qObject;
 };
-V4_ASSERT_IS_TRIVIAL(QQmlQPointer<QObject>)
+Q_STATIC_ASSERT(std::is_trivial< QQmlQPointer<QObject> >::value);
 #endif
 
 }
diff --git a/src/qml/memory/qv4mm.cpp b/src/qml/memory/qv4mm.cpp
index de97918fb0..203f1f424f 100644
--- a/src/qml/memory/qv4mm.cpp
+++ b/src/qml/memory/qv4mm.cpp
@@ -42,8 +42,10 @@
 #include "qv4objectproto_p.h"
 #include "qv4mm_p.h"
 #include "qv4qobjectwrapper_p.h"
+#include "qv4identifiertable_p.h"
 #include <QtCore/qalgorithms.h>
 #include <QtCore/private/qnumeric_p.h>
+#include <QtCore/qloggingcategory.h>
 #include <qqmlengine.h>
 #include "PageReservation.h"
 #include "PageAllocation.h"
@@ -59,6 +61,8 @@
 #include <algorithm>
 #include "qv4alloca_p.h"
 #include "qv4profiling_p.h"
+#include "qv4mapobject_p.h"
+#include "qv4setobject_p.h"
 
 //#define MM_STATS
 
@@ -91,6 +95,11 @@
 
 #define MIN_UNMANAGED_HEAPSIZE_GC_LIMIT std::size_t(128 * 1024)
 
+Q_LOGGING_CATEGORY(lcGcStats, "qt.qml.gc.statistics")
+Q_DECLARE_LOGGING_CATEGORY(lcGcStats)
+Q_LOGGING_CATEGORY(lcGcAllocatorStats, "qt.qml.gc.allocatorStats")
+Q_DECLARE_LOGGING_CATEGORY(lcGcAllocatorStats)
+
 using namespace WTF;
 
 QT_BEGIN_NAMESPACE
@@ -180,7 +189,7 @@ struct MemorySegment {
     }
 
     PageReservation pageReservation;
-    Chunk *base = 0;
+    Chunk *base = nullptr;
     quint64 allocatedMap = 0;
     size_t availableBytes = 0;
     uint nChunks = 0;
@@ -192,19 +201,19 @@ Chunk *MemorySegment::allocate(size_t size)
         // chunk allocated for one huge allocation
         Q_ASSERT(availableBytes >= size);
         pageReservation.commit(base, size);
-        allocatedMap = ~static_cast<quintptr>(0);
+        allocatedMap = ~static_cast<quint64>(0);
         return base;
     }
     size_t requiredChunks = (size + sizeof(Chunk) - 1)/sizeof(Chunk);
     uint sequence = 0;
-    Chunk *candidate = 0;
+    Chunk *candidate = nullptr;
     for (uint i = 0; i < nChunks; ++i) {
         if (!testBit(i)) {
             if (!candidate)
                 candidate = base + i;
             ++sequence;
         } else {
-            candidate = 0;
+            candidate = nullptr;
             sequence = 0;
         }
         if (sequence == requiredChunks) {
@@ -215,7 +224,7 @@ Chunk *MemorySegment::allocate(size_t size)
             return candidate;
         }
     }
-    return 0;
+    return nullptr;
 }
 
 struct ChunkAllocator {
@@ -279,64 +288,6 @@ QString binary(quintptr) { return QString(); }
 #define SDUMP if (1) ; else qDebug
 #endif
 
-void Heap::Base::markChildren(MarkStack *markStack)
-{
-    if (vtable()->markObjects)
-        vtable()->markObjects(this, markStack);
-    if (quint64 m = vtable()->markTable) {
-//            qDebug() << "using mark table:" << hex << m << "for" << h;
-        void **mem = reinterpret_cast<void **>(this);
-        while (m) {
-            MarkFlags mark = static_cast<MarkFlags>(m & 3);
-            switch (mark) {
-            case Mark_NoMark:
-                break;
-            case Mark_Value:
-//                    qDebug() << "marking value at " << mem;
-                reinterpret_cast<Value *>(mem)->mark(markStack);
-                break;
-            case Mark_Pointer: {
-//                    qDebug() << "marking pointer at " << mem;
-                Heap::Base *p = *reinterpret_cast<Heap::Base **>(mem);
-                if (p)
-                    p->mark(markStack);
-                break;
-            }
-            case Mark_ValueArray: {
-                Q_ASSERT(m == Mark_ValueArray);
-//                    qDebug() << "marking Value Array at offset" << hex << (mem - reinterpret_cast<void **>(h));
-                ValueArray<0> *a = reinterpret_cast<ValueArray<0> *>(mem);
-                Value *v = a->values;
-                const Value *end = v + a->alloc;
-                if (a->alloc > 32*1024) {
-                    // drain from time to time to avoid overflows in the js stack
-                    Heap::Base **currentBase = markStack->top;
-                    while (v < end) {
-                        v->mark(markStack);
-                        ++v;
-                        if (markStack->top >= currentBase + 32*1024) {
-                            Heap::Base **oldBase = markStack->base;
-                            markStack->base = currentBase;
-                            markStack->drain();
-                            markStack->base = oldBase;
-                        }
-                    }
-                } else {
-                    while (v < end) {
-                        v->mark(markStack);
-                        ++v;
-                    }
-                }
-                break;
-            }
-            }
-
-            m >>= 2;
-            ++mem;
-        }
-    }
-}
-
 // Stores a classname -> freed count mapping.
 typedef QHash<const char*, int> MMStatsHash;
 Q_GLOBAL_STATIC(MMStatsHash, freedObjectStatsGlobal)
@@ -348,7 +299,8 @@ static void increaseFreedCountForClass(const char *className)
     (*freedObjectStatsGlobal())[className]++;
 }
 
-bool Chunk::sweep(ClassDestroyStatsCallback classCountPtr)
+//bool Chunk::sweep(ClassDestroyStatsCallback classCountPtr)
+bool Chunk::sweep(ExecutionEngine *engine)
 {
     bool hasUsedSlots = false;
     SDUMP() << "sweeping chunk" << this;
@@ -386,14 +338,20 @@ bool Chunk::sweep(ClassDestroyStatsCallback classCountPtr)
 
             HeapItem *itemToFree = o + index;
             Heap::Base *b = *itemToFree;
-            const VTable *v = b->vtable();
-            if (Q_UNLIKELY(classCountPtr))
-                classCountPtr(v->className);
+            const VTable *v = b->internalClass->vtable;
+//            if (Q_UNLIKELY(classCountPtr))
+//                classCountPtr(v->className);
             if (v->destroy) {
                 v->destroy(b);
                 b->_checkIsDestroyed();
             }
+#ifdef V4_USE_HEAPTRACK
+            heaptrack_report_free(itemToFree);
+#endif
         }
+        Q_V4_PROFILE_DEALLOC(engine, qPopulationCount((objectBitmap[i] | extendsBitmap[i])
+                                                      - (blackBitmap[i] | e)) * Chunk::SlotSize,
+                             Profiling::SmallItem);
         objectBitmap[i] = blackBitmap[i];
         grayBitmap[i] = 0;
         hasUsedSlots |= (blackBitmap[i] != 0);
@@ -408,7 +366,7 @@ bool Chunk::sweep(ClassDestroyStatsCallback classCountPtr)
     return hasUsedSlots;
 }
 
-void Chunk::freeAll()
+void Chunk::freeAll(ExecutionEngine *engine)
 {
     //    DEBUG << "sweeping chunk" << this << (*freeList);
     HeapItem *o = realBase();
@@ -434,11 +392,16 @@ void Chunk::freeAll()
 
             HeapItem *itemToFree = o + index;
             Heap::Base *b = *itemToFree;
-            if (b->vtable()->destroy) {
-                b->vtable()->destroy(b);
+            if (b->internalClass->vtable->destroy) {
+                b->internalClass->vtable->destroy(b);
                 b->_checkIsDestroyed();
             }
+#ifdef V4_USE_HEAPTRACK
+            heaptrack_report_free(itemToFree);
+#endif
         }
+        Q_V4_PROFILE_DEALLOC(engine, (qPopulationCount(objectBitmap[i]|extendsBitmap[i])
+                             - qPopulationCount(e)) * Chunk::SlotSize, Profiling::SmallItem);
         objectBitmap[i] = 0;
         grayBitmap[i] = 0;
         extendsBitmap[i] = e;
@@ -452,10 +415,6 @@ void Chunk::resetBlackBits()
     memset(blackBitmap, 0, sizeof(blackBitmap));
 }
 
-#ifdef MM_STATS
-static uint nGrayItems = 0;
-#endif
-
 void Chunk::collectGrayItems(MarkStack *markStack)
 {
     //    DEBUG << "sweeping chunk" << this << (*freeList);
@@ -478,10 +437,6 @@ void Chunk::collectGrayItems(MarkStack *markStack)
             Heap::Base *b = *itemToFree;
             Q_ASSERT(b->inUse());
             markStack->push(b);
-#ifdef MM_STATS
-            ++nGrayItems;
-//            qDebug() << "adding gray item" << b << "to mark stack";
-#endif
         }
         grayBitmap[i] = 0;
         o += Chunk::Bits;
@@ -499,7 +454,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
 #else
     const int start = 1;
 #endif
-#ifdef MM_STATS
+#ifndef QT_NO_DEBUG
     uint freeSlots = 0;
     uint allocatedSlots = 0;
 #endif
@@ -509,7 +464,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
         if (!i)
             usedSlots |= (static_cast<quintptr>(1) << (HeaderSize/SlotSize)) - 1;
 #endif
-#ifdef MM_STATS
+#ifndef QT_NO_DEBUG
         allocatedSlots += qPopulationCount(usedSlots);
 //        qDebug() << hex << "   i=" << i << "used=" << usedSlots;
 #endif
@@ -526,7 +481,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
                     break;
                 }
                 usedSlots = (objectBitmap[i]|extendsBitmap[i]);
-#ifdef MM_STATS
+#ifndef QT_NO_DEBUG
                 allocatedSlots += qPopulationCount(usedSlots);
 //                qDebug() << hex << "   i=" << i << "used=" << usedSlots;
 #endif
@@ -537,7 +492,7 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
             usedSlots |= (quintptr(1) << index) - 1;
             uint freeEnd = i*Bits + index;
             uint nSlots = freeEnd - freeStart;
-#ifdef MM_STATS
+#ifndef QT_NO_DEBUG
 //            qDebug() << hex << "   got free slots from" << freeStart << "to" << freeEnd << "n=" << nSlots << "usedSlots=" << usedSlots;
             freeSlots += nSlots;
 #endif
@@ -548,62 +503,17 @@ void Chunk::sortIntoBins(HeapItem **bins, uint nBins)
             bins[bin] = freeItem;
         }
     }
-#ifdef MM_STATS
+#ifndef QT_NO_DEBUG
     Q_ASSERT(freeSlots + allocatedSlots == (EntriesInBitmap - start) * 8 * sizeof(quintptr));
 #endif
 }
 
-
-template<typename T>
-StackAllocator<T>::StackAllocator(ChunkAllocator *chunkAlloc)
-    : chunkAllocator(chunkAlloc)
-{
-    chunks.push_back(chunkAllocator->allocate());
-    firstInChunk = chunks.back()->first();
-    nextFree = firstInChunk;
-    lastInChunk = firstInChunk + (Chunk::AvailableSlots - 1)/requiredSlots*requiredSlots;
-}
-
-template<typename T>
-void StackAllocator<T>::freeAll()
-{
-    for (auto c : chunks)
-        chunkAllocator->free(c);
-}
-
-template<typename T>
-void StackAllocator<T>::nextChunk() {
-    Q_ASSERT(nextFree == lastInChunk);
-    ++currentChunk;
-    if (currentChunk >= chunks.size()) {
-        Chunk *newChunk = chunkAllocator->allocate();
-        chunks.push_back(newChunk);
-    }
-    firstInChunk = chunks.at(currentChunk)->first();
-    nextFree = firstInChunk;
-    lastInChunk = firstInChunk + (Chunk::AvailableSlots - 1)/requiredSlots*requiredSlots;
-}
-
-template<typename T>
-void QV4::StackAllocator<T>::prevChunk() {
-    Q_ASSERT(nextFree == firstInChunk);
-    Q_ASSERT(chunks.at(currentChunk) == nextFree->chunk());
-    Q_ASSERT(currentChunk > 0);
-    --currentChunk;
-    firstInChunk = chunks.at(currentChunk)->first();
-    lastInChunk = firstInChunk + (Chunk::AvailableSlots - 1)/requiredSlots*requiredSlots;
-    nextFree = lastInChunk;
-}
-
-template struct StackAllocator<Heap::CallContext>;
-
-
 HeapItem *BlockAllocator::allocate(size_t size, bool forceAllocation) {
     Q_ASSERT((size % Chunk::SlotSize) == 0);
     size_t slotsRequired = size >> Chunk::SlotSizeShift;
-#if MM_DEBUG
-    ++allocations[bin];
-#endif
+
+    if (allocationStats)
+        ++allocationStats[binForSlots(slotsRequired)];
 
     HeapItem **last;
 
@@ -679,8 +589,9 @@ HeapItem *BlockAllocator::allocate(size_t size, bool forceAllocation) {
 
     if (!m) {
         if (!forceAllocation)
-            return 0;
+            return nullptr;
         Chunk *newChunk = chunkAllocator->allocate();
+        Q_V4_PROFILE_ALLOC(engine, Chunk::DataSize, Profiling::HeapPage);
         chunks.push_back(newChunk);
         nextFree = newChunk->first();
         nFree = Chunk::AvailableSlots;
@@ -691,39 +602,48 @@ HeapItem *BlockAllocator::allocate(size_t size, bool forceAllocation) {
 
 done:
     m->setAllocatedSlots(slotsRequired);
+    Q_V4_PROFILE_ALLOC(engine, slotsRequired * Chunk::SlotSize, Profiling::SmallItem);
+#ifdef V4_USE_HEAPTRACK
+    heaptrack_report_alloc(m, slotsRequired * Chunk::SlotSize);
+#endif
     //        DEBUG << "   " << hex << m->chunk() << m->chunk()->objectBitmap[0] << m->chunk()->extendsBitmap[0] << (m - m->chunk()->realBase());
     return m;
 }
 
-void BlockAllocator::sweep(ClassDestroyStatsCallback classCountPtr)
+void BlockAllocator::sweep()
 {
-    nextFree = 0;
+    nextFree = nullptr;
     nFree = 0;
     memset(freeBins, 0, sizeof(freeBins));
 
 //    qDebug() << "BlockAlloc: sweep";
     usedSlotsAfterLastSweep = 0;
 
-    auto isFree = [this, classCountPtr] (Chunk *c) {
-        bool isUsed = c->sweep(classCountPtr);
+    auto firstEmptyChunk = std::partition(chunks.begin(), chunks.end(), [this](Chunk *c) {
+        return c->sweep(engine);
+    });
 
-        if (isUsed) {
-            c->sortIntoBins(freeBins, NumBins);
-            usedSlotsAfterLastSweep += c->nUsedSlots();
-        } else {
-            chunkAllocator->free(c);
-        }
-        return !isUsed;
-    };
+    std::for_each(chunks.begin(), firstEmptyChunk, [this](Chunk *c) {
+        c->sortIntoBins(freeBins, NumBins);
+        usedSlotsAfterLastSweep += c->nUsedSlots();
+    });
 
-    auto newEnd = std::remove_if(chunks.begin(), chunks.end(), isFree);
-    chunks.erase(newEnd, chunks.end());
+    // only free the chunks at the end to avoid that the sweep() calls indirectly
+    // access freed memory
+    std::for_each(firstEmptyChunk, chunks.end(), [this](Chunk *c) {
+        Q_V4_PROFILE_DEALLOC(engine, Chunk::DataSize, Profiling::HeapPage);
+        chunkAllocator->free(c);
+    });
+
+    chunks.erase(firstEmptyChunk, chunks.end());
 }
 
 void BlockAllocator::freeAll()
 {
+    for (auto c : chunks)
+        c->freeAll(engine);
     for (auto c : chunks) {
-        c->freeAll();
+        Q_V4_PROFILE_DEALLOC(engine, Chunk::DataSize, Profiling::HeapPage);
         chunkAllocator->free(c);
     }
 }
@@ -741,41 +661,26 @@ void BlockAllocator::collectGrayItems(MarkStack *markStack)
 
 }
 
-#if MM_DEBUG
-void BlockAllocator::stats() {
-    DEBUG << "MM stats:";
-    QString s;
-    for (int i = 0; i < 10; ++i) {
-        uint c = 0;
-        HeapItem *item = freeBins[i];
-        while (item) {
-            ++c;
-            item = item->freeData.next;
-        }
-        s += QString::number(c) + QLatin1String(", ");
-    }
-    HeapItem *item = freeBins[NumBins - 1];
-    uint c = 0;
-    while (item) {
-        ++c;
-        item = item->freeData.next;
-    }
-    s += QLatin1String("..., ") + QString::number(c);
-    DEBUG << "bins:" << s;
-    QString a;
-    for (int i = 0; i < 10; ++i)
-        a += QString::number(allocations[i]) + QLatin1String(", ");
-    a += QLatin1String("..., ") + QString::number(allocations[NumBins - 1]);
-    DEBUG << "allocs:" << a;
-    memset(allocations, 0, sizeof(allocations));
-}
-#endif
-
-
 HeapItem *HugeItemAllocator::allocate(size_t size) {
-    Chunk *c = chunkAllocator->allocate(size);
-    chunks.push_back(HugeChunk{c, size});
+    MemorySegment *m = nullptr;
+    Chunk *c = nullptr;
+    if (size >= MemorySegment::SegmentSize/2) {
+        // too large to handle through the ChunkAllocator, let's get our own memory segement
+        size += Chunk::HeaderSize; // space required for the Chunk header
+        size_t pageSize = WTF::pageSize();
+        size = (size + pageSize - 1) & ~(pageSize - 1); // align to page sizes
+        m = new MemorySegment(size);
+        c = m->allocate(size);
+    } else {
+        c = chunkAllocator->allocate(size);
+    }
+    Q_ASSERT(c);
+    chunks.push_back(HugeChunk{m, c, size});
     Chunk::setBit(c->objectBitmap, c->first() - c->realBase());
+    Q_V4_PROFILE_ALLOC(engine, size, Profiling::LargeItem);
+#ifdef V4_USE_HEAPTRACK
+    heaptrack_report_alloc(c, size);
+#endif
     return c->first();
 }
 
@@ -783,7 +688,7 @@ static void freeHugeChunk(ChunkAllocator *chunkAllocator, const HugeItemAllocato
 {
     HeapItem *itemToFree = c.chunk->first();
     Heap::Base *b = *itemToFree;
-    const VTable *v = b->vtable();
+    const VTable *v = b->internalClass->vtable;
     if (Q_UNLIKELY(classCountPtr))
         classCountPtr(v->className);
 
@@ -791,15 +696,27 @@ static void freeHugeChunk(ChunkAllocator *chunkAllocator, const HugeItemAllocato
         v->destroy(b);
         b->_checkIsDestroyed();
     }
-    chunkAllocator->free(c.chunk, c.size);
+    if (c.segment) {
+        // own memory segment
+        c.segment->free(c.chunk, c.size);
+        delete c.segment;
+    } else {
+        chunkAllocator->free(c.chunk, c.size);
+    }
+#ifdef V4_USE_HEAPTRACK
+    heaptrack_report_free(c.chunk);
+#endif
 }
 
 void HugeItemAllocator::sweep(ClassDestroyStatsCallback classCountPtr)
 {
     auto isBlack = [this, classCountPtr] (const HugeChunk &c) {
         bool b = c.chunk->first()->isBlack();
-        if (!b)
+        Chunk::clearBit(c.chunk->blackBitmap, c.chunk->first() - c.chunk->realBase());
+        if (!b) {
+            Q_V4_PROFILE_DEALLOC(engine, c.size, Profiling::LargeItem);
             freeHugeChunk(chunkAllocator, c, classCountPtr);
+        }
         return !b;
     };
 
@@ -828,6 +745,7 @@ void HugeItemAllocator::collectGrayItems(MarkStack *markStack)
 void HugeItemAllocator::freeAll()
 {
     for (auto &c : chunks) {
+        Q_V4_PROFILE_DEALLOC(engine, c.size, Profiling::LargeItem);
         freeHugeChunk(chunkAllocator, c, nullptr);
     }
 }
@@ -836,25 +754,24 @@ void HugeItemAllocator::freeAll()
 MemoryManager::MemoryManager(ExecutionEngine *engine)
     : engine(engine)
     , chunkAllocator(new ChunkAllocator)
-    , stackAllocator(chunkAllocator)
-    , blockAllocator(chunkAllocator)
-    , hugeItemAllocator(chunkAllocator)
+    , blockAllocator(chunkAllocator, engine)
+    , icAllocator(chunkAllocator, engine)
+    , hugeItemAllocator(chunkAllocator, engine)
     , m_persistentValues(new PersistentValueStorage(engine))
     , m_weakValues(new PersistentValueStorage(engine))
     , unmanagedHeapSizeGCLimit(MIN_UNMANAGED_HEAPSIZE_GC_LIMIT)
     , aggressiveGC(!qEnvironmentVariableIsEmpty("QV4_MM_AGGRESSIVE_GC"))
-    , gcStats(!qEnvironmentVariableIsEmpty(QV4_MM_STATS))
+    , gcStats(lcGcStats().isDebugEnabled())
+    , gcCollectorStats(lcGcAllocatorStats().isDebugEnabled())
 {
 #ifdef V4_USE_VALGRIND
     VALGRIND_CREATE_MEMPOOL(this, 0, true);
 #endif
+    memset(statistics.allocations, 0, sizeof(statistics.allocations));
+    if (gcStats)
+        blockAllocator.allocationStats = statistics.allocations;
 }
 
-#ifdef MM_STATS
-static int allocationCount = 0;
-static size_t lastAllocRequestedSlots = 0;
-#endif
-
 Heap::Base *MemoryManager::allocString(std::size_t unmanagedSize)
 {
     const size_t stringSize = align(sizeof(Heap::String));
@@ -907,9 +824,6 @@ Heap::Base *MemoryManager::allocData(std::size_t size)
         runGC();
         didRunGC = true;
     }
-#ifdef DETAILED_MM_STATS
-    willAllocate(size);
-#endif // DETAILED_MM_STATS
 
     Q_ASSERT(size >= Chunk::SlotSize);
     Q_ASSERT(size % Chunk::SlotSize == 0);
@@ -963,7 +877,7 @@ Heap::Object *MemoryManager::allocObjectWithMemberData(const QV4::VTable *vtable
             Chunk::clearBit(c->extendsBitmap, index);
         }
         o->memberData.set(engine, m);
-        m->internalClass = engine->internalClasses[EngineBase::Class_MemberData];
+        m->internalClass.set(engine, engine->internalClasses(EngineBase::Class_MemberData));
         Q_ASSERT(o->memberData->internalClass);
         m->values.alloc = static_cast<uint>((memberSize - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
         m->values.size = o->memberData->values.alloc;
@@ -990,7 +904,7 @@ void MarkStack::drain()
         Heap::Base *h = pop();
         ++markStackSize;
         Q_ASSERT(h); // at this point we should only have Heap::Base objects in this area on the stack. If not, weird things might happen.
-        h->markChildren(this);
+        h->internalClass->vtable->markObjects(h, this);
     }
 }
 
@@ -1059,8 +973,29 @@ void MemoryManager::sweep(bool lastSweep, ClassDestroyStatsCallback classCountPt
         // signal before we start sweeping the heap
         if (QObjectWrapper *qobjectWrapper = (*it).as<QObjectWrapper>())
             qobjectWrapper->destroyObject(lastSweep);
+    }
 
-        (*it) = Primitive::undefinedValue();
+    // remove objects from weak maps and sets
+    Heap::MapObject *map = weakMaps;
+    Heap::MapObject **lastMap = &weakMaps;
+    while (map) {
+        if (map->isMarked()) {
+            map->removeUnmarkedKeys();
+            *lastMap = map;
+            lastMap = &map->nextWeakMap;
+        }
+        map = map->nextWeakMap;
+    }
+
+    Heap::SetObject *set = weakSets;
+    Heap::SetObject **lastSet = &weakSets;
+    while (set) {
+        if (set->isMarked()) {
+            set->removeUnmarkedKeys();
+            *lastSet = set;
+            lastSet = &set->nextWeakSet;
+        }
+        set = set->nextWeakSet;
     }
 
     // onDestruction handlers may have accessed other QObject wrappers and reset their value, so ensure
@@ -1069,7 +1004,7 @@ void MemoryManager::sweep(bool lastSweep, ClassDestroyStatsCallback classCountPt
         Managed *m = (*it).managed();
         if (!m || m->markBit())
             continue;
-        (*it) = Primitive::undefinedValue();
+        (*it) = Value::undefinedValue();
     }
 
     // Now it is time to free QV4::QObjectWrapper Value, we must check the Value's tag to make sure its object has been destroyed
@@ -1096,13 +1031,18 @@ void MemoryManager::sweep(bool lastSweep, ClassDestroyStatsCallback classCountPt
         }
     }
 
-    blockAllocator.sweep(classCountPtr);
-    hugeItemAllocator.sweep(classCountPtr);
+
+    if (!lastSweep) {
+        engine->identifierTable->sweep();
+        blockAllocator.sweep(/*classCountPtr*/);
+        hugeItemAllocator.sweep(classCountPtr);
+        icAllocator.sweep(/*classCountPtr*/);
+    }
 }
 
 bool MemoryManager::shouldRunGC() const
 {
-    size_t total = blockAllocator.totalSlots();
+    size_t total = blockAllocator.totalSlots() + icAllocator.totalSlots();
     if (total > MinSlotsGCLimit && usedSlotsAfterLastFullSweep * GCOverallocation < total * 100)
         return true;
     return false;
@@ -1110,9 +1050,10 @@ bool MemoryManager::shouldRunGC() const
 
 size_t dumpBins(BlockAllocator *b, bool printOutput = true)
 {
+    const QLoggingCategory &stats = lcGcAllocatorStats();
     size_t totalSlotMem = 0;
     if (printOutput)
-        qDebug() << "Slot map:";
+        qDebug(stats) << "Slot map:";
     for (uint i = 0; i < BlockAllocator::NumBins; ++i) {
         uint nEntries = 0;
         HeapItem *h = b->freeBins[i];
@@ -1122,7 +1063,7 @@ size_t dumpBins(BlockAllocator *b, bool printOutput = true)
             h = h->freeData.next;
         }
         if (printOutput)
-            qDebug() << "    number of entries in slot" << i << ":" << nEntries;
+            qDebug(stats) << "    number of entries in slot" << i << ":" << nEntries;
     }
     SDUMP() << "    large slot map";
     HeapItem *h = b->freeBins[BlockAllocator::NumBins - 1];
@@ -1132,7 +1073,7 @@ size_t dumpBins(BlockAllocator *b, bool printOutput = true)
     }
 
     if (printOutput)
-        qDebug() << "  total mem in bins" << totalSlotMem*Chunk::SlotSize;
+        qDebug(stats) << "  total mem in bins" << totalSlotMem*Chunk::SlotSize;
     return totalSlotMem*Chunk::SlotSize;
 }
 
@@ -1146,33 +1087,34 @@ void MemoryManager::runGC()
     QScopedValueRollback<bool> gcBlocker(gcBlocked, true);
 //    qDebug() << "runGC";
 
-    if (!gcStats) {
-//        uint oldUsed = allocator.usedMem();
+    if (gcStats) {
+        statistics.maxReservedMem = qMax(statistics.maxReservedMem, getAllocatedMem());
+        statistics.maxAllocatedMem = qMax(statistics.maxAllocatedMem, getUsedMem() + getLargeItemsMem());
+    }
+
+    if (!gcCollectorStats) {
         mark();
         sweep();
-//        DEBUG << "RUN GC: allocated:" << allocator.allocatedMem() << "used before" << oldUsed << "used now" << allocator.usedMem();
     } else {
         bool triggeredByUnmanagedHeap = (unmanagedHeapSize > unmanagedHeapSizeGCLimit);
         size_t oldUnmanagedSize = unmanagedHeapSize;
+
         const size_t totalMem = getAllocatedMem();
         const size_t usedBefore = getUsedMem();
         const size_t largeItemsBefore = getLargeItemsMem();
 
-        qDebug() << "========== GC ==========";
+        const QLoggingCategory &stats = lcGcAllocatorStats();
+        qDebug(stats) << "========== GC ==========";
 #ifdef MM_STATS
-        qDebug() << "    Triggered by alloc request of" << lastAllocRequestedSlots << "slots.";
-        qDebug() << "    Allocations since last GC" << allocationCount;
+        qDebug(stats) << "    Triggered by alloc request of" << lastAllocRequestedSlots << "slots.";
+        qDebug(stats) << "    Allocations since last GC" << allocationCount;
         allocationCount = 0;
 #endif
         size_t oldChunks = blockAllocator.chunks.size();
-        qDebug() << "Allocated" << totalMem << "bytes in" << oldChunks << "chunks";
-        qDebug() << "Fragmented memory before GC" << (totalMem - usedBefore);
+        qDebug(stats) << "Allocated" << totalMem << "bytes in" << oldChunks << "chunks";
+        qDebug(stats) << "Fragmented memory before GC" << (totalMem - usedBefore);
         dumpBins(&blockAllocator);
 
-#ifdef MM_STATS
-        nGrayItems = 0;
-#endif
-
         QElapsedTimer t;
         t.start();
         mark();
@@ -1184,15 +1126,15 @@ void MemoryManager::runGC()
         qint64 sweepTime = t.nsecsElapsed()/1000;
 
         if (triggeredByUnmanagedHeap) {
-            qDebug() << "triggered by unmanaged heap:";
-            qDebug() << "   old unmanaged heap size:" << oldUnmanagedSize;
-            qDebug() << "   new unmanaged heap:" << unmanagedHeapSize;
-            qDebug() << "   unmanaged heap limit:" << unmanagedHeapSizeGCLimit;
+            qDebug(stats) << "triggered by unmanaged heap:";
+            qDebug(stats) << "   old unmanaged heap size:" << oldUnmanagedSize;
+            qDebug(stats) << "   new unmanaged heap:" << unmanagedHeapSize;
+            qDebug(stats) << "   unmanaged heap limit:" << unmanagedHeapSizeGCLimit;
         }
         size_t memInBins = dumpBins(&blockAllocator);
-        qDebug() << "Marked object in" << markTime << "us.";
-        qDebug() << "   " << markStackSize << "objects marked";
-        qDebug() << "Sweeped object in" << sweepTime << "us.";
+        qDebug(stats) << "Marked object in" << markTime << "us.";
+        qDebug(stats) << "   " << markStackSize << "objects marked";
+        qDebug(stats) << "Sweeped object in" << sweepTime << "us.";
 
         // sort our object types by number of freed instances
         MMStatsHash freedObjectStats;
@@ -1207,46 +1149,51 @@ void MemoryManager::runGC()
             return a.second > b.second && strcmp(a.first, b.first) < 0;
         });
 
-        qDebug() << "Used memory before GC:" << usedBefore;
-        qDebug() << "Used memory after GC:" << usedAfter;
-        qDebug() << "Freed up bytes      :" << (usedBefore - usedAfter);
-        qDebug() << "Freed up chunks     :" << (oldChunks - blockAllocator.chunks.size());
+        qDebug(stats) << "Used memory before GC:" << usedBefore;
+        qDebug(stats) << "Used memory after GC:" << usedAfter;
+        qDebug(stats) << "Freed up bytes      :" << (usedBefore - usedAfter);
+        qDebug(stats) << "Freed up chunks     :" << (oldChunks - blockAllocator.chunks.size());
         size_t lost = blockAllocator.allocatedMem() - memInBins - usedAfter;
         if (lost)
-            qDebug() << "!!!!!!!!!!!!!!!!!!!!! LOST MEM:" << lost << "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!";
+            qDebug(stats) << "!!!!!!!!!!!!!!!!!!!!! LOST MEM:" << lost << "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!";
         if (largeItemsBefore || largeItemsAfter) {
-            qDebug() << "Large item memory before GC:" << largeItemsBefore;
-            qDebug() << "Large item memory after GC:" << largeItemsAfter;
-            qDebug() << "Large item memory freed up:" << (largeItemsBefore - largeItemsAfter);
+            qDebug(stats) << "Large item memory before GC:" << largeItemsBefore;
+            qDebug(stats) << "Large item memory after GC:" << largeItemsAfter;
+            qDebug(stats) << "Large item memory freed up:" << (largeItemsBefore - largeItemsAfter);
         }
 
         for (auto it = freedObjectsSorted.cbegin(); it != freedObjectsSorted.cend(); ++it) {
-            qDebug().noquote() << QString::fromLatin1("Freed JS type: %1 (%2 instances)").arg(QString::fromLatin1(it->first), QString::number(it->second));
+            qDebug(stats).noquote() << QString::fromLatin1("Freed JS type: %1 (%2 instances)").arg(QString::fromLatin1(it->first), QString::number(it->second));
         }
 
-        qDebug() << "======== End GC ========";
+        qDebug(stats) << "======== End GC ========";
     }
 
+    if (gcStats)
+        statistics.maxUsedMem = qMax(statistics.maxUsedMem, getUsedMem() + getLargeItemsMem());
+
     if (aggressiveGC) {
         // ensure we don't 'loose' any memory
-        Q_ASSERT(blockAllocator.allocatedMem() == getUsedMem() + dumpBins(&blockAllocator, false));
+        Q_ASSERT(blockAllocator.allocatedMem()
+                 == blockAllocator.usedMem() + dumpBins(&blockAllocator, false));
     }
 
-    usedSlotsAfterLastFullSweep = blockAllocator.usedSlotsAfterLastSweep;
+    usedSlotsAfterLastFullSweep = blockAllocator.usedSlotsAfterLastSweep + icAllocator.usedSlotsAfterLastSweep;
 
     // reset all black bits
     blockAllocator.resetBlackBits();
     hugeItemAllocator.resetBlackBits();
+    icAllocator.resetBlackBits();
 }
 
 size_t MemoryManager::getUsedMem() const
 {
-    return blockAllocator.usedMem();
+    return blockAllocator.usedMem() + icAllocator.usedMem();
 }
 
 size_t MemoryManager::getAllocatedMem() const
 {
-    return blockAllocator.allocatedMem() + hugeItemAllocator.usedMem();
+    return blockAllocator.allocatedMem() + icAllocator.allocatedMem() + hugeItemAllocator.usedMem();
 }
 
 size_t MemoryManager::getLargeItemsMem() const
@@ -1254,14 +1201,28 @@ size_t MemoryManager::getLargeItemsMem() const
     return hugeItemAllocator.usedMem();
 }
 
+void MemoryManager::registerWeakMap(Heap::MapObject *map)
+{
+    map->nextWeakMap = weakMaps;
+    weakMaps = map;
+}
+
+void MemoryManager::registerWeakSet(Heap::SetObject *set)
+{
+    set->nextWeakSet = weakSets;
+    weakSets = set;
+}
+
 MemoryManager::~MemoryManager()
 {
     delete m_persistentValues;
 
+    dumpStats();
+
     sweep(/*lastSweep*/true);
     blockAllocator.freeAll();
     hugeItemAllocator.freeAll();
-    stackAllocator.freeAll();
+    icAllocator.freeAll();
 
     delete m_weakValues;
 #ifdef V4_USE_VALGRIND
@@ -1273,39 +1234,31 @@ MemoryManager::~MemoryManager()
 
 void MemoryManager::dumpStats() const
 {
-#ifdef DETAILED_MM_STATS
-    std::cerr << "=================" << std::endl;
-    std::cerr << "Allocation stats:" << std::endl;
-    std::cerr << "Requests for each chunk size:" << std::endl;
-    for (int i = 0; i < allocSizeCounters.size(); ++i) {
-        if (unsigned count = allocSizeCounters[i]) {
-            std::cerr << "\t" << (i << 4) << " bytes chunks: " << count << std::endl;
-        }
-    }
-#endif // DETAILED_MM_STATS
-}
+    if (!gcStats)
+        return;
 
-#ifdef DETAILED_MM_STATS
-void MemoryManager::willAllocate(std::size_t size)
-{
-    unsigned alignedSize = (size + 15) >> 4;
-    QVector<unsigned> &counters = allocSizeCounters;
-    if ((unsigned) counters.size() < alignedSize + 1)
-        counters.resize(alignedSize + 1);
-    counters[alignedSize]++;
+    const QLoggingCategory &stats = lcGcStats();
+    qDebug(stats) << "Qml GC memory allocation statistics:";
+    qDebug(stats) << "Total memory allocated:" << statistics.maxReservedMem;
+    qDebug(stats) << "Max memory used before a GC run:" << statistics.maxAllocatedMem;
+    qDebug(stats) << "Max memory used after a GC run:" << statistics.maxUsedMem;
+    qDebug(stats) << "Requests for different item sizes:";
+    for (int i = 1; i < BlockAllocator::NumBins - 1; ++i)
+        qDebug(stats) << "     <" << (i << Chunk::SlotSizeShift) << " bytes: " << statistics.allocations[i];
+    qDebug(stats) << "     >=" << ((BlockAllocator::NumBins - 1) << Chunk::SlotSizeShift) << " bytes: " << statistics.allocations[BlockAllocator::NumBins - 1];
 }
 
-#endif // DETAILED_MM_STATS
-
 void MemoryManager::collectFromJSStack(MarkStack *markStack) const
 {
     Value *v = engine->jsStackBase;
     Value *top = engine->jsStackTop;
     while (v < top) {
         Managed *m = v->managed();
-        if (m && m->inUse())
+        if (m) {
+            Q_ASSERT(m->inUse());
             // Skip pointers to already freed objects, they are bogus as well
             m->mark(markStack);
+        }
         ++v;
     }
 }
diff --git a/src/qml/memory/qv4mm_p.h b/src/qml/memory/qv4mm_p.h
index 17957d0cd6..bbbbb1aef6 100644
--- a/src/qml/memory/qv4mm_p.h
+++ b/src/qml/memory/qv4mm_p.h
@@ -58,8 +58,6 @@
 #include <private/qv4mmdefs_p.h>
 #include <QVector>
 
-//#define DETAILED_MM_STATS
-
 #define QV4_MM_MAXBLOCK_SHIFT "QV4_MM_MAXBLOCK_SHIFT"
 #define QV4_MM_MAX_CHUNK_SIZE "QV4_MM_MAX_CHUNK_SIZE"
 #define QV4_MM_STATS "QV4_MM_STATS"
@@ -71,60 +69,13 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 struct ChunkAllocator;
-
-template<typename T>
-struct StackAllocator {
-    Q_STATIC_ASSERT(sizeof(T) < Chunk::DataSize);
-    static const uint requiredSlots = (sizeof(T) + sizeof(HeapItem) - 1)/sizeof(HeapItem);
-
-    StackAllocator(ChunkAllocator *chunkAlloc);
-
-    T *allocate() {
-        HeapItem *m = nextFree;
-        if (Q_UNLIKELY(nextFree == lastInChunk)) {
-            nextChunk();
-        } else {
-            nextFree += requiredSlots;
-        }
-#if MM_DEBUG || !defined(QT_NO_DEBUG) || defined(QT_FORCE_ASSERTS)
-        Chunk *c = m->chunk();
-        Chunk::setBit(c->objectBitmap, m - c->realBase());
-#endif
-        return m->as<T>();
-    }
-    void free() {
-        if (Q_UNLIKELY(nextFree == firstInChunk)) {
-            prevChunk();
-        } else {
-            nextFree -= requiredSlots;
-        }
-#if MM_DEBUG || !defined(QT_NO_DEBUG) || defined(QT_FORCE_ASSERTS)
-        Chunk *c = nextFree->chunk();
-        Chunk::clearBit(c->objectBitmap, nextFree - c->realBase());
-#endif
-    }
-
-    void nextChunk();
-    void prevChunk();
-
-    void freeAll();
-
-    ChunkAllocator *chunkAllocator;
-    HeapItem *nextFree = 0;
-    HeapItem *firstInChunk = 0;
-    HeapItem *lastInChunk = 0;
-    std::vector<Chunk *> chunks;
-    uint currentChunk = 0;
-};
+struct MemorySegment;
 
 struct BlockAllocator {
-    BlockAllocator(ChunkAllocator *chunkAllocator)
-        : chunkAllocator(chunkAllocator)
+    BlockAllocator(ChunkAllocator *chunkAllocator, ExecutionEngine *engine)
+        : chunkAllocator(chunkAllocator), engine(engine)
     {
         memset(freeBins, 0, sizeof(freeBins));
-#if MM_DEBUG
-        memset(allocations, 0, sizeof(allocations));
-#endif
     }
 
     enum { NumBins = 8 };
@@ -133,10 +84,6 @@ struct BlockAllocator {
         return nSlots >= NumBins ? NumBins - 1 : nSlots;
     }
 
-#if MM_DEBUG
-    void stats();
-#endif
-
     HeapItem *allocate(size_t size, bool forceAllocation = false);
 
     size_t totalSlots() const {
@@ -153,26 +100,25 @@ struct BlockAllocator {
         return used;
     }
 
-    void sweep(ClassDestroyStatsCallback classCountPtr);
+    void sweep();
     void freeAll();
     void resetBlackBits();
     void collectGrayItems(MarkStack *markStack);
 
     // bump allocations
-    HeapItem *nextFree = 0;
+    HeapItem *nextFree = nullptr;
     size_t nFree = 0;
     size_t usedSlotsAfterLastSweep = 0;
     HeapItem *freeBins[NumBins];
     ChunkAllocator *chunkAllocator;
+    ExecutionEngine *engine;
     std::vector<Chunk *> chunks;
-#if MM_DEBUG
-    uint allocations[NumBins];
-#endif
+    uint *allocationStats = nullptr;
 };
 
 struct HugeItemAllocator {
-    HugeItemAllocator(ChunkAllocator *chunkAllocator)
-        : chunkAllocator(chunkAllocator)
+    HugeItemAllocator(ChunkAllocator *chunkAllocator, ExecutionEngine *engine)
+        : chunkAllocator(chunkAllocator), engine(engine)
     {}
 
     HeapItem *allocate(size_t size);
@@ -189,7 +135,9 @@ struct HugeItemAllocator {
     }
 
     ChunkAllocator *chunkAllocator;
+    ExecutionEngine *engine;
     struct HugeChunk {
+        MemorySegment *segment;
         Chunk *chunk;
         size_t size;
     };
@@ -211,226 +159,99 @@ public:
     Q_DECL_CONSTEXPR static inline std::size_t align(std::size_t size)
     { return (size + Chunk::SlotSize - 1) & ~(Chunk::SlotSize - 1); }
 
-    QV4::Heap::CallContext *allocSimpleCallContext()
+    template<typename ManagedType>
+    inline typename ManagedType::Data *allocManaged(std::size_t size, Heap::InternalClass *ic)
     {
-        Heap::CallContext *ctxt = stackAllocator.allocate();
-        memset(ctxt, 0, sizeof(Heap::SimpleCallContext));
-        ctxt->internalClass = SimpleCallContext::defaultInternalClass(engine);
-        Q_ASSERT(ctxt->internalClass && ctxt->internalClass->vtable);
-        ctxt->init();
-        return ctxt;
+        Q_STATIC_ASSERT(std::is_trivial< typename ManagedType::Data >::value);
+        size = align(size);
+        typename ManagedType::Data *d = static_cast<typename ManagedType::Data *>(allocData(size));
+        d->internalClass.set(engine, ic);
+        Q_ASSERT(d->internalClass && d->internalClass->vtable);
+        Q_ASSERT(ic->vtable == ManagedType::staticVTable());
+        return d;
+    }
 
+    template<typename ManagedType>
+    inline typename ManagedType::Data *allocManaged(std::size_t size, InternalClass *ic)
+    {
+        return allocManaged<ManagedType>(size, ic->d());
     }
-    void freeSimpleCallContext()
-    { stackAllocator.free(); }
 
     template<typename ManagedType>
     inline typename ManagedType::Data *allocManaged(std::size_t size)
     {
-        V4_ASSERT_IS_TRIVIAL(typename ManagedType::Data)
-        size = align(size);
-        Heap::Base *o = allocData(size);
-        InternalClass *ic = ManagedType::defaultInternalClass(engine);
-        ic = ic->changeVTable(ManagedType::staticVTable());
-        o->internalClass = ic;
-        Q_ASSERT(o->internalClass && o->internalClass->vtable);
-        return static_cast<typename ManagedType::Data *>(o);
+        Scope scope(engine);
+        Scoped<InternalClass> ic(scope, ManagedType::defaultInternalClass(engine));
+        return allocManaged<ManagedType>(size, ic);
     }
 
     template <typename ObjectType>
-    typename ObjectType::Data *allocateObject(InternalClass *ic)
+    typename ObjectType::Data *allocateObject(Heap::InternalClass *ic)
     {
         Heap::Object *o = allocObjectWithMemberData(ObjectType::staticVTable(), ic->size);
-        o->internalClass = ic;
-        Q_ASSERT(o->internalClass && o->internalClass->vtable);
-        Q_ASSERT(ic->vtable == ObjectType::staticVTable());
+        o->internalClass.set(engine, ic);
+        Q_ASSERT(o->internalClass.get() && o->vtable());
+        Q_ASSERT(o->vtable() == ObjectType::staticVTable());
         return static_cast<typename ObjectType::Data *>(o);
     }
 
     template <typename ObjectType>
+    typename ObjectType::Data *allocateObject(InternalClass *ic)
+    {
+        return allocateObject<ObjectType>(ic->d());
+    }
+
+    template <typename ObjectType>
     typename ObjectType::Data *allocateObject()
     {
-        InternalClass *ic = ObjectType::defaultInternalClass(engine);
+        Scope scope(engine);
+        Scoped<InternalClass> ic(scope,  ObjectType::defaultInternalClass(engine));
         ic = ic->changeVTable(ObjectType::staticVTable());
         ic = ic->changePrototype(ObjectType::defaultPrototype(engine)->d());
-        Heap::Object *o = allocObjectWithMemberData(ObjectType::staticVTable(), ic->size);
-        o->internalClass = ic;
-        Q_ASSERT(o->internalClass && o->internalClass->vtable);
-        Q_ASSERT(o->internalClass->prototype == ObjectType::defaultPrototype(engine)->d());
-        return static_cast<typename ObjectType::Data *>(o);
+        return allocateObject<ObjectType>(ic);
     }
 
     template <typename ManagedType, typename Arg1>
     typename ManagedType::Data *allocWithStringData(std::size_t unmanagedSize, Arg1 arg1)
     {
         typename ManagedType::Data *o = reinterpret_cast<typename ManagedType::Data *>(allocString(unmanagedSize));
-        o->internalClass = ManagedType::defaultInternalClass(engine);
+        o->internalClass.set(engine, ManagedType::defaultInternalClass(engine));
         Q_ASSERT(o->internalClass && o->internalClass->vtable);
         o->init(arg1);
         return o;
     }
 
-    template <typename ObjectType>
-    typename ObjectType::Data *allocObject(InternalClass *ic)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->init();
-        return t->d();
-    }
-
-    template <typename ObjectType>
-    typename ObjectType::Data *allocObject(InternalClass *ic, Object *prototype)
+    template <typename ObjectType, typename... Args>
+    typename ObjectType::Data *allocObject(Heap::InternalClass *ic, Args... args)
     {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        Q_ASSERT(t->internalClass()->prototype == (prototype ? prototype->d() : 0));
-        Q_UNUSED(prototype);
-        t->d_unchecked()->init();
-        return t->d();
+        typename ObjectType::Data *d = allocateObject<ObjectType>(ic);
+        d->init(args...);
+        return d;
     }
 
-    template <typename ObjectType, typename Arg1>
-    typename ObjectType::Data *allocObject(InternalClass *ic, Object *prototype, Arg1 arg1)
+    template <typename ObjectType, typename... Args>
+    typename ObjectType::Data *allocObject(InternalClass *ic, Args... args)
     {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        Q_ASSERT(t->internalClass()->prototype == (prototype ? prototype->d() : 0));
-        Q_UNUSED(prototype);
-        t->d_unchecked()->init(arg1);
-        return t->d();
+        typename ObjectType::Data *d = allocateObject<ObjectType>(ic);
+        d->init(args...);
+        return d;
     }
 
-    template <typename ObjectType, typename Arg1, typename Arg2>
-    typename ObjectType::Data *allocObject(InternalClass *ic, Object *prototype, Arg1 arg1, Arg2 arg2)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        Q_ASSERT(t->internalClass()->prototype == (prototype ? prototype->d() : 0));
-        Q_UNUSED(prototype);
-        t->d_unchecked()->init(arg1, arg2);
-        return t->d();
-    }
-
-    template <typename ObjectType, typename Arg1, typename Arg2, typename Arg3>
-    typename ObjectType::Data *allocObject(InternalClass *ic, Object *prototype, Arg1 arg1, Arg2 arg2, Arg3 arg3)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        Q_ASSERT(t->internalClass()->prototype == (prototype ? prototype->d() : 0));
-        Q_UNUSED(prototype);
-        t->d_unchecked()->init(arg1, arg2, arg3);
-        return t->d();
-    }
-
-    template <typename ObjectType, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
-    typename ObjectType::Data *allocObject(InternalClass *ic, Object *prototype, Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        Q_ASSERT(t->internalClass()->prototype == (prototype ? prototype->d() : 0));
-        Q_UNUSED(prototype);
-        t->d_unchecked()->init(arg1, arg2, arg3, arg4);
-        return t->d();
-    }
-
-    template <typename ObjectType>
-    typename ObjectType::Data *allocObject()
+    template <typename ObjectType, typename... Args>
+    typename ObjectType::Data *allocate(Args... args)
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>());
-        t->d_unchecked()->init();
+        t->d_unchecked()->init(args...);
         return t->d();
     }
 
-    template <typename ObjectType, typename Arg1>
-    typename ObjectType::Data *allocObject(Arg1 arg1)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>());
-        t->d_unchecked()->init(arg1);
-        return t->d();
-    }
-
-    template <typename ObjectType, typename Arg1, typename Arg2>
-    typename ObjectType::Data *allocObject(Arg1 arg1, Arg2 arg2)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>());
-        t->d_unchecked()->init(arg1, arg2);
-        return t->d();
-    }
-
-    template <typename ObjectType, typename Arg1, typename Arg2, typename Arg3>
-    typename ObjectType::Data *allocObject(Arg1 arg1, Arg2 arg2, Arg3 arg3)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>());
-        t->d_unchecked()->init(arg1, arg2, arg3);
-        return t->d();
-    }
-
-    template <typename ObjectType, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
-    typename ObjectType::Data *allocObject(Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4)
-    {
-        Scope scope(engine);
-        Scoped<ObjectType> t(scope, allocateObject<ObjectType>());
-        t->d_unchecked()->init(arg1, arg2, arg3, arg4);
-        return t->d();
-    }
-
-
-    template <typename ManagedType>
-    typename ManagedType::Data *alloc()
+    template <typename ManagedType, typename... Args>
+    typename ManagedType::Data *alloc(Args... args)
     {
         Scope scope(engine);
         Scoped<ManagedType> t(scope, allocManaged<ManagedType>(sizeof(typename ManagedType::Data)));
-        t->d_unchecked()->init();
-        return t->d();
-    }
-
-    template <typename ManagedType, typename Arg1>
-    typename ManagedType::Data *alloc(Arg1 arg1)
-    {
-        Scope scope(engine);
-        Scoped<ManagedType> t(scope, allocManaged<ManagedType>(sizeof(typename ManagedType::Data)));
-        t->d_unchecked()->init(arg1);
-        return t->d();
-    }
-
-    template <typename ManagedType, typename Arg1, typename Arg2>
-    typename ManagedType::Data *alloc(Arg1 arg1, Arg2 arg2)
-    {
-        Scope scope(engine);
-        Scoped<ManagedType> t(scope, allocManaged<ManagedType>(sizeof(typename ManagedType::Data)));
-        t->d_unchecked()->init(arg1, arg2);
-        return t->d();
-    }
-
-    template <typename ManagedType, typename Arg1, typename Arg2, typename Arg3>
-    typename ManagedType::Data *alloc(Arg1 arg1, Arg2 arg2, Arg3 arg3)
-    {
-        Scope scope(engine);
-        Scoped<ManagedType> t(scope, allocManaged<ManagedType>(sizeof(typename ManagedType::Data)));
-        t->d_unchecked()->init(arg1, arg2, arg3);
-        return t->d();
-    }
-
-    template <typename ManagedType, typename Arg1, typename Arg2, typename Arg3, typename Arg4>
-    typename ManagedType::Data *alloc(Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4)
-    {
-        Scope scope(engine);
-        Scoped<ManagedType> t(scope, allocManaged<ManagedType>(sizeof(typename ManagedType::Data)));
-        t->d_unchecked()->init(arg1, arg2, arg3, arg4);
-        return t->d();
-    }
-
-    template <typename ManagedType, typename Arg1, typename Arg2, typename Arg3, typename Arg4, typename Arg5>
-    typename ManagedType::Data *alloc(Arg1 arg1, Arg2 arg2, Arg3 arg3, Arg4 arg4, Arg5 arg5)
-    {
-        Scope scope(engine);
-        Scoped<ManagedType> t(scope, allocManaged<ManagedType>(sizeof(typename ManagedType::Data)));
-        t->d_unchecked()->init(arg1, arg2, arg3, arg4, arg5);
+        t->d_unchecked()->init(args...);
         return t->d();
     }
 
@@ -445,16 +266,23 @@ public:
     // called when a JS object grows itself. Specifically: Heap::String::append
     void changeUnmanagedHeapSizeUsage(qptrdiff delta) { unmanagedHeapSize += delta; }
 
+    template<typename ManagedType>
+    typename ManagedType::Data *allocIC()
+    {
+        size_t size = align(sizeof(typename ManagedType::Data));
+        Heap::Base *b = *icAllocator.allocate(size, true);
+        return static_cast<typename ManagedType::Data *>(b);
+    }
+
+    void registerWeakMap(Heap::MapObject *map);
+    void registerWeakSet(Heap::SetObject *set);
+
 protected:
     /// expects size to be aligned
     Heap::Base *allocString(std::size_t unmanagedSize);
     Heap::Base *allocData(std::size_t size);
     Heap::Object *allocObjectWithMemberData(const QV4::VTable *vtable, uint nMembers);
 
-#ifdef DETAILED_MM_STATS
-    void willAllocate(std::size_t size);
-#endif // DETAILED_MM_STATS
-
 private:
     void collectFromJSStack(MarkStack *markStack) const;
     void mark();
@@ -465,12 +293,14 @@ private:
 public:
     QV4::ExecutionEngine *engine;
     ChunkAllocator *chunkAllocator;
-    StackAllocator<Heap::CallContext> stackAllocator;
     BlockAllocator blockAllocator;
+    BlockAllocator icAllocator;
     HugeItemAllocator hugeItemAllocator;
     PersistentValueStorage *m_persistentValues;
     PersistentValueStorage *m_weakValues;
     QVector<Value *> m_pendingFreedObjectWrapperValue;
+    Heap::MapObject *weakMaps = nullptr;
+    Heap::SetObject *weakSets = nullptr;
 
     std::size_t unmanagedHeapSize = 0; // the amount of bytes of heap that is not managed by the memory manager, but which is held onto by managed items.
     std::size_t unmanagedHeapSizeGCLimit;
@@ -479,6 +309,17 @@ public:
     bool gcBlocked = false;
     bool aggressiveGC = false;
     bool gcStats = false;
+    bool gcCollectorStats = false;
+
+    int allocationCount = 0;
+    size_t lastAllocRequestedSlots = 0;
+
+    struct {
+        size_t maxReservedMem = 0;
+        size_t maxAllocatedMem = 0;
+        size_t maxUsedMem = 0;
+        uint allocations[BlockAllocator::NumBins];
+    } statistics;
 };
 
 }
diff --git a/src/qml/memory/qv4mmdefs_p.h b/src/qml/memory/qv4mmdefs_p.h
index 328797fb5e..8a53492822 100644
--- a/src/qml/memory/qv4mmdefs_p.h
+++ b/src/qml/memory/qv4mmdefs_p.h
@@ -187,9 +187,10 @@ struct Chunk {
     }
 
     bool sweep(ClassDestroyStatsCallback classCountPtr);
-    void freeAll();
     void resetBlackBits();
     void collectGrayItems(QV4::MarkStack *markStack);
+    bool sweep(ExecutionEngine *engine);
+    void freeAll(ExecutionEngine *engine);
 
     void sortIntoBins(HeapItem **bins, uint nBins);
 };
@@ -271,9 +272,9 @@ Q_STATIC_ASSERT((1 << Chunk::BitShift) == Chunk::Bits);
 
 struct MarkStack {
     MarkStack(ExecutionEngine *engine);
-    Heap::Base **top = 0;
-    Heap::Base **base = 0;
-    Heap::Base **limit = 0;
+    Heap::Base **top = nullptr;
+    Heap::Base **base = nullptr;
+    Heap::Base **limit = nullptr;
     ExecutionEngine *engine;
     void push(Heap::Base *m) {
         *top = m;
@@ -287,32 +288,8 @@ struct MarkStack {
 
 };
 
-// Some helper classes and macros to automate the generation of our
-// tables used for marking objects
-
-enum MarkFlags {
-    Mark_NoMark = 0,
-    Mark_Value = 1,
-    Mark_Pointer = 2,
-    Mark_ValueArray = 3
-};
-
-template <typename T>
-struct MarkFlagEvaluator {
-    static Q_CONSTEXPR quint64 value = 0;
-};
-template <typename T, size_t o>
-struct MarkFlagEvaluator<Heap::Pointer<T, o>> {
-    static Q_CONSTEXPR quint64 value = static_cast<quint64>(Mark_Pointer) << (2*o / sizeof(quintptr));
-};
-template <size_t o>
-struct MarkFlagEvaluator<ValueArray<o>> {
-    static Q_CONSTEXPR quint64 value = static_cast<quint64>(Mark_ValueArray) << (2*o / sizeof(quintptr));
-};
-template <size_t o>
-struct MarkFlagEvaluator<HeapValue<o>> {
-    static Q_CONSTEXPR quint64 value = static_cast<quint64>(Mark_Value) << (2 *o / sizeof(quintptr));
-};
+// Some helper to automate the generation of our
+// functions used for marking objects
 
 #define HEAP_OBJECT_OFFSET_MEMBER_EXPANSION(c, gcType, type, name) \
     HEAP_OBJECT_OFFSET_MEMBER_EXPANSION_##gcType(c, type, name)
@@ -334,25 +311,42 @@ struct MarkFlagEvaluator<HeapValue<o>> {
 #define HEAP_OBJECT_MEMBER_EXPANSION_ValueArray(c, type, name) \
     type<offsetof(c##OffsetStruct, name) + baseOffset> name;
 
-#define HEAP_OBJECT_MARK_EXPANSION(class, gcType, type, name) \
-    MarkFlagEvaluator<decltype(class::name)>::value |
+#define HEAP_OBJECT_MARKOBJECTS_EXPANSION(c, gcType, type, name) \
+    HEAP_OBJECT_MARKOBJECTS_EXPANSION_##gcType(c, type, name)
+#define HEAP_OBJECT_MARKOBJECTS_EXPANSION_Pointer(c, type, name) \
+    if (o->name) o->name.heapObject()->mark(stack);
+#define HEAP_OBJECT_MARKOBJECTS_EXPANSION_NoMark(c, type, name)
+#define HEAP_OBJECT_MARKOBJECTS_EXPANSION_HeapValue(c, type, name) \
+    o->name.mark(stack);
+#define HEAP_OBJECT_MARKOBJECTS_EXPANSION_ValueArray(c, type, name) \
+    o->name.mark(stack);
+
+
+#define DECLARE_HEAP_OBJECT_BASE(name, base) \
+    struct name##OffsetStruct { \
+        name##Members(name, HEAP_OBJECT_OFFSET_MEMBER_EXPANSION) \
+    }; \
+    struct name##SizeStruct : base, name##OffsetStruct {}; \
+    struct name##Data { \
+        typedef base SuperClass; \
+        static Q_CONSTEXPR size_t baseOffset = sizeof(name##SizeStruct) - sizeof(name##OffsetStruct); \
+        name##Members(name, HEAP_OBJECT_MEMBER_EXPANSION) \
+    }; \
+    Q_STATIC_ASSERT(sizeof(name##SizeStruct) == sizeof(name##Data) + name##Data::baseOffset); \
 
 #define DECLARE_HEAP_OBJECT(name, base) \
-struct name##OffsetStruct { \
-    name##Members(name, HEAP_OBJECT_OFFSET_MEMBER_EXPANSION) \
-}; \
-struct name##SizeStruct : base, name##OffsetStruct {}; \
-struct name##Data { \
-    static Q_CONSTEXPR size_t baseOffset = sizeof(name##SizeStruct) - sizeof(name##OffsetStruct); \
-    name##Members(name, HEAP_OBJECT_MEMBER_EXPANSION) \
-}; \
-Q_STATIC_ASSERT(sizeof(name##SizeStruct) == sizeof(name##Data) + name##Data::baseOffset); \
-static Q_CONSTEXPR quint64 name##_markTable = \
-    (name##Members(name##Data, HEAP_OBJECT_MARK_EXPANSION) 0) | QV4::Heap::base::markTable; \
-    \
-struct name : base, name##Data
-
-#define DECLARE_MARK_TABLE(class) static Q_CONSTEXPR quint64 markTable = class##_markTable
+    DECLARE_HEAP_OBJECT_BASE(name, base) \
+    struct name : base, name##Data
+#define DECLARE_EXPORTED_HEAP_OBJECT(name, base) \
+    DECLARE_HEAP_OBJECT_BASE(name, base) \
+    struct Q_QML_EXPORT name : base, name##Data
+
+#define DECLARE_MARKOBJECTS(class) \
+    static void markObjects(Heap::Base *b, MarkStack *stack) { \
+        class *o = static_cast<class *>(b); \
+        class##Data::SuperClass::markObjects(o, stack); \
+        class##Members(class, HEAP_OBJECT_MARKOBJECTS_EXPANSION) \
+    }
 
 }
 
diff --git a/src/qml/memory/qv4writebarrier_p.h b/src/qml/memory/qv4writebarrier_p.h
index 3182fd2aa9..8b04aa6cb1 100644
--- a/src/qml/memory/qv4writebarrier_p.h
+++ b/src/qml/memory/qv4writebarrier_p.h
@@ -51,7 +51,7 @@
 //
 
 #include <private/qv4global_p.h>
-#include <private/qv4value_p.h>
+#include <private/qv4enginebase_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -84,14 +84,7 @@ static Q_CONSTEXPR inline bool isRequired() {
     return false;
 }
 
-inline void write(EngineBase *engine, Heap::Base *base, Value *slot, Value value)
-{
-    Q_UNUSED(engine);
-    Q_UNUSED(base);
-    *slot = value;
-}
-
-inline void write(EngineBase *engine, Heap::Base *base, Value *slot, Heap::Base *value)
+inline void write(EngineBase *engine, Heap::Base *base, ReturnedValue *slot, ReturnedValue value)
 {
     Q_UNUSED(engine);
     Q_UNUSED(base);
@@ -109,96 +102,6 @@ inline void write(EngineBase *engine, Heap::Base *base, Heap::Base **slot, Heap:
 
 }
 
-namespace Heap {
-
-template <typename T, size_t o>
-struct Pointer {
-    static Q_CONSTEXPR size_t offset = o;
-    T operator->() const { return ptr; }
-    operator T () const { return ptr; }
-
-    Heap::Base *base() {
-        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
-        Q_ASSERT(base->inUse());
-        return base;
-    }
-
-    void set(ExecutionEngine *e, T newVal) {
-        WriteBarrier::write(e, base(), reinterpret_cast<Heap::Base **>(&ptr), reinterpret_cast<Heap::Base *>(newVal));
-    }
-
-    template <typename Type>
-    Type *cast() { return static_cast<Type *>(ptr); }
-
-private:
-    T ptr;
-};
-typedef Pointer<char *, 0> V4PointerCheck;
-V4_ASSERT_IS_TRIVIAL(V4PointerCheck)
-
-}
-
-template <size_t offset>
-struct HeapValue : Value {
-    Heap::Base *base() {
-        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
-        Q_ASSERT(base->inUse());
-        return base;
-    }
-
-    void set(ExecutionEngine *e, const Value &newVal) {
-        WriteBarrier::write(e, base(), this, newVal);
-    }
-    void set(ExecutionEngine *e, Heap::Base *b) {
-        WriteBarrier::write(e, base(), this, b);
-    }
-};
-
-template <size_t offset>
-struct ValueArray {
-    uint size;
-    uint alloc;
-    Value values[1];
-
-    Heap::Base *base() {
-        Heap::Base *base = reinterpret_cast<Heap::Base *>(this) - (offset/sizeof(Heap::Base));
-        Q_ASSERT(base->inUse());
-        return base;
-    }
-
-    void set(ExecutionEngine *e, uint index, Value v) {
-        WriteBarrier::write(e, base(), values + index, v);
-    }
-    void set(ExecutionEngine *e, uint index, Heap::Base *b) {
-        WriteBarrier::write(e, base(), values + index, b);
-    }
-    inline const Value &operator[] (uint index) const {
-        Q_ASSERT(index < alloc);
-        return values[index];
-    }
-    inline const Value *data() const {
-        return values;
-    }
-
-    void insertData(ExecutionEngine *e, uint index, Value v) {
-        for (uint i = size - 1; i > index; --i) {
-            values[i] = values[i - 1];
-        }
-        set(e, index, v);
-    }
-    void removeData(ExecutionEngine *e, uint index, int n = 1) {
-        Q_UNUSED(e);
-        for (uint i = index; i < size - n; ++i) {
-            values[i] = values[i + n];
-        }
-    }
-};
-
-// It's really important that the offset of values in this structure is
-// constant across all architecture,  otherwise JIT cross-compiled code will
-// have wrong offsets between host and target.
-Q_STATIC_ASSERT(offsetof(ValueArray<0>, values) == 8);
-
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/parser/parser.pri b/src/qml/parser/parser.pri
index e5b8ae2749..2c0175c94b 100644
--- a/src/qml/parser/parser.pri
+++ b/src/qml/parser/parser.pri
@@ -3,20 +3,25 @@ HEADERS += \
     $$PWD/qqmljsastfwd_p.h \
     $$PWD/qqmljsastvisitor_p.h \
     $$PWD/qqmljsengine_p.h \
-    $$PWD/qqmljsgrammar_p.h \
     $$PWD/qqmljslexer_p.h \
     $$PWD/qqmljsmemorypool_p.h \
-    $$PWD/qqmljsparser_p.h \
     $$PWD/qqmljsglobal_p.h \
     $$PWD/qqmljskeywords_p.h \
+    $$PWD/qqmljsengine_p.h \
+    $$PWD/qqmljsglobal_p.h \
+    $$PWD/qqmljssourcelocation_p.h
 
 SOURCES += \
     $$PWD/qqmljsast.cpp \
     $$PWD/qqmljsastvisitor.cpp \
     $$PWD/qqmljsengine_p.cpp \
-    $$PWD/qqmljsgrammar.cpp \
     $$PWD/qqmljslexer.cpp \
-    $$PWD/qqmljsparser.cpp \
 
-OTHER_FILES += \
-    $$PWD/qqmljs.g
+CONFIG += qlalr
+QLALRSOURCES = $$PWD/qqmljs.g
+QMAKE_QLALRFLAGS = --no-debug --qt
+
+OTHER_FILES += $$QLALRSOURCES
+
+# make sure we install the headers generated by qlalr
+private_headers.CONFIG += no_check_exist
diff --git a/src/qml/parser/qqmljs.g b/src/qml/parser/qqmljs.g
index ca84e0c157..b86dba6daa 100644
--- a/src/qml/parser/qqmljs.g
+++ b/src/qml/parser/qqmljs.g
@@ -40,8 +40,7 @@
 %parser         QQmlJSGrammar
 %decl           qqmljsparser_p.h
 %impl           qqmljsparser.cpp
-%expect         5
-%expect-rr      2
+%expect         1
 
 %token T_AND "&"                T_AND_AND "&&"              T_AND_EQ "&="
 %token T_BREAK "break"          T_CASE "case"               T_CATCH "catch"
@@ -64,7 +63,8 @@
 %token T_RBRACE "}"             T_RBRACKET "]"              T_REMAINDER "%"
 %token T_REMAINDER_EQ "%="      T_RETURN "return"           T_RPAREN ")"
 %token T_SEMICOLON ";"          T_AUTOMATIC_SEMICOLON       T_STAR "*"
-%token T_STAR_EQ "*="           T_STRING_LITERAL "string literal"
+%token T_STAR_STAR "**"         T_STAR_STAR_EQ "**="        T_STAR_EQ "*="
+%token T_STRING_LITERAL "string literal"
 %token T_PROPERTY "property"    T_SIGNAL "signal"           T_READONLY "readonly"
 %token T_SWITCH "switch"        T_THIS "this"               T_THROW "throw"
 %token T_TILDE "~"              T_TRY "try"                 T_TYPEOF "typeof"
@@ -77,13 +77,29 @@
 %token T_MULTILINE_STRING_LITERAL "multiline string literal"
 %token T_COMMENT "comment"
 %token T_COMPATIBILITY_SEMICOLON
+%token T_ARROW "=>"
+%token T_ENUM "enum"
+%token T_ELLIPSIS "..."
+%token T_YIELD "yield"
+%token T_SUPER "super"
+%token T_CLASS "class"
+%token T_EXTENDS "extends"
+%token T_STATIC "static"
+%token T_EXPORT "export"
+%token T_FROM "from"
+
+--- template strings
+%token T_NO_SUBSTITUTION_TEMPLATE"(no subst template)"
+%token T_TEMPLATE_HEAD "(template head)"
+%token T_TEMPLATE_MIDDLE "(template middle)"
+%token T_TEMPLATE_TAIL "(template tail)"
 
 --- context keywords.
 %token T_PUBLIC "public"
 %token T_IMPORT "import"
 %token T_PRAGMA "pragma"
 %token T_AS "as"
-%token T_ON "on"
+%token T_OF "of"
 %token T_GET "get"
 %token T_SET "set"
 
@@ -94,11 +110,16 @@
 %token T_FEED_UI_OBJECT_MEMBER
 %token T_FEED_JS_STATEMENT
 %token T_FEED_JS_EXPRESSION
-%token T_FEED_JS_SOURCE_ELEMENT
-%token T_FEED_JS_PROGRAM
+%token T_FEED_JS_SCRIPT
+%token T_FEED_JS_MODULE
 
-%nonassoc SHIFT_THERE
-%nonassoc T_IDENTIFIER T_COLON T_SIGNAL T_PROPERTY T_READONLY T_ON T_SET T_GET
+--- Lookahead handling
+%token T_FORCE_DECLARATION "(force decl)"
+%token T_FORCE_BLOCK "(force block)"
+%token T_FOR_LOOKAHEAD_OK "(for lookahead ok)"
+
+--%left T_PLUS T_MINUS
+%nonassoc T_IDENTIFIER T_COLON T_SIGNAL T_PROPERTY T_READONLY T_ON T_SET T_GET T_OF T_STATIC T_FROM T_AS
 %nonassoc REDUCE_HERE
 
 %start TopLevel
@@ -142,10 +163,10 @@
 **
 ****************************************************************************/
 
-#include "qqmljsengine_p.h"
-#include "qqmljslexer_p.h"
-#include "qqmljsast_p.h"
-#include "qqmljsmemorypool_p.h"
+#include <private/qqmljsengine_p.h>
+#include <private/qqmljslexer_p.h>
+#include <private/qqmljsast_p.h>
+#include <private/qqmljsmemorypool_p.h>
 
 #include <QtCore/qdebug.h>
 #include <QtCore/qcoreapplication.h>
@@ -220,10 +241,10 @@
 #ifndef QQMLJSPARSER_P_H
 #define QQMLJSPARSER_P_H
 
-#include "qqmljsglobal_p.h"
-#include "qqmljsgrammar_p.h"
-#include "qqmljsast_p.h"
-#include "qqmljsengine_p.h"
+#include <private/qqmljsglobal_p.h>
+#include <private/qqmljsgrammar_p.h>
+#include <private/qqmljsast_p.h>
+#include <private/qqmljsengine_p.h>
 
 #include <QtCore/qlist.h>
 #include <QtCore/qstring.h>
@@ -240,30 +261,42 @@ public:
     union Value {
       int ival;
       double dval;
+      AST::VariableScope scope;
+      AST::ForEachType forEachType;
       AST::ArgumentList *ArgumentList;
       AST::CaseBlock *CaseBlock;
       AST::CaseClause *CaseClause;
       AST::CaseClauses *CaseClauses;
       AST::Catch *Catch;
       AST::DefaultClause *DefaultClause;
-      AST::ElementList *ElementList;
       AST::Elision *Elision;
       AST::ExpressionNode *Expression;
+      AST::TemplateLiteral *Template;
       AST::Finally *Finally;
       AST::FormalParameterList *FormalParameterList;
-      AST::FunctionBody *FunctionBody;
       AST::FunctionDeclaration *FunctionDeclaration;
       AST::Node *Node;
       AST::PropertyName *PropertyName;
-      AST::PropertyAssignment *PropertyAssignment;
-      AST::PropertyAssignmentList *PropertyAssignmentList;
-      AST::SourceElement *SourceElement;
-      AST::SourceElements *SourceElements;
       AST::Statement *Statement;
       AST::StatementList *StatementList;
       AST::Block *Block;
-      AST::VariableDeclaration *VariableDeclaration;
       AST::VariableDeclarationList *VariableDeclarationList;
+      AST::Pattern *Pattern;
+      AST::PatternElement *PatternElement;
+      AST::PatternElementList *PatternElementList;
+      AST::PatternProperty *PatternProperty;
+      AST::PatternPropertyList *PatternPropertyList;
+      AST::ClassElementList *ClassElementList;
+      AST::ImportClause *ImportClause;
+      AST::FromClause *FromClause;
+      AST::NameSpaceImport *NameSpaceImport;
+      AST::ImportsList *ImportsList;
+      AST::NamedImports *NamedImports;
+      AST::ImportSpecifier *ImportSpecifier;
+      AST::ExportSpecifier *ExportSpecifier;
+      AST::ExportsList *ExportsList;
+      AST::ExportClause *ExportClause;
+      AST::ExportDeclaration *ExportDeclaration;
 
       AST::UiProgram *UiProgram;
       AST::UiHeaderItemList *UiHeaderItemList;
@@ -280,7 +313,7 @@ public:
       AST::UiObjectMemberList *UiObjectMemberList;
       AST::UiArrayMemberList *UiArrayMemberList;
       AST::UiQualifiedId *UiQualifiedId;
-      AST::UiQualifiedPragmaId *UiQualifiedPragmaId;
+      AST::UiEnumMemberList *UiEnumMemberList;
     };
 
 public:
@@ -288,12 +321,13 @@ public:
     ~Parser();
 
     // parse a UI program
-    bool parse() { return parse(T_FEED_UI_PROGRAM); }
+    bool parse() { ++functionNestingLevel; bool r = parse(T_FEED_UI_PROGRAM); --functionNestingLevel; return r; }
     bool parseStatement() { return parse(T_FEED_JS_STATEMENT); }
     bool parseExpression() { return parse(T_FEED_JS_EXPRESSION); }
-    bool parseSourceElement() { return parse(T_FEED_JS_SOURCE_ELEMENT); }
-    bool parseUiObjectMember() { return parse(T_FEED_UI_OBJECT_MEMBER); }
-    bool parseProgram() { return parse(T_FEED_JS_PROGRAM); }
+    bool parseUiObjectMember() { ++functionNestingLevel; bool r = parse(T_FEED_UI_OBJECT_MEMBER); --functionNestingLevel; return r; }
+    bool parseProgram() { return parse(T_FEED_JS_SCRIPT); }
+    bool parseScript() { return parse(T_FEED_JS_SCRIPT); }
+    bool parseModule() { return parse(T_FEED_JS_MODULE); }
 
     AST::UiProgram *ast() const
     { return AST::cast<AST::UiProgram *>(program); }
@@ -358,42 +392,68 @@ protected:
     inline QStringRef &stringRef(int index)
     { return string_stack [tos + index - 1]; }
 
+    inline QStringRef &rawStringRef(int index)
+    { return rawString_stack [tos + index - 1]; }
+
     inline AST::SourceLocation &loc(int index)
     { return location_stack [tos + index - 1]; }
 
     AST::UiQualifiedId *reparseAsQualifiedId(AST::ExpressionNode *expr);
-    AST::UiQualifiedPragmaId *reparseAsQualifiedPragmaId(AST::ExpressionNode *expr);
+
+    void pushToken(int token);
+    int lookaheadToken(Lexer *lexer);
+
+    void syntaxError(const AST::SourceLocation &location, const char *message) {
+        diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location, QLatin1String(message)));
+     }
+     void syntaxError(const AST::SourceLocation &location, const QString &message) {
+         diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location, message));
+      }
 
 protected:
     Engine *driver;
     MemoryPool *pool;
-    int tos;
-    int stack_size;
-    Value *sym_stack;
-    int *state_stack;
-    AST::SourceLocation *location_stack;
-    QStringRef *string_stack;
+    int tos = 0;
+    int stack_size = 0;
+    Value *sym_stack = nullptr;
+    int *state_stack = nullptr;
+    AST::SourceLocation *location_stack = nullptr;
+    QVector<QStringRef> string_stack;
+    QVector<QStringRef> rawString_stack;
 
-    AST::Node *program;
+    AST::Node *program = nullptr;
 
-    // error recovery
-    enum { TOKEN_BUFFER_SIZE = 3 };
+    // error recovery and lookahead handling
+    enum { TOKEN_BUFFER_SIZE = 5 };
 
     struct SavedToken {
        int token;
        double dval;
        AST::SourceLocation loc;
        QStringRef spell;
+       QStringRef raw;
     };
 
-    double yylval;
+    int yytoken = -1;
+    double yylval = 0.;
     QStringRef yytokenspell;
+    QStringRef yytokenraw;
     AST::SourceLocation yylloc;
     AST::SourceLocation yyprevlloc;
 
     SavedToken token_buffer[TOKEN_BUFFER_SIZE];
-    SavedToken *first_token;
-    SavedToken *last_token;
+    SavedToken *first_token = nullptr;
+    SavedToken *last_token = nullptr;
+
+    int functionNestingLevel = 0;
+
+    enum CoverExpressionType {
+        CE_Invalid,
+        CE_ParenthesizedExpression,
+        CE_FormalParameterList
+    };
+    AST::SourceLocation coverExpressionErrorLocation;
+    CoverExpressionType coverExpressionType = CE_Invalid;
 
     QList<DiagnosticMessage> diagnostic_messages;
 };
@@ -422,6 +482,8 @@ protected:
 //    qlalr --no-debug --no-lines --qt qqmljs.g
 //
 
+#define UNIMPLEMENTED syntaxError(loc(1), "Unimplemented"); return false
+
 using namespace QQmlJS;
 
 QT_QML_BEGIN_NAMESPACE
@@ -436,21 +498,13 @@ void Parser::reallocateStack()
     sym_stack = reinterpret_cast<Value*> (realloc(sym_stack, stack_size * sizeof(Value)));
     state_stack = reinterpret_cast<int*> (realloc(state_stack, stack_size * sizeof(int)));
     location_stack = reinterpret_cast<AST::SourceLocation*> (realloc(location_stack, stack_size * sizeof(AST::SourceLocation)));
-    string_stack = reinterpret_cast<QStringRef*> (realloc(string_stack, stack_size * sizeof(QStringRef)));
+    string_stack.resize(stack_size);
+    rawString_stack.resize(stack_size);
 }
 
 Parser::Parser(Engine *engine):
     driver(engine),
-    pool(engine->pool()),
-    tos(0),
-    stack_size(0),
-    sym_stack(0),
-    state_stack(0),
-    location_stack(0),
-    string_stack(0),
-    program(0),
-    first_token(0),
-    last_token(0)
+    pool(engine->pool())
 {
 }
 
@@ -460,7 +514,6 @@ Parser::~Parser()
         free(sym_stack);
         free(state_stack);
         free(location_stack);
-        free(string_stack);
     }
 }
 
@@ -502,29 +555,43 @@ AST::UiQualifiedId *Parser::reparseAsQualifiedId(AST::ExpressionNode *expr)
     return 0;
 }
 
-AST::UiQualifiedPragmaId *Parser::reparseAsQualifiedPragmaId(AST::ExpressionNode *expr)
+void Parser::pushToken(int token)
 {
-    if (AST::IdentifierExpression *idExpr = AST::cast<AST::IdentifierExpression *>(expr)) {
-        AST::UiQualifiedPragmaId *q = new (pool) AST::UiQualifiedPragmaId(idExpr->name);
-        q->identifierToken = idExpr->identifierToken;
+    Q_ASSERT(last_token);
+    Q_ASSERT(last_token < &token_buffer[TOKEN_BUFFER_SIZE]);
+    last_token->token = yytoken;
+    last_token->dval = yylval;
+    last_token->spell = yytokenspell;
+    last_token->raw = yytokenraw;
+    last_token->loc = yylloc;
+    ++last_token;
+    yytoken = token;
+}
 
-        return q->finish();
+int Parser::lookaheadToken(Lexer *lexer)
+{
+    if (yytoken < 0) {
+        yytoken = lexer->lex();
+        yylval = lexer->tokenValue();
+        yytokenspell = lexer->tokenSpell();
+        yytokenraw = lexer->rawString();
+        yylloc = location(lexer);
     }
-
-    return 0;
+    return yytoken;
 }
 
+//#define PARSER_DEBUG
 
 bool Parser::parse(int startToken)
 {
     Lexer *lexer = driver->lexer();
     bool hadErrors = false;
-    int yytoken = -1;
+    yytoken = -1;
     int action = 0;
 
     token_buffer[0].token = startToken;
     first_token = &token_buffer[0];
-    if (startToken == T_FEED_JS_PROGRAM && !lexer->qmlMode()) {
+    if (startToken == T_FEED_JS_SCRIPT && !lexer->qmlMode()) {
         Directives ignoreDirectives;
         Directives *directives = driver->directives();
         if (!directives)
@@ -547,8 +614,16 @@ bool Parser::parse(int startToken)
     program = 0;
 
     do {
-        if (++tos == stack_size)
+        if (++tos == stack_size) {
             reallocateStack();
+            if (stack_size > 10000) {
+                // We're now in some serious right-recursive stuff, which will probably result in
+                // an AST that's so deep that recursively visiting it will run out of stack space.
+                const QString msg = QCoreApplication::translate("QQmlParser", "Maximum statement or expression depth exceeded");
+                diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
+                return false;
+            }
+        }
 
         state_stack[tos] = action;
 
@@ -560,22 +635,34 @@ bool Parser::parse(int startToken)
                 yytoken = lexer->lex();
                 yylval = lexer->tokenValue();
                 yytokenspell = lexer->tokenSpell();
+                yytokenraw = lexer->rawString();
                 yylloc = location(lexer);
             } else {
                 yytoken = first_token->token;
                 yylval = first_token->dval;
                 yytokenspell = first_token->spell;
+                yytokenraw = first_token->raw;
                 yylloc = first_token->loc;
                 ++first_token;
+                if (first_token == last_token)
+                    first_token = last_token = &token_buffer[0];
             }
         }
 
+#ifdef PARSER_DEBUG
+       qDebug() << "   in state" << action;
+#endif
+
         action = t_action(action, yytoken);
+#ifdef PARSER_DEBUG
+       qDebug() << "   current token" << yytoken << (yytoken >= 0 ? spell[yytoken] : "(null)") << "new state" << action;
+#endif
         if (action > 0) {
             if (action != ACCEPT_STATE) {
                 yytoken = -1;
                 sym(1).dval = yylval;
                 stringRef(1) = yytokenspell;
+                rawStringRef(1) = yytokenraw;
                 loc(1) = yylloc;
             } else {
               --tos;
@@ -585,6 +672,10 @@ bool Parser::parse(int startToken)
           const int r = -action - 1;
           tos -= rhs[r];
 
+#ifdef PARSER_DEBUG
+          qDebug() << "        reducing through rule " << -action;
+#endif
+
           switch (r) {
 ./
 
@@ -592,2532 +683,3702 @@ bool Parser::parse(int startToken)
 -- Declarative UI
 --------------------------------------------------------------------------------------------------------
 
-TopLevel: T_FEED_UI_PROGRAM UiProgram ;
+TopLevel: T_FEED_UI_PROGRAM UiProgram;
 /.
-case $rule_number: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+        program = sym(1).Node;
+    } break;
 ./
 
-TopLevel: T_FEED_JS_STATEMENT Statement ;
+TopLevel: T_FEED_JS_STATEMENT Statement;
 /.
-case $rule_number: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+        program = sym(1).Node;
+    } break;
 ./
 
-TopLevel: T_FEED_JS_EXPRESSION Expression ;
+TopLevel: T_FEED_JS_EXPRESSION Expression;
 /.
-case $rule_number: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+        program = sym(1).Node;
+    } break;
 ./
 
-TopLevel: T_FEED_JS_SOURCE_ELEMENT SourceElement ;
+TopLevel: T_FEED_UI_OBJECT_MEMBER UiObjectMember;
 /.
-case $rule_number: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+        program = sym(1).Node;
+    } break;
 ./
 
-TopLevel: T_FEED_UI_OBJECT_MEMBER UiObjectMember ;
+TopLevel: T_FEED_JS_SCRIPT Script;
 /.
-case $rule_number: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+        program = sym(1).Node;
+    } break;
 ./
 
-TopLevel: T_FEED_JS_PROGRAM Program ;
+TopLevel: T_FEED_JS_MODULE Module;
 /.
-case $rule_number: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+        program = sym(1).Node;
+    } break;
 ./
 
+
 UiProgram: UiHeaderItemListOpt UiRootMember;
 /.
-case $rule_number: {
-  sym(1).UiProgram = new (pool) AST::UiProgram(sym(1).UiHeaderItemList,
-        sym(2).UiObjectMemberList->finish());
-} break;
+    case $rule_number: {
+        sym(1).UiProgram = new (pool) AST::UiProgram(sym(1).UiHeaderItemList, sym(2).UiObjectMemberList->finish());
+    } break;
 ./
 
-UiHeaderItemListOpt: Empty ;
-UiHeaderItemListOpt: UiHeaderItemList ;
+UiHeaderItemListOpt: Empty;
+UiHeaderItemListOpt: UiHeaderItemList;
 /.
-case $rule_number: {
-    sym(1).Node = sym(1).UiHeaderItemList->finish();
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).UiHeaderItemList->finish();
+    } break;
 ./
 
-UiHeaderItemList: UiPragma ;
+UiHeaderItemList: UiPragma;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiPragma);
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiPragma);
+    } break;
 ./
 
-UiHeaderItemList: UiImport ;
+UiHeaderItemList: UiImport;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiImport);
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiImport);
+    } break;
 ./
 
-UiHeaderItemList: UiHeaderItemList UiPragma ;
+UiHeaderItemList: UiHeaderItemList UiPragma;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiHeaderItemList, sym(2).UiPragma);
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiHeaderItemList, sym(2).UiPragma);
+    } break;
 ./
 
-UiHeaderItemList: UiHeaderItemList UiImport ;
+UiHeaderItemList: UiHeaderItemList UiImport;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiHeaderItemList, sym(2).UiImport);
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiHeaderItemList, sym(2).UiImport);
+    } break;
 ./
 
-PragmaId: MemberExpression ;
-
-ImportId: MemberExpression ;
+PragmaId: JsIdentifier;
 
-UiPragma: UiPragmaHead T_AUTOMATIC_SEMICOLON ;
-UiPragma: UiPragmaHead T_SEMICOLON ;
+UiPragma: T_PRAGMA PragmaId T_AUTOMATIC_SEMICOLON;
+UiPragma: T_PRAGMA PragmaId T_SEMICOLON;
 /.
-case $rule_number: {
-    sym(1).UiPragma->semicolonToken = loc(2);
-} break;
+    case $rule_number: {
+        AST::UiPragma *pragma = new (pool) AST::UiPragma(stringRef(2));
+        pragma->pragmaToken = loc(1);
+        pragma->semicolonToken = loc(3);
+        sym(1).Node = pragma;
+    } break;
 ./
 
-UiImport: UiImportHead T_AUTOMATIC_SEMICOLON ;
-UiImport: UiImportHead T_SEMICOLON ;
+ImportId: MemberExpression;
+
+UiImport: UiImportHead T_AUTOMATIC_SEMICOLON;
+UiImport: UiImportHead T_SEMICOLON;
 /.
-case $rule_number: {
-    sym(1).UiImport->semicolonToken = loc(2);
-} break;
+    case $rule_number: {
+        sym(1).UiImport->semicolonToken = loc(2);
+    } break;
 ./
 
-UiImport: UiImportHead T_NUMERIC_LITERAL T_AUTOMATIC_SEMICOLON ;
-UiImport: UiImportHead T_NUMERIC_LITERAL T_SEMICOLON ;
+UiImport: UiImportHead T_NUMERIC_LITERAL T_AUTOMATIC_SEMICOLON;
+UiImport: UiImportHead T_NUMERIC_LITERAL T_SEMICOLON;
 /.
-case $rule_number: {
-    sym(1).UiImport->versionToken = loc(2);
-    sym(1).UiImport->semicolonToken = loc(3);
-} break;
+    case $rule_number: {
+        sym(1).UiImport->versionToken = loc(2);
+        sym(1).UiImport->semicolonToken = loc(3);
+    } break;
 ./
 
-UiImport: UiImportHead T_NUMERIC_LITERAL T_AS JsIdentifier T_AUTOMATIC_SEMICOLON ;
-UiImport: UiImportHead T_NUMERIC_LITERAL T_AS JsIdentifier T_SEMICOLON ;
+UiImport: UiImportHead T_NUMERIC_LITERAL T_AS QmlIdentifier T_AUTOMATIC_SEMICOLON;
+UiImport: UiImportHead T_NUMERIC_LITERAL T_AS QmlIdentifier T_SEMICOLON;
 /.
-case $rule_number: {
-    sym(1).UiImport->versionToken = loc(2);
-    sym(1).UiImport->asToken = loc(3);
-    sym(1).UiImport->importIdToken = loc(4);
-    sym(1).UiImport->importId = stringRef(4);
-    sym(1).UiImport->semicolonToken = loc(5);
-} break;
+    case $rule_number: {
+        sym(1).UiImport->versionToken = loc(2);
+        sym(1).UiImport->asToken = loc(3);
+        sym(1).UiImport->importIdToken = loc(4);
+        sym(1).UiImport->importId = stringRef(4);
+        sym(1).UiImport->semicolonToken = loc(5);
+    } break;
 ./
 
-UiImport: UiImportHead T_AS JsIdentifier T_AUTOMATIC_SEMICOLON ;
-UiImport: UiImportHead T_AS JsIdentifier T_SEMICOLON ;
+UiImport: UiImportHead T_AS QmlIdentifier T_AUTOMATIC_SEMICOLON;
+UiImport: UiImportHead T_AS QmlIdentifier T_SEMICOLON;
 /.
-case $rule_number: {
-    sym(1).UiImport->asToken = loc(2);
-    sym(1).UiImport->importIdToken = loc(3);
-    sym(1).UiImport->importId = stringRef(3);
-    sym(1).UiImport->semicolonToken = loc(4);
-} break;
+    case $rule_number: {
+        sym(1).UiImport->asToken = loc(2);
+        sym(1).UiImport->importIdToken = loc(3);
+        sym(1).UiImport->importId = stringRef(3);
+        sym(1).UiImport->semicolonToken = loc(4);
+    } break;
 ./
 
-UiPragmaHead: T_PRAGMA PragmaId ;
+UiImportHead: T_IMPORT ImportId;
 /.
-case $rule_number: {
-    AST::UiPragma *node = 0;
+    case $rule_number: {
+        AST::UiImport *node = 0;
 
-    if (AST::UiQualifiedPragmaId *qualifiedId = reparseAsQualifiedPragmaId(sym(2).Expression)) {
-        node = new (pool) AST::UiPragma(qualifiedId);
-    }
+        if (AST::StringLiteral *importIdLiteral = AST::cast<AST::StringLiteral *>(sym(2).Expression)) {
+            node = new (pool) AST::UiImport(importIdLiteral->value);
+            node->fileNameToken = loc(2);
+        } else if (AST::UiQualifiedId *qualifiedId = reparseAsQualifiedId(sym(2).Expression)) {
+            node = new (pool) AST::UiImport(qualifiedId);
+            node->fileNameToken = loc(2);
+        }
 
-    sym(1).Node = node;
+        sym(1).Node = node;
 
-    if (node) {
-        node->pragmaToken = loc(1);
-    } else {
-       diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
-         QLatin1String("Expected a qualified name id")));
+        if (node) {
+            node->importToken = loc(1);
+        } else {
+           diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
+             QLatin1String("Expected a qualified name id or a string literal")));
 
-        return false; // ### remove me
-    }
-} break;
+            return false; // ### remove me
+        }
+    } break;
 ./
 
-
-UiImportHead: T_IMPORT ImportId ;
+Empty: ;
 /.
-case $rule_number: {
-    AST::UiImport *node = 0;
-
-    if (AST::StringLiteral *importIdLiteral = AST::cast<AST::StringLiteral *>(sym(2).Expression)) {
-        node = new (pool) AST::UiImport(importIdLiteral->value);
-        node->fileNameToken = loc(2);
-    } else if (AST::UiQualifiedId *qualifiedId = reparseAsQualifiedId(sym(2).Expression)) {
-        node = new (pool) AST::UiImport(qualifiedId);
-        node->fileNameToken = loc(2);
-    }
-
-    sym(1).Node = node;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
+./
 
-    if (node) {
-        node->importToken = loc(1);
-    } else {
-       diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
-         QLatin1String("Expected a qualified name id or a string literal")));
+UiRootMember: UiObjectDefinition;
+/.
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiObjectMemberList(sym(1).UiObjectMember);
+    } break;
+./
 
-        return false; // ### remove me
-    }
-} break;
+UiObjectMemberList: UiObjectMember;
+/.
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiObjectMemberList(sym(1).UiObjectMember);
+    } break;
 ./
 
-Empty: ;
+UiObjectMemberList: UiObjectMemberList UiObjectMember;
 /.
-case $rule_number: {
-    sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::UiObjectMemberList *node = new (pool) AST:: UiObjectMemberList(sym(1).UiObjectMemberList, sym(2).UiObjectMember);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiRootMember: UiObjectDefinition ;
+UiArrayMemberList: UiObjectDefinition;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiObjectMemberList(sym(1).UiObjectMember);
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiArrayMemberList(sym(1).UiObjectMember);
+    } break;
 ./
 
-UiObjectMemberList: UiObjectMember ;
+UiArrayMemberList: UiArrayMemberList T_COMMA UiObjectDefinition;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiObjectMemberList(sym(1).UiObjectMember);
-} break;
+    case $rule_number: {
+        AST::UiArrayMemberList *node = new (pool) AST::UiArrayMemberList(sym(1).UiArrayMemberList, sym(3).UiObjectMember);
+        node->commaToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMemberList: UiObjectMemberList UiObjectMember ;
+UiObjectInitializer: T_LBRACE T_RBRACE;
 /.
-case $rule_number: {
-    AST::UiObjectMemberList *node = new (pool) AST:: UiObjectMemberList(
-        sym(1).UiObjectMemberList, sym(2).UiObjectMember);
-    sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UiObjectInitializer *node = new (pool) AST::UiObjectInitializer((AST::UiObjectMemberList*)0);
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiArrayMemberList: UiObjectDefinition ;
+UiObjectInitializer: T_LBRACE UiObjectMemberList T_RBRACE;
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiArrayMemberList(sym(1).UiObjectMember);
-} break;
+    case $rule_number: {
+        AST::UiObjectInitializer *node = new (pool) AST::UiObjectInitializer(sym(2).UiObjectMemberList->finish());
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiArrayMemberList: UiArrayMemberList T_COMMA UiObjectDefinition ;
+UiObjectDefinition: UiQualifiedId UiObjectInitializer;
 /.
-case $rule_number: {
-    AST::UiArrayMemberList *node = new (pool) AST::UiArrayMemberList(
-        sym(1).UiArrayMemberList, sym(3).UiObjectMember);
-    node->commaToken = loc(2);
-    sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UiObjectDefinition *node = new (pool) AST::UiObjectDefinition(sym(1).UiQualifiedId, sym(2).UiObjectInitializer);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectInitializer: T_LBRACE T_RBRACE ;
+UiObjectMember: UiObjectDefinition;
+
+UiObjectMember: UiQualifiedId T_COLON ExpressionStatementLookahead T_LBRACKET UiArrayMemberList T_RBRACKET;
 /.
-case $rule_number: {
-    AST::UiObjectInitializer *node = new (pool) AST::UiObjectInitializer((AST::UiObjectMemberList*)0);
-    node->lbraceToken = loc(1);
-    node->rbraceToken = loc(2);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiArrayBinding *node = new (pool) AST::UiArrayBinding(sym(1).UiQualifiedId, sym(5).UiArrayMemberList->finish());
+        node->colonToken = loc(2);
+        node->lbracketToken = loc(4);
+        node->rbracketToken = loc(6);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectInitializer: T_LBRACE UiObjectMemberList T_RBRACE ;
+UiObjectMember: UiQualifiedId T_COLON ExpressionStatementLookahead UiQualifiedId UiObjectInitializer;
 /.
-case $rule_number: {
-    AST::UiObjectInitializer *node = new (pool) AST::UiObjectInitializer(sym(2).UiObjectMemberList->finish());
-    node->lbraceToken = loc(1);
-    node->rbraceToken = loc(3);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiObjectBinding *node = new (pool) AST::UiObjectBinding(
+            sym(1).UiQualifiedId, sym(4).UiQualifiedId, sym(5).UiObjectInitializer);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectDefinition: UiQualifiedId UiObjectInitializer ;
+UiObjectMember: UiQualifiedId T_ON UiQualifiedId  UiObjectInitializer;
 /.
-case $rule_number: {
-    AST::UiObjectDefinition *node = new (pool) AST::UiObjectDefinition(sym(1).UiQualifiedId,
-        sym(2).UiObjectInitializer);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiObjectBinding *node = new (pool) AST::UiObjectBinding(
+          sym(3).UiQualifiedId, sym(1).UiQualifiedId, sym(4).UiObjectInitializer);
+        node->colonToken = loc(2);
+        node->hasOnToken = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMember: UiObjectDefinition ;
 
-UiObjectMember: UiQualifiedId T_COLON T_LBRACKET UiArrayMemberList T_RBRACKET ;
+UiObjectLiteral: T_LBRACE ExpressionStatementLookahead UiPropertyDefinitionList T_RBRACE;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiObjectLiteral: T_LBRACE ExpressionStatementLookahead UiPropertyDefinitionList T_COMMA T_RBRACE;
 /.
-case $rule_number: {
-    AST::UiArrayBinding *node = new (pool) AST::UiArrayBinding(
-        sym(1).UiQualifiedId, sym(4).UiArrayMemberList->finish());
-    node->colonToken = loc(2);
-    node->lbracketToken = loc(3);
-    node->rbracketToken = loc(5);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::ObjectPattern *l = new (pool) AST::ObjectPattern(sym(3).PatternPropertyList->finish());
+        l->lbraceToken = loc(1);
+        l->rbraceToken = loc(4);
+        AST::ExpressionStatement *node = new (pool) AST::ExpressionStatement(l);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMember: UiQualifiedId             T_COLON UiQualifiedId  UiObjectInitializer ;
+
+UiScriptStatement: ExpressionStatementLookahead T_FORCE_DECLARATION ExpressionStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead T_FORCE_BLOCK Block;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead T_FORCE_BLOCK UiObjectLiteral;
 /.
-case $rule_number: {
-    AST::UiObjectBinding *node = new (pool) AST::UiObjectBinding(
-      sym(1).UiQualifiedId, sym(3).UiQualifiedId, sym(4).UiObjectInitializer);
-    node->colonToken = loc(2);
-    sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(3).Node;
+    } break;
 ./
 
-UiObjectMember: UiQualifiedId             T_ON UiQualifiedId  UiObjectInitializer ;
+
+UiScriptStatement: ExpressionStatementLookahead EmptyStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead ExpressionStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead IfStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead WithStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead SwitchStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiScriptStatement: ExpressionStatementLookahead TryStatement;
 /.
-case $rule_number: {
-    AST::UiObjectBinding *node = new (pool) AST::UiObjectBinding(
-      sym(3).UiQualifiedId, sym(1).UiQualifiedId, sym(4).UiObjectInitializer);
-    node->colonToken = loc(2);
-    node->hasOnToken = true;
-    sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+    } break;
 ./
 
-UiScriptStatement: Block ;
-UiScriptStatement: EmptyStatement ;
-UiScriptStatement: ExpressionStatement ;
-UiScriptStatement: IfStatement ;
-UiScriptStatement: WithStatement ;
-UiScriptStatement: SwitchStatement ;
-UiScriptStatement: TryStatement ;
-
-UiObjectMember: UiQualifiedId T_COLON UiScriptStatement ;
+UiObjectMember: UiQualifiedId T_COLON UiScriptStatement;
 /.
 case $rule_number:
 {
-    AST::UiScriptBinding *node = new (pool) AST::UiScriptBinding(
-        sym(1).UiQualifiedId, sym(3).Statement);
+    AST::UiScriptBinding *node = new (pool) AST::UiScriptBinding(sym(1).UiQualifiedId, sym(3).Statement);
     node->colonToken = loc(2);
     sym(1).Node = node;
-}   break;
+    } break;
 ./
 
-UiPropertyType: T_VAR ;
+UiPropertyType: T_VAR;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiPropertyType: T_RESERVED_WORD;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+UiPropertyType: T_IDENTIFIER;
 /.
-case $rule_number: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
+        node->identifierToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiPropertyType: T_RESERVED_WORD ;
+UiPropertyType: UiPropertyType T_DOT T_IDENTIFIER;
 /.
-case $rule_number: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(sym(1).UiQualifiedId, stringRef(3));
+        node->identifierToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiPropertyType: T_IDENTIFIER ;
+UiParameterListOpt: ;
 /.
-case $rule_number: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-UiPropertyType: UiPropertyType T_DOT T_IDENTIFIER ;
+UiParameterListOpt: UiParameterList;
 /.
-case $rule_number: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(sym(1).UiQualifiedId, stringRef(3));
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).UiParameterList->finish();
+    } break;
 ./
 
-UiParameterListOpt: ;
+UiParameterList: UiPropertyType QmlIdentifier;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::UiParameterList *node = new (pool) AST::UiParameterList(sym(1).UiQualifiedId->finish(), stringRef(2));
+        node->propertyTypeToken = loc(1);
+        node->identifierToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
+
+UiParameterList: UiParameterList T_COMMA UiPropertyType QmlIdentifier;
+/.
+    case $rule_number: {
+        AST::UiParameterList *node = new (pool) AST::UiParameterList(sym(1).UiParameterList, sym(3).UiQualifiedId->finish(), stringRef(4));
+        node->propertyTypeToken = loc(3);
+        node->commaToken = loc(2);
+        node->identifierToken = loc(4);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_SIGNAL T_IDENTIFIER T_LPAREN UiParameterListOpt T_RPAREN T_AUTOMATIC_SEMICOLON;
+UiObjectMember: T_SIGNAL T_IDENTIFIER T_LPAREN UiParameterListOpt T_RPAREN T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(nullptr, stringRef(2));
+        node->type = AST::UiPublicMember::Signal;
+        node->propertyToken = loc(1);
+        node->typeToken = loc(2);
+        node->identifierToken = loc(2);
+        node->parameters = sym(4).UiParameterList;
+        node->semicolonToken = loc(6);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_SIGNAL T_IDENTIFIER T_AUTOMATIC_SEMICOLON;
+UiObjectMember: T_SIGNAL T_IDENTIFIER T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(nullptr, stringRef(2));
+        node->type = AST::UiPublicMember::Signal;
+        node->propertyToken = loc(1);
+        node->typeToken = loc(2);
+        node->identifierToken = loc(2);
+        node->semicolonToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_AUTOMATIC_SEMICOLON;
+UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
+        node->typeModifier = stringRef(2);
+        node->propertyToken = loc(1);
+        node->typeModifierToken = loc(2);
+        node->typeToken = loc(4);
+        node->identifierToken = loc(6);
+        node->semicolonToken = loc(7);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_AUTOMATIC_SEMICOLON;
+UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
+        node->propertyToken = loc(1);
+        node->typeToken = loc(2);
+        node->identifierToken = loc(3);
+        node->semicolonToken = loc(4);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType QmlIdentifier T_AUTOMATIC_SEMICOLON;
+UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType QmlIdentifier T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
+        node->isDefaultMember = true;
+        node->defaultToken = loc(1);
+        node->propertyToken = loc(2);
+        node->typeToken = loc(3);
+        node->identifierToken = loc(4);
+        node->semicolonToken = loc(5);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_DEFAULT T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_AUTOMATIC_SEMICOLON;
+UiObjectMember: T_DEFAULT T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(5).UiQualifiedId->finish(), stringRef(7));
+        node->isDefaultMember = true;
+        node->defaultToken = loc(1);
+        node->typeModifier = stringRef(3);
+        node->propertyToken = loc(2);
+        node->typeModifierToken = loc(2);
+        node->typeToken = loc(4);
+        node->identifierToken = loc(7);
+        node->semicolonToken = loc(8);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3), sym(5).Statement);
+        node->propertyToken = loc(1);
+        node->typeToken = loc(2);
+        node->identifierToken = loc(3);
+        node->colonToken = loc(4);
+        sym(1).Node = node;
+    } break;
+./
+
+UiObjectMember: T_READONLY T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement;
+/.
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4), sym(6).Statement);
+        node->isReadonlyMember = true;
+        node->readonlyToken = loc(1);
+        node->propertyToken = loc(2);
+        node->typeToken = loc(3);
+        node->identifierToken = loc(4);
+        node->colonToken = loc(5);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiParameterListOpt: UiParameterList ;
+UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType QmlIdentifier T_COLON UiScriptStatement;
 /.
-case $rule_number: {
-  sym(1).Node = sym(1).UiParameterList->finish ();
-} break;
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4), sym(6).Statement);
+        node->isDefaultMember = true;
+        node->defaultToken = loc(1);
+        node->propertyToken = loc(2);
+        node->typeToken = loc(3);
+        node->identifierToken = loc(4);
+        node->colonToken = loc(5);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiParameterList: UiPropertyType JsIdentifier ;
+UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT QmlIdentifier T_COLON T_LBRACKET UiArrayMemberList T_RBRACKET;
 /.
-case $rule_number: {
-  AST::UiParameterList *node = new (pool) AST::UiParameterList(sym(1).UiQualifiedId->finish(), stringRef(2));
-  node->propertyTypeToken = loc(1);
-  node->identifierToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
+        node->typeModifier = stringRef(2);
+        node->propertyToken = loc(1);
+        node->typeModifierToken = loc(2);
+        node->typeToken = loc(4);
+        node->identifierToken = loc(6);
+        node->semicolonToken = loc(7); // insert a fake ';' before ':'
+
+        AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(6));
+        propertyName->identifierToken = loc(6);
+        propertyName->next = 0;
+
+        AST::UiArrayBinding *binding = new (pool) AST::UiArrayBinding(propertyName, sym(9).UiArrayMemberList->finish());
+        binding->colonToken = loc(7);
+        binding->lbracketToken = loc(8);
+        binding->rbracketToken = loc(10);
+
+        node->binding = binding;
+
+        sym(1).Node = node;
+    } break;
 ./
 
-UiParameterList: UiParameterList T_COMMA UiPropertyType JsIdentifier ;
+UiObjectMember: T_PROPERTY UiPropertyType QmlIdentifier T_COLON ExpressionStatementLookahead UiQualifiedId UiObjectInitializer;
 /.
-case $rule_number: {
-  AST::UiParameterList *node = new (pool) AST::UiParameterList(sym(1).UiParameterList, sym(3).UiQualifiedId->finish(), stringRef(4));
-  node->propertyTypeToken = loc(3);
-  node->commaToken = loc(2);
-  node->identifierToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
+        node->propertyToken = loc(1);
+        node->typeToken = loc(2);
+        node->identifierToken = loc(3);
+        node->semicolonToken = loc(4); // insert a fake ';' before ':'
+
+        AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(3));
+        propertyName->identifierToken = loc(3);
+        propertyName->next = 0;
+
+        AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
+          propertyName, sym(6).UiQualifiedId, sym(7).UiObjectInitializer);
+        binding->colonToken = loc(4);
+
+        node->binding = binding;
+
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMember: T_SIGNAL T_IDENTIFIER T_LPAREN UiParameterListOpt T_RPAREN T_AUTOMATIC_SEMICOLON ;
-UiObjectMember: T_SIGNAL T_IDENTIFIER T_LPAREN UiParameterListOpt T_RPAREN T_SEMICOLON ;
+UiObjectMember: T_READONLY T_PROPERTY UiPropertyType QmlIdentifier T_COLON ExpressionStatementLookahead UiQualifiedId UiObjectInitializer;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(nullptr, stringRef(2));
-    node->type = AST::UiPublicMember::Signal;
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(2);
-    node->parameters = sym(4).UiParameterList;
-    node->semicolonToken = loc(6);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
+        node->isReadonlyMember = true;
+        node->readonlyToken = loc(1);
+        node->propertyToken = loc(2);
+        node->typeToken = loc(3);
+        node->identifierToken = loc(4);
+        node->semicolonToken = loc(5); // insert a fake ';' before ':'
+
+        AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(4));
+        propertyName->identifierToken = loc(4);
+        propertyName->next = 0;
+
+        AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
+          propertyName, sym(7).UiQualifiedId, sym(8).UiObjectInitializer);
+        binding->colonToken = loc(5);
+
+        node->binding = binding;
+
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMember: T_SIGNAL T_IDENTIFIER T_AUTOMATIC_SEMICOLON ;
-UiObjectMember: T_SIGNAL T_IDENTIFIER T_SEMICOLON ;
+UiObjectMember: FunctionDeclaration;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(nullptr, stringRef(2));
-    node->type = AST::UiPublicMember::Signal;
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(2);
-    node->semicolonToken = loc(3);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
+    } break;
 ./
 
-UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT JsIdentifier T_AUTOMATIC_SEMICOLON ;
-UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT JsIdentifier T_SEMICOLON ;
+UiObjectMember: VariableStatement;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
-    node->typeModifier = stringRef(2);
-    node->propertyToken = loc(1);
-    node->typeModifierToken = loc(2);
-    node->typeToken = loc(4);
-    node->identifierToken = loc(6);
-    node->semicolonToken = loc(7);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
+    } break;
 ./
 
-UiObjectMember: T_PROPERTY UiPropertyType JsIdentifier T_AUTOMATIC_SEMICOLON ;
-UiObjectMember: T_PROPERTY UiPropertyType JsIdentifier T_SEMICOLON ;
+UiQualifiedId: MemberExpression;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(3);
-    node->semicolonToken = loc(4);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+      if (AST::ArrayMemberExpression *mem = AST::cast<AST::ArrayMemberExpression *>(sym(1).Expression)) {
+        diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Warning, mem->lbracketToken,
+          QLatin1String("Ignored annotation")));
+
+        sym(1).Expression = mem->base;
+      }
+
+      if (AST::UiQualifiedId *qualifiedId = reparseAsQualifiedId(sym(1).Expression)) {
+        sym(1).UiQualifiedId = qualifiedId;
+      } else {
+        sym(1).UiQualifiedId = 0;
+
+        diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
+          QLatin1String("Expected a qualified name id")));
+
+        return false; // ### recover
+      }
+    } break;
 ./
 
-UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType JsIdentifier T_AUTOMATIC_SEMICOLON ;
-UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType JsIdentifier T_SEMICOLON ;
+UiObjectMember: T_ENUM T_IDENTIFIER T_LBRACE EnumMemberList T_RBRACE;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
-    node->isDefaultMember = true;
-    node->defaultToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->semicolonToken = loc(5);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiEnumDeclaration *enumDeclaration = new (pool) AST::UiEnumDeclaration(stringRef(2), sym(4).UiEnumMemberList->finish());
+        enumDeclaration->enumToken = loc(1);
+        enumDeclaration->rbraceToken = loc(5);
+        sym(1).Node = enumDeclaration;
+        break;
+    }
 ./
 
-UiObjectMember: T_DEFAULT T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT JsIdentifier T_AUTOMATIC_SEMICOLON ;
-UiObjectMember: T_DEFAULT T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT JsIdentifier T_SEMICOLON ;
+EnumMemberList: T_IDENTIFIER;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(5).UiQualifiedId->finish(), stringRef(7));
-    node->isDefaultMember = true;
-    node->defaultToken = loc(1);
-    node->typeModifier = stringRef(3);
-    node->propertyToken = loc(2);
-    node->typeModifierToken = loc(2);
-    node->typeToken = loc(4);
-    node->identifierToken = loc(7);
-    node->semicolonToken = loc(8);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiEnumMemberList *node = new (pool) AST::UiEnumMemberList(stringRef(1));
+        node->memberToken = loc(1);
+        sym(1).Node = node;
+        break;
+    }
 ./
 
-UiObjectMember: T_PROPERTY UiPropertyType JsIdentifier T_COLON UiScriptStatement ;
+EnumMemberList: T_IDENTIFIER T_EQ T_NUMERIC_LITERAL;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3),
-        sym(5).Statement);
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(3);
-    node->colonToken = loc(4);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiEnumMemberList *node = new (pool) AST::UiEnumMemberList(stringRef(1), sym(3).dval);
+        node->memberToken = loc(1);
+        node->valueToken = loc(3);
+        sym(1).Node = node;
+        break;
+    }
 ./
 
-UiObjectMember: T_READONLY T_PROPERTY UiPropertyType JsIdentifier T_COLON UiScriptStatement ;
+EnumMemberList: EnumMemberList T_COMMA T_IDENTIFIER;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4),
-        sym(6).Statement);
-    node->isReadonlyMember = true;
-    node->readonlyToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->colonToken = loc(5);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiEnumMemberList *node = new (pool) AST::UiEnumMemberList(sym(1).UiEnumMemberList, stringRef(3));
+        node->memberToken = loc(3);
+        sym(1).Node = node;
+        break;
+    }
 ./
 
-UiObjectMember: T_DEFAULT T_PROPERTY UiPropertyType JsIdentifier T_COLON UiScriptStatement ;
+EnumMemberList: EnumMemberList T_COMMA T_IDENTIFIER T_EQ T_NUMERIC_LITERAL;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4),
-        sym(6).Statement);
-    node->isDefaultMember = true;
-    node->defaultToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->colonToken = loc(5);
-    sym(1).Node = node;
-}   break;
+    case $rule_number: {
+        AST::UiEnumMemberList *node = new (pool) AST::UiEnumMemberList(sym(1).UiEnumMemberList, stringRef(3), sym(5).dval);
+        node->memberToken = loc(3);
+        node->valueToken = loc(5);
+        sym(1).Node = node;
+        break;
+    }
 ./
 
-UiObjectMember: T_PROPERTY T_IDENTIFIER T_LT UiPropertyType T_GT JsIdentifier T_COLON T_LBRACKET UiArrayMemberList T_RBRACKET ;
+QmlIdentifier: T_IDENTIFIER;
+QmlIdentifier: T_PROPERTY;
+QmlIdentifier: T_SIGNAL;
+QmlIdentifier: T_READONLY;
+QmlIdentifier: T_ON;
+QmlIdentifier: T_GET;
+QmlIdentifier: T_SET;
+QmlIdentifier: T_FROM;
+QmlIdentifier: T_OF;
+
+JsIdentifier: T_IDENTIFIER;
+JsIdentifier: T_PROPERTY;
+JsIdentifier: T_SIGNAL;
+JsIdentifier: T_READONLY;
+JsIdentifier: T_ON;
+JsIdentifier: T_GET;
+JsIdentifier: T_SET;
+JsIdentifier: T_FROM;
+JsIdentifier: T_STATIC;
+JsIdentifier: T_OF;
+JsIdentifier: T_AS;
+
+IdentifierReference: JsIdentifier;
+BindingIdentifier: IdentifierReference;
+
+--------------------------------------------------------------------------------------------------------
+-- Expressions
+--------------------------------------------------------------------------------------------------------
+
+PrimaryExpression: T_THIS;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
-    node->typeModifier = stringRef(2);
-    node->propertyToken = loc(1);
-    node->typeModifierToken = loc(2);
-    node->typeToken = loc(4);
-    node->identifierToken = loc(6);
-    node->semicolonToken = loc(7); // insert a fake ';' before ':'
-
-    AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(6));
-    propertyName->identifierToken = loc(6);
-    propertyName->next = 0;
-
-    AST::UiArrayBinding *binding = new (pool) AST::UiArrayBinding(
-        propertyName, sym(9).UiArrayMemberList->finish());
-    binding->colonToken = loc(7);
-    binding->lbracketToken = loc(8);
-    binding->rbracketToken = loc(10);
-
-    node->binding = binding;
+    case $rule_number: {
+        AST::ThisExpression *node = new (pool) AST::ThisExpression();
+        node->thisToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-    sym(1).Node = node;
-}   break;
+PrimaryExpression: IdentifierReference;
+/.
+    case $rule_number: {
+        AST::IdentifierExpression *node = new (pool) AST::IdentifierExpression(stringRef(1));
+        node->identifierToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMember: T_PROPERTY UiPropertyType JsIdentifier T_COLON UiQualifiedId UiObjectInitializer ;
+PrimaryExpression: Literal;
+PrimaryExpression: ArrayLiteral;
+PrimaryExpression: ObjectLiteral;
+PrimaryExpression: FunctionExpression;
+PrimaryExpression: ClassExpression;
+PrimaryExpression: GeneratorExpression;
+PrimaryExpression: RegularExpressionLiteral;
+PrimaryExpression: TemplateLiteral;
+
+PrimaryExpression: CoverParenthesizedExpressionAndArrowParameterList;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(3);
-    node->semicolonToken = loc(4); // insert a fake ';' before ':'
+    case $rule_number: {
+        if (coverExpressionType != CE_ParenthesizedExpression) {
+            syntaxError(coverExpressionErrorLocation, "Expected token ')'.");
+            return false;
+        }
+    } break;
+./
 
-    AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(3));
-    propertyName->identifierToken = loc(3);
-    propertyName->next = 0;
+-- Parsing of the CoverParenthesizedExpressionAndArrowParameterList is restricted to the one rule below when this is parsed as a primary expression
+CoverParenthesizedExpressionAndArrowParameterList: T_LPAREN Expression_In T_RPAREN;
+/.
+    case $rule_number: {
+        AST::NestedExpression *node = new (pool) AST::NestedExpression(sym(2).Expression);
+        node->lparenToken = loc(1);
+        node->rparenToken = loc(3);
+        sym(1).Node = node;
+        coverExpressionType = CE_ParenthesizedExpression;
+    } break;
+./
 
-    AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
-      propertyName, sym(5).UiQualifiedId, sym(6).UiObjectInitializer);
-    binding->colonToken = loc(4);
+CoverParenthesizedExpressionAndArrowParameterList: T_LPAREN T_RPAREN;
+/.
+    case $rule_number: {
+        sym(1).Node = nullptr;
+        coverExpressionErrorLocation = loc(2);
+        coverExpressionType = CE_FormalParameterList;
+    } break;
+./
 
-    node->binding = binding;
+CoverParenthesizedExpressionAndArrowParameterList: T_LPAREN BindingRestElement T_RPAREN;
+/.
+    case $rule_number: {
+        AST::FormalParameterList *node = (new (pool) AST::FormalParameterList(nullptr, sym(2).PatternElement))->finish(pool);
+        sym(1).Node = node;
+        coverExpressionErrorLocation = loc(2);
+        coverExpressionType = CE_FormalParameterList;
+    } break;
+./
 
-    sym(1).Node = node;
-}   break;
+CoverParenthesizedExpressionAndArrowParameterList: T_LPAREN Expression_In T_COMMA BindingRestElementOpt T_RPAREN;
+/.
+    case $rule_number: {
+        AST::FormalParameterList *list = sym(2).Expression->reparseAsFormalParameterList(pool);
+        if (!list) {
+            syntaxError(loc(1), "Invalid Arrow parameter list.");
+            return false;
+        }
+        if (sym(4).Node) {
+            list = new (pool) AST::FormalParameterList(list, sym(4).PatternElement);
+        }
+        coverExpressionErrorLocation = loc(4);
+        coverExpressionType = CE_FormalParameterList;
+        sym(1).Node = list->finish(pool);
+    } break;
 ./
 
-UiObjectMember: T_READONLY T_PROPERTY UiPropertyType JsIdentifier T_COLON UiQualifiedId UiObjectInitializer ;
+Literal: T_NULL;
 /.
-case $rule_number: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
-    node->isReadonlyMember = true;
-    node->readonlyToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->semicolonToken = loc(5); // insert a fake ';' before ':'
+    case $rule_number: {
+        AST::NullExpression *node = new (pool) AST::NullExpression();
+        node->nullToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-    AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(4));
-    propertyName->identifierToken = loc(4);
-    propertyName->next = 0;
+Literal: T_TRUE;
+/.
+    case $rule_number: {
+        AST::TrueLiteral *node = new (pool) AST::TrueLiteral();
+        node->trueToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-    AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
-      propertyName, sym(6).UiQualifiedId, sym(7).UiObjectInitializer);
-    binding->colonToken = loc(5);
+Literal: T_FALSE;
+/.
+    case $rule_number: {
+        AST::FalseLiteral *node = new (pool) AST::FalseLiteral();
+        node->falseToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
+
+Literal: T_NUMERIC_LITERAL;
+/.
+    case $rule_number: {
+        AST::NumericLiteral *node = new (pool) AST::NumericLiteral(sym(1).dval);
+        node->literalToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-    node->binding = binding;
+Literal: T_MULTILINE_STRING_LITERAL;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
 
-    sym(1).Node = node;
-}   break;
+Literal: T_STRING_LITERAL;
+/.
+    case $rule_number: {
+        AST::StringLiteral *node = new (pool) AST::StringLiteral(stringRef(1));
+        node->literalToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-UiObjectMember: FunctionDeclaration ;
+RegularExpressionLiteral: T_DIVIDE_;
+/:
+#define J_SCRIPT_REGEXPLITERAL_RULE1 $rule_number
+:/
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
-}   break;
+{
+    Lexer::RegExpBodyPrefix prefix;
+    case $rule_number:
+        prefix = Lexer::NoPrefix;
+        goto scan_regexp;
 ./
 
-UiObjectMember: VariableStatement ;
+RegularExpressionLiteral: T_DIVIDE_EQ;
+/:
+#define J_SCRIPT_REGEXPLITERAL_RULE2 $rule_number
+:/
 /.
-case $rule_number: {
-    sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
-}   break;
+    case $rule_number:
+        prefix = Lexer::EqualPrefix;
+        goto scan_regexp;
+
+    scan_regexp: {
+        bool rx = lexer->scanRegExp(prefix);
+        if (!rx) {
+            diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location(lexer), lexer->errorMessage()));
+            return false;
+        }
+
+        loc(1).length = lexer->tokenLength();
+        yylloc = loc(1); // adjust the location of the current token
+
+        AST::RegExpLiteral *node = new (pool) AST::RegExpLiteral(driver->newStringRef(lexer->regExpPattern()), lexer->regExpFlags());
+        node->literalToken = loc(1);
+        sym(1).Node = node;
+    } break;
+}
 ./
 
-JsIdentifier: T_IDENTIFIER;
 
-JsIdentifier: T_PROPERTY ;
-JsIdentifier: T_SIGNAL ;
-JsIdentifier: T_READONLY ;
-JsIdentifier: T_ON ;
-JsIdentifier: T_GET ;
-JsIdentifier: T_SET ;
+ArrayLiteral: T_LBRACKET ElisionOpt T_RBRACKET;
+/.
+    case $rule_number: {
+        AST::PatternElementList *list = nullptr;
+        if (sym(2).Elision)
+            list = (new (pool) AST::PatternElementList(sym(2).Elision, nullptr))->finish();
+        AST::ArrayPattern *node = new (pool) AST::ArrayPattern(list);
+        node->lbracketToken = loc(1);
+        node->rbracketToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
 
---------------------------------------------------------------------------------------------------------
--- Expressions
---------------------------------------------------------------------------------------------------------
+ArrayLiteral: T_LBRACKET ElementList T_RBRACKET;
+/.
+    case $rule_number: {
+        AST::ArrayPattern *node = new (pool) AST::ArrayPattern(sym(2).PatternElementList->finish());
+        node->lbracketToken = loc(1);
+        node->rbracketToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
 
-PrimaryExpression: T_THIS ;
+ArrayLiteral: T_LBRACKET ElementList T_COMMA ElisionOpt T_RBRACKET;
 /.
-case $rule_number: {
-  AST::ThisExpression *node = new (pool) AST::ThisExpression();
-  node->thisToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        auto *list = sym(2).PatternElementList;
+        if (sym(4).Elision) {
+            AST::PatternElementList *l = new (pool) AST::PatternElementList(sym(4).Elision, nullptr);
+            list = list->append(l);
+        }
+        AST::ArrayPattern *node = new (pool) AST::ArrayPattern(list->finish());
+        node->lbracketToken = loc(1);
+        node->commaToken = loc(3);
+        node->rbracketToken = loc(5);
+        sym(1).Node = node;
+        Q_ASSERT(node->isValidArrayLiteral());
+    } break;
 ./
 
-PrimaryExpression: JsIdentifier ;
+ElementList: AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::IdentifierExpression *node = new (pool) AST::IdentifierExpression(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElement *e = new (pool) AST::PatternElement(sym(1).Expression);
+        sym(1).Node = new (pool) AST::PatternElementList(nullptr, e);
+    } break;
 ./
 
-PrimaryExpression: T_NULL ;
+ElementList: Elision AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::NullExpression *node = new (pool) AST::NullExpression();
-  node->nullToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElement *e = new (pool) AST::PatternElement(sym(2).Expression);
+        sym(1).Node = new (pool) AST::PatternElementList(sym(1).Elision->finish(), e);
+    } break;
 ./
 
-PrimaryExpression: T_TRUE ;
+ElementList: ElisionOpt SpreadElement;
 /.
-case $rule_number: {
-  AST::TrueLiteral *node = new (pool) AST::TrueLiteral();
-  node->trueToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElementList *node = new (pool) AST::PatternElementList(sym(1).Elision, sym(2).PatternElement);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_FALSE ;
+ElementList: ElementList T_COMMA ElisionOpt AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::FalseLiteral *node = new (pool) AST::FalseLiteral();
-  node->falseToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElement *e = new (pool) AST::PatternElement(sym(4).Expression);
+        AST::PatternElementList *node = new (pool) AST::PatternElementList(sym(3).Elision, e);
+        sym(1).Node = sym(1).PatternElementList->append(node);
+    } break;
 ./
 
-PrimaryExpression: T_NUMERIC_LITERAL ;
+ElementList: ElementList T_COMMA ElisionOpt SpreadElement;
 /.
-case $rule_number: {
-  AST::NumericLiteral *node = new (pool) AST::NumericLiteral(sym(1).dval);
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElementList *node = new (pool) AST::PatternElementList(sym(3).Elision, sym(4).PatternElement);
+        sym(1).Node = sym(1).PatternElementList->append(node);
+    } break;
 ./
 
-PrimaryExpression: T_MULTILINE_STRING_LITERAL ;
-/.case $rule_number:./
+Elision: T_COMMA;
+/.
+    case $rule_number: {
+        AST::Elision *node = new (pool) AST::Elision();
+        node->commaToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-PrimaryExpression: T_STRING_LITERAL ;
+Elision: Elision T_COMMA;
 /.
-case $rule_number: {
-  AST::StringLiteral *node = new (pool) AST::StringLiteral(stringRef(1));
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::Elision *node = new (pool) AST::Elision(sym(1).Elision);
+        node->commaToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_DIVIDE_ ;
-/:
-#define J_SCRIPT_REGEXPLITERAL_RULE1 $rule_number
-:/
+ElisionOpt: ;
 /.
-case $rule_number: {
-  bool rx = lexer->scanRegExp(Lexer::NoPrefix);
-  if (!rx) {
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location(lexer), lexer->errorMessage()));
-    return false; // ### remove me
-  }
-
-  loc(1).length = lexer->tokenLength();
-  yylloc = loc(1); // adjust the location of the current token
-
-  AST::RegExpLiteral *node = new (pool) AST::RegExpLiteral(
-    driver->newStringRef(lexer->regExpPattern()), lexer->regExpFlags());
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-PrimaryExpression: T_DIVIDE_EQ ;
-/:
-#define J_SCRIPT_REGEXPLITERAL_RULE2 $rule_number
-:/
+ElisionOpt: Elision;
 /.
-case $rule_number: {
-  bool rx = lexer->scanRegExp(Lexer::EqualPrefix);
-  if (!rx) {
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location(lexer), lexer->errorMessage()));
-    return false;
-  }
+    case $rule_number: {
+        sym(1).Node = sym(1).Elision->finish();
+    } break;
+./
+
+SpreadElement: T_ELLIPSIS AssignmentExpression;
+/.
+    case $rule_number: {
+        AST::PatternElement *node = new (pool) AST::PatternElement(sym(2).Expression, AST::PatternElement::SpreadElement);
+        sym(1).Node = node;
+    } break;
+./
 
-  loc(1).length = lexer->tokenLength();
-  yylloc = loc(1); // adjust the location of the current token
+ObjectLiteral: T_LBRACE T_RBRACE;
+/.
+    case $rule_number: {
+        AST::ObjectPattern *node = new (pool) AST::ObjectPattern();
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
 
-  AST::RegExpLiteral *node = new (pool) AST::RegExpLiteral(
-    driver->newStringRef(lexer->regExpPattern()), lexer->regExpFlags());
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
+ObjectLiteral: T_LBRACE PropertyDefinitionList T_RBRACE;
+/.
+    case $rule_number: {
+        AST::ObjectPattern *node = new (pool) AST::ObjectPattern(sym(2).PatternPropertyList->finish());
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_LBRACKET T_RBRACKET ;
+ObjectLiteral: T_LBRACE PropertyDefinitionList T_COMMA T_RBRACE;
 /.
-case $rule_number: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral((AST::Elision *) 0);
-  node->lbracketToken = loc(1);
-  node->rbracketToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ObjectPattern *node = new (pool) AST::ObjectPattern(sym(2).PatternPropertyList->finish());
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_LBRACKET Elision T_RBRACKET ;
+
+UiPropertyDefinitionList: UiPropertyDefinition;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+PropertyDefinitionList: PropertyDefinition;
 /.
-case $rule_number: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).Elision->finish());
-  node->lbracketToken = loc(1);
-  node->rbracketToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+      sym(1).Node = new (pool) AST::PatternPropertyList(sym(1).PatternProperty);
+    } break;
 ./
 
-PrimaryExpression: T_LBRACKET ElementList T_RBRACKET ;
+UiPropertyDefinitionList: UiPropertyDefinitionList T_COMMA UiPropertyDefinition;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+PropertyDefinitionList: PropertyDefinitionList T_COMMA PropertyDefinition;
 /.
-case $rule_number: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).ElementList->finish ());
-  node->lbracketToken = loc(1);
-  node->rbracketToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternPropertyList *node = new (pool) AST::PatternPropertyList(sym(1).PatternPropertyList, sym(3).PatternProperty);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_LBRACKET ElementList T_COMMA T_RBRACKET ;
+PropertyDefinition: IdentifierReference;
 /.
-case $rule_number: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).ElementList->finish (),
-    (AST::Elision *) 0);
-  node->lbracketToken = loc(1);
-  node->commaToken = loc(3);
-  node->rbracketToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::IdentifierPropertyName *name = new (pool) AST::IdentifierPropertyName(stringRef(1));
+        name->propertyNameToken = loc(1);
+        AST::IdentifierExpression *expr = new (pool) AST::IdentifierExpression(stringRef(1));
+        expr->identifierToken = loc(1);
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(name, expr);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_LBRACKET ElementList T_COMMA Elision T_RBRACKET ;
+-- Using this production should result in a syntax error when used in an ObjectLiteral
+PropertyDefinition: CoverInitializedName;
+
+CoverInitializedName: IdentifierReference Initializer_In;
 /.
-case $rule_number: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).ElementList->finish (),
-    sym(4).Elision->finish());
-  node->lbracketToken = loc(1);
-  node->commaToken = loc(3);
-  node->rbracketToken = loc(5);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::IdentifierPropertyName *name = new (pool) AST::IdentifierPropertyName(stringRef(1));
+        name->propertyNameToken = loc(1);
+        AST::IdentifierExpression *left = new (pool) AST::IdentifierExpression(stringRef(1));
+        left->identifierToken = loc(1);
+        // if initializer is an anonymous function expression, we need to assign identifierref as it's name
+        if (auto *f = asAnonymousFunctionDefinition(sym(2).Expression))
+            f->name = stringRef(1);
+        if (auto *c = asAnonymousClassDefinition(sym(2).Expression))
+            c->name = stringRef(1);
+        AST::BinaryExpression *assignment = new (pool) AST::BinaryExpression(left, QSOperator::Assign, sym(2).Expression);
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(name, assignment);
+        node->colonToken = loc(1);
+        sym(1).Node = node;
+
+    } break;
 ./
 
--- PrimaryExpression: T_LBRACE T_RBRACE ;
--- /.
--- case $rule_number: {
---   sym(1).Node = new (pool) AST::ObjectLiteral();
--- } break;
--- ./
+UiPropertyDefinition: UiPropertyName T_COLON AssignmentExpression_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+PropertyDefinition: PropertyName T_COLON AssignmentExpression_In;
+/.
+    case $rule_number: {
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(1).PropertyName, sym(3).Expression);
+        if (auto *f = asAnonymousFunctionDefinition(sym(3).Expression)) {
+            if (!AST::cast<AST::ComputedPropertyName *>(sym(1).PropertyName))
+                f->name = driver->newStringRef(sym(1).PropertyName->asString());
+        }
+        if (auto *c = asAnonymousClassDefinition(sym(3).Expression)) {
+            if (!AST::cast<AST::ComputedPropertyName *>(sym(1).PropertyName))
+                c->name = driver->newStringRef(sym(1).PropertyName->asString());
+        }
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
+
+PropertyDefinition: MethodDefinition;
+
+PropertyName: LiteralPropertyName;
+PropertyName: ComputedPropertyName;
+
+LiteralPropertyName: IdentifierName;
+/.
+    case $rule_number: {
+        AST::IdentifierPropertyName *node = new (pool) AST::IdentifierPropertyName(stringRef(1));
+        node->propertyNameToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-PrimaryExpression: T_LBRACE PropertyAssignmentListOpt T_RBRACE ;
+UiPropertyName: T_STRING_LITERAL;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LiteralPropertyName: T_STRING_LITERAL;
 /.
-case $rule_number: {
-  AST::ObjectLiteral *node = 0;
-  if (sym(2).Node)
-    node = new (pool) AST::ObjectLiteral(
-        sym(2).PropertyAssignmentList->finish ());
-  else
-    node = new (pool) AST::ObjectLiteral();
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::StringLiteralPropertyName *node = new (pool) AST::StringLiteralPropertyName(stringRef(1));
+        node->propertyNameToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_LBRACE PropertyAssignmentList T_COMMA T_RBRACE ;
+UiPropertyName: T_NUMERIC_LITERAL;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LiteralPropertyName: T_NUMERIC_LITERAL;
 /.
-case $rule_number: {
-  AST::ObjectLiteral *node = new (pool) AST::ObjectLiteral(
-    sym(2).PropertyAssignmentList->finish ());
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::NumericLiteralPropertyName *node = new (pool) AST::NumericLiteralPropertyName(sym(1).dval);
+        node->propertyNameToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-PrimaryExpression: T_LPAREN Expression T_RPAREN ;
+IdentifierName: IdentifierReference;
+IdentifierName: ReservedIdentifier;
+
+ReservedIdentifier: T_BREAK;
+ReservedIdentifier: T_CASE;
+ReservedIdentifier: T_CATCH;
+ReservedIdentifier: T_CONTINUE;
+ReservedIdentifier: T_DEFAULT;
+ReservedIdentifier: T_DELETE;
+ReservedIdentifier: T_DO;
+ReservedIdentifier: T_ELSE;
+ReservedIdentifier: T_ENUM;
+ReservedIdentifier: T_FALSE;
+ReservedIdentifier: T_FINALLY;
+ReservedIdentifier: T_FOR;
+ReservedIdentifier: T_FUNCTION;
+ReservedIdentifier: T_IF;
+ReservedIdentifier: T_IN;
+ReservedIdentifier: T_INSTANCEOF;
+ReservedIdentifier: T_NEW;
+ReservedIdentifier: T_NULL;
+ReservedIdentifier: T_RETURN;
+ReservedIdentifier: T_SWITCH;
+ReservedIdentifier: T_THIS;
+ReservedIdentifier: T_THROW;
+ReservedIdentifier: T_TRUE;
+ReservedIdentifier: T_TRY;
+ReservedIdentifier: T_TYPEOF;
+ReservedIdentifier: T_VAR;
+ReservedIdentifier: T_VOID;
+ReservedIdentifier: T_WHILE;
+ReservedIdentifier: T_CONST;
+ReservedIdentifier: T_LET;
+ReservedIdentifier: T_DEBUGGER;
+ReservedIdentifier: T_RESERVED_WORD;
+ReservedIdentifier: T_SUPER;
+ReservedIdentifier: T_WITH;
+ReservedIdentifier: T_CLASS;
+ReservedIdentifier: T_EXTENDS;
+ReservedIdentifier: T_EXPORT;
+ReservedIdentifier: T_IMPORT;
+
+ComputedPropertyName: T_LBRACKET AssignmentExpression_In T_RBRACKET;
+/.
+    case $rule_number: {
+        AST::ComputedPropertyName *node = new (pool) AST::ComputedPropertyName(sym(2).Expression);
+        node->propertyNameToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
+
+Initializer: T_EQ AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Initializer_In: T_EQ AssignmentExpression_In;
 /.
 case $rule_number: {
-  AST::NestedExpression *node = new (pool) AST::NestedExpression(sym(2).Expression);
-  node->lparenToken = loc(1);
-  node->rparenToken = loc(3);
-  sym(1).Node = node;
+    sym(1) = sym(2);
 } break;
 ./
 
 
-UiQualifiedId: MemberExpression ;
+InitializerOpt: ;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+InitializerOpt_In: ;
 /.
-case $rule_number: {
-  if (AST::ArrayMemberExpression *mem = AST::cast<AST::ArrayMemberExpression *>(sym(1).Expression)) {
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Warning, mem->lbracketToken,
-      QLatin1String("Ignored annotation")));
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
+./
 
-    sym(1).Expression = mem->base;
-  }
+InitializerOpt: Initializer;
+InitializerOpt_In: Initializer_In;
 
-  if (AST::UiQualifiedId *qualifiedId = reparseAsQualifiedId(sym(1).Expression)) {
-    sym(1).UiQualifiedId = qualifiedId;
-  } else {
-    sym(1).UiQualifiedId = 0;
+TemplateLiteral: T_NO_SUBSTITUTION_TEMPLATE;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
 
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
-      QLatin1String("Expected a qualified name id")));
+TemplateSpans: T_TEMPLATE_TAIL;
+/.
+    case $rule_number: {
+        AST::TemplateLiteral *node = new (pool) AST::TemplateLiteral(stringRef(1), rawStringRef(1), nullptr);
+        node->literalToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-    return false; // ### recover
-  }
-} break;
+TemplateSpans: T_TEMPLATE_MIDDLE Expression TemplateSpans;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+
+TemplateLiteral: T_TEMPLATE_HEAD Expression TemplateSpans;
+/.
+    case $rule_number: {
+        AST::TemplateLiteral *node = new (pool) AST::TemplateLiteral(stringRef(1), rawStringRef(1), sym(2).Expression);
+        node->next = sym(3).Template;
+        node->literalToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-ElementList: AssignmentExpression ;
+
+MemberExpression: PrimaryExpression;
+
+Super: T_SUPER;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::ElementList((AST::Elision *) 0, sym(1).Expression);
-} break;
+    case $rule_number: {
+        AST::SuperLiteral *node = new (pool) AST::SuperLiteral();
+        node->superToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-ElementList: Elision AssignmentExpression ;
+
+MemberExpression: Super T_LBRACKET Expression_In T_RBRACKET;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+MemberExpression: MemberExpression T_LBRACKET Expression_In T_RBRACKET;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::ElementList(sym(1).Elision->finish(), sym(2).Expression);
-} break;
+    case $rule_number: {
+        AST::ArrayMemberExpression *node = new (pool) AST::ArrayMemberExpression(sym(1).Expression, sym(3).Expression);
+        node->lbracketToken = loc(2);
+        node->rbracketToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-ElementList: ElementList T_COMMA AssignmentExpression ;
+
+-- the identifier has to be "target", catched at codegen time
+NewTarget: T_NEW T_DOT T_IDENTIFIER;
+/.  case $rule_number:
+    {
+        AST::IdentifierExpression *node = new (pool) AST::IdentifierExpression(stringRef(1));
+        node->identifierToken= loc(1);
+        sym(1).Node = node;
+    } Q_FALLTHROUGH();
+./
+MemberExpression: Super T_DOT IdentifierName;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+MemberExpression: MemberExpression T_DOT IdentifierName;
 /.
-case $rule_number: {
-  AST::ElementList *node = new (pool) AST::ElementList(sym(1).ElementList,
-    (AST::Elision *) 0, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FieldMemberExpression *node = new (pool) AST::FieldMemberExpression(sym(1).Expression, stringRef(3));
+        node->dotToken = loc(2);
+        node->identifierToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-ElementList: ElementList T_COMMA Elision AssignmentExpression ;
+MemberExpression: MetaProperty;
+
+MemberExpression: T_NEW MemberExpression T_LPAREN Arguments T_RPAREN;
 /.
-case $rule_number: {
-  AST::ElementList *node = new (pool) AST::ElementList(sym(1).ElementList, sym(3).Elision->finish(),
-    sym(4).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::NewMemberExpression *node = new (pool) AST::NewMemberExpression(sym(2).Expression, sym(4).ArgumentList);
+        node->newToken = loc(1);
+        node->lparenToken = loc(3);
+        node->rparenToken = loc(5);
+        sym(1).Node = node;
+    } break;
 ./
 
-Elision: T_COMMA ;
+MetaProperty: NewTarget;
+
+
+NewExpression: MemberExpression;
+
+NewExpression: T_NEW NewExpression;
 /.
-case $rule_number: {
-  AST::Elision *node = new (pool) AST::Elision();
-  node->commaToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::NewExpression *node = new (pool) AST::NewExpression(sym(2).Expression);
+        node->newToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-Elision: Elision T_COMMA ;
+
+CallExpression: CallExpression TemplateLiteral;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+MemberExpression: MemberExpression TemplateLiteral;
 /.
-case $rule_number: {
-  AST::Elision *node = new (pool) AST::Elision(sym(1).Elision);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::TaggedTemplate *node = new (pool) AST::TaggedTemplate(sym(1).Expression, sym(2).Template);
+        sym(1).Node = node;
+    } break;
 ./
 
-PropertyAssignment: PropertyName T_COLON AssignmentExpression ;
+CallExpression: MemberExpression T_LPAREN Arguments T_RPAREN;
 /.
-case $rule_number: {
-  AST::PropertyNameAndValue *node = new (pool) AST::PropertyNameAndValue(
-      sym(1).PropertyName, sym(3).Expression);
-  node->colonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::CallExpression *node = new (pool) AST::CallExpression(sym(1).Expression, sym(3).ArgumentList);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-PropertyAssignment: T_GET PropertyName T_LPAREN T_RPAREN T_LBRACE FunctionBodyOpt T_RBRACE ;
+CallExpression: Super T_LPAREN Arguments T_RPAREN;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+CallExpression: CallExpression T_LPAREN Arguments T_RPAREN;
 /.
-case $rule_number: {
-  AST::PropertyGetterSetter *node = new (pool) AST::PropertyGetterSetter(
-      sym(2).PropertyName, sym(6).FunctionBody);
-  node->getSetToken = loc(1);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(4);
-  node->lbraceToken = loc(5);
-  node->rbraceToken = loc(7);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::CallExpression *node = new (pool) AST::CallExpression(sym(1).Expression, sym(3).ArgumentList);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-PropertyAssignment: T_SET PropertyName T_LPAREN FormalParameterListOpt T_RPAREN T_LBRACE FunctionBodyOpt T_RBRACE ;
+CallExpression: CallExpression T_LBRACKET Expression_In T_RBRACKET;
 /.
-case $rule_number: {
-  AST::PropertyGetterSetter *node = new (pool) AST::PropertyGetterSetter(
-      sym(2).PropertyName, sym(4).FormalParameterList, sym(7).FunctionBody);
-  node->getSetToken = loc(1);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  node->lbraceToken = loc(6);
-  node->rbraceToken = loc(8);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ArrayMemberExpression *node = new (pool) AST::ArrayMemberExpression(sym(1).Expression, sym(3).Expression);
+        node->lbracketToken = loc(2);
+        node->rbracketToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-PropertyAssignmentList: PropertyAssignment ;
+CallExpression: CallExpression T_DOT IdentifierName;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::PropertyAssignmentList(sym(1).PropertyAssignment);
-} break;
+    case $rule_number: {
+        AST::FieldMemberExpression *node = new (pool) AST::FieldMemberExpression(sym(1).Expression, stringRef(3));
+        node->dotToken = loc(2);
+        node->identifierToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-PropertyAssignmentList: PropertyAssignmentList T_COMMA PropertyAssignment ;
+Arguments: ;
 /.
-case $rule_number: {
-  AST::PropertyAssignmentList *node = new (pool) AST::PropertyAssignmentList(
-    sym(1).PropertyAssignmentList, sym(3).PropertyAssignment);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-PropertyName: JsIdentifier %prec SHIFT_THERE ;
+Arguments: ArgumentList;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Arguments: ArgumentList T_COMMA;
 /.
-case $rule_number: {
-  AST::IdentifierPropertyName *node = new (pool) AST::IdentifierPropertyName(stringRef(1));
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).ArgumentList->finish();
+    } break;
 ./
 
-PropertyName: T_STRING_LITERAL ;
+ArgumentList: AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::StringLiteralPropertyName *node = new (pool) AST::StringLiteralPropertyName(stringRef(1));
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::ArgumentList(sym(1).Expression);
+    } break;
 ./
 
-PropertyName: T_NUMERIC_LITERAL ;
+ArgumentList: T_ELLIPSIS AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::NumericLiteralPropertyName *node = new (pool) AST::NumericLiteralPropertyName(sym(1).dval);
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ArgumentList *node = new (pool) AST::ArgumentList(sym(2).Expression);
+        node->isSpreadElement = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-PropertyName: ReservedIdentifier ;
+ArgumentList: ArgumentList T_COMMA AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::IdentifierPropertyName *node = new (pool) AST::IdentifierPropertyName(stringRef(1));
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ArgumentList *node = new (pool) AST::ArgumentList(sym(1).ArgumentList, sym(3).Expression);
+        node->commaToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-ReservedIdentifier: T_BREAK ;
-ReservedIdentifier: T_CASE ;
-ReservedIdentifier: T_CATCH ;
-ReservedIdentifier: T_CONTINUE ;
-ReservedIdentifier: T_DEFAULT ;
-ReservedIdentifier: T_DELETE ;
-ReservedIdentifier: T_DO ;
-ReservedIdentifier: T_ELSE ;
-ReservedIdentifier: T_FALSE ;
-ReservedIdentifier: T_FINALLY ;
-ReservedIdentifier: T_FOR ;
-ReservedIdentifier: T_FUNCTION ;
-ReservedIdentifier: T_IF ;
-ReservedIdentifier: T_IN ;
-ReservedIdentifier: T_INSTANCEOF ;
-ReservedIdentifier: T_NEW ;
-ReservedIdentifier: T_NULL ;
-ReservedIdentifier: T_RETURN ;
-ReservedIdentifier: T_SWITCH ;
-ReservedIdentifier: T_THIS ;
-ReservedIdentifier: T_THROW ;
-ReservedIdentifier: T_TRUE ;
-ReservedIdentifier: T_TRY ;
-ReservedIdentifier: T_TYPEOF ;
-ReservedIdentifier: T_VAR ;
-ReservedIdentifier: T_VOID ;
-ReservedIdentifier: T_WHILE ;
-ReservedIdentifier: T_CONST ;
-ReservedIdentifier: T_LET ;
-ReservedIdentifier: T_DEBUGGER ;
-ReservedIdentifier: T_RESERVED_WORD ;
-ReservedIdentifier: T_WITH ;
-
-PropertyIdentifier: JsIdentifier ;
-PropertyIdentifier: ReservedIdentifier ;
-
-MemberExpression: PrimaryExpression ;
-MemberExpression: FunctionExpression ;
-
-MemberExpression: MemberExpression T_LBRACKET Expression T_RBRACKET ;
+ArgumentList: ArgumentList T_COMMA T_ELLIPSIS AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::ArrayMemberExpression *node = new (pool) AST::ArrayMemberExpression(sym(1).Expression, sym(3).Expression);
-  node->lbracketToken = loc(2);
-  node->rbracketToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ArgumentList *node = new (pool) AST::ArgumentList(sym(1).ArgumentList, sym(4).Expression);
+        node->commaToken = loc(2);
+        node->isSpreadElement = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-MemberExpression: MemberExpression T_DOT PropertyIdentifier ;
+LeftHandSideExpression: NewExpression;
+LeftHandSideExpression: CallExpression;
+
+UpdateExpression: LeftHandSideExpression;
+
+UpdateExpression: LeftHandSideExpression T_PLUS_PLUS;
 /.
-case $rule_number: {
-  AST::FieldMemberExpression *node = new (pool) AST::FieldMemberExpression(sym(1).Expression, stringRef(3));
-  node->dotToken = loc(2);
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PostIncrementExpression *node = new (pool) AST::PostIncrementExpression(sym(1).Expression);
+        node->incrementToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-MemberExpression: T_NEW MemberExpression T_LPAREN ArgumentListOpt T_RPAREN ;
+UpdateExpression: LeftHandSideExpression T_MINUS_MINUS;
 /.
-case $rule_number: {
-  AST::NewMemberExpression *node = new (pool) AST::NewMemberExpression(sym(2).Expression, sym(4).ArgumentList);
-  node->newToken = loc(1);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PostDecrementExpression *node = new (pool) AST::PostDecrementExpression(sym(1).Expression);
+        node->decrementToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-NewExpression: MemberExpression ;
+UpdateExpression: T_PLUS_PLUS UnaryExpression;
+/.
+    case $rule_number: {
+        AST::PreIncrementExpression *node = new (pool) AST::PreIncrementExpression(sym(2).Expression);
+        node->incrementToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-NewExpression: T_NEW NewExpression ;
+UpdateExpression: T_MINUS_MINUS UnaryExpression;
 /.
-case $rule_number: {
-  AST::NewExpression *node = new (pool) AST::NewExpression(sym(2).Expression);
-  node->newToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PreDecrementExpression *node = new (pool) AST::PreDecrementExpression(sym(2).Expression);
+        node->decrementToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-CallExpression: MemberExpression T_LPAREN ArgumentListOpt T_RPAREN ;
+UnaryExpression: UpdateExpression;
+
+UnaryExpression: T_DELETE UnaryExpression;
 /.
-case $rule_number: {
-  AST::CallExpression *node = new (pool) AST::CallExpression(sym(1).Expression, sym(3).ArgumentList);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::DeleteExpression *node = new (pool) AST::DeleteExpression(sym(2).Expression);
+        node->deleteToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-CallExpression: CallExpression T_LPAREN ArgumentListOpt T_RPAREN ;
+UnaryExpression: T_VOID UnaryExpression;
 /.
-case $rule_number: {
-  AST::CallExpression *node = new (pool) AST::CallExpression(sym(1).Expression, sym(3).ArgumentList);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::VoidExpression *node = new (pool) AST::VoidExpression(sym(2).Expression);
+        node->voidToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-CallExpression: CallExpression T_LBRACKET Expression T_RBRACKET ;
+UnaryExpression: T_TYPEOF UnaryExpression;
 /.
-case $rule_number: {
-  AST::ArrayMemberExpression *node = new (pool) AST::ArrayMemberExpression(sym(1).Expression, sym(3).Expression);
-  node->lbracketToken = loc(2);
-  node->rbracketToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::TypeOfExpression *node = new (pool) AST::TypeOfExpression(sym(2).Expression);
+        node->typeofToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-CallExpression: CallExpression T_DOT PropertyIdentifier ;
+UnaryExpression: T_PLUS UnaryExpression;
 /.
-case $rule_number: {
-  AST::FieldMemberExpression *node = new (pool) AST::FieldMemberExpression(sym(1).Expression, stringRef(3));
-  node->dotToken = loc(2);
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::UnaryPlusExpression *node = new (pool) AST::UnaryPlusExpression(sym(2).Expression);
+        node->plusToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-ArgumentListOpt: ;
+UnaryExpression: T_MINUS UnaryExpression;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::UnaryMinusExpression *node = new (pool) AST::UnaryMinusExpression(sym(2).Expression);
+        node->minusToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-ArgumentListOpt: ArgumentList ;
+UnaryExpression: T_TILDE UnaryExpression;
 /.
-case $rule_number: {
-  sym(1).Node = sym(1).ArgumentList->finish();
-} break;
+    case $rule_number: {
+        AST::TildeExpression *node = new (pool) AST::TildeExpression(sym(2).Expression);
+        node->tildeToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-ArgumentList: AssignmentExpression ;
+UnaryExpression: T_NOT UnaryExpression;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::ArgumentList(sym(1).Expression);
-} break;
+    case $rule_number: {
+        AST::NotExpression *node = new (pool) AST::NotExpression(sym(2).Expression);
+        node->notToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-ArgumentList: ArgumentList T_COMMA AssignmentExpression ;
+ExponentiationExpression: UnaryExpression;
+
+ExponentiationExpression: UpdateExpression T_STAR_STAR ExponentiationExpression;
 /.
-case $rule_number: {
-  AST::ArgumentList *node = new (pool) AST::ArgumentList(sym(1).ArgumentList, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::Exp, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-LeftHandSideExpression: NewExpression ;
-LeftHandSideExpression: CallExpression ;
-PostfixExpression: LeftHandSideExpression ;
+MultiplicativeExpression: ExponentiationExpression;
 
-PostfixExpression: LeftHandSideExpression T_PLUS_PLUS ;
+MultiplicativeExpression: MultiplicativeExpression MultiplicativeOperator ExponentiationExpression;
 /.
-case $rule_number: {
-  AST::PostIncrementExpression *node = new (pool) AST::PostIncrementExpression(sym(1).Expression);
-  node->incrementToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, sym(2).ival, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-PostfixExpression: LeftHandSideExpression T_MINUS_MINUS ;
+MultiplicativeOperator: T_STAR;
 /.
-case $rule_number: {
-  AST::PostDecrementExpression *node = new (pool) AST::PostDecrementExpression(sym(1).Expression);
-  node->decrementToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::Mul;
+    } break;
 ./
 
-UnaryExpression: PostfixExpression ;
+MultiplicativeOperator: T_DIVIDE_;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::Div;
+    } break;
+./
 
-UnaryExpression: T_DELETE UnaryExpression ;
+MultiplicativeOperator: T_REMAINDER;
 /.
-case $rule_number: {
-  AST::DeleteExpression *node = new (pool) AST::DeleteExpression(sym(2).Expression);
-  node->deleteToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::Mod;
+    } break;
 ./
 
-UnaryExpression: T_VOID UnaryExpression ;
+AdditiveExpression: MultiplicativeExpression;
+
+AdditiveExpression: AdditiveExpression T_PLUS MultiplicativeExpression;
 /.
-case $rule_number: {
-  AST::VoidExpression *node = new (pool) AST::VoidExpression(sym(2).Expression);
-  node->voidToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::Add, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UnaryExpression: T_TYPEOF UnaryExpression ;
+AdditiveExpression: AdditiveExpression T_MINUS MultiplicativeExpression;
 /.
-case $rule_number: {
-  AST::TypeOfExpression *node = new (pool) AST::TypeOfExpression(sym(2).Expression);
-  node->typeofToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::Sub, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UnaryExpression: T_PLUS_PLUS UnaryExpression ;
+ShiftExpression: AdditiveExpression;
+
+ShiftExpression: ShiftExpression T_LT_LT AdditiveExpression;
 /.
-case $rule_number: {
-  AST::PreIncrementExpression *node = new (pool) AST::PreIncrementExpression(sym(2).Expression);
-  node->incrementToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::LShift, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UnaryExpression: T_MINUS_MINUS UnaryExpression ;
+ShiftExpression: ShiftExpression T_GT_GT AdditiveExpression;
 /.
-case $rule_number: {
-  AST::PreDecrementExpression *node = new (pool) AST::PreDecrementExpression(sym(2).Expression);
-  node->decrementToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::RShift, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UnaryExpression: T_PLUS UnaryExpression ;
+ShiftExpression: ShiftExpression T_GT_GT_GT AdditiveExpression;
 /.
-case $rule_number: {
-  AST::UnaryPlusExpression *node = new (pool) AST::UnaryPlusExpression(sym(2).Expression);
-  node->plusToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::URShift, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UnaryExpression: T_MINUS UnaryExpression ;
+RelationalExpression_In: ShiftExpression;
+RelationalExpression: ShiftExpression;
+
+RelationalExpression_In: RelationalExpression_In RelationalOperator ShiftExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+RelationalExpression: RelationalExpression RelationalOperator ShiftExpression;
 /.
-case $rule_number: {
-  AST::UnaryMinusExpression *node = new (pool) AST::UnaryMinusExpression(sym(2).Expression);
-  node->minusToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, sym(2).ival, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-UnaryExpression: T_TILDE UnaryExpression ;
+RelationalOperator: T_LT;
 /.
-case $rule_number: {
-  AST::TildeExpression *node = new (pool) AST::TildeExpression(sym(2).Expression);
-  node->tildeToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::Lt;
+    } break;
+./
+RelationalOperator: T_GT;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::Gt;
+    } break;
+./
+RelationalOperator: T_LE;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::Le;
+    } break;
+./
+RelationalOperator: T_GE;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::Ge;
+    } break;
+./
+RelationalOperator: T_INSTANCEOF;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::InstanceOf;
+    } break;
 ./
 
-UnaryExpression: T_NOT UnaryExpression ;
+RelationalExpression_In: RelationalExpression_In T_IN ShiftExpression;
 /.
-case $rule_number: {
-  AST::NotExpression *node = new (pool) AST::NotExpression(sym(2).Expression);
-  node->notToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::In, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-MultiplicativeExpression: UnaryExpression ;
+EqualityExpression_In: RelationalExpression_In;
+EqualityExpression: RelationalExpression;
 
-MultiplicativeExpression: MultiplicativeExpression T_STAR UnaryExpression ;
+EqualityExpression_In: EqualityExpression_In EqualityOperator RelationalExpression_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+EqualityExpression: EqualityExpression EqualityOperator RelationalExpression;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Mul, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, sym(2).ival, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-MultiplicativeExpression: MultiplicativeExpression T_DIVIDE_ UnaryExpression ;
+EqualityOperator: T_EQ_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Div, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::Equal;
+    } break;
 ./
-
-MultiplicativeExpression: MultiplicativeExpression T_REMAINDER UnaryExpression ;
+EqualityOperator: T_NOT_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Mod, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::NotEqual;
+    } break;
 ./
+EqualityOperator: T_EQ_EQ_EQ;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::StrictEqual;
+    } break;
+./
+EqualityOperator: T_NOT_EQ_EQ;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::StrictNotEqual;
+    } break;
+./
+
 
-AdditiveExpression: MultiplicativeExpression ;
+BitwiseANDExpression: EqualityExpression;
+BitwiseANDExpression_In: EqualityExpression_In;
 
-AdditiveExpression: AdditiveExpression T_PLUS MultiplicativeExpression ;
+BitwiseANDExpression: BitwiseANDExpression T_AND EqualityExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+BitwiseANDExpression_In: BitwiseANDExpression_In T_AND EqualityExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Add, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::BitAnd, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-AdditiveExpression: AdditiveExpression T_MINUS MultiplicativeExpression ;
+
+BitwiseXORExpression: BitwiseANDExpression;
+BitwiseXORExpression_In: BitwiseANDExpression_In;
+
+BitwiseXORExpression: BitwiseXORExpression T_XOR BitwiseANDExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+BitwiseXORExpression_In: BitwiseXORExpression_In T_XOR BitwiseANDExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Sub, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::BitXor, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-ShiftExpression: AdditiveExpression ;
+BitwiseORExpression: BitwiseXORExpression;
+BitwiseORExpression_In: BitwiseXORExpression_In;
 
-ShiftExpression: ShiftExpression T_LT_LT AdditiveExpression ;
+BitwiseORExpression: BitwiseORExpression T_OR BitwiseXORExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+BitwiseORExpression_In: BitwiseORExpression_In T_OR BitwiseXORExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::LShift, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::BitOr, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-ShiftExpression: ShiftExpression T_GT_GT AdditiveExpression ;
+LogicalANDExpression: BitwiseORExpression;
+LogicalANDExpression_In: BitwiseORExpression_In;
+
+LogicalANDExpression: LogicalANDExpression T_AND_AND BitwiseORExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LogicalANDExpression_In: LogicalANDExpression_In T_AND_AND BitwiseORExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::RShift, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::And, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-ShiftExpression: ShiftExpression T_GT_GT_GT AdditiveExpression ;
+LogicalORExpression: LogicalANDExpression;
+LogicalORExpression_In: LogicalANDExpression_In;
+
+LogicalORExpression: LogicalORExpression T_OR_OR LogicalANDExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LogicalORExpression_In: LogicalORExpression_In T_OR_OR LogicalANDExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::URShift, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::Or, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-RelationalExpression: ShiftExpression ;
 
-RelationalExpression: RelationalExpression T_LT ShiftExpression ;
+ConditionalExpression: LogicalORExpression;
+ConditionalExpression_In: LogicalORExpression_In;
+
+ConditionalExpression: LogicalORExpression T_QUESTION AssignmentExpression_In T_COLON AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+ConditionalExpression_In: LogicalORExpression_In T_QUESTION AssignmentExpression_In T_COLON AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Lt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ConditionalExpression *node = new (pool) AST::ConditionalExpression(sym(1).Expression, sym(3).Expression, sym(5).Expression);
+        node->questionToken = loc(2);
+        node->colonToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-RelationalExpression: RelationalExpression T_GT ShiftExpression ;
+AssignmentExpression: ConditionalExpression;
+AssignmentExpression_In: ConditionalExpression_In;
+
+AssignmentExpression: YieldExpression;
+AssignmentExpression_In: YieldExpression_In;
+
+AssignmentExpression: ArrowFunction;
+AssignmentExpression_In: ArrowFunction_In;
+
+AssignmentExpression: LeftHandSideExpression T_EQ AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+AssignmentExpression_In: LeftHandSideExpression T_EQ AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Gt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        // need to convert the LHS to an AssignmentPattern if it was an Array/ObjectLiteral
+        if (AST::Pattern *p = sym(1).Expression->patternCast()) {
+            AST::SourceLocation errorLoc;
+            QString errorMsg;
+            if (!p->convertLiteralToAssignmentPattern(pool, &errorLoc, &errorMsg)) {
+                syntaxError(errorLoc, errorMsg);
+                return false;
+            }
+        }
+        // if lhs is an identifier expression and rhs is an anonymous function expression, we need to assign the name of lhs to the function
+        if (auto *f = asAnonymousFunctionDefinition(sym(3).Expression)) {
+            if (auto *id = AST::cast<AST::IdentifierExpression *>(sym(1).Expression))
+                f->name = id->name;
+        }
+        if (auto *c = asAnonymousClassDefinition(sym(3).Expression)) {
+            if (auto *id = AST::cast<AST::IdentifierExpression *>(sym(1).Expression))
+                c->name = id->name;
+        }
+
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, QSOperator::Assign, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-RelationalExpression: RelationalExpression T_LE ShiftExpression ;
+AssignmentExpression: LeftHandSideExpression AssignmentOperator AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+AssignmentExpression_In: LeftHandSideExpression AssignmentOperator AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Le, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression, sym(2).ival, sym(3).Expression);
+        node->operatorToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-RelationalExpression: RelationalExpression T_GE ShiftExpression ;
+AssignmentOperator: T_STAR_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Ge, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceMul;
+    } break;
 ./
 
-RelationalExpression: RelationalExpression T_INSTANCEOF ShiftExpression ;
+AssignmentOperator: T_STAR_STAR_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::InstanceOf, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceExp;
+    } break;
 ./
 
-RelationalExpression: RelationalExpression T_IN ShiftExpression ;
+AssignmentOperator: T_DIVIDE_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::In, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceDiv;
+    } break;
 ./
 
-RelationalExpressionNotIn: ShiftExpression ;
+AssignmentOperator: T_REMAINDER_EQ;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceMod;
+    } break;
+./
 
-RelationalExpressionNotIn: RelationalExpressionNotIn T_LT ShiftExpression ;
+AssignmentOperator: T_PLUS_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Lt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceAdd;
+    } break;
 ./
 
-RelationalExpressionNotIn: RelationalExpressionNotIn T_GT ShiftExpression ;
+AssignmentOperator: T_MINUS_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Gt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceSub;
+    } break;
 ./
 
-RelationalExpressionNotIn: RelationalExpressionNotIn T_LE ShiftExpression ;
+AssignmentOperator: T_LT_LT_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Le, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceLeftShift;
+    } break;
 ./
 
-RelationalExpressionNotIn: RelationalExpressionNotIn T_GE ShiftExpression ;
+AssignmentOperator: T_GT_GT_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-   QSOperator::Ge, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceRightShift;
+    } break;
 ./
 
-RelationalExpressionNotIn: RelationalExpressionNotIn T_INSTANCEOF ShiftExpression ;
+AssignmentOperator: T_GT_GT_GT_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::InstanceOf, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceURightShift;
+    } break;
 ./
 
-EqualityExpression: RelationalExpression ;
+AssignmentOperator: T_AND_EQ;
+/.
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceAnd;
+    } break;
+./
 
-EqualityExpression: EqualityExpression T_EQ_EQ RelationalExpression ;
+AssignmentOperator: T_XOR_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Equal, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceXor;
+    } break;
 ./
 
-EqualityExpression: EqualityExpression T_NOT_EQ RelationalExpression ;
+AssignmentOperator: T_OR_EQ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::NotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).ival = QSOperator::InplaceOr;
+    } break;
 ./
 
-EqualityExpression: EqualityExpression T_EQ_EQ_EQ RelationalExpression ;
+Expression: AssignmentExpression;
+Expression_In: AssignmentExpression_In;
+
+Expression: Expression T_COMMA AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Expression_In: Expression_In T_COMMA AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+          AST::Expression *node = new (pool) AST::Expression(sym(1).Expression, sym(3).Expression);
+          node->commaToken = loc(2);
+          sym(1).Node = node;
+    } break;
 ./
 
-EqualityExpression: EqualityExpression T_NOT_EQ_EQ RelationalExpression ;
+ExpressionOpt: ;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+ExpressionOpt_In: ;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictNotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+      sym(1).Node = nullptr;
+    } break;
 ./
 
-EqualityExpressionNotIn: RelationalExpressionNotIn ;
+ExpressionOpt: Expression;
+ExpressionOpt_In: Expression_In;
+
+-- Statements
 
-EqualityExpressionNotIn: EqualityExpressionNotIn T_EQ_EQ RelationalExpressionNotIn ;
+Statement: ExpressionStatementLookahead T_FORCE_BLOCK BlockStatement;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Equal, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(3).Node;
+    } break;
 ./
 
-EqualityExpressionNotIn: EqualityExpressionNotIn T_NOT_EQ RelationalExpressionNotIn;
+Statement: ExpressionStatementLookahead VariableStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead EmptyStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead ExpressionStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead IfStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead BreakableStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead ContinueStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead BreakStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead ReturnStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead WithStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead LabelledStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead ThrowStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead TryStatement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+Statement: ExpressionStatementLookahead DebuggerStatement;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::NotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+    } break;
 ./
 
-EqualityExpressionNotIn: EqualityExpressionNotIn T_EQ_EQ_EQ RelationalExpressionNotIn ;
+Declaration: HoistableDeclaration;
+Declaration: ClassDeclaration;
+Declaration: LexicalDeclaration_In;
+
+HoistableDeclaration: FunctionDeclaration;
+HoistableDeclaration: GeneratorDeclaration;
+
+HoistableDeclaration_Default: FunctionDeclaration_Default;
+HoistableDeclaration_Default: GeneratorDeclaration_Default;
+
+BreakableStatement: IterationStatement;
+BreakableStatement: SwitchStatement;
+
+BlockStatement: Block;
+
+Block: T_LBRACE StatementListOpt T_RBRACE;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::Block *node = new (pool) AST::Block(sym(2).StatementList);
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-EqualityExpressionNotIn: EqualityExpressionNotIn T_NOT_EQ_EQ RelationalExpressionNotIn ;
+StatementList: StatementListItem;
+
+StatementList: StatementList StatementListItem;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictNotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).StatementList = sym(1).StatementList->append(sym(2).StatementList);
+    } break;
 ./
 
-BitwiseANDExpression: EqualityExpression ;
+StatementListItem: Statement;
+/.
+    case $rule_number: {
+        sym(1).StatementList = new (pool) AST::StatementList(sym(1).Statement);
+    } break;
+./
 
-BitwiseANDExpression: BitwiseANDExpression T_AND EqualityExpression ;
+StatementListItem: ExpressionStatementLookahead T_FORCE_DECLARATION Declaration T_AUTOMATIC_SEMICOLON;
+StatementListItem: ExpressionStatementLookahead T_FORCE_DECLARATION Declaration T_SEMICOLON;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitAnd, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::StatementList(sym(3).FunctionDeclaration);
+    } break;
 ./
 
-BitwiseANDExpressionNotIn: EqualityExpressionNotIn ;
+StatementListOpt: ExpressionStatementLookahead;
+/.
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
+./
 
-BitwiseANDExpressionNotIn: BitwiseANDExpressionNotIn T_AND EqualityExpressionNotIn ;
+StatementListOpt: StatementList;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitAnd, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).StatementList->finish();
+    } break;
 ./
 
-BitwiseXORExpression: BitwiseANDExpression ;
+LetOrConst: T_LET;
+/.
+    case $rule_number: {
+        sym(1).scope = AST::VariableScope::Let;
+    } break;
+./
+LetOrConst: T_CONST;
+/.
+    case $rule_number: {
+        sym(1).scope = AST::VariableScope::Const;
+    } break;
+./
 
-BitwiseXORExpression: BitwiseXORExpression T_XOR BitwiseANDExpression ;
+Var: T_VAR;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitXor, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).scope = AST::VariableScope::Var;
+    } break;
 ./
 
-BitwiseXORExpressionNotIn: BitwiseANDExpressionNotIn ;
+LexicalDeclaration: LetOrConst BindingList;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LexicalDeclaration_In: LetOrConst BindingList_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VarDeclaration: Var VariableDeclarationList;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VarDeclaration_In: Var VariableDeclarationList_In;
+/.
+    case $rule_number: {
+        AST::VariableStatement *node = new (pool) AST::VariableStatement(sym(2).VariableDeclarationList->finish(sym(1).scope));
+        node->declarationKindToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
+
+VariableStatement: VarDeclaration_In T_AUTOMATIC_SEMICOLON;
+VariableStatement: VarDeclaration_In T_SEMICOLON;
 
-BitwiseXORExpressionNotIn: BitwiseXORExpressionNotIn T_XOR BitwiseANDExpressionNotIn ;
+BindingList: LexicalBinding_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+BindingList_In: LexicalBinding_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclarationList: VariableDeclaration;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclarationList_In: VariableDeclaration_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitXor, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).PatternElement);
+    } break;
 ./
 
-BitwiseORExpression: BitwiseXORExpression ;
+BindingList: BindingList T_COMMA LexicalBinding;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+BindingList_In: BindingList_In T_COMMA LexicalBinding_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclarationList: VariableDeclarationList T_COMMA VariableDeclaration;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclarationList_In: VariableDeclarationList_In T_COMMA VariableDeclaration_In;
+/.
+    case $rule_number: {
+        AST::VariableDeclarationList *node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclarationList, sym(3).PatternElement);
+        node->commaToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
 
-BitwiseORExpression: BitwiseORExpression T_OR BitwiseXORExpression ;
+LexicalBinding: BindingIdentifier InitializerOpt;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LexicalBinding_In: BindingIdentifier InitializerOpt_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclaration: BindingIdentifier InitializerOpt;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclaration_In: BindingIdentifier InitializerOpt_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitOr, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        auto *node = new (pool) AST::PatternElement(stringRef(1), sym(2).Expression);
+        node->identifierToken = loc(1);
+        sym(1).Node = node;
+        // if initializer is an anonymous function expression, we need to assign identifierref as it's name
+        if (auto *f = asAnonymousFunctionDefinition(sym(2).Expression))
+            f->name = stringRef(1);
+        if (auto *c = asAnonymousClassDefinition(sym(2).Expression))
+            c->name = stringRef(1);
+    } break;
 ./
 
-BitwiseORExpressionNotIn: BitwiseXORExpressionNotIn ;
+LexicalBinding: BindingPattern Initializer;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+LexicalBinding_In: BindingPattern Initializer_In;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclaration: BindingPattern Initializer;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+VariableDeclaration_In: BindingPattern Initializer_In;
+/.
+    case $rule_number: {
+        auto *node = new (pool) AST::PatternElement(sym(1).Pattern, sym(2).Expression);
+        node->identifierToken = loc(1);
+        sym(1).Node = node;
+    } break;
+./
 
-BitwiseORExpressionNotIn: BitwiseORExpressionNotIn T_OR BitwiseXORExpressionNotIn ;
+BindingPattern:  T_LBRACE ObjectBindingPattern T_RBRACE;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitOr, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        auto *node = new (pool) AST::ObjectPattern(sym(2).PatternPropertyList);
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(3);
+        node->parseMode = AST::Pattern::Binding;
+        sym(1).Node = node;
+    } break;
 ./
 
-LogicalANDExpression: BitwiseORExpression ;
+BindingPattern: T_LBRACKET ArrayBindingPattern T_RBRACKET;
+/.
+    case $rule_number: {
+        auto *node = new (pool) AST::ArrayPattern(sym(2).PatternElementList);
+        node->lbracketToken = loc(1);
+        node->rbracketToken = loc(3);
+        node->parseMode = AST::Pattern::Binding;
+        sym(1).Node = node;
+    } break;
+./
+
+ObjectBindingPattern: ;
+/.
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
+./
+
+ObjectBindingPattern: BindingPropertyList;
+/. case $rule_number: ./
+ObjectBindingPattern: BindingPropertyList T_COMMA;
+/.
+    case $rule_number: {
+        sym(1).Node = sym(1).PatternPropertyList->finish();
+    } break;
+./
+
+ArrayBindingPattern: ElisionOpt BindingRestElementOpt;
+/.
+    case $rule_number: {
+        if (sym(1).Elision || sym(2).Node) {
+            auto *l = new (pool) AST::PatternElementList(sym(1).Elision, sym(2).PatternElement);
+            sym(1).Node = l->finish();
+        } else {
+            sym(1).Node = nullptr;
+        }
+    } break;
+./
 
-LogicalANDExpression: LogicalANDExpression T_AND_AND BitwiseORExpression ;
+ArrayBindingPattern: BindingElementList;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::And, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).PatternElementList->finish();
+    } break;
 ./
 
-LogicalANDExpressionNotIn: BitwiseORExpressionNotIn ;
+ArrayBindingPattern: BindingElementList T_COMMA ElisionOpt BindingRestElementOpt;
+/.
+    case $rule_number: {
+        if (sym(3).Elision || sym(4).Node) {
+            auto *l = new (pool) AST::PatternElementList(sym(3).Elision, sym(4).PatternElement);
+            l = sym(1).PatternElementList->append(l);
+            sym(1).Node = l;
+        }
+        sym(1).Node = sym(1).PatternElementList->finish();
+    } break;
+./
 
-LogicalANDExpressionNotIn: LogicalANDExpressionNotIn T_AND_AND BitwiseORExpressionNotIn ;
+BindingPropertyList: BindingProperty;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::And, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::PatternPropertyList(sym(1).PatternProperty);
+    } break;
+./
+
+BindingPropertyList: BindingPropertyList T_COMMA BindingProperty;
+/.
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::PatternPropertyList(sym(1).PatternPropertyList, sym(3).PatternProperty);
+    } break;
 ./
 
-LogicalORExpression: LogicalANDExpression ;
+BindingElementList: BindingElisionElement;
 
-LogicalORExpression: LogicalORExpression T_OR_OR LogicalANDExpression ;
+BindingElementList: BindingElementList T_COMMA BindingElisionElement;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Or, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).PatternElementList = sym(1).PatternElementList->append(sym(3).PatternElementList);
+    } break;
 ./
 
-LogicalORExpressionNotIn: LogicalANDExpressionNotIn ;
+BindingElisionElement: ElisionOpt BindingElement;
+/.
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::PatternElementList(sym(1).Elision, sym(2).PatternElement);
+    } break;
+./
 
-LogicalORExpressionNotIn: LogicalORExpressionNotIn T_OR_OR LogicalANDExpressionNotIn ;
+
+BindingProperty: BindingIdentifier InitializerOpt_In;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Or, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::StringLiteralPropertyName *name = new (pool) AST::StringLiteralPropertyName(stringRef(1));
+        name->propertyNameToken = loc(1);
+        // if initializer is an anonymous function expression, we need to assign identifierref as it's name
+        if (auto *f = asAnonymousFunctionDefinition(sym(2).Expression))
+            f->name = stringRef(1);
+        if (auto *c = asAnonymousClassDefinition(sym(2).Expression))
+            c->name = stringRef(1);
+        sym(1).Node = new (pool) AST::PatternProperty(name, stringRef(1), sym(2).Expression);
+    } break;
 ./
 
-ConditionalExpression: LogicalORExpression ;
+BindingProperty: PropertyName T_COLON BindingIdentifier InitializerOpt_In;
+/.
+    case $rule_number: {
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(1).PropertyName, stringRef(3), sym(4).Expression);
+        sym(1).Node = node;
+    } break;
+./
 
-ConditionalExpression: LogicalORExpression T_QUESTION AssignmentExpression T_COLON AssignmentExpression ;
+BindingProperty: PropertyName T_COLON BindingPattern InitializerOpt_In;
 /.
-case $rule_number: {
-  AST::ConditionalExpression *node = new (pool) AST::ConditionalExpression(sym(1).Expression,
-    sym(3).Expression, sym(5).Expression);
-  node->questionToken = loc(2);
-  node->colonToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(1).PropertyName, sym(3).Pattern, sym(4).Expression);
+        sym(1).Node = node;
+    } break;
 ./
 
-ConditionalExpressionNotIn: LogicalORExpressionNotIn ;
+BindingElement: BindingIdentifier InitializerOpt_In;
+/.
+    case $rule_number: {
+      AST::PatternElement *node = new (pool) AST::PatternElement(stringRef(1), sym(2).Expression);
+      node->identifierToken = loc(1);
+      // if initializer is an anonymous function expression, we need to assign identifierref as it's name
+      if (auto *f = asAnonymousFunctionDefinition(sym(2).Expression))
+          f->name = stringRef(1);
+      if (auto *c = asAnonymousClassDefinition(sym(2).Expression))
+          c->name = stringRef(1);
+      sym(1).Node = node;
+    } break;
+./
 
-ConditionalExpressionNotIn: LogicalORExpressionNotIn T_QUESTION AssignmentExpressionNotIn T_COLON AssignmentExpressionNotIn ;
+BindingElement: BindingPattern InitializerOpt_In;
 /.
-case $rule_number: {
-  AST::ConditionalExpression *node = new (pool) AST::ConditionalExpression(sym(1).Expression,
-    sym(3).Expression, sym(5).Expression);
-  node->questionToken = loc(2);
-  node->colonToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElement *node = new (pool) AST::PatternElement(sym(1).Pattern, sym(2).Expression);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentExpression: ConditionalExpression ;
+BindingRestElement: T_ELLIPSIS BindingIdentifier;
+/.
+    case $rule_number: {
+        AST::PatternElement *node = new (pool) AST::PatternElement(stringRef(2), nullptr, AST::PatternElement::RestElement);
+        node->identifierToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
 
-AssignmentExpression: LeftHandSideExpression AssignmentOperator AssignmentExpression ;
+BindingRestElement: T_ELLIPSIS BindingPattern;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    sym(2).ival, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::PatternElement *node = new (pool) AST::PatternElement(sym(2).Pattern, nullptr, AST::PatternElement::RestElement);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentExpressionNotIn: ConditionalExpressionNotIn ;
+BindingRestElementOpt: ;
+/.
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
+./
+
+BindingRestElementOpt: BindingRestElement;
 
-AssignmentExpressionNotIn: LeftHandSideExpression AssignmentOperator AssignmentExpressionNotIn ;
+
+EmptyStatement: T_SEMICOLON;
 /.
-case $rule_number: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    sym(2).ival, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::EmptyStatement *node = new (pool) AST::EmptyStatement();
+        node->semicolonToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_EQ ;
+-- Spec says it should have a "[lookahead ∉ { {, function, class, let [ }]" before the Expression statement.
+-- This is implemented with the rule below that is run before any statement and inserts a T_EXPRESSION_STATEMENT_OK
+-- token if it's ok to parse as an expression statement.
+ExpressionStatementLookahead: ;
+/:
+#define J_SCRIPT_EXPRESSIONSTATEMENTLOOKAHEAD_RULE $rule_number
+:/
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::Assign;
-} break;
+    case $rule_number: {
+        int token = lookaheadToken(lexer);
+        if (token == T_LBRACE)
+            pushToken(T_FORCE_BLOCK);
+        else if (token == T_FUNCTION || token == T_CLASS || token == T_LET || token == T_CONST)
+            pushToken(T_FORCE_DECLARATION);
+    } break;
 ./
 
-AssignmentOperator: T_STAR_EQ ;
+ExpressionStatement: Expression_In T_AUTOMATIC_SEMICOLON;
+ExpressionStatement: Expression_In T_SEMICOLON;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceMul;
-} break;
+    case $rule_number: {
+        AST::ExpressionStatement *node = new (pool) AST::ExpressionStatement(sym(1).Expression);
+        node->semicolonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_DIVIDE_EQ ;
+IfStatement: T_IF T_LPAREN Expression_In T_RPAREN Statement T_ELSE Statement;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceDiv;
-} break;
+    case $rule_number: {
+        AST::IfStatement *node = new (pool) AST::IfStatement(sym(3).Expression, sym(5).Statement, sym(7).Statement);
+        node->ifToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        node->elseToken = loc(6);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_REMAINDER_EQ ;
+IfStatement: T_IF T_LPAREN Expression_In T_RPAREN Statement;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceMod;
-} break;
+    case $rule_number: {
+        AST::IfStatement *node = new (pool) AST::IfStatement(sym(3).Expression, sym(5).Statement);
+        node->ifToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_PLUS_EQ ;
+
+IterationStatement: T_DO Statement T_WHILE T_LPAREN Expression_In T_RPAREN T_AUTOMATIC_SEMICOLON;
+IterationStatement: T_DO Statement T_WHILE T_LPAREN Expression_In T_RPAREN T_COMPATIBILITY_SEMICOLON;  -- for JSC/V8 compatibility
+IterationStatement: T_DO Statement T_WHILE T_LPAREN Expression_In T_RPAREN T_SEMICOLON;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceAdd;
-} break;
+    case $rule_number: {
+        AST::DoWhileStatement *node = new (pool) AST::DoWhileStatement(sym(2).Statement, sym(5).Expression);
+        node->doToken = loc(1);
+        node->whileToken = loc(3);
+        node->lparenToken = loc(4);
+        node->rparenToken = loc(6);
+        node->semicolonToken = loc(7);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_MINUS_EQ ;
+IterationStatement: T_WHILE T_LPAREN Expression_In T_RPAREN Statement;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceSub;
-} break;
+    case $rule_number: {
+        AST::WhileStatement *node = new (pool) AST::WhileStatement(sym(3).Expression, sym(5).Statement);
+        node->whileToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_LT_LT_EQ ;
+IterationStatement: T_FOR T_LPAREN ExpressionOpt T_SEMICOLON ExpressionOpt_In T_SEMICOLON ExpressionOpt_In T_RPAREN Statement; -- [lookahead != { let [ }]
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceLeftShift;
-} break;
+    case $rule_number: {
+        AST::ForStatement *node = new (pool) AST::ForStatement(sym(3).Expression, sym(5).Expression, sym(7).Expression, sym(9).Statement);
+        node->forToken = loc(1);
+        node->lparenToken = loc(2);
+        node->firstSemicolonToken = loc(4);
+        node->secondSemicolonToken = loc(6);
+        node->rparenToken = loc(8);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_GT_GT_EQ ;
+IterationStatement: T_FOR T_LPAREN VarDeclaration T_SEMICOLON ExpressionOpt_In T_SEMICOLON ExpressionOpt_In T_RPAREN Statement;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+IterationStatement: T_FOR T_LPAREN LexicalDeclaration T_SEMICOLON ExpressionOpt_In T_SEMICOLON ExpressionOpt_In T_RPAREN Statement;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceRightShift;
-} break;
+    case $rule_number: {
+        // ### get rid of the static_cast!
+        AST::ForStatement *node = new (pool) AST::ForStatement(
+          static_cast<AST::VariableStatement *>(sym(3).Node)->declarations, sym(5).Expression,
+          sym(7).Expression, sym(9).Statement);
+        node->forToken = loc(1);
+        node->lparenToken = loc(2);
+        node->firstSemicolonToken = loc(4);
+        node->secondSemicolonToken = loc(6);
+        node->rparenToken = loc(8);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_GT_GT_GT_EQ ;
+InOrOf: T_IN;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceURightShift;
-} break;
+    case $rule_number: {
+        sym(1).forEachType = AST::ForEachType::In;
+    } break;
 ./
 
-AssignmentOperator: T_AND_EQ ;
+InOrOf: T_OF;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceAnd;
-} break;
+    case $rule_number: {
+        sym(1).forEachType = AST::ForEachType::Of;
+    } break;
 ./
 
-AssignmentOperator: T_XOR_EQ ;
+IterationStatement: T_FOR T_LPAREN LeftHandSideExpression InOrOf Expression_In T_RPAREN Statement;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceXor;
-} break;
+    case $rule_number: {
+        // need to convert the LHS to an AssignmentPattern if it was an Array/ObjectLiteral
+        if (AST::Pattern *p = sym(3).Expression->patternCast()) {
+            AST::SourceLocation errorLoc;
+            QString errorMsg;
+            if (!p->convertLiteralToAssignmentPattern(pool, &errorLoc, &errorMsg)) {
+                syntaxError(errorLoc, errorMsg);
+                return false;
+            }
+        }
+        AST::ForEachStatement *node = new (pool) AST::ForEachStatement(sym(3).Expression, sym(5).Expression, sym(7).Statement);
+        node->forToken = loc(1);
+        node->lparenToken = loc(2);
+        node->inOfToken = loc(4);
+        node->rparenToken = loc(6);
+        node->type = sym(4).forEachType;
+        sym(1).Node = node;
+    } break;
+./
+
+IterationStatement: T_FOR T_LPAREN ForDeclaration InOrOf Expression_In T_RPAREN Statement;
+/.
+    case $rule_number: {
+        AST::ForEachStatement *node = new (pool) AST::ForEachStatement(sym(3).PatternElement, sym(5).Expression, sym(7).Statement);
+        node->forToken = loc(1);
+        node->lparenToken = loc(2);
+        node->inOfToken = loc(4);
+        node->rparenToken = loc(6);
+        node->type = sym(4).forEachType;
+        sym(1).Node = node;
+    } break;
+./
+
+ForDeclaration: LetOrConst BindingIdentifier;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+ForDeclaration: Var BindingIdentifier;
+/.
+    case $rule_number: {
+        auto *node = new (pool) AST::PatternElement(stringRef(2), nullptr);
+        node->identifierToken = loc(2);
+        node->scope = sym(1).scope;
+        node->isForDeclaration = true;
+        sym(1).Node = node;
+    } break;
+./
+
+ForDeclaration: LetOrConst BindingPattern;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+ForDeclaration: Var BindingPattern;
+/.
+    case $rule_number: {
+        auto *node = new (pool) AST::PatternElement(sym(2).Pattern, nullptr);
+        node->scope = sym(1).scope;
+        node->isForDeclaration = true;
+        sym(1).Node = node;
+    } break;
+./
+
+ContinueStatement: T_CONTINUE T_AUTOMATIC_SEMICOLON;
+ContinueStatement: T_CONTINUE T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::ContinueStatement *node = new (pool) AST::ContinueStatement();
+        node->continueToken = loc(1);
+        node->semicolonToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
+
+ContinueStatement: T_CONTINUE IdentifierReference T_AUTOMATIC_SEMICOLON;
+ContinueStatement: T_CONTINUE IdentifierReference T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::ContinueStatement *node = new (pool) AST::ContinueStatement(stringRef(2));
+        node->continueToken = loc(1);
+        node->identifierToken = loc(2);
+        node->semicolonToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
+
+BreakStatement: T_BREAK T_AUTOMATIC_SEMICOLON;
+BreakStatement: T_BREAK T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::BreakStatement *node = new (pool) AST::BreakStatement(QStringRef());
+        node->breakToken = loc(1);
+        node->semicolonToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
+
+BreakStatement: T_BREAK IdentifierReference T_AUTOMATIC_SEMICOLON;
+BreakStatement: T_BREAK IdentifierReference T_SEMICOLON;
+/.
+    case $rule_number: {
+        AST::BreakStatement *node = new (pool) AST::BreakStatement(stringRef(2));
+        node->breakToken = loc(1);
+        node->identifierToken = loc(2);
+        node->semicolonToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
+
+ReturnStatement: T_RETURN ExpressionOpt_In T_AUTOMATIC_SEMICOLON;
+ReturnStatement: T_RETURN ExpressionOpt_In T_SEMICOLON;
+/.
+    case $rule_number: {
+        if (!functionNestingLevel) {
+            syntaxError(loc(1), "Return statement not allowed outside of Function declaration.");
+            return false;
+        }
+        AST::ReturnStatement *node = new (pool) AST::ReturnStatement(sym(2).Expression);
+        node->returnToken = loc(1);
+        node->semicolonToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-AssignmentOperator: T_OR_EQ ;
+WithStatement: T_WITH T_LPAREN Expression_In T_RPAREN Statement;
 /.
-case $rule_number: {
-  sym(1).ival = QSOperator::InplaceOr;
-} break;
+    case $rule_number: {
+        AST::WithStatement *node = new (pool) AST::WithStatement(sym(3).Expression, sym(5).Statement);
+        node->withToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-Expression: AssignmentExpression ;
+SwitchStatement: T_SWITCH T_LPAREN Expression_In T_RPAREN CaseBlock;
+/.
+    case $rule_number: {
+        AST::SwitchStatement *node = new (pool) AST::SwitchStatement(sym(3).Expression, sym(5).CaseBlock);
+        node->switchToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
+./
 
-Expression: Expression T_COMMA AssignmentExpression ;
+CaseBlock: T_LBRACE CaseClausesOpt T_RBRACE;
 /.
-case $rule_number: {
-  AST::Expression *node = new (pool) AST::Expression(sym(1).Expression, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::CaseBlock *node = new (pool) AST::CaseBlock(sym(2).CaseClauses);
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-ExpressionOpt: ;
+CaseBlock: T_LBRACE CaseClausesOpt DefaultClause CaseClausesOpt T_RBRACE;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::CaseBlock *node = new (pool) AST::CaseBlock(sym(2).CaseClauses, sym(3).DefaultClause, sym(4).CaseClauses);
+        node->lbraceToken = loc(1);
+        node->rbraceToken = loc(5);
+        sym(1).Node = node;
+    } break;
 ./
 
-ExpressionOpt: Expression ;
+CaseClauses: CaseClause;
+/.
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::CaseClauses(sym(1).CaseClause);
+    } break;
+./
 
-ExpressionNotIn: AssignmentExpressionNotIn ;
+CaseClauses: CaseClauses CaseClause;
+/.
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::CaseClauses(sym(1).CaseClauses, sym(2).CaseClause);
+    } break;
+./
 
-ExpressionNotIn: ExpressionNotIn T_COMMA AssignmentExpressionNotIn ;
+CaseClausesOpt: ;
 /.
-case $rule_number: {
-  AST::Expression *node = new (pool) AST::Expression(sym(1).Expression, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-ExpressionNotInOpt: ;
+CaseClausesOpt: CaseClauses;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).CaseClauses->finish();
+    } break;
 ./
 
-ExpressionNotInOpt: ExpressionNotIn ;
+CaseClause: T_CASE Expression_In T_COLON StatementListOpt;
+/.
+    case $rule_number: {
+        AST::CaseClause *node = new (pool) AST::CaseClause(sym(2).Expression, sym(4).StatementList);
+        node->caseToken = loc(1);
+        node->colonToken = loc(3);
+        sym(1).Node = node;
+    } break;
+./
 
-Statement: Block ;
-Statement: VariableStatement ;
-Statement: EmptyStatement ;
-Statement: ExpressionStatement ;
-Statement: IfStatement ;
-Statement: IterationStatement ;
-Statement: ContinueStatement ;
-Statement: BreakStatement ;
-Statement: ReturnStatement ;
-Statement: WithStatement ;
-Statement: LabelledStatement ;
-Statement: SwitchStatement ;
-Statement: ThrowStatement ;
-Statement: TryStatement ;
-Statement: DebuggerStatement ;
+DefaultClause: T_DEFAULT T_COLON StatementListOpt;
+/.
+    case $rule_number: {
+        AST::DefaultClause *node = new (pool) AST::DefaultClause(sym(3).StatementList);
+        node->defaultToken = loc(1);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
+
+LabelledStatement: IdentifierReference T_COLON LabelledItem;
+/.
+    case $rule_number: {
+        AST::LabelledStatement *node = new (pool) AST::LabelledStatement(stringRef(1), sym(3).Statement);
+        node->identifierToken = loc(1);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
 
+LabelledItem: Statement;
 
-Block: T_LBRACE StatementListOpt T_RBRACE ;
+LabelledItem: ExpressionStatementLookahead T_FORCE_DECLARATION FunctionDeclaration;
 /.
-case $rule_number: {
-  AST::Block *node = new (pool) AST::Block(sym(2).StatementList);
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        syntaxError(loc(3), "FunctionDeclarations are not allowed after a label.");
+        return false;
+    } break;
 ./
 
-StatementList: Statement ;
+ThrowStatement: T_THROW Expression_In T_AUTOMATIC_SEMICOLON;
+ThrowStatement: T_THROW Expression_In T_SEMICOLON;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::StatementList(sym(1).Statement);
-} break;
+    case $rule_number: {
+        AST::ThrowStatement *node = new (pool) AST::ThrowStatement(sym(2).Expression);
+        node->throwToken = loc(1);
+        node->semicolonToken = loc(3);
+        sym(1).Node = node;
+    } break;
 ./
 
-StatementList: StatementList Statement ;
+TryStatement: T_TRY Block Catch;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::StatementList(sym(1).StatementList, sym(2).Statement);
-} break;
+    case $rule_number: {
+        AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Catch);
+        node->tryToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-StatementListOpt: ;
+TryStatement: T_TRY Block Finally;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Finally);
+        node->tryToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-StatementListOpt: StatementList ;
+TryStatement: T_TRY Block Catch Finally;
 /.
-case $rule_number: {
-  sym(1).Node = sym(1).StatementList->finish ();
-} break;
+    case $rule_number: {
+        AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Catch, sym(4).Finally);
+        node->tryToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableStatement: VariableDeclarationKind VariableDeclarationList T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-VariableStatement: VariableDeclarationKind VariableDeclarationList T_SEMICOLON ;
+Catch: T_CATCH T_LPAREN CatchParameter T_RPAREN Block;
 /.
-case $rule_number: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  if (sym(1).ival == T_LET)
-    s = AST::VariableDeclaration::BlockScope;
-  else if (sym(1).ival == T_CONST)
-    s = AST::VariableDeclaration::ReadOnlyBlockScope;
-
-  AST::VariableStatement *node = new (pool) AST::VariableStatement(sym(2).VariableDeclarationList->finish(s));
-  node->declarationKindToken = loc(1);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::Catch *node = new (pool) AST::Catch(sym(3).PatternElement, sym(5).Block);
+        node->catchToken = loc(1);
+        node->lparenToken = loc(2);
+        node->identifierToken = loc(3);
+        node->rparenToken = loc(4);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationKind: T_LET ;
+Finally: T_FINALLY Block;
 /.
-case $rule_number: {
-  sym(1).ival = T_LET;
-} break;
+    case $rule_number: {
+        AST::Finally *node = new (pool) AST::Finally(sym(2).Block);
+        node->finallyToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationKind: T_CONST ;
+CatchParameter: BindingIdentifier;
 /.
-case $rule_number: {
-  sym(1).ival = T_CONST;
-} break;
+    case $rule_number: {
+        AST::PatternElement *node = new (pool) AST::PatternElement(stringRef(1));
+        node->identifierToken = loc(1);
+        node->scope = AST::VariableScope::Let;
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationKind: T_VAR ;
+CatchParameter: BindingPattern;
 /.
-case $rule_number: {
-  sym(1).ival = T_VAR;
-} break;
+    case $rule_number: {
+        AST::PatternElement *node = new (pool) AST::PatternElement(sym(1).Pattern);
+        node->scope = AST::VariableScope::Let;
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationList: VariableDeclaration ;
+DebuggerStatement: T_DEBUGGER T_AUTOMATIC_SEMICOLON; -- automatic semicolon
+DebuggerStatement: T_DEBUGGER T_SEMICOLON;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclaration);
-} break;
+    case $rule_number: {
+        AST::DebuggerStatement *node = new (pool) AST::DebuggerStatement();
+        node->debuggerToken = loc(1);
+        node->semicolonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationList: VariableDeclarationList T_COMMA VariableDeclaration ;
+-- tell the parser to prefer function declarations to function expressions.
+-- That is, the `Function' symbol is used to mark the start of a function
+-- declaration.
+-- This is still required for parsing QML, where MemberExpression and FunctionDeclaration would
+-- otherwise conflict.
+Function: T_FUNCTION %prec REDUCE_HERE;
+
+FunctionDeclaration: Function BindingIdentifier T_LPAREN FormalParameters T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  AST::VariableDeclarationList *node = new (pool) AST::VariableDeclarationList(
-    sym(1).VariableDeclarationList, sym(3).VariableDeclaration);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(stringRef(2), sym(4).FormalParameterList, sym(7).StatementList);
+        node->functionToken = loc(1);
+        node->identifierToken = loc(2);
+        node->lparenToken = loc(3);
+        node->rparenToken = loc(5);
+        node->lbraceToken = loc(6);
+        node->rbraceToken = loc(8);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationListNotIn: VariableDeclarationNotIn ;
+
+FunctionDeclaration_Default: FunctionDeclaration;
+FunctionDeclaration_Default: Function T_LPAREN FormalParameters T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclaration);
-} break;
+    case $rule_number: {
+        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(QStringRef(), sym(3).FormalParameterList, sym(6).StatementList);
+        node->functionToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        node->lbraceToken = loc(5);
+        node->rbraceToken = loc(7);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationListNotIn: VariableDeclarationListNotIn T_COMMA VariableDeclarationNotIn ;
+FunctionExpression: T_FUNCTION BindingIdentifier T_LPAREN FormalParameters T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclarationList, sym(3).VariableDeclaration);
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(stringRef(2), sym(4).FormalParameterList, sym(7).StatementList);
+        node->functionToken = loc(1);
+        if (! stringRef(2).isNull())
+          node->identifierToken = loc(2);
+        node->lparenToken = loc(3);
+        node->rparenToken = loc(5);
+        node->lbraceToken = loc(6);
+        node->rbraceToken = loc(8);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclaration: JsIdentifier InitialiserOpt ;
+FunctionExpression: T_FUNCTION T_LPAREN FormalParameters T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  AST::VariableDeclaration *node = new (pool) AST::VariableDeclaration(stringRef(1), sym(2).Expression, s);
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(QStringRef(), sym(3).FormalParameterList, sym(6).StatementList);
+        node->functionToken = loc(1);
+        node->lparenToken = loc(2);
+        node->rparenToken = loc(4);
+        node->lbraceToken = loc(5);
+        node->rbraceToken = loc(7);
+        sym(1).Node = node;
+    } break;
 ./
 
-VariableDeclarationNotIn: JsIdentifier InitialiserNotInOpt ;
+StrictFormalParameters: FormalParameters;
+
+FormalParameters: ;
 /.
-case $rule_number: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  AST::VariableDeclaration *node = new (pool) AST::VariableDeclaration(stringRef(1), sym(2).Expression, s);
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-Initialiser: T_EQ AssignmentExpression ;
+FormalParameters: BindingRestElement;
 /.
-case $rule_number: {
-  // ### TODO: AST for initializer
-  sym(1) = sym(2);
-} break;
+    case $rule_number: {
+        AST::FormalParameterList *node = (new (pool) AST::FormalParameterList(nullptr, sym(1).PatternElement))->finish(pool);
+        sym(1).Node = node;
+    } break;
 ./
 
-InitialiserOpt: ;
+FormalParameters: FormalParameterList;
+/. case $rule_number: ./
+FormalParameters: FormalParameterList T_COMMA;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(1).FormalParameterList->finish(pool);
+    } break;
 ./
 
-InitialiserOpt: Initialiser ;
+FormalParameters: FormalParameterList T_COMMA BindingRestElement;
+/.
+    case $rule_number: {
+        AST::FormalParameterList *node = (new (pool) AST::FormalParameterList(sym(1).FormalParameterList, sym(3).PatternElement))->finish(pool);
+        sym(1).Node = node;
+    } break;
+./
 
-InitialiserNotIn: T_EQ AssignmentExpressionNotIn ;
+FormalParameterList: BindingElement;
 /.
-case $rule_number: {
-  // ### TODO: AST for initializer
-  sym(1) = sym(2);
-} break;
+    case $rule_number: {
+        AST::FormalParameterList *node = new (pool) AST::FormalParameterList(nullptr, sym(1).PatternElement);
+        sym(1).Node = node;
+    } break;
 ./
 
-InitialiserNotInOpt: ;
+
+FormalParameterList: FormalParameterList T_COMMA BindingElement;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::FormalParameterList *node = new (pool) AST::FormalParameterList(sym(1).FormalParameterList, sym(3).PatternElement);
+        sym(1).Node = node;
+    } break;
 ./
 
-InitialiserNotInOpt: InitialiserNotIn ;
+FormalParameter: BindingElement;
 
-EmptyStatement: T_SEMICOLON ;
+FunctionLBrace: T_LBRACE;
 /.
-case $rule_number: {
-  AST::EmptyStatement *node = new (pool) AST::EmptyStatement();
-  node->semicolonToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        ++functionNestingLevel;
+    } break;
 ./
 
-ExpressionStatement: Expression T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-ExpressionStatement: Expression T_SEMICOLON ;
+FunctionRBrace: T_RBRACE;
 /.
-case $rule_number: {
-  AST::ExpressionStatement *node = new (pool) AST::ExpressionStatement(sym(1).Expression);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        --functionNestingLevel;
+    } break;
 ./
 
-IfStatement: T_IF T_LPAREN Expression T_RPAREN Statement T_ELSE Statement ;
+
+FunctionBody: StatementListOpt;
+
+ArrowFunction: ArrowParameters T_ARROW ConciseBodyLookahead AssignmentExpression; -- [lookahead ≠ {]
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+ArrowFunction_In: ArrowParameters T_ARROW ConciseBodyLookahead AssignmentExpression_In; -- [lookahead ≠ {]
 /.
-case $rule_number: {
-  AST::IfStatement *node = new (pool) AST::IfStatement(sym(3).Expression, sym(5).Statement, sym(7).Statement);
-  node->ifToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  node->elseToken = loc(6);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ReturnStatement *ret = new (pool) AST::ReturnStatement(sym(4).Expression);
+        ret->returnToken = sym(4).Node->firstSourceLocation();
+        ret->semicolonToken = sym(4).Node->lastSourceLocation();
+        AST::StatementList *statements = (new (pool) AST::StatementList(ret))->finish();
+        AST::FunctionExpression *f = new (pool) AST::FunctionExpression(QStringRef(), sym(1).FormalParameterList, statements);
+        f->isArrowFunction = true;
+        f->functionToken = sym(1).Node ? sym(1).Node->firstSourceLocation() : loc(1);
+        f->lbraceToken = sym(4).Node->firstSourceLocation();
+        f->rbraceToken = sym(4).Node->lastSourceLocation();
+        sym(1).Node = f;
+    } break;
 ./
 
-IfStatement: T_IF T_LPAREN Expression T_RPAREN Statement ;
+ArrowFunction: ArrowParameters T_ARROW ConciseBodyLookahead T_FORCE_BLOCK FunctionLBrace FunctionBody FunctionRBrace;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+ArrowFunction_In: ArrowParameters T_ARROW ConciseBodyLookahead T_FORCE_BLOCK FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  AST::IfStatement *node = new (pool) AST::IfStatement(sym(3).Expression, sym(5).Statement);
-  node->ifToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *f = new (pool) AST::FunctionExpression(QStringRef(), sym(1).FormalParameterList, sym(6).StatementList);
+        f->isArrowFunction = true;
+        f->functionToken = sym(1).Node ? sym(1).Node->firstSourceLocation() : loc(1);
+        f->lbraceToken = loc(6);
+        f->rbraceToken = loc(7);
+        sym(1).Node = f;
+    } break;
 ./
 
+ArrowParameters: BindingIdentifier;
+/.
+    case $rule_number: {
+        AST::PatternElement *e = new (pool) AST::PatternElement(stringRef(1), nullptr, AST::PatternElement::Binding);
+        e->identifierToken = loc(1);
+        sym(1).FormalParameterList = (new (pool) AST::FormalParameterList(nullptr, e))->finish(pool);
+    } break;
+./
 
-IterationStatement: T_DO Statement T_WHILE T_LPAREN Expression T_RPAREN T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-IterationStatement: T_DO Statement T_WHILE T_LPAREN Expression T_RPAREN T_COMPATIBILITY_SEMICOLON ;  -- for JSC/V8 compatibility
-IterationStatement: T_DO Statement T_WHILE T_LPAREN Expression T_RPAREN T_SEMICOLON ;
+-- CoverParenthesizedExpressionAndArrowParameterList for ArrowParameters i being refined to:
+-- ArrowFormalParameters: T_LPAREN StrictFormalParameters T_RPAREN
+ArrowParameters: CoverParenthesizedExpressionAndArrowParameterList;
 /.
-case $rule_number: {
-  AST::DoWhileStatement *node = new (pool) AST::DoWhileStatement(sym(2).Statement, sym(5).Expression);
-  node->doToken = loc(1);
-  node->whileToken = loc(3);
-  node->lparenToken = loc(4);
-  node->rparenToken = loc(6);
-  node->semicolonToken = loc(7);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        if (coverExpressionType != CE_FormalParameterList) {
+            AST::NestedExpression *ne = static_cast<AST::NestedExpression *>(sym(1).Node);
+            AST::FormalParameterList *list = ne->expression->reparseAsFormalParameterList(pool);
+            if (!list) {
+                syntaxError(loc(1), "Invalid Arrow parameter list.");
+                return false;
+            }
+            sym(1).Node = list->finish(pool);
+        }
+    } break;
 ./
 
-IterationStatement: T_WHILE T_LPAREN Expression T_RPAREN Statement ;
+ConciseBodyLookahead: ;
+/:
+#define J_SCRIPT_CONCISEBODYLOOKAHEAD_RULE $rule_number
+:/
 /.
-case $rule_number: {
-  AST::WhileStatement *node = new (pool) AST::WhileStatement(sym(3).Expression, sym(5).Statement);
-  node->whileToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        if (lookaheadToken(lexer) == T_LBRACE)
+            pushToken(T_FORCE_BLOCK);
+    } break;
 ./
 
-IterationStatement: T_FOR T_LPAREN ExpressionNotInOpt T_SEMICOLON ExpressionOpt T_SEMICOLON ExpressionOpt T_RPAREN Statement ;
+MethodDefinition: PropertyName T_LPAREN StrictFormalParameters T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  AST::ForStatement *node = new (pool) AST::ForStatement(sym(3).Expression,
-    sym(5).Expression, sym(7).Expression, sym(9).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->firstSemicolonToken = loc(4);
-  node->secondSemicolonToken = loc(6);
-  node->rparenToken = loc(8);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *f = new (pool) AST::FunctionExpression(stringRef(1), sym(3).FormalParameterList, sym(6).StatementList);
+        f->functionToken = sym(1).PropertyName->firstSourceLocation();
+        f->lparenToken = loc(2);
+        f->rparenToken = loc(4);
+        f->lbraceToken = loc(5);
+        f->rbraceToken = loc(7);
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(1).PropertyName, f, AST::PatternProperty::Method);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-IterationStatement: T_FOR T_LPAREN T_VAR VariableDeclarationListNotIn T_SEMICOLON ExpressionOpt T_SEMICOLON ExpressionOpt T_RPAREN Statement ;
+MethodDefinition: T_STAR PropertyName GeneratorLParen StrictFormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
-case $rule_number: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  AST::LocalForStatement *node = new (pool) AST::LocalForStatement(
-     sym(4).VariableDeclarationList->finish(s), sym(6).Expression,
-     sym(8).Expression, sym(10).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->varToken = loc(3);
-  node->firstSemicolonToken = loc(5);
-  node->secondSemicolonToken = loc(7);
-  node->rparenToken = loc(9);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *f = new (pool) AST::FunctionExpression(stringRef(2), sym(4).FormalParameterList, sym(7).StatementList);
+        f->functionToken = sym(2).PropertyName->firstSourceLocation();
+        f->lparenToken = loc(3);
+        f->rparenToken = loc(5);
+        f->lbraceToken = loc(6);
+        f->rbraceToken = loc(8);
+        f->isGenerator = true;
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(2).PropertyName, f, AST::PatternProperty::Method);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
+./
+
+
+MethodDefinition: T_GET PropertyName T_LPAREN T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
+/.
+    case $rule_number: {
+        AST::FunctionExpression *f = new (pool) AST::FunctionExpression(stringRef(2), nullptr, sym(6).StatementList);
+        f->functionToken = sym(2).PropertyName->firstSourceLocation();
+        f->lparenToken = loc(3);
+        f->rparenToken = loc(4);
+        f->lbraceToken = loc(5);
+        f->rbraceToken = loc(7);
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(2).PropertyName, f, AST::PatternProperty::Getter);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-IterationStatement: T_FOR T_LPAREN LeftHandSideExpression T_IN Expression T_RPAREN Statement ;
+MethodDefinition: T_SET PropertyName T_LPAREN PropertySetParameterList T_RPAREN FunctionLBrace FunctionBody FunctionRBrace;
 /.
-case $rule_number: {
-  AST:: ForEachStatement *node = new (pool) AST::ForEachStatement(sym(3).Expression,
-    sym(5).Expression, sym(7).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->inToken = loc(4);
-  node->rparenToken = loc(6);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *f = new (pool) AST::FunctionExpression(stringRef(2), sym(4).FormalParameterList, sym(7).StatementList);
+        f->functionToken = sym(2).PropertyName->firstSourceLocation();
+        f->lparenToken = loc(3);
+        f->rparenToken = loc(5);
+        f->lbraceToken = loc(6);
+        f->rbraceToken = loc(8);
+        AST::PatternProperty *node = new (pool) AST::PatternProperty(sym(2).PropertyName, f, AST::PatternProperty::Setter);
+        node->colonToken = loc(2);
+        sym(1).Node = node;
+    } break;
 ./
 
-IterationStatement: T_FOR T_LPAREN T_VAR VariableDeclarationNotIn T_IN Expression T_RPAREN Statement ;
+
+PropertySetParameterList: FormalParameter;
 /.
-case $rule_number: {
-  AST::LocalForEachStatement *node = new (pool) AST::LocalForEachStatement(
-    sym(4).VariableDeclaration, sym(6).Expression, sym(8).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->varToken = loc(3);
-  node->inToken = loc(5);
-  node->rparenToken = loc(7);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FormalParameterList *node = (new (pool) AST::FormalParameterList(nullptr, sym(1).PatternElement))->finish(pool);
+        sym(1).Node = node;
+    } break;
 ./
 
-ContinueStatement: T_CONTINUE T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-ContinueStatement: T_CONTINUE T_SEMICOLON ;
+GeneratorLParen: T_LPAREN;
 /.
-case $rule_number: {
-  AST::ContinueStatement *node = new (pool) AST::ContinueStatement();
-  node->continueToken = loc(1);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        lexer->enterGeneratorBody();
+    } break;
 ./
 
-ContinueStatement: T_CONTINUE JsIdentifier T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-ContinueStatement: T_CONTINUE JsIdentifier T_SEMICOLON ;
+GeneratorRBrace: T_RBRACE;
 /.
-case $rule_number: {
-  AST::ContinueStatement *node = new (pool) AST::ContinueStatement(stringRef(2));
-  node->continueToken = loc(1);
-  node->identifierToken = loc(2);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        --functionNestingLevel;
+        lexer->leaveGeneratorBody();
+    } break;
 ./
 
-BreakStatement: T_BREAK T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-BreakStatement: T_BREAK T_SEMICOLON ;
+GeneratorDeclaration: Function T_STAR BindingIdentifier GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
-case $rule_number: {
-  AST::BreakStatement *node = new (pool) AST::BreakStatement(QStringRef());
-  node->breakToken = loc(1);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(stringRef(3), sym(5).FormalParameterList, sym(8).StatementList);
+        node->functionToken = loc(1);
+        node->identifierToken = loc(3);
+        node->lparenToken = loc(4);
+        node->rparenToken = loc(6);
+        node->lbraceToken = loc(7);
+        node->rbraceToken = loc(9);
+        node->isGenerator = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-BreakStatement: T_BREAK JsIdentifier T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-BreakStatement: T_BREAK JsIdentifier T_SEMICOLON ;
+GeneratorDeclaration_Default: GeneratorDeclaration;
+GeneratorDeclaration_Default: Function T_STAR GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
+/.
+    case $rule_number: {
+        AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(QStringRef(), sym(4).FormalParameterList, sym(7).StatementList);
+        node->functionToken = loc(1);
+        node->lparenToken = loc(3);
+        node->rparenToken = loc(5);
+        node->lbraceToken = loc(6);
+        node->rbraceToken = loc(8);
+        node->isGenerator = true;
+        sym(1).Node = node;
+    } break;
+./
+
+GeneratorExpression: T_FUNCTION T_STAR BindingIdentifier GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
-case $rule_number: {
-  AST::BreakStatement *node = new (pool) AST::BreakStatement(stringRef(2));
-  node->breakToken = loc(1);
-  node->identifierToken = loc(2);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(stringRef(3), sym(5).FormalParameterList, sym(8).StatementList);
+        node->functionToken = loc(1);
+        if (!stringRef(3).isNull())
+          node->identifierToken = loc(3);
+        node->lparenToken = loc(4);
+        node->rparenToken = loc(6);
+        node->lbraceToken = loc(7);
+        node->rbraceToken = loc(9);
+        node->isGenerator = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-ReturnStatement: T_RETURN ExpressionOpt T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-ReturnStatement: T_RETURN ExpressionOpt T_SEMICOLON ;
+GeneratorExpression: T_FUNCTION T_STAR GeneratorLParen FormalParameters T_RPAREN FunctionLBrace GeneratorBody GeneratorRBrace;
 /.
-case $rule_number: {
-  AST::ReturnStatement *node = new (pool) AST::ReturnStatement(sym(2).Expression);
-  node->returnToken = loc(1);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::FunctionExpression *node = new (pool) AST::FunctionExpression(QStringRef(), sym(4).FormalParameterList, sym(7).StatementList);
+        node->functionToken = loc(1);
+        node->lparenToken = loc(3);
+        node->rparenToken = loc(5);
+        node->lbraceToken = loc(6);
+        node->rbraceToken = loc(8);
+        node->isGenerator = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-WithStatement: T_WITH T_LPAREN Expression T_RPAREN Statement ;
+GeneratorBody: FunctionBody;
+
+YieldExpression: T_YIELD;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+YieldExpression_In: T_YIELD;
 /.
-case $rule_number: {
-  AST::WithStatement *node = new (pool) AST::WithStatement(sym(3).Expression, sym(5).Statement);
-  node->withToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::YieldExpression *node = new (pool) AST::YieldExpression();
+        node->yieldToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-SwitchStatement: T_SWITCH T_LPAREN Expression T_RPAREN CaseBlock ;
+YieldExpression: T_YIELD T_STAR AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+YieldExpression_In: T_YIELD T_STAR AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::SwitchStatement *node = new (pool) AST::SwitchStatement(sym(3).Expression, sym(5).CaseBlock);
-  node->switchToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::YieldExpression *node = new (pool) AST::YieldExpression(sym(3).Expression);
+        node->yieldToken = loc(1);
+        node->isYieldStar = true;
+        sym(1).Node = node;
+    } break;
 ./
 
-CaseBlock: T_LBRACE CaseClausesOpt T_RBRACE ;
+YieldExpression: T_YIELD AssignmentExpression;
+/.  case $rule_number: Q_FALLTHROUGH(); ./
+YieldExpression_In: T_YIELD AssignmentExpression_In;
 /.
-case $rule_number: {
-  AST::CaseBlock *node = new (pool) AST::CaseBlock(sym(2).CaseClauses);
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::YieldExpression *node = new (pool) AST::YieldExpression(sym(2).Expression);
+        node->yieldToken = loc(1);
+        sym(1).Node = node;
+    } break;
 ./
 
-CaseBlock: T_LBRACE CaseClausesOpt DefaultClause CaseClausesOpt T_RBRACE ;
+
+ClassDeclaration: T_CLASS BindingIdentifier ClassHeritageOpt ClassLBrace ClassBodyOpt ClassRBrace;
 /.
-case $rule_number: {
-  AST::CaseBlock *node = new (pool) AST::CaseBlock(sym(2).CaseClauses, sym(3).DefaultClause, sym(4).CaseClauses);
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(5);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ClassDeclaration *node = new (pool) AST::ClassDeclaration(stringRef(2), sym(3).Expression, sym(5).ClassElementList);
+        node->classToken = loc(1);
+        node->identifierToken = loc(2);
+        node->lbraceToken = loc(4);
+        node->rbraceToken = loc(6);
+        sym(1).Node = node;
+    } break;
 ./
 
-CaseClauses: CaseClause ;
+ClassExpression: T_CLASS BindingIdentifier ClassHeritageOpt ClassLBrace ClassBodyOpt ClassRBrace;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::CaseClauses(sym(1).CaseClause);
-} break;
+    case $rule_number: {
+        AST::ClassExpression *node = new (pool) AST::ClassExpression(stringRef(2), sym(3).Expression, sym(5).ClassElementList);
+        node->classToken = loc(1);
+        node->identifierToken = loc(2);
+        node->lbraceToken = loc(4);
+        node->rbraceToken = loc(6);
+        sym(1).Node = node;
+    } break;
 ./
 
-CaseClauses: CaseClauses CaseClause ;
+ClassDeclaration_Default: T_CLASS ClassHeritageOpt ClassLBrace ClassBodyOpt ClassRBrace;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::CaseClauses(sym(1).CaseClauses, sym(2).CaseClause);
-} break;
+    case $rule_number: {
+        AST::ClassDeclaration *node = new (pool) AST::ClassDeclaration(QStringRef(), sym(2).Expression, sym(4).ClassElementList);
+        node->classToken = loc(1);
+        node->lbraceToken = loc(3);
+        node->rbraceToken = loc(5);
+        sym(1).Node = node;
+    } break;
 ./
 
-CaseClausesOpt: ;
+ClassExpression: T_CLASS ClassHeritageOpt ClassLBrace ClassBodyOpt ClassRBrace;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        AST::ClassExpression *node = new (pool) AST::ClassExpression(QStringRef(), sym(2).Expression, sym(4).ClassElementList);
+        node->classToken = loc(1);
+        node->lbraceToken = loc(3);
+        node->rbraceToken = loc(5);
+        sym(1).Node = node;
+    } break;
 ./
 
-CaseClausesOpt: CaseClauses ;
+ClassDeclaration_Default: ClassDeclaration;
+
+ClassLBrace: T_LBRACE;
 /.
-case $rule_number: {
-  sym(1).Node = sym(1).CaseClauses->finish ();
-} break;
+    case $rule_number: {
+        lexer->setStaticIsKeyword(true);
+    } break;
 ./
 
-CaseClause: T_CASE Expression T_COLON StatementListOpt ;
+ClassRBrace: T_RBRACE;
+/. case $rule_number: ./
+ClassStaticQualifier: T_STATIC;
 /.
-case $rule_number: {
-  AST::CaseClause *node = new (pool) AST::CaseClause(sym(2).Expression, sym(4).StatementList);
-  node->caseToken = loc(1);
-  node->colonToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        lexer->setStaticIsKeyword(false);
+    } break;
 ./
 
-DefaultClause: T_DEFAULT T_COLON StatementListOpt ;
+ClassHeritageOpt: ;
 /.
-case $rule_number: {
-  AST::DefaultClause *node = new (pool) AST::DefaultClause(sym(3).StatementList);
-  node->defaultToken = loc(1);
-  node->colonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-LabelledStatement: JsIdentifier T_COLON Statement ;
+ClassHeritageOpt: T_EXTENDS LeftHandSideExpression;
 /.
-case $rule_number: {
-  AST::LabelledStatement *node = new (pool) AST::LabelledStatement(stringRef(1), sym(3).Statement);
-  node->identifierToken = loc(1);
-  node->colonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = sym(2).Node;
+    } break;
 ./
 
-ThrowStatement: T_THROW Expression T_AUTOMATIC_SEMICOLON ;  -- automatic semicolon
-ThrowStatement: T_THROW Expression T_SEMICOLON ;
+ClassBodyOpt: ;
 /.
-case $rule_number: {
-  AST::ThrowStatement *node = new (pool) AST::ThrowStatement(sym(2).Expression);
-  node->throwToken = loc(1);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-TryStatement: T_TRY Block Catch ;
+ClassBodyOpt: ClassElementList;
 /.
-case $rule_number: {
-  AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Catch);
-  node->tryToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        if (sym(1).Node)
+            sym(1).Node = sym(1).ClassElementList->finish();
+    } break;
 ./
 
-TryStatement: T_TRY Block Finally ;
+ClassElementList: ClassElement;
+
+ClassElementList: ClassElementList ClassElement;
 /.
-case $rule_number: {
-  AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Finally);
-  node->tryToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        if (sym(1).Node) {
+            if (sym(2).Node)
+                sym(1).ClassElementList = sym(1).ClassElementList->append(sym(2).ClassElementList);
+        } else if (sym(2).Node) {
+            sym(1).Node = sym(2).Node;
+        }
+    } break;
 ./
 
-TryStatement: T_TRY Block Catch Finally ;
+ClassElement: MethodDefinition;
 /.
-case $rule_number: {
-  AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Catch, sym(4).Finally);
-  node->tryToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        AST::ClassElementList *node = new (pool) AST::ClassElementList(sym(1).PatternProperty, false);
+        sym(1).Node = node;
+    } break;
 ./
 
-Catch: T_CATCH T_LPAREN JsIdentifier T_RPAREN Block ;
+ClassElement: ClassStaticQualifier MethodDefinition;
 /.
-case $rule_number: {
-  AST::Catch *node = new (pool) AST::Catch(stringRef(3), sym(5).Block);
-  node->catchToken = loc(1);
-  node->lparenToken = loc(2);
-  node->identifierToken = loc(3);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        lexer->setStaticIsKeyword(true);
+        AST::ClassElementList *node = new (pool) AST::ClassElementList(sym(2).PatternProperty, true);
+        sym(1).Node = node;
+    } break;
 ./
 
-Finally: T_FINALLY Block ;
+ClassElement: T_SEMICOLON;
 /.
-case $rule_number: {
-  AST::Finally *node = new (pool) AST::Finally(sym(2).Block);
-  node->finallyToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
-DebuggerStatement: T_DEBUGGER T_AUTOMATIC_SEMICOLON ; -- automatic semicolon
-DebuggerStatement: T_DEBUGGER T_SEMICOLON ;
+-- Scripts and Modules
+
+Script: ;
 /.
-case $rule_number: {
-  AST::DebuggerStatement *node = new (pool) AST::DebuggerStatement();
-  node->debuggerToken = loc(1);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = nullptr;
+    } break;
 ./
 
--- tell the parser to prefer function declarations to function expressions.
--- That is, the `Function' symbol is used to mark the start of a function
--- declaration.
-Function: T_FUNCTION %prec REDUCE_HERE ;
+Script: ScriptBody;
 
-FunctionDeclaration: Function JsIdentifier T_LPAREN FormalParameterListOpt T_RPAREN T_LBRACE FunctionBodyOpt T_RBRACE ;
+ScriptBody: StatementList;
 /.
-case $rule_number: {
-  AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(stringRef(2), sym(4).FormalParameterList, sym(7).FunctionBody);
-  node->functionToken = loc(1);
-  node->identifierToken = loc(2);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  node->lbraceToken = loc(6);
-  node->rbraceToken = loc(8);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).Node = new (pool) AST::Program(sym(1).StatementList->finish());
+    } break;
 ./
 
-FunctionExpression: T_FUNCTION JsIdentifier T_LPAREN FormalParameterListOpt T_RPAREN T_LBRACE FunctionBodyOpt T_RBRACE ;
+Module: ModuleBodyOpt;
+/.  case $rule_number: {
+        sym(1).Node = new (pool) AST::ESModule(sym(1).StatementList);
+    } break;
+./
+
+ModuleBody: ModuleItemList;
 /.
-case $rule_number: {
-  AST::FunctionExpression *node = new (pool) AST::FunctionExpression(stringRef(2), sym(4).FormalParameterList, sym(7).FunctionBody);
-  node->functionToken = loc(1);
-  if (! stringRef(2).isNull())
-      node->identifierToken = loc(2);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  node->lbraceToken = loc(6);
-  node->rbraceToken = loc(8);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).StatementList = sym(1).StatementList->finish();
+    } break;
 ./
 
-FunctionExpression: T_FUNCTION T_LPAREN FormalParameterListOpt T_RPAREN T_LBRACE FunctionBodyOpt T_RBRACE ;
+ModuleBodyOpt: ;
 /.
-case $rule_number: {
-  AST::FunctionExpression *node = new (pool) AST::FunctionExpression(QStringRef(), sym(3).FormalParameterList, sym(6).FunctionBody);
-  node->functionToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  node->lbraceToken = loc(5);
-  node->rbraceToken = loc(7);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).StatementList = nullptr;
+    } break;
 ./
+ModuleBodyOpt: ModuleBody;
+
+ModuleItemList: ModuleItem;
 
-FormalParameterList: JsIdentifier ;
+ModuleItemList: ModuleItemList ModuleItem;
 /.
-case $rule_number: {
-  AST::FormalParameterList *node = new (pool) AST::FormalParameterList(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).StatementList = sym(1).StatementList->append(sym(2).StatementList);
+    } break;
 ./
 
-FormalParameterList: FormalParameterList T_COMMA JsIdentifier ;
+ModuleItem: ImportDeclaration T_AUTOMATIC_SEMICOLON;
+/. case $rule_number:  Q_FALLTHROUGH(); ./
+ModuleItem: ImportDeclaration T_SEMICOLON;
+/. case $rule_number:  Q_FALLTHROUGH(); ./
+ModuleItem: ExportDeclaration T_AUTOMATIC_SEMICOLON;
+/. case $rule_number:  Q_FALLTHROUGH(); ./
+ModuleItem: ExportDeclaration T_SEMICOLON;
 /.
-case $rule_number: {
-  AST::FormalParameterList *node = new (pool) AST::FormalParameterList(sym(1).FormalParameterList, stringRef(3));
-  node->commaToken = loc(2);
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
+    case $rule_number: {
+        sym(1).StatementList = new (pool) AST::StatementList(sym(1).Node);
+    } break;
 ./
 
-FormalParameterListOpt: ;
+ModuleItem: StatementListItem;
+
+ImportDeclaration: T_IMPORT ImportClause FromClause;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        auto decl = new (pool) AST::ImportDeclaration(sym(2).ImportClause, sym(3).FromClause);
+        decl->importToken = loc(1);
+        sym(1).Node = decl;
+    } break;
+./
+ImportDeclaration: T_IMPORT ModuleSpecifier;
+/.
+    case $rule_number: {
+        auto decl = new (pool) AST::ImportDeclaration(stringRef(2));
+        decl->importToken = loc(1);
+        decl->moduleSpecifierToken = loc(2);
+        sym(1).Node = decl;
+    } break;
 ./
 
-FormalParameterListOpt: FormalParameterList ;
+ImportClause: ImportedDefaultBinding;
 /.
-case $rule_number: {
-  sym(1).Node = sym(1).FormalParameterList->finish ();
-} break;
+    case $rule_number: {
+        auto clause = new (pool) AST::ImportClause(stringRef(1));
+        clause->importedDefaultBindingToken = loc(1);
+        sym(1).ImportClause = clause;
+    } break;
+./
+ImportClause: NameSpaceImport;
+/.
+    case $rule_number: {
+        sym(1).ImportClause = new (pool) AST::ImportClause(sym(1).NameSpaceImport);
+    } break;
+./
+ImportClause: NamedImports;
+/.
+    case $rule_number: {
+        sym(1).ImportClause = new (pool) AST::ImportClause(sym(1).NamedImports);
+    } break;
+./
+ImportClause: ImportedDefaultBinding T_COMMA NameSpaceImport;
+/.
+    case $rule_number: {
+        auto importClause = new (pool) AST::ImportClause(stringRef(1), sym(3).NameSpaceImport);
+        importClause->importedDefaultBindingToken = loc(1);
+        sym(1).ImportClause = importClause;
+    } break;
+./
+ImportClause: ImportedDefaultBinding T_COMMA NamedImports;
+/.
+    case $rule_number: {
+        auto importClause = new (pool) AST::ImportClause(stringRef(1), sym(3).NamedImports);
+        importClause->importedDefaultBindingToken = loc(1);
+        sym(1).ImportClause = importClause;
+    } break;
 ./
 
-FunctionBodyOpt: ;
+ImportedDefaultBinding: ImportedBinding;
+
+NameSpaceImport: T_STAR T_AS ImportedBinding;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        auto import = new (pool) AST::NameSpaceImport(stringRef(3));
+        import->starToken = loc(1);
+        import->importedBindingToken = loc(3);
+        sym(1).NameSpaceImport = import;
+    } break;
 ./
 
-FunctionBodyOpt: FunctionBody ;
+NamedImports: T_LBRACE T_RBRACE;
+/.
+    case $rule_number: {
+        auto namedImports = new (pool) AST::NamedImports();
+        namedImports->leftBraceToken = loc(1);
+        namedImports->rightBraceToken = loc(2);
+        sym(1).NamedImports = namedImports;
+    } break;
+./
+NamedImports: T_LBRACE ImportsList T_RBRACE;
+/.
+    case $rule_number: {
+        auto namedImports = new (pool) AST::NamedImports(sym(2).ImportsList->finish());
+        namedImports->leftBraceToken = loc(1);
+        namedImports->rightBraceToken = loc(3);
+        sym(1).NamedImports = namedImports;
+    } break;
+./
+NamedImports: T_LBRACE ImportsList T_COMMA T_RBRACE;
+/.
+    case $rule_number: {
+        auto namedImports = new (pool) AST::NamedImports(sym(2).ImportsList->finish());
+        namedImports->leftBraceToken = loc(1);
+        namedImports->rightBraceToken = loc(4);
+        sym(1).NamedImports = namedImports;
+    } break;
+./
 
-FunctionBody: SourceElements ;
+FromClause: T_FROM ModuleSpecifier;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::FunctionBody(sym(1).SourceElements->finish ());
-} break;
+    case $rule_number: {
+        auto clause = new (pool) AST::FromClause(stringRef(2));
+        clause->fromToken = loc(1);
+        clause->moduleSpecifierToken = loc(2);
+        sym(1).FromClause = clause;
+    } break;
 ./
 
-Program: Empty ;
+ImportsList: ImportSpecifier;
+/.
+    case $rule_number: {
+        auto importsList = new (pool) AST::ImportsList(sym(1).ImportSpecifier);
+        importsList->importSpecifierToken = loc(1);
+        sym(1).ImportsList = importsList;
+    } break;
+./
+ImportsList: ImportsList T_COMMA ImportSpecifier;
+/.
+    case $rule_number: {
+        auto importsList = new (pool) AST::ImportsList(sym(1).ImportsList, sym(3).ImportSpecifier);
+        importsList->importSpecifierToken = loc(3);
+        sym(1).ImportsList = importsList;
+    } break;
+./
 
-Program: SourceElements ;
+ImportSpecifier: ImportedBinding;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::Program(sym(1).SourceElements->finish ());
-} break;
+    case $rule_number: {
+        auto importSpecifier = new (pool) AST::ImportSpecifier(stringRef(1));
+        importSpecifier->importedBindingToken = loc(1);
+        sym(1).ImportSpecifier = importSpecifier;
+    } break;
 ./
+ImportSpecifier: IdentifierName T_AS ImportedBinding;
+/.
+    case $rule_number: {
+    auto importSpecifier = new (pool) AST::ImportSpecifier(stringRef(1), stringRef(3));
+    importSpecifier->identifierToken = loc(1);
+    importSpecifier->importedBindingToken = loc(3);
+    sym(1).ImportSpecifier = importSpecifier;
+    } break;
+./
+
+ModuleSpecifier: T_STRING_LITERAL;
 
-SourceElements: SourceElement ;
+ImportedBinding: BindingIdentifier;
+
+ExportDeclarationLookahead: ;
+/:
+#define J_SCRIPT_EXPORTDECLARATIONLOOKAHEAD_RULE $rule_number
+:/
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::SourceElements(sym(1).SourceElement);
-} break;
+    case $rule_number: {
+        int token = lookaheadToken(lexer);
+        if (token == T_FUNCTION || token == T_CLASS)
+            pushToken(T_FORCE_DECLARATION);
+    } break;
 ./
 
-SourceElements: SourceElements SourceElement ;
+ExportDeclaration: T_EXPORT T_STAR FromClause;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::SourceElements(sym(1).SourceElements, sym(2).SourceElement);
-} break;
+    case $rule_number: {
+        auto exportDeclaration = new (pool) AST::ExportDeclaration(sym(3).FromClause);
+        exportDeclaration->exportToken = loc(1);
+        sym(1).ExportDeclaration = exportDeclaration;
+    } break;
+./
+ExportDeclaration: T_EXPORT ExportClause FromClause;
+/.
+    case $rule_number: {
+        auto exportDeclaration = new (pool) AST::ExportDeclaration(sym(2).ExportClause, sym(3).FromClause);
+        exportDeclaration->exportToken = loc(1);
+        sym(1).ExportDeclaration = exportDeclaration;
+    } break;
+./
+ExportDeclaration: T_EXPORT ExportClause;
+/.
+    case $rule_number: {
+        auto exportDeclaration = new (pool) AST::ExportDeclaration(sym(2).ExportClause);
+        exportDeclaration->exportToken = loc(1);
+        sym(1).ExportDeclaration = exportDeclaration;
+    } break;
+./
+ExportDeclaration: T_EXPORT VariableStatement;
+/. case $rule_number:  Q_FALLTHROUGH(); ./
+ExportDeclaration: T_EXPORT Declaration;
+/.
+    case $rule_number: {
+        auto exportDeclaration = new (pool) AST::ExportDeclaration(/*exportDefault=*/false, sym(2).Node);
+        exportDeclaration->exportToken = loc(1);
+        sym(1).ExportDeclaration = exportDeclaration;
+    } break;
+./
+ExportDeclaration: T_EXPORT T_DEFAULT ExportDeclarationLookahead T_FORCE_DECLARATION HoistableDeclaration_Default;
+/.
+    case $rule_number: {
+        if (auto *f = AST::cast<AST::FunctionDeclaration*>(sym(5).Node)) {
+            if (f->name.isEmpty()) {
+                f->name = stringRef(2);
+                f->identifierToken = loc(2);
+            }
+        }
+    } Q_FALLTHROUGH();
+./
+ExportDeclaration: T_EXPORT T_DEFAULT ExportDeclarationLookahead T_FORCE_DECLARATION ClassDeclaration_Default;
+/.
+    case $rule_number: {
+        // Emulate 15.2.3.11
+        if (auto *cls = AST::cast<AST::ClassDeclaration*>(sym(5).Node)) {
+            if (cls->name.isEmpty()) {
+                cls->name = stringRef(2);
+                cls->identifierToken = loc(2);
+            }
+        }
+
+        auto exportDeclaration = new (pool) AST::ExportDeclaration(/*exportDefault=*/true, sym(5).Node);
+        exportDeclaration->exportToken = loc(1);
+        sym(1).ExportDeclaration = exportDeclaration;
+    } break;
 ./
+ExportDeclaration: T_EXPORT T_DEFAULT ExportDeclarationLookahead AssignmentExpression_In; -- [lookahead ∉ { function, class }]
+/.
+    case $rule_number: {
+        // if lhs is an identifier expression and rhs is an anonymous function expression, we need to assign the name of lhs to the function
+        if (auto *f = asAnonymousFunctionDefinition(sym(4).Node)) {
+            f->name = stringRef(2);
+        }
+        if (auto *c = asAnonymousClassDefinition(sym(4).Expression)) {
+            c->name = stringRef(2);
+        }
 
-SourceElement: Statement ;
+        auto exportDeclaration = new (pool) AST::ExportDeclaration(/*exportDefault=*/true, sym(4).Node);
+        exportDeclaration->exportToken = loc(1);
+        sym(1).ExportDeclaration = exportDeclaration;
+    } break;
+./
+
+ExportClause: T_LBRACE T_RBRACE;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::StatementSourceElement(sym(1).Statement);
-} break;
+    case $rule_number: {
+        auto exportClause = new (pool) AST::ExportClause();
+        exportClause->leftBraceToken = loc(1);
+        exportClause->rightBraceToken = loc(2);
+        sym(1).ExportClause = exportClause;
+    } break;
+./
+ExportClause: T_LBRACE ExportsList T_RBRACE;
+/.
+    case $rule_number: {
+        auto exportClause = new (pool) AST::ExportClause(sym(2).ExportsList->finish());
+        exportClause->leftBraceToken = loc(1);
+        exportClause->rightBraceToken = loc(3);
+        sym(1).ExportClause = exportClause;
+    } break;
+./
+ExportClause: T_LBRACE ExportsList T_COMMA T_RBRACE;
+/.
+    case $rule_number: {
+        auto exportClause = new (pool) AST::ExportClause(sym(2).ExportsList->finish());
+        exportClause->leftBraceToken = loc(1);
+        exportClause->rightBraceToken = loc(4);
+        sym(1).ExportClause = exportClause;
+    } break;
 ./
 
-SourceElement: FunctionDeclaration ;
+ExportsList: ExportSpecifier;
 /.
-case $rule_number: {
-  sym(1).Node = new (pool) AST::FunctionSourceElement(sym(1).FunctionDeclaration);
-} break;
+    case $rule_number: {
+        sym(1).ExportsList = new (pool) AST::ExportsList(sym(1).ExportSpecifier);
+    } break;
+./
+ExportsList: ExportsList T_COMMA ExportSpecifier;
+/.
+    case $rule_number: {
+        sym(1).ExportsList = new (pool) AST::ExportsList(sym(1).ExportsList, sym(3).ExportSpecifier);
+    } break;
 ./
 
-PropertyAssignmentListOpt: ;
+ExportSpecifier: IdentifierName;
 /.
-case $rule_number: {
-  sym(1).Node = 0;
-} break;
+    case $rule_number: {
+        auto exportSpecifier = new (pool) AST::ExportSpecifier(stringRef(1));
+        exportSpecifier->identifierToken = loc(1);
+        sym(1).ExportSpecifier = exportSpecifier;
+    } break;
+./
+ExportSpecifier: IdentifierName T_AS IdentifierName;
+/.
+    case $rule_number: {
+        auto exportSpecifier = new (pool) AST::ExportSpecifier(stringRef(1), stringRef(3));
+        exportSpecifier->identifierToken = loc(1);
+        exportSpecifier->exportedIdentifierToken = loc(3);
+        sym(1).ExportSpecifier = exportSpecifier;
+    } break;
 ./
 
-PropertyAssignmentListOpt: PropertyAssignmentList ;
+-- Old top level code
 
 /.
+    // ------------ end of switch statement
             } // switch
             action = nt_action(state_stack[tos], lhs[r] - TERMINAL_COUNT);
         } // if
     } while (action != 0);
 
+#ifdef PARSER_DEBUG
+    qDebug() << "Done or error.";
+#endif
+
     if (first_token == last_token) {
         const int errorState = state_stack[tos];
 
         // automatic insertion of `;'
         if (yytoken != -1 && ((t_action(errorState, T_AUTOMATIC_SEMICOLON) && lexer->canInsertAutomaticSemicolon(yytoken))
                               || t_action(errorState, T_COMPATIBILITY_SEMICOLON))) {
+#ifdef PARSER_DEBUG
+            qDebug() << "Inserting automatic semicolon.";
+#endif
             SavedToken &tk = token_buffer[0];
             tk.token = yytoken;
             tk.dval = yylval;
             tk.spell = yytokenspell;
+            tk.raw = yytokenraw;
             tk.loc = yylloc;
 
             yylloc = yyprevlloc;
@@ -3144,14 +4405,19 @@ PropertyAssignmentListOpt: PropertyAssignmentList ;
         token_buffer[0].token = yytoken;
         token_buffer[0].dval = yylval;
         token_buffer[0].spell = yytokenspell;
+        token_buffer[0].raw = yytokenraw;
         token_buffer[0].loc = yylloc;
 
         token_buffer[1].token = yytoken       = lexer->lex();
         token_buffer[1].dval  = yylval        = lexer->tokenValue();
         token_buffer[1].spell = yytokenspell  = lexer->tokenSpell();
+        token_buffer[1].raw   = yytokenraw    = lexer->rawString();
         token_buffer[1].loc   = yylloc        = location(lexer);
 
         if (t_action(errorState, yytoken)) {
+#ifdef PARSER_DEBUG
+            qDebug() << "Parse error, trying to recover.";
+#endif
             QString msg;
             int token = token_buffer[0].token;
             if (token < 0 || token >= TERMINAL_COUNT)
@@ -3185,26 +4451,20 @@ PropertyAssignmentListOpt: PropertyAssignmentList ;
         for (int *tk = tokens; *tk != EOF_SYMBOL; ++tk) {
             int a = t_action(errorState, *tk);
             if (a > 0 && t_action(a, yytoken)) {
+#ifdef PARSER_DEBUG
+                qDebug() << "Parse error, trying to recover (2).";
+#endif
                 const QString msg = QCoreApplication::translate("QQmlParser", "Expected token `%1'").arg(QLatin1String(spell[*tk]));
                 diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
 
-                yytoken = *tk;
-                yylval = 0;
-                yylloc = token_buffer[0].loc;
-                yylloc.length = 0;
-
-                first_token = &token_buffer[0];
-                last_token = &token_buffer[2];
-
-                action = errorState;
+                pushToken(*tk);
                 goto _Lcheck_token;
             }
         }
 
         for (int tk = 1; tk < TERMINAL_COUNT; ++tk) {
             if (tk == T_AUTOMATIC_SEMICOLON || tk == T_FEED_UI_PROGRAM    ||
-                tk == T_FEED_JS_STATEMENT   || tk == T_FEED_JS_EXPRESSION ||
-                tk == T_FEED_JS_SOURCE_ELEMENT)
+                tk == T_FEED_JS_STATEMENT   || tk == T_FEED_JS_EXPRESSION)
                continue;
 
             int a = t_action(errorState, tk);
@@ -3212,12 +4472,7 @@ PropertyAssignmentListOpt: PropertyAssignmentList ;
                 const QString msg = QCoreApplication::translate("QQmlParser", "Expected token `%1'").arg(QLatin1String(spell[tk]));
                 diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
 
-                yytoken = tk;
-                yylval = 0;
-                yylloc = token_buffer[0].loc;
-                yylloc.length = 0;
-
-                action = errorState;
+                pushToken(tk);
                 goto _Lcheck_token;
             }
         }
diff --git a/src/qml/parser/qqmljsast.cpp b/src/qml/parser/qqmljsast.cpp
index 7f8cecca8f..4ebb2d3b5c 100644
--- a/src/qml/parser/qqmljsast.cpp
+++ b/src/qml/parser/qqmljsast.cpp
@@ -45,6 +45,27 @@ QT_QML_BEGIN_NAMESPACE
 
 namespace QQmlJS { namespace AST {
 
+FunctionExpression *asAnonymousFunctionDefinition(Node *n)
+{
+    if (!n)
+        return nullptr;
+    FunctionExpression *f = n->asFunctionDefinition();
+    if (!f || !f->name.isNull())
+        return nullptr;
+    return f;
+}
+
+ClassExpression *asAnonymousClassDefinition(Node *n)
+{
+    if (!n)
+        return nullptr;
+    ClassExpression *c = n->asClassDefinition();
+    if (!c || !c->name.isNull())
+        return nullptr;
+    return c;
+}
+
+
 void Node::accept(Visitor *visitor)
 {
     if (visitor->preVisit(this)) {
@@ -61,22 +82,42 @@ void Node::accept(Node *node, Visitor *visitor)
 
 ExpressionNode *Node::expressionCast()
 {
-    return 0;
+    return nullptr;
 }
 
 BinaryExpression *Node::binaryExpressionCast()
 {
-    return 0;
+    return nullptr;
 }
 
 Statement *Node::statementCast()
 {
-    return 0;
+    return nullptr;
 }
 
 UiObjectMember *Node::uiObjectMemberCast()
 {
-    return 0;
+    return nullptr;
+}
+
+LeftHandSideExpression *Node::leftHandSideExpressionCast()
+{
+    return nullptr;
+}
+
+Pattern *Node::patternCast()
+{
+    return nullptr;
+}
+
+FunctionExpression *Node::asFunctionDefinition()
+{
+    return nullptr;
+}
+
+ClassExpression *Node::asClassDefinition()
+{
+    return nullptr;
 }
 
 ExpressionNode *ExpressionNode::expressionCast()
@@ -84,6 +125,42 @@ ExpressionNode *ExpressionNode::expressionCast()
     return this;
 }
 
+FormalParameterList *ExpressionNode::reparseAsFormalParameterList(MemoryPool *pool)
+{
+    AST::ExpressionNode *expr = this;
+    AST::FormalParameterList *f = nullptr;
+    if (AST::Expression *commaExpr = AST::cast<AST::Expression *>(expr)) {
+        f = commaExpr->left->reparseAsFormalParameterList(pool);
+        if (!f)
+            return nullptr;
+
+        expr = commaExpr->right;
+    }
+
+    AST::ExpressionNode *rhs = nullptr;
+    if (AST::BinaryExpression *assign = AST::cast<AST::BinaryExpression *>(expr)) {
+            if (assign->op != QSOperator::Assign)
+                return nullptr;
+        expr = assign->left;
+        rhs = assign->right;
+    }
+    AST::PatternElement *binding = nullptr;
+    if (AST::IdentifierExpression *idExpr = AST::cast<AST::IdentifierExpression *>(expr)) {
+        binding = new (pool) AST::PatternElement(idExpr->name, rhs);
+        binding->identifierToken = idExpr->identifierToken;
+    } else if (AST::Pattern *p = expr->patternCast()) {
+        SourceLocation loc;
+        QString s;
+        if (!p->convertLiteralToAssignmentPattern(pool, &loc, &s))
+            return nullptr;
+        binding = new (pool) AST::PatternElement(p, rhs);
+        binding->identifierToken = p->firstSourceLocation();
+    }
+    if (!binding)
+        return nullptr;
+    return new (pool) AST::FormalParameterList(f, binding);
+}
+
 BinaryExpression *BinaryExpression::binaryExpressionCast()
 {
     return this;
@@ -107,6 +184,16 @@ void NestedExpression::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
+FunctionExpression *NestedExpression::asFunctionDefinition()
+{
+    return expression->asFunctionDefinition();
+}
+
+ClassExpression *NestedExpression::asClassDefinition()
+{
+    return expression->asClassDefinition();
+}
+
 void ThisExpression::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
@@ -147,7 +234,7 @@ void FalseLiteral::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void StringLiteral::accept0(Visitor *visitor)
+void SuperLiteral::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
     }
@@ -155,7 +242,8 @@ void StringLiteral::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void NumericLiteral::accept0(Visitor *visitor)
+
+void StringLiteral::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
     }
@@ -163,81 +251,231 @@ void NumericLiteral::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void RegExpLiteral::accept0(Visitor *visitor)
+void TemplateLiteral::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
+        if (next)
+            accept(next, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void ArrayLiteral::accept0(Visitor *visitor)
+void NumericLiteral::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(elements, visitor);
-        accept(elision, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void ObjectLiteral::accept0(Visitor *visitor)
+void RegExpLiteral::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(properties, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void ElementList::accept0(Visitor *visitor)
+void ArrayPattern::accept0(Visitor *visitor)
 {
-    if (visitor->visit(this)) {
-        for (ElementList *it = this; it; it = it->next) {
-            accept(it->elision, visitor);
-            accept(it->expression, visitor);
-        }
-    }
+    if (visitor->visit(this))
+        accept(elements, visitor);
 
     visitor->endVisit(this);
 }
 
-void Elision::accept0(Visitor *visitor)
+bool ArrayPattern::isValidArrayLiteral(SourceLocation *errorLocation) const {
+    for (PatternElementList *it = elements; it != nullptr; it = it->next) {
+        PatternElement *e = it->element;
+        if (e && e->bindingTarget != nullptr) {
+            if (errorLocation)
+                *errorLocation = e->firstSourceLocation();
+            return false;
+        }
+    }
+    return true;
+}
+
+void ObjectPattern::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        // ###
+        accept(properties, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void PropertyNameAndValue::accept0(Visitor *visitor)
-{
-    if (visitor->visit(this)) {
-        accept(name, visitor);
-        accept(value, visitor);
+/*
+  This is the grammar for AssignmentPattern that we need to convert the literal to:
+
+    AssignmentPattern:
+        ObjectAssignmentPattern
+        ArrayAssignmentPattern
+    ArrayAssignmentPattern:
+        [ ElisionOpt AssignmentRestElementOpt ]
+        [ AssignmentElementList ]
+        [ AssignmentElementList , ElisionOpt AssignmentRestElementOpt ]
+    AssignmentElementList:
+        AssignmentElisionElement
+        AssignmentElementList , AssignmentElisionElement
+    AssignmentElisionElement:
+        ElisionOpt AssignmentElement
+    AssignmentRestElement:
+        ... DestructuringAssignmentTarget
+
+    ObjectAssignmentPattern:
+        {}
+        { AssignmentPropertyList }
+        { AssignmentPropertyList, }
+    AssignmentPropertyList:
+        AssignmentProperty
+        AssignmentPropertyList , AssignmentProperty
+    AssignmentProperty:
+        IdentifierReference InitializerOpt_In
+    PropertyName:
+        AssignmentElement
+
+    AssignmentElement:
+        DestructuringAssignmentTarget InitializerOpt_In
+    DestructuringAssignmentTarget:
+        LeftHandSideExpression
+
+  It was originally parsed with the following grammar:
+
+ArrayLiteral:
+    [ ElisionOpt ]
+    [ ElementList ]
+    [ ElementList , ElisionOpt ]
+ElementList:
+    ElisionOpt AssignmentExpression_In
+    ElisionOpt SpreadElement
+    ElementList , ElisionOpt AssignmentExpression_In
+    ElementList , Elisionopt SpreadElement
+SpreadElement:
+    ... AssignmentExpression_In
+ObjectLiteral:
+    {}
+    { PropertyDefinitionList }
+    { PropertyDefinitionList , }
+PropertyDefinitionList:
+    PropertyDefinition
+    PropertyDefinitionList , PropertyDefinition
+PropertyDefinition:
+    IdentifierReference
+    CoverInitializedName
+    PropertyName : AssignmentExpression_In
+    MethodDefinition
+PropertyName:
+    LiteralPropertyName
+    ComputedPropertyName
+
+*/
+bool ArrayPattern::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage)
+{
+    if (parseMode == Binding)
+        return true;
+    for (auto *it = elements; it; it = it->next) {
+        if (!it->element)
+            continue;
+        if (it->element->type == PatternElement::SpreadElement && it->next) {
+            *errorLocation = it->element->firstSourceLocation();
+            *errorMessage = QString::fromLatin1("'...' can only appear as last element in a destructuring list.");
+            return false;
+        }
+        if (!it->element->convertLiteralToAssignmentPattern(pool, errorLocation, errorMessage))
+            return false;
     }
+    parseMode = Binding;
+    return true;
+}
 
-    visitor->endVisit(this);
+bool ObjectPattern::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage)
+{
+    if (parseMode == Binding)
+        return true;
+    for (auto *it = properties; it; it = it->next) {
+        if (!it->property->convertLiteralToAssignmentPattern(pool, errorLocation, errorMessage))
+            return false;
+    }
+    parseMode = Binding;
+    return true;
 }
 
-void PropertyGetterSetter::accept0(Visitor *visitor)
+bool PatternElement::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage)
 {
-    if (visitor->visit(this)) {
-        accept(name, visitor);
-        accept(formals, visitor);
-        accept(functionBody, visitor);
+    Q_ASSERT(type == Literal || type == SpreadElement);
+    Q_ASSERT(bindingIdentifier.isNull());
+    Q_ASSERT(bindingTarget == nullptr);
+    Q_ASSERT(bindingTarget == nullptr);
+    Q_ASSERT(initializer);
+    ExpressionNode *init = initializer;
+
+    initializer = nullptr;
+    LeftHandSideExpression *lhs = init->leftHandSideExpressionCast();
+    if (type == SpreadElement) {
+        if (!lhs) {
+            *errorLocation = init->firstSourceLocation();
+            *errorMessage = QString::fromLatin1("Invalid lhs expression after '...' in destructuring expression.");
+            return false;
+        }
+    } else {
+        type = PatternElement::Binding;
+
+        if (BinaryExpression *b = init->binaryExpressionCast()) {
+            if (b->op != QSOperator::Assign) {
+                *errorLocation = b->operatorToken;
+                *errorMessage = QString::fromLatin1("Invalid assignment operation in destructuring expression");
+                return false;
+            }
+            lhs = b->left->leftHandSideExpressionCast();
+            initializer = b->right;
+            Q_ASSERT(lhs);
+        } else {
+            lhs = init->leftHandSideExpressionCast();
+        }
+        if (!lhs) {
+            *errorLocation = init->firstSourceLocation();
+            *errorMessage = QString::fromLatin1("Destructuring target is not a left hand side expression.");
+            return false;
+        }
     }
 
-    visitor->endVisit(this);
+    if (auto *i = cast<IdentifierExpression *>(lhs)) {
+        bindingIdentifier = i->name;
+        identifierToken = i->identifierToken;
+        return true;
+    }
+
+    bindingTarget = lhs;
+    if (auto *p = lhs->patternCast()) {
+        if (!p->convertLiteralToAssignmentPattern(pool, errorLocation, errorMessage))
+            return false;
+    }
+    return true;
+}
+
+bool PatternProperty::convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage)
+{
+    Q_ASSERT(type != SpreadElement);
+    if (type == Binding)
+        return true;
+    if (type == Getter || type == Setter) {
+        *errorLocation = firstSourceLocation();
+        *errorMessage = QString::fromLatin1("Invalid getter/setter in destructuring expression.");
+        return false;
+    }
+    if (type == Method)
+        type = Literal;
+    Q_ASSERT(type == Literal);
+    return PatternElement::convertLiteralToAssignmentPattern(pool, errorLocation, errorMessage);
 }
 
-void PropertyAssignmentList::accept0(Visitor *visitor)
+
+void Elision::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        for (PropertyAssignmentList *it = this; it; it = it->next) {
-            accept(it->assignment, visitor);
-        }
+        // ###
     }
 
     visitor->endVisit(this);
@@ -267,6 +505,28 @@ void NumericLiteralPropertyName::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
+namespace {
+struct LocaleWithoutZeroPadding : public QLocale
+{
+    LocaleWithoutZeroPadding()
+        : QLocale(QLocale::C)
+    {
+        setNumberOptions(QLocale::OmitLeadingZeroInExponent | QLocale::OmitGroupSeparator);
+    }
+};
+}
+
+QString NumericLiteralPropertyName::asString()const
+{
+    // Can't use QString::number here anymore as it does zero padding by default now.
+
+    // In C++11 this initialization is thread-safe (6.7 [stmt.dcl] p4)
+    static LocaleWithoutZeroPadding locale;
+    // Because of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83562 we can't use thread_local
+    // for the locale variable and therefore rely on toString(double) to be thread-safe.
+    return locale.toString(id, 'g', 16);
+}
+
 void ArrayMemberExpression::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
@@ -496,15 +756,6 @@ void VariableDeclarationList::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void VariableDeclaration::accept0(Visitor *visitor)
-{
-    if (visitor->visit(this)) {
-        accept(expression, visitor);
-    }
-
-    visitor->endVisit(this);
-}
-
 void EmptyStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
@@ -557,17 +808,6 @@ void ForStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
         accept(initialiser, visitor);
-        accept(condition, visitor);
-        accept(expression, visitor);
-        accept(statement, visitor);
-    }
-
-    visitor->endVisit(this);
-}
-
-void LocalForStatement::accept0(Visitor *visitor)
-{
-    if (visitor->visit(this)) {
         accept(declarations, visitor);
         accept(condition, visitor);
         accept(expression, visitor);
@@ -580,7 +820,7 @@ void LocalForStatement::accept0(Visitor *visitor)
 void ForEachStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(initialiser, visitor);
+        accept(lhs, visitor);
         accept(expression, visitor);
         accept(statement, visitor);
     }
@@ -588,18 +828,15 @@ void ForEachStatement::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void LocalForEachStatement::accept0(Visitor *visitor)
+void ContinueStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(declaration, visitor);
-        accept(expression, visitor);
-        accept(statement, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void ContinueStatement::accept0(Visitor *visitor)
+void BreakStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
     }
@@ -607,15 +844,16 @@ void ContinueStatement::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void BreakStatement::accept0(Visitor *visitor)
+void ReturnStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
+        accept(expression, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void ReturnStatement::accept0(Visitor *visitor)
+void YieldExpression::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
         accept(expression, visitor);
@@ -624,6 +862,7 @@ void ReturnStatement::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
+
 void WithStatement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
@@ -717,6 +956,7 @@ void TryStatement::accept0(Visitor *visitor)
 void Catch::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
+        accept(patternElement, visitor);
         accept(statement, visitor);
     }
 
@@ -752,57 +992,182 @@ void FunctionExpression::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
+FunctionExpression *FunctionExpression::asFunctionDefinition()
+{
+    return this;
+}
+
+QStringList FormalParameterList::formals() const
+{
+    QStringList formals;
+    int i = 0;
+    for (const FormalParameterList *it = this; it; it = it->next) {
+        if (it->element) {
+            QString name = it->element->bindingIdentifier.toString();
+            int duplicateIndex = formals.indexOf(name);
+            if (duplicateIndex >= 0) {
+                // change the name of the earlier argument to enforce the lookup semantics from the spec
+                formals[duplicateIndex] += QLatin1String("#") + QString::number(i);
+            }
+            formals += name;
+        }
+        ++i;
+    }
+    return formals;
+}
+
+QStringList FormalParameterList::boundNames() const
+{
+    QStringList names;
+    for (const FormalParameterList *it = this; it; it = it->next) {
+        if (it->element)
+            it->element->boundNames(&names);
+    }
+    return names;
+}
+
 void FormalParameterList::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        // ###
+        accept(element, visitor);
+        if (next)
+            accept(next, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void FunctionBody::accept0(Visitor *visitor)
+FormalParameterList *FormalParameterList::finish(QQmlJS::MemoryPool *pool)
+{
+    FormalParameterList *front = next;
+    next = nullptr;
+
+    int i = 0;
+    for (const FormalParameterList *it = this; it; it = it->next) {
+        if (it->element && it->element->bindingIdentifier.isEmpty())
+            it->element->bindingIdentifier = pool->newString(QLatin1String("arg#") + QString::number(i));
+        ++i;
+    }
+    return front;
+}
+
+void Program::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(elements, visitor);
+        accept(statements, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void Program::accept0(Visitor *visitor)
+void ImportSpecifier::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(elements, visitor);
+
+    }
+    visitor->endVisit(this);
+}
+
+void ImportsList::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        for (ImportsList *it = this; it; it = it->next) {
+            accept(it->importSpecifier, visitor);
+        }
+    }
+
+    visitor->endVisit(this);
+}
+
+void NamedImports::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(importsList, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void SourceElements::accept0(Visitor *visitor)
+void FromClause::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        for (SourceElements *it = this; it; it = it->next) {
-            accept(it->element, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void NameSpaceImport::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+    }
+
+    visitor->endVisit(this);
+}
+
+void ImportClause::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(nameSpaceImport, visitor);
+        accept(namedImports, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void ImportDeclaration::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(importClause, visitor);
+        accept(fromClause, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void ExportSpecifier::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+
+    }
+
+    visitor->endVisit(this);
+}
+
+void ExportsList::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        for (ExportsList *it = this; it; it = it->next) {
+            accept(it->exportSpecifier, visitor);
         }
     }
 
     visitor->endVisit(this);
 }
 
-void FunctionSourceElement::accept0(Visitor *visitor)
+void ExportClause::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(declaration, visitor);
+        accept(exportsList, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void StatementSourceElement::accept0(Visitor *visitor)
+void ExportDeclaration::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(statement, visitor);
+        accept(fromClause, visitor);
+        accept(exportClause, visitor);
+        accept(variableStatementOrDeclaration, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void ESModule::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(body, visitor);
     }
 
     visitor->endVisit(this);
@@ -930,7 +1295,7 @@ void UiImport::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void UiQualifiedPragmaId::accept0(Visitor *visitor)
+void UiPragma::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
     }
@@ -938,35 +1303,190 @@ void UiQualifiedPragmaId::accept0(Visitor *visitor)
     visitor->endVisit(this);
 }
 
-void UiPragma::accept0(Visitor *visitor)
+void UiHeaderItemList::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(pragmaType, visitor);
+        accept(headerItem, visitor);
+        accept(next, visitor);
     }
 
     visitor->endVisit(this);
 }
 
-void UiHeaderItemList::accept0(Visitor *visitor)
+
+void UiSourceElement::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(headerItem, visitor);
-        accept(next, visitor);
+        accept(sourceElement, visitor);
     }
 
     visitor->endVisit(this);
 }
 
+void UiEnumDeclaration::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(members, visitor);
+    }
+
+    visitor->endVisit(this);
+}
 
-void UiSourceElement::accept0(Visitor *visitor)
+void UiEnumMemberList::accept0(Visitor *visitor)
 {
     if (visitor->visit(this)) {
-        accept(sourceElement, visitor);
     }
 
     visitor->endVisit(this);
 }
 
+void TaggedTemplate::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(base, visitor);
+        accept(templateLiteral, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void PatternElement::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(bindingTarget, visitor);
+        accept(initializer, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void PatternElement::boundNames(QStringList *names)
+{
+    if (bindingTarget) {
+        if (PatternElementList *e = elementList())
+            e->boundNames(names);
+        else if (PatternPropertyList *p = propertyList())
+            p->boundNames(names);
+    } else {
+        names->append(bindingIdentifier.toString());
+    }
+}
+
+void PatternElementList::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(elision, visitor);
+        accept(element, visitor);
+        if (next)
+            accept(next, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void PatternElementList::boundNames(QStringList *names)
+{
+    for (PatternElementList *it = this; it; it = it->next) {
+        if (it->element)
+            it->element->boundNames(names);
+    }
+}
+
+void PatternProperty::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(name, visitor);
+        accept(bindingTarget, visitor);
+        accept(initializer, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void PatternProperty::boundNames(QStringList *names)
+{
+    PatternElement::boundNames(names);
+}
+
+void PatternPropertyList::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(property, visitor);
+        if (next)
+            accept(next, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void PatternPropertyList::boundNames(QStringList *names)
+{
+    for (PatternPropertyList *it = this; it; it = it->next)
+        it->property->boundNames(names);
+}
+
+void ComputedPropertyName::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(expression, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void ClassExpression::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(heritage, visitor);
+        accept(elements, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+ClassExpression *ClassExpression::asClassDefinition()
+{
+    return this;
+}
+
+void ClassDeclaration::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(heritage, visitor);
+        accept(elements, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+void ClassElementList::accept0(Visitor *visitor)
+{
+    if (visitor->visit(this)) {
+        accept(property, visitor);
+        if (next)
+            accept(next, visitor);
+    }
+
+    visitor->endVisit(this);
+}
+
+ClassElementList *ClassElementList::finish()
+{
+    ClassElementList *front = next;
+    next = nullptr;
+    return front;
+}
+
+Pattern *Pattern::patternCast()
+{
+    return this;
+}
+
+LeftHandSideExpression *LeftHandSideExpression::leftHandSideExpressionCast()
+{
+    return this;
+}
+
 } } // namespace QQmlJS::AST
 
 QT_QML_END_NAMESPACE
diff --git a/src/qml/parser/qqmljsast_p.h b/src/qml/parser/qqmljsast_p.h
index 0de419d697..43aeec6525 100644
--- a/src/qml/parser/qqmljsast_p.h
+++ b/src/qml/parser/qqmljsast_p.h
@@ -77,6 +77,8 @@ enum Op {
     Div,
     InplaceDiv,
     Equal,
+    Exp,
+    InplaceExp,
     Ge,
     Gt,
     In,
@@ -100,7 +102,8 @@ enum Op {
     Sub,
     URShift,
     InplaceURightShift,
-    InplaceXor
+    InplaceXor,
+    Invalid
 };
 
 } // namespace QSOperator
@@ -109,6 +112,13 @@ namespace QQmlJS {
 
 namespace AST {
 
+enum class VariableScope {
+    NoScope,
+    Var,
+    Let,
+    Const
+};
+
 template <typename T1, typename T2>
 T1 cast(T2 *ast)
 {
@@ -118,6 +128,9 @@ T1 cast(T2 *ast)
     return 0;
 }
 
+FunctionExpression *asAnonymousFunctionDefinition(AST::Node *n);
+ClassExpression *asAnonymousClassDefinition(AST::Node *n);
+
 class QML_PARSER_EXPORT Node: public Managed
 {
 public:
@@ -125,7 +138,7 @@ public:
         Kind_Undefined,
 
         Kind_ArgumentList,
-        Kind_ArrayLiteral,
+        Kind_ArrayPattern,
         Kind_ArrayMemberExpression,
         Kind_BinaryExpression,
         Kind_Block,
@@ -147,6 +160,7 @@ public:
         Kind_Expression,
         Kind_ExpressionStatement,
         Kind_FalseLiteral,
+        Kind_SuperLiteral,
         Kind_FieldMemberExpression,
         Kind_Finally,
         Kind_ForEachStatement,
@@ -155,38 +169,50 @@ public:
         Kind_FunctionBody,
         Kind_FunctionDeclaration,
         Kind_FunctionExpression,
-        Kind_FunctionSourceElement,
+        Kind_ClassExpression,
+        Kind_ClassDeclaration,
         Kind_IdentifierExpression,
         Kind_IdentifierPropertyName,
+        Kind_ComputedPropertyName,
         Kind_IfStatement,
         Kind_LabelledStatement,
-        Kind_LocalForEachStatement,
-        Kind_LocalForStatement,
+        Kind_NameSpaceImport,
+        Kind_ImportSpecifier,
+        Kind_ImportsList,
+        Kind_NamedImports,
+        Kind_ImportClause,
+        Kind_FromClause,
+        Kind_ImportDeclaration,
+        Kind_Module,
+        Kind_ExportSpecifier,
+        Kind_ExportsList,
+        Kind_ExportClause,
+        Kind_ExportDeclaration,
         Kind_NewExpression,
         Kind_NewMemberExpression,
         Kind_NotExpression,
         Kind_NullExpression,
+        Kind_YieldExpression,
         Kind_NumericLiteral,
         Kind_NumericLiteralPropertyName,
-        Kind_ObjectLiteral,
+        Kind_ObjectPattern,
         Kind_PostDecrementExpression,
         Kind_PostIncrementExpression,
         Kind_PreDecrementExpression,
         Kind_PreIncrementExpression,
         Kind_Program,
-        Kind_PropertyAssignmentList,
+        Kind_PropertyDefinitionList,
         Kind_PropertyGetterSetter,
         Kind_PropertyName,
         Kind_PropertyNameAndValue,
         Kind_RegExpLiteral,
         Kind_ReturnStatement,
-        Kind_SourceElement,
-        Kind_SourceElements,
         Kind_StatementList,
-        Kind_StatementSourceElement,
         Kind_StringLiteral,
         Kind_StringLiteralPropertyName,
         Kind_SwitchStatement,
+        Kind_TemplateLiteral,
+        Kind_TaggedTemplate,
         Kind_ThisExpression,
         Kind_ThrowStatement,
         Kind_TildeExpression,
@@ -202,6 +228,12 @@ public:
         Kind_WhileStatement,
         Kind_WithStatement,
         Kind_NestedExpression,
+        Kind_ClassElementList,
+        Kind_PatternElement,
+        Kind_PatternElementList,
+        Kind_PatternProperty,
+        Kind_PatternPropertyList,
+
 
         Kind_UiArrayBinding,
         Kind_UiImport,
@@ -215,14 +247,14 @@ public:
         Kind_UiParameterList,
         Kind_UiPublicMember,
         Kind_UiQualifiedId,
-        Kind_UiQualifiedPragmaId,
         Kind_UiScriptBinding,
         Kind_UiSourceElement,
-        Kind_UiHeaderItemList
+        Kind_UiHeaderItemList,
+        Kind_UiEnumDeclaration,
+        Kind_UiEnumMemberList
     };
 
-    inline Node()
-        : kind(Kind_Undefined) {}
+    inline Node() {}
 
     // NOTE: node destructors are never called,
     //       instead we block free the memory
@@ -233,6 +265,11 @@ public:
     virtual BinaryExpression *binaryExpressionCast();
     virtual Statement *statementCast();
     virtual UiObjectMember *uiObjectMemberCast();
+    virtual LeftHandSideExpression *leftHandSideExpressionCast();
+    virtual Pattern *patternCast();
+    // implements the IsFunctionDefinition rules in the spec
+    virtual FunctionExpression *asFunctionDefinition();
+    virtual ClassExpression *asClassDefinition();
 
     void accept(Visitor *visitor);
     static void accept(Node *node, Visitor *visitor);
@@ -245,7 +282,7 @@ public:
     virtual SourceLocation lastSourceLocation() const = 0;
 
 // attributes
-    int kind;
+    int kind = Kind_Undefined;
 };
 
 class QML_PARSER_EXPORT ExpressionNode: public Node
@@ -254,6 +291,14 @@ public:
     ExpressionNode() {}
 
     ExpressionNode *expressionCast() override;
+
+    AST::FormalParameterList *reparseAsFormalParameterList(MemoryPool *pool);
+
+};
+
+class QML_PARSER_EXPORT LeftHandSideExpression : public ExpressionNode
+{
+    LeftHandSideExpression *leftHandSideExpressionCast() override;
 };
 
 class QML_PARSER_EXPORT Statement: public Node
@@ -264,7 +309,7 @@ public:
     Statement *statementCast() override;
 };
 
-class QML_PARSER_EXPORT NestedExpression: public ExpressionNode
+class QML_PARSER_EXPORT NestedExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(NestedExpression)
@@ -281,13 +326,17 @@ public:
     SourceLocation lastSourceLocation() const override
     { return rparenToken; }
 
+    FunctionExpression *asFunctionDefinition() override;
+    ClassExpression *asClassDefinition() override;
+
+
 // attributes
     ExpressionNode *expression;
     SourceLocation lparenToken;
     SourceLocation rparenToken;
 };
 
-class QML_PARSER_EXPORT ThisExpression: public ExpressionNode
+class QML_PARSER_EXPORT ThisExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(ThisExpression)
@@ -306,7 +355,7 @@ public:
     SourceLocation thisToken;
 };
 
-class QML_PARSER_EXPORT IdentifierExpression: public ExpressionNode
+class QML_PARSER_EXPORT IdentifierExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(IdentifierExpression)
@@ -327,7 +376,7 @@ public:
     SourceLocation identifierToken;
 };
 
-class QML_PARSER_EXPORT NullExpression: public ExpressionNode
+class QML_PARSER_EXPORT NullExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(NullExpression)
@@ -346,7 +395,7 @@ public:
     SourceLocation nullToken;
 };
 
-class QML_PARSER_EXPORT TrueLiteral: public ExpressionNode
+class QML_PARSER_EXPORT TrueLiteral: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(TrueLiteral)
@@ -365,7 +414,7 @@ public:
     SourceLocation trueToken;
 };
 
-class QML_PARSER_EXPORT FalseLiteral: public ExpressionNode
+class QML_PARSER_EXPORT FalseLiteral: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(FalseLiteral)
@@ -384,7 +433,27 @@ public:
     SourceLocation falseToken;
 };
 
-class QML_PARSER_EXPORT NumericLiteral: public ExpressionNode
+class QML_PARSER_EXPORT SuperLiteral : public LeftHandSideExpression
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(SuperLiteral)
+
+    SuperLiteral() { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return superToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return superToken; }
+
+// attributes
+    SourceLocation superToken;
+};
+
+
+class QML_PARSER_EXPORT NumericLiteral: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(NumericLiteral)
@@ -405,7 +474,7 @@ public:
     SourceLocation literalToken;
 };
 
-class QML_PARSER_EXPORT StringLiteral: public ExpressionNode
+class QML_PARSER_EXPORT StringLiteral: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(StringLiteral)
@@ -426,7 +495,31 @@ public:
     SourceLocation literalToken;
 };
 
-class QML_PARSER_EXPORT RegExpLiteral: public ExpressionNode
+class QML_PARSER_EXPORT TemplateLiteral : public LeftHandSideExpression
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(TemplateLiteral)
+
+    TemplateLiteral(const QStringRef &str, const QStringRef &raw, ExpressionNode *e)
+        : value(str), rawValue(raw), expression(e), next(nullptr)
+    { kind = K; }
+
+    SourceLocation firstSourceLocation() const override
+    { return literalToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return next ? next->lastSourceLocation() : (expression ? expression->lastSourceLocation() : literalToken); }
+
+    void accept0(Visitor *visitor) override;
+
+    QStringRef value;
+    QStringRef rawValue;
+    ExpressionNode *expression;
+    TemplateLiteral *next;
+    SourceLocation literalToken;
+};
+
+class QML_PARSER_EXPORT RegExpLiteral: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(RegExpLiteral)
@@ -448,22 +541,26 @@ public:
     SourceLocation literalToken;
 };
 
-class QML_PARSER_EXPORT ArrayLiteral: public ExpressionNode
+class QML_PARSER_EXPORT Pattern : public LeftHandSideExpression
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(ArrayLiteral)
-
-    ArrayLiteral(Elision *e):
-        elements (0), elision (e)
-        { kind = K; }
+    enum ParseMode {
+        Literal,
+        Binding
+    };
+    Pattern *patternCast() override;
+    virtual bool convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage) = 0;
+    ParseMode parseMode = Literal;
+};
 
-    ArrayLiteral(ElementList *elts):
-        elements (elts), elision (0)
-        { kind = K; }
+class QML_PARSER_EXPORT ArrayPattern : public Pattern
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ArrayPattern)
 
-    ArrayLiteral(ElementList *elts, Elision *e):
-        elements (elts), elision (e)
-        { kind = K; }
+    ArrayPattern(PatternElementList *elts)
+        : elements(elts)
+    { kind = K; }
 
     void accept0(Visitor *visitor) override;
 
@@ -473,24 +570,28 @@ public:
     SourceLocation lastSourceLocation() const override
     { return rbracketToken; }
 
+    bool isValidArrayLiteral(SourceLocation *errorLocation = nullptr) const;
+
+    bool convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage) override;
+
 // attributes
-    ElementList *elements;
-    Elision *elision;
+    PatternElementList *elements = nullptr;
     SourceLocation lbracketToken;
     SourceLocation commaToken;
     SourceLocation rbracketToken;
 };
 
-class QML_PARSER_EXPORT ObjectLiteral: public ExpressionNode
+class QML_PARSER_EXPORT ObjectPattern : public Pattern
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(ObjectLiteral)
+    QQMLJS_DECLARE_AST_NODE(ObjectPattern)
 
-    ObjectLiteral():
-        properties (0) { kind = K; }
+    ObjectPattern()
+        { kind = K; }
 
-    ObjectLiteral(PropertyAssignmentList *plist):
-        properties (plist) { kind = K; }
+    ObjectPattern(PatternPropertyList *plist)
+        : properties(plist)
+    { kind = K; }
 
     void accept0(Visitor *visitor) override;
 
@@ -500,8 +601,10 @@ public:
     SourceLocation lastSourceLocation() const override
     { return rbraceToken; }
 
+    bool convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage) override;
+
 // attributes
-    PropertyAssignmentList *properties;
+    PatternPropertyList *properties = nullptr;
     SourceLocation lbraceToken;
     SourceLocation rbraceToken;
 };
@@ -532,7 +635,7 @@ public:
     inline Elision *finish ()
     {
         Elision *front = next;
-        next = 0;
+        next = nullptr;
         return front;
     }
 
@@ -541,53 +644,6 @@ public:
     SourceLocation commaToken;
 };
 
-class QML_PARSER_EXPORT ElementList: public Node
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(ElementList)
-
-    ElementList(Elision *e, ExpressionNode *expr):
-        elision (e), expression (expr), next (this)
-    { kind = K; }
-
-    ElementList(ElementList *previous, Elision *e, ExpressionNode *expr):
-        elision (e), expression (expr)
-    {
-        kind = K;
-        next = previous->next;
-        previous->next = this;
-    }
-
-    inline ElementList *finish ()
-    {
-        ElementList *front = next;
-        next = 0;
-        return front;
-    }
-
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    {
-        if (elision)
-            return elision->firstSourceLocation();
-        return expression->firstSourceLocation();
-    }
-
-    SourceLocation lastSourceLocation() const override
-    {
-        if (next)
-            return next->lastSourceLocation();
-        return expression->lastSourceLocation();
-    }
-
-// attributes
-    Elision *elision;
-    ExpressionNode *expression;
-    ElementList *next;
-    SourceLocation commaToken;
-};
-
 class QML_PARSER_EXPORT PropertyName: public Node
 {
 public:
@@ -607,116 +663,186 @@ public:
     SourceLocation propertyNameToken;
 };
 
-class QML_PARSER_EXPORT PropertyAssignment: public Node
+class QML_PARSER_EXPORT PatternElement : public Node
 {
 public:
-    PropertyAssignment(PropertyName *n)
-        : name(n)
-    {}
+    QQMLJS_DECLARE_AST_NODE(PatternElement)
+
+    enum Type {
+        // object literal types
+        Literal,
+        Method,
+        Getter,
+        Setter,
+
+        // used by both bindings and literals
+        SpreadElement,
+        RestElement = SpreadElement,
+
+        // binding types
+        Binding,
+    };
+
+    PatternElement(ExpressionNode *i = nullptr, Type t = Literal)
+        : initializer(i), type(t)
+    { kind = K; }
+
+    PatternElement(const QStringRef &n, ExpressionNode *i = nullptr, Type t = Binding)
+        : bindingIdentifier(n), initializer(i), type(t)
+    {
+        Q_ASSERT(t >= RestElement);
+        kind = K;
+    }
+
+    PatternElement(Pattern *pattern, ExpressionNode *i = nullptr, Type t = Binding)
+        : bindingTarget(pattern), initializer(i), type(t)
+    {
+        Q_ASSERT(t >= RestElement);
+        kind = K;
+    }
+
+    void accept0(Visitor *visitor) override;
+    virtual bool convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage);
+
+    SourceLocation firstSourceLocation() const override
+    { return identifierToken.isValid() ? identifierToken : (bindingTarget ? bindingTarget->firstSourceLocation() : initializer->firstSourceLocation()); }
+
+    SourceLocation lastSourceLocation() const override
+    { return initializer ? initializer->lastSourceLocation() : (bindingTarget ? bindingTarget->lastSourceLocation() : identifierToken); }
+
+    ExpressionNode *destructuringTarget() const { return bindingTarget; }
+    Pattern *destructuringPattern() const { return bindingTarget ? bindingTarget->patternCast() : nullptr; }
+    PatternElementList *elementList() const { ArrayPattern *a = cast<ArrayPattern *>(bindingTarget); return a ? a->elements : nullptr; }
+    PatternPropertyList *propertyList() const { ObjectPattern *o = cast<ObjectPattern *>(bindingTarget); return o ? o->properties : nullptr;  }
+
+    bool isVariableDeclaration() const { return scope != VariableScope::NoScope; }
+    bool isLexicallyScoped() const { return scope == VariableScope::Let || scope == VariableScope::Const; }
+
+    virtual void boundNames(QStringList *names);
+
 // attributes
-    PropertyName *name;
+    SourceLocation identifierToken;
+    QStringRef bindingIdentifier;
+    ExpressionNode *bindingTarget = nullptr;
+    ExpressionNode *initializer = nullptr;
+    Type type = Literal;
+    // when used in a VariableDeclarationList
+    VariableScope scope = VariableScope::NoScope;
+    bool isForDeclaration = false;
 };
 
-class QML_PARSER_EXPORT PropertyAssignmentList: public Node
+class QML_PARSER_EXPORT PatternElementList : public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(PropertyAssignmentList)
+    QQMLJS_DECLARE_AST_NODE(PatternElementList)
 
-    PropertyAssignmentList(PropertyAssignment *assignment)
-        : assignment(assignment)
-        , next(this)
+    PatternElementList(Elision *elision, PatternElement *element)
+        : elision(elision), element(element), next(this)
     { kind = K; }
 
-    PropertyAssignmentList(PropertyAssignmentList *previous, PropertyAssignment *assignment)
-        : assignment(assignment)
-    {
-        kind = K;
-        next = previous->next;
-        previous->next = this;
+    PatternElementList *append(PatternElementList *n) {
+        n->next = next;
+        next = n;
+        return n;
     }
 
-    inline PropertyAssignmentList *finish ()
+    inline PatternElementList *finish ()
     {
-        PropertyAssignmentList *front = next;
+        PatternElementList *front = next;
         next = 0;
         return front;
     }
 
     void accept0(Visitor *visitor) override;
 
+    void boundNames(QStringList *names);
+
     SourceLocation firstSourceLocation() const override
-    { return assignment->firstSourceLocation(); }
+    { return elision ? elision->firstSourceLocation() : element->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : assignment->lastSourceLocation(); }
+    { return next ? next->lastSourceLocation() : (element ? element->lastSourceLocation() : elision->lastSourceLocation()); }
 
-// attributes
-    PropertyAssignment *assignment;
-    PropertyAssignmentList *next;
-    SourceLocation commaToken;
+    Elision *elision = nullptr;
+    PatternElement *element = nullptr;
+    PatternElementList *next;
 };
 
-class QML_PARSER_EXPORT PropertyNameAndValue: public PropertyAssignment
+class QML_PARSER_EXPORT PatternProperty : public PatternElement
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(PropertyNameAndValue)
+    QQMLJS_DECLARE_AST_NODE(PatternProperty)
+
+    PatternProperty(PropertyName *name, ExpressionNode *i = nullptr, Type t = Literal)
+        : PatternElement(i, t), name(name)
+    { kind = K; }
+
+    PatternProperty(PropertyName *name, const QStringRef &n, ExpressionNode *i = nullptr)
+        : PatternElement(n, i), name(name)
+    { kind = K; }
 
-    PropertyNameAndValue(PropertyName *n, ExpressionNode *v)
-        : PropertyAssignment(n), value(v)
+    PatternProperty(PropertyName *name, Pattern *pattern, ExpressionNode *i = nullptr)
+        : PatternElement(pattern, i), name(name)
     { kind = K; }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
     { return name->firstSourceLocation(); }
-
     SourceLocation lastSourceLocation() const override
-    { return value->lastSourceLocation(); }
+    {
+        SourceLocation loc = PatternElement::lastSourceLocation();
+        return loc.isValid() ? loc : name->lastSourceLocation();
+    }
+
+    void boundNames(QStringList *names) override;
+    bool convertLiteralToAssignmentPattern(MemoryPool *pool, SourceLocation *errorLocation, QString *errorMessage) override;
 
 // attributes
+    PropertyName *name;
     SourceLocation colonToken;
-    ExpressionNode *value;
-    SourceLocation commaToken;
 };
 
-class QML_PARSER_EXPORT PropertyGetterSetter: public PropertyAssignment
+
+class QML_PARSER_EXPORT PatternPropertyList : public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(PropertyGetterSetter)
-
-    enum Type {
-        Getter,
-        Setter
-    };
+    QQMLJS_DECLARE_AST_NODE(PatternPropertyList)
 
-    PropertyGetterSetter(PropertyName *n, FunctionBody *b)
-        : PropertyAssignment(n), type(Getter), formals(0), functionBody (b)
+    PatternPropertyList(PatternProperty *property)
+        : property(property), next(this)
     { kind = K; }
 
-    PropertyGetterSetter(PropertyName *n, FormalParameterList *f, FunctionBody *b)
-        : PropertyAssignment(n), type(Setter), formals(f), functionBody (b)
-    { kind = K; }
+    PatternPropertyList(PatternPropertyList *previous, PatternProperty *property)
+        : property(property), next(this)
+    {
+        kind = K;
+        next = previous->next;
+        previous->next = this;
+    }
 
     void accept0(Visitor *visitor) override;
 
+    void boundNames(QStringList *names);
+
+    inline PatternPropertyList *finish ()
+    {
+        PatternPropertyList *front = next;
+        next = 0;
+        return front;
+    }
+
     SourceLocation firstSourceLocation() const override
-    { return getSetToken; }
+    { return property->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return rbraceToken; }
+    { return next ? next->lastSourceLocation() : property->lastSourceLocation(); }
 
-// attributes
-    Type type;
-    SourceLocation getSetToken;
-    SourceLocation lparenToken;
-    FormalParameterList *formals;
-    SourceLocation rparenToken;
-    SourceLocation lbraceToken;
-    FunctionBody *functionBody;
-    SourceLocation rbraceToken;
+    PatternProperty *property;
+    PatternPropertyList *next;
 };
 
-class QML_PARSER_EXPORT IdentifierPropertyName: public PropertyName
+class QML_PARSER_EXPORT IdentifierPropertyName : public PropertyName
 {
 public:
     QQMLJS_DECLARE_AST_NODE(IdentifierPropertyName)
@@ -758,13 +884,37 @@ public:
 
     void accept0(Visitor *visitor) override;
 
-    QString asString() const override { return QString::number(id, 'g', 16); }
+    QString asString() const override;
 
 // attributes
     double id;
 };
 
-class QML_PARSER_EXPORT ArrayMemberExpression: public ExpressionNode
+class QML_PARSER_EXPORT ComputedPropertyName : public PropertyName
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ComputedPropertyName)
+
+    ComputedPropertyName(ExpressionNode *expression)
+        : expression(expression)
+    { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    QString asString() const override { return QString(); }
+
+    SourceLocation firstSourceLocation() const override
+    { return expression->firstSourceLocation(); }
+
+    SourceLocation lastSourceLocation() const override
+    { return expression->lastSourceLocation(); }
+
+// attributes
+    ExpressionNode *expression;
+};
+
+
+class QML_PARSER_EXPORT ArrayMemberExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(ArrayMemberExpression)
@@ -788,7 +938,7 @@ public:
     SourceLocation rbracketToken;
 };
 
-class QML_PARSER_EXPORT FieldMemberExpression: public ExpressionNode
+class QML_PARSER_EXPORT FieldMemberExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(FieldMemberExpression)
@@ -812,7 +962,29 @@ public:
     SourceLocation identifierToken;
 };
 
-class QML_PARSER_EXPORT NewMemberExpression: public ExpressionNode
+class QML_PARSER_EXPORT TaggedTemplate : public LeftHandSideExpression
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(TaggedTemplate)
+
+    TaggedTemplate(ExpressionNode *b, TemplateLiteral *t)
+        : base (b), templateLiteral(t)
+    { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return base->firstSourceLocation(); }
+
+    SourceLocation lastSourceLocation() const override
+    { return templateLiteral->lastSourceLocation(); }
+
+    // attributes
+    ExpressionNode *base;
+    TemplateLiteral *templateLiteral;
+};
+
+class QML_PARSER_EXPORT NewMemberExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(NewMemberExpression)
@@ -837,7 +1009,7 @@ public:
     SourceLocation rparenToken;
 };
 
-class QML_PARSER_EXPORT NewExpression: public ExpressionNode
+class QML_PARSER_EXPORT NewExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(NewExpression)
@@ -858,7 +1030,7 @@ public:
     SourceLocation newToken;
 };
 
-class QML_PARSER_EXPORT CallExpression: public ExpressionNode
+class QML_PARSER_EXPORT CallExpression: public LeftHandSideExpression
 {
 public:
     QQMLJS_DECLARE_AST_NODE(CallExpression)
@@ -914,7 +1086,7 @@ public:
     inline ArgumentList *finish ()
     {
         ArgumentList *front = next;
-        next = 0;
+        next = nullptr;
         return front;
     }
 
@@ -922,6 +1094,7 @@ public:
     ExpressionNode *expression;
     ArgumentList *next;
     SourceLocation commaToken;
+    bool isSpreadElement = false;
 };
 
 class QML_PARSER_EXPORT PostIncrementExpression: public ExpressionNode
@@ -1255,16 +1428,15 @@ class QML_PARSER_EXPORT StatementList: public Node
 public:
     QQMLJS_DECLARE_AST_NODE(StatementList)
 
-    StatementList(Statement *stmt):
-        statement (stmt), next (this)
-        { kind = K; }
+    // ### This should be a Statement, but FunctionDeclaration currently doesn't inherit it.
+    StatementList(Node *stmt)
+        : statement(stmt), next (this)
+    { kind = K; }
 
-    StatementList(StatementList *previous, Statement *stmt):
-        statement (stmt)
-    {
-        kind = K;
-        next = previous->next;
-        previous->next = this;
+    StatementList *append(StatementList *n) {
+        n->next = next;
+        next = n;
+        return n;
     }
 
     void accept0(Visitor *visitor) override;
@@ -1278,81 +1450,26 @@ public:
     inline StatementList *finish ()
     {
         StatementList *front = next;
-        next = 0;
+        next = nullptr;
         return front;
     }
 
 // attributes
-    Statement *statement;
+    Node *statement = nullptr;
     StatementList *next;
 };
 
-class QML_PARSER_EXPORT VariableStatement: public Statement
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(VariableStatement)
-
-    VariableStatement(VariableDeclarationList *vlist):
-        declarations (vlist)
-        { kind = K; }
-
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    { return declarationKindToken; }
-
-    SourceLocation lastSourceLocation() const override
-    { return semicolonToken; }
-
-// attributes
-    VariableDeclarationList *declarations;
-    SourceLocation declarationKindToken;
-    SourceLocation semicolonToken;
-};
-
-class QML_PARSER_EXPORT VariableDeclaration: public Node
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(VariableDeclaration)
-
-    enum VariableScope {
-        FunctionScope,
-        BlockScope, // let
-        ReadOnlyBlockScope // const
-    };
-
-    VariableDeclaration(const QStringRef &n, ExpressionNode *e, VariableScope s):
-        name (n), expression (e), scope(s)
-        { kind = K; }
-
-    bool isLexicallyScoped() const { return scope != FunctionScope; }
-
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    { return identifierToken; }
-
-    SourceLocation lastSourceLocation() const override
-    { return expression ? expression->lastSourceLocation() : identifierToken; }
-
-// attributes
-    QStringRef name;
-    ExpressionNode *expression;
-    SourceLocation identifierToken;
-    VariableScope scope;
-};
-
 class QML_PARSER_EXPORT VariableDeclarationList: public Node
 {
 public:
     QQMLJS_DECLARE_AST_NODE(VariableDeclarationList)
 
-    VariableDeclarationList(VariableDeclaration *decl):
-        declaration (decl), next (this)
-        { kind = K; }
+    VariableDeclarationList(PatternElement *decl)
+        : declaration(decl), next(this)
+    { kind = K; }
 
-    VariableDeclarationList(VariableDeclarationList *previous, VariableDeclaration *decl):
-        declaration (decl)
+    VariableDeclarationList(VariableDeclarationList *previous, PatternElement *decl)
+        : declaration(decl)
     {
         kind = K;
         next = previous->next;
@@ -1371,23 +1488,45 @@ public:
         return declaration->lastSourceLocation();
     }
 
-    inline VariableDeclarationList *finish(VariableDeclaration::VariableScope s)
+    inline VariableDeclarationList *finish(VariableScope s)
     {
         VariableDeclarationList *front = next;
-        next = 0;
+        next = nullptr;
         VariableDeclarationList *vdl;
-        for (vdl = front; vdl != 0; vdl = vdl->next) {
+        for (vdl = front; vdl != nullptr; vdl = vdl->next) {
             vdl->declaration->scope = s;
         }
         return front;
     }
 
 // attributes
-    VariableDeclaration *declaration;
+    PatternElement *declaration;
     VariableDeclarationList *next;
     SourceLocation commaToken;
 };
 
+class QML_PARSER_EXPORT VariableStatement: public Statement
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(VariableStatement)
+
+    VariableStatement(VariableDeclarationList *vlist):
+        declarations (vlist)
+        { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return declarationKindToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return declarations->lastSourceLocation(); }
+
+// attributes
+    VariableDeclarationList *declarations;
+    SourceLocation declarationKindToken;
+};
+
 class QML_PARSER_EXPORT EmptyStatement: public Statement
 {
 public:
@@ -1421,7 +1560,7 @@ public:
     { return expression->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return semicolonToken; }
+    { return expression->lastSourceLocation(); }
 
 // attributes
     ExpressionNode *expression;
@@ -1433,7 +1572,7 @@ class QML_PARSER_EXPORT IfStatement: public Statement
 public:
     QQMLJS_DECLARE_AST_NODE(IfStatement)
 
-    IfStatement(ExpressionNode *e, Statement *t, Statement *f = 0):
+    IfStatement(ExpressionNode *e, Statement *t, Statement *f = nullptr):
         expression (e), ok (t), ko (f)
         { kind = K; }
 
@@ -1521,35 +1660,11 @@ public:
         initialiser (i), condition (c), expression (e), statement (stmt)
         { kind = K; }
 
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    { return forToken; }
-
-    SourceLocation lastSourceLocation() const override
-    { return statement->lastSourceLocation(); }
-
-// attributes
-    ExpressionNode *initialiser;
-    ExpressionNode *condition;
-    ExpressionNode *expression;
-    Statement *statement;
-    SourceLocation forToken;
-    SourceLocation lparenToken;
-    SourceLocation firstSemicolonToken;
-    SourceLocation secondSemicolonToken;
-    SourceLocation rparenToken;
-};
-
-class QML_PARSER_EXPORT LocalForStatement: public Statement
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(LocalForStatement)
-
-    LocalForStatement(VariableDeclarationList *vlist, ExpressionNode *c, ExpressionNode *e, Statement *stmt):
+    ForStatement(VariableDeclarationList *vlist, ExpressionNode *c, ExpressionNode *e, Statement *stmt):
         declarations (vlist), condition (c), expression (e), statement (stmt)
         { kind = K; }
 
+
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
@@ -1559,26 +1674,34 @@ public:
     { return statement->lastSourceLocation(); }
 
 // attributes
-    VariableDeclarationList *declarations;
+    ExpressionNode *initialiser = nullptr;
+    VariableDeclarationList *declarations = nullptr;
     ExpressionNode *condition;
     ExpressionNode *expression;
     Statement *statement;
     SourceLocation forToken;
     SourceLocation lparenToken;
-    SourceLocation varToken;
     SourceLocation firstSemicolonToken;
     SourceLocation secondSemicolonToken;
     SourceLocation rparenToken;
 };
 
+enum class ForEachType {
+    In,
+    Of
+};
+
 class QML_PARSER_EXPORT ForEachStatement: public Statement
 {
 public:
     QQMLJS_DECLARE_AST_NODE(ForEachStatement)
 
-    ForEachStatement(ExpressionNode *i, ExpressionNode *e, Statement *stmt):
-        initialiser (i), expression (e), statement (stmt)
-        { kind = K; }
+    ForEachStatement(ExpressionNode *i, ExpressionNode *e, Statement *stmt)
+        : lhs(i), expression(e), statement(stmt)
+    { kind = K; }
+    ForEachStatement(PatternElement *v, ExpressionNode *e, Statement *stmt)
+        : lhs(v), expression(e), statement(stmt)
+    { kind = K; }
 
     void accept0(Visitor *visitor) override;
 
@@ -1588,42 +1711,19 @@ public:
     SourceLocation lastSourceLocation() const override
     { return statement->lastSourceLocation(); }
 
-// attributes
-    ExpressionNode *initialiser;
-    ExpressionNode *expression;
-    Statement *statement;
-    SourceLocation forToken;
-    SourceLocation lparenToken;
-    SourceLocation inToken;
-    SourceLocation rparenToken;
-};
-
-class QML_PARSER_EXPORT LocalForEachStatement: public Statement
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(LocalForEachStatement)
-
-    LocalForEachStatement(VariableDeclaration *v, ExpressionNode *e, Statement *stmt):
-        declaration (v), expression (e), statement (stmt)
-        { kind = K; }
-
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    { return forToken; }
-
-    SourceLocation lastSourceLocation() const override
-    { return statement->lastSourceLocation(); }
+    PatternElement *declaration() const {
+        return AST::cast<PatternElement *>(lhs);
+    }
 
 // attributes
-    VariableDeclaration *declaration;
+    Node *lhs;
     ExpressionNode *expression;
     Statement *statement;
     SourceLocation forToken;
     SourceLocation lparenToken;
-    SourceLocation varToken;
-    SourceLocation inToken;
+    SourceLocation inOfToken;
     SourceLocation rparenToken;
+    ForEachType type;
 };
 
 class QML_PARSER_EXPORT ContinueStatement: public Statement
@@ -1694,6 +1794,28 @@ public:
     SourceLocation semicolonToken;
 };
 
+class QML_PARSER_EXPORT YieldExpression: public ExpressionNode
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(YieldExpression)
+
+    YieldExpression(ExpressionNode *e = nullptr):
+        expression (e) { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return yieldToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return expression ? expression->lastSourceLocation() : yieldToken; }
+
+// attributes
+    ExpressionNode *expression;
+    bool isYieldStar = false;
+    SourceLocation yieldToken;
+};
+
 class QML_PARSER_EXPORT WithStatement: public Statement
 {
 public:
@@ -1724,7 +1846,7 @@ class QML_PARSER_EXPORT CaseBlock: public Node
 public:
     QQMLJS_DECLARE_AST_NODE(CaseBlock)
 
-    CaseBlock(CaseClauses *c, DefaultClause *d = 0, CaseClauses *r = 0):
+    CaseBlock(CaseClauses *c, DefaultClause *d = nullptr, CaseClauses *r = nullptr):
         clauses (c), defaultClause (d), moreClauses (r)
         { kind = K; }
 
@@ -1821,7 +1943,7 @@ public:
     inline CaseClauses *finish ()
     {
         CaseClauses *front = next;
-        next = 0;
+        next = nullptr;
         return front;
     }
 
@@ -1904,9 +2026,9 @@ class QML_PARSER_EXPORT Catch: public Node
 public:
     QQMLJS_DECLARE_AST_NODE(Catch)
 
-    Catch(const QStringRef &n, Block *stmt):
-        name (n), statement (stmt)
-        { kind = K; }
+    Catch(PatternElement *p, Block *stmt)
+        : patternElement(p), statement(stmt)
+    { kind = K; }
 
     void accept0(Visitor *visitor) override;
 
@@ -1917,7 +2039,7 @@ public:
     { return statement->lastSourceLocation(); }
 
 // attributes
-    QStringRef name;
+    PatternElement *patternElement;
     Block *statement;
     SourceLocation catchToken;
     SourceLocation lparenToken;
@@ -1957,11 +2079,11 @@ public:
         { kind = K; }
 
     TryStatement(Statement *stmt, Finally *f):
-        statement (stmt), catchExpression (0), finallyExpression (f)
+        statement (stmt), catchExpression (nullptr), finallyExpression (f)
         { kind = K; }
 
     TryStatement(Statement *stmt, Catch *c):
-        statement (stmt), catchExpression (c), finallyExpression (0)
+        statement (stmt), catchExpression (c), finallyExpression (nullptr)
         { kind = K; }
 
     void accept0(Visitor *visitor) override;
@@ -1991,7 +2113,7 @@ class QML_PARSER_EXPORT FunctionExpression: public ExpressionNode
 public:
     QQMLJS_DECLARE_AST_NODE(FunctionExpression)
 
-    FunctionExpression(const QStringRef &n, FormalParameterList *f, FunctionBody *b):
+    FunctionExpression(const QStringRef &n, FormalParameterList *f, StatementList *b):
         name (n), formals (f), body (b)
         { kind = K; }
 
@@ -2003,10 +2125,14 @@ public:
     SourceLocation lastSourceLocation() const override
     { return rbraceToken; }
 
+    FunctionExpression *asFunctionDefinition() override;
+
 // attributes
     QStringRef name;
+    bool isArrowFunction = false;
+    bool isGenerator = false;
     FormalParameterList *formals;
-    FunctionBody *body;
+    StatementList *body;
     SourceLocation functionToken;
     SourceLocation identifierToken;
     SourceLocation lparenToken;
@@ -2020,7 +2146,7 @@ class QML_PARSER_EXPORT FunctionDeclaration: public FunctionExpression
 public:
     QQMLJS_DECLARE_AST_NODE(FunctionDeclaration)
 
-    FunctionDeclaration(const QStringRef &n, FormalParameterList *f, FunctionBody *b):
+    FunctionDeclaration(const QStringRef &n, FormalParameterList *f, StatementList *b):
         FunctionExpression(n, f, b)
         { kind = K; }
 
@@ -2032,168 +2158,593 @@ class QML_PARSER_EXPORT FormalParameterList: public Node
 public:
     QQMLJS_DECLARE_AST_NODE(FormalParameterList)
 
-    FormalParameterList(const QStringRef &n):
-        name (n), next (this)
+    FormalParameterList(FormalParameterList *previous, PatternElement *e)
+        : element(e)
+    {
+        kind = K;
+        if (previous) {
+            next = previous->next;
+            previous->next = this;
+        } else {
+            next = this;
+        }
+    }
+
+    FormalParameterList *append(FormalParameterList *n) {
+        n->next = next;
+        next = n;
+        return n;
+    }
+
+    bool isSimpleParameterList()
+    {
+        AST::FormalParameterList *formals = this;
+        while (formals) {
+            PatternElement *e = formals->element;
+            if (e && e->type == PatternElement::RestElement)
+                return false;
+            if (e && (e->initializer || e->bindingTarget))
+                return false;
+            formals = formals->next;
+        }
+        return true;
+    }
+
+    int length()
+    {
+        // the length property of Function objects
+        int l = 0;
+        AST::FormalParameterList *formals = this;
+        while (formals) {
+            PatternElement *e = formals->element;
+            if (!e || e->initializer)
+                break;
+            if (e->type == PatternElement::RestElement)
+                break;
+            ++l;
+            formals = formals->next;
+        }
+        return l;
+    }
+
+    bool containsName(const QString &name) const {
+        for (const FormalParameterList *it = this; it; it = it->next) {
+            PatternElement *b = it->element;
+            // ### handle binding patterns
+            if (b && b->bindingIdentifier == name)
+                return true;
+        }
+        return false;
+    }
+
+    QStringList formals() const;
+
+    QStringList boundNames() const;
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return element->firstSourceLocation(); }
+
+    SourceLocation lastSourceLocation() const override
+    { return next ? next->lastSourceLocation() : element->lastSourceLocation(); }
+
+    FormalParameterList *finish(MemoryPool *pool);
+
+// attributes
+    PatternElement *element = nullptr;
+    FormalParameterList *next;
+};
+
+class QML_PARSER_EXPORT ClassExpression : public ExpressionNode
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ClassExpression)
+
+    ClassExpression(const QStringRef &n, ExpressionNode *heritage, ClassElementList *elements)
+        : name(n), heritage(heritage), elements(elements)
         { kind = K; }
 
-    FormalParameterList(FormalParameterList *previous, const QStringRef &n):
-        name (n)
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return classToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return rbraceToken; }
+
+    ClassExpression *asClassDefinition() override;
+
+// attributes
+    QStringRef name;
+    ExpressionNode *heritage;
+    ClassElementList *elements;
+    SourceLocation classToken;
+    SourceLocation identifierToken;
+    SourceLocation lbraceToken;
+    SourceLocation rbraceToken;
+};
+
+class QML_PARSER_EXPORT ClassDeclaration: public ClassExpression
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ClassDeclaration)
+
+    ClassDeclaration(const QStringRef &n, ExpressionNode *heritage, ClassElementList *elements)
+        : ClassExpression(n, heritage, elements)
+        { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+};
+
+
+class QML_PARSER_EXPORT ClassElementList : public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ClassElementList)
+
+    ClassElementList(PatternProperty *property, bool isStatic)
+        : isStatic(isStatic), property(property)
     {
         kind = K;
-        next = previous->next;
-        previous->next = this;
+        next = this;
+    }
+
+    ClassElementList *append(ClassElementList *n) {
+        n->next = next;
+        next = n;
+        return n;
     }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
-    { return identifierToken; }
+    { return property->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : identifierToken; }
+    {
+        if (next)
+            return next->lastSourceLocation();
+        return property->lastSourceLocation();
+    }
+
+    ClassElementList *finish();
+
+    bool isStatic;
+    ClassElementList *next;
+    PatternProperty *property;
+};
+
+class QML_PARSER_EXPORT Program: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(Program)
 
-    inline FormalParameterList *finish ()
+    Program(StatementList *statements)
+        : statements(statements)
+    { kind = K; }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return statements ? statements->firstSourceLocation() : SourceLocation(); }
+
+    SourceLocation lastSourceLocation() const override
+    { return statements ? statements->lastSourceLocation() : SourceLocation(); }
+
+// attributes
+    StatementList *statements;
+};
+
+class QML_PARSER_EXPORT ImportSpecifier: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ImportSpecifier)
+
+    ImportSpecifier(const QStringRef &importedBinding)
+        : importedBinding(importedBinding)
     {
-        FormalParameterList *front = next;
-        next = 0;
-        return front;
+        kind = K;
+    }
+
+    ImportSpecifier(const QStringRef &identifier, const QStringRef &importedBinding)
+        : identifier(identifier), importedBinding(importedBinding)
+    {
+        kind = K;
     }
 
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return identifier.isNull() ? importedBindingToken : identifierToken; }
+    SourceLocation lastSourceLocation() const override
+    { return importedBindingToken; }
+
 // attributes
-    QStringRef name;
-    FormalParameterList *next;
-    SourceLocation commaToken;
     SourceLocation identifierToken;
+    SourceLocation importedBindingToken;
+    QStringRef identifier;
+    QStringRef importedBinding;
 };
 
-class QML_PARSER_EXPORT SourceElement: public Node
+class QML_PARSER_EXPORT ImportsList: public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(SourceElement)
+    QQMLJS_DECLARE_AST_NODE(ImportsList)
 
-    inline SourceElement()
-        { kind = K; }
+    ImportsList(ImportSpecifier *importSpecifier)
+        : importSpecifier(importSpecifier)
+    {
+        kind = K;
+        next = this;
+    }
+
+    ImportsList(ImportsList *previous, ImportSpecifier *importSpecifier)
+        : importSpecifier(importSpecifier)
+    {
+        kind = K;
+        if (previous) {
+            next = previous->next;
+            previous->next = this;
+        } else {
+            next = this;
+        }
+    }
+
+    ImportsList *finish()
+    {
+        ImportsList *head = next;
+        next = nullptr;
+        return head;
+    }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return importSpecifierToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return next ? next->lastSourceLocation() : importSpecifierToken; }
+
+// attributes
+    SourceLocation importSpecifierToken;
+    ImportSpecifier *importSpecifier;
+    ImportsList *next = this;
 };
 
-class QML_PARSER_EXPORT SourceElements: public Node
+class QML_PARSER_EXPORT NamedImports: public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(SourceElements)
+    QQMLJS_DECLARE_AST_NODE(NamedImports)
 
-    SourceElements(SourceElement *elt):
-        element (elt), next (this)
-        { kind = K; }
+    NamedImports()
+    {
+        kind = K;
+    }
 
-    SourceElements(SourceElements *previous, SourceElement *elt):
-        element (elt)
+    NamedImports(ImportsList *importsList)
+        : importsList(importsList)
     {
         kind = K;
-        next = previous->next;
-        previous->next = this;
     }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
-    { return element->firstSourceLocation(); }
-
+    { return leftBraceToken; }
     SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : element->lastSourceLocation(); }
+    { return rightBraceToken; }
 
-    inline SourceElements *finish ()
+// attributes
+    SourceLocation leftBraceToken;
+    SourceLocation rightBraceToken;
+    ImportsList *importsList = nullptr;
+};
+
+class QML_PARSER_EXPORT NameSpaceImport: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(NameSpaceImport)
+
+    NameSpaceImport(const QStringRef &importedBinding)
+        : importedBinding(importedBinding)
     {
-        SourceElements *front = next;
-        next = 0;
-        return front;
+        kind = K;
     }
 
+    void accept0(Visitor *visitor) override;
+
+    virtual SourceLocation firstSourceLocation() const override
+    { return starToken; }
+    virtual SourceLocation lastSourceLocation() const override
+    { return importedBindingToken; }
+
 // attributes
-    SourceElement *element;
-    SourceElements *next;
+    SourceLocation starToken;
+    SourceLocation importedBindingToken;
+    QStringRef importedBinding;
 };
 
-class QML_PARSER_EXPORT FunctionBody: public Node
+class QML_PARSER_EXPORT ImportClause: public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(FunctionBody)
+    QQMLJS_DECLARE_AST_NODE(ImportClause)
 
-    FunctionBody(SourceElements *elts):
-        elements (elts)
-        { kind = K; }
+    ImportClause(const QStringRef &importedDefaultBinding)
+        : importedDefaultBinding(importedDefaultBinding)
+    {
+        kind = K;
+    }
+
+    ImportClause(NameSpaceImport *nameSpaceImport)
+        : nameSpaceImport(nameSpaceImport)
+    {
+        kind = K;
+    }
+
+    ImportClause(NamedImports *namedImports)
+        : namedImports(namedImports)
+    {
+        kind = K;
+    }
+
+    ImportClause(const QStringRef &importedDefaultBinding, NameSpaceImport *nameSpaceImport)
+        : importedDefaultBinding(importedDefaultBinding)
+        , nameSpaceImport(nameSpaceImport)
+    {
+        kind = K;
+    }
+
+    ImportClause(const QStringRef &importedDefaultBinding, NamedImports *namedImports)
+        : importedDefaultBinding(importedDefaultBinding)
+        , namedImports(namedImports)
+    {
+        kind = K;
+    }
+
+    void accept0(Visitor *visitor) override;
+
+    virtual SourceLocation firstSourceLocation() const override
+    { return importedDefaultBinding.isNull() ? (nameSpaceImport ? nameSpaceImport->firstSourceLocation() : namedImports->firstSourceLocation()) :  importedDefaultBindingToken; }
+    virtual SourceLocation lastSourceLocation() const override
+    { return importedDefaultBinding.isNull() ? (nameSpaceImport ? nameSpaceImport->lastSourceLocation() : namedImports->lastSourceLocation()) : importedDefaultBindingToken; }
+
+// attributes
+    SourceLocation importedDefaultBindingToken;
+    QStringRef importedDefaultBinding;
+    NameSpaceImport *nameSpaceImport = nullptr;
+    NamedImports *namedImports = nullptr;
+};
+
+class QML_PARSER_EXPORT FromClause: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(FromClause)
+
+    FromClause(const QStringRef &moduleSpecifier)
+        : moduleSpecifier(moduleSpecifier)
+    {
+        kind = K;
+    }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
-    { return elements ? elements->firstSourceLocation() : SourceLocation(); }
+    { return fromToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return elements ? elements->lastSourceLocation() : SourceLocation(); }
+    { return moduleSpecifierToken; }
 
 // attributes
-    SourceElements *elements;
+    SourceLocation fromToken;
+    SourceLocation moduleSpecifierToken;
+    QStringRef moduleSpecifier;
 };
 
-class QML_PARSER_EXPORT Program: public Node
+class QML_PARSER_EXPORT ImportDeclaration: public Statement
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(Program)
+    QQMLJS_DECLARE_AST_NODE(ImportDeclaration)
 
-    Program(SourceElements *elts):
-        elements (elts)
-        { kind = K; }
+    ImportDeclaration(ImportClause *importClause, FromClause *fromClause)
+        : importClause(importClause), fromClause(fromClause)
+    {
+        kind = K;
+    }
+
+    ImportDeclaration(const QStringRef &moduleSpecifier)
+        : moduleSpecifier(moduleSpecifier)
+    {
+        kind = K;
+    }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
-    { return elements ? elements->firstSourceLocation() : SourceLocation(); }
+    { return importToken; }
 
     SourceLocation lastSourceLocation() const override
-    { return elements ? elements->lastSourceLocation() : SourceLocation(); }
+    { return moduleSpecifier.isNull() ? fromClause->lastSourceLocation() : moduleSpecifierToken; }
 
 // attributes
-    SourceElements *elements;
+    SourceLocation importToken;
+    SourceLocation moduleSpecifierToken;
+    QStringRef moduleSpecifier;
+    ImportClause *importClause = nullptr;
+    FromClause *fromClause = nullptr;
 };
 
-class QML_PARSER_EXPORT FunctionSourceElement: public SourceElement
+class QML_PARSER_EXPORT ExportSpecifier: public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(FunctionSourceElement)
+    QQMLJS_DECLARE_AST_NODE(ExportSpecifier)
 
-    FunctionSourceElement(FunctionDeclaration *f):
-        declaration (f)
-        { kind = K; }
+    ExportSpecifier(const QStringRef &identifier)
+        : identifier(identifier), exportedIdentifier(identifier)
+    {
+        kind = K;
+    }
+
+    ExportSpecifier(const QStringRef &identifier, const QStringRef &exportedIdentifier)
+        : identifier(identifier), exportedIdentifier(exportedIdentifier)
+    {
+        kind = K;
+    }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
-    { return declaration->firstSourceLocation(); }
+    { return identifierToken; }
+    SourceLocation lastSourceLocation() const override
+    { return exportedIdentifierToken.isValid() ? exportedIdentifierToken : identifierToken; }
+
+// attributes
+    SourceLocation identifierToken;
+    SourceLocation exportedIdentifierToken;
+    QStringRef identifier;
+    QStringRef exportedIdentifier;
+};
+
+class QML_PARSER_EXPORT ExportsList: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ExportsList)
 
+    ExportsList(ExportSpecifier *exportSpecifier)
+        : exportSpecifier(exportSpecifier)
+    {
+        kind = K;
+        next = this;
+    }
+
+    ExportsList(ExportsList *previous, ExportSpecifier *exportSpecifier)
+        : exportSpecifier(exportSpecifier)
+    {
+        kind = K;
+        if (previous) {
+            next = previous->next;
+            previous->next = this;
+        } else {
+            next = this;
+        }
+    }
+
+    ExportsList *finish()
+    {
+        ExportsList *head = next;
+        next = nullptr;
+        return head;
+    }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return exportSpecifier->firstSourceLocation(); }
     SourceLocation lastSourceLocation() const override
-    { return declaration->lastSourceLocation(); }
+    { return next ? next->lastSourceLocation() : exportSpecifier->lastSourceLocation(); }
 
 // attributes
-    FunctionDeclaration *declaration;
+    ExportSpecifier *exportSpecifier;
+    ExportsList *next;
 };
 
-class QML_PARSER_EXPORT StatementSourceElement: public SourceElement
+class QML_PARSER_EXPORT ExportClause: public Node
 {
 public:
-    QQMLJS_DECLARE_AST_NODE(StatementSourceElement)
+    QQMLJS_DECLARE_AST_NODE(ExportClause)
 
-    StatementSourceElement(Statement *stmt):
-        statement (stmt)
-        { kind = K; }
+    ExportClause()
+    {
+        kind = K;
+    }
+
+    ExportClause(ExportsList *exportsList)
+        : exportsList(exportsList)
+    {
+        kind = K;
+    }
 
     void accept0(Visitor *visitor) override;
 
     SourceLocation firstSourceLocation() const override
-    { return statement->firstSourceLocation(); }
+    { return leftBraceToken; }
+    SourceLocation lastSourceLocation() const override
+    { return rightBraceToken; }
+
+// attributes
+    SourceLocation leftBraceToken;
+    SourceLocation rightBraceToken;
+    ExportsList *exportsList = nullptr;
+};
+
+class QML_PARSER_EXPORT ExportDeclaration: public Statement
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(ExportDeclaration)
+
+    ExportDeclaration(FromClause *fromClause)
+        : fromClause(fromClause)
+    {
+        exportAll = true;
+        kind = K;
+    }
+
+    ExportDeclaration(ExportClause *exportClause, FromClause *fromClause)
+        : exportClause(exportClause), fromClause(fromClause)
+    {
+        kind = K;
+    }
+
+    ExportDeclaration(ExportClause *exportClause)
+        : exportClause(exportClause)
+    {
+        kind = K;
+    }
 
+    ExportDeclaration(bool exportDefault, Node *variableStatementOrDeclaration)
+        : variableStatementOrDeclaration(variableStatementOrDeclaration)
+        , exportDefault(exportDefault)
+    {
+        kind = K;
+    }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return exportToken; }
     SourceLocation lastSourceLocation() const override
-    { return statement->lastSourceLocation(); }
+    { return fromClause ? fromClause->lastSourceLocation() : (exportClause ? exportClause->lastSourceLocation() : variableStatementOrDeclaration->lastSourceLocation()); }
 
 // attributes
-    Statement *statement;
+    SourceLocation exportToken;
+    bool exportAll = false;
+    ExportClause *exportClause = nullptr;
+    FromClause *fromClause = nullptr;
+    Node *variableStatementOrDeclaration = nullptr;
+    bool exportDefault = false;
+};
+
+class QML_PARSER_EXPORT ESModule: public Node
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(Module)
+
+    ESModule(StatementList *body)
+        : body(body)
+    {
+        kind = K;
+    }
+
+    void accept0(Visitor *visitor) override;
+
+    SourceLocation firstSourceLocation() const override
+    { return body ? body->firstSourceLocation() : SourceLocation(); }
+
+    SourceLocation lastSourceLocation() const override
+    { return body ? body->lastSourceLocation() : SourceLocation(); }
+
+// attributes
+    StatementList *body;
 };
 
 class QML_PARSER_EXPORT DebuggerStatement: public Statement
@@ -2237,7 +2788,7 @@ public:
     UiQualifiedId *finish()
     {
         UiQualifiedId *head = next;
-        next = 0;
+        next = nullptr;
         return head;
     }
 
@@ -2261,7 +2812,7 @@ public:
     QQMLJS_DECLARE_AST_NODE(UiImport)
 
     UiImport(const QStringRef &fileName)
-        : fileName(fileName), importUri(0)
+        : fileName(fileName), importUri(nullptr)
     { kind = K; }
 
     UiImport(UiQualifiedId *uri)
@@ -2325,7 +2876,7 @@ public:
     UiObjectMemberList *finish()
     {
         UiObjectMemberList *head = next;
-        next = 0;
+        next = nullptr;
         return head;
     }
 
@@ -2334,51 +2885,13 @@ public:
     UiObjectMember *member;
 };
 
-class QML_PARSER_EXPORT UiQualifiedPragmaId: public Node
-{
-public:
-    QQMLJS_DECLARE_AST_NODE(UiQualifiedPragmaId)
-
-    UiQualifiedPragmaId(const QStringRef &name)
-        : next(this), name(name)
-    { kind = K; }
-
-    UiQualifiedPragmaId(UiQualifiedPragmaId *previous, const QStringRef &name)
-        : name(name)
-    {
-        kind = K;
-        next = previous->next;
-        previous->next = this;
-    }
-
-    UiQualifiedPragmaId *finish()
-    {
-        UiQualifiedPragmaId *head = next;
-        next = 0;
-        return head;
-    }
-
-    void accept0(Visitor *visitor) override;
-
-    SourceLocation firstSourceLocation() const override
-    { return identifierToken; }
-
-    SourceLocation lastSourceLocation() const override
-    { return next ? next->lastSourceLocation() : identifierToken; }
-
-// attributes
-    UiQualifiedPragmaId *next;
-    QStringRef name;
-    SourceLocation identifierToken;
-};
-
 class QML_PARSER_EXPORT UiPragma: public Node
 {
 public:
     QQMLJS_DECLARE_AST_NODE(UiPragma)
 
-    UiPragma(UiQualifiedPragmaId *type)
-        : pragmaType(type)
+    UiPragma(QStringRef name)
+        : name(name)
     { kind = K; }
 
     void accept0(Visitor *visitor) override;
@@ -2390,7 +2903,7 @@ public:
     { return semicolonToken; }
 
 // attributes
-    UiQualifiedPragmaId *pragmaType;
+    QStringRef name;
     SourceLocation pragmaToken;
     SourceLocation semicolonToken;
 };
@@ -2427,7 +2940,7 @@ public:
     UiHeaderItemList *finish()
     {
         UiHeaderItemList *head = next;
-        next = 0;
+        next = nullptr;
         return head;
     }
 
@@ -2506,7 +3019,7 @@ public:
     UiArrayMemberList *finish()
     {
         UiArrayMemberList *head = next;
-        next = 0;
+        next = nullptr;
         return head;
     }
 
@@ -2567,7 +3080,7 @@ public:
     inline UiParameterList *finish ()
     {
         UiParameterList *front = next;
-        next = 0;
+        next = nullptr;
         return front;
     }
 
@@ -2587,13 +3100,13 @@ public:
 
     UiPublicMember(UiQualifiedId *memberType,
                    const QStringRef &name)
-        : type(Property), memberType(memberType), name(name), statement(0), binding(0), isDefaultMember(false), isReadonlyMember(false), parameters(0)
+        : type(Property), memberType(memberType), name(name), statement(nullptr), binding(nullptr), isDefaultMember(false), isReadonlyMember(false), parameters(nullptr)
     { kind = K; }
 
     UiPublicMember(UiQualifiedId *memberType,
                    const QStringRef &name,
                    Statement *statement)
-        : type(Property), memberType(memberType), name(name), statement(statement), binding(0), isDefaultMember(false), isReadonlyMember(false), parameters(0)
+        : type(Property), memberType(memberType), name(name), statement(statement), binding(nullptr), isDefaultMember(false), isReadonlyMember(false), parameters(nullptr)
     { kind = K; }
 
     void accept0(Visitor *visitor) override;
@@ -2785,6 +3298,81 @@ public:
     SourceLocation rbracketToken;
 };
 
+class QML_PARSER_EXPORT UiEnumMemberList: public Node
+{
+    QQMLJS_DECLARE_AST_NODE(UiEnumMemberList)
+public:
+    UiEnumMemberList(const QStringRef &member, double v = 0.0)
+        : next(this), member(member), value(v)
+    { kind = K; }
+
+    UiEnumMemberList(UiEnumMemberList *previous, const QStringRef &member)
+        : member(member)
+    {
+        kind = K;
+        next = previous->next;
+        previous->next = this;
+        value = previous->value + 1;
+    }
+
+    UiEnumMemberList(UiEnumMemberList *previous, const QStringRef &member, double v)
+        : member(member), value(v)
+    {
+        kind = K;
+        next = previous->next;
+        previous->next = this;
+    }
+
+    SourceLocation firstSourceLocation() const override
+    { return memberToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return next ? next->lastSourceLocation() :
+                    valueToken.isValid() ? valueToken : memberToken; }
+
+    void accept0(Visitor *visitor) override;
+
+    UiEnumMemberList *finish()
+    {
+        UiEnumMemberList *head = next;
+        next = nullptr;
+        return head;
+    }
+
+// attributes
+    UiEnumMemberList *next;
+    QStringRef member;
+    double value;
+    SourceLocation memberToken;
+    SourceLocation valueToken;
+};
+
+class QML_PARSER_EXPORT UiEnumDeclaration: public UiObjectMember
+{
+public:
+    QQMLJS_DECLARE_AST_NODE(UiEnumDeclaration)
+
+    UiEnumDeclaration(const QStringRef &name,
+                      UiEnumMemberList *members)
+        : name(name)
+        , members(members)
+    { kind = K; }
+
+    SourceLocation firstSourceLocation() const override
+    { return enumToken; }
+
+    SourceLocation lastSourceLocation() const override
+    { return rbraceToken; }
+
+    void accept0(Visitor *visitor) override;
+
+// attributes
+    SourceLocation enumToken;
+    SourceLocation rbraceToken;
+    QStringRef name;
+    UiEnumMemberList *members;
+};
+
 } } // namespace AST
 
 
diff --git a/src/qml/parser/qqmljsastfwd_p.h b/src/qml/parser/qqmljsastfwd_p.h
index 189eb72a57..7795e0ce71 100644
--- a/src/qml/parser/qqmljsastfwd_p.h
+++ b/src/qml/parser/qqmljsastfwd_p.h
@@ -41,6 +41,7 @@
 #define QQMLJSAST_FWD_P_H
 
 #include "qqmljsglobal_p.h"
+#include "qqmljssourcelocation_p.h"
 
 #include <QtCore/qglobal.h>
 
@@ -59,27 +60,6 @@ QT_QML_BEGIN_NAMESPACE
 
 namespace QQmlJS { namespace AST {
 
-class SourceLocation
-{
-public:
-    explicit SourceLocation(quint32 offset = 0, quint32 length = 0, quint32 line = 0, quint32 column = 0)
-        : offset(offset), length(length),
-          startLine(line), startColumn(column)
-    { }
-
-    bool isValid() const { return length != 0; }
-
-    quint32 begin() const { return offset; }
-    quint32 end() const { return offset + length; }
-
-// attributes
-    // ### encode
-    quint32 offset;
-    quint32 length;
-    quint32 startLine;
-    quint32 startColumn;
-};
-
 class Visitor;
 class Node;
 class ExpressionNode;
@@ -89,22 +69,27 @@ class IdentifierExpression;
 class NullExpression;
 class TrueLiteral;
 class FalseLiteral;
+class SuperLiteral;
 class NumericLiteral;
 class StringLiteral;
+class TemplateLiteral;
 class RegExpLiteral;
-class ArrayLiteral;
-class ObjectLiteral;
-class ElementList;
+class Pattern;
+class ArrayPattern;
+class ObjectPattern;
+class PatternElement;
+class PatternElementList;
+class PatternProperty;
+class PatternPropertyList;
 class Elision;
-class PropertyAssignmentList;
-class PropertyGetterSetter;
-class PropertyNameAndValue;
 class PropertyName;
 class IdentifierPropertyName;
 class StringLiteralPropertyName;
 class NumericLiteralPropertyName;
+class ComputedPropertyName;
 class ArrayMemberExpression;
 class FieldMemberExpression;
+class TaggedTemplate;
 class NewMemberExpression;
 class NewExpression;
 class CallExpression;
@@ -123,20 +108,19 @@ class NotExpression;
 class BinaryExpression;
 class ConditionalExpression;
 class Expression; // ### rename
+class YieldExpression;
 class Block;
+class LeftHandSideExpression;
 class StatementList;
 class VariableStatement;
 class VariableDeclarationList;
-class VariableDeclaration;
 class EmptyStatement;
 class ExpressionStatement;
 class IfStatement;
 class DoWhileStatement;
 class WhileStatement;
 class ForStatement;
-class LocalForStatement;
 class ForEachStatement;
-class LocalForEachStatement;
 class ContinueStatement;
 class BreakStatement;
 class ReturnStatement;
@@ -154,14 +138,26 @@ class Finally;
 class FunctionDeclaration;
 class FunctionExpression;
 class FormalParameterList;
-class FunctionBody;
+class ExportSpecifier;
+class ExportsList;
+class ExportClause;
+class ExportDeclaration;
 class Program;
-class SourceElements;
-class SourceElement;
-class FunctionSourceElement;
-class StatementSourceElement;
+class ImportSpecifier;
+class ImportsList;
+class NamedImports;
+class NameSpaceImport;
+class NamedImport;
+class ImportClause;
+class FromClause;
+class ImportDeclaration;
+class ModuleItem;
+class ESModule;
 class DebuggerStatement;
 class NestedExpression;
+class ClassExpression;
+class ClassDeclaration;
+class ClassElementList;
 
 // ui elements
 class UiProgram;
@@ -179,8 +175,9 @@ class UiObjectMember;
 class UiObjectMemberList;
 class UiArrayMemberList;
 class UiQualifiedId;
-class UiQualifiedPragmaId;
 class UiHeaderItemList;
+class UiEnumDeclaration;
+class UiEnumMemberList;
 
 } } // namespace AST
 
diff --git a/src/qml/parser/qqmljsastvisitor_p.h b/src/qml/parser/qqmljsastvisitor_p.h
index e582a8f6a7..c925096de6 100644
--- a/src/qml/parser/qqmljsastvisitor_p.h
+++ b/src/qml/parser/qqmljsastvisitor_p.h
@@ -83,7 +83,8 @@ public:
     virtual bool visit(UiObjectMemberList *) { return true; }
     virtual bool visit(UiArrayMemberList *) { return true; }
     virtual bool visit(UiQualifiedId *) { return true; }
-    virtual bool visit(UiQualifiedPragmaId *) { return true; }
+    virtual bool visit(UiEnumDeclaration *) { return true; }
+    virtual bool visit(UiEnumMemberList *) { return true; }
 
     virtual void endVisit(UiProgram *) {}
     virtual void endVisit(UiImport *) {}
@@ -100,7 +101,8 @@ public:
     virtual void endVisit(UiObjectMemberList *) {}
     virtual void endVisit(UiArrayMemberList *) {}
     virtual void endVisit(UiQualifiedId *) {}
-    virtual void endVisit(UiQualifiedPragmaId *) {}
+    virtual void endVisit(UiEnumDeclaration *) {}
+    virtual void endVisit(UiEnumMemberList *) { }
 
     // QQmlJS
     virtual bool visit(ThisExpression *) { return true; }
@@ -118,35 +120,41 @@ public:
     virtual bool visit(FalseLiteral *) { return true; }
     virtual void endVisit(FalseLiteral *) {}
 
+    virtual bool visit(SuperLiteral *) { return true; }
+    virtual void endVisit(SuperLiteral *) {}
+
     virtual bool visit(StringLiteral *) { return true; }
     virtual void endVisit(StringLiteral *) {}
 
+    virtual bool visit(TemplateLiteral *) { return true; }
+    virtual void endVisit(TemplateLiteral *) {}
+
     virtual bool visit(NumericLiteral *) { return true; }
     virtual void endVisit(NumericLiteral *) {}
 
     virtual bool visit(RegExpLiteral *) { return true; }
     virtual void endVisit(RegExpLiteral *) {}
 
-    virtual bool visit(ArrayLiteral *) { return true; }
-    virtual void endVisit(ArrayLiteral *) {}
+    virtual bool visit(ArrayPattern *) { return true; }
+    virtual void endVisit(ArrayPattern *) {}
 
-    virtual bool visit(ObjectLiteral *) { return true; }
-    virtual void endVisit(ObjectLiteral *) {}
+    virtual bool visit(ObjectPattern *) { return true; }
+    virtual void endVisit(ObjectPattern *) {}
 
-    virtual bool visit(ElementList *) { return true; }
-    virtual void endVisit(ElementList *) {}
+    virtual bool visit(PatternElementList *) { return true; }
+    virtual void endVisit(PatternElementList *) {}
 
-    virtual bool visit(Elision *) { return true; }
-    virtual void endVisit(Elision *) {}
+    virtual bool visit(PatternPropertyList *) { return true; }
+    virtual void endVisit(PatternPropertyList *) {}
 
-    virtual bool visit(PropertyAssignmentList *) { return true; }
-    virtual void endVisit(PropertyAssignmentList *) {}
+    virtual bool visit(PatternElement *) { return true; }
+    virtual void endVisit(PatternElement *) {}
 
-    virtual bool visit(PropertyNameAndValue *) { return true; }
-    virtual void endVisit(PropertyNameAndValue *) {}
+    virtual bool visit(PatternProperty *) { return true; }
+    virtual void endVisit(PatternProperty *) {}
 
-    virtual bool visit(PropertyGetterSetter *) { return true; }
-    virtual void endVisit(PropertyGetterSetter *) {}
+    virtual bool visit(Elision *) { return true; }
+    virtual void endVisit(Elision *) {}
 
     virtual bool visit(NestedExpression *) { return true; }
     virtual void endVisit(NestedExpression *) {}
@@ -160,12 +168,18 @@ public:
     virtual bool visit(NumericLiteralPropertyName *) { return true; }
     virtual void endVisit(NumericLiteralPropertyName *) {}
 
+    virtual bool visit(ComputedPropertyName *) { return true; }
+    virtual void endVisit(ComputedPropertyName *) {}
+
     virtual bool visit(ArrayMemberExpression *) { return true; }
     virtual void endVisit(ArrayMemberExpression *) {}
 
     virtual bool visit(FieldMemberExpression *) { return true; }
     virtual void endVisit(FieldMemberExpression *) {}
 
+    virtual bool visit(TaggedTemplate *) { return true; }
+    virtual void endVisit(TaggedTemplate *) {}
+
     virtual bool visit(NewMemberExpression *) { return true; }
     virtual void endVisit(NewMemberExpression *) {}
 
@@ -232,9 +246,6 @@ public:
     virtual bool visit(VariableDeclarationList *) { return true; }
     virtual void endVisit(VariableDeclarationList *) {}
 
-    virtual bool visit(VariableDeclaration *) { return true; }
-    virtual void endVisit(VariableDeclaration *) {}
-
     virtual bool visit(EmptyStatement *) { return true; }
     virtual void endVisit(EmptyStatement *) {}
 
@@ -253,15 +264,9 @@ public:
     virtual bool visit(ForStatement *) { return true; }
     virtual void endVisit(ForStatement *) {}
 
-    virtual bool visit(LocalForStatement *) { return true; }
-    virtual void endVisit(LocalForStatement *) {}
-
     virtual bool visit(ForEachStatement *) { return true; }
     virtual void endVisit(ForEachStatement *) {}
 
-    virtual bool visit(LocalForEachStatement *) { return true; }
-    virtual void endVisit(LocalForEachStatement *) {}
-
     virtual bool visit(ContinueStatement *) { return true; }
     virtual void endVisit(ContinueStatement *) {}
 
@@ -271,6 +276,9 @@ public:
     virtual bool visit(ReturnStatement *) { return true; }
     virtual void endVisit(ReturnStatement *) {}
 
+    virtual bool visit(YieldExpression *) { return true; }
+    virtual void endVisit(YieldExpression *) {}
+
     virtual bool visit(WithStatement *) { return true; }
     virtual void endVisit(WithStatement *) {}
 
@@ -313,20 +321,56 @@ public:
     virtual bool visit(FormalParameterList *) { return true; }
     virtual void endVisit(FormalParameterList *) {}
 
-    virtual bool visit(FunctionBody *) { return true; }
-    virtual void endVisit(FunctionBody *) {}
+    virtual bool visit(ClassExpression *) { return true; }
+    virtual void endVisit(ClassExpression *) {}
+
+    virtual bool visit(ClassDeclaration *) { return true; }
+    virtual void endVisit(ClassDeclaration *) {}
+
+    virtual bool visit(ClassElementList *) { return true; }
+    virtual void endVisit(ClassElementList *) {}
 
     virtual bool visit(Program *) { return true; }
     virtual void endVisit(Program *) {}
 
-    virtual bool visit(SourceElements *) { return true; }
-    virtual void endVisit(SourceElements *) {}
+    virtual bool visit(NameSpaceImport *) { return true; }
+    virtual void endVisit(NameSpaceImport *) {}
+
+    virtual bool visit(ImportSpecifier *) { return true; }
+    virtual void endVisit(ImportSpecifier *) {}
+
+    virtual bool visit(ImportsList *) { return true; }
+    virtual void endVisit(ImportsList *) {}
+
+    virtual bool visit(NamedImports *) { return true; }
+    virtual void endVisit(NamedImports *) {}
+
+    virtual bool visit(FromClause *) { return true; }
+    virtual void endVisit(FromClause *) {}
+
+    virtual bool visit(ImportClause *) { return true; }
+    virtual void endVisit(ImportClause *) {}
+
+    virtual bool visit(ImportDeclaration *) { return true; }
+    virtual void endVisit(ImportDeclaration *) {}
+
+    virtual bool visit(ExportSpecifier *) { return true; }
+    virtual void endVisit(ExportSpecifier *) {}
+
+    virtual bool visit(ExportsList *) { return true; }
+    virtual void endVisit(ExportsList *) {}
+
+    virtual bool visit(ExportClause *) { return true; }
+    virtual void endVisit(ExportClause *) {}
+
+    virtual bool visit(ExportDeclaration *) { return true; }
+    virtual void endVisit(ExportDeclaration *) {}
 
-    virtual bool visit(FunctionSourceElement *) { return true; }
-    virtual void endVisit(FunctionSourceElement *) {}
+    virtual bool visit(ModuleItem *) { return true; }
+    virtual void endVisit(ModuleItem *) {}
 
-    virtual bool visit(StatementSourceElement *) { return true; }
-    virtual void endVisit(StatementSourceElement *) {}
+    virtual bool visit(ESModule *) { return true; }
+    virtual void endVisit(ESModule *) {}
 
     virtual bool visit(DebuggerStatement *) { return true; }
     virtual void endVisit(DebuggerStatement *) {}
diff --git a/src/qml/parser/qqmljsengine_p.cpp b/src/qml/parser/qqmljsengine_p.cpp
index 7a6d9c3826..97ce6ebea3 100644
--- a/src/qml/parser/qqmljsengine_p.cpp
+++ b/src/qml/parser/qqmljsengine_p.cpp
@@ -112,15 +112,8 @@ double integerFromString(const char *buf, int size, int radix)
     return result;
 }
 
-double integerFromString(const QString &str, int radix)
-{
-    QByteArray ba = QStringRef(&str).trimmed().toLatin1();
-    return integerFromString(ba.constData(), ba.size(), radix);
-}
-
-
 Engine::Engine()
-    : _lexer(0), _directives(0)
+    : _lexer(nullptr), _directives(nullptr)
 { }
 
 Engine::~Engine()
diff --git a/src/qml/parser/qqmljsengine_p.h b/src/qml/parser/qqmljsengine_p.h
index 8cbe69a0ba..07b5026eb9 100644
--- a/src/qml/parser/qqmljsengine_p.h
+++ b/src/qml/parser/qqmljsengine_p.h
@@ -52,8 +52,8 @@
 //
 
 #include "qqmljsglobal_p.h"
-#include "qqmljsastfwd_p.h"
 #include "qqmljsmemorypool_p.h"
+#include "qqmljssourcelocation_p.h"
 
 #include <QtCore/qstring.h>
 #include <QtCore/qset.h>
@@ -63,16 +63,41 @@ QT_QML_BEGIN_NAMESPACE
 namespace QQmlJS {
 
 class Lexer;
-class Directives;
 class MemoryPool;
 
+class QML_PARSER_EXPORT Directives {
+public:
+    virtual ~Directives() {}
+
+    virtual void pragmaLibrary()
+    {
+    }
+
+    virtual void importFile(const QString &jsfile, const QString &module, int line, int column)
+    {
+        Q_UNUSED(jsfile);
+        Q_UNUSED(module);
+        Q_UNUSED(line);
+        Q_UNUSED(column);
+    }
+
+    virtual void importModule(const QString &uri, const QString &version, const QString &module, int line, int column)
+    {
+        Q_UNUSED(uri);
+        Q_UNUSED(version);
+        Q_UNUSED(module);
+        Q_UNUSED(line);
+        Q_UNUSED(column);
+    }
+};
+
+
 class QML_PARSER_EXPORT DiagnosticMessage
 {
 public:
-    enum Kind { Warning, Error };
+    enum Kind { Hint, Warning, Error };
 
-    DiagnosticMessage()
-        : kind(Error) {}
+    DiagnosticMessage() {}
 
     DiagnosticMessage(Kind kind, const AST::SourceLocation &loc, const QString &message)
         : kind(kind), loc(loc), message(message) {}
@@ -83,7 +108,7 @@ public:
     bool isError() const
     { return kind == Error; }
 
-    Kind kind;
+    Kind kind = Error;
     AST::SourceLocation loc;
     QString message;
 };
diff --git a/src/qml/parser/qqmljsgrammar.cpp b/src/qml/parser/qqmljsgrammar.cpp
deleted file mode 100644
index ca5a4bbd85..0000000000
--- a/src/qml/parser/qqmljsgrammar.cpp
+++ /dev/null
@@ -1,1111 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-// This file was generated by qlalr - DO NOT EDIT!
-#include "qqmljsgrammar_p.h"
-
-QT_BEGIN_NAMESPACE
-
-const char *const QQmlJSGrammar::spell [] = {
-  "end of file", "&", "&&", "&=", "break", "case", "catch", ":", ",", "continue", 
-  "default", "delete", "/", "/=", "do", ".", "else", "=", "==", "===", 
-  "finally", "for", "function", ">=", ">", ">>", ">>=", ">>>", ">>>=", "identifier", 
-  "if", "in", "instanceof", "{", "[", "<=", "(", "<", "<<", "<<=", 
-  "-", "-=", "--", "new", "!", "!=", "!==", "numeric literal", "|", "|=", 
-  "||", "+", "+=", "++", "?", "}", "]", "%", "%=", "return", 
-  ")", ";", 0, "*", "*=", "string literal", "property", "signal", "readonly", "switch", 
-  "this", "throw", "~", "try", "typeof", "var", "void", "while", "with", "^", 
-  "^=", "null", "true", "false", "const", "let", "debugger", "reserved word", "multiline string literal", "comment", 
-  0, "public", "import", "pragma", "as", "on", "get", "set", 0, 0, 
-  0, 0, 0, 0, 0, 0, 0};
-
-const short QQmlJSGrammar::lhs [] = {
-  107, 107, 107, 107, 107, 107, 108, 114, 114, 117, 
-  117, 117, 117, 120, 122, 118, 118, 119, 119, 119, 
-  119, 119, 119, 119, 119, 123, 124, 116, 115, 127, 
-  127, 128, 128, 129, 129, 126, 112, 112, 112, 112, 
-  131, 131, 131, 131, 131, 131, 131, 112, 139, 139, 
-  139, 139, 140, 140, 141, 141, 112, 112, 112, 112, 
-  112, 112, 112, 112, 112, 112, 112, 112, 112, 112, 
-  112, 112, 112, 112, 112, 112, 125, 125, 125, 125, 
-  125, 125, 125, 144, 144, 144, 144, 144, 144, 144, 
-  144, 144, 144, 144, 144, 144, 144, 144, 144, 144, 
-  144, 130, 146, 146, 146, 146, 145, 145, 150, 150, 
-  150, 148, 148, 151, 151, 151, 151, 154, 154, 154, 
-  154, 154, 154, 154, 154, 154, 154, 154, 154, 154, 
-  154, 154, 154, 154, 154, 154, 154, 154, 154, 154, 
-  154, 154, 154, 154, 154, 154, 154, 154, 154, 155, 
-  155, 121, 121, 121, 121, 121, 158, 158, 159, 159, 
-  159, 159, 157, 157, 160, 160, 161, 161, 162, 162, 
-  162, 163, 163, 163, 163, 163, 163, 163, 163, 163, 
-  163, 164, 164, 164, 164, 165, 165, 165, 166, 166, 
-  166, 166, 167, 167, 167, 167, 167, 167, 167, 168, 
-  168, 168, 168, 168, 168, 169, 169, 169, 169, 169, 
-  170, 170, 170, 170, 170, 171, 171, 172, 172, 173, 
-  173, 174, 174, 175, 175, 176, 176, 177, 177, 178, 
-  178, 179, 179, 180, 180, 181, 181, 182, 182, 149, 
-  149, 183, 183, 184, 184, 184, 184, 184, 184, 184, 
-  184, 184, 184, 184, 184, 110, 110, 185, 185, 186, 
-  186, 187, 187, 109, 109, 109, 109, 109, 109, 109, 
-  109, 109, 109, 109, 109, 109, 109, 109, 132, 196, 
-  196, 195, 195, 143, 143, 197, 197, 197, 198, 198, 
-  200, 200, 199, 201, 204, 202, 202, 205, 203, 203, 
-  133, 134, 134, 135, 135, 188, 188, 188, 188, 188, 
-  188, 188, 188, 189, 189, 189, 189, 190, 190, 190, 
-  190, 191, 191, 136, 137, 206, 206, 209, 209, 207, 
-  207, 210, 208, 192, 193, 193, 138, 138, 138, 211, 
-  212, 194, 194, 213, 142, 156, 156, 214, 214, 153, 
-  153, 152, 152, 215, 113, 113, 216, 216, 111, 111, 
-  147, 147, 217};
-
-const short QQmlJSGrammar::rhs [] = {
-  2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
-  1, 2, 2, 1, 1, 2, 2, 2, 2, 3, 
-  3, 5, 5, 4, 4, 2, 2, 0, 1, 1, 
-  2, 1, 3, 2, 3, 2, 1, 5, 4, 4, 
-  1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 
-  1, 3, 0, 1, 2, 4, 6, 6, 3, 3, 
-  7, 7, 4, 4, 5, 5, 8, 8, 5, 6, 
-  6, 10, 6, 7, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 2, 3, 3, 4, 5, 3, 4, 
-  3, 1, 1, 2, 3, 4, 1, 2, 3, 7, 
-  8, 1, 3, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 4, 3, 5, 1, 2, 4, 4, 
-  4, 3, 0, 1, 1, 3, 1, 1, 1, 2, 
-  2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 
-  2, 1, 3, 3, 3, 1, 3, 3, 1, 3, 
-  3, 3, 1, 3, 3, 3, 3, 3, 3, 1, 
-  3, 3, 3, 3, 3, 1, 3, 3, 3, 3, 
-  1, 3, 3, 3, 3, 1, 3, 1, 3, 1, 
-  3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 
-  3, 1, 3, 1, 3, 1, 5, 1, 5, 1, 
-  3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 1, 1, 1, 3, 0, 1, 1, 
-  3, 0, 1, 1, 1, 1, 1, 1, 1, 1, 
-  1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 
-  2, 0, 1, 3, 3, 1, 1, 1, 1, 3, 
-  1, 3, 2, 2, 2, 0, 1, 2, 0, 1, 
-  1, 2, 2, 7, 5, 7, 7, 7, 5, 9, 
-  10, 7, 8, 2, 2, 3, 3, 2, 2, 3, 
-  3, 3, 3, 5, 5, 3, 5, 1, 2, 0, 
-  1, 4, 3, 3, 3, 3, 3, 3, 4, 5, 
-  2, 2, 2, 1, 8, 8, 7, 1, 3, 0, 
-  1, 0, 1, 1, 1, 1, 1, 2, 1, 1, 
-  0, 1, 2};
-
-const short QQmlJSGrammar::action_default [] = {
-  0, 0, 28, 0, 0, 0, 28, 0, 189, 256, 
-  220, 228, 224, 168, 240, 216, 3, 153, 85, 169, 
-  232, 236, 157, 186, 167, 172, 152, 206, 193, 0, 
-  92, 93, 88, 0, 82, 77, 361, 0, 0, 0, 
-  0, 90, 0, 0, 86, 89, 81, 0, 0, 78, 
-  80, 83, 79, 91, 84, 0, 87, 0, 0, 182, 
-  0, 0, 169, 188, 171, 170, 0, 0, 0, 184, 
-  185, 183, 187, 0, 217, 0, 0, 0, 0, 207, 
-  0, 0, 0, 0, 0, 0, 197, 0, 0, 0, 
-  191, 192, 190, 195, 199, 198, 196, 194, 209, 208, 
-  210, 0, 225, 0, 221, 0, 0, 163, 150, 162, 
-  151, 118, 119, 120, 145, 121, 147, 122, 123, 124, 
-  125, 126, 127, 128, 129, 130, 131, 132, 146, 133, 
-  134, 148, 135, 136, 137, 138, 139, 140, 141, 142, 
-  143, 144, 149, 0, 0, 161, 257, 164, 0, 165, 
-  0, 166, 160, 0, 253, 246, 244, 251, 252, 250, 
-  249, 255, 248, 247, 245, 254, 241, 0, 229, 0, 
-  0, 233, 0, 0, 237, 0, 0, 163, 155, 0, 
-  154, 0, 159, 173, 0, 350, 350, 351, 0, 348, 
-  0, 349, 0, 352, 264, 271, 270, 278, 266, 0, 
-  267, 0, 353, 0, 360, 268, 269, 85, 274, 272, 
-  357, 354, 359, 275, 0, 287, 0, 0, 0, 0, 
-  344, 0, 361, 286, 258, 301, 0, 0, 0, 288, 
-  0, 0, 276, 277, 0, 265, 273, 302, 303, 0, 
-  350, 0, 0, 352, 0, 345, 346, 0, 334, 358, 
-  0, 318, 319, 320, 321, 0, 314, 315, 316, 317, 
-  342, 343, 0, 0, 0, 0, 0, 306, 307, 308, 
-  262, 260, 222, 230, 226, 242, 218, 263, 0, 169, 
-  234, 238, 211, 200, 0, 0, 219, 0, 0, 0, 
-  0, 212, 0, 0, 0, 0, 0, 204, 202, 205, 
-  203, 201, 214, 213, 215, 0, 227, 0, 223, 0, 
-  261, 169, 0, 243, 258, 259, 0, 258, 0, 0, 
-  310, 0, 0, 0, 312, 0, 231, 0, 0, 235, 
-  0, 0, 239, 299, 0, 291, 300, 294, 0, 298, 
-  0, 258, 292, 0, 258, 0, 0, 311, 0, 0, 
-  0, 313, 0, 0, 0, 305, 0, 304, 85, 112, 
-  362, 0, 0, 117, 280, 283, 0, 118, 287, 121, 
-  147, 123, 124, 88, 128, 129, 82, 130, 286, 133, 
-  86, 89, 258, 83, 91, 136, 84, 138, 87, 140, 
-  141, 288, 143, 144, 149, 0, 114, 113, 116, 100, 
-  115, 99, 0, 109, 281, 279, 0, 0, 0, 352, 
-  0, 110, 157, 158, 163, 0, 156, 0, 322, 323, 
-  0, 350, 0, 0, 352, 0, 111, 0, 0, 0, 
-  325, 330, 328, 331, 0, 0, 329, 330, 0, 326, 
-  0, 327, 282, 333, 0, 282, 332, 0, 335, 336, 
-  0, 282, 337, 338, 0, 0, 339, 0, 0, 0, 
-  340, 341, 175, 174, 0, 0, 0, 309, 0, 0, 
-  0, 324, 296, 289, 0, 297, 293, 0, 295, 284, 
-  0, 285, 290, 0, 0, 352, 0, 347, 103, 0, 
-  0, 107, 94, 0, 96, 105, 0, 97, 106, 108, 
-  98, 104, 95, 0, 101, 179, 177, 181, 178, 176, 
-  180, 355, 6, 356, 4, 2, 75, 102, 0, 0, 
-  78, 80, 79, 37, 5, 0, 76, 0, 51, 50, 
-  49, 0, 0, 51, 0, 0, 0, 52, 0, 67, 
-  68, 0, 65, 0, 66, 41, 42, 43, 44, 46, 
-  47, 71, 45, 0, 51, 0, 0, 0, 0, 0, 
-  61, 0, 62, 0, 0, 32, 0, 0, 72, 33, 
-  0, 36, 34, 30, 0, 35, 31, 0, 63, 0, 
-  64, 157, 0, 69, 73, 0, 0, 0, 0, 157, 
-  282, 0, 70, 85, 118, 287, 121, 147, 123, 124, 
-  88, 128, 129, 130, 286, 133, 86, 89, 258, 91, 
-  136, 84, 138, 87, 140, 141, 288, 143, 144, 149, 
-  74, 0, 59, 53, 60, 54, 0, 0, 0, 0, 
-  56, 0, 57, 58, 55, 0, 0, 0, 0, 48, 
-  0, 38, 39, 0, 40, 8, 0, 0, 9, 0, 
-  11, 0, 10, 0, 1, 27, 15, 14, 26, 13, 
-  12, 29, 7, 0, 18, 0, 19, 0, 24, 25, 
-  0, 20, 21, 0, 22, 23, 16, 17, 363};
-
-const short QQmlJSGrammar::goto_default [] = {
-  7, 654, 212, 199, 210, 524, 512, 649, 662, 511, 
-  648, 652, 650, 658, 22, 655, 653, 651, 18, 523, 
-  574, 564, 571, 566, 551, 194, 198, 200, 205, 236, 
-  213, 233, 555, 626, 625, 204, 235, 26, 490, 489, 
-  361, 360, 9, 359, 362, 203, 483, 363, 109, 17, 
-  148, 24, 13, 147, 19, 25, 59, 23, 8, 28, 
-  27, 282, 15, 276, 10, 272, 12, 274, 11, 273, 
-  20, 280, 21, 281, 14, 275, 271, 312, 417, 277, 
-  278, 206, 196, 195, 209, 208, 232, 197, 366, 365, 
-  234, 474, 473, 334, 335, 476, 337, 475, 336, 430, 
-  434, 437, 433, 432, 452, 453, 201, 187, 202, 211, 
-  0};
-
-const short QQmlJSGrammar::action_index [] = {
-  308, 1392, 2787, 2787, 2890, 1102, 71, 6, 103, -107, 
-  10, -35, -64, 287, -107, 310, 11, -107, -107, 815, 
-  30, 112, 183, 214, -107, -107, -107, 463, 203, 1392, 
-  -107, -107, -107, 536, -107, -107, 2478, 1786, 1392, 1392, 
-  1392, -107, 1005, 1392, -107, -107, -107, 1392, 1392, -107, 
-  -107, -107, -107, -107, -107, 1392, -107, 1392, 1392, -107, 
-  1392, 1392, 75, 204, -107, -107, 1392, 1392, 1392, -107, 
-  -107, -107, 221, 1392, 306, 1392, 1392, 1392, 1392, 463, 
-  1392, 1392, 1392, 1392, 1392, 1392, 200, 1392, 1392, 1392, 
-  149, 145, 108, 231, 241, 295, 379, 379, 463, 463, 
-  463, 1392, -70, 1392, 4, 2375, 1392, 1392, -107, -107, 
-  -107, -107, -107, -107, -107, -107, -107, -107, -107, -107, 
-  -107, -107, -107, -107, -107, -107, -107, -107, -107, -107, 
-  -107, -107, -107, -107, -107, -107, -107, -107, -107, -107, 
-  -107, -107, -107, 105, 1392, -107, -107, -5, -58, -107, 
-  1392, -107, -107, 1392, -107, -107, -107, -107, -107, -107, 
-  -107, -107, -107, -107, -107, -107, -107, 1392, -44, 1392, 
-  1392, 5, 7, 1392, -107, 2375, 1392, 1392, -107, 134, 
-  -107, -43, -107, -107, -16, 541, 541, 15, -36, -107, 
-  462, -107, -4, 2787, -107, -107, -107, -107, -107, 213, 
-  -107, 449, -107, -20, -107, -107, -107, 31, -107, -107, 
-  -107, 2787, -107, -107, 616, -107, 711, 144, 2890, 21, 
-  42, 43, 3096, -107, 1392, -107, 62, 1392, 101, -107, 
-  102, 99, -107, -107, 417, -107, -107, -107, -107, 93, 
-  441, 56, 92, 2787, 34, -107, -107, 2890, -107, -107, 
-  118, -107, -107, -107, -107, 125, -107, -107, -107, -107, 
-  -107, -107, -14, 33, 1392, 137, 193, -107, -107, -107, 
-  1488, -107, 44, -1, -42, -107, 316, -8, -60, 718, 
-  97, 87, 368, 222, 359, 1392, 313, 1392, 1392, 1392, 
-  1392, 342, 1392, 1392, 1392, 1392, 1392, 271, 270, 263, 
-  262, 225, 346, 352, 362, 1392, -51, 1392, 29, 1392, 
-  -107, 815, 1392, -107, 1392, 28, -22, 1392, -19, 2890, 
-  -107, 1392, 160, 2890, -107, 1392, 0, 1392, 1392, 97, 
-  45, 1392, -107, 37, 142, 25, -107, -107, 1392, -107, 
-  541, 1392, -107, 9, 1392, 12, 2890, -107, 1392, 128, 
-  2890, -107, 1392, 124, 2890, 61, 2890, -107, 60, -107, 
-  67, 26, 73, -107, -107, 2890, 49, 544, 80, 556, 
-  114, 1392, 2890, 85, 58, 482, 2581, 64, 88, 1005, 
-  90, 94, 1588, 2581, 96, 70, 197, 1392, 100, 76, 
-  1392, 104, 1392, 82, 84, 2684, -107, -107, -107, -107, 
-  -107, -107, 1392, -107, -107, -107, 95, 63, 91, 2787, 
-  53, -107, 217, -107, 1392, 50, -107, 120, -107, -107, 
-  40, 372, 8, 27, 2787, 3, -107, 1392, 141, 20, 
-  -107, 46, -107, 41, 147, 1392, -107, 39, 36, -107, 
-  -15, -107, 2890, -107, 297, 2890, -107, 175, -107, -107, 
-  187, 2890, 14, -107, -3, -2, -107, 459, -34, -6, 
-  -107, -107, -107, -107, 1392, 139, 2890, -107, 1392, 132, 
-  2890, -107, 1, -107, 251, -107, -107, 1392, -107, -107, 
-  541, -107, -107, -48, -23, 2787, -47, -107, -107, 113, 
-  1984, -107, -107, 1885, -107, -107, 1687, -107, -107, -107, 
-  -107, -107, -107, 107, -107, -107, -107, -107, -107, -107, 
-  -107, -107, -107, 2787, -107, -107, -107, 131, -50, 910, 
-  243, -45, -7, -107, -107, 232, -107, 206, -12, -107, 
-  -107, 633, 189, -107, 198, 13, 385, -107, 153, -107, 
-  -107, 184, -107, 2080, -107, -107, -107, -107, -107, -107, 
-  -107, -107, -107, 208, 18, 633, 219, 129, 353, 292, 
-  -107, 48, -107, 910, 122, -107, 81, 910, -107, -107, 
-  1296, -107, -107, -107, 1199, -107, -107, 224, -107, 2080, 
-  -107, 311, 81, -107, -107, 205, 633, 98, 2176, 304, 
-  2993, 69, -107, 89, 613, 86, 597, 109, 1392, 2890, 
-  83, 55, 467, 52, 79, 804, 78, 77, 1588, 66, 
-  47, 59, 1392, 57, 32, 1392, 54, 1392, 38, 35, 
-  -107, 255, -107, 228, -107, 51, 2, 524, 195, 532, 
-  -107, 133, -107, -107, -107, 2272, 910, 1786, 17, -107, 
-  152, -107, -107, 16, -107, -107, 910, 910, 119, 910, 
-  -107, 302, -107, 148, -107, -107, 143, 140, -107, -107, 
-  -107, -107, -107, 369, -107, 249, -107, 111, -107, -107, 
-  364, -107, -107, 65, -107, -107, -107, -107, -107, 
-
-  -111, 55, 62, 77, 71, 279, -7, -111, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -74, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, 70, 
-  -111, -111, -111, -8, -111, -111, -6, -28, 12, 84, 
-  85, -111, 93, 100, -111, -111, -111, 101, 104, -111, 
-  -111, -111, -111, -111, -111, 107, -111, 112, 118, -111, 
-  182, 184, -111, -111, -111, -111, 218, 215, 209, -111, 
-  -111, -111, -111, 202, -111, 195, 193, 192, 191, -111, 
-  189, 183, 181, 175, 168, 155, -111, 170, 153, 150, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, 151, -111, 142, -111, 172, 30, -4, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, -2, -111, -111, -111, -111, -111, 
-  0, -111, -111, 9, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, 125, -111, 122, 
-  10, -111, -111, 22, -111, 236, 46, 127, -111, -111, 
-  -111, -111, -111, -111, -111, 37, 124, -111, -111, -111, 
-  39, -111, -111, 42, -111, -111, -111, -111, -111, -111, 
-  -111, 44, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, 94, -111, -111, 47, -111, 48, -111, 128, -111, 
-  50, -111, 91, -111, -3, -111, -111, 66, 53, -111, 
-  -111, -111, -111, -111, 57, -111, -111, -111, -111, -111, 
-  79, -111, -111, 78, -111, -111, -111, 82, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, 67, -111, -111, -111, -111, -111, 
-  61, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, 59, 258, -111, 259, 268, 269, 
-  272, -111, 60, 63, 73, 74, 75, -111, -111, -111, 
-  -111, -111, -111, -111, -111, 252, -111, 242, -111, 233, 
-  -111, -111, 232, -111, 87, -111, -111, 89, -111, 133, 
-  -111, 51, -111, 135, -111, 231, -111, 223, 222, -111, 
-  -111, 221, -111, -111, -111, -111, -111, -111, 219, -111, 
-  92, 102, -111, -111, 110, -111, 171, -111, 40, -111, 
-  173, -111, 38, -111, 176, -111, 179, -111, -111, -111, 
-  -111, -111, -111, -111, -111, 180, -111, 19, -111, 18, 
-  -111, 145, 185, -111, -111, 17, 166, -111, -111, 65, 
-  -111, -111, 29, 177, -111, -111, -111, 25, -111, 5, 
-  159, -111, 164, -111, -111, 207, -111, -111, -111, -111, 
-  -111, -111, -18, -111, -111, -111, -111, -111, -111, 212, 
-  -111, -111, -111, -111, 216, -111, -111, -111, -111, -111, 
-  -111, 213, -111, -111, 86, -111, -111, 16, -111, -111, 
-  -111, -111, -111, -85, -111, 14, -111, -84, -111, -111, 
-  -111, -111, 286, -111, -111, 287, -111, -111, -111, -111, 
-  -111, 214, -94, -111, -111, -16, -111, -10, -111, -19, 
-  -111, -111, -111, -111, 2, -111, 83, -111, 105, -111, 
-  81, -111, -111, -111, -111, -111, -111, -41, -111, -111, 
-  131, -111, -111, -111, -111, 76, -111, -111, -111, -111, 
-  -35, -111, -111, 64, -111, -111, -29, -111, -111, -111, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, 208, -111, -111, -111, -111, -111, 20, 
-  -111, -111, -111, -111, -111, -111, -111, 13, -111, -111, 
-  -111, 26, 15, -111, -111, -111, 32, -111, -111, -111, 
-  -111, -111, -111, 329, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, -111, -111, 54, 56, -111, 58, -111, 
-  -111, -111, -111, 68, -111, -111, -111, 72, -111, -111, 
-  330, -111, -111, -111, 327, -111, -111, -111, -111, 389, 
-  -111, -111, 52, -111, -111, 31, 49, -111, 371, -111, 
-  134, 34, -111, -111, 43, -111, 41, -111, 108, 141, 
-  -111, -111, 35, -111, -111, 97, -111, -111, 45, -111, 
-  -111, -111, 36, -111, 21, 129, -111, 146, -111, -111, 
-  -111, -111, -111, -1, -111, -111, -111, 11, -5, 7, 
-  -111, -111, -111, -111, -111, 353, 311, 408, 4, -111, 
-  -111, -111, -111, 1, -111, -111, 8, 6, 249, 248, 
-  -111, -111, -111, -111, -111, -111, -111, -111, -111, -111, 
-  -111, -111, -111, 3, -111, -111, -111, -111, -111, -111, 
-  -14, -111, -111, -111, -111, -111, -111, -111, -111};
-
-const short QQmlJSGrammar::action_info [] = {
-  309, 314, 152, 150, 101, 73, 678, 167, 487, 103, 
-  485, 73, 484, 101, 173, 103, 527, 182, 477, 144, 
-  186, 585, 621, 190, 192, 532, 459, 451, 307, 193, 
-  285, 451, 167, 457, 455, 246, 144, 307, 247, 317, 
-  441, 319, 537, 442, 435, 285, 435, 305, 305, 570, 
-  570, 435, 331, 431, 338, 556, 348, 270, 426, 628, 
-  424, -142, 631, 263, -139, 451, -137, 247, 423, 264, 
-  344, 468, 346, -115, 464, 395, 421, 356, 185, 352, 
-  402, 401, 563, 427, -116, -134, -146, -145, 352, 245, 
-  -126, 270, -126, -145, 270, -146, 247, -134, 427, 325, 
-  352, -116, 570, -115, 405, 588, 427, -139, 411, 451, 
-  416, -142, 0, 144, 570, 144, 242, 64, 464, 0, 
-  468, 493, 0, 408, 409, 243, 675, 674, 65, 240, 
-  567, 407, 144, 0, 451, 468, 144, 327, 464, 0, 
-  144, 328, 144, 60, 535, 144, 175, 144, 60, 144, 
-  340, 0, 0, 558, 61, 175, 0, 438, 175, 61, 
-  567, 145, 169, 646, 647, 176, 170, 504, 144, 494, 
-  261, 260, 669, 668, 176, 261, 260, 176, 568, 254, 
-  253, 419, 418, 144, 354, 60, 259, 258, 350, 60, 
-  180, 543, 470, 454, 633, 632, 61, 266, 175, 466, 
-  61, 429, 439, 341, -137, 261, 260, 455, 641, 677, 
-  676, 646, 647, 535, 540, 539, 66, 176, 533, 177, 
-  323, 144, 536, 175, 533, 87, 66, 88, 87, 0, 
-  88, 579, 175, 66, 533, 528, 449, 448, 89, 635, 
-  0, 89, 176, 0, 414, 544, 542, 87, 533, 88, 
-  87, 176, 88, 414, 269, 267, 87, 533, 88, 480, 
-  89, 67, 0, 89, 530, 570, 87, 68, 88, 89, 
-  530, 67, 554, 0, 238, 237, 529, 68, 67, 89, 
-  530, 530, 529, 268, 68, 580, 578, 87, 87, 88, 
-  88, 623, 529, 529, 530, 87, 87, 88, 88, 561, 
-  89, 89, 105, 530, 445, 144, 529, 0, 89, 89, 
-  672, 671, 481, 479, 0, 529, 624, 622, 530, 175, 
-  87, 106, 88, 107, 75, 76, 175, 636, 75, 76, 
-  529, 287, 288, 89, 287, 288, 0, -102, 176, 0, 
-  177, 0, 0, 670, -102, 176, 0, 177, 0, 665, 
-  0, 77, 78, 562, 560, 77, 78, 0, 289, 290, 
-  0, 289, 290, 666, 664, 292, 293, 0, 0, 292, 
-  293, 0, 0, 0, 294, 292, 293, 295, 294, 296, 
-  0, 295, 35, 296, 294, 292, 293, 295, 35, 296, 
-  0, 292, 293, 35, 294, 0, 663, 295, 35, 296, 
-  294, 35, 0, 295, 87, 296, 88, 6, 5, 4, 
-  1, 3, 2, 0, 35, 0, 0, 89, 0, 49, 
-  52, 50, 0, 0, 0, 49, 52, 50, 0, 0, 
-  49, 52, 50, 0, 0, 49, 52, 50, 49, 52, 
-  50, 0, 0, 0, 0, 0, 35, 0, 46, 34, 
-  51, 49, 52, 50, 46, 34, 51, 0, 0, 46, 
-  34, 51, 0, 0, 46, 34, 51, 46, 34, 51, 
-  35, 0, 0, 0, 0, 0, 0, 0, 35, 0, 
-  46, 34, 51, 49, 52, 50, 80, 81, 35, 0, 
-  0, 35, 0, 0, 82, 83, 35, 0, 84, 0, 
-  85, 0, 0, 185, 0, 0, 0, 49, 52, 50, 
-  0, 35, 46, 34, 51, 49, 52, 50, 185, 0, 
-  0, 0, 0, 0, 0, 49, 52, 50, 49, 52, 
-  50, 0, 0, 49, 52, 50, 46, 34, 51, 535, 
-  0, 0, 0, 0, 46, 34, 51, 535, 49, 52, 
-  50, 0, 0, 35, 46, 34, 51, 46, 34, 51, 
-  0, 35, 46, 34, 51, 35, 0, 0, 0, 0, 
-  35, 0, 185, 35, 0, 0, 0, 46, 34, 51, 
-  0, 0, 0, 0, 0, 35, 0, 0, 0, 0, 
-  49, 52, 50, 0, 0, 0, 0, 0, 49, 52, 
-  50, 0, 49, 52, 50, 252, 251, 49, 52, 50, 
-  49, 52, 50, 0, 0, 0, 0, 257, 256, 46, 
-  34, 51, 49, 52, 50, 0, 35, 46, 34, 51, 
-  0, 46, 34, 51, 0, 0, 46, 34, 51, 46, 
-  34, 51, 35, 0, 0, 35, 0, 0, 535, 0, 
-  0, 46, 34, 51, 0, 0, 0, 0, 257, 256, 
-  0, 0, 35, 49, 52, 50, 0, 0, 0, 0, 
-  0, 0, 0, 0, 252, 251, 0, 252, 251, 49, 
-  52, 50, 49, 52, 50, 0, 0, 0, 0, 0, 
-  0, 0, 46, 34, 51, 0, 0, 0, 0, 49, 
-  52, 50, 0, 0, 0, 0, 0, 0, 46, 34, 
-  51, 46, 34, 51, 0, 0, 0, 0, 0, 0, 
-  0, 154, 0, 0, 0, 0, 0, 0, 46, 34, 
-  51, 155, 0, 0, 0, 156, 0, 0, 0, 0, 
-  35, 0, 0, 0, 157, 0, 158, 0, 0, 321, 
-  0, 0, 0, 0, 0, 0, 0, 159, 0, 160, 
-  64, 0, 0, 0, 0, 0, 0, 161, 0, 0, 
-  162, 65, 257, 256, 0, 0, 163, 49, 52, 50, 
-  0, 0, 164, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 165, 0, 
-  0, 0, 0, 0, 0, 0, 46, 34, 51, 0, 
-  0, 0, 0, 0, 0, 0, 30, 31, 154, 0, 
-  0, 0, 0, 0, 0, 0, 33, 0, 155, 0, 
-  0, 0, 156, 35, 0, 0, 0, 36, 37, 0, 
-  38, 157, 0, 158, 0, 0, 0, 42, 0, 0, 
-  0, 45, 0, 0, 159, 0, 160, 64, 0, 0, 
-  0, 0, 0, 0, 161, 0, 0, 162, 65, 53, 
-  49, 52, 50, 163, 54, 0, 0, 0, 0, 164, 
-  0, 0, 0, 0, 0, 44, 56, 32, 0, 0, 
-  0, 0, 41, 0, 0, 165, 0, 0, 0, 46, 
-  34, 51, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 30, 31, 0, 0, 0, 0, 0, 0, 
-  0, 0, 33, 0, 0, 0, 0, 0, 0, 35, 
-  0, 0, 0, 36, 37, 0, 38, 0, 0, 0, 
-  0, 0, 0, 519, 0, 0, 0, 45, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 53, 49, 52, 50, 0, 
-  54, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 44, 56, 32, 0, 0, 0, 0, 41, 0, 
-  0, 0, 0, 0, 0, 46, 34, 51, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 30, 31, 0, 
-  0, 0, 0, 0, 0, 0, 0, 33, 0, 0, 
-  0, 0, 0, 0, 35, 0, 0, 0, 36, 37, 
-  0, 38, 0, 0, 0, 0, 0, 0, 42, 0, 
-  0, 0, 45, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  53, 49, 52, 50, 0, 54, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 44, 56, 32, 0, 
-  0, 0, 0, 41, 0, 0, 0, 0, 0, 0, 
-  46, 34, 51, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 518, 0, 30, 31, 0, 0, 0, 0, 
-  0, 0, 0, 0, 220, 0, 0, 0, 0, 0, 
-  0, 35, 0, 0, 0, 36, 37, 0, 38, 0, 
-  0, 0, 0, 0, 0, 519, 0, 0, 0, 45, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 53, 520, 522, 
-  521, 0, 54, 0, 0, 0, 0, 229, 0, 0, 
-  0, 0, 0, 44, 56, 32, 215, 223, 0, 0, 
-  41, 0, 0, 0, 0, 0, 0, 46, 34, 51, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 518, 
-  0, 30, 31, 0, 0, 0, 0, 0, 0, 0, 
-  0, 220, 0, 0, 0, 0, 0, 0, 35, 0, 
-  0, 0, 36, 37, 0, 38, 0, 0, 0, 0, 
-  0, 0, 519, 0, 0, 0, 45, 0, 0, 0, 
-  0, 0, 0, 0, 575, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 53, 520, 522, 521, 0, 54, 
-  0, 0, 0, 0, 229, 0, 0, 0, 0, 0, 
-  44, 56, 32, 215, 223, 0, 0, 41, 0, 0, 
-  0, 0, 0, 0, 46, 34, 51, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 518, 0, 30, 31, 
-  0, 0, 0, 0, 0, 0, 0, 0, 220, 0, 
-  0, 0, 0, 0, 0, 35, 0, 0, 0, 36, 
-  37, 0, 38, 0, 0, 0, 0, 0, 0, 519, 
-  0, 0, 0, 45, 0, 0, 0, 0, 0, 0, 
-  0, 572, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 53, 520, 522, 521, 0, 54, 0, 0, 0, 
-  0, 229, 0, 0, 0, 0, 0, 44, 56, 32, 
-  215, 223, 0, 0, 41, 0, 0, 0, 0, 0, 
-  0, 46, 34, 51, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 29, 30, 31, 0, 0, 0, 0, 
-  0, 0, 0, 0, 33, 0, 0, 0, 0, 0, 
-  0, 35, 0, 0, 0, 36, 37, 0, 38, 0, 
-  0, 0, 39, 0, 40, 42, 43, 0, 0, 45, 
-  0, 0, 0, 47, 0, 48, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 53, 49, 52, 
-  50, 0, 54, 0, 55, 0, 57, 0, 58, 0, 
-  0, 0, 0, 44, 56, 32, 0, 0, 0, 0, 
-  41, 0, 0, 0, 0, 0, 0, 46, 34, 51, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 29, 
-  30, 31, 0, 0, 0, 0, 0, 0, 0, 0, 
-  33, 0, 0, 0, 0, 0, 0, 35, 0, 0, 
-  0, 36, 37, 0, 38, 0, 0, 0, 39, 0, 
-  40, 42, 43, 0, 0, 45, 0, 0, 0, 47, 
-  0, 48, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 53, 49, 52, 50, 0, 54, 0, 
-  55, 0, 57, 284, 58, 0, 0, 0, 0, 44, 
-  56, 32, 0, 0, 0, 0, 41, 0, 0, 0, 
-  0, 0, 0, 46, 34, 51, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, -135, 0, 0, 0, 29, 
-  30, 31, 0, 0, 0, 0, 0, 0, 0, 0, 
-  33, 0, 0, 0, 0, 0, 0, 35, 0, 0, 
-  0, 36, 37, 0, 38, 0, 0, 0, 39, 0, 
-  40, 42, 43, 0, 0, 45, 0, 0, 0, 47, 
-  0, 48, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 53, 49, 52, 50, 0, 54, 0, 
-  55, 0, 57, 0, 58, 0, 0, 0, 0, 44, 
-  56, 32, 0, 0, 0, 0, 41, 0, 0, 0, 
-  0, 0, 0, 46, 34, 51, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 499, 0, 0, 29, 30, 
-  31, 0, 0, 0, 0, 0, 0, 0, 0, 33, 
-  0, 0, 0, 0, 0, 0, 35, 0, 0, 0, 
-  36, 37, 0, 38, 0, 0, 0, 39, 0, 40, 
-  42, 43, 0, 0, 45, 0, 0, 0, 47, 0, 
-  48, 0, 0, 500, 0, 0, 0, 0, 0, 0, 
-  0, 0, 53, 49, 52, 50, 0, 54, 0, 55, 
-  0, 57, 0, 58, 0, 0, 0, 0, 44, 56, 
-  32, 0, 0, 0, 0, 41, 0, 0, 0, 0, 
-  0, 0, 46, 34, 51, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 491, 0, 0, 29, 30, 31, 
-  0, 0, 0, 0, 0, 0, 0, 0, 33, 0, 
-  0, 0, 0, 0, 0, 35, 0, 0, 0, 36, 
-  37, 0, 38, 0, 0, 0, 39, 0, 40, 42, 
-  43, 0, 0, 45, 0, 0, 0, 47, 0, 48, 
-  0, 0, 492, 0, 0, 0, 0, 0, 0, 0, 
-  0, 53, 49, 52, 50, 0, 54, 0, 55, 0, 
-  57, 0, 58, 0, 0, 0, 0, 44, 56, 32, 
-  0, 0, 0, 0, 41, 0, 0, 0, 0, 0, 
-  0, 46, 34, 51, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 491, 0, 0, 29, 30, 31, 0, 
-  0, 0, 0, 0, 0, 0, 0, 33, 0, 0, 
-  0, 0, 0, 0, 35, 0, 0, 0, 36, 37, 
-  0, 38, 0, 0, 0, 39, 0, 40, 42, 43, 
-  0, 0, 45, 0, 0, 0, 47, 0, 48, 0, 
-  0, 497, 0, 0, 0, 0, 0, 0, 0, 0, 
-  53, 49, 52, 50, 0, 54, 0, 55, 0, 57, 
-  0, 58, 0, 0, 0, 0, 44, 56, 32, 0, 
-  0, 0, 0, 41, 0, 0, 0, 0, 0, 0, 
-  46, 34, 51, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 499, 0, 0, 29, 30, 31, 0, 0, 
-  0, 0, 0, 0, 0, 0, 33, 0, 0, 0, 
-  0, 0, 0, 35, 0, 0, 0, 36, 37, 0, 
-  38, 0, 0, 0, 39, 0, 40, 42, 43, 0, 
-  0, 45, 0, 0, 0, 47, 0, 48, 0, 0, 
-  502, 0, 0, 0, 0, 0, 0, 0, 0, 53, 
-  49, 52, 50, 0, 54, 0, 55, 0, 57, 0, 
-  58, 0, 0, 0, 0, 44, 56, 32, 0, 0, 
-  0, 0, 41, 0, 0, 0, 0, 0, 0, 46, 
-  34, 51, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 29, 30, 31, 0, 0, 0, 0, 0, 0, 
-  0, 0, 33, 0, 0, 0, 0, 0, 0, 35, 
-  221, 0, 0, 222, 37, 0, 38, 0, 0, 0, 
-  39, 0, 40, 42, 43, 0, 0, 45, 0, 0, 
-  0, 47, 0, 48, 0, 0, 0, 0, 0, 0, 
-  0, 225, 0, 0, 0, 53, 49, 52, 50, 226, 
-  54, 0, 55, 228, 57, 0, 58, 0, 231, 0, 
-  0, 44, 56, 32, 0, 0, 0, 0, 41, 0, 
-  0, 0, 0, 0, 0, 46, 34, 51, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 29, 30, 31, 
-  0, 0, 0, 0, 0, 0, 0, 0, 33, 0, 
-  0, 0, 0, 0, 0, 35, 221, 0, 0, 590, 
-  37, 0, 38, 0, 0, 0, 39, 0, 40, 42, 
-  43, 0, 0, 45, 0, 0, 0, 47, 0, 48, 
-  0, 0, 0, 0, 0, 0, 0, 225, 0, 0, 
-  0, 53, 49, 52, 50, 226, 54, 0, 55, 228, 
-  57, 0, 58, 0, 231, 0, 0, 44, 56, 32, 
-  0, 0, 0, 0, 41, 0, 0, 0, 0, 0, 
-  0, 46, 34, 51, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 29, 30, 31, 0, 0, 0, 0, 
-  0, 0, 0, 0, 33, 0, 0, 0, 0, 0, 
-  0, 35, 221, 0, 0, 590, 637, 0, 38, 0, 
-  0, 0, 39, 0, 40, 42, 43, 0, 0, 45, 
-  0, 0, 0, 47, 0, 48, 0, 0, 0, 0, 
-  0, 0, 0, 225, 0, 0, 0, 53, 49, 52, 
-  50, 226, 54, 0, 55, 228, 57, 0, 58, 0, 
-  231, 0, 0, 44, 56, 32, 0, 0, 0, 0, 
-  41, 0, 0, 0, 0, 0, 0, 46, 34, 51, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 111, 
-  112, 113, 0, 0, 115, 117, 118, 0, 0, 119, 
-  0, 120, 0, 0, 0, 122, 123, 124, 0, 0, 
-  0, 0, 0, 0, 35, 125, 126, 127, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 129, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 132, 0, 0, 0, 0, 0, 
-  0, 49, 52, 50, 133, 134, 135, 0, 137, 138, 
-  139, 140, 141, 142, 0, 0, 130, 136, 121, 114, 
-  128, 116, 131, 0, 0, 0, 0, 0, 0, 0, 
-  46, 34, 51, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 111, 112, 113, 0, 0, 115, 117, 118, 
-  0, 0, 119, 0, 120, 0, 0, 0, 122, 123, 
-  124, 0, 0, 0, 0, 0, 0, 35, 125, 126, 
-  127, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 129, 0, 0, 0, 398, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 132, 0, 0, 
-  0, 0, 0, 400, 49, 52, 50, 133, 134, 135, 
-  0, 137, 138, 139, 140, 141, 142, 0, 0, 130, 
-  136, 121, 114, 128, 116, 131, 0, 0, 0, 0, 
-  0, 0, 0, 46, 376, 383, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 111, 112, 113, 0, 0, 
-  115, 117, 118, 0, 0, 119, 0, 120, 0, 0, 
-  0, 122, 123, 124, 0, 0, 0, 0, 0, 0, 
-  35, 125, 126, 127, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 129, 0, 0, 0, 398, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  132, 0, 0, 0, 0, 0, 400, 49, 52, 50, 
-  133, 134, 135, 0, 137, 138, 139, 140, 141, 142, 
-  0, 0, 130, 136, 121, 114, 128, 116, 131, 0, 
-  0, 0, 0, 0, 0, 0, 46, 34, 51, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 111, 112, 
-  113, 0, 0, 115, 117, 118, 0, 0, 119, 0, 
-  120, 0, 0, 0, 122, 123, 124, 0, 0, 0, 
-  0, 0, 0, 35, 125, 126, 127, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 129, 0, 0, 
-  0, 398, 0, 0, 0, 0, 0, 0, 0, 399, 
-  0, 0, 0, 132, 0, 0, 0, 0, 0, 400, 
-  49, 52, 50, 133, 134, 135, 0, 137, 138, 139, 
-  140, 141, 142, 0, 0, 130, 136, 121, 114, 128, 
-  116, 131, 0, 0, 0, 0, 0, 0, 0, 46, 
-  376, 383, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 214, 0, 0, 0, 0, 216, 0, 29, 30, 
-  31, 218, 0, 0, 0, 0, 0, 0, 219, 220, 
-  0, 0, 0, 0, 0, 0, 35, 221, 0, 0, 
-  222, 37, 0, 38, 0, 0, 0, 39, 0, 40, 
-  42, 43, 0, 0, 45, 0, 0, 0, 47, 0, 
-  48, 0, 0, 0, 0, 0, 224, 0, 225, 0, 
-  0, 0, 53, 49, 52, 50, 226, 54, 227, 55, 
-  228, 57, 229, 58, 230, 231, 0, 0, 44, 56, 
-  32, 215, 223, 217, 0, 41, 0, 0, 0, 0, 
-  0, 0, 46, 34, 51, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 214, 0, 0, 0, 0, 216, 
-  0, 29, 30, 31, 218, 0, 0, 0, 0, 0, 
-  0, 219, 33, 0, 0, 0, 0, 0, 0, 35, 
-  221, 0, 0, 222, 37, 0, 38, 0, 0, 0, 
-  39, 0, 40, 42, 43, 0, 0, 45, 0, 0, 
-  0, 47, 0, 48, 0, 0, 0, 0, 0, 224, 
-  0, 225, 0, 0, 0, 53, 49, 52, 50, 226, 
-  54, 227, 55, 228, 57, 229, 58, 230, 231, 0, 
-  0, 44, 56, 32, 215, 223, 217, 0, 41, 0, 
-  0, 0, 0, 0, 0, 46, 34, 51, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 594, 112, 113, 
-  0, 0, 596, 117, 598, 30, 31, 599, 0, 120, 
-  0, 0, 0, 122, 601, 602, 0, 0, 0, 0, 
-  0, 0, 35, 603, 126, 127, 222, 37, 0, 38, 
-  0, 0, 0, 39, 0, 40, 605, 43, 0, 0, 
-  607, 0, 0, 0, 47, 0, 48, 0, 0, 0, 
-  0, 0, 608, 0, 225, 0, 0, 0, 609, 49, 
-  52, 50, 610, 611, 612, 55, 614, 615, 616, 617, 
-  618, 619, 0, 0, 606, 613, 600, 595, 604, 597, 
-  131, 41, 0, 0, 0, 0, 0, 0, 46, 376, 
-  383, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  367, 112, 113, 0, 0, 369, 117, 371, 30, 31, 
-  372, 0, 120, 0, 0, 0, 122, 374, 375, 0, 
-  0, 0, 0, 0, 0, 35, 377, 126, 127, 222, 
-  37, 0, 38, 0, 0, 0, 39, 0, 40, 379, 
-  43, 0, 0, 381, 0, 0, 0, 47, 0, 48, 
-  0, -282, 0, 0, 0, 382, 0, 225, 0, 0, 
-  0, 384, 49, 52, 50, 385, 386, 387, 55, 389, 
-  390, 391, 392, 393, 394, 0, 0, 380, 388, 373, 
-  368, 378, 370, 131, 41, 0, 0, 0, 0, 0, 
-  0, 46, 376, 383, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 
-
-  315, 478, 645, 153, 673, 465, 460, 501, 458, 461, 
-  184, 456, 396, 498, 488, 503, 440, 444, 436, 428, 
-  657, 667, 656, 644, 403, 630, 642, 629, 447, 634, 
-  450, 627, 315, 143, 553, 184, 255, 250, 149, 447, 
-  146, 353, 151, 349, 541, 531, 450, 534, 315, 179, 
-  538, 166, 172, 184, 322, 189, 620, 191, 16, 255, 
-  207, 250, 239, 586, 174, 250, 255, 587, 184, 447, 
-  265, 0, 577, 515, 584, 472, 559, 333, 450, 412, 
-  207, 514, 517, 471, 248, 467, 517, 565, 557, 207, 
-  315, 569, 315, 364, 207, 207, 207, 189, 249, 207, 
-  207, 207, 496, 0, 207, 315, 495, 412, 469, 358, 
-  333, 412, 207, 315, 62, 279, 413, 62, 0, 297, 
-  283, 486, 298, 244, 62, 241, 183, 62, 62, 62, 
-  262, 425, 299, 300, 301, 320, 364, 324, 62, 62, 
-  505, 506, 189, 262, 413, 0, 207, 0, 413, 472, 
-  0, 207, 593, 207, 62, 62, 507, 508, 62, 207, 
-  509, 62, 62, 510, 183, 316, 62, 318, 462, 149, 
-  188, 513, 62, 347, 463, 351, 62, 181, 355, 62, 
-  343, 357, 404, 62, 396, 462, 342, 262, 345, 207, 
-  108, 207, 171, 168, 207, 396, 62, 207, 207, 62, 
-  62, 183, 463, 207, 62, 62, 104, 62, 92, 62, 
-  406, 91, 249, 62, 97, 462, 364, 102, 62, 110, 
-  463, 420, 62, 482, 62, 396, 207, 96, 90, 62, 
-  207, 189, 207, 0, 95, 62, 62, 62, 62, 63, 
-  94, 72, 93, 62, 0, 62, 62, 62, 86, 62, 
-  397, 100, 99, 98, 108, 79, 62, 410, 149, 422, 
-  660, 659, 517, 62, 74, 71, 415, 661, 0, 62, 
-  0, 70, 62, 311, 69, 311, 311, 62, 283, 0, 
-  283, 283, 283, 110, 178, 62, 311, 311, 364, 364, 
-  283, 283, 283, 517, 329, 339, 62, 332, 330, 0, 
-  326, 283, 525, 0, 207, 207, 62, 308, 313, 310, 
-  0, 283, 62, 62, 516, 526, 0, 283, 283, 306, 
-  291, 286, 62, 62, 0, 517, 62, 283, 283, 302, 
-  303, 283, 576, 304, 643, 573, 0, 0, 0, 0, 
-  0, 517, 0, 0, 517, 0, 0, 0, 0, 0, 
-  525, 0, 0, 525, 545, 546, 547, 548, 552, 549, 
-  550, 0, 516, 526, 0, 516, 526, 589, 0, 0, 
-  0, 0, 0, 0, 443, 446, 638, 639, 545, 546, 
-  547, 548, 552, 549, 550, 589, 0, 0, 0, 0, 
-  0, 0, 0, 0, 591, 592, 545, 546, 547, 548, 
-  552, 549, 550, 581, 0, 0, 0, 0, 0, 0, 
-  0, 0, 582, 583, 545, 546, 547, 548, 552, 549, 
-  550, 0, 581, 0, 0, 0, 0, 565, 0, 640, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  488, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-  0, 0, 0, 0, 0, 0, 0, 0, 0};
-
-const short QQmlJSGrammar::action_check [] = {
-  8, 61, 60, 8, 48, 1, 0, 2, 55, 79, 
-  33, 1, 60, 48, 7, 79, 66, 60, 17, 8, 
-  36, 66, 29, 8, 60, 37, 60, 33, 79, 33, 
-  1, 33, 2, 36, 20, 55, 8, 79, 7, 61, 
-  55, 60, 29, 7, 5, 1, 5, 48, 48, 33, 
-  33, 5, 7, 33, 17, 37, 31, 36, 55, 8, 
-  33, 7, 60, 77, 7, 33, 7, 7, 60, 36, 
-  61, 36, 60, 7, 36, 8, 36, 16, 36, 36, 
-  7, 55, 34, 36, 7, 7, 7, 7, 36, 55, 
-  7, 36, 7, 7, 36, 7, 7, 7, 36, 2, 
-  36, 7, 33, 7, 55, 7, 36, 7, 55, 33, 
-  60, 7, -1, 8, 33, 8, 60, 42, 36, -1, 
-  36, 8, -1, 60, 33, 33, 61, 62, 53, 36, 
-  8, 36, 8, -1, 33, 36, 8, 50, 36, -1, 
-  8, 54, 8, 40, 15, 8, 15, 8, 40, 8, 
-  8, -1, -1, 24, 51, 15, -1, 10, 15, 51, 
-  8, 56, 50, 92, 93, 34, 54, 60, 8, 56, 
-  61, 62, 61, 62, 34, 61, 62, 34, 56, 61, 
-  62, 61, 62, 8, 60, 40, 61, 62, 60, 40, 
-  56, 7, 60, 6, 61, 62, 51, 60, 15, 60, 
-  51, 60, 55, 61, 7, 61, 62, 20, 56, 61, 
-  62, 92, 93, 15, 61, 62, 12, 34, 29, 36, 
-  60, 8, 24, 15, 29, 25, 12, 27, 25, -1, 
-  27, 7, 15, 12, 29, 29, 61, 62, 38, 7, 
-  -1, 38, 34, -1, 36, 61, 62, 25, 29, 27, 
-  25, 34, 27, 36, 61, 62, 25, 29, 27, 8, 
-  38, 57, -1, 38, 75, 33, 25, 63, 27, 38, 
-  75, 57, 29, -1, 61, 62, 87, 63, 57, 38, 
-  75, 75, 87, 90, 63, 61, 62, 25, 25, 27, 
-  27, 36, 87, 87, 75, 25, 25, 27, 27, 7, 
-  38, 38, 15, 75, 7, 8, 87, -1, 38, 38, 
-  61, 62, 61, 62, -1, 87, 61, 62, 75, 15, 
-  25, 34, 27, 36, 18, 19, 15, 95, 18, 19, 
-  87, 18, 19, 38, 18, 19, -1, 33, 34, -1, 
-  36, -1, -1, 94, 33, 34, -1, 36, -1, 47, 
-  -1, 45, 46, 61, 62, 45, 46, -1, 45, 46, 
-  -1, 45, 46, 61, 62, 23, 24, -1, -1, 23, 
-  24, -1, -1, -1, 32, 23, 24, 35, 32, 37, 
-  -1, 35, 29, 37, 32, 23, 24, 35, 29, 37, 
-  -1, 23, 24, 29, 32, -1, 94, 35, 29, 37, 
-  32, 29, -1, 35, 25, 37, 27, 99, 100, 101, 
-  102, 103, 104, -1, 29, -1, -1, 38, -1, 66, 
-  67, 68, -1, -1, -1, 66, 67, 68, -1, -1, 
-  66, 67, 68, -1, -1, 66, 67, 68, 66, 67, 
-  68, -1, -1, -1, -1, -1, 29, -1, 95, 96, 
-  97, 66, 67, 68, 95, 96, 97, -1, -1, 95, 
-  96, 97, -1, -1, 95, 96, 97, 95, 96, 97, 
-  29, -1, -1, -1, -1, -1, -1, -1, 29, -1, 
-  95, 96, 97, 66, 67, 68, 23, 24, 29, -1, 
-  -1, 29, -1, -1, 31, 32, 29, -1, 35, -1, 
-  37, -1, -1, 36, -1, -1, -1, 66, 67, 68, 
-  -1, 29, 95, 96, 97, 66, 67, 68, 36, -1, 
-  -1, -1, -1, -1, -1, 66, 67, 68, 66, 67, 
-  68, -1, -1, 66, 67, 68, 95, 96, 97, 15, 
-  -1, -1, -1, -1, 95, 96, 97, 15, 66, 67, 
-  68, -1, -1, 29, 95, 96, 97, 95, 96, 97, 
-  -1, 29, 95, 96, 97, 29, -1, -1, -1, -1, 
-  29, -1, 36, 29, -1, -1, -1, 95, 96, 97, 
-  -1, -1, -1, -1, -1, 29, -1, -1, -1, -1, 
-  66, 67, 68, -1, -1, -1, -1, -1, 66, 67, 
-  68, -1, 66, 67, 68, 61, 62, 66, 67, 68, 
-  66, 67, 68, -1, -1, -1, -1, 61, 62, 95, 
-  96, 97, 66, 67, 68, -1, 29, 95, 96, 97, 
-  -1, 95, 96, 97, -1, -1, 95, 96, 97, 95, 
-  96, 97, 29, -1, -1, 29, -1, -1, 15, -1, 
-  -1, 95, 96, 97, -1, -1, -1, -1, 61, 62, 
-  -1, -1, 29, 66, 67, 68, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 61, 62, -1, 61, 62, 66, 
-  67, 68, 66, 67, 68, -1, -1, -1, -1, -1, 
-  -1, -1, 95, 96, 97, -1, -1, -1, -1, 66, 
-  67, 68, -1, -1, -1, -1, -1, -1, 95, 96, 
-  97, 95, 96, 97, -1, -1, -1, -1, -1, -1, 
-  -1, 3, -1, -1, -1, -1, -1, -1, 95, 96, 
-  97, 13, -1, -1, -1, 17, -1, -1, -1, -1, 
-  29, -1, -1, -1, 26, -1, 28, -1, -1, 31, 
-  -1, -1, -1, -1, -1, -1, -1, 39, -1, 41, 
-  42, -1, -1, -1, -1, -1, -1, 49, -1, -1, 
-  52, 53, 61, 62, -1, -1, 58, 66, 67, 68, 
-  -1, -1, 64, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, 80, -1, 
-  -1, -1, -1, -1, -1, -1, 95, 96, 97, -1, 
-  -1, -1, -1, -1, -1, -1, 12, 13, 3, -1, 
-  -1, -1, -1, -1, -1, -1, 22, -1, 13, -1, 
-  -1, -1, 17, 29, -1, -1, -1, 33, 34, -1, 
-  36, 26, -1, 28, -1, -1, -1, 43, -1, -1, 
-  -1, 47, -1, -1, 39, -1, 41, 42, -1, -1, 
-  -1, -1, -1, -1, 49, -1, -1, 52, 53, 65, 
-  66, 67, 68, 58, 70, -1, -1, -1, -1, 64, 
-  -1, -1, -1, -1, -1, 81, 82, 83, -1, -1, 
-  -1, -1, 88, -1, -1, 80, -1, -1, -1, 95, 
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-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 12, 13, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 22, -1, -1, -1, -1, -1, -1, 29, 
-  -1, -1, -1, 33, 34, -1, 36, -1, -1, -1, 
-  -1, -1, -1, 43, -1, -1, -1, 47, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, 65, 66, 67, 68, -1, 
-  70, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 81, 82, 83, -1, -1, -1, -1, 88, -1, 
-  -1, -1, -1, -1, -1, 95, 96, 97, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 12, 13, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 22, -1, -1, 
-  -1, -1, -1, -1, 29, -1, -1, -1, 33, 34, 
-  -1, 36, -1, -1, -1, -1, -1, -1, 43, -1, 
-  -1, -1, 47, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  65, 66, 67, 68, -1, 70, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, 81, 82, 83, -1, 
-  -1, -1, -1, 88, -1, -1, -1, -1, -1, -1, 
-  95, 96, 97, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 10, -1, 12, 13, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 22, -1, -1, -1, -1, -1, 
-  -1, 29, -1, -1, -1, 33, 34, -1, 36, -1, 
-  -1, -1, -1, -1, -1, 43, -1, -1, -1, 47, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 65, 66, 67, 
-  68, -1, 70, -1, -1, -1, -1, 75, -1, -1, 
-  -1, -1, -1, 81, 82, 83, 84, 85, -1, -1, 
-  88, -1, -1, -1, -1, -1, -1, 95, 96, 97, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, 10, 
-  -1, 12, 13, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 22, -1, -1, -1, -1, -1, -1, 29, -1, 
-  -1, -1, 33, 34, -1, 36, -1, -1, -1, -1, 
-  -1, -1, 43, -1, -1, -1, 47, -1, -1, -1, 
-  -1, -1, -1, -1, 55, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 65, 66, 67, 68, -1, 70, 
-  -1, -1, -1, -1, 75, -1, -1, -1, -1, -1, 
-  81, 82, 83, 84, 85, -1, -1, 88, -1, -1, 
-  -1, -1, -1, -1, 95, 96, 97, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, 10, -1, 12, 13, 
-  -1, -1, -1, -1, -1, -1, -1, -1, 22, -1, 
-  -1, -1, -1, -1, -1, 29, -1, -1, -1, 33, 
-  34, -1, 36, -1, -1, -1, -1, -1, -1, 43, 
-  -1, -1, -1, 47, -1, -1, -1, -1, -1, -1, 
-  -1, 55, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 65, 66, 67, 68, -1, 70, -1, -1, -1, 
-  -1, 75, -1, -1, -1, -1, -1, 81, 82, 83, 
-  84, 85, -1, -1, 88, -1, -1, -1, -1, -1, 
-  -1, 95, 96, 97, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, 11, 12, 13, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 22, -1, -1, -1, -1, -1, 
-  -1, 29, -1, -1, -1, 33, 34, -1, 36, -1, 
-  -1, -1, 40, -1, 42, 43, 44, -1, -1, 47, 
-  -1, -1, -1, 51, -1, 53, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 65, 66, 67, 
-  68, -1, 70, -1, 72, -1, 74, -1, 76, -1, 
-  -1, -1, -1, 81, 82, 83, -1, -1, -1, -1, 
-  88, -1, -1, -1, -1, -1, -1, 95, 96, 97, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, 11, 
-  12, 13, -1, -1, -1, -1, -1, -1, -1, -1, 
-  22, -1, -1, -1, -1, -1, -1, 29, -1, -1, 
-  -1, 33, 34, -1, 36, -1, -1, -1, 40, -1, 
-  42, 43, 44, -1, -1, 47, -1, -1, -1, 51, 
-  -1, 53, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, 65, 66, 67, 68, -1, 70, -1, 
-  72, -1, 74, 75, 76, -1, -1, -1, -1, 81, 
-  82, 83, -1, -1, -1, -1, 88, -1, -1, -1, 
-  -1, -1, -1, 95, 96, 97, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, 7, -1, -1, -1, 11, 
-  12, 13, -1, -1, -1, -1, -1, -1, -1, -1, 
-  22, -1, -1, -1, -1, -1, -1, 29, -1, -1, 
-  -1, 33, 34, -1, 36, -1, -1, -1, 40, -1, 
-  42, 43, 44, -1, -1, 47, -1, -1, -1, 51, 
-  -1, 53, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, 65, 66, 67, 68, -1, 70, -1, 
-  72, -1, 74, -1, 76, -1, -1, -1, -1, 81, 
-  82, 83, -1, -1, -1, -1, 88, -1, -1, -1, 
-  -1, -1, -1, 95, 96, 97, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, 8, -1, -1, 11, 12, 
-  13, -1, -1, -1, -1, -1, -1, -1, -1, 22, 
-  -1, -1, -1, -1, -1, -1, 29, -1, -1, -1, 
-  33, 34, -1, 36, -1, -1, -1, 40, -1, 42, 
-  43, 44, -1, -1, 47, -1, -1, -1, 51, -1, 
-  53, -1, -1, 56, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 65, 66, 67, 68, -1, 70, -1, 72, 
-  -1, 74, -1, 76, -1, -1, -1, -1, 81, 82, 
-  83, -1, -1, -1, -1, 88, -1, -1, -1, -1, 
-  -1, -1, 95, 96, 97, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 8, -1, -1, 11, 12, 13, 
-  -1, -1, -1, -1, -1, -1, -1, -1, 22, -1, 
-  -1, -1, -1, -1, -1, 29, -1, -1, -1, 33, 
-  34, -1, 36, -1, -1, -1, 40, -1, 42, 43, 
-  44, -1, -1, 47, -1, -1, -1, 51, -1, 53, 
-  -1, -1, 56, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 65, 66, 67, 68, -1, 70, -1, 72, -1, 
-  74, -1, 76, -1, -1, -1, -1, 81, 82, 83, 
-  -1, -1, -1, -1, 88, -1, -1, -1, -1, -1, 
-  -1, 95, 96, 97, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, 8, -1, -1, 11, 12, 13, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 22, -1, -1, 
-  -1, -1, -1, -1, 29, -1, -1, -1, 33, 34, 
-  -1, 36, -1, -1, -1, 40, -1, 42, 43, 44, 
-  -1, -1, 47, -1, -1, -1, 51, -1, 53, -1, 
-  -1, 56, -1, -1, -1, -1, -1, -1, -1, -1, 
-  65, 66, 67, 68, -1, 70, -1, 72, -1, 74, 
-  -1, 76, -1, -1, -1, -1, 81, 82, 83, -1, 
-  -1, -1, -1, 88, -1, -1, -1, -1, -1, -1, 
-  95, 96, 97, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 8, -1, -1, 11, 12, 13, -1, -1, 
-  -1, -1, -1, -1, -1, -1, 22, -1, -1, -1, 
-  -1, -1, -1, 29, -1, -1, -1, 33, 34, -1, 
-  36, -1, -1, -1, 40, -1, 42, 43, 44, -1, 
-  -1, 47, -1, -1, -1, 51, -1, 53, -1, -1, 
-  56, -1, -1, -1, -1, -1, -1, -1, -1, 65, 
-  66, 67, 68, -1, 70, -1, 72, -1, 74, -1, 
-  76, -1, -1, -1, -1, 81, 82, 83, -1, -1, 
-  -1, -1, 88, -1, -1, -1, -1, -1, -1, 95, 
-  96, 97, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 11, 12, 13, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 22, -1, -1, -1, -1, -1, -1, 29, 
-  30, -1, -1, 33, 34, -1, 36, -1, -1, -1, 
-  40, -1, 42, 43, 44, -1, -1, 47, -1, -1, 
-  -1, 51, -1, 53, -1, -1, -1, -1, -1, -1, 
-  -1, 61, -1, -1, -1, 65, 66, 67, 68, 69, 
-  70, -1, 72, 73, 74, -1, 76, -1, 78, -1, 
-  -1, 81, 82, 83, -1, -1, -1, -1, 88, -1, 
-  -1, -1, -1, -1, -1, 95, 96, 97, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 11, 12, 13, 
-  -1, -1, -1, -1, -1, -1, -1, -1, 22, -1, 
-  -1, -1, -1, -1, -1, 29, 30, -1, -1, 33, 
-  34, -1, 36, -1, -1, -1, 40, -1, 42, 43, 
-  44, -1, -1, 47, -1, -1, -1, 51, -1, 53, 
-  -1, -1, -1, -1, -1, -1, -1, 61, -1, -1, 
-  -1, 65, 66, 67, 68, 69, 70, -1, 72, 73, 
-  74, -1, 76, -1, 78, -1, -1, 81, 82, 83, 
-  -1, -1, -1, -1, 88, -1, -1, -1, -1, -1, 
-  -1, 95, 96, 97, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, 11, 12, 13, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 22, -1, -1, -1, -1, -1, 
-  -1, 29, 30, -1, -1, 33, 34, -1, 36, -1, 
-  -1, -1, 40, -1, 42, 43, 44, -1, -1, 47, 
-  -1, -1, -1, 51, -1, 53, -1, -1, -1, -1, 
-  -1, -1, -1, 61, -1, -1, -1, 65, 66, 67, 
-  68, 69, 70, -1, 72, 73, 74, -1, 76, -1, 
-  78, -1, -1, 81, 82, 83, -1, -1, -1, -1, 
-  88, -1, -1, -1, -1, -1, -1, 95, 96, 97, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, 4, 
-  5, 6, -1, -1, 9, 10, 11, -1, -1, 14, 
-  -1, 16, -1, -1, -1, 20, 21, 22, -1, -1, 
-  -1, -1, -1, -1, 29, 30, 31, 32, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, 43, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 59, -1, -1, -1, -1, -1, 
-  -1, 66, 67, 68, 69, 70, 71, -1, 73, 74, 
-  75, 76, 77, 78, -1, -1, 81, 82, 83, 84, 
-  85, 86, 87, -1, -1, -1, -1, -1, -1, -1, 
-  95, 96, 97, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 4, 5, 6, -1, -1, 9, 10, 11, 
-  -1, -1, 14, -1, 16, -1, -1, -1, 20, 21, 
-  22, -1, -1, -1, -1, -1, -1, 29, 30, 31, 
-  32, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 43, -1, -1, -1, 47, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 59, -1, -1, 
-  -1, -1, -1, 65, 66, 67, 68, 69, 70, 71, 
-  -1, 73, 74, 75, 76, 77, 78, -1, -1, 81, 
-  82, 83, 84, 85, 86, 87, -1, -1, -1, -1, 
-  -1, -1, -1, 95, 96, 97, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, 4, 5, 6, -1, -1, 
-  9, 10, 11, -1, -1, 14, -1, 16, -1, -1, 
-  -1, 20, 21, 22, -1, -1, -1, -1, -1, -1, 
-  29, 30, 31, 32, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 43, -1, -1, -1, 47, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  59, -1, -1, -1, -1, -1, 65, 66, 67, 68, 
-  69, 70, 71, -1, 73, 74, 75, 76, 77, 78, 
-  -1, -1, 81, 82, 83, 84, 85, 86, 87, -1, 
-  -1, -1, -1, -1, -1, -1, 95, 96, 97, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, 4, 5, 
-  6, -1, -1, 9, 10, 11, -1, -1, 14, -1, 
-  16, -1, -1, -1, 20, 21, 22, -1, -1, -1, 
-  -1, -1, -1, 29, 30, 31, 32, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 43, -1, -1, 
-  -1, 47, -1, -1, -1, -1, -1, -1, -1, 55, 
-  -1, -1, -1, 59, -1, -1, -1, -1, -1, 65, 
-  66, 67, 68, 69, 70, 71, -1, 73, 74, 75, 
-  76, 77, 78, -1, -1, 81, 82, 83, 84, 85, 
-  86, 87, -1, -1, -1, -1, -1, -1, -1, 95, 
-  96, 97, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, 4, -1, -1, -1, -1, 9, -1, 11, 12, 
-  13, 14, -1, -1, -1, -1, -1, -1, 21, 22, 
-  -1, -1, -1, -1, -1, -1, 29, 30, -1, -1, 
-  33, 34, -1, 36, -1, -1, -1, 40, -1, 42, 
-  43, 44, -1, -1, 47, -1, -1, -1, 51, -1, 
-  53, -1, -1, -1, -1, -1, 59, -1, 61, -1, 
-  -1, -1, 65, 66, 67, 68, 69, 70, 71, 72, 
-  73, 74, 75, 76, 77, 78, -1, -1, 81, 82, 
-  83, 84, 85, 86, -1, 88, -1, -1, -1, -1, 
-  -1, -1, 95, 96, 97, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 4, -1, -1, -1, -1, 9, 
-  -1, 11, 12, 13, 14, -1, -1, -1, -1, -1, 
-  -1, 21, 22, -1, -1, -1, -1, -1, -1, 29, 
-  30, -1, -1, 33, 34, -1, 36, -1, -1, -1, 
-  40, -1, 42, 43, 44, -1, -1, 47, -1, -1, 
-  -1, 51, -1, 53, -1, -1, -1, -1, -1, 59, 
-  -1, 61, -1, -1, -1, 65, 66, 67, 68, 69, 
-  70, 71, 72, 73, 74, 75, 76, 77, 78, -1, 
-  -1, 81, 82, 83, 84, 85, 86, -1, 88, -1, 
-  -1, -1, -1, -1, -1, 95, 96, 97, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, 4, 5, 6, 
-  -1, -1, 9, 10, 11, 12, 13, 14, -1, 16, 
-  -1, -1, -1, 20, 21, 22, -1, -1, -1, -1, 
-  -1, -1, 29, 30, 31, 32, 33, 34, -1, 36, 
-  -1, -1, -1, 40, -1, 42, 43, 44, -1, -1, 
-  47, -1, -1, -1, 51, -1, 53, -1, -1, -1, 
-  -1, -1, 59, -1, 61, -1, -1, -1, 65, 66, 
-  67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 
-  77, 78, -1, -1, 81, 82, 83, 84, 85, 86, 
-  87, 88, -1, -1, -1, -1, -1, -1, 95, 96, 
-  97, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  4, 5, 6, -1, -1, 9, 10, 11, 12, 13, 
-  14, -1, 16, -1, -1, -1, 20, 21, 22, -1, 
-  -1, -1, -1, -1, -1, 29, 30, 31, 32, 33, 
-  34, -1, 36, -1, -1, -1, 40, -1, 42, 43, 
-  44, -1, -1, 47, -1, -1, -1, 51, -1, 53, 
-  -1, 55, -1, -1, -1, 59, -1, 61, -1, -1, 
-  -1, 65, 66, 67, 68, 69, 70, 71, 72, 73, 
-  74, 75, 76, 77, 78, -1, -1, 81, 82, 83, 
-  84, 85, 86, 87, 88, -1, -1, -1, -1, -1, 
-  -1, 95, 96, 97, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, 
-
-  3, 42, 9, 77, 18, 3, 25, 42, 18, 25, 
-  18, 105, 18, 42, 42, 3, 100, 3, 103, 3, 
-  14, 18, 14, 22, 42, 18, 22, 32, 3, 18, 
-  25, 32, 3, 3, 14, 18, 18, 18, 42, 3, 
-  42, 3, 42, 3, 18, 32, 25, 32, 3, 3, 
-  18, 42, 42, 18, 3, 18, 22, 18, 3, 18, 
-  18, 18, 18, 32, 42, 18, 18, 18, 18, 3, 
-  3, -1, 18, 2, 22, 18, 18, 18, 25, 14, 
-  18, 4, 14, 2, 2, 2, 14, 19, 32, 18, 
-  3, 19, 3, 2, 18, 18, 18, 18, 4, 18, 
-  18, 18, 38, -1, 18, 3, 42, 14, 3, 18, 
-  18, 14, 18, 3, 54, 54, 51, 54, -1, 59, 
-  59, 45, 59, 45, 54, 46, 56, 54, 54, 54, 
-  2, 45, 59, 59, 59, 2, 2, 2, 54, 54, 
-  56, 56, 18, 2, 51, -1, 18, -1, 51, 18, 
-  -1, 18, 18, 18, 54, 54, 56, 56, 54, 18, 
-  56, 54, 54, 56, 56, 78, 54, 78, 56, 42, 
-  46, 109, 54, 2, 56, 2, 54, 50, 2, 54, 
-  78, 2, 2, 54, 18, 56, 94, 2, 78, 18, 
-  18, 18, 70, 68, 18, 18, 54, 18, 18, 54, 
-  54, 56, 56, 18, 54, 54, 64, 54, 58, 54, 
-  44, 58, 4, 54, 59, 56, 2, 66, 54, 47, 
-  56, 44, 54, 92, 54, 18, 18, 59, 58, 54, 
-  18, 18, 18, -1, 59, 54, 54, 54, 54, 57, 
-  59, 57, 59, 54, -1, 54, 54, 54, 59, 54, 
-  43, 60, 60, 60, 18, 60, 54, 45, 42, 46, 
-  11, 12, 14, 54, 62, 56, 50, 19, -1, 54, 
-  -1, 56, 54, 54, 56, 54, 54, 54, 59, -1, 
-  59, 59, 59, 47, 48, 54, 54, 54, 2, 2, 
-  59, 59, 59, 14, 71, 76, 54, 76, 76, -1, 
-  69, 59, 23, -1, 18, 18, 54, 65, 76, 76, 
-  -1, 59, 54, 54, 35, 36, -1, 59, 59, 67, 
-  61, 63, 54, 54, -1, 14, 54, 59, 59, 61, 
-  61, 59, 5, 61, 23, 5, -1, -1, -1, -1, 
-  -1, 14, -1, -1, 14, -1, -1, -1, -1, -1, 
-  23, -1, -1, 23, 25, 26, 27, 28, 29, 30, 
-  31, -1, 35, 36, -1, 35, 36, 14, -1, -1, 
-  -1, -1, -1, -1, 88, 88, 23, 24, 25, 26, 
-  27, 28, 29, 30, 31, 14, -1, -1, -1, -1, 
-  -1, -1, -1, -1, 23, 24, 25, 26, 27, 28, 
-  29, 30, 31, 14, -1, -1, -1, -1, -1, -1, 
-  -1, -1, 23, 24, 25, 26, 27, 28, 29, 30, 
-  31, -1, 14, -1, -1, -1, -1, 19, -1, 21, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  42, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
-  -1, -1, -1, -1, -1, -1, -1, -1, -1};
-
-QT_END_NAMESPACE
diff --git a/src/qml/parser/qqmljsgrammar_p.h b/src/qml/parser/qqmljsgrammar_p.h
deleted file mode 100644
index b4f762d28b..0000000000
--- a/src/qml/parser/qqmljsgrammar_p.h
+++ /dev/null
@@ -1,214 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists for the convenience
-// of other Qt classes.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-// This file was generated by qlalr - DO NOT EDIT!
-#ifndef QQMLJSGRAMMAR_P_H
-#define QQMLJSGRAMMAR_P_H
-
-#include <QtCore/qglobal.h>
-
-QT_BEGIN_NAMESPACE
-
-class QQmlJSGrammar
-{
-public:
-  enum VariousConstants {
-    EOF_SYMBOL = 0,
-    REDUCE_HERE = 106,
-    SHIFT_THERE = 105,
-    T_AND = 1,
-    T_AND_AND = 2,
-    T_AND_EQ = 3,
-    T_AS = 94,
-    T_AUTOMATIC_SEMICOLON = 62,
-    T_BREAK = 4,
-    T_CASE = 5,
-    T_CATCH = 6,
-    T_COLON = 7,
-    T_COMMA = 8,
-    T_COMMENT = 89,
-    T_COMPATIBILITY_SEMICOLON = 90,
-    T_CONST = 84,
-    T_CONTINUE = 9,
-    T_DEBUGGER = 86,
-    T_DEFAULT = 10,
-    T_DELETE = 11,
-    T_DIVIDE_ = 12,
-    T_DIVIDE_EQ = 13,
-    T_DO = 14,
-    T_DOT = 15,
-    T_ELSE = 16,
-    T_EQ = 17,
-    T_EQ_EQ = 18,
-    T_EQ_EQ_EQ = 19,
-    T_ERROR = 98,
-    T_FALSE = 83,
-    T_FEED_JS_EXPRESSION = 102,
-    T_FEED_JS_PROGRAM = 104,
-    T_FEED_JS_SOURCE_ELEMENT = 103,
-    T_FEED_JS_STATEMENT = 101,
-    T_FEED_UI_OBJECT_MEMBER = 100,
-    T_FEED_UI_PROGRAM = 99,
-    T_FINALLY = 20,
-    T_FOR = 21,
-    T_FUNCTION = 22,
-    T_GE = 23,
-    T_GET = 96,
-    T_GT = 24,
-    T_GT_GT = 25,
-    T_GT_GT_EQ = 26,
-    T_GT_GT_GT = 27,
-    T_GT_GT_GT_EQ = 28,
-    T_IDENTIFIER = 29,
-    T_IF = 30,
-    T_IMPORT = 92,
-    T_IN = 31,
-    T_INSTANCEOF = 32,
-    T_LBRACE = 33,
-    T_LBRACKET = 34,
-    T_LE = 35,
-    T_LET = 85,
-    T_LPAREN = 36,
-    T_LT = 37,
-    T_LT_LT = 38,
-    T_LT_LT_EQ = 39,
-    T_MINUS = 40,
-    T_MINUS_EQ = 41,
-    T_MINUS_MINUS = 42,
-    T_MULTILINE_STRING_LITERAL = 88,
-    T_NEW = 43,
-    T_NOT = 44,
-    T_NOT_EQ = 45,
-    T_NOT_EQ_EQ = 46,
-    T_NULL = 81,
-    T_NUMERIC_LITERAL = 47,
-    T_ON = 95,
-    T_OR = 48,
-    T_OR_EQ = 49,
-    T_OR_OR = 50,
-    T_PLUS = 51,
-    T_PLUS_EQ = 52,
-    T_PLUS_PLUS = 53,
-    T_PRAGMA = 93,
-    T_PROPERTY = 66,
-    T_PUBLIC = 91,
-    T_QUESTION = 54,
-    T_RBRACE = 55,
-    T_RBRACKET = 56,
-    T_READONLY = 68,
-    T_REMAINDER = 57,
-    T_REMAINDER_EQ = 58,
-    T_RESERVED_WORD = 87,
-    T_RETURN = 59,
-    T_RPAREN = 60,
-    T_SEMICOLON = 61,
-    T_SET = 97,
-    T_SIGNAL = 67,
-    T_STAR = 63,
-    T_STAR_EQ = 64,
-    T_STRING_LITERAL = 65,
-    T_SWITCH = 69,
-    T_THIS = 70,
-    T_THROW = 71,
-    T_TILDE = 72,
-    T_TRUE = 82,
-    T_TRY = 73,
-    T_TYPEOF = 74,
-    T_VAR = 75,
-    T_VOID = 76,
-    T_WHILE = 77,
-    T_WITH = 78,
-    T_XOR = 79,
-    T_XOR_EQ = 80,
-
-    ACCEPT_STATE = 678,
-    RULE_COUNT = 363,
-    STATE_COUNT = 679,
-    TERMINAL_COUNT = 107,
-    NON_TERMINAL_COUNT = 111,
-
-    GOTO_INDEX_OFFSET = 679,
-    GOTO_INFO_OFFSET = 3203,
-    GOTO_CHECK_OFFSET = 3203
-  };
-
-  static const char  *const    spell [];
-  static const short             lhs [];
-  static const short             rhs [];
-  static const short    goto_default [];
-  static const short  action_default [];
-  static const short    action_index [];
-  static const short     action_info [];
-  static const short    action_check [];
-
-  static inline int nt_action (int state, int nt)
-  {
-    const int yyn = action_index [GOTO_INDEX_OFFSET + state] + nt;
-    if (yyn < 0 || action_check [GOTO_CHECK_OFFSET + yyn] != nt)
-      return goto_default [nt];
-
-    return action_info [GOTO_INFO_OFFSET + yyn];
-  }
-
-  static inline int t_action (int state, int token)
-  {
-    const int yyn = action_index [state] + token;
-
-    if (yyn < 0 || action_check [yyn] != token)
-      return - action_default [state];
-
-    return action_info [yyn];
-  }
-};
-
-
-QT_END_NAMESPACE
-#endif // QQMLJSGRAMMAR_P_H
-
diff --git a/src/qml/parser/qqmljskeywords_p.h b/src/qml/parser/qqmljskeywords_p.h
index 8b789526a5..b0a4951ece 100644
--- a/src/qml/parser/qqmljskeywords_p.h
+++ b/src/qml/parser/qqmljskeywords_p.h
@@ -57,10 +57,10 @@ QT_QML_BEGIN_NAMESPACE
 
 namespace QQmlJS {
 
-static inline int classify2(const QChar *s, bool qmlMode) {
+static inline int classify2(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'a') {
     if (s[1].unicode() == 's') {
-      return qmlMode ? Lexer::T_AS : Lexer::T_IDENTIFIER;
+      return Lexer::T_AS;
     }
   }
   else if (s[0].unicode() == 'd') {
@@ -76,15 +76,18 @@ static inline int classify2(const QChar *s, bool qmlMode) {
       return Lexer::T_IN;
     }
   }
-  else if (qmlMode && s[0].unicode() == 'o') {
+  else if (s[0].unicode() == 'o') {
     if (s[1].unicode() == 'n') {
-      return qmlMode ? Lexer::T_ON : Lexer::T_IDENTIFIER;
+      return (parseModeFlags & Lexer::QmlMode) ? Lexer::T_ON : Lexer::T_IDENTIFIER;
+    }
+    else if (s[1].unicode() == 'f') {
+      return Lexer::T_OF;
     }
   }
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify3(const QChar *s, bool qmlMode) {
+static inline int classify3(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'f') {
     if (s[1].unicode() == 'o') {
       if (s[2].unicode() == 'r') {
@@ -102,7 +105,7 @@ static inline int classify3(const QChar *s, bool qmlMode) {
   else if (s[0].unicode() == 'i') {
     if (s[1].unicode() == 'n') {
       if (s[2].unicode() == 't') {
-        return qmlMode ? int(Lexer::T_INT) : int(Lexer::T_IDENTIFIER);
+        return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_INT) : int(Lexer::T_IDENTIFIER);
       }
     }
   }
@@ -144,12 +147,12 @@ static inline int classify3(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify4(const QChar *s, bool qmlMode) {
+static inline int classify4(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'b') {
     if (s[1].unicode() == 'y') {
       if (s[2].unicode() == 't') {
         if (s[3].unicode() == 'e') {
-          return qmlMode ? int(Lexer::T_BYTE) : int(Lexer::T_IDENTIFIER);
+          return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_BYTE) : int(Lexer::T_IDENTIFIER);
         }
       }
     }
@@ -165,7 +168,7 @@ static inline int classify4(const QChar *s, bool qmlMode) {
     else if (s[1].unicode() == 'h') {
       if (s[2].unicode() == 'a') {
         if (s[3].unicode() == 'r') {
-          return qmlMode ? int(Lexer::T_CHAR) : int(Lexer::T_IDENTIFIER);
+          return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_CHAR) : int(Lexer::T_IDENTIFIER);
         }
       }
     }
@@ -181,7 +184,16 @@ static inline int classify4(const QChar *s, bool qmlMode) {
     else if (s[1].unicode() == 'n') {
       if (s[2].unicode() == 'u') {
         if (s[3].unicode() == 'm') {
-          return Lexer::T_ENUM;
+          return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_ENUM) : int(Lexer::T_RESERVED_WORD);
+        }
+      }
+    }
+  }
+  else if (s[0].unicode() == 'f') {
+    if (s[1].unicode() == 'r') {
+      if (s[2].unicode() == 'o') {
+        if (s[3].unicode() == 'm') {
+          return int(Lexer::T_FROM);
         }
       }
     }
@@ -190,7 +202,7 @@ static inline int classify4(const QChar *s, bool qmlMode) {
     if (s[1].unicode() == 'o') {
       if (s[2].unicode() == 't') {
         if (s[3].unicode() == 'o') {
-          return qmlMode ? int(Lexer::T_GOTO) : int(Lexer::T_IDENTIFIER);
+          return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_GOTO) : int(Lexer::T_IDENTIFIER);
         }
       }
     }
@@ -199,7 +211,7 @@ static inline int classify4(const QChar *s, bool qmlMode) {
     if (s[1].unicode() == 'o') {
       if (s[2].unicode() == 'n') {
         if (s[3].unicode() == 'g') {
-          return qmlMode ? int(Lexer::T_LONG) : int(Lexer::T_IDENTIFIER);
+          return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_LONG) : int(Lexer::T_IDENTIFIER);
         }
       }
     }
@@ -250,7 +262,7 @@ static inline int classify4(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify5(const QChar *s, bool qmlMode) {
+static inline int classify5(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'b') {
     if (s[1].unicode() == 'r') {
       if (s[2].unicode() == 'e') {
@@ -305,7 +317,7 @@ static inline int classify5(const QChar *s, bool qmlMode) {
       if (s[2].unicode() == 'n') {
         if (s[3].unicode() == 'a') {
           if (s[4].unicode() == 'l') {
-            return qmlMode ? int(Lexer::T_FINAL) : int(Lexer::T_IDENTIFIER);
+            return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_FINAL) : int(Lexer::T_IDENTIFIER);
           }
         }
       }
@@ -314,7 +326,7 @@ static inline int classify5(const QChar *s, bool qmlMode) {
       if (s[2].unicode() == 'o') {
         if (s[3].unicode() == 'a') {
           if (s[4].unicode() == 't') {
-            return qmlMode ? int(Lexer::T_FLOAT) : int(Lexer::T_IDENTIFIER);
+            return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_FLOAT) : int(Lexer::T_IDENTIFIER);
           }
         }
       }
@@ -325,7 +337,7 @@ static inline int classify5(const QChar *s, bool qmlMode) {
       if (s[2].unicode() == 'o') {
         if (s[3].unicode() == 'r') {
           if (s[4].unicode() == 't') {
-            return qmlMode ? int(Lexer::T_SHORT) : int(Lexer::T_IDENTIFIER);
+            return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_SHORT) : int(Lexer::T_IDENTIFIER);
           }
         }
       }
@@ -334,7 +346,7 @@ static inline int classify5(const QChar *s, bool qmlMode) {
       if (s[2].unicode() == 'p') {
         if (s[3].unicode() == 'e') {
           if (s[4].unicode() == 'r') {
-            return qmlMode ? int(Lexer::T_SUPER) : int(Lexer::T_RESERVED_WORD);
+            return int(Lexer::T_SUPER);
           }
         }
       }
@@ -362,10 +374,21 @@ static inline int classify5(const QChar *s, bool qmlMode) {
       }
     }
   }
+  else if (s[0].unicode() == 'y') {
+    if (s[1].unicode() == 'i') {
+      if (s[2].unicode() == 'e') {
+        if (s[3].unicode() == 'l') {
+          if (s[4].unicode() == 'd') {
+            return (parseModeFlags & Lexer::YieldIsKeyword) ? Lexer::T_YIELD : Lexer::T_IDENTIFIER;
+          }
+        }
+      }
+    }
+  }
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify6(const QChar *s, bool qmlMode) {
+static inline int classify6(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'd') {
     if (s[1].unicode() == 'e') {
       if (s[2].unicode() == 'l') {
@@ -383,7 +406,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 'b') {
           if (s[4].unicode() == 'l') {
             if (s[5].unicode() == 'e') {
-              return qmlMode ? int(Lexer::T_DOUBLE) : int(Lexer::T_IDENTIFIER);
+              return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_DOUBLE) : int(Lexer::T_IDENTIFIER);
             }
           }
         }
@@ -409,7 +432,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 'o') {
           if (s[4].unicode() == 'r') {
             if (s[5].unicode() == 't') {
-              return qmlMode ? int(Lexer::T_IMPORT) : int(Lexer::T_RESERVED_WORD);
+              return Lexer::T_IMPORT;
             }
           }
         }
@@ -422,7 +445,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 'i') {
           if (s[4].unicode() == 'v') {
             if (s[5].unicode() == 'e') {
-              return qmlMode ? int(Lexer::T_NATIVE) : int(Lexer::T_IDENTIFIER);
+              return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_NATIVE) : int(Lexer::T_IDENTIFIER);
             }
           }
         }
@@ -435,7 +458,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 'l') {
           if (s[4].unicode() == 'i') {
             if (s[5].unicode() == 'c') {
-              return qmlMode ? Lexer::T_PUBLIC : Lexer::T_IDENTIFIER;
+              return (parseModeFlags & Lexer::QmlMode) ? Lexer::T_PUBLIC : Lexer::T_IDENTIFIER;
             }
           }
         }
@@ -446,7 +469,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 'g') {
           if (s[4].unicode() == 'm') {
             if (s[5].unicode() == 'a') {
-              return qmlMode ? Lexer::T_PRAGMA : Lexer::T_IDENTIFIER;
+              return (parseModeFlags & Lexer::QmlMode) ? Lexer::T_PRAGMA : Lexer::T_IDENTIFIER;
             }
           }
         }
@@ -467,7 +490,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
     }
   }
   else if (s[0].unicode() == 's') {
-    if (qmlMode && s[1].unicode() == 'i') {
+    if ((parseModeFlags & Lexer::QmlMode) && s[1].unicode() == 'i') {
       if (s[2].unicode() == 'g') {
         if (s[3].unicode() == 'n') {
           if (s[4].unicode() == 'a') {
@@ -483,7 +506,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 't') {
           if (s[4].unicode() == 'i') {
             if (s[5].unicode() == 'c') {
-              return qmlMode ? int(Lexer::T_STATIC) : int(Lexer::T_IDENTIFIER);
+              return (parseModeFlags & Lexer::StaticIsKeyword) ? int(Lexer::T_STATIC) : int(Lexer::T_IDENTIFIER);
             }
           }
         }
@@ -507,7 +530,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
         if (s[3].unicode() == 'o') {
           if (s[4].unicode() == 'w') {
             if (s[5].unicode() == 's') {
-              return qmlMode ? int(Lexer::T_THROWS) : int(Lexer::T_IDENTIFIER);
+              return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_THROWS) : int(Lexer::T_IDENTIFIER);
             }
           }
         }
@@ -528,7 +551,7 @@ static inline int classify6(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify7(const QChar *s, bool qmlMode) {
+static inline int classify7(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'b') {
     if (s[1].unicode() == 'o') {
       if (s[2].unicode() == 'o') {
@@ -536,7 +559,7 @@ static inline int classify7(const QChar *s, bool qmlMode) {
           if (s[4].unicode() == 'e') {
             if (s[5].unicode() == 'a') {
               if (s[6].unicode() == 'n') {
-                return qmlMode ? int(Lexer::T_BOOLEAN) : int(Lexer::T_IDENTIFIER);
+                return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_BOOLEAN) : int(Lexer::T_IDENTIFIER);
               }
             }
           }
@@ -596,7 +619,7 @@ static inline int classify7(const QChar *s, bool qmlMode) {
           if (s[4].unicode() == 'a') {
             if (s[5].unicode() == 'g') {
               if (s[6].unicode() == 'e') {
-                return qmlMode ? int(Lexer::T_PACKAGE) : int(Lexer::T_IDENTIFIER);
+                return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_PACKAGE) : int(Lexer::T_IDENTIFIER);
               }
             }
           }
@@ -609,7 +632,7 @@ static inline int classify7(const QChar *s, bool qmlMode) {
           if (s[4].unicode() == 'a') {
             if (s[5].unicode() == 't') {
               if (s[6].unicode() == 'e') {
-                return qmlMode ? int(Lexer::T_PRIVATE) : int(Lexer::T_IDENTIFIER);
+                return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_PRIVATE) : int(Lexer::T_IDENTIFIER);
               }
             }
           }
@@ -620,7 +643,7 @@ static inline int classify7(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify8(const QChar *s, bool qmlMode) {
+static inline int classify8(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'a') {
     if (s[1].unicode() == 'b') {
       if (s[2].unicode() == 's') {
@@ -629,7 +652,7 @@ static inline int classify8(const QChar *s, bool qmlMode) {
             if (s[5].unicode() == 'a') {
               if (s[6].unicode() == 'c') {
                 if (s[7].unicode() == 't') {
-                  return qmlMode ? int(Lexer::T_ABSTRACT) : int(Lexer::T_IDENTIFIER);
+                  return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_ABSTRACT) : int(Lexer::T_IDENTIFIER);
                 }
               }
             }
@@ -689,7 +712,7 @@ static inline int classify8(const QChar *s, bool qmlMode) {
       }
     }
   }
-  else if (qmlMode && s[0].unicode() == 'p') {
+  else if ((parseModeFlags & Lexer::QmlMode) && s[0].unicode() == 'p') {
     if (s[1].unicode() == 'r') {
       if (s[2].unicode() == 'o') {
         if (s[3].unicode() == 'p') {
@@ -706,7 +729,7 @@ static inline int classify8(const QChar *s, bool qmlMode) {
       }
     }
   }
-  else if (qmlMode && s[0].unicode() == 'r') {
+  else if ((parseModeFlags & Lexer::QmlMode) && s[0].unicode() == 'r') {
     if (s[1].unicode() == 'e') {
       if (s[2].unicode() == 'a') {
         if (s[3].unicode() == 'd') {
@@ -731,7 +754,7 @@ static inline int classify8(const QChar *s, bool qmlMode) {
             if (s[5].unicode() == 'i') {
               if (s[6].unicode() == 'l') {
                 if (s[7].unicode() == 'e') {
-                  return qmlMode ? int(Lexer::T_VOLATILE) : int(Lexer::T_IDENTIFIER);
+                  return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_VOLATILE) : int(Lexer::T_IDENTIFIER);
                 }
               }
             }
@@ -743,7 +766,7 @@ static inline int classify8(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify9(const QChar *s, bool qmlMode) {
+static inline int classify9(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'i') {
     if (s[1].unicode() == 'n') {
       if (s[2].unicode() == 't') {
@@ -753,7 +776,7 @@ static inline int classify9(const QChar *s, bool qmlMode) {
               if (s[6].unicode() == 'a') {
                 if (s[7].unicode() == 'c') {
                   if (s[8].unicode() == 'e') {
-                    return qmlMode ? int(Lexer::T_INTERFACE) : int(Lexer::T_IDENTIFIER);
+                    return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_INTERFACE) : int(Lexer::T_IDENTIFIER);
                   }
                 }
               }
@@ -772,7 +795,7 @@ static inline int classify9(const QChar *s, bool qmlMode) {
               if (s[6].unicode() == 't') {
                 if (s[7].unicode() == 'e') {
                   if (s[8].unicode() == 'd') {
-                    return qmlMode ? int(Lexer::T_PROTECTED) : int(Lexer::T_IDENTIFIER);
+                    return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_PROTECTED) : int(Lexer::T_IDENTIFIER);
                   }
                 }
               }
@@ -791,7 +814,7 @@ static inline int classify9(const QChar *s, bool qmlMode) {
               if (s[6].unicode() == 'e') {
                 if (s[7].unicode() == 'n') {
                   if (s[8].unicode() == 't') {
-                    return qmlMode ? int(Lexer::T_TRANSIENT) : int(Lexer::T_IDENTIFIER);
+                    return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_TRANSIENT) : int(Lexer::T_IDENTIFIER);
                   }
                 }
               }
@@ -804,7 +827,7 @@ static inline int classify9(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify10(const QChar *s, bool qmlMode) {
+static inline int classify10(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 'i') {
     if (s[1].unicode() == 'm') {
       if (s[2].unicode() == 'p') {
@@ -815,7 +838,7 @@ static inline int classify10(const QChar *s, bool qmlMode) {
                 if (s[7].unicode() == 'n') {
                   if (s[8].unicode() == 't') {
                     if (s[9].unicode() == 's') {
-                      return qmlMode ? int(Lexer::T_IMPLEMENTS) : int(Lexer::T_IDENTIFIER);
+                      return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_IMPLEMENTS) : int(Lexer::T_IDENTIFIER);
                     }
                   }
                 }
@@ -848,7 +871,7 @@ static inline int classify10(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-static inline int classify12(const QChar *s, bool qmlMode) {
+static inline int classify12(const QChar *s, int parseModeFlags) {
   if (s[0].unicode() == 's') {
     if (s[1].unicode() == 'y') {
       if (s[2].unicode() == 'n') {
@@ -861,7 +884,7 @@ static inline int classify12(const QChar *s, bool qmlMode) {
                     if (s[9].unicode() == 'z') {
                       if (s[10].unicode() == 'e') {
                         if (s[11].unicode() == 'd') {
-                          return qmlMode ? int(Lexer::T_SYNCHRONIZED) : int(Lexer::T_IDENTIFIER);
+                          return (parseModeFlags & Lexer::QmlMode) ? int(Lexer::T_SYNCHRONIZED) : int(Lexer::T_IDENTIFIER);
                         }
                       }
                     }
@@ -877,18 +900,18 @@ static inline int classify12(const QChar *s, bool qmlMode) {
   return Lexer::T_IDENTIFIER;
 }
 
-int Lexer::classify(const QChar *s, int n, bool qmlMode) {
+int Lexer::classify(const QChar *s, int n, int parseModeFlags) {
   switch (n) {
-    case 2: return classify2(s, qmlMode);
-    case 3: return classify3(s, qmlMode);
-    case 4: return classify4(s, qmlMode);
-    case 5: return classify5(s, qmlMode);
-    case 6: return classify6(s, qmlMode);
-    case 7: return classify7(s, qmlMode);
-    case 8: return classify8(s, qmlMode);
-    case 9: return classify9(s, qmlMode);
-    case 10: return classify10(s, qmlMode);
-    case 12: return classify12(s, qmlMode);
+    case 2: return classify2(s, parseModeFlags);
+    case 3: return classify3(s, parseModeFlags);
+    case 4: return classify4(s, parseModeFlags);
+    case 5: return classify5(s, parseModeFlags);
+    case 6: return classify6(s, parseModeFlags);
+    case 7: return classify7(s, parseModeFlags);
+    case 8: return classify8(s, parseModeFlags);
+    case 9: return classify9(s, parseModeFlags);
+    case 10: return classify10(s, parseModeFlags);
+    case 12: return classify12(s, parseModeFlags);
     default: return Lexer::T_IDENTIFIER;
   } // switch
 }
diff --git a/src/qml/parser/qqmljslexer.cpp b/src/qml/parser/qqmljslexer.cpp
index 53e67fde03..c53b13f64d 100644
--- a/src/qml/parser/qqmljslexer.cpp
+++ b/src/qml/parser/qqmljslexer.cpp
@@ -58,6 +58,8 @@ static inline int regExpFlagFromChar(const QChar &ch)
     case 'g': return Lexer::RegExp_Global;
     case 'i': return Lexer::RegExp_IgnoreCase;
     case 'm': return Lexer::RegExp_Multiline;
+    case 'u': return Lexer::RegExp_Unicode;
+    case 'y': return Lexer::RegExp_Sticky;
     }
     return 0;
 }
@@ -77,21 +79,15 @@ static inline QChar convertHex(QChar c1, QChar c2)
     return QChar((convertHex(c1.unicode()) << 4) + convertHex(c2.unicode()));
 }
 
-static inline QChar convertUnicode(QChar c1, QChar c2, QChar c3, QChar c4)
-{
-    return QChar((convertHex(c3.unicode()) << 4) + convertHex(c4.unicode()),
-                 (convertHex(c1.unicode()) << 4) + convertHex(c2.unicode()));
-}
-
 Lexer::Lexer(Engine *engine)
     : _engine(engine)
-    , _codePtr(0)
-    , _lastLinePtr(0)
-    , _tokenLinePtr(0)
-    , _tokenStartPtr(0)
+    , _codePtr(nullptr)
+    , _endPtr(nullptr)
+    , _tokenStartPtr(nullptr)
     , _char(QLatin1Char('\n'))
     , _errorCode(NoError)
     , _currentLineNumber(0)
+    , _currentColumnNumber(0)
     , _tokenValue(0)
     , _parenthesesState(IgnoreParentheses)
     , _parenthesesCount(0)
@@ -100,6 +96,7 @@ Lexer::Lexer(Engine *engine)
     , _tokenKind(0)
     , _tokenLength(0)
     , _tokenLine(0)
+    , _tokenColumn(0)
     , _validTokenText(false)
     , _prohibitAutomaticSemicolon(false)
     , _restrictedKeyword(false)
@@ -133,17 +130,17 @@ void Lexer::setCode(const QString &code, int lineno, bool qmlMode)
     _tokenText.reserve(1024);
     _errorMessage.clear();
     _tokenSpell = QStringRef();
+    _rawString = QStringRef();
 
     _codePtr = code.unicode();
     _endPtr = _codePtr + code.length();
-    _lastLinePtr = _codePtr;
-    _tokenLinePtr = _codePtr;
     _tokenStartPtr = _codePtr;
 
     _char = QLatin1Char('\n');
     _errorCode = NoError;
 
     _currentLineNumber = lineno;
+    _currentColumnNumber = 0;
     _tokenValue = 0;
 
     // parentheses state
@@ -155,6 +152,7 @@ void Lexer::setCode(const QString &code, int lineno, bool qmlMode)
     _patternFlags = 0;
     _tokenLength = 0;
     _tokenLine = lineno;
+    _tokenColumn = 0;
 
     _validTokenText = false;
     _prohibitAutomaticSemicolon = false;
@@ -166,14 +164,22 @@ void Lexer::setCode(const QString &code, int lineno, bool qmlMode)
 
 void Lexer::scanChar()
 {
-    unsigned sequenceLength = isLineTerminatorSequence();
+    if (_skipLinefeed) {
+        Q_ASSERT(*_codePtr == QLatin1Char('\n'));
+        ++_codePtr;
+        _skipLinefeed = false;
+    }
     _char = *_codePtr++;
-    if (sequenceLength == 2)
-        _char = *_codePtr++;
+    ++_currentColumnNumber;
 
-    if (unsigned sequenceLength = isLineTerminatorSequence()) {
-        _lastLinePtr = _codePtr + sequenceLength - 1; // points to the first character after the newline
+    if (isLineTerminator()) {
+        if (_char == QLatin1Char('\r')) {
+            if (_codePtr < _endPtr && *_codePtr == QLatin1Char('\n'))
+                _skipLinefeed = true;
+            _char = QLatin1Char('\n');
+        }
         ++_currentLineNumber;
+        _currentColumnNumber = 0;
     }
 }
 
@@ -221,13 +227,34 @@ inline bool isBinop(int tok)
         return false;
     }
 }
+
+int hexDigit(QChar c)
+{
+    if (c >= QLatin1Char('0') && c <= QLatin1Char('9'))
+        return c.unicode() - '0';
+    if (c >= QLatin1Char('a') && c <= QLatin1Char('f'))
+        return c.unicode() - 'a' + 10;
+    if (c >= QLatin1Char('A') && c <= QLatin1Char('F'))
+        return c.unicode() - 'A' + 10;
+    return -1;
+}
+
+int octalDigit(QChar c)
+{
+    if (c >= QLatin1Char('0') && c <= QLatin1Char('7'))
+        return c.unicode() - '0';
+    return -1;
+}
+
 } // anonymous namespace
 
 int Lexer::lex()
 {
     const int previousTokenKind = _tokenKind;
 
+  again:
     _tokenSpell = QStringRef();
+    _rawString = QStringRef();
     _tokenKind = scanToken();
     _tokenLength = _codePtr - _tokenStartPtr - 1;
 
@@ -238,6 +265,9 @@ int Lexer::lex()
     // update the flags
     switch (_tokenKind) {
     case T_LBRACE:
+        if (_bracesCount > 0)
+            ++_bracesCount;
+        Q_FALLTHROUGH();
     case T_SEMICOLON:
     case T_QUESTION:
     case T_COLON:
@@ -265,9 +295,15 @@ int Lexer::lex()
     case T_CONTINUE:
     case T_BREAK:
     case T_RETURN:
+    case T_YIELD:
     case T_THROW:
         _restrictedKeyword = true;
         break;
+    case T_RBRACE:
+        if (_bracesCount > 0)
+            --_bracesCount;
+        if (_bracesCount == 0)
+            goto again;
     } // switch
 
     // update the parentheses state
@@ -294,39 +330,57 @@ int Lexer::lex()
     return _tokenKind;
 }
 
-bool Lexer::isUnicodeEscapeSequence(const QChar *chars)
-{
-    if (isHexDigit(chars[0]) && isHexDigit(chars[1]) && isHexDigit(chars[2]) && isHexDigit(chars[3]))
-        return true;
-
-    return false;
-}
-
-QChar Lexer::decodeUnicodeEscapeCharacter(bool *ok)
+uint Lexer::decodeUnicodeEscapeCharacter(bool *ok)
 {
-    if (_char == QLatin1Char('u') && isUnicodeEscapeSequence(&_codePtr[0])) {
-        scanChar(); // skip u
+    Q_ASSERT(_char == QLatin1Char('u'));
+    scanChar(); // skip u
+    if (_codePtr + 4 <= _endPtr && isHexDigit(_char)) {
+        uint codePoint = 0;
+        for (int i = 0; i < 4; ++i) {
+            int digit = hexDigit(_char);
+            if (digit < 0)
+                goto error;
+            codePoint *= 16;
+            codePoint += digit;
+            scanChar();
+        }
 
-        const QChar c1 = _char;
-        scanChar();
+        *ok = true;
+        return codePoint;
+    } else if (_codePtr < _endPtr && _char == QLatin1Char('{')) {
+        scanChar(); // skip '{'
+        uint codePoint = 0;
+        if (!isHexDigit(_char))
+            // need at least one hex digit
+            goto error;
 
-        const QChar c2 = _char;
-        scanChar();
+        while (_codePtr <= _endPtr) {
+            int digit = hexDigit(_char);
+            if (digit < 0)
+                break;
+            codePoint *= 16;
+            codePoint += digit;
+            if (codePoint > 0x10ffff)
+                goto error;
+            scanChar();
+        }
 
-        const QChar c3 = _char;
-        scanChar();
+        if (_char != QLatin1Char('}'))
+            goto error;
 
-        const QChar c4 = _char;
-        scanChar();
+        scanChar(); // skip '}'
 
-        if (ok)
-            *ok = true;
 
-        return convertUnicode(c1, c2, c3, c4);
+        *ok = true;
+        return codePoint;
     }
 
+  error:
+    _errorCode = IllegalUnicodeEscapeSequence;
+    _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
+
     *ok = false;
-    return QChar();
+    return 0;
 }
 
 QChar Lexer::decodeHexEscapeCharacter(bool *ok)
@@ -350,15 +404,15 @@ QChar Lexer::decodeHexEscapeCharacter(bool *ok)
     return QChar();
 }
 
-static inline bool isIdentifierStart(QChar ch)
+static inline bool isIdentifierStart(uint ch)
 {
     // fast path for ascii
-    if ((ch.unicode() >= 'a' && ch.unicode() <= 'z') ||
-        (ch.unicode() >= 'A' && ch.unicode() <= 'Z') ||
+    if ((ch >= 'a' && ch <= 'z') ||
+        (ch >= 'A' && ch <= 'Z') ||
         ch == '$' || ch == '_')
         return true;
 
-    switch (ch.category()) {
+    switch (QChar::category(ch)) {
     case QChar::Number_Letter:
     case QChar::Letter_Uppercase:
     case QChar::Letter_Lowercase:
@@ -372,17 +426,17 @@ static inline bool isIdentifierStart(QChar ch)
     return false;
 }
 
-static bool isIdentifierPart(QChar ch)
+static bool isIdentifierPart(uint ch)
 {
     // fast path for ascii
-    if ((ch.unicode() >= 'a' && ch.unicode() <= 'z') ||
-        (ch.unicode() >= 'A' && ch.unicode() <= 'Z') ||
-        (ch.unicode() >= '0' && ch.unicode() <= '9') ||
+    if ((ch >= 'a' && ch <= 'z') ||
+        (ch >= 'A' && ch <= 'Z') ||
+        (ch >= '0' && ch <= '9') ||
         ch == '$' || ch == '_' ||
-        ch.unicode() == 0x200c /* ZWNJ */ || ch.unicode() == 0x200d /* ZWJ */)
+        ch == 0x200c /* ZWNJ */ || ch == 0x200d /* ZWJ */)
         return true;
 
-    switch (ch.category()) {
+    switch (QChar::category(ch)) {
     case QChar::Mark_NonSpacing:
     case QChar::Mark_SpacingCombining:
 
@@ -411,19 +465,23 @@ int Lexer::scanToken()
         return tk;
     }
 
+    if (_bracesCount == 0) {
+        // we're inside a Template string
+        return scanString(TemplateContinuation);
+    }
+
+
     _terminator = false;
 
 again:
     _validTokenText = false;
-    _tokenLinePtr = _lastLinePtr;
 
     while (_char.isSpace()) {
-        if (unsigned sequenceLength = isLineTerminatorSequence()) {
-            _tokenLinePtr = _codePtr + sequenceLength - 1;
-
+        if (isLineTerminator()) {
             if (_restrictedKeyword) {
                 // automatic semicolon insertion
                 _tokenLine = _currentLineNumber;
+                _tokenColumn = _currentColumnNumber;
                 _tokenStartPtr = _codePtr - 1;
                 return T_SEMICOLON;
             } else {
@@ -437,6 +495,7 @@ again:
 
     _tokenStartPtr = _codePtr - 1;
     _tokenLine = _currentLineNumber;
+    _tokenColumn = _currentColumnNumber;
 
     if (_codePtr > _endPtr)
         return EOF_SYMBOL;
@@ -500,6 +559,9 @@ again:
                 return T_EQ_EQ_EQ;
             }
             return T_EQ_EQ;
+        } else if (_char == QLatin1Char('>')) {
+            scanChar();
+            return T_ARROW;
         }
         return T_EQ;
 
@@ -556,50 +618,18 @@ again:
         return T_DIVIDE_;
 
     case '.':
-        if (_char.isDigit()) {
-            QVarLengthArray<char,32> chars;
-
-            chars.append(ch.unicode()); // append the `.'
-
-            while (_char.isDigit()) {
-                chars.append(_char.unicode());
+        if (isDecimalDigit(_char.unicode()))
+            return scanNumber(ch);
+        if (_char == QLatin1Char('.')) {
+            scanChar();
+            if (_char == QLatin1Char('.')) {
                 scanChar();
-            }
-
-            if (_char == QLatin1Char('e') || _char == QLatin1Char('E')) {
-                if (_codePtr[0].isDigit() || ((_codePtr[0] == QLatin1Char('+') || _codePtr[0] == QLatin1Char('-')) &&
-                                              _codePtr[1].isDigit())) {
-
-                    chars.append(_char.unicode());
-                    scanChar(); // consume `e'
-
-                    if (_char == QLatin1Char('+') || _char == QLatin1Char('-')) {
-                        chars.append(_char.unicode());
-                        scanChar(); // consume the sign
-                    }
-
-                    while (_char.isDigit()) {
-                        chars.append(_char.unicode());
-                        scanChar();
-                    }
-                }
-            }
-
-            chars.append('\0');
-
-            const char *begin = chars.constData();
-            const char *end = 0;
-            bool ok = false;
-
-            _tokenValue = qstrtod(begin, &end, &ok);
-
-            if (end - begin != chars.size() - 1) {
-                _errorCode = IllegalExponentIndicator;
-                _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal syntax for exponential number");
+                return T_ELLIPSIS;
+            } else {
+                _errorCode = IllegalCharacter;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "Unexpected token '.'");
                 return T_ERROR;
             }
-
-            return T_NUMERIC_LITERAL;
         }
         return T_DOT;
 
@@ -610,7 +640,7 @@ again:
         } else if (_char == QLatin1Char('-')) {
             scanChar();
 
-            if (_terminator && !_delimited && !_prohibitAutomaticSemicolon) {
+            if (_terminator && !_delimited && !_prohibitAutomaticSemicolon && _tokenKind != T_LPAREN) {
                 _stackToken = T_MINUS_MINUS;
                 return T_SEMICOLON;
             }
@@ -628,7 +658,7 @@ again:
         } else if (_char == QLatin1Char('+')) {
             scanChar();
 
-            if (_terminator && !_delimited && !_prohibitAutomaticSemicolon) {
+            if (_terminator && !_delimited && !_prohibitAutomaticSemicolon && _tokenKind != T_LPAREN) {
                 _stackToken = T_PLUS_PLUS;
                 return T_SEMICOLON;
             }
@@ -641,6 +671,13 @@ again:
         if (_char == QLatin1Char('=')) {
             scanChar();
             return T_STAR_EQ;
+        } else if (_char == QLatin1Char('*')) {
+            scanChar();
+            if (_char == QLatin1Char('=')) {
+                scanChar();
+                return T_STAR_STAR_EQ;
+            }
+            return T_STAR_STAR;
         }
         return T_STAR;
 
@@ -675,141 +712,12 @@ again:
         }
         return T_NOT;
 
+    case '`':
+        _outerTemplateBraceCount.push(_bracesCount);
+        Q_FALLTHROUGH();
     case '\'':
-    case '"': {
-        const QChar quote = ch;
-        bool multilineStringLiteral = false;
-
-        const QChar *startCode = _codePtr;
-
-        if (_engine) {
-            while (_codePtr <= _endPtr) {
-                if (isLineTerminator()) {
-                    if (qmlMode())
-                        break;
-                    _errorCode = IllegalCharacter;
-                    _errorMessage = QCoreApplication::translate("QQmlParser", "Stray newline in string literal");
-                    return T_ERROR;
-                } else if (_char == QLatin1Char('\\')) {
-                    break;
-                } else if (_char == quote) {
-                    _tokenSpell = _engine->midRef(startCode - _code.unicode() - 1, _codePtr - startCode);
-                    scanChar();
-
-                    return T_STRING_LITERAL;
-                }
-                scanChar();
-            }
-        }
-
-        _validTokenText = true;
-        _tokenText.resize(0);
-        startCode--;
-        while (startCode != _codePtr - 1)
-            _tokenText += *startCode++;
-
-        while (_codePtr <= _endPtr) {
-            if (unsigned sequenceLength = isLineTerminatorSequence()) {
-                multilineStringLiteral = true;
-                _tokenText += _char;
-                if (sequenceLength == 2)
-                    _tokenText += *_codePtr;
-                scanChar();
-            } else if (_char == quote) {
-                scanChar();
-
-                if (_engine)
-                    _tokenSpell = _engine->newStringRef(_tokenText);
-
-                return multilineStringLiteral ? T_MULTILINE_STRING_LITERAL : T_STRING_LITERAL;
-            } else if (_char == QLatin1Char('\\')) {
-                scanChar();
-                if (_codePtr > _endPtr) {
-                    _errorCode = IllegalEscapeSequence;
-                    _errorMessage = QCoreApplication::translate("QQmlParser", "End of file reached at escape sequence");
-                    return T_ERROR;
-                }
-
-                QChar u;
-
-                switch (_char.unicode()) {
-                // unicode escape sequence
-                case 'u': {
-                    bool ok = false;
-                    u = decodeUnicodeEscapeCharacter(&ok);
-                    if (! ok) {
-                        _errorCode = IllegalUnicodeEscapeSequence;
-                        _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
-                        return T_ERROR;
-                    }
-                } break;
-
-                // hex escape sequence
-                case 'x': {
-                    bool ok = false;
-                    u = decodeHexEscapeCharacter(&ok);
-                    if (!ok) {
-                        _errorCode = IllegalHexadecimalEscapeSequence;
-                        _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal hexadecimal escape sequence");
-                        return T_ERROR;
-                    }
-                } break;
-
-                // single character escape sequence
-                case '\\': u = QLatin1Char('\\'); scanChar(); break;
-                case '\'': u = QLatin1Char('\''); scanChar(); break;
-                case '\"': u = QLatin1Char('\"'); scanChar(); break;
-                case 'b':  u = QLatin1Char('\b'); scanChar(); break;
-                case 'f':  u = QLatin1Char('\f'); scanChar(); break;
-                case 'n':  u = QLatin1Char('\n'); scanChar(); break;
-                case 'r':  u = QLatin1Char('\r'); scanChar(); break;
-                case 't':  u = QLatin1Char('\t'); scanChar(); break;
-                case 'v':  u = QLatin1Char('\v'); scanChar(); break;
-
-                case '0':
-                    if (! _codePtr->isDigit()) {
-                        scanChar();
-                        u = QLatin1Char('\0');
-                        break;
-                    }
-                    // fall through
-                case '1':
-                case '2':
-                case '3':
-                case '4':
-                case '5':
-                case '6':
-                case '7':
-                case '8':
-                case '9':
-                    _errorCode = IllegalEscapeSequence;
-                    _errorMessage = QCoreApplication::translate("QQmlParser", "Octal escape sequences are not allowed");
-                    return T_ERROR;
-
-                case '\r':
-                case '\n':
-                case 0x2028u:
-                case 0x2029u:
-                    scanChar();
-                    continue;
-
-                default:
-                    // non escape character
-                    u = _char;
-                    scanChar();
-                }
-
-                _tokenText += u;
-            } else {
-                _tokenText += _char;
-                scanChar();
-            }
-        }
-
-        _errorCode = UnclosedStringLiteral;
-        _errorMessage = QCoreApplication::translate("QQmlParser", "Unclosed string at end of line");
-        return T_ERROR;
-    }
+    case '"':
+        return scanString(ScanStringMode(ch.unicode()));
     case '0':
     case '1':
     case '2':
@@ -823,28 +731,36 @@ again:
         return scanNumber(ch);
 
     default: {
-        QChar c = ch;
+        uint c = ch.unicode();
         bool identifierWithEscapeChars = false;
-        if (c == QLatin1Char('\\') && _char == QLatin1Char('u')) {
+        if (QChar::isHighSurrogate(c) && QChar::isLowSurrogate(_char.unicode())) {
+            c = QChar::surrogateToUcs4(ushort(c), _char.unicode());
+            scanChar();
+        } else if (c == '\\' && _char == QLatin1Char('u')) {
             identifierWithEscapeChars = true;
             bool ok = false;
             c = decodeUnicodeEscapeCharacter(&ok);
-            if (! ok) {
-                _errorCode = IllegalUnicodeEscapeSequence;
-                _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
+            if (!ok)
                 return T_ERROR;
-            }
         }
         if (isIdentifierStart(c)) {
             if (identifierWithEscapeChars) {
                 _tokenText.resize(0);
-                _tokenText += c;
+                if (QChar::requiresSurrogates(c)) {
+                    _tokenText += QChar(QChar::highSurrogate(c));
+                    _tokenText += QChar(QChar::lowSurrogate(c));
+                } else {
+                    _tokenText += QChar(c);
+                }
                 _validTokenText = true;
             }
-            while (true) {
-                c = _char;
-                if (_char == QLatin1Char('\\') && _codePtr[0] == QLatin1Char('u')) {
-                    if (! identifierWithEscapeChars) {
+            while (_codePtr <= _endPtr) {
+                c = _char.unicode();
+                if (QChar::isHighSurrogate(c) && QChar::isLowSurrogate(_codePtr->unicode())) {
+                    scanChar();
+                    c = QChar::surrogateToUcs4(ushort(c), _char.unicode());
+                } else if (_char == QLatin1Char('\\') && _codePtr[0] == QLatin1Char('u')) {
+                    if (!identifierWithEscapeChars) {
                         identifierWithEscapeChars = true;
                         _tokenText.resize(0);
                         _tokenText.insert(0, _tokenStartPtr, _codePtr - _tokenStartPtr - 1);
@@ -854,38 +770,52 @@ again:
                     scanChar(); // skip '\\'
                     bool ok = false;
                     c = decodeUnicodeEscapeCharacter(&ok);
-                    if (! ok) {
-                        _errorCode = IllegalUnicodeEscapeSequence;
-                        _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
+                    if (!ok)
                         return T_ERROR;
-                    }
-                    if (isIdentifierPart(c))
-                        _tokenText += c;
-                    continue;
-                } else if (isIdentifierPart(c)) {
-                    if (identifierWithEscapeChars)
-                        _tokenText += c;
 
-                    scanChar();
+                    if (!isIdentifierPart(c))
+                        break;
+
+                    if (identifierWithEscapeChars) {
+                        if (QChar::requiresSurrogates(c)) {
+                            _tokenText += QChar(QChar::highSurrogate(c));
+                            _tokenText += QChar(QChar::lowSurrogate(c));
+                        } else {
+                            _tokenText += QChar(c);
+                        }
+                    }
                     continue;
                 }
 
-                _tokenLength = _codePtr - _tokenStartPtr - 1;
+                if (!isIdentifierPart(c))
+                    break;
 
-                int kind = T_IDENTIFIER;
+                if (identifierWithEscapeChars) {
+                    if (QChar::requiresSurrogates(c)) {
+                        _tokenText += QChar(QChar::highSurrogate(c));
+                        _tokenText += QChar(QChar::lowSurrogate(c));
+                    } else {
+                        _tokenText += QChar(c);
+                    }
+                }
+                scanChar();
+            }
 
-                if (! identifierWithEscapeChars)
-                    kind = classify(_tokenStartPtr, _tokenLength, _qmlMode);
+            _tokenLength = _codePtr - _tokenStartPtr - 1;
 
-                if (_engine) {
-                    if (kind == T_IDENTIFIER && identifierWithEscapeChars)
-                        _tokenSpell = _engine->newStringRef(_tokenText);
-                    else
-                        _tokenSpell = _engine->midRef(_tokenStartPtr - _code.unicode(), _tokenLength);
-                }
+            int kind = T_IDENTIFIER;
 
-                return kind;
+            if (!identifierWithEscapeChars)
+                kind = classify(_tokenStartPtr, _tokenLength, parseModeFlags());
+
+            if (_engine) {
+                if (kind == T_IDENTIFIER && identifierWithEscapeChars)
+                    _tokenSpell = _engine->newStringRef(_tokenText);
+                else
+                    _tokenSpell = _engine->midRef(_tokenStartPtr - _code.unicode(), _tokenLength);
             }
+
+            return kind;
         }
         }
 
@@ -895,93 +825,292 @@ again:
     return T_ERROR;
 }
 
-int Lexer::scanNumber(QChar ch)
+int Lexer::scanString(ScanStringMode mode)
 {
-    if (ch != QLatin1Char('0')) {
-        QVarLengthArray<char, 64> buf;
-        buf += ch.toLatin1();
-
-        QChar n = _char;
-        const QChar *code = _codePtr;
-        while (n.isDigit()) {
-            buf += n.toLatin1();
-            n = *code++;
-        }
+    QChar quote = (mode == TemplateContinuation) ? QChar(TemplateHead) : QChar(mode);
+    bool multilineStringLiteral = false;
+
+    const QChar *startCode = _codePtr - 1;
+    // in case we just parsed a \r, we need to reset this flag to get things working
+    // correctly in the loop below and afterwards
+    _skipLinefeed = false;
 
-        if (n != QLatin1Char('.') && n != QLatin1Char('e') && n != QLatin1Char('E')) {
-            if (code != _codePtr) {
-                _codePtr = code - 1;
+    if (_engine) {
+        while (_codePtr <= _endPtr) {
+            if (isLineTerminator()) {
+                if ((quote == QLatin1Char('`') || qmlMode()))
+                    break;
+                _errorCode = IllegalCharacter;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "Stray newline in string literal");
+                return T_ERROR;
+            } else if (_char == QLatin1Char('\\')) {
+                break;
+            } else if (_char == '$' && quote == QLatin1Char('`')) {
+                break;
+            } else if (_char == quote) {
+                _tokenSpell = _engine->midRef(startCode - _code.unicode(), _codePtr - startCode - 1);
+                _rawString = _tokenSpell;
                 scanChar();
+
+                if (quote == QLatin1Char('`'))
+                    _bracesCount = _outerTemplateBraceCount.pop();
+
+                if (mode == TemplateHead)
+                    return T_NO_SUBSTITUTION_TEMPLATE;
+                else if (mode == TemplateContinuation)
+                    return T_TEMPLATE_TAIL;
+                else
+                    return T_STRING_LITERAL;
             }
-            buf.append('\0');
-            _tokenValue = strtod(buf.constData(), 0);
-            return T_NUMERIC_LITERAL;
+            // don't use scanChar() here, that would transform \r sequences and the midRef() call would create the wrong result
+            _char = *_codePtr++;
+            ++_currentColumnNumber;
         }
-    } else if (_char.isDigit() && !qmlMode()) {
-        _errorCode = IllegalCharacter;
-        _errorMessage = QCoreApplication::translate("QQmlParser", "Decimal numbers can't start with '0'");
-        return T_ERROR;
     }
 
-    QVarLengthArray<char,32> chars;
-    chars.append(ch.unicode());
+    // rewind by one char, so things gets scanned correctly
+    --_codePtr;
 
-    if (ch == QLatin1Char('0') && (_char == QLatin1Char('x') || _char == QLatin1Char('X'))) {
-        ch = _char; // remember the x or X to use it in the error message below.
+    _validTokenText = true;
+    _tokenText = QString(startCode, _codePtr - startCode);
 
-        // parse hex integer literal
-        chars.append(_char.unicode());
-        scanChar(); // consume `x'
+    auto setRawString = [&](const QChar *end) {
+        QString raw(startCode, end - startCode - 1);
+        raw.replace(QLatin1String("\r\n"), QLatin1String("\n"));
+        raw.replace(QLatin1Char('\r'), QLatin1Char('\n'));
+        _rawString = _engine->newStringRef(raw);
+    };
 
-        while (isHexDigit(_char)) {
-            chars.append(_char.unicode());
+    scanChar();
+
+    while (_codePtr <= _endPtr) {
+        if (_char == quote) {
+            scanChar();
+
+            if (_engine) {
+                _tokenSpell = _engine->newStringRef(_tokenText);
+                if (quote == QLatin1Char('`'))
+                    setRawString(_codePtr - 1);
+            }
+
+            if (quote == QLatin1Char('`'))
+                _bracesCount = _outerTemplateBraceCount.pop();
+
+            if (mode == TemplateContinuation)
+                return T_TEMPLATE_TAIL;
+            else if (mode == TemplateHead)
+                return T_NO_SUBSTITUTION_TEMPLATE;
+
+            return multilineStringLiteral ? T_MULTILINE_STRING_LITERAL : T_STRING_LITERAL;
+        } else if (quote == QLatin1Char('`') && _char == QLatin1Char('$') && *_codePtr == '{') {
+            scanChar();
+            scanChar();
+            _bracesCount = 1;
+            if (_engine) {
+                _tokenSpell = _engine->newStringRef(_tokenText);
+                setRawString(_codePtr - 2);
+            }
+
+            return (mode == TemplateHead ? T_TEMPLATE_HEAD : T_TEMPLATE_MIDDLE);
+        } else if (_char == QLatin1Char('\\')) {
+            scanChar();
+            if (_codePtr > _endPtr) {
+                _errorCode = IllegalEscapeSequence;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "End of file reached at escape sequence");
+                return T_ERROR;
+            }
+
+            QChar u;
+
+            switch (_char.unicode()) {
+            // unicode escape sequence
+            case 'u': {
+                bool ok = false;
+                uint codePoint = decodeUnicodeEscapeCharacter(&ok);
+                if (!ok)
+                    return T_ERROR;
+                if (QChar::requiresSurrogates(codePoint)) {
+                    // need to use a surrogate pair
+                    _tokenText += QChar(QChar::highSurrogate(codePoint));
+                    u = QChar::lowSurrogate(codePoint);
+                } else {
+                    u = codePoint;
+                }
+            } break;
+
+            // hex escape sequence
+            case 'x': {
+                bool ok = false;
+                u = decodeHexEscapeCharacter(&ok);
+                if (!ok) {
+                    _errorCode = IllegalHexadecimalEscapeSequence;
+                    _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal hexadecimal escape sequence");
+                    return T_ERROR;
+                }
+            } break;
+
+            // single character escape sequence
+            case '\\': u = QLatin1Char('\\'); scanChar(); break;
+            case '\'': u = QLatin1Char('\''); scanChar(); break;
+            case '\"': u = QLatin1Char('\"'); scanChar(); break;
+            case 'b':  u = QLatin1Char('\b'); scanChar(); break;
+            case 'f':  u = QLatin1Char('\f'); scanChar(); break;
+            case 'n':  u = QLatin1Char('\n'); scanChar(); break;
+            case 'r':  u = QLatin1Char('\r'); scanChar(); break;
+            case 't':  u = QLatin1Char('\t'); scanChar(); break;
+            case 'v':  u = QLatin1Char('\v'); scanChar(); break;
+
+            case '0':
+                if (! _codePtr->isDigit()) {
+                    scanChar();
+                    u = QLatin1Char('\0');
+                    break;
+                }
+                Q_FALLTHROUGH();
+            case '1':
+            case '2':
+            case '3':
+            case '4':
+            case '5':
+            case '6':
+            case '7':
+            case '8':
+            case '9':
+                _errorCode = IllegalEscapeSequence;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "Octal escape sequences are not allowed");
+                return T_ERROR;
+
+            case '\r':
+            case '\n':
+            case 0x2028u:
+            case 0x2029u:
+                scanChar();
+                continue;
+
+            default:
+                // non escape character
+                u = _char;
+                scanChar();
+            }
+
+            _tokenText += u;
+        } else {
+            _tokenText += _char;
             scanChar();
         }
+    }
+
+    _errorCode = UnclosedStringLiteral;
+    _errorMessage = QCoreApplication::translate("QQmlParser", "Unclosed string at end of line");
+    return T_ERROR;
+}
+
+int Lexer::scanNumber(QChar ch)
+{
+    if (ch == QLatin1Char('0')) {
+        if (_char == QLatin1Char('x') || _char == QLatin1Char('X')) {
+            ch = _char; // remember the x or X to use it in the error message below.
+
+            // parse hex integer literal
+            scanChar(); // consume 'x'
+
+            if (!isHexDigit(_char)) {
+                _errorCode = IllegalNumber;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "At least one hexadecimal digit is required after '0%1'").arg(ch);
+                return T_ERROR;
+            }
+
+            double d = 0.;
+            while (1) {
+                int digit = ::hexDigit(_char);
+                if (digit < 0)
+                    break;
+                d *= 16;
+                d += digit;
+                scanChar();
+            }
+
+            _tokenValue = d;
+            return T_NUMERIC_LITERAL;
+        } else if (_char == QLatin1Char('o') || _char == QLatin1Char('O')) {
+            ch = _char; // remember the o or O to use it in the error message below.
 
-        if (chars.size() < 3) {
-            _errorCode = IllegalHexNumber;
-            _errorMessage = QCoreApplication::translate("QQmlParser", "At least one hexadecimal digit is required after '0%1'").arg(ch);
+            // parse octal integer literal
+            scanChar(); // consume 'o'
+
+            if (!isOctalDigit(_char.unicode())) {
+                _errorCode = IllegalNumber;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "At least one octal digit is required after '0%1'").arg(ch);
+                return T_ERROR;
+            }
+
+            double d = 0.;
+            while (1) {
+                int digit = ::octalDigit(_char);
+                if (digit < 0)
+                    break;
+                d *= 8;
+                d += digit;
+                scanChar();
+            }
+
+            _tokenValue = d;
+            return T_NUMERIC_LITERAL;
+        } else if (_char == QLatin1Char('b') || _char == QLatin1Char('B')) {
+            ch = _char; // remember the b or B to use it in the error message below.
+
+            // parse binary integer literal
+            scanChar(); // consume 'b'
+
+            if (_char.unicode() != '0' && _char.unicode() != '1') {
+                _errorCode = IllegalNumber;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "At least one binary digit is required after '0%1'").arg(ch);
+                return T_ERROR;
+            }
+
+            double d = 0.;
+            while (1) {
+                int digit = 0;
+                if (_char.unicode() == '1')
+                    digit = 1;
+                else if (_char.unicode() != '0')
+                    break;
+                d *= 2;
+                d += digit;
+                scanChar();
+            }
+
+            _tokenValue = d;
+            return T_NUMERIC_LITERAL;
+        } else if (_char.isDigit() && !qmlMode()) {
+            _errorCode = IllegalCharacter;
+            _errorMessage = QCoreApplication::translate("QQmlParser", "Decimal numbers can't start with '0'");
             return T_ERROR;
         }
-
-        _tokenValue = integerFromString(chars.constData(), chars.size(), 16);
-        return T_NUMERIC_LITERAL;
     }
 
     // decimal integer literal
-    while (_char.isDigit()) {
-        chars.append(_char.unicode());
-        scanChar(); // consume the digit
-    }
-
-    if (_char == QLatin1Char('.')) {
-        chars.append(_char.unicode());
-        scanChar(); // consume `.'
+    QVarLengthArray<char,32> chars;
+    chars.append(ch.unicode());
 
+    if (ch != QLatin1Char('.')) {
         while (_char.isDigit()) {
             chars.append(_char.unicode());
-            scanChar();
+            scanChar(); // consume the digit
         }
 
-        if (_char == QLatin1Char('e') || _char == QLatin1Char('E')) {
-            if (_codePtr[0].isDigit() || ((_codePtr[0] == QLatin1Char('+') || _codePtr[0] == QLatin1Char('-')) &&
-                                          _codePtr[1].isDigit())) {
-
-                chars.append(_char.unicode());
-                scanChar(); // consume `e'
+        if (_char == QLatin1Char('.')) {
+            chars.append(_char.unicode());
+            scanChar(); // consume `.'
+        }
+    }
 
-                if (_char == QLatin1Char('+') || _char == QLatin1Char('-')) {
-                    chars.append(_char.unicode());
-                    scanChar(); // consume the sign
-                }
+    while (_char.isDigit()) {
+        chars.append(_char.unicode());
+        scanChar();
+    }
 
-                while (_char.isDigit()) {
-                    chars.append(_char.unicode());
-                    scanChar();
-                }
-            }
-        }
-    } else if (_char == QLatin1Char('e') || _char == QLatin1Char('E')) {
+    if (_char == QLatin1Char('e') || _char == QLatin1Char('E')) {
         if (_codePtr[0].isDigit() || ((_codePtr[0] == QLatin1Char('+') || _codePtr[0] == QLatin1Char('-')) &&
                                       _codePtr[1].isDigit())) {
 
@@ -1000,16 +1129,10 @@ int Lexer::scanNumber(QChar ch)
         }
     }
 
-    if (chars.length() == 1) {
-        // if we ended up with a single digit, then it was a '0'
-        _tokenValue = 0;
-        return T_NUMERIC_LITERAL;
-    }
-
     chars.append('\0');
 
     const char *begin = chars.constData();
-    const char *end = 0;
+    const char *end = nullptr;
     bool ok = false;
 
     _tokenValue = qstrtod(begin, &end, &ok);
@@ -1173,16 +1296,6 @@ bool Lexer::isOctalDigit(ushort c)
     return (c >= '0' && c <= '7');
 }
 
-int Lexer::tokenEndLine() const
-{
-    return _currentLineNumber;
-}
-
-int Lexer::tokenEndColumn() const
-{
-    return _codePtr - _lastLinePtr;
-}
-
 QString Lexer::tokenText() const
 {
     if (_validTokenText)
@@ -1255,6 +1368,7 @@ static const int uriTokens[] = {
     QQmlJSGrammar::T_FUNCTION,
     QQmlJSGrammar::T_IF,
     QQmlJSGrammar::T_IN,
+    QQmlJSGrammar::T_OF,
     QQmlJSGrammar::T_INSTANCEOF,
     QQmlJSGrammar::T_NEW,
     QQmlJSGrammar::T_NULL,
@@ -1301,7 +1415,7 @@ bool Lexer::scanDirectives(Directives *directives, DiagnosticMessage *error)
 
         lex(); // skip T_DOT
 
-        if (! (_tokenKind == T_IDENTIFIER || _tokenKind == T_RESERVED_WORD))
+        if (! (_tokenKind == T_IDENTIFIER || _tokenKind == T_IMPORT))
             return true; // expected a valid QML/JS directive
 
         const QString directiveName = tokenText();
@@ -1395,7 +1509,7 @@ bool Lexer::scanDirectives(Directives *directives, DiagnosticMessage *error)
             //
             // recognize the mandatory `as' followed by the module name
             //
-            if (! (lex() == T_IDENTIFIER && tokenText() == QLatin1String("as") && tokenStartLine() == lineNumber)) {
+            if (! (lex() == T_AS && tokenStartLine() == lineNumber)) {
                 if (fileImport)
                     error->message = QCoreApplication::translate("QQmlParser", "File import requires a qualifier");
                 else
diff --git a/src/qml/parser/qqmljslexer_p.h b/src/qml/parser/qqmljslexer_p.h
index af5597b625..03f33f6e06 100644
--- a/src/qml/parser/qqmljslexer_p.h
+++ b/src/qml/parser/qqmljslexer_p.h
@@ -51,10 +51,11 @@
 // We mean it.
 //
 
-#include "qqmljsglobal_p.h"
-#include "qqmljsgrammar_p.h"
+#include <private/qqmljsglobal_p.h>
+#include <private/qqmljsgrammar_p.h>
 
 #include <QtCore/qstring.h>
+#include <QtCore/qstack.h>
 
 QT_QML_BEGIN_NAMESPACE
 
@@ -62,32 +63,7 @@ namespace QQmlJS {
 
 class Engine;
 class DiagnosticMessage;
-
-class QML_PARSER_EXPORT Directives {
-public:
-    virtual ~Directives() {}
-
-    virtual void pragmaLibrary()
-    {
-    }
-
-    virtual void importFile(const QString &jsfile, const QString &module, int line, int column)
-    {
-        Q_UNUSED(jsfile);
-        Q_UNUSED(module);
-        Q_UNUSED(line);
-        Q_UNUSED(column);
-    }
-
-    virtual void importModule(const QString &uri, const QString &version, const QString &module, int line, int column)
-    {
-        Q_UNUSED(uri);
-        Q_UNUSED(version);
-        Q_UNUSED(module);
-        Q_UNUSED(line);
-        Q_UNUSED(column);
-    }
-};
+class Directives;
 
 class QML_PARSER_EXPORT Lexer: public QQmlJSGrammar
 {
@@ -97,11 +73,7 @@ public:
         T_BOOLEAN = T_RESERVED_WORD,
         T_BYTE = T_RESERVED_WORD,
         T_CHAR = T_RESERVED_WORD,
-        T_CLASS = T_RESERVED_WORD,
         T_DOUBLE = T_RESERVED_WORD,
-        T_ENUM = T_RESERVED_WORD,
-        T_EXPORT = T_RESERVED_WORD,
-        T_EXTENDS = T_RESERVED_WORD,
         T_FINAL = T_RESERVED_WORD,
         T_FLOAT = T_RESERVED_WORD,
         T_GOTO = T_RESERVED_WORD,
@@ -114,8 +86,6 @@ public:
         T_PRIVATE = T_RESERVED_WORD,
         T_PROTECTED = T_RESERVED_WORD,
         T_SHORT = T_RESERVED_WORD,
-        T_STATIC = T_RESERVED_WORD,
-        T_SUPER = T_RESERVED_WORD,
         T_SYNCHRONIZED = T_RESERVED_WORD,
         T_THROWS = T_RESERVED_WORD,
         T_TRANSIENT = T_RESERVED_WORD,
@@ -125,7 +95,7 @@ public:
     enum Error {
         NoError,
         IllegalCharacter,
-        IllegalHexNumber,
+        IllegalNumber,
         UnclosedStringLiteral,
         IllegalEscapeSequence,
         IllegalUnicodeEscapeSequence,
@@ -143,13 +113,34 @@ public:
     enum RegExpFlag {
         RegExp_Global     = 0x01,
         RegExp_IgnoreCase = 0x02,
-        RegExp_Multiline  = 0x04
+        RegExp_Multiline  = 0x04,
+        RegExp_Unicode    = 0x08,
+        RegExp_Sticky     = 0x10
+    };
+
+    enum ParseModeFlags {
+        QmlMode = 0x1,
+        YieldIsKeyword = 0x2,
+        StaticIsKeyword = 0x4
     };
 
 public:
     Lexer(Engine *engine);
 
+    int parseModeFlags() const {
+        int flags = 0;
+        if (qmlMode())
+            flags |= QmlMode|StaticIsKeyword;
+        if (yieldIsKeyWord())
+            flags |= YieldIsKeyword;
+        if (_staticIsKeyword)
+            flags |= StaticIsKeyword;
+        return flags;
+    }
+
     bool qmlMode() const;
+    bool yieldIsKeyWord() const { return _generatorLevel != 0; }
+    void setStaticIsKeyword(bool b) { _staticIsKeyword = b; }
 
     QString code() const;
     void setCode(const QString &code, int lineno, bool qmlMode = true);
@@ -167,12 +158,10 @@ public:
     int tokenLength() const { return _tokenLength; }
 
     int tokenStartLine() const { return _tokenLine; }
-    int tokenStartColumn() const { return _tokenStartPtr - _tokenLinePtr + 1; }
-
-    int tokenEndLine() const;
-    int tokenEndColumn() const;
+    int tokenStartColumn() const { return _tokenColumn; }
 
     inline QStringRef tokenSpell() const { return _tokenSpell; }
+    inline QStringRef rawString() const { return _rawString; }
     double tokenValue() const { return _tokenValue; }
     QString tokenText() const;
 
@@ -189,13 +178,23 @@ public:
         BalancedParentheses
     };
 
+    void enterGeneratorBody() { ++_generatorLevel; }
+    void leaveGeneratorBody() { --_generatorLevel; }
+
 protected:
-    int classify(const QChar *s, int n, bool qmlMode);
+    static int classify(const QChar *s, int n, int parseModeFlags);
 
 private:
     inline void scanChar();
     int scanToken();
     int scanNumber(QChar ch);
+    enum ScanStringMode {
+        SingleQuote = '\'',
+        DoubleQuote = '"',
+        TemplateHead = '`',
+        TemplateContinuation = 0
+    };
+    int scanString(ScanStringMode mode);
 
     bool isLineTerminator() const;
     unsigned isLineTerminatorSequence() const;
@@ -203,10 +202,9 @@ private:
     static bool isDecimalDigit(ushort c);
     static bool isHexDigit(QChar c);
     static bool isOctalDigit(ushort c);
-    static bool isUnicodeEscapeSequence(const QChar *chars);
 
     void syncProhibitAutomaticSemicolon();
-    QChar decodeUnicodeEscapeCharacter(bool *ok);
+    uint decodeUnicodeEscapeCharacter(bool *ok);
     QChar decodeHexEscapeCharacter(bool *ok);
 
 private:
@@ -216,29 +214,34 @@ private:
     QString _tokenText;
     QString _errorMessage;
     QStringRef _tokenSpell;
+    QStringRef _rawString;
 
     const QChar *_codePtr;
     const QChar *_endPtr;
-    const QChar *_lastLinePtr;
-    const QChar *_tokenLinePtr;
     const QChar *_tokenStartPtr;
 
     QChar _char;
     Error _errorCode;
 
     int _currentLineNumber;
+    int _currentColumnNumber;
     double _tokenValue;
 
     // parentheses state
     ParenthesesState _parenthesesState;
     int _parenthesesCount;
 
+    // template string stack
+    QStack<int> _outerTemplateBraceCount;
+    int _bracesCount = -1;
+
     int _stackToken;
 
     int _patternFlags;
     int _tokenKind;
     int _tokenLength;
     int _tokenLine;
+    int _tokenColumn;
 
     bool _validTokenText;
     bool _prohibitAutomaticSemicolon;
@@ -247,6 +250,9 @@ private:
     bool _followsClosingBrace;
     bool _delimited;
     bool _qmlMode;
+    bool _skipLinefeed = false;
+    int _generatorLevel = 0;
+    bool _staticIsKeyword = false;
 };
 
 } // end of namespace QQmlJS
diff --git a/src/qml/parser/qqmljsmemorypool_p.h b/src/qml/parser/qqmljsmemorypool_p.h
index 536f5d4239..bcd6d8672b 100644
--- a/src/qml/parser/qqmljsmemorypool_p.h
+++ b/src/qml/parser/qqmljsmemorypool_p.h
@@ -71,13 +71,7 @@ class QML_PARSER_EXPORT MemoryPool : public QSharedData
     void operator =(const MemoryPool &other);
 
 public:
-    MemoryPool()
-        : _blocks(0),
-          _allocatedBlocks(0),
-          _blockCount(-1),
-          _ptr(0),
-          _end(0)
-    { }
+    MemoryPool() {}
 
     ~MemoryPool()
     {
@@ -89,11 +83,12 @@ public:
 
             free(_blocks);
         }
+        qDeleteAll(strings);
     }
 
     inline void *allocate(size_t size)
     {
-        size = (size + 7) & ~7;
+        size = (size + 7) & ~size_t(7);
         if (Q_LIKELY(_ptr && (_ptr + size < _end))) {
             void *addr = _ptr;
             _ptr += size;
@@ -105,15 +100,24 @@ public:
     void reset()
     {
         _blockCount = -1;
-        _ptr = _end = 0;
+        _ptr = _end = nullptr;
     }
 
     template <typename Tp> Tp *New() { return new (this->allocate(sizeof(Tp))) Tp(); }
+    template <typename Tp, typename... Ta> Tp *New(Ta... args)
+    { return new (this->allocate(sizeof(Tp))) Tp(args...); }
+
+    QStringRef newString(const QString &string) {
+        strings.append(new QString(string));
+        return QStringRef(strings.last());
+    }
 
 private:
     Q_NEVER_INLINE void *allocate_helper(size_t size)
     {
-        Q_ASSERT(size < BLOCK_SIZE);
+        size_t currentBlockSize = DEFAULT_BLOCK_SIZE;
+        while (Q_UNLIKELY(size >= currentBlockSize))
+            currentBlockSize *= 2;
 
         if (++_blockCount == _allocatedBlocks) {
             if (! _allocatedBlocks)
@@ -121,22 +125,22 @@ private:
             else
                 _allocatedBlocks *= 2;
 
-            _blocks = (char **) realloc(_blocks, sizeof(char *) * _allocatedBlocks);
+            _blocks = reinterpret_cast<char **>(realloc(_blocks, sizeof(char *) * size_t(_allocatedBlocks)));
             Q_CHECK_PTR(_blocks);
 
             for (int index = _blockCount; index < _allocatedBlocks; ++index)
-                _blocks[index] = 0;
+                _blocks[index] = nullptr;
         }
 
         char *&block = _blocks[_blockCount];
 
         if (! block) {
-            block = (char *) malloc(BLOCK_SIZE);
+            block = reinterpret_cast<char *>(malloc(currentBlockSize));
             Q_CHECK_PTR(block);
         }
 
         _ptr = block;
-        _end = _ptr + BLOCK_SIZE;
+        _end = _ptr + currentBlockSize;
 
         void *addr = _ptr;
         _ptr += size;
@@ -144,33 +148,107 @@ private:
     }
 
 private:
-    char **_blocks;
-    int _allocatedBlocks;
-    int _blockCount;
-    char *_ptr;
-    char *_end;
+    char **_blocks = nullptr;
+    int _allocatedBlocks = 0;
+    int _blockCount = -1;
+    char *_ptr = nullptr;
+    char *_end = nullptr;
+    QVector<QString*> strings;
 
     enum
     {
-        BLOCK_SIZE = 8 * 1024,
+        DEFAULT_BLOCK_SIZE = 8 * 1024,
         DEFAULT_BLOCK_COUNT = 8
     };
 };
 
 class QML_PARSER_EXPORT Managed
 {
-    Managed(const Managed &other);
-    void operator = (const Managed &other);
-
+    Q_DISABLE_COPY(Managed)
 public:
-    Managed() {}
-    ~Managed() {}
+    Managed() = default;
+    ~Managed() = default;
 
     void *operator new(size_t size, MemoryPool *pool) { return pool->allocate(size); }
     void operator delete(void *) {}
     void operator delete(void *, MemoryPool *) {}
 };
 
+template <typename T>
+class FixedPoolArray
+{
+    T *data;
+    int count = 0;
+
+public:
+    FixedPoolArray()
+        : data(nullptr)
+    {}
+
+    FixedPoolArray(MemoryPool *pool, int size)
+    { allocate(pool, size); }
+
+    void allocate(MemoryPool *pool, int size)
+    {
+        count = size;
+        data = reinterpret_cast<T*>(pool->allocate(count * sizeof(T)));
+    }
+
+    void allocate(MemoryPool *pool, const QVector<T> &vector)
+    {
+        count = vector.count();
+        data = reinterpret_cast<T*>(pool->allocate(count * sizeof(T)));
+
+        if (QTypeInfo<T>::isComplex) {
+            for (int i = 0; i < count; ++i)
+                new (data + i) T(vector.at(i));
+        } else {
+            memcpy(data, static_cast<const void*>(vector.constData()), count * sizeof(T));
+        }
+    }
+
+    template <typename Container>
+    void allocate(MemoryPool *pool, const Container &container)
+    {
+        count = container.count();
+        data = reinterpret_cast<T*>(pool->allocate(count * sizeof(T)));
+        typename Container::ConstIterator it = container.constBegin();
+        for (int i = 0; i < count; ++i)
+            new (data + i) T(*it++);
+    }
+
+    int size() const
+    { return count; }
+
+    const T &at(int index) const {
+        Q_ASSERT(index >= 0 && index < count);
+        return data[index];
+    }
+
+    T &at(int index) {
+        Q_ASSERT(index >= 0 && index < count);
+        return data[index];
+    }
+
+    T &operator[](int index) {
+        return at(index);
+    }
+
+
+    int indexOf(const T &value) const {
+        for (int i = 0; i < count; ++i)
+            if (data[i] == value)
+                return i;
+        return -1;
+    }
+
+    const T *begin() const { return data; }
+    const T *end() const { return data + count; }
+
+    T *begin() { return data; }
+    T *end() { return data + count; }
+};
+
 } // namespace QQmlJS
 
 QT_QML_END_NAMESPACE
diff --git a/src/qml/parser/qqmljsparser.cpp b/src/qml/parser/qqmljsparser.cpp
deleted file mode 100644
index 636b959097..0000000000
--- a/src/qml/parser/qqmljsparser.cpp
+++ /dev/null
@@ -1,1971 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qqmljsengine_p.h"
-#include "qqmljslexer_p.h"
-#include "qqmljsast_p.h"
-#include "qqmljsmemorypool_p.h"
-
-#include <QtCore/qdebug.h>
-#include <QtCore/qcoreapplication.h>
-
-#include <string.h>
-
-
-
-#include "qqmljsparser_p.h"
-
-#include <QtCore/qvarlengtharray.h>
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is automatically generated from qqmljs.g.
-// Changes should be made to that file, not here. Any change to this file will
-// be lost!
-//
-// To regenerate this file, run:
-//    qlalr --no-debug --no-lines --qt qqmljs.g
-//
-
-using namespace QQmlJS;
-
-QT_QML_BEGIN_NAMESPACE
-
-void Parser::reallocateStack()
-{
-    if (! stack_size)
-        stack_size = 128;
-    else
-        stack_size <<= 1;
-
-    sym_stack = reinterpret_cast<Value*> (realloc(sym_stack, stack_size * sizeof(Value)));
-    state_stack = reinterpret_cast<int*> (realloc(state_stack, stack_size * sizeof(int)));
-    location_stack = reinterpret_cast<AST::SourceLocation*> (realloc(location_stack, stack_size * sizeof(AST::SourceLocation)));
-    string_stack = reinterpret_cast<QStringRef*> (realloc(string_stack, stack_size * sizeof(QStringRef)));
-}
-
-Parser::Parser(Engine *engine):
-    driver(engine),
-    pool(engine->pool()),
-    tos(0),
-    stack_size(0),
-    sym_stack(0),
-    state_stack(0),
-    location_stack(0),
-    string_stack(0),
-    program(0),
-    first_token(0),
-    last_token(0)
-{
-}
-
-Parser::~Parser()
-{
-    if (stack_size) {
-        free(sym_stack);
-        free(state_stack);
-        free(location_stack);
-        free(string_stack);
-    }
-}
-
-static inline AST::SourceLocation location(Lexer *lexer)
-{
-    AST::SourceLocation loc;
-    loc.offset = lexer->tokenOffset();
-    loc.length = lexer->tokenLength();
-    loc.startLine = lexer->tokenStartLine();
-    loc.startColumn = lexer->tokenStartColumn();
-    return loc;
-}
-
-AST::UiQualifiedId *Parser::reparseAsQualifiedId(AST::ExpressionNode *expr)
-{
-    QVarLengthArray<QStringRef, 4> nameIds;
-    QVarLengthArray<AST::SourceLocation, 4> locations;
-
-    AST::ExpressionNode *it = expr;
-    while (AST::FieldMemberExpression *m = AST::cast<AST::FieldMemberExpression *>(it)) {
-        nameIds.append(m->name);
-        locations.append(m->identifierToken);
-        it = m->base;
-    }
-
-    if (AST::IdentifierExpression *idExpr = AST::cast<AST::IdentifierExpression *>(it)) {
-        AST::UiQualifiedId *q = new (pool) AST::UiQualifiedId(idExpr->name);
-        q->identifierToken = idExpr->identifierToken;
-
-        AST::UiQualifiedId *currentId = q;
-        for (int i = nameIds.size() - 1; i != -1; --i) {
-            currentId = new (pool) AST::UiQualifiedId(currentId, nameIds[i]);
-            currentId->identifierToken = locations[i];
-        }
-
-        return currentId->finish();
-    }
-
-    return 0;
-}
-
-AST::UiQualifiedPragmaId *Parser::reparseAsQualifiedPragmaId(AST::ExpressionNode *expr)
-{
-    if (AST::IdentifierExpression *idExpr = AST::cast<AST::IdentifierExpression *>(expr)) {
-        AST::UiQualifiedPragmaId *q = new (pool) AST::UiQualifiedPragmaId(idExpr->name);
-        q->identifierToken = idExpr->identifierToken;
-
-        return q->finish();
-    }
-
-    return 0;
-}
-
-
-bool Parser::parse(int startToken)
-{
-    Lexer *lexer = driver->lexer();
-    bool hadErrors = false;
-    int yytoken = -1;
-    int action = 0;
-
-    token_buffer[0].token = startToken;
-    first_token = &token_buffer[0];
-    if (startToken == T_FEED_JS_PROGRAM && !lexer->qmlMode()) {
-        Directives ignoreDirectives;
-        Directives *directives = driver->directives();
-        if (!directives)
-            directives = &ignoreDirectives;
-        DiagnosticMessage error;
-        if (!lexer->scanDirectives(directives, &error)) {
-            diagnostic_messages.append(error);
-            return false;
-        }
-        token_buffer[1].token = lexer->tokenKind();
-        token_buffer[1].dval = lexer->tokenValue();
-        token_buffer[1].loc = location(lexer);
-        token_buffer[1].spell = lexer->tokenSpell();
-        last_token = &token_buffer[2];
-    } else {
-        last_token = &token_buffer[1];
-    }
-
-    tos = -1;
-    program = 0;
-
-    do {
-        if (++tos == stack_size)
-            reallocateStack();
-
-        state_stack[tos] = action;
-
-    _Lcheck_token:
-        if (yytoken == -1 && -TERMINAL_COUNT != action_index[action]) {
-            yyprevlloc = yylloc;
-
-            if (first_token == last_token) {
-                yytoken = lexer->lex();
-                yylval = lexer->tokenValue();
-                yytokenspell = lexer->tokenSpell();
-                yylloc = location(lexer);
-            } else {
-                yytoken = first_token->token;
-                yylval = first_token->dval;
-                yytokenspell = first_token->spell;
-                yylloc = first_token->loc;
-                ++first_token;
-            }
-        }
-
-        action = t_action(action, yytoken);
-        if (action > 0) {
-            if (action != ACCEPT_STATE) {
-                yytoken = -1;
-                sym(1).dval = yylval;
-                stringRef(1) = yytokenspell;
-                loc(1) = yylloc;
-            } else {
-              --tos;
-              return ! hadErrors;
-            }
-        } else if (action < 0) {
-          const int r = -action - 1;
-          tos -= rhs[r];
-
-          switch (r) {
-
-case 0: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
-
-case 1: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
-
-case 2: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
-
-case 3: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
-
-case 4: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
-
-case 5: {
-  sym(1).Node = sym(2).Node;
-  program = sym(1).Node;
-} break;
-
-case 6: {
-  sym(1).UiProgram = new (pool) AST::UiProgram(sym(1).UiHeaderItemList,
-        sym(2).UiObjectMemberList->finish());
-} break;
-
-case 8: {
-    sym(1).Node = sym(1).UiHeaderItemList->finish();
-} break;
-
-case 9: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiPragma);
-} break;
-
-case 10: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiImport);
-} break;
-
-case 11: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiHeaderItemList, sym(2).UiPragma);
-} break;
-
-case 12: {
-    sym(1).Node = new (pool) AST::UiHeaderItemList(sym(1).UiHeaderItemList, sym(2).UiImport);
-} break;
-
-case 16: {
-    sym(1).UiPragma->semicolonToken = loc(2);
-} break;
-
-case 18: {
-    sym(1).UiImport->semicolonToken = loc(2);
-} break;
-
-case 20: {
-    sym(1).UiImport->versionToken = loc(2);
-    sym(1).UiImport->semicolonToken = loc(3);
-} break;
-
-case 22: {
-    sym(1).UiImport->versionToken = loc(2);
-    sym(1).UiImport->asToken = loc(3);
-    sym(1).UiImport->importIdToken = loc(4);
-    sym(1).UiImport->importId = stringRef(4);
-    sym(1).UiImport->semicolonToken = loc(5);
-} break;
-
-case 24: {
-    sym(1).UiImport->asToken = loc(2);
-    sym(1).UiImport->importIdToken = loc(3);
-    sym(1).UiImport->importId = stringRef(3);
-    sym(1).UiImport->semicolonToken = loc(4);
-} break;
-
-case 25: {
-    AST::UiPragma *node = 0;
-
-    if (AST::UiQualifiedPragmaId *qualifiedId = reparseAsQualifiedPragmaId(sym(2).Expression)) {
-        node = new (pool) AST::UiPragma(qualifiedId);
-    }
-
-    sym(1).Node = node;
-
-    if (node) {
-        node->pragmaToken = loc(1);
-    } else {
-       diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
-         QLatin1String("Expected a qualified name id")));
-
-        return false; // ### remove me
-    }
-} break;
-
-case 26: {
-    AST::UiImport *node = 0;
-
-    if (AST::StringLiteral *importIdLiteral = AST::cast<AST::StringLiteral *>(sym(2).Expression)) {
-        node = new (pool) AST::UiImport(importIdLiteral->value);
-        node->fileNameToken = loc(2);
-    } else if (AST::UiQualifiedId *qualifiedId = reparseAsQualifiedId(sym(2).Expression)) {
-        node = new (pool) AST::UiImport(qualifiedId);
-        node->fileNameToken = loc(2);
-    }
-
-    sym(1).Node = node;
-
-    if (node) {
-        node->importToken = loc(1);
-    } else {
-       diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
-         QLatin1String("Expected a qualified name id or a string literal")));
-
-        return false; // ### remove me
-    }
-} break;
-
-case 27: {
-    sym(1).Node = 0;
-} break;
-
-case 28: {
-    sym(1).Node = new (pool) AST::UiObjectMemberList(sym(1).UiObjectMember);
-} break;
-
-case 29: {
-    sym(1).Node = new (pool) AST::UiObjectMemberList(sym(1).UiObjectMember);
-} break;
-
-case 30: {
-    AST::UiObjectMemberList *node = new (pool) AST:: UiObjectMemberList(
-        sym(1).UiObjectMemberList, sym(2).UiObjectMember);
-    sym(1).Node = node;
-} break;
-
-case 31: {
-    sym(1).Node = new (pool) AST::UiArrayMemberList(sym(1).UiObjectMember);
-} break;
-
-case 32: {
-    AST::UiArrayMemberList *node = new (pool) AST::UiArrayMemberList(
-        sym(1).UiArrayMemberList, sym(3).UiObjectMember);
-    node->commaToken = loc(2);
-    sym(1).Node = node;
-} break;
-
-case 33: {
-    AST::UiObjectInitializer *node = new (pool) AST::UiObjectInitializer((AST::UiObjectMemberList*)0);
-    node->lbraceToken = loc(1);
-    node->rbraceToken = loc(2);
-    sym(1).Node = node;
-}   break;
-
-case 34: {
-    AST::UiObjectInitializer *node = new (pool) AST::UiObjectInitializer(sym(2).UiObjectMemberList->finish());
-    node->lbraceToken = loc(1);
-    node->rbraceToken = loc(3);
-    sym(1).Node = node;
-}   break;
-
-case 35: {
-    AST::UiObjectDefinition *node = new (pool) AST::UiObjectDefinition(sym(1).UiQualifiedId,
-        sym(2).UiObjectInitializer);
-    sym(1).Node = node;
-}   break;
-
-case 37: {
-    AST::UiArrayBinding *node = new (pool) AST::UiArrayBinding(
-        sym(1).UiQualifiedId, sym(4).UiArrayMemberList->finish());
-    node->colonToken = loc(2);
-    node->lbracketToken = loc(3);
-    node->rbracketToken = loc(5);
-    sym(1).Node = node;
-}   break;
-
-case 38: {
-    AST::UiObjectBinding *node = new (pool) AST::UiObjectBinding(
-      sym(1).UiQualifiedId, sym(3).UiQualifiedId, sym(4).UiObjectInitializer);
-    node->colonToken = loc(2);
-    sym(1).Node = node;
-} break;
-
-case 39: {
-    AST::UiObjectBinding *node = new (pool) AST::UiObjectBinding(
-      sym(3).UiQualifiedId, sym(1).UiQualifiedId, sym(4).UiObjectInitializer);
-    node->colonToken = loc(2);
-    node->hasOnToken = true;
-    sym(1).Node = node;
-} break;
-
-case 47:
-{
-    AST::UiScriptBinding *node = new (pool) AST::UiScriptBinding(
-        sym(1).UiQualifiedId, sym(3).Statement);
-    node->colonToken = loc(2);
-    sym(1).Node = node;
-}   break;
-
-case 48: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 49: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 50: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 51: {
-  AST::UiQualifiedId *node = new (pool) AST::UiQualifiedId(sym(1).UiQualifiedId, stringRef(3));
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 52: {
-  sym(1).Node = 0;
-} break;
-
-case 53: {
-  sym(1).Node = sym(1).UiParameterList->finish ();
-} break;
-
-case 54: {
-  AST::UiParameterList *node = new (pool) AST::UiParameterList(sym(1).UiQualifiedId->finish(), stringRef(2));
-  node->propertyTypeToken = loc(1);
-  node->identifierToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 55: {
-  AST::UiParameterList *node = new (pool) AST::UiParameterList(sym(1).UiParameterList, sym(3).UiQualifiedId->finish(), stringRef(4));
-  node->propertyTypeToken = loc(3);
-  node->commaToken = loc(2);
-  node->identifierToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 57: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(nullptr, stringRef(2));
-    node->type = AST::UiPublicMember::Signal;
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(2);
-    node->parameters = sym(4).UiParameterList;
-    node->semicolonToken = loc(6);
-    sym(1).Node = node;
-}   break;
-
-case 59: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(nullptr, stringRef(2));
-    node->type = AST::UiPublicMember::Signal;
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(2);
-    node->semicolonToken = loc(3);
-    sym(1).Node = node;
-}   break;
-
-case 61: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
-    node->typeModifier = stringRef(2);
-    node->propertyToken = loc(1);
-    node->typeModifierToken = loc(2);
-    node->typeToken = loc(4);
-    node->identifierToken = loc(6);
-    node->semicolonToken = loc(7);
-    sym(1).Node = node;
-}   break;
-
-case 63: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(3);
-    node->semicolonToken = loc(4);
-    sym(1).Node = node;
-}   break;
-
-case 65: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
-    node->isDefaultMember = true;
-    node->defaultToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->semicolonToken = loc(5);
-    sym(1).Node = node;
-}   break;
-
-case 67: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(5).UiQualifiedId->finish(), stringRef(7));
-    node->isDefaultMember = true;
-    node->defaultToken = loc(1);
-    node->typeModifier = stringRef(3);
-    node->propertyToken = loc(2);
-    node->typeModifierToken = loc(2);
-    node->typeToken = loc(4);
-    node->identifierToken = loc(7);
-    node->semicolonToken = loc(8);
-    sym(1).Node = node;
-}   break;
-
-case 68: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3),
-        sym(5).Statement);
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(3);
-    node->colonToken = loc(4);
-    sym(1).Node = node;
-}   break;
-
-case 69: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4),
-        sym(6).Statement);
-    node->isReadonlyMember = true;
-    node->readonlyToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->colonToken = loc(5);
-    sym(1).Node = node;
-}   break;
-
-case 70: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4),
-        sym(6).Statement);
-    node->isDefaultMember = true;
-    node->defaultToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->colonToken = loc(5);
-    sym(1).Node = node;
-}   break;
-
-case 71: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(4).UiQualifiedId->finish(), stringRef(6));
-    node->typeModifier = stringRef(2);
-    node->propertyToken = loc(1);
-    node->typeModifierToken = loc(2);
-    node->typeToken = loc(4);
-    node->identifierToken = loc(6);
-    node->semicolonToken = loc(7); // insert a fake ';' before ':'
-
-    AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(6));
-    propertyName->identifierToken = loc(6);
-    propertyName->next = 0;
-
-    AST::UiArrayBinding *binding = new (pool) AST::UiArrayBinding(
-        propertyName, sym(9).UiArrayMemberList->finish());
-    binding->colonToken = loc(7);
-    binding->lbracketToken = loc(8);
-    binding->rbracketToken = loc(10);
-
-    node->binding = binding;
-
-    sym(1).Node = node;
-}   break;
-
-case 72: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(2).UiQualifiedId->finish(), stringRef(3));
-    node->propertyToken = loc(1);
-    node->typeToken = loc(2);
-    node->identifierToken = loc(3);
-    node->semicolonToken = loc(4); // insert a fake ';' before ':'
-
-    AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(3));
-    propertyName->identifierToken = loc(3);
-    propertyName->next = 0;
-
-    AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
-      propertyName, sym(5).UiQualifiedId, sym(6).UiObjectInitializer);
-    binding->colonToken = loc(4);
-
-    node->binding = binding;
-
-    sym(1).Node = node;
-}   break;
-
-case 73: {
-    AST::UiPublicMember *node = new (pool) AST::UiPublicMember(sym(3).UiQualifiedId->finish(), stringRef(4));
-    node->isReadonlyMember = true;
-    node->readonlyToken = loc(1);
-    node->propertyToken = loc(2);
-    node->typeToken = loc(3);
-    node->identifierToken = loc(4);
-    node->semicolonToken = loc(5); // insert a fake ';' before ':'
-
-    AST::UiQualifiedId *propertyName = new (pool) AST::UiQualifiedId(stringRef(4));
-    propertyName->identifierToken = loc(4);
-    propertyName->next = 0;
-
-    AST::UiObjectBinding *binding = new (pool) AST::UiObjectBinding(
-      propertyName, sym(6).UiQualifiedId, sym(7).UiObjectInitializer);
-    binding->colonToken = loc(5);
-
-    node->binding = binding;
-
-    sym(1).Node = node;
-}   break;
-
-case 74: {
-    sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
-}   break;
-
-case 75: {
-    sym(1).Node = new (pool) AST::UiSourceElement(sym(1).Node);
-}   break;
-
-case 83: {
-  AST::ThisExpression *node = new (pool) AST::ThisExpression();
-  node->thisToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 84: {
-  AST::IdentifierExpression *node = new (pool) AST::IdentifierExpression(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 85: {
-  AST::NullExpression *node = new (pool) AST::NullExpression();
-  node->nullToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 86: {
-  AST::TrueLiteral *node = new (pool) AST::TrueLiteral();
-  node->trueToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 87: {
-  AST::FalseLiteral *node = new (pool) AST::FalseLiteral();
-  node->falseToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 88: {
-  AST::NumericLiteral *node = new (pool) AST::NumericLiteral(sym(1).dval);
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
-case 89:
-case 90: {
-  AST::StringLiteral *node = new (pool) AST::StringLiteral(stringRef(1));
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 91: {
-  bool rx = lexer->scanRegExp(Lexer::NoPrefix);
-  if (!rx) {
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location(lexer), lexer->errorMessage()));
-    return false; // ### remove me
-  }
-
-  loc(1).length = lexer->tokenLength();
-  yylloc = loc(1); // adjust the location of the current token
-
-  AST::RegExpLiteral *node = new (pool) AST::RegExpLiteral(
-    driver->newStringRef(lexer->regExpPattern()), lexer->regExpFlags());
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 92: {
-  bool rx = lexer->scanRegExp(Lexer::EqualPrefix);
-  if (!rx) {
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, location(lexer), lexer->errorMessage()));
-    return false;
-  }
-
-  loc(1).length = lexer->tokenLength();
-  yylloc = loc(1); // adjust the location of the current token
-
-  AST::RegExpLiteral *node = new (pool) AST::RegExpLiteral(
-    driver->newStringRef(lexer->regExpPattern()), lexer->regExpFlags());
-  node->literalToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 93: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral((AST::Elision *) 0);
-  node->lbracketToken = loc(1);
-  node->rbracketToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 94: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).Elision->finish());
-  node->lbracketToken = loc(1);
-  node->rbracketToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 95: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).ElementList->finish ());
-  node->lbracketToken = loc(1);
-  node->rbracketToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 96: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).ElementList->finish (),
-    (AST::Elision *) 0);
-  node->lbracketToken = loc(1);
-  node->commaToken = loc(3);
-  node->rbracketToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 97: {
-  AST::ArrayLiteral *node = new (pool) AST::ArrayLiteral(sym(2).ElementList->finish (),
-    sym(4).Elision->finish());
-  node->lbracketToken = loc(1);
-  node->commaToken = loc(3);
-  node->rbracketToken = loc(5);
-  sym(1).Node = node;
-} break;
-
-case 98: {
-  AST::ObjectLiteral *node = 0;
-  if (sym(2).Node)
-    node = new (pool) AST::ObjectLiteral(
-        sym(2).PropertyAssignmentList->finish ());
-  else
-    node = new (pool) AST::ObjectLiteral();
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 99: {
-  AST::ObjectLiteral *node = new (pool) AST::ObjectLiteral(
-    sym(2).PropertyAssignmentList->finish ());
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 100: {
-  AST::NestedExpression *node = new (pool) AST::NestedExpression(sym(2).Expression);
-  node->lparenToken = loc(1);
-  node->rparenToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 101: {
-  if (AST::ArrayMemberExpression *mem = AST::cast<AST::ArrayMemberExpression *>(sym(1).Expression)) {
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Warning, mem->lbracketToken,
-      QLatin1String("Ignored annotation")));
-
-    sym(1).Expression = mem->base;
-  }
-
-  if (AST::UiQualifiedId *qualifiedId = reparseAsQualifiedId(sym(1).Expression)) {
-    sym(1).UiQualifiedId = qualifiedId;
-  } else {
-    sym(1).UiQualifiedId = 0;
-
-    diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, loc(1),
-      QLatin1String("Expected a qualified name id")));
-
-    return false; // ### recover
-  }
-} break;
-
-case 102: {
-  sym(1).Node = new (pool) AST::ElementList((AST::Elision *) 0, sym(1).Expression);
-} break;
-
-case 103: {
-  sym(1).Node = new (pool) AST::ElementList(sym(1).Elision->finish(), sym(2).Expression);
-} break;
-
-case 104: {
-  AST::ElementList *node = new (pool) AST::ElementList(sym(1).ElementList,
-    (AST::Elision *) 0, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 105: {
-  AST::ElementList *node = new (pool) AST::ElementList(sym(1).ElementList, sym(3).Elision->finish(),
-    sym(4).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 106: {
-  AST::Elision *node = new (pool) AST::Elision();
-  node->commaToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 107: {
-  AST::Elision *node = new (pool) AST::Elision(sym(1).Elision);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 108: {
-  AST::PropertyNameAndValue *node = new (pool) AST::PropertyNameAndValue(
-      sym(1).PropertyName, sym(3).Expression);
-  node->colonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 109: {
-  AST::PropertyGetterSetter *node = new (pool) AST::PropertyGetterSetter(
-      sym(2).PropertyName, sym(6).FunctionBody);
-  node->getSetToken = loc(1);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(4);
-  node->lbraceToken = loc(5);
-  node->rbraceToken = loc(7);
-  sym(1).Node = node;
-} break;
-
-case 110: {
-  AST::PropertyGetterSetter *node = new (pool) AST::PropertyGetterSetter(
-      sym(2).PropertyName, sym(4).FormalParameterList, sym(7).FunctionBody);
-  node->getSetToken = loc(1);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  node->lbraceToken = loc(6);
-  node->rbraceToken = loc(8);
-  sym(1).Node = node;
-} break;
-
-case 111: {
-  sym(1).Node = new (pool) AST::PropertyAssignmentList(sym(1).PropertyAssignment);
-} break;
-
-case 112: {
-  AST::PropertyAssignmentList *node = new (pool) AST::PropertyAssignmentList(
-    sym(1).PropertyAssignmentList, sym(3).PropertyAssignment);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 113: {
-  AST::IdentifierPropertyName *node = new (pool) AST::IdentifierPropertyName(stringRef(1));
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 114: {
-  AST::StringLiteralPropertyName *node = new (pool) AST::StringLiteralPropertyName(stringRef(1));
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 115: {
-  AST::NumericLiteralPropertyName *node = new (pool) AST::NumericLiteralPropertyName(sym(1).dval);
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 116: {
-  AST::IdentifierPropertyName *node = new (pool) AST::IdentifierPropertyName(stringRef(1));
-  node->propertyNameToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 153: {
-  AST::ArrayMemberExpression *node = new (pool) AST::ArrayMemberExpression(sym(1).Expression, sym(3).Expression);
-  node->lbracketToken = loc(2);
-  node->rbracketToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 154: {
-  AST::FieldMemberExpression *node = new (pool) AST::FieldMemberExpression(sym(1).Expression, stringRef(3));
-  node->dotToken = loc(2);
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 155: {
-  AST::NewMemberExpression *node = new (pool) AST::NewMemberExpression(sym(2).Expression, sym(4).ArgumentList);
-  node->newToken = loc(1);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  sym(1).Node = node;
-} break;
-
-case 157: {
-  AST::NewExpression *node = new (pool) AST::NewExpression(sym(2).Expression);
-  node->newToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 158: {
-  AST::CallExpression *node = new (pool) AST::CallExpression(sym(1).Expression, sym(3).ArgumentList);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 159: {
-  AST::CallExpression *node = new (pool) AST::CallExpression(sym(1).Expression, sym(3).ArgumentList);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 160: {
-  AST::ArrayMemberExpression *node = new (pool) AST::ArrayMemberExpression(sym(1).Expression, sym(3).Expression);
-  node->lbracketToken = loc(2);
-  node->rbracketToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 161: {
-  AST::FieldMemberExpression *node = new (pool) AST::FieldMemberExpression(sym(1).Expression, stringRef(3));
-  node->dotToken = loc(2);
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 162: {
-  sym(1).Node = 0;
-} break;
-
-case 163: {
-  sym(1).Node = sym(1).ArgumentList->finish();
-} break;
-
-case 164: {
-  sym(1).Node = new (pool) AST::ArgumentList(sym(1).Expression);
-} break;
-
-case 165: {
-  AST::ArgumentList *node = new (pool) AST::ArgumentList(sym(1).ArgumentList, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 169: {
-  AST::PostIncrementExpression *node = new (pool) AST::PostIncrementExpression(sym(1).Expression);
-  node->incrementToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 170: {
-  AST::PostDecrementExpression *node = new (pool) AST::PostDecrementExpression(sym(1).Expression);
-  node->decrementToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 172: {
-  AST::DeleteExpression *node = new (pool) AST::DeleteExpression(sym(2).Expression);
-  node->deleteToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 173: {
-  AST::VoidExpression *node = new (pool) AST::VoidExpression(sym(2).Expression);
-  node->voidToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 174: {
-  AST::TypeOfExpression *node = new (pool) AST::TypeOfExpression(sym(2).Expression);
-  node->typeofToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 175: {
-  AST::PreIncrementExpression *node = new (pool) AST::PreIncrementExpression(sym(2).Expression);
-  node->incrementToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 176: {
-  AST::PreDecrementExpression *node = new (pool) AST::PreDecrementExpression(sym(2).Expression);
-  node->decrementToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 177: {
-  AST::UnaryPlusExpression *node = new (pool) AST::UnaryPlusExpression(sym(2).Expression);
-  node->plusToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 178: {
-  AST::UnaryMinusExpression *node = new (pool) AST::UnaryMinusExpression(sym(2).Expression);
-  node->minusToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 179: {
-  AST::TildeExpression *node = new (pool) AST::TildeExpression(sym(2).Expression);
-  node->tildeToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 180: {
-  AST::NotExpression *node = new (pool) AST::NotExpression(sym(2).Expression);
-  node->notToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 182: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Mul, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 183: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Div, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 184: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Mod, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 186: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Add, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 187: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Sub, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 189: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::LShift, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 190: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::RShift, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 191: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::URShift, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 193: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Lt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 194: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Gt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 195: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Le, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 196: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Ge, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 197: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::InstanceOf, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 198: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::In, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 200: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Lt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 201: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Gt, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 202: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Le, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 203: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-   QSOperator::Ge, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 204: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::InstanceOf, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 206: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Equal, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 207: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::NotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 208: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 209: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictNotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 211: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Equal, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 212: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::NotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 213: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 214: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::StrictNotEqual, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 216: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitAnd, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 218: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitAnd, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 220: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitXor, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 222: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitXor, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 224: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitOr, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 226: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::BitOr, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 228: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::And, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 230: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::And, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 232: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Or, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 234: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    QSOperator::Or, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 236: {
-  AST::ConditionalExpression *node = new (pool) AST::ConditionalExpression(sym(1).Expression,
-    sym(3).Expression, sym(5).Expression);
-  node->questionToken = loc(2);
-  node->colonToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 238: {
-  AST::ConditionalExpression *node = new (pool) AST::ConditionalExpression(sym(1).Expression,
-    sym(3).Expression, sym(5).Expression);
-  node->questionToken = loc(2);
-  node->colonToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 240: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    sym(2).ival, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 242: {
-  AST::BinaryExpression *node = new (pool) AST::BinaryExpression(sym(1).Expression,
-    sym(2).ival, sym(3).Expression);
-  node->operatorToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 243: {
-  sym(1).ival = QSOperator::Assign;
-} break;
-
-case 244: {
-  sym(1).ival = QSOperator::InplaceMul;
-} break;
-
-case 245: {
-  sym(1).ival = QSOperator::InplaceDiv;
-} break;
-
-case 246: {
-  sym(1).ival = QSOperator::InplaceMod;
-} break;
-
-case 247: {
-  sym(1).ival = QSOperator::InplaceAdd;
-} break;
-
-case 248: {
-  sym(1).ival = QSOperator::InplaceSub;
-} break;
-
-case 249: {
-  sym(1).ival = QSOperator::InplaceLeftShift;
-} break;
-
-case 250: {
-  sym(1).ival = QSOperator::InplaceRightShift;
-} break;
-
-case 251: {
-  sym(1).ival = QSOperator::InplaceURightShift;
-} break;
-
-case 252: {
-  sym(1).ival = QSOperator::InplaceAnd;
-} break;
-
-case 253: {
-  sym(1).ival = QSOperator::InplaceXor;
-} break;
-
-case 254: {
-  sym(1).ival = QSOperator::InplaceOr;
-} break;
-
-case 256: {
-  AST::Expression *node = new (pool) AST::Expression(sym(1).Expression, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 257: {
-  sym(1).Node = 0;
-} break;
-
-case 260: {
-  AST::Expression *node = new (pool) AST::Expression(sym(1).Expression, sym(3).Expression);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 261: {
-  sym(1).Node = 0;
-} break;
-
-case 278: {
-  AST::Block *node = new (pool) AST::Block(sym(2).StatementList);
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 279: {
-  sym(1).Node = new (pool) AST::StatementList(sym(1).Statement);
-} break;
-
-case 280: {
-  sym(1).Node = new (pool) AST::StatementList(sym(1).StatementList, sym(2).Statement);
-} break;
-
-case 281: {
-  sym(1).Node = 0;
-} break;
-
-case 282: {
-  sym(1).Node = sym(1).StatementList->finish ();
-} break;
-
-case 284: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  if (sym(1).ival == T_LET)
-    s = AST::VariableDeclaration::BlockScope;
-  else if (sym(1).ival == T_CONST)
-    s = AST::VariableDeclaration::ReadOnlyBlockScope;
-
-  AST::VariableStatement *node = new (pool) AST::VariableStatement(sym(2).VariableDeclarationList->finish(s));
-  node->declarationKindToken = loc(1);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 285: {
-  sym(1).ival = T_LET;
-} break;
-
-case 286: {
-  sym(1).ival = T_CONST;
-} break;
-
-case 287: {
-  sym(1).ival = T_VAR;
-} break;
-
-case 288: {
-  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclaration);
-} break;
-
-case 289: {
-  AST::VariableDeclarationList *node = new (pool) AST::VariableDeclarationList(
-    sym(1).VariableDeclarationList, sym(3).VariableDeclaration);
-  node->commaToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 290: {
-  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclaration);
-} break;
-
-case 291: {
-  sym(1).Node = new (pool) AST::VariableDeclarationList(sym(1).VariableDeclarationList, sym(3).VariableDeclaration);
-} break;
-
-case 292: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  AST::VariableDeclaration *node = new (pool) AST::VariableDeclaration(stringRef(1), sym(2).Expression, s);
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 293: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  AST::VariableDeclaration *node = new (pool) AST::VariableDeclaration(stringRef(1), sym(2).Expression, s);
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 294: {
-  // ### TODO: AST for initializer
-  sym(1) = sym(2);
-} break;
-
-case 295: {
-  sym(1).Node = 0;
-} break;
-
-case 297: {
-  // ### TODO: AST for initializer
-  sym(1) = sym(2);
-} break;
-
-case 298: {
-  sym(1).Node = 0;
-} break;
-
-case 300: {
-  AST::EmptyStatement *node = new (pool) AST::EmptyStatement();
-  node->semicolonToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 302: {
-  AST::ExpressionStatement *node = new (pool) AST::ExpressionStatement(sym(1).Expression);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 303: {
-  AST::IfStatement *node = new (pool) AST::IfStatement(sym(3).Expression, sym(5).Statement, sym(7).Statement);
-  node->ifToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  node->elseToken = loc(6);
-  sym(1).Node = node;
-} break;
-
-case 304: {
-  AST::IfStatement *node = new (pool) AST::IfStatement(sym(3).Expression, sym(5).Statement);
-  node->ifToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 307: {
-  AST::DoWhileStatement *node = new (pool) AST::DoWhileStatement(sym(2).Statement, sym(5).Expression);
-  node->doToken = loc(1);
-  node->whileToken = loc(3);
-  node->lparenToken = loc(4);
-  node->rparenToken = loc(6);
-  node->semicolonToken = loc(7);
-  sym(1).Node = node;
-} break;
-
-case 308: {
-  AST::WhileStatement *node = new (pool) AST::WhileStatement(sym(3).Expression, sym(5).Statement);
-  node->whileToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 309: {
-  AST::ForStatement *node = new (pool) AST::ForStatement(sym(3).Expression,
-    sym(5).Expression, sym(7).Expression, sym(9).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->firstSemicolonToken = loc(4);
-  node->secondSemicolonToken = loc(6);
-  node->rparenToken = loc(8);
-  sym(1).Node = node;
-} break;
-
-case 310: {
-  AST::VariableDeclaration::VariableScope s = AST::VariableDeclaration::FunctionScope;
-  AST::LocalForStatement *node = new (pool) AST::LocalForStatement(
-     sym(4).VariableDeclarationList->finish(s), sym(6).Expression,
-     sym(8).Expression, sym(10).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->varToken = loc(3);
-  node->firstSemicolonToken = loc(5);
-  node->secondSemicolonToken = loc(7);
-  node->rparenToken = loc(9);
-  sym(1).Node = node;
-} break;
-
-case 311: {
-  AST:: ForEachStatement *node = new (pool) AST::ForEachStatement(sym(3).Expression,
-    sym(5).Expression, sym(7).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->inToken = loc(4);
-  node->rparenToken = loc(6);
-  sym(1).Node = node;
-} break;
-
-case 312: {
-  AST::LocalForEachStatement *node = new (pool) AST::LocalForEachStatement(
-    sym(4).VariableDeclaration, sym(6).Expression, sym(8).Statement);
-  node->forToken = loc(1);
-  node->lparenToken = loc(2);
-  node->varToken = loc(3);
-  node->inToken = loc(5);
-  node->rparenToken = loc(7);
-  sym(1).Node = node;
-} break;
-
-case 314: {
-  AST::ContinueStatement *node = new (pool) AST::ContinueStatement();
-  node->continueToken = loc(1);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 316: {
-  AST::ContinueStatement *node = new (pool) AST::ContinueStatement(stringRef(2));
-  node->continueToken = loc(1);
-  node->identifierToken = loc(2);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 318: {
-  AST::BreakStatement *node = new (pool) AST::BreakStatement(QStringRef());
-  node->breakToken = loc(1);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 320: {
-  AST::BreakStatement *node = new (pool) AST::BreakStatement(stringRef(2));
-  node->breakToken = loc(1);
-  node->identifierToken = loc(2);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 322: {
-  AST::ReturnStatement *node = new (pool) AST::ReturnStatement(sym(2).Expression);
-  node->returnToken = loc(1);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 323: {
-  AST::WithStatement *node = new (pool) AST::WithStatement(sym(3).Expression, sym(5).Statement);
-  node->withToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 324: {
-  AST::SwitchStatement *node = new (pool) AST::SwitchStatement(sym(3).Expression, sym(5).CaseBlock);
-  node->switchToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 325: {
-  AST::CaseBlock *node = new (pool) AST::CaseBlock(sym(2).CaseClauses);
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 326: {
-  AST::CaseBlock *node = new (pool) AST::CaseBlock(sym(2).CaseClauses, sym(3).DefaultClause, sym(4).CaseClauses);
-  node->lbraceToken = loc(1);
-  node->rbraceToken = loc(5);
-  sym(1).Node = node;
-} break;
-
-case 327: {
-  sym(1).Node = new (pool) AST::CaseClauses(sym(1).CaseClause);
-} break;
-
-case 328: {
-  sym(1).Node = new (pool) AST::CaseClauses(sym(1).CaseClauses, sym(2).CaseClause);
-} break;
-
-case 329: {
-  sym(1).Node = 0;
-} break;
-
-case 330: {
-  sym(1).Node = sym(1).CaseClauses->finish ();
-} break;
-
-case 331: {
-  AST::CaseClause *node = new (pool) AST::CaseClause(sym(2).Expression, sym(4).StatementList);
-  node->caseToken = loc(1);
-  node->colonToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 332: {
-  AST::DefaultClause *node = new (pool) AST::DefaultClause(sym(3).StatementList);
-  node->defaultToken = loc(1);
-  node->colonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 333: {
-  AST::LabelledStatement *node = new (pool) AST::LabelledStatement(stringRef(1), sym(3).Statement);
-  node->identifierToken = loc(1);
-  node->colonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 335: {
-  AST::ThrowStatement *node = new (pool) AST::ThrowStatement(sym(2).Expression);
-  node->throwToken = loc(1);
-  node->semicolonToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 336: {
-  AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Catch);
-  node->tryToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 337: {
-  AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Finally);
-  node->tryToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 338: {
-  AST::TryStatement *node = new (pool) AST::TryStatement(sym(2).Statement, sym(3).Catch, sym(4).Finally);
-  node->tryToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 339: {
-  AST::Catch *node = new (pool) AST::Catch(stringRef(3), sym(5).Block);
-  node->catchToken = loc(1);
-  node->lparenToken = loc(2);
-  node->identifierToken = loc(3);
-  node->rparenToken = loc(4);
-  sym(1).Node = node;
-} break;
-
-case 340: {
-  AST::Finally *node = new (pool) AST::Finally(sym(2).Block);
-  node->finallyToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 342: {
-  AST::DebuggerStatement *node = new (pool) AST::DebuggerStatement();
-  node->debuggerToken = loc(1);
-  node->semicolonToken = loc(2);
-  sym(1).Node = node;
-} break;
-
-case 344: {
-  AST::FunctionDeclaration *node = new (pool) AST::FunctionDeclaration(stringRef(2), sym(4).FormalParameterList, sym(7).FunctionBody);
-  node->functionToken = loc(1);
-  node->identifierToken = loc(2);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  node->lbraceToken = loc(6);
-  node->rbraceToken = loc(8);
-  sym(1).Node = node;
-} break;
-
-case 345: {
-  AST::FunctionExpression *node = new (pool) AST::FunctionExpression(stringRef(2), sym(4).FormalParameterList, sym(7).FunctionBody);
-  node->functionToken = loc(1);
-  if (! stringRef(2).isNull())
-      node->identifierToken = loc(2);
-  node->lparenToken = loc(3);
-  node->rparenToken = loc(5);
-  node->lbraceToken = loc(6);
-  node->rbraceToken = loc(8);
-  sym(1).Node = node;
-} break;
-
-case 346: {
-  AST::FunctionExpression *node = new (pool) AST::FunctionExpression(QStringRef(), sym(3).FormalParameterList, sym(6).FunctionBody);
-  node->functionToken = loc(1);
-  node->lparenToken = loc(2);
-  node->rparenToken = loc(4);
-  node->lbraceToken = loc(5);
-  node->rbraceToken = loc(7);
-  sym(1).Node = node;
-} break;
-
-case 347: {
-  AST::FormalParameterList *node = new (pool) AST::FormalParameterList(stringRef(1));
-  node->identifierToken = loc(1);
-  sym(1).Node = node;
-} break;
-
-case 348: {
-  AST::FormalParameterList *node = new (pool) AST::FormalParameterList(sym(1).FormalParameterList, stringRef(3));
-  node->commaToken = loc(2);
-  node->identifierToken = loc(3);
-  sym(1).Node = node;
-} break;
-
-case 349: {
-  sym(1).Node = 0;
-} break;
-
-case 350: {
-  sym(1).Node = sym(1).FormalParameterList->finish ();
-} break;
-
-case 351: {
-  sym(1).Node = 0;
-} break;
-
-case 353: {
-  sym(1).Node = new (pool) AST::FunctionBody(sym(1).SourceElements->finish ());
-} break;
-
-case 355: {
-  sym(1).Node = new (pool) AST::Program(sym(1).SourceElements->finish ());
-} break;
-
-case 356: {
-  sym(1).Node = new (pool) AST::SourceElements(sym(1).SourceElement);
-} break;
-
-case 357: {
-  sym(1).Node = new (pool) AST::SourceElements(sym(1).SourceElements, sym(2).SourceElement);
-} break;
-
-case 358: {
-  sym(1).Node = new (pool) AST::StatementSourceElement(sym(1).Statement);
-} break;
-
-case 359: {
-  sym(1).Node = new (pool) AST::FunctionSourceElement(sym(1).FunctionDeclaration);
-} break;
-
-case 360: {
-  sym(1).Node = 0;
-} break;
-
-            } // switch
-            action = nt_action(state_stack[tos], lhs[r] - TERMINAL_COUNT);
-        } // if
-    } while (action != 0);
-
-    if (first_token == last_token) {
-        const int errorState = state_stack[tos];
-
-        // automatic insertion of `;'
-        if (yytoken != -1 && ((t_action(errorState, T_AUTOMATIC_SEMICOLON) && lexer->canInsertAutomaticSemicolon(yytoken))
-                              || t_action(errorState, T_COMPATIBILITY_SEMICOLON))) {
-            SavedToken &tk = token_buffer[0];
-            tk.token = yytoken;
-            tk.dval = yylval;
-            tk.spell = yytokenspell;
-            tk.loc = yylloc;
-
-            yylloc = yyprevlloc;
-            yylloc.offset += yylloc.length;
-            yylloc.startColumn += yylloc.length;
-            yylloc.length = 0;
-
-            //const QString msg = QCoreApplication::translate("QQmlParser", "Missing `;'");
-            //diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Warning, yylloc, msg));
-
-            first_token = &token_buffer[0];
-            last_token = &token_buffer[1];
-
-            yytoken = T_SEMICOLON;
-            yylval = 0;
-
-            action = errorState;
-
-            goto _Lcheck_token;
-        }
-
-        hadErrors = true;
-
-        token_buffer[0].token = yytoken;
-        token_buffer[0].dval = yylval;
-        token_buffer[0].spell = yytokenspell;
-        token_buffer[0].loc = yylloc;
-
-        token_buffer[1].token = yytoken       = lexer->lex();
-        token_buffer[1].dval  = yylval        = lexer->tokenValue();
-        token_buffer[1].spell = yytokenspell  = lexer->tokenSpell();
-        token_buffer[1].loc   = yylloc        = location(lexer);
-
-        if (t_action(errorState, yytoken)) {
-            QString msg;
-            int token = token_buffer[0].token;
-            if (token < 0 || token >= TERMINAL_COUNT)
-                msg = QCoreApplication::translate("QQmlParser", "Syntax error");
-            else
-                msg = QCoreApplication::translate("QQmlParser", "Unexpected token `%1'").arg(QLatin1String(spell[token]));
-            diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
-
-            action = errorState;
-            goto _Lcheck_token;
-        }
-
-        static int tokens[] = {
-            T_PLUS,
-            T_EQ,
-
-            T_COMMA,
-            T_COLON,
-            T_SEMICOLON,
-
-            T_RPAREN, T_RBRACKET, T_RBRACE,
-
-            T_NUMERIC_LITERAL,
-            T_IDENTIFIER,
-
-            T_LPAREN, T_LBRACKET, T_LBRACE,
-
-            EOF_SYMBOL
-        };
-
-        for (int *tk = tokens; *tk != EOF_SYMBOL; ++tk) {
-            int a = t_action(errorState, *tk);
-            if (a > 0 && t_action(a, yytoken)) {
-                const QString msg = QCoreApplication::translate("QQmlParser", "Expected token `%1'").arg(QLatin1String(spell[*tk]));
-                diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
-
-                yytoken = *tk;
-                yylval = 0;
-                yylloc = token_buffer[0].loc;
-                yylloc.length = 0;
-
-                first_token = &token_buffer[0];
-                last_token = &token_buffer[2];
-
-                action = errorState;
-                goto _Lcheck_token;
-            }
-        }
-
-        for (int tk = 1; tk < TERMINAL_COUNT; ++tk) {
-            if (tk == T_AUTOMATIC_SEMICOLON || tk == T_FEED_UI_PROGRAM    ||
-                tk == T_FEED_JS_STATEMENT   || tk == T_FEED_JS_EXPRESSION ||
-                tk == T_FEED_JS_SOURCE_ELEMENT)
-               continue;
-
-            int a = t_action(errorState, tk);
-            if (a > 0 && t_action(a, yytoken)) {
-                const QString msg = QCoreApplication::translate("QQmlParser", "Expected token `%1'").arg(QLatin1String(spell[tk]));
-                diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
-
-                yytoken = tk;
-                yylval = 0;
-                yylloc = token_buffer[0].loc;
-                yylloc.length = 0;
-
-                action = errorState;
-                goto _Lcheck_token;
-            }
-        }
-
-        const QString msg = QCoreApplication::translate("QQmlParser", "Syntax error");
-        diagnostic_messages.append(DiagnosticMessage(DiagnosticMessage::Error, token_buffer[0].loc, msg));
-    }
-
-    return false;
-}
-
-QT_QML_END_NAMESPACE
-
-
diff --git a/src/qml/parser/qqmljsparser_p.h b/src/qml/parser/qqmljsparser_p.h
deleted file mode 100644
index f382cd7563..0000000000
--- a/src/qml/parser/qqmljsparser_p.h
+++ /dev/null
@@ -1,257 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is automatically generated from qqmljs.g.
-// Changes should be made to that file, not here. Any change to this file will
-// be lost!
-//
-// To regenerate this file, run:
-//    qlalr --no-debug --no-lines --qt qqmljs.g
-//
-
-#ifndef QQMLJSPARSER_P_H
-#define QQMLJSPARSER_P_H
-
-#include "qqmljsglobal_p.h"
-#include "qqmljsgrammar_p.h"
-#include "qqmljsast_p.h"
-#include "qqmljsengine_p.h"
-
-#include <QtCore/qlist.h>
-#include <QtCore/qstring.h>
-
-QT_QML_BEGIN_NAMESPACE
-
-namespace QQmlJS {
-
-class Engine;
-
-class QML_PARSER_EXPORT Parser: protected QQmlJSGrammar
-{
-public:
-    union Value {
-      int ival;
-      double dval;
-      AST::ArgumentList *ArgumentList;
-      AST::CaseBlock *CaseBlock;
-      AST::CaseClause *CaseClause;
-      AST::CaseClauses *CaseClauses;
-      AST::Catch *Catch;
-      AST::DefaultClause *DefaultClause;
-      AST::ElementList *ElementList;
-      AST::Elision *Elision;
-      AST::ExpressionNode *Expression;
-      AST::Finally *Finally;
-      AST::FormalParameterList *FormalParameterList;
-      AST::FunctionBody *FunctionBody;
-      AST::FunctionDeclaration *FunctionDeclaration;
-      AST::Node *Node;
-      AST::PropertyName *PropertyName;
-      AST::PropertyAssignment *PropertyAssignment;
-      AST::PropertyAssignmentList *PropertyAssignmentList;
-      AST::SourceElement *SourceElement;
-      AST::SourceElements *SourceElements;
-      AST::Statement *Statement;
-      AST::StatementList *StatementList;
-      AST::Block *Block;
-      AST::VariableDeclaration *VariableDeclaration;
-      AST::VariableDeclarationList *VariableDeclarationList;
-
-      AST::UiProgram *UiProgram;
-      AST::UiHeaderItemList *UiHeaderItemList;
-      AST::UiPragma *UiPragma;
-      AST::UiImport *UiImport;
-      AST::UiParameterList *UiParameterList;
-      AST::UiPublicMember *UiPublicMember;
-      AST::UiObjectDefinition *UiObjectDefinition;
-      AST::UiObjectInitializer *UiObjectInitializer;
-      AST::UiObjectBinding *UiObjectBinding;
-      AST::UiScriptBinding *UiScriptBinding;
-      AST::UiArrayBinding *UiArrayBinding;
-      AST::UiObjectMember *UiObjectMember;
-      AST::UiObjectMemberList *UiObjectMemberList;
-      AST::UiArrayMemberList *UiArrayMemberList;
-      AST::UiQualifiedId *UiQualifiedId;
-      AST::UiQualifiedPragmaId *UiQualifiedPragmaId;
-    };
-
-public:
-    Parser(Engine *engine);
-    ~Parser();
-
-    // parse a UI program
-    bool parse() { return parse(T_FEED_UI_PROGRAM); }
-    bool parseStatement() { return parse(T_FEED_JS_STATEMENT); }
-    bool parseExpression() { return parse(T_FEED_JS_EXPRESSION); }
-    bool parseSourceElement() { return parse(T_FEED_JS_SOURCE_ELEMENT); }
-    bool parseUiObjectMember() { return parse(T_FEED_UI_OBJECT_MEMBER); }
-    bool parseProgram() { return parse(T_FEED_JS_PROGRAM); }
-
-    AST::UiProgram *ast() const
-    { return AST::cast<AST::UiProgram *>(program); }
-
-    AST::Statement *statement() const
-    {
-        if (! program)
-            return 0;
-
-        return program->statementCast();
-    }
-
-    AST::ExpressionNode *expression() const
-    {
-        if (! program)
-            return 0;
-
-        return program->expressionCast();
-    }
-
-    AST::UiObjectMember *uiObjectMember() const
-    {
-        if (! program)
-            return 0;
-
-        return program->uiObjectMemberCast();
-    }
-
-    AST::Node *rootNode() const
-    { return program; }
-
-    QList<DiagnosticMessage> diagnosticMessages() const
-    { return diagnostic_messages; }
-
-    inline DiagnosticMessage diagnosticMessage() const
-    {
-        for (const DiagnosticMessage &d : diagnostic_messages) {
-            if (d.kind != DiagnosticMessage::Warning)
-                return d;
-        }
-
-        return DiagnosticMessage();
-    }
-
-    inline QString errorMessage() const
-    { return diagnosticMessage().message; }
-
-    inline int errorLineNumber() const
-    { return diagnosticMessage().loc.startLine; }
-
-    inline int errorColumnNumber() const
-    { return diagnosticMessage().loc.startColumn; }
-
-protected:
-    bool parse(int startToken);
-
-    void reallocateStack();
-
-    inline Value &sym(int index)
-    { return sym_stack [tos + index - 1]; }
-
-    inline QStringRef &stringRef(int index)
-    { return string_stack [tos + index - 1]; }
-
-    inline AST::SourceLocation &loc(int index)
-    { return location_stack [tos + index - 1]; }
-
-    AST::UiQualifiedId *reparseAsQualifiedId(AST::ExpressionNode *expr);
-    AST::UiQualifiedPragmaId *reparseAsQualifiedPragmaId(AST::ExpressionNode *expr);
-
-protected:
-    Engine *driver;
-    MemoryPool *pool;
-    int tos;
-    int stack_size;
-    Value *sym_stack;
-    int *state_stack;
-    AST::SourceLocation *location_stack;
-    QStringRef *string_stack;
-
-    AST::Node *program;
-
-    // error recovery
-    enum { TOKEN_BUFFER_SIZE = 3 };
-
-    struct SavedToken {
-       int token;
-       double dval;
-       AST::SourceLocation loc;
-       QStringRef spell;
-    };
-
-    double yylval;
-    QStringRef yytokenspell;
-    AST::SourceLocation yylloc;
-    AST::SourceLocation yyprevlloc;
-
-    SavedToken token_buffer[TOKEN_BUFFER_SIZE];
-    SavedToken *first_token;
-    SavedToken *last_token;
-
-    QList<DiagnosticMessage> diagnostic_messages;
-};
-
-} // end of namespace QQmlJS
-
-
-
-#define J_SCRIPT_REGEXPLITERAL_RULE1 91
-
-#define J_SCRIPT_REGEXPLITERAL_RULE2 92
-
-QT_QML_END_NAMESPACE
-
-
-
-#endif // QQMLJSPARSER_P_H
diff --git a/src/qml/parser/qqmljssourcelocation_p.h b/src/qml/parser/qqmljssourcelocation_p.h
new file mode 100644
index 0000000000..dc307ba168
--- /dev/null
+++ b/src/qml/parser/qqmljssourcelocation_p.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLJSSOURCELOCATION_P_H
+#define QQMLJSSOURCELOCATION_P_H
+
+#include "qqmljsglobal_p.h"
+
+#include <QtCore/qglobal.h>
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+QT_QML_BEGIN_NAMESPACE
+
+namespace QQmlJS { namespace AST {
+
+class SourceLocation
+{
+public:
+    explicit SourceLocation(quint32 offset = 0, quint32 length = 0, quint32 line = 0, quint32 column = 0)
+        : offset(offset), length(length),
+          startLine(line), startColumn(column)
+    { }
+
+    bool isValid() const { return length != 0; }
+
+    quint32 begin() const { return offset; }
+    quint32 end() const { return offset + length; }
+
+// attributes
+    // ### encode
+    quint32 offset;
+    quint32 length;
+    quint32 startLine;
+    quint32 startColumn;
+};
+
+} } // namespace AST
+
+QT_QML_END_NAMESPACE
+
+#endif
diff --git a/src/qml/qml.pro b/src/qml/qml.pro
index be3956bb61..94717a8f43 100644
--- a/src/qml/qml.pro
+++ b/src/qml/qml.pro
@@ -6,8 +6,8 @@ qtConfig(qml-network): \
 
 DEFINES   += QT_NO_URL_CAST_FROM_STRING QT_NO_INTEGER_EVENT_COORDINATES
 
-win32-msvc*|win32-icc:QMAKE_LFLAGS += /BASE:0x66000000
-win32-msvc*:DEFINES *= _CRT_SECURE_NO_WARNINGS
+msvc:equals(QT_ARCH, i386): QMAKE_LFLAGS += /BASE:0x66000000
+msvc:DEFINES *= _CRT_SECURE_NO_WARNINGS
 win32:!winrt:LIBS += -lshell32
 solaris-cc*:QMAKE_CXXFLAGS_RELEASE -= -O2
 
@@ -16,13 +16,38 @@ gcc:isEqual(QT_ARCH, "mips"): QMAKE_CXXFLAGS += -fno-reorder-blocks
 
 DEFINES += QT_NO_FOREACH
 
+!build_pass {
+    # Create a header containing a hash that describes this library.  For a
+    # released version of Qt, we'll use the .tag file that is updated by git
+    # archive with the commit hash. For unreleased versions, we'll ask git
+    # describe. Note that it won't update unless qmake is run again, even if
+    # the commit change also changed something in this library.
+    tagFile = $$PWD/../../.tag
+    tag =
+    exists($$tagFile) {
+        tag = $$cat($$tagFile, singleline)
+        QMAKE_INTERNAL_INCLUDED_FILES += $$tagFile
+    }
+    !equals(tag, "$${LITERAL_DOLLAR}Format:%H$${LITERAL_DOLLAR}") {
+        QML_COMPILE_HASH = $$tag
+    } else:exists($$PWD/../../.git) {
+        commit = $$system(git rev-parse HEAD)
+        QML_COMPILE_HASH = $$commit
+    }
+    compile_hash_contents = \
+        "// Generated file, DO NOT EDIT" \
+        "$${LITERAL_HASH}define QML_COMPILE_HASH \"$$QML_COMPILE_HASH\"" \
+        "$${LITERAL_HASH}define QML_COMPILE_HASH_LENGTH $$str_size($$QML_COMPILE_HASH)"
+    write_file("$$OUT_PWD/qml_compile_hash_p.h", compile_hash_contents)|error()
+}
+
 exists("qqml_enable_gcov") {
     QMAKE_CXXFLAGS = -fprofile-arcs -ftest-coverage -fno-elide-constructors
     LIBS_PRIVATE += -lgcov
 }
 
 # QTBUG-55238, disable new optimizer for MSVC 2015/Update 3.
-release:win32-msvc*:equals(QT_CL_MAJOR_VERSION, 19):equals(QT_CL_MINOR_VERSION, 00): \
+release:msvc:equals(QT_CL_MAJOR_VERSION, 19):equals(QT_CL_MINOR_VERSION, 00): \
         greaterThan(QT_CL_PATCH_VERSION, 24212):QMAKE_CXXFLAGS += -d2SSAOptimizer-
 
 QMAKE_DOCS = $$PWD/doc/qtqml.qdocconf
@@ -44,14 +69,17 @@ include(memory/memory.pri)
 include(parser/parser.pri)
 include(compiler/compiler.pri)
 include(jsapi/jsapi.pri)
-include(jit/jit.pri)
 include(jsruntime/jsruntime.pri)
+include(jit/jit.pri)
 include(qml/qml.pri)
 include(debugger/debugger.pri)
-qtConfig(animation) {
+include(qmldirparser/qmldirparser.pri)
+qtConfig(qml-animation) {
     include(animations/animations.pri)
 }
 include(types/types.pri)
+include(../3rdparty/masm/masm-defs.pri)
+include(../3rdparty/masm/masm.pri)
 
 MODULE_PLUGIN_TYPES = \
     qmltooling
diff --git a/src/qml/qml/ftw/ftw.pri b/src/qml/qml/ftw/ftw.pri
index 87d80d04bc..0bb8cb954e 100644
--- a/src/qml/qml/ftw/ftw.pri
+++ b/src/qml/qml/ftw/ftw.pri
@@ -12,12 +12,14 @@ HEADERS +=  \
     $$PWD/qflagpointer_p.h \
     $$PWD/qlazilyallocated_p.h \
     $$PWD/qqmlnullablevalue_p.h \
-    $$PWD/qdeferredcleanup_p.h \
+    $$PWD/qstringhash_p.h \
+    $$PWD/qlinkedstringhash_p.h
 
 SOURCES += \
     $$PWD/qintrusivelist.cpp \
     $$PWD/qhashedstring.cpp \
     $$PWD/qqmlthread.cpp \
+    $$PWD/qstringhash.cpp
 
 # mirrors logic in $$QT_SOURCE_TREE/config.tests/unix/clock-gettime/clock-gettime.pri
 # clock_gettime() is implemented in librt on these systems
diff --git a/src/qml/qml/ftw/qbitfield_p.h b/src/qml/qml/ftw/qbitfield_p.h
index 8f35842249..92017580d6 100644
--- a/src/qml/qml/ftw/qbitfield_p.h
+++ b/src/qml/qml/ftw/qbitfield_p.h
@@ -77,12 +77,12 @@ private:
 };
 
 QBitField::QBitField()
-: bits(0), ownData(0), data(0)
+: bits(0), ownData(nullptr), data(nullptr)
 {
 }
 
 QBitField::QBitField(const quint32 *bitData, int bitCount)
-: bits((quint32)bitCount), ownData(0), data(bitData)
+: bits((quint32)bitCount), ownData(nullptr), data(bitData)
 {
 }
 
diff --git a/src/qml/qml/ftw/qfieldlist_p.h b/src/qml/qml/ftw/qfieldlist_p.h
index d83d708b5e..2bf07fb20d 100644
--- a/src/qml/qml/ftw/qfieldlist_p.h
+++ b/src/qml/qml/ftw/qfieldlist_p.h
@@ -141,7 +141,7 @@ N *QForwardFieldList<N, nextMember>::takeFirst()
     N *value = *_first;
     if (value) {
         _first = next(value);
-        value->*nextMember = 0;
+        value->*nextMember = nullptr;
     }
     return value;
 }
@@ -149,7 +149,7 @@ N *QForwardFieldList<N, nextMember>::takeFirst()
 template<class N, N *N::*nextMember>
 void QForwardFieldList<N, nextMember>::prepend(N *v)
 {
-    Q_ASSERT(v->*nextMember == 0);
+    Q_ASSERT(v->*nextMember == nullptr);
     v->*nextMember = *_first;
     _first = v;
 }
@@ -229,7 +229,7 @@ void QForwardFieldList<N, nextMember>::setFlag2Value(bool v)
 
 template<class N, N *N::*nextMember>
 QFieldList<N, nextMember>::QFieldList()
-: _first(0), _last(0), _flag(0), _count(0)
+: _first(nullptr), _last(nullptr), _flag(0), _count(0)
 {
 }
 
@@ -246,10 +246,10 @@ N *QFieldList<N, nextMember>::takeFirst()
     if (value) {
         _first = next(value);
         if (_last == value) {
-            Q_ASSERT(_first == 0);
-            _last = 0;
+            Q_ASSERT(_first == nullptr);
+            _last = nullptr;
         }
-        value->*nextMember = 0;
+        value->*nextMember = nullptr;
         --_count;
     }
     return value;
@@ -258,7 +258,7 @@ N *QFieldList<N, nextMember>::takeFirst()
 template<class N, N *N::*nextMember>
 void QFieldList<N, nextMember>::append(N *v)
 {
-    Q_ASSERT(v->*nextMember == 0);
+    Q_ASSERT(v->*nextMember == nullptr);
     if (isEmpty()) {
         _first = v;
         _last = v;
@@ -272,7 +272,7 @@ void QFieldList<N, nextMember>::append(N *v)
 template<class N, N *N::*nextMember>
 void QFieldList<N, nextMember>::prepend(N *v)
 {
-    Q_ASSERT(v->*nextMember == 0);
+    Q_ASSERT(v->*nextMember == nullptr);
     if (isEmpty()) {
         _first = v;
         _last = v;
@@ -375,7 +375,7 @@ void QFieldList<N, nextMember>::copyAndClear(QFieldList<N, nextMember> &o)
     _first = o._first;
     _last = o._last;
     _count = o._count;
-    o._first = o._last = 0;
+    o._first = o._last = nullptr;
     o._count = 0;
 }
 
@@ -391,8 +391,8 @@ void QFieldList<N, nextMember>::copyAndClearAppend(QForwardFieldList<N, nextMemb
 template<class N, N *N::*nextMember>
 void QFieldList<N, nextMember>::copyAndClearPrepend(QForwardFieldList<N, nextMember> &o)
 {
-    _first = 0;
-    _last = 0;
+    _first = nullptr;
+    _last = nullptr;
     _count = 0;
     while (N *n = o.takeFirst()) prepend(n);
 }
diff --git a/src/qml/qml/ftw/qfinitestack_p.h b/src/qml/qml/ftw/qfinitestack_p.h
index f1f1a551d5..9a74199137 100644
--- a/src/qml/qml/ftw/qfinitestack_p.h
+++ b/src/qml/qml/ftw/qfinitestack_p.h
@@ -81,7 +81,7 @@ private:
 
 template<typename T>
 QFiniteStack<T>::QFiniteStack()
-: _array(0), _alloc(0), _size(0)
+: _array(nullptr), _alloc(0), _size(0)
 {
 }
 
@@ -156,7 +156,7 @@ T &QFiniteStack<T>::operator[](int index)
 template<typename T>
 void QFiniteStack<T>::allocate(int size)
 {
-    Q_ASSERT(_array == 0);
+    Q_ASSERT(_array == nullptr);
     Q_ASSERT(_alloc == 0);
     Q_ASSERT(_size == 0);
 
@@ -177,7 +177,7 @@ void QFiniteStack<T>::deallocate()
 
     free(_array);
 
-    _array = 0;
+    _array = nullptr;
     _alloc = 0;
     _size = 0;
 }
diff --git a/src/qml/qml/ftw/qflagpointer_p.h b/src/qml/qml/ftw/qflagpointer_p.h
index 6954a8f09c..71b41cd30b 100644
--- a/src/qml/qml/ftw/qflagpointer_p.h
+++ b/src/qml/qml/ftw/qflagpointer_p.h
@@ -82,8 +82,10 @@ public:
 
     inline T *data() const;
 
+    inline explicit operator bool() const;
+
 private:
-    quintptr ptr_value;
+    quintptr ptr_value = 0;
 
     static const quintptr FlagBit = 0x1;
     static const quintptr Flag2Bit = 0x2;
@@ -115,7 +117,7 @@ public:
     inline T2 *asT2() const;
 
 private:
-    quintptr ptr_value;
+    quintptr ptr_value = 0;
 
     static const quintptr FlagBit = 0x1;
     static const quintptr Flag2Bit = 0x2;
@@ -124,7 +126,6 @@ private:
 
 template<typename T>
 QFlagPointer<T>::QFlagPointer()
-: ptr_value(0)
 {
 }
 
@@ -231,9 +232,14 @@ T *QFlagPointer<T>::data() const
     return (T *)(ptr_value & ~FlagsMask);
 }
 
+template<typename T>
+QFlagPointer<T>::operator bool() const
+{
+    return data() != nullptr;
+}
+
 template<typename T, typename T2>
 QBiPointer<T, T2>::QBiPointer()
-: ptr_value(0)
 {
 }
 
diff --git a/src/qml/qml/ftw/qhashedstring.cpp b/src/qml/qml/ftw/qhashedstring.cpp
index 117670dbfc..bb6688599d 100644
--- a/src/qml/qml/ftw/qhashedstring.cpp
+++ b/src/qml/qml/ftw/qhashedstring.cpp
@@ -39,136 +39,7 @@
 
 #include "qhashedstring_p.h"
 
-
-
-/*
-    A QHash has initially around pow(2, MinNumBits) buckets. For
-    example, if MinNumBits is 4, it has 17 buckets.
-*/
-const int MinNumBits = 4;
-
-/*
-    The prime_deltas array is a table of selected prime values, even
-    though it doesn't look like one. The primes we are using are 1,
-    2, 5, 11, 17, 37, 67, 131, 257, ..., i.e. primes in the immediate
-    surrounding of a power of two.
-
-    The primeForNumBits() function returns the prime associated to a
-    power of two. For example, primeForNumBits(8) returns 257.
-*/
-
-static const uchar prime_deltas[] = {
-    0,  0,  1,  3,  1,  5,  3,  3,  1,  9,  7,  5,  3,  9, 25,  3,
-    1, 21,  3, 21,  7, 15,  9,  5,  3, 29, 15,  0,  0,  0,  0,  0
-};
-
-static inline int primeForNumBits(int numBits)
-{
-    return (1 << numBits) + prime_deltas[numBits];
-}
-
-void QStringHashData::rehashToSize(int size)
-{
-    short bits = qMax(MinNumBits, (int)numBits);
-    while (primeForNumBits(bits) < size) bits++;
-
-    if (bits > numBits)
-        rehashToBits(bits);
-}
-
-void QStringHashData::rehashToBits(short bits)
-{
-    numBits = qMax(MinNumBits, (int)bits);
-
-    int nb = primeForNumBits(numBits);
-    if (nb == numBuckets && buckets)
-        return;
-
-#ifdef QSTRINGHASH_LINK_DEBUG
-    if (linkCount)
-        qFatal("QStringHash: Illegal attempt to rehash a linked hash.");
-#endif
-
-    QStringHashNode **newBuckets = new QStringHashNode *[nb];
-    ::memset(newBuckets, 0, sizeof(QStringHashNode *) * nb);
-
-    // Preserve the existing order within buckets so that items with the
-    // same key will retain the same find/findNext order
-    for (int i = 0; i < numBuckets; ++i) {
-        QStringHashNode *bucket = buckets[i];
-        if (bucket)
-            rehashNode(newBuckets, nb, bucket);
-    }
-
-    delete [] buckets;
-    buckets = newBuckets;
-    numBuckets = nb;
-}
-
-void QStringHashData::rehashNode(QStringHashNode **newBuckets, int nb, QStringHashNode *node)
-{
-    QStringHashNode *next = node->next.data();
-    if (next)
-        rehashNode(newBuckets, nb, next);
-
-    int bucket = node->hash % nb;
-    node->next = newBuckets[bucket];
-    newBuckets[bucket] = node;
-}
-
-// Copy of QString's qMemCompare
-bool QHashedString::compare(const QChar *lhs, const QChar *rhs, int length)
-{
-    Q_ASSERT(lhs && rhs);
-    const quint16 *a = (const quint16 *)lhs;
-    const quint16 *b = (const quint16 *)rhs;
-
-    if (a == b || !length)
-        return true;
-
-    union {
-        const quint16 *w;
-        const quint32 *d;
-        quintptr value;
-    } sa, sb;
-    sa.w = a;
-    sb.w = b;
-
-    // check alignment
-    if ((sa.value & 2) == (sb.value & 2)) {
-        // both addresses have the same alignment
-        if (sa.value & 2) {
-            // both addresses are not aligned to 4-bytes boundaries
-            // compare the first character
-            if (*sa.w != *sb.w)
-                return false;
-            --length;
-            ++sa.w;
-            ++sb.w;
-
-            // now both addresses are 4-bytes aligned
-        }
-
-        // both addresses are 4-bytes aligned
-        // do a fast 32-bit comparison
-        const quint32 *e = sa.d + (length >> 1);
-        for ( ; sa.d != e; ++sa.d, ++sb.d) {
-            if (*sa.d != *sb.d)
-                return false;
-        }
-
-        // do we have a tail?
-        return (length & 1) ? *sa.w == *sb.w : true;
-    } else {
-        // one of the addresses isn't 4-byte aligned but the other is
-        const quint16 *e = sa.w + length;
-        for ( ; sa.w != e; ++sa.w, ++sb.w) {
-            if (*sa.w != *sb.w)
-                return false;
-        }
-    }
-    return true;
-}
+QT_BEGIN_NAMESPACE
 
 QHashedStringRef QHashedStringRef::mid(int offset, int length) const
 {
@@ -228,3 +99,4 @@ QString QHashedCStringRef::toUtf16() const
     return rv;
 }
 
+QT_END_NAMESPACE
diff --git a/src/qml/qml/ftw/qhashedstring_p.h b/src/qml/qml/ftw/qhashedstring_p.h
index 9ee50ec931..b9f3f81219 100644
--- a/src/qml/qml/ftw/qhashedstring_p.h
+++ b/src/qml/qml/ftw/qhashedstring_p.h
@@ -63,9 +63,6 @@
 
 QT_BEGIN_NAMESPACE
 
-// Enable this to debug hash linking assumptions.
-// #define QSTRINGHASH_LINK_DEBUG
-
 class QHashedStringRef;
 class Q_QML_PRIVATE_EXPORT QHashedString : public QString
 {
@@ -94,7 +91,7 @@ private:
     friend class QStringHashNode;
 
     inline void computeHash() const;
-    mutable quint32 m_hash;
+    mutable quint32 m_hash = 0;
 };
 
 class QHashedCStringRef;
@@ -142,9 +139,9 @@ private:
 
     inline void computeHash() const;
 
-    const QChar *m_data;
-    int m_length;
-    mutable quint32 m_hash;
+    const QChar *m_data = nullptr;
+    int m_length = 0;
+    mutable quint32 m_hash = 0;
 };
 
 class Q_AUTOTEST_EXPORT QHashedCStringRef
@@ -169,864 +166,11 @@ private:
 
     inline void computeHash() const;
 
-    const char *m_data;
-    int m_length;
-    mutable quint32 m_hash;
-};
-
-class QStringHashData;
-class Q_AUTOTEST_EXPORT QStringHashNode
-{
-public:
-    QStringHashNode()
-    : length(0), hash(0), symbolId(0), ckey(0)
-    {
-    }
-
-    QStringHashNode(const QHashedString &key)
-    : length(key.length()), hash(key.hash()), symbolId(0)
-    {
-        strData = const_cast<QHashedString &>(key).data_ptr();
-        setQString(true);
-        strData->ref.ref();
-    }
-
-    QStringHashNode(const QHashedCStringRef &key)
-    : length(key.length()), hash(key.hash()), symbolId(0), ckey(key.constData())
-    {
-    }
-
-    QStringHashNode(const QStringHashNode &o)
-    : length(o.length), hash(o.hash), symbolId(o.symbolId), ckey(o.ckey)
-    {
-        setQString(o.isQString());
-        if (isQString()) { strData->ref.ref(); }
-    }
-
-    ~QStringHashNode()
-    {
-        if (isQString()) { if (!strData->ref.deref()) free(strData); }
-    }
-
-    QFlagPointer<QStringHashNode> next;
-
-    qint32 length;
-    quint32 hash;
-    quint32 symbolId;
-
-    union {
-        const char *ckey;
-        QStringData *strData;
-    };
-
-    inline QHashedString key() const
-    {
-        if (isQString())
-            return QHashedString(QString((QChar *)strData->data(), length), hash);
-
-        return QHashedString(QString::fromLatin1(ckey, length), hash);
-    }
-
-    bool isQString() const { return next.flag(); }
-    void setQString(bool v) { if (v) next.setFlag(); else next.clearFlag(); }
-
-    inline char *cStrData() const { return (char *)ckey; }
-    inline quint16 *utf16Data() const { return (quint16 *)strData->data(); }
-
-    inline bool equals(const QV4::Value &string) const {
-        QString s = string.toQStringNoThrow();
-        if (isQString()) {
-            QStringDataPtr dd;
-            dd.ptr = strData;
-            strData->ref.ref();
-            return QString(dd) == s;
-        } else {
-            return QLatin1String(cStrData(), length) == s;
-        }
-    }
-
-    inline bool equals(const QV4::String *string) const {
-        if (length != string->d()->length() || hash != string->hashValue())
-                return false;
-        if (isQString()) {
-            QStringDataPtr dd;
-            dd.ptr = strData;
-            strData->ref.ref();
-            return QString(dd) == string->toQString();
-        } else {
-            return QLatin1String(cStrData(), length) == string->toQString();
-        }
-    }
-
-    inline bool equals(const QHashedStringRef &string) const {
-        return length == string.length() &&
-               hash == string.hash() &&
-               (isQString()?QHashedString::compare(string.constData(), (const QChar *)utf16Data(), length):
-                            QHashedString::compare(string.constData(), cStrData(), length));
-    }
-
-    inline bool equals(const QHashedCStringRef &string) const {
-        return length == string.length() &&
-               hash == string.hash() &&
-               (isQString()?QHashedString::compare((const QChar *)utf16Data(), string.constData(), length):
-                            QHashedString::compare(string.constData(), cStrData(), length));
-    }
-};
-
-class Q_AUTOTEST_EXPORT QStringHashData
-{
-public:
-    QStringHashData()
-    : buckets(0), numBuckets(0), size(0), numBits(0)
-#ifdef QSTRINGHASH_LINK_DEBUG
-      , linkCount(0)
-#endif
-    {}
-
-    QStringHashNode **buckets;
-    int numBuckets;
-    int size;
-    short numBits;
-#ifdef QSTRINGHASH_LINK_DEBUG
-    int linkCount;
-#endif
-
-    struct IteratorData {
-        IteratorData() : n(0), p(0) {}
-        QStringHashNode *n;
-        void *p;
-    };
-    void rehashToBits(short);
-    void rehashToSize(int);
-    void rehashNode(QStringHashNode **newBuckets, int nb, QStringHashNode *node);
-
-private:
-    QStringHashData(const QStringHashData &);
-    QStringHashData &operator=(const QStringHashData &);
-};
-
-// For a supplied key type, in what form do we need to keep a hashed version?
-template<typename T>
-struct HashedForm {};
-
-template<> struct HashedForm<QString> { typedef QHashedString Type; };
-template<> struct HashedForm<QStringRef> { typedef QHashedStringRef Type; };
-template<> struct HashedForm<QHashedString> { typedef const QHashedString &Type; };
-template<> struct HashedForm<QV4::String *> { typedef const QV4::String *Type; };
-template<> struct HashedForm<const QV4::String *> { typedef const QV4::String *Type; };
-template<> struct HashedForm<QHashedStringRef> { typedef const QHashedStringRef &Type; };
-template<> struct HashedForm<QLatin1String> { typedef QHashedCStringRef Type; };
-template<> struct HashedForm<QHashedCStringRef> { typedef const QHashedCStringRef &Type; };
-
-class QStringHashBase
-{
-public:
-    static HashedForm<QString>::Type hashedString(const QString &s) { return QHashedString(s);}
-    static HashedForm<QStringRef>::Type hashedString(const QStringRef &s) { return QHashedStringRef(s.constData(), s.size());}
-    static HashedForm<QHashedString>::Type hashedString(const QHashedString &s) { return s; }
-    static HashedForm<QV4::String *>::Type hashedString(QV4::String *s) { return s; }
-    static HashedForm<const QV4::String *>::Type hashedString(const QV4::String *s) { return s; }
-    static HashedForm<QHashedStringRef>::Type hashedString(const QHashedStringRef &s) { return s; }
-
-    static HashedForm<QLatin1String>::Type hashedString(const QLatin1String &s) { return QHashedCStringRef(s.data(), s.size()); }
-    static HashedForm<QHashedCStringRef>::Type hashedString(const QHashedCStringRef &s) { return s; }
-
-    static const QString &toQString(const QString &s) { return s; }
-    static const QString &toQString(const QHashedString &s) { return s; }
-    static QString toQString(const QV4::String *s) { return s->toQString(); }
-    static QString toQString(const QHashedStringRef &s) { return s.toString(); }
-
-    static QString toQString(const QLatin1String &s) { return QString(s); }
-    static QString toQString(const QHashedCStringRef &s) { return s.toUtf16(); }
-
-    static inline quint32 hashOf(const QHashedStringRef &s) { return s.hash(); }
-    static inline quint32 hashOf(QV4::String *s) { return s->hashValue(); }
-    static inline quint32 hashOf(const QV4::String *s) { return s->hashValue(); }
-
-    template<typename K>
-    static inline quint32 hashOf(const K &key) { return hashedString(key).hash(); }
-};
-
-template<class T>
-class QStringHash : public QStringHashBase
-{
-public:
-    typedef QHashedString key_type;
-    typedef T mapped_type;
-
-    struct Node : public QStringHashNode {
-        Node(const QHashedString &key, const T &value) : QStringHashNode(key), value(value) {}
-        Node(const QHashedCStringRef &key, const T &value) : QStringHashNode(key), value(value) {}
-        Node(const Node &o) : QStringHashNode(o), value(o.value) {}
-        Node() {}
-        T value;
-    };
-    struct NewedNode : public Node {
-        NewedNode(const QHashedString &key, const T &value) : Node(key, value), nextNewed(0) {}
-        NewedNode(const QHashedCStringRef &key, const T &value) : Node(key, value), nextNewed(0) {}
-        NewedNode(const Node &o) : Node(o), nextNewed(0) {}
-        NewedNode *nextNewed;
-    };
-    struct ReservedNodePool
-    {
-        ReservedNodePool() : count(0), used(0), nodes(0) {}
-        ~ReservedNodePool() { delete [] nodes; }
-        int count;
-        int used;
-        Node *nodes;
-    };
-
-    QStringHashData data;
-    NewedNode *newedNodes;
-    ReservedNodePool *nodePool;
-    const QStringHash<T> *link;
-
-    template<typename K>
-    inline Node *findNode(const K &) const;
-
-    inline Node *createNode(const Node &o);
-
-    template<typename K>
-    inline Node *createNode(const K &, const T &);
-
-    inline Node *insertNode(Node *, quint32);
-
-    inline void initializeNode(Node *, const QHashedString &key);
-    inline void initializeNode(Node *, const QHashedCStringRef &key);
-
-    template<typename K>
-    inline Node *takeNode(const K &key, const T &value);
-
-    inline Node *takeNode(const Node &o);
-
-    inline void copy(const QStringHash<T> &);
-
-    void copyNode(const QStringHashNode *otherNode);
-
-    inline QStringHashData::IteratorData iterateFirst() const;
-    static inline QStringHashData::IteratorData iterateNext(const QStringHashData::IteratorData &);
-
-public:
-    inline QStringHash();
-    inline QStringHash(const QStringHash &);
-    inline ~QStringHash();
-
-    QStringHash &operator=(const QStringHash<T> &);
-
-    void copyAndReserve(const QStringHash<T> &other, int additionalReserve);
-    void linkAndReserve(const QStringHash<T> &other, int additionalReserve);
-
-    inline bool isEmpty() const;
-    inline void clear();
-    inline int count() const;
-
-    inline int numBuckets() const;
-    inline bool isLinked() const;
-
-    class ConstIterator {
-    public:
-        inline ConstIterator();
-        inline ConstIterator(const QStringHashData::IteratorData &);
-
-        inline ConstIterator &operator++();
-
-        inline bool operator==(const ConstIterator &o) const;
-        inline bool operator!=(const ConstIterator &o) const;
-
-        template<typename K>
-        inline bool equals(const K &) const;
-
-        inline QHashedString key() const;
-        inline const T &value() const;
-        inline const T &operator*() const;
-
-        inline Node *node() const;
-    private:
-        QStringHashData::IteratorData d;
-    };
-
-    template<typename K>
-    inline void insert(const K &, const T &);
-
-    inline void insert(const ConstIterator  &);
-
-    template<typename K>
-    inline T *value(const K &) const;
-
-    inline T *value(const QV4::String *string) const;
-    inline T *value(const ConstIterator &) const;
-
-    template<typename K>
-    inline bool contains(const K &) const;
-
-    template<typename K>
-    inline T &operator[](const K &);
-
-    inline ConstIterator begin() const;
-    inline ConstIterator end() const;
-
-    inline ConstIterator iterator(Node *n) const;
-
-    template<typename K>
-    inline ConstIterator find(const K &) const;
-
-    inline void reserve(int);
-};
-
-template<class T>
-QStringHash<T>::QStringHash()
-: newedNodes(0), nodePool(0), link(0)
-{
-}
-
-template<class T>
-QStringHash<T>::QStringHash(const QStringHash<T> &other)
-: newedNodes(0), nodePool(0), link(0)
-{
-    data.numBits = other.data.numBits;
-    data.size = other.data.size;
-    reserve(other.count());
-    copy(other);
-}
-
-template<class T>
-QStringHash<T> &QStringHash<T>::operator=(const QStringHash<T> &other)
-{
-    if (&other == this)
-        return *this;
-
-    clear();
-
-    data.numBits = other.data.numBits;
-    data.size = other.data.size;
-    reserve(other.count());
-    copy(other);
-
-    return *this;
-}
-
-template<class T>
-void QStringHash<T>::copyAndReserve(const QStringHash<T> &other, int additionalReserve)
-{
-    clear();
-    data.numBits = other.data.numBits;
-    reserve(other.count() + additionalReserve);
-    copy(other);
-}
-
-template<class T>
-void QStringHash<T>::linkAndReserve(const QStringHash<T> &other, int additionalReserve)
-{
-    clear();
-
-    if (other.count()) {
-        data.size = other.data.size;
-        data.rehashToSize(other.count() + additionalReserve);
-
-        if (data.numBuckets == other.data.numBuckets) {
-            nodePool = new ReservedNodePool;
-            nodePool->count = additionalReserve;
-            nodePool->used = 0;
-            nodePool->nodes = new Node[additionalReserve];
-
-#ifdef QSTRINGHASH_LINK_DEBUG
-            data.linkCount++;
-            const_cast<QStringHash<T>&>(other).data.linkCount++;
-#endif
-
-            for (int ii = 0; ii < data.numBuckets; ++ii)
-                data.buckets[ii] = (Node *)other.data.buckets[ii];
-
-            link = &other;
-            return;
-        }
-
-        data.size = 0;
-    }
-
-    data.numBits = other.data.numBits;
-    reserve(other.count() + additionalReserve);
-    copy(other);
-}
-
-template<class T>
-QStringHash<T>::~QStringHash()
-{
-    clear();
-}
-
-template<class T>
-void QStringHash<T>::clear()
-{
-#ifdef QSTRINGHASH_LINK_DEBUG
-    if (link) {
-        data.linkCount--;
-        const_cast<QStringHash<T> *>(link)->data.linkCount--;
-    }
-
-    if (data.linkCount)
-        qFatal("QStringHash: Illegal attempt to clear a linked hash.");
-#endif
-
-    // Delete the individually allocated nodes
-    NewedNode *n = newedNodes;
-    while (n) {
-        NewedNode *c = n;
-        n = c->nextNewed;
-        delete c;
-    }
-    // Delete the pool allocated nodes
-    if (nodePool) delete nodePool;
-    delete [] data.buckets;
-
-    data.buckets = 0;
-    data.numBuckets = 0;
-    data.numBits = 0;
-    data.size = 0;
-
-    newedNodes = 0;
-    nodePool = 0;
-    link = 0;
-}
-
-template<class T>
-bool QStringHash<T>::isEmpty() const
-{
-    return data.size== 0;
-}
-
-template<class T>
-int QStringHash<T>::count() const
-{
-    return data.size;
-}
-
-template<class T>
-int QStringHash<T>::numBuckets() const
-{
-    return data.numBuckets;
-}
-
-template<class T>
-bool QStringHash<T>::isLinked() const
-{
-    return link != 0;
-}
-
-template<class T>
-void QStringHash<T>::initializeNode(Node *node, const QHashedString &key)
-{
-    node->length = key.length();
-    node->hash = key.hash();
-    node->strData = const_cast<QHashedString &>(key).data_ptr();
-    node->strData->ref.ref();
-    node->setQString(true);
-}
-
-template<class T>
-void QStringHash<T>::initializeNode(Node *node, const QHashedCStringRef &key)
-{
-    node->length = key.length();
-    node->hash = key.hash();
-    node->ckey = key.constData();
-}
-
-template<class T>
-template<class K>
-typename QStringHash<T>::Node *QStringHash<T>::takeNode(const K &key, const T &value)
-{
-    if (nodePool && nodePool->used != nodePool->count) {
-        Node *rv = nodePool->nodes + nodePool->used++;
-        initializeNode(rv, hashedString(key));
-        rv->value = value;
-        return rv;
-    } else {
-        NewedNode *rv = new NewedNode(hashedString(key), value);
-        rv->nextNewed = newedNodes;
-        newedNodes = rv;
-        return rv;
-    }
-}
-
-template<class T>
-typename QStringHash<T>::Node *QStringHash<T>::takeNode(const Node &o)
-{
-    if (nodePool && nodePool->used != nodePool->count) {
-        Node *rv = nodePool->nodes + nodePool->used++;
-        rv->length = o.length;
-        rv->hash = o.hash;
-        if (o.isQString()) {
-            rv->strData = o.strData;
-            rv->strData->ref.ref();
-            rv->setQString(true);
-        } else {
-            rv->ckey = o.ckey;
-        }
-        rv->symbolId = o.symbolId;
-        rv->value = o.value;
-        return rv;
-    } else {
-        NewedNode *rv = new NewedNode(o);
-        rv->nextNewed = newedNodes;
-        newedNodes = rv;
-        return rv;
-    }
-}
-
-template<class T>
-void QStringHash<T>::copyNode(const QStringHashNode *otherNode)
-{
-    // Copy the predecessor before the successor
-    QStringHashNode *next = otherNode->next.data();
-    if (next)
-        copyNode(next);
-
-    Node *mynode = takeNode(*(const Node *)otherNode);
-    int bucket = mynode->hash % data.numBuckets;
-    mynode->next = data.buckets[bucket];
-    data.buckets[bucket] = mynode;
-}
-
-template<class T>
-void QStringHash<T>::copy(const QStringHash<T> &other)
-{
-    Q_ASSERT(data.size == 0);
-
-    data.size = other.data.size;
-
-    // Ensure buckets array is created
-    data.rehashToBits(data.numBits);
-
-    // Preserve the existing order within buckets
-    for (int i = 0; i < other.data.numBuckets; ++i) {
-        QStringHashNode *bucket = other.data.buckets[i];
-        if (bucket)
-            copyNode(bucket);
-    }
-}
-
-template<class T>
-QStringHashData::IteratorData
-QStringHash<T>::iterateNext(const QStringHashData::IteratorData &d)
-{
-    QStringHash<T> *This = (QStringHash<T> *)d.p;
-    Node *node = (Node *)d.n;
-
-    if (This->nodePool && node >= This->nodePool->nodes &&
-        node < (This->nodePool->nodes + This->nodePool->used)) {
-        node--;
-        if (node < This->nodePool->nodes)
-            node = 0;
-    } else {
-        NewedNode *nn = (NewedNode *)node;
-        node = nn->nextNewed;
-
-        if (node == 0 && This->nodePool && This->nodePool->used)
-            node = This->nodePool->nodes + This->nodePool->used - 1;
-    }
-
-    if (node == 0 && This->link)
-        return This->link->iterateFirst();
-
-    QStringHashData::IteratorData rv;
-    rv.n = node;
-    rv.p = d.p;
-    return rv;
-}
-
-template<class T>
-QStringHashData::IteratorData QStringHash<T>::iterateFirst() const
-{
-    Node *n = 0;
-    if (newedNodes)
-        n = newedNodes;
-    else if (nodePool && nodePool->used)
-        n = nodePool->nodes + nodePool->used - 1;
-
-    if (n == 0 && link)
-        return link->iterateFirst();
-
-    QStringHashData::IteratorData rv;
-    rv.n = n;
-    rv.p = const_cast<QStringHash<T> *>(this);
-    return rv;
-}
-
-template<class T>
-typename QStringHash<T>::ConstIterator QStringHash<T>::iterator(Node *n) const
-{
-    if (!n)
-        return ConstIterator();
-
-    const QStringHash<T> *container = this;
-
-    if (link) {
-        // This node could be in the linked hash
-        if ((n >= nodePool->nodes) && (n < (nodePool->nodes + nodePool->used))) {
-            // The node is in this hash
-        } else if ((n >= link->nodePool->nodes) && (n < (link->nodePool->nodes + link->nodePool->used))) {
-            // The node is in the linked hash
-            container = link;
-        } else {
-            const NewedNode *ln = link->newedNodes;
-            while (ln) {
-                if (ln == n) {
-                    // This node is in the linked hash's newed list
-                    container = link;
-                    break;
-                }
-                ln = ln->nextNewed;
-            }
-        }
-    }
-
-    QStringHashData::IteratorData rv;
-    rv.n = n;
-    rv.p = const_cast<QStringHash<T> *>(container);
-    return ConstIterator(rv);
-}
-
-template<class T>
-typename QStringHash<T>::Node *QStringHash<T>::createNode(const Node &o)
-{
-    Node *n = takeNode(o);
-    return insertNode(n, n->hash);
-}
-
-template<class T>
-template<class K>
-typename QStringHash<T>::Node *QStringHash<T>::createNode(const K &key, const T &value)
-{
-    Node *n = takeNode(key, value);
-    return insertNode(n, hashOf(key));
-}
-
-template<class T>
-typename QStringHash<T>::Node *QStringHash<T>::insertNode(Node *n, quint32 hash)
-{
-    if (data.size >= data.numBuckets)
-        data.rehashToBits(data.numBits + 1);
-
-    int bucket = hash % data.numBuckets;
-    n->next = data.buckets[bucket];
-    data.buckets[bucket] = n;
-
-    data.size++;
-
-    return n;
-}
-
-template<class T>
-template<class K>
-void QStringHash<T>::insert(const K &key, const T &value)
-{
-    // If this is a linked hash, we can't rely on owning the node, so we always
-    // create a new one.
-    Node *n = link?0:findNode(key);
-    if (n) n->value = value;
-    else createNode(key, value);
-}
-
-template<class T>
-void QStringHash<T>::insert(const ConstIterator &iter)
-{
-    insert(iter.key(), iter.value());
-}
-
-template<class T>
-template<class K>
-typename QStringHash<T>::Node *QStringHash<T>::findNode(const K &key) const
-{
-    QStringHashNode *node = data.numBuckets?data.buckets[hashOf(key) % data.numBuckets]:0;
-
-    typename HashedForm<K>::Type hashedKey(hashedString(key));
-    while (node && !node->equals(hashedKey))
-        node = (*node->next);
-
-    return (Node *)node;
-}
-
-template<class T>
-template<class K>
-T *QStringHash<T>::value(const K &key) const
-{
-    Node *n = findNode(key);
-    return n?&n->value:0;
-}
-
-template<class T>
-T *QStringHash<T>::value(const ConstIterator &iter) const
-{
-    Node *n = iter.node();
-    return value(n->key());
-}
-
-template<class T>
-T *QStringHash<T>::value(const QV4::String *string) const
-{
-    Node *n = findNode(string);
-    return n?&n->value:0;
-}
-
-template<class T>
-template<class K>
-bool QStringHash<T>::contains(const K &key) const
-{
-    return 0 != value(key);
-}
-
-template<class T>
-template<class K>
-T &QStringHash<T>::operator[](const K &key)
-{
-    Node *n = findNode(key);
-    if (n) return n->value;
-    else return createNode(key, T())->value;
-}
-
-template<class T>
-void QStringHash<T>::reserve(int n)
-{
-    if (nodePool || 0 == n)
-        return;
-
-    nodePool = new ReservedNodePool;
-    nodePool->count = n;
-    nodePool->used = 0;
-    nodePool->nodes = new Node[n];
-
-    data.rehashToSize(n);
-}
-
-template<class T>
-QStringHash<T>::ConstIterator::ConstIterator()
-{
-}
-
-template<class T>
-QStringHash<T>::ConstIterator::ConstIterator(const QStringHashData::IteratorData &d)
-: d(d)
-{
-}
-
-template<class T>
-typename QStringHash<T>::ConstIterator &QStringHash<T>::ConstIterator::operator++()
-{
-    d = QStringHash<T>::iterateNext(d);
-    return *this;
-}
-
-template<class T>
-bool QStringHash<T>::ConstIterator::operator==(const ConstIterator &o) const
-{
-    return d.n == o.d.n;
-}
-
-template<class T>
-bool QStringHash<T>::ConstIterator::operator!=(const ConstIterator &o) const
-{
-    return d.n != o.d.n;
-}
-
-template<class T>
-template<typename K>
-bool QStringHash<T>::ConstIterator::equals(const K &key) const
-{
-    return d.n->equals(key);
-}
-
-template<class T>
-QHashedString QStringHash<T>::ConstIterator::key() const
-{
-    Node *n = (Node *)d.n;
-    return n->key();
-}
-template<class T>
-const T &QStringHash<T>::ConstIterator::value() const
-{
-    Node *n = (Node *)d.n;
-    return n->value;
-}
-
-template<class T>
-const T &QStringHash<T>::ConstIterator::operator*() const
-{
-    Node *n = (Node *)d.n;
-    return n->value;
-}
-
-template<class T>
-typename QStringHash<T>::Node *QStringHash<T>::ConstIterator::node() const
-{
-    Node *n = (Node *)d.n;
-    return n;
-}
-
-template<class T>
-typename QStringHash<T>::ConstIterator QStringHash<T>::begin() const
-{
-    return ConstIterator(iterateFirst());
-}
-
-template<class T>
-typename QStringHash<T>::ConstIterator QStringHash<T>::end() const
-{
-    return ConstIterator();
-}
-
-template<class T>
-template<class K>
-typename QStringHash<T>::ConstIterator QStringHash<T>::find(const K &key) const
-{
-    return iterator(findNode(key));
-}
-
-template<class T>
-class QStringMultiHash : public QStringHash<T>
-{
-public:
-    typedef typename QStringHash<T>::ConstIterator ConstIterator;
-
-    template<typename K>
-    inline void insert(const K &, const T &);
-
-    inline void insert(const ConstIterator &);
-
-    inline ConstIterator findNext(const ConstIterator &) const;
+    const char *m_data = nullptr;
+    int m_length = 0;
+    mutable quint32 m_hash = 0;
 };
 
-template<class T>
-template<class K>
-void QStringMultiHash<T>::insert(const K &key, const T &value)
-{
-    // Always create a new node
-    QStringHash<T>::createNode(key, value);
-}
-
-template<class T>
-void QStringMultiHash<T>::insert(const ConstIterator &iter)
-{
-    // Always create a new node
-    QStringHash<T>::createNode(iter.key(), iter.value());
-}
-
-template<class T>
-typename QStringHash<T>::ConstIterator QStringMultiHash<T>::findNext(const ConstIterator &iter) const
-{
-    QStringHashNode *node = iter.node();
-    if (node) {
-        QHashedString key(node->key());
-
-        while ((node = *node->next)) {
-            if (node->equals(key)) {
-                return QStringHash<T>::iterator(static_cast<typename QStringHash<T>::Node *>(node));
-            }
-        }
-    }
-
-    return ConstIterator();
-}
-
 inline uint qHash(const QHashedString &string)
 {
     return uint(string.hash());
@@ -1038,7 +182,7 @@ inline uint qHash(const QHashedStringRef &string)
 }
 
 QHashedString::QHashedString()
-: QString(), m_hash(0)
+: QString()
 {
 }
 
@@ -1089,7 +233,6 @@ quint32 QHashedString::existingHash() const
 }
 
 QHashedStringRef::QHashedStringRef()
-: m_data(0), m_length(0), m_hash(0)
 {
 }
 
@@ -1236,7 +379,6 @@ quint32 QHashedStringRef::hash() const
 }
 
 QHashedCStringRef::QHashedCStringRef()
-: m_data(0), m_length(0), m_hash(0)
 {
 }
 
@@ -1311,12 +453,12 @@ bool QHashedString::compare(const char *lhs, const char *rhs, int length)
 
 quint32 QHashedString::stringHash(const QChar *data, int length)
 {
-    return QV4::String::createHashValue(data, length, Q_NULLPTR);
+    return QV4::String::createHashValue(data, length, nullptr);
 }
 
 quint32 QHashedString::stringHash(const char *data, int length)
 {
-    return QV4::String::createHashValue(data, length, Q_NULLPTR);
+    return QV4::String::createHashValue(data, length, nullptr);
 }
 
 void QHashedString::computeHash() const
diff --git a/src/qml/qml/ftw/qintrusivelist_p.h b/src/qml/qml/ftw/qintrusivelist_p.h
index 3d749e697e..8992be9f93 100644
--- a/src/qml/qml/ftw/qintrusivelist_p.h
+++ b/src/qml/qml/ftw/qintrusivelist_p.h
@@ -95,7 +95,7 @@ public:
 private:
     static inline N *nodeToN(QIntrusiveListNode *node);
 
-    QIntrusiveListNode *__first;
+    QIntrusiveListNode *__first = nullptr;
 };
 
 class QIntrusiveListNode
@@ -107,13 +107,13 @@ public:
     inline void remove();
     inline bool isInList() const;
 
-    QIntrusiveListNode *_next;
-    QIntrusiveListNode**_prev;
+    QIntrusiveListNode *_next = nullptr;
+    QIntrusiveListNode**_prev = nullptr;
 };
 
 template<class N, QIntrusiveListNode N::*member>
 QIntrusiveList<N, member>::iterator::iterator()
-: _value(0)
+: _value(nullptr)
 {
 }
 
@@ -165,7 +165,7 @@ typename QIntrusiveList<N, member>::iterator &QIntrusiveList<N, member>::iterato
 
 template<class N, QIntrusiveListNode N::*member>
 QIntrusiveList<N, member>::QIntrusiveList()
-: __first(0)
+
 {
 }
 
@@ -178,7 +178,7 @@ QIntrusiveList<N, member>::~QIntrusiveList()
 template<class N, QIntrusiveListNode N::*member>
 bool QIntrusiveList<N, member>::isEmpty() const
 {
-    return __first == 0;
+    return __first == nullptr;
 }
 
 template<class N, QIntrusiveListNode N::*member>
@@ -215,14 +215,14 @@ bool QIntrusiveList<N, member>::contains(N *n) const
 template<class N, QIntrusiveListNode N::*member>
 N *QIntrusiveList<N, member>::first() const
 {
-    return __first?nodeToN(__first):0;
+    return __first?nodeToN(__first):nullptr;
 }
 
 template<class N, QIntrusiveListNode N::*member>
 N *QIntrusiveList<N, member>::next(N *current)
 {
     QIntrusiveListNode *nextnode = (current->*member)._next;
-    N *nextstruct = nextnode?nodeToN(nextnode):0;
+    N *nextstruct = nextnode?nodeToN(nextnode):nullptr;
     return nextstruct;
 }
 
@@ -241,11 +241,10 @@ typename QIntrusiveList<N, member>::iterator QIntrusiveList<N, member>::end()
 template<class N, QIntrusiveListNode N::*member>
 N *QIntrusiveList<N, member>::nodeToN(QIntrusiveListNode *node)
 {
-    return (N *)((char *)node - ((char *)&(((N *)0)->*member) - (char *)0));
+    return (N *)((char *)node - ((char *)&(((N *)nullptr)->*member) - (char *)nullptr));
 }
 
 QIntrusiveListNode::QIntrusiveListNode()
-: _next(0), _prev(0)
 {
 }
 
@@ -258,13 +257,13 @@ void QIntrusiveListNode::remove()
 {
     if (_prev) *_prev = _next;
     if (_next) _next->_prev = _prev;
-    _prev = 0;
-    _next = 0;
+    _prev = nullptr;
+    _next = nullptr;
 }
 
 bool QIntrusiveListNode::isInList() const
 {
-    return _prev != 0;
+    return _prev != nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/ftw/qlinkedstringhash_p.h b/src/qml/qml/ftw/qlinkedstringhash_p.h
new file mode 100644
index 0000000000..67ced7fbbf
--- /dev/null
+++ b/src/qml/qml/ftw/qlinkedstringhash_p.h
@@ -0,0 +1,238 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QLINKEDSTRINGHASH_P_H
+#define QLINKEDSTRINGHASH_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qstringhash_p.h>
+
+QT_BEGIN_NAMESPACE
+
+template<class T>
+class QLinkedStringHash : private QStringHash<T>
+{
+public:
+    using typename QStringHash<T>::Node;
+    using typename QStringHash<T>::NewedNode;
+    using typename QStringHash<T>::ReservedNodePool;
+    using typename QStringHash<T>::mapped_type;
+
+    using ConstIteratorData = QStringHashData::IteratorData<const QLinkedStringHash>;
+    using ConstIterator = typename QStringHash<T>::template Iterator<ConstIteratorData, const T>;
+
+    void linkAndReserve(const QLinkedStringHash<T> &other, int additionalReserve)
+    {
+        clear();
+
+        if (other.count()) {
+            data.size = other.data.size;
+            data.rehashToSize(other.count() + additionalReserve);
+
+            if (data.numBuckets == other.data.numBuckets) {
+                nodePool = new ReservedNodePool;
+                nodePool->count = additionalReserve;
+                nodePool->used = 0;
+                nodePool->nodes = new Node[additionalReserve];
+
+                for (int ii = 0; ii < data.numBuckets; ++ii)
+                    data.buckets[ii] = (Node *)other.data.buckets[ii];
+
+                link = &other;
+                return;
+            }
+
+            data.size = 0;
+        }
+
+        data.numBits = other.data.numBits;
+        reserve(other.count() + additionalReserve);
+        copy(other);
+    }
+
+    inline bool isLinked() const
+    {
+        return link != 0;
+    }
+
+    void clear()
+    {
+        QStringHash<T>::clear();
+        link = nullptr;
+    }
+
+    template<typename K>
+    void insert(const K &key, const T &value)
+    {
+        // If this is a linked hash, we can't rely on owning the node, so we always
+        // create a new one.
+        Node *n = link ? nullptr : QStringHash<T>::findNode(key);
+        if (n)
+            n->value = value;
+        else
+            QStringHash<T>::createNode(key, value);
+    }
+
+    template<typename K>
+    inline ConstIterator find(const K &key) const
+    {
+        return iterator(QStringHash<T>::findNode(key));
+    }
+
+    ConstIterator begin() const
+    {
+        return ConstIterator(
+                QStringHash<T>::template iterateFirst<const QLinkedStringHash<T>,
+                                                      ConstIteratorData>(this));
+    }
+
+    ConstIterator end() const { return ConstIterator(); }
+
+    inline T *value(const ConstIterator &iter) { return value(iter.node()->key()); }
+
+    using QStringHash<T>::value;
+    using QStringHash<T>::reserve;
+    using QStringHash<T>::copy;
+
+protected:
+    friend QStringHash<T>;
+    using QStringHash<T>::data;
+    using QStringHash<T>::nodePool;
+
+    using QStringHash<T>::createNode;
+
+    inline ConstIteratorData iterateFirst() const
+    {
+        const ConstIteratorData rv
+                = QStringHash<T>::template iterateFirst<const QLinkedStringHash<T>,
+                                                        ConstIteratorData>(this);
+        return (rv.n == nullptr && link) ? link->iterateFirst() : rv;
+    }
+
+    static inline ConstIteratorData iterateNext(const ConstIteratorData &d)
+    {
+        const QLinkedStringHash<T> *self = d.p;
+        const ConstIteratorData rv = QStringHash<T>::iterateNext(d);
+        return (rv.n == nullptr && self->link) ? self->link->iterateFirst() : rv;
+    }
+
+    inline ConstIterator iterator(Node *n) const
+    {
+        if (!n)
+            return ConstIterator();
+
+        const QLinkedStringHash<T> *container = this;
+
+        if (link) {
+            // This node could be in the linked hash
+            if ((n >= nodePool->nodes) && (n < (nodePool->nodes + nodePool->used))) {
+                // The node is in this hash
+            } else if ((n >= link->nodePool->nodes)
+                       && (n < (link->nodePool->nodes + link->nodePool->used))) {
+                // The node is in the linked hash
+                container = link;
+            } else {
+                const NewedNode *ln = link->newedNodes;
+                while (ln) {
+                    if (ln == n) {
+                        // This node is in the linked hash's newed list
+                        container = link;
+                        break;
+                    }
+                    ln = ln->nextNewed;
+                }
+            }
+        }
+
+
+        ConstIteratorData rv;
+        rv.n = n;
+        rv.p = container;
+        return ConstIterator(rv);
+    }
+
+    const QLinkedStringHash<T> *link = nullptr;
+};
+
+template<class T>
+class QLinkedStringMultiHash : public QLinkedStringHash<T>
+{
+public:
+    using ConstIterator = typename QLinkedStringHash<T>::ConstIterator;
+
+    template<typename K>
+    inline void insert(const K &key, const T &value)
+    {
+        // Always create a new node
+        QLinkedStringHash<T>::createNode(key, value);
+    }
+
+    inline void insert(const ConstIterator &iter)
+    {
+        // Always create a new node
+        QLinkedStringHash<T>::createNode(iter.key(), iter.value());
+    }
+
+    inline ConstIterator findNext(const ConstIterator &iter) const
+    {
+        if (auto *node = iter.node()) {
+            QHashedString key(node->key());
+            while ((node = static_cast<typename QLinkedStringHash<T>::Node *>(*node->next))) {
+                if (node->equals(key))
+                    return QLinkedStringHash<T>::iterator(node);
+            }
+        }
+
+        return ConstIterator();
+    }
+};
+
+QT_END_NAMESPACE
+
+#endif // QLINKEDSTRINGHASH_P_H
diff --git a/src/qml/qml/ftw/qpodvector_p.h b/src/qml/qml/ftw/qpodvector_p.h
index cafe3367de..b2fb481793 100644
--- a/src/qml/qml/ftw/qpodvector_p.h
+++ b/src/qml/qml/ftw/qpodvector_p.h
@@ -61,7 +61,7 @@ class QPODVector
 {
 public:
     QPODVector()
-    : m_count(0), m_capacity(0), m_data(0) {}
+    : m_count(0), m_capacity(0), m_data(nullptr) {}
     ~QPODVector() { if (m_data) ::free(m_data); }
 
     const T &at(int idx) const {
@@ -87,11 +87,11 @@ public:
     void insert(int idx, const T &v) {
         if (m_count == m_capacity) {
             m_capacity += Increment;
-            m_data = (T *)realloc(m_data, m_capacity * sizeof(T));
+            m_data = (T *)realloc(static_cast<void *>(m_data), m_capacity * sizeof(T));
         }
         int moveCount = m_count - idx;
         if (moveCount)
-            ::memmove(m_data + idx + 1, m_data + idx, moveCount * sizeof(T));
+            ::memmove(static_cast<void *>(m_data + idx + 1), static_cast<const void *>(m_data + idx), moveCount * sizeof(T));
         m_count++;
         m_data[idx] = v;
     }
@@ -99,7 +99,7 @@ public:
     void reserve(int count) {
         if (count >= m_capacity) {
             m_capacity = (count + (Increment-1)) & (0xFFFFFFFF - Increment + 1);
-            m_data = (T *)realloc(m_data, m_capacity * sizeof(T));
+            m_data = (T *)realloc(static_cast<void *>(m_data), m_capacity * sizeof(T));
         }
     }
 
@@ -108,7 +108,7 @@ public:
         reserve(newSize);
         int moveCount = m_count - idx;
         if (moveCount)
-            ::memmove(m_data + idx + count,  m_data + idx,
+            ::memmove(static_cast<void *>(m_data + idx + count),  static_cast<const void *>(m_data + idx),
                       moveCount * sizeof(T));
         m_count = newSize;
     }
@@ -116,7 +116,7 @@ public:
     void remove(int idx, int count = 1) {
         int moveCount = m_count - (idx + count);
         if (moveCount)
-            ::memmove(m_data + idx, m_data + idx + count,
+            ::memmove(static_cast<void *>(m_data + idx), static_cast<const void *>(m_data + idx + count),
                       moveCount * sizeof(T));
         m_count -= count;
     }
@@ -154,7 +154,7 @@ public:
         other.m_data = m_data;
         m_count = 0;
         m_capacity = 0;
-        m_data = 0;
+        m_data = nullptr;
     }
 
     QPODVector<T,Increment> &operator<<(const T &v) { append(v); return *this; }
diff --git a/src/qml/qml/ftw/qqmlnullablevalue_p.h b/src/qml/qml/ftw/qqmlnullablevalue_p.h
index 7a9e4d7b8a..5b3d2fc456 100644
--- a/src/qml/qml/ftw/qqmlnullablevalue_p.h
+++ b/src/qml/qml/ftw/qqmlnullablevalue_p.h
@@ -57,7 +57,7 @@ template<typename T>
 struct QQmlNullableValue
 {
     QQmlNullableValue()
-    : isNull(true), value(T()) {}
+    : value(T()) {}
     QQmlNullableValue(const QQmlNullableValue<T> &o)
     : isNull(o.isNull), value(o.value) {}
     QQmlNullableValue(const T &t)
@@ -70,7 +70,7 @@ struct QQmlNullableValue
 
     void invalidate() { isNull = true; }
     bool isValid() const { return !isNull; }
-    bool isNull;
+    bool isNull = true;
     T value;
 };
 
diff --git a/src/qml/qml/ftw/qqmlrefcount_p.h b/src/qml/qml/ftw/qqmlrefcount_p.h
index 225e18156c..140f129b21 100644
--- a/src/qml/qml/ftw/qqmlrefcount_p.h
+++ b/src/qml/qml/ftw/qqmlrefcount_p.h
@@ -60,18 +60,18 @@ QT_BEGIN_NAMESPACE
 
 class Q_QML_PRIVATE_EXPORT QQmlRefCount
 {
+    Q_DISABLE_COPY_MOVE(QQmlRefCount)
 public:
     inline QQmlRefCount();
-    inline virtual ~QQmlRefCount();
-    inline void addref();
-    inline void release();
+    inline void addref() const;
+    inline void release() const;
     inline int count() const;
 
 protected:
-    inline virtual void destroy();
+    inline virtual ~QQmlRefCount();
 
 private:
-    QAtomicInt refCount;
+    mutable QAtomicInt refCount;
 };
 
 template<class T>
@@ -85,19 +85,23 @@ public:
     inline QQmlRefPointer();
     inline QQmlRefPointer(T *, Mode m = AddRef);
     inline QQmlRefPointer(const QQmlRefPointer<T> &);
+    inline QQmlRefPointer(QQmlRefPointer<T> &&);
     inline ~QQmlRefPointer();
 
     inline QQmlRefPointer<T> &operator=(const QQmlRefPointer<T> &o);
+    inline QQmlRefPointer<T> &operator=(QQmlRefPointer<T> &&o);
 
     inline bool isNull() const { return !o; }
 
     inline T* operator->() const { return o; }
     inline T& operator*() const { return *o; }
-    inline operator T*() const { return o; }
+    explicit inline operator bool() const { return o != nullptr; }
     inline T* data() const { return o; }
 
     inline QQmlRefPointer<T> &adopt(T *);
 
+    inline T* take() { T *res = o; o = nullptr; return res; }
+
 private:
     T *o;
 };
@@ -112,17 +116,17 @@ QQmlRefCount::~QQmlRefCount()
     Q_ASSERT(refCount.load() == 0);
 }
 
-void QQmlRefCount::addref()
+void QQmlRefCount::addref() const
 {
     Q_ASSERT(refCount.load() > 0);
     refCount.ref();
 }
 
-void QQmlRefCount::release()
+void QQmlRefCount::release() const
 {
     Q_ASSERT(refCount.load() > 0);
     if (!refCount.deref())
-        destroy();
+        delete this;
 }
 
 int QQmlRefCount::count() const
@@ -130,14 +134,9 @@ int QQmlRefCount::count() const
     return refCount.load();
 }
 
-void QQmlRefCount::destroy()
-{
-    delete this;
-}
-
 template<class T>
 QQmlRefPointer<T>::QQmlRefPointer()
-: o(0)
+: o(nullptr)
 {
 }
 
@@ -156,6 +155,12 @@ QQmlRefPointer<T>::QQmlRefPointer(const QQmlRefPointer<T> &other)
     if (o) o->addref();
 }
 
+template <class T>
+QQmlRefPointer<T>::QQmlRefPointer(QQmlRefPointer<T> &&other)
+    : o(other.take())
+{
+}
+
 template<class T>
 QQmlRefPointer<T>::~QQmlRefPointer()
 {
@@ -171,6 +176,14 @@ QQmlRefPointer<T> &QQmlRefPointer<T>::operator=(const QQmlRefPointer<T> &other)
     return *this;
 }
 
+template <class T>
+QQmlRefPointer<T> &QQmlRefPointer<T>::operator=(QQmlRefPointer<T> &&other)
+{
+    QQmlRefPointer<T> m(std::move(other));
+    qSwap(o, m.o);
+    return *this;
+}
+
 /*!
 Takes ownership of \a other.  take() does *not* add a reference, as it assumes ownership
 of the callers reference of other.
diff --git a/src/qml/qml/ftw/qqmlthread.cpp b/src/qml/qml/ftw/qqmlthread.cpp
index ffa6e29290..2ef1dc7e93 100644
--- a/src/qml/qml/ftw/qqmlthread.cpp
+++ b/src/qml/qml/ftw/qqmlthread.cpp
@@ -57,6 +57,7 @@ public:
 
     void run() override;
 
+    inline QMutex &mutex() { return _mutex; }
     inline void lock() { _mutex.lock(); }
     inline void unlock() { _mutex.unlock(); }
     inline void wait() { _wait.wait(&_mutex); }
@@ -123,7 +124,7 @@ bool QQmlThreadPrivate::MainObject::event(QEvent *e)
 
 QQmlThreadPrivate::QQmlThreadPrivate(QQmlThread *q)
 : q(q), m_threadProcessing(false), m_mainProcessing(false), m_shutdown(false),
-  m_mainThreadWaiting(false), mainSync(0), m_mainObject(this)
+  m_mainThreadWaiting(false), mainSync(nullptr), m_mainObject(this)
 {
     setObjectName(QStringLiteral("QQmlThread"));
 }
@@ -155,7 +156,7 @@ void QQmlThreadPrivate::mainEvent()
     m_mainProcessing = true;
 
     while (!mainList.isEmpty() || mainSync) {
-        bool isSync = mainSync != 0;
+        bool isSync = mainSync != nullptr;
         QQmlThread::Message *message = isSync?mainSync:mainList.takeFirst();
         unlock();
 
@@ -165,7 +166,7 @@ void QQmlThreadPrivate::mainEvent()
         lock();
 
         if (isSync) {
-            mainSync = 0;
+            mainSync = nullptr;
             wakeOne();
         }
     }
@@ -233,20 +234,27 @@ void QQmlThread::shutdown()
 {
     d->lock();
     Q_ASSERT(!d->m_shutdown);
-    d->m_shutdown = true;
-    if (d->threadList.isEmpty() && d->m_threadProcessing == false) {
-        if (QCoreApplication::closingDown()) {
-            d->quit();
+
+    for (;;) {
+        if (d->mainSync || !d->mainList.isEmpty()) {
             d->unlock();
-            d->QThread::wait();
-            return;
+            d->mainEvent();
+            d->lock();
+        } else if (!d->threadList.isEmpty()) {
+            d->wait();
         } else {
-            d->triggerThreadEvent();
+            break;
         }
-    } else if (d->mainSync) {
-        d->wakeOne();
     }
-    d->wait();
+
+    d->m_shutdown = true;
+    if (QCoreApplication::closingDown()) {
+        d->quit();
+    } else {
+        d->triggerThreadEvent();
+        d->wait();
+    }
+
     d->unlock();
     d->QThread::wait();
 }
@@ -256,6 +264,11 @@ bool QQmlThread::isShutdown() const
     return d->m_shutdown;
 }
 
+QMutex &QQmlThread::mutex()
+{
+    return d->mutex();
+}
+
 void QQmlThread::lock()
 {
     d->lock();
@@ -303,6 +316,12 @@ void QQmlThread::shutdownThread()
 
 void QQmlThread::internalCallMethodInThread(Message *message)
 {
+#if !QT_CONFIG(thread)
+    message->call(this);
+    delete message;
+    return;
+#endif
+
     Q_ASSERT(!isThisThread());
     d->lock();
     Q_ASSERT(d->m_mainThreadWaiting == false);
@@ -321,7 +340,7 @@ void QQmlThread::internalCallMethodInThread(Message *message)
             message->call(this);
             delete message;
             lock();
-            d->mainSync = 0;
+            d->mainSync = nullptr;
             wakeOne();
         } else {
             d->wait();
@@ -338,7 +357,7 @@ void QQmlThread::internalCallMethodInMain(Message *message)
 
     d->lock();
 
-    Q_ASSERT(d->mainSync == 0);
+    Q_ASSERT(d->mainSync == nullptr);
     d->mainSync = message;
 
     if (d->m_mainThreadWaiting) {
@@ -352,7 +371,7 @@ void QQmlThread::internalCallMethodInMain(Message *message)
     while (d->mainSync) {
         if (d->m_shutdown) {
             delete d->mainSync;
-            d->mainSync = 0;
+            d->mainSync = nullptr;
             break;
         }
         d->wait();
@@ -363,6 +382,10 @@ void QQmlThread::internalCallMethodInMain(Message *message)
 
 void QQmlThread::internalPostMethodToThread(Message *message)
 {
+#if !QT_CONFIG(thread)
+    internalPostMethodToMain(message);
+    return;
+#endif
     Q_ASSERT(!isThisThread());
     d->lock();
     bool wasEmpty = d->threadList.isEmpty();
@@ -398,7 +421,7 @@ void QQmlThread::waitForNextMessage()
             message->call(this);
             delete message;
             lock();
-            d->mainSync = 0;
+            d->mainSync = nullptr;
             wakeOne();
         } else {
             d->wait();
diff --git a/src/qml/qml/ftw/qqmlthread_p.h b/src/qml/qml/ftw/qqmlthread_p.h
index 295235e255..b5c580fe8b 100644
--- a/src/qml/qml/ftw/qqmlthread_p.h
+++ b/src/qml/qml/ftw/qqmlthread_p.h
@@ -59,6 +59,7 @@
 QT_BEGIN_NAMESPACE
 
 class QThread;
+class QMutex;
 
 class QQmlThreadPrivate;
 class QQmlThread
@@ -71,6 +72,7 @@ public:
     void shutdown();
     bool isShutdown() const;
 
+    QMutex &mutex();
     void lock();
     void unlock();
     void wakeOne();
@@ -124,7 +126,7 @@ private:
     friend class QQmlThreadPrivate;
 
     struct Message {
-        Message() : next(0) {}
+        Message() : next(nullptr) {}
         virtual ~Message() {}
         Message *next;
         virtual void call(QQmlThread *) = 0;
diff --git a/src/qml/qml/ftw/qrecursionwatcher_p.h b/src/qml/qml/ftw/qrecursionwatcher_p.h
index 99228b9583..56b714f922 100644
--- a/src/qml/qml/ftw/qrecursionwatcher_p.h
+++ b/src/qml/qml/ftw/qrecursionwatcher_p.h
@@ -74,7 +74,7 @@ private:
 };
 
 QRecursionNode::QRecursionNode()
-: _r(0)
+: _r(nullptr)
 {
 }
 
@@ -89,7 +89,7 @@ QRecursionWatcher<T, Node>::QRecursionWatcher(T *t)
 template<class T, QRecursionNode T::*Node>
 QRecursionWatcher<T, Node>::~QRecursionWatcher()
 {
-    if ((_t->*Node)._r == &_r) (_t->*Node)._r = 0;
+    if ((_t->*Node)._r == &_r) (_t->*Node)._r = nullptr;
 }
 
 template<class T, QRecursionNode T::*Node>
diff --git a/src/qml/qml/ftw/qrecyclepool_p.h b/src/qml/qml/ftw/qrecyclepool_p.h
index 42a2f13729..39f4f88512 100644
--- a/src/qml/qml/ftw/qrecyclepool_p.h
+++ b/src/qml/qml/ftw/qrecyclepool_p.h
@@ -61,7 +61,7 @@ class QRecyclePoolPrivate
 public:
     QRecyclePoolPrivate()
     : recyclePoolHold(true), outstandingItems(0), cookie(QRECYCLEPOOLCOOKIE),
-      currentPage(0), nextAllocated(0)
+      currentPage(nullptr), nextAllocated(nullptr)
     {
     }
 
@@ -178,7 +178,7 @@ void QRecyclePoolPrivate<T, Step>::releaseIfPossible()
 template<typename T, int Step>
 T *QRecyclePoolPrivate<T, Step>::allocate()
 {
-    PoolType *rv = 0;
+    PoolType *rv = nullptr;
     if (nextAllocated) {
         rv = nextAllocated;
         nextAllocated = rv->nextAllocated;
diff --git a/src/qml/qml/ftw/qstringhash.cpp b/src/qml/qml/ftw/qstringhash.cpp
new file mode 100644
index 0000000000..a483dcb810
--- /dev/null
+++ b/src/qml/qml/ftw/qstringhash.cpp
@@ -0,0 +1,168 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qstringhash_p.h"
+
+QT_BEGIN_NAMESPACE
+
+/*
+    A QHash has initially around pow(2, MinNumBits) buckets. For
+    example, if MinNumBits is 4, it has 17 buckets.
+*/
+static const int MinNumBits = 4;
+
+/*
+    The prime_deltas array is a table of selected prime values, even
+    though it doesn't look like one. The primes we are using are 1,
+    2, 5, 11, 17, 37, 67, 131, 257, ..., i.e. primes in the immediate
+    surrounding of a power of two.
+
+    The primeForNumBits() function returns the prime associated to a
+    power of two. For example, primeForNumBits(8) returns 257.
+*/
+
+static const uchar prime_deltas[] = {
+    0,  0,  1,  3,  1,  5,  3,  3,  1,  9,  7,  5,  3,  9, 25,  3,
+    1, 21,  3, 21,  7, 15,  9,  5,  3, 29, 15,  0,  0,  0,  0,  0
+};
+
+static inline int primeForNumBits(int numBits)
+{
+    return (1 << numBits) + prime_deltas[numBits];
+}
+
+void QStringHashData::rehashToSize(int size)
+{
+    short bits = qMax(MinNumBits, (int)numBits);
+    while (primeForNumBits(bits) < size) bits++;
+
+    if (bits > numBits)
+        rehashToBits(bits);
+}
+
+void QStringHashData::rehashToBits(short bits)
+{
+    numBits = qMax(MinNumBits, (int)bits);
+
+    int nb = primeForNumBits(numBits);
+    if (nb == numBuckets && buckets)
+        return;
+
+    QStringHashNode **newBuckets = new QStringHashNode *[nb];
+    ::memset(newBuckets, 0, sizeof(QStringHashNode *) * nb);
+
+    // Preserve the existing order within buckets so that items with the
+    // same key will retain the same find/findNext order
+    for (int i = 0; i < numBuckets; ++i) {
+        QStringHashNode *bucket = buckets[i];
+        if (bucket)
+            rehashNode(newBuckets, nb, bucket);
+    }
+
+    delete [] buckets;
+    buckets = newBuckets;
+    numBuckets = nb;
+}
+
+void QStringHashData::rehashNode(QStringHashNode **newBuckets, int nb, QStringHashNode *node)
+{
+    QStringHashNode *next = node->next.data();
+    if (next)
+        rehashNode(newBuckets, nb, next);
+
+    int bucket = node->hash % nb;
+    node->next = newBuckets[bucket];
+    newBuckets[bucket] = node;
+}
+
+// Copy of QString's qMemCompare
+bool QHashedString::compare(const QChar *lhs, const QChar *rhs, int length)
+{
+    Q_ASSERT(lhs && rhs);
+    const quint16 *a = (const quint16 *)lhs;
+    const quint16 *b = (const quint16 *)rhs;
+
+    if (a == b || !length)
+        return true;
+
+    union {
+        const quint16 *w;
+        const quint32 *d;
+        quintptr value;
+    } sa, sb;
+    sa.w = a;
+    sb.w = b;
+
+    // check alignment
+    if ((sa.value & 2) == (sb.value & 2)) {
+        // both addresses have the same alignment
+        if (sa.value & 2) {
+            // both addresses are not aligned to 4-bytes boundaries
+            // compare the first character
+            if (*sa.w != *sb.w)
+                return false;
+            --length;
+            ++sa.w;
+            ++sb.w;
+
+            // now both addresses are 4-bytes aligned
+        }
+
+        // both addresses are 4-bytes aligned
+        // do a fast 32-bit comparison
+        const quint32 *e = sa.d + (length >> 1);
+        for ( ; sa.d != e; ++sa.d, ++sb.d) {
+            if (*sa.d != *sb.d)
+                return false;
+        }
+
+        // do we have a tail?
+        return (length & 1) ? *sa.w == *sb.w : true;
+    } else {
+        // one of the addresses isn't 4-byte aligned but the other is
+        const quint16 *e = sa.w + length;
+        for ( ; sa.w != e; ++sa.w, ++sb.w) {
+            if (*sa.w != *sb.w)
+                return false;
+        }
+    }
+    return true;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/ftw/qstringhash_p.h b/src/qml/qml/ftw/qstringhash_p.h
new file mode 100644
index 0000000000..c7251e8837
--- /dev/null
+++ b/src/qml/qml/ftw/qstringhash_p.h
@@ -0,0 +1,758 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSTRINGHASH_P_H
+#define QSTRINGHASH_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qhashedstring_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QStringHashData;
+class Q_AUTOTEST_EXPORT QStringHashNode
+{
+public:
+    QStringHashNode()
+    : ckey(nullptr)
+    {
+    }
+
+    QStringHashNode(const QHashedString &key)
+    : length(key.length()), hash(key.hash()), symbolId(0)
+    {
+        strData = const_cast<QHashedString &>(key).data_ptr();
+        setQString(true);
+        strData->ref.ref();
+    }
+
+    QStringHashNode(const QHashedCStringRef &key)
+    : length(key.length()), hash(key.hash()), symbolId(0), ckey(key.constData())
+    {
+    }
+
+    QStringHashNode(const QStringHashNode &o)
+    : length(o.length), hash(o.hash), symbolId(o.symbolId), ckey(o.ckey)
+    {
+        setQString(o.isQString());
+        if (isQString()) { strData->ref.ref(); }
+    }
+
+    ~QStringHashNode()
+    {
+        if (isQString()) { if (!strData->ref.deref()) free(strData); }
+    }
+
+    QFlagPointer<QStringHashNode> next;
+
+    qint32 length = 0;
+    quint32 hash = 0;
+    quint32 symbolId = 0;
+
+    union {
+        const char *ckey;
+        QStringData *strData;
+    };
+
+    inline QHashedString key() const
+    {
+        if (isQString())
+            return QHashedString(QString((QChar *)strData->data(), length), hash);
+
+        return QHashedString(QString::fromLatin1(ckey, length), hash);
+    }
+
+    bool isQString() const { return next.flag(); }
+    void setQString(bool v) { if (v) next.setFlag(); else next.clearFlag(); }
+
+    inline char *cStrData() const { return (char *)ckey; }
+    inline quint16 *utf16Data() const { return (quint16 *)strData->data(); }
+
+    inline bool equals(const QV4::Value &string) const {
+        QString s = string.toQStringNoThrow();
+        if (isQString()) {
+            QStringDataPtr dd;
+            dd.ptr = strData;
+            strData->ref.ref();
+            return QString(dd) == s;
+        } else {
+            return QLatin1String(cStrData(), length) == s;
+        }
+    }
+
+    inline bool equals(const QV4::String *string) const {
+        if (length != string->d()->length() || hash != string->hashValue())
+                return false;
+        if (isQString()) {
+            QStringDataPtr dd;
+            dd.ptr = strData;
+            strData->ref.ref();
+            return QString(dd) == string->toQString();
+        } else {
+            return QLatin1String(cStrData(), length) == string->toQString();
+        }
+    }
+
+    inline bool equals(const QHashedStringRef &string) const {
+        return length == string.length() &&
+               hash == string.hash() &&
+               (isQString()?QHashedString::compare(string.constData(), (const QChar *)utf16Data(), length):
+                            QHashedString::compare(string.constData(), cStrData(), length));
+    }
+
+    inline bool equals(const QHashedCStringRef &string) const {
+        return length == string.length() &&
+               hash == string.hash() &&
+               (isQString()?QHashedString::compare((const QChar *)utf16Data(), string.constData(), length):
+                            QHashedString::compare(string.constData(), cStrData(), length));
+    }
+};
+
+class Q_AUTOTEST_EXPORT QStringHashData
+{
+public:
+    QStringHashData() {}
+
+    QStringHashNode **buckets = nullptr;
+    int numBuckets = 0;
+    int size = 0;
+    short numBits = 0;
+
+    template<typename StringHash>
+    struct IteratorData {
+        IteratorData(QStringHashNode *n = nullptr, StringHash *p = nullptr) : n(n), p(p) {}
+
+        template<typename OtherData>
+        IteratorData(const OtherData &other) : n(other.n), p(other.p) {}
+
+        QStringHashNode *n;
+        StringHash *p;
+    };
+    void rehashToBits(short);
+    void rehashToSize(int);
+    void rehashNode(QStringHashNode **newBuckets, int nb, QStringHashNode *node);
+
+private:
+    QStringHashData(const QStringHashData &);
+    QStringHashData &operator=(const QStringHashData &);
+};
+
+// For a supplied key type, in what form do we need to keep a hashed version?
+template<typename T>
+struct HashedForm {};
+
+template<> struct HashedForm<QString> { typedef QHashedString Type; };
+template<> struct HashedForm<QStringRef> { typedef QHashedStringRef Type; };
+template<> struct HashedForm<QHashedString> { typedef const QHashedString &Type; };
+template<> struct HashedForm<QV4::String *> { typedef const QV4::String *Type; };
+template<> struct HashedForm<const QV4::String *> { typedef const QV4::String *Type; };
+template<> struct HashedForm<QHashedStringRef> { typedef const QHashedStringRef &Type; };
+template<> struct HashedForm<QLatin1String> { typedef QHashedCStringRef Type; };
+template<> struct HashedForm<QHashedCStringRef> { typedef const QHashedCStringRef &Type; };
+
+class QStringHashBase
+{
+public:
+    static HashedForm<QString>::Type hashedString(const QString &s) { return QHashedString(s);}
+    static HashedForm<QStringRef>::Type hashedString(const QStringRef &s) { return QHashedStringRef(s.constData(), s.size());}
+    static HashedForm<QHashedString>::Type hashedString(const QHashedString &s) { return s; }
+    static HashedForm<QV4::String *>::Type hashedString(QV4::String *s) { return s; }
+    static HashedForm<const QV4::String *>::Type hashedString(const QV4::String *s) { return s; }
+    static HashedForm<QHashedStringRef>::Type hashedString(const QHashedStringRef &s) { return s; }
+
+    static HashedForm<QLatin1String>::Type hashedString(const QLatin1String &s) { return QHashedCStringRef(s.data(), s.size()); }
+    static HashedForm<QHashedCStringRef>::Type hashedString(const QHashedCStringRef &s) { return s; }
+
+    static const QString &toQString(const QString &s) { return s; }
+    static const QString &toQString(const QHashedString &s) { return s; }
+    static QString toQString(const QV4::String *s) { return s->toQString(); }
+    static QString toQString(const QHashedStringRef &s) { return s.toString(); }
+
+    static QString toQString(const QLatin1String &s) { return QString(s); }
+    static QString toQString(const QHashedCStringRef &s) { return s.toUtf16(); }
+
+    static inline quint32 hashOf(const QHashedStringRef &s) { return s.hash(); }
+    static inline quint32 hashOf(QV4::String *s) { return s->hashValue(); }
+    static inline quint32 hashOf(const QV4::String *s) { return s->hashValue(); }
+
+    template<typename K>
+    static inline quint32 hashOf(const K &key) { return hashedString(key).hash(); }
+};
+
+template<class T>
+class QStringHash : public QStringHashBase
+{
+public:
+    typedef QHashedString key_type;
+    typedef T mapped_type;
+
+    using MutableIteratorData = QStringHashData::IteratorData<QStringHash<T>>;
+    using ConstIteratorData = QStringHashData::IteratorData<const QStringHash<T>>;
+
+    struct Node : public QStringHashNode {
+        Node(const QHashedString &key, const T &value) : QStringHashNode(key), value(value) {}
+        Node(const QHashedCStringRef &key, const T &value) : QStringHashNode(key), value(value) {}
+        Node(const Node &o) : QStringHashNode(o), value(o.value) {}
+        Node() {}
+        T value;
+    };
+    struct NewedNode : public Node {
+        NewedNode(const QHashedString &key, const T &value) : Node(key, value), nextNewed(nullptr) {}
+        NewedNode(const QHashedCStringRef &key, const T &value) : Node(key, value), nextNewed(nullptr) {}
+        NewedNode(const Node &o) : Node(o), nextNewed(nullptr) {}
+        NewedNode *nextNewed;
+    };
+    struct ReservedNodePool
+    {
+        ReservedNodePool() : nodes(nullptr) {}
+        ~ReservedNodePool() { delete [] nodes; }
+        int count = 0;
+        int used = 0;
+        Node *nodes;
+    };
+
+    QStringHashData data;
+    NewedNode *newedNodes;
+    ReservedNodePool *nodePool;
+
+    template<typename K>
+    inline Node *findNode(const K &) const;
+
+    inline Node *createNode(const Node &o);
+
+    template<typename K>
+    inline Node *createNode(const K &, const T &);
+
+    inline Node *insertNode(Node *, quint32);
+
+    inline void initializeNode(Node *, const QHashedString &key);
+    inline void initializeNode(Node *, const QHashedCStringRef &key);
+
+    template<typename K>
+    inline Node *takeNode(const K &key, const T &value);
+
+    inline Node *takeNode(const Node &o);
+
+    inline void copy(const QStringHash<T> &);
+
+    void copyNode(const QStringHashNode *otherNode);
+
+    template<typename StringHash, typename Data>
+    static inline Data iterateFirst(StringHash *self);
+
+    template<typename Data>
+    static inline Data iterateNext(const Data &);
+
+public:
+    inline QStringHash();
+    inline QStringHash(const QStringHash &);
+    inline ~QStringHash();
+
+    QStringHash &operator=(const QStringHash<T> &);
+
+    void copyAndReserve(const QStringHash<T> &other, int additionalReserve);
+
+    inline bool isEmpty() const;
+    inline void clear();
+    inline int count() const;
+
+    inline int numBuckets() const;
+
+    template<typename Data, typename Value>
+    class Iterator {
+    public:
+        inline Iterator() = default;
+        inline Iterator(const Data &d) : d(d) {}
+
+        inline Iterator &operator++()
+        {
+            d = QStringHash<T>::iterateNext(d);
+            return *this;
+        }
+
+        inline bool operator==(const Iterator &o) const { return d.n == o.d.n; }
+        inline bool operator!=(const Iterator &o) const { return d.n != o.d.n; }
+
+        template<typename K>
+        inline bool equals(const K &key) const { return d.n->equals(key); }
+
+        inline QHashedString key() const { return static_cast<Node *>(d.n)->key(); }
+        inline Value &value() const { return static_cast<Node *>(d.n)->value; }
+        inline Value &operator*() const { return static_cast<Node *>(d.n)->value; }
+
+        Node *node() const { return static_cast<Node *>(d.n); }
+    private:
+        Data d;
+    };
+
+    using MutableIterator = Iterator<MutableIteratorData, T>;
+    using ConstIterator = Iterator<ConstIteratorData, const T>;
+
+    template<typename K>
+    inline void insert(const K &, const T &);
+    inline void insert(const MutableIterator &);
+    inline void insert(const ConstIterator &);
+
+    template<typename K>
+    inline T *value(const K &) const;
+    inline T *value(const QV4::String *string) const;
+    inline T *value(const MutableIterator &) const;
+    inline T *value(const ConstIterator &) const;
+
+    template<typename K>
+    inline bool contains(const K &) const;
+
+    template<typename K>
+    inline T &operator[](const K &);
+
+    inline MutableIterator begin();
+    inline ConstIterator begin() const;
+    inline ConstIterator constBegin() const { return begin(); }
+
+    inline MutableIterator end();
+    inline ConstIterator end() const;
+    inline ConstIterator constEnd() const { return end(); }
+
+    template<typename K>
+    inline MutableIterator find(const K &);
+
+    template<typename K>
+    inline ConstIterator find(const K &) const;
+
+    inline void reserve(int);
+};
+
+template<class T>
+QStringHash<T>::QStringHash()
+: newedNodes(nullptr), nodePool(nullptr)
+{
+}
+
+template<class T>
+QStringHash<T>::QStringHash(const QStringHash<T> &other)
+: newedNodes(nullptr), nodePool(nullptr)
+{
+    data.numBits = other.data.numBits;
+    data.size = other.data.size;
+    reserve(other.count());
+    copy(other);
+}
+
+template<class T>
+QStringHash<T> &QStringHash<T>::operator=(const QStringHash<T> &other)
+{
+    if (&other == this)
+        return *this;
+
+    clear();
+
+    data.numBits = other.data.numBits;
+    data.size = other.data.size;
+    reserve(other.count());
+    copy(other);
+
+    return *this;
+}
+
+template<class T>
+void QStringHash<T>::copyAndReserve(const QStringHash<T> &other, int additionalReserve)
+{
+    clear();
+    data.numBits = other.data.numBits;
+    reserve(other.count() + additionalReserve);
+    copy(other);
+}
+
+template<class T>
+QStringHash<T>::~QStringHash()
+{
+    clear();
+}
+
+template<class T>
+void QStringHash<T>::clear()
+{
+    // Delete the individually allocated nodes
+    NewedNode *n = newedNodes;
+    while (n) {
+        NewedNode *c = n;
+        n = c->nextNewed;
+        delete c;
+    }
+    // Delete the pool allocated nodes
+    if (nodePool) delete nodePool;
+    delete [] data.buckets;
+
+    data.buckets = nullptr;
+    data.numBuckets = 0;
+    data.numBits = 0;
+    data.size = 0;
+
+    newedNodes = nullptr;
+    nodePool = nullptr;
+}
+
+template<class T>
+bool QStringHash<T>::isEmpty() const
+{
+    return data.size== 0;
+}
+
+template<class T>
+int QStringHash<T>::count() const
+{
+    return data.size;
+}
+
+template<class T>
+int QStringHash<T>::numBuckets() const
+{
+    return data.numBuckets;
+}
+
+template<class T>
+void QStringHash<T>::initializeNode(Node *node, const QHashedString &key)
+{
+    node->length = key.length();
+    node->hash = key.hash();
+    node->strData = const_cast<QHashedString &>(key).data_ptr();
+    node->strData->ref.ref();
+    node->setQString(true);
+}
+
+template<class T>
+void QStringHash<T>::initializeNode(Node *node, const QHashedCStringRef &key)
+{
+    node->length = key.length();
+    node->hash = key.hash();
+    node->ckey = key.constData();
+}
+
+template<class T>
+template<class K>
+typename QStringHash<T>::Node *QStringHash<T>::takeNode(const K &key, const T &value)
+{
+    if (nodePool && nodePool->used != nodePool->count) {
+        Node *rv = nodePool->nodes + nodePool->used++;
+        initializeNode(rv, hashedString(key));
+        rv->value = value;
+        return rv;
+    } else {
+        NewedNode *rv = new NewedNode(hashedString(key), value);
+        rv->nextNewed = newedNodes;
+        newedNodes = rv;
+        return rv;
+    }
+}
+
+template<class T>
+typename QStringHash<T>::Node *QStringHash<T>::takeNode(const Node &o)
+{
+    if (nodePool && nodePool->used != nodePool->count) {
+        Node *rv = nodePool->nodes + nodePool->used++;
+        rv->length = o.length;
+        rv->hash = o.hash;
+        if (o.isQString()) {
+            rv->strData = o.strData;
+            rv->strData->ref.ref();
+            rv->setQString(true);
+        } else {
+            rv->ckey = o.ckey;
+        }
+        rv->symbolId = o.symbolId;
+        rv->value = o.value;
+        return rv;
+    } else {
+        NewedNode *rv = new NewedNode(o);
+        rv->nextNewed = newedNodes;
+        newedNodes = rv;
+        return rv;
+    }
+}
+
+template<class T>
+void QStringHash<T>::copyNode(const QStringHashNode *otherNode)
+{
+    // Copy the predecessor before the successor
+    QStringHashNode *next = otherNode->next.data();
+    if (next)
+        copyNode(next);
+
+    Node *mynode = takeNode(*(const Node *)otherNode);
+    int bucket = mynode->hash % data.numBuckets;
+    mynode->next = data.buckets[bucket];
+    data.buckets[bucket] = mynode;
+}
+
+template<class T>
+void QStringHash<T>::copy(const QStringHash<T> &other)
+{
+    Q_ASSERT(data.size == 0);
+
+    data.size = other.data.size;
+
+    // Ensure buckets array is created
+    data.rehashToBits(data.numBits);
+
+    // Preserve the existing order within buckets
+    for (int i = 0; i < other.data.numBuckets; ++i) {
+        QStringHashNode *bucket = other.data.buckets[i];
+        if (bucket)
+            copyNode(bucket);
+    }
+}
+
+template<class T>
+template<typename Data>
+Data QStringHash<T>::iterateNext(const Data &d)
+{
+    auto *This = d.p;
+    Node *node = (Node *)d.n;
+
+    if (This->nodePool && node >= This->nodePool->nodes &&
+        node < (This->nodePool->nodes + This->nodePool->used)) {
+        node--;
+        if (node < This->nodePool->nodes)
+            node = nullptr;
+    } else {
+        NewedNode *nn = (NewedNode *)node;
+        node = nn->nextNewed;
+
+        if (node == nullptr && This->nodePool && This->nodePool->used)
+            node = This->nodePool->nodes + This->nodePool->used - 1;
+    }
+
+    Data rv;
+    rv.n = node;
+    rv.p = d.p;
+    return rv;
+}
+
+template<class T>
+template<typename StringHash, typename Data>
+Data QStringHash<T>::iterateFirst(StringHash *self)
+{
+    typename StringHash::Node *n = nullptr;
+    if (self->newedNodes)
+        n = self->newedNodes;
+    else if (self->nodePool && self->nodePool->used)
+        n = self->nodePool->nodes + self->nodePool->used - 1;
+
+    Data rv;
+    rv.n = n;
+    rv.p = self;
+    return rv;
+}
+
+template<class T>
+typename QStringHash<T>::Node *QStringHash<T>::createNode(const Node &o)
+{
+    Node *n = takeNode(o);
+    return insertNode(n, n->hash);
+}
+
+template<class T>
+template<class K>
+typename QStringHash<T>::Node *QStringHash<T>::createNode(const K &key, const T &value)
+{
+    Node *n = takeNode(key, value);
+    return insertNode(n, hashOf(key));
+}
+
+template<class T>
+typename QStringHash<T>::Node *QStringHash<T>::insertNode(Node *n, quint32 hash)
+{
+    if (data.size >= data.numBuckets)
+        data.rehashToBits(data.numBits + 1);
+
+    int bucket = hash % data.numBuckets;
+    n->next = data.buckets[bucket];
+    data.buckets[bucket] = n;
+
+    data.size++;
+
+    return n;
+}
+
+template<class T>
+template<class K>
+void QStringHash<T>::insert(const K &key, const T &value)
+{
+    Node *n = findNode(key);
+    if (n)
+        n->value = value;
+    else
+        createNode(key, value);
+}
+
+template<class T>
+void QStringHash<T>::insert(const MutableIterator &iter)
+{
+    insert(iter.key(), iter.value());
+}
+
+template<class T>
+void QStringHash<T>::insert(const ConstIterator &iter)
+{
+    insert(iter.key(), iter.value());
+}
+
+template<class T>
+template<class K>
+typename QStringHash<T>::Node *QStringHash<T>::findNode(const K &key) const
+{
+    QStringHashNode *node = data.numBuckets?data.buckets[hashOf(key) % data.numBuckets]:nullptr;
+
+    typename HashedForm<K>::Type hashedKey(hashedString(key));
+    while (node && !node->equals(hashedKey))
+        node = (*node->next);
+
+    return (Node *)node;
+}
+
+template<class T>
+template<class K>
+T *QStringHash<T>::value(const K &key) const
+{
+    Node *n = findNode(key);
+    return n?&n->value:nullptr;
+}
+
+template<typename T>
+T *QStringHash<T>::value(const MutableIterator &iter) const
+{
+    return value(iter.node()->key());
+}
+
+template<class T>
+T *QStringHash<T>::value(const ConstIterator &iter) const
+{
+    return value(iter.node()->key());
+}
+
+template<class T>
+T *QStringHash<T>::value(const QV4::String *string) const
+{
+    Node *n = findNode(string);
+    return n?&n->value:nullptr;
+}
+
+template<class T>
+template<class K>
+bool QStringHash<T>::contains(const K &key) const
+{
+    return nullptr != value(key);
+}
+
+template<class T>
+template<class K>
+T &QStringHash<T>::operator[](const K &key)
+{
+    Node *n = findNode(key);
+    if (n) return n->value;
+    else return createNode(key, T())->value;
+}
+
+template<class T>
+void QStringHash<T>::reserve(int n)
+{
+    if (nodePool || 0 == n)
+        return;
+
+    nodePool = new ReservedNodePool;
+    nodePool->count = n;
+    nodePool->used = 0;
+    nodePool->nodes = new Node[n];
+
+    data.rehashToSize(n);
+}
+
+template<class T>
+typename QStringHash<T>::MutableIterator QStringHash<T>::begin()
+{
+    return MutableIterator(iterateFirst<QStringHash<T>, MutableIteratorData>(this));
+}
+
+template<class T>
+typename QStringHash<T>::ConstIterator QStringHash<T>::begin() const
+{
+    return ConstIterator(iterateFirst<const QStringHash<T>, ConstIteratorData>(this));
+}
+
+template<class T>
+typename QStringHash<T>::MutableIterator QStringHash<T>::end()
+{
+    return MutableIterator();
+}
+
+template<class T>
+typename QStringHash<T>::ConstIterator QStringHash<T>::end() const
+{
+    return ConstIterator();
+}
+
+template<class T>
+template<class K>
+typename QStringHash<T>::MutableIterator QStringHash<T>::find(const K &key)
+{
+    Node *n = findNode(key);
+    return n ? MutableIterator(MutableIteratorData(n, this)) : MutableIterator();
+}
+
+template<class T>
+template<class K>
+typename QStringHash<T>::ConstIterator QStringHash<T>::find(const K &key) const
+{
+    Node *n = findNode(key);
+    return n ? ConstIterator(ConstIteratorData(n, this)) : ConstIterator();
+}
+
+QT_END_NAMESPACE
+
+#endif // QSTRINGHASH_P_H
diff --git a/src/qml/qml/qml.pri b/src/qml/qml/qml.pri
index 412dc6cba2..0895e5ae68 100644
--- a/src/qml/qml/qml.pri
+++ b/src/qml/qml/qml.pri
@@ -1,4 +1,5 @@
 SOURCES += \
+    $$PWD/qqml.cpp \
     $$PWD/qqmlopenmetaobject.cpp \
     $$PWD/qqmlvmemetaobject.cpp \
     $$PWD/qqmlengine.cpp \
@@ -14,16 +15,21 @@ SOURCES += \
     $$PWD/qqmlvme.cpp \
     $$PWD/qqmlboundsignal.cpp \
     $$PWD/qqmlmetatype.cpp \
+    $$PWD/qqmlmetatypedata.cpp \
     $$PWD/qqmlstringconverters.cpp \
+    $$PWD/qqmltype.cpp \
+    $$PWD/qqmltypemodule.cpp \
+    $$PWD/qqmltypemoduleversion.cpp \
     $$PWD/qqmlparserstatus.cpp \
     $$PWD/qqmltypeloader.cpp \
     $$PWD/qqmlinfo.cpp \
-    $$PWD/qqmlerror.cpp \
     $$PWD/qqmlvaluetype.cpp \
-    $$PWD/qqmlxmlhttprequest.cpp \
     $$PWD/qqmlcleanup.cpp \
     $$PWD/qqmlpropertycache.cpp \
+    $$PWD/qqmlmetaobject.cpp \
     $$PWD/qqmlnotifier.cpp \
+    $$PWD/qqmlobjectorgadget.cpp \
+    $$PWD/qqmlstaticmetaobject.cpp \
     $$PWD/qqmltypenotavailable.cpp \
     $$PWD/qqmltypenamecache.cpp \
     $$PWD/qqmlscriptstring.cpp \
@@ -31,7 +37,6 @@ SOURCES += \
     $$PWD/qqmlextensionplugin.cpp \
     $$PWD/qqmlimport.cpp \
     $$PWD/qqmllist.cpp \
-    $$PWD/qqmllocale.cpp \
     $$PWD/qqmljavascriptexpression.cpp \
     $$PWD/qqmlabstractbinding.cpp \
     $$PWD/qqmlvaluetypeproxybinding.cpp \
@@ -46,7 +51,6 @@ SOURCES += \
     $$PWD/qqmltypewrapper.cpp \
     $$PWD/qqmlfileselector.cpp \
     $$PWD/qqmlobjectcreator.cpp \
-    $$PWD/qqmldirparser.cpp \
     $$PWD/qqmldelayedcallqueue.cpp \
     $$PWD/qqmlloggingcategory.cpp
 
@@ -72,6 +76,12 @@ HEADERS += \
     $$PWD/qqmlexpression_p.h \
     $$PWD/qqmlprivate.h \
     $$PWD/qqmlmetatype_p.h \
+    $$PWD/qqmlmetatypedata_p.h \
+    $$PWD/qqmltype_p.h \
+    $$PWD/qqmltype_p_p.h \
+    $$PWD/qqmltypemodule_p.h \
+    $$PWD/qqmltypemodule_p_p.h \
+    $$PWD/qqmltypemoduleversion_p.h \
     $$PWD/qqmlengine.h \
     $$PWD/qqmlcontext.h \
     $$PWD/qqmlexpression.h \
@@ -83,13 +93,20 @@ HEADERS += \
     $$PWD/qqmllist.h \
     $$PWD/qqmllist_p.h \
     $$PWD/qqmldata_p.h \
-    $$PWD/qqmlerror.h \
     $$PWD/qqmlvaluetype_p.h \
-    $$PWD/qqmlxmlhttprequest_p.h \
     $$PWD/qqmlcleanup_p.h \
+    $$PWD/qqmlenumdata_p.h \
+    $$PWD/qqmlenumvalue_p.h \
     $$PWD/qqmlpropertycache_p.h \
+    $$PWD/qqmlpropertycachemethodarguments_p.h \
+    $$PWD/qqmlpropertycachevector_p.h \
+    $$PWD/qqmlpropertydata_p.h \
     $$PWD/qqmlpropertyindex_p.h \
+    $$PWD/qqmlpropertyrawdata_p.h \
+    $$PWD/qqmlmetaobject_p.h \
     $$PWD/qqmlnotifier_p.h \
+    $$PWD/qqmlobjectorgadget_p.h \
+    $$PWD/qqmlstaticmetaobject_p.h \
     $$PWD/qqmltypenotavailable_p.h \
     $$PWD/qqmltypenamecache_p.h \
     $$PWD/qqmlscriptstring.h \
@@ -99,7 +116,6 @@ HEADERS += \
     $$PWD/qqmlimport_p.h \
     $$PWD/qqmlextensionplugin.h \
     $$PWD/qqmlscriptstring_p.h \
-    $$PWD/qqmllocale_p.h \
     $$PWD/qqmlcomponentattached_p.h \
     $$PWD/qqmljavascriptexpression_p.h \
     $$PWD/qqmlabstractbinding_p.h \
@@ -116,9 +132,25 @@ HEADERS += \
     $$PWD/qqmlfileselector_p.h \
     $$PWD/qqmlfileselector.h \
     $$PWD/qqmlobjectcreator_p.h \
-    $$PWD/qqmldirparser_p.h \
     $$PWD/qqmldelayedcallqueue_p.h \
     $$PWD/qqmlloggingcategory_p.h
 
+qtConfig(qml-xml-http-request) {
+    HEADERS += \
+        $$PWD/qqmlxmlhttprequest_p.h
+
+    SOURCES += \
+        $$PWD/qqmlxmlhttprequest.cpp
+
+}
+
+qtConfig(qml-locale) {
+    HEADERS += \
+        $$PWD/qqmllocale_p.h
+
+    SOURCES += \
+        $$PWD/qqmllocale.cpp
+}
+
 include(ftw/ftw.pri)
 include(v8/v8.pri)
diff --git a/src/qml/qml/qqml.cpp b/src/qml/qml/qqml.cpp
new file mode 100644
index 0000000000..c1a8ed2a3d
--- /dev/null
+++ b/src/qml/qml/qqml.cpp
@@ -0,0 +1,116 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqml.h"
+
+#include <QtQml/qqmlprivate.h>
+
+#include <private/qqmlengine_p.h>
+#include <private/qqmlmetatype_p.h>
+#include <private/qqmlmetatypedata_p.h>
+#include <private/qqmltype_p_p.h>
+#include <private/qqmltypemodule_p_p.h>
+
+#include <QtCore/qmutex.h>
+
+QT_BEGIN_NAMESPACE
+
+void qmlClearTypeRegistrations() // Declared in qqml.h
+{
+    QQmlMetaType::clearTypeRegistrations();
+    QQmlEnginePrivate::baseModulesUninitialized = true; //So the engine re-registers its types
+#if QT_CONFIG(library)
+    qmlClearEnginePlugins();
+#endif
+}
+
+//From qqml.h
+bool qmlProtectModule(const char *uri, int majVersion)
+{
+    return QQmlMetaType::protectModule(uri, majVersion);
+}
+
+//From qqml.h
+void qmlRegisterModule(const char *uri, int versionMajor, int versionMinor)
+{
+    QQmlMetaType::registerModule(uri, versionMajor, versionMinor);
+}
+
+//From qqml.h
+int qmlTypeId(const char *uri, int versionMajor, int versionMinor, const char *qmlName)
+{
+    return QQmlMetaType::typeId(uri, versionMajor, versionMinor, qmlName);
+}
+
+/*
+This method is "over generalized" to allow us to (potentially) register more types of things in
+the future without adding exported symbols.
+*/
+int QQmlPrivate::qmlregister(RegistrationType type, void *data)
+{
+    if (type == AutoParentRegistration) {
+        return QQmlMetaType::registerAutoParentFunction(
+                *reinterpret_cast<RegisterAutoParent *>(data));
+    } else if (type == QmlUnitCacheHookRegistration) {
+        return QQmlMetaType::registerUnitCacheHook(
+                *reinterpret_cast<RegisterQmlUnitCacheHook *>(data));
+    }
+
+    QQmlType dtype;
+    if (type == TypeRegistration)
+        dtype = QQmlMetaType::registerType(*reinterpret_cast<RegisterType *>(data));
+    else if (type == InterfaceRegistration)
+        dtype = QQmlMetaType::registerInterface(*reinterpret_cast<RegisterInterface *>(data));
+    else if (type == SingletonRegistration)
+        dtype = QQmlMetaType::registerSingletonType(*reinterpret_cast<RegisterSingletonType *>(data));
+    else if (type == CompositeRegistration)
+        dtype = QQmlMetaType::registerCompositeType(*reinterpret_cast<RegisterCompositeType *>(data));
+    else if (type == CompositeSingletonRegistration)
+        dtype = QQmlMetaType::registerCompositeSingletonType(*reinterpret_cast<RegisterCompositeSingletonType *>(data));
+    else
+        return -1;
+
+    if (!dtype.isValid())
+        return -1;
+
+    QQmlMetaType::registerUndeletableType(dtype);
+    return dtype.index();
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqml.h b/src/qml/qml/qqml.h
index ddb4af0b81..05a9f70247 100644
--- a/src/qml/qml/qqml.h
+++ b/src/qml/qml/qqml.h
@@ -112,10 +112,10 @@ int qmlRegisterType()
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
         0,
-        Q_NULLPTR,
+        nullptr,
         QString(),
 
-        Q_NULLPTR, 0, 0, Q_NULLPTR, &T::staticMetaObject,
+        nullptr, 0, 0, nullptr, &T::staticMetaObject,
 
         QQmlPrivate::attachedPropertiesFunc<T>(),
         QQmlPrivate::attachedPropertiesMetaObject<T>(),
@@ -124,9 +124,9 @@ int qmlRegisterType()
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -146,7 +146,7 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
         0,
-        Q_NULLPTR,
+        nullptr,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -158,9 +158,9 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -178,7 +178,7 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
         0,
-        Q_NULLPTR,
+        nullptr,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -190,9 +190,9 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         metaObjectRevision
     };
 
@@ -217,7 +217,7 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
         0,
-        Q_NULLPTR,
+        nullptr,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -231,7 +231,7 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -256,7 +256,7 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
         0,
-        Q_NULLPTR,
+        nullptr,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -270,7 +270,7 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        Q_NULLPTR,
+        nullptr,
         metaObjectRevision
     };
 
@@ -301,9 +301,9 @@ int qmlRegisterType(const char *uri, int versionMajor, int versionMinor, const c
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -332,9 +332,9 @@ int qmlRegisterType(const char *uri, int versionMajor, int versionMinor, const c
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         metaObjectRevision
     };
 
@@ -354,7 +354,7 @@ int qmlRegisterRevision(const char *uri, int versionMajor, int versionMinor)
         sizeof(T), QQmlPrivate::createInto<T>,
         QString(),
 
-        uri, versionMajor, versionMinor, 0, &T::staticMetaObject,
+        uri, versionMajor, versionMinor, nullptr, &T::staticMetaObject,
 
         QQmlPrivate::attachedPropertiesFunc<T>(),
         QQmlPrivate::attachedPropertiesMetaObject<T>(),
@@ -363,9 +363,9 @@ int qmlRegisterRevision(const char *uri, int versionMajor, int versionMinor)
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         metaObjectRevision
     };
 
@@ -384,10 +384,10 @@ int qmlRegisterExtendedType()
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
         0,
-        Q_NULLPTR,
+        nullptr,
         QString(),
 
-        Q_NULLPTR, 0, 0, Q_NULLPTR, &T::staticMetaObject,
+        nullptr, 0, 0, nullptr, &T::staticMetaObject,
 
         QQmlPrivate::attachedPropertiesFunc<T>(),
         QQmlPrivate::attachedPropertiesMetaObject<T>(),
@@ -398,7 +398,7 @@ int qmlRegisterExtendedType()
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -437,7 +437,7 @@ int qmlRegisterExtendedType(const char *uri, int versionMajor, int versionMinor,
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -487,7 +487,7 @@ int qmlRegisterCustomType(const char *uri, int versionMajor, int versionMinor,
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
         parser,
         0
@@ -496,6 +496,38 @@ int qmlRegisterCustomType(const char *uri, int versionMajor, int versionMinor,
     return QQmlPrivate::qmlregister(QQmlPrivate::TypeRegistration, &type);
 }
 
+template<typename T, int metaObjectRevision>
+int qmlRegisterCustomType(const char *uri, int versionMajor, int versionMinor,
+                          const char *qmlName, QQmlCustomParser *parser)
+{
+    QML_GETTYPENAMES
+
+    QQmlPrivate::RegisterType type = {
+        1,
+
+        qRegisterNormalizedMetaType<T *>(pointerName.constData()),
+        qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
+        sizeof(T), QQmlPrivate::createInto<T>,
+        QString(),
+
+        uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
+
+        QQmlPrivate::attachedPropertiesFunc<T>(),
+        QQmlPrivate::attachedPropertiesMetaObject<T>(),
+
+        QQmlPrivate::StaticCastSelector<T,QQmlParserStatus>::cast(),
+        QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
+        QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
+
+        nullptr, nullptr,
+
+        parser,
+        metaObjectRevision
+    };
+
+    return QQmlPrivate::qmlregister(QQmlPrivate::TypeRegistration, &type);
+}
+
 template<typename T, typename E>
 int qmlRegisterCustomExtendedType(const char *uri, int versionMajor, int versionMinor,
                           const char *qmlName, QQmlCustomParser *parser)
@@ -583,7 +615,7 @@ inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versi
 
         uri, versionMajor, versionMinor, typeName,
 
-        callback, Q_NULLPTR, Q_NULLPTR, 0, 0
+        callback, nullptr, nullptr, 0, 0
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
@@ -601,7 +633,7 @@ inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versi
 
         uri, versionMajor, versionMinor, typeName,
 
-        Q_NULLPTR, callback, &T::staticMetaObject, qRegisterNormalizedMetaType<T *>(pointerName.constData()), 0
+        nullptr, callback, &T::staticMetaObject, qRegisterNormalizedMetaType<T *>(pointerName.constData()), 0
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
@@ -645,6 +677,8 @@ inline int qmlRegisterType(const QUrl &url, const char *uri, int versionMajor, i
     return QQmlPrivate::qmlregister(QQmlPrivate::CompositeRegistration, &type);
 }
 
+int Q_QML_EXPORT qmlTypeId(const char *uri, int versionMajor, int versionMinor, const char *qmlName);
+
 QT_END_NAMESPACE
 
 QML_DECLARE_TYPE(QObject)
diff --git a/src/qml/qml/qqmlabstractbinding.cpp b/src/qml/qml/qqmlabstractbinding.cpp
index b1c320afd4..42891c1a8e 100644
--- a/src/qml/qml/qqmlabstractbinding.cpp
+++ b/src/qml/qml/qqmlabstractbinding.cpp
@@ -83,7 +83,7 @@ void QQmlAbstractBinding::addToObject()
         // Value type
 
         // Find the value type proxy (if there is one)
-        QQmlValueTypeProxyBinding *proxy = 0;
+        QQmlValueTypeProxyBinding *proxy = nullptr;
         if (data->hasBindingBit(coreIndex)) {
             QQmlAbstractBinding *b = data->bindings;
             while (b && (b->targetPropertyIndex().coreIndex() != coreIndex ||
@@ -137,7 +137,7 @@ void QQmlAbstractBinding::removeFromObject()
 
     QQmlAbstractBinding::Ptr next;
     next = nextBinding();
-    setNextBinding(0);
+    setNextBinding(nullptr);
 
     int coreIndex = targetPropertyIndex().coreIndex();
     if (targetPropertyIndex().hasValueTypeIndex()) {
diff --git a/src/qml/qml/qqmlabstractbinding_p.h b/src/qml/qml/qqmlabstractbinding_p.h
index bea2d253e4..fc53be3e7b 100644
--- a/src/qml/qml/qqmlabstractbinding_p.h
+++ b/src/qml/qml/qqmlabstractbinding_p.h
@@ -95,8 +95,8 @@ public:
     { return m_nextBinding.flag2(); }
 
     struct RefCount {
-        RefCount() : refCount(0) {}
-        int refCount;
+        RefCount() {}
+        int refCount = 0;
         void ref() { ++refCount; }
         int deref() { return --refCount; }
         operator int() const { return refCount; }
diff --git a/src/qml/qml/qqmlabstracturlinterceptor.h b/src/qml/qml/qqmlabstracturlinterceptor.h
index 665b37fb3a..af231f51b2 100644
--- a/src/qml/qml/qqmlabstracturlinterceptor.h
+++ b/src/qml/qml/qqmlabstracturlinterceptor.h
@@ -55,8 +55,8 @@ public:
         UrlString = 0x1000
     };
 
-    QQmlAbstractUrlInterceptor() {}
-    virtual ~QQmlAbstractUrlInterceptor() {}
+    QQmlAbstractUrlInterceptor() = default;
+    virtual ~QQmlAbstractUrlInterceptor() = default;
     virtual QUrl intercept(const QUrl &path, DataType type) = 0;
 };
 
diff --git a/src/qml/qml/qqmlapplicationengine.cpp b/src/qml/qml/qqmlapplicationengine.cpp
index faab8bf926..1b7a433a84 100644
--- a/src/qml/qml/qqmlapplicationengine.cpp
+++ b/src/qml/qml/qqmlapplicationengine.cpp
@@ -70,11 +70,13 @@ void QQmlApplicationEnginePrivate::cleanUp()
 void QQmlApplicationEnginePrivate::init()
 {
     Q_Q(QQmlApplicationEngine);
-    q->connect(q, SIGNAL(quit()), QCoreApplication::instance(), SLOT(quit()));
-    q->connect(q, &QQmlApplicationEngine::exit, QCoreApplication::instance(), &QCoreApplication::exit);
+    q->connect(q, &QQmlApplicationEngine::quit, QCoreApplication::instance(),
+               &QCoreApplication::quit, Qt::QueuedConnection);
+    q->connect(q, &QQmlApplicationEngine::exit, QCoreApplication::instance(),
+               &QCoreApplication::exit, Qt::QueuedConnection);
 #if QT_CONFIG(translation)
     QTranslator* qtTranslator = new QTranslator;
-    if (qtTranslator->load(QLatin1String("qt_") + QLocale::system().name(), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+    if (qtTranslator->load(QLocale(), QLatin1String("qt"), QLatin1String("_"), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
         QCoreApplication::installTranslator(qtTranslator);
     translators << qtTranslator;
 #endif
@@ -91,7 +93,7 @@ void QQmlApplicationEnginePrivate::loadTranslations(const QUrl &rootFile)
     QFileInfo fi(rootFile.toLocalFile());
 
     QTranslator *translator = new QTranslator;
-    if (translator->load(QLatin1String("qml_") + QLocale::system().name(), fi.path() + QLatin1String("/i18n"))) {
+    if (translator->load(QLocale(), QLatin1String("qml"), QLatin1String("_"), fi.path() + QLatin1String("/i18n"))) {
         QCoreApplication::installTranslator(translator);
         translators << translator;
     } else {
@@ -128,7 +130,7 @@ void QQmlApplicationEnginePrivate::finishLoad(QQmlComponent *c)
     case QQmlComponent::Error:
         qWarning() << "QQmlApplicationEngine failed to load component";
         qWarning() << qPrintable(c->errorString());
-        q->objectCreated(0, c->url());
+        q->objectCreated(nullptr, c->url());
         break;
     case QQmlComponent::Ready: {
         auto newObj = c->create();
@@ -248,10 +250,12 @@ QQmlApplicationEngine::~QQmlApplicationEngine()
 /*!
   Loads the root QML file located at \a url. The object tree defined by the file
   is created immediately for local file urls. Remote urls are loaded asynchronously,
-  listen to the objectCreated signal to determine when the object
-  tree is ready.
+  listen to the \l {QQmlApplicationEngine::objectCreated()}{objectCreated} signal to
+  determine when the object tree is ready.
 
-  If an error occurs, error messages are printed with qWarning.
+  If an error occurs, the \l {QQmlApplicationEngine::objectCreated()}{objectCreated}
+  signal is emitted with a null pointer as parameter and error messages are printed
+  with qWarning.
 */
 void QQmlApplicationEngine::load(const QUrl &url)
 {
diff --git a/src/qml/qml/qqmlapplicationengine.h b/src/qml/qml/qqmlapplicationengine.h
index 6c57f46c72..bb5d6b5d68 100644
--- a/src/qml/qml/qqmlapplicationengine.h
+++ b/src/qml/qml/qqmlapplicationengine.h
@@ -53,10 +53,10 @@ class Q_QML_EXPORT QQmlApplicationEngine : public QQmlEngine
 {
     Q_OBJECT
 public:
-    QQmlApplicationEngine(QObject *parent = Q_NULLPTR);
-    QQmlApplicationEngine(const QUrl &url, QObject *parent = Q_NULLPTR);
-    QQmlApplicationEngine(const QString &filePath, QObject *parent = Q_NULLPTR);
-    ~QQmlApplicationEngine();
+    QQmlApplicationEngine(QObject *parent = nullptr);
+    QQmlApplicationEngine(const QUrl &url, QObject *parent = nullptr);
+    QQmlApplicationEngine(const QString &filePath, QObject *parent = nullptr);
+    ~QQmlApplicationEngine() override;
 
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     QList<QObject*> rootObjects(); // ### Qt 6: remove
diff --git a/src/qml/qml/qqmlapplicationengine_p.h b/src/qml/qml/qqmlapplicationengine_p.h
index 4795170bed..6cf6828832 100644
--- a/src/qml/qml/qqmlapplicationengine_p.h
+++ b/src/qml/qml/qqmlapplicationengine_p.h
@@ -74,7 +74,6 @@ public:
     void loadTranslations(const QUrl &rootFile);
     void finishLoad(QQmlComponent *component);
     QList<QObject *> objects;
-    QObject *appObj;
 
 #if QT_CONFIG(translation)
     QList<QTranslator *> translators;
diff --git a/src/qml/qml/qqmlbinding.cpp b/src/qml/qml/qqmlbinding.cpp
index 62288a5845..a949df4968 100644
--- a/src/qml/qml/qqmlbinding.cpp
+++ b/src/qml/qml/qqmlbinding.cpp
@@ -51,9 +51,11 @@
 #include <private/qqmlvaluetypewrapper_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 #include <private/qv4variantobject_p.h>
+#include <private/qv4jscall_p.h>
 
 #include <QVariant>
 #include <QtCore/qdebug.h>
+#include <QVector>
 
 QT_BEGIN_NAMESPACE
 
@@ -69,7 +71,7 @@ QQmlBinding *QQmlBinding::create(const QQmlPropertyData *property, const QQmlScr
         return b;
 
     QString url;
-    QV4::Function *runtimeFunction = 0;
+    QV4::Function *runtimeFunction = nullptr;
 
     QQmlContextData *ctxtdata = QQmlContextData::get(scriptPrivate->context);
     QQmlEnginePrivate *engine = QQmlEnginePrivate::get(scriptPrivate->context->engine());
@@ -83,7 +85,7 @@ QQmlBinding *QQmlBinding::create(const QQmlPropertyData *property, const QQmlScr
     b->QQmlJavaScriptExpression::setContext(QQmlContextData::get(ctxt ? ctxt : scriptPrivate->context));
     b->setScopeObject(obj ? obj : scriptPrivate->scope);
 
-    QV4::ExecutionEngine *v4 = QQmlEnginePrivate::get(b->context()->engine)->v4engine();
+    QV4::ExecutionEngine *v4 = b->context()->engine->handle();
     if (runtimeFunction) {
         QV4::Scope scope(v4);
         QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(v4->rootContext(), ctxtdata, b->scopeObject()));
@@ -96,6 +98,21 @@ QQmlBinding *QQmlBinding::create(const QQmlPropertyData *property, const QQmlScr
     return b;
 }
 
+QQmlSourceLocation QQmlBinding::sourceLocation() const
+{
+    if (m_sourceLocation)
+        return *m_sourceLocation;
+    return QQmlJavaScriptExpression::sourceLocation();
+}
+
+void QQmlBinding::setSourceLocation(const QQmlSourceLocation &location)
+{
+    if (m_sourceLocation)
+        delete m_sourceLocation;
+    m_sourceLocation = new QQmlSourceLocation(location);
+}
+
+
 QQmlBinding *QQmlBinding::create(const QQmlPropertyData *property, const QString &str, QObject *obj,
                                  QQmlContextData *ctxt, const QString &url, quint16 lineNumber)
 {
@@ -127,6 +144,7 @@ QQmlBinding *QQmlBinding::create(const QQmlPropertyData *property, QV4::Function
 
 QQmlBinding::~QQmlBinding()
 {
+    delete m_sourceLocation;
 }
 
 void QQmlBinding::setNotifyOnValueChanged(bool v)
@@ -149,7 +167,7 @@ void QQmlBinding::update(QQmlPropertyData::WriteFlags flags)
         QQmlPropertyData vtd;
         getPropertyData(&d, &vtd);
         Q_ASSERT(d);
-        QQmlProperty p = QQmlPropertyPrivate::restore(targetObject(), *d, &vtd, 0);
+        QQmlProperty p = QQmlPropertyPrivate::restore(targetObject(), *d, &vtd, nullptr);
         QQmlAbstractBinding::printBindingLoopError(p);
         return;
     }
@@ -157,19 +175,41 @@ void QQmlBinding::update(QQmlPropertyData::WriteFlags flags)
 
     DeleteWatcher watcher(this);
 
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(context()->engine);
-    QV4::Scope scope(ep->v4engine());
+    QQmlEngine *engine = context()->engine;
+    QV4::Scope scope(engine->handle());
 
     if (canUseAccessor())
         flags.setFlag(QQmlPropertyData::BypassInterceptor);
 
-    QQmlBindingProfiler prof(ep->profiler, function());
+    QQmlBindingProfiler prof(QQmlEnginePrivate::get(engine)->profiler, function());
     doUpdate(watcher, flags, scope);
 
     if (!watcher.wasDeleted())
         setUpdatingFlag(false);
 }
 
+QV4::ReturnedValue QQmlBinding::evaluate(bool *isUndefined)
+{
+    QV4::ExecutionEngine *v4 = context()->engine->handle();
+    int argc = 0;
+    const QV4::Value *argv = nullptr;
+    const QV4::Value *thisObject = nullptr;
+    QV4::BoundFunction *b = nullptr;
+    if ((b = static_cast<QV4::BoundFunction *>(m_boundFunction.valueRef()))) {
+        QV4::Heap::MemberData *args = b->boundArgs();
+        if (args) {
+            argc = args->values.size;
+            argv = args->values.data();
+        }
+        thisObject = &b->d()->boundThis;
+    }
+    QV4::Scope scope(v4);
+    QV4::JSCallData jsCall(scope, argc, argv, thisObject);
+
+    return QQmlJavaScriptExpression::evaluate(jsCall.callData(), isUndefined);
+}
+
+
 // QQmlBindingBinding is for target properties which are of type "binding" (instead of, say, int or
 // double). The reason for being is that GenericBinding::fastWrite needs a compile-time constant
 // expression for the switch for the compiler to generate the optimal code, but
@@ -179,7 +219,7 @@ class QQmlBindingBinding: public QQmlBinding
 {
 protected:
     void doUpdate(const DeleteWatcher &,
-                  QQmlPropertyData::WriteFlags flags, QV4::Scope &) Q_DECL_OVERRIDE Q_DECL_FINAL
+                  QQmlPropertyData::WriteFlags flags, QV4::Scope &) override final
     {
         Q_ASSERT(!m_targetIndex.hasValueTypeIndex());
         QQmlPropertyData *pd = nullptr;
@@ -195,19 +235,18 @@ class QQmlNonbindingBinding: public QQmlBinding
 {
 protected:
     void doUpdate(const DeleteWatcher &watcher,
-                  QQmlPropertyData::WriteFlags flags, QV4::Scope &scope) Q_DECL_OVERRIDE Q_DECL_FINAL
+                  QQmlPropertyData::WriteFlags flags, QV4::Scope &scope) override
     {
         auto ep = QQmlEnginePrivate::get(scope.engine);
         ep->referenceScarceResources();
 
         bool isUndefined = false;
 
-        QV4::ScopedCallData callData(scope);
-        QQmlJavaScriptExpression::evaluate(callData, &isUndefined, scope);
+        QV4::ScopedValue result(scope, evaluate(&isUndefined));
 
         bool error = false;
         if (!watcher.wasDeleted() && isAddedToObject() && !hasError())
-            error = !write(scope.result, isUndefined, flags);
+            error = !write(result, isUndefined, flags);
 
         if (!watcher.wasDeleted()) {
 
@@ -237,7 +276,7 @@ class GenericBinding: public QQmlNonbindingBinding
 protected:
     // Returns true if successful, false if an error description was set on expression
     Q_ALWAYS_INLINE bool write(const QV4::Value &result, bool isUndefined,
-                               QQmlPropertyData::WriteFlags flags) Q_DECL_OVERRIDE Q_DECL_FINAL
+                               QQmlPropertyData::WriteFlags flags) override final
     {
         Q_ASSERT(targetObject());
 
@@ -277,7 +316,7 @@ protected:
                 break;
             default:
                 if (const QV4::QQmlValueTypeWrapper *vtw = result.as<const QV4::QQmlValueTypeWrapper>()) {
-                    if (vtw->d()->valueType->typeId == pd->propType()) {
+                    if (vtw->d()->valueType->metaType.id() == pd->propType()) {
                         return vtw->write(m_target.data(), pd->coreIndex());
                     }
                 }
@@ -296,13 +335,69 @@ protected:
     }
 };
 
+class QQmlTranslationBinding : public GenericBinding<QMetaType::QString> {
+public:
+    QQmlTranslationBinding(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QV4::CompiledData::Binding *binding)
+    {
+        setCompilationUnit(compilationUnit);
+        m_binding = binding;
+    }
+
+    QQmlSourceLocation sourceLocation() const override final
+    {
+        return QQmlSourceLocation(m_compilationUnit->fileName(), m_binding->valueLocation.line, m_binding->valueLocation.column);
+    }
+
+
+    void doUpdate(const DeleteWatcher &watcher,
+                  QQmlPropertyData::WriteFlags flags, QV4::Scope &scope) override final
+    {
+        if (watcher.wasDeleted())
+            return;
+
+        if (!isAddedToObject() || hasError())
+            return;
+
+        const QString result = m_binding->valueAsString(m_compilationUnit.data());
+
+        Q_ASSERT(targetObject());
+
+        QQmlPropertyData *pd;
+        QQmlPropertyData vpd;
+        getPropertyData(&pd, &vpd);
+        Q_ASSERT(pd);
+        if (pd->propType() == QMetaType::QString) {
+            doStore(result, pd, flags);
+        } else {
+            QV4::ScopedString value(scope, scope.engine->newString(result));
+            slowWrite(*pd, vpd, value, /*isUndefined*/false, flags);
+        }
+    }
+
+    bool hasDependencies() const override final { return true; }
+
+private:
+    const QV4::CompiledData::Binding *m_binding;
+};
+
+QQmlBinding *QQmlBinding::createTranslationBinding(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit, const QV4::CompiledData::Binding *binding, QObject *obj, QQmlContextData *ctxt)
+{
+    QQmlTranslationBinding *b = new QQmlTranslationBinding(unit, binding);
+
+    b->setNotifyOnValueChanged(true);
+    b->QQmlJavaScriptExpression::setContext(ctxt);
+    b->setScopeObject(obj);
+
+    return b;
+}
+
 Q_NEVER_INLINE bool QQmlBinding::slowWrite(const QQmlPropertyData &core,
                                            const QQmlPropertyData &valueTypeData,
                                            const QV4::Value &result,
                                            bool isUndefined, QQmlPropertyData::WriteFlags flags)
 {
     QQmlEngine *engine = context()->engine;
-    QV8Engine *v8engine = QQmlEnginePrivate::getV8Engine(engine);
+    QV4::ExecutionEngine *v4engine = engine->handle();
 
     int type = valueTypeData.isValid() ? valueTypeData.propType() : core.propType();
 
@@ -313,13 +408,13 @@ Q_NEVER_INLINE bool QQmlBinding::slowWrite(const QQmlPropertyData &core,
 
     if (isUndefined) {
     } else if (core.isQList()) {
-        value = QV8Engine::getV4(v8engine)->toVariant(result, qMetaTypeId<QList<QObject *> >());
+        value = v4engine->toVariant(result, qMetaTypeId<QList<QObject *> >());
     } else if (result.isNull() && core.isQObject()) {
-        value = QVariant::fromValue((QObject *)0);
+        value = QVariant::fromValue((QObject *)nullptr);
     } else if (core.propType() == qMetaTypeId<QList<QUrl> >()) {
-        value = QQmlPropertyPrivate::resolvedUrlSequence(QV8Engine::getV4(v8engine)->toVariant(result, qMetaTypeId<QList<QUrl> >()), context());
+        value = QQmlPropertyPrivate::resolvedUrlSequence(v4engine->toVariant(result, qMetaTypeId<QList<QUrl> >()), context());
     } else if (!isVarProperty && type != qMetaTypeId<QJSValue>()) {
-        value = QV8Engine::getV4(v8engine)->toVariant(result, type);
+        value = v4engine->toVariant(result, type);
     }
 
     if (hasError()) {
@@ -337,7 +432,7 @@ Q_NEVER_INLINE bool QQmlBinding::slowWrite(const QQmlPropertyData &core,
         Q_ASSERT(vmemo);
         vmemo->setVMEProperty(core.coreIndex(), result);
     } else if (isUndefined && core.isResettable()) {
-        void *args[] = { 0 };
+        void *args[] = { nullptr };
         QMetaObject::metacall(m_target.data(), QMetaObject::ResetProperty, core.coreIndex(), args);
     } else if (isUndefined && type == qMetaTypeId<QVariant>()) {
         QQmlPropertyPrivate::writeValueProperty(m_target.data(), core, valueTypeData, QVariant(), context(), flags);
@@ -348,7 +443,7 @@ Q_NEVER_INLINE bool QQmlBinding::slowWrite(const QQmlPropertyData &core,
             return false;
         }
         QQmlPropertyPrivate::writeValueProperty(m_target.data(), core, valueTypeData, QVariant::fromValue(
-                               QJSValue(QV8Engine::getV4(v8engine), result.asReturnedValue())),
+                               QJSValue(v4engine, result.asReturnedValue())),
                            context(), flags);
     } else if (isUndefined) {
         const QLatin1String typeName(QMetaType::typeName(type)
@@ -368,8 +463,8 @@ Q_NEVER_INLINE bool QQmlBinding::slowWrite(const QQmlPropertyData &core,
         if (watcher.wasDeleted())
             return true;
 
-        const char *valueType = 0;
-        const char *propertyType = 0;
+        const char *valueType = nullptr;
+        const char *propertyType = nullptr;
 
         const int userType = value.userType();
         if (userType == QMetaType::QObjectStar) {
@@ -406,27 +501,30 @@ Q_NEVER_INLINE bool QQmlBinding::slowWrite(const QQmlPropertyData &core,
 
 QVariant QQmlBinding::evaluate()
 {
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(context()->engine);
+    QQmlEngine *engine = context()->engine;
+    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
     ep->referenceScarceResources();
 
     bool isUndefined = false;
 
-    QV4::Scope scope(ep->v4engine());
-    QV4::ScopedCallData callData(scope);
-    QQmlJavaScriptExpression::evaluate(callData, &isUndefined, scope);
+    QV4::Scope scope(engine->handle());
+    QV4::ScopedValue result(scope, QQmlJavaScriptExpression::evaluate(&isUndefined));
 
     ep->dereferenceScarceResources();
 
-    return scope.engine->toVariant(scope.result, qMetaTypeId<QList<QObject*> >());
+    return scope.engine->toVariant(result, qMetaTypeId<QList<QObject*> >());
 }
 
 QString QQmlBinding::expressionIdentifier() const
 {
-    auto f = function();
-    QString url = f->sourceFile();
-    quint16 lineNumber = f->compiledFunction->location.line;
-    quint16 columnNumber = f->compiledFunction->location.column;
-    return url + QString::asprintf(":%u:%u", uint(lineNumber), uint(columnNumber));
+    if (auto f = function()) {
+        QString url = f->sourceFile();
+        quint16 lineNumber = f->compiledFunction->location.line;
+        quint16 columnNumber = f->compiledFunction->location.column;
+        return url + QString::asprintf(":%u:%u", uint(lineNumber), uint(columnNumber));
+    }
+
+    return QStringLiteral("[native code]");
 }
 
 void QQmlBinding::expressionChanged()
@@ -441,6 +539,7 @@ void QQmlBinding::refresh()
 
 void QQmlBinding::setEnabled(bool e, QQmlPropertyData::WriteFlags flags)
 {
+    const bool wasEnabled = enabledFlag();
     setEnabledFlag(e);
     setNotifyOnValueChanged(e);
 
@@ -450,13 +549,13 @@ void QQmlBinding::setEnabled(bool e, QQmlPropertyData::WriteFlags flags)
             m_nextBinding.clearFlag2();
     }
 
-    if (e)
+    if (e && !wasEnabled)
         update(flags);
 }
 
 QString QQmlBinding::expression() const
 {
-    return QStringLiteral("function() { [code] }");
+    return QStringLiteral("function() { [native code] }");
 }
 
 void QQmlBinding::setTarget(const QQmlProperty &prop)
@@ -465,13 +564,13 @@ void QQmlBinding::setTarget(const QQmlProperty &prop)
     setTarget(prop.object(), pd->core, &pd->valueTypeData);
 }
 
-void QQmlBinding::setTarget(QObject *object, const QQmlPropertyData &core, const QQmlPropertyData *valueType)
+bool QQmlBinding::setTarget(QObject *object, const QQmlPropertyData &core, const QQmlPropertyData *valueType)
 {
     m_target = object;
 
     if (!object) {
         m_targetIndex = QQmlPropertyIndex();
-        return;
+        return false;
     }
 
     int coreIndex = core.coreIndex();
@@ -481,18 +580,19 @@ void QQmlBinding::setTarget(QObject *object, const QQmlPropertyData &core, const
 
         int aValueTypeIndex;
         if (!vme->aliasTarget(coreIndex, &object, &coreIndex, &aValueTypeIndex)) {
-            m_target = 0;
+            // can't resolve id (yet)
+            m_target = nullptr;
             m_targetIndex = QQmlPropertyIndex();
-            return;
+            return false;
         }
         if (valueTypeIndex == -1)
             valueTypeIndex = aValueTypeIndex;
 
         QQmlData *data = QQmlData::get(object, false);
         if (!data || !data->propertyCache) {
-            m_target = 0;
+            m_target = nullptr;
             m_targetIndex = QQmlPropertyIndex();
-            return;
+            return false;
         }
         QQmlPropertyData *propertyData = data->propertyCache->property(coreIndex);
         Q_ASSERT(propertyData);
@@ -508,6 +608,8 @@ void QQmlBinding::setTarget(QObject *object, const QQmlPropertyData &core, const
         data->propertyCache = QQmlEnginePrivate::get(context()->engine)->cache(m_target->metaObject());
         data->propertyCache->addref();
     }
+
+    return true;
 }
 
 void QQmlBinding::getPropertyData(QQmlPropertyData **propertyData, QQmlPropertyData *valueTypeData) const
@@ -515,7 +617,12 @@ void QQmlBinding::getPropertyData(QQmlPropertyData **propertyData, QQmlPropertyD
     Q_ASSERT(propertyData);
 
     QQmlData *data = QQmlData::get(*m_target, false);
-    Q_ASSERT(data && data->propertyCache);
+    Q_ASSERT(data);
+
+    if (Q_UNLIKELY(!data->propertyCache)) {
+        data->propertyCache = QQmlEnginePrivate::get(context()->engine)->cache(m_target->metaObject());
+        data->propertyCache->addref();
+    }
 
     *propertyData = data->propertyCache->property(m_targetIndex.coreIndex());
     Q_ASSERT(*propertyData);
@@ -530,6 +637,42 @@ void QQmlBinding::getPropertyData(QQmlPropertyData **propertyData, QQmlPropertyD
     }
 }
 
+QVector<QQmlProperty> QQmlBinding::dependencies() const
+{
+    QVector<QQmlProperty> dependencies;
+    if (!m_target.data())
+        return dependencies;
+
+    for (const auto &guardList : { permanentGuards, activeGuards }) {
+        for (QQmlJavaScriptExpressionGuard *guard = guardList.first(); guard; guard = guardList.next(guard)) {
+            if (guard->signalIndex() == -1) // guard's sender is a QQmlNotifier, not a QObject*.
+                continue;
+
+            QObject *senderObject = guard->senderAsObject();
+            if (!senderObject)
+                continue;
+
+            const QMetaObject *senderMeta = senderObject->metaObject();
+            if (!senderMeta)
+                continue;
+
+            for (int i = 0; i < senderMeta->propertyCount(); i++) {
+                QMetaProperty property = senderMeta->property(i);
+                if (property.notifySignalIndex() == QMetaObjectPrivate::signal(senderMeta, guard->signalIndex()).methodIndex()) {
+                    dependencies.push_back(QQmlProperty(senderObject, QString::fromUtf8(senderObject->metaObject()->property(i).name())));
+                }
+            }
+        }
+    }
+
+    return dependencies;
+}
+
+bool QQmlBinding::hasDependencies() const
+{
+    return !permanentGuards.isEmpty() || !activeGuards.isEmpty() || translationsCaptured();
+}
+
 class QObjectPointerBinding: public QQmlNonbindingBinding
 {
     QQmlMetaObject targetMetaObject;
@@ -541,7 +684,7 @@ public:
 
 protected:
     Q_ALWAYS_INLINE bool write(const QV4::Value &result, bool isUndefined,
-                               QQmlPropertyData::WriteFlags flags) Q_DECL_OVERRIDE Q_DECL_FINAL
+                               QQmlPropertyData::WriteFlags flags) override final
     {
         QQmlPropertyData *pd;
         QQmlPropertyData vtpd;
diff --git a/src/qml/qml/qqmlbinding_p.h b/src/qml/qml/qqmlbinding_p.h
index 0f2fb329f5..f192de4342 100644
--- a/src/qml/qml/qqmlbinding_p.h
+++ b/src/qml/qml/qqmlbinding_p.h
@@ -72,22 +72,26 @@ class Q_QML_PRIVATE_EXPORT QQmlBinding : public QQmlJavaScriptExpression,
 {
     friend class QQmlAbstractBinding;
 public:
+    typedef QExplicitlySharedDataPointer<QQmlBinding> Ptr;
+
     static QQmlBinding *create(const QQmlPropertyData *, const QQmlScriptString &, QObject *, QQmlContext *);
     static QQmlBinding *create(const QQmlPropertyData *, const QString &, QObject *, QQmlContextData *,
                                const QString &url = QString(), quint16 lineNumber = 0);
     static QQmlBinding *create(const QQmlPropertyData *property, QV4::Function *function,
                                QObject *obj, QQmlContextData *ctxt, QV4::ExecutionContext *scope);
-    ~QQmlBinding();
+    static QQmlBinding *createTranslationBinding(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit, const QV4::CompiledData::Binding *binding,
+                                                 QObject *obj, QQmlContextData *ctxt);
+    ~QQmlBinding() override;
 
     void setTarget(const QQmlProperty &);
-    void setTarget(QObject *, const QQmlPropertyData &, const QQmlPropertyData *valueType);
+    bool setTarget(QObject *, const QQmlPropertyData &, const QQmlPropertyData *valueType);
 
     void setNotifyOnValueChanged(bool);
 
-    void refresh() Q_DECL_OVERRIDE;
+    void refresh() override;
 
-    void setEnabled(bool, QQmlPropertyData::WriteFlags flags = QQmlPropertyData::DontRemoveBinding) Q_DECL_OVERRIDE;
-    QString expression() const Q_DECL_OVERRIDE;
+    void setEnabled(bool, QQmlPropertyData::WriteFlags flags = QQmlPropertyData::DontRemoveBinding) override;
+    QString expression() const override;
     void update(QQmlPropertyData::WriteFlags flags = QQmlPropertyData::DontRemoveBinding);
 
     typedef int Identifier;
@@ -100,6 +104,22 @@ public:
     QString expressionIdentifier() const override;
     void expressionChanged() override;
 
+    QQmlSourceLocation sourceLocation() const override;
+    void setSourceLocation(const QQmlSourceLocation &location);
+    void setBoundFunction(QV4::BoundFunction *boundFunction) {
+        m_boundFunction.set(boundFunction->engine(), *boundFunction);
+    }
+
+    /**
+     * This method returns a snapshot of the currently tracked dependencies of
+     * this binding. The dependencies can change upon reevaluation. This method is
+     * used in GammaRay to visualize binding hierarchies.
+     *
+     * Call this method from the UI thread.
+     */
+    QVector<QQmlProperty> dependencies() const;
+    virtual bool hasDependencies() const;
+
 protected:
     virtual void doUpdate(const DeleteWatcher &watcher,
                           QQmlPropertyData::WriteFlags flags, QV4::Scope &scope) = 0;
@@ -110,6 +130,8 @@ protected:
     bool slowWrite(const QQmlPropertyData &core, const QQmlPropertyData &valueTypeData,
                    const QV4::Value &result, bool isUndefined, QQmlPropertyData::WriteFlags flags);
 
+    QV4::ReturnedValue evaluate(bool *isUndefined);
+
 private:
     inline bool updatingFlag() const;
     inline void setUpdatingFlag(bool);
@@ -117,6 +139,9 @@ private:
     inline void setEnabledFlag(bool);
 
     static QQmlBinding *newBinding(QQmlEnginePrivate *engine, const QQmlPropertyData *property);
+
+    QQmlSourceLocation *m_sourceLocation = nullptr; // used for Qt.binding() created functions
+    QV4::PersistentValue m_boundFunction; // used for Qt.binding() that are created from a bound function object
 };
 
 bool QQmlBinding::updatingFlag() const
diff --git a/src/qml/qml/qqmlboundsignal.cpp b/src/qml/qml/qqmlboundsignal.cpp
index 19ece44beb..cf6f831818 100644
--- a/src/qml/qml/qqmlboundsignal.cpp
+++ b/src/qml/qml/qqmlboundsignal.cpp
@@ -44,7 +44,6 @@
 #include "qqmlengine_p.h"
 #include "qqmlexpression_p.h"
 #include "qqmlcontext_p.h"
-#include "qqmlmetatype_p.h"
 #include "qqml.h"
 #include "qqmlcontext.h"
 #include "qqmlglobal_p.h"
@@ -55,6 +54,7 @@
 
 #include <private/qjsvalue_p.h>
 #include <private/qv4value_p.h>
+#include <private/qv4jscall_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 
 #include <QtCore/qdebug.h>
@@ -73,8 +73,7 @@ QQmlBoundSignalExpression::QQmlBoundSignalExpression(QObject *target, int index,
 {
     init(ctxt, scope);
 
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine());
-    QV4::ExecutionEngine *v4 = ep->v4engine();
+    QV4::ExecutionEngine *v4 = engine()->handle();
 
     QString function;
 
@@ -110,34 +109,34 @@ QQmlBoundSignalExpression::QQmlBoundSignalExpression(QObject *target, int index,
       m_index(index),
       m_target(target)
 {
-    setupFunction(scope, function);
-    init(ctxt, scopeObject);
-}
-
-QQmlBoundSignalExpression::QQmlBoundSignalExpression(QObject *target, int index, QQmlContextData *ctxt, QObject *scope, QV4::Function *runtimeFunction)
-    : QQmlJavaScriptExpression(),
-      m_index(index),
-      m_target(target)
-{
     // It's important to call init first, because m_index gets remapped in case of cloned signals.
-    init(ctxt, scope);
-
-    QV4::ExecutionEngine *engine = QQmlEnginePrivate::getV4Engine(ctxt->engine);
+    init(ctxt, scopeObject);
 
-    QList<QByteArray> signalParameters = QMetaObjectPrivate::signal(m_target->metaObject(), m_index).parameterNames();
-    if (!signalParameters.isEmpty()) {
-        QString error;
-        QQmlPropertyCache::signalParameterStringForJS(engine, signalParameters, &error);
-        if (!error.isEmpty()) {
-            qmlWarning(scopeObject()) << error;
-            return;
+    QV4::ExecutionEngine *engine = ctxt->engine->handle();
+
+    // If the function is marked as having a nested function, then the user wrote:
+    //   onSomeSignal: function() { /*....*/ }
+    // So take that nested function:
+    if (auto closure = function->nestedFunction()) {
+        function = closure;
+    } else {
+        QList<QByteArray> signalParameters = QMetaObjectPrivate::signal(m_target->metaObject(), m_index).parameterNames();
+        if (!signalParameters.isEmpty()) {
+            QString error;
+            QQmlPropertyCache::signalParameterStringForJS(engine, signalParameters, &error);
+            if (!error.isEmpty()) {
+                qmlWarning(scopeObject) << error;
+                return;
+            }
+            function->updateInternalClass(engine, signalParameters);
         }
-        runtimeFunction->updateInternalClass(engine, signalParameters);
     }
 
     QV4::Scope valueScope(engine);
-    QV4::Scoped<QV4::QmlContext> qmlContext(valueScope, QV4::QmlContext::create(engine->rootContext(), ctxt, scope));
-    setupFunction(qmlContext, runtimeFunction);
+    QV4::Scoped<QV4::QmlContext> qmlContext(valueScope, scope);
+    if (!qmlContext)
+        qmlContext = QV4::QmlContext::create(engine->rootContext(), ctxt, scopeObject);
+    setupFunction(qmlContext, function);
 }
 
 void QQmlBoundSignalExpression::init(QQmlContextData *ctxt, QObject *scope)
@@ -168,7 +167,7 @@ void QQmlBoundSignalExpression::expressionChanged()
 QString QQmlBoundSignalExpression::expression() const
 {
     if (expressionFunctionValid())
-        return QStringLiteral("function() { [code] }");
+        return QStringLiteral("function() { [native code] }");
     return QString();
 }
 
@@ -181,46 +180,48 @@ void QQmlBoundSignalExpression::evaluate(void **a)
     if (!expressionFunctionValid())
         return;
 
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine());
-    QV4::Scope scope(ep->v4engine());
+    QQmlEngine *qmlengine = engine();
+    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(qmlengine);
+    QV4::ExecutionEngine *v4 = qmlengine->handle();
+    QV4::Scope scope(v4);
 
     ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
 
     QQmlMetaObject::ArgTypeStorage storage;
     //TODO: lookup via signal index rather than method index as an optimization
     int methodIndex = QMetaObjectPrivate::signal(m_target->metaObject(), m_index).methodIndex();
-    int *argsTypes = QQmlMetaObject(m_target).methodParameterTypes(methodIndex, &storage, 0);
+    int *argsTypes = QQmlMetaObject(m_target).methodParameterTypes(methodIndex, &storage, nullptr);
     int argCount = argsTypes ? *argsTypes : 0;
 
-    QV4::ScopedCallData callData(scope, argCount);
+    QV4::JSCallData jsCall(scope, argCount);
     for (int ii = 0; ii < argCount; ++ii) {
         int type = argsTypes[ii + 1];
         //### ideally we would use metaTypeToJS, however it currently gives different results
         //    for several cases (such as QVariant type and QObject-derived types)
         //args[ii] = engine->metaTypeToJS(type, a[ii + 1]);
         if (type == qMetaTypeId<QJSValue>()) {
-            if (QV4::Value *v4Value = QJSValuePrivate::valueForData(reinterpret_cast<QJSValue *>(a[ii + 1]), &callData->args[ii]))
-                callData->args[ii] = *v4Value;
+            if (QV4::Value *v4Value = QJSValuePrivate::valueForData(reinterpret_cast<QJSValue *>(a[ii + 1]), &jsCall->args[ii]))
+                jsCall->args[ii] = *v4Value;
             else
-                callData->args[ii] = QV4::Encode::undefined();
+                jsCall->args[ii] = QV4::Encode::undefined();
         } else if (type == QMetaType::QVariant) {
-            callData->args[ii] = scope.engine->fromVariant(*((QVariant *)a[ii + 1]));
+            jsCall->args[ii] = scope.engine->fromVariant(*((QVariant *)a[ii + 1]));
         } else if (type == QMetaType::Int) {
             //### optimization. Can go away if we switch to metaTypeToJS, or be expanded otherwise
-            callData->args[ii] = QV4::Primitive::fromInt32(*reinterpret_cast<const int*>(a[ii + 1]));
+            jsCall->args[ii] = QV4::Value::fromInt32(*reinterpret_cast<const int*>(a[ii + 1]));
         } else if (type == qMetaTypeId<QQmlV4Handle>()) {
-            callData->args[ii] = *reinterpret_cast<QQmlV4Handle *>(a[ii + 1]);
+            jsCall->args[ii] = *reinterpret_cast<QQmlV4Handle *>(a[ii + 1]);
         } else if (ep->isQObject(type)) {
             if (!*reinterpret_cast<void* const *>(a[ii + 1]))
-                callData->args[ii] = QV4::Primitive::nullValue();
+                jsCall->args[ii] = QV4::Value::nullValue();
             else
-                callData->args[ii] = QV4::QObjectWrapper::wrap(ep->v4engine(), *reinterpret_cast<QObject* const *>(a[ii + 1]));
+                jsCall->args[ii] = QV4::QObjectWrapper::wrap(v4, *reinterpret_cast<QObject* const *>(a[ii + 1]));
         } else {
-            callData->args[ii] = scope.engine->fromVariant(QVariant(type, a[ii + 1]));
+            jsCall->args[ii] = scope.engine->fromVariant(QVariant(type, a[ii + 1]));
         }
     }
 
-    QQmlJavaScriptExpression::evaluate(callData, 0, scope);
+    QQmlJavaScriptExpression::evaluate(jsCall.callData(), nullptr);
 
     ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
 }
@@ -232,17 +233,18 @@ void QQmlBoundSignalExpression::evaluate(const QList<QVariant> &args)
     if (!expressionFunctionValid())
         return;
 
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine());
-    QV4::Scope scope(ep->v4engine());
+    QQmlEngine *qmlengine = engine();
+    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(qmlengine);
+    QV4::Scope scope(qmlengine->handle());
 
     ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
 
-    QV4::ScopedCallData callData(scope, args.count());
+    QV4::JSCallData jsCall(scope, args.count());
     for (int ii = 0; ii < args.count(); ++ii) {
-        callData->args[ii] = scope.engine->fromVariant(args[ii]);
+        jsCall->args[ii] = scope.engine->fromVariant(args[ii]);
     }
 
-    QQmlJavaScriptExpression::evaluate(callData, 0, scope);
+    QQmlJavaScriptExpression::evaluate(jsCall.callData(), nullptr);
 
     ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
 }
@@ -257,8 +259,8 @@ void QQmlBoundSignalExpression::evaluate(const QList<QVariant> &args)
 QQmlBoundSignal::QQmlBoundSignal(QObject *target, int signal, QObject *owner,
                                  QQmlEngine *engine)
     : QQmlNotifierEndpoint(QQmlNotifierEndpoint::QQmlBoundSignal),
-      m_prevSignal(0), m_nextSignal(0),
-      m_enabled(true), m_expression(0)
+      m_prevSignal(nullptr), m_nextSignal(nullptr),
+      m_enabled(true), m_expression(nullptr)
 {
     addToObject(owner);
 
@@ -295,8 +297,8 @@ void QQmlBoundSignal::removeFromObject()
     if (m_prevSignal) {
         *m_prevSignal = m_nextSignal;
         if (m_nextSignal) m_nextSignal->m_prevSignal = m_prevSignal;
-        m_prevSignal = 0;
-        m_nextSignal = 0;
+        m_prevSignal = nullptr;
+        m_nextSignal = nullptr;
     }
 }
 
diff --git a/src/qml/qml/qqmlboundsignal_p.h b/src/qml/qml/qqmlboundsignal_p.h
index 3a0b8aed59..d1ec67210e 100644
--- a/src/qml/qml/qqmlboundsignal_p.h
+++ b/src/qml/qml/qqmlboundsignal_p.h
@@ -73,10 +73,8 @@ public:
                               const QString &parameterString = QString());
 
     QQmlBoundSignalExpression(QObject *target, int index,
-                              QQmlContextData *ctxt, QObject *scopeObject, QV4::Function *function, QV4::ExecutionContext *scope);
-
-    QQmlBoundSignalExpression(QObject *target, int index,
-                              QQmlContextData *ctxt, QObject *scope, QV4::Function *runtimeFunction);
+                              QQmlContextData *ctxt, QObject *scopeObject, QV4::Function *function,
+                              QV4::ExecutionContext *scope = nullptr);
 
     // inherited from QQmlJavaScriptExpression.
     QString expressionIdentifier() const override;
@@ -89,14 +87,14 @@ public:
     QString expression() const;
     QObject *target() const { return m_target; }
 
-    QQmlEngine *engine() const { return context() ? context()->engine : 0; }
+    QQmlEngine *engine() const { return context() ? context()->engine : nullptr; }
 
 private:
-    ~QQmlBoundSignalExpression();
+    ~QQmlBoundSignalExpression() override;
 
     void init(QQmlContextData *ctxt, QObject *scope);
 
-    bool expressionFunctionValid() const { return function() != 0; }
+    bool expressionFunctionValid() const { return function() != nullptr; }
 
     int m_index;
     QObject *m_target;
diff --git a/src/qml/qml/qqmlboundsignalexpressionpointer_p.h b/src/qml/qml/qqmlboundsignalexpressionpointer_p.h
index de651315f8..eabe6666b4 100644
--- a/src/qml/qml/qqmlboundsignalexpressionpointer_p.h
+++ b/src/qml/qml/qqmlboundsignalexpressionpointer_p.h
@@ -58,7 +58,7 @@ class QQmlBoundSignalExpression;
 class Q_QML_PRIVATE_EXPORT QQmlBoundSignalExpressionPointer
 {
 public:
-    inline QQmlBoundSignalExpressionPointer() : o(0) {}
+    inline QQmlBoundSignalExpressionPointer() {}
     QQmlBoundSignalExpressionPointer(QQmlBoundSignalExpression *);
     QQmlBoundSignalExpressionPointer(const QQmlBoundSignalExpressionPointer &);
     ~QQmlBoundSignalExpressionPointer();
@@ -73,7 +73,7 @@ public:
     QQmlBoundSignalExpressionPointer &take(QQmlBoundSignalExpression *);
 
 private:
-    QQmlBoundSignalExpression *o;
+    QQmlBoundSignalExpression *o = nullptr;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlcleanup.cpp b/src/qml/qml/qqmlcleanup.cpp
index 708537a303..0d57ef5fe8 100644
--- a/src/qml/qml/qqmlcleanup.cpp
+++ b/src/qml/qml/qqmlcleanup.cpp
@@ -58,7 +58,7 @@ called by QQmlEngine just before it destroys the context.
 Create a QQmlCleanup that is not associated with any engine.
 */
 QQmlCleanup::QQmlCleanup()
-: prev(0), next(0), engine(0)
+: prev(nullptr), next(nullptr), engine(nullptr)
 {
 }
 
@@ -66,7 +66,7 @@ QQmlCleanup::QQmlCleanup()
 Create a QQmlCleanup for \a engine
 */
 QQmlCleanup::QQmlCleanup(QQmlEngine *engine)
-: prev(0), next(0), engine(0)
+: prev(nullptr), next(nullptr), engine(nullptr)
 {
     if (!engine)
         return;
@@ -109,8 +109,8 @@ QQmlCleanup::~QQmlCleanup()
 
     if (prev) *prev = next;
     if (next) next->prev = prev;
-    prev = 0;
-    next = 0;
+    prev = nullptr;
+    next = nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlcleanup_p.h b/src/qml/qml/qqmlcleanup_p.h
index a1db656477..0e15c28b9d 100644
--- a/src/qml/qml/qqmlcleanup_p.h
+++ b/src/qml/qml/qqmlcleanup_p.h
@@ -64,7 +64,7 @@ public:
     QQmlCleanup(QQmlEngine *);
     virtual ~QQmlCleanup();
 
-    bool hasEngine() const { return prev != 0; }
+    bool hasEngine() const { return prev != nullptr; }
     void addToEngine(QQmlEngine *);
 protected:
     virtual void clear() = 0;
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index e7a45482e6..57ea685a5d 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -58,6 +58,7 @@
 #include <private/qv4scopedvalue_p.h>
 #include <private/qv4objectiterator_p.h>
 #include <private/qv4qobjectwrapper_p.h>
+#include <private/qv4jscall_p.h>
 
 #include <QDir>
 #include <QStack>
@@ -88,7 +89,7 @@ V4_DEFINE_EXTENSION(QQmlComponentExtension, componentExtension);
     \since 5.0
     \inmodule QtQml
 
-    \brief The QQmlComponent class encapsulates a QML component definition
+    \brief The QQmlComponent class encapsulates a QML component definition.
 
     Components are reusable, encapsulated QML types with well-defined interfaces.
 
@@ -173,8 +174,6 @@ V4_DEFINE_EXTENSION(QQmlComponentExtension, componentExtension);
         }
     }
     \endcode
-
-    Note that the \l {Qt Quick 1} version is named QDeclarativeComponent.
 */
 
 /*!
@@ -182,7 +181,7 @@ V4_DEFINE_EXTENSION(QQmlComponentExtension, componentExtension);
     \instantiates QQmlComponent
     \ingroup qml-utility-elements
     \inqmlmodule QtQml
-    \brief Encapsulates a QML component definition
+    \brief Encapsulates a QML component definition.
 
     Components are reusable, encapsulated QML types with well-defined interfaces.
 
@@ -240,6 +239,9 @@ V4_DEFINE_EXTENSION(QQmlComponentExtension, componentExtension);
     \li main.qml
     \li \snippet qml/component/main.qml 0
     \endtable
+
+    It is important that the lifetime of the creation context outlive any created objects. See
+    \l{Maintaining Dynamically Created Objects} for more details.
 */
 
 /*!
@@ -314,7 +316,7 @@ void QQmlComponentPrivate::typeDataReady(QQmlTypeData *)
     Q_ASSERT(typeData);
 
     fromTypeData(typeData);
-    typeData = 0;
+    typeData = nullptr;
     progress = 1.0;
 
     emit q->statusChanged(q->status());
@@ -330,7 +332,7 @@ void QQmlComponentPrivate::typeDataProgress(QQmlTypeData *, qreal p)
     emit q->progressChanged(p);
 }
 
-void QQmlComponentPrivate::fromTypeData(QQmlTypeData *data)
+void QQmlComponentPrivate::fromTypeData(const QQmlRefPointer<QQmlTypeData> &data)
 {
     url = data->finalUrl();
     compilationUnit = data->compilationUnit();
@@ -339,16 +341,13 @@ void QQmlComponentPrivate::fromTypeData(QQmlTypeData *data)
         Q_ASSERT(data->isError());
         state.errors = data->errors();
     }
-
-    data->release();
 }
 
 void QQmlComponentPrivate::clear()
 {
     if (typeData) {
         typeData->unregisterCallback(this);
-        typeData->release();
-        typeData = 0;
+        typeData = nullptr;
     }
 
     compilationUnit = nullptr;
@@ -383,7 +382,7 @@ QQmlComponent::~QQmlComponent()
 
     if (d->typeData) {
         d->typeData->unregisterCallback(d);
-        d->typeData->release();
+        d->typeData = nullptr;
     }
 }
 
@@ -496,8 +495,7 @@ QQmlComponent::QQmlComponent(QQmlEngine *engine, QObject *parent)
     Create a QQmlComponent from the given \a url and give it the
     specified \a parent and \a engine.
 
-    Ensure that the URL provided is full and correct, in particular, use
-    \l QUrl::fromLocalFile() when loading a file from the local filesystem.
+    \include qqmlcomponent.qdoc url-note
 
     \sa loadUrl()
 */
@@ -511,8 +509,7 @@ QQmlComponent::QQmlComponent(QQmlEngine *engine, const QUrl &url, QObject *paren
     specified \a parent and \a engine. If \a mode is \l Asynchronous,
     the component will be loaded and compiled asynchronously.
 
-    Ensure that the URL provided is full and correct, in particular, use
-    \l QUrl::fromLocalFile() when loading a file from the local filesystem.
+    \include qqmlcomponent.qdoc url-note
 
     \sa loadUrl()
 */
@@ -548,7 +545,7 @@ QQmlComponent::QQmlComponent(QQmlEngine *engine, const QString &fileName,
     : QQmlComponent(engine, parent)
 {
     Q_D(QQmlComponent);
-    const QUrl url = QDir::isAbsolutePath(fileName) ? QUrl::fromLocalFile(fileName) : d->engine->baseUrl().resolved(QUrl(fileName));
+    const QUrl url = QDir::isAbsolutePath(fileName) ? QUrl::fromLocalFile(fileName) : QUrl(fileName);
     d->loadUrl(url, mode);
 }
 
@@ -561,7 +558,7 @@ QQmlComponent::QQmlComponent(QQmlEngine *engine, QV4::CompiledData::CompilationU
     Q_D(QQmlComponent);
     d->compilationUnit = compilationUnit;
     d->start = start;
-    d->url = compilationUnit->url();
+    d->url = compilationUnit->finalUrl();
     d->progress = 1.0;
 }
 
@@ -578,7 +575,7 @@ void QQmlComponent::setData(const QByteArray &data, const QUrl &url)
 
     d->url = url;
 
-    QQmlTypeData *typeData = QQmlEnginePrivate::get(d->engine)->typeLoader.getType(data, url);
+    QQmlRefPointer<QQmlTypeData> typeData = QQmlEnginePrivate::get(d->engine)->typeLoader.getType(data, url);
 
     if (typeData->isCompleteOrError()) {
         d->fromTypeData(typeData);
@@ -593,8 +590,8 @@ void QQmlComponent::setData(const QByteArray &data, const QUrl &url)
 }
 
 /*!
-Returns the QQmlContext the component was created in. This is only
-valid for components created directly from QML.
+    Returns the QQmlContext the component was created in. This is only
+    valid for components created directly from QML.
 */
 QQmlContext *QQmlComponent::creationContext() const
 {
@@ -606,10 +603,20 @@ QQmlContext *QQmlComponent::creationContext() const
 }
 
 /*!
+    Returns the QQmlEngine of this component.
+
+    \since 5.12
+*/
+QQmlEngine *QQmlComponent::engine() const
+{
+    Q_D(const QQmlComponent);
+    return d->engine;
+}
+
+/*!
     Load the QQmlComponent from the provided \a url.
 
-    Ensure that the URL provided is full and correct, in particular, use
-    \l QUrl::fromLocalFile() when loading a file from the local filesystem.
+    \include qqmlcomponent.qdoc url-note
 */
 void QQmlComponent::loadUrl(const QUrl &url)
 {
@@ -621,8 +628,7 @@ void QQmlComponent::loadUrl(const QUrl &url)
     Load the QQmlComponent from the provided \a url.
     If \a mode is \l Asynchronous, the component will be loaded and compiled asynchronously.
 
-    Ensure that the URL provided is full and correct, in particular, use
-    \l QUrl::fromLocalFile() when loading a file from the local filesystem.
+    \include qqmlcomponent.qdoc url-note
 */
 void QQmlComponent::loadUrl(const QUrl &url, QQmlComponent::CompilationMode mode)
 {
@@ -635,11 +641,21 @@ void QQmlComponentPrivate::loadUrl(const QUrl &newUrl, QQmlComponent::Compilatio
     Q_Q(QQmlComponent);
     clear();
 
-    if ((newUrl.isRelative() && !newUrl.isEmpty())
-    || newUrl.scheme() == QLatin1String("file")) // Workaround QTBUG-11929
-        url = engine->baseUrl().resolved(newUrl);
-    else
+    if (newUrl.isRelative()) {
+        // The new URL is a relative URL like QUrl("main.qml").
+        url = engine->baseUrl().resolved(QUrl(newUrl.toString()));
+    } else if (engine->baseUrl().isLocalFile() && newUrl.isLocalFile() && !QDir::isAbsolutePath(newUrl.toLocalFile())) {
+        // The new URL is a file on disk but it's a relative path; e.g.:
+        // QUrl::fromLocalFile("main.qml") or QUrl("file:main.qml")
+        // We need to remove the scheme so that it becomes a relative URL with a relative path:
+        QUrl fixedUrl(newUrl);
+        fixedUrl.setScheme(QString());
+        // Then, turn it into an absolute URL with an absolute path by resolving it against the engine's baseUrl().
+        // This is a compatibility hack for QTBUG-58837.
+        url = engine->baseUrl().resolved(fixedUrl);
+    } else {
         url = newUrl;
+    }
 
     if (newUrl.isEmpty()) {
         QQmlError error;
@@ -657,7 +673,7 @@ void QQmlComponentPrivate::loadUrl(const QUrl &newUrl, QQmlComponent::Compilatio
             ? QQmlTypeLoader::Asynchronous
             : QQmlTypeLoader::PreferSynchronous;
 
-    QQmlTypeData *data = QQmlEnginePrivate::get(engine)->typeLoader.getType(url, loaderMode);
+    QQmlRefPointer<QQmlTypeData> data = QQmlEnginePrivate::get(engine)->typeLoader.getType(url, loaderMode);
 
     if (data->isCompleteOrError()) {
         fromTypeData(data);
@@ -740,12 +756,12 @@ QQmlComponent::QQmlComponent(QQmlComponentPrivate &dd, QObject *parent)
 }
 
 /*!
-    Create an object instance from this component. Returns 0 if creation
+    Create an object instance from this component. Returns \nullptr if creation
     failed. \a context specifies the context within which to create the object
     instance.
 
-    If \a context is 0 (the default), it will create the instance in the
-    engine' s \l {QQmlEngine::rootContext()}{root context}.
+    If \a context is \nullptr (the default), it will create the instance in the
+    \l {QQmlEngine::rootContext()}{root context} of the engine.
 
     The ownership of the returned object instance is transferred to the caller.
 
@@ -775,7 +791,7 @@ QObject *QQmlComponent::create(QQmlContext *context)
     In general, programmers should use QQmlComponent::create() to create object
     instances.
 
-    Create an object instance from this component. Returns 0 if creation
+    Create an object instance from this component. Returns \nullptr if creation
     failed. \a publicContext specifies the context within which to create the object
     instance.
 
@@ -813,38 +829,35 @@ QQmlComponentPrivate::beginCreate(QQmlContextData *context)
     Q_Q(QQmlComponent);
     if (!context) {
         qWarning("QQmlComponent: Cannot create a component in a null context");
-        return 0;
+        return nullptr;
     }
 
     if (!context->isValid()) {
         qWarning("QQmlComponent: Cannot create a component in an invalid context");
-        return 0;
+        return nullptr;
     }
 
     if (context->engine != engine) {
         qWarning("QQmlComponent: Must create component in context from the same QQmlEngine");
-        return 0;
+        return nullptr;
     }
 
     if (state.completePending) {
         qWarning("QQmlComponent: Cannot create new component instance before completing the previous");
-        return 0;
+        return nullptr;
     }
 
     if (!q->isReady()) {
         qWarning("QQmlComponent: Component is not ready");
-        return 0;
+        return nullptr;
     }
 
     // Do not create infinite recursion in object creation
     static const int maxCreationDepth = 10;
-    if (++creationDepth.localData() >= maxCreationDepth) {
+    if (creationDepth.localData() >= maxCreationDepth) {
         qWarning("QQmlComponent: Component creation is recursing - aborting");
-        --creationDepth.localData();
-        return 0;
+        return nullptr;
     }
-    Q_ASSERT(creationDepth.localData() >= 1);
-    depthIncreased = true;
 
     QQmlEnginePrivate *enginePriv = QQmlEnginePrivate::get(engine);
 
@@ -853,7 +866,7 @@ QQmlComponentPrivate::beginCreate(QQmlContextData *context)
     state.completePending = true;
 
     enginePriv->referenceScarceResources();
-    QObject *rv = 0;
+    QObject *rv = nullptr;
     state.creator.reset(new QQmlObjectCreator(context, compilationUnit, creationContext));
     rv = state.creator->create(start);
     if (!rv)
@@ -868,29 +881,39 @@ QQmlComponentPrivate::beginCreate(QQmlContextData *context)
         ddata->indestructible = true;
         ddata->explicitIndestructibleSet = true;
         ddata->rootObjectInCreation = false;
-    } else {
-        Q_ASSERT(creationDepth.localData() >= 1);
-        --creationDepth.localData();
-        depthIncreased = false;
     }
 
     return rv;
 }
 
 void QQmlComponentPrivate::beginDeferred(QQmlEnginePrivate *enginePriv,
-                                                 QObject *object, ConstructionState *state)
+                                                 QObject *object, DeferredState *deferredState)
 {
-    enginePriv->inProgressCreations++;
-    state->errors.clear();
-    state->completePending = true;
-
     QQmlData *ddata = QQmlData::get(object);
-    Q_ASSERT(ddata->deferredData);
-    QQmlData::DeferredData *deferredData = ddata->deferredData;
-    QQmlContextData *creationContext = 0;
-    state->creator.reset(new QQmlObjectCreator(deferredData->context->parent, deferredData->compilationUnit, creationContext));
-    if (!state->creator->populateDeferredProperties(object))
-        state->errors << state->creator->errors;
+    Q_ASSERT(!ddata->deferredData.isEmpty());
+
+    deferredState->constructionStates.reserve(ddata->deferredData.size());
+
+    for (QQmlData::DeferredData *deferredData : qAsConst(ddata->deferredData)) {
+        enginePriv->inProgressCreations++;
+
+        ConstructionState *state = new ConstructionState;
+        state->completePending = true;
+
+        QQmlContextData *creationContext = nullptr;
+        state->creator.reset(new QQmlObjectCreator(deferredData->context->parent, deferredData->compilationUnit, creationContext));
+
+        if (!state->creator->populateDeferredProperties(object, deferredData))
+            state->errors << state->creator->errors;
+
+        deferredState->constructionStates += state;
+    }
+}
+
+void QQmlComponentPrivate::completeDeferred(QQmlEnginePrivate *enginePriv, QQmlComponentPrivate::DeferredState *deferredState)
+{
+    for (ConstructionState *state : qAsConst(deferredState->constructionStates))
+        complete(enginePriv, state);
 }
 
 void QQmlComponentPrivate::complete(QQmlEnginePrivate *enginePriv, ConstructionState *state)
@@ -905,8 +928,7 @@ void QQmlComponentPrivate::complete(QQmlEnginePrivate *enginePriv, ConstructionS
 
         if (0 == enginePriv->inProgressCreations) {
             while (enginePriv->erroredBindings) {
-                enginePriv->warning(enginePriv->erroredBindings);
-                enginePriv->erroredBindings->removeError();
+                enginePriv->warning(enginePriv->erroredBindings->removeError());
             }
         }
     }
@@ -932,19 +954,15 @@ void QQmlComponent::completeCreate()
 void QQmlComponentPrivate::completeCreate()
 {
     if (state.completePending) {
+        ++creationDepth.localData();
         QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
         complete(ep, &state);
-    }
-
-    if (depthIncreased) {
-        Q_ASSERT(creationDepth.localData() >= 1);
         --creationDepth.localData();
-        depthIncreased = false;
     }
 }
 
 QQmlComponentAttached::QQmlComponentAttached(QObject *parent)
-: QObject(parent), prev(0), next(0)
+: QObject(parent), prev(nullptr), next(nullptr)
 {
 }
 
@@ -952,8 +970,8 @@ QQmlComponentAttached::~QQmlComponentAttached()
 {
     if (prev) *prev = next;
     if (next) next->prev = prev;
-    prev = 0;
-    next = 0;
+    prev = nullptr;
+    next = nullptr;
 }
 
 /*!
@@ -1059,7 +1077,6 @@ void QQmlComponentPrivate::incubateObject(
     QQmlComponentPrivate *componentPriv = QQmlComponentPrivate::get(component);
 
     incubatorPriv->compilationUnit = componentPriv->compilationUnit;
-    incubatorPriv->compilationUnit->addref();
     incubatorPriv->enginePriv = enginePriv;
     incubatorPriv->creator.reset(new QQmlObjectCreator(context, componentPriv->compilationUnit, componentPriv->creationContext));
     incubatorPriv->subComponentToCreate = componentPriv->start;
@@ -1083,7 +1100,7 @@ namespace Heap {
     Member(class, NoMark, QQmlQPointer<QObject>, parent)
 
 DECLARE_HEAP_OBJECT(QmlIncubatorObject, Object) {
-    DECLARE_MARK_TABLE(QmlIncubatorObject);
+    DECLARE_MARKOBJECTS(QmlIncubatorObject);
 
     void init(QQmlIncubator::IncubationMode = QQmlIncubator::Asynchronous);
     inline void destroy();
@@ -1096,11 +1113,11 @@ struct QmlIncubatorObject : public QV4::Object
     V4_OBJECT2(QmlIncubatorObject, Object)
     V4_NEEDS_DESTROY
 
-    static void method_get_statusChanged(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_set_statusChanged(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_status(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_object(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_forceCompletion(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_get_statusChanged(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set_statusChanged(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_status(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_object(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_forceCompletion(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
     void statusChanged(QQmlIncubator::Status);
     void setInitialState(QObject *);
@@ -1115,22 +1132,23 @@ class QQmlComponentIncubator : public QQmlIncubator
 public:
     QQmlComponentIncubator(QV4::Heap::QmlIncubatorObject *inc, IncubationMode mode)
         : QQmlIncubator(mode)
-        , incubatorObject(inc)
-    {}
+    {
+        incubatorObject.set(inc->internalClass->engine, inc);
+    }
 
     void statusChanged(Status s) override {
-        QV4::Scope scope(incubatorObject->internalClass->engine);
-        QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject);
+        QV4::Scope scope(incubatorObject.engine());
+        QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject.as<QV4::QmlIncubatorObject>());
         i->statusChanged(s);
     }
 
     void setInitialState(QObject *o) override {
-        QV4::Scope scope(incubatorObject->internalClass->engine);
-        QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject);
+        QV4::Scope scope(incubatorObject.engine());
+        QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject.as<QV4::QmlIncubatorObject>());
         i->setInitialState(o);
     }
 
-    QV4::Heap::QmlIncubatorObject *incubatorObject;
+    QV4::PersistentValue incubatorObject; // keep a strong internal reference while incubating
 };
 
 
@@ -1204,14 +1222,13 @@ void QQmlComponentPrivate::setInitialProperties(QV4::ExecutionEngine *engine, QV
     QV4::Scope scope(engine);
     QV4::ScopedObject object(scope);
     QV4::ScopedObject valueMap(scope, v);
-    QV4::ObjectIterator it(scope, valueMap, QV4::ObjectIterator::EnumerableOnly|QV4::ObjectIterator::WithProtoChain);
+    QV4::ObjectIterator it(scope, valueMap, QV4::ObjectIterator::EnumerableOnly);
     QV4::ScopedString name(scope);
     QV4::ScopedValue val(scope);
     if (engine->hasException)
         return;
 
-    QV4::ExecutionContextSaver saver(scope);
-    engine->pushContext(qmlContext);
+    QV4::ScopedStackFrame frame(scope, qmlContext->d());
 
     while (1) {
         name = it.nextPropertyNameAsString(val);
@@ -1250,10 +1267,10 @@ void QQmlComponent::createObject(QQmlV4Function *args)
     Q_ASSERT(d->engine);
     Q_ASSERT(args);
 
-    QObject *parent = 0;
+    QObject *parent = nullptr;
     QV4::ExecutionEngine *v4 = args->v4engine();
     QV4::Scope scope(v4);
-    QV4::ScopedValue valuemap(scope, QV4::Primitive::undefinedValue());
+    QV4::ScopedValue valuemap(scope, QV4::Value::undefinedValue());
 
     if (args->length() >= 1) {
         QV4::Scoped<QV4::QObjectWrapper> qobjectWrapper(scope, (*args)[0]);
@@ -1367,8 +1384,8 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
     QV4::ExecutionEngine *v4 = args->v4engine();
     QV4::Scope scope(v4);
 
-    QObject *parent = 0;
-    QV4::ScopedValue valuemap(scope, QV4::Primitive::undefinedValue());
+    QObject *parent = nullptr;
+    QV4::ScopedValue valuemap(scope, QV4::Value::undefinedValue());
     QQmlIncubator::IncubationMode mode = QQmlIncubator::Asynchronous;
 
     if (args->length() >= 1) {
@@ -1400,9 +1417,9 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
 
     QQmlComponentExtension *e = componentExtension(args->v4engine());
 
-    QV4::Scoped<QV4::QmlIncubatorObject> r(scope, v4->memoryManager->allocObject<QV4::QmlIncubatorObject>(mode));
+    QV4::Scoped<QV4::QmlIncubatorObject> r(scope, v4->memoryManager->allocate<QV4::QmlIncubatorObject>(mode));
     QV4::ScopedObject p(scope, e->incubationProto.value());
-    r->setPrototype(p);
+    r->setPrototypeOf(p);
 
     if (!valuemap->isUndefined())
         r->d()->valuemap.set(scope.engine, valuemap);
@@ -1422,8 +1439,7 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
 // XXX used by QSGLoader
 void QQmlComponentPrivate::initializeObjectWithInitialProperties(QV4::QmlContext *qmlContext, const QV4::Value &valuemap, QObject *toCreate)
 {
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
-    QV4::ExecutionEngine *v4engine = QV8Engine::getV4(ep->v8engine());
+    QV4::ExecutionEngine *v4engine = engine->handle();
     QV4::Scope scope(v4engine);
 
     QV4::ScopedValue object(scope, QV4::QObjectWrapper::wrap(v4engine, toCreate));
@@ -1439,25 +1455,27 @@ QQmlComponentExtension::QQmlComponentExtension(QV4::ExecutionEngine *v4)
     QV4::ScopedObject proto(scope, v4->newObject());
     proto->defineAccessorProperty(QStringLiteral("onStatusChanged"),
                                   QV4::QmlIncubatorObject::method_get_statusChanged, QV4::QmlIncubatorObject::method_set_statusChanged);
-    proto->defineAccessorProperty(QStringLiteral("status"), QV4::QmlIncubatorObject::method_get_status, 0);
-    proto->defineAccessorProperty(QStringLiteral("object"), QV4::QmlIncubatorObject::method_get_object, 0);
+    proto->defineAccessorProperty(QStringLiteral("status"), QV4::QmlIncubatorObject::method_get_status, nullptr);
+    proto->defineAccessorProperty(QStringLiteral("object"), QV4::QmlIncubatorObject::method_get_object, nullptr);
     proto->defineDefaultProperty(QStringLiteral("forceCompletion"), QV4::QmlIncubatorObject::method_forceCompletion);
 
     incubationProto.set(v4, proto);
 }
 
-void QV4::QmlIncubatorObject::method_get_object(const BuiltinFunction *, Scope &scope, CallData *callData)
+QV4::ReturnedValue QV4::QmlIncubatorObject::method_get_object(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QV4::Scoped<QmlIncubatorObject> o(scope, callData->thisObject.as<QmlIncubatorObject>());
+    QV4::Scope scope(b);
+    QV4::Scoped<QmlIncubatorObject> o(scope, thisObject->as<QmlIncubatorObject>());
     if (!o)
         THROW_TYPE_ERROR();
 
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, o->d()->incubator->object());
+    return QV4::QObjectWrapper::wrap(scope.engine, o->d()->incubator->object());
 }
 
-void QV4::QmlIncubatorObject::method_forceCompletion(const BuiltinFunction *, Scope &scope, CallData *callData)
+QV4::ReturnedValue QV4::QmlIncubatorObject::method_forceCompletion(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QV4::Scoped<QmlIncubatorObject> o(scope, callData->thisObject.as<QmlIncubatorObject>());
+    QV4::Scope scope(b);
+    QV4::Scoped<QmlIncubatorObject> o(scope, thisObject->as<QmlIncubatorObject>());
     if (!o)
         THROW_TYPE_ERROR();
 
@@ -1466,31 +1484,34 @@ void QV4::QmlIncubatorObject::method_forceCompletion(const BuiltinFunction *, Sc
     RETURN_UNDEFINED();
 }
 
-void QV4::QmlIncubatorObject::method_get_status(const BuiltinFunction *, Scope &scope, CallData *callData)
+QV4::ReturnedValue QV4::QmlIncubatorObject::method_get_status(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QV4::Scoped<QmlIncubatorObject> o(scope, callData->thisObject.as<QmlIncubatorObject>());
+    QV4::Scope scope(b);
+    QV4::Scoped<QmlIncubatorObject> o(scope, thisObject->as<QmlIncubatorObject>());
     if (!o)
         THROW_TYPE_ERROR();
 
-    scope.result = QV4::Encode(o->d()->incubator->status());
+    return QV4::Encode(o->d()->incubator->status());
 }
 
-void QV4::QmlIncubatorObject::method_get_statusChanged(const BuiltinFunction *, Scope &scope, CallData *callData)
+QV4::ReturnedValue QV4::QmlIncubatorObject::method_get_statusChanged(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    QV4::Scoped<QmlIncubatorObject> o(scope, callData->thisObject.as<QmlIncubatorObject>());
+    QV4::Scope scope(b);
+    QV4::Scoped<QmlIncubatorObject> o(scope, thisObject->as<QmlIncubatorObject>());
     if (!o)
         THROW_TYPE_ERROR();
 
-    scope.result = o->d()->statusChanged;
+    return QV4::Encode(o->d()->statusChanged);
 }
 
-void QV4::QmlIncubatorObject::method_set_statusChanged(const BuiltinFunction *, Scope &scope, CallData *callData)
+QV4::ReturnedValue QV4::QmlIncubatorObject::method_set_statusChanged(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QV4::Scoped<QmlIncubatorObject> o(scope, callData->thisObject.as<QmlIncubatorObject>());
-    if (!o || callData->argc < 1)
+    QV4::Scope scope(b);
+    QV4::Scoped<QmlIncubatorObject> o(scope, thisObject->as<QmlIncubatorObject>());
+    if (!o || argc < 1)
         THROW_TYPE_ERROR();
 
-    o->d()->statusChanged.set(scope.engine, callData->args[0]);
+    o->d()->statusChanged.set(scope.engine, argv[0]);
 
     RETURN_UNDEFINED();
 }
@@ -1502,8 +1523,8 @@ QQmlComponentExtension::~QQmlComponentExtension()
 void QV4::Heap::QmlIncubatorObject::init(QQmlIncubator::IncubationMode m)
 {
     Object::init();
-    valuemap.set(internalClass->engine, QV4::Primitive::undefinedValue());
-    statusChanged.set(internalClass->engine, QV4::Primitive::undefinedValue());
+    valuemap.set(internalClass->engine, QV4::Value::undefinedValue());
+    statusChanged.set(internalClass->engine, QV4::Value::undefinedValue());
     parent.init();
     qmlContext.set(internalClass->engine, nullptr);
     incubator = new QQmlComponentIncubator(this, m);
@@ -1542,15 +1563,18 @@ void QV4::QmlIncubatorObject::statusChanged(QQmlIncubator::Status s)
 
     QV4::ScopedFunctionObject f(scope, d()->statusChanged);
     if (f) {
-        QV4::ScopedCallData callData(scope, 1);
-        callData->thisObject = this;
-        callData->args[0] = QV4::Primitive::fromUInt32(s);
-        f->call(scope, callData);
+        QV4::JSCallData jsCallData(scope, 1);
+        *jsCallData->thisObject = this;
+        jsCallData->args[0] = QV4::Value::fromUInt32(s);
+        f->call(jsCallData);
         if (scope.hasException()) {
             QQmlError error = scope.engine->catchExceptionAsQmlError();
             QQmlEnginePrivate::warning(QQmlEnginePrivate::get(scope.engine->qmlEngine()), error);
         }
     }
+
+    if (s != QQmlIncubator::Loading)
+        d()->incubator->incubatorObject.clear();
 }
 
 #undef INITIALPROPERTIES_SOURCE
diff --git a/src/qml/qml/qqmlcomponent.h b/src/qml/qml/qqmlcomponent.h
index ca60f01eb5..20199d0b21 100644
--- a/src/qml/qml/qqmlcomponent.h
+++ b/src/qml/qml/qqmlcomponent.h
@@ -77,13 +77,13 @@ public:
     enum CompilationMode { PreferSynchronous, Asynchronous };
     Q_ENUM(CompilationMode)
 
-    QQmlComponent(QObject *parent = Q_NULLPTR);
-    QQmlComponent(QQmlEngine *, QObject *parent = Q_NULLPTR);
-    QQmlComponent(QQmlEngine *, const QString &fileName, QObject *parent = Q_NULLPTR);
-    QQmlComponent(QQmlEngine *, const QString &fileName, CompilationMode mode, QObject *parent = Q_NULLPTR);
-    QQmlComponent(QQmlEngine *, const QUrl &url, QObject *parent = Q_NULLPTR);
-    QQmlComponent(QQmlEngine *, const QUrl &url, CompilationMode mode, QObject *parent = Q_NULLPTR);
-    virtual ~QQmlComponent();
+    QQmlComponent(QObject *parent = nullptr);
+    QQmlComponent(QQmlEngine *, QObject *parent = nullptr);
+    QQmlComponent(QQmlEngine *, const QString &fileName, QObject *parent = nullptr);
+    QQmlComponent(QQmlEngine *, const QString &fileName, CompilationMode mode, QObject *parent = nullptr);
+    QQmlComponent(QQmlEngine *, const QUrl &url, QObject *parent = nullptr);
+    QQmlComponent(QQmlEngine *, const QUrl &url, CompilationMode mode, QObject *parent = nullptr);
+    ~QQmlComponent() override;
 
     enum Status { Null, Ready, Loading, Error };
     Q_ENUM(Status)
@@ -101,14 +101,15 @@ public:
 
     QUrl url() const;
 
-    virtual QObject *create(QQmlContext *context = Q_NULLPTR);
+    virtual QObject *create(QQmlContext *context = nullptr);
     virtual QObject *beginCreate(QQmlContext *);
     virtual void completeCreate();
 
-    void create(QQmlIncubator &, QQmlContext *context = Q_NULLPTR,
-                QQmlContext *forContext = Q_NULLPTR);
+    void create(QQmlIncubator &, QQmlContext *context = nullptr,
+                QQmlContext *forContext = nullptr);
 
     QQmlContext *creationContext() const;
+    QQmlEngine *engine() const;
 
     static QQmlComponentAttached *qmlAttachedProperties(QObject *);
 
diff --git a/src/qml/qml/qqmlcomponent_p.h b/src/qml/qml/qqmlcomponent_p.h
index 6414025574..4d9e4c6c15 100644
--- a/src/qml/qml/qqmlcomponent_p.h
+++ b/src/qml/qml/qqmlcomponent_p.h
@@ -79,7 +79,7 @@ class Q_QML_PRIVATE_EXPORT QQmlComponentPrivate : public QObjectPrivate, public
 
 public:
     QQmlComponentPrivate()
-        : typeData(0), progress(0.), start(-1), engine(0), creationContext(0), depthIncreased(false) {}
+        : progress(0.), start(-1), engine(nullptr), creationContext(nullptr) {}
 
     void loadUrl(const QUrl &newUrl, QQmlComponent::CompilationMode mode = QQmlComponent::PreferSynchronous);
 
@@ -88,18 +88,18 @@ public:
     void initializeObjectWithInitialProperties(QV4::QmlContext *qmlContext, const QV4::Value &valuemap, QObject *toCreate);
     static void setInitialProperties(QV4::ExecutionEngine *engine, QV4::QmlContext *qmlContext, const QV4::Value &o, const QV4::Value &v);
 
-    void incubateObject(
+    virtual void incubateObject(
             QQmlIncubator *incubationTask,
             QQmlComponent *component,
             QQmlEngine *engine,
             QQmlContextData *context,
             QQmlContextData *forContext);
 
-    QQmlTypeData *typeData;
+    QQmlRefPointer<QQmlTypeData> typeData;
     void typeDataReady(QQmlTypeData *) override;
     void typeDataProgress(QQmlTypeData *, qreal) override;
 
-    void fromTypeData(QQmlTypeData *data);
+    void fromTypeData(const QQmlRefPointer<QQmlTypeData> &data);
 
     QUrl url;
     qreal progress;
@@ -121,13 +121,21 @@ public:
     };
     ConstructionState state;
 
-    static void beginDeferred(QQmlEnginePrivate *enginePriv, QObject *object,
-                              ConstructionState *state);
+    struct DeferredState {
+        ~DeferredState() {
+            qDeleteAll(constructionStates);
+            constructionStates.clear();
+        }
+        QVector<ConstructionState *> constructionStates;
+    };
+
+    static void beginDeferred(QQmlEnginePrivate *enginePriv, QObject *object, DeferredState* deferredState);
+    static void completeDeferred(QQmlEnginePrivate *enginePriv, DeferredState *deferredState);
+
     static void complete(QQmlEnginePrivate *enginePriv, ConstructionState *state);
 
     QQmlEngine *engine;
     QQmlGuardedContextData creationContext;
-    bool depthIncreased;
 
     void clear();
 
diff --git a/src/qml/qml/qqmlcomponentattached_p.h b/src/qml/qml/qqmlcomponentattached_p.h
index 8236aac1af..e3bca18857 100644
--- a/src/qml/qml/qqmlcomponentattached_p.h
+++ b/src/qml/qml/qqmlcomponentattached_p.h
@@ -62,7 +62,7 @@ class Q_QML_PRIVATE_EXPORT QQmlComponentAttached : public QObject
 {
     Q_OBJECT
 public:
-    QQmlComponentAttached(QObject *parent = 0);
+    QQmlComponentAttached(QObject *parent = nullptr);
     ~QQmlComponentAttached();
 
     void add(QQmlComponentAttached **a) {
@@ -72,7 +72,7 @@ public:
     void rem() {
         if (next) next->prev = prev;
         *prev = next;
-        next = 0; prev = 0;
+        next = nullptr; prev = nullptr;
     }
     QQmlComponentAttached **prev;
     QQmlComponentAttached *next;
diff --git a/src/qml/qml/qqmlcontext.cpp b/src/qml/qml/qqmlcontext.cpp
index 1476c276f4..3710cee162 100644
--- a/src/qml/qml/qqmlcontext.cpp
+++ b/src/qml/qml/qqmlcontext.cpp
@@ -56,7 +56,7 @@
 QT_BEGIN_NAMESPACE
 
 QQmlContextPrivate::QQmlContextPrivate()
-: data(0), notifyIndex(-1)
+: data(nullptr), notifyIndex(-1)
 {
 }
 
@@ -161,6 +161,7 @@ QQmlContext::QQmlContext(QQmlEngine *e, bool)
 {
     Q_D(QQmlContext);
     d->data = new QQmlContextData(this);
+    ++d->data->refCount;
 
     d->data->engine = e;
 }
@@ -174,8 +175,9 @@ QQmlContext::QQmlContext(QQmlEngine *engine, QObject *parent)
 {
     Q_D(QQmlContext);
     d->data = new QQmlContextData(this);
+    ++d->data->refCount;
 
-    d->data->setParent(engine?QQmlContextData::get(engine->rootContext()):0);
+    d->data->setParent(engine?QQmlContextData::get(engine->rootContext()):nullptr);
 }
 
 /*!
@@ -187,18 +189,20 @@ QQmlContext::QQmlContext(QQmlContext *parentContext, QObject *parent)
 {
     Q_D(QQmlContext);
     d->data = new QQmlContextData(this);
+    ++d->data->refCount;
 
-    d->data->setParent(parentContext?QQmlContextData::get(parentContext):0);
+    d->data->setParent(parentContext?QQmlContextData::get(parentContext):nullptr);
 }
 
 /*!
     \internal
 */
 QQmlContext::QQmlContext(QQmlContextData *data)
-: QObject(*(new QQmlContextPrivate), 0)
+: QObject(*(new QQmlContextPrivate), nullptr)
 {
     Q_D(QQmlContext);
     d->data = data;
+    // don't add a refcount here, as the data owns this context
 }
 
 /*!
@@ -212,7 +216,8 @@ QQmlContext::~QQmlContext()
 {
     Q_D(QQmlContext);
 
-    if (!d->data->isInternal)
+    d->data->publicContext = nullptr;
+    if (!--d->data->refCount)
         d->data->destroy();
 }
 
@@ -245,7 +250,7 @@ QQmlEngine *QQmlContext::engine() const
 QQmlContext *QQmlContext::parentContext() const
 {
     Q_D(const QQmlContext);
-    return d->data->parent?d->data->parent->asQQmlContext():0;
+    return d->data->parent?d->data->parent->asQQmlContext():nullptr;
 }
 
 /*!
@@ -301,16 +306,7 @@ void QQmlContext::setContextProperty(const QString &name, const QVariant &value)
         return;
     }
 
-    if (data->engine) {
-        bool ok;
-        QObject *o = QQmlEnginePrivate::get(data->engine)->toQObject(value, &ok);
-        if (ok) {
-            setContextProperty(name, o);
-            return;
-        }
-    }
-
-    QV4::IdentifierHash<int> &properties = data->detachedPropertyNames();
+    QV4::IdentifierHash &properties = data->detachedPropertyNames();
     int idx = properties.value(name);
     if (idx == -1) {
         properties.add(name, data->idValueCount + d->propertyValues.count());
@@ -319,7 +315,7 @@ void QQmlContext::setContextProperty(const QString &name, const QVariant &value)
         data->refreshExpressions();
     } else {
         d->propertyValues[idx] = value;
-        QMetaObject::activate(this, d->notifyIndex, idx, 0);
+        QMetaObject::activate(this, d->notifyIndex, idx, nullptr);
     }
 }
 
@@ -330,37 +326,54 @@ void QQmlContext::setContextProperty(const QString &name, const QVariant &value)
 */
 void QQmlContext::setContextProperty(const QString &name, QObject *value)
 {
-    Q_D(QQmlContext);
-    if (d->notifyIndex == -1)
-        d->notifyIndex = QMetaObjectPrivate::absoluteSignalCount(&QQmlContext::staticMetaObject);
+    setContextProperty(name, QVariant::fromValue(value));
+}
+
+/*!
+    \since 5.11
+
+    Set a batch of \a properties on this context.
+
+    Setting all properties in one batch avoids unnecessary
+    refreshing  expressions, and is therefore recommended
+    instead of calling \l setContextProperty() for each individual property.
+
+    \sa QQmlContext::setContextProperty()
+*/
+void QQmlContext::setContextProperties(const QVector<PropertyPair> &properties)
+{
+    Q_D(const QQmlContext);
 
     QQmlContextData *data = d->data;
 
-    if (data->isInternal) {
-        qWarning("QQmlContext: Cannot set property on internal context.");
-        return;
-    }
+    QQmlJavaScriptExpression *expressions = data->expressions;
+    QQmlContextData *childContexts = data->childContexts;
 
-    if (!isValid()) {
-        qWarning("QQmlContext: Cannot set property on invalid context.");
-        return;
-    }
+    data->expressions = nullptr;
+    data->childContexts = nullptr;
 
-    QV4::IdentifierHash<int> &properties = data->detachedPropertyNames();
-    int idx = properties.value(name);
+    for (auto property : properties)
+        setContextProperty(property.name, property.value);
 
-    if (idx == -1) {
-        properties.add(name, data->idValueCount + d->propertyValues.count());
-        d->propertyValues.append(QVariant::fromValue(value));
+    data->expressions = expressions;
+    data->childContexts = childContexts;
 
-        data->refreshExpressions();
-    } else {
-        d->propertyValues[idx] = QVariant::fromValue(value);
-        QMetaObject::activate(this, d->notifyIndex, idx, 0);
-    }
+    data->refreshExpressions();
 }
 
 /*!
+    \since 5.11
+
+    \class QQmlContext::PropertyPair
+    \inmodule QtQml
+
+    This struct contains a property name and a property value.
+    It is used as a parameter for the \c setContextProperties function.
+
+    \sa QQmlContext::setContextProperties()
+*/
+
+/*!
   Returns the value of the \a name property for this context
   as a QVariant.
  */
@@ -372,7 +385,7 @@ QVariant QQmlContext::contextProperty(const QString &name) const
 
     QQmlContextData *data = d->data;
 
-    const QV4::IdentifierHash<int> &properties = data->propertyNames();
+    const QV4::IdentifierHash &properties = data->propertyNames();
     if (properties.count())
         idx = properties.value(name);
 
@@ -508,7 +521,7 @@ QObject *QQmlContextPrivate::context_at(QQmlListProperty<QObject> *prop, int ind
     int contextProperty = (int)(quintptr)prop->data;
 
     if (d->propertyValues.at(contextProperty).userType() != qMetaTypeId<QList<QObject*> >()) {
-        return 0;
+        return nullptr;
     } else {
         return ((const QList<QObject*> *)d->propertyValues.at(contextProperty).constData())->at(index);
     }
@@ -521,12 +534,12 @@ QQmlContextData::QQmlContextData()
 }
 
 QQmlContextData::QQmlContextData(QQmlContext *ctxt)
-: parent(0), engine(0), isInternal(false), ownedByParent(false), isJSContext(false),
-  isPragmaLibraryContext(false), unresolvedNames(false), hasEmittedDestruction(false), isRootObjectInCreation(false),
-  publicContext(ctxt), activeVMEData(0), componentObjectIndex(-1),
-  contextObject(0), childContexts(0), nextChild(0), prevChild(0),
-  expressions(0), contextObjects(0), contextGuards(0), idValues(0), idValueCount(0), linkedContext(0),
-  componentAttached(0)
+    : engine(nullptr), isInternal(false), isJSContext(false),
+      isPragmaLibraryContext(false), unresolvedNames(false), hasEmittedDestruction(false), isRootObjectInCreation(false),
+      stronglyReferencedByParent(false), publicContext(ctxt), incubator(nullptr), componentObjectIndex(-1),
+      contextObject(nullptr), nextChild(nullptr), prevChild(nullptr),
+      expressions(nullptr), contextObjects(nullptr), idValues(nullptr), idValueCount(0),
+      componentAttached(nullptr)
 {
 }
 
@@ -543,8 +556,8 @@ void QQmlContextData::emitDestruction()
                 componentAttached = a->next;
                 if (componentAttached) componentAttached->prev = &componentAttached;
 
-                a->next = 0;
-                a->prev = 0;
+                a->next = nullptr;
+                a->prev = nullptr;
 
                 emit a->destruction();
             }
@@ -563,22 +576,32 @@ void QQmlContextData::invalidate()
     emitDestruction();
 
     while (childContexts) {
-        if (childContexts->ownedByParent) {
+        Q_ASSERT(childContexts != this);
+        if (childContexts->stronglyReferencedByParent && !--childContexts->refCount)
             childContexts->destroy();
-        } else {
+        else
             childContexts->invalidate();
-        }
     }
 
     if (prevChild) {
         *prevChild = nextChild;
         if (nextChild) nextChild->prevChild = prevChild;
-        nextChild = 0;
-        prevChild = 0;
+        nextChild = nullptr;
+        prevChild = nullptr;
     }
 
-    engine = 0;
-    parent = 0;
+    importedScripts.clear();
+
+    engine = nullptr;
+    parent = nullptr;
+}
+
+void QQmlContextData::clearContextRecursively()
+{
+    clearContext();
+
+    for (auto ctxIt = childContexts; ctxIt; ctxIt = ctxIt->nextChild)
+        ctxIt->clearContextRecursively();
 }
 
 void QQmlContextData::clearContext()
@@ -589,63 +612,85 @@ void QQmlContextData::clearContext()
     while (expression) {
         QQmlJavaScriptExpression *nextExpression = expression->m_nextExpression;
 
-        expression->m_prevExpression = 0;
-        expression->m_nextExpression = 0;
+        expression->m_prevExpression = nullptr;
+        expression->m_nextExpression = nullptr;
 
-        expression->setContext(0);
+        expression->setContext(nullptr);
 
         expression = nextExpression;
     }
-    expressions = 0;
+    expressions = nullptr;
 }
 
 void QQmlContextData::destroy()
 {
-    if (linkedContext)
-        linkedContext->destroy();
+    Q_ASSERT(refCount == 0);
+    linkedContext = nullptr;
 
-    if (engine) invalidate();
+    // avoid recursion
+    ++refCount;
+    if (engine)
+        invalidate();
 
+    Q_ASSERT(refCount == 1);
     clearContext();
+    Q_ASSERT(refCount == 1);
 
     while (contextObjects) {
         QQmlData *co = contextObjects;
         contextObjects = contextObjects->nextContextObject;
 
-        co->context = 0;
-        co->outerContext = 0;
-        co->nextContextObject = 0;
-        co->prevContextObject = 0;
+        if (co->context == this)
+            co->context = nullptr;
+        co->outerContext = nullptr;
+        co->nextContextObject = nullptr;
+        co->prevContextObject = nullptr;
     }
+    Q_ASSERT(refCount == 1);
 
     QQmlGuardedContextData *contextGuard = contextGuards;
     while (contextGuard) {
         QQmlGuardedContextData *next = contextGuard->m_next;
-        contextGuard->m_next = 0;
-        contextGuard->m_prev = 0;
-        contextGuard->m_contextData = 0;
+        contextGuard->m_next = nullptr;
+        contextGuard->m_prev = nullptr;
+        contextGuard->m_contextData = nullptr;
         contextGuard = next;
     }
-    contextGuards = 0;
+    contextGuards = nullptr;
+    Q_ASSERT(refCount == 1);
 
     delete [] idValues;
+    idValues = nullptr;
 
-    if (isInternal)
+    Q_ASSERT(refCount == 1);
+    if (publicContext) {
+        // the QQmlContext destructor will remove one ref again
+        ++refCount;
         delete publicContext;
+    }
+
+    Q_ASSERT(refCount == 1);
+    --refCount;
+    Q_ASSERT(refCount == 0);
 
     delete this;
 }
 
-void QQmlContextData::setParent(QQmlContextData *p, bool parentTakesOwnership)
+void QQmlContextData::setParent(QQmlContextData *p, bool stronglyReferencedByParent)
 {
+    if (p == parent)
+        return;
     if (p) {
+        Q_ASSERT(!parent);
         parent = p;
+        this->stronglyReferencedByParent = stronglyReferencedByParent;
+        if (stronglyReferencedByParent)
+            ++refCount; // balanced in QQmlContextData::invalidate()
         engine = p->engine;
         nextChild = p->childContexts;
         if (nextChild) nextChild->prevChild = &nextChild;
         prevChild = &p->childContexts;
         p->childContexts = this;
-        ownedByParent = parentTakesOwnership;
     }
 }
 
@@ -660,6 +705,10 @@ void QQmlContextData::refreshExpressionsRecursive(QQmlJavaScriptExpression *expr
         expression->refresh();
 }
 
+QQmlContextData::~QQmlContextData()
+{
+}
+
 static inline bool expressions_to_run(QQmlContextData *ctxt, bool isGlobalRefresh)
 {
     return ctxt->expressions && (!isGlobalRefresh || ctxt->unresolvedNames);
@@ -713,7 +762,7 @@ void QQmlContextData::refreshExpressionsRecursive(bool isGlobal)
 // *structure* (not values) changes.
 void QQmlContextData::refreshExpressions()
 {
-    bool isGlobal = (parent == 0);
+    bool isGlobal = (parent == nullptr);
 
     // For efficiency, we try and minimize the number of guards we have to create
     if (expressions_to_run(this, isGlobal) && childContexts) {
@@ -735,13 +784,17 @@ void QQmlContextData::refreshExpressions()
     }
 }
 
-void QQmlContextData::addObject(QObject *o)
+void QQmlContextData::addObject(QQmlData *data)
 {
-    QQmlData *data = QQmlData::get(o, true);
-
-    Q_ASSERT(data->context == 0);
+    if (data->outerContext) {
+        if (data->nextContextObject)
+            data->nextContextObject->prevContextObject = data->prevContextObject;
+        if (data->prevContextObject)
+            *data->prevContextObject = data->nextContextObject;
+        else if (data->outerContext->contextObjects == data)
+            data->outerContext->contextObjects = data->nextContextObject;
+    }
 
-    data->context = this;
     data->outerContext = this;
 
     data->nextContextObject = contextObjects;
@@ -759,7 +812,7 @@ void QQmlContextData::setIdProperty(int idx, QObject *obj)
 
 QString QQmlContextData::findObjectId(const QObject *obj) const
 {
-    const QV4::IdentifierHash<int> &properties = propertyNames();
+    const QV4::IdentifierHash &properties = propertyNames();
     if (propertyNameCache.isEmpty())
         return QString();
 
@@ -795,24 +848,24 @@ QQmlContextPrivate *QQmlContextData::asQQmlContextPrivate()
 void QQmlContextData::initFromTypeCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit, int subComponentIndex)
 {
     typeCompilationUnit = unit;
-    componentObjectIndex = subComponentIndex == -1 ? typeCompilationUnit->data->indexOfRootObject : subComponentIndex;
+    componentObjectIndex = subComponentIndex == -1 ? /*root object*/0 : subComponentIndex;
     Q_ASSERT(!idValues);
-    idValueCount = typeCompilationUnit->data->objectAt(componentObjectIndex)->nNamedObjectsInComponent;
+    idValueCount = typeCompilationUnit->objectAt(componentObjectIndex)->nNamedObjectsInComponent;
     idValues = new ContextGuard[idValueCount];
 }
 
-const QV4::IdentifierHash<int> &QQmlContextData::propertyNames() const
+const QV4::IdentifierHash &QQmlContextData::propertyNames() const
 {
     if (propertyNameCache.isEmpty()) {
         if (typeCompilationUnit)
             propertyNameCache = typeCompilationUnit->namedObjectsPerComponent(componentObjectIndex);
         else
-            propertyNameCache = QV4::IdentifierHash<int>(QV8Engine::getV4(engine));
+            propertyNameCache = QV4::IdentifierHash(engine->handle());
     }
     return propertyNameCache;
 }
 
-QV4::IdentifierHash<int> &QQmlContextData::detachedPropertyNames()
+QV4::IdentifierHash &QQmlContextData::detachedPropertyNames()
 {
     propertyNames();
     propertyNameCache.detach();
@@ -822,14 +875,14 @@ QV4::IdentifierHash<int> &QQmlContextData::detachedPropertyNames()
 QUrl QQmlContextData::url() const
 {
     if (typeCompilationUnit)
-        return typeCompilationUnit->url();
+        return typeCompilationUnit->finalUrl();
     return baseUrl;
 }
 
 QString QQmlContextData::urlString() const
 {
     if (typeCompilationUnit)
-        return typeCompilationUnit->fileName();
+        return typeCompilationUnit->finalUrlString();
     return baseUrlString;
 }
 
diff --git a/src/qml/qml/qqmlcontext.h b/src/qml/qml/qqmlcontext.h
index 781eac44fc..7ed70c7619 100644
--- a/src/qml/qml/qqmlcontext.h
+++ b/src/qml/qml/qqmlcontext.h
@@ -42,6 +42,8 @@
 
 #include <QtCore/qurl.h>
 #include <QtCore/qobject.h>
+#include <QtCore/qlist.h>
+#include <QtCore/qpair.h>
 #include <QtQml/qjsvalue.h>
 #include <QtCore/qmetatype.h>
 #include <QtCore/qvariant.h>
@@ -62,9 +64,11 @@ class Q_QML_EXPORT QQmlContext : public QObject
     Q_DECLARE_PRIVATE(QQmlContext)
 
 public:
-    QQmlContext(QQmlEngine *parent, QObject *objParent = Q_NULLPTR);
-    QQmlContext(QQmlContext *parent, QObject *objParent = Q_NULLPTR);
-    virtual ~QQmlContext();
+    struct PropertyPair { QString name; QVariant value; };
+
+    QQmlContext(QQmlEngine *parent, QObject *objParent = nullptr);
+    QQmlContext(QQmlContext *parent, QObject *objParent = nullptr);
+    ~QQmlContext() override;
 
     bool isValid() const;
 
@@ -77,6 +81,7 @@ public:
     QVariant contextProperty(const QString &) const;
     void setContextProperty(const QString &, QObject *);
     void setContextProperty(const QString &, const QVariant &);
+    void setContextProperties(const QVector<PropertyPair> &properties);
 
     // ### Qt 6: no need for a mutable object, this should become a const QObject pointer
     QString nameForObject(QObject *) const;
diff --git a/src/qml/qml/qqmlcontext_p.h b/src/qml/qml/qqmlcontext_p.h
index 4d2bb72352..7e3cef8e1d 100644
--- a/src/qml/qml/qqmlcontext_p.h
+++ b/src/qml/qml/qqmlcontext_p.h
@@ -78,6 +78,8 @@ class QQmlExpression;
 class QQmlExpressionPrivate;
 class QQmlJavaScriptExpression;
 class QQmlContextData;
+class QQmlGuardedContextData;
+class QQmlIncubatorPrivate;
 
 class QQmlContextPrivate : public QObjectPrivate
 {
@@ -105,7 +107,7 @@ public:
 };
 
 class QQmlComponentAttached;
-class QQmlGuardedContextData;
+
 class Q_QML_PRIVATE_EXPORT QQmlContextData
 {
 public:
@@ -113,7 +115,7 @@ public:
     QQmlContextData(QQmlContext *);
     void emitDestruction();
     void clearContext();
-    void destroy();
+    void clearContextRecursively();
     void invalidate();
 
     inline bool isValid() const {
@@ -121,13 +123,13 @@ public:
     }
 
     // My parent context and engine
-    QQmlContextData *parent;
+    QQmlContextData *parent = nullptr;
     QQmlEngine *engine;
 
-    void setParent(QQmlContextData *, bool parentTakesOwnership = false);
+    void setParent(QQmlContextData *, bool stronglyReferencedByParent = false);
     void refreshExpressions();
 
-    void addObject(QObject *);
+    void addObject(QQmlData *data);
 
     QUrl resolvedUrl(const QUrl &);
 
@@ -135,18 +137,19 @@ public:
     // If internal is false publicContext owns this.
     QQmlContext *asQQmlContext();
     QQmlContextPrivate *asQQmlContextPrivate();
+    quint32 refCount = 0;
     quint32 isInternal:1;
-    quint32 ownedByParent:1; // unrelated to isInternal; parent context deletes children if true.
     quint32 isJSContext:1;
     quint32 isPragmaLibraryContext:1;
     quint32 unresolvedNames:1; // True if expressions in this context failed to resolve a toplevel name
     quint32 hasEmittedDestruction:1;
     quint32 isRootObjectInCreation:1;
+    quint32 stronglyReferencedByParent:1;
     quint32 dummy:25;
     QQmlContext *publicContext;
 
-    // VME data that is constructing this context if any
-    void *activeVMEData;
+    // The incubator that is constructing this context if any
+    QQmlIncubatorPrivate *incubator;
 
     // Compilation unit for contexts that belong to a compiled type.
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> typeCompilationUnit;
@@ -157,9 +160,9 @@ public:
     void initFromTypeCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit, int subComponentIndex);
 
     // flag indicates whether the context owns the cache (after mutation) or not.
-    mutable QV4::IdentifierHash<int> propertyNameCache;
-    const QV4::IdentifierHash<int> &propertyNames() const;
-    QV4::IdentifierHash<int> &detachedPropertyNames();
+    mutable QV4::IdentifierHash propertyNameCache;
+    const QV4::IdentifierHash &propertyNames() const;
+    QV4::IdentifierHash &detachedPropertyNames();
 
     // Context object
     QObject *contextObject;
@@ -177,7 +180,7 @@ public:
     QQmlRefPointer<QQmlTypeNameCache> imports;
 
     // My children
-    QQmlContextData *childContexts;
+    QQmlContextData *childContexts = nullptr;
 
     // My peers in parent's childContexts list
     QQmlContextData  *nextChild;
@@ -190,7 +193,7 @@ public:
     QQmlData *contextObjects;
 
     // Doubly-linked list of context guards (XXX merge with contextObjects)
-    QQmlGuardedContextData *contextGuards;
+    QQmlGuardedContextData *contextGuards = nullptr;
 
     // id guards
     struct ContextGuard : public QQmlGuard<QObject>
@@ -209,7 +212,7 @@ public:
     void setIdProperty(int, QObject *);
 
     // Linked contexts. this owns linkedContext.
-    QQmlContextData *linkedContext;
+    QQmlContextDataRef linkedContext;
 
     // Linked list of uses of the Component attached property in this
     // context
@@ -223,93 +226,139 @@ public:
     }
 
 private:
+    friend class QQmlContextDataRef;
+    friend class QQmlContext; // needs to do manual refcounting :/
     void refreshExpressionsRecursive(bool isGlobal);
     void refreshExpressionsRecursive(QQmlJavaScriptExpression *);
-    ~QQmlContextData() {}
+    ~QQmlContextData();
+    void destroy();
 };
 
+
 class QQmlGuardedContextData
 {
 public:
-    inline QQmlGuardedContextData();
-    inline QQmlGuardedContextData(QQmlContextData *);
-    inline ~QQmlGuardedContextData();
-
-    inline QQmlContextData *contextData() const;
+    inline QQmlGuardedContextData() = default;
+    inline QQmlGuardedContextData(QQmlContextData *data)
+    { setContextData(data); }
+    inline ~QQmlGuardedContextData()
+    { clear(); }
+
+    inline QQmlContextData *contextData() const
+    { return m_contextData; }
     inline void setContextData(QQmlContextData *);
 
     inline bool isNull() const { return !m_contextData; }
 
     inline operator QQmlContextData*() const { return m_contextData; }
     inline QQmlContextData* operator->() const { return m_contextData; }
-    inline QQmlGuardedContextData &operator=(QQmlContextData *d);
+    inline QQmlGuardedContextData &operator=(QQmlContextData *d) {
+        setContextData(d); return *this;
+    }
 
 private:
-    QQmlGuardedContextData &operator=(const QQmlGuardedContextData &);
-    QQmlGuardedContextData(const QQmlGuardedContextData &);
+    QQmlGuardedContextData &operator=(const QQmlGuardedContextData &) = delete;
+    QQmlGuardedContextData(const QQmlGuardedContextData &) = delete;
     friend class QQmlContextData;
 
     inline void clear();
 
-    QQmlContextData *m_contextData;
-    QQmlGuardedContextData  *m_next;
-    QQmlGuardedContextData **m_prev;
+    QQmlContextData *m_contextData = nullptr;
+    QQmlGuardedContextData  *m_next = nullptr;
+    QQmlGuardedContextData **m_prev = nullptr;
 };
 
-QQmlGuardedContextData::QQmlGuardedContextData()
-: m_contextData(0), m_next(0), m_prev(0)
+
+void QQmlGuardedContextData::setContextData(QQmlContextData *contextData)
+ {
+    if (m_contextData == contextData)
+        return;
+    clear();
+
+    if (contextData) {
+        m_contextData = contextData;
+        m_next = contextData->contextGuards;
+        if (m_next) m_next->m_prev = &m_next;
+        m_prev = &contextData->contextGuards;
+        contextData->contextGuards = this;
+    }
+}
+
+void QQmlGuardedContextData::clear()
+{
+    if (m_prev) {
+        *m_prev = m_next;
+        if (m_next) m_next->m_prev = m_prev;
+        m_contextData = nullptr;
+        m_next = nullptr;
+        m_prev = nullptr;
+    }
+}
+
+QQmlContextDataRef::QQmlContextDataRef()
+    : m_contextData(nullptr)
 {
 }
 
-QQmlGuardedContextData::QQmlGuardedContextData(QQmlContextData *data)
-: m_contextData(0), m_next(0), m_prev(0)
+QQmlContextDataRef::QQmlContextDataRef(const QQmlContextDataRef &other)
+    : m_contextData(other.m_contextData)
 {
-    setContextData(data);
+    if (m_contextData)
+        ++m_contextData->refCount;
 }
 
-QQmlGuardedContextData::~QQmlGuardedContextData()
+QQmlContextDataRef::QQmlContextDataRef(QQmlContextData *data)
+    : m_contextData(data)
+{
+    if (m_contextData)
+        ++m_contextData->refCount;
+}
+
+QQmlContextDataRef::~QQmlContextDataRef()
 {
     clear();
 }
 
-void QQmlGuardedContextData::setContextData(QQmlContextData *contextData)
+void QQmlContextDataRef::setContextData(QQmlContextData *contextData)
 {
+    if (m_contextData == contextData)
+        return;
     clear();
 
     if (contextData) {
         m_contextData = contextData;
-        m_next = contextData->contextGuards;
-        if (m_next) m_next->m_prev = &m_next;
-        m_prev = &contextData->contextGuards;
-        contextData->contextGuards = this;
+        ++m_contextData->refCount;
     }
 }
 
-QQmlContextData *QQmlGuardedContextData::contextData() const
+QQmlContextData *QQmlContextDataRef::contextData() const
 {
     return m_contextData;
 }
 
-void QQmlGuardedContextData::clear()
+void QQmlContextDataRef::clear()
 {
-    if (m_prev) {
-        *m_prev = m_next;
-        if (m_next) m_next->m_prev = m_prev;
-        m_contextData = 0;
-        m_next = 0;
-        m_prev = 0;
-    }
+    if (m_contextData && !--m_contextData->refCount)
+        m_contextData->destroy();
+    m_contextData = nullptr;
 }
 
-QQmlGuardedContextData &
-QQmlGuardedContextData::operator=(QQmlContextData *d)
+QQmlContextDataRef &
+QQmlContextDataRef::operator=(QQmlContextData *d)
 {
     setContextData(d);
     return *this;
 }
 
+QQmlContextDataRef &
+QQmlContextDataRef::operator=(const QQmlContextDataRef &other)
+{
+    setContextData(other.m_contextData);
+    return *this;
+}
+
 QQmlContextData::ContextGuard::ContextGuard()
-: context(0)
+: context(nullptr)
 {
 }
 
diff --git a/src/qml/qml/qqmlcustomparser.cpp b/src/qml/qml/qqmlcustomparser.cpp
index 6ad641b8b1..5cf87f5264 100644
--- a/src/qml/qml/qqmlcustomparser.cpp
+++ b/src/qml/qml/qqmlcustomparser.cpp
@@ -135,17 +135,17 @@ int QQmlCustomParser::evaluateEnum(const QByteArray& script, bool *ok) const
     if (scope != QLatin1String("Qt")) {
         if (imports.isNull())
             return -1;
-        QQmlType *type = 0;
+        QQmlType type;
 
         if (imports.isT1()) {
-            imports.asT1()->resolveType(scope, &type, 0, 0, 0);
+            imports.asT1()->resolveType(scope, &type, nullptr, nullptr, nullptr);
         } else {
             QQmlTypeNameCache::Result result = imports.asT2()->query(scope);
             if (result.isValid())
                 type = result.type;
         }
 
-        if (!type)
+        if (!type.isValid())
             return -1;
 
         int dot2 = script.indexOf('.', dot+1);
@@ -153,9 +153,9 @@ int QQmlCustomParser::evaluateEnum(const QByteArray& script, bool *ok) const
         QByteArray enumValue = script.mid(dot2Valid ? dot2 + 1 : dot + 1);
         QByteArray scopedEnumName = (dot2Valid ? script.mid(dot + 1, dot2 - dot - 1) : QByteArray());
         if (!scopedEnumName.isEmpty())
-            return type->scopedEnumValue(engine, scopedEnumName, enumValue, ok);
+            return type.scopedEnumValue(engine, scopedEnumName, enumValue, ok);
         else
-            return type->enumValue(engine, QHashedCStringRef(enumValue.constData(), enumValue.length()), ok);
+            return type.enumValue(engine, QHashedCStringRef(enumValue.constData(), enumValue.length()), ok);
     }
 
     QByteArray enumValue = script.mid(dot + 1);
@@ -177,12 +177,10 @@ const QMetaObject *QQmlCustomParser::resolveType(const QString& name) const
 {
     if (!imports.isT1())
         return nullptr;
-    QQmlType *qmltype = 0;
-    if (!imports.asT1()->resolveType(name, &qmltype, 0, 0, 0))
+    QQmlType qmltype;
+    if (!imports.asT1()->resolveType(name, &qmltype, nullptr, nullptr, nullptr))
         return nullptr;
-    if (!qmltype)
-        return nullptr;
-    return qmltype->metaObject();
+    return qmltype.metaObject();
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlcustomparser_p.h b/src/qml/qml/qqmlcustomparser_p.h
index 5eb409990d..aa933553a8 100644
--- a/src/qml/qml/qqmlcustomparser_p.h
+++ b/src/qml/qml/qqmlcustomparser_p.h
@@ -51,7 +51,6 @@
 // We mean it.
 //
 
-#include "qqmlmetatype_p.h"
 #include "qqmlerror.h"
 #include "qqmlbinding_p.h"
 #include <private/qqmltypecompiler_p.h>
@@ -74,15 +73,15 @@ public:
     };
     Q_DECLARE_FLAGS(Flags, Flag)
 
-    QQmlCustomParser() : engine(0), validator(0), m_flags(NoFlag) {}
-    QQmlCustomParser(Flags f) : engine(0), validator(0), m_flags(f) {}
+    QQmlCustomParser() : engine(nullptr), validator(nullptr), m_flags(NoFlag) {}
+    QQmlCustomParser(Flags f) : engine(nullptr), validator(nullptr), m_flags(f) {}
     virtual ~QQmlCustomParser() {}
 
     void clearErrors();
     Flags flags() const { return m_flags; }
 
-    virtual void verifyBindings(const QV4::CompiledData::Unit *, const QList<const QV4::CompiledData::Binding *> &) = 0;
-    virtual void applyBindings(QObject *, QV4::CompiledData::CompilationUnit *, const QList<const QV4::CompiledData::Binding *> &) = 0;
+    virtual void verifyBindings(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &, const QList<const QV4::CompiledData::Binding *> &) = 0;
+    virtual void applyBindings(QObject *, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &, const QList<const QV4::CompiledData::Binding *> &) = 0;
 
     QVector<QQmlCompileError> errors() const { return exceptions; }
 
diff --git a/src/qml/qml/qqmldata_p.h b/src/qml/qml/qqmldata_p.h
index 2083326cd5..2468de6857 100644
--- a/src/qml/qml/qqmldata_p.h
+++ b/src/qml/qml/qqmldata_p.h
@@ -56,7 +56,9 @@
 #include <private/qqmlpropertyindex_p.h>
 #include <private/qv4value_p.h>
 #include <private/qv4persistent_p.h>
+#include <private/qqmlrefcount_p.h>
 #include <qjsengine.h>
+#include <qvector.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -75,9 +77,38 @@ class QQmlNotifierEndpoint;
 namespace QV4 {
 namespace CompiledData {
 struct CompilationUnit;
+struct Binding;
 }
 }
 
+// This is declared here because QQmlData below needs it and this file
+// in turn is included from qqmlcontext_p.h.
+class QQmlContextData;
+class Q_QML_PRIVATE_EXPORT QQmlContextDataRef
+{
+public:
+    inline QQmlContextDataRef();
+    inline QQmlContextDataRef(QQmlContextData *);
+    inline QQmlContextDataRef(const QQmlContextDataRef &);
+    inline ~QQmlContextDataRef();
+
+    inline QQmlContextData *contextData() const;
+    inline void setContextData(QQmlContextData *);
+
+    inline bool isNull() const { return !m_contextData; }
+
+    inline operator QQmlContextData*() const { return m_contextData; }
+    inline QQmlContextData* operator->() const { return m_contextData; }
+    inline QQmlContextDataRef &operator=(QQmlContextData *d);
+    inline QQmlContextDataRef &operator=(const QQmlContextDataRef &other);
+
+private:
+
+    inline void clear();
+
+    QQmlContextData *m_contextData;
+};
+
 // This class is structured in such a way, that simply zero'ing it is the
 // default state for elemental object allocations.  This is crucial in the
 // workings of the QQmlInstruction::CreateSimpleObject instruction.
@@ -86,6 +117,7 @@ class Q_QML_PRIVATE_EXPORT QQmlData : public QAbstractDeclarativeData
 {
 public:
     QQmlData();
+    ~QQmlData();
 
     static inline void init() {
         static bool initialized = false;
@@ -114,7 +146,6 @@ public:
 
     quint32 ownedByQml1:1; // This bit is shared with QML1's QDeclarativeData.
     quint32 ownMemory:1;
-    quint32 ownContext:1;
     quint32 indestructible:1;
     quint32 explicitIndestructibleSet:1;
     quint32 hasTaintedV4Object:1;
@@ -127,18 +158,21 @@ public:
     quint32 hasInterceptorMetaObject:1;
     quint32 hasVMEMetaObject:1;
     quint32 parentFrozen:1;
-    quint32 dummy:21;
+    quint32 dummy:6;
 
     // When bindingBitsSize < sizeof(ptr), we store the binding bit flags inside
     // bindingBitsValue. When we need more than sizeof(ptr) bits, we allocated
     // sufficient space and use bindingBits to point to it.
-    int bindingBitsSize;
+    quint32 bindingBitsArraySize : 16;
     typedef quintptr BindingBitsType;
+    enum {
+        BitsPerType = sizeof(BindingBitsType) * 8,
+        InlineBindingArraySize = 2
+    };
     union {
         BindingBitsType *bindingBits;
-        BindingBitsType bindingBitsValue;
+        BindingBitsType bindingBitsValue[InlineBindingArraySize];
     };
-    enum { MaxInlineBits = sizeof(BindingBitsType) * 8 };
 
     struct NotifyList {
         quint64 connectionMask;
@@ -161,9 +195,10 @@ public:
     void disconnectNotifiers();
 
     // The context that created the C++ object
-    QQmlContextData *context;
+    QQmlContextData *context = nullptr;
     // The outermost context in which this object lives
-    QQmlContextData *outerContext;
+    QQmlContextData *outerContext = nullptr;
+    QQmlContextDataRef ownContext;
 
     QQmlAbstractBinding *bindings;
     QQmlBoundSignal *signalHandlers;
@@ -173,12 +208,12 @@ public:
     QQmlData**prevContextObject;
 
     inline bool hasBindingBit(int) const;
-    void clearBindingBit(int);
-    void setBindingBit(QObject *obj, int);
+    inline void setBindingBit(QObject *obj, int);
+    inline void clearBindingBit(int);
 
     inline bool hasPendingBindingBit(int index) const;
-    void setPendingBindingBit(QObject *obj, int);
-    void clearPendingBindingBit(int);
+    inline void setPendingBindingBit(QObject *obj, int);
+    inline void clearPendingBindingBit(int);
 
     quint16 lineNumber;
     quint16 columnNumber;
@@ -186,12 +221,19 @@ public:
     quint32 jsEngineId; // id of the engine that created the jsWrapper
 
     struct DeferredData {
+        DeferredData();
+        ~DeferredData();
         unsigned int deferredIdx;
-        QV4::CompiledData::CompilationUnit *compilationUnit;//Not always the same as the other compilation unit
+        QMultiHash<int, const QV4::CompiledData::Binding *> bindings;
+        QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;//Not always the same as the other compilation unit
         QQmlContextData *context;//Could be either context or outerContext
+        Q_DISABLE_COPY(DeferredData);
     };
-    QV4::CompiledData::CompilationUnit *compilationUnit;
-    DeferredData *deferredData;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
+    QVector<DeferredData *> deferredData;
+
+    void deferData(int objectIndex, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &, QQmlContextData *);
+    void releaseDeferredData();
 
     QV4::WeakValue jsWrapper;
 
@@ -205,13 +247,13 @@ public:
         // to be avoided because QObjectPrivate::currentChildBeingDeleted is in use.
         if (priv->isDeletingChildren || priv->wasDeleted) {
             Q_ASSERT(!create);
-            return 0;
+            return nullptr;
         } else if (priv->declarativeData) {
             return static_cast<QQmlData *>(priv->declarativeData);
         } else if (create) {
             return createQQmlData(priv);
         } else {
-            return 0;
+            return nullptr;
         }
     }
 
@@ -222,10 +264,10 @@ public:
         return false;
     }
 
-    bool hasExtendedData() const { return extendedData != 0; }
+    bool hasExtendedData() const { return extendedData != nullptr; }
     QHash<int, QObject *> *attachedProperties() const;
 
-    static inline bool wasDeleted(QObject *);
+    static inline bool wasDeleted(const QObject *);
 
     static void markAsDeleted(QObject *);
     static void setQueuedForDeletion(QObject *);
@@ -241,6 +283,9 @@ public:
         return createPropertyCache(engine, object);
     }
 
+    Q_ALWAYS_INLINE static uint offsetForBit(int bit) { return static_cast<uint>(bit) / BitsPerType; }
+    Q_ALWAYS_INLINE static BindingBitsType bitFlagForBit(int bit) { return BindingBitsType(1) << (static_cast<uint>(bit) & (BitsPerType - 1)); }
+
 private:
     // For attachedProperties
     mutable QQmlDataExtended *extendedData;
@@ -252,26 +297,47 @@ private:
 
     Q_ALWAYS_INLINE bool hasBitSet(int bit) const
     {
-        if (bindingBitsSize <= bit)
+        uint offset = offsetForBit(bit);
+        if (bindingBitsArraySize <= offset)
             return false;
 
-        if (bindingBitsSize == MaxInlineBits)
-            return bindingBitsValue & (BindingBitsType(1) << bit);
-        else
-            return bindingBits[bit / MaxInlineBits] & (BindingBitsType(1) << (bit % MaxInlineBits));
+        const BindingBitsType *bits = (bindingBitsArraySize == InlineBindingArraySize) ? bindingBitsValue : bindingBits;
+        return bits[offset] & bitFlagForBit(bit);
+    }
+
+    Q_ALWAYS_INLINE void clearBit(int bit)
+    {
+        uint offset = QQmlData::offsetForBit(bit);
+        if (bindingBitsArraySize > offset) {
+            BindingBitsType *bits = (bindingBitsArraySize == InlineBindingArraySize) ? bindingBitsValue : bindingBits;
+            bits[offset] &= ~QQmlData::bitFlagForBit(bit);
+        }
+    }
+
+    Q_ALWAYS_INLINE void setBit(QObject *obj, int bit)
+    {
+        uint offset = QQmlData::offsetForBit(bit);
+        BindingBitsType *bits = (bindingBitsArraySize == InlineBindingArraySize) ? bindingBitsValue : bindingBits;
+        if (Q_UNLIKELY(bindingBitsArraySize <= offset))
+            bits = growBits(obj, bit);
+        bits[offset] |= QQmlData::bitFlagForBit(bit);
     }
+
+    Q_NEVER_INLINE BindingBitsType *growBits(QObject *obj, int bit);
+
+    Q_DISABLE_COPY(QQmlData);
 };
 
-bool QQmlData::wasDeleted(QObject *object)
+bool QQmlData::wasDeleted(const QObject *object)
 {
     if (!object)
         return true;
 
-    QObjectPrivate *priv = QObjectPrivate::get(object);
+    const QObjectPrivate *priv = QObjectPrivate::get(object);
     if (!priv || priv->wasDeleted)
         return true;
 
-    QQmlData *ddata = QQmlData::get(object);
+    const QQmlData *ddata = QQmlData::get(object);
     return ddata && ddata->isQueuedForDeletion;
 }
 
@@ -280,7 +346,7 @@ QQmlNotifierEndpoint *QQmlData::notify(int index)
     Q_ASSERT(index <= 0xFFFF);
 
     if (!notifyList || !(notifyList->connectionMask & (1ULL << quint64(index % 64)))) {
-        return 0;
+        return nullptr;
     } else if (index < notifyList->notifiesSize) {
         return notifyList->notifies[index];
     } else if (index <= notifyList->maximumTodoIndex) {
@@ -290,7 +356,7 @@ QQmlNotifierEndpoint *QQmlData::notify(int index)
     if (index < notifyList->notifiesSize) {
         return notifyList->notifies[index];
     } else {
-        return 0;
+        return nullptr;
     }
 }
 
@@ -311,6 +377,20 @@ bool QQmlData::hasBindingBit(int coreIndex) const
     return hasBitSet(coreIndex * 2);
 }
 
+void QQmlData::setBindingBit(QObject *obj, int coreIndex)
+{
+    Q_ASSERT(coreIndex >= 0);
+    Q_ASSERT(coreIndex <= 0xffff);
+    setBit(obj, coreIndex * 2);
+}
+
+void QQmlData::clearBindingBit(int coreIndex)
+{
+    Q_ASSERT(coreIndex >= 0);
+    Q_ASSERT(coreIndex <= 0xffff);
+    clearBit(coreIndex * 2);
+}
+
 bool QQmlData::hasPendingBindingBit(int coreIndex) const
 {
     Q_ASSERT(coreIndex >= 0);
@@ -319,6 +399,20 @@ bool QQmlData::hasPendingBindingBit(int coreIndex) const
     return hasBitSet(coreIndex * 2 + 1);
 }
 
+void QQmlData::setPendingBindingBit(QObject *obj, int coreIndex)
+{
+    Q_ASSERT(coreIndex >= 0);
+    Q_ASSERT(coreIndex <= 0xffff);
+    setBit(obj, coreIndex * 2 + 1);
+}
+
+void QQmlData::clearPendingBindingBit(int coreIndex)
+{
+    Q_ASSERT(coreIndex >= 0);
+    Q_ASSERT(coreIndex <= 0xffff);
+    clearBit(coreIndex * 2 + 1);
+}
+
 void QQmlData::flushPendingBinding(QObject *o, QQmlPropertyIndex propertyIndex)
 {
     QQmlData *data = QQmlData::get(o, false);
diff --git a/src/qml/qml/qqmldelayedcallqueue.cpp b/src/qml/qml/qqmldelayedcallqueue.cpp
index 13e62ec696..61cb0a9065 100644
--- a/src/qml/qml/qqmldelayedcallqueue.cpp
+++ b/src/qml/qml/qqmldelayedcallqueue.cpp
@@ -42,6 +42,7 @@
 #include <private/qqmlengine_p.h>
 #include <private/qqmljavascriptexpression_p.h>
 #include <private/qv4value_p.h>
+#include <private/qv4jscall_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 
 #include <QQmlError>
@@ -63,17 +64,17 @@ void QQmlDelayedCallQueue::DelayedFunctionCall::execute(QV4::ExecutionEngine *en
         QV4::Scope scope(engine);
 
         QV4::ArrayObject *array = m_args.as<QV4::ArrayObject>();
+        const QV4::FunctionObject *callback = m_function.as<QV4::FunctionObject>();
+        Q_ASSERT(callback);
         const int argCount = array ? array->getLength() : 0;
-        QV4::ScopedCallData callData(scope, argCount);
-        callData->thisObject = QV4::Encode::undefined();
+        QV4::JSCallData jsCallData(scope, argCount);
+        *jsCallData->thisObject = QV4::Encode::undefined();
 
         for (int i = 0; i < argCount; i++) {
-            callData->args[i] = array->getIndexed(i);
+            jsCallData->args[i] = array->get(i);
         }
 
-        const QV4::FunctionObject *callback = m_function.as<QV4::FunctionObject>();
-        Q_ASSERT(callback);
-        callback->call(scope, callData);
+        callback->call(jsCallData);
 
         if (scope.engine->hasException) {
             QQmlError error = scope.engine->catchExceptionAsQmlError();
@@ -88,7 +89,7 @@ void QQmlDelayedCallQueue::DelayedFunctionCall::execute(QV4::ExecutionEngine *en
 //
 
 QQmlDelayedCallQueue::QQmlDelayedCallQueue()
-    : QObject(0), m_engine(0), m_callbackOutstanding(false)
+    : QObject(nullptr), m_engine(nullptr), m_callbackOutstanding(false)
 {
 }
 
@@ -105,17 +106,19 @@ void QQmlDelayedCallQueue::init(QV4::ExecutionEngine* engine)
     m_tickedMethod = metaObject.method(methodIndex);
 }
 
-void QQmlDelayedCallQueue::addUniquelyAndExecuteLater(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+QV4::ReturnedValue QQmlDelayedCallQueue::addUniquelyAndExecuteLater(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    QV4::Scope scope(b);
+    if (argc == 0)
         THROW_GENERIC_ERROR("Qt.callLater: no arguments given");
 
-    const QV4::FunctionObject *func = callData->args[0].as<QV4::FunctionObject>();
+    const QV4::FunctionObject *func = argv[0].as<QV4::FunctionObject>();
 
     if (!func)
         THROW_GENERIC_ERROR("Qt.callLater: first argument not a function or signal");
 
     QPair<QObject *, int> functionData = QV4::QObjectMethod::extractQtMethod(func);
+    QV4::ReturnedValue arg0 = argc ? argv[0].asReturnedValue() : QV4::Encode::undefined();
 
     QVector<DelayedFunctionCall>::Iterator iter;
     if (functionData.second != -1) {
@@ -134,7 +137,7 @@ void QQmlDelayedCallQueue::addUniquelyAndExecuteLater(const QV4::BuiltinFunction
         iter = m_delayedFunctionCalls.begin();
         while (iter != m_delayedFunctionCalls.end()) {
             DelayedFunctionCall& dfc = *iter;
-            if (callData->argument(0) == dfc.m_function.value()) {
+            if (arg0 == dfc.m_function.value()) {
                 break; // Already stored!
             }
             ++iter;
@@ -147,7 +150,7 @@ void QQmlDelayedCallQueue::addUniquelyAndExecuteLater(const QV4::BuiltinFunction
         m_delayedFunctionCalls.erase(iter);
         m_delayedFunctionCalls.append(dfc);
     } else {
-        m_delayedFunctionCalls.append(QV4::PersistentValue(m_engine, callData->argument(0)));
+        m_delayedFunctionCalls.append(QV4::PersistentValue(m_engine, arg0));
     }
 
     DelayedFunctionCall& dfc = m_delayedFunctionCalls.last();
@@ -158,33 +161,32 @@ void QQmlDelayedCallQueue::addUniquelyAndExecuteLater(const QV4::BuiltinFunction
             dfc.m_guarded = true;
         } else if (func->scope()->type == QV4::Heap::ExecutionContext::Type_QmlContext) {
             QV4::QmlContext::Data *g = static_cast<QV4::QmlContext::Data *>(func->scope());
-            Q_ASSERT(g->qml->scopeObject);
-            dfc.m_objectGuard = QQmlGuard<QObject>(g->qml->scopeObject);
+            Q_ASSERT(g->qml()->scopeObject);
+            dfc.m_objectGuard = QQmlGuard<QObject>(g->qml()->scopeObject);
             dfc.m_guarded = true;
         }
     }
-    storeAnyArguments(dfc, callData, 1, m_engine);
+    storeAnyArguments(dfc, argv, argc, 1, m_engine);
 
     if (!m_callbackOutstanding) {
         m_tickedMethod.invoke(this, Qt::QueuedConnection);
         m_callbackOutstanding = true;
     }
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void QQmlDelayedCallQueue::storeAnyArguments(DelayedFunctionCall &dfc, const QV4::CallData *callData, int offset, QV4::ExecutionEngine *engine)
+void QQmlDelayedCallQueue::storeAnyArguments(DelayedFunctionCall &dfc, const QV4::Value *argv, int argc, int offset, QV4::ExecutionEngine *engine)
 {
-    const int length = callData->argc - offset;
+    const int length = argc - offset;
     if (length == 0) {
         dfc.m_args.clear();
         return;
     }
     QV4::Scope scope(engine);
     QV4::ScopedArrayObject array(scope, engine->newArrayObject(length));
-    int i = 0;
-    for (int j = offset; j < callData->argc; ++i, ++j) {
-        array->putIndexed(i, callData->args[j]);
-    }
+    uint i = 0;
+    for (int j = offset, ej = argc; j < ej; ++i, ++j)
+        array->put(i, argv[j]);
     dfc.m_args.set(engine, array);
 }
 
diff --git a/src/qml/qml/qqmldelayedcallqueue_p.h b/src/qml/qml/qqmldelayedcallqueue_p.h
index cffde4f0c0..7962318561 100644
--- a/src/qml/qml/qqmldelayedcallqueue_p.h
+++ b/src/qml/qml/qqmldelayedcallqueue_p.h
@@ -60,17 +60,16 @@
 
 QT_BEGIN_NAMESPACE
 
-class QV8Engine;
 class QQmlDelayedCallQueue : public QObject
 {
     Q_OBJECT
 public:
     QQmlDelayedCallQueue();
-    ~QQmlDelayedCallQueue();
+    ~QQmlDelayedCallQueue() override;
 
     void init(QV4::ExecutionEngine *);
 
-    void addUniquelyAndExecuteLater(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    QV4::ReturnedValue addUniquelyAndExecuteLater(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 
 public Q_SLOTS:
     void ticked();
@@ -90,7 +89,7 @@ private:
         bool m_guarded;
     };
 
-    void storeAnyArguments(DelayedFunctionCall& dfc, const QV4::CallData *callData, int offset, QV4::ExecutionEngine *engine);
+    void storeAnyArguments(DelayedFunctionCall& dfc, const QV4::Value *argv, int argc, int offset, QV4::ExecutionEngine *engine);
     void executeAllExpired_Later();
 
     QV4::ExecutionEngine *m_engine;
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index d8779e0d12..0a26ed89cc 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -48,7 +48,6 @@
 #include "qqmlcomponent.h"
 #include "qqmlvme_p.h"
 #include "qqmlstringconverters_p.h"
-#include "qqmlxmlhttprequest_p.h"
 #include "qqmlscriptstring.h"
 #include "qqmlglobal_p.h"
 #include "qqmlcomponent_p.h"
@@ -79,18 +78,26 @@
 
 #include <private/qobject_p.h>
 #include <private/qmetaobject_p.h>
+#if QT_CONFIG(qml_locale)
 #include <private/qqmllocale_p.h>
+#endif
 #include <private/qqmlbind_p.h>
 #include <private/qqmlconnections_p.h>
-#if QT_CONFIG(animation)
+#if QT_CONFIG(qml_animation)
 #include <private/qqmltimer_p.h>
 #endif
+#if QT_CONFIG(qml_list_model)
 #include <private/qqmllistmodel_p.h>
+#endif
 #include <private/qqmlplatform_p.h>
 #include <private/qquickpackage_p.h>
+#if QT_CONFIG(qml_delegate_model)
 #include <private/qqmldelegatemodel_p.h>
+#endif
 #include <private/qqmlobjectmodel_p.h>
+#if QT_CONFIG(qml_worker_script)
 #include <private/qquickworkerscript_p.h>
+#endif
 #include <private/qqmlinstantiator_p.h>
 #include <private/qqmlloggingcategory_p.h>
 
@@ -109,9 +116,6 @@ Q_DECLARE_METATYPE(QQmlProperty)
 
 QT_BEGIN_NAMESPACE
 
-typedef QQmlData::BindingBitsType BindingBitsType;
-enum { MaxInlineBits = QQmlData::MaxInlineBits };
-
 void qmlRegisterBaseTypes(const char *uri, int versionMajor, int versionMinor)
 {
     QQmlEnginePrivate::registerBaseTypes(uri, versionMajor, versionMinor);
@@ -131,21 +135,21 @@ int qmlRegisterUncreatableMetaObject(const QMetaObject &staticMetaObject,
         0,
         0,
         0,
-        Q_NULLPTR,
+        nullptr,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &staticMetaObject,
 
         QQmlAttachedPropertiesFunc(),
-        Q_NULLPTR,
+        nullptr,
 
         0,
         0,
         0,
 
-        Q_NULLPTR, Q_NULLPTR,
+        nullptr, nullptr,
 
-        Q_NULLPTR,
+        nullptr,
         0
     };
 
@@ -157,7 +161,7 @@ int qmlRegisterUncreatableMetaObject(const QMetaObject &staticMetaObject,
     \instantiates QObject
   \inqmlmodule QtQml
   \ingroup qml-utility-elements
-  \brief A basic QML type
+  \brief A basic QML type.
 
   The QtObject type is a non-visual element which contains only the
   objectName property.
@@ -218,28 +222,40 @@ void QQmlEnginePrivate::registerBaseTypes(const char *uri, int versionMajor, int
     qmlRegisterType<QObject>(uri,versionMajor,versionMinor,"QtObject");
     qmlRegisterType<QQmlBind>(uri, versionMajor, versionMinor,"Binding");
     qmlRegisterType<QQmlBind,8>(uri, versionMajor, (versionMinor < 8 ? 8 : versionMinor), "Binding"); //Only available in >=2.8
-    qmlRegisterType<QQmlConnections,1>(uri, versionMajor, (versionMinor < 3 ? 3 : versionMinor), "Connections"); //Only available in >=2.3
-    qmlRegisterType<QQmlConnections>(uri, versionMajor, versionMinor,"Connections");
-#if QT_CONFIG(animation)
+    qmlRegisterCustomType<QQmlConnections>(uri, versionMajor, 0, "Connections", new QQmlConnectionsParser);
+    if (!strcmp(uri, "QtQuick"))
+        qmlRegisterCustomType<QQmlConnections,1>(uri, versionMajor, 7, "Connections", new QQmlConnectionsParser); //Only available in QtQuick >=2.7
+    else
+        qmlRegisterCustomType<QQmlConnections,1>(uri, versionMajor, 3, "Connections", new QQmlConnectionsParser); //Only available in QtQml >=2.3
+#if QT_CONFIG(qml_animation)
     qmlRegisterType<QQmlTimer>(uri, versionMajor, versionMinor,"Timer");
 #endif
     qmlRegisterType<QQmlInstantiator>(uri, versionMajor, (versionMinor < 1 ? 1 : versionMinor), "Instantiator"); //Only available in >=2.1
-    qmlRegisterCustomType<QQmlConnections>(uri, versionMajor, versionMinor,"Connections", new QQmlConnectionsParser);
     qmlRegisterType<QQmlInstanceModel>();
-    qmlRegisterType<QQmlLoggingCategory>(uri, versionMajor, (versionMinor < 8 ? 8 : versionMinor), "LoggingCategory"); //Only available in >=2.8
+
+    qmlRegisterType<QQmlLoggingCategory>(uri, versionMajor, 8, "LoggingCategory"); //Only available in >=2.8
+    qmlRegisterType<QQmlLoggingCategory,1>(uri, versionMajor, 12, "LoggingCategory"); //Only available in >=2.12
 }
 
 
 // These QtQuick types' implementation resides in the QtQml module
 void QQmlEnginePrivate::registerQtQuick2Types(const char *uri, int versionMajor, int versionMinor)
 {
+#if QT_CONFIG(qml_list_model)
     qmlRegisterType<QQmlListElement>(uri, versionMajor, versionMinor, "ListElement"); // Now in QtQml.Models, here for compatibility
     qmlRegisterCustomType<QQmlListModel>(uri, versionMajor, versionMinor, "ListModel", new QQmlListModelParser); // Now in QtQml.Models, here for compatibility
+#endif
+#if QT_CONFIG(qml_worker_script)
     qmlRegisterType<QQuickWorkerScript>(uri, versionMajor, versionMinor, "WorkerScript");
+#endif
     qmlRegisterType<QQuickPackage>(uri, versionMajor, versionMinor, "Package");
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+#if QT_CONFIG(qml_delegate_model)
     qmlRegisterType<QQmlDelegateModel>(uri, versionMajor, versionMinor, "VisualDataModel");
     qmlRegisterType<QQmlDelegateModelGroup>(uri, versionMajor, versionMinor, "VisualDataGroup");
+#endif
     qmlRegisterType<QQmlObjectModel>(uri, versionMajor, versionMinor, "VisualItemModel");
+#endif // < Qt 6
 }
 
 void QQmlEnginePrivate::defineQtQuick2Module()
@@ -249,7 +265,12 @@ void QQmlEnginePrivate::defineQtQuick2Module()
 
     // register the QtQuick2 types which are implemented in the QtQml module.
     registerQtQuick2Types("QtQuick",2,0);
+#if QT_CONFIG(qml_locale)
     qmlRegisterUncreatableType<QQmlLocale>("QtQuick", 2, 0, "Locale", QQmlEngine::tr("Locale cannot be instantiated.  Use Qt.locale()"));
+#endif
+
+    // Auto-increment the import to stay in sync with ALL future QtQuick minor versions from 5.11 onward
+    qmlRegisterModule("QtQuick", 2, QT_VERSION_MINOR);
 }
 
 bool QQmlEnginePrivate::designerMode()
@@ -445,6 +466,7 @@ The following functions are also on the Qt object.
         \li \c "tvos" - tvOS
         \li \c "linux" - Linux
         \li \c "osx" - \macos
+        \li \c "qnx" - QNX (since Qt 5.9.3)
         \li \c "unix" - Other Unix-based OS
         \li \c "windows" - Windows
         \li \c "winrt" - WinRT / UWP
@@ -596,7 +618,7 @@ The following functions are also on the Qt object.
     \li application.font
     \endlist
 
-    \sa Screen, Window, Window.screen
+    \sa Screen, Window, {QtQuick.Window::Window::screen}{Window.screen}
 */
 
 /*!
@@ -639,6 +661,10 @@ The following functions are also on the Qt object.
 
 /*!
 \qmlmethod object Qt::include(string url, jsobject callback)
+\deprecated
+
+This method should not be used. Use ECMAScript modules instead and the native
+JavaScript \c import and \c export statements instead.
 
 Includes another JavaScript file. This method can only be used from within JavaScript files,
 and not regular QML files.
@@ -665,26 +691,26 @@ the same object as is returned from the Qt.include() call.
 // Qt.include() is implemented in qv4include.cpp
 
 QQmlEnginePrivate::QQmlEnginePrivate(QQmlEngine *e)
-: propertyCapture(0), rootContext(0),
-#ifndef QT_NO_QML_DEBUGGER
-  profiler(0),
+: propertyCapture(nullptr), rootContext(nullptr),
+#if QT_CONFIG(qml_debug)
+  profiler(nullptr),
 #endif
   outputWarningsToMsgLog(true),
-  cleanup(0), erroredBindings(0), inProgressCreations(0),
-  workerScriptEngine(0),
-  activeObjectCreator(0),
+  cleanup(nullptr), erroredBindings(nullptr), inProgressCreations(0),
+#if QT_CONFIG(qml_worker_script)
+  workerScriptEngine(nullptr),
+#endif
+  activeObjectCreator(nullptr),
 #if QT_CONFIG(qml_network)
-  networkAccessManager(0), networkAccessManagerFactory(0),
+  networkAccessManager(nullptr), networkAccessManagerFactory(nullptr),
 #endif
-  urlInterceptor(0), scarceResourcesRefCount(0), importDatabase(e), typeLoader(e),
-  uniqueId(1), incubatorCount(0), incubationController(0)
+  urlInterceptor(nullptr), scarceResourcesRefCount(0), importDatabase(e), typeLoader(e),
+  uniqueId(1), incubatorCount(0), incubationController(nullptr)
 {
 }
 
 QQmlEnginePrivate::~QQmlEnginePrivate()
 {
-    typedef QHash<QPair<QQmlType *, int>, QQmlPropertyCache *>::const_iterator TypePropertyCacheIt;
-
     if (inProgressCreations)
         qWarning() << QQmlEngine::tr("There are still \"%1\" items in the process of being created at engine destruction.").arg(inProgressCreations);
 
@@ -692,18 +718,18 @@ QQmlEnginePrivate::~QQmlEnginePrivate()
         QQmlCleanup *c = cleanup;
         cleanup = c->next;
         if (cleanup) cleanup->prev = &cleanup;
-        c->next = 0;
-        c->prev = 0;
+        c->next = nullptr;
+        c->prev = nullptr;
         c->clear();
     }
 
     doDeleteInEngineThread();
 
-    if (incubationController) incubationController->d = 0;
-    incubationController = 0;
+    if (incubationController) incubationController->d = nullptr;
+    incubationController = nullptr;
+
+    QQmlMetaType::freeUnusedTypesAndCaches();
 
-    for (TypePropertyCacheIt iter = typePropertyCache.cbegin(), end = typePropertyCache.cend(); iter != end; ++iter)
-        (*iter)->release();
     for (auto iter = m_compositeTypes.cbegin(), end = m_compositeTypes.cend(); iter != end; ++iter) {
         iter.value()->isRegisteredWithEngine = false;
 
@@ -712,7 +738,7 @@ QQmlEnginePrivate::~QQmlEnginePrivate()
         QMetaType::unregisterType(iter.value()->metaTypeId);
         QMetaType::unregisterType(iter.value()->listMetaTypeId);
     }
-#ifndef QT_NO_QML_DEBUGGER
+#if QT_CONFIG(qml_debug)
     delete profiler;
 #endif
 }
@@ -720,11 +746,22 @@ QQmlEnginePrivate::~QQmlEnginePrivate()
 void QQmlPrivate::qdeclarativeelement_destructor(QObject *o)
 {
     if (QQmlData *d = QQmlData::get(o)) {
-        if (d->ownContext && d->context) {
-            d->context->destroy();
-            d->context = 0;
+        if (d->ownContext) {
+            for (QQmlContextData *lc = d->ownContext->linkedContext; lc; lc = lc->linkedContext) {
+                lc->invalidate();
+                if (lc->contextObject == o)
+                    lc->contextObject = nullptr;
+            }
+            d->ownContext->invalidate();
+            if (d->ownContext->contextObject == o)
+                d->ownContext->contextObject = nullptr;
+            d->ownContext = nullptr;
+            d->context = nullptr;
         }
 
+        if (d->outerContext && d->outerContext->contextObject == o)
+            d->outerContext->contextObject = nullptr;
+
         // Mark this object as in the process of deletion to
         // prevent it resolving in bindings
         QQmlData::markAsDeleted(o);
@@ -737,17 +774,22 @@ void QQmlPrivate::qdeclarativeelement_destructor(QObject *o)
 }
 
 QQmlData::QQmlData()
-    : ownedByQml1(false), ownMemory(true), ownContext(false), indestructible(true), explicitIndestructibleSet(false),
+    : ownedByQml1(false), ownMemory(true), indestructible(true), explicitIndestructibleSet(false),
       hasTaintedV4Object(false), isQueuedForDeletion(false), rootObjectInCreation(false),
       hasInterceptorMetaObject(false), hasVMEMetaObject(false), parentFrozen(false),
-      bindingBitsSize(MaxInlineBits), bindingBitsValue(0), notifyList(0), context(0), outerContext(0),
-      bindings(0), signalHandlers(0), nextContextObject(0), prevContextObject(0),
-      lineNumber(0), columnNumber(0), jsEngineId(0), compilationUnit(0), deferredData(0),
-      propertyCache(0), guards(0), extendedData(0)
+      bindingBitsArraySize(InlineBindingArraySize), notifyList(nullptr),
+      bindings(nullptr), signalHandlers(nullptr), nextContextObject(nullptr), prevContextObject(nullptr),
+      lineNumber(0), columnNumber(0), jsEngineId(0),
+      propertyCache(nullptr), guards(nullptr), extendedData(nullptr)
 {
+    memset(bindingBitsValue, 0, sizeof(bindingBitsValue));
     init();
 }
 
+QQmlData::~QQmlData()
+{
+}
+
 void QQmlData::destroyed(QAbstractDeclarativeData *d, QObject *o)
 {
     QQmlData *ddata = static_cast<QQmlData *>(d);
@@ -811,7 +853,7 @@ void QQmlData::signalEmitted(QAbstractDeclarativeData *, QObject *object, int in
         void **args = (void **) malloc((parameterTypes.count() + 1) *sizeof(void *));
 
         types[0] = 0; // return type
-        args[0] = 0; // return value
+        args[0] = nullptr; // return value
 
         for (int ii = 0; ii < parameterTypes.count(); ++ii) {
             const QByteArray &typeName = parameterTypes.at(ii);
@@ -832,7 +874,7 @@ void QQmlData::signalEmitted(QAbstractDeclarativeData *, QObject *object, int in
             args[ii + 1] = QMetaType::create(types[ii + 1], a[ii + 1]);
         }
 
-        QMetaCallEvent *ev = new QMetaCallEvent(m.methodIndex(), 0, 0, object, index,
+        QMetaCallEvent *ev = new QMetaCallEvent(m.methodIndex(), 0, nullptr, object, index,
                                                 parameterTypes.count() + 1, types, args);
 
         QQmlThreadNotifierProxyObject *mpo = new QQmlThreadNotifierProxyObject;
@@ -890,8 +932,14 @@ void QQmlData::setQueuedForDeletion(QObject *object)
 {
     if (object) {
         if (QQmlData *ddata = QQmlData::get(object)) {
-            if (ddata->ownContext && ddata->context)
+            if (ddata->ownContext) {
+                Q_ASSERT(ddata->ownContext == ddata->context);
                 ddata->context->emitDestruction();
+                if (ddata->ownContext->contextObject == object)
+                    ddata->ownContext->contextObject = nullptr;
+                ddata->ownContext = nullptr;
+                ddata->context = nullptr;
+            }
             ddata->isQueuedForDeletion = true;
         }
     }
@@ -913,6 +961,14 @@ void QQmlData::flushPendingBindingImpl(QQmlPropertyIndex index)
                             QQmlPropertyData::DontRemoveBinding);
 }
 
+QQmlData::DeferredData::DeferredData()
+{
+}
+
+QQmlData::DeferredData::~DeferredData()
+{
+}
+
 bool QQmlEnginePrivate::baseModulesUninitialized = true;
 void QQmlEnginePrivate::init()
 {
@@ -921,7 +977,12 @@ void QQmlEnginePrivate::init()
     if (baseModulesUninitialized) {
         qmlRegisterType<QQmlComponent>("QML", 1, 0, "Component"); // required for the Compiler.
         registerBaseTypes("QtQml", 2, 0); // import which provides language building blocks.
+#if QT_CONFIG(qml_locale)
         qmlRegisterUncreatableType<QQmlLocale>("QtQml", 2, 2, "Locale", QQmlEngine::tr("Locale cannot be instantiated.  Use Qt.locale()"));
+#endif
+
+        // Auto-increment the import to stay in sync with ALL future QtQml minor versions from 5.11 onward
+        qmlRegisterModule("QtQml", 2, QT_VERSION_MINOR);
 
         QQmlData::init();
         baseModulesUninitialized = false;
@@ -941,6 +1002,7 @@ void QQmlEnginePrivate::init()
     rootContext = new QQmlContext(q,true);
 }
 
+#if QT_CONFIG(qml_worker_script)
 QQuickWorkerScriptEngine *QQmlEnginePrivate::getWorkerScriptEngine()
 {
     Q_Q(QQmlEngine);
@@ -948,6 +1010,7 @@ QQuickWorkerScriptEngine *QQmlEnginePrivate::getWorkerScriptEngine()
         workerScriptEngine = new QQuickWorkerScriptEngine(q);
     return workerScriptEngine;
 }
+#endif
 
 /*!
   \class QQmlEngine
@@ -977,8 +1040,6 @@ QQuickWorkerScriptEngine *QQmlEnginePrivate::getWorkerScriptEngine()
   In this case, the Text item will be created in the engine's
   \l {QQmlEngine::rootContext()}{root context}.
 
-  Note that the \l {Qt Quick 1} version is called QDeclarativeEngine.
-
   \sa QQmlComponent, QQmlContext, {QML Global Object}
 */
 
@@ -1028,12 +1089,12 @@ QQmlEngine::~QQmlEngine()
     // we do this here and not in the private dtor since otherwise a crash can
     // occur (if we are the QObject parent of the QObject singleton instance)
     // XXX TODO: performance -- store list of singleton types separately?
-    const QList<QQmlType*> singletonTypes = QQmlMetaType::qmlSingletonTypes();
-    for (QQmlType *currType : singletonTypes)
-        currType->singletonInstanceInfo()->destroy(this);
+    QList<QQmlType> singletonTypes = QQmlMetaType::qmlSingletonTypes();
+    for (const QQmlType &currType : singletonTypes)
+        currType.singletonInstanceInfo()->destroy(this);
 
     delete d->rootContext;
-    d->rootContext = 0;
+    d->rootContext = nullptr;
 }
 
 /*! \fn void QQmlEngine::quit()
@@ -1075,7 +1136,9 @@ QQmlEngine::~QQmlEngine()
 void QQmlEngine::clearComponentCache()
 {
     Q_D(QQmlEngine);
+    d->typeLoader.lock();
     d->typeLoader.clearCache();
+    d->typeLoader.unlock();
 }
 
 /*!
@@ -1146,7 +1209,7 @@ void QQmlEnginePrivate::registerFinalizeCallback(QObject *obj, int index)
     if (activeObjectCreator) {
         activeObjectCreator->finalizeCallbacks()->append(qMakePair(QPointer<QObject>(obj), index));
     } else {
-        void *args[] = { 0 };
+        void *args[] = { nullptr };
         QMetaObject::metacall(obj, QMetaObject::InvokeMetaMethod, index, args);
     }
 }
@@ -1161,6 +1224,8 @@ void QQmlEnginePrivate::registerFinalizeCallback(QObject *obj, int index)
   support.
 
   The factory must be set before executing the engine.
+
+  \note QQmlEngine does not take ownership of the factory.
 */
 void QQmlEngine::setNetworkAccessManagerFactory(QQmlNetworkAccessManagerFactory *factory)
 {
@@ -1243,9 +1308,7 @@ void QQmlEngine::addImageProvider(const QString &providerId, QQmlImageProviderBa
 }
 
 /*!
-  Returns the image provider set for \a providerId.
-
-  Returns the provider if it was found; otherwise returns 0.
+  Returns the image provider set for \a providerId if found; otherwise returns \nullptr.
 
   \sa QQuickImageProvider
 */
@@ -1328,6 +1391,95 @@ void QQmlEngine::setOutputWarningsToStandardError(bool enabled)
 }
 
 /*!
+  \fn template<typename T> T QQmlEngine::singletonInstance(int qmlTypeId)
+
+  Returns the instance of a singleton type that was registered under \a qmlTypeId.
+
+  The template argument \e T may be either QJSValue or a pointer to a QObject-derived
+  type and depends on how the singleton was registered. If no instance of \e T has been
+  created yet, it is created now. If \a qmlTypeId does not represent a valid singleton
+  type, either a default constructed QJSValue or a \c nullptr is returned.
+
+  QObject* example:
+  \code
+  class MySingleton : public QObject {
+    Q_OBJECT
+    static int typeId;
+    // ...
+  };
+
+  // Register with QObject* callback
+  MySingleton::typeId = qmlRegisterSingletonType<MySingleton>(...);
+
+  // Retrieve as QObject*
+  QQmlEngine engine;
+  MySingleton* instance = engine.singletonInstance<MySingleton*>(MySingleton::typeId);
+  \endcode
+
+  QJSValue example:
+  \code
+  // Register with QJSValue callback
+  int typeId = qmlRegisterSingletonType(...);
+
+  // Retrieve as QJSValue
+  QQmlEngine engine;
+  QJSValue instance = engine.singletonInstance<QJSValue>(typeId);
+  \endcode
+
+  It is recommended to store the QML type id during registration, e.g. as a static member
+  in the singleton class. Otherwise, a costly lookup via qmlTypeId() has to be performed
+  at run-time.
+
+  \sa qmlRegisterSingletonType(), qmlTypeId()
+  \since 5.12
+*/
+template<>
+QJSValue QQmlEngine::singletonInstance<QJSValue>(int qmlTypeId)
+{
+    QQmlType type = QQmlMetaType::qmlType(qmlTypeId, QQmlMetaType::TypeIdCategory::QmlType);
+
+    if (!type.isValid() || !type.isSingleton())
+        return QJSValue();
+
+    QQmlType::SingletonInstanceInfo* info = type.singletonInstanceInfo();
+    info->init(this);
+
+    if (QObject* o = info->qobjectApi(this))
+        return this->newQObject(o);
+    else {
+        QJSValue value = info->scriptApi(this);
+        if (!value.isUndefined())
+            return value;
+    }
+
+    return QJSValue();
+}
+
+/*!
+  Refreshes all binding expressions that use strings marked for translation.
+
+  Call this function after you have installed a new translator with
+  QCoreApplication::installTranslator, to ensure that your user-interface
+  shows up-to-date translations.
+
+  \note Due to a limitation in the implementation, this function
+  refreshes all the engine's bindings, not only those that use strings
+  marked for translation.
+  This may be optimized in a future release.
+
+  \since 5.10
+*/
+void QQmlEngine::retranslate()
+{
+    Q_D(QQmlEngine);
+    QQmlContextData *context = QQmlContextData::get(d->rootContext)->childContexts;
+    while (context) {
+        context->refreshExpressions();
+        context = context->nextChild;
+    }
+}
+
+/*!
   Returns the QQmlContext for the \a object, or 0 if no
   context has been set.
 
@@ -1339,13 +1491,13 @@ void QQmlEngine::setOutputWarningsToStandardError(bool enabled)
 QQmlContext *QQmlEngine::contextForObject(const QObject *object)
 {
     if(!object)
-        return 0;
+        return nullptr;
 
     QQmlData *data = QQmlData::get(object);
     if (data && data->outerContext)
         return data->outerContext->asQQmlContext();
 
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -1368,7 +1520,9 @@ void QQmlEngine::setContextForObject(QObject *object, QQmlContext *context)
     }
 
     QQmlContextData *contextData = QQmlContextData::get(context);
-    contextData->addObject(object);
+    Q_ASSERT(data->context == nullptr);
+    data->context = contextData;
+    contextData->addObject(data);
 }
 
 /*!
@@ -1447,6 +1601,9 @@ bool QQmlEngine::event(QEvent *e)
     Q_D(QQmlEngine);
     if (e->type() == QEvent::User)
         d->doDeleteInEngineThread();
+    else if (e->type() == QEvent::LanguageChange) {
+        retranslate();
+    }
 
     return QJSEngine::event(e);
 }
@@ -1468,18 +1625,16 @@ void qmlExecuteDeferred(QObject *object)
 {
     QQmlData *data = QQmlData::get(object);
 
-    if (data && data->deferredData && !data->wasDeleted(object)) {
+    if (data && !data->deferredData.isEmpty() && !data->wasDeleted(object)) {
         QQmlEnginePrivate *ep = QQmlEnginePrivate::get(data->context->engine);
 
-        QQmlComponentPrivate::ConstructionState state;
+        QQmlComponentPrivate::DeferredState state;
         QQmlComponentPrivate::beginDeferred(ep, object, &state);
 
         // Release the reference for the deferral action (we still have one from construction)
-        data->deferredData->compilationUnit->release();
-        delete data->deferredData;
-        data->deferredData = 0;
+        data->releaseDeferredData();
 
-        QQmlComponentPrivate::complete(ep, &state);
+        QQmlComponentPrivate::completeDeferred(ep, &state);
     }
 }
 
@@ -1492,7 +1647,7 @@ QQmlEngine *qmlEngine(const QObject *obj)
 {
     QQmlData *data = QQmlData::get(obj, false);
     if (!data || !data->context)
-        return 0;
+        return nullptr;
     return data->context->engine;
 }
 
@@ -1500,7 +1655,7 @@ QObject *qmlAttachedPropertiesObjectById(int id, const QObject *object, bool cre
 {
     QQmlData *data = QQmlData::get(object, create);
     if (!data)
-        return 0; // Attached properties are only on objects created by QML, unless explicitly requested (create==true)
+        return nullptr; // Attached properties are only on objects created by QML, unless explicitly requested (create==true)
 
     QObject *rv = data->hasExtendedData()?data->attachedProperties()->value(id):0;
     if (rv || !create)
@@ -1509,7 +1664,7 @@ QObject *qmlAttachedPropertiesObjectById(int id, const QObject *object, bool cre
     QQmlEnginePrivate *engine = QQmlEnginePrivate::get(data->context);
     QQmlAttachedPropertiesFunc pf = QQmlMetaType::attachedPropertiesFuncById(engine, id);
     if (!pf)
-        return 0;
+        return nullptr;
 
     rv = pf(const_cast<QObject *>(object));
 
@@ -1523,12 +1678,12 @@ QObject *qmlAttachedPropertiesObject(int *idCache, const QObject *object,
                                      const QMetaObject *attachedMetaObject, bool create)
 {
     if (*idCache == -1) {
-        QQmlEngine *engine = object ? qmlEngine(object) : 0;
-        *idCache = QQmlMetaType::attachedPropertiesFuncId(engine ? QQmlEnginePrivate::get(engine) : 0, attachedMetaObject);
+        QQmlEngine *engine = object ? qmlEngine(object) : nullptr;
+        *idCache = QQmlMetaType::attachedPropertiesFuncId(engine ? QQmlEnginePrivate::get(engine) : nullptr, attachedMetaObject);
     }
 
     if (*idCache == -1 || !object)
-        return 0;
+        return nullptr;
 
     return qmlAttachedPropertiesObjectById(*idCache, object, create);
 }
@@ -1588,7 +1743,7 @@ void QQmlData::NotifyList::layout(QQmlNotifierEndpoint *endpoint)
 {
     // Add a temporary sentinel at beginning of list. This will be overwritten
     // when the end point is inserted into the notifies further down.
-    endpoint->prev = 0;
+    endpoint->prev = nullptr;
 
     while (endpoint->next) {
         Q_ASSERT(reinterpret_cast<QQmlNotifierEndpoint *>(endpoint->next->prev) == endpoint);
@@ -1634,7 +1789,41 @@ void QQmlData::NotifyList::layout()
     }
 
     maximumTodoIndex = 0;
-    todo = 0;
+    todo = nullptr;
+}
+
+void QQmlData::deferData(int objectIndex, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, QQmlContextData *context)
+{
+    QQmlData::DeferredData *deferData = new QQmlData::DeferredData;
+    deferData->deferredIdx = objectIndex;
+    deferData->compilationUnit = compilationUnit;
+    deferData->context = context;
+
+    const QV4::CompiledData::Object *compiledObject = compilationUnit->objectAt(objectIndex);
+    const QV4::CompiledData::BindingPropertyData &propertyData = compilationUnit->bindingPropertyDataPerObject.at(objectIndex);
+
+    const QV4::CompiledData::Binding *binding = compiledObject->bindingTable();
+    for (quint32 i = 0; i < compiledObject->nBindings; ++i, ++binding) {
+        const QQmlPropertyData *property = propertyData.at(i);
+        if (property && binding->flags & QV4::CompiledData::Binding::IsDeferredBinding)
+            deferData->bindings.insert(property->coreIndex(), binding);
+    }
+
+    deferredData.append(deferData);
+}
+
+void QQmlData::releaseDeferredData()
+{
+    auto it = deferredData.begin();
+    while (it != deferredData.end()) {
+        DeferredData *deferData = *it;
+        if (deferData->bindings.isEmpty()) {
+            delete deferData;
+            it = deferredData.erase(it);
+        } else {
+            ++it;
+        }
+    }
 }
 
 void QQmlData::addNotify(int index, QQmlNotifierEndpoint *endpoint)
@@ -1644,8 +1833,8 @@ void QQmlData::addNotify(int index, QQmlNotifierEndpoint *endpoint)
         notifyList->connectionMask = 0;
         notifyList->maximumTodoIndex = 0;
         notifyList->notifiesSize = 0;
-        notifyList->todo = 0;
-        notifyList->notifies = 0;
+        notifyList->todo = nullptr;
+        notifyList->notifies = nullptr;
     }
 
     Q_ASSERT(!endpoint->isConnected());
@@ -1681,7 +1870,7 @@ void QQmlData::disconnectNotifiers()
         }
         free(notifyList->notifies);
         free(notifyList);
-        notifyList = 0;
+        notifyList = nullptr;
     }
 }
 
@@ -1697,6 +1886,8 @@ void QQmlData::destroyed(QObject *object)
         nextContextObject->prevContextObject = prevContextObject;
     if (prevContextObject)
         *prevContextObject = nextContextObject;
+    else if (outerContext && outerContext->contextObjects == this)
+        outerContext->contextObjects = nextContextObject;
 
     QQmlAbstractBinding *binding = bindings;
     while (binding) {
@@ -1706,16 +1897,10 @@ void QQmlData::destroyed(QObject *object)
     if (bindings && !bindings->ref.deref())
         delete bindings;
 
-    if (compilationUnit) {
-        compilationUnit->release();
-        compilationUnit = 0;
-    }
+    compilationUnit = nullptr;
 
-    if (deferredData) {
-        deferredData->compilationUnit->release();
-        delete deferredData;
-        deferredData = 0;
-    }
+    qDeleteAll(deferredData);
+    deferredData.clear();
 
     QQmlBoundSignal *signalHandler = signalHandlers;
     while (signalHandler) {
@@ -1749,24 +1934,23 @@ void QQmlData::destroyed(QObject *object)
         }
 
         QQmlBoundSignal *next = signalHandler->m_nextSignal;
-        signalHandler->m_prevSignal = 0;
-        signalHandler->m_nextSignal = 0;
+        signalHandler->m_prevSignal = nullptr;
+        signalHandler->m_nextSignal = nullptr;
         delete signalHandler;
         signalHandler = next;
     }
 
-    if (bindingBitsSize > MaxInlineBits)
+    if (bindingBitsArraySize > InlineBindingArraySize)
         free(bindingBits);
 
     if (propertyCache)
         propertyCache->release();
 
-    if (ownContext && context)
-        context->destroy();
+    ownContext = nullptr;
 
     while (guards) {
         QQmlGuard<QObject> *guard = static_cast<QQmlGuard<QObject> *>(guards);
-        *guard = (QObject *)0;
+        *guard = (QObject *)nullptr;
         guard->objectDestroyed(object);
     }
 
@@ -1803,78 +1987,27 @@ void QQmlData::parentChanged(QObject *object, QObject *parent)
     }
 }
 
-static void QQmlData_setBit(QQmlData *data, QObject *obj, int bit)
-{
-    if (Q_UNLIKELY(data->bindingBitsSize <= bit)) {
-        int props = QQmlMetaObject(obj).propertyCount();
-        Q_ASSERT(bit < 2 * props);
-
-        int arraySize = (2 * props + MaxInlineBits - 1) / MaxInlineBits;
-        Q_ASSERT(arraySize > 1);
-
-        // special handling for 32 here is to make sure we wipe the first byte
-        // when going from bindingBitsValue to bindingBits, and preserve the old
-        // set bits so we can restore them after the allocation
-        int oldArraySize = data->bindingBitsSize > MaxInlineBits ? data->bindingBitsSize / MaxInlineBits : 0;
-        quintptr oldValue = data->bindingBitsSize == MaxInlineBits ? data->bindingBitsValue : 0;
-
-        data->bindingBits = static_cast<BindingBitsType *>(realloc((data->bindingBitsSize == MaxInlineBits) ? 0 : data->bindingBits,
-                                                                   arraySize * sizeof(BindingBitsType)));
-
-        memset(data->bindingBits + oldArraySize,
-               0x00,
-               sizeof(BindingBitsType) * (arraySize - oldArraySize));
-
-        data->bindingBitsSize = arraySize * MaxInlineBits;
-
-        // reinstate bindingBitsValue after we dropped it
-        if (oldValue) {
-            memcpy(data->bindingBits, &oldValue, sizeof(oldValue));
-        }
-    }
-
-    if (data->bindingBitsSize == MaxInlineBits)
-        data->bindingBitsValue |= BindingBitsType(1) << bit;
-    else
-        data->bindingBits[bit / MaxInlineBits] |= (BindingBitsType(1) << (bit % MaxInlineBits));
-}
-
-static void QQmlData_clearBit(QQmlData *data, int bit)
+QQmlData::BindingBitsType *QQmlData::growBits(QObject *obj, int bit)
 {
-    if (data->bindingBitsSize > bit) {
-        if (data->bindingBitsSize == MaxInlineBits)
-            data->bindingBitsValue &= ~(BindingBitsType(1) << (bit % MaxInlineBits));
-        else
-            data->bindingBits[bit / MaxInlineBits] &= ~(BindingBitsType(1) << (bit % MaxInlineBits));
-    }
-}
+    BindingBitsType *bits = (bindingBitsArraySize == InlineBindingArraySize) ? bindingBitsValue : bindingBits;
+    int props = QQmlMetaObject(obj).propertyCount();
+    Q_ASSERT(bit < 2 * props);
+    Q_UNUSED(bit); // .. for Q_NO_DEBUG mode when the assert above expands to empty
 
-void QQmlData::clearBindingBit(int coreIndex)
-{
-    Q_ASSERT(coreIndex >= 0);
-    Q_ASSERT(coreIndex <= 0xffff);
-    QQmlData_clearBit(this, coreIndex * 2);
-}
-
-void QQmlData::setBindingBit(QObject *obj, int coreIndex)
-{
-    Q_ASSERT(coreIndex >= 0);
-    Q_ASSERT(coreIndex <= 0xffff);
-    QQmlData_setBit(this, obj, coreIndex * 2);
-}
+    uint arraySize = (2 * static_cast<uint>(props) + BitsPerType - 1) / BitsPerType;
+    Q_ASSERT(arraySize > 1);
+    Q_ASSERT(arraySize <= 0xffff); // max for bindingBitsArraySize
 
-void QQmlData::clearPendingBindingBit(int coreIndex)
-{
-    Q_ASSERT(coreIndex >= 0);
-    Q_ASSERT(coreIndex <= 0xffff);
-    QQmlData_clearBit(this, coreIndex * 2 + 1);
-}
+    BindingBitsType *newBits = static_cast<BindingBitsType *>(malloc(arraySize*sizeof(BindingBitsType)));
+    memcpy(newBits, bits, bindingBitsArraySize * sizeof(BindingBitsType));
+    memset(newBits + bindingBitsArraySize, 0, sizeof(BindingBitsType) * (arraySize - bindingBitsArraySize));
 
-void QQmlData::setPendingBindingBit(QObject *obj, int coreIndex)
-{
-    Q_ASSERT(coreIndex >= 0);
-    Q_ASSERT(coreIndex <= 0xffff);
-    QQmlData_setBit(this, obj, coreIndex * 2 + 1);
+    if (bindingBitsArraySize > InlineBindingArraySize)
+        free(bits);
+    bindingBits = newBits;
+    bits = newBits;
+    bindingBitsArraySize = arraySize;
+    return bits;
 }
 
 QQmlData *QQmlData::createQQmlData(QObjectPrivate *priv)
@@ -1916,23 +2049,23 @@ static void dumpwarning(const QQmlError &error)
     switch (error.messageType()) {
     case QtDebugMsg:
         QMessageLogger(error.url().toString().toLatin1().constData(),
-                       error.line(), 0).debug().nospace()
+                       error.line(), nullptr).debug().nospace()
                 << qPrintable(error.toString());
         break;
     case QtInfoMsg:
         QMessageLogger(error.url().toString().toLatin1().constData(),
-                       error.line(), 0).info().nospace()
+                       error.line(), nullptr).info().nospace()
                 << qPrintable(error.toString());
         break;
     case QtWarningMsg:
     case QtFatalMsg: // fatal does not support streaming, and furthermore, is actually fatal. Probably not desirable for QML.
         QMessageLogger(error.url().toString().toLatin1().constData(),
-                       error.line(), 0).warning().nospace()
+                       error.line(), nullptr).warning().nospace()
                 << qPrintable(error.toString());
         break;
     case QtCriticalMsg:
         QMessageLogger(error.url().toString().toLatin1().constData(),
-                       error.line(), 0).critical().nospace()
+                       error.line(), nullptr).critical().nospace()
                 << qPrintable(error.toString());
         break;
     }
@@ -1960,11 +2093,6 @@ void QQmlEnginePrivate::warning(const QList<QQmlError> &errors)
         dumpwarning(errors);
 }
 
-void QQmlEnginePrivate::warning(QQmlDelayedError *error)
-{
-    warning(error->error());
-}
-
 void QQmlEnginePrivate::warning(QQmlEngine *engine, const QQmlError &error)
 {
     if (engine)
@@ -1981,14 +2109,6 @@ void QQmlEnginePrivate::warning(QQmlEngine *engine, const QList<QQmlError> &erro
         dumpwarning(error);
 }
 
-void QQmlEnginePrivate::warning(QQmlEngine *engine, QQmlDelayedError *error)
-{
-    if (engine)
-        QQmlEnginePrivate::get(engine)->warning(error);
-    else
-        dumpwarning(error->error());
-}
-
 void QQmlEnginePrivate::warning(QQmlEnginePrivate *engine, const QQmlError &error)
 {
     if (engine)
@@ -2005,13 +2125,32 @@ void QQmlEnginePrivate::warning(QQmlEnginePrivate *engine, const QList<QQmlError
         dumpwarning(error);
 }
 
+QList<QQmlError> QQmlEnginePrivate::qmlErrorFromDiagnostics(const QString &fileName, const QList<DiagnosticMessage> &diagnosticMessages)
+{
+    QList<QQmlError> errors;
+    for (const DiagnosticMessage &m : diagnosticMessages) {
+        if (m.isWarning()) {
+            qWarning("%s:%d : %s", qPrintable(fileName), m.loc.startLine, qPrintable(m.message));
+            continue;
+        }
+
+        QQmlError error;
+        error.setUrl(QUrl(fileName));
+        error.setDescription(m.message);
+        error.setLine(m.loc.startLine);
+        error.setColumn(m.loc.startColumn);
+        errors << error;
+    }
+    return errors;
+}
+
 void QQmlEnginePrivate::cleanupScarceResources()
 {
     // iterate through the list and release them all.
     // note that the actual SRD is owned by the JS engine,
     // so we cannot delete the SRD; but we can free the
     // memory used by the variant in the SRD.
-    QV4::ExecutionEngine *engine = QV8Engine::getV4(v8engine());
+    QV4::ExecutionEngine *engine = v4engine();
     while (QV4::ExecutionEngine::ScarceResourceData *sr = engine->scarceResources.first()) {
         sr->data = QVariant();
         engine->scarceResources.remove(sr);
@@ -2200,108 +2339,6 @@ QString QQmlEnginePrivate::offlineStorageDatabaseDirectory() const
     return q->offlineStoragePath() + QDir::separator() + QLatin1String("Databases") + QDir::separator();
 }
 
-QQmlPropertyCache *QQmlEnginePrivate::createCache(QQmlType *type, int minorVersion)
-{
-    QList<QQmlType *> types;
-
-    int maxMinorVersion = 0;
-
-    const QMetaObject *metaObject = type->metaObject();
-
-    while (metaObject) {
-        QQmlType *t = QQmlMetaType::qmlType(metaObject, type->module(),
-                                                            type->majorVersion(), minorVersion);
-        if (t) {
-            maxMinorVersion = qMax(maxMinorVersion, t->minorVersion());
-            types << t;
-        } else {
-            types << 0;
-        }
-
-        metaObject = metaObject->superClass();
-    }
-
-    if (QQmlPropertyCache *c = typePropertyCache.value(qMakePair(type, maxMinorVersion))) {
-        c->addref();
-        typePropertyCache.insert(qMakePair(type, minorVersion), c);
-        return c;
-    }
-
-    QQmlPropertyCache *raw = cache(type->metaObject());
-
-    bool hasCopied = false;
-
-    for (int ii = 0; ii < types.count(); ++ii) {
-        QQmlType *currentType = types.at(ii);
-        if (!currentType)
-            continue;
-
-        int rev = currentType->metaObjectRevision();
-        int moIndex = types.count() - 1 - ii;
-
-        if (raw->allowedRevisionCache[moIndex] != rev) {
-            if (!hasCopied) {
-                raw = raw->copy();
-                hasCopied = true;
-            }
-            raw->allowedRevisionCache[moIndex] = rev;
-        }
-    }
-
-    // Test revision compatibility - the basic rule is:
-    //    * Anything that is excluded, cannot overload something that is not excluded *
-
-    // Signals override:
-    //    * other signals and methods of the same name.
-    //    * properties named on<Signal Name>
-    //    * automatic <property name>Changed notify signals
-
-    // Methods override:
-    //    * other methods of the same name
-
-    // Properties override:
-    //    * other elements of the same name
-
-#if 0
-    bool overloadError = false;
-    QString overloadName;
-
-    for (QQmlPropertyCache::StringCache::ConstIterator iter = raw->stringCache.begin();
-         !overloadError && iter != raw->stringCache.end();
-         ++iter) {
-
-        QQmlPropertyData *d = *iter;
-        if (raw->isAllowedInRevision(d))
-            continue; // Not excluded - no problems
-
-        // check that a regular "name" overload isn't happening
-        QQmlPropertyData *current = d;
-        while (!overloadError && current) {
-            current = d->overrideData(current);
-            if (current && raw->isAllowedInRevision(current))
-                overloadError = true;
-        }
-    }
-
-    if (overloadError) {
-        if (hasCopied) raw->release();
-
-        error.setDescription(QLatin1String("Type ") + type->qmlTypeName() + QLatin1Char(' ') + QString::number(type->majorVersion()) + QLatin1Char('.') + QString::number(minorVersion) + QLatin1String(" contains an illegal property \"") + overloadName + QLatin1String("\".  This is an error in the type's implementation."));
-        return 0;
-    }
-#endif
-
-    if (!hasCopied) raw->addref();
-    typePropertyCache.insert(qMakePair(type, minorVersion), raw);
-
-    if (minorVersion != maxMinorVersion) {
-        raw->addref();
-        typePropertyCache.insert(qMakePair(type, maxMinorVersion), raw);
-    }
-
-    return raw;
-}
-
 bool QQmlEnginePrivate::isQObject(int t)
 {
     Locker locker(this);
@@ -2325,26 +2362,17 @@ QQmlMetaType::TypeCategory QQmlEnginePrivate::typeCategory(int t) const
     Locker locker(this);
     if (m_compositeTypes.contains(t))
         return QQmlMetaType::Object;
-    else if (m_qmlLists.contains(t))
-        return QQmlMetaType::List;
-    else
-        return QQmlMetaType::typeCategory(t);
+    return QQmlMetaType::typeCategory(t);
 }
 
 bool QQmlEnginePrivate::isList(int t) const
 {
-    Locker locker(this);
-    return m_qmlLists.contains(t) || QQmlMetaType::isList(t);
+    return QQmlMetaType::isList(t);
 }
 
 int QQmlEnginePrivate::listType(int t) const
 {
-    Locker locker(this);
-    QHash<int, int>::ConstIterator iter = m_qmlLists.constFind(t);
-    if (iter != m_qmlLists.cend())
-        return *iter;
-    else
-        return QQmlMetaType::listType(t);
+    return QQmlMetaType::listType(t);
 }
 
 QQmlMetaObject QQmlEnginePrivate::rawMetaObjectForType(int t) const
@@ -2352,10 +2380,10 @@ QQmlMetaObject QQmlEnginePrivate::rawMetaObjectForType(int t) const
     Locker locker(this);
     auto iter = m_compositeTypes.constFind(t);
     if (iter != m_compositeTypes.cend()) {
-        return QQmlMetaObject((*iter)->rootPropertyCache());
+        return QQmlMetaObject((*iter)->rootPropertyCache().data());
     } else {
-        QQmlType *type = QQmlMetaType::qmlType(t);
-        return QQmlMetaObject(type?type->baseMetaObject():0);
+        QQmlType type = QQmlMetaType::qmlType(t);
+        return QQmlMetaObject(type.baseMetaObject());
     }
 }
 
@@ -2364,10 +2392,10 @@ QQmlMetaObject QQmlEnginePrivate::metaObjectForType(int t) const
     Locker locker(this);
     auto iter = m_compositeTypes.constFind(t);
     if (iter != m_compositeTypes.cend()) {
-        return QQmlMetaObject((*iter)->rootPropertyCache());
+        return QQmlMetaObject((*iter)->rootPropertyCache().data());
     } else {
-        QQmlType *type = QQmlMetaType::qmlType(t);
-        return QQmlMetaObject(type?type->metaObject():0);
+        QQmlType type = QQmlMetaType::qmlType(t);
+        return QQmlMetaObject(type.metaObject());
     }
 }
 
@@ -2376,69 +2404,47 @@ QQmlPropertyCache *QQmlEnginePrivate::propertyCacheForType(int t)
     Locker locker(this);
     auto iter = m_compositeTypes.constFind(t);
     if (iter != m_compositeTypes.cend()) {
-        return (*iter)->rootPropertyCache();
+        return (*iter)->rootPropertyCache().data();
     } else {
-        QQmlType *type = QQmlMetaType::qmlType(t);
+        QQmlType type = QQmlMetaType::qmlType(t);
         locker.unlock();
-        return type?cache(type->metaObject()):0;
+        return type.isValid() ? cache(type.metaObject()) : nullptr;
     }
 }
 
-QQmlPropertyCache *QQmlEnginePrivate::rawPropertyCacheForType(int t)
+QQmlPropertyCache *QQmlEnginePrivate::rawPropertyCacheForType(int t, int minorVersion)
 {
     Locker locker(this);
     auto iter = m_compositeTypes.constFind(t);
     if (iter != m_compositeTypes.cend()) {
-        return (*iter)->rootPropertyCache();
+        return (*iter)->rootPropertyCache().data();
     } else {
-        QQmlType *type = QQmlMetaType::qmlType(t);
+        QQmlType type = QQmlMetaType::qmlType(t);
         locker.unlock();
-        return type?cache(type->baseMetaObject()):0;
+
+        if (minorVersion >= 0)
+            return type.isValid() ? cache(type, minorVersion) : nullptr;
+        else
+            return type.isValid() ? cache(type.baseMetaObject()) : nullptr;
     }
 }
 
 void QQmlEnginePrivate::registerInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit)
 {
-    QByteArray name = compilationUnit->rootPropertyCache()->className();
-
-    QByteArray ptr = name + '*';
-    QByteArray lst = "QQmlListProperty<" + name + '>';
-
-    int ptr_type = QMetaType::registerNormalizedType(ptr,
-                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QObject*>::Destruct,
-                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QObject*>::Construct,
-                                                     sizeof(QObject*),
-                                                     static_cast<QFlags<QMetaType::TypeFlag> >(QtPrivate::QMetaTypeTypeFlags<QObject*>::Flags),
-                                                     0);
-    int lst_type = QMetaType::registerNormalizedType(lst,
-                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QQmlListProperty<QObject> >::Destruct,
-                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QQmlListProperty<QObject> >::Construct,
-                                                     sizeof(QQmlListProperty<QObject>),
-                                                     static_cast<QFlags<QMetaType::TypeFlag> >(QtPrivate::QMetaTypeTypeFlags<QQmlListProperty<QObject> >::Flags),
-                                                     static_cast<QMetaObject*>(0));
-
-    compilationUnit->metaTypeId = ptr_type;
-    compilationUnit->listMetaTypeId = lst_type;
     compilationUnit->isRegisteredWithEngine = true;
 
     Locker locker(this);
-    m_qmlLists.insert(lst_type, ptr_type);
     // The QQmlCompiledData is not referenced here, but it is removed from this
     // hash in the QQmlCompiledData destructor
-    m_compositeTypes.insert(ptr_type, compilationUnit);
+    m_compositeTypes.insert(compilationUnit->metaTypeId, compilationUnit);
 }
 
 void QQmlEnginePrivate::unregisterInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit)
 {
-    int ptr_type = compilationUnit->metaTypeId;
-    int lst_type = compilationUnit->listMetaTypeId;
+    compilationUnit->isRegisteredWithEngine = false;
 
     Locker locker(this);
-    m_qmlLists.remove(lst_type);
-    m_compositeTypes.remove(ptr_type);
-
-    QMetaType::unregisterType(ptr_type);
-    QMetaType::unregisterType(lst_type);
+    m_compositeTypes.remove(compilationUnit->metaTypeId);
 }
 
 bool QQmlEnginePrivate::isTypeLoaded(const QUrl &url) const
diff --git a/src/qml/qml/qqmlengine.h b/src/qml/qml/qqmlengine.h
index 8cada954fe..871e6bd9b4 100644
--- a/src/qml/qml/qqmlengine.h
+++ b/src/qml/qml/qqmlengine.h
@@ -46,7 +46,6 @@
 #include <QtQml/qjsengine.h>
 #include <QtQml/qqml.h>
 #include <QtQml/qqmlerror.h>
-#include <QtQml/qqmldebug.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -97,8 +96,8 @@ class Q_QML_EXPORT QQmlEngine : public QJSEngine
     Q_PROPERTY(QString offlineStoragePath READ offlineStoragePath WRITE setOfflineStoragePath)
     Q_OBJECT
 public:
-    explicit QQmlEngine(QObject *p = Q_NULLPTR);
-    virtual ~QQmlEngine();
+    explicit QQmlEngine(QObject *p = nullptr);
+    ~QQmlEngine() override;
 
     QQmlContext *rootContext() const;
 
@@ -144,6 +143,13 @@ public:
     bool outputWarningsToStandardError() const;
     void setOutputWarningsToStandardError(bool);
 
+    template<typename T>
+    T singletonInstance(int qmlTypeId);
+
+public Q_SLOTS:
+    void retranslate();
+
+public:
     static QQmlContext *contextForObject(const QObject *);
     static void setContextForObject(QObject *, QQmlContext *);
 
@@ -164,6 +170,19 @@ private:
     Q_DECLARE_PRIVATE(QQmlEngine)
 };
 
+template<>
+Q_QML_EXPORT QJSValue QQmlEngine::singletonInstance<QJSValue>(int qmlTypeId);
+
+template<typename T>
+T QQmlEngine::singletonInstance(int qmlTypeId) {
+    QJSValue instance = singletonInstance<QJSValue>(qmlTypeId);
+    if (!instance.isQObject())
+        return nullptr;
+
+    QObject *object = instance.toQObject();
+    return qobject_cast<T>(object);
+}
+
 QT_END_NAMESPACE
 
 #endif // QQMLENGINE_H
diff --git a/src/qml/qml/qqmlengine_p.h b/src/qml/qml/qqmlengine_p.h
index 1bdeacd524..20d451d607 100644
--- a/src/qml/qml/qqmlengine_p.h
+++ b/src/qml/qml/qqmlengine_p.h
@@ -62,9 +62,7 @@
 #include "qqmlcontext_p.h"
 #include "qqmlexpression.h"
 #include "qqmlproperty_p.h"
-#include "qqmlpropertycache_p.h"
 #include "qqmlmetatype_p.h"
-#include "qqmldirparser_p.h"
 #include <private/qintrusivelist_p.h>
 #include <private/qrecyclepool_p.h>
 #include <private/qfieldlist_p.h>
@@ -80,6 +78,7 @@
 
 #include <private/qv8engine_p.h>
 #include <private/qjsengine_p.h>
+#include <private/qqmldirparser_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -101,6 +100,7 @@ class QDir;
 class QQmlIncubator;
 class QQmlProfiler;
 class QQmlPropertyCapture;
+class QQmlMetaObject;
 
 // This needs to be declared here so that the pool for it can live in QQmlEnginePrivate.
 // The inline method definitions are in qqmljavascriptexpression_p.h
@@ -122,7 +122,7 @@ class Q_QML_PRIVATE_EXPORT QQmlEnginePrivate : public QJSEnginePrivate
     Q_DECLARE_PUBLIC(QQmlEngine)
 public:
     QQmlEnginePrivate(QQmlEngine *);
-    ~QQmlEnginePrivate();
+    ~QQmlEnginePrivate() override;
 
     void init();
     // No mutex protecting baseModulesUninitialized, because use outside QQmlEngine
@@ -135,7 +135,7 @@ public:
 
     QQmlContext *rootContext;
 
-#ifdef QT_NO_QML_DEBUGGER
+#if !QT_CONFIG(qml_debug)
     static const quintptr profiler = 0;
 #else
     QQmlProfiler *profiler;
@@ -150,11 +150,13 @@ public:
     QQmlDelayedError *erroredBindings;
     int inProgressCreations;
 
-    QV8Engine *v8engine() const { return q_func()->handle(); }
-    QV4::ExecutionEngine *v4engine() const { return QV8Engine::getV4(q_func()->handle()); }
+    QV8Engine *v8engine() const { return q_func()->handle()->v8Engine; }
+    QV4::ExecutionEngine *v4engine() const { return q_func()->handle(); }
 
+#if QT_CONFIG(qml_worker_script)
     QQuickWorkerScriptEngine *getWorkerScriptEngine();
     QQuickWorkerScriptEngine *workerScriptEngine;
+#endif
 
     QUrl baseUrl;
 
@@ -204,23 +206,23 @@ public:
     template<typename T>
     inline void deleteInEngineThread(T *);
     template<typename T>
-    inline static void deleteInEngineThread(QQmlEngine *, T *);
+    inline static void deleteInEngineThread(QQmlEnginePrivate *, T *);
     QString offlineStorageDatabaseDirectory() const;
 
     // These methods may be called from the loader thread
-    inline QQmlPropertyCache *cache(QQmlType *, int);
+    inline QQmlPropertyCache *cache(const QQmlType &, int);
     using QJSEnginePrivate::cache;
 
     // These methods may be called from the loader thread
     bool isQObject(int);
-    QObject *toQObject(const QVariant &, bool *ok = 0) const;
+    QObject *toQObject(const QVariant &, bool *ok = nullptr) const;
     QQmlMetaType::TypeCategory typeCategory(int) const;
     bool isList(int) const;
     int listType(int) const;
     QQmlMetaObject rawMetaObjectForType(int) const;
     QQmlMetaObject metaObjectForType(int) const;
     QQmlPropertyCache *propertyCacheForType(int);
-    QQmlPropertyCache *rawPropertyCacheForType(int);
+    QQmlPropertyCache *rawPropertyCacheForType(int, int minorVersion = -1);
     void registerInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit);
     void unregisterInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit);
 
@@ -231,10 +233,8 @@ public:
     void sendExit(int retCode = 0);
     void warning(const QQmlError &);
     void warning(const QList<QQmlError> &);
-    void warning(QQmlDelayedError *);
     static void warning(QQmlEngine *, const QQmlError &);
     static void warning(QQmlEngine *, const QList<QQmlError> &);
-    static void warning(QQmlEngine *, QQmlDelayedError *);
     static void warning(QQmlEnginePrivate *, const QQmlError &);
     static void warning(QQmlEnginePrivate *, const QList<QQmlError> &);
 
@@ -247,6 +247,8 @@ public:
     inline static QQmlEngine *get(QQmlEnginePrivate *p);
     inline static QQmlEnginePrivate *get(QV4::ExecutionEngine *e);
 
+    static QList<QQmlError> qmlErrorFromDiagnostics(const QString &fileName, const QList<QQmlJS::DiagnosticMessage> &diagnosticMessages);
+
     static void registerBaseTypes(const char *uri, int versionMajor, int versionMinor);
     static void registerQtQuick2Types(const char *uri, int versionMajor, int versionMinor);
     static void defineQtQuick2Module();
@@ -259,18 +261,13 @@ public:
     mutable QMutex networkAccessManagerMutex;
 
 private:
-    // Must be called locked
-    QQmlPropertyCache *createCache(QQmlType *, int);
-
     // These members must be protected by a QQmlEnginePrivate::Locker as they are required by
     // the threaded loader.  Only access them through their respective accessor methods.
-    QHash<QPair<QQmlType *, int>, QQmlPropertyCache *> typePropertyCache;
-    QHash<int, int> m_qmlLists;
     QHash<int, QV4::CompiledData::CompilationUnit *> m_compositeTypes;
     static bool s_designerMode;
 
     // These members is protected by the full QQmlEnginePrivate::mutex mutex
-    struct Deletable { Deletable():next(0) {} virtual ~Deletable() {} Deletable *next; };
+    struct Deletable { Deletable():next(nullptr) {} virtual ~Deletable() {} Deletable *next; };
     QFieldList<Deletable, &Deletable::next> toDeleteInEngineThread;
     void doDeleteInEngineThread();
 
@@ -300,7 +297,7 @@ inline void QQmlEnginePrivate::dereferenceScarceResources()
     // expression must have completed.  We can safely release the
     // scarce resources.
     if (Q_LIKELY(scarceResourcesRefCount == 0)) {
-        QV4::ExecutionEngine *engine = QV8Engine::getV4(v8engine());
+        QV4::ExecutionEngine *engine = v4engine();
         if (Q_UNLIKELY(!engine->scarceResources.isEmpty())) {
             cleanupScarceResources();
         }
@@ -346,7 +343,7 @@ void QQmlEnginePrivate::deleteInEngineThread(T *value)
     } else {
         struct I : public Deletable {
             I(T *value) : value(value) {}
-            ~I() { delete value; }
+            ~I() override { delete value; }
             T *value;
         };
         I *i = new I(value);
@@ -364,10 +361,10 @@ Delete \a value in the \a engine thread.  If the calling thread is the engine
 thread, \a value will be deleted immediately.
 */
 template<typename T>
-void QQmlEnginePrivate::deleteInEngineThread(QQmlEngine *engine, T *value)
+void QQmlEnginePrivate::deleteInEngineThread(QQmlEnginePrivate *engine, T *value)
 {
     Q_ASSERT(engine);
-    QQmlEnginePrivate::get(engine)->deleteInEngineThread<T>(value);
+    engine->deleteInEngineThread<T>(value);
 }
 
 /*!
@@ -375,31 +372,29 @@ Returns a QQmlPropertyCache for \a type with \a minorVersion.
 
 The returned cache is not referenced, so if it is to be stored, call addref().
 */
-QQmlPropertyCache *QQmlEnginePrivate::cache(QQmlType *type, int minorVersion)
+QQmlPropertyCache *QQmlEnginePrivate::cache(const QQmlType &type, int minorVersion)
 {
-    Q_ASSERT(type);
+    Q_ASSERT(type.isValid());
 
-    if (minorVersion == -1 || !type->containsRevisionedAttributes())
-        return cache(type->metaObject());
+    if (minorVersion == -1 || !type.containsRevisionedAttributes())
+        return cache(type.metaObject(), minorVersion);
 
     Locker locker(this);
-    QQmlPropertyCache *rv = typePropertyCache.value(qMakePair(type, minorVersion));
-    if (!rv) rv = createCache(type, minorVersion);
-    return rv;
+    return QQmlMetaType::propertyCache(type, minorVersion);
 }
 
 QV8Engine *QQmlEnginePrivate::getV8Engine(QQmlEngine *e)
 {
     Q_ASSERT(e);
 
-    return e->d_func()->v8engine();
+    return e->handle()->v8Engine;
 }
 
 QV4::ExecutionEngine *QQmlEnginePrivate::getV4Engine(QQmlEngine *e)
 {
     Q_ASSERT(e);
 
-    return e->d_func()->v4engine();
+    return e->handle();
 }
 
 QQmlEnginePrivate *QQmlEnginePrivate::get(QQmlEngine *e)
@@ -418,12 +413,12 @@ const QQmlEnginePrivate *QQmlEnginePrivate::get(const QQmlEngine *e)
 
 QQmlEnginePrivate *QQmlEnginePrivate::get(QQmlContext *c)
 {
-    return (c && c->engine()) ? QQmlEnginePrivate::get(c->engine()) : 0;
+    return (c && c->engine()) ? QQmlEnginePrivate::get(c->engine()) : nullptr;
 }
 
 QQmlEnginePrivate *QQmlEnginePrivate::get(QQmlContextData *c)
 {
-    return (c && c->engine) ? QQmlEnginePrivate::get(c->engine) : 0;
+    return (c && c->engine) ? QQmlEnginePrivate::get(c->engine) : nullptr;
 }
 
 QQmlEngine *QQmlEnginePrivate::get(QQmlEnginePrivate *p)
@@ -435,11 +430,9 @@ QQmlEngine *QQmlEnginePrivate::get(QQmlEnginePrivate *p)
 
 QQmlEnginePrivate *QQmlEnginePrivate::get(QV4::ExecutionEngine *e)
 {
-    if (!e->v8Engine)
-        return 0;
-    QQmlEngine *qmlEngine = e->v8Engine->engine();
+    QQmlEngine *qmlEngine = e->qmlEngine();
     if (!qmlEngine)
-        return 0;
+        return nullptr;
     return get(qmlEngine);
 }
 
diff --git a/src/qml/qml/qqmlenumdata_p.h b/src/qml/qml/qqmlenumdata_p.h
new file mode 100644
index 0000000000..df99c2c1bc
--- /dev/null
+++ b/src/qml/qml/qqmlenumdata_p.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLENUMDATA_P_H
+#define QQMLENUMDATA_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmlenumvalue_p.h>
+
+QT_BEGIN_NAMESPACE
+
+struct QQmlEnumData
+{
+    QString name;
+    QVector<QQmlEnumValue> values;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLENUMDATA_P_H
diff --git a/src/qml/qml/qqmlenumvalue_p.h b/src/qml/qml/qqmlenumvalue_p.h
new file mode 100644
index 0000000000..ea0fc244cb
--- /dev/null
+++ b/src/qml/qml/qqmlenumvalue_p.h
@@ -0,0 +1,68 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLENUMVALUE_P_H
+#define QQMLENUMVALUE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qstring.h>
+
+QT_BEGIN_NAMESPACE
+
+struct QQmlEnumValue
+{
+    QQmlEnumValue() {}
+    QQmlEnumValue(const QString &n, int v) : namedValue(n), value(v) {}
+    QString namedValue;
+    int value = -1;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLENUMVALUE_P_H
diff --git a/src/qml/qml/qqmlexpression.cpp b/src/qml/qml/qqmlexpression.cpp
index b70db5ed86..ac2629979f 100644
--- a/src/qml/qml/qqmlexpression.cpp
+++ b/src/qml/qml/qqmlexpression.cpp
@@ -46,6 +46,7 @@
 #include "qqmlscriptstring_p.h"
 #include "qqmlbinding_p.h"
 #include <private/qv8engine_p.h>
+#include <private/qqmlsourcecoordinate_p.h>
 
 #include <QtCore/qdebug.h>
 
@@ -74,7 +75,7 @@ void QQmlExpressionPrivate::init(QQmlContextData *ctxt, const QString &expr, QOb
 void QQmlExpressionPrivate::init(QQmlContextData *ctxt, QV4::Function *runtimeFunction, QObject *me)
 {
     expressionFunctionValid = true;
-    QV4::ExecutionEngine *engine = QQmlEnginePrivate::getV4Engine(ctxt->engine);
+    QV4::ExecutionEngine *engine = ctxt->engine->handle();
     QV4::Scope scope(engine);
     QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(engine->rootContext(), ctxt, me));
     setupFunction(qmlContext, runtimeFunction);
@@ -110,8 +111,6 @@ void QQmlExpressionPrivate::init(QQmlContextData *ctxt, QV4::Function *runtimeFu
     QQmlExpression *expr = new QQmlExpression(engine->rootContext(), myObject, "width * 2");
     int result = expr->evaluate().toInt();  // result = 400
     \endcode
-
-    Note that the \l {Qt Quick 1} version is called QDeclarativeExpression.
 */
 
 /*!
@@ -121,7 +120,7 @@ void QQmlExpressionPrivate::init(QQmlContextData *ctxt, QV4::Function *runtimeFu
     null expression object and its value will always be an invalid QVariant.
  */
 QQmlExpression::QQmlExpression()
-: QObject(*new QQmlExpressionPrivate, 0)
+: QObject(*new QQmlExpressionPrivate, nullptr)
 {
 }
 
@@ -147,7 +146,7 @@ QQmlExpression::QQmlExpression(const QQmlScriptString &script, QQmlContext *ctxt
 
     QQmlContextData *evalCtxtData = QQmlContextData::get(ctxt ? ctxt : scriptPrivate->context);
     QObject *scopeObject = scope ? scope : scriptPrivate->scope;
-    QV4::Function *runtimeFunction = 0;
+    QV4::Function *runtimeFunction = nullptr;
 
     if (scriptPrivate->context) {
         QQmlContextData *ctxtdata = QQmlContextData::get(scriptPrivate->context);
@@ -191,7 +190,7 @@ QQmlExpression::QQmlExpression(QQmlContext *ctxt,
 */
 QQmlExpression::QQmlExpression(QQmlContextData *ctxt, QObject *scope,
                                                const QString &expression)
-: QObject(*new QQmlExpressionPrivate, 0)
+: QObject(*new QQmlExpressionPrivate, nullptr)
 {
     Q_D(QQmlExpression);
     d->init(ctxt, expression, scope);
@@ -202,7 +201,6 @@ QQmlExpression::QQmlExpression(QQmlContextData *ctxt, QObject *scope,
 */
 QQmlExpression::~QQmlExpression()
 {
-    clearError();
 }
 
 /*!
@@ -212,7 +210,7 @@ QQmlExpression::~QQmlExpression()
 QQmlEngine *QQmlExpression::engine() const
 {
     Q_D(const QQmlExpression);
-    return d->context()?d->context()->engine:0;
+    return d->context()?d->context()->engine:nullptr;
 }
 
 /*!
@@ -223,7 +221,7 @@ QQmlContext *QQmlExpression::context() const
 {
     Q_D(const QQmlExpression);
     QQmlContextData *data = d->context();
-    return data?data->asQQmlContext():0;
+    return data?data->asQQmlContext():nullptr;
 }
 
 /*!
@@ -248,15 +246,19 @@ void QQmlExpression::setExpression(const QString &expression)
 }
 
 // Must be called with a valid handle scope
-void QQmlExpressionPrivate::v4value(bool *isUndefined, QV4::Scope &scope)
+QV4::ReturnedValue QQmlExpressionPrivate::v4value(bool *isUndefined)
 {
     if (!expressionFunctionValid) {
         createQmlBinding(context(), scopeObject(), expression, url, line);
         expressionFunctionValid = true;
+        if (hasError()) {
+            if (isUndefined)
+                *isUndefined = true;
+            return QV4::Encode::undefined();
+        }
     }
 
-    QV4::ScopedCallData callData(scope);
-    evaluate(callData, isUndefined, scope);
+    return evaluate(isUndefined);
 }
 
 QVariant QQmlExpressionPrivate::value(bool *isUndefined)
@@ -268,16 +270,17 @@ QVariant QQmlExpressionPrivate::value(bool *isUndefined)
         return QVariant();
     }
 
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(q->engine());
+    QQmlEngine *engine = q->engine();
+    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
     QVariant rv;
 
     ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
 
     {
-        QV4::Scope scope(QV8Engine::getV4(ep->v8engine()));
-        v4value(isUndefined, scope);
+        QV4::Scope scope(engine->handle());
+        QV4::ScopedValue result(scope, v4value(isUndefined));
         if (!hasError())
-            rv = scope.engine->toVariant(scope.result, -1);
+            rv = scope.engine->toVariant(result, -1);
     }
 
     ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
diff --git a/src/qml/qml/qqmlexpression.h b/src/qml/qml/qqmlexpression.h
index 5239d59c8a..0eceeb12e1 100644
--- a/src/qml/qml/qqmlexpression.h
+++ b/src/qml/qml/qqmlexpression.h
@@ -60,9 +60,9 @@ class Q_QML_EXPORT QQmlExpression : public QObject
     Q_OBJECT
 public:
     QQmlExpression();
-    QQmlExpression(QQmlContext *, QObject *, const QString &, QObject * = Q_NULLPTR);
-    explicit QQmlExpression(const QQmlScriptString &, QQmlContext * = Q_NULLPTR, QObject * = Q_NULLPTR, QObject * = Q_NULLPTR);
-    virtual ~QQmlExpression();
+    QQmlExpression(QQmlContext *, QObject *, const QString &, QObject * = nullptr);
+    explicit QQmlExpression(const QQmlScriptString &, QQmlContext * = nullptr, QObject * = nullptr, QObject * = nullptr);
+    ~QQmlExpression() override;
 
     QQmlEngine *engine() const;
     QQmlContext *context() const;
@@ -84,7 +84,7 @@ public:
     void clearError();
     QQmlError error() const;
 
-    QVariant evaluate(bool *valueIsUndefined = Q_NULLPTR);
+    QVariant evaluate(bool *valueIsUndefined = nullptr);
 
 Q_SIGNALS:
     void valueChanged();
diff --git a/src/qml/qml/qqmlexpression_p.h b/src/qml/qml/qqmlexpression_p.h
index 44342a957b..da10b31b2c 100644
--- a/src/qml/qml/qqmlexpression_p.h
+++ b/src/qml/qml/qqmlexpression_p.h
@@ -68,14 +68,14 @@ class QQmlExpressionPrivate : public QObjectPrivate,
     Q_DECLARE_PUBLIC(QQmlExpression)
 public:
     QQmlExpressionPrivate();
-    ~QQmlExpressionPrivate();
+    ~QQmlExpressionPrivate() override;
 
     void init(QQmlContextData *, const QString &, QObject *);
     void init(QQmlContextData *, QV4::Function *runtimeFunction, QObject *);
 
-    QVariant value(bool *isUndefined = 0);
+    QVariant value(bool *isUndefined = nullptr);
 
-    void v4value(bool *isUndefined, QV4::Scope &scope);
+    QV4::ReturnedValue v4value(bool *isUndefined = nullptr);
 
     static inline QQmlExpressionPrivate *get(QQmlExpression *expr);
     static inline QQmlExpression *get(QQmlExpressionPrivate *expr);
diff --git a/src/qml/qml/qqmlextensioninterface.h b/src/qml/qml/qqmlextensioninterface.h
index ef56d5e312..d2eb79c5c9 100644
--- a/src/qml/qml/qqmlextensioninterface.h
+++ b/src/qml/qml/qqmlextensioninterface.h
@@ -51,14 +51,14 @@ class QQmlEngine;
 class Q_QML_EXPORT QQmlTypesExtensionInterface
 {
 public:
-    virtual ~QQmlTypesExtensionInterface() {}
+    virtual ~QQmlTypesExtensionInterface() = default;
     virtual void registerTypes(const char *uri) = 0;
 };
 
 class Q_QML_EXPORT QQmlExtensionInterface : public QQmlTypesExtensionInterface
 {
 public:
-    virtual ~QQmlExtensionInterface() {}
+    ~QQmlExtensionInterface() override = default;
     virtual void initializeEngine(QQmlEngine *engine, const char *uri) = 0;
 };
 
@@ -66,7 +66,10 @@ public:
 
 Q_DECLARE_INTERFACE(QQmlTypesExtensionInterface, "org.qt-project.Qt.QQmlTypesExtensionInterface/1.0")
 
+// NOTE: When changing this to a new version and deciding to add backup code to
+// continue to support the previous version, make sure to support both of these iids.
 #define QQmlExtensionInterface_iid "org.qt-project.Qt.QQmlExtensionInterface/1.0"
+#define QQmlExtensionInterface_iid_old "org.qt-project.Qt.QQmlExtensionInterface"
 
 Q_DECLARE_INTERFACE(QQmlExtensionInterface, QQmlExtensionInterface_iid)
 
diff --git a/src/qml/qml/qqmlextensionplugin.cpp b/src/qml/qml/qqmlextensionplugin.cpp
index b0e6a24616..c1c971f0a9 100644
--- a/src/qml/qml/qqmlextensionplugin.cpp
+++ b/src/qml/qml/qqmlextensionplugin.cpp
@@ -55,8 +55,6 @@ QT_BEGIN_NAMESPACE
     The \l {Writing QML Extensions with C++} tutorial also contains a chapter
     on creating QML plugins.
 
-    Note that the \l {Qt Quick 1} version is called QDeclarativeExtensionPlugin.
-
     \sa QQmlEngine::importPlugin(), {How to Create Qt Plugins}
 */
 
@@ -121,7 +119,9 @@ void QQmlExtensionPlugin::initializeEngine(QQmlEngine *engine, const char *uri)
   \class QQmlExtensionInterface
   \internal
   \inmodule QtQml
+*/
 
+/*!
   \class QQmlTypesExtensionInterface
   \internal
   \inmodule QtQml
diff --git a/src/qml/qml/qqmlextensionplugin.h b/src/qml/qml/qqmlextensionplugin.h
index c0915c0abe..55e9b89dae 100644
--- a/src/qml/qml/qqmlextensionplugin.h
+++ b/src/qml/qml/qqmlextensionplugin.h
@@ -58,8 +58,8 @@ class Q_QML_EXPORT QQmlExtensionPlugin
     Q_INTERFACES(QQmlExtensionInterface)
     Q_INTERFACES(QQmlTypesExtensionInterface)
 public:
-    explicit QQmlExtensionPlugin(QObject *parent = Q_NULLPTR);
-    ~QQmlExtensionPlugin();
+    explicit QQmlExtensionPlugin(QObject *parent = nullptr);
+    ~QQmlExtensionPlugin() override;
 
     QUrl baseUrl() const;
 
diff --git a/src/qml/qml/qqmlfile.cpp b/src/qml/qml/qqmlfile.cpp
index 4e4db086b0..465a342129 100644
--- a/src/qml/qml/qqmlfile.cpp
+++ b/src/qml/qml/qqmlfile.cpp
@@ -64,6 +64,7 @@ static char file_string[] = "file";
 
 #if defined(Q_OS_ANDROID)
 static char assets_string[] = "assets";
+static char content_string[] = "content";
 #endif
 
 class QQmlFilePrivate;
@@ -131,7 +132,7 @@ int QQmlFileNetworkReply::replyFinishedIndex = -1;
 int QQmlFileNetworkReply::replyDownloadProgressIndex = -1;
 
 QQmlFileNetworkReply::QQmlFileNetworkReply(QQmlEngine *e, QQmlFilePrivate *p, const QUrl &url)
-: m_engine(e), m_p(p), m_redirectCount(0), m_reply(0)
+: m_engine(e), m_p(p), m_redirectCount(0), m_reply(nullptr)
 {
     if (finishedIndex == -1) {
         finishedIndex = QMetaMethod::fromSignal(&QQmlFileNetworkReply::finished).methodIndex();
@@ -194,9 +195,9 @@ void QQmlFileNetworkReply::networkFinished()
     }
 
     m_reply->deleteLater();
-    m_reply = 0;
+    m_reply = nullptr;
 
-    m_p->reply = 0;
+    m_p->reply = nullptr;
     emit finished();
     delete this;
 }
@@ -210,7 +211,7 @@ void QQmlFileNetworkReply::networkDownloadProgress(qint64 a, qint64 b)
 QQmlFilePrivate::QQmlFilePrivate()
 : error(None)
 #if QT_CONFIG(qml_network)
-, reply(0)
+, reply(nullptr)
 #endif
 {
 }
@@ -237,7 +238,7 @@ QQmlFile::~QQmlFile()
     delete d->reply;
 #endif
     delete d;
-    d = 0;
+    d = nullptr;
 }
 
 bool QQmlFile::isNull() const
@@ -452,6 +453,8 @@ bool QQmlFile::isSynchronous(const QUrl &url)
 #if defined(Q_OS_ANDROID)
     } else if (scheme.length() == 6 && 0 == scheme.compare(QLatin1String(assets_string), Qt::CaseInsensitive)) {
         return true;
+    } else if (scheme.length() == 7 && 0 == scheme.compare(QLatin1String(content_string), Qt::CaseInsensitive)) {
+        return true;
 #endif
 
     } else {
@@ -492,7 +495,10 @@ bool QQmlFile::isSynchronous(const QString &url)
         return url.length() >= 8 /* assets:/ */ &&
                url.startsWith(QLatin1String(assets_string), Qt::CaseInsensitive) &&
                url[6] == QLatin1Char(':') && url[7] == QLatin1Char('/');
-
+    } else if (f == QLatin1Char('c') || f == QLatin1Char('C')) {
+        return url.length() >= 9 /* content:/ */ &&
+               url.startsWith(QLatin1String(content_string), Qt::CaseInsensitive) &&
+               url[7] == QLatin1Char(':') && url[8] == QLatin1Char('/');
     }
 #endif
 
@@ -556,7 +562,10 @@ bool QQmlFile::isLocalFile(const QString &url)
         return url.length() >= 8 /* assets:/ */ &&
                url.startsWith(QLatin1String(assets_string), Qt::CaseInsensitive) &&
                url[6] == QLatin1Char(':') && url[7] == QLatin1Char('/');
-
+    } else if (f == QLatin1Char('c') || f == QLatin1Char('C')) {
+        return url.length() >= 9 /* content:/ */ &&
+               url.startsWith(QLatin1String(content_string), Qt::CaseInsensitive) &&
+               url[7] == QLatin1Char(':') && url[8] == QLatin1Char('/');
     }
 #endif
 
@@ -580,6 +589,8 @@ QString QQmlFile::urlToLocalFileOrQrc(const QUrl& url)
         if (url.authority().isEmpty())
             return url.toString();
         return QString();
+    } else if (url.scheme().compare(QLatin1String("content"), Qt::CaseInsensitive) == 0) {
+        return url.toString();
     }
 #endif
 
@@ -603,6 +614,12 @@ empty string.
 */
 QString QQmlFile::urlToLocalFileOrQrc(const QString& url)
 {
+    if (url.startsWith(QLatin1String("qrc://"), Qt::CaseInsensitive)) {
+        if (url.length() > 6)
+            return QLatin1Char(':') + url.midRef(6);
+        return QString();
+    }
+
     if (url.startsWith(QLatin1String("qrc:"), Qt::CaseInsensitive)) {
         if (url.length() > 4)
             return QLatin1Char(':') + url.midRef(4);
@@ -612,6 +629,8 @@ QString QQmlFile::urlToLocalFileOrQrc(const QString& url)
 #if defined(Q_OS_ANDROID)
     else if (url.startsWith(QLatin1String("assets:"), Qt::CaseInsensitive)) {
         return url;
+    } else if (url.startsWith(QLatin1String("content:"), Qt::CaseInsensitive)) {
+        return url;
     }
 #endif
 
diff --git a/src/qml/qml/qqmlfileselector.cpp b/src/qml/qml/qqmlfileselector.cpp
index be6216d3ff..32dce8b4bc 100644
--- a/src/qml/qml/qqmlfileselector.cpp
+++ b/src/qml/qml/qqmlfileselector.cpp
@@ -52,7 +52,7 @@ Q_GLOBAL_STATIC(interceptorSelectorMap, interceptorInstances);
    \class QQmlFileSelector
    \since 5.2
    \inmodule QtQml
-   \brief A class for applying a QFileSelector to QML file loading
+   \brief A class for applying a QFileSelector to QML file loading.
 
   QQmlFileSelector will automatically apply a QFileSelector to
   qml file and asset paths.
@@ -115,8 +115,8 @@ QQmlFileSelector::~QQmlFileSelector()
 {
     Q_D(QQmlFileSelector);
     if (d->engine && QQmlFileSelector::get(d->engine) == this) {
-        d->engine->setUrlInterceptor(0);
-        d->engine = 0;
+        d->engine->setUrlInterceptor(nullptr);
+        d->engine = nullptr;
     }
     interceptorInstances()->remove(d->myInstance.data());
 }
@@ -200,7 +200,7 @@ QQmlFileSelector* QQmlFileSelector::get(QQmlEngine* engine)
     QQmlAbstractUrlInterceptor* current = engine->urlInterceptor();
     if (current && interceptorInstances()->contains(current))
         return interceptorInstances()->value(current);
-    return 0;
+    return nullptr;
 }
 
 /*!
diff --git a/src/qml/qml/qqmlfileselector.h b/src/qml/qml/qqmlfileselector.h
index 03b951420e..9b70e3936d 100644
--- a/src/qml/qml/qqmlfileselector.h
+++ b/src/qml/qml/qqmlfileselector.h
@@ -54,8 +54,8 @@ class Q_QML_EXPORT QQmlFileSelector : public QObject
     Q_OBJECT
     Q_DECLARE_PRIVATE(QQmlFileSelector)
 public:
-    explicit QQmlFileSelector(QQmlEngine *engine, QObject *parent = Q_NULLPTR);
-    ~QQmlFileSelector();
+    explicit QQmlFileSelector(QQmlEngine *engine, QObject *parent = nullptr);
+    ~QQmlFileSelector() override;
     QFileSelector *selector() const Q_DECL_NOTHROW;
     void setSelector(QFileSelector *selector);
     void setExtraSelectors(QStringList &strings); // TODO Qt6: remove
diff --git a/src/qml/qml/qqmlglobal.cpp b/src/qml/qml/qqmlglobal.cpp
index 6418812bae..1d60c518c4 100644
--- a/src/qml/qml/qqmlglobal.cpp
+++ b/src/qml/qml/qqmlglobal.cpp
@@ -48,7 +48,7 @@
 QT_BEGIN_NAMESPACE
 
 QQmlValueTypeProvider::QQmlValueTypeProvider()
-    : next(0)
+    : next(nullptr)
 {
 }
 
@@ -65,7 +65,7 @@ const QMetaObject *QQmlValueTypeProvider::metaObjectForMetaType(int type)
             return mo;
     } while ((p = p->next));
 
-    return 0;
+    return nullptr;
 }
 
 bool QQmlValueTypeProvider::initValueType(int type, QVariant& dst)
@@ -218,7 +218,7 @@ bool QQmlValueTypeProvider::writeValueType(int type, const void *src, QVariant&
     return false;
 }
 
-const QMetaObject *QQmlValueTypeProvider::getMetaObjectForMetaType(int) { return 0; }
+const QMetaObject *QQmlValueTypeProvider::getMetaObjectForMetaType(int) { return nullptr; }
 bool QQmlValueTypeProvider::init(int, QVariant&) { return false; }
 bool QQmlValueTypeProvider::create(int, int, const void *[], QVariant *) { return false; }
 bool QQmlValueTypeProvider::createFromString(int, const QString &, void *, size_t) { return false; }
@@ -232,11 +232,11 @@ bool QQmlValueTypeProvider::read(const QVariant&, void *, int) { return false; }
 bool QQmlValueTypeProvider::write(int, const void *, QVariant&) { return false; }
 
 Q_GLOBAL_STATIC(QQmlValueTypeProvider, nullValueTypeProvider)
-static QQmlValueTypeProvider *valueTypeProvider = 0;
+static QQmlValueTypeProvider *valueTypeProvider = nullptr;
 
 static QQmlValueTypeProvider **getValueTypeProvider(void)
 {
-    if (valueTypeProvider == 0) {
+    if (valueTypeProvider == nullptr) {
         valueTypeProvider = nullValueTypeProvider;
     }
 
@@ -294,7 +294,7 @@ QVariant QQmlColorProvider::lighter(const QVariant &, qreal) { return QVariant()
 QVariant QQmlColorProvider::darker(const QVariant &, qreal) { return QVariant(); }
 QVariant QQmlColorProvider::tint(const QVariant &, const QVariant &) { return QVariant(); }
 
-static QQmlColorProvider *colorProvider = 0;
+static QQmlColorProvider *colorProvider = nullptr;
 
 Q_QML_PRIVATE_EXPORT QQmlColorProvider *QQml_setColorProvider(QQmlColorProvider *newProvider)
 {
@@ -305,7 +305,7 @@ Q_QML_PRIVATE_EXPORT QQmlColorProvider *QQml_setColorProvider(QQmlColorProvider
 
 static QQmlColorProvider **getColorProvider(void)
 {
-    if (colorProvider == 0) {
+    if (colorProvider == nullptr) {
         qWarning() << "Warning: QQml_colorProvider: no color provider has been set!";
         static QQmlColorProvider nullColorProvider;
         colorProvider = &nullColorProvider;
@@ -345,7 +345,7 @@ QObject *QQmlGuiProvider::styleHints()
 
 QString QQmlGuiProvider::pluginName() const { return QString(); }
 
-static QQmlGuiProvider *guiProvider = 0;
+static QQmlGuiProvider *guiProvider = nullptr;
 
 Q_QML_PRIVATE_EXPORT QQmlGuiProvider *QQml_setGuiProvider(QQmlGuiProvider *newProvider)
 {
@@ -356,7 +356,7 @@ Q_QML_PRIVATE_EXPORT QQmlGuiProvider *QQml_setGuiProvider(QQmlGuiProvider *newPr
 
 static QQmlGuiProvider **getGuiProvider(void)
 {
-    if (guiProvider == 0) {
+    if (guiProvider == nullptr) {
         static QQmlGuiProvider nullGuiProvider; //Still provides an application with no GUI support
         guiProvider = &nullGuiProvider;
     }
diff --git a/src/qml/qml/qqmlglobal_p.h b/src/qml/qml/qqmlglobal_p.h
index a6c113f5a7..e2d53ab555 100644
--- a/src/qml/qml/qqmlglobal_p.h
+++ b/src/qml/qml/qqmlglobal_p.h
@@ -53,7 +53,7 @@
 
 #include <private/qtqmlglobal_p.h>
 #include <QtCore/QObject>
-#include <private/qqmlpropertycache_p.h>
+#include <private/qqmlmetaobject_p.h>
 #include <private/qmetaobject_p.h>
 #include <private/qv8engine_p.h>
 
@@ -174,16 +174,6 @@ T qmlobject_cast(QObject *object)
         return 0;
 }
 
-inline quint16 qmlSourceCoordinate(int n)
-{
-    return (n > 0 && n <= static_cast<int>(USHRT_MAX)) ? static_cast<quint16>(n) : 0;
-}
-
-inline int qmlSourceCoordinate(quint16 n)
-{
-    return (n == 0) ? -1 : static_cast<int>(n);
-}
-
 #define IS_SIGNAL_CONNECTED(Sender, SenderType, Name, Arguments) \
 do { \
     QObject *sender = (Sender); \
@@ -193,16 +183,6 @@ do { \
     return QObjectPrivate::get(sender)->isSignalConnected(signalIdx); \
 } while (0)
 
-struct QQmlGraphics_DerivedObject : public QObject
-{
-    void setParent_noEvent(QObject *parent) {
-        bool sce = d_ptr->sendChildEvents;
-        d_ptr->sendChildEvents = false;
-        setParent(parent);
-        d_ptr->sendChildEvents = sce;
-    }
-};
-
 /*!
     Returns true if the case of \a fileName is equivalent to the file case of
     \a fileName on disk, and false otherwise.
@@ -230,7 +210,11 @@ bool QQml_isFileCaseCorrect(const QString &fileName, int length = -1);
 */
 inline void QQml_setParent_noEvent(QObject *object, QObject *parent)
 {
-    static_cast<QQmlGraphics_DerivedObject *>(object)->setParent_noEvent(parent);
+    QObjectPrivate *d_ptr = QObjectPrivate::get(object);
+    bool sce = d_ptr->sendChildEvents;
+    d_ptr->sendChildEvents = false;
+    object->setParent(parent);
+    d_ptr->sendChildEvents = sce;
 }
 
 class Q_QML_PRIVATE_EXPORT QQmlValueTypeProvider
@@ -329,7 +313,7 @@ class Q_QML_PRIVATE_EXPORT QQmlApplication : public QObject
     Q_PROPERTY(QString organization READ organization WRITE setOrganization NOTIFY organizationChanged)
     Q_PROPERTY(QString domain READ domain WRITE setDomain NOTIFY domainChanged)
 public:
-    QQmlApplication(QObject* parent=0);
+    QQmlApplication(QObject* parent=nullptr);
 
     QStringList args();
 
@@ -353,7 +337,7 @@ Q_SIGNALS:
     void domainChanged();
 
 protected:
-    QQmlApplication(QQmlApplicationPrivate &dd, QObject* parent=0);
+    QQmlApplication(QQmlApplicationPrivate &dd, QObject* parent=nullptr);
 
 private:
     Q_DISABLE_COPY(QQmlApplication)
@@ -374,12 +358,12 @@ public:
 
 struct QQmlSourceLocation
 {
-    QQmlSourceLocation() : line(0), column(0) {}
+    QQmlSourceLocation() {}
     QQmlSourceLocation(const QString &sourceFile, quint16 line, quint16 column)
         : sourceFile(sourceFile), line(line), column(column) {}
     QString sourceFile;
-    quint16 line;
-    quint16 column;
+    quint16 line = 0;
+    quint16 column = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlguard_p.h b/src/qml/qml/qqmlguard_p.h
index 52526276be..3ac63926a0 100644
--- a/src/qml/qml/qqmlguard_p.h
+++ b/src/qml/qml/qqmlguard_p.h
@@ -65,9 +65,9 @@ public:
     inline QQmlGuardImpl(const QQmlGuardImpl &);
     inline ~QQmlGuardImpl();
 
-    QObject *o;
-    QQmlGuardImpl  *next;
-    QQmlGuardImpl **prev;
+    QObject *o = nullptr;
+    QQmlGuardImpl  *next = nullptr;
+    QQmlGuardImpl **prev = nullptr;
 
     inline void addGuard();
     inline void remGuard();
@@ -106,6 +106,34 @@ protected:
     virtual void objectDestroyed(T *) {}
 };
 
+template <typename T>
+class QQmlStrongJSQObjectReference : public QQmlGuard<T>
+{
+public:
+    void setObject(T *o, QObject *parent) {
+        T *old = this->object();
+        if (o == old)
+            return;
+
+        if (m_jsOwnership && old && old->parent() == parent)
+            QQml_setParent_noEvent(old, nullptr);
+
+        this->QQmlGuard<T>::operator=(o);
+
+        if (o && !o->parent() && !QQmlData::keepAliveDuringGarbageCollection(o)) {
+            m_jsOwnership = true;
+            QQml_setParent_noEvent(o, parent);
+        } else {
+            m_jsOwnership = false;
+        }
+    }
+
+private:
+    using QQmlGuard<T>::setObject;
+    using QQmlGuard<T>::operator=;
+    bool m_jsOwnership = false;
+};
+
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QQmlGuard<QObject>)
@@ -113,18 +141,17 @@ Q_DECLARE_METATYPE(QQmlGuard<QObject>)
 QT_BEGIN_NAMESPACE
 
 QQmlGuardImpl::QQmlGuardImpl()
-: o(0), next(0), prev(0)
 {
 }
 
 QQmlGuardImpl::QQmlGuardImpl(QObject *g)
-: o(g), next(0), prev(0)
+: o(g)
 {
     if (o) addGuard();
 }
 
 QQmlGuardImpl::QQmlGuardImpl(const QQmlGuardImpl &g)
-: o(g.o), next(0), prev(0)
+: o(g.o)
 {
     if (o) addGuard();
 }
@@ -132,7 +159,7 @@ QQmlGuardImpl::QQmlGuardImpl(const QQmlGuardImpl &g)
 QQmlGuardImpl::~QQmlGuardImpl()
 {
     if (prev) remGuard();
-    o = 0;
+    o = nullptr;
 }
 
 void QQmlGuardImpl::addGuard()
@@ -155,8 +182,8 @@ void QQmlGuardImpl::remGuard()
 
     if (next) next->prev = prev;
     *prev = next;
-    next = 0;
-    prev = 0;
+    next = nullptr;
+    prev = nullptr;
 }
 
 template<class T>
diff --git a/src/qml/qml/qqmlimport.cpp b/src/qml/qml/qqmlimport.cpp
index ee5b38717b..90c2c1fb96 100644
--- a/src/qml/qml/qqmlimport.cpp
+++ b/src/qml/qml/qqmlimport.cpp
@@ -54,6 +54,7 @@
 #include <private/qqmltypenamecache_p.h>
 #include <private/qqmlengine_p.h>
 #include <private/qfieldlist_p.h>
+#include <private/qqmltypemodule_p.h>
 #include <QtCore/qjsonobject.h>
 #include <QtCore/qjsonarray.h>
 
@@ -131,83 +132,6 @@ bool isPathAbsolute(const QString &path)
 #endif
 }
 
-/*
-    \internal
-
-    Fetches the QQmlType instance registered for \a urlString, creating a
-    registration for it if it is not already registered, using the associated
-    \a typeName, \a isCompositeSingleton, \a majorVersion and \a minorVersion
-    details.
-
-    Errors (if there are any) are placed into \a errors, if it is nonzero. Note
-    that errors are treated as fatal if \a errors is not set.
-*/
-QQmlType *fetchOrCreateTypeForUrl(const QString &urlString, const QHashedStringRef& typeName,
-                        bool isCompositeSingleton, QList<QQmlError> *errors,
-                        int majorVersion=-1, int minorVersion=-1)
-{
-    QUrl url(urlString); // ### unfortunate (costly) conversion
-    QQmlType *ret = QQmlMetaType::qmlType(url);
-    if (ret)
-        return ret;
-
-    int dot = typeName.indexOf(QLatin1Char('.'));
-    QHashedStringRef unqualifiedtype = dot < 0 ? typeName : QHashedStringRef(typeName.constData() + dot + 1, typeName.length() - dot - 1);
-
-    // We need a pointer, but we were passed a string. Take a copy so we
-    // can guarentee it will live long enough to reach qmlregister.
-    QByteArray buf(unqualifiedtype.toString().toUtf8());
-
-    // Register the type. Note that the URI parameters here are empty; for
-    // file type imports, we do not place them in a URI as we don't
-    // necessarily have a good and unique one (picture a library import,
-    // which may be found in multiple plugin locations on disk), but there
-    // are other reasons for this too.
-    //
-    // By not putting them in a URI, we prevent the types from being
-    // registered on a QQmlTypeModule; this is important, as once types are
-    // placed on there, they cannot be easily removed, meaning if the
-    // developer subsequently loads a different import (meaning different
-    // types) with the same URI (using, say, a different plugin path), it is
-    // very undesirable that we continue to associate the types from the
-    // "old" URI with that new module.
-    //
-    // Not having URIs also means that the types cannot be found by name
-    // etc, the only way to look them up is through QQmlImports -- for
-    // better or worse.
-    if (isCompositeSingleton) {
-        QQmlPrivate::RegisterCompositeSingletonType reg = {
-            url,
-            "", // uri
-            majorVersion,
-            minorVersion,
-            buf.constData()
-        };
-        ret = QQmlMetaType::qmlTypeFromIndex(QQmlPrivate::qmlregister(QQmlPrivate::CompositeSingletonRegistration, &reg));
-    } else {
-        QQmlPrivate::RegisterCompositeType reg = {
-            url,
-            "", // uri
-            majorVersion,
-            minorVersion,
-            buf.constData()
-        };
-        ret = QQmlMetaType::qmlTypeFromIndex(QQmlPrivate::qmlregister(QQmlPrivate::CompositeRegistration, &reg));
-    }
-
-    // This means that the type couldn't be found by URL, but could not be
-    // registered either, meaning we most likely were passed some kind of bad
-    // data.
-    if (!ret) {
-        if (!errors) // Cannot list errors properly, just quit
-            qFatal("%s", QQmlMetaType::typeRegistrationFailures().join('\n').toLatin1().constData());
-        QQmlError error;
-        error.setDescription(QQmlMetaType::typeRegistrationFailures().join('\n'));
-        errors->prepend(error);
-    }
-    return ret;
-}
-
 } // namespace
 
 struct RegisteredPlugin {
@@ -295,7 +219,10 @@ public:
                              QList<QQmlError> *errors);
 
     bool resolveType(const QHashedStringRef &type, int *vmajor, int *vminor,
-                     QQmlType** type_return, QList<QQmlError> *errors);
+                     QQmlType *type_return, QList<QQmlError> *errors,
+                     QQmlType::RegistrationType registrationType,
+                     QQmlImport::RecursionRestriction recursionRestriction
+                     = QQmlImport::PreventRecursion);
 
     QUrl baseUrl;
     QString base;
@@ -315,17 +242,17 @@ public:
                              QQmlImportDatabase *database,
                              QString *outQmldirFilePath, QString *outUrl);
 
-    static bool validateQmldirVersion(const QQmlTypeLoaderQmldirContent *qmldir, const QString &uri, int vmaj, int vmin,
+    static bool validateQmldirVersion(const QQmlTypeLoaderQmldirContent &qmldir, const QString &uri, int vmaj, int vmin,
                                       QList<QQmlError> *errors);
 
     bool importExtension(const QString &absoluteFilePath, const QString &uri,
                          int vmaj, int vmin,
                          QQmlImportDatabase *database,
-                         const QQmlTypeLoaderQmldirContent *qmldir,
+                         const QQmlTypeLoaderQmldirContent &qmldir,
                          QList<QQmlError> *errors);
 
     bool getQmldirContent(const QString &qmldirIdentifier, const QString &uri,
-                          const QQmlTypeLoaderQmldirContent **qmldir, QList<QQmlError> *errors);
+                          QQmlTypeLoaderQmldirContent *qmldir, QList<QQmlError> *errors);
 
     QString resolvedUri(const QString &dir_arg, QQmlImportDatabase *database);
 
@@ -420,13 +347,14 @@ void QQmlImports::populateCache(QQmlTypeNameCache *cache) const
         const QQmlImportNamespace &set = *ns;
 
         // positioning is important; we must create the namespace even if there is no module.
-        QQmlTypeNameCache::Import &typeimport = cache->m_namedImports[set.prefix];
+        QQmlImportRef &typeimport = cache->m_namedImports[set.prefix];
         typeimport.m_qualifier = set.prefix;
 
         for (int ii = set.imports.count() - 1; ii >= 0; --ii) {
             const QQmlImportInstance *import = set.imports.at(ii);
             QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion);
             if (module) {
+                QQmlImportRef &typeimport = cache->m_namedImports[set.prefix];
                 typeimport.modules.append(QQmlTypeModuleVersion(module, import->minversion));
             }
         }
@@ -470,6 +398,17 @@ void findCompositeSingletons(const QQmlImportNamespace &set, QList<QQmlImports::
                 resultList.append(ref);
             }
         }
+
+        if (QQmlTypeModule *module = QQmlMetaType::typeModule(import->uri, import->majversion)) {
+            module->walkCompositeSingletons([&resultList, &set](const QQmlType &singleton) {
+                QQmlImports::CompositeSingletonReference ref;
+                ref.typeName = singleton.elementName();
+                ref.prefix = set.prefix;
+                ref.majorVersion = singleton.majorVersion();
+                ref.minorVersion = singleton.minorVersion();
+                resultList.append(ref);
+            });
+        }
     }
 }
 
@@ -494,6 +433,20 @@ QList<QQmlImports::CompositeSingletonReference> QQmlImports::resolvedCompositeSi
         findCompositeSingletons(set, compositeSingletons, baseUrl());
     }
 
+    std::stable_sort(compositeSingletons.begin(), compositeSingletons.end(),
+                     [](const QQmlImports::CompositeSingletonReference &lhs,
+                        const QQmlImports::CompositeSingletonReference &rhs) {
+        if (lhs.prefix != rhs.prefix)
+            return lhs.prefix < rhs.prefix;
+
+        if (lhs.typeName != rhs.typeName)
+            return lhs.typeName < rhs.typeName;
+
+        return lhs.majorVersion != rhs.majorVersion
+            ? lhs.majorVersion < rhs.majorVersion
+            : lhs.minorVersion < rhs.minorVersion;
+    });
+
     return compositeSingletons;
 }
 
@@ -619,8 +572,10 @@ QString QQmlImports::versionString(int vmaj, int vmin, ImportVersion version)
   \sa addFileImport(), addLibraryImport
 */
 bool QQmlImports::resolveType(const QHashedStringRef &type,
-                              QQmlType** type_return, int *vmaj, int *vmin,
-                              QQmlImportNamespace** ns_return, QList<QQmlError> *errors) const
+                              QQmlType *type_return, int *vmaj, int *vmin,
+                              QQmlImportNamespace** ns_return, QList<QQmlError> *errors,
+                              QQmlType::RegistrationType registrationType,
+                              QQmlImport::RecursionRestriction recursionRestriction) const
 {
     QQmlImportNamespace* ns = d->findQualifiedNamespace(type);
     if (ns) {
@@ -629,17 +584,20 @@ bool QQmlImports::resolveType(const QHashedStringRef &type,
         return true;
     }
     if (type_return) {
-        if (d->resolveType(type,vmaj,vmin,type_return, errors)) {
+        if (d->resolveType(type, vmaj, vmin, type_return, errors, registrationType,
+                           recursionRestriction)) {
             if (qmlImportTrace()) {
 #define RESOLVE_TYPE_DEBUG qDebug().nospace() << "QQmlImports(" << qPrintable(baseUrl().toString()) \
                                               << ')' << "::resolveType: " << type.toString() << " => "
 
-                if (type_return && *type_return && (*type_return)->isCompositeSingleton())
-                    RESOLVE_TYPE_DEBUG << (*type_return)->typeName() << ' ' << (*type_return)->sourceUrl() << " TYPE/URL-SINGLETON";
-                else if (type_return && *type_return && (*type_return)->isComposite())
-                    RESOLVE_TYPE_DEBUG << (*type_return)->typeName() << ' ' << (*type_return)->sourceUrl() << " TYPE/URL";
-                else if (type_return && *type_return)
-                    RESOLVE_TYPE_DEBUG << (*type_return)->typeName() << " TYPE";
+                if (type_return && type_return->isValid()) {
+                    if (type_return->isCompositeSingleton())
+                        RESOLVE_TYPE_DEBUG << type_return->typeName() << ' ' << type_return->sourceUrl() << " TYPE/URL-SINGLETON";
+                    else if (type_return->isComposite())
+                        RESOLVE_TYPE_DEBUG << type_return->typeName() << ' ' << type_return->sourceUrl() << " TYPE/URL";
+                    else
+                        RESOLVE_TYPE_DEBUG << type_return->typeName() << " TYPE";
+                }
 #undef RESOLVE_TYPE_DEBUG
             }
             return true;
@@ -648,14 +606,15 @@ bool QQmlImports::resolveType(const QHashedStringRef &type,
     return false;
 }
 
-bool QQmlImportInstance::setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoaderQmldirContent *qmldir, QQmlImportNamespace *nameSpace, QList<QQmlError> *errors)
+bool QQmlImportInstance::setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoaderQmldirContent &qmldir, QQmlImportNamespace *nameSpace, QList<QQmlError> *errors)
 {
     Q_ASSERT(resolvedUrl.endsWith(Slash));
     url = resolvedUrl;
+    localDirectoryPath = QQmlFile::urlToLocalFileOrQrc(url);
 
-    qmlDirComponents = qmldir->components();
+    qmlDirComponents = qmldir.components();
 
-    const QQmlDirScripts &scripts = qmldir->scripts();
+    const QQmlDirScripts &scripts = qmldir.scripts();
     if (!scripts.isEmpty()) {
         // Verify that we haven't imported these scripts already
         for (QList<QQmlImportInstance *>::const_iterator it = nameSpace->imports.constBegin();
@@ -704,21 +663,27 @@ QQmlDirScripts QQmlImportInstance::getVersionedScripts(const QQmlDirScripts &qml
 
   If the return pointer is 0, the corresponding search is not done.
 */
-bool QQmlImports::resolveType(QQmlImportNamespace* ns, const QHashedStringRef &type,
-                              QQmlType** type_return, int *vmaj, int *vmin) const
+bool QQmlImports::resolveType(QQmlImportNamespace *ns, const QHashedStringRef &type,
+                              QQmlType *type_return, int *vmaj, int *vmin,
+                              QQmlType::RegistrationType registrationType) const
 {
-    return ns->resolveType(d->typeLoader,type,vmaj,vmin,type_return);
+    return ns->resolveType(d->typeLoader, type, vmaj, vmin, type_return, nullptr, nullptr, registrationType);
 }
 
-bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader,
-                                              const QHashedStringRef& type, int *vmajor, int *vminor,
-                                              QQmlType** type_return, QString *base, bool *typeRecursionDetected) const
+bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef& type,
+                                     int *vmajor, int *vminor, QQmlType *type_return, QString *base,
+                                     bool *typeRecursionDetected,
+                                     QQmlType::RegistrationType registrationType,
+                                     QQmlImport::RecursionRestriction recursionRestriction,
+                                     QList<QQmlError> *errors) const
 {
     if (majversion >= 0 && minversion >= 0) {
-        QQmlType *t = QQmlMetaType::qmlType(type, uri, majversion, minversion);
-        if (t) {
-            if (vmajor) *vmajor = majversion;
-            if (vminor) *vminor = minversion;
+        QQmlType t = QQmlMetaType::qmlType(type, uri, majversion, minversion);
+        if (t.isValid()) {
+            if (vmajor)
+                *vmajor = majversion;
+            if (vminor)
+                *vminor = minversion;
             if (type_return)
                 *type_return = t;
             return true;
@@ -733,9 +698,22 @@ bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader,
         QQmlDirComponents::ConstIterator candidate = end;
         for ( ; it != end && it.key() == typeStr; ++it) {
             const QQmlDirParser::Component &c = *it;
+            switch (registrationType) {
+            case QQmlType::AnyRegistrationType:
+                break;
+            case QQmlType::CompositeSingletonType:
+                if (!c.singleton)
+                    continue;
+                break;
+            default:
+                if (c.singleton)
+                    continue;
+                break;
+            }
 
             // importing version -1 means import ALL versions
             if ((majversion == -1) ||
+                (implicitlyImported && c.internal) || // allow the implicit import of internal types
                 (c.majorVersion == majversion && c.minorVersion <= minversion)) {
                 // Is this better than the previous candidate?
                 if ((candidate == end) ||
@@ -747,7 +725,7 @@ bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader,
                             if (resolveLocalUrl(*base, c.fileName) != componentUrl)
                                 continue; // failed attempt to access an internal type
                         }
-                        if (*base == componentUrl) {
+                        if (recursionRestriction == QQmlImport::PreventRecursion && *base == componentUrl) {
                             if (typeRecursionDetected)
                                 *typeRecursionDetected = true;
                             continue; // no recursion
@@ -764,40 +742,57 @@ bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader,
         if (candidate != end) {
             if (!base) // ensure we have a componentUrl
                 componentUrl = resolveLocalUrl(QString(url + candidate->typeName + dotqml_string), candidate->fileName);
-            int major = vmajor ? *vmajor : -1;
-            int minor = vminor ? *vminor : -1;
-            QQmlType *returnType = fetchOrCreateTypeForUrl(componentUrl, type, isCompositeSingleton, 0,
-                                                 major, minor);
+            QQmlType returnType = QQmlMetaType::typeForUrl(componentUrl, type, isCompositeSingleton,
+                                                           nullptr, candidate->majorVersion,
+                                                           candidate->minorVersion);
+            if (vmajor)
+                *vmajor = candidate->majorVersion;
+            if (vminor)
+                *vminor = candidate->minorVersion;
             if (type_return)
                 *type_return = returnType;
-            return returnType != 0;
+            return returnType.isValid();
         }
-    } else if (!isLibrary) {
+    } else if (!isLibrary && !localDirectoryPath.isEmpty()) {
         QString qmlUrl;
         bool exists = false;
 
         const QString urlsToTry[2] = {
-            url + QString::fromRawData(type.constData(), type.length()) + dotqml_string, // Type -> Type.qml
-            url + QString::fromRawData(type.constData(), type.length()) + dotuidotqml_string // Type -> Type.ui.qml
+            typeStr + dotqml_string, // Type -> Type.qml
+            typeStr + dotuidotqml_string // Type -> Type.ui.qml
         };
         for (uint i = 0; i < sizeof(urlsToTry) / sizeof(urlsToTry[0]); ++i) {
-            const QString url = urlsToTry[i];
-            exists = !typeLoader->absoluteFilePath(QQmlFile::urlToLocalFileOrQrc(url)).isEmpty();
+            exists = typeLoader->fileExists(localDirectoryPath, urlsToTry[i]);
             if (exists) {
-                qmlUrl = url;
+#if defined(Q_OS_MACOS) || defined(Q_OS_WIN)
+                // don't let function.qml confuse the use of "new Function(...)" for example.
+                if (!QQml_isFileCaseCorrect(localDirectoryPath + urlsToTry[i])) {
+                    exists = false;
+                    if (errors) {
+                        QQmlError caseError;
+                        caseError.setDescription(QLatin1String("File name case mismatch"));
+                        errors->append(caseError);
+                    }
+                    break;
+                }
+#else
+                Q_UNUSED(errors);
+#endif
+                qmlUrl = url + urlsToTry[i];
                 break;
             }
         }
 
         if (exists) {
-            if (base && (*base == qmlUrl)) { // no recursion
+            if (recursionRestriction == QQmlImport::PreventRecursion && base && (*base == qmlUrl)) { // no recursion
                 if (typeRecursionDetected)
                     *typeRecursionDetected = true;
             } else {
-                QQmlType *returnType = fetchOrCreateTypeForUrl(qmlUrl, type, false, 0);
+                QQmlType returnType = QQmlMetaType::typeForUrl(
+                        qmlUrl, type, registrationType == QQmlType::CompositeSingletonType, nullptr);
                 if (type_return)
                     *type_return = returnType;
-                return returnType != 0;
+                return returnType.isValid();
             }
         }
     }
@@ -806,9 +801,11 @@ bool QQmlImportInstance::resolveType(QQmlTypeLoader *typeLoader,
 }
 
 bool QQmlImportsPrivate::resolveType(const QHashedStringRef& type, int *vmajor, int *vminor,
-                                     QQmlType** type_return, QList<QQmlError> *errors)
+                                     QQmlType *type_return, QList<QQmlError> *errors,
+                                     QQmlType::RegistrationType registrationType,
+                                     QQmlImport::RecursionRestriction recursionRestriction)
 {
-    QQmlImportNamespace *s = 0;
+    QQmlImportNamespace *s = nullptr;
     int dot = type.indexOf(Dot);
     if (dot >= 0) {
         QHashedStringRef namespaceName(type.constData(), dot);
@@ -835,12 +832,16 @@ bool QQmlImportsPrivate::resolveType(const QHashedStringRef& type, int *vmajor,
     }
     QHashedStringRef unqualifiedtype = dot < 0 ? type : QHashedStringRef(type.constData()+dot+1, type.length()-dot-1);
     if (s) {
-        if (s->resolveType(typeLoader,unqualifiedtype,vmajor,vminor,type_return, &base, errors))
+        if (s->resolveType(typeLoader, unqualifiedtype, vmajor, vminor, type_return, &base, errors,
+                           registrationType, recursionRestriction))
             return true;
         if (s->imports.count() == 1 && !s->imports.at(0)->isLibrary && type_return && s != &unqualifiedset) {
             // qualified, and only 1 url
-            *type_return = fetchOrCreateTypeForUrl(resolveLocalUrl(s->imports.at(0)->url, unqualifiedtype.toString() + QLatin1String(".qml")), type, false, errors);
-            return (*type_return != 0);
+            *type_return = QQmlMetaType::typeForUrl(
+                    resolveLocalUrl(s->imports.at(0)->url,
+                                    unqualifiedtype.toString() + QLatin1String(".qml")),
+                    type, false, errors);
+            return type_return->isValid();
         }
     }
 
@@ -857,19 +858,22 @@ QQmlImportInstance *QQmlImportNamespace::findImport(const QString &uri) const
 }
 
 bool QQmlImportNamespace::resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef &type,
-                                      int *vmajor, int *vminor, QQmlType** type_return,
-                                      QString *base, QList<QQmlError> *errors)
+                                      int *vmajor, int *vminor, QQmlType *type_return,
+                                      QString *base, QList<QQmlError> *errors,
+                                      QQmlType::RegistrationType registrationType,
+                                      QQmlImport::RecursionRestriction recursionRestriction)
 {
     bool typeRecursionDetected = false;
     for (int i=0; i<imports.count(); ++i) {
         const QQmlImportInstance *import = imports.at(i);
-        if (import->resolveType(typeLoader, type, vmajor, vminor, type_return,
-                               base, &typeRecursionDetected)) {
+        if (import->resolveType(typeLoader, type, vmajor, vminor, type_return, base,
+                                &typeRecursionDetected, registrationType, recursionRestriction, errors)) {
             if (qmlCheckTypes()) {
                 // check for type clashes
                 for (int j = i+1; j<imports.count(); ++j) {
                     const QQmlImportInstance *import2 = imports.at(j);
-                    if (import2->resolveType(typeLoader, type, vmajor, vminor, 0, base)) {
+                    if (import2->resolveType(typeLoader, type, vmajor, vminor, nullptr, base,
+                                             nullptr, registrationType)) {
                         if (errors) {
                             QString u1 = import->url;
                             QString u2 = import2->url;
@@ -935,10 +939,10 @@ QQmlImportNamespace *QQmlImportsPrivate::findQualifiedNamespace(const QHashedStr
         if (prefix == ns->prefix)
             return ns;
     }
-    return 0;
+    return nullptr;
 }
 
-/*!
+/*
     Returns the list of possible versioned URI combinations. For example, if \a uri is
     QtQml.Models, \a vmaj is 2, and \a vmin is 0, this method returns the following:
     [QtQml.Models.2.0, QtQml.2.0.Models, QtQml.Models.2, QtQml.2.Models, QtQml.Models]
@@ -966,15 +970,15 @@ static QVector<QStaticPlugin> makePlugins()
     // the list the first time called to only contain QML plugins:
     const auto staticPlugins = QPluginLoader::staticPlugins();
     for (const QStaticPlugin &plugin : staticPlugins) {
-        if (plugin.metaData().value(QLatin1String("IID")).toString()
-                == QLatin1String(QQmlExtensionInterface_iid)) {
+        const QString iid = plugin.metaData().value(QLatin1String("IID")).toString();
+        if (iid == QLatin1String(QQmlExtensionInterface_iid) || iid == QLatin1String(QQmlExtensionInterface_iid_old)) {
             plugins.append(plugin);
         }
     }
     return plugins;
 }
 
-/*!
+/*
     Get all static plugins that are QML plugins and has a meta data URI that matches with one of
     \a versionUris, which is a list of all possible versioned URI combinations - see versionUriList()
     above.
@@ -1016,7 +1020,7 @@ static inline QString msgCannotLoadPlugin(const QString &uri, const QString &why
 }
 #endif
 
-/*!
+/*
 Import an extension defined by a qmldir file.
 
 \a qmldirFilePath is a raw file path.
@@ -1025,26 +1029,26 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
                                          const QString &uri,
                                          int vmaj, int vmin,
                                          QQmlImportDatabase *database,
-                                         const QQmlTypeLoaderQmldirContent *qmldir,
+                                         const QQmlTypeLoaderQmldirContent &qmldir,
                                          QList<QQmlError> *errors)
 {
-    Q_ASSERT(qmldir);
+    Q_ASSERT(qmldir.hasContent());
 
     if (qmlImportTrace())
         qDebug().nospace() << "QQmlImports(" << qPrintable(base) << ")::importExtension: "
                            << "loaded " << qmldirFilePath;
 
-    if (designerSupportRequired && !qmldir->designerSupported()) {
+    if (designerSupportRequired && !qmldir.designerSupported()) {
         if (errors) {
             QQmlError error;
-            error.setDescription(QQmlImportDatabase::tr("module does not support the designer \"%1\"").arg(qmldir->typeNamespace()));
+            error.setDescription(QQmlImportDatabase::tr("module does not support the designer \"%1\"").arg(qmldir.typeNamespace()));
             error.setUrl(QUrl::fromLocalFile(qmldirFilePath));
             errors->prepend(error);
         }
         return false;
     }
 
-    int qmldirPluginCount = qmldir->plugins().count();
+    int qmldirPluginCount = qmldir.plugins().count();
     if (qmldirPluginCount == 0)
         return true;
 
@@ -1055,7 +1059,7 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
         // listed plugin inside qmldir. And for this reason, mixing dynamic and static plugins inside a
         // single module is not recommended.
 
-        QString typeNamespace = qmldir->typeNamespace();
+        QString typeNamespace = qmldir.typeNamespace();
         QString qmldirPath = qmldirFilePath;
         int slash = qmldirPath.lastIndexOf(Slash);
         if (slash > 0)
@@ -1065,7 +1069,7 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
         int staticPluginsFound = 0;
 
 #if defined(QT_SHARED)
-        const auto qmldirPlugins = qmldir->plugins();
+        const auto qmldirPlugins = qmldir.plugins();
         for (const QQmlDirParser::Plugin &plugin : qmldirPlugins) {
             QString resolvedFilePath = database->resolvePlugin(typeLoader, qmldirPath, plugin.path, plugin.name);
             if (!resolvedFilePath.isEmpty()) {
@@ -1131,7 +1135,7 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
                 if (qmldirPluginCount > 1 && staticPluginsFound > 0)
                     error.setDescription(QQmlImportDatabase::tr("could not resolve all plugins for module \"%1\"").arg(uri));
                 else
-                    error.setDescription(QQmlImportDatabase::tr("module \"%1\" plugin \"%2\" not found").arg(uri).arg(qmldir->plugins()[dynamicPluginsFound].name));
+                    error.setDescription(QQmlImportDatabase::tr("module \"%1\" plugin \"%2\" not found").arg(uri).arg(qmldir.plugins()[dynamicPluginsFound].name));
                 error.setUrl(QUrl::fromLocalFile(qmldirFilePath));
                 errors->prepend(error);
             }
@@ -1144,17 +1148,17 @@ bool QQmlImportsPrivate::importExtension(const QString &qmldirFilePath,
 }
 
 bool QQmlImportsPrivate::getQmldirContent(const QString &qmldirIdentifier, const QString &uri,
-                                          const QQmlTypeLoaderQmldirContent **qmldir, QList<QQmlError> *errors)
+                                          QQmlTypeLoaderQmldirContent *qmldir, QList<QQmlError> *errors)
 {
     Q_ASSERT(errors);
     Q_ASSERT(qmldir);
 
     *qmldir = typeLoader->qmldirContent(qmldirIdentifier);
-    if (*qmldir) {
+    if ((*qmldir).hasContent()) {
         // Ensure that parsing was successful
-        if ((*qmldir)->hasError()) {
+        if ((*qmldir).hasError()) {
             QUrl url = QUrl::fromLocalFile(qmldirIdentifier);
-            const QList<QQmlError> qmldirErrors = (*qmldir)->errors(uri);
+            const QList<QQmlError> qmldirErrors = (*qmldir).errors(uri);
             for (int i = 0; i < qmldirErrors.size(); ++i) {
                 QQmlError error = qmldirErrors.at(i);
                 error.setUrl(url);
@@ -1188,10 +1192,12 @@ QString QQmlImportsPrivate::resolvedUri(const QString &dir_arg, QQmlImportDataba
     stableRelativePath.replace(Backslash, Slash);
 
     // remove optional versioning in dot notation from uri
-    int lastSlash = stableRelativePath.lastIndexOf(Slash);
-    if (lastSlash >= 0) {
-        int versionDot = stableRelativePath.indexOf(Dot, lastSlash);
-        if (versionDot >= 0)
+    int versionDot = stableRelativePath.lastIndexOf(Dot);
+    if (versionDot >= 0) {
+        int nextSlash = stableRelativePath.indexOf(Slash, versionDot);
+        if (nextSlash >= 0)
+            stableRelativePath.remove(versionDot, nextSlash - versionDot);
+        else
             stableRelativePath = stableRelativePath.left(versionDot);
     }
 
@@ -1212,7 +1218,7 @@ bool QQmlImportsPrivate::locateQmldir(const QString &uri, int vmaj, int vmin, QQ
 
     // Check cache first
 
-    QQmlImportDatabase::QmldirCache *cacheHead = 0;
+    QQmlImportDatabase::QmldirCache *cacheHead = nullptr;
     {
     QQmlImportDatabase::QmldirCache **cachePtr = database->qmldirCache.value(uri);
     if (cachePtr) {
@@ -1231,11 +1237,20 @@ bool QQmlImportsPrivate::locateQmldir(const QString &uri, int vmaj, int vmin, QQ
 
     QQmlTypeLoader &typeLoader = QQmlEnginePrivate::get(database->engine)->typeLoader;
 
-    QStringList localImportPaths = database->importPathList(QQmlImportDatabase::Local);
+    // Interceptor might redirect remote files to local ones.
+    QQmlAbstractUrlInterceptor *interceptor = typeLoader.engine()->urlInterceptor();
+    QStringList localImportPaths = database->importPathList(
+                interceptor ? QQmlImportDatabase::LocalOrRemote : QQmlImportDatabase::Local);
 
     // Search local import paths for a matching version
     const QStringList qmlDirPaths = QQmlImports::completeQmldirPaths(uri, localImportPaths, vmaj, vmin);
-    for (const QString &qmldirPath : qmlDirPaths) {
+    for (QString qmldirPath : qmlDirPaths) {
+        if (interceptor) {
+            qmldirPath = QQmlFile::urlToLocalFileOrQrc(
+                        interceptor->intercept(QQmlImports::urlFromLocalFileOrQrcOrUrl(qmldirPath),
+                                               QQmlAbstractUrlInterceptor::QmldirFile));
+        }
+
         QString absoluteFilePath = typeLoader.absoluteFilePath(qmldirPath);
         if (!absoluteFilePath.isEmpty()) {
             QString url;
@@ -1269,14 +1284,14 @@ bool QQmlImportsPrivate::locateQmldir(const QString &uri, int vmaj, int vmin, QQ
     return false;
 }
 
-bool QQmlImportsPrivate::validateQmldirVersion(const QQmlTypeLoaderQmldirContent *qmldir, const QString &uri, int vmaj, int vmin,
+bool QQmlImportsPrivate::validateQmldirVersion(const QQmlTypeLoaderQmldirContent &qmldir, const QString &uri, int vmaj, int vmin,
                                                QList<QQmlError> *errors)
 {
     int lowest_min = INT_MAX;
     int highest_min = INT_MIN;
 
     typedef QQmlDirComponents::const_iterator ConstIterator;
-    const QQmlDirComponents &components = qmldir->components();
+    const QQmlDirComponents &components = qmldir.components();
 
     ConstIterator cend = components.constEnd();
     for (ConstIterator cit = components.constBegin(); cit != cend; ++cit) {
@@ -1300,7 +1315,7 @@ bool QQmlImportsPrivate::validateQmldirVersion(const QQmlTypeLoaderQmldirContent
     }
 
     typedef QList<QQmlDirParser::Script>::const_iterator SConstIterator;
-    const QQmlDirScripts &scripts = qmldir->scripts();
+    const QQmlDirScripts &scripts = qmldir.scripts();
 
     SConstIterator send = scripts.constEnd();
     for (SConstIterator sit = scripts.constBegin(); sit != send; ++sit) {
@@ -1335,7 +1350,7 @@ bool QQmlImportsPrivate::validateQmldirVersion(const QQmlTypeLoaderQmldirContent
 
 QQmlImportNamespace *QQmlImportsPrivate::importNamespace(const QString &prefix) const
 {
-    QQmlImportNamespace *nameSpace = 0;
+    QQmlImportNamespace *nameSpace = nullptr;
 
     if (prefix.isEmpty()) {
         nameSpace = &unqualifiedset;
@@ -1365,6 +1380,7 @@ QQmlImportInstance *QQmlImportsPrivate::addImportToNamespace(QQmlImportNamespace
     QQmlImportInstance *import = new QQmlImportInstance;
     import->uri = uri;
     import->url = url;
+    import->localDirectoryPath = QQmlFile::urlToLocalFileOrQrc(url);
     import->majversion = vmaj;
     import->minversion = vmin;
     import->isLibrary = (type == QV4::CompiledData::Import::ImportLibrary);
@@ -1392,14 +1408,14 @@ bool QQmlImportsPrivate::addLibraryImport(const QString& uri, const QString &pre
     Q_ASSERT(inserted);
 
     if (!incomplete) {
-        const QQmlTypeLoaderQmldirContent *qmldir = 0;
+        QQmlTypeLoaderQmldirContent qmldir;
 
         if (!qmldirIdentifier.isEmpty()) {
             if (!getQmldirContent(qmldirIdentifier, uri, &qmldir, errors))
                 return false;
 
-            if (qmldir) {
-                if (!importExtension(qmldir->pluginLocation(), uri, vmaj, vmin, database, qmldir, errors))
+            if (qmldir.hasContent()) {
+                if (!importExtension(qmldir.pluginLocation(), uri, vmaj, vmin, database, qmldir, errors))
                     return false;
 
                 if (!inserted->setQmldirContent(qmldirUrl, qmldir, nameSpace, errors))
@@ -1417,7 +1433,7 @@ bool QQmlImportsPrivate::addLibraryImport(const QString& uri, const QString &pre
                     error.setDescription(QQmlImportDatabase::tr("module \"%1\" is not installed").arg(uri));
                 errors->prepend(error);
                 return false;
-            } else if ((vmaj >= 0) && (vmin >= 0) && qmldir) {
+            } else if ((vmaj >= 0) && (vmin >= 0) && qmldir.hasContent()) {
                 // Verify that the qmldir content is valid for this version
                 if (!validateQmldirVersion(qmldir, uri, vmaj, vmin, errors))
                     return false;
@@ -1444,6 +1460,10 @@ bool QQmlImportsPrivate::addFileImport(const QString& uri, const QString &prefix
     QString qmldirUrl = resolveLocalUrl(base, importUri + (importUri.endsWith(Slash)
                                                            ? String_qmldir
                                                            : Slash_qmldir));
+    if (QQmlAbstractUrlInterceptor *interceptor = typeLoader->engine()->urlInterceptor()) {
+        qmldirUrl = interceptor->intercept(QUrl(qmldirUrl),
+                                           QQmlAbstractUrlInterceptor::QmldirFile).toString();
+    }
     QString qmldirIdentifier;
 
     if (QQmlFile::isLocalFile(qmldirUrl)) {
@@ -1489,16 +1509,30 @@ bool QQmlImportsPrivate::addFileImport(const QString& uri, const QString &prefix
     if (!url.endsWith(Slash) && !url.endsWith(Backslash))
         url += Slash;
 
+    // ### For enum support, we are now adding the implicit import always (and earlier). Bail early
+    //     if the implicit import has already been explicitly added, otherwise we can run into issues
+    //     with duplicate imports. However remember that we attempted to add this as implicit import, to
+    //     allow for the loading of internal types.
+    if (isImplicitImport) {
+        for (QList<QQmlImportInstance *>::const_iterator it = nameSpace->imports.constBegin();
+             it != nameSpace->imports.constEnd(); ++it) {
+            if ((*it)->url == url) {
+                (*it)->implicitlyImported = true;
+                return true;
+            }
+        }
+    }
+
     QQmlImportInstance *inserted = addImportToNamespace(nameSpace, importUri, url, vmaj, vmin, QV4::CompiledData::Import::ImportFile, errors, isImplicitImport);
     Q_ASSERT(inserted);
 
     if (!incomplete && !qmldirIdentifier.isEmpty()) {
-        const QQmlTypeLoaderQmldirContent *qmldir = 0;
+        QQmlTypeLoaderQmldirContent qmldir;
         if (!getQmldirContent(qmldirIdentifier, importUri, &qmldir, errors))
             return false;
 
-        if (qmldir) {
-            if (!importExtension(qmldir->pluginLocation(), importUri, vmaj, vmin, database, qmldir, errors))
+        if (qmldir.hasContent()) {
+            if (!importExtension(qmldir.pluginLocation(), importUri, vmaj, vmin, database, qmldir, errors))
                 return false;
 
             if (!inserted->setQmldirContent(url, qmldir, nameSpace, errors))
@@ -1517,20 +1551,20 @@ bool QQmlImportsPrivate::updateQmldirContent(const QString &uri, const QString &
     Q_ASSERT(nameSpace);
 
     if (QQmlImportInstance *import = nameSpace->findImport(uri)) {
-        const QQmlTypeLoaderQmldirContent *qmldir = 0;
+        QQmlTypeLoaderQmldirContent qmldir;
         if (!getQmldirContent(qmldirIdentifier, uri, &qmldir, errors))
             return false;
 
-        if (qmldir) {
+        if (qmldir.hasContent()) {
             int vmaj = import->majversion;
             int vmin = import->minversion;
-            if (!importExtension(qmldir->pluginLocation(), uri, vmaj, vmin, database, qmldir, errors))
+            if (!importExtension(qmldir.pluginLocation(), uri, vmaj, vmin, database, qmldir, errors))
                 return false;
 
             if (import->setQmldirContent(qmldirUrl, qmldir, nameSpace, errors)) {
                 if (import->qmlDirComponents.isEmpty() && import->qmlDirScripts.isEmpty()) {
-                    // The implicit import qmldir can be empty
-                    if (uri != QLatin1String(".")) {
+                    // The implicit import qmldir can be empty, and plugins have no extra versions
+                    if (uri != QLatin1String(".") && !QQmlMetaType::isModule(uri, vmaj, vmin)) {
                         QQmlError error;
                         if (QQmlMetaType::isAnyModule(uri))
                             error.setDescription(QQmlImportDatabase::tr("module \"%1\" version %2.%3 is not installed").arg(uri).arg(vmaj).arg(vmin));
@@ -1658,6 +1692,16 @@ bool QQmlImports::isLocal(const QUrl &url)
     return !QQmlFile::urlToLocalFileOrQrc(url).isEmpty();
 }
 
+QUrl QQmlImports::urlFromLocalFileOrQrcOrUrl(const QString &file)
+{
+    QUrl url(QLatin1String(file.at(0) == Colon ? "qrc" : "") + file);
+
+    // We don't support single character schemes as those conflict with windows drive letters.
+    if (url.scheme().length() < 2)
+        return QUrl::fromLocalFile(file);
+    return url;
+}
+
 void QQmlImports::setDesignerSupportRequired(bool b)
 {
     designerSupportRequired = b;
@@ -1675,18 +1719,18 @@ QQmlImportDatabase::QQmlImportDatabase(QQmlEngine *e)
     filePluginPath << QLatin1String(".");
     // Search order is applicationDirPath(), qrc:/qt-project.org/imports, $QML2_IMPORT_PATH, QLibraryInfo::Qml2ImportsPath
 
-    QString installImportsPath =  QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath);
+    QString installImportsPath = QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath);
     addImportPath(installImportsPath);
 
     // env import paths
     if (Q_UNLIKELY(!qEnvironmentVariableIsEmpty("QML2_IMPORT_PATH"))) {
-        const QByteArray envImportPath = qgetenv("QML2_IMPORT_PATH");
+        const QString envImportPath = qEnvironmentVariable("QML2_IMPORT_PATH");
 #if defined(Q_OS_WIN)
         QLatin1Char pathSep(';');
 #else
         QLatin1Char pathSep(':');
 #endif
-        QStringList paths = QString::fromLatin1(envImportPath).split(pathSep, QString::SkipEmptyParts);
+        QStringList paths = envImportPath.split(pathSep, QString::SkipEmptyParts);
         for (int ii = paths.count() - 1; ii >= 0; --ii)
             addImportPath(paths.at(ii));
     }
@@ -1914,79 +1958,7 @@ bool QQmlImportDatabase::registerPluginTypes(QObject *instance, const QString &b
 {
     if (qmlImportTrace())
         qDebug().nospace() << "QQmlImportDatabase::registerPluginTypes: " << uri << " from " << basePath;
-
-    QQmlTypesExtensionInterface *iface = qobject_cast<QQmlTypesExtensionInterface *>(instance);
-    if (!iface) {
-        if (errors) {
-            QQmlError error;
-            error.setDescription(tr("Module loaded for URI '%1' does not implement QQmlTypesExtensionInterface").arg(typeNamespace));
-            errors->prepend(error);
-        }
-        return false;
-    }
-
-    const QByteArray bytes = uri.toUtf8();
-    const char *moduleId = bytes.constData();
-
-    QStringList registrationFailures;
-    {
-        // Create a scope for QWriteLocker to keep it as narrow as possible, and
-        // to ensure that we release it before the call to initalizeEngine below
-        QMutexLocker lock(QQmlMetaType::typeRegistrationLock());
-
-        if (!typeNamespace.isEmpty()) {
-            // This is an 'identified' module
-            if (typeNamespace != uri) {
-                // The namespace for type registrations must match the URI for locating the module
-                if (errors) {
-                    QQmlError error;
-                    error.setDescription(tr("Module namespace '%1' does not match import URI '%2'").arg(typeNamespace).arg(uri));
-                    errors->prepend(error);
-                }
-                return false;
-            }
-
-            if (QQmlMetaType::namespaceContainsRegistrations(typeNamespace, vmaj)) {
-                // Other modules have already installed to this namespace
-                if (errors) {
-                    QQmlError error;
-                    error.setDescription(tr("Namespace '%1' has already been used for type registration").arg(typeNamespace));
-                    errors->prepend(error);
-                }
-                return false;
-            } else {
-                QQmlMetaType::protectNamespace(typeNamespace);
-            }
-        } else {
-            // This is not an identified module - provide a warning
-            qWarning().nospace() << qPrintable(tr("Module '%1' does not contain a module identifier directive - it cannot be protected from external registrations.").arg(uri));
-        }
-
-        QQmlMetaType::setTypeRegistrationNamespace(typeNamespace);
-
-        if (QQmlExtensionPlugin *plugin = qobject_cast<QQmlExtensionPlugin *>(instance)) {
-            // basepath should point to the directory of the module, not the plugin file itself:
-            QQmlExtensionPluginPrivate::get(plugin)->baseUrl = QUrl::fromLocalFile(basePath);
-        }
-
-        iface->registerTypes(moduleId);
-
-        registrationFailures = QQmlMetaType::typeRegistrationFailures();
-        QQmlMetaType::setTypeRegistrationNamespace(QString());
-    } // QWriteLocker lock(QQmlMetaType::typeRegistrationLock())
-
-    if (!registrationFailures.isEmpty()) {
-        if (errors) {
-            for (const QString &failure : qAsConst(registrationFailures)) {
-                QQmlError error;
-                error.setDescription(failure);
-                errors->prepend(error);
-            }
-        }
-        return false;
-    }
-
-    return true;
+    return QQmlMetaType::registerPluginTypes(instance, basePath, uri, typeNamespace, vmaj, errors);
 }
 
 /*!
@@ -1998,29 +1970,38 @@ bool QQmlImportDatabase::importStaticPlugin(QObject *instance, const QString &ba
     // Dynamic plugins are differentiated by their filepath. For static plugins we
     // don't have that information so we use their address as key instead.
     const QString uniquePluginID = QString::asprintf("%p", instance);
-    StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
-    QMutexLocker lock(&plugins->mutex);
+    {
+        StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
+        QMutexLocker lock(&plugins->mutex);
 
-    // Plugin types are global across all engines and should only be
-    // registered once. But each engine still needs to be initialized.
-    bool typesRegistered = plugins->contains(uniquePluginID);
-    bool engineInitialized = initializedPlugins.contains(uniquePluginID);
+        // Plugin types are global across all engines and should only be
+        // registered once. But each engine still needs to be initialized.
+        bool typesRegistered = plugins->contains(uniquePluginID);
 
-    if (typesRegistered) {
-        Q_ASSERT_X(plugins->value(uniquePluginID).uri == uri,
-                   "QQmlImportDatabase::importStaticPlugin",
-                   "Internal error: Static plugin imported previously with different uri");
-    } else {
-        RegisteredPlugin plugin;
-        plugin.uri = uri;
-        plugin.loader = 0;
-        plugins->insert(uniquePluginID, plugin);
+        if (typesRegistered) {
+            Q_ASSERT_X(plugins->value(uniquePluginID).uri == uri,
+                       "QQmlImportDatabase::importStaticPlugin",
+                       "Internal error: Static plugin imported previously with different uri");
+        } else {
+            RegisteredPlugin plugin;
+            plugin.uri = uri;
+            plugin.loader = nullptr;
+            plugins->insert(uniquePluginID, plugin);
 
-        if (!registerPluginTypes(instance, basePath, uri, typeNamespace, vmaj, errors))
-            return false;
+            if (!registerPluginTypes(instance, basePath, uri, typeNamespace, vmaj, errors))
+                return false;
+        }
+
+        // Release the lock on plugins early as we're done with the global part. Releasing the lock
+        // also allows other QML loader threads to acquire the lock while this thread is blocking
+        // in the initializeEngine call to the gui thread (which in turn may be busy waiting for
+        // other QML loader threads and thus not process the initializeEngine call).
     }
 
-    if (!engineInitialized) {
+    // The plugin's per-engine initialization does not need lock protection, as this function is
+    // only called from the engine specific loader thread and importDynamicPlugin as well as
+    // importStaticPlugin are the only places of access.
+    if (!initializedPlugins.contains(uniquePluginID)) {
         initializedPlugins.insert(uniquePluginID);
 
         if (QQmlExtensionInterface *eiface = qobject_cast<QQmlExtensionInterface *>(instance)) {
@@ -2042,68 +2023,77 @@ bool QQmlImportDatabase::importDynamicPlugin(const QString &filePath, const QStr
     QFileInfo fileInfo(filePath);
     const QString absoluteFilePath = fileInfo.absoluteFilePath();
 
+    QObject *instance = nullptr;
     bool engineInitialized = initializedPlugins.contains(absoluteFilePath);
-    StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
-    QMutexLocker lock(&plugins->mutex);
-    bool typesRegistered = plugins->contains(absoluteFilePath);
-
-    if (typesRegistered) {
-        Q_ASSERT_X(plugins->value(absoluteFilePath).uri == uri,
-                   "QQmlImportDatabase::importDynamicPlugin",
-                   "Internal error: Plugin imported previously with different uri");
-    }
-
-    if (!engineInitialized || !typesRegistered) {
-        if (!QQml_isFileCaseCorrect(absoluteFilePath)) {
-            if (errors) {
-                QQmlError error;
-                error.setDescription(tr("File name case mismatch for \"%1\"").arg(absoluteFilePath));
-                errors->prepend(error);
-            }
-            return false;
+    {
+        StringRegisteredPluginMap *plugins = qmlEnginePluginsWithRegisteredTypes();
+        QMutexLocker lock(&plugins->mutex);
+        bool typesRegistered = plugins->contains(absoluteFilePath);
+
+        if (typesRegistered) {
+            Q_ASSERT_X(plugins->value(absoluteFilePath).uri == uri,
+                       "QQmlImportDatabase::importDynamicPlugin",
+                       "Internal error: Plugin imported previously with different uri");
         }
 
-        QPluginLoader* loader = 0;
-        if (!typesRegistered) {
-            loader = new QPluginLoader(absoluteFilePath);
-
-            if (!loader->load()) {
+        if (!engineInitialized || !typesRegistered) {
+            if (!QQml_isFileCaseCorrect(absoluteFilePath)) {
                 if (errors) {
                     QQmlError error;
-                    error.setDescription(loader->errorString());
+                    error.setDescription(tr("File name case mismatch for \"%1\"").arg(absoluteFilePath));
                     errors->prepend(error);
                 }
-                delete loader;
                 return false;
             }
-        } else {
-            loader = plugins->value(absoluteFilePath).loader;
-        }
 
-       QObject *instance = loader->instance();
+            QPluginLoader* loader = nullptr;
+            if (!typesRegistered) {
+                loader = new QPluginLoader(absoluteFilePath);
 
-        if (!typesRegistered) {
-            RegisteredPlugin plugin;
-            plugin.uri = uri;
-            plugin.loader = loader;
-            plugins->insert(absoluteFilePath, plugin);
+                if (!loader->load()) {
+                    if (errors) {
+                        QQmlError error;
+                        error.setDescription(loader->errorString());
+                        errors->prepend(error);
+                    }
+                    delete loader;
+                    return false;
+                }
+            } else {
+                loader = plugins->value(absoluteFilePath).loader;
+            }
 
-            // Continue with shared code path for dynamic and static plugins:
-            if (!registerPluginTypes(instance, fileInfo.absolutePath(), uri, typeNamespace, vmaj, errors))
-                return false;
+            instance = loader->instance();
+
+            if (!typesRegistered) {
+                RegisteredPlugin plugin;
+                plugin.uri = uri;
+                plugin.loader = loader;
+                plugins->insert(absoluteFilePath, plugin);
+
+                // Continue with shared code path for dynamic and static plugins:
+                if (!registerPluginTypes(instance, fileInfo.absolutePath(), uri, typeNamespace, vmaj, errors))
+                    return false;
+            }
         }
 
-        if (!engineInitialized) {
-             // things on the engine (eg. adding new global objects) have to be done for every
-             // engine.
-             // XXX protect against double initialization
-             initializedPlugins.insert(absoluteFilePath);
-
-             if (QQmlExtensionInterface *eiface = qobject_cast<QQmlExtensionInterface *>(instance)) {
-                 QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
-                 ep->typeLoader.initializeEngine(eiface, uri.toUtf8().constData());
-             }
-         }
+    // Release the lock on plugins early as we're done with the global part. Releasing the lock
+    // also allows other QML loader threads to acquire the lock while this thread is blocking
+    // in the initializeEngine call to the gui thread (which in turn may be busy waiting for
+    // other QML loader threads and thus not process the initializeEngine call).
+    }
+
+
+    if (!engineInitialized) {
+        // The plugin's per-engine initialization does not need lock protection, as this function is
+        // only called from the engine specific loader thread and importDynamicPlugin as well as
+        // importStaticPlugin are the only places of access.
+        initializedPlugins.insert(absoluteFilePath);
+
+        if (QQmlExtensionInterface *eiface = qobject_cast<QQmlExtensionInterface *>(instance)) {
+            QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
+            ep->typeLoader.initializeEngine(eiface, uri.toUtf8().constData());
+        }
     }
 
     return true;
@@ -2119,8 +2109,8 @@ bool QQmlImportDatabase::importDynamicPlugin(const QString &filePath, const QStr
 
 void QQmlImportDatabase::clearDirCache()
 {
-    QStringHash<QmldirCache *>::ConstIterator itr = qmldirCache.begin();
-    while (itr != qmldirCache.end()) {
+    QStringHash<QmldirCache *>::ConstIterator itr = qmldirCache.constBegin();
+    while (itr != qmldirCache.constEnd()) {
         QmldirCache *cache = *itr;
         do {
             QmldirCache *nextCache = cache->next;
diff --git a/src/qml/qml/qqmlimport_p.h b/src/qml/qml/qqmlimport_p.h
index 7c691a468c..d3055b552c 100644
--- a/src/qml/qml/qqmlimport_p.h
+++ b/src/qml/qml/qqmlimport_p.h
@@ -45,8 +45,8 @@
 #include <QtCore/qset.h>
 #include <QtCore/qstringlist.h>
 #include <private/qqmldirparser_p.h>
-#include <private/qqmlmetatype_p.h>
-#include <private/qhashedstring_p.h>
+#include <private/qqmltype_p.h>
+#include <private/qstringhash_p.h>
 
 //
 //  W A R N I N G
@@ -70,30 +70,39 @@ class QQmlImportDatabase;
 class QQmlTypeLoader;
 class QQmlTypeLoaderQmldirContent;
 
+namespace QQmlImport {
+    enum RecursionRestriction { PreventRecursion, AllowRecursion };
+}
+
 struct QQmlImportInstance
 {
     QString uri; // e.g. QtQuick
     QString url; // the base path of the import
+    QString localDirectoryPath; // the base path of the import if it's a local file
     int majversion; // the major version imported
     int minversion; // the minor version imported
     bool isLibrary; // true means that this is not a file import
+    bool implicitlyImported = false;
     QQmlDirComponents qmlDirComponents; // a copy of the components listed in the qmldir
     QQmlDirScripts qmlDirScripts; // a copy of the scripts in the qmldir
 
-    bool setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoaderQmldirContent *qmldir,
+    bool setQmldirContent(const QString &resolvedUrl, const QQmlTypeLoaderQmldirContent &qmldir,
                           QQmlImportNamespace *nameSpace, QList<QQmlError> *errors);
 
     static QQmlDirScripts getVersionedScripts(const QQmlDirScripts &qmldirscripts, int vmaj, int vmin);
 
     bool resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef &type,
-                     int *vmajor, int *vminor, QQmlType** type_return,
-                     QString *base = 0, bool *typeRecursionDetected = 0) const;
+                     int *vmajor, int *vminor, QQmlType* type_return,
+                     QString *base = nullptr, bool *typeRecursionDetected = nullptr,
+                     QQmlType::RegistrationType = QQmlType::AnyRegistrationType,
+                     QQmlImport::RecursionRestriction recursionRestriction = QQmlImport::PreventRecursion,
+                     QList<QQmlError> *errors = nullptr) const;
 };
 
 class QQmlImportNamespace
 {
 public:
-    QQmlImportNamespace() : nextNamespace(0) {}
+    QQmlImportNamespace() : nextNamespace(nullptr) {}
     ~QQmlImportNamespace() { qDeleteAll(imports); }
 
     QList<QQmlImportInstance *> imports;
@@ -101,8 +110,10 @@ public:
     QQmlImportInstance *findImport(const QString &uri) const;
 
     bool resolveType(QQmlTypeLoader *typeLoader, const QHashedStringRef& type,
-                     int *vmajor, int *vminor, QQmlType** type_return,
-                     QString *base = 0, QList<QQmlError> *errors = 0);
+                     int *vmajor, int *vminor, QQmlType* type_return,
+                     QString *base = nullptr, QList<QQmlError> *errors = nullptr,
+                     QQmlType::RegistrationType registrationType = QQmlType::AnyRegistrationType,
+                     QQmlImport::RecursionRestriction recursionRestriction = QQmlImport::PreventRecursion);
 
     // Prefix when used as a qualified import.  Otherwise empty.
     QHashedString prefix;
@@ -125,13 +136,18 @@ public:
     QUrl baseUrl() const;
 
     bool resolveType(const QHashedStringRef &type,
-                     QQmlType** type_return,
+                     QQmlType *type_return,
                      int *version_major, int *version_minor,
-                     QQmlImportNamespace** ns_return,
-                     QList<QQmlError> *errors = 0) const;
-    bool resolveType(QQmlImportNamespace*,
+                     QQmlImportNamespace **ns_return,
+                     QList<QQmlError> *errors = nullptr,
+                     QQmlType::RegistrationType registrationType = QQmlType::AnyRegistrationType,
+                     QQmlImport::RecursionRestriction recursionRestriction
+                     = QQmlImport::PreventRecursion) const;
+    bool resolveType(QQmlImportNamespace *,
                      const QHashedStringRef& type,
-                     QQmlType** type_return, int *version_major, int *version_minor) const;
+                     QQmlType *type_return, int *version_major, int *version_minor,
+                     QQmlType::RegistrationType registrationType
+                     = QQmlType::AnyRegistrationType) const;
 
     bool addImplicitImport(QQmlImportDatabase *importDb, QList<QQmlError> *errors);
 
@@ -177,6 +193,7 @@ public:
 
     static bool isLocal(const QString &url);
     static bool isLocal(const QUrl &url);
+    static QUrl urlFromLocalFileOrQrcOrUrl(const QString &);
 
     static void setDesignerSupportRequired(bool b);
 
diff --git a/src/qml/qml/qqmlincubator.cpp b/src/qml/qml/qqmlincubator.cpp
index 54d0b240f5..39da550d63 100644
--- a/src/qml/qml/qqmlincubator.cpp
+++ b/src/qml/qml/qqmlincubator.cpp
@@ -45,9 +45,6 @@
 #include "qqmlmemoryprofiler_p.h"
 #include "qqmlobjectcreator_p.h"
 
-// XXX TODO
-//   - check that the Component.onCompleted behavior is the same as 4.8 in the synchronous and
-//     async if nested cases
 void QQmlEnginePrivate::incubate(QQmlIncubator &i, QQmlContextData *forContext)
 {
     QExplicitlySharedDataPointer<QQmlIncubatorPrivate> p(i.d);
@@ -64,8 +61,8 @@ void QQmlEnginePrivate::incubate(QQmlIncubator &i, QQmlContextData *forContext)
         QExplicitlySharedDataPointer<QQmlIncubatorPrivate> parentIncubator;
         QQmlContextData *cctxt = forContext;
         while (cctxt) {
-            if (cctxt->activeVMEData) {
-                parentIncubator = (QQmlIncubatorPrivate *)cctxt->activeVMEData;
+            if (cctxt->incubator) {
+                parentIncubator = cctxt->incubator;
                 break;
             }
             cctxt = cctxt->parent;
@@ -113,7 +110,7 @@ void QQmlEngine::setIncubationController(QQmlIncubationController *controller)
 {
     Q_D(QQmlEngine);
     if (d->incubationController)
-        d->incubationController->d = 0;
+        d->incubationController->d = nullptr;
     d->incubationController = controller;
     if (controller) controller->d = d;
 }
@@ -131,7 +128,7 @@ QQmlIncubationController *QQmlEngine::incubationController() const
 
 QQmlIncubatorPrivate::QQmlIncubatorPrivate(QQmlIncubator *q, QQmlIncubator::IncubationMode m)
     : q(q), status(QQmlIncubator::Null), mode(m), isAsynchronous(false), progress(Execute),
-      result(0), enginePriv(0), waitingOnMe(0)
+      result(nullptr), enginePriv(nullptr), waitingOnMe(nullptr)
 {
 }
 
@@ -150,16 +147,16 @@ void QQmlIncubatorPrivate::clear()
         if (controller)
              controller->incubatingObjectCountChanged(enginePriv->incubatorCount);
     }
-    enginePriv = 0;
+    enginePriv = nullptr;
     if (!rootContext.isNull()) {
-        rootContext->activeVMEData = 0;
-        rootContext = 0;
+        rootContext->incubator = nullptr;
+        rootContext = nullptr;
     }
 
     if (nextWaitingFor.isInList()) {
         Q_ASSERT(waitingOnMe);
         nextWaitingFor.remove();
-        waitingOnMe = 0;
+        waitingOnMe = nullptr;
     }
 
     // if we're waiting on any incubators then they should be cleared too.
@@ -174,12 +171,12 @@ void QQmlIncubatorPrivate::clear()
     vmeGuard.clear();
     if (creator && guardOk)
         creator->clear();
-    creator.reset(0);
+    creator.reset(nullptr);
 }
 
 /*!
 \class QQmlIncubationController
-\brief QQmlIncubationController instances drive the progress of QQmlIncubators
+\brief QQmlIncubationController instances drive the progress of QQmlIncubators.
 \inmodule QtQml
 
 In order to behave asynchronously and not introduce stutters or freezes in an application,
@@ -221,15 +218,15 @@ than a static amount like 5 milliseconds - while not disturbing the application.
 Create a new incubation controller.
 */
 QQmlIncubationController::QQmlIncubationController()
-: d(0)
+: d(nullptr)
 {
 }
 
 /*! \internal */
 QQmlIncubationController::~QQmlIncubationController()
 {
-    if (d) QQmlEnginePrivate::get(d)->setIncubationController(0);
-    d = 0;
+    if (d) QQmlEnginePrivate::get(d)->setIncubationController(nullptr);
+    d = nullptr;
 }
 
 /*!
@@ -275,7 +272,7 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
     if (!compilationUnit)
         return;
 
-    QML_MEMORY_SCOPE_URL(compilationUnit->url());
+    QML_MEMORY_SCOPE_URL(compilationUnit->finalUrl());
 
     QExplicitlySharedDataPointer<QQmlIncubatorPrivate> protectThis(this);
 
@@ -285,8 +282,9 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
 
     if (!vmeGuard.isOK()) {
         QQmlError error;
+        error.setMessageType(QtInfoMsg);
         error.setUrl(compilationUnit->url());
-        error.setDescription(QQmlComponent::tr("Object destroyed during incubation"));
+        error.setDescription(QQmlComponent::tr("Object or context destroyed during incubation"));
         errors << error;
         progress = QQmlIncubatorPrivate::Completed;
 
@@ -297,8 +295,8 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
 
     if (progress == QQmlIncubatorPrivate::Execute) {
         enginePriv->referenceScarceResources();
-        QObject *tresult = 0;
-        tresult = creator->create(subComponentToCreate, /*parent*/0, &i);
+        QObject *tresult = nullptr;
+        tresult = creator->create(subComponentToCreate, /*parent*/nullptr, &i);
         if (!tresult)
             errors = creator->errors;
         enginePriv->dereferenceScarceResources();
@@ -307,7 +305,7 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
             return;
 
         result = tresult;
-        if (errors.isEmpty() && result == 0)
+        if (errors.isEmpty() && result == nullptr)
             goto finishIncubate;
 
         if (result) {
@@ -343,7 +341,7 @@ void QQmlIncubatorPrivate::incubate(QQmlInstantiationInterrupt &i)
             if (watcher.hasRecursed())
                 return;
 
-            QQmlContextData *ctxt = 0;
+            QQmlContextData *ctxt = nullptr;
             ctxt = creator->finalize(i);
             if (ctxt) {
                 rootContext = ctxt;
@@ -370,33 +368,14 @@ finishIncubate:
         enginePriv->inProgressCreations--;
 
         if (0 == enginePriv->inProgressCreations) {
-            while (enginePriv->erroredBindings) {
-                enginePriv->warning(enginePriv->erroredBindings);
-                enginePriv->erroredBindings->removeError();
-            }
+            while (enginePriv->erroredBindings)
+                enginePriv->warning(enginePriv->erroredBindings->removeError());
         }
     } else if (!creator.isNull()) {
         vmeGuard.guard(creator.data());
     }
 }
 
-void QQmlIncubatorPrivate::cancel(QObject *object, QQmlContext *context)
-{
-    if (!context)
-        context = qmlContext(object);
-    if (!context)
-        return;
-
-    QQmlContextData *data = QQmlContextData::get(context);
-    QQmlIncubatorPrivate *p = (QQmlIncubatorPrivate *)data->activeVMEData;
-    if (!p)
-        return;
-
-    p->vmeGuard.unguard(object);
-    if (!p->creator.isNull())
-        p->creator->cancel(object);
-}
-
 /*!
 Incubate objects for \a msecs, or until there are no more objects to incubate.
 */
@@ -526,12 +505,12 @@ QQmlIncubator::QQmlIncubator(IncubationMode mode)
 /*! \internal */
 QQmlIncubator::~QQmlIncubator()
 {
-    d->q = 0;
+    d->q = nullptr;
 
     if (!d->ref.deref()) {
         delete d;
     }
-    d = 0;
+    d = nullptr;
 }
 
 /*!
@@ -577,28 +556,26 @@ void QQmlIncubator::clear()
     if (s == Loading) {
         Q_ASSERT(d->compilationUnit);
         if (d->result) d->result->deleteLater();
-        d->result = 0;
+        d->result = nullptr;
     }
 
     d->clear();
 
     Q_ASSERT(d->compilationUnit.isNull());
-    Q_ASSERT(d->waitingOnMe.data() == 0);
+    Q_ASSERT(d->waitingOnMe.data() == nullptr);
     Q_ASSERT(d->waitingFor.isEmpty());
 
     d->errors.clear();
     d->progress = QQmlIncubatorPrivate::Execute;
-    d->result = 0;
+    d->result = nullptr;
 
     if (s == Loading) {
         Q_ASSERT(enginePriv);
 
         enginePriv->inProgressCreations--;
         if (0 == enginePriv->inProgressCreations) {
-            while (enginePriv->erroredBindings) {
-                enginePriv->warning(enginePriv->erroredBindings);
-                enginePriv->erroredBindings->removeError();
-            }
+            while (enginePriv->erroredBindings)
+                enginePriv->warning(enginePriv->erroredBindings->removeError());
         }
     }
 
@@ -677,7 +654,7 @@ Return the incubated object if the status is Ready, otherwise 0.
 QObject *QQmlIncubator::object() const
 {
     if (status() != Ready)
-        return 0;
+        return nullptr;
     else
         return d->result;
 }
diff --git a/src/qml/qml/qqmlincubator_p.h b/src/qml/qml/qqmlincubator_p.h
index 758e0a29f6..676ba1a29a 100644
--- a/src/qml/qml/qqmlincubator_p.h
+++ b/src/qml/qml/qqmlincubator_p.h
@@ -102,9 +102,6 @@ public:
 
     void forceCompletion(QQmlInstantiationInterrupt &i);
     void incubate(QQmlInstantiationInterrupt &i);
-
-    // used by Qt Quick Controls 2
-    Q_QML_PRIVATE_EXPORT static void cancel(QObject *object, QQmlContext *context = 0);
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlinfo.cpp b/src/qml/qml/qqmlinfo.cpp
index dae15e2eca..6322302422 100644
--- a/src/qml/qml/qqmlinfo.cpp
+++ b/src/qml/qml/qqmlinfo.cpp
@@ -50,6 +50,12 @@
 QT_BEGIN_NAMESPACE
 
 /*!
+    \namespace QtQml
+    \inmodule QtQml
+    \brief Provides functions for producing logging messages for QML types.
+*/
+
+/*!
     \fn QQmlInfo QtQml::qmlDebug(const QObject *object)
     \relates QQmlEngine
     \since 5.9
@@ -57,6 +63,7 @@ QT_BEGIN_NAMESPACE
     Prints debug messages that include the file and line number for the
     specified QML \a object.
 
+//! [qqmlinfo-desc]
     When QML types produce logging messages, it improves traceability
     if they include the QML file and line number on which the
     particular instance was instantiated.
@@ -65,6 +72,7 @@ QT_BEGIN_NAMESPACE
     the file and line number is not available for that instance
     (either it was not instantiated by the QML engine or location
     information is disabled), "unknown location" will be used instead.
+//! [qqmlinfo-desc]
 
     For example,
 
@@ -74,7 +82,7 @@ QT_BEGIN_NAMESPACE
 
     prints
 
-    \code
+    \badcode
     QML MyCustomType (unknown location): Internal state: 42
     \endcode
 
@@ -88,14 +96,7 @@ QT_BEGIN_NAMESPACE
     Prints informational messages that include the file and line number for the
     specified QML \a object.
 
-    When QML types produce logging messages, it improves traceability
-    if they include the QML file and line number on which the
-    particular instance was instantiated.
-
-    To include the file and line number, an object must be passed.  If
-    the file and line number is not available for that instance
-    (either it was not instantiated by the QML engine or location
-    information is disabled), "unknown location" will be used instead.
+    \include qqmlinfo.cpp qqmlinfo-desc
 
     For example,
 
@@ -105,7 +106,7 @@ QT_BEGIN_NAMESPACE
 
     prints
 
-    \code
+    \badcode
     QML MyCustomType (unknown location): component property is a write-once property
     \endcode
 
@@ -116,7 +117,6 @@ QT_BEGIN_NAMESPACE
     \sa QtQml::qmlDebug, QtQml::qmlWarning
 */
 
-
 /*!
     \fn QQmlInfo QtQml::qmlWarning(const QObject *object)
     \relates QQmlEngine
@@ -125,14 +125,7 @@ QT_BEGIN_NAMESPACE
     Prints warning messages that include the file and line number for the
     specified QML \a object.
 
-    When QML types produce logging messages, it improves traceability
-    if they include the QML file and line number on which the
-    particular instance was instantiated.
-
-    To include the file and line number, an object must be passed.  If
-    the file and line number is not available for that instance
-    (either it was not instantiated by the QML engine or location
-    information is disabled), "unknown location" will be used instead.
+    \include qqmlinfo.cpp qqmlinfo-desc
 
     For example,
 
@@ -142,13 +135,43 @@ QT_BEGIN_NAMESPACE
 
     prints
 
-    \code
+    \badcode
     QML MyCustomType (unknown location): property cannot be set to 0
     \endcode
 
     \sa QtQml::qmlDebug, QtQml::qmlInfo
 */
 
+/*!
+    \fn QQmlInfo QtQml::qmlDebug(const QObject *object, const QQmlError &error)
+    \internal
+*/
+
+/*!
+    \fn QQmlInfo QtQml::qmlDebug(const QObject *object, const QList<QQmlError> &errors)
+    \internal
+*/
+
+/*!
+    \fn QQmlInfo QtQml::qmlInfo(const QObject *object, const QQmlError &error)
+    \internal
+*/
+
+/*!
+    \fn QQmlInfo QtQml::qmlInfo(const QObject *object, const QList<QQmlError> &errors)
+    \internal
+*/
+
+/*!
+    \fn QQmlInfo QtQml::qmlWarning(const QObject *object, const QQmlError &error)
+    \internal
+*/
+
+/*!
+    \fn QQmlInfo QtQml::qmlWarning(const QObject *object, const QList<QQmlError> &errors)
+    \internal
+*/
+
 class QQmlInfoPrivate
 {
 public:
@@ -182,7 +205,7 @@ QQmlInfo::~QQmlInfo()
     if (0 == --d->ref) {
         QList<QQmlError> errors = d->errors;
 
-        QQmlEngine *engine = 0;
+        QQmlEngine *engine = nullptr;
 
         if (!d->buffer.isEmpty()) {
             QQmlError error;
diff --git a/src/qml/qml/qqmljavascriptexpression.cpp b/src/qml/qml/qqmljavascriptexpression.cpp
index 17cccc0bbd..380163202a 100644
--- a/src/qml/qml/qqmljavascriptexpression.cpp
+++ b/src/qml/qml/qqmljavascriptexpression.cpp
@@ -46,6 +46,7 @@
 #include <private/qv4script_p.h>
 #include <private/qv4errorobject_p.h>
 #include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 #include <private/qqmlglobal_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 #include <private/qqmlbuiltinfunctions_p.h>
@@ -92,12 +93,10 @@ void QQmlDelayedError::catchJavaScriptException(QV4::ExecutionEngine *engine)
 
 
 QQmlJavaScriptExpression::QQmlJavaScriptExpression()
-    : m_error(0),
-      m_context(0),
-      m_prevExpression(0),
-      m_nextExpression(0),
-      m_v4Function(0),
-      m_sourceLocation(0)
+    :  m_context(nullptr),
+      m_prevExpression(nullptr),
+      m_nextExpression(nullptr),
+      m_v4Function(nullptr)
 {
 }
 
@@ -111,10 +110,9 @@ QQmlJavaScriptExpression::~QQmlJavaScriptExpression()
 
     clearActiveGuards();
     clearPermanentGuards();
+    clearError();
     if (m_scopeObject.isT2()) // notify DeleteWatcher of our deletion.
-        m_scopeObject.asT2()->_s = 0;
-
-    delete m_sourceLocation;
+        m_scopeObject.asT2()->_s = nullptr;
 }
 
 void QQmlJavaScriptExpression::setNotifyOnValueChanged(bool v)
@@ -135,28 +133,19 @@ void QQmlJavaScriptExpression::resetNotifyOnValueChanged()
 
 QQmlSourceLocation QQmlJavaScriptExpression::sourceLocation() const
 {
-    if (m_sourceLocation)
-        return *m_sourceLocation;
     if (m_v4Function)
         return m_v4Function->sourceLocation();
     return QQmlSourceLocation();
 }
 
-void QQmlJavaScriptExpression::setSourceLocation(const QQmlSourceLocation &location)
-{
-    if (m_sourceLocation)
-        delete m_sourceLocation;
-    m_sourceLocation = new QQmlSourceLocation(location);
-}
-
 void QQmlJavaScriptExpression::setContext(QQmlContextData *context)
 {
     if (m_prevExpression) {
         *m_prevExpression = m_nextExpression;
         if (m_nextExpression)
             m_nextExpression->m_prevExpression = m_prevExpression;
-        m_prevExpression = 0;
-        m_nextExpression = 0;
+        m_prevExpression = nullptr;
+        m_nextExpression = nullptr;
     }
 
     m_context = context;
@@ -179,9 +168,16 @@ void QQmlJavaScriptExpression::refresh()
 {
 }
 
+QV4::ReturnedValue QQmlJavaScriptExpression::evaluate(bool *isUndefined)
+{
+    QV4::ExecutionEngine *v4 = m_context->engine->handle();
+    QV4::Scope scope(v4);
+    QV4::JSCallData jsCall(scope);
 
+    return evaluate(jsCall.callData(), isUndefined);
+}
 
-void QQmlJavaScriptExpression::evaluate(QV4::CallData *callData, bool *isUndefined, QV4::Scope &scope)
+QV4::ReturnedValue QQmlJavaScriptExpression::evaluate(QV4::CallData *callData, bool *isUndefined)
 {
     Q_ASSERT(m_context && m_context->engine);
 
@@ -189,7 +185,7 @@ void QQmlJavaScriptExpression::evaluate(QV4::CallData *callData, bool *isUndefin
     if (!v4Function) {
         if (isUndefined)
             *isUndefined = true;
-        return;
+        return QV4::Encode::undefined();
     }
 
     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(m_context->engine);
@@ -202,26 +198,27 @@ void QQmlJavaScriptExpression::evaluate(QV4::CallData *callData, bool *isUndefin
     QQmlPropertyCapture capture(m_context->engine, this, &watcher);
 
     QQmlPropertyCapture *lastPropertyCapture = ep->propertyCapture;
-    ep->propertyCapture = notifyOnValueChanged() ? &capture : 0;
+    ep->propertyCapture = notifyOnValueChanged() ? &capture : nullptr;
 
 
     if (notifyOnValueChanged())
         capture.guards.copyAndClearPrepend(activeGuards);
 
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(ep->v8engine());
-    scope.result = QV4::Primitive::undefinedValue();
+    QV4::ExecutionEngine *v4 = m_context->engine->handle();
     callData->thisObject = v4->globalObject;
     if (scopeObject()) {
-        QV4::ScopedValue value(scope, QV4::QObjectWrapper::wrap(v4, scopeObject()));
-        if (value->isObject())
-            callData->thisObject = value;
+         QV4::ReturnedValue scope = QV4::QObjectWrapper::wrap(v4, scopeObject());
+        if (QV4::Value::fromReturnedValue(scope).isObject())
+            callData->thisObject = scope;
     }
 
-    QV4::ExecutionContext *outer = static_cast<QV4::ExecutionContext *>(m_qmlScope.valueRef());
-    if (v4Function->canUseSimpleFunction()) {
-        outer->simpleCall(scope, callData, v4Function);
-    } else {
-        outer->call(scope, callData, v4Function);
+    Q_ASSERT(m_qmlScope.valueRef());
+    QV4::ReturnedValue res = v4Function->call(&callData->thisObject, callData->args, callData->argc(), static_cast<QV4::ExecutionContext *>(m_qmlScope.valueRef()));
+    QV4::Scope scope(v4);
+    QV4::ScopedValue result(scope, res);
+    if (v4Function->hasQmlDependencies) {
+        QV4::Heap::QmlContext *qc = m_qmlScope.as<QV4::QmlContext>()->d();
+        QQmlPropertyCapture::registerQmlDependencies(qc, v4, v4Function->compiledFunction);
     }
 
     if (scope.hasException()) {
@@ -233,7 +230,7 @@ void QQmlJavaScriptExpression::evaluate(QV4::CallData *callData, bool *isUndefin
             *isUndefined = true;
     } else {
         if (isUndefined)
-            *isUndefined = scope.result.isUndefined();
+            *isUndefined = result->isUndefined();
 
         if (!watcher.wasDeleted() && hasDelayedError())
             delayedError()->clearError();
@@ -243,13 +240,18 @@ void QQmlJavaScriptExpression::evaluate(QV4::CallData *callData, bool *isUndefin
         for (int ii = 0; ii < capture.errorString->count(); ++ii)
             qWarning("%s", qPrintable(capture.errorString->at(ii)));
         delete capture.errorString;
-        capture.errorString = 0;
+        capture.errorString = nullptr;
     }
 
     while (QQmlJavaScriptExpressionGuard *g = capture.guards.takeFirst())
         g->Delete();
 
+    if (!watcher.wasDeleted())
+        setTranslationsCaptured(capture.translationCaptured);
+
     ep->propertyCapture = lastPropertyCapture;
+
+    return result->asReturnedValue();
 }
 
 void QQmlPropertyCapture::captureProperty(QQmlNotifier *n, Duration duration)
@@ -262,7 +264,7 @@ void QQmlPropertyCapture::captureProperty(QQmlNotifier *n, Duration duration)
     while (!guards.isEmpty() && !guards.first()->isConnected(n))
         guards.takeFirst()->Delete();
 
-    QQmlJavaScriptExpressionGuard *g = 0;
+    QQmlJavaScriptExpressionGuard *g = nullptr;
     if (!guards.isEmpty()) {
         g = guards.takeFirst();
         g->cancelNotify();
@@ -282,7 +284,7 @@ void QQmlPropertyCapture::captureProperty(QQmlNotifier *n, Duration duration)
 
     \a n is in the signal index range (see QObjectPrivate::signalIndex()).
 */
-void QQmlPropertyCapture::captureProperty(QObject *o, int c, int n, Duration duration)
+void QQmlPropertyCapture::captureProperty(QObject *o, int c, int n, Duration duration, bool doNotify)
 {
     if (watcher->wasDeleted())
         return;
@@ -311,14 +313,14 @@ void QQmlPropertyCapture::captureProperty(QObject *o, int c, int n, Duration dur
         while (!guards.isEmpty() && !guards.first()->isConnected(o, n))
             guards.takeFirst()->Delete();
 
-        QQmlJavaScriptExpressionGuard *g = 0;
+        QQmlJavaScriptExpressionGuard *g = nullptr;
         if (!guards.isEmpty()) {
             g = guards.takeFirst();
             g->cancelNotify();
             Q_ASSERT(g->isConnected(o, n));
         } else {
             g = QQmlJavaScriptExpressionGuard::New(expression, engine);
-            g->connect(o, n, engine);
+            g->connect(o, n, engine, doNotify);
         }
 
         if (duration == Permanently)
@@ -328,12 +330,11 @@ void QQmlPropertyCapture::captureProperty(QObject *o, int c, int n, Duration dur
     }
 }
 
-void QQmlPropertyCapture::registerQmlDependencies(const QV4::CompiledData::Function *compiledFunction, const QV4::Scope &scope)
+void QQmlPropertyCapture::registerQmlDependencies(QV4::Heap::QmlContext *context, const QV4::ExecutionEngine *engine, const QV4::CompiledData::Function *compiledFunction)
 {
     // Let the caller check and avoid the function call :)
     Q_ASSERT(compiledFunction->hasQmlDependencies());
 
-    QV4::ExecutionEngine *engine = scope.engine;
     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine->qmlEngine());
     if (!ep)
         return;
@@ -346,10 +347,10 @@ void QQmlPropertyCapture::registerQmlDependencies(const QV4::CompiledData::Funct
 
     capture->expression->m_permanentDependenciesRegistered = true;
 
-    QV4::Scoped<QV4::QmlContext> context(scope, engine->qmlContext());
-    QQmlContextData *qmlContext = context->qmlContext();
+    QV4::Heap::QQmlContextWrapper *wrapper = context->qml();
+    QQmlContextData *qmlContext = wrapper->context->contextData();
 
-    const QV4::CompiledData::LEUInt32 *idObjectDependency = compiledFunction->qmlIdObjectDependencyTable();
+    const quint32_le *idObjectDependency = compiledFunction->qmlIdObjectDependencyTable();
     const int idObjectDependencyCount = compiledFunction->nDependingIdObjects;
     for (int i = 0; i < idObjectDependencyCount; ++i, ++idObjectDependency) {
         Q_ASSERT(int(*idObjectDependency) < qmlContext->idValueCount);
@@ -358,7 +359,7 @@ void QQmlPropertyCapture::registerQmlDependencies(const QV4::CompiledData::Funct
     }
 
     Q_ASSERT(qmlContext->contextObject);
-    const QV4::CompiledData::LEUInt32 *contextPropertyDependency = compiledFunction->qmlContextPropertiesDependencyTable();
+    const quint32_le *contextPropertyDependency = compiledFunction->qmlContextPropertiesDependencyTable();
     const int contextPropertyDependencyCount = compiledFunction->nDependingContextProperties;
     for (int i = 0; i < contextPropertyDependencyCount; ++i) {
         const int propertyIndex = *contextPropertyDependency++;
@@ -367,8 +368,8 @@ void QQmlPropertyCapture::registerQmlDependencies(const QV4::CompiledData::Funct
                                  QQmlPropertyCapture::Permanently);
     }
 
-    QObject *scopeObject = context->qmlScope();
-    const QV4::CompiledData::LEUInt32 *scopePropertyDependency = compiledFunction->qmlScopePropertiesDependencyTable();
+    QObject *scopeObject = wrapper->scopeObject;
+    const quint32_le *scopePropertyDependency = compiledFunction->qmlScopePropertiesDependencyTable();
     const int scopePropertyDependencyCount = compiledFunction->nDependingScopeProperties;
     for (int i = 0; i < scopePropertyDependencyCount; ++i) {
         const int propertyIndex = *scopePropertyDependency++;
@@ -393,7 +394,7 @@ QQmlDelayedError *QQmlJavaScriptExpression::delayedError()
 {
     if (!m_error)
         m_error = new QQmlDelayedError;
-    return m_error;
+    return m_error.data();
 }
 
 QV4::ReturnedValue
@@ -403,11 +404,11 @@ QQmlJavaScriptExpression::evalFunction(QQmlContextData *ctxt, QObject *scopeObje
     QQmlEngine *engine = ctxt->engine;
     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
 
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(ep->v8engine());
+    QV4::ExecutionEngine *v4 = engine->handle();
     QV4::Scope scope(v4);
 
     QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(v4->rootContext(), ctxt, scopeObject));
-    QV4::Script script(v4, qmlContext, code, filename, line);
+    QV4::Script script(v4, qmlContext, /*parse as QML binding*/true, code, filename, line);
     QV4::ScopedValue result(scope);
     script.parse();
     if (!v4->hasException)
@@ -433,22 +434,18 @@ void QQmlJavaScriptExpression::createQmlBinding(QQmlContextData *ctxt, QObject *
     QQmlEngine *engine = ctxt->engine;
     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
 
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(ep->v8engine());
+    QV4::ExecutionEngine *v4 = engine->handle();
     QV4::Scope scope(v4);
 
     QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(v4->rootContext(), ctxt, qmlScope));
-    QV4::Script script(v4, qmlContext, code, filename, line);
+    QV4::Script script(v4, qmlContext, /*parse as QML binding*/true, code, filename, line);
     script.parse();
     if (v4->hasException) {
-        QQmlError error = v4->catchExceptionAsQmlError();
-        if (error.description().isEmpty())
-            error.setDescription(QLatin1String("Exception occurred during function evaluation"));
-        if (error.line() == -1)
-            error.setLine(line);
-        if (error.url().isEmpty())
-            error.setUrl(QUrl::fromLocalFile(filename));
-        error.setObject(qmlScope);
-        ep->warning(error);
+        QQmlDelayedError *error = delayedError();
+        error->catchJavaScriptException(v4);
+        error->setErrorObject(qmlScope);
+        if (!error->addError(ep))
+            ep->warning(error->error());
         return;
     }
     setupFunction(qmlContext, script.vmFunction);
@@ -460,7 +457,12 @@ void QQmlJavaScriptExpression::setupFunction(QV4::ExecutionContext *qmlContext,
         return;
     m_qmlScope.set(qmlContext->engine(), *qmlContext);
     m_v4Function = f;
-    m_compilationUnit = m_v4Function->compilationUnit;
+    setCompilationUnit(m_v4Function->compilationUnit);
+}
+
+void QQmlJavaScriptExpression::setCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit)
+{
+    m_compilationUnit = compilationUnit;
 }
 
 void QQmlJavaScriptExpression::clearActiveGuards()
diff --git a/src/qml/qml/qqmljavascriptexpression_p.h b/src/qml/qml/qqmljavascriptexpression_p.h
index 646cc5ab3d..de3fba0774 100644
--- a/src/qml/qml/qqmljavascriptexpression_p.h
+++ b/src/qml/qml/qqmljavascriptexpression_p.h
@@ -62,17 +62,19 @@ struct QQmlSourceLocation;
 class QQmlDelayedError
 {
 public:
-    inline QQmlDelayedError() : nextError(0), prevError(0) {}
-    inline ~QQmlDelayedError() { removeError(); }
+    inline QQmlDelayedError() : nextError(nullptr), prevError(nullptr) {}
+    inline ~QQmlDelayedError() { (void)removeError(); }
 
     bool addError(QQmlEnginePrivate *);
 
-    inline void removeError() {
-        if (!prevError) return;
-        if (nextError) nextError->prevError = prevError;
-        *prevError = nextError;
-        nextError = 0;
-        prevError = 0;
+    Q_REQUIRED_RESULT inline QQmlError removeError() {
+        if (prevError) {
+            if (nextError) nextError->prevError = prevError;
+            *prevError = nextError;
+            nextError = nullptr;
+            prevError = nullptr;
+        }
+        return m_error;
     }
 
     inline bool isValid() const { return m_error.isValid(); }
@@ -103,7 +105,8 @@ public:
     virtual QString expressionIdentifier() const = 0;
     virtual void expressionChanged() = 0;
 
-    void evaluate(QV4::CallData *callData, bool *isUndefined, QV4::Scope &scope);
+    QV4::ReturnedValue evaluate(bool *isUndefined);
+    QV4::ReturnedValue evaluate(QV4::CallData *callData, bool *isUndefined);
 
     inline bool notifyOnValueChanged() const;
 
@@ -113,10 +116,9 @@ public:
     inline QObject *scopeObject() const;
     inline void setScopeObject(QObject *v);
 
-    QQmlSourceLocation sourceLocation() const;
-    void setSourceLocation(const QQmlSourceLocation &location);
+    virtual QQmlSourceLocation sourceLocation() const;
 
-    bool isValid() const { return context() != 0; }
+    bool isValid() const { return context() != nullptr; }
 
     QQmlContextData *context() const { return m_context; }
     void setContext(QQmlContextData *context);
@@ -160,13 +162,7 @@ protected:
     }
 
     void setupFunction(QV4::ExecutionContext *qmlContext, QV4::Function *f);
-
-private:
-    friend class QQmlContextData;
-    friend class QQmlPropertyCapture;
-    friend void QQmlJavaScriptExpressionGuard_callback(QQmlNotifierEndpoint *, void **);
-
-    QQmlDelayedError *m_error;
+    void setCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit);
 
     // We store some flag bits in the following flag pointers.
     //    activeGuards:flag1  - notifyOnValueChanged
@@ -175,6 +171,18 @@ private:
     QForwardFieldList<QQmlJavaScriptExpressionGuard, &QQmlJavaScriptExpressionGuard::next> activeGuards;
     QForwardFieldList<QQmlJavaScriptExpressionGuard, &QQmlJavaScriptExpressionGuard::next> permanentGuards;
 
+    void setTranslationsCaptured(bool captured) { m_error.setFlagValue(captured); }
+    bool translationsCaptured() const { return m_error.flag(); }
+
+private:
+    friend class QQmlContextData;
+    friend class QQmlPropertyCapture;
+    friend void QQmlJavaScriptExpressionGuard_callback(QQmlNotifierEndpoint *, void **);
+    friend class QQmlTranslationBinding;
+
+    // m_error:flag1 translationsCapturedDuringEvaluation
+    QFlagPointer<QQmlDelayedError> m_error;
+
     QQmlContextData *m_context;
     QQmlJavaScriptExpression **m_prevExpression;
     QQmlJavaScriptExpression  *m_nextExpression;
@@ -183,18 +191,17 @@ private:
     QV4::PersistentValue m_qmlScope;
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> m_compilationUnit;
     QV4::Function *m_v4Function;
-    QQmlSourceLocation *m_sourceLocation; // used for Qt.binding() created functions
 };
 
 class QQmlPropertyCapture
 {
 public:
     QQmlPropertyCapture(QQmlEngine *engine, QQmlJavaScriptExpression *e, QQmlJavaScriptExpression::DeleteWatcher *w)
-    : engine(engine), expression(e), watcher(w), errorString(0) { }
+    : engine(engine), expression(e), watcher(w), errorString(nullptr) { }
 
     ~QQmlPropertyCapture()  {
         Q_ASSERT(guards.isEmpty());
-        Q_ASSERT(errorString == 0);
+        Q_ASSERT(errorString == nullptr);
     }
 
     enum Duration {
@@ -202,19 +209,21 @@ public:
         Permanently
     };
 
-    static void registerQmlDependencies(const QV4::CompiledData::Function *compiledFunction, const QV4::Scope &scope);
+    static void registerQmlDependencies(QV4::Heap::QmlContext *context, const QV4::ExecutionEngine *engine, const QV4::CompiledData::Function *compiledFunction);
     void captureProperty(QQmlNotifier *, Duration duration = OnlyOnce);
-    void captureProperty(QObject *, int, int, Duration duration = OnlyOnce);
+    void captureProperty(QObject *, int, int, Duration duration = OnlyOnce, bool doNotify = true);
+    void captureTranslation() { translationCaptured = true; }
 
     QQmlEngine *engine;
     QQmlJavaScriptExpression *expression;
     QQmlJavaScriptExpression::DeleteWatcher *watcher;
     QFieldList<QQmlJavaScriptExpressionGuard, &QQmlJavaScriptExpressionGuard::next> guards;
     QStringList *errorString;
+    bool translationCaptured = false;
 };
 
 QQmlJavaScriptExpression::DeleteWatcher::DeleteWatcher(QQmlJavaScriptExpression *e)
-: _c(0), _w(0), _s(e)
+: _c(nullptr), _w(nullptr), _s(e)
 {
     if (e->m_scopeObject.isT1()) {
         _w = &_s;
@@ -228,14 +237,14 @@ QQmlJavaScriptExpression::DeleteWatcher::DeleteWatcher(QQmlJavaScriptExpression
 
 QQmlJavaScriptExpression::DeleteWatcher::~DeleteWatcher()
 {
-    Q_ASSERT(*_w == 0 || (*_w == _s && _s->m_scopeObject.isT2()));
+    Q_ASSERT(*_w == nullptr || (*_w == _s && _s->m_scopeObject.isT2()));
     if (*_w && _s->m_scopeObject.asT2() == this)
         _s->m_scopeObject = _c;
 }
 
 bool QQmlJavaScriptExpression::DeleteWatcher::wasDeleted() const
 {
-    return *_w == 0;
+    return *_w == nullptr;
 }
 
 bool QQmlJavaScriptExpression::notifyOnValueChanged() const
@@ -257,24 +266,23 @@ void QQmlJavaScriptExpression::setScopeObject(QObject *v)
 
 bool QQmlJavaScriptExpression::hasError() const
 {
-    return m_error && m_error->isValid();
+    return !m_error.isNull() && m_error->isValid();
 }
 
 bool QQmlJavaScriptExpression::hasDelayedError() const
 {
-    return m_error;
+    return !m_error.isNull();
 }
 
 inline void QQmlJavaScriptExpression::clearError()
 {
-    if (m_error)
-        delete m_error;
-    m_error = 0;
+    delete m_error.data();
+    m_error = nullptr;
 }
 
 QQmlJavaScriptExpressionGuard::QQmlJavaScriptExpressionGuard(QQmlJavaScriptExpression *e)
     : QQmlNotifierEndpoint(QQmlNotifierEndpoint::QQmlJavaScriptExpressionGuard),
-      expression(e), next(0)
+      expression(e), next(nullptr)
 {
 }
 
diff --git a/src/qml/qml/qqmllist.cpp b/src/qml/qml/qqmllist.cpp
index 2c71293363..5425bf498c 100644
--- a/src/qml/qml/qqmllist.cpp
+++ b/src/qml/qml/qqmllist.cpp
@@ -55,7 +55,7 @@ QQmlListReference QQmlListReferencePrivate::init(const QQmlListProperty<QObject>
 
     if (!prop.object) return rv;
 
-    QQmlEnginePrivate *p = engine?QQmlEnginePrivate::get(engine):0;
+    QQmlEnginePrivate *p = engine?QQmlEnginePrivate::get(engine):nullptr;
 
     int listType = p?p->listType(propType):QQmlMetaType::listType(propType);
     if (listType == -1) return rv;
@@ -109,15 +109,13 @@ Attempting to add objects of the incorrect type to a list property will fail.
 
 Like with normal lists, when accessing a list element by index, it is the callers responsibility to ensure
 that it does not request an out of range element using the count() method before calling at().
-
-The \l {Qt Quick 1} version of this class is named QDeclarativeListReference.
 */
 
 /*!
 Constructs an invalid instance.
 */
 QQmlListReference::QQmlListReference()
-: d(0)
+: d(nullptr)
 {
 }
 
@@ -131,27 +129,27 @@ Passing \a engine is required to access some QML created list properties.  If in
 is available, pass it.
 */
 QQmlListReference::QQmlListReference(QObject *object, const char *property, QQmlEngine *engine)
-: d(0)
+: d(nullptr)
 {
     if (!object || !property) return;
 
     QQmlPropertyData local;
     QQmlPropertyData *data =
-        QQmlPropertyCache::property(engine, object, QLatin1String(property), 0, local);
+        QQmlPropertyCache::property(engine, object, QLatin1String(property), nullptr, local);
 
     if (!data || !data->isQList()) return;
 
-    QQmlEnginePrivate *p = engine?QQmlEnginePrivate::get(engine):0;
+    QQmlEnginePrivate *p = engine?QQmlEnginePrivate::get(engine):nullptr;
 
     int listType = p?p->listType(data->propType()):QQmlMetaType::listType(data->propType());
     if (listType == -1) return;
 
     d = new QQmlListReferencePrivate;
     d->object = object;
-    d->elementType = p?p->rawMetaObjectForType(listType):QQmlMetaType::qmlType(listType)->baseMetaObject();
+    d->elementType = p ? p->rawMetaObjectForType(listType) : QQmlMetaType::qmlType(listType).baseMetaObject();
     d->propertyType = data->propType();
 
-    void *args[] = { &d->property, 0 };
+    void *args[] = { &d->property, nullptr };
     QMetaObject::metacall(object, QMetaObject::ReadProperty, data->coreIndex(), args);
 }
 
@@ -186,17 +184,17 @@ bool QQmlListReference::isValid() const
 }
 
 /*!
-Returns the list property's object.  Returns 0 if the reference is invalid.
+Returns the list property's object. Returns \nullptr if the reference is invalid.
 */
 QObject *QQmlListReference::object() const
 {
     if (isValid()) return d->object;
-    else return 0;
+    else return nullptr;
 }
 
 /*!
-Returns the QMetaObject for the elements stored in the list property.  Returns 0 if the reference
-is invalid.
+Returns the QMetaObject for the elements stored in the list property,
+or \nullptr if the reference is invalid.
 
 The QMetaObject can be used ahead of time to determine whether a given instance can be added
 to a list.
@@ -204,7 +202,7 @@ to a list.
 const QMetaObject *QQmlListReference::listElementType() const
 {
     if (isValid()) return d->elementType.metaObject();
-    else return 0;
+    else return nullptr;
 }
 
 /*!
@@ -301,7 +299,7 @@ Returns the list element at \a index, or 0 if the operation failed.
 */
 QObject *QQmlListReference::at(int index) const
 {
-    if (!canAt()) return 0;
+    if (!canAt()) return nullptr;
 
     return d->property.at(&d->property, index);
 }
@@ -361,25 +359,22 @@ List properties should have no setter.  In the example above, the Q_PROPERTY()
 declarative will look like this:
 
 \code
-Q_PROPERTY(QQmlListProperty<Fruit> fruit READ fruit);
+Q_PROPERTY(QQmlListProperty<Fruit> fruit READ fruit)
 \endcode
 
 QML list properties are type-safe - in this case \c {Fruit} is a QObject type that
 \c {Apple}, \c {Orange} and \c {Banana} all derive from.
 
-The \l {Qt Quick 1} version of this class is named QDeclarativeListProperty.
-
 \sa {Extending QML - Object and List Property Types Example}
-
 */
 
 /*!
-\fn QQmlListProperty::QQmlListProperty()
+\fn template<typename T> QQmlListProperty<T>::QQmlListProperty()
 \internal
 */
 
 /*!
-\fn QQmlListProperty::QQmlListProperty(QObject *object, QList<T *> &list)
+\fn template<typename T> QQmlListProperty<T>::QQmlListProperty(QObject *object, QList<T *> &list)
 
 Convenience constructor for making a QQmlListProperty value from an existing
 QList \a list.  The \a list reference must remain valid for as long as \a object
@@ -391,7 +386,7 @@ can be very useful while prototyping.
 */
 
 /*!
-\fn QQmlListProperty::QQmlListProperty(QObject *object, void *data,
+\fn template<typename T> QQmlListProperty<T>::QQmlListProperty(QObject *object, void *data,
                                     CountFunction count, AtFunction at)
 
 Construct a readonly QQmlListProperty from a set of operation functions
@@ -401,7 +396,7 @@ remains valid while \a object exists.
 */
 
 /*!
-\fn QQmlListProperty::QQmlListProperty(QObject *object, void *data, AppendFunction append,
+\fn template<typename T> QQmlListProperty<T>::QQmlListProperty(QObject *object, void *data, AppendFunction append,
                                      CountFunction count, AtFunction at,
                                      ClearFunction clear)
 
@@ -432,7 +427,7 @@ Return the number of elements in the list \a property.
 */
 
 /*!
-\fn bool QQmlListProperty::operator==(const QQmlListProperty &other) const
+\fn template<typename T> bool QQmlListProperty<T>::operator==(const QQmlListProperty &other) const
 
 Returns true if this QQmlListProperty is equal to \a other, otherwise false.
 */
diff --git a/src/qml/qml/qqmllist.h b/src/qml/qml/qqmllist.h
index e3955deee5..90ec57c911 100644
--- a/src/qml/qml/qqmllist.h
+++ b/src/qml/qml/qqmllist.h
@@ -61,20 +61,15 @@ public:
     typedef void (*ClearFunction)(QQmlListProperty<T> *);
 
     QQmlListProperty()
-        : object(Q_NULLPTR),
-          data(Q_NULLPTR),
-          append(Q_NULLPTR),
-          count(Q_NULLPTR),
-          at(Q_NULLPTR),
-          clear(Q_NULLPTR),
-          dummy1(Q_NULLPTR),
-          dummy2(Q_NULLPTR)
+        : append(nullptr),
+          count(nullptr),
+          at(nullptr),
+          clear(nullptr)
     {}
     QQmlListProperty(QObject *o, QList<T *> &list)
         : object(o), data(&list), append(qlist_append), count(qlist_count), at(qlist_at),
-          clear(qlist_clear),
-          dummy1(Q_NULLPTR),
-          dummy2(Q_NULLPTR)
+          clear(qlist_clear)
+
     {}
     QQmlListProperty(QObject *o, void *d, AppendFunction a, CountFunction c, AtFunction t,
                     ClearFunction r )
@@ -83,18 +78,15 @@ public:
           append(a),
           count(c),
           at(t),
-          clear(r),
-          dummy1(Q_NULLPTR),
-          dummy2(Q_NULLPTR)
+          clear(r)
+
     {}
     QQmlListProperty(QObject *o, void *d, CountFunction c, AtFunction t)
         : object(o),
           data(d),
-          append(Q_NULLPTR),
+          append(nullptr),
           count(c), at(t),
-          clear(Q_NULLPTR),
-          dummy1(Q_NULLPTR),
-          dummy2(Q_NULLPTR)
+          clear(nullptr)
     {}
     bool operator==(const QQmlListProperty &o) const {
         return object == o.object &&
@@ -105,8 +97,8 @@ public:
                clear == o.clear;
     }
 
-    QObject *object;
-    void *data;
+    QObject *object = nullptr;
+    void *data = nullptr;
 
     AppendFunction append;
 
@@ -115,8 +107,8 @@ public:
 
     ClearFunction clear;
 
-    void *dummy1;
-    void *dummy2;
+    void *dummy1 = nullptr;
+    void *dummy2 = nullptr;
 
 private:
     static void qlist_append(QQmlListProperty *p, T *v) {
@@ -140,7 +132,7 @@ class Q_QML_EXPORT QQmlListReference
 {
 public:
     QQmlListReference();
-    QQmlListReference(QObject *, const char *property, QQmlEngine * = Q_NULLPTR);
+    QQmlListReference(QObject *, const char *property, QQmlEngine * = nullptr);
     QQmlListReference(const QQmlListReference &);
     QQmlListReference &operator=(const QQmlListReference &);
     ~QQmlListReference();
diff --git a/src/qml/qml/qqmllist_p.h b/src/qml/qml/qqmllist_p.h
index 04bab8d929..e182ced51d 100644
--- a/src/qml/qml/qqmllist_p.h
+++ b/src/qml/qml/qqmllist_p.h
@@ -52,7 +52,7 @@
 //
 
 #include "qqmllist.h"
-#include "qqmlpropertycache_p.h"
+#include "qqmlmetaobject_p.h"
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/qml/qml/qqmllistwrapper.cpp b/src/qml/qml/qqmllistwrapper.cpp
index 43677e0d78..2f769c1aef 100644
--- a/src/qml/qml/qqmllistwrapper.cpp
+++ b/src/qml/qml/qqmllistwrapper.cpp
@@ -74,10 +74,10 @@ ReturnedValue QmlListWrapper::create(ExecutionEngine *engine, QObject *object, i
 
     Scope scope(engine);
 
-    Scoped<QmlListWrapper> r(scope, engine->memoryManager->allocObject<QmlListWrapper>());
+    Scoped<QmlListWrapper> r(scope, engine->memoryManager->allocate<QmlListWrapper>());
     r->d()->object = object;
     r->d()->propertyType = propType;
-    void *args[] = { &r->d()->property(), 0 };
+    void *args[] = { &r->d()->property(), nullptr };
     QMetaObject::metacall(object, QMetaObject::ReadProperty, propId, args);
     return r.asReturnedValue();
 }
@@ -86,7 +86,7 @@ ReturnedValue QmlListWrapper::create(ExecutionEngine *engine, const QQmlListProp
 {
     Scope scope(engine);
 
-    Scoped<QmlListWrapper> r(scope, engine->memoryManager->allocObject<QmlListWrapper>());
+    Scoped<QmlListWrapper> r(scope, engine->memoryManager->allocate<QmlListWrapper>());
     r->d()->object = prop.object;
     r->d()->property() = prop;
     r->d()->propertyType = propType;
@@ -102,68 +102,73 @@ QVariant QmlListWrapper::toVariant() const
 }
 
 
-ReturnedValue QmlListWrapper::get(const Managed *m, String *name, bool *hasProperty)
+ReturnedValue QmlListWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<QmlListWrapper>());
     const QmlListWrapper *w = static_cast<const QmlListWrapper *>(m);
     QV4::ExecutionEngine *v4 = w->engine();
 
-    if (name->equals(v4->id_length()) && !w->d()->object.isNull()) {
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
         quint32 count = w->d()->property().count ? w->d()->property().count(&w->d()->property()) : 0;
-        return Primitive::fromUInt32(count).asReturnedValue();
-    }
-
-    uint idx = name->asArrayIndex();
-    if (idx != UINT_MAX)
-        return getIndexed(m, idx, hasProperty);
-
-    return Object::get(m, name, hasProperty);
-}
-
-ReturnedValue QmlListWrapper::getIndexed(const Managed *m, uint index, bool *hasProperty)
-{
-    Q_UNUSED(hasProperty);
-
-    Q_ASSERT(m->as<QmlListWrapper>());
-    const QmlListWrapper *w = static_cast<const QmlListWrapper *>(m);
-    QV4::ExecutionEngine *v4 = w->engine();
+        if (index < count && w->d()->property().at) {
+            if (hasProperty)
+                *hasProperty = true;
+            return QV4::QObjectWrapper::wrap(v4, w->d()->property().at(&w->d()->property(), index));
+        }
 
-    quint32 count = w->d()->property().count ? w->d()->property().count(&w->d()->property()) : 0;
-    if (index < count && w->d()->property().at) {
         if (hasProperty)
-            *hasProperty = true;
-        return QV4::QObjectWrapper::wrap(v4, w->d()->property().at(&w->d()->property(), index));
+            *hasProperty = false;
+        return Value::undefinedValue().asReturnedValue();
+    } else if (id.isString()) {
+        if (id == v4->id_length()->propertyKey() && !w->d()->object.isNull()) {
+            quint32 count = w->d()->property().count ? w->d()->property().count(&w->d()->property()) : 0;
+            return Value::fromUInt32(count).asReturnedValue();
+        }
     }
 
-    if (hasProperty)
-        *hasProperty = false;
-    return Primitive::undefinedValue().asReturnedValue();
+    return Object::virtualGet(m, id, receiver, hasProperty);
 }
 
-bool QmlListWrapper::put(Managed *m, String *name, const Value &value)
+bool QmlListWrapper::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
     // doesn't do anything. Should we throw?
     Q_UNUSED(m);
-    Q_UNUSED(name);
+    Q_UNUSED(id);
     Q_UNUSED(value);
+    Q_UNUSED(receiver);
     return false;
 }
 
-void QmlListWrapper::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attrs)
+struct QmlListWrapperOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
 {
-    name->setM(0);
-    *index = UINT_MAX;
-    Q_ASSERT(m->as<QmlListWrapper>());
-    QmlListWrapper *w = static_cast<QmlListWrapper *>(m);
+    ~QmlListWrapperOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey QmlListWrapperOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs)
+{
+    const QmlListWrapper *w = static_cast<const QmlListWrapper *>(o);
+
     quint32 count = w->d()->property().count ? w->d()->property().count(&w->d()->property()) : 0;
-    if (it->arrayIndex < count) {
-        *index = it->arrayIndex;
-        ++it->arrayIndex;
-        *attrs = QV4::Attr_Data;
-        p->value = QV4::QObjectWrapper::wrap(w->engine(), w->d()->property().at(&w->d()->property(), *index));
-        return;
+    if (arrayIndex < count) {
+        uint index = arrayIndex;
+        ++arrayIndex;
+        if (attrs)
+            *attrs = QV4::Attr_Data;
+        if (pd)
+            pd->value = QV4::QObjectWrapper::wrap(w->engine(), w->d()->property().at(&w->d()->property(), index));
+        return PropertyKey::fromArrayIndex(index);
     }
-    return QV4::Object::advanceIterator(m, it, name, index, p, attrs);
+
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+OwnPropertyKeyIterator *QmlListWrapper::virtualOwnPropertyKeys(const Object *m, Value *target)
+{
+    *target = *m;
+    return new QmlListWrapperOwnPropertyKeyIterator;
 }
 
 void PropertyListPrototype::init(ExecutionEngine *)
@@ -171,9 +176,10 @@ void PropertyListPrototype::init(ExecutionEngine *)
     defineDefaultProperty(QStringLiteral("push"), method_push, 1);
 }
 
-void PropertyListPrototype::method_push(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue PropertyListPrototype::method_push(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    ScopedObject instance(scope, callData->thisObject.toObject(scope.engine));
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
     if (!instance)
         RETURN_UNDEFINED();
     QmlListWrapper *w = instance->as<QmlListWrapper>();
@@ -183,12 +189,13 @@ void PropertyListPrototype::method_push(const BuiltinFunction *, Scope &scope, C
         THROW_GENERIC_ERROR("List doesn't define an Append function");
 
     QV4::ScopedObject so(scope);
-    for (int i = 0; i < callData->argc; ++i)
+    for (int i = 0, ei = argc; i < ei; ++i)
     {
-        so = callData->args[i].toObject(scope.engine);
+        so = argv[i].toObject(scope.engine);
         if (QV4::QObjectWrapper *wrapper = so->as<QV4::QObjectWrapper>())
             w->d()->property().append(&w->d()->property(), wrapper->object() );
     }
+    return Encode::undefined();
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmllistwrapper_p.h b/src/qml/qml/qqmllistwrapper_p.h
index 84dadba01a..c185122ad9 100644
--- a/src/qml/qml/qqmllistwrapper_p.h
+++ b/src/qml/qml/qqmllistwrapper_p.h
@@ -93,17 +93,16 @@ struct Q_QML_EXPORT QmlListWrapper : Object
 
     QVariant toVariant() const;
 
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
-    static bool put(Managed *m, String *name, const Value &value);
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
 };
 
 struct PropertyListPrototype : Object
 {
     void init(ExecutionEngine *engine);
 
-    static void method_push(const BuiltinFunction *, Scope &, CallData *callData);
+    static ReturnedValue method_push(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 };
 
 }
diff --git a/src/qml/qml/qqmllocale.cpp b/src/qml/qml/qqmllocale.cpp
index 326b36c5cd..2b17037df0 100644
--- a/src/qml/qml/qqmllocale.cpp
+++ b/src/qml/qml/qqmllocale.cpp
@@ -58,8 +58,7 @@ DEFINE_OBJECT_VTABLE(QQmlLocaleData);
 
 #define THROW_ERROR(string) \
     do { \
-        scope.result = scope.engine->throwError(QString::fromUtf8(string)); \
-        return; \
+        return scope.engine->throwError(QString::fromUtf8(string)); \
     } while (false)
 
 
@@ -78,7 +77,7 @@ static bool isLocaleObject(const QV4::Value &val)
 
 void QQmlDateExtension::registerExtension(QV4::ExecutionEngine *engine)
 {
-    engine->datePrototype()->defineDefaultProperty(QStringLiteral("toLocaleString"), method_toLocaleString);
+    engine->datePrototype()->defineDefaultProperty(engine->id_toLocaleString(), method_toLocaleString);
     engine->datePrototype()->defineDefaultProperty(QStringLiteral("toLocaleTimeString"), method_toLocaleTimeString);
     engine->datePrototype()->defineDefaultProperty(QStringLiteral("toLocaleDateString"), method_toLocaleDateString);
     engine->dateCtor()->defineDefaultProperty(QStringLiteral("fromLocaleString"), method_fromLocaleString);
@@ -87,42 +86,37 @@ void QQmlDateExtension::registerExtension(QV4::ExecutionEngine *engine)
     engine->dateCtor()->defineDefaultProperty(QStringLiteral("timeZoneUpdated"), method_timeZoneUpdated);
 }
 
-void QQmlDateExtension::method_toLocaleString(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_toLocaleString(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    if (callData->argc > 2) {
-        QV4::DatePrototype::method_toLocaleString(b, scope, callData);
-        return;
-    }
+    Scope scope(b);
+    if (argc > 2)
+        return QV4::DatePrototype::method_toLocaleString(b, thisObject, argv, argc);
 
-    QV4::DateObject *date = callData->thisObject.as<DateObject>();
-    if (!date) {
-        QV4::DatePrototype::method_toLocaleString(b, scope, callData);
-        return;
-    }
+    const QV4::DateObject *date = thisObject->as<DateObject>();
+    if (!date)
+        return QV4::DatePrototype::method_toLocaleString(b, thisObject, argv, argc);
 
     QDateTime dt = date->toQDateTime();
 
-    if (callData->argc == 0) {
+    if (argc == 0) {
         // Use QLocale for standard toLocaleString() function
         QLocale locale;
         RETURN_RESULT(scope.engine->newString(locale.toString(dt)));
     }
 
-    if (!isLocaleObject(callData->args[0])) {
-        QV4::DatePrototype::method_toLocaleString(b, scope, callData); // Use the default Date toLocaleString()
-        return;
-    }
+    if (!isLocaleObject(argv[0]))
+        return QV4::DatePrototype::method_toLocaleString(b, thisObject, argv, argc); // Use the default Date toLocaleString()
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QLocale::FormatType enumFormat = QLocale::LongFormat;
     QString formattedDt;
-    if (callData->argc == 2) {
-        if (String *s = callData->args[1].stringValue()) {
+    if (argc == 2) {
+        if (String *s = argv[1].stringValue()) {
             QString format = s->toQString();
             formattedDt = r->d()->locale->toString(dt, format);
-        } else if (callData->args[1].isNumber()) {
-            quint32 intFormat = callData->args[1].toNumber();
+        } else if (argv[1].isNumber()) {
+            quint32 intFormat = argv[1].toNumber();
             QLocale::FormatType format = QLocale::FormatType(intFormat);
             formattedDt = r->d()->locale->toString(dt, format);
         } else {
@@ -132,44 +126,41 @@ void QQmlDateExtension::method_toLocaleString(const BuiltinFunction *b, Scope &s
          formattedDt = r->d()->locale->toString(dt, enumFormat);
     }
 
-    scope.result = scope.engine->newString(formattedDt);
+    RETURN_RESULT(scope.engine->newString(formattedDt));
 }
 
-void QQmlDateExtension::method_toLocaleTimeString(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_toLocaleTimeString(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    if (callData->argc > 2) {
-        QV4::DatePrototype::method_toLocaleTimeString(b, scope, callData);
-        return;
-    }
+    Scope scope(b);
+    if (argc > 2)
+        return QV4::DatePrototype::method_toLocaleTimeString(b, thisObject, argv, argc);
 
-    QV4::DateObject *date = callData->thisObject.as<DateObject>();
-    if (!date) {
-        QV4::DatePrototype::method_toLocaleTimeString(b, scope, callData);
-        return;
-    }
+    const QV4::DateObject *date = thisObject->as<DateObject>();
+    if (!date)
+        return QV4::DatePrototype::method_toLocaleTimeString(b, thisObject, argv, argc);
 
     QDateTime dt = date->toQDateTime();
     QTime time = dt.time();
 
-    if (callData->argc == 0) {
+    if (argc == 0) {
         // Use QLocale for standard toLocaleString() function
         QLocale locale;
         RETURN_RESULT(scope.engine->newString(locale.toString(time)));
     }
 
-    if (!isLocaleObject(callData->args[0]))
-        return QV4::DatePrototype::method_toLocaleTimeString(b, scope, callData); // Use the default Date toLocaleTimeString()
+    if (!isLocaleObject(argv[0]))
+        return QV4::DatePrototype::method_toLocaleTimeString(b, thisObject, argv, argc); // Use the default Date toLocaleTimeString()
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QLocale::FormatType enumFormat = QLocale::LongFormat;
     QString formattedTime;
-    if (callData->argc == 2) {
-        if (String *s = callData->args[1].stringValue()) {
+    if (argc == 2) {
+        if (String *s = argv[1].stringValue()) {
             QString format = s->toQString();
             formattedTime = r->d()->locale->toString(time, format);
-        } else if (callData->args[1].isNumber()) {
-            quint32 intFormat = callData->args[1].toNumber();
+        } else if (argv[1].isNumber()) {
+            quint32 intFormat = argv[1].toNumber();
             QLocale::FormatType format = QLocale::FormatType(intFormat);
             formattedTime = r->d()->locale->toString(time, format);
         } else {
@@ -179,44 +170,41 @@ void QQmlDateExtension::method_toLocaleTimeString(const BuiltinFunction *b, Scop
          formattedTime = r->d()->locale->toString(time, enumFormat);
     }
 
-    scope.result = scope.engine->newString(formattedTime);
+    RETURN_RESULT(scope.engine->newString(formattedTime));
 }
 
-void QQmlDateExtension::method_toLocaleDateString(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_toLocaleDateString(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    if (callData->argc > 2) {
-        QV4::DatePrototype::method_toLocaleDateString(b, scope, callData);
-        return;
-    }
+    Scope scope(b);
+    if (argc > 2)
+        return QV4::DatePrototype::method_toLocaleDateString(b, thisObject, argv, argc);
 
-    QV4::DateObject *dateObj = callData->thisObject.as<DateObject>();
-    if (!dateObj) {
-        QV4::DatePrototype::method_toLocaleDateString(b, scope, callData);
-        return;
-    }
+    const QV4::DateObject *dateObj = thisObject->as<DateObject>();
+    if (!dateObj)
+        return QV4::DatePrototype::method_toLocaleDateString(b, thisObject, argv, argc);
 
     QDateTime dt = dateObj->toQDateTime();
     QDate date = dt.date();
 
-    if (callData->argc == 0) {
+    if (argc == 0) {
         // Use QLocale for standard toLocaleString() function
         QLocale locale;
         RETURN_RESULT(scope.engine->newString(locale.toString(date)));
     }
 
-    if (!isLocaleObject(callData->args[0]))
-        return QV4::DatePrototype::method_toLocaleDateString(b, scope, callData); // Use the default Date toLocaleDateString()
+    if (!isLocaleObject(argv[0]))
+        return QV4::DatePrototype::method_toLocaleDateString(b, thisObject, argv, argc); // Use the default Date toLocaleDateString()
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QLocale::FormatType enumFormat = QLocale::LongFormat;
     QString formattedDate;
-    if (callData->argc == 2) {
-        if (String *s = callData->args[1].stringValue()) {
+    if (argc == 2) {
+        if (String *s = argv[1].stringValue()) {
             QString format = s->toQString();
             formattedDate = r->d()->locale->toString(date, format);
-        } else if (callData->args[1].isNumber()) {
-            quint32 intFormat = callData->args[1].toNumber();
+        } else if (argv[1].isNumber()) {
+            quint32 intFormat = argv[1].toNumber();
             QLocale::FormatType format = QLocale::FormatType(intFormat);
             formattedDate = r->d()->locale->toString(date, format);
         } else {
@@ -226,14 +214,15 @@ void QQmlDateExtension::method_toLocaleDateString(const BuiltinFunction *b, Scop
          formattedDate = r->d()->locale->toString(date, enumFormat);
     }
 
-    scope.result = scope.engine->newString(formattedDate);
+    RETURN_RESULT(scope.engine->newString(formattedDate));
 }
 
-void QQmlDateExtension::method_fromLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_fromLocaleString(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *argv, int argc)
 {
+    QV4::Scope scope(b);
     QV4::ExecutionEngine * const engine = scope.engine;
-    if (callData->argc == 1) {
-        if (String *s = callData->args[0].stringValue()) {
+    if (argc == 1) {
+        if (String *s = argv[0].stringValue()) {
             QLocale locale;
             QString dateString = s->toQString();
             QDateTime dt = locale.toDateTime(dateString);
@@ -241,20 +230,20 @@ void QQmlDateExtension::method_fromLocaleString(const BuiltinFunction *, Scope &
         }
     }
 
-    if (callData->argc < 1 || callData->argc > 3 || !isLocaleObject(callData->args[0]))
+    if (argc < 1 || argc > 3 || !isLocaleObject(argv[0]))
         THROW_ERROR("Locale: Date.fromLocaleString(): Invalid arguments");
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QLocale::FormatType enumFormat = QLocale::LongFormat;
     QDateTime dt;
-    QString dateString = callData->args[1].toQStringNoThrow();
-    if (callData->argc == 3) {
-        if (String *s = callData->args[2].stringValue()) {
+    QString dateString = argv[1].toQStringNoThrow();
+    if (argc == 3) {
+        if (String *s = argv[2].stringValue()) {
             QString format = s->toQString();
             dt = r->d()->locale->toDateTime(dateString, format);
-        } else if (callData->args[2].isNumber()) {
-            quint32 intFormat = callData->args[2].toNumber();
+        } else if (argv[2].isNumber()) {
+            quint32 intFormat = argv[2].toNumber();
             QLocale::FormatType format = QLocale::FormatType(intFormat);
             dt = r->d()->locale->toDateTime(dateString, format);
         } else {
@@ -264,15 +253,16 @@ void QQmlDateExtension::method_fromLocaleString(const BuiltinFunction *, Scope &
         dt = r->d()->locale->toDateTime(dateString, enumFormat);
     }
 
-    scope.result = engine->newDateObject(dt);
+    RETURN_RESULT(engine->newDateObject(dt));
 }
 
-void QQmlDateExtension::method_fromLocaleTimeString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_fromLocaleTimeString(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *argv, int argc)
 {
+    QV4::Scope scope(b);
     QV4::ExecutionEngine * const engine = scope.engine;
 
-    if (callData->argc == 1) {
-        if (String *s = callData->args[0].stringValue()) {
+    if (argc == 1) {
+        if (String *s = argv[0].stringValue()) {
             QLocale locale;
             QString timeString = s->toQString();
             QTime time = locale.toTime(timeString);
@@ -282,20 +272,20 @@ void QQmlDateExtension::method_fromLocaleTimeString(const BuiltinFunction *, Sco
         }
     }
 
-    if (callData->argc < 1 || callData->argc > 3 || !isLocaleObject(callData->args[0]))
+    if (argc < 1 || argc > 3 || !isLocaleObject(argv[0]))
         THROW_ERROR("Locale: Date.fromLocaleTimeString(): Invalid arguments");
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QLocale::FormatType enumFormat = QLocale::LongFormat;
     QTime tm;
-    QString dateString = callData->args[1].toQStringNoThrow();
-    if (callData->argc == 3) {
-        if (String *s = callData->args[2].stringValue()) {
+    QString dateString = argv[1].toQStringNoThrow();
+    if (argc == 3) {
+        if (String *s = argv[2].stringValue()) {
             QString format = s->toQString();
             tm = r->d()->locale->toTime(dateString, format);
-        } else if (callData->args[2].isNumber()) {
-            quint32 intFormat = callData->args[2].toNumber();
+        } else if (argv[2].isNumber()) {
+            quint32 intFormat = argv[2].toNumber();
             QLocale::FormatType format = QLocale::FormatType(intFormat);
             tm = r->d()->locale->toTime(dateString, format);
         } else {
@@ -314,12 +304,13 @@ void QQmlDateExtension::method_fromLocaleTimeString(const BuiltinFunction *, Sco
     RETURN_RESULT(engine->newDateObject(dt));
 }
 
-void QQmlDateExtension::method_fromLocaleDateString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_fromLocaleDateString(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *argv, int argc)
 {
+    QV4::Scope scope(b);
     QV4::ExecutionEngine * const engine = scope.engine;
 
-    if (callData->argc == 1) {
-        if (String *s = callData->args[0].stringValue()) {
+    if (argc == 1) {
+        if (String *s = argv[0].stringValue()) {
             QLocale locale;
             QString dateString = s->toQString();
             QDate date = locale.toDate(dateString);
@@ -327,20 +318,20 @@ void QQmlDateExtension::method_fromLocaleDateString(const BuiltinFunction *, Sco
         }
     }
 
-    if (callData->argc < 1 || callData->argc > 3 || !isLocaleObject(callData->args[0]))
+    if (argc < 1 || argc > 3 || !isLocaleObject(argv[0]))
         THROW_ERROR("Locale: Date.fromLocaleDateString(): Invalid arguments");
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QLocale::FormatType enumFormat = QLocale::LongFormat;
     QDate dt;
-    QString dateString = callData->args[1].toQStringNoThrow();
-    if (callData->argc == 3) {
-        if (String *s = callData->args[2].stringValue()) {
+    QString dateString = argv[1].toQStringNoThrow();
+    if (argc == 3) {
+        if (String *s = argv[2].stringValue()) {
             QString format = s->toQString();
             dt = r->d()->locale->toDate(dateString, format);
-        } else if (callData->args[2].isNumber()) {
-            quint32 intFormat = callData->args[2].toNumber();
+        } else if (argv[2].isNumber()) {
+            quint32 intFormat = argv[2].toNumber();
             QLocale::FormatType format = QLocale::FormatType(intFormat);
             dt = r->d()->locale->toDate(dateString, format);
         } else {
@@ -353,12 +344,13 @@ void QQmlDateExtension::method_fromLocaleDateString(const BuiltinFunction *, Sco
     RETURN_RESULT(engine->newDateObject(QDateTime(dt)));
 }
 
-void QQmlDateExtension::method_timeZoneUpdated(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlDateExtension::method_timeZoneUpdated(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *, int argc)
 {
-    if (callData->argc != 0)
+    QV4::Scope scope(b);
+    if (argc != 0)
         THROW_ERROR("Locale: Date.timeZoneUpdated(): Invalid arguments");
 
-    QV4::DatePrototype::timezoneUpdated();
+    QV4::DatePrototype::timezoneUpdated(scope.engine);
 
     RETURN_UNDEFINED();
 }
@@ -368,96 +360,97 @@ void QQmlDateExtension::method_timeZoneUpdated(const BuiltinFunction *, Scope &s
 
 void QQmlNumberExtension::registerExtension(QV4::ExecutionEngine *engine)
 {
-    engine->numberPrototype()->defineDefaultProperty(QStringLiteral("toLocaleString"), method_toLocaleString);
+    engine->numberPrototype()->defineDefaultProperty(engine->id_toLocaleString(), method_toLocaleString);
     engine->numberPrototype()->defineDefaultProperty(QStringLiteral("toLocaleCurrencyString"), method_toLocaleCurrencyString);
     engine->numberCtor()->defineDefaultProperty(QStringLiteral("fromLocaleString"), method_fromLocaleString);
 }
 
-void QQmlNumberExtension::method_toLocaleString(const BuiltinFunction *b, Scope &scope, CallData *callData)
+QV4::ReturnedValue QQmlNumberExtension::method_toLocaleString(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    if (callData->argc > 3)
+    QV4::Scope scope(b);
+    if (argc > 3)
         THROW_ERROR("Locale: Number.toLocaleString(): Invalid arguments");
 
-    double number = callData->thisObject.toNumber();
+    double number = thisObject->toNumber();
 
-    if (callData->argc == 0) {
+    if (argc == 0) {
         // Use QLocale for standard toLocaleString() function
         QLocale locale;
         RETURN_RESULT(scope.engine->newString(locale.toString(number)));
     }
 
-    if (!isLocaleObject(callData->args[0])) {
-        QV4::NumberPrototype::method_toLocaleString(b, scope, callData); // Use the default Number toLocaleString()
-        return;
-    }
+    if (!isLocaleObject(argv[0]))
+        return QV4::NumberPrototype::method_toLocaleString(b, thisObject, argv, argc); // Use the default Number toLocaleString()
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     quint16 format = 'f';
-    if (callData->argc > 1) {
-        if (!callData->args[1].isString())
+    if (argc > 1) {
+        if (!argv[1].isString())
             THROW_ERROR("Locale: Number.toLocaleString(): Invalid arguments");
-        QString fs = callData->args[1].toQString();
+        QString fs = argv[1].toQString();
         if (fs.length())
             format = fs.at(0).unicode();
     }
     int prec = 2;
-    if (callData->argc > 2) {
-        if (!callData->args[2].isNumber())
+    if (argc > 2) {
+        if (!argv[2].isNumber())
             THROW_ERROR("Locale: Number.toLocaleString(): Invalid arguments");
-         prec = callData->args[2].toInt32();
+         prec = argv[2].toInt32();
     }
 
-    scope.result = scope.engine->newString(r->d()->locale->toString(number, (char)format, prec));
+    RETURN_RESULT(scope.engine->newString(r->d()->locale->toString(number, (char)format, prec)));
 }
 
-void QQmlNumberExtension::method_toLocaleCurrencyString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlNumberExtension::method_toLocaleCurrencyString(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    if (callData->argc > 2)
+    QV4::Scope scope(b);
+    if (argc > 2)
         THROW_ERROR("Locale: Number.toLocaleCurrencyString(): Invalid arguments");
 
-    double number = callData->thisObject.toNumber();
+    double number = thisObject->toNumber();
 
-    if (callData->argc == 0) {
+    if (argc == 0) {
         // Use QLocale for standard toLocaleString() function
         QLocale locale;
         RETURN_RESULT(scope.engine->newString(locale.toString(number)));
     }
 
-    if (!isLocaleObject(callData->args[0]))
+    if (!isLocaleObject(argv[0]))
         THROW_ERROR("Locale: Number.toLocaleCurrencyString(): Invalid arguments");
 
-    GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+    GET_LOCALE_DATA_RESOURCE(argv[0]);
 
     QString symbol;
-    if (callData->argc > 1) {
-        if (!callData->args[1].isString())
+    if (argc > 1) {
+        if (!argv[1].isString())
             THROW_ERROR("Locale: Number.toLocaleString(): Invalid arguments");
-        symbol = callData->args[1].toQStringNoThrow();
+        symbol = argv[1].toQStringNoThrow();
     }
 
     RETURN_RESULT(scope.engine->newString(r->d()->locale->toCurrencyString(number, symbol)));
 }
 
-void QQmlNumberExtension::method_fromLocaleString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlNumberExtension::method_fromLocaleString(const QV4::FunctionObject *b, const QV4::Value *, const QV4::Value *argv, int argc)
 {
-    if (callData->argc < 1 || callData->argc > 2)
+    QV4::Scope scope(b);
+    if (argc < 1 || argc > 2)
         THROW_ERROR("Locale: Number.fromLocaleString(): Invalid arguments");
 
     int numberIdx = 0;
     QLocale locale;
 
-    if (callData->argc == 2) {
-        if (!isLocaleObject(callData->args[0]))
+    if (argc == 2) {
+        if (!isLocaleObject(argv[0]))
             THROW_ERROR("Locale: Number.fromLocaleString(): Invalid arguments");
 
-        GET_LOCALE_DATA_RESOURCE(callData->args[0]);
+        GET_LOCALE_DATA_RESOURCE(argv[0]);
         locale = *r->d()->locale;
 
         numberIdx = 1;
     }
 
-    QString ns = callData->args[numberIdx].toQString();
+    QString ns = argv[numberIdx].toQString();
     if (!ns.length())
         RETURN_RESULT(QV4::Encode(Q_QNAN));
 
@@ -467,45 +460,49 @@ void QQmlNumberExtension::method_fromLocaleString(const BuiltinFunction *, Scope
     if (!ok)
         THROW_ERROR("Locale: Number.fromLocaleString(): Invalid format");
 
-    scope.result = QV4::Encode(val);
+    RETURN_RESULT(QV4::Encode(val));
 }
 
 //--------------
 // Locale object
 
-void QQmlLocaleData::method_get_firstDayOfWeek(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocaleData::method_get_firstDayOfWeek(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QLocale *locale = getThisLocale(scope, callData);
+    QV4::Scope scope(b);
+    const QLocale *locale = getThisLocale(scope, thisObject);
     if (!locale)
-        return;
+        return Encode::undefined();
     int fdow = int(locale->firstDayOfWeek());
     if (fdow == 7)
         fdow = 0; // Qt::Sunday = 7, but Sunday is 0 in JS Date
-    scope.result = QV4::Encode(fdow);
+    RETURN_RESULT(fdow);
 }
 
-void QQmlLocaleData::method_get_measurementSystem(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocaleData::method_get_measurementSystem(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QLocale *locale = getThisLocale(scope, callData);
+    QV4::Scope scope(b);
+    const QLocale *locale = getThisLocale(scope, thisObject);
     if (!locale)
-        return;
-    scope.result = QV4::Encode(locale->measurementSystem());
+        return Encode::undefined();
+    return QV4::Encode(locale->measurementSystem());
 }
 
-void QQmlLocaleData::method_get_textDirection(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocaleData::method_get_textDirection(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QLocale *locale = getThisLocale(scope, callData);
+    QV4::Scope scope(b);
+    const QLocale *locale = getThisLocale(scope, thisObject);
     if (!locale)
-        return;
+        return Encode::undefined();
 
-    scope.result = QV4::Encode(locale->textDirection());
+    return QV4::Encode(locale->textDirection());
 }
 
-void QQmlLocaleData::method_get_weekDays(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocaleData::method_get_weekDays(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QLocale *locale = getThisLocale(scope, callData);
+    QV4::Scope scope(b);
+    const QLocale *locale = getThisLocale(scope, thisObject);
     if (!locale)
-        return;
+        return Encode::undefined();
 
     QList<Qt::DayOfWeek> days = locale->weekdays();
 
@@ -515,18 +512,19 @@ void QQmlLocaleData::method_get_weekDays(const BuiltinFunction *, Scope &scope,
         int day = days.at(i);
         if (day == 7) // JS Date days in range 0(Sunday) to 6(Saturday)
             day = 0;
-        result->arrayPut(i, QV4::Primitive::fromInt32(day));
+        result->arrayPut(i, QV4::Value::fromInt32(day));
     }
     result->setArrayLengthUnchecked(days.size());
 
-    scope.result = result.asReturnedValue();
+    return result.asReturnedValue();
 }
 
-void QQmlLocaleData::method_get_uiLanguages(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocaleData::method_get_uiLanguages(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QLocale *locale = getThisLocale(scope, callData);
+    QV4::Scope scope(b);
+    const QLocale *locale = getThisLocale(scope, thisObject);
     if (!locale)
-        return;
+        return Encode::undefined();
 
     QStringList langs = locale->uiLanguages();
     QV4::ScopedArrayObject result(scope, scope.engine->newArrayObject());
@@ -537,40 +535,42 @@ void QQmlLocaleData::method_get_uiLanguages(const BuiltinFunction *, Scope &scop
 
     result->setArrayLengthUnchecked(langs.size());
 
-    scope.result = result.asReturnedValue();
+    return result.asReturnedValue();
 }
 
-void QQmlLocaleData::method_currencySymbol(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocaleData::method_currencySymbol(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    QLocale *locale = getThisLocale(scope, callData);
+    QV4::Scope scope(b);
+    const QLocale *locale = getThisLocale(scope, thisObject);
     if (!locale)
-        return;
+        return Encode::undefined();
 
-    if (callData->argc > 1)
+    if (argc > 1)
         THROW_ERROR("Locale: currencySymbol(): Invalid arguments");
 
     QLocale::CurrencySymbolFormat format = QLocale::CurrencySymbol;
-    if (callData->argc == 1) {
-        quint32 intFormat = callData->args[0].toNumber();
+    if (argc == 1) {
+        quint32 intFormat = argv[0].toNumber();
         format = QLocale::CurrencySymbolFormat(intFormat);
     }
 
-    scope.result = scope.engine->newString(locale->currencySymbol(format));
+    RETURN_RESULT(scope.engine->newString(locale->currencySymbol(format)));
 }
 
 #define LOCALE_FORMAT(FUNC) \
-void QQmlLocaleData::method_ ##FUNC (const BuiltinFunction *, Scope &scope, CallData *callData) { \
-    QLocale *locale = getThisLocale(scope, callData); \
+ReturnedValue QQmlLocaleData::method_ ##FUNC (const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc) { \
+    QV4::Scope scope(b); \
+    const QLocale *locale = getThisLocale(scope, thisObject); \
     if (!locale) \
-        return; \
-    if (callData->argc > 1) \
+        return Encode::undefined(); \
+    if (argc > 1) \
         THROW_ERROR("Locale: " #FUNC "(): Invalid arguments"); \
     QLocale::FormatType format = QLocale::LongFormat;\
-    if (callData->argc == 1) { \
-        quint32 intFormat = callData->args[0].toUInt32(); \
+    if (argc == 1) { \
+        quint32 intFormat = argv[0].toUInt32(); \
         format = QLocale::FormatType(intFormat); \
     } \
-    scope.result = scope.engine->newString(locale-> FUNC (format)); \
+    RETURN_RESULT(scope.engine->newString(locale-> FUNC (format))); \
 }
 
 LOCALE_FORMAT(dateTimeFormat)
@@ -579,20 +579,21 @@ LOCALE_FORMAT(dateFormat)
 
 // +1 added to idx because JS is 0-based, whereas QLocale months begin at 1.
 #define LOCALE_FORMATTED_MONTHNAME(VARIABLE) \
-void QQmlLocaleData::method_ ## VARIABLE (const BuiltinFunction *, Scope &scope, CallData *callData) {\
-    QLocale *locale = getThisLocale(scope, callData); \
+ReturnedValue QQmlLocaleData::method_ ## VARIABLE (const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc) {\
+    Scope scope(b); \
+    const QLocale *locale = getThisLocale(scope, thisObject); \
     if (!locale) \
-        return; \
-    if (callData->argc < 1 || callData->argc > 2) \
+        return Encode::undefined(); \
+    if (argc < 1 || argc > 2) \
         THROW_ERROR("Locale: " #VARIABLE "(): Invalid arguments"); \
     QLocale::FormatType enumFormat = QLocale::LongFormat; \
-    int idx = callData->args[0].toInt32() + 1; \
+    int idx = argv[0].toInt32() + 1; \
     if (idx < 1 || idx > 12) \
         THROW_ERROR("Locale: Invalid month"); \
     QString name; \
-    if (callData->argc == 2) { \
-        if (callData->args[1].isNumber()) { \
-            quint32 intFormat = callData->args[1].toUInt32(); \
+    if (argc == 2) { \
+        if (argv[1].isNumber()) { \
+            quint32 intFormat = argv[1].toUInt32(); \
             QLocale::FormatType format = QLocale::FormatType(intFormat); \
             name = locale-> VARIABLE(idx, format); \
         } else { \
@@ -601,26 +602,27 @@ void QQmlLocaleData::method_ ## VARIABLE (const BuiltinFunction *, Scope &scope,
     } else { \
         name = locale-> VARIABLE(idx, enumFormat); \
     } \
-    scope.result = scope.engine->newString(name); \
+    RETURN_RESULT(scope.engine->newString(name)); \
 }
 
 // 0 -> 7 as Qt::Sunday is 7, but Sunday is 0 in JS Date
 #define LOCALE_FORMATTED_DAYNAME(VARIABLE) \
-void QQmlLocaleData::method_ ## VARIABLE (const BuiltinFunction *, Scope &scope, CallData *callData) {\
-    QLocale *locale = getThisLocale(scope, callData); \
+ReturnedValue QQmlLocaleData::method_ ## VARIABLE (const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc) {\
+    Scope scope(b); \
+    const QLocale *locale = getThisLocale(scope, thisObject); \
     if (!locale) \
-        return; \
-    if (callData->argc < 1 || callData->argc > 2) \
+        return Encode::undefined(); \
+    if (argc < 1 || argc > 2) \
         THROW_ERROR("Locale: " #VARIABLE "(): Invalid arguments"); \
     QLocale::FormatType enumFormat = QLocale::LongFormat; \
-    int idx = callData->args[0].toInt32(); \
+    int idx = argv[0].toInt32(); \
     if (idx < 0 || idx > 7) \
         THROW_ERROR("Locale: Invalid day"); \
     if (idx == 0) idx = 7; \
     QString name; \
-    if (callData->argc == 2) { \
-        if (callData->args[1].isNumber()) { \
-            quint32 intFormat = callData->args[1].toUInt32(); \
+    if (argc == 2) { \
+        if (argv[1].isNumber()) { \
+            quint32 intFormat = argv[1].toUInt32(); \
             QLocale::FormatType format = QLocale::FormatType(intFormat); \
             name = locale-> VARIABLE(idx, format); \
         } else { \
@@ -629,7 +631,7 @@ void QQmlLocaleData::method_ ## VARIABLE (const BuiltinFunction *, Scope &scope,
     } else { \
         name = locale-> VARIABLE(idx, enumFormat); \
     } \
-    scope.result = scope.engine->newString(name); \
+    RETURN_RESULT(scope.engine->newString(name)); \
 }
 
 LOCALE_FORMATTED_MONTHNAME(monthName)
@@ -637,12 +639,14 @@ LOCALE_FORMATTED_MONTHNAME(standaloneMonthName)
 LOCALE_FORMATTED_DAYNAME(dayName)
 LOCALE_FORMATTED_DAYNAME(standaloneDayName)
 
-#define LOCALE_STRING_PROPERTY(VARIABLE) void QQmlLocaleData::method_get_ ## VARIABLE (const BuiltinFunction *, Scope &scope, CallData *callData) \
+#define LOCALE_STRING_PROPERTY(VARIABLE) \
+ReturnedValue QQmlLocaleData::method_get_ ## VARIABLE (const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int) \
 { \
-    QLocale *locale = getThisLocale(scope, callData); \
+    Scope scope(b); \
+    const QLocale *locale = getThisLocale(scope, thisObject); \
     if (!locale) \
-        return; \
-    scope.result = scope.engine->newString(locale-> VARIABLE());\
+        return Encode::undefined(); \
+    RETURN_RESULT(scope.engine->newString(locale-> VARIABLE()));\
 }
 
 LOCALE_STRING_PROPERTY(name)
@@ -680,23 +684,23 @@ QV4LocaleDataDeletable::QV4LocaleDataDeletable(QV4::ExecutionEngine *engine)
     o->defineDefaultProperty(QStringLiteral("monthName"), QQmlLocaleData::method_monthName, 0);
     o->defineDefaultProperty(QStringLiteral("currencySymbol"), QQmlLocaleData::method_currencySymbol, 0);
     o->defineDefaultProperty(QStringLiteral("dateTimeFormat"), QQmlLocaleData::method_dateTimeFormat, 0);
-    o->defineAccessorProperty(QStringLiteral("name"), QQmlLocaleData::method_get_name, 0);
-    o->defineAccessorProperty(QStringLiteral("positiveSign"), QQmlLocaleData::method_get_positiveSign, 0);
-    o->defineAccessorProperty(QStringLiteral("uiLanguages"), QQmlLocaleData::method_get_uiLanguages, 0);
-    o->defineAccessorProperty(QStringLiteral("firstDayOfWeek"), QQmlLocaleData::method_get_firstDayOfWeek, 0);
-    o->defineAccessorProperty(QStringLiteral("pmText"), QQmlLocaleData::method_get_pmText, 0);
-    o->defineAccessorProperty(QStringLiteral("percent"), QQmlLocaleData::method_get_percent, 0);
-    o->defineAccessorProperty(QStringLiteral("textDirection"), QQmlLocaleData::method_get_textDirection, 0);
-    o->defineAccessorProperty(QStringLiteral("weekDays"), QQmlLocaleData::method_get_weekDays, 0);
-    o->defineAccessorProperty(QStringLiteral("negativeSign"), QQmlLocaleData::method_get_negativeSign, 0);
-    o->defineAccessorProperty(QStringLiteral("groupSeparator"), QQmlLocaleData::method_get_groupSeparator, 0);
-    o->defineAccessorProperty(QStringLiteral("decimalPoint"), QQmlLocaleData::method_get_decimalPoint, 0);
-    o->defineAccessorProperty(QStringLiteral("nativeLanguageName"), QQmlLocaleData::method_get_nativeLanguageName, 0);
-    o->defineAccessorProperty(QStringLiteral("nativeCountryName"), QQmlLocaleData::method_get_nativeCountryName, 0);
-    o->defineAccessorProperty(QStringLiteral("zeroDigit"), QQmlLocaleData::method_get_zeroDigit, 0);
-    o->defineAccessorProperty(QStringLiteral("amText"), QQmlLocaleData::method_get_amText, 0);
-    o->defineAccessorProperty(QStringLiteral("measurementSystem"), QQmlLocaleData::method_get_measurementSystem, 0);
-    o->defineAccessorProperty(QStringLiteral("exponential"), QQmlLocaleData::method_get_exponential, 0);
+    o->defineAccessorProperty(QStringLiteral("name"), QQmlLocaleData::method_get_name, nullptr);
+    o->defineAccessorProperty(QStringLiteral("positiveSign"), QQmlLocaleData::method_get_positiveSign, nullptr);
+    o->defineAccessorProperty(QStringLiteral("uiLanguages"), QQmlLocaleData::method_get_uiLanguages, nullptr);
+    o->defineAccessorProperty(QStringLiteral("firstDayOfWeek"), QQmlLocaleData::method_get_firstDayOfWeek, nullptr);
+    o->defineAccessorProperty(QStringLiteral("pmText"), QQmlLocaleData::method_get_pmText, nullptr);
+    o->defineAccessorProperty(QStringLiteral("percent"), QQmlLocaleData::method_get_percent, nullptr);
+    o->defineAccessorProperty(QStringLiteral("textDirection"), QQmlLocaleData::method_get_textDirection, nullptr);
+    o->defineAccessorProperty(QStringLiteral("weekDays"), QQmlLocaleData::method_get_weekDays, nullptr);
+    o->defineAccessorProperty(QStringLiteral("negativeSign"), QQmlLocaleData::method_get_negativeSign, nullptr);
+    o->defineAccessorProperty(QStringLiteral("groupSeparator"), QQmlLocaleData::method_get_groupSeparator, nullptr);
+    o->defineAccessorProperty(QStringLiteral("decimalPoint"), QQmlLocaleData::method_get_decimalPoint, nullptr);
+    o->defineAccessorProperty(QStringLiteral("nativeLanguageName"), QQmlLocaleData::method_get_nativeLanguageName, nullptr);
+    o->defineAccessorProperty(QStringLiteral("nativeCountryName"), QQmlLocaleData::method_get_nativeCountryName, nullptr);
+    o->defineAccessorProperty(QStringLiteral("zeroDigit"), QQmlLocaleData::method_get_zeroDigit, nullptr);
+    o->defineAccessorProperty(QStringLiteral("amText"), QQmlLocaleData::method_get_amText, nullptr);
+    o->defineAccessorProperty(QStringLiteral("measurementSystem"), QQmlLocaleData::method_get_measurementSystem, nullptr);
+    o->defineAccessorProperty(QStringLiteral("exponential"), QQmlLocaleData::method_get_exponential, nullptr);
 
     prototype.set(engine, o);
 }
@@ -711,7 +715,7 @@ V4_DEFINE_EXTENSION(QV4LocaleDataDeletable, localeV4Data);
     \qmltype Locale
     \instantiates QQmlLocale
     \inqmlmodule QtQml
-    \brief Provides locale specific properties and formatted data
+    \brief Provides locale specific properties and formatted data.
 
     The Locale object may only be created via the \l{QtQml::Qt::locale()}{Qt.locale()} function.
     It cannot be created directly.
@@ -821,10 +825,10 @@ QV4::ReturnedValue QQmlLocale::wrap(ExecutionEngine *v4, const QLocale &locale)
 {
     QV4::Scope scope(v4);
     QV4LocaleDataDeletable *d = localeV4Data(scope.engine);
-    QV4::Scoped<QQmlLocaleData> wrapper(scope, v4->memoryManager->allocObject<QQmlLocaleData>());
+    QV4::Scoped<QQmlLocaleData> wrapper(scope, v4->memoryManager->allocate<QQmlLocaleData>());
     *wrapper->d()->locale = locale;
     QV4::ScopedObject p(scope, d->prototype.value());
-    wrapper->setPrototype(p);
+    wrapper->setPrototypeOf(p);
     return wrapper.asReturnedValue();
 }
 
@@ -833,22 +837,18 @@ void QQmlLocale::registerStringLocaleCompare(QV4::ExecutionEngine *engine)
     engine->stringPrototype()->defineDefaultProperty(QStringLiteral("localeCompare"), method_localeCompare);
 }
 
-void QQmlLocale::method_localeCompare(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue QQmlLocale::method_localeCompare(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    if (callData->argc != 1 || (!callData->args[0].isString() && !callData->args[0].as<StringObject>())) {
-        QV4::StringPrototype::method_localeCompare(b, scope, callData);
-        return;
-    }
+    if (argc != 1 || (!argv[0].isString() && !argv[0].as<StringObject>()))
+        return QV4::StringPrototype::method_localeCompare(b, thisObject, argv, argc);
 
-    if (!callData->thisObject.isString() && !callData->thisObject.as<StringObject>()) {
-        QV4::StringPrototype::method_localeCompare(b, scope, callData);
-        return;
-    }
+    if (!thisObject->isString() && !thisObject->as<StringObject>())
+        return QV4::StringPrototype::method_localeCompare(b, thisObject, argv, argc);
 
-    QString thisString = callData->thisObject.toQStringNoThrow();
-    QString thatString = callData->args[0].toQStringNoThrow();
+    QString thisString = thisObject->toQStringNoThrow();
+    QString thatString = argv[0].toQStringNoThrow();
 
-    scope.result = QV4::Encode(QString::localeAwareCompare(thisString, thatString));
+    return QV4::Encode(QString::localeAwareCompare(thisString, thatString));
 }
 
 /*!
diff --git a/src/qml/qml/qqmllocale_p.h b/src/qml/qml/qqmllocale_p.h
index 1a2ffc72b0..859c36e11b 100644
--- a/src/qml/qml/qqmllocale_p.h
+++ b/src/qml/qml/qqmllocale_p.h
@@ -58,6 +58,8 @@
 #include <private/qqmlglobal_p.h>
 #include <private/qv4object_p.h>
 
+QT_REQUIRE_CONFIG(qml_locale);
+
 QT_BEGIN_NAMESPACE
 
 
@@ -67,13 +69,13 @@ public:
     static void registerExtension(QV4::ExecutionEngine *engine);
 
 private:
-    static void method_toLocaleString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_toLocaleTimeString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_toLocaleDateString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_fromLocaleString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_fromLocaleTimeString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_fromLocaleDateString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_timeZoneUpdated(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue method_toLocaleString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_toLocaleTimeString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_toLocaleDateString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_fromLocaleString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_fromLocaleTimeString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_fromLocaleDateString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_timeZoneUpdated(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 };
 
 
@@ -83,9 +85,9 @@ public:
     static void registerExtension(QV4::ExecutionEngine *engine);
 
 private:
-    static void method_toLocaleString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_fromLocaleString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_toLocaleCurrencyString(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue method_toLocaleString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_fromLocaleString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_toLocaleCurrencyString(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 };
 
 
@@ -135,7 +137,7 @@ public:
 private:
     QQmlLocale();
 
-    static void method_localeCompare(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue method_localeCompare(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 };
 
 namespace QV4 {
@@ -158,43 +160,43 @@ struct QQmlLocaleData : public QV4::Object
     V4_OBJECT2(QQmlLocaleData, Object)
     V4_NEEDS_DESTROY
 
-    static QLocale *getThisLocale(QV4::Scope &scope, QV4::CallData *callData) {
-        QV4::Object *o = callData->thisObject.as<Object>();
-        QQmlLocaleData *thisObject = o ? o->as<QQmlLocaleData>() : 0;
-        if (!thisObject) {
+    static QLocale *getThisLocale(QV4::Scope &scope, const QV4::Value *thisObject) {
+        const QV4::Object *o = thisObject->as<Object>();
+        const QQmlLocaleData *data = o ? o->as<QQmlLocaleData>() : nullptr;
+        if (!data) {
             scope.engine->throwTypeError();
-            return 0;
+            return nullptr;
         }
-        return thisObject->d()->locale;
+        return data->d()->locale;
     }
 
-    static void method_currencySymbol(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_dateTimeFormat(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_timeFormat(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_dateFormat(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_monthName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_standaloneMonthName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_dayName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_standaloneDayName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-
-    static void method_get_firstDayOfWeek(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_measurementSystem(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_textDirection(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_weekDays(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_uiLanguages(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-
-    static void method_get_name(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_nativeLanguageName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_nativeCountryName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_decimalPoint(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_groupSeparator(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_percent(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_zeroDigit(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_negativeSign(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_positiveSign(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_exponential(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_amText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_pmText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue method_currencySymbol(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_dateTimeFormat(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_timeFormat(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_dateFormat(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_monthName(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_standaloneMonthName(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_dayName(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_standaloneDayName(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+
+    static QV4::ReturnedValue method_get_firstDayOfWeek(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_measurementSystem(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_textDirection(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_weekDays(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_uiLanguages(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+
+    static QV4::ReturnedValue method_get_name(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_nativeLanguageName(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_nativeCountryName(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_decimalPoint(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_groupSeparator(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_percent(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_zeroDigit(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_negativeSign(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_positiveSign(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_exponential(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_amText(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue method_get_pmText(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 };
 
 }
diff --git a/src/qml/qml/qqmlloggingcategory.cpp b/src/qml/qml/qqmlloggingcategory.cpp
index 08f8552ab6..b59a26e17e 100644
--- a/src/qml/qml/qqmlloggingcategory.cpp
+++ b/src/qml/qml/qqmlloggingcategory.cpp
@@ -45,7 +45,7 @@
     \qmltype LoggingCategory
     \ingroup qml-utility-elements
     \inqmlmodule QtQml
-    \brief Defines a logging category in QML
+    \brief Defines a logging category in QML.
     \since 5.8
 
     A logging category can be passed to console.log() and friends as the first argument.
@@ -59,6 +59,7 @@
         LoggingCategory {
             id: category
             name: "com.qt.category"
+            defaultLogLevel: LoggingCategory.Warning
         }
 
         Component.onCompleted: {
@@ -84,6 +85,17 @@
     \sa QLoggingCategory::categoryName()
 */
 
+/*!
+    \qmlproperty enumeration QtQml::LoggingCategory::defaultLogLevel
+    \since 5.12
+
+    Holds the default log level of the logging category. By default it is
+    created with the LoggingCategory.Debug log level.
+
+    \note This property needs to be set when declaring the LoggingCategory
+    and cannot be changed later.
+*/
+
 QQmlLoggingCategory::QQmlLoggingCategory(QObject *parent)
     : QObject(parent)
     , m_initialized(false)
@@ -99,6 +111,11 @@ QString QQmlLoggingCategory::name() const
     return QString::fromUtf8(m_name);
 }
 
+QQmlLoggingCategory::DefaultLogLevel QQmlLoggingCategory::defaultLogLevel() const
+{
+    return m_defaultLogLevel;
+}
+
 QLoggingCategory *QQmlLoggingCategory::category() const
 {
     return m_category.data();
@@ -111,10 +128,25 @@ void QQmlLoggingCategory::classBegin()
 void QQmlLoggingCategory::componentComplete()
 {
     m_initialized = true;
-    if (m_name.isNull())
+    if (m_name.isNull()) {
         qmlWarning(this) << QLatin1String("Declaring the name of the LoggingCategory is mandatory and cannot be changed later !");
+    } else {
+        QScopedPointer<QLoggingCategory> category(new QLoggingCategory(m_name.constData(), QtMsgType(m_defaultLogLevel)));
+        m_category.swap(category);
+    }
 }
 
+void QQmlLoggingCategory::setDefaultLogLevel(DefaultLogLevel defaultLogLevel)
+{
+    if (m_initialized) {
+        qmlWarning(this) << QLatin1String("The defaultLogLevel of a LoggingCategory cannot be changed after the Item is created");
+        return;
+    }
+
+    m_defaultLogLevel = defaultLogLevel;
+}
+
+
 void QQmlLoggingCategory::setName(const QString &name)
 {
     if (m_initialized) {
@@ -123,8 +155,6 @@ void QQmlLoggingCategory::setName(const QString &name)
     }
 
     m_name = name.toUtf8();
-    QScopedPointer<QLoggingCategory> category(new QLoggingCategory(m_name.constData()));
-    m_category.swap(category);
 }
 
 #include "moc_qqmlloggingcategory_p.cpp"
diff --git a/src/qml/qml/qqmlloggingcategory_p.h b/src/qml/qml/qqmlloggingcategory_p.h
index 2b7f2f5b53..ece06e04b4 100644
--- a/src/qml/qml/qqmlloggingcategory_p.h
+++ b/src/qml/qml/qqmlloggingcategory_p.h
@@ -65,11 +65,23 @@ class QQmlLoggingCategory : public QObject, public QQmlParserStatus
     Q_INTERFACES(QQmlParserStatus)
 
     Q_PROPERTY(QString name READ name WRITE setName)
+    Q_PROPERTY(DefaultLogLevel defaultLogLevel READ defaultLogLevel WRITE setDefaultLogLevel REVISION 1)
 
 public:
-    QQmlLoggingCategory(QObject *parent = 0);
+    enum DefaultLogLevel {
+        Debug = QtDebugMsg,
+        Info = QtInfoMsg,
+        Warning = QtWarningMsg,
+        Critical = QtCriticalMsg,
+        Fatal = QtFatalMsg
+    };
+    Q_ENUM(DefaultLogLevel);
+
+    QQmlLoggingCategory(QObject *parent = nullptr);
     virtual ~QQmlLoggingCategory();
 
+    DefaultLogLevel defaultLogLevel() const;
+    void setDefaultLogLevel(DefaultLogLevel defaultLogLevel);
     QString name() const;
     void setName(const QString &name);
 
@@ -81,6 +93,7 @@ public:
 private:
     QByteArray m_name;
     QScopedPointer<QLoggingCategory> m_category;
+    DefaultLogLevel m_defaultLogLevel = Debug;
     bool m_initialized;
 };
 
diff --git a/src/qml/qml/qqmlmetaobject.cpp b/src/qml/qml/qqmlmetaobject.cpp
new file mode 100644
index 0000000000..a967f46b12
--- /dev/null
+++ b/src/qml/qml/qqmlmetaobject.cpp
@@ -0,0 +1,327 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlmetaobject_p.h"
+
+#include <private/qqmlengine_p.h>
+#include <private/qqmlpropertycachemethodarguments_p.h>
+
+QT_BEGIN_NAMESPACE
+
+struct StaticQtMetaObject : public QObject
+{
+    static const QMetaObject *get()
+    { return &staticQtMetaObject; }
+};
+
+static bool isNamedEnumeratorInScope(const QMetaObject *resolvedMetaObject, const QByteArray &scope,
+                                     const QByteArray &name)
+{
+    for (int i = resolvedMetaObject->enumeratorCount() - 1; i >= 0; --i) {
+        QMetaEnum m = resolvedMetaObject->enumerator(i);
+        if ((m.name() == name) && (scope.isEmpty() || (m.scope() == scope)))
+            return true;
+    }
+    return false;
+}
+
+static bool isNamedEnumerator(const QMetaObject *metaObj, const QByteArray &scopedName)
+{
+    QByteArray scope;
+    QByteArray name;
+    int scopeIdx = scopedName.lastIndexOf("::");
+    if (scopeIdx != -1) {
+        scope = scopedName.left(scopeIdx);
+        name = scopedName.mid(scopeIdx + 2);
+    } else {
+        name = scopedName;
+    }
+
+    if (scope == "Qt")
+        return isNamedEnumeratorInScope(StaticQtMetaObject::get(), scope, name);
+
+    if (isNamedEnumeratorInScope(metaObj, scope, name))
+        return true;
+
+    if (metaObj->d.relatedMetaObjects && !scope.isEmpty()) {
+        for (auto related = metaObj->d.relatedMetaObjects; *related; ++related) {
+            if (isNamedEnumeratorInScope(*related, scope, name))
+                return true;
+        }
+    }
+
+    return false;
+}
+
+// Returns true if \a from is assignable to a property of type \a to
+bool QQmlMetaObject::canConvert(const QQmlMetaObject &from, const QQmlMetaObject &to)
+{
+    Q_ASSERT(!from.isNull() && !to.isNull());
+
+    struct I { static bool equal(const QMetaObject *lhs, const QMetaObject *rhs) {
+            return lhs == rhs || (lhs && rhs && lhs->d.stringdata == rhs->d.stringdata);
+        } };
+
+    const QMetaObject *tom = to._m.isT1()?to._m.asT1()->metaObject():to._m.asT2();
+    if (tom == &QObject::staticMetaObject) return true;
+
+    if (from._m.isT1() && to._m.isT1()) { // QQmlPropertyCache -> QQmlPropertyCache
+        QQmlPropertyCache *fromp = from._m.asT1();
+        QQmlPropertyCache *top = to._m.asT1();
+
+        while (fromp) {
+            if (fromp == top) return true;
+            fromp = fromp->parent();
+        }
+    } else if (from._m.isT1() && to._m.isT2()) { // QQmlPropertyCache -> QMetaObject
+        QQmlPropertyCache *fromp = from._m.asT1();
+
+        while (fromp) {
+            const QMetaObject *fromm = fromp->metaObject();
+            if (fromm && I::equal(fromm, tom)) return true;
+            fromp = fromp->parent();
+        }
+    } else if (from._m.isT2() && to._m.isT1()) { // QMetaObject -> QQmlPropertyCache
+        const QMetaObject *fromm = from._m.asT2();
+
+        if (!tom) return false;
+
+        while (fromm) {
+            if (I::equal(fromm, tom)) return true;
+            fromm = fromm->superClass();
+        }
+    } else { // QMetaObject -> QMetaObject
+        const QMetaObject *fromm = from._m.asT2();
+
+        while (fromm) {
+            if (I::equal(fromm, tom)) return true;
+            fromm = fromm->superClass();
+        }
+    }
+
+    return false;
+}
+
+void QQmlMetaObject::resolveGadgetMethodOrPropertyIndex(QMetaObject::Call type, const QMetaObject **metaObject, int *index)
+{
+    int offset;
+
+    switch (type) {
+    case QMetaObject::ReadProperty:
+    case QMetaObject::WriteProperty:
+    case QMetaObject::ResetProperty:
+    case QMetaObject::QueryPropertyDesignable:
+    case QMetaObject::QueryPropertyEditable:
+    case QMetaObject::QueryPropertyScriptable:
+    case QMetaObject::QueryPropertyStored:
+    case QMetaObject::QueryPropertyUser:
+        offset = (*metaObject)->propertyOffset();
+        while (*index < offset) {
+            *metaObject = (*metaObject)->superClass();
+            offset = (*metaObject)->propertyOffset();
+        }
+        break;
+    case QMetaObject::InvokeMetaMethod:
+        offset = (*metaObject)->methodOffset();
+        while (*index < offset) {
+            *metaObject = (*metaObject)->superClass();
+            offset = (*metaObject)->methodOffset();
+        }
+        break;
+    default:
+        offset = 0;
+        Q_UNIMPLEMENTED();
+        offset = INT_MAX;
+    }
+
+    *index -= offset;
+}
+
+QQmlPropertyCache *QQmlMetaObject::propertyCache(QQmlEnginePrivate *e) const
+{
+    if (_m.isNull()) return nullptr;
+    if (_m.isT1()) return _m.asT1();
+    else return e->cache(_m.asT2());
+}
+
+int QQmlMetaObject::methodReturnType(const QQmlPropertyData &data, QByteArray *unknownTypeError) const
+{
+    Q_ASSERT(!_m.isNull() && data.coreIndex() >= 0);
+
+    int type = data.propType();
+
+    const char *propTypeName = nullptr;
+
+    if (type == QMetaType::UnknownType) {
+        // Find the return type name from the method info
+        QMetaMethod m;
+
+        if (_m.isT1()) {
+            QQmlPropertyCache *c = _m.asT1();
+            Q_ASSERT(data.coreIndex() < c->methodIndexCacheStart + c->methodIndexCache.count());
+
+            while (data.coreIndex() < c->methodIndexCacheStart)
+                c = c->_parent;
+
+            const QMetaObject *metaObject = c->createMetaObject();
+            Q_ASSERT(metaObject);
+            m = metaObject->method(data.coreIndex());
+        } else {
+            m = _m.asT2()->method(data.coreIndex());
+        }
+
+        type = m.returnType();
+        propTypeName = m.typeName();
+    }
+
+    if (QMetaType::sizeOf(type) <= int(sizeof(int))) {
+        if (QMetaType::typeFlags(type) & QMetaType::IsEnumeration)
+            return QMetaType::Int;
+
+        if (isNamedEnumerator(metaObject(), propTypeName))
+            return QMetaType::Int;
+
+        if (type == QMetaType::UnknownType) {
+            if (unknownTypeError)
+                *unknownTypeError = propTypeName;
+        }
+    } // else we know that it's a known type, as sizeOf(UnknownType) == 0
+
+    return type;
+}
+
+int *QQmlMetaObject::methodParameterTypes(int index, ArgTypeStorage *argStorage,
+                                          QByteArray *unknownTypeError) const
+{
+    Q_ASSERT(!_m.isNull() && index >= 0);
+
+    if (_m.isT1()) {
+        typedef QQmlPropertyCacheMethodArguments A;
+
+        QQmlPropertyCache *c = _m.asT1();
+        Q_ASSERT(index < c->methodIndexCacheStart + c->methodIndexCache.count());
+
+        while (index < c->methodIndexCacheStart)
+            c = c->_parent;
+
+        QQmlPropertyData *rv = const_cast<QQmlPropertyData *>(&c->methodIndexCache.at(index - c->methodIndexCacheStart));
+
+        if (rv->arguments() && static_cast<A *>(rv->arguments())->argumentsValid)
+            return static_cast<A *>(rv->arguments())->arguments;
+
+        const QMetaObject *metaObject = c->createMetaObject();
+        Q_ASSERT(metaObject);
+        QMetaMethod m = metaObject->method(index);
+
+        int argc = m.parameterCount();
+        if (!rv->arguments()) {
+            A *args = c->createArgumentsObject(argc, m.parameterNames());
+            rv->setArguments(args);
+        }
+        A *args = static_cast<A *>(rv->arguments());
+
+        QList<QByteArray> argTypeNames; // Only loaded if needed
+
+        for (int ii = 0; ii < argc; ++ii) {
+            int type = m.parameterType(ii);
+
+            if (QMetaType::sizeOf(type) > int(sizeof(int))) {
+                // Cannot be passed as int
+                // We know that it's a known type, as sizeOf(UnknownType) == 0
+            } else if (QMetaType::typeFlags(type) & QMetaType::IsEnumeration) {
+                type = QMetaType::Int;
+            } else {
+                if (argTypeNames.isEmpty())
+                    argTypeNames = m.parameterTypes();
+                if (isNamedEnumerator(metaObject, argTypeNames.at(ii))) {
+                    type = QMetaType::Int;
+                } else if (type == QMetaType::UnknownType){
+                    if (unknownTypeError)
+                        *unknownTypeError = argTypeNames.at(ii);
+                    return nullptr;
+                }
+
+            }
+            args->arguments[ii + 1] = type;
+        }
+        args->argumentsValid = true;
+        return static_cast<A *>(rv->arguments())->arguments;
+
+    } else {
+        QMetaMethod m = _m.asT2()->method(index);
+        return methodParameterTypes(m, argStorage, unknownTypeError);
+
+    }
+}
+
+int *QQmlMetaObject::methodParameterTypes(const QMetaMethod &m, ArgTypeStorage *argStorage,
+                                          QByteArray *unknownTypeError) const
+{
+    Q_ASSERT(argStorage);
+
+    int argc = m.parameterCount();
+    argStorage->resize(argc + 1);
+    argStorage->operator[](0) = argc;
+    QList<QByteArray> argTypeNames; // Only loaded if needed
+
+    for (int ii = 0; ii < argc; ++ii) {
+        int type = m.parameterType(ii);
+        if (QMetaType::sizeOf(type) > int(sizeof(int))) {
+            // Cannot be passed as int
+            // We know that it's a known type, as sizeOf(UnknownType) == 0
+        } else if (QMetaType::typeFlags(type) & QMetaType::IsEnumeration) {
+            type = QMetaType::Int;
+        } else {
+            if (argTypeNames.isEmpty())
+                argTypeNames = m.parameterTypes();
+            if (isNamedEnumerator(_m.asT2(), argTypeNames.at(ii))) {
+                type = QMetaType::Int;
+            } else if (type == QMetaType::UnknownType) {
+                if (unknownTypeError)
+                    *unknownTypeError = argTypeNames.at(ii);
+                return nullptr;
+            }
+        }
+        argStorage->operator[](ii + 1) = type;
+    }
+
+    return argStorage->data();
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlmetaobject_p.h b/src/qml/qml/qqmlmetaobject_p.h
new file mode 100644
index 0000000000..65d6361b90
--- /dev/null
+++ b/src/qml/qml/qqmlmetaobject_p.h
@@ -0,0 +1,187 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLMETAOBJECT_P_H
+#define QQMLMETAOBJECT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQml/qtqmlglobal.h>
+
+#include <private/qflagpointer_p.h>
+#include <private/qqmlpropertycache_p.h>
+
+#include <QtCore/qvarlengtharray.h>
+#include <QtCore/qmetaobject.h>
+
+QT_BEGIN_NAMESPACE
+
+// QQmlMetaObject serves as a wrapper around either QMetaObject or QQmlPropertyCache.
+// This is necessary as we delay creation of QMetaObject for synthesized QObjects, but
+// we don't want to needlessly generate QQmlPropertyCaches every time we encounter a
+// QObject type used in assignment or when we don't have a QQmlEngine etc.
+//
+// This class does NOT reference the propertycache.
+class QQmlEnginePrivate;
+class QQmlPropertyData;
+class Q_QML_EXPORT QQmlMetaObject
+{
+public:
+    typedef QVarLengthArray<int, 9> ArgTypeStorage;
+
+    inline QQmlMetaObject();
+    inline QQmlMetaObject(QObject *);
+    inline QQmlMetaObject(const QMetaObject *);
+    inline QQmlMetaObject(QQmlPropertyCache *);
+    inline QQmlMetaObject(const QQmlMetaObject &);
+
+    inline QQmlMetaObject &operator=(const QQmlMetaObject &);
+
+    inline bool isNull() const;
+
+    inline const char *className() const;
+    inline int propertyCount() const;
+
+    inline bool hasMetaObject() const;
+    inline const QMetaObject *metaObject() const;
+
+    QQmlPropertyCache *propertyCache(QQmlEnginePrivate *) const;
+
+    int methodReturnType(const QQmlPropertyData &data, QByteArray *unknownTypeError) const;
+    int *methodParameterTypes(int index, ArgTypeStorage *argStorage,
+                              QByteArray *unknownTypeError) const;
+
+    static bool canConvert(const QQmlMetaObject &from, const QQmlMetaObject &to);
+
+    // static_metacall (on Gadgets) doesn't call the base implementation and therefore
+    // we need a helper to find the correct meta object and property/method index.
+    static void resolveGadgetMethodOrPropertyIndex(QMetaObject::Call type, const QMetaObject **metaObject, int *index);
+
+protected:
+    QBiPointer<QQmlPropertyCache, const QMetaObject> _m;
+    int *methodParameterTypes(const QMetaMethod &method, ArgTypeStorage *argStorage,
+                              QByteArray *unknownTypeError) const;
+
+};
+
+QQmlMetaObject::QQmlMetaObject()
+{
+}
+
+QQmlMetaObject::QQmlMetaObject(QObject *o)
+{
+    if (o) {
+        QQmlData *ddata = QQmlData::get(o, false);
+        if (ddata && ddata->propertyCache) _m = ddata->propertyCache;
+        else _m = o->metaObject();
+    }
+}
+
+QQmlMetaObject::QQmlMetaObject(const QMetaObject *m)
+    : _m(m)
+{
+}
+
+QQmlMetaObject::QQmlMetaObject(QQmlPropertyCache *m)
+    : _m(m)
+{
+}
+
+QQmlMetaObject::QQmlMetaObject(const QQmlMetaObject &o)
+    : _m(o._m)
+{
+}
+
+QQmlMetaObject &QQmlMetaObject::operator=(const QQmlMetaObject &o)
+{
+    _m = o._m;
+    return *this;
+}
+
+bool QQmlMetaObject::isNull() const
+{
+    return _m.isNull();
+}
+
+const char *QQmlMetaObject::className() const
+{
+    if (_m.isNull()) {
+        return nullptr;
+    } else if (_m.isT1()) {
+        return _m.asT1()->className();
+    } else {
+        return _m.asT2()->className();
+    }
+}
+
+int QQmlMetaObject::propertyCount() const
+{
+    if (_m.isNull()) {
+        return 0;
+    } else if (_m.isT1()) {
+        return _m.asT1()->propertyCount();
+    } else {
+        return _m.asT2()->propertyCount();
+    }
+}
+
+bool QQmlMetaObject::hasMetaObject() const
+{
+    return _m.isT2() || (!_m.isNull() && _m.asT1()->metaObject());
+}
+
+const QMetaObject *QQmlMetaObject::metaObject() const
+{
+    if (_m.isNull()) return nullptr;
+    if (_m.isT1()) return _m.asT1()->createMetaObject();
+    else return _m.asT2();
+}
+
+QT_END_NAMESPACE
+
+#endif // QQMLMETAOBJECT_P_H
diff --git a/src/qml/qml/qqmlmetatype.cpp b/src/qml/qml/qqmlmetatype.cpp
index 0672618225..0da96f61e4 100644
--- a/src/qml/qml/qqmlmetatype.cpp
+++ b/src/qml/qml/qqmlmetatype.cpp
@@ -37,321 +37,71 @@
 **
 ****************************************************************************/
 
-#include <QtQml/qqmlprivate.h>
 #include "qqmlmetatype_p.h"
 
-#include <private/qqmlproxymetaobject_p.h>
-#include <private/qqmlcustomparser_p.h>
-#include <private/qhashedstring_p.h>
-#include <private/qqmlimport_p.h>
-
-#include <QtCore/qdebug.h>
-#include <QtCore/qstringlist.h>
-#include <QtCore/qmetaobject.h>
-#include <QtCore/qbitarray.h>
-#include <QtCore/qreadwritelock.h>
-#include <QtCore/private/qmetaobject_p.h>
-
-#include <qmetatype.h>
-#include <qobjectdefs.h>
-#include <qbytearray.h>
-#include <qreadwritelock.h>
-#include <qstring.h>
-#include <qstringlist.h>
-#include <qvector.h>
-
-#include <ctype.h>
-#include "qqmlcomponent.h"
+#include <private/qqmlmetatypedata_p.h>
+#include <private/qqmltypemodule_p_p.h>
+#include <private/qqmltype_p_p.h>
+#include <private/qqmltypeloader_p.h>
+#include <private/qqmlextensionplugin_p.h>
 
-QT_BEGIN_NAMESPACE
-
-struct QQmlMetaTypeData
-{
-    QQmlMetaTypeData();
-    ~QQmlMetaTypeData();
-    QList<QQmlType *> types;
-    typedef QHash<int, QQmlType *> Ids;
-    Ids idToType;
-    typedef QHash<QHashedStringRef,QQmlType *> Names;
-    Names nameToType;
-    typedef QHash<QUrl, QQmlType *> Files; //For file imported composite types only
-    Files urlToType;
-    Files urlToNonFileImportType; // For non-file imported composite and composite
-                                  // singleton types. This way we can locate any
-                                  // of them by url, even if it was registered as
-                                  // a module via QQmlPrivate::RegisterCompositeType
-    typedef QHash<const QMetaObject *, QQmlType *> MetaObjects;
-    MetaObjects metaObjectToType;
-    typedef QHash<int, QQmlMetaType::StringConverter> StringConverters;
-    StringConverters stringConverters;
-
-    struct VersionedUri {
-        VersionedUri()
-        : majorVersion(0) {}
-        VersionedUri(const QHashedString &uri, int majorVersion)
-        : uri(uri), majorVersion(majorVersion) {}
-        bool operator==(const VersionedUri &other) const {
-            return other.majorVersion == majorVersion && other.uri == uri;
-        }
-        QHashedString uri;
-        int majorVersion;
-    };
-    typedef QHash<VersionedUri, QQmlTypeModule *> TypeModules;
-    TypeModules uriToModule;
-
-    QBitArray objects;
-    QBitArray interfaces;
-    QBitArray lists;
-
-    QList<QQmlPrivate::AutoParentFunction> parentFunctions;
-    QVector<QQmlPrivate::QmlUnitCacheLookupFunction> lookupCachedQmlUnit;
+#include <QtCore/qcoreapplication.h>
+#include <QtCore/qmutex.h>
+#include <QtCore/qloggingcategory.h>
 
-    QSet<QString> protectedNamespaces;
+Q_DECLARE_LOGGING_CATEGORY(DBG_DISK_CACHE)
 
-    QString typeRegistrationNamespace;
-    QStringList typeRegistrationFailures;
-};
+QT_BEGIN_NAMESPACE
 
-class QQmlTypeModulePrivate
+struct LockedData : private QQmlMetaTypeData
 {
-public:
-    QQmlTypeModulePrivate()
-    : minMinorVersion(INT_MAX), maxMinorVersion(0), locked(false) {}
-
-    static QQmlTypeModulePrivate* get(QQmlTypeModule* q) { return q->d; }
-
-    QQmlMetaTypeData::VersionedUri uri;
-
-    int minMinorVersion;
-    int maxMinorVersion;
-    bool locked;
-
-    void add(QQmlType *);
-
-    QStringHash<QList<QQmlType *> > typeHash;
-    QList<QQmlType *> types;
+    friend class QQmlMetaTypeDataPtr;
 };
 
-Q_GLOBAL_STATIC(QQmlMetaTypeData, metaTypeData)
+Q_GLOBAL_STATIC(LockedData, metaTypeData)
 Q_GLOBAL_STATIC_WITH_ARGS(QMutex, metaTypeDataLock, (QMutex::Recursive))
 
-static uint qHash(const QQmlMetaTypeData::VersionedUri &v)
-{
-    return v.uri.hash() ^ qHash(v.majorVersion);
-}
-
-QQmlMetaTypeData::QQmlMetaTypeData()
-{
-}
-
-QQmlMetaTypeData::~QQmlMetaTypeData()
-{
-    for (int i = 0; i < types.count(); ++i)
-        delete types.at(i);
-
-    for (TypeModules::const_iterator i = uriToModule.constBegin(), cend = uriToModule.constEnd(); i != cend; ++i)
-        delete *i;
-}
-
-class QQmlTypePrivate
+class QQmlMetaTypeDataPtr
 {
+    Q_DISABLE_COPY_MOVE(QQmlMetaTypeDataPtr)
 public:
-    QQmlTypePrivate(QQmlType::RegistrationType type);
-    ~QQmlTypePrivate();
-
-    void init() const;
-    void initEnums() const;
-    void insertEnums(const QMetaObject *metaObject) const;
+    QQmlMetaTypeDataPtr() : locker(metaTypeDataLock()), data(metaTypeData()) {}
+    ~QQmlMetaTypeDataPtr() = default;
 
-    QQmlType::RegistrationType regType;
+    QQmlMetaTypeData &operator*() { return *data; }
+    QQmlMetaTypeData *operator->() { return data; }
+    operator QQmlMetaTypeData *() { return data; }
 
-    struct QQmlCppTypeData
-    {
-        int allocationSize;
-        void (*newFunc)(void *);
-        QString noCreationReason;
-        int parserStatusCast;
-        QObject *(*extFunc)(QObject *);
-        const QMetaObject *extMetaObject;
-        QQmlCustomParser *customParser;
-        QQmlAttachedPropertiesFunc attachedPropertiesFunc;
-        const QMetaObject *attachedPropertiesType;
-        int attachedPropertiesId;
-        int propertyValueSourceCast;
-        int propertyValueInterceptorCast;
-    };
-
-    struct QQmlSingletonTypeData
-    {
-        QQmlType::SingletonInstanceInfo *singletonInstanceInfo;
-    };
+    const QQmlMetaTypeData &operator*() const { return *data; }
+    const QQmlMetaTypeData *operator->() const { return data; }
+    operator const QQmlMetaTypeData *() const { return data; }
 
-    struct QQmlCompositeTypeData
-    {
-        QUrl url;
-    };
-
-    union extraData {
-        QQmlCppTypeData* cd;
-        QQmlSingletonTypeData* sd;
-        QQmlCompositeTypeData* fd;
-    } extraData;
-
-    const char *iid;
-    QHashedString module;
-    QString name;
-    QString elementName;
-    int version_maj;
-    int version_min;
-    int typeId;
-    int listId;
-    int revision;
-    mutable bool containsRevisionedAttributes;
-    mutable QQmlType *superType;
-    const QMetaObject *baseMetaObject;
-
-    int index;
-    mutable volatile bool isSetup:1;
-    mutable volatile bool isEnumSetup:1;
-    mutable bool haveSuperType:1;
-    mutable QList<QQmlProxyMetaObject::ProxyData> metaObjects;
-    mutable QStringHash<int> enums;
-    mutable QStringHash<int> scopedEnumIndex; // maps from enum name to index in scopedEnums
-    mutable QList<QStringHash<int>*> scopedEnums;
-
-    static QHash<const QMetaObject *, int> attachedPropertyIds;
+private:
+    QMutexLocker locker;
+    LockedData *data = nullptr;
 };
 
-void QQmlType::SingletonInstanceInfo::init(QQmlEngine *e)
-{
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(e->handle());
-    v4->pushGlobalContext();
-    if (scriptCallback && scriptApi(e).isUndefined()) {
-        setScriptApi(e, scriptCallback(e, e));
-    } else if (qobjectCallback && !qobjectApi(e)) {
-        QObject *o = qobjectCallback(e, e);
-        setQObjectApi(e, o);
-        if (!o) {
-            qFatal("qmlRegisterSingletonType(): \"%s\" is not available because the callback function returns a null pointer.", qPrintable(typeName));
-        }
-        // if this object can use a property cache, create it now
-        QQmlData::ensurePropertyCache(e, o);
-    } else if (!url.isEmpty() && !qobjectApi(e)) {
-        QQmlComponent component(e, url, QQmlComponent::PreferSynchronous);
-        QObject *o = component.create();
-        setQObjectApi(e, o);
-    }
-    v4->popContext();
-}
-
-void QQmlType::SingletonInstanceInfo::destroy(QQmlEngine *e)
-{
-    // cleans up the engine-specific singleton instances if they exist.
-    scriptApis.remove(e);
-    QObject *o = qobjectApis.take(e);
-    if (o) {
-        QQmlData *ddata = QQmlData::get(o, false);
-        if (url.isEmpty() && ddata && ddata->indestructible && ddata->explicitIndestructibleSet)
-            return;
-        delete o;
-    }
-}
-
-void QQmlType::SingletonInstanceInfo::setQObjectApi(QQmlEngine *e, QObject *o)
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data,
+                                       const QQmlPrivate::RegisterInterface &type)
 {
-    qobjectApis.insert(e, o);
-}
-
-QObject *QQmlType::SingletonInstanceInfo::qobjectApi(QQmlEngine *e) const
-{
-    return qobjectApis.value(e);
-}
-
-void QQmlType::SingletonInstanceInfo::setScriptApi(QQmlEngine *e, const QJSValue &v)
-{
-    scriptApis.insert(e, v);
-}
-
-QJSValue QQmlType::SingletonInstanceInfo::scriptApi(QQmlEngine *e) const
-{
-    return scriptApis.value(e);
-}
-
-QHash<const QMetaObject *, int> QQmlTypePrivate::attachedPropertyIds;
-
-QQmlTypePrivate::QQmlTypePrivate(QQmlType::RegistrationType type)
-: regType(type), iid(0), typeId(0), listId(0), revision(0),
-    containsRevisionedAttributes(false), superType(0), baseMetaObject(0),
-    index(-1), isSetup(false), isEnumSetup(false), haveSuperType(false)
-{
-    switch (type) {
-    case QQmlType::CppType:
-        extraData.cd = new QQmlCppTypeData;
-        extraData.cd->allocationSize = 0;
-        extraData.cd->newFunc = 0;
-        extraData.cd->parserStatusCast = -1;
-        extraData.cd->extFunc = 0;
-        extraData.cd->extMetaObject = 0;
-        extraData.cd->customParser = 0;
-        extraData.cd->attachedPropertiesFunc = 0;
-        extraData.cd->attachedPropertiesType = 0;
-        extraData.cd->propertyValueSourceCast = -1;
-        extraData.cd->propertyValueInterceptorCast = -1;
-        break;
-    case QQmlType::SingletonType:
-    case QQmlType::CompositeSingletonType:
-        extraData.sd = new QQmlSingletonTypeData;
-        extraData.sd->singletonInstanceInfo = 0;
-        break;
-    case QQmlType::InterfaceType:
-        extraData.cd = 0;
-        break;
-    case QQmlType::CompositeType:
-        extraData.fd = new QQmlCompositeTypeData;
-        break;
-    default: qFatal("QQmlTypePrivate Internal Error.");
-    }
-}
-
-QQmlTypePrivate::~QQmlTypePrivate()
-{
-    qDeleteAll(scopedEnums);
-    switch (regType) {
-    case QQmlType::CppType:
-        delete extraData.cd->customParser;
-        delete extraData.cd;
-        break;
-    case QQmlType::SingletonType:
-    case QQmlType::CompositeSingletonType:
-        delete extraData.sd->singletonInstanceInfo;
-        delete extraData.sd;
-        break;
-    case QQmlType::CompositeType:
-        delete extraData.fd;
-        break;
-    default: //Also InterfaceType, because it has no extra data
-        break;
-    }
-}
-
-QQmlType::QQmlType(int index, const QQmlPrivate::RegisterInterface &interface)
-: d(new QQmlTypePrivate(InterfaceType))
-{
-    d->iid = interface.iid;
-    d->typeId = interface.typeId;
-    d->listId = interface.listId;
-    d->index = index;
+    auto *d = new QQmlTypePrivate(QQmlType::InterfaceType);
+    d->iid = type.iid;
+    d->typeId = type.typeId;
+    d->listId = type.listId;
     d->isSetup = true;
     d->version_maj = 0;
     d->version_min = 0;
+    data->registerType(d);
+    return d;
 }
 
-QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::RegisterSingletonType &type)
-: d(new QQmlTypePrivate(SingletonType))
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterSingletonType &type)
 {
-    d->elementName = elementName;
-    d->module = QString::fromUtf8(type.uri);
+    auto *d = new QQmlTypePrivate(QQmlType::SingletonType);
+    data->registerType(d);
 
+    d->setName(QString::fromUtf8(type.uri), elementName);
     d->version_maj = type.versionMajor;
     d->version_min = type.versionMinor;
 
@@ -364,37 +114,22 @@ QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::Reg
             d->revision = type.revision;
     }
 
-    d->index = index;
-
-    d->extraData.sd->singletonInstanceInfo = new SingletonInstanceInfo;
+    d->extraData.sd->singletonInstanceInfo = new QQmlType::SingletonInstanceInfo;
     d->extraData.sd->singletonInstanceInfo->scriptCallback = type.scriptApi;
     d->extraData.sd->singletonInstanceInfo->qobjectCallback = type.qobjectApi;
     d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
     d->extraData.sd->singletonInstanceInfo->instanceMetaObject
-        = (type.qobjectApi && type.version >= 1) ? type.instanceMetaObject : 0;
-}
+            = (type.qobjectApi && type.version >= 1) ? type.instanceMetaObject : nullptr;
 
-QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::RegisterCompositeSingletonType &type)
-  : d(new QQmlTypePrivate(CompositeSingletonType))
-{
-    d->elementName = elementName;
-    d->module = QString::fromUtf8(type.uri);
-
-    d->version_maj = type.versionMajor;
-    d->version_min = type.versionMinor;
-
-    d->index = index;
-
-    d->extraData.sd->singletonInstanceInfo = new SingletonInstanceInfo;
-    d->extraData.sd->singletonInstanceInfo->url = type.url;
-    d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
+    return d;
 }
 
-QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::RegisterType &type)
-: d(new QQmlTypePrivate(CppType))
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterType &type)
 {
-    d->elementName = elementName;
-    d->module = QString::fromUtf8(type.uri);
+    QQmlTypePrivate *d = new QQmlTypePrivate(QQmlType::CppType);
+    data->registerType(d);
+    d->setName(QString::fromUtf8(type.uri), elementName);
 
     d->version_maj = type.versionMajor;
     d->version_min = type.versionMinor;
@@ -409,10 +144,8 @@ QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::Reg
     d->extraData.cd->attachedPropertiesFunc = type.attachedPropertiesFunction;
     d->extraData.cd->attachedPropertiesType = type.attachedPropertiesMetaObject;
     if (d->extraData.cd->attachedPropertiesType) {
-        QHash<const QMetaObject *, int>::Iterator iter = d->attachedPropertyIds.find(d->baseMetaObject);
-        if (iter == d->attachedPropertyIds.end())
-            iter = d->attachedPropertyIds.insert(d->baseMetaObject, index);
-        d->extraData.cd->attachedPropertiesId = *iter;
+        d->extraData.cd->attachedPropertiesId = data->attachedPropertyId(d->baseMetaObject,
+                                                                         d->index);
     } else {
         d->extraData.cd->attachedPropertiesId = -1;
     }
@@ -421,158 +154,52 @@ QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::Reg
     d->extraData.cd->propertyValueInterceptorCast = type.valueInterceptorCast;
     d->extraData.cd->extFunc = type.extensionObjectCreate;
     d->extraData.cd->customParser = type.customParser;
-    d->index = index;
+    d->extraData.cd->registerEnumClassesUnscoped = true;
 
     if (type.extensionMetaObject)
         d->extraData.cd->extMetaObject = type.extensionMetaObject;
-}
-
-QQmlType::QQmlType(int index, const QString &elementName, const QQmlPrivate::RegisterCompositeType &type)
-: d(new QQmlTypePrivate(CompositeType))
-{
-    d->index = index;
-    d->elementName = elementName;
 
-    d->module = QString::fromUtf8(type.uri);
-    d->version_maj = type.versionMajor;
-    d->version_min = type.versionMinor;
-
-    d->extraData.fd->url = type.url;
-}
-
-QQmlType::~QQmlType()
-{
-    delete d;
-}
-
-const QHashedString &QQmlType::module() const
-{
-    return d->module;
-}
-
-int QQmlType::majorVersion() const
-{
-    return d->version_maj;
-}
-
-int QQmlType::minorVersion() const
-{
-    return d->version_min;
-}
-
-bool QQmlType::availableInVersion(int vmajor, int vminor) const
-{
-    Q_ASSERT(vmajor >= 0 && vminor >= 0);
-    return vmajor == d->version_maj && vminor >= d->version_min;
-}
-
-bool QQmlType::availableInVersion(const QHashedStringRef &module, int vmajor, int vminor) const
-{
-    Q_ASSERT(vmajor >= 0 && vminor >= 0);
-    return module == d->module && vmajor == d->version_maj && vminor >= d->version_min;
-}
-
-// returns the nearest _registered_ super class
-QQmlType *QQmlType::superType() const
-{
-    if (!d->haveSuperType && d->baseMetaObject) {
-        const QMetaObject *mo = d->baseMetaObject->superClass();
-        while (mo && !d->superType) {
-            d->superType = QQmlMetaType::qmlType(mo, d->module, d->version_maj, d->version_min);
-            mo = mo->superClass();
-        }
-        d->haveSuperType = true;
+    // Check if the user wants only scoped enum classes
+    if (d->baseMetaObject) {
+        auto indexOfClassInfo = d->baseMetaObject->indexOfClassInfo("RegisterEnumClassesUnscoped");
+        if (indexOfClassInfo != -1 && QString::fromUtf8(d->baseMetaObject->classInfo(indexOfClassInfo).value()) == QLatin1String("false"))
+            d->extraData.cd->registerEnumClassesUnscoped = false;
     }
 
-    return d->superType;
+    return d;
 }
 
-QQmlType *QQmlType::resolveCompositeBaseType(QQmlEnginePrivate *engine) const
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterCompositeType &type)
 {
-    Q_ASSERT(isComposite());
-    if (!engine)
-        return 0;
-    QQmlRefPointer<QQmlTypeData> td(engine->typeLoader.getType(sourceUrl()), QQmlRefPointer<QQmlTypeData>::Adopt);
-    if (td.isNull() || !td->isComplete())
-        return 0;
-    QV4::CompiledData::CompilationUnit *compilationUnit = td->compilationUnit();
-    const QMetaObject *mo = compilationUnit->rootPropertyCache()->firstCppMetaObject();
-    return QQmlMetaType::qmlType(mo);
-}
-
-int QQmlType::resolveCompositeEnumValue(QQmlEnginePrivate *engine, const QString &name, bool *ok) const
-{
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->enumValue(engine, name, ok);
-}
-
-int QQmlType::resolveCompositeScopedEnumIndex(QQmlEnginePrivate *engine, const QV4::String *name, bool *ok) const
-{
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->scopedEnumIndex(engine, name, ok);
-}
-
-int QQmlType::resolveCompositeScopedEnumIndex(QQmlEnginePrivate *engine, const QString &name, bool *ok) const
-{
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->scopedEnumIndex(engine, name, ok);
-}
-
+    auto *d = new QQmlTypePrivate(QQmlType::CompositeType);
+    data->registerType(d);
+    d->setName(QString::fromUtf8(type.uri), elementName);
+    d->version_maj = type.versionMajor;
+    d->version_min = type.versionMinor;
 
-int QQmlType::resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, int index, const QV4::String *name, bool *ok) const
-{
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->scopedEnumValue(engine, index, name, ok);
+    d->extraData.fd->url = QQmlTypeLoader::normalize(type.url);
+    return d;
 }
 
-int QQmlType::resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &name, bool *ok) const
+static QQmlTypePrivate *createQQmlType(QQmlMetaTypeData *data, const QString &elementName,
+                                       const QQmlPrivate::RegisterCompositeSingletonType &type)
 {
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->scopedEnumValue(engine, index, name, ok);
-}
+    auto *d = new QQmlTypePrivate(QQmlType::CompositeSingletonType);
+    data->registerType(d);
+    d->setName(QString::fromUtf8(type.uri), elementName);
 
-int QQmlType::resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &scopedName, const QByteArray &name, bool *ok) const
-{
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->scopedEnumValue(engine, scopedName, name, ok);
-}
+    d->version_maj = type.versionMajor;
+    d->version_min = type.versionMinor;
 
-int QQmlType::resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &scopedName, const QStringRef &name, bool *ok) const
-{
-    Q_ASSERT(isComposite());
-    *ok = false;
-    QQmlType *type = resolveCompositeBaseType(engine);
-    if (!type)
-        return -1;
-    return type->scopedEnumValue(engine, scopedName, name, ok);
+    d->extraData.sd->singletonInstanceInfo = new QQmlType::SingletonInstanceInfo;
+    d->extraData.sd->singletonInstanceInfo->url = QQmlTypeLoader::normalize(type.url);
+    d->extraData.sd->singletonInstanceInfo->typeName = QString::fromUtf8(type.typeName);
+    return d;
 }
 
-static void clone(QMetaObjectBuilder &builder, const QMetaObject *mo,
-                  const QMetaObject *ignoreStart, const QMetaObject *ignoreEnd)
+void QQmlMetaType::clone(QMetaObjectBuilder &builder, const QMetaObject *mo,
+                         const QMetaObject *ignoreStart, const QMetaObject *ignoreEnd)
 {
     // Set classname
     builder.setClassName(ignoreEnd->className());
@@ -639,699 +266,10 @@ static void clone(QMetaObjectBuilder &builder, const QMetaObject *mo,
     }
 }
 
-static bool isPropertyRevisioned(const QMetaObject *mo, int index)
-{
-    int i = index;
-    i -= mo->propertyOffset();
-    if (i < 0 && mo->d.superdata)
-        return isPropertyRevisioned(mo->d.superdata, index);
-
-    const QMetaObjectPrivate *mop = reinterpret_cast<const QMetaObjectPrivate*>(mo->d.data);
-    if (i >= 0 && i < mop->propertyCount) {
-        int handle = mop->propertyData + 3*i;
-        int flags = mo->d.data[handle + 2];
-
-        return (flags & Revisioned);
-    }
-
-    return false;
-}
-
-void QQmlTypePrivate::init() const
-{
-    if (isSetup)
-        return;
-
-    QMutexLocker lock(metaTypeDataLock());
-    if (isSetup)
-        return;
-
-    const QMetaObject *mo = baseMetaObject;
-    if (!mo) {
-        // version 0 singleton type without metaobject information
-        return;
-    }
-
-    if (regType == QQmlType::CppType) {
-        // Setup extended meta object
-        // XXX - very inefficient
-        if (extraData.cd->extFunc) {
-            QMetaObjectBuilder builder;
-            clone(builder, extraData.cd->extMetaObject, extraData.cd->extMetaObject, extraData.cd->extMetaObject);
-            builder.setFlags(QMetaObjectBuilder::DynamicMetaObject);
-            QMetaObject *mmo = builder.toMetaObject();
-            mmo->d.superdata = mo;
-            QQmlProxyMetaObject::ProxyData data = { mmo, extraData.cd->extFunc, 0, 0 };
-            metaObjects << data;
-        }
-    }
-
-    mo = mo->d.superdata;
-    while(mo) {
-        QQmlType *t = metaTypeData()->metaObjectToType.value(mo);
-        if (t) {
-            if (t->d->regType == QQmlType::CppType) {
-                if (t->d->extraData.cd->extFunc) {
-                    QMetaObjectBuilder builder;
-                    clone(builder, t->d->extraData.cd->extMetaObject, t->d->baseMetaObject, baseMetaObject);
-                    builder.setFlags(QMetaObjectBuilder::DynamicMetaObject);
-                    QMetaObject *mmo = builder.toMetaObject();
-                    mmo->d.superdata = baseMetaObject;
-                    if (!metaObjects.isEmpty())
-                        metaObjects.constLast().metaObject->d.superdata = mmo;
-                    QQmlProxyMetaObject::ProxyData data = { mmo, t->d->extraData.cd->extFunc, 0, 0 };
-                    metaObjects << data;
-                }
-            }
-        }
-        mo = mo->d.superdata;
-    }
-
-    for (int ii = 0; ii < metaObjects.count(); ++ii) {
-        metaObjects[ii].propertyOffset =
-            metaObjects.at(ii).metaObject->propertyOffset();
-        metaObjects[ii].methodOffset =
-            metaObjects.at(ii).metaObject->methodOffset();
-    }
-
-    // Check for revisioned details
-    {
-        const QMetaObject *mo = 0;
-        if (metaObjects.isEmpty())
-            mo = baseMetaObject;
-        else
-            mo = metaObjects.constFirst().metaObject;
-
-        for (int ii = 0; !containsRevisionedAttributes && ii < mo->propertyCount(); ++ii) {
-            if (isPropertyRevisioned(mo, ii))
-                containsRevisionedAttributes = true;
-        }
-
-        for (int ii = 0; !containsRevisionedAttributes && ii < mo->methodCount(); ++ii) {
-            if (mo->method(ii).revision() != 0)
-                containsRevisionedAttributes = true;
-        }
-    }
-
-    isSetup = true;
-    lock.unlock();
-}
-
-void QQmlTypePrivate::initEnums() const
-{
-    if (isEnumSetup) return;
-
-    init();
-
-    QMutexLocker lock(metaTypeDataLock());
-    if (isEnumSetup) return;
-
-    if (baseMetaObject) // could be singleton type without metaobject
-        insertEnums(baseMetaObject);
-
-    isEnumSetup = true;
-}
-
-void QQmlTypePrivate::insertEnums(const QMetaObject *metaObject) const
-{
-    // Add any enum values defined by 'related' classes
-    if (metaObject->d.relatedMetaObjects) {
-        const QMetaObject * const *related = metaObject->d.relatedMetaObjects;
-        if (related) {
-            while (*related)
-                insertEnums(*related++);
-        }
-    }
-
-    // Add any enum values defined by this class, overwriting any inherited values
-    for (int ii = 0; ii < metaObject->enumeratorCount(); ++ii) {
-        QMetaEnum e = metaObject->enumerator(ii);
-        const bool isScoped = e.isScoped();
-        QStringHash<int> *scoped = isScoped ? new QStringHash<int>() : 0;
-
-        for (int jj = 0; jj < e.keyCount(); ++jj) {
-            const QString key = QString::fromUtf8(e.key(jj));
-            const int value = e.value(jj);
-            enums.insert(key, value);
-            if (isScoped)
-                scoped->insert(key, value);
-        }
-
-        if (isScoped) {
-            scopedEnums << scoped;
-            scopedEnumIndex.insert(QString::fromUtf8(e.name()), scopedEnums.count()-1);
-        }
-    }
-}
-
-QByteArray QQmlType::typeName() const
-{
-    if (d->regType == SingletonType || d->regType == CompositeSingletonType)
-        return d->extraData.sd->singletonInstanceInfo->typeName.toUtf8();
-    else if (d->baseMetaObject)
-        return d->baseMetaObject->className();
-    else
-        return QByteArray();
-}
-
-const QString &QQmlType::elementName() const
-{
-    return d->elementName;
-}
-
-const QString &QQmlType::qmlTypeName() const
-{
-    if (d->name.isEmpty()) {
-        if (!d->module.isEmpty())
-            d->name = static_cast<QString>(d->module) + QLatin1Char('/') + d->elementName;
-        else
-            d->name = d->elementName;
-    }
-
-    return d->name;
-}
-
-QObject *QQmlType::create() const
-{
-    if (!isCreatable())
-        return 0;
-
-    d->init();
-
-    QObject *rv = (QObject *)operator new(d->extraData.cd->allocationSize);
-    d->extraData.cd->newFunc(rv);
-
-    if (rv && !d->metaObjects.isEmpty())
-        (void)new QQmlProxyMetaObject(rv, &d->metaObjects);
-
-    return rv;
-}
-
-void QQmlType::create(QObject **out, void **memory, size_t additionalMemory) const
-{
-    if (!isCreatable())
-        return;
-
-    d->init();
-
-    QObject *rv = (QObject *)operator new(d->extraData.cd->allocationSize + additionalMemory);
-    d->extraData.cd->newFunc(rv);
-
-    if (rv && !d->metaObjects.isEmpty())
-        (void)new QQmlProxyMetaObject(rv, &d->metaObjects);
-
-    *out = rv;
-    *memory = ((char *)rv) + d->extraData.cd->allocationSize;
-}
-
-QQmlType::SingletonInstanceInfo *QQmlType::singletonInstanceInfo() const
-{
-    if (d->regType != SingletonType && d->regType != CompositeSingletonType)
-        return 0;
-    return d->extraData.sd->singletonInstanceInfo;
-}
-
-QQmlCustomParser *QQmlType::customParser() const
-{
-    if (d->regType != CppType)
-        return 0;
-    return d->extraData.cd->customParser;
-}
-
-QQmlType::CreateFunc QQmlType::createFunction() const
-{
-    if (d->regType != CppType)
-        return 0;
-    return d->extraData.cd->newFunc;
-}
-
-QString QQmlType::noCreationReason() const
-{
-    if (d->regType != CppType)
-        return QString();
-    return d->extraData.cd->noCreationReason;
-}
-
-int QQmlType::createSize() const
-{
-    if (d->regType != CppType)
-        return 0;
-    return d->extraData.cd->allocationSize;
-}
-
-bool QQmlType::isCreatable() const
-{
-    return d->regType == CppType && d->extraData.cd->newFunc;
-}
-
-bool QQmlType::isExtendedType() const
-{
-    d->init();
-
-    return !d->metaObjects.isEmpty();
-}
-
-bool QQmlType::isSingleton() const
-{
-    return d->regType == SingletonType || d->regType == CompositeSingletonType;
-}
-
-bool QQmlType::isInterface() const
-{
-    return d->regType == InterfaceType;
-}
-
-bool QQmlType::isComposite() const
-{
-    return d->regType == CompositeType || d->regType == CompositeSingletonType;
-}
-
-bool QQmlType::isCompositeSingleton() const
-{
-    return d->regType == CompositeSingletonType;
-}
-
-int QQmlType::typeId() const
-{
-    return d->typeId;
-}
-
-int QQmlType::qListTypeId() const
-{
-    return d->listId;
-}
-
-const QMetaObject *QQmlType::metaObject() const
-{
-    d->init();
-
-    if (d->metaObjects.isEmpty())
-        return d->baseMetaObject;
-    else
-        return d->metaObjects.constFirst().metaObject;
-
-}
-
-const QMetaObject *QQmlType::baseMetaObject() const
-{
-    return d->baseMetaObject;
-}
-
-bool QQmlType::containsRevisionedAttributes() const
-{
-    d->init();
-
-    return d->containsRevisionedAttributes;
-}
-
-int QQmlType::metaObjectRevision() const
-{
-    return d->revision;
-}
-
-QQmlAttachedPropertiesFunc QQmlType::attachedPropertiesFunction(QQmlEnginePrivate *engine) const
-{
-    if (d->regType == CppType)
-        return d->extraData.cd->attachedPropertiesFunc;
-
-    QQmlType *base = 0;
-    if (d->regType == CompositeType)
-        base = resolveCompositeBaseType(engine);
-    return base ? base->attachedPropertiesFunction(engine) : 0;
-}
-
-const QMetaObject *QQmlType::attachedPropertiesType(QQmlEnginePrivate *engine) const
-{
-    if (d->regType == CppType)
-        return d->extraData.cd->attachedPropertiesType;
-
-    QQmlType *base = 0;
-    if (d->regType == CompositeType)
-        base = resolveCompositeBaseType(engine);
-    return base ? base->attachedPropertiesType(engine) : 0;
-}
-
-/*
-This is the id passed to qmlAttachedPropertiesById().  This is different from the index
-for the case that a single class is registered under two or more names (eg. Item in
-Qt 4.7 and QtQuick 1.0).
-*/
-int QQmlType::attachedPropertiesId(QQmlEnginePrivate *engine) const
-{
-    if (d->regType == CppType)
-        return d->extraData.cd->attachedPropertiesId;
-
-    QQmlType *base = 0;
-    if (d->regType == CompositeType)
-        base = resolveCompositeBaseType(engine);
-    return base ? base->attachedPropertiesId(engine) : 0;
-}
-
-int QQmlType::parserStatusCast() const
-{
-    if (d->regType != CppType)
-        return -1;
-    return d->extraData.cd->parserStatusCast;
-}
-
-int QQmlType::propertyValueSourceCast() const
-{
-    if (d->regType != CppType)
-        return -1;
-    return d->extraData.cd->propertyValueSourceCast;
-}
-
-int QQmlType::propertyValueInterceptorCast() const
-{
-    if (d->regType != CppType)
-        return -1;
-    return d->extraData.cd->propertyValueInterceptorCast;
-}
-
-const char *QQmlType::interfaceIId() const
-{
-    if (d->regType != InterfaceType)
-        return 0;
-    return d->iid;
-}
-
-int QQmlType::index() const
-{
-    return d->index;
-}
-
-QUrl QQmlType::sourceUrl() const
-{
-    if (d->regType == CompositeType)
-        return d->extraData.fd->url;
-    else if (d->regType == CompositeSingletonType)
-        return d->extraData.sd->singletonInstanceInfo->url;
-    else
-        return QUrl();
-}
-
-int QQmlType::enumValue(QQmlEnginePrivate *engine, const QHashedStringRef &name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeEnumValue(engine, name.toString(), ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->enums.value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::enumValue(QQmlEnginePrivate *engine, const QHashedCStringRef &name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeEnumValue(engine, name.toUtf16(), ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->enums.value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::enumValue(QQmlEnginePrivate *engine, const QV4::String *name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeEnumValue(engine, name->toQString(), ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->enums.value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::scopedEnumIndex(QQmlEnginePrivate *engine, const QV4::String *name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeScopedEnumIndex(engine, name, ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->scopedEnumIndex.value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::scopedEnumIndex(QQmlEnginePrivate *engine, const QString &name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeScopedEnumIndex(engine, name, ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->scopedEnumIndex.value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, int index, const QV4::String *name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeScopedEnumValue(engine, index, name, ok);
-    *ok = true;
-
-    Q_ASSERT(index > -1 && index < d->scopedEnums.count());
-    int *rv = d->scopedEnums.at(index)->value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeScopedEnumValue(engine, index, name, ok);
-    *ok = true;
-
-    Q_ASSERT(index > -1 && index < d->scopedEnums.count());
-    int *rv = d->scopedEnums.at(index)->value(name);
-    if (rv)
-        return *rv;
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &scopedEnumName, const QByteArray &name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeScopedEnumValue(engine, scopedEnumName, name, ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->scopedEnumIndex.value(QHashedCStringRef(scopedEnumName.constData(), scopedEnumName.length()));
-    if (rv) {
-        int index = *rv;
-        Q_ASSERT(index > -1 && index < d->scopedEnums.count());
-        rv = d->scopedEnums.at(index)->value(QHashedCStringRef(name.constData(), name.length()));
-        if (rv)
-            return *rv;
-    }
-
-    *ok = false;
-    return -1;
-}
-
-int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &scopedEnumName, const QStringRef &name, bool *ok) const
-{
-    Q_ASSERT(ok);
-    if (isComposite())
-        return resolveCompositeScopedEnumValue(engine, scopedEnumName, name, ok);
-    *ok = true;
-
-    d->initEnums();
-
-    int *rv = d->scopedEnumIndex.value(QHashedStringRef(scopedEnumName));
-    if (rv) {
-        int index = *rv;
-        Q_ASSERT(index > -1 && index < d->scopedEnums.count());
-        rv = d->scopedEnums.at(index)->value(QHashedStringRef(name));
-        if (rv)
-            return *rv;
-    }
-
-    *ok = false;
-    return -1;
-}
-
-QQmlTypeModule::QQmlTypeModule()
-: d(new QQmlTypeModulePrivate)
-{
-}
-
-QQmlTypeModule::~QQmlTypeModule()
-{
-    delete d; d = 0;
-}
-
-QString QQmlTypeModule::module() const
-{
-    return d->uri.uri;
-}
-
-int QQmlTypeModule::majorVersion() const
-{
-    return d->uri.majorVersion;
-}
-
-int QQmlTypeModule::minimumMinorVersion() const
-{
-    return d->minMinorVersion;
-}
-
-int QQmlTypeModule::maximumMinorVersion() const
-{
-    return d->maxMinorVersion;
-}
-
-void QQmlTypeModulePrivate::add(QQmlType *type)
-{
-    minMinorVersion = qMin(minMinorVersion, type->minorVersion());
-    maxMinorVersion = qMax(maxMinorVersion, type->minorVersion());
-
-    QList<QQmlType *> &list = typeHash[type->elementName()];
-    for (int ii = 0; ii < list.count(); ++ii) {
-        if (list.at(ii)->minorVersion() < type->minorVersion()) {
-            list.insert(ii, type);
-            return;
-        }
-    }
-    list.append(type);
-}
-
-QQmlType *QQmlTypeModule::type(const QHashedStringRef &name, int minor) const
-{
-    QMutexLocker lock(metaTypeDataLock());
-
-    QList<QQmlType *> *types = d->typeHash.value(name);
-    if (!types) return 0;
-
-    for (int ii = 0; ii < types->count(); ++ii)
-        if (types->at(ii)->minorVersion() <= minor)
-            return types->at(ii);
-
-    return 0;
-}
-
-QQmlType *QQmlTypeModule::type(const QV4::String *name, int minor) const
-{
-    QMutexLocker lock(metaTypeDataLock());
-
-    QList<QQmlType *> *types = d->typeHash.value(name);
-    if (!types) return 0;
-
-    for (int ii = 0; ii < types->count(); ++ii)
-        if (types->at(ii)->minorVersion() <= minor)
-            return types->at(ii);
-
-    return 0;
-}
-
-QList<QQmlType*> QQmlTypeModule::singletonTypes(int minor) const
-{
-    QMutexLocker lock(metaTypeDataLock());
-
-    QList<QQmlType *> retn;
-    for (int ii = 0; ii < d->types.count(); ++ii) {
-        QQmlType *curr = d->types.at(ii);
-        if (curr->isSingleton() && curr->minorVersion() <= minor)
-            retn.append(curr);
-    }
-
-    return retn;
-}
-
-QQmlTypeModuleVersion::QQmlTypeModuleVersion()
-: m_module(0), m_minor(0)
-{
-}
-
-QQmlTypeModuleVersion::QQmlTypeModuleVersion(QQmlTypeModule *module, int minor)
-: m_module(module), m_minor(minor)
-{
-    Q_ASSERT(m_module);
-    Q_ASSERT(m_minor >= 0);
-}
-
-QQmlTypeModuleVersion::QQmlTypeModuleVersion(const QQmlTypeModuleVersion &o)
-: m_module(o.m_module), m_minor(o.m_minor)
-{
-}
-
-QQmlTypeModuleVersion &QQmlTypeModuleVersion::operator=(const QQmlTypeModuleVersion &o)
-{
-    m_module = o.m_module;
-    m_minor = o.m_minor;
-    return *this;
-}
-
-QQmlTypeModule *QQmlTypeModuleVersion::module() const
-{
-    return m_module;
-}
-
-int QQmlTypeModuleVersion::minorVersion() const
-{
-    return m_minor;
-}
-
-QQmlType *QQmlTypeModuleVersion::type(const QHashedStringRef &name) const
-{
-    if (m_module) return m_module->type(name, m_minor);
-    else return 0;
-}
-
-QQmlType *QQmlTypeModuleVersion::type(const QV4::String *name) const
-{
-    if (m_module) return m_module->type(name, m_minor);
-    else return 0;
-}
-
-void qmlClearTypeRegistrations() // Declared in qqml.h
+void QQmlMetaType::clearTypeRegistrations()
 {
     //Only cleans global static, assumed no running engine
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-
-    for (int i = 0; i < data->types.count(); ++i)
-        delete data->types.at(i);
+    QQmlMetaTypeDataPtr data;
 
     for (QQmlMetaTypeData::TypeModules::const_iterator i = data->uriToModule.constBegin(), cend = data->uriToModule.constEnd(); i != cend; ++i)
         delete *i;
@@ -1343,50 +281,41 @@ void qmlClearTypeRegistrations() // Declared in qqml.h
     data->urlToNonFileImportType.clear();
     data->metaObjectToType.clear();
     data->uriToModule.clear();
-
-    QQmlEnginePrivate::baseModulesUninitialized = true; //So the engine re-registers its types
-#if QT_CONFIG(library)
-    qmlClearEnginePlugins();
-#endif
+    data->undeletableTypes.clear();
 }
 
-int registerAutoParentFunction(QQmlPrivate::RegisterAutoParent &autoparent)
+int QQmlMetaType::registerAutoParentFunction(QQmlPrivate::RegisterAutoParent &autoparent)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
     data->parentFunctions.append(autoparent.function);
 
     return data->parentFunctions.count() - 1;
 }
 
-int registerInterface(const QQmlPrivate::RegisterInterface &interface)
+QQmlType QQmlMetaType::registerInterface(const QQmlPrivate::RegisterInterface &type)
 {
-    if (interface.version > 0)
+    if (type.version > 0)
         qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
 
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-
-    int index = data->types.count();
-
-    QQmlType *type = new QQmlType(index, interface);
+    QQmlMetaTypeDataPtr data;
+    QQmlTypePrivate *priv = createQQmlType(data, type);
+    Q_ASSERT(priv);
 
-    data->types.append(type);
-    data->idToType.insert(type->typeId(), type);
-    data->idToType.insert(type->qListTypeId(), type);
+    data->idToType.insert(priv->typeId, priv);
+    data->idToType.insert(priv->listId, priv);
     // XXX No insertMulti, so no multi-version interfaces?
-    if (!type->elementName().isEmpty())
-        data->nameToType.insert(type->elementName(), type);
+    if (!priv->elementName.isEmpty())
+        data->nameToType.insert(priv->elementName, priv);
 
-    if (data->interfaces.size() <= interface.typeId)
-        data->interfaces.resize(interface.typeId + 16);
-    if (data->lists.size() <= interface.listId)
-        data->lists.resize(interface.listId + 16);
-    data->interfaces.setBit(interface.typeId, true);
-    data->lists.setBit(interface.listId, true);
+    if (data->interfaces.size() <= type.typeId)
+        data->interfaces.resize(type.typeId + 16);
+    if (data->lists.size() <= type.listId)
+        data->lists.resize(type.listId + 16);
+    data->interfaces.setBit(type.typeId, true);
+    data->lists.setBit(type.listId, true);
 
-    return index;
+    return QQmlType(priv);
 }
 
 QString registrationTypeString(QQmlType::RegistrationType typeType)
@@ -1404,14 +333,21 @@ QString registrationTypeString(QQmlType::RegistrationType typeType)
 }
 
 // NOTE: caller must hold a QMutexLocker on "data"
-bool checkRegistration(QQmlType::RegistrationType typeType, QQmlMetaTypeData *data, const char *uri, const QString &typeName, int majorVersion = -1)
+bool checkRegistration(QQmlType::RegistrationType typeType, QQmlMetaTypeData *data,
+                       const char *uri, const QString &typeName, int majorVersion = -1)
 {
     if (!typeName.isEmpty()) {
+        if (typeName.at(0).isLower()) {
+            QString failure(QCoreApplication::translate("qmlRegisterType", "Invalid QML %1 name \"%2\"; type names must begin with an uppercase letter"));
+            data->recordTypeRegFailure(failure.arg(registrationTypeString(typeType)).arg(typeName));
+            return false;
+        }
+
         int typeNameLen = typeName.length();
         for (int ii = 0; ii < typeNameLen; ++ii) {
             if (!(typeName.at(ii).isLetterOrNumber() || typeName.at(ii) == '_')) {
                 QString failure(QCoreApplication::translate("qmlRegisterType", "Invalid QML %1 name \"%2\""));
-                data->typeRegistrationFailures.append(failure.arg(registrationTypeString(typeType)).arg(typeName));
+                data->recordTypeRegFailure(failure.arg(registrationTypeString(typeType)).arg(typeName));
                 return false;
             }
         }
@@ -1420,20 +356,12 @@ bool checkRegistration(QQmlType::RegistrationType typeType, QQmlMetaTypeData *da
     if (uri && !typeName.isEmpty()) {
         QString nameSpace = QString::fromUtf8(uri);
 
-        if (!data->typeRegistrationNamespace.isEmpty()) {
-            // We can only install types into the registered namespace
-            if (nameSpace != data->typeRegistrationNamespace) {
-                QString failure(QCoreApplication::translate("qmlRegisterType",
-                                                            "Cannot install %1 '%2' into unregistered namespace '%3'"));
-                data->typeRegistrationFailures.append(failure.arg(registrationTypeString(typeType)).arg(typeName).arg(nameSpace));
-                return false;
-            }
-        } else if (data->typeRegistrationNamespace != nameSpace) {
+        if (data->typeRegistrationNamespace.isEmpty() && !nameSpace.isEmpty()) {
             // Is the target namespace protected against further registrations?
             if (data->protectedNamespaces.contains(nameSpace)) {
                 QString failure(QCoreApplication::translate("qmlRegisterType",
                                                             "Cannot install %1 '%2' into protected namespace '%3'"));
-                data->typeRegistrationFailures.append(failure.arg(registrationTypeString(typeType)).arg(typeName).arg(nameSpace));
+                data->recordTypeRegFailure(failure.arg(registrationTypeString(typeType)).arg(typeName).arg(nameSpace));
                 return false;
             }
         } else if (majorVersion >= 0) {
@@ -1441,10 +369,10 @@ bool checkRegistration(QQmlType::RegistrationType typeType, QQmlMetaTypeData *da
             versionedUri.uri = nameSpace;
             versionedUri.majorVersion = majorVersion;
             if (QQmlTypeModule* qqtm = data->uriToModule.value(versionedUri, 0)){
-                if (QQmlTypeModulePrivate::get(qqtm)->locked){
+                if (qqtm->isLocked()){
                     QString failure(QCoreApplication::translate("qmlRegisterType",
                                                                 "Cannot install %1 '%2' into protected module '%3' version '%4'"));
-                    data->typeRegistrationFailures.append(failure.arg(registrationTypeString(typeType)).arg(typeName).arg(nameSpace).arg(majorVersion));
+                    data->recordTypeRegFailure(failure.arg(registrationTypeString(typeType)).arg(typeName).arg(nameSpace).arg(majorVersion));
                     return false;
                 }
             }
@@ -1460,230 +388,425 @@ QQmlTypeModule *getTypeModule(const QHashedString &uri, int majorVersion, QQmlMe
     QQmlMetaTypeData::VersionedUri versionedUri(uri, majorVersion);
     QQmlTypeModule *module = data->uriToModule.value(versionedUri);
     if (!module) {
-        module = new QQmlTypeModule;
-        module->d->uri = versionedUri;
+        module = new QQmlTypeModule(versionedUri.uri, versionedUri.majorVersion);
         data->uriToModule.insert(versionedUri, module);
     }
     return module;
 }
 
 // NOTE: caller must hold a QMutexLocker on "data"
-void addTypeToData(QQmlType* type, QQmlMetaTypeData *data)
+void addTypeToData(QQmlTypePrivate *type, QQmlMetaTypeData *data)
 {
-    if (!type->elementName().isEmpty())
-        data->nameToType.insertMulti(type->elementName(), type);
+    Q_ASSERT(type);
 
-    if (type->baseMetaObject())
-        data->metaObjectToType.insertMulti(type->baseMetaObject(), type);
+    if (!type->elementName.isEmpty())
+        data->nameToType.insertMulti(type->elementName, type);
 
-    if (type->typeId()) {
-        data->idToType.insert(type->typeId(), type);
-        if (data->objects.size() <= type->typeId())
-            data->objects.resize(type->typeId() + 16);
-        data->objects.setBit(type->typeId(), true);
+    if (type->baseMetaObject)
+        data->metaObjectToType.insertMulti(type->baseMetaObject, type);
+
+    if (type->typeId) {
+        data->idToType.insert(type->typeId, type);
+        if (data->objects.size() <= type->typeId)
+            data->objects.resize(type->typeId + 16);
+        data->objects.setBit(type->typeId, true);
     }
 
-    if (type->qListTypeId()) {
-        if (data->lists.size() <= type->qListTypeId())
-            data->lists.resize(type->qListTypeId() + 16);
-        data->lists.setBit(type->qListTypeId(), true);
-        data->idToType.insert(type->qListTypeId(), type);
+    if (type->listId) {
+        if (data->lists.size() <= type->listId)
+            data->lists.resize(type->listId + 16);
+        data->lists.setBit(type->listId, true);
+        data->idToType.insert(type->listId, type);
     }
 
-    if (!type->module().isEmpty()) {
-        const QHashedString &mod = type->module();
+    if (!type->module.isEmpty()) {
+        const QHashedString &mod = type->module;
 
-        QQmlTypeModule *module = getTypeModule(mod, type->majorVersion(), data);
+        QQmlTypeModule *module = getTypeModule(mod, type->version_maj, data);
         Q_ASSERT(module);
-        module->d->add(type);
+        module->add(type);
     }
 }
 
-int registerType(const QQmlPrivate::RegisterType &type)
+QQmlType QQmlMetaType::registerType(const QQmlPrivate::RegisterType &type)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
+
     QString elementName = QString::fromUtf8(type.elementName);
     if (!checkRegistration(QQmlType::CppType, data, type.uri, elementName, type.versionMajor))
-        return -1;
+        return QQmlType();
 
-    int index = data->types.count();
+    QQmlTypePrivate *priv = createQQmlType(data, elementName, type);
 
-    QQmlType *dtype = new QQmlType(index, elementName, type);
-
-    data->types.append(dtype);
-    addTypeToData(dtype, data);
+    addTypeToData(priv, data);
     if (!type.typeId)
-        data->idToType.insert(dtype->typeId(), dtype);
+        data->idToType.insert(priv->typeId, priv);
 
-    return index;
+    return QQmlType(priv);
 }
 
-int registerSingletonType(const QQmlPrivate::RegisterSingletonType &type)
+QQmlType QQmlMetaType::registerSingletonType(const QQmlPrivate::RegisterSingletonType &type)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
+
     QString typeName = QString::fromUtf8(type.typeName);
     if (!checkRegistration(QQmlType::SingletonType, data, type.uri, typeName, type.versionMajor))
-        return -1;
-
-    int index = data->types.count();
+        return QQmlType();
 
-    QQmlType *dtype = new QQmlType(index, typeName, type);
+    QQmlTypePrivate *priv = createQQmlType(data, typeName, type);
 
-    data->types.append(dtype);
-    addTypeToData(dtype, data);
+    addTypeToData(priv, data);
 
-    return index;
+    return QQmlType(priv);
 }
 
-int registerCompositeSingletonType(const QQmlPrivate::RegisterCompositeSingletonType &type)
+QQmlType QQmlMetaType::registerCompositeSingletonType(const QQmlPrivate::RegisterCompositeSingletonType &type)
 {
     // Assumes URL is absolute and valid. Checking of user input should happen before the URL enters type.
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
+
     QString typeName = QString::fromUtf8(type.typeName);
     bool fileImport = false;
     if (*(type.uri) == '\0')
         fileImport = true;
-    if (!checkRegistration(QQmlType::CompositeSingletonType, data, fileImport ? 0 : type.uri, typeName))
-        return -1;
-
-    int index = data->types.count();
+    if (!checkRegistration(QQmlType::CompositeSingletonType, data, fileImport ? nullptr : type.uri, typeName))
+        return QQmlType();
 
-    QQmlType *dtype = new QQmlType(index, typeName, type);
-
-    data->types.append(dtype);
-    addTypeToData(dtype, data);
+    QQmlTypePrivate *priv = createQQmlType(data, typeName, type);
+    addTypeToData(priv, data);
 
     QQmlMetaTypeData::Files *files = fileImport ? &(data->urlToType) : &(data->urlToNonFileImportType);
-    files->insertMulti(type.url, dtype);
+    files->insertMulti(QQmlTypeLoader::normalize(type.url), priv);
 
-    return index;
+    return QQmlType(priv);
 }
 
-int registerCompositeType(const QQmlPrivate::RegisterCompositeType &type)
+QQmlType QQmlMetaType::registerCompositeType(const QQmlPrivate::RegisterCompositeType &type)
 {
     // Assumes URL is absolute and valid. Checking of user input should happen before the URL enters type.
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
+
     QString typeName = QString::fromUtf8(type.typeName);
     bool fileImport = false;
     if (*(type.uri) == '\0')
         fileImport = true;
-    if (!checkRegistration(QQmlType::CompositeType, data, fileImport?0:type.uri, typeName, type.versionMajor))
-        return -1;
+    if (!checkRegistration(QQmlType::CompositeType, data, fileImport?nullptr:type.uri, typeName, type.versionMajor))
+        return QQmlType();
 
-    int index = data->types.count();
-
-    QQmlType *dtype = new QQmlType(index, typeName, type);
-    data->types.append(dtype);
-    addTypeToData(dtype, data);
+    QQmlTypePrivate *priv = createQQmlType(data, typeName, type);
+    addTypeToData(priv, data);
 
     QQmlMetaTypeData::Files *files = fileImport ? &(data->urlToType) : &(data->urlToNonFileImportType);
-    files->insertMulti(type.url, dtype);
+    files->insertMulti(QQmlTypeLoader::normalize(type.url), priv);
+
+    return QQmlType(priv);
+}
+
+void QQmlMetaType::registerInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit)
+{
+    QByteArray name = compilationUnit->rootPropertyCache()->className();
+
+    QByteArray ptr = name + '*';
+    QByteArray lst = "QQmlListProperty<" + name + '>';
 
-    return index;
+    int ptr_type = QMetaType::registerNormalizedType(ptr,
+                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QObject*>::Destruct,
+                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QObject*>::Construct,
+                                                     sizeof(QObject*),
+                                                     static_cast<QFlags<QMetaType::TypeFlag> >(QtPrivate::QMetaTypeTypeFlags<QObject*>::Flags),
+                                                     nullptr);
+    int lst_type = QMetaType::registerNormalizedType(lst,
+                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QQmlListProperty<QObject> >::Destruct,
+                                                     QtMetaTypePrivate::QMetaTypeFunctionHelper<QQmlListProperty<QObject> >::Construct,
+                                                     sizeof(QQmlListProperty<QObject>),
+                                                     static_cast<QFlags<QMetaType::TypeFlag> >(QtPrivate::QMetaTypeTypeFlags<QQmlListProperty<QObject> >::Flags),
+                                                     static_cast<QMetaObject*>(nullptr));
+
+    compilationUnit->metaTypeId = ptr_type;
+    compilationUnit->listMetaTypeId = lst_type;
+
+    QQmlMetaTypeDataPtr data;
+    data->qmlLists.insert(lst_type, ptr_type);
+}
+
+void QQmlMetaType::unregisterInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit)
+{
+    int ptr_type = compilationUnit->metaTypeId;
+    int lst_type = compilationUnit->listMetaTypeId;
+
+    QQmlMetaTypeDataPtr data;
+    data->qmlLists.remove(lst_type);
+
+    QMetaType::unregisterType(ptr_type);
+    QMetaType::unregisterType(lst_type);
 }
 
-int registerQmlUnitCacheHook(const QQmlPrivate::RegisterQmlUnitCacheHook &hookRegistration)
+int QQmlMetaType::registerUnitCacheHook(
+        const QQmlPrivate::RegisterQmlUnitCacheHook &hookRegistration)
 {
     if (hookRegistration.version > 0)
         qFatal("qmlRegisterType(): Cannot mix incompatible QML versions.");
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+
+    QQmlMetaTypeDataPtr data;
     data->lookupCachedQmlUnit << hookRegistration.lookupCachedQmlUnit;
     return 0;
 }
 
-/*
-This method is "over generalized" to allow us to (potentially) register more types of things in
-the future without adding exported symbols.
-*/
-int QQmlPrivate::qmlregister(RegistrationType type, void *data)
-{
-    if (type == TypeRegistration) {
-        return registerType(*reinterpret_cast<RegisterType *>(data));
-    } else if (type == InterfaceRegistration) {
-        return registerInterface(*reinterpret_cast<RegisterInterface *>(data));
-    } else if (type == AutoParentRegistration) {
-        return registerAutoParentFunction(*reinterpret_cast<RegisterAutoParent *>(data));
-    } else if (type == SingletonRegistration) {
-        return registerSingletonType(*reinterpret_cast<RegisterSingletonType *>(data));
-    } else if (type == CompositeRegistration) {
-        return registerCompositeType(*reinterpret_cast<RegisterCompositeType *>(data));
-    } else if (type == CompositeSingletonRegistration) {
-        return registerCompositeSingletonType(*reinterpret_cast<RegisterCompositeSingletonType *>(data));
-    } else if (type == QmlUnitCacheHookRegistration) {
-        return registerQmlUnitCacheHook(*reinterpret_cast<RegisterQmlUnitCacheHook *>(data));
-    }
-    return -1;
-}
-
-//From qqml.h
-bool qmlProtectModule(const char *uri, int majVersion)
+bool QQmlMetaType::protectModule(const char *uri, int majVersion)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
     QQmlMetaTypeData::VersionedUri versionedUri;
     versionedUri.uri = QString::fromUtf8(uri);
     versionedUri.majorVersion = majVersion;
 
     if (QQmlTypeModule* qqtm = data->uriToModule.value(versionedUri, 0)) {
-        QQmlTypeModulePrivate::get(qqtm)->locked = true;
+        qqtm->lock();
         return true;
     }
     return false;
 }
 
-//From qqml.h
-void qmlRegisterModule(const char *uri, int versionMajor, int versionMinor)
+void QQmlMetaType::registerModule(const char *uri, int versionMajor, int versionMinor)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
     QQmlTypeModule *module = getTypeModule(QString::fromUtf8(uri), versionMajor, data);
     Q_ASSERT(module);
 
-    QQmlTypeModulePrivate *p = QQmlTypeModulePrivate::get(module);
-    p->minMinorVersion = qMin(p->minMinorVersion, versionMinor);
-    p->maxMinorVersion = qMax(p->maxMinorVersion, versionMinor);
+    module->addMinorVersion(versionMinor);
+}
+
+int QQmlMetaType::typeId(const char *uri, int versionMajor, int versionMinor, const char *qmlName)
+{
+    QQmlMetaTypeDataPtr data;
+
+    QQmlTypeModule *module = getTypeModule(QString::fromUtf8(uri), versionMajor, data);
+    if (!module)
+        return -1;
+
+    QQmlType type = module->type(QHashedStringRef(QString::fromUtf8(qmlName)), versionMinor);
+    if (!type.isValid())
+        return -1;
+
+    return type.index();
+}
+
+void QQmlMetaType::registerUndeletableType(const QQmlType &dtype)
+{
+    QQmlMetaTypeDataPtr data;
+    data->undeletableTypes.insert(dtype);
 }
 
-bool QQmlMetaType::namespaceContainsRegistrations(const QString &uri, int majorVersion)
+int QQmlMetaType::registerAttachedPropertyId(const QMetaObject *metaObject, int index)
 {
-    const QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
+    return data->attachedPropertyId(metaObject, index);
+}
+
+bool QQmlMetaType::unregisterAttachedPropertyId(const QMetaObject *metaObject, int index)
+{
+    QQmlMetaTypeDataPtr data;
+    // This is run from the QQmlType dtor. QQmlTypes in user code can outlive QQmlMetaTypeData.
+    return data ? data->removeAttachedPropertyId(metaObject, index) : false;
+}
 
+static bool namespaceContainsRegistrations(const QQmlMetaTypeData *data, const QString &uri,
+                                           int majorVersion)
+{
     // Has any type previously been installed to this namespace?
     QHashedString nameSpace(uri);
-    for (const QQmlType *type : data->types)
-        if (type->module() == nameSpace && type->majorVersion() == majorVersion)
+    for (const QQmlType &type : data->types) {
+        if (type.module() == nameSpace && type.majorVersion() == majorVersion)
             return true;
+    }
 
     return false;
 }
 
-void QQmlMetaType::protectNamespace(const QString &uri)
+class QQmlMetaTypeRegistrationFailureRecorder
 {
-    QQmlMetaTypeData *data = metaTypeData();
+    Q_DISABLE_COPY_MOVE(QQmlMetaTypeRegistrationFailureRecorder)
+public:
+    QQmlMetaTypeRegistrationFailureRecorder(QQmlMetaTypeData *data, QStringList *failures)
+        : data(data)
+    {
+        data->setTypeRegistrationFailures(failures);
+    }
 
-    data->protectedNamespaces.insert(uri);
-}
+    ~QQmlMetaTypeRegistrationFailureRecorder()
+    {
+        data->setTypeRegistrationFailures(nullptr);
+    }
+
+    QQmlMetaTypeData *data = nullptr;
+};
 
-void QQmlMetaType::setTypeRegistrationNamespace(const QString &uri)
+
+bool QQmlMetaType::registerPluginTypes(QObject *instance, const QString &basePath,
+                                       const QString &uri, const QString &typeNamespace, int vmaj,
+                                       QList<QQmlError> *errors)
 {
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlTypesExtensionInterface *iface = qobject_cast<QQmlTypesExtensionInterface *>(instance);
+    if (!iface) {
+        if (errors) {
+            QQmlError error;
+            error.setDescription(QStringLiteral("Module loaded for URI '%1' does not implement "
+                                                "QQmlTypesExtensionInterface").arg(typeNamespace));
+            errors->prepend(error);
+        }
+        return false;
+    }
+
+    if (!typeNamespace.isEmpty() && typeNamespace != uri) {
+        // This is an 'identified' module
+        // The namespace for type registrations must match the URI for locating the module
+        if (errors) {
+            QQmlError error;
+            error.setDescription(
+                    QStringLiteral("Module namespace '%1' does not match import URI '%2'")
+                            .arg(typeNamespace).arg(uri));
+            errors->prepend(error);
+        }
+        return false;
+    }
+
+    QStringList failures;
+    QQmlMetaTypeDataPtr data;
+    {
+        QQmlMetaTypeRegistrationFailureRecorder failureRecorder(data, &failures);
+        if (!typeNamespace.isEmpty()) {
+            // This is an 'identified' module
+            if (namespaceContainsRegistrations(data, typeNamespace, vmaj)) {
+                // Other modules have already installed to this namespace
+                if (errors) {
+                    QQmlError error;
+                    error.setDescription(QStringLiteral("Namespace '%1' has already been used "
+                                                        "for type registration")
+                                                 .arg(typeNamespace));
+                    errors->prepend(error);
+                }
+                return false;
+            }
+
+            data->protectedNamespaces.insert(uri);
+        } else {
+            // This is not an identified module - provide a warning
+            qWarning().nospace() << qPrintable(
+                    QStringLiteral("Module '%1' does not contain a module identifier directive - "
+                                   "it cannot be protected from external registrations.").arg(uri));
+        }
+
+        if (auto *plugin = qobject_cast<QQmlExtensionPlugin *>(instance)) {
+        // basepath should point to the directory of the module, not the plugin file itself:
+        QQmlExtensionPluginPrivate::get(plugin)->baseUrl
+                = QQmlImports::urlFromLocalFileOrQrcOrUrl(basePath);
+        }
+
+        data->typeRegistrationNamespace = typeNamespace;
+        const QByteArray bytes = uri.toUtf8();
+        const char *moduleId = bytes.constData();
+        iface->registerTypes(moduleId);
+        data->typeRegistrationNamespace.clear();
+    }
 
-    data->typeRegistrationNamespace = uri;
-    data->typeRegistrationFailures.clear();
+    if (!failures.isEmpty()) {
+        if (errors) {
+            for (const QString &failure : qAsConst(failures)) {
+                QQmlError error;
+                error.setDescription(failure);
+                errors->prepend(error);
+            }
+        }
+        return false;
+    }
+
+    return true;
 }
 
-QStringList QQmlMetaType::typeRegistrationFailures()
-{
-    QQmlMetaTypeData *data = metaTypeData();
+/*
+    \internal
+
+    Fetches the QQmlType instance registered for \a urlString, creating a
+    registration for it if it is not already registered, using the associated
+    \a typeName, \a isCompositeSingleton, \a majorVersion and \a minorVersion
+    details.
+
+    Errors (if there are any) are placed into \a errors, if it is nonzero.
+    Otherwise errors are printed as warnings.
+*/
+QQmlType QQmlMetaType::typeForUrl(const QString &urlString,
+                                  const QHashedStringRef &qualifiedType,
+                                  bool isCompositeSingleton, QList<QQmlError> *errors,
+                                  int majorVersion, int minorVersion)
+{
+    // ### unfortunate (costly) conversion
+    const QUrl url = QQmlTypeLoader::normalize(QUrl(urlString));
+
+    QQmlMetaTypeDataPtr data;
+    QQmlType ret(data->urlToType.value(url));
+    if (ret.isValid() && ret.sourceUrl() == url)
+        return ret;
+
+    const int dot = qualifiedType.indexOf(QLatin1Char('.'));
+    const QString typeName = dot < 0
+            ? qualifiedType.toString()
+            : QString(qualifiedType.constData() + dot + 1, qualifiedType.length() - dot - 1);
+
+    QStringList failures;
+    QQmlMetaTypeRegistrationFailureRecorder failureRecorder(data, &failures);
+
+    // Register the type. Note that the URI parameters here are empty; for
+    // file type imports, we do not place them in a URI as we don't
+    // necessarily have a good and unique one (picture a library import,
+    // which may be found in multiple plugin locations on disk), but there
+    // are other reasons for this too.
+    //
+    // By not putting them in a URI, we prevent the types from being
+    // registered on a QQmlTypeModule; this is important, as once types are
+    // placed on there, they cannot be easily removed, meaning if the
+    // developer subsequently loads a different import (meaning different
+    // types) with the same URI (using, say, a different plugin path), it is
+    // very undesirable that we continue to associate the types from the
+    // "old" URI with that new module.
+    //
+    // Not having URIs also means that the types cannot be found by name
+    // etc, the only way to look them up is through QQmlImports -- for
+    // better or worse.
+    const QQmlType::RegistrationType registrationType = isCompositeSingleton
+            ? QQmlType::CompositeSingletonType
+            : QQmlType::CompositeType;
+    if (checkRegistration(registrationType, data, nullptr, typeName, majorVersion)) {
+        auto *priv = new QQmlTypePrivate(registrationType);
+        priv->setName(QString(), typeName);
+        priv->version_maj = majorVersion;
+        priv->version_min = minorVersion;
+
+        if (isCompositeSingleton) {
+            priv->extraData.sd->singletonInstanceInfo = new QQmlType::SingletonInstanceInfo;
+            priv->extraData.sd->singletonInstanceInfo->url = url;
+            priv->extraData.sd->singletonInstanceInfo->typeName = typeName;
+        } else {
+            priv->extraData.fd->url = url;
+        }
 
-    return data->typeRegistrationFailures;
+        data->registerType(priv);
+        addTypeToData(priv, data);
+        data->urlToType.insertMulti(url, priv);
+        return QQmlType(priv);
+    }
+
+    // This means that the type couldn't be found by URL, but could not be
+    // registered either, meaning we most likely were passed some kind of bad
+    // data.
+    if (errors) {
+        QQmlError error;
+        error.setDescription(failures.join('\n'));
+        errors->prepend(error);
+    } else {
+        qWarning("%s", failures.join('\n').toLatin1().constData());
+    }
+    return QQmlType();
 }
 
 QMutex *QQmlMetaType::typeRegistrationLock()
@@ -1696,8 +819,7 @@ QMutex *QQmlMetaType::typeRegistrationLock()
 */
 bool QQmlMetaType::isAnyModule(const QString &uri)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
     for (QQmlMetaTypeData::TypeModules::ConstIterator iter = data->uriToModule.cbegin();
          iter != data->uriToModule.cend(); ++iter) {
@@ -1713,14 +835,13 @@ bool QQmlMetaType::isAnyModule(const QString &uri)
 */
 bool QQmlMetaType::isLockedModule(const QString &uri, int majVersion)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
     QQmlMetaTypeData::VersionedUri versionedUri;
     versionedUri.uri = uri;
     versionedUri.majorVersion = majVersion;
     if (QQmlTypeModule* qqtm = data->uriToModule.value(versionedUri, 0))
-        return QQmlTypeModulePrivate::get(qqtm)->locked;
+        return qqtm->isLocked();
     return false;
 }
 
@@ -1734,9 +855,7 @@ bool QQmlMetaType::isLockedModule(const QString &uri, int majVersion)
 bool QQmlMetaType::isModule(const QString &module, int versionMajor, int versionMinor)
 {
     Q_ASSERT(versionMajor >= 0 && versionMinor >= 0);
-    QMutexLocker lock(metaTypeDataLock());
-
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
     // first, check Types
     QQmlTypeModule *tm =
@@ -1749,15 +868,13 @@ bool QQmlMetaType::isModule(const QString &module, int versionMajor, int version
 
 QQmlTypeModule *QQmlMetaType::typeModule(const QString &uri, int majorVersion)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
     return data->uriToModule.value(QQmlMetaTypeData::VersionedUri(uri, majorVersion));
 }
 
 QList<QQmlPrivate::AutoParentFunction> QQmlMetaType::parentFunctions()
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
     return data->parentFunctions;
 }
 
@@ -1765,7 +882,7 @@ QObject *QQmlMetaType::toQObject(const QVariant &v, bool *ok)
 {
     if (!isQObject(v.userType())) {
         if (ok) *ok = false;
-        return 0;
+        return nullptr;
     }
 
     if (ok) *ok = true;
@@ -1778,8 +895,7 @@ bool QQmlMetaType::isQObject(int userType)
     if (userType == QMetaType::QObjectStar)
         return true;
 
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
     return userType >= 0 && userType < data->objects.size() && data->objects.testBit(userType);
 }
 
@@ -1788,34 +904,37 @@ bool QQmlMetaType::isQObject(int userType)
  */
 int QQmlMetaType::listType(int id)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-    QQmlType *type = data->idToType.value(id);
-    if (type && type->qListTypeId() == id)
-        return type->typeId();
+    QQmlMetaTypeDataPtr data;
+    QHash<int, int>::ConstIterator iter = data->qmlLists.constFind(id);
+    if (iter != data->qmlLists.cend())
+        return *iter;
+    QQmlTypePrivate *type = data->idToType.value(id);
+    if (type && type->listId == id)
+        return type->typeId;
     else
         return 0;
 }
 
 int QQmlMetaType::attachedPropertiesFuncId(QQmlEnginePrivate *engine, const QMetaObject *mo)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
 
-    QQmlType *type = data->metaObjectToType.value(mo);
-    if (type && type->attachedPropertiesFunction(engine))
-        return type->attachedPropertiesId(engine);
-    else
-        return -1;
+    for (auto it = data->metaObjectToType.constFind(mo), end = data->metaObjectToType.constEnd();
+         it != end && it.key() == mo; ++it) {
+        const QQmlType type(it.value());
+        if (type.attachedPropertiesFunction(engine))
+            return type.attachedPropertiesId(engine);
+    }
+
+    return -1;
 }
 
 QQmlAttachedPropertiesFunc QQmlMetaType::attachedPropertiesFuncById(QQmlEnginePrivate *engine, int id)
 {
     if (id < 0)
-        return 0;
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-    return data->types.at(id)->attachedPropertiesFunction(engine);
+        return nullptr;
+    QQmlMetaTypeDataPtr data;
+    return data->types.at(id).attachedPropertiesFunction(engine);
 }
 
 QMetaProperty QQmlMetaType::defaultProperty(const QMetaObject *metaObject)
@@ -1877,9 +996,10 @@ QQmlMetaType::TypeCategory QQmlMetaType::typeCategory(int userType)
     if (userType == QMetaType::QObjectStar)
         return Object;
 
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-    if (userType < data->objects.size() && data->objects.testBit(userType))
+    QQmlMetaTypeDataPtr data;
+    if (data->qmlLists.contains(userType))
+        return List;
+    else if (userType < data->objects.size() && data->objects.testBit(userType))
         return Object;
     else if (userType < data->lists.size() && data->lists.testBit(userType))
         return List;
@@ -1887,29 +1007,36 @@ QQmlMetaType::TypeCategory QQmlMetaType::typeCategory(int userType)
         return Unknown;
 }
 
+/*!
+    See qmlRegisterInterface() for information about when this will return true.
+*/
 bool QQmlMetaType::isInterface(int userType)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
     return userType >= 0 && userType < data->interfaces.size() && data->interfaces.testBit(userType);
 }
 
 const char *QQmlMetaType::interfaceIId(int userType)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-    QQmlType *type = data->idToType.value(userType);
-    lock.unlock();
-    if (type && type->isInterface() && type->typeId() == userType)
-        return type->interfaceIId();
+
+    QQmlTypePrivate *typePrivate = nullptr;
+    {
+        QQmlMetaTypeDataPtr data;
+        typePrivate = data->idToType.value(userType);
+    }
+
+    QQmlType type(typePrivate);
+    if (type.isInterface() && type.typeId() == userType)
+        return type.interfaceIId();
     else
-        return 0;
+        return nullptr;
 }
 
 bool QQmlMetaType::isList(int userType)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
+    if (data->qmlLists.contains(userType))
+        return true;
     return userType >= 0 && userType < data->lists.size() && data->lists.testBit(userType);
 }
 
@@ -1930,9 +1057,7 @@ bool QQmlMetaType::isList(int userType)
  */
 void QQmlMetaType::registerCustomStringConverter(int type, StringConverter converter)
 {
-    QMutexLocker lock(metaTypeDataLock());
-
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data;
     if (data->stringConverters.contains(type))
         return;
     data->stringConverters.insert(type, converter);
@@ -1944,9 +1069,7 @@ void QQmlMetaType::registerCustomStringConverter(int type, StringConverter conve
  */
 QQmlMetaType::StringConverter QQmlMetaType::customStringConverter(int type)
 {
-    QMutexLocker lock(metaTypeDataLock());
-
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
     return data->stringConverters.value(type);
 }
 
@@ -1954,11 +1077,11 @@ QQmlMetaType::StringConverter QQmlMetaType::customStringConverter(int type)
     Returns the type (if any) of URI-qualified named \a qualifiedName and version specified
     by \a version_major and \a version_minor.
 */
-QQmlType *QQmlMetaType::qmlType(const QString &qualifiedName, int version_major, int version_minor)
+QQmlType QQmlMetaType::qmlType(const QString &qualifiedName, int version_major, int version_minor)
 {
     int slash = qualifiedName.indexOf(QLatin1Char('/'));
     if (slash <= 0)
-        return 0;
+        return QQmlType();
 
     QHashedStringRef module(qualifiedName.constData(), slash);
     QHashedStringRef name(qualifiedName.constData() + slash + 1, qualifiedName.length() - slash - 1);
@@ -1970,33 +1093,31 @@ QQmlType *QQmlMetaType::qmlType(const QString &qualifiedName, int version_major,
     Returns the type (if any) of \a name in \a module and version specified
     by \a version_major and \a version_minor.
 */
-QQmlType *QQmlMetaType::qmlType(const QHashedStringRef &name, const QHashedStringRef &module, int version_major, int version_minor)
+QQmlType QQmlMetaType::qmlType(const QHashedStringRef &name, const QHashedStringRef &module, int version_major, int version_minor)
 {
     Q_ASSERT(version_major >= 0 && version_minor >= 0);
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
 
     QQmlMetaTypeData::Names::ConstIterator it = data->nameToType.constFind(name);
     while (it != data->nameToType.cend() && it.key() == name) {
+        QQmlType t(*it);
         // XXX version_major<0 just a kludge for QQmlPropertyPrivate::initProperty
-        if (version_major < 0 || module.isEmpty() || (*it)->availableInVersion(module, version_major,version_minor))
-            return (*it);
+        if (version_major < 0 || module.isEmpty() || t.availableInVersion(module, version_major,version_minor))
+            return t;
         ++it;
     }
 
-    return 0;
+    return QQmlType();
 }
 
 /*!
     Returns the type (if any) that corresponds to the \a metaObject.  Returns null if no
     type is registered.
 */
-QQmlType *QQmlMetaType::qmlType(const QMetaObject *metaObject)
+QQmlType QQmlMetaType::qmlType(const QMetaObject *metaObject)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-
-    return data->metaObjectToType.value(metaObject);
+    const QQmlMetaTypeDataPtr data;
+    return QQmlType(data->metaObjectToType.value(metaObject));
 }
 
 /*!
@@ -2004,37 +1125,41 @@ QQmlType *QQmlMetaType::qmlType(const QMetaObject *metaObject)
     by \a version_major and \a version_minor in module specified by \a uri.  Returns null if no
     type is registered.
 */
-QQmlType *QQmlMetaType::qmlType(const QMetaObject *metaObject, const QHashedStringRef &module, int version_major, int version_minor)
+QQmlType QQmlMetaType::qmlType(const QMetaObject *metaObject, const QHashedStringRef &module, int version_major, int version_minor)
 {
     Q_ASSERT(version_major >= 0 && version_minor >= 0);
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
 
     QQmlMetaTypeData::MetaObjects::const_iterator it = data->metaObjectToType.constFind(metaObject);
     while (it != data->metaObjectToType.cend() && it.key() == metaObject) {
-        QQmlType *t = *it;
-        if (version_major < 0 || module.isEmpty() || t->availableInVersion(module, version_major,version_minor))
+        QQmlType t(*it);
+        if (version_major < 0 || module.isEmpty() || t.availableInVersion(module, version_major,version_minor))
             return t;
         ++it;
     }
 
-    return 0;
+    return QQmlType();
 }
 
 /*!
-    Returns the type (if any) that corresponds to the QVariant::Type \a userType.
-    Returns null if no type is registered.
+    Returns the type (if any) that corresponds to \a typeId.  Depending on \a category, the
+    \a typeId is interpreted either as QVariant::Type or as QML type id returned by one of the
+    qml type registration functions.  Returns null if no type is registered.
 */
-QQmlType *QQmlMetaType::qmlType(int userType)
-{
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-
-    QQmlType *type = data->idToType.value(userType);
-    if (type && type->typeId() == userType)
-        return type;
-    else
-        return 0;
+QQmlType QQmlMetaType::qmlType(int typeId, TypeIdCategory category)
+{
+    const QQmlMetaTypeDataPtr data;
+
+    if (category == TypeIdCategory::MetaType) {
+        QQmlTypePrivate *type = data->idToType.value(typeId);
+        if (type && type->typeId == typeId)
+            return QQmlType(type);
+    } else if (category == TypeIdCategory::QmlType) {
+        QQmlType type = data->types.value(typeId);
+        if (type.isValid())
+            return type;
+    }
+    return QQmlType();
 }
 
 /*!
@@ -2043,34 +1168,94 @@ QQmlType *QQmlMetaType::qmlType(int userType)
 
     Returns null if no such type is registered.
 */
-QQmlType *QQmlMetaType::qmlType(const QUrl &url, bool includeNonFileImports /* = false */)
+QQmlType QQmlMetaType::qmlType(const QUrl &unNormalizedUrl, bool includeNonFileImports /* = false */)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QUrl url = QQmlTypeLoader::normalize(unNormalizedUrl);
+    const QQmlMetaTypeDataPtr data;
 
-    QQmlType *type = data->urlToType.value(url);
-    if (!type && includeNonFileImports)
-        type = data->urlToNonFileImportType.value(url);
+    QQmlType type(data->urlToType.value(url));
+    if (!type.isValid() && includeNonFileImports)
+        type = QQmlType(data->urlToNonFileImportType.value(url));
 
-    if (type && type->sourceUrl() == url)
+    if (type.sourceUrl() == url)
         return type;
     else
-        return 0;
+        return QQmlType();
 }
 
-/*!
-    Returns the type (if any) with the given \a index in the global type store.
-    This is for use when you just got the index back from a qmlRegister function.
-    Returns null if the index is out of bounds.
-*/
-QQmlType *QQmlMetaType::qmlTypeFromIndex(int idx)
+QQmlPropertyCache *QQmlMetaType::propertyCache(const QMetaObject *metaObject, int minorVersion)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    QQmlMetaTypeDataPtr data; // not const: the cache is created on demand
+    return data->propertyCache(metaObject, minorVersion);
+}
+
+QQmlPropertyCache *QQmlMetaType::propertyCache(const QQmlType &type, int minorVersion)
+{
+    QQmlMetaTypeDataPtr data; // not const: the cache is created on demand
+    return data->propertyCache(type, minorVersion);
+}
+
+void QQmlMetaType::unregisterType(int typeIndex)
+{
+    QQmlMetaTypeDataPtr data;
+    if (const QQmlTypePrivate *d = data->types.value(typeIndex).priv()) {
+        removeQQmlTypePrivate(data->idToType, d);
+        removeQQmlTypePrivate(data->nameToType, d);
+        removeQQmlTypePrivate(data->urlToType, d);
+        removeQQmlTypePrivate(data->urlToNonFileImportType, d);
+        removeQQmlTypePrivate(data->metaObjectToType, d);
+        for (auto & module : data->uriToModule)
+            module->remove(d);
+        data->types[typeIndex] = QQmlType();
+    }
+}
+
+void QQmlMetaType::freeUnusedTypesAndCaches()
+{
+    QQmlMetaTypeDataPtr data;
+
+    bool deletedAtLeastOneType;
+    do {
+        deletedAtLeastOneType = false;
+        QList<QQmlType>::Iterator it = data->types.begin();
+        while (it != data->types.end()) {
+            const QQmlTypePrivate *d = (*it).priv();
+            if (d && d->count() == 1) {
+                deletedAtLeastOneType = true;
 
-    if (idx < 0 || idx >= data->types.count())
-            return 0;
-    return data->types.at(idx);
+                removeQQmlTypePrivate(data->idToType, d);
+                removeQQmlTypePrivate(data->nameToType, d);
+                removeQQmlTypePrivate(data->urlToType, d);
+                removeQQmlTypePrivate(data->urlToNonFileImportType, d);
+                removeQQmlTypePrivate(data->metaObjectToType, d);
+
+                for (auto &module : data->uriToModule)
+                    module->remove(d);
+
+                *it = QQmlType();
+            } else {
+                ++it;
+            }
+        }
+    } while (deletedAtLeastOneType);
+
+    bool deletedAtLeastOneCache;
+    do {
+        deletedAtLeastOneCache = false;
+        QHash<const QMetaObject *, QQmlPropertyCache *>::Iterator it = data->propertyCaches.begin();
+        while (it != data->propertyCaches.end()) {
+
+            if ((*it)->count() == 1) {
+                QQmlPropertyCache *pc = nullptr;
+                qSwap(pc, *it);
+                it = data->propertyCaches.erase(it);
+                pc->release();
+                deletedAtLeastOneCache = true;
+            } else {
+                ++it;
+            }
+        }
+    } while (deletedAtLeastOneCache);
 }
 
 /*!
@@ -2078,14 +1263,14 @@ QQmlType *QQmlMetaType::qmlTypeFromIndex(int idx)
 */
 QList<QString> QQmlMetaType::qmlTypeNames()
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
 
     QList<QString> names;
     names.reserve(data->nameToType.count());
     QQmlMetaTypeData::Names::ConstIterator it = data->nameToType.cbegin();
     while (it != data->nameToType.cend()) {
-        names += (*it)->qmlTypeName();
+        QQmlType t(*it);
+        names += t.qmlTypeName();
         ++it;
     }
 
@@ -2095,51 +1280,77 @@ QList<QString> QQmlMetaType::qmlTypeNames()
 /*!
     Returns the list of registered QML types.
 */
-QList<QQmlType*> QQmlMetaType::qmlTypes()
+QList<QQmlType> QQmlMetaType::qmlTypes()
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
+
+    QList<QQmlType> types;
+    for (QQmlTypePrivate *t : data->nameToType)
+        types.append(QQmlType(t));
 
-    return data->nameToType.values();
+    return types;
 }
 
 /*!
     Returns the list of all registered types.
 */
-QList<QQmlType*> QQmlMetaType::qmlAllTypes()
+QList<QQmlType> QQmlMetaType::qmlAllTypes()
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
-
+    const QQmlMetaTypeDataPtr data;
     return data->types;
 }
 
 /*!
     Returns the list of registered QML singleton types.
 */
-QList<QQmlType*> QQmlMetaType::qmlSingletonTypes()
+QList<QQmlType> QQmlMetaType::qmlSingletonTypes()
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
 
-    QList<QQmlType*> retn;
-    for (const auto type : qAsConst(data->nameToType)) {
-        if (type->isSingleton())
+    QList<QQmlType> retn;
+    for (const auto t : qAsConst(data->nameToType)) {
+        QQmlType type(t);
+        if (type.isSingleton())
             retn.append(type);
     }
     return retn;
 }
 
-const QQmlPrivate::CachedQmlUnit *QQmlMetaType::findCachedCompilationUnit(const QUrl &uri)
+const QV4::CompiledData::Unit *QQmlMetaType::findCachedCompilationUnit(const QUrl &uri, CachedUnitLookupError *status)
 {
-    QMutexLocker lock(metaTypeDataLock());
-    QQmlMetaTypeData *data = metaTypeData();
+    const QQmlMetaTypeDataPtr data;
 
     for (const auto lookup : qAsConst(data->lookupCachedQmlUnit)) {
-        if (const QQmlPrivate::CachedQmlUnit *unit = lookup(uri))
-            return unit;
+        if (const QQmlPrivate::CachedQmlUnit *unit = lookup(uri)) {
+            QString error;
+            if (!unit->qmlData->verifyHeader(QDateTime(), &error)) {
+                qCDebug(DBG_DISK_CACHE) << "Error loading pre-compiled file " << uri << ":" << error;
+                if (status)
+                    *status = CachedUnitLookupError::VersionMismatch;
+                return nullptr;
+            }
+            if (status)
+                *status = CachedUnitLookupError::NoError;
+            return unit->qmlData;
+        }
     }
-    return 0;
+
+    if (status)
+        *status = CachedUnitLookupError::NoUnitFound;
+
+    return nullptr;
+}
+
+void QQmlMetaType::prependCachedUnitLookupFunction(QQmlPrivate::QmlUnitCacheLookupFunction handler)
+{
+    QQmlMetaTypeDataPtr data;
+    data->lookupCachedQmlUnit.prepend(handler);
+}
+
+void QQmlMetaType::removeCachedUnitLookupFunction(QQmlPrivate::QmlUnitCacheLookupFunction handler)
+{
+    QQmlMetaTypeDataPtr data;
+    data->lookupCachedQmlUnit.removeAll(handler);
 }
 
 /*!
@@ -2152,9 +1363,9 @@ QString QQmlMetaType::prettyTypeName(const QObject *object)
     if (!object)
         return typeName;
 
-    const QQmlType *type = QQmlMetaType::qmlType(object->metaObject());
-    if (type) {
-        typeName = type->qmlTypeName();
+    QQmlType type = QQmlMetaType::qmlType(object->metaObject());
+    if (type.isValid()) {
+        typeName = type.qmlTypeName();
         const int lastSlash = typeName.lastIndexOf(QLatin1Char('/'));
         if (lastSlash != -1)
             typeName = typeName.mid(lastSlash + 1);
@@ -2170,8 +1381,8 @@ QString QQmlMetaType::prettyTypeName(const QObject *object)
         if (marker != -1) {
             typeName = typeName.leftRef(marker) + QLatin1Char('*');
             type = QQmlMetaType::qmlType(QMetaType::type(typeName.toLatin1()));
-            if (type) {
-                QString qmlTypeName = type->qmlTypeName();
+            if (type.isValid()) {
+                QString qmlTypeName = type.qmlTypeName();
                 const int lastSlash = qmlTypeName.lastIndexOf(QLatin1Char('/'));
                 if (lastSlash != -1)
                     qmlTypeName = qmlTypeName.mid(lastSlash + 1);
@@ -2184,4 +1395,38 @@ QString QQmlMetaType::prettyTypeName(const QObject *object)
     return typeName;
 }
 
+QList<QQmlProxyMetaObject::ProxyData> QQmlMetaType::proxyData(const QMetaObject *mo,
+                                                              const QMetaObject *baseMetaObject,
+                                                              QMetaObject *lastMetaObject)
+{
+    QList<QQmlProxyMetaObject::ProxyData> metaObjects;
+    mo = mo->d.superdata;
+
+    const QQmlMetaTypeDataPtr data;
+
+    while (mo) {
+        QQmlTypePrivate *t = data->metaObjectToType.value(mo);
+        if (t) {
+            if (t->regType == QQmlType::CppType) {
+                if (t->extraData.cd->extFunc) {
+                    QMetaObjectBuilder builder;
+                    clone(builder, t->extraData.cd->extMetaObject, t->baseMetaObject, baseMetaObject);
+                    builder.setFlags(QMetaObjectBuilder::DynamicMetaObject);
+                    QMetaObject *mmo = builder.toMetaObject();
+                    mmo->d.superdata = baseMetaObject;
+                    if (!metaObjects.isEmpty())
+                        metaObjects.constLast().metaObject->d.superdata = mmo;
+                    else if (lastMetaObject)
+                        lastMetaObject->d.superdata = mmo;
+                    QQmlProxyMetaObject::ProxyData data = { mmo, t->extraData.cd->extFunc, 0, 0 };
+                    metaObjects << data;
+                }
+            }
+        }
+        mo = mo->d.superdata;
+    }
+
+    return metaObjects;
+}
+
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlmetatype_p.h b/src/qml/qml/qqmlmetatype_p.h
index 4dd28bbd36..dde9cf68d7 100644
--- a/src/qml/qml/qqmlmetatype_p.h
+++ b/src/qml/qml/qqmlmetatype_p.h
@@ -51,43 +51,67 @@
 // We mean it.
 //
 
-#include "qqml.h"
 #include <private/qtqmlglobal_p.h>
-
-#include <QtCore/qglobal.h>
-#include <QtCore/qvariant.h>
-#include <QtCore/qbitarray.h>
-#include <QtQml/qjsvalue.h>
+#include <private/qqmltype_p.h>
+#include <private/qqmlproxymetaobject_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QQmlType;
-class QQmlEngine;
-class QQmlEnginePrivate;
-class QQmlCustomParser;
-class QQmlTypePrivate;
 class QQmlTypeModule;
-class QHashedString;
-class QHashedStringRef;
 class QMutex;
-
-namespace QV4 { struct String; }
+class QQmlError;
 
 class Q_QML_PRIVATE_EXPORT QQmlMetaType
 {
 public:
+    static QQmlType registerType(const QQmlPrivate::RegisterType &type);
+    static QQmlType registerInterface(const QQmlPrivate::RegisterInterface &type);
+    static QQmlType registerSingletonType(const QQmlPrivate::RegisterSingletonType &type);
+    static QQmlType registerCompositeSingletonType(const QQmlPrivate::RegisterCompositeSingletonType &type);
+    static QQmlType registerCompositeType(const QQmlPrivate::RegisterCompositeType &type);
+    static bool registerPluginTypes(QObject *instance, const QString &basePath,
+                                    const QString &uri, const QString &typeNamespace, int vmaj,
+                                    QList<QQmlError> *errors);
+    static QQmlType typeForUrl(const QString &urlString, const QHashedStringRef& typeName,
+                               bool isCompositeSingleton, QList<QQmlError> *errors,
+                               int majorVersion = -1, int minorVersion = -1);
+
+    static void unregisterType(int type);
+
+    static void registerInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit);
+    static void unregisterInternalCompositeType(QV4::CompiledData::CompilationUnit *compilationUnit);
+
+    static void registerModule(const char *uri, int versionMajor, int versionMinor);
+    static bool protectModule(const char *uri, int majVersion);
+
+    static int typeId(const char *uri, int versionMajor, int versionMinor, const char *qmlName);
+
+    static void registerUndeletableType(const QQmlType &dtype);
+
+    static int registerAttachedPropertyId(const QMetaObject *metaObject, int index);
+    static bool unregisterAttachedPropertyId(const QMetaObject *metaObject, int index);
+
     static QList<QString> qmlTypeNames();
-    static QList<QQmlType*> qmlTypes();
-    static QList<QQmlType*> qmlSingletonTypes();
-    static QList<QQmlType*> qmlAllTypes();
-
-    static QQmlType *qmlType(const QString &qualifiedName, int, int);
-    static QQmlType *qmlType(const QHashedStringRef &name, const QHashedStringRef &module, int, int);
-    static QQmlType *qmlType(const QMetaObject *);
-    static QQmlType *qmlType(const QMetaObject *metaObject, const QHashedStringRef &module, int version_major, int version_minor);
-    static QQmlType *qmlType(int);
-    static QQmlType *qmlType(const QUrl &url, bool includeNonFileImports = false);
-    static QQmlType *qmlTypeFromIndex(int);
+    static QList<QQmlType> qmlTypes();
+    static QList<QQmlType> qmlSingletonTypes();
+    static QList<QQmlType> qmlAllTypes();
+
+    enum class TypeIdCategory {
+        MetaType,
+        QmlType
+    };
+
+    static QQmlType qmlType(const QString &qualifiedName, int, int);
+    static QQmlType qmlType(const QHashedStringRef &name, const QHashedStringRef &module, int, int);
+    static QQmlType qmlType(const QMetaObject *);
+    static QQmlType qmlType(const QMetaObject *metaObject, const QHashedStringRef &module, int version_major, int version_minor);
+    static QQmlType qmlType(int typeId, TypeIdCategory category = TypeIdCategory::MetaType);
+    static QQmlType qmlType(const QUrl &unNormalizedUrl, bool includeNonFileImports = false);
+
+    static QQmlPropertyCache *propertyCache(const QMetaObject *metaObject, int minorVersion = -1);
+    static QQmlPropertyCache *propertyCache(const QQmlType &type, int minorVersion);
+
+    static void freeUnusedTypesAndCaches();
 
     static QMetaProperty defaultProperty(const QMetaObject *);
     static QMetaProperty defaultProperty(QObject *);
@@ -95,7 +119,7 @@ public:
     static QMetaMethod defaultMethod(QObject *);
 
     static bool isQObject(int);
-    static QObject *toQObject(const QVariant &, bool *ok = 0);
+    static QObject *toQObject(const QVariant &, bool *ok = nullptr);
 
     static int listType(int);
     static int attachedPropertiesFuncId(QQmlEnginePrivate *engine, const QMetaObject *);
@@ -119,196 +143,47 @@ public:
 
     static QList<QQmlPrivate::AutoParentFunction> parentFunctions();
 
-    static const QQmlPrivate::CachedQmlUnit *findCachedCompilationUnit(const QUrl &uri);
-
-    static bool namespaceContainsRegistrations(const QString &, int majorVersion);
+    enum class CachedUnitLookupError {
+        NoError,
+        NoUnitFound,
+        VersionMismatch
+    };
 
-    static void protectNamespace(const QString &);
+    static const QV4::CompiledData::Unit *findCachedCompilationUnit(const QUrl &uri, CachedUnitLookupError *status);
 
-    static void setTypeRegistrationNamespace(const QString &);
-    static QStringList typeRegistrationFailures();
+    // used by tst_qqmlcachegen.cpp
+    static void prependCachedUnitLookupFunction(QQmlPrivate::QmlUnitCacheLookupFunction handler);
+    static void removeCachedUnitLookupFunction(QQmlPrivate::QmlUnitCacheLookupFunction handler);
 
     static QMutex *typeRegistrationLock();
 
     static QString prettyTypeName(const QObject *object);
-};
-
-struct QQmlMetaTypeData;
-class QHashedCStringRef;
-class Q_QML_PRIVATE_EXPORT QQmlType
-{
-public:
-    QByteArray typeName() const;
-    const QString &qmlTypeName() const;
-    const QString &elementName() const;
-
-    const QHashedString &module() const;
-    int majorVersion() const;
-    int minorVersion() const;
-
-    bool availableInVersion(int vmajor, int vminor) const;
-    bool availableInVersion(const QHashedStringRef &module, int vmajor, int vminor) const;
-
-    QObject *create() const;
-    void create(QObject **, void **, size_t) const;
-
-    typedef void (*CreateFunc)(void *);
-    CreateFunc createFunction() const;
-    int createSize() const;
-
-    QQmlCustomParser *customParser() const;
 
-    bool isCreatable() const;
-    bool isExtendedType() const;
-    QString noCreationReason() const;
-
-    bool isSingleton() const;
-    bool isInterface() const;
-    bool isComposite() const;
-    bool isCompositeSingleton() const;
-
-    int typeId() const;
-    int qListTypeId() const;
-
-    const QMetaObject *metaObject() const;
-    const QMetaObject *baseMetaObject() const;
-    int metaObjectRevision() const;
-    bool containsRevisionedAttributes() const;
-
-    QQmlAttachedPropertiesFunc attachedPropertiesFunction(QQmlEnginePrivate *engine) const;
-    const QMetaObject *attachedPropertiesType(QQmlEnginePrivate *engine) const;
-    int attachedPropertiesId(QQmlEnginePrivate *engine) const;
-
-    int parserStatusCast() const;
-    const char *interfaceIId() const;
-    int propertyValueSourceCast() const;
-    int propertyValueInterceptorCast() const;
-
-    int index() const;
-
-    class Q_QML_PRIVATE_EXPORT SingletonInstanceInfo
+    template <typename QQmlTypeContainer>
+    static void removeQQmlTypePrivate(QQmlTypeContainer &container,
+                                      const QQmlTypePrivate *reference)
     {
-    public:
-        SingletonInstanceInfo()
-            : scriptCallback(0), qobjectCallback(0), instanceMetaObject(0) {}
-
-        QJSValue (*scriptCallback)(QQmlEngine *, QJSEngine *);
-        QObject *(*qobjectCallback)(QQmlEngine *, QJSEngine *);
-        const QMetaObject *instanceMetaObject;
-        QString typeName;
-        QUrl url; // used by composite singletons
-
-        void setQObjectApi(QQmlEngine *, QObject *);
-        QObject *qobjectApi(QQmlEngine *) const;
-        void setScriptApi(QQmlEngine *, const QJSValue &);
-        QJSValue scriptApi(QQmlEngine *) const;
-
-        void init(QQmlEngine *);
-        void destroy(QQmlEngine *);
-
-        QHash<QQmlEngine *, QJSValue> scriptApis;
-        QHash<QQmlEngine *, QObject *> qobjectApis;
-    };
-    SingletonInstanceInfo *singletonInstanceInfo() const;
-
-    QUrl sourceUrl() const;
-
-    int enumValue(QQmlEnginePrivate *engine, const QHashedStringRef &, bool *ok) const;
-    int enumValue(QQmlEnginePrivate *engine, const QHashedCStringRef &, bool *ok) const;
-    int enumValue(QQmlEnginePrivate *engine, const QV4::String *, bool *ok) const;
-
-    int scopedEnumIndex(QQmlEnginePrivate *engine, const QV4::String *, bool *ok) const;
-    int scopedEnumIndex(QQmlEnginePrivate *engine, const QString &, bool *ok) const;
-    int scopedEnumValue(QQmlEnginePrivate *engine, int index, const QV4::String *, bool *ok) const;
-    int scopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &, bool *ok) const;
-    int scopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &, const QByteArray &, bool *ok) const;
-    int scopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &, const QStringRef &, bool *ok) const;
-
-private:
-    QQmlType *superType() const;
-    QQmlType *resolveCompositeBaseType(QQmlEnginePrivate *engine) const;
-    int resolveCompositeEnumValue(QQmlEnginePrivate *engine, const QString &name, bool *ok) const;
-    int resolveCompositeScopedEnumIndex(QQmlEnginePrivate *engine, const QV4::String *, bool *ok) const;
-    int resolveCompositeScopedEnumIndex(QQmlEnginePrivate *engine, const QString &name, bool *ok) const;
-    int resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, int index, const QV4::String *, bool *ok) const;
-    int resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &name, bool *ok) const;
-    int resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &scopedName, const QByteArray &name, bool *ok) const;
-    int resolveCompositeScopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &scopedName, const QStringRef &name, bool *ok) const;
-    friend class QQmlTypePrivate;
-    friend struct QQmlMetaTypeData;
-
-    enum RegistrationType {
-        CppType = 0,
-        SingletonType = 1,
-        InterfaceType = 2,
-        CompositeType = 3,
-        CompositeSingletonType = 4
-    };
-    friend QString registrationTypeString(RegistrationType);
-    friend bool checkRegistration(RegistrationType, QQmlMetaTypeData *, const char *, const QString &, int);
-    friend int registerType(const QQmlPrivate::RegisterType &);
-    friend int registerSingletonType(const QQmlPrivate::RegisterSingletonType &);
-    friend int registerInterface(const QQmlPrivate::RegisterInterface &);
-    friend int registerCompositeType(const QQmlPrivate::RegisterCompositeType &);
-    friend int registerCompositeSingletonType(const QQmlPrivate::RegisterCompositeSingletonType &);
-    friend int registerQmlUnitCacheHook(const QQmlPrivate::RegisterQmlUnitCacheHook &);
-    friend Q_QML_EXPORT void qmlClearTypeRegistrations();
-    QQmlType(int, const QQmlPrivate::RegisterInterface &);
-    QQmlType(int, const QString &, const QQmlPrivate::RegisterSingletonType &);
-    QQmlType(int, const QString &, const QQmlPrivate::RegisterType &);
-    QQmlType(int, const QString &, const QQmlPrivate::RegisterCompositeType &);
-    QQmlType(int, const QString &, const QQmlPrivate::RegisterCompositeSingletonType &);
-    ~QQmlType();
-
-    QQmlTypePrivate *d;
-};
-
-class QQmlTypeModulePrivate;
-class QQmlTypeModule
-{
-public:
-    QString module() const;
-    int majorVersion() const;
-
-    int minimumMinorVersion() const;
-    int maximumMinorVersion() const;
-
-    QQmlType *type(const QHashedStringRef &, int) const;
-    QQmlType *type(const QV4::String *, int) const;
-
-    QList<QQmlType*> singletonTypes(int) const;
-
-private:
-    //Used by register functions and creates the QQmlTypeModule for them
-    friend QQmlTypeModule *getTypeModule(const QHashedString &uri, int majorVersion, QQmlMetaTypeData *data);
-    friend void addTypeToData(QQmlType* type, QQmlMetaTypeData *data);
-    friend struct QQmlMetaTypeData;
-    friend Q_QML_EXPORT void qmlClearTypeRegistrations();
-    friend class QQmlTypeModulePrivate;
-
-    QQmlTypeModule();
-    ~QQmlTypeModule();
-    QQmlTypeModulePrivate *d;
+        for (typename QQmlTypeContainer::iterator it = container.begin(); it != container.end();) {
+            if (*it == reference)
+                it = container.erase(it);
+            else
+                ++it;
+        }
+    }
+
+    static int registerAutoParentFunction(QQmlPrivate::RegisterAutoParent &autoparent);
+    static int registerUnitCacheHook(const QQmlPrivate::RegisterQmlUnitCacheHook &hookRegistration);
+    static void clearTypeRegistrations();
+
+    static QList<QQmlProxyMetaObject::ProxyData> proxyData(const QMetaObject *mo,
+                                                           const QMetaObject *baseMetaObject,
+                                                           QMetaObject *lastMetaObject);
+
+    static void clone(QMetaObjectBuilder &builder, const QMetaObject *mo,
+                      const QMetaObject *ignoreStart, const QMetaObject *ignoreEnd);
 };
 
-class QQmlTypeModuleVersion
-{
-public:
-    QQmlTypeModuleVersion();
-    QQmlTypeModuleVersion(QQmlTypeModule *, int);
-    QQmlTypeModuleVersion(const QQmlTypeModuleVersion &);
-    QQmlTypeModuleVersion &operator=(const QQmlTypeModuleVersion &);
-
-    QQmlTypeModule *module() const;
-    int minorVersion() const;
-
-    QQmlType *type(const QHashedStringRef &) const;
-    QQmlType *type(const QV4::String *) const;
-
-private:
-    QQmlTypeModule *m_module;
-    int m_minor;
-};
+Q_DECLARE_TYPEINFO(QQmlMetaType, Q_MOVABLE_TYPE);
 
 QT_END_NAMESPACE
 
diff --git a/src/qml/qml/qqmlmetatypedata.cpp b/src/qml/qml/qqmlmetatypedata.cpp
new file mode 100644
index 0000000000..13c46e4911
--- /dev/null
+++ b/src/qml/qml/qqmlmetatypedata.cpp
@@ -0,0 +1,204 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlmetatypedata_p.h"
+
+#include <private/qqmltype_p_p.h>
+#include <private/qqmltypemodule_p.h>
+#include <private/qqmlpropertycache_p.h>
+
+QT_BEGIN_NAMESPACE
+
+QQmlMetaTypeData::QQmlMetaTypeData()
+{
+}
+
+QQmlMetaTypeData::~QQmlMetaTypeData()
+{
+    for (TypeModules::const_iterator i = uriToModule.constBegin(), cend = uriToModule.constEnd(); i != cend; ++i)
+        delete *i;
+    for (QHash<const QMetaObject *, QQmlPropertyCache *>::Iterator it = propertyCaches.begin(), end = propertyCaches.end();
+         it != end; ++it)
+        (*it)->release();
+
+    // Do this before the attached properties disappear.
+    types.clear();
+    undeletableTypes.clear();
+}
+
+// This expects a "fresh" QQmlTypePrivate and adopts its reference.
+void QQmlMetaTypeData::registerType(QQmlTypePrivate *priv)
+{
+    for (int i = 0; i < types.count(); ++i) {
+        if (!types.at(i).isValid()) {
+            types[i] = QQmlType(priv);
+            priv->index = i;
+            return;
+        }
+    }
+    types.append(QQmlType(priv));
+    priv->index = types.count() - 1;
+    priv->release();
+}
+
+QQmlPropertyCache *QQmlMetaTypeData::propertyCache(const QMetaObject *metaObject, int minorVersion)
+{
+    if (QQmlPropertyCache *rv = propertyCaches.value(metaObject))
+        return rv;
+
+    if (!metaObject->superClass()) {
+        QQmlPropertyCache *rv = new QQmlPropertyCache(metaObject);
+        propertyCaches.insert(metaObject, rv);
+        return rv;
+    }
+    QQmlPropertyCache *super = propertyCache(metaObject->superClass(), minorVersion);
+    QQmlPropertyCache *rv = super->copyAndAppend(metaObject, minorVersion);
+    propertyCaches.insert(metaObject, rv);
+    return rv;
+}
+
+QQmlPropertyCache *QQmlMetaTypeData::propertyCache(const QQmlType &type, int minorVersion)
+{
+    Q_ASSERT(type.isValid());
+
+    if (QQmlPropertyCache *pc = type.key()->propertyCacheForMinorVersion(minorVersion))
+        return pc;
+
+    QVector<QQmlType> types;
+
+    int maxMinorVersion = 0;
+
+    const QMetaObject *metaObject = type.metaObject();
+
+    while (metaObject) {
+        QQmlType t = QQmlMetaType::qmlType(metaObject, type.module(), type.majorVersion(), minorVersion);
+        if (t.isValid()) {
+            maxMinorVersion = qMax(maxMinorVersion, t.minorVersion());
+            types << t;
+        } else {
+            types << QQmlType();
+        }
+
+        metaObject = metaObject->superClass();
+    }
+
+    if (QQmlPropertyCache *pc = type.key()->propertyCacheForMinorVersion(maxMinorVersion)) {
+        const_cast<QQmlTypePrivate*>(type.key())->setPropertyCacheForMinorVersion(minorVersion, pc);
+        return pc;
+    }
+
+    QQmlPropertyCache *raw = propertyCache(type.metaObject(), minorVersion);
+
+    bool hasCopied = false;
+
+    for (int ii = 0; ii < types.count(); ++ii) {
+        QQmlType currentType = types.at(ii);
+        if (!currentType.isValid())
+            continue;
+
+        int rev = currentType.metaObjectRevision();
+        int moIndex = types.count() - 1 - ii;
+
+        if (raw->allowedRevision(moIndex) != rev) {
+            if (!hasCopied) {
+                // TODO: The copy should be mutable, and the original should be const
+                //       Considering this, the setAllowedRevision() below does not violate
+                //       the immutability of already published property caches.
+                raw = raw->copy();
+                hasCopied = true;
+            }
+            raw->setAllowedRevision(moIndex, rev);
+        }
+    }
+
+    // Test revision compatibility - the basic rule is:
+    //    * Anything that is excluded, cannot overload something that is not excluded *
+
+    // Signals override:
+    //    * other signals and methods of the same name.
+    //    * properties named on<Signal Name>
+    //    * automatic <property name>Changed notify signals
+
+    // Methods override:
+    //    * other methods of the same name
+
+    // Properties override:
+    //    * other elements of the same name
+
+#if 0
+    bool overloadError = false;
+    QString overloadName;
+
+    for (QQmlPropertyCache::StringCache::ConstIterator iter = raw->stringCache.begin();
+         !overloadError && iter != raw->stringCache.end();
+         ++iter) {
+
+        QQmlPropertyData *d = *iter;
+        if (raw->isAllowedInRevision(d))
+            continue; // Not excluded - no problems
+
+        // check that a regular "name" overload isn't happening
+        QQmlPropertyData *current = d;
+        while (!overloadError && current) {
+            current = d->overrideData(current);
+            if (current && raw->isAllowedInRevision(current))
+                overloadError = true;
+        }
+    }
+
+    if (overloadError) {
+        if (hasCopied) raw->release();
+
+        error.setDescription(QLatin1String("Type ") + type.qmlTypeName() + QLatin1Char(' ') + QString::number(type.majorVersion()) + QLatin1Char('.') + QString::number(minorVersion) + QLatin1String(" contains an illegal property \"") + overloadName + QLatin1String("\".  This is an error in the type's implementation."));
+        return 0;
+    }
+#endif
+
+    const_cast<QQmlTypePrivate*>(type.key())->setPropertyCacheForMinorVersion(minorVersion, raw);
+
+    if (hasCopied)
+        raw->release();
+
+    if (minorVersion != maxMinorVersion)
+        const_cast<QQmlTypePrivate*>(type.key())->setPropertyCacheForMinorVersion(maxMinorVersion, raw);
+
+    return raw;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlmetatypedata_p.h b/src/qml/qml/qqmlmetatypedata_p.h
new file mode 100644
index 0000000000..2c5a32be1b
--- /dev/null
+++ b/src/qml/qml/qqmlmetatypedata_p.h
@@ -0,0 +1,161 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLMETATYPEDATA_P_H
+#define QQMLMETATYPEDATA_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmltype_p.h>
+#include <private/qqmlmetatype_p.h>
+#include <private/qhashedstring_p.h>
+
+#include <QtCore/qset.h>
+#include <QtCore/qvector.h>
+#include <QtCore/qbitarray.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlTypePrivate;
+struct QQmlMetaTypeData
+{
+    QQmlMetaTypeData();
+    ~QQmlMetaTypeData();
+    void registerType(QQmlTypePrivate *priv);
+    QList<QQmlType> types;
+    QSet<QQmlType> undeletableTypes;
+    typedef QHash<int, QQmlTypePrivate *> Ids;
+    Ids idToType;
+    typedef QHash<QHashedStringRef, QQmlTypePrivate *> Names;
+    Names nameToType;
+    typedef QHash<QUrl, QQmlTypePrivate *> Files; //For file imported composite types only
+    Files urlToType;
+    Files urlToNonFileImportType; // For non-file imported composite and composite
+            // singleton types. This way we can locate any
+            // of them by url, even if it was registered as
+            // a module via QQmlPrivate::RegisterCompositeType
+    typedef QHash<const QMetaObject *, QQmlTypePrivate *> MetaObjects;
+    MetaObjects metaObjectToType;
+    typedef QHash<int, QQmlMetaType::StringConverter> StringConverters;
+    StringConverters stringConverters;
+
+    struct VersionedUri {
+        VersionedUri()
+            : majorVersion(0) {}
+        VersionedUri(const QHashedString &uri, int majorVersion)
+            : uri(uri), majorVersion(majorVersion) {}
+        bool operator==(const VersionedUri &other) const {
+            return other.majorVersion == majorVersion && other.uri == uri;
+        }
+        QHashedString uri;
+        int majorVersion;
+    };
+    typedef QHash<VersionedUri, QQmlTypeModule *> TypeModules;
+    TypeModules uriToModule;
+
+    QBitArray objects;
+    QBitArray interfaces;
+    QBitArray lists;
+
+    QList<QQmlPrivate::AutoParentFunction> parentFunctions;
+    QVector<QQmlPrivate::QmlUnitCacheLookupFunction> lookupCachedQmlUnit;
+
+    QSet<QString> protectedNamespaces;
+
+    QString typeRegistrationNamespace;
+
+    QHash<int, int> qmlLists;
+
+    QHash<const QMetaObject *, QQmlPropertyCache *> propertyCaches;
+    QQmlPropertyCache *propertyCache(const QMetaObject *metaObject, int minorVersion);
+    QQmlPropertyCache *propertyCache(const QQmlType &type, int minorVersion);
+
+    void setTypeRegistrationFailures(QStringList *failures)
+    {
+        m_typeRegistrationFailures = failures;
+    }
+
+    void recordTypeRegFailure(const QString &message)
+    {
+        if (m_typeRegistrationFailures)
+            m_typeRegistrationFailures->append(message);
+        else
+            qWarning("%s", message.toUtf8().constData());
+    }
+
+    int attachedPropertyId(const QMetaObject *metaObject, int ownIndex)
+    {
+        auto iter = attachedPropertyIds.find(metaObject);
+        return (iter == attachedPropertyIds.end())
+                ? *attachedPropertyIds.insert(metaObject, ownIndex)
+                : *iter;
+    }
+
+    bool removeAttachedPropertyId(const QMetaObject *metaObject, int ownIndex)
+    {
+        auto iter = attachedPropertyIds.find(metaObject);
+        if (iter != attachedPropertyIds.end() && *iter == ownIndex) {
+            attachedPropertyIds.erase(iter);
+            return true;
+        }
+        return false;
+    }
+
+private:
+    QStringList *m_typeRegistrationFailures = nullptr;
+    QHash<const QMetaObject *, int> attachedPropertyIds;
+};
+
+inline uint qHash(const QQmlMetaTypeData::VersionedUri &v)
+{
+    return v.uri.hash() ^ qHash(v.majorVersion);
+}
+
+QT_END_NAMESPACE
+
+#endif // QQMLMETATYPEDATA_P_H
diff --git a/src/qml/qml/qqmlnetworkaccessmanagerfactory.cpp b/src/qml/qml/qqmlnetworkaccessmanagerfactory.cpp
index 1680253d73..c14a91c1fa 100644
--- a/src/qml/qml/qqmlnetworkaccessmanagerfactory.cpp
+++ b/src/qml/qml/qqmlnetworkaccessmanagerfactory.cpp
@@ -80,8 +80,6 @@ QT_BEGIN_NAMESPACE
     For more information about signals and threads, see
     \l {Threads and QObjects} and \l {Signals and Slots Across Threads}.
 
-    The \l {Qt Quick 1} version of this class is named QDeclarativeNetworkAccessManagerFactory.
-
     \sa {C++ Extensions: Network Access Manager Factory Example}{Network Access Manager Factory Example}
 */
 
diff --git a/src/qml/qml/qqmlnotifier.cpp b/src/qml/qml/qqmlnotifier.cpp
index 538ca822ee..0706b8c0cf 100644
--- a/src/qml/qml/qqmlnotifier.cpp
+++ b/src/qml/qml/qqmlnotifier.cpp
@@ -51,7 +51,7 @@ void QQmlJavaScriptExpressionGuard_callback(QQmlNotifierEndpoint *, void **);
 void QQmlVMEMetaObjectEndpoint_callback(QQmlNotifierEndpoint *, void **);
 
 static Callback QQmlNotifier_callbacks[] = {
-    0,
+    nullptr,
     QQmlBoundSignal_callback,
     QQmlJavaScriptExpressionGuard_callback,
     QQmlVMEMetaObjectEndpoint_callback
@@ -59,9 +59,9 @@ static Callback QQmlNotifier_callbacks[] = {
 
 namespace {
     struct NotifyListTraversalData {
-        NotifyListTraversalData(QQmlNotifierEndpoint *ep = 0)
+        NotifyListTraversalData(QQmlNotifierEndpoint *ep = nullptr)
             : originalSenderPtr(0)
-            , disconnectWatch(0)
+            , disconnectWatch(nullptr)
             , endpoint(ep)
         {}
 
@@ -74,7 +74,7 @@ namespace {
 void QQmlNotifier::notify(QQmlData *ddata, int notifierIndex)
 {
     if (QQmlNotifierEndpoint *ep = ddata->notify(notifierIndex))
-        emitNotify(ep, Q_NULLPTR);
+        emitNotify(ep, nullptr);
 }
 
 void QQmlNotifier::emitNotify(QQmlNotifierEndpoint *endpoint, void **a)
@@ -90,24 +90,20 @@ void QQmlNotifier::emitNotify(QQmlNotifierEndpoint *endpoint, void **a)
         NotifyListTraversalData &data = stack[i];
 
         if (!data.endpoint->isNotifying()) {
-            data.originalSenderPtr = data.endpoint->senderPtr;
+            data.endpoint->startNotifying(&data.originalSenderPtr);
             data.disconnectWatch = &data.originalSenderPtr;
-            data.endpoint->senderPtr = qintptr(data.disconnectWatch) | 0x1;
         } else {
             data.disconnectWatch = (qintptr *)(data.endpoint->senderPtr & ~0x1);
         }
     }
 
     while (--i >= 0) {
-        const NotifyListTraversalData &data = stack.at(i);
+        NotifyListTraversalData &data = stack[i];
         if (*data.disconnectWatch) {
-
             Q_ASSERT(QQmlNotifier_callbacks[data.endpoint->callback]);
             QQmlNotifier_callbacks[data.endpoint->callback](data.endpoint, a);
-
             if (data.disconnectWatch == &data.originalSenderPtr && data.originalSenderPtr) {
-                // End of notifying, restore values
-                data.endpoint->senderPtr = data.originalSenderPtr;
+                data.endpoint->stopNotifying(&data.originalSenderPtr);
             }
         }
     }
@@ -117,7 +113,7 @@ void QQmlNotifier::emitNotify(QQmlNotifierEndpoint *endpoint, void **a)
     \a sourceSignal MUST be in the signal index range (see QObjectPrivate::signalIndex()).
     This is different from QMetaMethod::methodIndex().
 */
-void QQmlNotifierEndpoint::connect(QObject *source, int sourceSignal, QQmlEngine *engine)
+void QQmlNotifierEndpoint::connect(QObject *source, int sourceSignal, QQmlEngine *engine, bool doNotify)
 {
     disconnect();
 
@@ -137,13 +133,16 @@ void QQmlNotifierEndpoint::connect(QObject *source, int sourceSignal, QQmlEngine
                qPrintable(engineName));
     }
 
-    senderPtr = qintptr(source);
+    setSender(qintptr(source));
     this->sourceSignal = sourceSignal;
     QQmlPropertyPrivate::flushSignal(source, sourceSignal);
     QQmlData *ddata = QQmlData::get(source, true);
     ddata->addNotify(sourceSignal, this);
-    QObjectPrivate * const priv = QObjectPrivate::get(source);
-    priv->connectNotify(QMetaObjectPrivate::signal(source->metaObject(), sourceSignal));
+    if (doNotify) {
+        needsConnectNotify = doNotify;
+        QObjectPrivate * const priv = QObjectPrivate::get(source);
+        priv->connectNotify(QMetaObjectPrivate::signal(source->metaObject(), sourceSignal));
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlnotifier_p.h b/src/qml/qml/qqmlnotifier_p.h
index dad79e0e55..67d80a9d86 100644
--- a/src/qml/qml/qqmlnotifier_p.h
+++ b/src/qml/qml/qqmlnotifier_p.h
@@ -73,7 +73,7 @@ private:
     friend class QQmlThreadNotifierProxyObject;
 
     static void emitNotify(QQmlNotifierEndpoint *, void **a);
-    QQmlNotifierEndpoint *endpoints;
+    QQmlNotifierEndpoint *endpoints = nullptr;
 };
 
 class QQmlEngine;
@@ -100,15 +100,24 @@ public:
     inline bool isConnected(QObject *source, int sourceSignal) const;
     inline bool isConnected(QQmlNotifier *) const;
 
-    void connect(QObject *source, int sourceSignal, QQmlEngine *engine);
+    void connect(QObject *source, int sourceSignal, QQmlEngine *engine, bool doNotify = true);
     inline void connect(QQmlNotifier *);
     inline void disconnect();
 
     inline bool isNotifying() const;
+    inline void startNotifying(qintptr *originalSenderPtr);
+    inline void stopNotifying(qintptr *originalSenderPtr);
+
     inline void cancelNotify();
 
     inline int signalIndex() const { return sourceSignal; }
 
+    inline qintptr sender() const;
+    inline void setSender(qintptr sender);
+
+    inline QObject *senderAsObject() const;
+    inline QQmlNotifier *senderAsNotifier() const;
+
 private:
     friend class QQmlData;
     friend class QQmlNotifier;
@@ -117,17 +126,15 @@ private:
     // endpoint is connected to.  While the endpoint is notifying, the
     // senderPtr points to another qintptr that contains this value.
     qintptr senderPtr;
-    inline QObject *senderAsObject() const;
-    inline QQmlNotifier *senderAsNotifier() const;
 
     Callback callback:4;
+    int needsConnectNotify:1;
     // The index is in the range returned by QObjectPrivate::signalIndex().
     // This is different from QMetaMethod::methodIndex().
-    signed int sourceSignal:28;
+    signed int sourceSignal:27;
 };
 
 QQmlNotifier::QQmlNotifier()
-: endpoints(0)
 {
 }
 
@@ -137,25 +144,22 @@ QQmlNotifier::~QQmlNotifier()
     while (endpoint) {
         QQmlNotifierEndpoint *n = endpoint;
         endpoint = n->next;
-
-        if (n->isNotifying()) *((qintptr *)(n->senderPtr & ~0x1)) = 0;
-
-        n->next = 0;
-        n->prev = 0;
-        n->senderPtr = 0;
+        n->setSender(0x0);
+        n->next = nullptr;
+        n->prev = nullptr;
         n->sourceSignal = -1;
     }
-    endpoints = 0;
+    endpoints = nullptr;
 }
 
 void QQmlNotifier::notify()
 {
-    void *args[] = { 0 };
+    void *args[] = { nullptr };
     if (endpoints) emitNotify(endpoints, args);
 }
 
 QQmlNotifierEndpoint::QQmlNotifierEndpoint(Callback callback)
-: next(0), prev(0), senderPtr(0), callback(callback), sourceSignal(-1)
+: next(nullptr), prev(nullptr), senderPtr(0), callback(callback), needsConnectNotify(false), sourceSignal(-1)
 {
 }
 
@@ -166,7 +170,7 @@ QQmlNotifierEndpoint::~QQmlNotifierEndpoint()
 
 bool QQmlNotifierEndpoint::isConnected() const
 {
-    return prev != 0;
+    return prev != nullptr;
 }
 
 /*! \internal
@@ -192,7 +196,7 @@ void QQmlNotifierEndpoint::connect(QQmlNotifier *notifier)
     if (next) { next->prev = &next; }
     notifier->endpoints = this;
     prev = &notifier->endpoints;
-    senderPtr = qintptr(notifier);
+    setSender(qintptr(notifier));
 }
 
 void QQmlNotifierEndpoint::disconnect()
@@ -204,14 +208,15 @@ void QQmlNotifierEndpoint::disconnect()
 
     if (sourceSignal != -1) {
         QObject * const obj = senderAsObject();
+        Q_ASSERT(obj);
         QObjectPrivate * const priv = QObjectPrivate::get(obj);
-        priv->disconnectNotify(QMetaObjectPrivate::signal(obj->metaObject(), sourceSignal));
+        if (needsConnectNotify)
+            priv->disconnectNotify(QMetaObjectPrivate::signal(obj->metaObject(), sourceSignal));
     }
 
-    if (isNotifying()) *((qintptr *)(senderPtr & ~0x1)) = 0;
-    next = 0;
-    prev = 0;
-    senderPtr = 0;
+    setSender(0x0);
+    next = nullptr;
+    prev = nullptr;
     sourceSignal = -1;
 }
 
@@ -227,26 +232,60 @@ bool QQmlNotifierEndpoint::isNotifying() const
     return senderPtr & 0x1;
 }
 
+void QQmlNotifierEndpoint::startNotifying(qintptr *originalSenderPtr)
+{
+    Q_ASSERT(*originalSenderPtr == 0);
+    // Set the endpoint to notifying:
+    // - Save the original senderPtr,
+    *originalSenderPtr = senderPtr;
+    // - Take a pointer of it,
+    // - And assign that to the senderPtr, including a flag to signify "notifying".
+    senderPtr = qintptr(originalSenderPtr) | 0x1;
+}
+
+void QQmlNotifierEndpoint::stopNotifying(qintptr *originalSenderPtr)
+{
+    // End of notifying, restore values
+    Q_ASSERT((senderPtr & ~0x1) == qintptr(originalSenderPtr));
+    senderPtr = *originalSenderPtr;
+    *originalSenderPtr = 0;
+}
+
 /*!
 Cancel any notifies that are in progress.
 */
 void QQmlNotifierEndpoint::cancelNotify()
 {
     if (isNotifying()) {
-        qintptr sp = *((qintptr *)(senderPtr & ~0x1));
-        *((qintptr *)(senderPtr & ~0x1)) = 0;
-        senderPtr = sp;
+        auto *ptr = (qintptr *)(senderPtr & ~0x1);
+        Q_ASSERT(ptr);
+        senderPtr = *ptr;
+        *ptr = 0;
     }
 }
 
+qintptr QQmlNotifierEndpoint::sender() const
+{
+    return isNotifying() ? *(qintptr *)(senderPtr & ~0x1) : senderPtr;
+}
+
+void QQmlNotifierEndpoint::setSender(qintptr sender)
+{
+    // If we're just notifying, we write through to the originalSenderPtr
+    if (isNotifying())
+        *(qintptr *)(senderPtr & ~0x1) = sender;
+    else
+        senderPtr = sender;
+}
+
 QObject *QQmlNotifierEndpoint::senderAsObject() const
 {
-    return isNotifying()?((QObject *)(*((qintptr *)(senderPtr & ~0x1)))):((QObject *)senderPtr);
+    return (QObject *)(sender());
 }
 
 QQmlNotifier *QQmlNotifierEndpoint::senderAsNotifier() const
 {
-    return isNotifying()?((QQmlNotifier *)(*((qintptr *)(senderPtr & ~0x1)))):((QQmlNotifier *)senderPtr);
+    return (QQmlNotifier *)(sender());
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 2cbcfbbfb6..c36b3ed386 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -55,6 +55,7 @@
 #include <private/qqmlvaluetypeproxybinding_p.h>
 #include <private/qqmldebugconnector_p.h>
 #include <private/qqmldebugserviceinterfaces_p.h>
+#include <private/qjsvalue_p.h>
 
 QT_USE_NAMESPACE
 
@@ -70,24 +71,24 @@ struct ActiveOCRestorer
 };
 }
 
-QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, QV4::CompiledData::CompilationUnit *compilationUnit, QQmlContextData *creationContext, void *activeVMEDataForRootContext)
+QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, QQmlContextData *creationContext,
+                                     QQmlIncubatorPrivate *incubator)
     : phase(Startup)
     , compilationUnit(compilationUnit)
-    , resolvedTypes(compilationUnit->resolvedTypes)
     , propertyCaches(&compilationUnit->propertyCaches)
     , sharedState(new QQmlObjectCreatorSharedState)
     , topLevelCreator(true)
-    , activeVMEDataForRootContext(activeVMEDataForRootContext)
+    , incubator(incubator)
 {
     init(parentContext);
 
-    sharedState->componentAttached = 0;
+    sharedState->componentAttached = nullptr;
     sharedState->allCreatedBindings.allocate(compilationUnit->totalBindingsCount);
     sharedState->allParserStatusCallbacks.allocate(compilationUnit->totalParserStatusCount);
     sharedState->allCreatedObjects.allocate(compilationUnit->totalObjectCount);
-    sharedState->allJavaScriptObjects = 0;
+    sharedState->allJavaScriptObjects = nullptr;
     sharedState->creationContext = creationContext;
-    sharedState->rootContext = 0;
+    sharedState->rootContext = nullptr;
 
     if (auto profiler = QQmlEnginePrivate::get(engine)->profiler) {
         Q_QML_PROFILE_IF_ENABLED(QQmlProfilerDefinitions::ProfileCreating, profiler,
@@ -97,14 +98,13 @@ QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, QV4::Compil
     }
 }
 
-QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, QV4::CompiledData::CompilationUnit *compilationUnit, QQmlObjectCreatorSharedState *inheritedSharedState)
+QQmlObjectCreator::QQmlObjectCreator(QQmlContextData *parentContext, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, QQmlObjectCreatorSharedState *inheritedSharedState)
     : phase(Startup)
     , compilationUnit(compilationUnit)
-    , resolvedTypes(compilationUnit->resolvedTypes)
     , propertyCaches(&compilationUnit->propertyCaches)
     , sharedState(inheritedSharedState)
     , topLevelCreator(false)
-    , activeVMEDataForRootContext(0)
+    , incubator(nullptr)
 {
     init(parentContext);
 }
@@ -113,23 +113,23 @@ void QQmlObjectCreator::init(QQmlContextData *providedParentContext)
 {
     parentContext = providedParentContext;
     engine = parentContext->engine;
-    v4 = QV8Engine::getV4(engine);
+    v4 = engine->handle();
 
     if (compilationUnit && !compilationUnit->engine)
         compilationUnit->linkToEngine(v4);
 
-    qmlUnit = compilationUnit->data;
-    context = 0;
-    _qobject = 0;
-    _scopeObject = 0;
-    _bindingTarget = 0;
-    _valueTypeProperty = 0;
-    _compiledObject = 0;
+    qmlUnit = compilationUnit->unitData();
+    context = nullptr;
+    _qobject = nullptr;
+    _scopeObject = nullptr;
+    _bindingTarget = nullptr;
+    _valueTypeProperty = nullptr;
+    _compiledObject = nullptr;
     _compiledObjectIndex = -1;
-    _ddata = 0;
-    _propertyCache = 0;
-    _vmeMetaObject = 0;
-    _qmlContext = 0;
+    _ddata = nullptr;
+    _propertyCache = nullptr;
+    _vmeMetaObject = nullptr;
+    _qmlContext = nullptr;
 }
 
 QQmlObjectCreator::~QQmlObjectCreator()
@@ -141,7 +141,7 @@ QQmlObjectCreator::~QQmlObjectCreator()
         for (int i = 0; i < sharedState->allParserStatusCallbacks.count(); ++i) {
             QQmlParserStatus *ps = sharedState->allParserStatusCallbacks.at(i);
             if (ps)
-                ps->d = 0;
+                ps->d = nullptr;
         }
         while (sharedState->componentAttached) {
             QQmlComponentAttached *a = sharedState->componentAttached;
@@ -162,9 +162,9 @@ QObject *QQmlObjectCreator::create(int subComponentIndex, QObject *parent, QQmlI
     int objectToCreate;
 
     if (subComponentIndex == -1) {
-        objectToCreate = qmlUnit->indexOfRootObject;
+        objectToCreate = /*root object*/0;
     } else {
-        const QV4::CompiledData::Object *compObj = qmlUnit->objectAt(subComponentIndex);
+        const QV4::CompiledData::Object *compObj = compilationUnit->objectAt(subComponentIndex);
         objectToCreate = compObj->bindingTable()->value.objectIndex;
     }
 
@@ -176,7 +176,7 @@ QObject *QQmlObjectCreator::create(int subComponentIndex, QObject *parent, QQmlI
 
     if (!sharedState->rootContext) {
         sharedState->rootContext = context;
-        sharedState->rootContext->activeVMEData = activeVMEDataForRootContext;
+        sharedState->rootContext->incubator = incubator;
         sharedState->rootContext->isRootObjectInCreation = true;
     }
 
@@ -191,8 +191,8 @@ QObject *QQmlObjectCreator::create(int subComponentIndex, QObject *parent, QQmlI
         context->importedScripts.set(v4, scripts);
         QV4::ScopedValue v(scope);
         for (int i = 0; i < compilationUnit->dependentScripts.count(); ++i) {
-            QQmlScriptData *s = compilationUnit->dependentScripts.at(i);
-            scripts->putIndexed(i, (v = s->scriptValueForContext(context)));
+            QQmlRefPointer<QQmlScriptData> s = compilationUnit->dependentScripts.at(i);
+            scripts->put(i, (v = s->scriptValueForContext(context)));
         }
     } else if (sharedState->creationContext) {
         context->importedScripts = sharedState->creationContext->importedScripts;
@@ -202,19 +202,16 @@ QObject *QQmlObjectCreator::create(int subComponentIndex, QObject *parent, QQmlI
     if (instance) {
         QQmlData *ddata = QQmlData::get(instance);
         Q_ASSERT(ddata);
-        if (ddata->compilationUnit)
-            ddata->compilationUnit->release();
         ddata->compilationUnit = compilationUnit;
-        ddata->compilationUnit->addref();
     }
 
     if (topLevelCreator)
-        sharedState->allJavaScriptObjects = 0;
+        sharedState->allJavaScriptObjects = nullptr;
 
     phase = CreatingObjectsPhase2;
 
     if (interrupt && interrupt->shouldInterrupt())
-        return 0;
+        return nullptr;
 
     phase = ObjectsCreated;
 
@@ -232,10 +229,11 @@ QObject *QQmlObjectCreator::create(int subComponentIndex, QObject *parent, QQmlI
     return instance;
 }
 
-bool QQmlObjectCreator::populateDeferredProperties(QObject *instance)
+// ### unify or keep in sync with populateDeferredBinding()
+bool QQmlObjectCreator::populateDeferredProperties(QObject *instance, QQmlData::DeferredData *deferredData)
 {
     QQmlData *declarativeData = QQmlData::get(instance);
-    context = declarativeData->deferredData->context;
+    context = deferredData->context;
     sharedState->rootContext = context;
 
     QObject *bindingTarget = instance;
@@ -252,17 +250,17 @@ bool QQmlObjectCreator::populateDeferredProperties(QObject *instance)
     Q_ASSERT(!sharedState->allJavaScriptObjects);
     sharedState->allJavaScriptObjects = valueScope.alloc(compilationUnit->totalObjectCount);
 
-    QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc(1));
+    QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc());
 
     qSwap(_qmlContext, qmlContext);
 
     qSwap(_propertyCache, cache);
     qSwap(_qobject, instance);
 
-    int objectIndex = declarativeData->deferredData->deferredIdx;
+    int objectIndex = deferredData->deferredIdx;
     qSwap(_compiledObjectIndex, objectIndex);
 
-    const QV4::CompiledData::Object *obj = qmlUnit->objectAt(_compiledObjectIndex);
+    const QV4::CompiledData::Object *obj = compilationUnit->objectAt(_compiledObjectIndex);
     qSwap(_compiledObject, obj);
 
     qSwap(_ddata, declarativeData);
@@ -282,6 +280,80 @@ bool QQmlObjectCreator::populateDeferredProperties(QObject *instance)
     qSwap(_qmlContext, qmlContext);
     qSwap(_scopeObject, scopeObject);
 
+    deferredData->bindings.clear();
+    phase = ObjectsCreated;
+
+    return errors.isEmpty();
+}
+
+// ### unify or keep in sync with populateDeferredProperties()
+bool QQmlObjectCreator::populateDeferredBinding(const QQmlProperty &qmlProperty, QQmlData::DeferredData *deferredData, const QV4::CompiledData::Binding *binding)
+{
+    Q_ASSERT(binding->flags & QV4::CompiledData::Binding::IsDeferredBinding);
+
+    QObject *instance = qmlProperty.object();
+    QQmlData *declarativeData = QQmlData::get(instance);
+    context = deferredData->context;
+    sharedState->rootContext = context;
+
+    QObject *bindingTarget = instance;
+
+    QQmlRefPointer<QQmlPropertyCache> cache = declarativeData->propertyCache;
+    QQmlVMEMetaObject *vmeMetaObject = QQmlVMEMetaObject::get(instance);
+
+    QObject *scopeObject = instance;
+    qSwap(_scopeObject, scopeObject);
+
+    QV4::Scope valueScope(v4);
+
+    Q_ASSERT(topLevelCreator);
+    if (!sharedState->allJavaScriptObjects)
+        sharedState->allJavaScriptObjects = valueScope.alloc(compilationUnit->totalObjectCount);
+
+    QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc());
+
+    qSwap(_qmlContext, qmlContext);
+
+    qSwap(_propertyCache, cache);
+    qSwap(_qobject, instance);
+
+    int objectIndex = deferredData->deferredIdx;
+    qSwap(_compiledObjectIndex, objectIndex);
+
+    const QV4::CompiledData::Object *obj = compilationUnit->objectAt(_compiledObjectIndex);
+    qSwap(_compiledObject, obj);
+
+    qSwap(_ddata, declarativeData);
+    qSwap(_bindingTarget, bindingTarget);
+    qSwap(_vmeMetaObject, vmeMetaObject);
+
+    QQmlListProperty<void> savedList;
+    qSwap(_currentList, savedList);
+
+    const QQmlPropertyData &property = QQmlPropertyPrivate::get(qmlProperty)->core;
+
+    if (property.isQList()) {
+        void *argv[1] = { (void*)&_currentList };
+        QMetaObject::metacall(_qobject, QMetaObject::ReadProperty, property.coreIndex(), argv);
+    } else if (_currentList.object) {
+        _currentList = QQmlListProperty<void>();
+    }
+
+    setPropertyBinding(&property, binding);
+
+    qSwap(_currentList, savedList);
+
+    qSwap(_vmeMetaObject, vmeMetaObject);
+    qSwap(_bindingTarget, bindingTarget);
+    qSwap(_ddata, declarativeData);
+    qSwap(_compiledObject, obj);
+    qSwap(_compiledObjectIndex, objectIndex);
+    qSwap(_qobject, instance);
+    qSwap(_propertyCache, cache);
+
+    qSwap(_qmlContext, qmlContext);
+    qSwap(_scopeObject, scopeObject);
+
     phase = ObjectsCreated;
 
     return errors.isEmpty();
@@ -299,7 +371,7 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             propertyType = QMetaType::Int;
         } else {
             // ### This should be resolved earlier at compile time and the binding value should be changed accordingly.
-            QVariant value = binding->valueAsString(qmlUnit);
+            QVariant value = binding->valueAsString(compilationUnit.data());
             bool ok = QQmlPropertyPrivate::write(_qobject, *property, value, context);
             Q_ASSERT(ok);
             Q_UNUSED(ok);
@@ -307,13 +379,35 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
         }
     }
 
+    auto assertOrNull = [&](bool ok)
+    {
+        Q_ASSERT(ok || binding->type == QV4::CompiledData::Binding::Type_Null);
+        Q_UNUSED(ok);
+    };
+
+    auto assertType = [&](QV4::CompiledData::Binding::ValueType type)
+    {
+        Q_ASSERT(binding->type == type || binding->type == QV4::CompiledData::Binding::Type_Null);
+        Q_UNUSED(type);
+    };
+
+    if (property->isQObject()) {
+        if (binding->type == QV4::CompiledData::Binding::Type_Null) {
+            QObject *value = nullptr;
+            const bool ok = property->writeProperty(_qobject, &value, propertyWriteFlags);
+            Q_ASSERT(ok);
+            Q_UNUSED(ok);
+            return;
+        }
+    }
+
     switch (propertyType) {
     case QMetaType::QVariant: {
         if (binding->type == QV4::CompiledData::Binding::Type_Number) {
-            double n = binding->valueAsNumber();
+            double n = binding->valueAsNumber(compilationUnit->constants);
             if (double(int(n)) == n) {
                 if (property->isVarProperty()) {
-                    _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Primitive::fromInt32(int(n)));
+                    _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Value::fromInt32(int(n)));
                 } else {
                     int i = int(n);
                     QVariant value(i);
@@ -321,7 +415,7 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
                 }
             } else {
                 if (property->isVarProperty()) {
-                    _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Primitive::fromDouble(n));
+                    _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Value::fromDouble(n));
                 } else {
                     QVariant value(n);
                     property->writeProperty(_qobject, &value, propertyWriteFlags);
@@ -329,13 +423,20 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             }
         } else if (binding->type == QV4::CompiledData::Binding::Type_Boolean) {
             if (property->isVarProperty()) {
-                _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Primitive::fromBoolean(binding->valueAsBoolean()));
+                _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Value::fromBoolean(binding->valueAsBoolean()));
             } else {
                 QVariant value(binding->valueAsBoolean());
                 property->writeProperty(_qobject, &value, propertyWriteFlags);
             }
+        } else if (binding->type == QV4::CompiledData::Binding::Type_Null) {
+            if (property->isVarProperty()) {
+                _vmeMetaObject->setVMEProperty(property->coreIndex(), QV4::Value::nullValue());
+            } else {
+                QVariant nullValue = QVariant::fromValue(nullptr);
+                property->writeProperty(_qobject, &nullValue, propertyWriteFlags);
+            }
         } else {
-            QString stringValue = binding->valueAsString(qmlUnit);
+            QString stringValue = binding->valueAsString(compilationUnit.data());
             if (property->isVarProperty()) {
                 QV4::ScopedString s(scope, v4->newString(stringValue));
                 _vmeMetaObject->setVMEProperty(property->coreIndex(), s);
@@ -347,29 +448,29 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
     }
     break;
     case QVariant::String: {
-        Q_ASSERT(binding->evaluatesToString());
-        QString value = binding->valueAsString(qmlUnit);
+        assertOrNull(binding->evaluatesToString());
+        QString value = binding->valueAsString(compilationUnit.data());
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::StringList: {
-        Q_ASSERT(binding->evaluatesToString());
-        QStringList value(binding->valueAsString(qmlUnit));
+        assertOrNull(binding->evaluatesToString());
+        QStringList value(binding->valueAsString(compilationUnit.data()));
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::ByteArray: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_String);
-        QByteArray value(binding->valueAsString(qmlUnit).toUtf8());
+        assertType(QV4::CompiledData::Binding::Type_String);
+        QByteArray value(binding->valueAsString(compilationUnit.data()).toUtf8());
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Url: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_String);
-        QString string = binding->valueAsString(qmlUnit);
+        assertType(QV4::CompiledData::Binding::Type_String);
+        QString string = binding->valueAsString(compilationUnit.data());
         // Encoded dir-separators defeat QUrl processing - decode them first
         string.replace(QLatin1String("%2f"), QLatin1String("/"), Qt::CaseInsensitive);
-        QUrl value = string.isEmpty() ? QUrl() : compilationUnit->url().resolved(QUrl(string));
+        QUrl value = string.isEmpty() ? QUrl() : compilationUnit->finalUrl().resolved(QUrl(string));
         // Apply URL interceptor
         if (engine->urlInterceptor())
             value = engine->urlInterceptor()->intercept(value, QQmlAbstractUrlInterceptor::UrlString);
@@ -377,37 +478,37 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
     }
     break;
     case QVariant::UInt: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Number);
-        double d = binding->valueAsNumber();
+        assertType(QV4::CompiledData::Binding::Type_Number);
+        double d = binding->valueAsNumber(compilationUnit->constants);
         uint value = uint(d);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
         break;
     }
     break;
     case QVariant::Int: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Number);
-        double d = binding->valueAsNumber();
+        assertType(QV4::CompiledData::Binding::Type_Number);
+        double d = binding->valueAsNumber(compilationUnit->constants);
         int value = int(d);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
         break;
     }
     break;
     case QMetaType::Float: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Number);
-        float value = float(binding->valueAsNumber());
+        assertType(QV4::CompiledData::Binding::Type_Number);
+        float value = float(binding->valueAsNumber(compilationUnit->constants));
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Double: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Number);
-        double value = binding->valueAsNumber();
+        assertType(QV4::CompiledData::Binding::Type_Number);
+        double value = binding->valueAsNumber(compilationUnit->constants);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Color: {
         bool ok = false;
-        uint colorValue = QQmlStringConverters::rgbaFromString(binding->valueAsString(qmlUnit), &ok);
-        Q_ASSERT(ok);
+        uint colorValue = QQmlStringConverters::rgbaFromString(binding->valueAsString(compilationUnit.data()), &ok);
+        assertOrNull(ok);
         struct { void *data[4]; } buffer;
         if (QQml_valueTypeProvider()->storeValueType(property->propType(), &colorValue, &buffer, sizeof(buffer))) {
             property->writeProperty(_qobject, &buffer, propertyWriteFlags);
@@ -417,76 +518,76 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
 #if QT_CONFIG(datestring)
     case QVariant::Date: {
         bool ok = false;
-        QDate value = QQmlStringConverters::dateFromString(binding->valueAsString(qmlUnit), &ok);
-        Q_ASSERT(ok);
+        QDate value = QQmlStringConverters::dateFromString(binding->valueAsString(compilationUnit.data()), &ok);
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Time: {
         bool ok = false;
-        QTime value = QQmlStringConverters::timeFromString(binding->valueAsString(qmlUnit), &ok);
-        Q_ASSERT(ok);
+        QTime value = QQmlStringConverters::timeFromString(binding->valueAsString(compilationUnit.data()), &ok);
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::DateTime: {
         bool ok = false;
-        QDateTime value = QQmlStringConverters::dateTimeFromString(binding->valueAsString(qmlUnit), &ok);
+        QDateTime value = QQmlStringConverters::dateTimeFromString(binding->valueAsString(compilationUnit.data()), &ok);
         // ### VME compatibility :(
         {
             const qint64 date = value.date().toJulianDay();
             const int msecsSinceStartOfDay = value.time().msecsSinceStartOfDay();
             value = QDateTime(QDate::fromJulianDay(date), QTime::fromMSecsSinceStartOfDay(msecsSinceStartOfDay));
         }
-        Q_ASSERT(ok);
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
 #endif // datestring
     case QVariant::Point: {
         bool ok = false;
-        QPoint value = QQmlStringConverters::pointFFromString(binding->valueAsString(qmlUnit), &ok).toPoint();
-        Q_ASSERT(ok);
+        QPoint value = QQmlStringConverters::pointFFromString(binding->valueAsString(compilationUnit.data()), &ok).toPoint();
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::PointF: {
         bool ok = false;
-        QPointF value = QQmlStringConverters::pointFFromString(binding->valueAsString(qmlUnit), &ok);
-        Q_ASSERT(ok);
+        QPointF value = QQmlStringConverters::pointFFromString(binding->valueAsString(compilationUnit.data()), &ok);
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Size: {
         bool ok = false;
-        QSize value = QQmlStringConverters::sizeFFromString(binding->valueAsString(qmlUnit), &ok).toSize();
-        Q_ASSERT(ok);
+        QSize value = QQmlStringConverters::sizeFFromString(binding->valueAsString(compilationUnit.data()), &ok).toSize();
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::SizeF: {
         bool ok = false;
-        QSizeF value = QQmlStringConverters::sizeFFromString(binding->valueAsString(qmlUnit), &ok);
-        Q_ASSERT(ok);
+        QSizeF value = QQmlStringConverters::sizeFFromString(binding->valueAsString(compilationUnit.data()), &ok);
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Rect: {
         bool ok = false;
-        QRect value = QQmlStringConverters::rectFFromString(binding->valueAsString(qmlUnit), &ok).toRect();
-        Q_ASSERT(ok);
+        QRect value = QQmlStringConverters::rectFFromString(binding->valueAsString(compilationUnit.data()), &ok).toRect();
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::RectF: {
         bool ok = false;
-        QRectF value = QQmlStringConverters::rectFFromString(binding->valueAsString(qmlUnit), &ok);
-        Q_ASSERT(ok);
+        QRectF value = QQmlStringConverters::rectFFromString(binding->valueAsString(compilationUnit.data()), &ok);
+        assertOrNull(ok);
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
     break;
     case QVariant::Bool: {
-        Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Boolean);
+        assertType(QV4::CompiledData::Binding::Type_Boolean);
         bool value = binding->valueAsBoolean();
         property->writeProperty(_qobject, &value, propertyWriteFlags);
     }
@@ -496,8 +597,8 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             float xp;
             float yp;
         } vec;
-        bool ok = QQmlStringConverters::createFromString(QMetaType::QVector2D, binding->valueAsString(qmlUnit), &vec, sizeof(vec));
-        Q_ASSERT(ok);
+        bool ok = QQmlStringConverters::createFromString(QMetaType::QVector2D, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec));
+        assertOrNull(ok);
         Q_UNUSED(ok);
         property->writeProperty(_qobject, &vec, propertyWriteFlags);
     }
@@ -508,8 +609,8 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             float yp;
             float zy;
         } vec;
-        bool ok = QQmlStringConverters::createFromString(QMetaType::QVector3D, binding->valueAsString(qmlUnit), &vec, sizeof(vec));
-        Q_ASSERT(ok);
+        bool ok = QQmlStringConverters::createFromString(QMetaType::QVector3D, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec));
+        assertOrNull(ok);
         Q_UNUSED(ok);
         property->writeProperty(_qobject, &vec, propertyWriteFlags);
     }
@@ -521,8 +622,8 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             float zy;
             float wp;
         } vec;
-        bool ok = QQmlStringConverters::createFromString(QMetaType::QVector4D, binding->valueAsString(qmlUnit), &vec, sizeof(vec));
-        Q_ASSERT(ok);
+        bool ok = QQmlStringConverters::createFromString(QMetaType::QVector4D, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec));
+        assertOrNull(ok);
         Q_UNUSED(ok);
         property->writeProperty(_qobject, &vec, propertyWriteFlags);
     }
@@ -534,48 +635,49 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             float yp;
             float zp;
         } vec;
-        bool ok = QQmlStringConverters::createFromString(QMetaType::QQuaternion, binding->valueAsString(qmlUnit), &vec, sizeof(vec));
-        Q_ASSERT(ok);
+        bool ok = QQmlStringConverters::createFromString(QMetaType::QQuaternion, binding->valueAsString(compilationUnit.data()), &vec, sizeof(vec));
+        assertOrNull(ok);
         Q_UNUSED(ok);
         property->writeProperty(_qobject, &vec, propertyWriteFlags);
     }
     break;
     case QVariant::RegExp:
-        Q_ASSERT(!"not possible");
+        assertOrNull(!"not possible");
         break;
     default: {
         // generate single literal value assignment to a list property if required
         if (property->propType() == qMetaTypeId<QList<qreal> >()) {
-            Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Number);
+            assertType(QV4::CompiledData::Binding::Type_Number);
             QList<qreal> value;
-            value.append(binding->valueAsNumber());
+            value.append(binding->valueAsNumber(compilationUnit->constants));
             property->writeProperty(_qobject, &value, propertyWriteFlags);
             break;
         } else if (property->propType() == qMetaTypeId<QList<int> >()) {
-            Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Number);
-            double n = binding->valueAsNumber();
+            assertType(QV4::CompiledData::Binding::Type_Number);
+            double n = binding->valueAsNumber(compilationUnit->constants);
             QList<int> value;
             value.append(int(n));
             property->writeProperty(_qobject, &value, propertyWriteFlags);
             break;
         } else if (property->propType() == qMetaTypeId<QList<bool> >()) {
-            Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Boolean);
+            assertType(QV4::CompiledData::Binding::Type_Boolean);
             QList<bool> value;
             value.append(binding->valueAsBoolean());
             property->writeProperty(_qobject, &value, propertyWriteFlags);
             break;
         } else if (property->propType() == qMetaTypeId<QList<QUrl> >()) {
-            Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_String);
-            QString urlString = binding->valueAsString(qmlUnit);
-            QUrl u = urlString.isEmpty() ? QUrl() : compilationUnit->url().resolved(QUrl(urlString));
+            assertType(QV4::CompiledData::Binding::Type_String);
+            QString urlString = binding->valueAsString(compilationUnit.data());
+            QUrl u = urlString.isEmpty() ? QUrl()
+                                         : compilationUnit->finalUrl().resolved(QUrl(urlString));
             QList<QUrl> value;
             value.append(u);
             property->writeProperty(_qobject, &value, propertyWriteFlags);
             break;
         } else if (property->propType() == qMetaTypeId<QList<QString> >()) {
-            Q_ASSERT(binding->evaluatesToString());
+            assertOrNull(binding->evaluatesToString());
             QList<QString> value;
-            value.append(binding->valueAsString(qmlUnit));
+            value.append(binding->valueAsString(compilationUnit.data()));
             property->writeProperty(_qobject, &value, propertyWriteFlags);
             break;
         } else if (property->propType() == qMetaTypeId<QJSValue>()) {
@@ -583,20 +685,22 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
             if (binding->type == QV4::CompiledData::Binding::Type_Boolean) {
                 value = QJSValue(binding->valueAsBoolean());
             } else if (binding->type == QV4::CompiledData::Binding::Type_Number) {
-                double n = binding->valueAsNumber();
+                double n = binding->valueAsNumber(compilationUnit->constants);
                 if (double(int(n)) == n) {
                     value = QJSValue(int(n));
                 } else
                     value = QJSValue(n);
+            } else if (binding->type == QV4::CompiledData::Binding::Type_Null) {
+                value = QJSValue::NullValue;
             } else {
-                value = QJSValue(binding->valueAsString(qmlUnit));
+                value = QJSValue(binding->valueAsString(compilationUnit.data()));
             }
             property->writeProperty(_qobject, &value, propertyWriteFlags);
             break;
         }
 
         // otherwise, try a custom type assignment
-        QString stringValue = binding->valueAsString(qmlUnit);
+        QString stringValue = binding->valueAsString(compilationUnit.data());
         QQmlMetaType::StringConverter converter = QQmlMetaType::customStringConverter(property->propType());
         Q_ASSERT(converter);
         QVariant value = (*converter)(stringValue);
@@ -613,11 +717,11 @@ void QQmlObjectCreator::setPropertyValue(const QQmlPropertyData *property, const
     }
 }
 
-static QQmlType *qmlTypeForObject(QObject *object)
+static QQmlType qmlTypeForObject(QObject *object)
 {
-    QQmlType *type = 0;
+    QQmlType type;
     const QMetaObject *mo = object->metaObject();
-    while (mo && !type) {
+    while (mo && !type.isValid()) {
         type = QQmlMetaType::qmlType(mo);
         mo = mo->superClass();
     }
@@ -654,7 +758,7 @@ void QQmlObjectCreator::setupBindings(bool applyDeferredBindings)
         } else if (binding) {
             QQmlValueTypeProxyBinding *proxy = static_cast<QQmlValueTypeProxyBinding *>(binding);
 
-            if (qmlTypeForObject(_bindingTarget)) {
+            if (qmlTypeForObject(_bindingTarget).isValid()) {
                 quint32 bindingSkipList = 0;
 
                 QQmlPropertyData *defaultProperty = _compiledObject->indexOfDefaultPropertyOrAlias != -1 ? _propertyCache->parent()->defaultProperty() : _propertyCache->defaultProperty();
@@ -706,78 +810,78 @@ void QQmlObjectCreator::setupBindings(bool applyDeferredBindings)
     qSwap(_currentList, savedList);
 }
 
-bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, const QV4::CompiledData::Binding *binding)
+bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *bindingProperty, const QV4::CompiledData::Binding *binding)
 {
     if (binding->type == QV4::CompiledData::Binding::Type_AttachedProperty) {
-        Q_ASSERT(stringAt(qmlUnit->objectAt(binding->value.objectIndex)->inheritedTypeNameIndex).isEmpty());
-        QV4::CompiledData::ResolvedTypeReference *tr = resolvedTypes.value(binding->propertyNameIndex);
+        Q_ASSERT(stringAt(compilationUnit->objectAt(binding->value.objectIndex)->inheritedTypeNameIndex).isEmpty());
+        QV4::CompiledData::ResolvedTypeReference *tr = resolvedType(binding->propertyNameIndex);
         Q_ASSERT(tr);
-        QQmlType *attachedType = tr->type;
-        if (!attachedType) {
+        QQmlType attachedType = tr->type;
+        if (!attachedType.isValid()) {
             QQmlTypeNameCache::Result res = context->imports->query(stringAt(binding->propertyNameIndex));
             if (res.isValid())
                 attachedType = res.type;
             else
                 return false;
         }
-        const int id = attachedType->attachedPropertiesId(QQmlEnginePrivate::get(engine));
+        const int id = attachedType.attachedPropertiesId(QQmlEnginePrivate::get(engine));
         QObject *qmlObject = qmlAttachedPropertiesObjectById(id, _qobject);
-        if (!populateInstance(binding->value.objectIndex, qmlObject, qmlObject, /*value type property*/0))
+        if (!populateInstance(binding->value.objectIndex, qmlObject, qmlObject, /*value type property*/nullptr))
             return false;
         return true;
     }
 
     // ### resolve this at compile time
-    if (property && property->propType() == qMetaTypeId<QQmlScriptString>()) {
-        QQmlScriptString ss(binding->valueAsScriptString(qmlUnit), context->asQQmlContext(), _scopeObject);
+    if (bindingProperty && bindingProperty->propType() == qMetaTypeId<QQmlScriptString>()) {
+        QQmlScriptString ss(binding->valueAsScriptString(compilationUnit.data()), context->asQQmlContext(), _scopeObject);
         ss.d.data()->bindingId = binding->type == QV4::CompiledData::Binding::Type_Script ? binding->value.compiledScriptIndex : (quint32)QQmlBinding::Invalid;
         ss.d.data()->lineNumber = binding->location.line;
         ss.d.data()->columnNumber = binding->location.column;
         ss.d.data()->isStringLiteral = binding->type == QV4::CompiledData::Binding::Type_String;
         ss.d.data()->isNumberLiteral = binding->type == QV4::CompiledData::Binding::Type_Number;
-        ss.d.data()->numberValue = binding->valueAsNumber();
+        ss.d.data()->numberValue = binding->valueAsNumber(compilationUnit->constants);
 
         QQmlPropertyData::WriteFlags propertyWriteFlags = QQmlPropertyData::BypassInterceptor |
                                                             QQmlPropertyData::RemoveBindingOnAliasWrite;
         int propertyWriteStatus = -1;
-        void *argv[] = { &ss, 0, &propertyWriteStatus, &propertyWriteFlags };
-        QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, property->coreIndex(), argv);
+        void *argv[] = { &ss, nullptr, &propertyWriteStatus, &propertyWriteFlags };
+        QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, bindingProperty->coreIndex(), argv);
         return true;
     }
 
-    QObject *createdSubObject = 0;
+    QObject *createdSubObject = nullptr;
     if (binding->type == QV4::CompiledData::Binding::Type_Object) {
         createdSubObject = createInstance(binding->value.objectIndex, _bindingTarget);
         if (!createdSubObject)
             return false;
     }
 
-    if (!property) // ### error
+    if (!bindingProperty) // ### error
         return true;
 
     if (binding->type == QV4::CompiledData::Binding::Type_GroupProperty) {
-        const QV4::CompiledData::Object *obj = qmlUnit->objectAt(binding->value.objectIndex);
+        const QV4::CompiledData::Object *obj = compilationUnit->objectAt(binding->value.objectIndex);
         if (stringAt(obj->inheritedTypeNameIndex).isEmpty()) {
 
-            QObject *groupObject = 0;
-            QQmlValueType *valueType = 0;
-            const QQmlPropertyData *valueTypeProperty = 0;
+            QObject *groupObject = nullptr;
+            QQmlValueType *valueType = nullptr;
+            const QQmlPropertyData *valueTypeProperty = nullptr;
             QObject *bindingTarget = _bindingTarget;
 
-            if (QQmlValueTypeFactory::isValueType(property->propType())) {
-                valueType = QQmlValueTypeFactory::valueType(property->propType());
+            if (QQmlValueTypeFactory::isValueType(bindingProperty->propType())) {
+                valueType = QQmlValueTypeFactory::valueType(bindingProperty->propType());
                 if (!valueType) {
                     recordError(binding->location, tr("Cannot set properties on %1 as it is null").arg(stringAt(binding->propertyNameIndex)));
                     return false;
                 }
 
-                valueType->read(_qobject, property->coreIndex());
+                valueType->read(_qobject, bindingProperty->coreIndex());
 
                 groupObject = valueType;
-                valueTypeProperty = property;
+                valueTypeProperty = bindingProperty;
             } else {
                 void *argv[1] = { &groupObject };
-                QMetaObject::metacall(_qobject, QMetaObject::ReadProperty, property->coreIndex(), argv);
+                QMetaObject::metacall(_qobject, QMetaObject::ReadProperty, bindingProperty->coreIndex(), argv);
                 if (!groupObject) {
                     recordError(binding->location, tr("Cannot set properties on %1 as it is null").arg(stringAt(binding->propertyNameIndex)));
                     return false;
@@ -790,28 +894,24 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
                 return false;
 
             if (valueType)
-                valueType->write(_qobject, property->coreIndex(), QQmlPropertyData::BypassInterceptor);
+                valueType->write(_qobject, bindingProperty->coreIndex(), QQmlPropertyData::BypassInterceptor);
 
             return true;
         }
     }
 
-    if (_ddata->hasBindingBit(property->coreIndex()) && !(binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression)
+    if (_ddata->hasBindingBit(bindingProperty->coreIndex()) && !(binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression)
         && !(binding->flags & QV4::CompiledData::Binding::IsOnAssignment)
         && !_valueTypeProperty)
-        QQmlPropertyPrivate::removeBinding(_bindingTarget, QQmlPropertyIndex(property->coreIndex()));
-
-    if (binding->type == QV4::CompiledData::Binding::Type_Script) {
-        QV4::Function *runtimeFunction = compilationUnit->runtimeFunctions[binding->value.compiledScriptIndex];
-
-        QV4::Scope scope(v4);
-        QV4::Scoped<QV4::QmlContext> qmlContext(scope, currentQmlContext());
+        QQmlPropertyPrivate::removeBinding(_bindingTarget, QQmlPropertyIndex(bindingProperty->coreIndex()));
 
+    if (binding->type == QV4::CompiledData::Binding::Type_Script || binding->isTranslationBinding()) {
         if (binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression) {
-            int signalIndex = _propertyCache->methodIndexToSignalIndex(property->coreIndex());
+            QV4::Function *runtimeFunction = compilationUnit->runtimeFunctions[binding->value.compiledScriptIndex];
+            int signalIndex = _propertyCache->methodIndexToSignalIndex(bindingProperty->coreIndex());
             QQmlBoundSignal *bs = new QQmlBoundSignal(_bindingTarget, signalIndex, _scopeObject, engine);
             QQmlBoundSignalExpression *expr = new QQmlBoundSignalExpression(_bindingTarget, signalIndex,
-                                                                            context, _scopeObject, runtimeFunction, qmlContext);
+                                                                            context, _scopeObject, runtimeFunction, currentQmlContext());
 
             bs->takeExpression(expr);
         } else {
@@ -820,29 +920,44 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
             // the point property (_qobjectForBindings) and after evaluating the expression,
             // the result is written to a value type virtual property, that contains the sub-index
             // of the "x" property.
-            QQmlBinding *qmlBinding;
-            const QQmlPropertyData *prop = property;
+            QQmlBinding::Ptr qmlBinding;
+            const QQmlPropertyData *targetProperty = bindingProperty;
             const QQmlPropertyData *subprop = nullptr;
             if (_valueTypeProperty) {
-                prop = _valueTypeProperty;
-                subprop = property;
+                targetProperty = _valueTypeProperty;
+                subprop = bindingProperty;
+            }
+            if (binding->isTranslationBinding()) {
+                qmlBinding = QQmlBinding::createTranslationBinding(compilationUnit, binding, _scopeObject, context);
+            } else {
+                QV4::Function *runtimeFunction = compilationUnit->runtimeFunctions[binding->value.compiledScriptIndex];
+                qmlBinding = QQmlBinding::create(targetProperty, runtimeFunction, _scopeObject, context, currentQmlContext());
             }
-            qmlBinding = QQmlBinding::create(prop, runtimeFunction, _scopeObject, context, qmlContext);
-            qmlBinding->setTarget(_bindingTarget, *prop, subprop);
 
-            sharedState->allCreatedBindings.push(QQmlAbstractBinding::Ptr(qmlBinding));
+            auto bindingTarget = _bindingTarget;
+            auto valueTypeProperty = _valueTypeProperty;
+            auto assignBinding = [qmlBinding, bindingTarget, targetProperty, subprop, bindingProperty, valueTypeProperty](QQmlObjectCreatorSharedState *sharedState) -> bool {
+                if (!qmlBinding->setTarget(bindingTarget, *targetProperty, subprop) && targetProperty->isAlias())
+                    return false;
 
-            if (property->isAlias()) {
-                QQmlPropertyPrivate::setBinding(qmlBinding, QQmlPropertyPrivate::DontEnable);
-            } else {
-                qmlBinding->addToObject();
+                sharedState->allCreatedBindings.push(qmlBinding);
+
+                if (bindingProperty->isAlias()) {
+                    QQmlPropertyPrivate::setBinding(qmlBinding.data(), QQmlPropertyPrivate::DontEnable);
+                } else {
+                    qmlBinding->addToObject();
 
-                if (!_valueTypeProperty) {
-                    QQmlData *targetDeclarativeData = QQmlData::get(_bindingTarget);
-                    Q_ASSERT(targetDeclarativeData);
-                    targetDeclarativeData->setPendingBindingBit(_bindingTarget, property->coreIndex());
+                    if (!valueTypeProperty) {
+                        QQmlData *targetDeclarativeData = QQmlData::get(bindingTarget);
+                        Q_ASSERT(targetDeclarativeData);
+                        targetDeclarativeData->setPendingBindingBit(bindingTarget, bindingProperty->coreIndex());
+                    }
                 }
-            }
+
+                return true;
+            };
+            if (!assignBinding(sharedState.data()))
+                pendingAliasBindings.push_back(assignBinding);
         }
         return true;
     }
@@ -850,29 +965,29 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
     if (binding->type == QV4::CompiledData::Binding::Type_Object) {
         if (binding->flags & QV4::CompiledData::Binding::IsOnAssignment) {
             // ### determine value source and interceptor casts ahead of time.
-            QQmlType *type = qmlTypeForObject(createdSubObject);
-            Q_ASSERT(type);
+            QQmlType type = qmlTypeForObject(createdSubObject);
+            Q_ASSERT(type.isValid());
 
-            int valueSourceCast = type->propertyValueSourceCast();
+            int valueSourceCast = type.propertyValueSourceCast();
             if (valueSourceCast != -1) {
                 QQmlPropertyValueSource *vs = reinterpret_cast<QQmlPropertyValueSource *>(reinterpret_cast<char *>(createdSubObject) + valueSourceCast);
                 QObject *target = createdSubObject->parent();
                 QQmlProperty prop;
                 if (_valueTypeProperty)
-                    prop = QQmlPropertyPrivate::restore(target, *_valueTypeProperty, property, context);
+                    prop = QQmlPropertyPrivate::restore(target, *_valueTypeProperty, bindingProperty, context);
                 else
-                    prop = QQmlPropertyPrivate::restore(target, *property, nullptr, context);
+                    prop = QQmlPropertyPrivate::restore(target, *bindingProperty, nullptr, context);
                 vs->setTarget(prop);
                 return true;
             }
-            int valueInterceptorCast = type->propertyValueInterceptorCast();
+            int valueInterceptorCast = type.propertyValueInterceptorCast();
             if (valueInterceptorCast != -1) {
                 QQmlPropertyValueInterceptor *vi = reinterpret_cast<QQmlPropertyValueInterceptor *>(reinterpret_cast<char *>(createdSubObject) + valueInterceptorCast);
                 QObject *target = createdSubObject->parent();
 
                 QQmlPropertyIndex propertyIndex;
-                if (property->isAlias()) {
-                    QQmlPropertyIndex originalIndex(property->coreIndex(), _valueTypeProperty ? _valueTypeProperty->coreIndex() : -1);
+                if (bindingProperty->isAlias()) {
+                    QQmlPropertyIndex originalIndex(bindingProperty->coreIndex(), _valueTypeProperty ? _valueTypeProperty->coreIndex() : -1);
                     QQmlPropertyIndex propIndex;
                     QQmlPropertyPrivate::findAliasTarget(target, originalIndex, &target, &propIndex);
                     QQmlData *data = QQmlData::get(target);
@@ -889,9 +1004,9 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
                 } else {
                     QQmlProperty prop;
                     if (_valueTypeProperty)
-                        prop = QQmlPropertyPrivate::restore(target, *_valueTypeProperty, property, context);
+                        prop = QQmlPropertyPrivate::restore(target, *_valueTypeProperty, bindingProperty, context);
                     else
-                        prop = QQmlPropertyPrivate::restore(target, *property, nullptr, context);
+                        prop = QQmlPropertyPrivate::restore(target, *bindingProperty, nullptr, context);
                     vi->setTarget(prop);
                     propertyIndex = QQmlPropertyPrivate::propertyIndex(prop);
                 }
@@ -907,8 +1022,8 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
 
         // Assigning object to signal property?
         if (binding->flags & QV4::CompiledData::Binding::IsSignalHandlerObject) {
-            if (!property->isFunction()) {
-                recordError(binding->valueLocation, tr("Cannot assign an object to signal property %1").arg(property->name(_qobject)));
+            if (!bindingProperty->isFunction()) {
+                recordError(binding->valueLocation, tr("Cannot assign an object to signal property %1").arg(bindingProperty->name(_qobject)));
                 return false;
             }
             QMetaMethod method = QQmlMetaType::defaultMethod(createdSubObject);
@@ -917,7 +1032,7 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
                 return false;
             }
 
-            QMetaMethod signalMethod = _qobject->metaObject()->method(property->coreIndex());
+            QMetaMethod signalMethod = _qobject->metaObject()->method(bindingProperty->coreIndex());
             if (!QMetaObject::checkConnectArgs(signalMethod, method)) {
                 recordError(binding->valueLocation,
                             tr("Cannot connect mismatched signal/slot %1 %vs. %2")
@@ -926,41 +1041,52 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
                 return false;
             }
 
-            QQmlPropertyPrivate::connect(_qobject, property->coreIndex(), createdSubObject, method.methodIndex());
+            QQmlPropertyPrivate::connect(_qobject, bindingProperty->coreIndex(), createdSubObject, method.methodIndex());
             return true;
         }
 
         QQmlPropertyData::WriteFlags propertyWriteFlags = QQmlPropertyData::BypassInterceptor |
                                                             QQmlPropertyData::RemoveBindingOnAliasWrite;
         int propertyWriteStatus = -1;
-        void *argv[] = { 0, 0, &propertyWriteStatus, &propertyWriteFlags };
+        void *argv[] = { nullptr, nullptr, &propertyWriteStatus, &propertyWriteFlags };
 
-        if (const char *iid = QQmlMetaType::interfaceIId(property->propType())) {
+        if (const char *iid = QQmlMetaType::interfaceIId(bindingProperty->propType())) {
             void *ptr = createdSubObject->qt_metacast(iid);
             if (ptr) {
                 argv[0] = &ptr;
-                QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, property->coreIndex(), argv);
+                QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, bindingProperty->coreIndex(), argv);
             } else {
                 recordError(binding->location, tr("Cannot assign object to interface property"));
                 return false;
             }
-        } else if (property->propType() == QMetaType::QVariant) {
-            if (property->isVarProperty()) {
+        } else if (bindingProperty->propType() == QMetaType::QVariant) {
+            if (bindingProperty->isVarProperty()) {
                 QV4::Scope scope(v4);
-                QV4::ScopedValue wrappedObject(scope, QV4::QObjectWrapper::wrap(QV8Engine::getV4(engine), createdSubObject));
-                _vmeMetaObject->setVMEProperty(property->coreIndex(), wrappedObject);
+                QV4::ScopedValue wrappedObject(scope, QV4::QObjectWrapper::wrap(engine->handle(), createdSubObject));
+                _vmeMetaObject->setVMEProperty(bindingProperty->coreIndex(), wrappedObject);
             } else {
                 QVariant value = QVariant::fromValue(createdSubObject);
                 argv[0] = &value;
-                QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, property->coreIndex(), argv);
+                QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, bindingProperty->coreIndex(), argv);
             }
-        } else if (property->isQList()) {
+        } else if (bindingProperty->propType() == qMetaTypeId<QJSValue>()) {
+            QV4::Scope scope(v4);
+            QV4::ScopedValue wrappedObject(scope, QV4::QObjectWrapper::wrap(engine->handle(), createdSubObject));
+            if (bindingProperty->isVarProperty()) {
+                _vmeMetaObject->setVMEProperty(bindingProperty->coreIndex(), wrappedObject);
+            } else {
+                QJSValue value;
+                QJSValuePrivate::setValue(&value, v4, wrappedObject);
+                argv[0] = &value;
+                QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, bindingProperty->coreIndex(), argv);
+            }
+        } else if (bindingProperty->isQList()) {
             Q_ASSERT(_currentList.object);
 
             void *itemToAdd = createdSubObject;
 
-            const char *iid = 0;
-            int listItemType = QQmlEnginePrivate::get(engine)->listType(property->propType());
+            const char *iid = nullptr;
+            int listItemType = QQmlEnginePrivate::get(engine)->listType(bindingProperty->propType());
             if (listItemType != -1)
                 iid = QQmlMetaType::interfaceIId(listItemType);
             if (iid)
@@ -976,17 +1102,17 @@ bool QQmlObjectCreator::setPropertyBinding(const QQmlPropertyData *property, con
         } else {
             // pointer compatibility was tested in QQmlPropertyValidator at type compile time
             argv[0] = &createdSubObject;
-            QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, property->coreIndex(), argv);
+            QMetaObject::metacall(_qobject, QMetaObject::WriteProperty, bindingProperty->coreIndex(), argv);
         }
         return true;
     }
 
-    if (property->isQList()) {
+    if (bindingProperty->isQList()) {
         recordError(binding->location, tr("Cannot assign primitives to lists"));
         return false;
     }
 
-    setPropertyValue(property, binding);
+    setPropertyValue(bindingProperty, binding);
     return true;
 }
 
@@ -996,7 +1122,7 @@ void QQmlObjectCreator::setupFunctions()
     QV4::ScopedValue function(scope);
     QV4::ScopedContext qmlContext(scope, currentQmlContext());
 
-    const QV4::CompiledData::LEUInt32 *functionIdx = _compiledObject->functionOffsetTable();
+    const quint32_le *functionIdx = _compiledObject->functionOffsetTable();
     for (quint32 i = 0; i < _compiledObject->nFunctions; ++i, ++functionIdx) {
         QV4::Function *runtimeFunction = compilationUnit->runtimeFunctions[*functionIdx];
         const QString name = runtimeFunction->name()->toQString();
@@ -1026,50 +1152,48 @@ void QQmlObjectCreator::registerObjectWithContextById(const QV4::CompiledData::O
         context->setIdProperty(object->id, instance);
 }
 
-QV4::Heap::QmlContext *QQmlObjectCreator::currentQmlContext()
+void QQmlObjectCreator::createQmlContext()
 {
-    if (!_qmlContext->isManaged())
-        _qmlContext->setM(QV4::QmlContext::create(v4->rootContext(), context, _scopeObject));
-
-    return _qmlContext->d();
+    _qmlContext->setM(QV4::QmlContext::create(v4->rootContext(), context, _scopeObject));
 }
 
 QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isContextObject)
 {
-    const QV4::CompiledData::Object *obj = qmlUnit->objectAt(index);
+    const QV4::CompiledData::Object *obj = compilationUnit->objectAt(index);
     QQmlObjectCreationProfiler profiler(sharedState->profiler.profiler, obj);
 
     ActiveOCRestorer ocRestorer(this, QQmlEnginePrivate::get(engine));
 
     bool isComponent = false;
-    QObject *instance = 0;
-    QQmlData *ddata = 0;
-    QQmlCustomParser *customParser = 0;
-    QQmlParserStatus *parserStatus = 0;
+    QObject *instance = nullptr;
+    QQmlData *ddata = nullptr;
+    QQmlCustomParser *customParser = nullptr;
+    QQmlParserStatus *parserStatus = nullptr;
     bool installPropertyCache = true;
 
     if (obj->flags & QV4::CompiledData::Object::IsComponent) {
         isComponent = true;
-        QQmlComponent *component = new QQmlComponent(engine, compilationUnit, index, parent);
+        QQmlComponent *component = new QQmlComponent(engine, compilationUnit.data(), index, parent);
         Q_QML_OC_PROFILE(sharedState->profiler, profiler.update(
-                             compilationUnit, obj, QStringLiteral("<component>"), context->url()));
+                         compilationUnit.data(), obj, QStringLiteral("<component>"), context->url()));
         QQmlComponentPrivate::get(component)->creationContext = context;
         instance = component;
         ddata = QQmlData::get(instance, /*create*/true);
     } else {
-        QV4::CompiledData::ResolvedTypeReference *typeRef = resolvedTypes.value(obj->inheritedTypeNameIndex);
+        QV4::CompiledData::ResolvedTypeReference *typeRef
+                = resolvedType(obj->inheritedTypeNameIndex);
         Q_ASSERT(typeRef);
         installPropertyCache = !typeRef->isFullyDynamicType;
-        QQmlType *type = typeRef->type;
-        if (type) {
+        QQmlType type = typeRef->type;
+        if (type.isValid()) {
             Q_QML_OC_PROFILE(sharedState->profiler, profiler.update(
-                                 compilationUnit, obj, type->qmlTypeName(), context->url()));
+                             compilationUnit.data(), obj, type.qmlTypeName(), context->url()));
 
-            void *ddataMemory = 0;
-            type->create(&instance, &ddataMemory, sizeof(QQmlData));
+            void *ddataMemory = nullptr;
+            type.create(&instance, &ddataMemory, sizeof(QQmlData));
             if (!instance) {
                 recordError(obj->location, tr("Unable to create object of type %1").arg(stringAt(obj->inheritedTypeNameIndex)));
-                return 0;
+                return nullptr;
             }
 
             {
@@ -1080,11 +1204,11 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
                 p->declarativeData = ddata;
             }
 
-            const int parserStatusCast = type->parserStatusCast();
+            const int parserStatusCast = type.parserStatusCast();
             if (parserStatusCast != -1)
                 parserStatus = reinterpret_cast<QQmlParserStatus*>(reinterpret_cast<char *>(instance) + parserStatusCast);
 
-            customParser = type->customParser();
+            customParser = type.customParser();
 
             if (sharedState->rootContext && sharedState->rootContext->isRootObjectInCreation) {
                 QQmlData *ddata = QQmlData::get(instance, /*create*/true);
@@ -1096,31 +1220,39 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
         } else {
             Q_ASSERT(typeRef->compilationUnit);
             Q_QML_OC_PROFILE(sharedState->profiler, profiler.update(
-                                 compilationUnit, obj, typeRef->compilationUnit->fileName(),
-                                 context->url()));
-            if (typeRef->compilationUnit->data->isSingleton())
+                             compilationUnit.data(), obj, typeRef->compilationUnit->fileName(),
+                             context->url()));
+            if (typeRef->compilationUnit->unitData()->isSingleton())
             {
                 recordError(obj->location, tr("Composite Singleton Type %1 is not creatable").arg(stringAt(obj->inheritedTypeNameIndex)));
-                return 0;
+                return nullptr;
             }
 
             QQmlObjectCreator subCreator(context, typeRef->compilationUnit, sharedState.data());
             instance = subCreator.create();
             if (!instance) {
                 errors += subCreator.errors;
-                return 0;
+                return nullptr;
             }
         }
-        if (parent)
+        if (instance->isWidgetType()) {
+            if (parent && parent->isWidgetType()) {
+                QAbstractDeclarativeData::setWidgetParent(instance, parent);
+            } else {
+                // No parent! Layouts need to handle this through a default property that
+                // reparents accordingly. Otherwise the garbage collector will collect.
+            }
+        } else if (parent) {
             QQml_setParent_noEvent(instance, parent);
+        }
 
         ddata = QQmlData::get(instance, /*create*/true);
-        ddata->lineNumber = obj->location.line;
-        ddata->columnNumber = obj->location.column;
     }
+    ddata->lineNumber = obj->location.line;
+    ddata->columnNumber = obj->location.column;
 
     ddata->setImplicitDestructible();
-    if (static_cast<quint32>(index) == qmlUnit->indexOfRootObject || ddata->rootObjectInCreation) {
+    if (static_cast<quint32>(index) == /*root object*/0 || ddata->rootObjectInCreation) {
         if (ddata->context) {
             Q_ASSERT(ddata->context != context);
             Q_ASSERT(ddata->outerContext);
@@ -1128,13 +1260,15 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
             QQmlContextData *c = ddata->context;
             while (c->linkedContext) c = c->linkedContext;
             c->linkedContext = context;
-        } else
-            context->addObject(instance);
-        ddata->ownContext = true;
-    } else if (!ddata->context)
-        context->addObject(instance);
+        } else {
+            ddata->context = context;
+        }
+        ddata->ownContext = ddata->context;
+    } else if (!ddata->context) {
+        ddata->context = context;
+    }
 
-    ddata->outerContext = context;
+    context->addObject(ddata);
 
     if (parserStatus) {
         parserStatus->classBegin();
@@ -1152,20 +1286,20 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
 
     if (customParser && obj->flags & QV4::CompiledData::Object::HasCustomParserBindings) {
         customParser->engine = QQmlEnginePrivate::get(engine);
-        customParser->imports = compilationUnit->typeNameCache;
+        customParser->imports = compilationUnit->typeNameCache.data();
 
         QList<const QV4::CompiledData::Binding *> bindings;
-        const QV4::CompiledData::Object *obj = qmlUnit->objectAt(index);
+        const QV4::CompiledData::Object *obj = compilationUnit->objectAt(index);
         const QV4::CompiledData::Binding *binding = obj->bindingTable();
         for (quint32 i = 0; i < obj->nBindings; ++i, ++binding) {
             if (binding->flags & QV4::CompiledData::Binding::IsCustomParserBinding) {
                 bindings << binding;
             }
         }
-        customParser->applyBindings(instance, compilationUnit, bindings);
+        customParser->applyBindings(instance, compilationUnit.data(), bindings);
 
-        customParser->engine = 0;
-        customParser->imports = (QQmlTypeNameCache*)0;
+        customParser->engine = nullptr;
+        customParser->imports = (QQmlTypeNameCache*)nullptr;
     }
 
     if (isComponent) {
@@ -1178,7 +1312,7 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
     if (installPropertyCache) {
         if (ddata->propertyCache)
             ddata->propertyCache->release();;
-        ddata->propertyCache = cache;
+        ddata->propertyCache = cache.data();
         ddata->propertyCache->addref();
     }
 
@@ -1190,16 +1324,37 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
     ++sharedState->allJavaScriptObjects;
 
     QV4::Scope valueScope(v4);
-    QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc(1));
+    QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc());
 
     qSwap(_qmlContext, qmlContext);
 
-    bool result = populateInstance(index, instance, /*binding target*/instance, /*value type property*/0);
+    bool ok = populateInstance(index, instance, /*binding target*/instance, /*value type property*/nullptr);
+    if (ok) {
+        if (isContextObject && !pendingAliasBindings.empty()) {
+            bool processedAtLeastOneBinding = false;
+            do {
+                processedAtLeastOneBinding = false;
+                for (std::vector<PendingAliasBinding>::iterator it = pendingAliasBindings.begin();
+                        it != pendingAliasBindings.end(); ) {
+                    if ((*it)(sharedState.data())) {
+                        it = pendingAliasBindings.erase(it);
+                        processedAtLeastOneBinding = true;
+                    } else {
+                        ++it;
+                    }
+                }
+            } while (processedAtLeastOneBinding && pendingAliasBindings.empty());
+            Q_ASSERT(pendingAliasBindings.empty());
+        }
+    } else {
+        // an error occurred, so we can't setup the pending alias bindings
+        pendingAliasBindings.clear();
+    }
 
     qSwap(_qmlContext, qmlContext);
     qSwap(_scopeObject, scopeObject);
 
-    return result ? instance : 0;
+    return ok ? instance : nullptr;
 }
 
 QQmlContextData *QQmlObjectCreator::finalize(QQmlInstantiationInterrupt &interrupt)
@@ -1221,9 +1376,14 @@ QQmlContextData *QQmlObjectCreator::finalize(QQmlInstantiationInterrupt &interru
         data->clearPendingBindingBit(b->targetPropertyIndex().coreIndex());
         b->setEnabled(true, QQmlPropertyData::BypassInterceptor |
                       QQmlPropertyData::DontRemoveBinding);
+        if (!b->isValueTypeProxy()) {
+            QQmlBinding *binding = static_cast<QQmlBinding*>(b.data());
+            if (!binding->hasError() && !binding->hasDependencies())
+                b->removeFromObject();
+        }
 
         if (watcher.hasRecursed() || interrupt.shouldInterrupt())
-            return 0;
+            return nullptr;
     }
 
     if (QQmlVME::componentCompleteEnabled()) { // the qml designer does the component complete later
@@ -1232,12 +1392,12 @@ QQmlContextData *QQmlObjectCreator::finalize(QQmlInstantiationInterrupt &interru
             QQmlParserStatus *status = sharedState->allParserStatusCallbacks.pop();
 
             if (status && status->d) {
-                status->d = 0;
+                status->d = nullptr;
                 status->componentComplete();
             }
 
             if (watcher.hasRecursed() || interrupt.shouldInterrupt())
-                return 0;
+                return nullptr;
         }
     }
 
@@ -1245,11 +1405,11 @@ QQmlContextData *QQmlObjectCreator::finalize(QQmlInstantiationInterrupt &interru
         QQmlEnginePrivate::FinalizeCallback callback = sharedState->finalizeCallbacks.at(ii);
         QObject *obj = callback.first;
         if (obj) {
-            void *args[] = { 0 };
+            void *args[] = { nullptr };
             QMetaObject::metacall(obj, QMetaObject::InvokeMetaMethod, callback.second, args);
         }
         if (watcher.hasRecursed())
-            return 0;
+            return nullptr;
     }
     sharedState->finalizeCallbacks.clear();
 
@@ -1264,7 +1424,7 @@ QQmlContextData *QQmlObjectCreator::finalize(QQmlInstantiationInterrupt &interru
             emit a->completed();
 
         if (watcher.hasRecursed() || interrupt.shouldInterrupt())
-            return 0;
+            return nullptr;
     }
 
     phase = Done;
@@ -1272,21 +1432,6 @@ QQmlContextData *QQmlObjectCreator::finalize(QQmlInstantiationInterrupt &interru
     return sharedState->rootContext;
 }
 
-void QQmlObjectCreator::cancel(QObject *object)
-{
-    int last = sharedState->allCreatedObjects.count() - 1;
-    int i = last;
-    while (i >= 0) {
-        if (sharedState->allCreatedObjects.at(i) == object) {
-            if (i < last)
-                qSwap(sharedState->allCreatedObjects[i], sharedState->allCreatedObjects[last]);
-            sharedState->allCreatedObjects.pop();
-            break;
-        }
-        --i;
-    }
-}
-
 void QQmlObjectCreator::clear()
 {
     if (phase == Done || phase == Finalizing || phase == Startup)
@@ -1311,7 +1456,7 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
     qSwap(_qobject, instance);
     qSwap(_valueTypeProperty, valueTypeProperty);
     qSwap(_compiledObjectIndex, index);
-    const QV4::CompiledData::Object *obj = qmlUnit->objectAt(_compiledObjectIndex);
+    const QV4::CompiledData::Object *obj = compilationUnit->objectAt(_compiledObjectIndex);
     qSwap(_compiledObject, obj);
     qSwap(_ddata, declarativeData);
     qSwap(_bindingTarget, bindingTarget);
@@ -1321,14 +1466,14 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
 
     QQmlRefPointer<QQmlPropertyCache> cache = propertyCaches->at(_compiledObjectIndex);
 
-    QQmlVMEMetaObject *vmeMetaObject = 0;
+    QQmlVMEMetaObject *vmeMetaObject = nullptr;
     if (propertyCaches->needsVMEMetaObject(_compiledObjectIndex)) {
         Q_ASSERT(!cache.isNull());
         // install on _object
-        vmeMetaObject = new QQmlVMEMetaObject(_qobject, cache, compilationUnit, _compiledObjectIndex);
+        vmeMetaObject = new QQmlVMEMetaObject(v4, _qobject, cache, compilationUnit, _compiledObjectIndex);
         if (_ddata->propertyCache)
             _ddata->propertyCache->release();
-        _ddata->propertyCache = cache;
+        _ddata->propertyCache = cache.data();
         _ddata->propertyCache->addref();
         scopeObjectProtector = _ddata->jsWrapper.value();
     } else {
@@ -1340,14 +1485,8 @@ bool QQmlObjectCreator::populateInstance(int index, QObject *instance, QObject *
     qSwap(_propertyCache, cache);
     qSwap(_vmeMetaObject, vmeMetaObject);
 
-    if (_compiledObject->flags & QV4::CompiledData::Object::HasDeferredBindings) {
-        QQmlData::DeferredData *deferData = new QQmlData::DeferredData;
-        deferData->deferredIdx = _compiledObjectIndex;
-        deferData->compilationUnit = compilationUnit;
-        deferData->compilationUnit->addref();
-        deferData->context = context;
-        _ddata->deferredData = deferData;
-    }
+    if (_compiledObject->flags & QV4::CompiledData::Object::HasDeferredBindings)
+        _ddata->deferData(_compiledObjectIndex, compilationUnit, context);
 
     if (_compiledObject->nFunctions > 0)
         setupFunctions();
diff --git a/src/qml/qml/qqmlobjectcreator_p.h b/src/qml/qml/qqmlobjectcreator_p.h
index 982324be3c..5aca60e2f0 100644
--- a/src/qml/qml/qqmlobjectcreator_p.h
+++ b/src/qml/qml/qqmlobjectcreator_p.h
@@ -65,6 +65,7 @@ QT_BEGIN_NAMESPACE
 class QQmlAbstractBinding;
 struct QQmlTypeCompiler;
 class QQmlInstantiationInterrupt;
+class QQmlIncubatorPrivate;
 
 struct QQmlObjectCreatorSharedState : public QSharedData
 {
@@ -80,17 +81,17 @@ struct QQmlObjectCreatorSharedState : public QSharedData
     QRecursionNode recursionNode;
 };
 
-class QQmlObjectCreator
+class Q_QML_PRIVATE_EXPORT QQmlObjectCreator
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlObjectCreator)
 public:
-    QQmlObjectCreator(QQmlContextData *parentContext, QV4::CompiledData::CompilationUnit *compilationUnit, QQmlContextData *creationContext, void *activeVMEDataForRootContext = 0);
+    QQmlObjectCreator(QQmlContextData *parentContext, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, QQmlContextData *creationContext, QQmlIncubatorPrivate  *incubator = nullptr);
     ~QQmlObjectCreator();
 
-    QObject *create(int subComponentIndex = -1, QObject *parent = 0, QQmlInstantiationInterrupt *interrupt = 0);
-    bool populateDeferredProperties(QObject *instance);
+    QObject *create(int subComponentIndex = -1, QObject *parent = nullptr, QQmlInstantiationInterrupt *interrupt = nullptr);
+    bool populateDeferredProperties(QObject *instance, QQmlData::DeferredData *deferredData);
+    bool populateDeferredBinding(const QQmlProperty &qmlProperty, QQmlData::DeferredData *deferredData, const QV4::CompiledData::Binding *binding);
     QQmlContextData *finalize(QQmlInstantiationInterrupt &interrupt);
-    void cancel(QObject *object);
     void clear();
 
     QQmlComponentAttached **componentAttachment() const { return &sharedState->componentAttached; }
@@ -103,11 +104,11 @@ public:
     QFiniteStack<QPointer<QObject> > &allCreatedObjects() const { return sharedState->allCreatedObjects; }
 
 private:
-    QQmlObjectCreator(QQmlContextData *contextData, QV4::CompiledData::CompilationUnit *compilationUnit, QQmlObjectCreatorSharedState *inheritedSharedState);
+    QQmlObjectCreator(QQmlContextData *contextData, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, QQmlObjectCreatorSharedState *inheritedSharedState);
 
     void init(QQmlContextData *parentContext);
 
-    QObject *createInstance(int index, QObject *parent = 0, bool isContextObject = false);
+    QObject *createInstance(int index, QObject *parent = nullptr, bool isContextObject = false);
 
     bool populateInstance(int index, QObject *instance,
                           QObject *bindingTarget, const QQmlPropertyData *valueTypeProperty);
@@ -117,12 +118,17 @@ private:
     void setPropertyValue(const QQmlPropertyData *property, const QV4::CompiledData::Binding *binding);
     void setupFunctions();
 
-    QString stringAt(int idx) const { return qmlUnit->stringAt(idx); }
+    QString stringAt(int idx) const { return compilationUnit->stringAt(idx); }
     void recordError(const QV4::CompiledData::Location &location, const QString &description);
 
     void registerObjectWithContextById(const QV4::CompiledData::Object *object, QObject *instance) const;
 
-    QV4::Heap::QmlContext *currentQmlContext();
+    inline QV4::QmlContext *currentQmlContext();
+    Q_NEVER_INLINE void createQmlContext();
+    QV4::CompiledData::ResolvedTypeReference *resolvedType(int id) const
+    {
+        return compilationUnit->resolvedType(id);
+    }
 
     enum Phase {
         Startup,
@@ -135,15 +141,14 @@ private:
 
     QQmlEngine *engine;
     QV4::ExecutionEngine *v4;
-    QV4::CompiledData::CompilationUnit *compilationUnit;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
     const QV4::CompiledData::Unit *qmlUnit;
     QQmlGuardedContextData parentContext;
     QQmlContextData *context;
-    const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypes;
     const QQmlPropertyCacheVector *propertyCaches;
     QExplicitlySharedDataPointer<QQmlObjectCreatorSharedState> sharedState;
     bool topLevelCreator;
-    void *activeVMEDataForRootContext;
+    QQmlIncubatorPrivate *incubator;
 
     QObject *_qobject;
     QObject *_scopeObject;
@@ -159,6 +164,9 @@ private:
     QV4::QmlContext *_qmlContext;
 
     friend struct QQmlObjectCreatorRecursionWatcher;
+
+    typedef std::function<bool(QQmlObjectCreatorSharedState *sharedState)> PendingAliasBinding;
+    std::vector<PendingAliasBinding> pendingAliasBindings;
 };
 
 struct QQmlObjectCreatorRecursionWatcher
@@ -172,6 +180,14 @@ private:
     QRecursionWatcher<QQmlObjectCreatorSharedState, &QQmlObjectCreatorSharedState::recursionNode> watcher;
 };
 
+QV4::QmlContext *QQmlObjectCreator::currentQmlContext()
+{
+    if (!_qmlContext->isManaged())
+        _qmlContext->setM(QV4::QmlContext::create(v4->rootContext(), context, _scopeObject));
+
+    return _qmlContext;
+}
+
 QT_END_NAMESPACE
 
 #endif // QQMLOBJECTCREATOR_P_H
diff --git a/src/qml/qml/qqmlobjectorgadget.cpp b/src/qml/qml/qqmlobjectorgadget.cpp
new file mode 100644
index 0000000000..1d4916d7d1
--- /dev/null
+++ b/src/qml/qml/qqmlobjectorgadget.cpp
@@ -0,0 +1,60 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlobjectorgadget_p.h"
+
+QT_BEGIN_NAMESPACE
+
+void QQmlObjectOrGadget::metacall(QMetaObject::Call type, int index, void **argv) const
+{
+    if (ptr.isNull()) {
+        const QMetaObject *metaObject = _m.asT2();
+        metaObject->d.static_metacall(nullptr, type, index, argv);
+    }
+    else if (ptr.isT1()) {
+        QMetaObject::metacall(ptr.asT1(), type, index, argv);
+    }
+    else {
+        const QMetaObject *metaObject = _m.asT1()->metaObject();
+        QQmlMetaObject::resolveGadgetMethodOrPropertyIndex(type, &metaObject, &index);
+        metaObject->d.static_metacall(reinterpret_cast<QObject*>(ptr.asT2()), type, index, argv);
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlobjectorgadget_p.h b/src/qml/qml/qqmlobjectorgadget_p.h
new file mode 100644
index 0000000000..c5f5f58a3a
--- /dev/null
+++ b/src/qml/qml/qqmlobjectorgadget_p.h
@@ -0,0 +1,83 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLOBJECTORGADGET_P_H
+#define QQMLOBJECTORGADGET_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmlmetaobject_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlObjectOrGadget: public QQmlMetaObject
+{
+public:
+    QQmlObjectOrGadget(QObject *obj)
+        : QQmlMetaObject(obj),
+        ptr(obj)
+    {}
+    QQmlObjectOrGadget(QQmlPropertyCache *propertyCache, void *gadget)
+        : QQmlMetaObject(propertyCache)
+        , ptr(gadget)
+    {}
+
+    void metacall(QMetaObject::Call type, int index, void **argv) const;
+
+private:
+    QBiPointer<QObject, void> ptr;
+
+protected:
+    QQmlObjectOrGadget(const QMetaObject* metaObject)
+        : QQmlMetaObject(metaObject)
+    {}
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLOBJECTORGADGET_P_H
diff --git a/src/qml/qml/qqmlopenmetaobject.cpp b/src/qml/qml/qqmlopenmetaobject.cpp
index 49f02476a2..fc798a2c23 100644
--- a/src/qml/qml/qqmlopenmetaobject.cpp
+++ b/src/qml/qml/qqmlopenmetaobject.cpp
@@ -51,7 +51,7 @@ QT_BEGIN_NAMESPACE
 class QQmlOpenMetaObjectTypePrivate
 {
 public:
-    QQmlOpenMetaObjectTypePrivate() : mem(0), cache(0), engine(0) {}
+    QQmlOpenMetaObjectTypePrivate() : mem(nullptr), cache(nullptr), engine(nullptr) {}
 
     void init(const QMetaObject *metaObj);
 
@@ -83,7 +83,7 @@ QQmlOpenMetaObjectType::~QQmlOpenMetaObjectType()
 
 void QQmlOpenMetaObjectType::clear()
 {
-    d->engine = 0;
+    d->engine = nullptr;
 }
 
 int QQmlOpenMetaObjectType::propertyOffset() const
@@ -181,46 +181,75 @@ void QQmlOpenMetaObjectTypePrivate::init(const QMetaObject *metaObj)
 class QQmlOpenMetaObjectPrivate
 {
 public:
-    QQmlOpenMetaObjectPrivate(QQmlOpenMetaObject *_q)
-        : q(_q), parent(0), type(0), cacheProperties(false) {}
+    QQmlOpenMetaObjectPrivate(QQmlOpenMetaObject *_q, bool _autoCreate, QObject *obj)
+        : q(_q), object(obj), autoCreate(_autoCreate) {}
+
+    struct Property {
+    private:
+        QVariant m_value;
+        QPointer<QObject> qobjectTracker;
+    public:
+        bool valueSet = false;
+
+        QVariant value() const {
+            if (QMetaType::typeFlags(m_value.userType()) & QMetaType::PointerToQObject
+                && qobjectTracker.isNull())
+                return QVariant::fromValue<QObject*>(nullptr);
+            return m_value;
+        }
+        QVariant &valueRef() { return m_value; }
+        void setValue(const QVariant &v) {
+            m_value = v;
+            valueSet = true;
+            if (QMetaType::typeFlags(v.userType()) & QMetaType::PointerToQObject)
+                qobjectTracker = m_value.value<QObject*>();
+        }
+    };
 
-    inline QPair<QVariant, bool> &getDataRef(int idx) {
-        while (data.count() <= idx)
-            data << QPair<QVariant, bool>(QVariant(), false);
-        return data[idx];
+    inline void setPropertyValue(int idx, const QVariant &value) {
+        if (data.count() <= idx)
+            data.resize(idx + 1);
+        data[idx].setValue(value);
     }
 
-    inline QVariant &getData(int idx) {
-        QPair<QVariant, bool> &prop = getDataRef(idx);
-        if (!prop.second) {
-            prop.first = q->initialValue(idx);
-            prop.second = true;
-        }
-        return prop.first;
+    inline Property &propertyRef(int idx) {
+        if (data.count() <= idx)
+            data.resize(idx + 1);
+        Property &prop = data[idx];
+        if (!prop.valueSet)
+            prop.setValue(q->initialValue(idx));
+        return prop;
+    }
+
+    inline QVariant propertyValue(int idx) {
+        auto &prop = propertyRef(idx);
+        return prop.value();
+    }
+
+    inline QVariant &propertyValueRef(int idx) {
+        auto &prop = propertyRef(idx);
+        return prop.valueRef();
     }
 
-    inline bool hasData(int idx) const {
+    inline bool hasProperty(int idx) const {
         if (idx >= data.count())
             return false;
-        return data[idx].second;
+        return data[idx].valueSet;
     }
 
-    bool autoCreate;
     QQmlOpenMetaObject *q;
-    QAbstractDynamicMetaObject *parent;
-    QList<QPair<QVariant, bool> > data;
+    QAbstractDynamicMetaObject *parent = nullptr;
+    QVector<Property> data;
     QObject *object;
-    QQmlOpenMetaObjectType *type;
-    bool cacheProperties;
+    QQmlRefPointer<QQmlOpenMetaObjectType> type;
+    bool autoCreate;
+    bool cacheProperties = false;
 };
 
 QQmlOpenMetaObject::QQmlOpenMetaObject(QObject *obj, const QMetaObject *base, bool automatic)
-: d(new QQmlOpenMetaObjectPrivate(this))
+: d(new QQmlOpenMetaObjectPrivate(this, automatic, obj))
 {
-    d->autoCreate = automatic;
-    d->object = obj;
-
-    d->type = new QQmlOpenMetaObjectType(base ? base : obj->metaObject(), 0);
+    d->type.adopt(new QQmlOpenMetaObjectType(base ? base : obj->metaObject(), nullptr));
     d->type->d->referers.insert(this);
 
     QObjectPrivate *op = QObjectPrivate::get(obj);
@@ -230,13 +259,9 @@ QQmlOpenMetaObject::QQmlOpenMetaObject(QObject *obj, const QMetaObject *base, bo
 }
 
 QQmlOpenMetaObject::QQmlOpenMetaObject(QObject *obj, QQmlOpenMetaObjectType *type, bool automatic)
-: d(new QQmlOpenMetaObjectPrivate(this))
+: d(new QQmlOpenMetaObjectPrivate(this, automatic, obj))
 {
-    d->autoCreate = automatic;
-    d->object = obj;
-
     d->type = type;
-    d->type->addref();
     d->type->d->referers.insert(this);
 
     QObjectPrivate *op = QObjectPrivate::get(obj);
@@ -250,13 +275,12 @@ QQmlOpenMetaObject::~QQmlOpenMetaObject()
     if (d->parent)
         delete d->parent;
     d->type->d->referers.remove(this);
-    d->type->release();
     delete d;
 }
 
 QQmlOpenMetaObjectType *QQmlOpenMetaObject::type() const
 {
-    return d->type;
+    return d->type.data();
 }
 
 void QQmlOpenMetaObject::emitPropertyNotification(const QByteArray &propertyName)
@@ -264,7 +288,7 @@ void QQmlOpenMetaObject::emitPropertyNotification(const QByteArray &propertyName
     QHash<QByteArray, int>::ConstIterator iter = d->type->d->names.constFind(propertyName);
     if (iter == d->type->d->names.constEnd())
         return;
-    activate(d->object, *iter + d->type->d->signalOffset, 0);
+    activate(d->object, *iter + d->type->d->signalOffset, nullptr);
 }
 
 int QQmlOpenMetaObject::metaCall(QObject *o, QMetaObject::Call c, int id, void **a)
@@ -276,15 +300,13 @@ int QQmlOpenMetaObject::metaCall(QObject *o, QMetaObject::Call c, int id, void *
         int propId = id - d->type->d->propertyOffset;
         if (c == QMetaObject::ReadProperty) {
             propertyRead(propId);
-            *reinterpret_cast<QVariant *>(a[0]) = d->getData(propId);
+            *reinterpret_cast<QVariant *>(a[0]) = d->propertyValue(propId);
         } else if (c == QMetaObject::WriteProperty) {
-            if (propId >= d->data.count() || d->data.at(propId).first != *reinterpret_cast<QVariant *>(a[0]))  {
+            if (propId >= d->data.count() || d->data.at(propId).value() != *reinterpret_cast<QVariant *>(a[0]))  {
                 propertyWrite(propId);
-                QPair<QVariant, bool> &prop = d->getDataRef(propId);
-                prop.first = propertyWriteValue(propId, *reinterpret_cast<QVariant *>(a[0]));
-                prop.second = true;
+                d->setPropertyValue(propId, propertyWriteValue(propId, *reinterpret_cast<QVariant *>(a[0])));
                 propertyWritten(propId);
-                activate(o, d->type->d->signalOffset + propId, 0);
+                activate(o, d->type->d->signalOffset + propId, nullptr);
             }
         }
         return -1;
@@ -303,15 +325,13 @@ QAbstractDynamicMetaObject *QQmlOpenMetaObject::parent() const
 
 QVariant QQmlOpenMetaObject::value(int id) const
 {
-    return d->getData(id);
+    return d->propertyValue(id);
 }
 
 void QQmlOpenMetaObject::setValue(int id, const QVariant &value)
 {
-    QPair<QVariant, bool> &prop = d->getDataRef(id);
-    prop.first = propertyWriteValue(id, value);
-    prop.second = true;
-    activate(d->object, id + d->type->d->signalOffset, 0);
+    d->setPropertyValue(id, propertyWriteValue(id, value));
+    activate(d->object, id + d->type->d->signalOffset, nullptr);
 }
 
 QVariant QQmlOpenMetaObject::value(const QByteArray &name) const
@@ -320,23 +340,18 @@ QVariant QQmlOpenMetaObject::value(const QByteArray &name) const
     if (iter == d->type->d->names.cend())
         return QVariant();
 
-    return d->getData(*iter);
+    return d->propertyValue(*iter);
 }
 
-QVariant &QQmlOpenMetaObject::operator[](const QByteArray &name)
+QVariant &QQmlOpenMetaObject::valueRef(const QByteArray &name)
 {
     QHash<QByteArray, int>::ConstIterator iter = d->type->d->names.constFind(name);
     Q_ASSERT(iter != d->type->d->names.cend());
 
-    return d->getData(*iter);
-}
-
-QVariant &QQmlOpenMetaObject::operator[](int id)
-{
-    return d->getData(id);
+    return d->propertyValueRef(*iter);
 }
 
-bool QQmlOpenMetaObject::setValue(const QByteArray &name, const QVariant &val)
+bool QQmlOpenMetaObject::setValue(const QByteArray &name, const QVariant &val, bool force)
 {
     QHash<QByteArray, int>::ConstIterator iter = d->type->d->names.constFind(name);
 
@@ -348,12 +363,11 @@ bool QQmlOpenMetaObject::setValue(const QByteArray &name, const QVariant &val)
     }
 
     if (id >= 0) {
-        QVariant &dataVal = d->getData(id);
-        if (dataVal == val)
+        if (!force && d->propertyValue(id) == val)
             return false;
 
-        dataVal = val;
-        activate(d->object, id + d->type->d->signalOffset, 0);
+        d->setPropertyValue(id, val);
+        activate(d->object, id + d->type->d->signalOffset, nullptr);
         return true;
     }
 
@@ -363,7 +377,7 @@ bool QQmlOpenMetaObject::setValue(const QByteArray &name, const QVariant &val)
 // returns true if this value has been initialized by a call to either value() or setValue()
 bool QQmlOpenMetaObject::hasValue(int id) const
 {
-    return d->hasData(id);
+    return d->hasProperty(id);
 }
 
 void QQmlOpenMetaObject::setCached(bool c)
@@ -376,13 +390,13 @@ void QQmlOpenMetaObject::setCached(bool c)
     QQmlData *qmldata = QQmlData::get(d->object, true);
     if (d->cacheProperties) {
         if (!d->type->d->cache)
-            d->type->d->cache = new QQmlPropertyCache(QV8Engine::getV4(d->type->d->engine), this);
+            d->type->d->cache = new QQmlPropertyCache(this);
         qmldata->propertyCache = d->type->d->cache;
         d->type->d->cache->addref();
     } else {
         if (d->type->d->cache)
             d->type->d->cache->release();
-        qmldata->propertyCache = 0;
+        qmldata->propertyCache = nullptr;
     }
 }
 
@@ -395,7 +409,7 @@ int QQmlOpenMetaObject::createProperty(const char *name, const char *)
         if (QQmlData *ddata = QQmlData::get(d->object, /*create*/false)) {
             if (ddata->propertyCache) {
                 ddata->propertyCache->release();
-                ddata->propertyCache = 0;
+                ddata->propertyCache = nullptr;
             }
         }
 
diff --git a/src/qml/qml/qqmlopenmetaobject_p.h b/src/qml/qml/qqmlopenmetaobject_p.h
index 4bb92489a5..168a2a6f7f 100644
--- a/src/qml/qml/qqmlopenmetaobject_p.h
+++ b/src/qml/qml/qqmlopenmetaobject_p.h
@@ -69,7 +69,7 @@ class Q_QML_PRIVATE_EXPORT QQmlOpenMetaObjectType : public QQmlRefCount, public
 {
 public:
     QQmlOpenMetaObjectType(const QMetaObject *base, QQmlEngine *engine);
-    ~QQmlOpenMetaObjectType();
+    ~QQmlOpenMetaObjectType() override;
 
     void createProperties(const QVector<QByteArray> &names);
     int createProperty(const QByteArray &name);
@@ -95,16 +95,15 @@ class QQmlOpenMetaObjectPrivate;
 class Q_QML_PRIVATE_EXPORT QQmlOpenMetaObject : public QAbstractDynamicMetaObject
 {
 public:
-    QQmlOpenMetaObject(QObject *, const QMetaObject * = 0, bool = true);
+    QQmlOpenMetaObject(QObject *, const QMetaObject * = nullptr, bool = true);
     QQmlOpenMetaObject(QObject *, QQmlOpenMetaObjectType *, bool = true);
-    ~QQmlOpenMetaObject();
+    ~QQmlOpenMetaObject() override;
 
     QVariant value(const QByteArray &) const;
-    bool setValue(const QByteArray &, const QVariant &);
+    bool setValue(const QByteArray &, const QVariant &, bool force = false);
     QVariant value(int) const;
     void setValue(int, const QVariant &);
-    QVariant &operator[](const QByteArray &);
-    QVariant &operator[](int);
+    QVariant &valueRef(const QByteArray &);
     bool hasValue(int) const;
 
     int count() const;
diff --git a/src/qml/qml/qqmlparserstatus.cpp b/src/qml/qml/qqmlparserstatus.cpp
index ad07cac7ef..b8f4bb8c19 100644
--- a/src/qml/qml/qqmlparserstatus.cpp
+++ b/src/qml/qml/qqmlparserstatus.cpp
@@ -81,13 +81,11 @@ QT_BEGIN_NAMESPACE
         void componentComplete();
     }
     \endcode
-
-    The \l {Qt Quick 1} version of this class is named QDeclarativeParserStatus.
 */
 
 /*! \internal */
 QQmlParserStatus::QQmlParserStatus()
-: d(0)
+: d(nullptr)
 {
 }
 
@@ -95,7 +93,7 @@ QQmlParserStatus::QQmlParserStatus()
 QQmlParserStatus::~QQmlParserStatus()
 {
     if(d)
-        (*d) = 0;
+        (*d) = nullptr;
 }
 
 /*!
diff --git a/src/qml/qml/qqmlplatform.cpp b/src/qml/qml/qqmlplatform.cpp
index a8c402af2e..0acf20bbb4 100644
--- a/src/qml/qml/qqmlplatform.cpp
+++ b/src/qml/qml/qqmlplatform.cpp
@@ -72,6 +72,8 @@ QString QQmlPlatform::os()
     return QStringLiteral("windows");
 #elif defined(Q_OS_LINUX)
     return QStringLiteral("linux");
+#elif defined(Q_OS_QNX)
+    return QStringLiteral("qnx");
 #elif defined(Q_OS_UNIX)
     return QStringLiteral("unix");
 #else
diff --git a/src/qml/qml/qqmlplatform_p.h b/src/qml/qml/qqmlplatform_p.h
index 6246ca7105..af33dffca3 100644
--- a/src/qml/qml/qqmlplatform_p.h
+++ b/src/qml/qml/qqmlplatform_p.h
@@ -64,7 +64,7 @@ class Q_QML_PRIVATE_EXPORT QQmlPlatform : public QObject
     Q_PROPERTY(QString pluginName READ pluginName CONSTANT)
 
 public:
-    explicit QQmlPlatform(QObject *parent = 0);
+    explicit QQmlPlatform(QObject *parent = nullptr);
     virtual ~QQmlPlatform();
 
     static QString os();
diff --git a/src/qml/qml/qqmlprivate.h b/src/qml/qml/qqmlprivate.h
index eeb5b4c302..c0232a7691 100644
--- a/src/qml/qml/qqmlprivate.h
+++ b/src/qml/qml/qqmlprivate.h
@@ -69,7 +69,6 @@ namespace CompiledData {
 struct Unit;
 struct CompilationUnit;
 }
-typedef CompiledData::CompilationUnit *(*CompilationUnitFactoryFunction)();
 }
 namespace QmlIR {
 struct Document;
@@ -96,12 +95,24 @@ namespace QQmlPrivate
 {
     void Q_QML_EXPORT qdeclarativeelement_destructor(QObject *);
     template<typename T>
-    class QQmlElement : public T
+    class QQmlElement final : public T
     {
     public:
-        virtual ~QQmlElement() {
+        ~QQmlElement() override {
             QQmlPrivate::qdeclarativeelement_destructor(this);
         }
+        static void operator delete(void *ptr) {
+            // We allocate memory from this class in QQmlType::create
+            // along with some additional memory.
+            // So we override the operator delete in order to avoid the
+            // sized operator delete to be called with a different size than
+            // the size that was allocated.
+            ::operator delete (ptr);
+        }
+        static void operator delete(void *, void *) {
+            // Deliberately empty placement delete operator.
+            // Silences MSVC warning C4291: no matching operator delete found
+        }
     };
 
     template<typename T>
@@ -168,8 +179,8 @@ namespace QQmlPrivate
     class AttachedPropertySelector
     {
     public:
-        static inline QQmlAttachedPropertiesFunc func() { return 0; }
-        static inline const QMetaObject *metaObject() { return 0; }
+        static inline QQmlAttachedPropertiesFunc func() { return nullptr; }
+        static inline const QMetaObject *metaObject() { return nullptr; }
     };
     template<typename T>
     class AttachedPropertySelector<T, 1>
@@ -284,8 +295,8 @@ namespace QQmlPrivate
 
     struct CachedQmlUnit {
         const QV4::CompiledData::Unit *qmlData;
-        QV4::CompilationUnitFactoryFunction createCompilationUnit;
-        QmlIR::IRLoaderFunction loadIR;
+        void *unused1;
+        void *unused2;
     };
 
     typedef const CachedQmlUnit *(*QmlUnitCacheLookupFunction)(const QUrl &url);
diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index 9b5f7b0a06..000b88ebaa 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -111,15 +111,13 @@ qWarning() << "Current pixel size:" << property.read().toInt();
 property.write(24);
 qWarning() << "Pixel size should now be 24:" << property.read().toInt();
 \endcode
-
-The \l {Qt Quick 1} version of this class was named QDeclarativeProperty.
 */
 
 /*!
     Create an invalid QQmlProperty.
 */
 QQmlProperty::QQmlProperty()
-: d(0)
+: d(nullptr)
 {
 }
 
@@ -128,7 +126,7 @@ QQmlProperty::~QQmlProperty()
 {
     if (d)
         d->release();
-    d = 0;
+    d = nullptr;
 }
 
 /*!
@@ -150,8 +148,8 @@ QQmlProperty::QQmlProperty(QObject *obj)
 QQmlProperty::QQmlProperty(QObject *obj, QQmlContext *ctxt)
 : d(new QQmlPropertyPrivate)
 {
-    d->context = ctxt?QQmlContextData::get(ctxt):0;
-    d->engine = ctxt?ctxt->engine():0;
+    d->context = ctxt?QQmlContextData::get(ctxt):nullptr;
+    d->engine = ctxt?ctxt->engine():nullptr;
     d->initDefault(obj);
 }
 
@@ -164,7 +162,7 @@ QQmlProperty::QQmlProperty(QObject *obj, QQmlContext *ctxt)
 QQmlProperty::QQmlProperty(QObject *obj, QQmlEngine *engine)
   : d(new QQmlPropertyPrivate)
 {
-    d->context = 0;
+    d->context = nullptr;
     d->engine = engine;
     d->initDefault(obj);
 }
@@ -190,7 +188,7 @@ QQmlProperty::QQmlProperty(QObject *obj, const QString &name)
 : d(new QQmlPropertyPrivate)
 {
     d->initProperty(obj, name);
-    if (!isValid()) d->object = 0;
+    if (!isValid()) d->object = nullptr;
 }
 
 /*!
@@ -203,10 +201,10 @@ QQmlProperty::QQmlProperty(QObject *obj, const QString &name)
 QQmlProperty::QQmlProperty(QObject *obj, const QString &name, QQmlContext *ctxt)
 : d(new QQmlPropertyPrivate)
 {
-    d->context = ctxt?QQmlContextData::get(ctxt):0;
-    d->engine = ctxt?ctxt->engine():0;
+    d->context = ctxt?QQmlContextData::get(ctxt):nullptr;
+    d->engine = ctxt?ctxt->engine():nullptr;
     d->initProperty(obj, name);
-    if (!isValid()) { d->object = 0; d->context = 0; d->engine = 0; }
+    if (!isValid()) { d->object = nullptr; d->context = nullptr; d->engine = nullptr; }
 }
 
 /*!
@@ -217,14 +215,30 @@ QQmlProperty::QQmlProperty(QObject *obj, const QString &name, QQmlContext *ctxt)
 QQmlProperty::QQmlProperty(QObject *obj, const QString &name, QQmlEngine *engine)
 : d(new QQmlPropertyPrivate)
 {
-    d->context = 0;
+    d->context = nullptr;
     d->engine = engine;
     d->initProperty(obj, name);
-    if (!isValid()) { d->object = 0; d->context = 0; d->engine = 0; }
+    if (!isValid()) { d->object = nullptr; d->context = nullptr; d->engine = nullptr; }
+}
+
+QQmlProperty QQmlPropertyPrivate::create(QObject *target, const QString &propertyName, QQmlContextData *context)
+{
+    QQmlProperty result;
+    auto d = new QQmlPropertyPrivate;
+    result.d = d;
+    d->context = context;
+    d->engine = context ? context->engine : nullptr;
+    d->initProperty(target, propertyName);
+    if (!result.isValid()) {
+        d->object = nullptr;
+        d->context = nullptr;
+        d->engine = nullptr;
+    }
+    return result;
 }
 
 QQmlPropertyPrivate::QQmlPropertyPrivate()
-: context(0), engine(0), object(0), isNameCached(false)
+: context(nullptr), engine(nullptr), object(nullptr), isNameCached(false)
 {
 }
 
@@ -232,98 +246,104 @@ QQmlContextData *QQmlPropertyPrivate::effectiveContext() const
 {
     if (context) return context;
     else if (engine) return QQmlContextData::get(engine->rootContext());
-    else return 0;
+    else return nullptr;
 }
 
 void QQmlPropertyPrivate::initProperty(QObject *obj, const QString &name)
 {
     if (!obj) return;
 
-    QQmlTypeNameCache *typeNameCache = context?context->imports:0;
-
-    const auto path = name.splitRef(QLatin1Char('.'));
-    if (path.isEmpty()) return;
+    QQmlRefPointer<QQmlTypeNameCache> typeNameCache = context?context->imports:nullptr;
 
     QObject *currentObject = obj;
-
-    // Everything up to the last property must be an "object type" property
-    for (int ii = 0; ii < path.count() - 1; ++ii) {
-        const QStringRef &pathName = path.at(ii);
-
-        if (typeNameCache) {
-            QQmlTypeNameCache::Result r = typeNameCache->query(pathName);
-            if (r.isValid()) {
-                if (r.type) {
-                    QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
-                    QQmlAttachedPropertiesFunc func = r.type->attachedPropertiesFunction(enginePrivate);
-                    if (!func) return; // Not an attachable type
-
-                    currentObject = qmlAttachedPropertiesObjectById(r.type->attachedPropertiesId(enginePrivate), currentObject);
-                    if (!currentObject) return; // Something is broken with the attachable type
-                } else if (r.importNamespace) {
-                    if ((ii + 1) == path.count()) return; // No type following the namespace
-
-                    ++ii; r = typeNameCache->query(path.at(ii), r.importNamespace);
-                    if (!r.type) return; // Invalid type in namespace
-
-                    QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
-                    QQmlAttachedPropertiesFunc func = r.type->attachedPropertiesFunction(enginePrivate);
-                    if (!func) return; // Not an attachable type
-
-                    currentObject = qmlAttachedPropertiesObjectById(r.type->attachedPropertiesId(enginePrivate), currentObject);
-                    if (!currentObject) return; // Something is broken with the attachable type
-
-                } else if (r.scriptIndex != -1) {
-                    return; // Not a type
-                } else {
-                    Q_ASSERT(!"Unreachable");
+    QVector<QStringRef> path;
+    QStringRef terminal(&name);
+
+    if (name.contains(QLatin1Char('.'))) {
+        path = name.splitRef(QLatin1Char('.'));
+        if (path.isEmpty()) return;
+
+        // Everything up to the last property must be an "object type" property
+        for (int ii = 0; ii < path.count() - 1; ++ii) {
+            const QStringRef &pathName = path.at(ii);
+
+            // Types must begin with an uppercase letter (see checkRegistration()
+            // in qqmlmetatype.cpp for the enforcement of this).
+            if (typeNameCache && !pathName.isEmpty() && pathName.at(0).isUpper()) {
+                QQmlTypeNameCache::Result r = typeNameCache->query(pathName);
+                if (r.isValid()) {
+                    if (r.type.isValid()) {
+                        QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
+                        QQmlAttachedPropertiesFunc func = r.type.attachedPropertiesFunction(enginePrivate);
+                        if (!func) return; // Not an attachable type
+
+                        currentObject = qmlAttachedPropertiesObjectById(r.type.attachedPropertiesId(enginePrivate), currentObject);
+                        if (!currentObject) return; // Something is broken with the attachable type
+                    } else if (r.importNamespace) {
+                        if ((ii + 1) == path.count()) return; // No type following the namespace
+
+                        ++ii; r = typeNameCache->query(path.at(ii), r.importNamespace);
+                        if (!r.type.isValid()) return; // Invalid type in namespace
+
+                        QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(engine);
+                        QQmlAttachedPropertiesFunc func = r.type.attachedPropertiesFunction(enginePrivate);
+                        if (!func) return; // Not an attachable type
+
+                        currentObject = qmlAttachedPropertiesObjectById(r.type.attachedPropertiesId(enginePrivate), currentObject);
+                        if (!currentObject) return; // Something is broken with the attachable type
+
+                    } else if (r.scriptIndex != -1) {
+                        return; // Not a type
+                    } else {
+                        Q_ASSERT(!"Unreachable");
+                    }
+                    continue;
                 }
-                continue;
+
             }
 
-        }
+            QQmlPropertyData local;
+            QQmlPropertyData *property =
+                    QQmlPropertyCache::property(engine, currentObject, pathName, context, local);
 
-        QQmlPropertyData local;
-        QQmlPropertyData *property =
-            QQmlPropertyCache::property(engine, currentObject, pathName, context, local);
+            if (!property) return; // Not a property
+            if (property->isFunction())
+                return; // Not an object property
 
-        if (!property) return; // Not a property
-        if (property->isFunction())
-            return; // Not an object property
+            if (ii == (path.count() - 2) && QQmlValueTypeFactory::isValueType(property->propType())) {
+                // We're now at a value type property
+                const QMetaObject *valueTypeMetaObject = QQmlValueTypeFactory::metaObjectForMetaType(property->propType());
+                if (!valueTypeMetaObject) return; // Not a value type
 
-        if (ii == (path.count() - 2) && QQmlValueTypeFactory::isValueType(property->propType())) {
-            // We're now at a value type property
-            const QMetaObject *valueTypeMetaObject = QQmlValueTypeFactory::metaObjectForMetaType(property->propType());
-            if (!valueTypeMetaObject) return; // Not a value type
+                int idx = valueTypeMetaObject->indexOfProperty(path.last().toUtf8().constData());
+                if (idx == -1) return; // Value type property does not exist
 
-            int idx = valueTypeMetaObject->indexOfProperty(path.last().toUtf8().constData());
-            if (idx == -1) return; // Value type property does not exist
+                QMetaProperty vtProp = valueTypeMetaObject->property(idx);
 
-            QMetaProperty vtProp = valueTypeMetaObject->property(idx);
+                Q_ASSERT(vtProp.userType() <= 0x0000FFFF);
+                Q_ASSERT(idx <= 0x0000FFFF);
 
-            Q_ASSERT(vtProp.userType() <= 0x0000FFFF);
-            Q_ASSERT(idx <= 0x0000FFFF);
+                object = currentObject;
+                core = *property;
+                valueTypeData.setFlags(QQmlPropertyData::flagsForProperty(vtProp));
+                valueTypeData.setPropType(vtProp.userType());
+                valueTypeData.setCoreIndex(idx);
 
-            object = currentObject;
-            core = *property;
-            valueTypeData.setFlags(QQmlPropertyData::flagsForProperty(vtProp));
-            valueTypeData.setPropType(vtProp.userType());
-            valueTypeData.setCoreIndex(idx);
+                return;
+            } else {
+                if (!property->isQObject())
+                    return; // Not an object property
 
-            return;
-        } else {
-            if (!property->isQObject())
-                return; // Not an object property
+                property->readProperty(currentObject, &currentObject);
+                if (!currentObject) return; // No value
 
-            property->readProperty(currentObject, &currentObject);
-            if (!currentObject) return; // No value
+            }
 
         }
 
+        terminal = path.last();
     }
 
-    const QStringRef &terminal = path.last();
-
     if (terminal.count() >= 3 &&
         terminal.at(0) == QLatin1Char('o') &&
         terminal.at(1) == QLatin1Char('n') &&
@@ -467,7 +487,7 @@ QQmlPropertyPrivate::propertyTypeCategory() const
 const char *QQmlProperty::propertyTypeName() const
 {
     if (!d)
-        return 0;
+        return nullptr;
     if (d->isValueType()) {
         const QMetaObject *valueTypeMetaObject = QQmlValueTypeFactory::metaObjectForMetaType(d->core.propType());
         Q_ASSERT(valueTypeMetaObject);
@@ -475,7 +495,7 @@ const char *QQmlProperty::propertyTypeName() const
     } else if (d->object && type() & Property && d->core.isValid()) {
         return d->object->metaObject()->property(d->core.coreIndex()).typeName();
     } else {
-        return 0;
+        return nullptr;
     }
 }
 
@@ -559,7 +579,7 @@ bool QQmlProperty::isSignalProperty() const
 */
 QObject *QQmlProperty::object() const
 {
-    return d ? d->object : 0;
+    return d ? d->object : nullptr;
 }
 
 /*!
@@ -697,7 +717,7 @@ QQmlAbstractBinding *
 QQmlPropertyPrivate::binding(const QQmlProperty &that)
 {
     if (!that.d || !that.isProperty() || !that.d->object)
-        return 0;
+        return nullptr;
 
     QQmlPropertyIndex thatIndex(that.d->core.coreIndex(), that.d->valueTypeData.coreIndex());
     return binding(that.d->object, thatIndex);
@@ -759,7 +779,7 @@ static void removeOldBinding(QObject *object, QQmlPropertyIndex index, QQmlPrope
         return;
 
     if (!(flags & QQmlPropertyPrivate::DontEnable))
-        oldBinding->setEnabled(false, 0);
+        oldBinding->setEnabled(false, nullptr);
     oldBinding->removeFromObject();
 }
 
@@ -793,13 +813,13 @@ QQmlPropertyPrivate::binding(QObject *object, QQmlPropertyIndex index)
 
     QQmlData *data = QQmlData::get(object);
     if (!data)
-        return 0;
+        return nullptr;
 
     const int coreIndex = index.coreIndex();
     const int valueTypeIndex = index.valueTypeIndex();
 
-    if (!data->hasBindingBit(coreIndex))
-        return 0;
+    if (coreIndex < 0 || !data->hasBindingBit(coreIndex))
+        return nullptr;
 
     QQmlAbstractBinding *binding = data->bindings;
     while (binding && (binding->targetPropertyIndex().coreIndex() != coreIndex ||
@@ -825,11 +845,11 @@ void QQmlPropertyPrivate::findAliasTarget(QObject *object, QQmlPropertyIndex bin
         int valueTypeIndex = bindingIndex.valueTypeIndex();
 
         QQmlPropertyData *propertyData =
-            data->propertyCache?data->propertyCache->property(coreIndex):0;
+            data->propertyCache?data->propertyCache->property(coreIndex):nullptr;
         if (propertyData && propertyData->isAlias()) {
             QQmlVMEMetaObject *vme = QQmlVMEMetaObject::getForProperty(object, coreIndex);
 
-            QObject *aObject = 0; int aCoreIndex = -1; int aValueTypeIndex = -1;
+            QObject *aObject = nullptr; int aCoreIndex = -1; int aValueTypeIndex = -1;
             if (vme->aliasTarget(coreIndex, &aObject, &aCoreIndex, &aValueTypeIndex)) {
                 // This will either be a value type sub-reference or an alias to a value-type sub-reference not both
                 Q_ASSERT(valueTypeIndex == -1 || aValueTypeIndex == -1);
@@ -855,6 +875,7 @@ void QQmlPropertyPrivate::findAliasTarget(QObject *object, QQmlPropertyIndex bin
 void QQmlPropertyPrivate::setBinding(QQmlAbstractBinding *binding, BindingFlags flags, QQmlPropertyData::WriteFlags writeFlags)
 {
     Q_ASSERT(binding);
+    Q_ASSERT(binding->targetObject());
 
     QObject *object = binding->targetObject();
     const QQmlPropertyIndex index = binding->targetPropertyIndex();
@@ -884,11 +905,11 @@ QQmlBoundSignalExpression *
 QQmlPropertyPrivate::signalExpression(const QQmlProperty &that)
 {
     if (!(that.type() & QQmlProperty::SignalProperty))
-        return 0;
+        return nullptr;
 
     QQmlData *data = QQmlData::get(that.d->object);
     if (!data)
-        return 0;
+        return nullptr;
 
     QQmlBoundSignal *signalHandler = data->signalHandlers;
 
@@ -898,7 +919,7 @@ QQmlPropertyPrivate::signalExpression(const QQmlProperty &that)
     if (signalHandler)
         return signalHandler->expression();
 
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -925,7 +946,7 @@ void QQmlPropertyPrivate::takeSignalExpression(const QQmlProperty &that,
         return;
     }
 
-    QQmlData *data = QQmlData::get(that.d->object, 0 != expr);
+    QQmlData *data = QQmlData::get(that.d->object, nullptr != expr);
     if (!data)
         return;
 
@@ -1032,7 +1053,7 @@ QVariant QQmlPropertyPrivate::readValueProperty()
 
     } else if (core.isQObject()) {
 
-        QObject *rv = 0;
+        QObject *rv = nullptr;
         core.readProperty(object, &rv);
         return QVariant::fromValue(rv);
 
@@ -1043,11 +1064,11 @@ QVariant QQmlPropertyPrivate::readValueProperty()
 
         QVariant value;
         int status = -1;
-        void *args[] = { 0, &value, &status };
+        void *args[] = { nullptr, &value, &status };
         if (core.propType() == QMetaType::QVariant) {
             args[0] = &value;
         } else {
-            value = QVariant(core.propType(), (void*)0);
+            value = QVariant(core.propType(), (void*)nullptr);
             args[0] = value.data();
         }
         core.readPropertyWithArgs(object, args);
@@ -1275,10 +1296,10 @@ bool QQmlPropertyPrivate::write(QObject *object,
         if (enginePriv) {
             listType = enginePriv->rawMetaObjectForType(enginePriv->listType(property.propType()));
         } else {
-            QQmlType *type = QQmlMetaType::qmlType(QQmlMetaType::listType(property.propType()));
-            if (!type)
+            QQmlType type = QQmlMetaType::qmlType(QQmlMetaType::listType(property.propType()));
+            if (!type.isValid())
                 return false;
-            listType = type->baseMetaObject();
+            listType = type.baseMetaObject();
         }
         if (listType.isNull())
             return false;
@@ -1393,8 +1414,9 @@ QQmlMetaObject QQmlPropertyPrivate::rawMetaObjectForType(QQmlEnginePrivate *engi
         return metaType.metaObject();
     if (engine)
         return engine->rawMetaObjectForType(userType);
-    if (QQmlType *type = QQmlMetaType::qmlType(userType))
-        return QQmlMetaObject(type->baseMetaObject());
+    QQmlType type = QQmlMetaType::qmlType(userType);
+    if (type.isValid())
+        return QQmlMetaObject(type.baseMetaObject());
     return QQmlMetaObject();
 }
 
@@ -1405,7 +1427,7 @@ QQmlMetaObject QQmlPropertyPrivate::rawMetaObjectForType(QQmlEnginePrivate *engi
  */
 bool QQmlProperty::write(const QVariant &value) const
 {
-    return QQmlPropertyPrivate::write(*this, value, 0);
+    return QQmlPropertyPrivate::write(*this, value, nullptr);
 }
 
 /*!
@@ -1474,7 +1496,7 @@ bool QQmlProperty::write(QObject *object, const QString &name, const QVariant &v
 bool QQmlProperty::reset() const
 {
     if (isResettable()) {
-        void *args[] = { 0 };
+        void *args[] = { nullptr };
         QMetaObject::metacall(d->object, QMetaObject::ResetProperty, d->core.coreIndex(), args);
         return true;
     } else {
@@ -1545,6 +1567,9 @@ bool QQmlProperty::connectNotifySignal(QObject *dest, int method) const
     represent a regular Qt property or if it has no
     change notifier signal, or if the \a dest object does
     not have the specified \a slot.
+
+    \note \a slot should be passed using the SLOT() macro so it is
+    correctly identified.
 */
 bool QQmlProperty::connectNotifySignal(QObject *dest, const char *slot) const
 {
diff --git a/src/qml/qml/qqmlproperty_p.h b/src/qml/qml/qqmlproperty_p.h
index 53062a2f13..bafcba5971 100644
--- a/src/qml/qml/qqmlproperty_p.h
+++ b/src/qml/qml/qqmlproperty_p.h
@@ -56,7 +56,8 @@
 
 #include <private/qobject_p.h>
 #include <private/qtqmlglobal_p.h>
-#include <private/qqmlpropertycache_p.h>
+#include <private/qqmlrefcount_p.h>
+#include <private/qqmlcontext_p.h>
 #include <private/qqmlboundsignalexpressionpointer_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -64,6 +65,7 @@ QT_BEGIN_NAMESPACE
 class QQmlContext;
 class QQmlEnginePrivate;
 class QQmlJavaScriptExpression;
+class QQmlMetaObject;
 
 class Q_QML_PRIVATE_EXPORT QQmlPropertyPrivate : public QQmlRefCount
 {
@@ -104,9 +106,9 @@ public:
     static bool writeValueProperty(QObject *,
                                    const QQmlPropertyData &, const QQmlPropertyData &valueTypeData,
                                    const QVariant &, QQmlContextData *,
-                                   QQmlPropertyData::WriteFlags flags = 0);
+                                   QQmlPropertyData::WriteFlags flags = nullptr);
     static bool write(QObject *, const QQmlPropertyData &, const QVariant &,
-                      QQmlContextData *, QQmlPropertyData::WriteFlags flags = 0);
+                      QQmlContextData *, QQmlPropertyData::WriteFlags flags = nullptr);
     static void findAliasTarget(QObject *, QQmlPropertyIndex, QObject **, QQmlPropertyIndex *);
 
     enum BindingFlag {
@@ -140,10 +142,12 @@ public:
     static QMetaMethod findSignalByName(const QMetaObject *mo, const QByteArray &);
     static bool connect(const QObject *sender, int signal_index,
                         const QObject *receiver, int method_index,
-                        int type = 0, int *types = 0);
+                        int type = 0, int *types = nullptr);
     static void flushSignal(const QObject *sender, int signal_index);
 
     static QVariant resolvedUrlSequence(const QVariant &value, QQmlContextData *context);
+    static QQmlProperty create(QObject *target, const QString &propertyName, QQmlContextData *context);
+
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QQmlPropertyPrivate::BindingFlags)
diff --git a/src/qml/qml/qqmlpropertycache.cpp b/src/qml/qml/qqmlpropertycache.cpp
index d18159841c..46457a8d76 100644
--- a/src/qml/qml/qqmlpropertycache.cpp
+++ b/src/qml/qml/qqmlpropertycache.cpp
@@ -46,6 +46,7 @@
 
 #include <private/qmetaobject_p.h>
 #include <private/qmetaobjectbuilder_p.h>
+#include <private/qqmlpropertycachemethodarguments_p.h>
 
 #include <private/qv4value_p.h>
 
@@ -65,21 +66,6 @@ QT_BEGIN_NAMESPACE
 
 #define Q_INT16_MAX 32767
 
-class QQmlPropertyCacheMethodArguments
-{
-public:
-    QQmlPropertyCacheMethodArguments *next;
-
-    //for signal handler rewrites
-    QString *signalParameterStringForJS;
-    int parameterError:1;
-    int argumentsValid:1;
-
-    QList<QByteArray> *names;
-
-    int arguments[1];
-};
-
 // Flags that do *NOT* depend on the property's QMetaProperty::userType() and thus are quick
 // to load
 static QQmlPropertyData::Flags fastFlagsForProperty(const QMetaProperty &p)
@@ -99,7 +85,7 @@ static QQmlPropertyData::Flags fastFlagsForProperty(const QMetaProperty &p)
 
 // Flags that do depend on the property's QMetaProperty::userType() and thus are slow to
 // load
-static void flagsForPropertyType(int propType, QQmlEngine *engine, QQmlPropertyData::Flags &flags)
+static void flagsForPropertyType(int propType, QQmlPropertyData::Flags &flags)
 {
     Q_ASSERT(propType != -1);
 
@@ -116,9 +102,7 @@ static void flagsForPropertyType(int propType, QQmlEngine *engine, QQmlPropertyD
     } else if (propType == qMetaTypeId<QQmlV4Handle>()) {
         flags.type = QQmlPropertyData::Flags::V4HandleType;
     } else {
-        QQmlMetaType::TypeCategory cat =
-            engine ? QQmlEnginePrivate::get(engine)->typeCategory(propType)
-                   : QQmlMetaType::typeCategory(propType);
+        QQmlMetaType::TypeCategory cat = QQmlMetaType::typeCategory(propType);
 
         if (cat == QQmlMetaType::Object || QMetaType::typeFlags(propType) & QMetaType::PointerToQObject)
             flags.type = QQmlPropertyData::Flags::QObjectDerivedType;
@@ -136,10 +120,10 @@ static int metaObjectSignalCount(const QMetaObject *metaObject)
 }
 
 QQmlPropertyData::Flags
-QQmlPropertyData::flagsForProperty(const QMetaProperty &p, QQmlEngine *engine)
+QQmlPropertyData::flagsForProperty(const QMetaProperty &p)
 {
     auto flags = fastFlagsForProperty(p);
-    flagsForPropertyType(p.userType(), engine, flags);
+    flagsForPropertyType(p.userType(), flags);
     return flags;
 }
 
@@ -166,13 +150,13 @@ void QQmlPropertyData::lazyLoad(const QMetaProperty &p)
     }
 }
 
-void QQmlPropertyData::load(const QMetaProperty &p, QQmlEngine *engine)
+void QQmlPropertyData::load(const QMetaProperty &p)
 {
     setPropType(p.userType());
     setCoreIndex(p.propertyIndex());
     setNotifyIndex(QMetaObjectPrivate::signalIndex(p.notifySignal()));
     setFlags(fastFlagsForProperty(p));
-    flagsForPropertyType(propType(), engine, _flags);
+    flagsForPropertyType(propType(), _flags);
     Q_ASSERT(p.revision() <= Q_INT16_MAX);
     setRevision(p.revision());
 }
@@ -244,29 +228,36 @@ void QQmlPropertyData::lazyLoad(const QMetaMethod &m)
 /*!
 Creates a new empty QQmlPropertyCache.
 */
-QQmlPropertyCache::QQmlPropertyCache(QV4::ExecutionEngine *e)
-    : engine(e), _parent(0), propertyIndexCacheStart(0), methodIndexCacheStart(0),
+QQmlPropertyCache::QQmlPropertyCache()
+    : _parent(nullptr), propertyIndexCacheStart(0), methodIndexCacheStart(0),
       signalHandlerIndexCacheStart(0), _hasPropertyOverrides(false), _ownMetaObject(false),
-      _metaObject(0), argumentsCache(0), _jsFactoryMethodIndex(-1)
+      _metaObject(nullptr), argumentsCache(nullptr), _jsFactoryMethodIndex(-1)
 {
-    Q_ASSERT(engine);
 }
 
 /*!
 Creates a new QQmlPropertyCache of \a metaObject.
 */
-QQmlPropertyCache::QQmlPropertyCache(QV4::ExecutionEngine *e, const QMetaObject *metaObject)
-    : QQmlPropertyCache(e)
+QQmlPropertyCache::QQmlPropertyCache(const QMetaObject *metaObject, int metaObjectRevision)
+    : QQmlPropertyCache()
 {
     Q_ASSERT(metaObject);
 
     update(metaObject);
+
+    if (metaObjectRevision > 0) {
+        // Set the revision of the meta object that this cache describes to be
+        // 'metaObjectRevision'. This is useful when constructing a property cache
+        // from a type that was created directly in C++, and not through QML. For such
+        // types, the revision for each recorded QMetaObject would normally be zero, which
+        // would exclude any revisioned properties.
+        for (int metaObjectOffset = 0; metaObjectOffset < allowedRevisionCache.size(); ++metaObjectOffset)
+            allowedRevisionCache[metaObjectOffset] = metaObjectRevision;
+    }
 }
 
 QQmlPropertyCache::~QQmlPropertyCache()
 {
-    clear();
-
     QQmlPropertyCacheMethodArguments *args = argumentsCache;
     while (args) {
         QQmlPropertyCacheMethodArguments *next = args->next;
@@ -282,26 +273,13 @@ QQmlPropertyCache::~QQmlPropertyCache()
     if (_parent) _parent->release();
 
     if (_ownMetaObject) free(const_cast<QMetaObject *>(_metaObject));
-    _metaObject = 0;
-    _parent = 0;
-    engine = 0;
-}
-
-void QQmlPropertyCache::destroy()
-{
-    delete this;
-}
-
-// This is inherited from QQmlCleanup, so it should only clear the things
-// that are tied to the specific QQmlEngine.
-void QQmlPropertyCache::clear()
-{
-    engine = 0;
+    _metaObject = nullptr;
+    _parent = nullptr;
 }
 
 QQmlPropertyCache *QQmlPropertyCache::copy(int reserve)
 {
-    QQmlPropertyCache *cache = new QQmlPropertyCache(engine);
+    QQmlPropertyCache *cache = new QQmlPropertyCache();
     cache->_parent = this;
     cache->_parent->addref();
     cache->propertyIndexCacheStart = propertyIndexCache.count() + propertyIndexCacheStart;
@@ -321,13 +299,14 @@ QQmlPropertyCache *QQmlPropertyCache::copy()
 }
 
 QQmlPropertyCache *QQmlPropertyCache::copyAndReserve(int propertyCount, int methodCount,
-                                                     int signalCount)
+                                                     int signalCount, int enumCount)
 {
     QQmlPropertyCache *rv = copy(propertyCount + methodCount + signalCount);
     rv->propertyIndexCache.reserve(propertyCount);
     rv->methodIndexCache.reserve(methodCount);
     rv->signalHandlerIndexCache.reserve(signalCount);
-    rv->_metaObject = 0;
+    rv->enumCache.reserve(enumCount);
+    rv->_metaObject = nullptr;
 
     return rv;
 }
@@ -338,13 +317,14 @@ QQmlPropertyCache *QQmlPropertyCache::copyAndReserve(int propertyCount, int meth
     This is different from QMetaMethod::methodIndex().
 */
 void QQmlPropertyCache::appendProperty(const QString &name, QQmlPropertyData::Flags flags,
-                                       int coreIndex, int propType, int notifyIndex)
+                                       int coreIndex, int propType, int minorVersion, int notifyIndex)
 {
     QQmlPropertyData data;
     data.setPropType(propType);
     data.setCoreIndex(coreIndex);
     data.setNotifyIndex(notifyIndex);
     data.setFlags(flags);
+    data.setTypeMinorVersion(minorVersion);
 
     QQmlPropertyData *old = findNamedProperty(name);
     if (old)
@@ -353,7 +333,7 @@ void QQmlPropertyCache::appendProperty(const QString &name, QQmlPropertyData::Fl
     int index = propertyIndexCache.count();
     propertyIndexCache.append(data);
 
-    setNamedProperty(name, index + propertyOffset(), propertyIndexCache.data() + index, (old != 0));
+    setNamedProperty(name, index + propertyOffset(), propertyIndexCache.data() + index, (old != nullptr));
 }
 
 void QQmlPropertyCache::appendSignal(const QString &name, QQmlPropertyData::Flags flags,
@@ -390,8 +370,8 @@ void QQmlPropertyCache::appendSignal(const QString &name, QQmlPropertyData::Flag
     QString handlerName = QLatin1String("on") + name;
     handlerName[2] = handlerName.at(2).toUpper();
 
-    setNamedProperty(name, methodIndex + methodOffset(), methodIndexCache.data() + methodIndex, (old != 0));
-    setNamedProperty(handlerName, signalHandlerIndex + signalOffset(), signalHandlerIndexCache.data() + signalHandlerIndex, (old != 0));
+    setNamedProperty(name, methodIndex + methodOffset(), methodIndexCache.data() + methodIndex, (old != nullptr));
+    setNamedProperty(handlerName, signalHandlerIndex + signalOffset(), signalHandlerIndexCache.data() + signalHandlerIndex, (old != nullptr));
 }
 
 void QQmlPropertyCache::appendMethod(const QString &name, QQmlPropertyData::Flags flags,
@@ -418,7 +398,15 @@ void QQmlPropertyCache::appendMethod(const QString &name, QQmlPropertyData::Flag
     int methodIndex = methodIndexCache.count();
     methodIndexCache.append(data);
 
-    setNamedProperty(name, methodIndex + methodOffset(), methodIndexCache.data() + methodIndex, (old != 0));
+    setNamedProperty(name, methodIndex + methodOffset(), methodIndexCache.data() + methodIndex, (old != nullptr));
+}
+
+void QQmlPropertyCache::appendEnum(const QString &name, const QVector<QQmlEnumValue> &values)
+{
+    QQmlEnumData data;
+    data.name = name;
+    data.values = values;
+    enumCache.append(data);
 }
 
 // Returns this property cache's metaObject, creating it if necessary.
@@ -438,7 +426,7 @@ const QMetaObject *QQmlPropertyCache::createMetaObject()
 
 QQmlPropertyData *QQmlPropertyCache::defaultProperty() const
 {
-    return property(defaultPropertyName(), 0, 0);
+    return property(defaultPropertyName(), nullptr, nullptr);
 }
 
 void QQmlPropertyCache::setParent(QQmlPropertyCache *newParent)
@@ -462,7 +450,7 @@ QQmlPropertyCache::copyAndAppend(const QMetaObject *metaObject,
 
 QQmlPropertyCache *
 QQmlPropertyCache::copyAndAppend(const QMetaObject *metaObject,
-                                 int revision,
+                                 int typeMinorVersion,
                                  QQmlPropertyData::Flags propertyFlags,
                                  QQmlPropertyData::Flags methodFlags,
                                  QQmlPropertyData::Flags signalFlags)
@@ -476,19 +464,17 @@ QQmlPropertyCache::copyAndAppend(const QMetaObject *metaObject,
                                          QMetaObjectPrivate::get(metaObject)->signalCount +
                                          QMetaObjectPrivate::get(metaObject)->propertyCount);
 
-    rv->append(metaObject, revision, propertyFlags, methodFlags, signalFlags);
+    rv->append(metaObject, typeMinorVersion, propertyFlags, methodFlags, signalFlags);
 
     return rv;
 }
 
 void QQmlPropertyCache::append(const QMetaObject *metaObject,
-                               int revision,
+                               int typeMinorVersion,
                                QQmlPropertyData::Flags propertyFlags,
                                QQmlPropertyData::Flags methodFlags,
                                QQmlPropertyData::Flags signalFlags)
 {
-    Q_UNUSED(revision);
-
     _metaObject = metaObject;
 
     bool dynamicMetaObject = isDynamicMetaObject(metaObject);
@@ -551,7 +537,7 @@ void QQmlPropertyCache::append(const QMetaObject *metaObject,
         }
 
         QQmlPropertyData *data = &methodIndexCache[ii - methodIndexCacheStart];
-        QQmlPropertyData *sigdata = 0;
+        QQmlPropertyData *sigdata = nullptr;
 
         if (m.methodType() == QMetaMethod::Signal)
             data->setFlags(signalFlags);
@@ -570,24 +556,24 @@ void QQmlPropertyCache::append(const QMetaObject *metaObject,
             sigdata->_flags.isSignalHandler = true;
         }
 
-        QQmlPropertyData *old = 0;
+        QQmlPropertyData *old = nullptr;
 
         if (utf8) {
             QHashedString methodName(QString::fromUtf8(rawName, cptr - rawName));
             if (StringCache::mapped_type *it = stringCache.value(methodName))
                 old = it->second;
-            setNamedProperty(methodName, ii, data, (old != 0));
+            setNamedProperty(methodName, ii, data, (old != nullptr));
 
             if (data->isSignal()) {
                 QHashedString on(QLatin1String("on") % methodName.at(0).toUpper() % methodName.midRef(1));
-                setNamedProperty(on, ii, sigdata, (old != 0));
+                setNamedProperty(on, ii, sigdata, (old != nullptr));
                 ++signalHandlerIndex;
             }
         } else {
             QHashedCStringRef methodName(rawName, cptr - rawName);
             if (StringCache::mapped_type *it = stringCache.value(methodName))
                 old = it->second;
-            setNamedProperty(methodName, ii, data, (old != 0));
+            setNamedProperty(methodName, ii, data, (old != nullptr));
 
             if (data->isSignal()) {
                 int length = methodName.length();
@@ -601,7 +587,7 @@ void QQmlPropertyCache::append(const QMetaObject *metaObject,
                 str[length + 2] = '\0';
 
                 QHashedString on(QString::fromLatin1(str.data()));
-                setNamedProperty(on, ii, data, (old != 0));
+                setNamedProperty(on, ii, data, (old != nullptr));
                 ++signalHandlerIndex;
             }
         }
@@ -638,24 +624,25 @@ void QQmlPropertyCache::append(const QMetaObject *metaObject,
 
         data->setFlags(propertyFlags);
         data->lazyLoad(p);
+        data->setTypeMinorVersion(typeMinorVersion);
 
         data->_flags.isDirect = !dynamicMetaObject;
 
         Q_ASSERT((allowedRevisionCache.count() - 1) < Q_INT16_MAX);
         data->setMetaObjectOffset(allowedRevisionCache.count() - 1);
 
-        QQmlPropertyData *old = 0;
+        QQmlPropertyData *old = nullptr;
 
         if (utf8) {
             QHashedString propName(QString::fromUtf8(str, cptr - str));
             if (StringCache::mapped_type *it = stringCache.value(propName))
                 old = it->second;
-            setNamedProperty(propName, ii, data, (old != 0));
+            setNamedProperty(propName, ii, data, (old != nullptr));
         } else {
             QHashedCStringRef propName(str, cptr - str);
             if (StringCache::mapped_type *it = stringCache.value(propName))
                 old = it->second;
-            setNamedProperty(propName, ii, data, (old != 0));
+            setNamedProperty(propName, ii, data, (old != nullptr));
         }
 
         bool isGadget = true;
@@ -711,7 +698,7 @@ void QQmlPropertyCache::resolve(QQmlPropertyData *data) const
                 data->setPropType(registerResult == -1 ? QMetaType::UnknownType : registerResult);
             }
         }
-        flagsForPropertyType(data->propType(), engine->qmlEngine(), data->_flags);
+        flagsForPropertyType(data->propType(), data->_flags);
     }
 }
 
@@ -758,7 +745,7 @@ void QQmlPropertyCache::invalidate(const QMetaObject *metaObject)
     signalHandlerIndexCache.clear();
 
     _hasPropertyOverrides = false;
-    argumentsCache = 0;
+    argumentsCache = nullptr;
 
     int pc = metaObject->propertyCount();
     int mc = metaObject->methodCount();
@@ -781,8 +768,12 @@ void QQmlPropertyCache::invalidate(const QMetaObject *metaObject)
 
 QQmlPropertyData *QQmlPropertyCache::findProperty(StringCache::ConstIterator it, QObject *object, QQmlContextData *context) const
 {
-    QQmlData *data = (object ? QQmlData::get(object) : 0);
-    const QQmlVMEMetaObject *vmemo = (data && data->hasVMEMetaObject ? static_cast<const QQmlVMEMetaObject *>(object->metaObject()) : 0);
+    QQmlData *data = (object ? QQmlData::get(object) : nullptr);
+    const QQmlVMEMetaObject *vmemo = nullptr;
+    if (data && data->hasVMEMetaObject) {
+        QObjectPrivate *op = QObjectPrivate::get(object);
+        vmemo = static_cast<const QQmlVMEMetaObject *>(op->metaObject);
+    }
     return findProperty(it, vmemo, context);
 }
 
@@ -826,9 +817,9 @@ QQmlPropertyData *QQmlPropertyCache::findProperty(StringCache::ConstIterator it,
         }
 
         if (vmemo) {
-            const int methodCount = vmemo->methodCount();
-            const int signalCount = vmemo->signalCount();
-            const int propertyCount = vmemo->propertyCount();
+            const int methodCount = vmemo->cache->methodCount();
+            const int signalCount = vmemo->cache->signalCount();
+            const int propertyCount = vmemo->cache->propertyCount();
 
             // Ensure that the property we resolve to is accessible from this meta-object
             do {
@@ -853,7 +844,7 @@ QQmlPropertyData *QQmlPropertyCache::findProperty(StringCache::ConstIterator it,
         return ensureResolved(result);
     }
 
-    return 0;
+    return nullptr;
 }
 
 QString QQmlPropertyData::name(QObject *object) const
@@ -887,45 +878,15 @@ void QQmlPropertyData::markAsOverrideOf(QQmlPropertyData *predecessor)
     predecessor->_flags.isOverridden = true;
 }
 
-struct StaticQtMetaObject : public QObject
-{
-    static const QMetaObject *get()
-        { return &staticQtMetaObject; }
-};
-
-static int EnumType(const QMetaObject *metaobj, const QByteArray &str, int type)
-{
-    QByteArray scope;
-    QByteArray name;
-    int scopeIdx = str.lastIndexOf("::");
-    if (scopeIdx != -1) {
-        scope = str.left(scopeIdx);
-        name = str.mid(scopeIdx + 2);
-    } else {
-        name = str;
-    }
-    const QMetaObject *meta;
-    if (scope == "Qt")
-        meta = StaticQtMetaObject::get();
-    else
-        meta = metaobj;
-    for (int i = meta->enumeratorCount() - 1; i >= 0; --i) {
-        QMetaEnum m = meta->enumerator(i);
-        if ((m.name() == name) && (scope.isEmpty() || (m.scope() == scope)))
-            return QVariant::Int;
-    }
-    return type;
-}
-
 QQmlPropertyCacheMethodArguments *QQmlPropertyCache::createArgumentsObject(int argc, const QList<QByteArray> &names)
 {
     typedef QQmlPropertyCacheMethodArguments A;
     A *args = static_cast<A *>(malloc(sizeof(A) + (argc) * sizeof(int)));
     args->arguments[0] = argc;
     args->argumentsValid = false;
-    args->signalParameterStringForJS = 0;
+    args->signalParameterStringForJS = nullptr;
     args->parameterError = false;
-    args->names = argc ? new QList<QByteArray>(names) : 0;
+    args->names = argc ? new QList<QByteArray>(names) : nullptr;
     args->next = argumentsCache;
     argumentsCache = args;
     return args;
@@ -1031,10 +992,10 @@ static QQmlPropertyData qQmlPropertyCacheCreate(const QMetaObject *metaObject, c
                     }
                     /* If the "cmo" variable didn't change, set it to 0 to
                      * avoid running into an infinite loop */
-                    if (!changed) cmo = 0;
+                    if (!changed) cmo = nullptr;
                 }
             } else {
-                cmo = 0;
+                cmo = nullptr;
             }
         }
     }
@@ -1061,7 +1022,7 @@ QQmlPropertyData *
 qQmlPropertyCacheProperty(QJSEngine *engine, QObject *obj, T name,
                           QQmlContextData *context, QQmlPropertyData &local)
 {
-    QQmlPropertyCache *cache = 0;
+    QQmlPropertyCache *cache = nullptr;
 
     QQmlData *ddata = QQmlData::get(obj, false);
 
@@ -1077,7 +1038,7 @@ qQmlPropertyCacheProperty(QJSEngine *engine, QObject *obj, T name,
         }
     }
 
-    QQmlPropertyData *rv = 0;
+    QQmlPropertyData *rv = nullptr;
 
     if (cache) {
         rv = cache->property(name, obj, context);
@@ -1218,7 +1179,7 @@ void QQmlPropertyCache::toMetaObjectBuilder(QMetaObjectBuilder &builder)
         // '+=' reserves extra capacity. Follow-up appending will be probably free.
         signature += methods.at(ii).first.toUtf8() + '(';
 
-        QQmlPropertyCacheMethodArguments *arguments = 0;
+        QQmlPropertyCacheMethodArguments *arguments = nullptr;
         if (data->hasArguments()) {
             arguments = (QQmlPropertyCacheMethodArguments *)data->arguments();
             Q_ASSERT(arguments->argumentsValid);
@@ -1245,8 +1206,18 @@ void QQmlPropertyCache::toMetaObjectBuilder(QMetaObjectBuilder &builder)
             method.setReturnType(returnType);
     }
 
+    for (int ii = 0; ii < enumCache.count(); ++ii) {
+        const QQmlEnumData &enumData = enumCache.at(ii);
+        QMetaEnumBuilder enumeration = builder.addEnumerator(enumData.name.toUtf8());
+        enumeration.setIsScoped(true);
+        for (int jj = 0; jj < enumData.values.count(); ++jj) {
+            const QQmlEnumValue &value = enumData.values.at(jj);
+            enumeration.addKey(value.namedValue.toUtf8(), value.value);
+        }
+    }
+
     if (!_defaultPropertyName.isEmpty()) {
-        QQmlPropertyData *dp = property(_defaultPropertyName, 0, 0);
+        QQmlPropertyData *dp = property(_defaultPropertyName, nullptr, nullptr);
         if (dp && dp->coreIndex() >= propertyIndexCacheStart) {
             Q_ASSERT(!dp->isFunction());
             builder.addClassInfo("DefaultProperty", _defaultPropertyName.toUtf8());
@@ -1354,19 +1325,21 @@ template <typename StringVisitor>
 int visitEnumerations(const QMetaObject &mo, StringVisitor visitString)
 {
     const QMetaObjectPrivate *const priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
-    const int intsPerEnumerator = 4;
+    const int intsPerEnumerator = priv->revision >= 8 ? 5 : 4;
 
     int fieldCount = priv->enumeratorCount * intsPerEnumerator;
 
     for (int i = 0; i < priv->enumeratorCount; ++i) {
         const uint *enumeratorData = mo.d.data + priv->enumeratorData + i * intsPerEnumerator;
 
-        const uint keyCount = enumeratorData[2];
+        const uint keyCount = enumeratorData[intsPerEnumerator == 5 ? 3 : 2];
         fieldCount += keyCount * 2;
 
         visitString(enumeratorData[0]); // name
+        if (intsPerEnumerator == 5)
+            visitString(enumeratorData[1]); // enum name
 
-        const uint keyOffset = enumeratorData[3];
+        const uint keyOffset = enumeratorData[intsPerEnumerator == 5 ? 4 : 3];
 
         for (uint j = 0; j < keyCount; ++j) {
             visitString(mo.d.data[keyOffset + 2 * j]);
@@ -1406,7 +1379,7 @@ bool QQmlPropertyCache::determineMetaObjectSizes(const QMetaObject &mo, int *fie
                                                  int *stringCount)
 {
     const QMetaObjectPrivate *priv = reinterpret_cast<const QMetaObjectPrivate*>(mo.d.data);
-    if (priv->revision != 7) {
+    if (priv->revision < 7 || priv->revision > 8) {
         return false;
     }
 
@@ -1485,259 +1458,4 @@ QList<QByteArray> QQmlPropertyCache::signalParameterNames(int index) const
     return QList<QByteArray>();
 }
 
-// Returns true if \a from is assignable to a property of type \a to
-bool QQmlMetaObject::canConvert(const QQmlMetaObject &from, const QQmlMetaObject &to)
-{
-    Q_ASSERT(!from.isNull() && !to.isNull());
-
-    struct I { static bool equal(const QMetaObject *lhs, const QMetaObject *rhs) {
-        return lhs == rhs || (lhs && rhs && lhs->d.stringdata == rhs->d.stringdata);
-    } };
-
-    const QMetaObject *tom = to._m.isT1()?to._m.asT1()->metaObject():to._m.asT2();
-    if (tom == &QObject::staticMetaObject) return true;
-
-    if (from._m.isT1() && to._m.isT1()) { // QQmlPropertyCache -> QQmlPropertyCache
-        QQmlPropertyCache *fromp = from._m.asT1();
-        QQmlPropertyCache *top = to._m.asT1();
-
-        while (fromp) {
-            if (fromp == top) return true;
-            fromp = fromp->parent();
-        }
-    } else if (from._m.isT1() && to._m.isT2()) { // QQmlPropertyCache -> QMetaObject
-        QQmlPropertyCache *fromp = from._m.asT1();
-
-        while (fromp) {
-            const QMetaObject *fromm = fromp->metaObject();
-            if (fromm && I::equal(fromm, tom)) return true;
-            fromp = fromp->parent();
-        }
-    } else if (from._m.isT2() && to._m.isT1()) { // QMetaObject -> QQmlPropertyCache
-        const QMetaObject *fromm = from._m.asT2();
-
-        if (!tom) return false;
-
-        while (fromm) {
-            if (I::equal(fromm, tom)) return true;
-            fromm = fromm->superClass();
-        }
-    } else { // QMetaObject -> QMetaObject
-        const QMetaObject *fromm = from._m.asT2();
-
-        while (fromm) {
-            if (I::equal(fromm, tom)) return true;
-            fromm = fromm->superClass();
-        }
-    }
-
-    return false;
-}
-
-void QQmlMetaObject::resolveGadgetMethodOrPropertyIndex(QMetaObject::Call type, const QMetaObject **metaObject, int *index)
-{
-    int offset;
-
-    switch (type) {
-    case QMetaObject::ReadProperty:
-    case QMetaObject::WriteProperty:
-    case QMetaObject::ResetProperty:
-    case QMetaObject::QueryPropertyDesignable:
-    case QMetaObject::QueryPropertyEditable:
-    case QMetaObject::QueryPropertyScriptable:
-    case QMetaObject::QueryPropertyStored:
-    case QMetaObject::QueryPropertyUser:
-        offset = (*metaObject)->propertyOffset();
-        while (*index < offset) {
-            *metaObject = (*metaObject)->superClass();
-            offset = (*metaObject)->propertyOffset();
-        }
-        break;
-    case QMetaObject::InvokeMetaMethod:
-        offset = (*metaObject)->methodOffset();
-        while (*index < offset) {
-            *metaObject = (*metaObject)->superClass();
-            offset = (*metaObject)->methodOffset();
-        }
-        break;
-    default:
-        offset = 0;
-        Q_UNIMPLEMENTED();
-        offset = INT_MAX;
-    }
-
-    *index -= offset;
-}
-
-QQmlPropertyCache *QQmlMetaObject::propertyCache(QQmlEnginePrivate *e) const
-{
-    if (_m.isNull()) return 0;
-    if (_m.isT1()) return _m.asT1();
-    else return e->cache(_m.asT2());
-}
-
-int QQmlMetaObject::methodReturnType(const QQmlPropertyData &data, QByteArray *unknownTypeError) const
-{
-    Q_ASSERT(!_m.isNull() && data.coreIndex() >= 0);
-
-    int type = data.propType();
-
-    const char *propTypeName = 0;
-
-    if (type == QMetaType::UnknownType) {
-        // Find the return type name from the method info
-        QMetaMethod m;
-
-        if (_m.isT1()) {
-            QQmlPropertyCache *c = _m.asT1();
-            Q_ASSERT(data.coreIndex() < c->methodIndexCacheStart + c->methodIndexCache.count());
-
-            while (data.coreIndex() < c->methodIndexCacheStart)
-                c = c->_parent;
-
-            const QMetaObject *metaObject = c->createMetaObject();
-            Q_ASSERT(metaObject);
-            m = metaObject->method(data.coreIndex());
-        } else {
-            m = _m.asT2()->method(data.coreIndex());
-        }
-
-        type = m.returnType();
-        propTypeName = m.typeName();
-    }
-
-    QMetaType::TypeFlags flags = QMetaType::typeFlags(type);
-    if (flags & QMetaType::IsEnumeration) {
-        type = QVariant::Int;
-    } else if (type == QMetaType::UnknownType ||
-               (type >= (int)QVariant::UserType && !(flags & QMetaType::PointerToQObject) &&
-               type != qMetaTypeId<QJSValue>())) {
-        //the UserType clause is to catch registered QFlags
-        type = EnumType(metaObject(), propTypeName, type);
-    }
-
-    if (type == QMetaType::UnknownType) {
-        if (unknownTypeError) *unknownTypeError = propTypeName;
-    }
-
-    return type;
-}
-
-int *QQmlMetaObject::methodParameterTypes(int index, ArgTypeStorage *argStorage,
-                                          QByteArray *unknownTypeError) const
-{
-    Q_ASSERT(!_m.isNull() && index >= 0);
-
-    if (_m.isT1()) {
-        typedef QQmlPropertyCacheMethodArguments A;
-
-        QQmlPropertyCache *c = _m.asT1();
-        Q_ASSERT(index < c->methodIndexCacheStart + c->methodIndexCache.count());
-
-        while (index < c->methodIndexCacheStart)
-            c = c->_parent;
-
-        QQmlPropertyData *rv = const_cast<QQmlPropertyData *>(&c->methodIndexCache.at(index - c->methodIndexCacheStart));
-
-        if (rv->arguments() && static_cast<A *>(rv->arguments())->argumentsValid)
-            return static_cast<A *>(rv->arguments())->arguments;
-
-        const QMetaObject *metaObject = c->createMetaObject();
-        Q_ASSERT(metaObject);
-        QMetaMethod m = metaObject->method(index);
-
-        int argc = m.parameterCount();
-        if (!rv->arguments()) {
-            A *args = c->createArgumentsObject(argc, m.parameterNames());
-            rv->setArguments(args);
-        }
-        A *args = static_cast<A *>(rv->arguments());
-
-        QList<QByteArray> argTypeNames; // Only loaded if needed
-
-        for (int ii = 0; ii < argc; ++ii) {
-            int type = m.parameterType(ii);
-            QMetaType::TypeFlags flags = QMetaType::typeFlags(type);
-            if (flags & QMetaType::IsEnumeration)
-                type = QVariant::Int;
-            else if (type == QMetaType::UnknownType ||
-                     (type >= (int)QVariant::UserType && !(flags & QMetaType::PointerToQObject) &&
-                      type != qMetaTypeId<QJSValue>())) {
-                //the UserType clause is to catch registered QFlags
-                if (argTypeNames.isEmpty())
-                    argTypeNames = m.parameterTypes();
-                type = EnumType(metaObject, argTypeNames.at(ii), type);
-            }
-            if (type == QMetaType::UnknownType) {
-                if (unknownTypeError) *unknownTypeError = argTypeNames.at(ii);
-                return 0;
-            }
-            args->arguments[ii + 1] = type;
-        }
-        args->argumentsValid = true;
-        return static_cast<A *>(rv->arguments())->arguments;
-
-    } else {
-        QMetaMethod m = _m.asT2()->method(index);
-        return methodParameterTypes(m, argStorage, unknownTypeError);
-
-    }
-}
-
-int *QQmlMetaObject::methodParameterTypes(const QMetaMethod &m, ArgTypeStorage *argStorage,
-                                          QByteArray *unknownTypeError) const
-{
-    Q_ASSERT(argStorage);
-
-    int argc = m.parameterCount();
-    argStorage->resize(argc + 1);
-    argStorage->operator[](0) = argc;
-    QList<QByteArray> argTypeNames; // Only loaded if needed
-
-    for (int ii = 0; ii < argc; ++ii) {
-        int type = m.parameterType(ii);
-        QMetaType::TypeFlags flags = QMetaType::typeFlags(type);
-        if (flags & QMetaType::IsEnumeration)
-            type = QVariant::Int;
-        else if (type == QMetaType::UnknownType ||
-                 (type >= (int)QVariant::UserType && !(flags & QMetaType::PointerToQObject) &&
-                  type != qMetaTypeId<QJSValue>())) {
-            //the UserType clause is to catch registered QFlags)
-            if (argTypeNames.isEmpty())
-                argTypeNames = m.parameterTypes();
-            type = EnumType(_m.asT2(), argTypeNames.at(ii), type);
-        }
-        if (type == QMetaType::UnknownType) {
-            if (unknownTypeError) *unknownTypeError = argTypeNames.at(ii);
-            return 0;
-        }
-        argStorage->operator[](ii + 1) = type;
-    }
-
-    return argStorage->data();
-}
-
-void QQmlObjectOrGadget::metacall(QMetaObject::Call type, int index, void **argv) const
-{
-    if (ptr.isNull()) {
-        const QMetaObject *metaObject = _m.asT2();
-        metaObject->d.static_metacall(0, type, index, argv);
-    }
-    else if (ptr.isT1()) {
-        QMetaObject::metacall(ptr.asT1(), type, index, argv);
-    }
-    else {
-        const QMetaObject *metaObject = _m.asT1()->metaObject();
-        QQmlMetaObject::resolveGadgetMethodOrPropertyIndex(type, &metaObject, &index);
-        metaObject->d.static_metacall(reinterpret_cast<QObject*>(ptr.asT2()), type, index, argv);
-    }
-}
-
-int *QQmlStaticMetaObject::constructorParameterTypes(int index, ArgTypeStorage *dummy,
-                                                     QByteArray *unknownTypeError) const
-{
-    QMetaMethod m = _m.asT2()->constructor(index);
-    return methodParameterTypes(m, dummy, unknownTypeError);
-}
-
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlpropertycache_p.h b/src/qml/qml/qqmlpropertycache_p.h
index 64be1cb206..4f47e5d351 100644
--- a/src/qml/qml/qqmlpropertycache_p.h
+++ b/src/qml/qml/qqmlpropertycache_p.h
@@ -57,310 +57,34 @@
 #include "qqmlnotifier_p.h"
 #include <private/qqmlpropertyindex_p.h>
 
-#include <private/qhashedstring_p.h>
+#include <private/qlinkedstringhash_p.h>
 #include <QtCore/qvarlengtharray.h>
 #include <QtCore/qvector.h>
 
 #include <private/qv4value_p.h>
+#include <private/qqmlpropertydata_p.h>
+#include <private/qqmlenumdata_p.h>
+#include <private/qqmlenumvalue_p.h>
 
 #include <limits>
 
 QT_BEGIN_NAMESPACE
 
 class QCryptographicHash;
-class QMetaProperty;
-class QQmlEngine;
 class QJSEngine;
-class QQmlPropertyData;
 class QMetaObjectBuilder;
-class QQmlPropertyCacheMethodArguments;
 class QQmlVMEMetaObject;
-template <typename T> class QQmlPropertyCacheCreator;
-template <typename T> class QQmlPropertyCacheAliasCreator;
-
-// We have this somewhat awful split between RawData and Data so that RawData can be
-// used in unions.  In normal code, you should always use Data which initializes RawData
-// to an invalid state on construction.
-class QQmlPropertyRawData
-{
-public:
-    typedef QObjectPrivate::StaticMetaCallFunction StaticMetaCallFunction;
-
-    struct Flags {
-        enum Types {
-            OtherType            = 0,
-            FunctionType         = 1, // Is an invokable
-            QObjectDerivedType   = 2, // Property type is a QObject* derived type
-            EnumType             = 3, // Property type is an enum
-            QListType            = 4, // Property type is a QML list
-            QmlBindingType       = 5, // Property type is a QQmlBinding*
-            QJSValueType         = 6, // Property type is a QScriptValue
-            V4HandleType         = 7, // Property type is a QQmlV4Handle
-            VarPropertyType      = 8, // Property type is a "var" property of VMEMO
-            QVariantType         = 9  // Property is a QVariant
-        };
-
-        // The _otherBits (which "pad" the Flags struct to align it nicely) are used
-        // to store the relative property index. It will only get used when said index fits. See
-        // trySetStaticMetaCallFunction for details.
-        // (Note: this padding is done here, because certain compilers have surprising behavior
-        // when an enum is declared in-between two bit fields.)
-        enum { BitsLeftInFlags = 10 };
-        unsigned _otherBits       : BitsLeftInFlags; // align to 32 bits
-
-        // Can apply to all properties, except IsFunction
-        unsigned isConstant       : 1; // Has CONST flag
-        unsigned isWritable       : 1; // Has WRITE function
-        unsigned isResettable     : 1; // Has RESET function
-        unsigned isAlias          : 1; // Is a QML alias to another property
-        unsigned isFinal          : 1; // Has FINAL flag
-        unsigned isOverridden     : 1; // Is overridden by a extension property
-        unsigned isDirect         : 1; // Exists on a C++ QMetaObject
-
-        unsigned type             : 4; // stores an entry of Types
-
-        // Apply only to IsFunctions
-        unsigned isVMEFunction    : 1; // Function was added by QML
-        unsigned hasArguments     : 1; // Function takes arguments
-        unsigned isSignal         : 1; // Function is a signal
-        unsigned isVMESignal      : 1; // Signal was added by QML
-        unsigned isV4Function     : 1; // Function takes QQmlV4Function* args
-        unsigned isSignalHandler  : 1; // Function is a signal handler
-        unsigned isOverload       : 1; // Function is an overload of another function
-        unsigned isCloned         : 1; // The function was marked as cloned
-        unsigned isConstructor    : 1; // The function was marked is a constructor
-
-        // Internal QQmlPropertyCache flags
-        unsigned notFullyResolved : 1; // True if the type data is to be lazily resolved
-        unsigned overrideIndexIsProperty: 1;
-
-        inline Flags();
-        inline bool operator==(const Flags &other) const;
-        inline void copyPropertyTypeFlags(Flags from);
-    };
-
-    Flags flags() const { return _flags; }
-    void setFlags(Flags f)
-    {
-        unsigned otherBits = _flags._otherBits;
-        _flags = f;
-        _flags._otherBits = otherBits;
-    }
-
-    bool isValid() const { return coreIndex() != -1; }
-
-    bool isConstant() const { return _flags.isConstant; }
-    bool isWritable() const { return _flags.isWritable; }
-    void setWritable(bool onoff) { _flags.isWritable = onoff; }
-    bool isResettable() const { return _flags.isResettable; }
-    bool isAlias() const { return _flags.isAlias; }
-    bool isFinal() const { return _flags.isFinal; }
-    bool isOverridden() const { return _flags.isOverridden; }
-    bool isDirect() const { return _flags.isDirect; }
-    bool hasStaticMetaCallFunction() const { return staticMetaCallFunction() != nullptr; }
-    bool isFunction() const { return _flags.type == Flags::FunctionType; }
-    bool isQObject() const { return _flags.type == Flags::QObjectDerivedType; }
-    bool isEnum() const { return _flags.type == Flags::EnumType; }
-    bool isQList() const { return _flags.type == Flags::QListType; }
-    bool isQmlBinding() const { return _flags.type == Flags::QmlBindingType; }
-    bool isQJSValue() const { return _flags.type == Flags::QJSValueType; }
-    bool isV4Handle() const { return _flags.type == Flags::V4HandleType; }
-    bool isVarProperty() const { return _flags.type == Flags::VarPropertyType; }
-    bool isQVariant() const { return _flags.type == Flags::QVariantType; }
-    bool isVMEFunction() const { return _flags.isVMEFunction; }
-    bool hasArguments() const { return _flags.hasArguments; }
-    bool isSignal() const { return _flags.isSignal; }
-    bool isVMESignal() const { return _flags.isVMESignal; }
-    bool isV4Function() const { return _flags.isV4Function; }
-    bool isSignalHandler() const { return _flags.isSignalHandler; }
-    bool isOverload() const { return _flags.isOverload; }
-    void setOverload(bool onoff) { _flags.isOverload = onoff; }
-    bool isCloned() const { return _flags.isCloned; }
-    bool isConstructor() const { return _flags.isConstructor; }
-
-    bool hasOverride() const { return overrideIndex() >= 0; }
-    bool hasRevision() const { return revision() != 0; }
-
-    bool isFullyResolved() const { return !_flags.notFullyResolved; }
-
-    int propType() const { Q_ASSERT(isFullyResolved()); return _propType; }
-    void setPropType(int pt)
-    {
-        Q_ASSERT(pt >= 0);
-        Q_ASSERT(pt <= std::numeric_limits<qint16>::max());
-        _propType = quint16(pt);
-    }
-
-    int notifyIndex() const { return _notifyIndex; }
-    void setNotifyIndex(int idx)
-    {
-        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
-        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
-        _notifyIndex = qint16(idx);
-    }
-
-    bool overrideIndexIsProperty() const { return _flags.overrideIndexIsProperty; }
-    void setOverrideIndexIsProperty(bool onoff) { _flags.overrideIndexIsProperty = onoff; }
-
-    int overrideIndex() const { return _overrideIndex; }
-    void setOverrideIndex(int idx)
-    {
-        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
-        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
-        _overrideIndex = qint16(idx);
-    }
-
-    int coreIndex() const { return _coreIndex; }
-    void setCoreIndex(int idx)
-    {
-        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
-        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
-        _coreIndex = qint16(idx);
-    }
-
-    int revision() const { return _revision; }
-    void setRevision(int rev)
-    {
-        Q_ASSERT(rev >= std::numeric_limits<qint16>::min());
-        Q_ASSERT(rev <= std::numeric_limits<qint16>::max());
-        _revision = qint16(rev);
-    }
-
-    QQmlPropertyCacheMethodArguments *arguments() const { return _arguments; }
-    void setArguments(QQmlPropertyCacheMethodArguments *args) { _arguments = args; }
-
-    int metaObjectOffset() const { return _metaObjectOffset; }
-    void setMetaObjectOffset(int off)
-    {
-        Q_ASSERT(off >= std::numeric_limits<qint16>::min());
-        Q_ASSERT(off <= std::numeric_limits<qint16>::max());
-        _metaObjectOffset = qint16(off);
-    }
-
-    StaticMetaCallFunction staticMetaCallFunction() const { return _staticMetaCallFunction; }
-    void trySetStaticMetaCallFunction(StaticMetaCallFunction f, unsigned relativePropertyIndex)
-    {
-        if (relativePropertyIndex < (1 << Flags::BitsLeftInFlags) - 1) {
-            _flags._otherBits = relativePropertyIndex;
-            _staticMetaCallFunction = f;
-        }
-    }
-    quint16 relativePropertyIndex() const { Q_ASSERT(hasStaticMetaCallFunction()); return _flags._otherBits; }
-
-private:
-    Flags _flags;
-    qint16 _coreIndex;
-    quint16 _propType;
-
-    // The notify index is in the range returned by QObjectPrivate::signalIndex().
-    // This is different from QMetaMethod::methodIndex().
-    qint16 _notifyIndex;
-    qint16 _overrideIndex;
-
-    qint16 _revision;
-    qint16 _metaObjectOffset;
-
-    QQmlPropertyCacheMethodArguments *_arguments;
-    StaticMetaCallFunction _staticMetaCallFunction;
-
-    friend class QQmlPropertyData;
-    friend class QQmlPropertyCache;
-};
-
-#if QT_POINTER_SIZE == 4
-Q_STATIC_ASSERT(sizeof(QQmlPropertyRawData) == 24);
-#else // QT_POINTER_SIZE == 8
-Q_STATIC_ASSERT(sizeof(QQmlPropertyRawData) == 32);
-#endif
-
-class QQmlPropertyData : public QQmlPropertyRawData
-{
-public:
-    enum WriteFlag {
-        BypassInterceptor = 0x01,
-        DontRemoveBinding = 0x02,
-        RemoveBindingOnAliasWrite = 0x04
-    };
-    Q_DECLARE_FLAGS(WriteFlags, WriteFlag)
-
-    inline QQmlPropertyData();
-    inline QQmlPropertyData(const QQmlPropertyRawData &);
-
-    inline bool operator==(const QQmlPropertyRawData &);
-
-    static Flags flagsForProperty(const QMetaProperty &, QQmlEngine *engine = 0);
-    void load(const QMetaProperty &, QQmlEngine *engine = 0);
-    void load(const QMetaMethod &);
-    QString name(QObject *) const;
-    QString name(const QMetaObject *) const;
-
-    void markAsOverrideOf(QQmlPropertyData *predecessor);
-
-    inline void readProperty(QObject *target, void *property) const
-    {
-        void *args[] = { property, 0 };
-        readPropertyWithArgs(target, args);
-    }
-
-    inline void readPropertyWithArgs(QObject *target, void *args[]) const
-    {
-        if (hasStaticMetaCallFunction())
-            staticMetaCallFunction()(target, QMetaObject::ReadProperty, relativePropertyIndex(), args);
-        else if (isDirect())
-            target->qt_metacall(QMetaObject::ReadProperty, coreIndex(), args);
-        else
-            QMetaObject::metacall(target, QMetaObject::ReadProperty, coreIndex(), args);
-    }
-
-    bool writeProperty(QObject *target, void *value, WriteFlags flags) const
-    {
-        int status = -1;
-        void *argv[] = { value, 0, &status, &flags };
-        if (flags.testFlag(BypassInterceptor) && hasStaticMetaCallFunction())
-            staticMetaCallFunction()(target, QMetaObject::WriteProperty, relativePropertyIndex(), argv);
-        else if (flags.testFlag(BypassInterceptor) && isDirect())
-            target->qt_metacall(QMetaObject::WriteProperty, coreIndex(), argv);
-        else
-            QMetaObject::metacall(target, QMetaObject::WriteProperty, coreIndex(), argv);
-        return true;
-    }
-
-    static Flags defaultSignalFlags()
-    {
-        Flags f;
-        f.isSignal = true;
-        f.type = Flags::FunctionType;
-        f.isVMESignal = true;
-        return f;
-    }
-
-    static Flags defaultSlotFlags()
-    {
-        Flags f;
-        f.type = Flags::FunctionType;
-        f.isVMEFunction = true;
-        return f;
-    }
-
-private:
-    friend class QQmlPropertyCache;
-    void lazyLoad(const QMetaProperty &);
-    void lazyLoad(const QMetaMethod &);
-    bool notFullyResolved() const { return _flags.notFullyResolved; }
-};
-
 class QQmlPropertyCacheMethodArguments;
-class Q_QML_PRIVATE_EXPORT QQmlPropertyCache : public QQmlRefCount, public QQmlCleanup
+
+class Q_QML_PRIVATE_EXPORT QQmlPropertyCache : public QQmlRefCount
 {
 public:
-    QQmlPropertyCache(QV4::ExecutionEngine *);
-    QQmlPropertyCache(QV4::ExecutionEngine *, const QMetaObject *);
-    virtual ~QQmlPropertyCache();
+    QQmlPropertyCache();
+    QQmlPropertyCache(const QMetaObject *, int metaObjectRevision = 0);
+    ~QQmlPropertyCache() override;
 
     void update(const QMetaObject *);
     void invalidate(const QMetaObject *);
-    // Used by qmlpuppet. Remove as soon Creator requires Qt 5.5.
-    void invalidate(void *, const QMetaObject *mo) { invalidate(mo); }
 
     QQmlPropertyCache *copy();
 
@@ -368,19 +92,20 @@ public:
                 QQmlPropertyRawData::Flags propertyFlags = QQmlPropertyData::Flags(),
                 QQmlPropertyRawData::Flags methodFlags = QQmlPropertyData::Flags(),
                 QQmlPropertyRawData::Flags signalFlags = QQmlPropertyData::Flags());
-    QQmlPropertyCache *copyAndAppend(const QMetaObject *, int revision,
+    QQmlPropertyCache *copyAndAppend(const QMetaObject *, int typeMinorVersion,
                 QQmlPropertyRawData::Flags propertyFlags = QQmlPropertyData::Flags(),
                 QQmlPropertyRawData::Flags methodFlags = QQmlPropertyData::Flags(),
                 QQmlPropertyRawData::Flags signalFlags = QQmlPropertyData::Flags());
 
     QQmlPropertyCache *copyAndReserve(int propertyCount,
-                                      int methodCount, int signalCount);
+                                      int methodCount, int signalCount, int enumCount);
     void appendProperty(const QString &, QQmlPropertyRawData::Flags flags, int coreIndex,
-                        int propType, int notifyIndex);
+                        int propType, int revision, int notifyIndex);
     void appendSignal(const QString &, QQmlPropertyRawData::Flags, int coreIndex,
-                      const int *types = 0, const QList<QByteArray> &names = QList<QByteArray>());
+                      const int *types = nullptr, const QList<QByteArray> &names = QList<QByteArray>());
     void appendMethod(const QString &, QQmlPropertyData::Flags flags, int coreIndex,
                       const QList<QByteArray> &names = QList<QByteArray>());
+    void appendEnum(const QString &, const QVector<QQmlEnumValue> &);
 
     const QMetaObject *metaObject() const;
     const QMetaObject *createMetaObject();
@@ -395,6 +120,7 @@ public:
     QQmlPropertyData *property(int) const;
     QQmlPropertyData *method(int) const;
     QQmlPropertyData *signal(int index) const;
+    QQmlEnumData *qmlEnum(int) const;
     int methodIndexToSignalIndex(int) const;
 
     QString defaultPropertyName() const;
@@ -424,7 +150,7 @@ public:
     static int originalClone(QObject *, int index);
 
     QList<QByteArray> signalParameterNames(int index) const;
-    static QString signalParameterStringForJS(QV4::ExecutionEngine *engine, const QList<QByteArray> &parameterNameList, QString *errorString = 0);
+    static QString signalParameterStringForJS(QV4::ExecutionEngine *engine, const QList<QByteArray> &parameterNameList, QString *errorString = nullptr);
 
     const char *className() const;
 
@@ -434,6 +160,7 @@ public:
     inline int methodOffset() const;
     inline int signalCount() const;
     inline int signalOffset() const;
+    inline int qmlEnumCount() const;
 
     static bool isDynamicMetaObject(const QMetaObject *);
 
@@ -446,9 +173,8 @@ public:
 
     QByteArray checksum(bool *ok);
 
-protected:
-    void destroy() override;
-    void clear() override;
+    int allowedRevision(int index) const { return allowedRevisionCache[index]; }
+    void setAllowedRevision(int index, int allowed) { allowedRevisionCache[index] = allowed; }
 
 private:
     friend class QQmlEnginePrivate;
@@ -460,7 +186,7 @@ private:
 
     inline QQmlPropertyCache *copy(int reserve);
 
-    void append(const QMetaObject *, int revision,
+    void append(const QMetaObject *, int typeMinorVersion,
                 QQmlPropertyRawData::Flags propertyFlags = QQmlPropertyRawData::Flags(),
                 QQmlPropertyRawData::Flags methodFlags = QQmlPropertyData::Flags(),
                 QQmlPropertyRawData::Flags signalFlags = QQmlPropertyData::Flags());
@@ -468,7 +194,7 @@ private:
     QQmlPropertyCacheMethodArguments *createArgumentsObject(int count, const QList<QByteArray> &names);
 
     typedef QVector<QQmlPropertyData> IndexCache;
-    typedef QStringMultiHash<QPair<int, QQmlPropertyData *> > StringCache;
+    typedef QLinkedStringMultiHash<QPair<int, QQmlPropertyData *> > StringCache;
     typedef QVector<int> AllowedRevisionCache;
 
     QQmlPropertyData *findProperty(StringCache::ConstIterator it, QObject *, QQmlContextData *) const;
@@ -493,9 +219,6 @@ private:
         _hasPropertyOverrides |= isOverride;
     }
 
-public:
-    QV4::ExecutionEngine *engine;
-
 private:
     QQmlPropertyCache *_parent;
     int propertyIndexCacheStart;
@@ -507,6 +230,7 @@ private:
     IndexCache signalHandlerIndexCache;
     StringCache stringCache;
     AllowedRevisionCache allowedRevisionCache;
+    QVector<QQmlEnumData> enumCache;
 
     bool _hasPropertyOverrides : 1;
     bool _ownMetaObject : 1;
@@ -519,169 +243,7 @@ private:
     QByteArray _checksum;
 };
 
-// QQmlMetaObject serves as a wrapper around either QMetaObject or QQmlPropertyCache.
-// This is necessary as we delay creation of QMetaObject for synthesized QObjects, but
-// we don't want to needlessly generate QQmlPropertyCaches every time we encounter a
-// QObject type used in assignment or when we don't have a QQmlEngine etc.
-//
-// This class does NOT reference the propertycache.
-class QQmlEnginePrivate;
-class Q_QML_EXPORT QQmlMetaObject
-{
-public:
-    typedef QVarLengthArray<int, 9> ArgTypeStorage;
-
-    inline QQmlMetaObject();
-    inline QQmlMetaObject(QObject *);
-    inline QQmlMetaObject(const QMetaObject *);
-    inline QQmlMetaObject(QQmlPropertyCache *);
-    inline QQmlMetaObject(const QQmlMetaObject &);
-
-    inline QQmlMetaObject &operator=(const QQmlMetaObject &);
-
-    inline bool isNull() const;
-
-    inline const char *className() const;
-    inline int propertyCount() const;
-
-    inline bool hasMetaObject() const;
-    inline const QMetaObject *metaObject() const;
-
-    QQmlPropertyCache *propertyCache(QQmlEnginePrivate *) const;
-
-    int methodReturnType(const QQmlPropertyData &data, QByteArray *unknownTypeError) const;
-    int *methodParameterTypes(int index, ArgTypeStorage *argStorage,
-                              QByteArray *unknownTypeError) const;
-
-    static bool canConvert(const QQmlMetaObject &from, const QQmlMetaObject &to);
-
-    // static_metacall (on Gadgets) doesn't call the base implementation and therefore
-    // we need a helper to find the correct meta object and property/method index.
-    static void resolveGadgetMethodOrPropertyIndex(QMetaObject::Call type, const QMetaObject **metaObject, int *index);
-
-protected:
-    QBiPointer<QQmlPropertyCache, const QMetaObject> _m;
-    int *methodParameterTypes(const QMetaMethod &method, ArgTypeStorage *argStorage,
-                              QByteArray *unknownTypeError) const;
-
-};
-
-class QQmlObjectOrGadget: public QQmlMetaObject
-{
-public:
-    QQmlObjectOrGadget(QObject *obj)
-        : QQmlMetaObject(obj),
-          ptr(obj)
-    {}
-    QQmlObjectOrGadget(QQmlPropertyCache *propertyCache, void *gadget)
-        : QQmlMetaObject(propertyCache)
-        , ptr(gadget)
-    {}
-
-    void metacall(QMetaObject::Call type, int index, void **argv) const;
-
-private:
-    QBiPointer<QObject, void> ptr;
-
-protected:
-    QQmlObjectOrGadget(const QMetaObject* metaObject)
-        : QQmlMetaObject(metaObject)
-    {}
-
-};
-
-class QQmlStaticMetaObject : public QQmlObjectOrGadget {
-public:
-    QQmlStaticMetaObject(const QMetaObject* metaObject)
-        : QQmlObjectOrGadget(metaObject)
-    {}
-    int *constructorParameterTypes(int index, ArgTypeStorage *dummy, QByteArray *unknownTypeError) const;
-};
-
-QQmlPropertyRawData::Flags::Flags()
-    : _otherBits(0)
-    , isConstant(false)
-    , isWritable(false)
-    , isResettable(false)
-    , isAlias(false)
-    , isFinal(false)
-    , isOverridden(false)
-    , isDirect(false)
-    , type(OtherType)
-    , isVMEFunction(false)
-    , hasArguments(false)
-    , isSignal(false)
-    , isVMESignal(false)
-    , isV4Function(false)
-    , isSignalHandler(false)
-    , isOverload(false)
-    , isCloned(false)
-    , isConstructor(false)
-    , notFullyResolved(false)
-    , overrideIndexIsProperty(false)
-{}
-
-bool QQmlPropertyRawData::Flags::operator==(const QQmlPropertyRawData::Flags &other) const
-{
-    return isConstant == other.isConstant &&
-            isWritable == other.isWritable &&
-            isResettable == other.isResettable &&
-            isAlias == other.isAlias &&
-            isFinal == other.isFinal &&
-            isOverridden == other.isOverridden &&
-            type == other.type &&
-            isVMEFunction == other.isVMEFunction &&
-            hasArguments == other.hasArguments &&
-            isSignal == other.isSignal &&
-            isVMESignal == other.isVMESignal &&
-            isV4Function == other.isV4Function &&
-            isSignalHandler == other.isSignalHandler &&
-            isOverload == other.isOverload &&
-            isCloned == other.isCloned &&
-            isConstructor == other.isConstructor &&
-            notFullyResolved == other.notFullyResolved &&
-            overrideIndexIsProperty == other.overrideIndexIsProperty;
-}
-
-void QQmlPropertyRawData::Flags::copyPropertyTypeFlags(QQmlPropertyRawData::Flags from)
-{
-    switch (from.type) {
-    case QObjectDerivedType:
-    case EnumType:
-    case QListType:
-    case QmlBindingType:
-    case QJSValueType:
-    case V4HandleType:
-    case QVariantType:
-        type = from.type;
-    }
-}
-
-QQmlPropertyData::QQmlPropertyData()
-{
-    setCoreIndex(-1);
-    setPropType(0);
-    setNotifyIndex(-1);
-    setOverrideIndex(-1);
-    setRevision(0);
-    setMetaObjectOffset(-1);
-    setArguments(nullptr);
-    trySetStaticMetaCallFunction(nullptr, 0);
-}
-
-QQmlPropertyData::QQmlPropertyData(const QQmlPropertyRawData &d)
-{
-    *(static_cast<QQmlPropertyRawData *>(this)) = d;
-}
-
-bool QQmlPropertyData::operator==(const QQmlPropertyRawData &other)
-{
-    return flags() == other.flags() &&
-           propType() == other.propType() &&
-           coreIndex() == other.coreIndex() &&
-           notifyIndex() == other.notifyIndex() &&
-           revision() == other.revision();
-}
+typedef QQmlRefPointer<QQmlPropertyCache> QQmlPropertyCachePtr;
 
 inline QQmlPropertyData *QQmlPropertyCache::ensureResolved(QQmlPropertyData *p) const
 {
@@ -701,7 +263,7 @@ inline const QMetaObject *QQmlPropertyCache::metaObject() const
 // QML
 inline const QMetaObject *QQmlPropertyCache::firstCppMetaObject() const
 {
-    while (_parent && (_metaObject == 0 || _ownMetaObject))
+    while (_parent && (_metaObject == nullptr || _ownMetaObject))
         return _parent->firstCppMetaObject();
     return _metaObject;
 }
@@ -709,7 +271,7 @@ inline const QMetaObject *QQmlPropertyCache::firstCppMetaObject() const
 inline QQmlPropertyData *QQmlPropertyCache::property(int index) const
 {
     if (index < 0 || index >= (propertyIndexCacheStart + propertyIndexCache.count()))
-        return 0;
+        return nullptr;
 
     if (index < propertyIndexCacheStart)
         return _parent->property(index);
@@ -721,7 +283,7 @@ inline QQmlPropertyData *QQmlPropertyCache::property(int index) const
 inline QQmlPropertyData *QQmlPropertyCache::method(int index) const
 {
     if (index < 0 || index >= (methodIndexCacheStart + methodIndexCache.count()))
-        return 0;
+        return nullptr;
 
     if (index < methodIndexCacheStart)
         return _parent->method(index);
@@ -737,7 +299,7 @@ inline QQmlPropertyData *QQmlPropertyCache::method(int index) const
 inline QQmlPropertyData *QQmlPropertyCache::signal(int index) const
 {
     if (index < 0 || index >= (signalHandlerIndexCacheStart + signalHandlerIndexCache.count()))
-        return 0;
+        return nullptr;
 
     if (index < signalHandlerIndexCacheStart)
         return _parent->signal(index);
@@ -747,6 +309,14 @@ inline QQmlPropertyData *QQmlPropertyCache::signal(int index) const
     return ensureResolved(rv);
 }
 
+inline QQmlEnumData *QQmlPropertyCache::qmlEnum(int index) const
+{
+    if (index < 0 || index >= enumCache.count())
+        return nullptr;
+
+    return const_cast<QQmlEnumData *>(&enumCache.at(index));
+}
+
 inline int QQmlPropertyCache::methodIndexToSignalIndex(int index) const
 {
     if (index < 0 || index >= (methodIndexCacheStart + methodIndexCache.count()))
@@ -773,7 +343,7 @@ QQmlPropertyData *
 QQmlPropertyCache::overrideData(QQmlPropertyData *data) const
 {
     if (!data->hasOverride())
-        return 0;
+        return nullptr;
 
     if (data->overrideIndexIsProperty())
         return property(data->overrideIndex());
@@ -817,6 +387,11 @@ int QQmlPropertyCache::signalOffset() const
     return signalHandlerIndexCacheStart;
 }
 
+int QQmlPropertyCache::qmlEnumCount() const
+{
+    return enumCache.count();
+}
+
 bool QQmlPropertyCache::callJSFactoryMethod(QObject *object, void **args) const
 {
     if (_jsFactoryMethodIndex != -1) {
@@ -828,124 +403,6 @@ bool QQmlPropertyCache::callJSFactoryMethod(QObject *object, void **args) const
     return false;
 }
 
-QQmlMetaObject::QQmlMetaObject()
-{
-}
-
-QQmlMetaObject::QQmlMetaObject(QObject *o)
-{
-    if (o) {
-        QQmlData *ddata = QQmlData::get(o, false);
-        if (ddata && ddata->propertyCache) _m = ddata->propertyCache;
-        else _m = o->metaObject();
-    }
-}
-
-QQmlMetaObject::QQmlMetaObject(const QMetaObject *m)
-: _m(m)
-{
-}
-
-QQmlMetaObject::QQmlMetaObject(QQmlPropertyCache *m)
-: _m(m)
-{
-}
-
-QQmlMetaObject::QQmlMetaObject(const QQmlMetaObject &o)
-: _m(o._m)
-{
-}
-
-QQmlMetaObject &QQmlMetaObject::operator=(const QQmlMetaObject &o)
-{
-    _m = o._m;
-    return *this;
-}
-
-bool QQmlMetaObject::isNull() const
-{
-    return _m.isNull();
-}
-
-const char *QQmlMetaObject::className() const
-{
-    if (_m.isNull()) {
-        return 0;
-    } else if (_m.isT1()) {
-        return _m.asT1()->className();
-    } else {
-        return _m.asT2()->className();
-    }
-}
-
-int QQmlMetaObject::propertyCount() const
-{
-    if (_m.isNull()) {
-        return 0;
-    } else if (_m.isT1()) {
-        return _m.asT1()->propertyCount();
-    } else {
-        return _m.asT2()->propertyCount();
-    }
-}
-
-bool QQmlMetaObject::hasMetaObject() const
-{
-    return _m.isT2() || (!_m.isNull() && _m.asT1()->metaObject());
-}
-
-const QMetaObject *QQmlMetaObject::metaObject() const
-{
-    if (_m.isNull()) return 0;
-    if (_m.isT1()) return _m.asT1()->createMetaObject();
-    else return _m.asT2();
-}
-
-class QQmlPropertyCacheVector
-{
-public:
-    QQmlPropertyCacheVector() {}
-    QQmlPropertyCacheVector(QQmlPropertyCacheVector &&other)
-        : data(std::move(other.data)) {}
-    QQmlPropertyCacheVector &operator=(QQmlPropertyCacheVector &&other) {
-        QVector<QFlagPointer<QQmlPropertyCache>> moved(std::move(other.data));
-        data.swap(moved);
-        return *this;
-    }
-
-    ~QQmlPropertyCacheVector() { clear(); }
-    void resize(int size) { return data.resize(size); }
-    int count() const { return data.count(); }
-    void clear()
-    {
-        for (int i = 0; i < data.count(); ++i) {
-            if (QQmlPropertyCache *cache = data.at(i).data())
-                cache->release();
-        }
-        data.clear();
-    }
-
-    void append(QQmlPropertyCache *cache) { cache->addref(); data.append(cache); }
-    QQmlPropertyCache *at(int index) const { return data.at(index).data(); }
-    void set(int index, QQmlPropertyCache *replacement) {
-        if (QQmlPropertyCache *oldCache = data.at(index).data()) {
-            if (replacement == oldCache)
-                return;
-            oldCache->release();
-        }
-        data[index] = replacement;
-        replacement->addref();
-    }
-
-    void setNeedsVMEMetaObject(int index) { data[index].setFlag(); }
-    bool needsVMEMetaObject(int index) const { return data.at(index).flag(); }
-private:
-    Q_DISABLE_COPY(QQmlPropertyCacheVector)
-    QVector<QFlagPointer<QQmlPropertyCache>> data;
-};
-
-Q_DECLARE_OPERATORS_FOR_FLAGS(QQmlPropertyData::WriteFlags)
-
 QT_END_NAMESPACE
 
 #endif // QQMLPROPERTYCACHE_P_H
diff --git a/src/qml/qml/qqmlpropertycachemethodarguments_p.h b/src/qml/qml/qqmlpropertycachemethodarguments_p.h
new file mode 100644
index 0000000000..62f09bdfff
--- /dev/null
+++ b/src/qml/qml/qqmlpropertycachemethodarguments_p.h
@@ -0,0 +1,77 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLPROPERTYCACHEMETODARGUMENTS_P_H
+#define QQMLPROPERTYCACHEMETODARGUMENTS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qlist.h>
+#include <QtCore/qbytearray.h>
+
+QT_BEGIN_NAMESPACE
+
+class QString;
+class QQmlPropertyCacheMethodArguments
+{
+public:
+    QQmlPropertyCacheMethodArguments *next;
+
+    //for signal handler rewrites
+    QString *signalParameterStringForJS;
+    int parameterError:1;
+    int argumentsValid:1;
+
+    QList<QByteArray> *names;
+
+    int arguments[1];
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLPROPERTYCACHEMETODARGUMENTS_P_H
diff --git a/src/qml/qml/qqmlpropertycachevector_p.h b/src/qml/qml/qqmlpropertycachevector_p.h
new file mode 100644
index 0000000000..1dff7c61a6
--- /dev/null
+++ b/src/qml/qml/qqmlpropertycachevector_p.h
@@ -0,0 +1,104 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLPROPERTYCACHEVECTOR_P_H
+#define QQMLPROPERTYCACHEVECTOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qflagpointer_p.h>
+#include <private/qqmlpropertycache_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlPropertyCacheVector
+{
+public:
+    QQmlPropertyCacheVector() {}
+    QQmlPropertyCacheVector(QQmlPropertyCacheVector &&other)
+        : data(std::move(other.data)) {}
+    QQmlPropertyCacheVector &operator=(QQmlPropertyCacheVector &&other) {
+        QVector<QFlagPointer<QQmlPropertyCache>> moved(std::move(other.data));
+        data.swap(moved);
+        return *this;
+    }
+
+    ~QQmlPropertyCacheVector() { clear(); }
+    void resize(int size) { return data.resize(size); }
+    int count() const { return data.count(); }
+    void clear()
+    {
+        for (int i = 0; i < data.count(); ++i) {
+            if (QQmlPropertyCache *cache = data.at(i).data())
+                cache->release();
+        }
+        data.clear();
+    }
+
+    void append(QQmlPropertyCache *cache) { cache->addref(); data.append(cache); }
+    QQmlPropertyCache *at(int index) const { return data.at(index).data(); }
+    void set(int index, const QQmlRefPointer<QQmlPropertyCache> &replacement) {
+        if (QQmlPropertyCache *oldCache = data.at(index).data()) {
+            if (replacement.data() == oldCache)
+                return;
+            oldCache->release();
+        }
+        data[index] = replacement.data();
+        replacement->addref();
+    }
+
+    void setNeedsVMEMetaObject(int index) { data[index].setFlag(); }
+    bool needsVMEMetaObject(int index) const { return data.at(index).flag(); }
+private:
+    Q_DISABLE_COPY(QQmlPropertyCacheVector)
+    QVector<QFlagPointer<QQmlPropertyCache>> data;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLPROPERTYCACHEVECTOR_P_H
diff --git a/src/qml/qml/qqmlpropertydata_p.h b/src/qml/qml/qqmlpropertydata_p.h
new file mode 100644
index 0000000000..a292bcc769
--- /dev/null
+++ b/src/qml/qml/qqmlpropertydata_p.h
@@ -0,0 +1,164 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLPROPERTYDATA_P_H
+#define QQMLPROPERTYDATA_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmlpropertyrawdata_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlPropertyData : public QQmlPropertyRawData
+{
+public:
+    enum WriteFlag {
+        BypassInterceptor = 0x01,
+        DontRemoveBinding = 0x02,
+        RemoveBindingOnAliasWrite = 0x04
+    };
+    Q_DECLARE_FLAGS(WriteFlags, WriteFlag)
+
+    inline QQmlPropertyData();
+    inline QQmlPropertyData(const QQmlPropertyRawData &);
+
+    inline bool operator==(const QQmlPropertyRawData &);
+
+    static Flags flagsForProperty(const QMetaProperty &);
+    void load(const QMetaProperty &);
+    void load(const QMetaMethod &);
+    QString name(QObject *) const;
+    QString name(const QMetaObject *) const;
+
+    void markAsOverrideOf(QQmlPropertyData *predecessor);
+
+    inline void readProperty(QObject *target, void *property) const
+    {
+        void *args[] = { property, nullptr };
+        readPropertyWithArgs(target, args);
+    }
+
+    inline void readPropertyWithArgs(QObject *target, void *args[]) const
+    {
+        if (hasStaticMetaCallFunction())
+            staticMetaCallFunction()(target, QMetaObject::ReadProperty, relativePropertyIndex(), args);
+        else if (isDirect())
+            target->qt_metacall(QMetaObject::ReadProperty, coreIndex(), args);
+        else
+            QMetaObject::metacall(target, QMetaObject::ReadProperty, coreIndex(), args);
+    }
+
+    bool writeProperty(QObject *target, void *value, WriteFlags flags) const
+    {
+        int status = -1;
+        void *argv[] = { value, nullptr, &status, &flags };
+        if (flags.testFlag(BypassInterceptor) && hasStaticMetaCallFunction())
+            staticMetaCallFunction()(target, QMetaObject::WriteProperty, relativePropertyIndex(), argv);
+        else if (flags.testFlag(BypassInterceptor) && isDirect())
+            target->qt_metacall(QMetaObject::WriteProperty, coreIndex(), argv);
+        else
+            QMetaObject::metacall(target, QMetaObject::WriteProperty, coreIndex(), argv);
+        return true;
+    }
+
+    static Flags defaultSignalFlags()
+    {
+        Flags f;
+        f.isSignal = true;
+        f.type = Flags::FunctionType;
+        f.isVMESignal = true;
+        return f;
+    }
+
+    static Flags defaultSlotFlags()
+    {
+        Flags f;
+        f.type = Flags::FunctionType;
+        f.isVMEFunction = true;
+        return f;
+    }
+
+private:
+    friend class QQmlPropertyCache;
+    void lazyLoad(const QMetaProperty &);
+    void lazyLoad(const QMetaMethod &);
+    bool notFullyResolved() const { return _flags.notFullyResolved; }
+};
+
+QQmlPropertyData::QQmlPropertyData()
+{
+    setCoreIndex(-1);
+    setPropType(0);
+    setNotifyIndex(-1);
+    setOverrideIndex(-1);
+    setRevision(0);
+    setMetaObjectOffset(-1);
+    setArguments(nullptr);
+    trySetStaticMetaCallFunction(nullptr, 0);
+}
+
+QQmlPropertyData::QQmlPropertyData(const QQmlPropertyRawData &d)
+{
+    *(static_cast<QQmlPropertyRawData *>(this)) = d;
+}
+
+bool QQmlPropertyData::operator==(const QQmlPropertyRawData &other)
+{
+    return flags() == other.flags() &&
+            propType() == other.propType() &&
+            coreIndex() == other.coreIndex() &&
+            notifyIndex() == other.notifyIndex() &&
+            revision() == other.revision();
+}
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(QQmlPropertyData::WriteFlags)
+
+QT_END_NAMESPACE
+
+#endif // QQMLPROPERTYDATA_P_H
diff --git a/src/qml/qml/qqmlpropertyrawdata_p.h b/src/qml/qml/qqmlpropertyrawdata_p.h
new file mode 100644
index 0000000000..833c0f6ad0
--- /dev/null
+++ b/src/qml/qml/qqmlpropertyrawdata_p.h
@@ -0,0 +1,341 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLPROPERTYRAWDATA_P_H
+#define QQMLPROPERTYRAWDATA_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qobject_p.h>
+
+QT_BEGIN_NAMESPACE
+
+// We have this somewhat awful split between RawData and Data so that RawData can be
+// used in unions.  In normal code, you should always use Data which initializes RawData
+// to an invalid state on construction.
+// ### We should be able to remove this split nowadays
+class QQmlPropertyCacheMethodArguments;
+class QQmlPropertyRawData
+{
+public:
+    typedef QObjectPrivate::StaticMetaCallFunction StaticMetaCallFunction;
+
+    struct Flags {
+        enum Types {
+            OtherType            = 0,
+            FunctionType         = 1, // Is an invokable
+            QObjectDerivedType   = 2, // Property type is a QObject* derived type
+            EnumType             = 3, // Property type is an enum
+            QListType            = 4, // Property type is a QML list
+            QmlBindingType       = 5, // Property type is a QQmlBinding*
+            QJSValueType         = 6, // Property type is a QScriptValue
+            V4HandleType         = 7, // Property type is a QQmlV4Handle
+            VarPropertyType      = 8, // Property type is a "var" property of VMEMO
+            QVariantType         = 9  // Property is a QVariant
+        };
+
+        // The _otherBits (which "pad" the Flags struct to align it nicely) are used
+        // to store the relative property index. It will only get used when said index fits. See
+        // trySetStaticMetaCallFunction for details.
+        // (Note: this padding is done here, because certain compilers have surprising behavior
+        // when an enum is declared in-between two bit fields.)
+        enum { BitsLeftInFlags = 10 };
+        unsigned _otherBits       : BitsLeftInFlags; // align to 32 bits
+
+        // Can apply to all properties, except IsFunction
+        unsigned isConstant       : 1; // Has CONST flag
+        unsigned isWritable       : 1; // Has WRITE function
+        unsigned isResettable     : 1; // Has RESET function
+        unsigned isAlias          : 1; // Is a QML alias to another property
+        unsigned isFinal          : 1; // Has FINAL flag
+        unsigned isOverridden     : 1; // Is overridden by a extension property
+        unsigned isDirect         : 1; // Exists on a C++ QMetaObject
+
+        unsigned type             : 4; // stores an entry of Types
+
+        // Apply only to IsFunctions
+        unsigned isVMEFunction    : 1; // Function was added by QML
+        unsigned hasArguments     : 1; // Function takes arguments
+        unsigned isSignal         : 1; // Function is a signal
+        unsigned isVMESignal      : 1; // Signal was added by QML
+        unsigned isV4Function     : 1; // Function takes QQmlV4Function* args
+        unsigned isSignalHandler  : 1; // Function is a signal handler
+        unsigned isOverload       : 1; // Function is an overload of another function
+        unsigned isCloned         : 1; // The function was marked as cloned
+        unsigned isConstructor    : 1; // The function was marked is a constructor
+
+        // Internal QQmlPropertyCache flags
+        unsigned notFullyResolved : 1; // True if the type data is to be lazily resolved
+        unsigned overrideIndexIsProperty: 1;
+
+        inline Flags();
+        inline bool operator==(const Flags &other) const;
+        inline void copyPropertyTypeFlags(Flags from);
+    };
+
+    Flags flags() const { return _flags; }
+    void setFlags(Flags f)
+    {
+        unsigned otherBits = _flags._otherBits;
+        _flags = f;
+        _flags._otherBits = otherBits;
+    }
+
+    bool isValid() const { return coreIndex() != -1; }
+
+    bool isConstant() const { return _flags.isConstant; }
+    bool isWritable() const { return _flags.isWritable; }
+    void setWritable(bool onoff) { _flags.isWritable = onoff; }
+    bool isResettable() const { return _flags.isResettable; }
+    bool isAlias() const { return _flags.isAlias; }
+    bool isFinal() const { return _flags.isFinal; }
+    bool isOverridden() const { return _flags.isOverridden; }
+    bool isDirect() const { return _flags.isDirect; }
+    bool hasStaticMetaCallFunction() const { return staticMetaCallFunction() != nullptr; }
+    bool isFunction() const { return _flags.type == Flags::FunctionType; }
+    bool isQObject() const { return _flags.type == Flags::QObjectDerivedType; }
+    bool isEnum() const { return _flags.type == Flags::EnumType; }
+    bool isQList() const { return _flags.type == Flags::QListType; }
+    bool isQmlBinding() const { return _flags.type == Flags::QmlBindingType; }
+    bool isQJSValue() const { return _flags.type == Flags::QJSValueType; }
+    bool isV4Handle() const { return _flags.type == Flags::V4HandleType; }
+    bool isVarProperty() const { return _flags.type == Flags::VarPropertyType; }
+    bool isQVariant() const { return _flags.type == Flags::QVariantType; }
+    bool isVMEFunction() const { return _flags.isVMEFunction; }
+    bool hasArguments() const { return _flags.hasArguments; }
+    bool isSignal() const { return _flags.isSignal; }
+    bool isVMESignal() const { return _flags.isVMESignal; }
+    bool isV4Function() const { return _flags.isV4Function; }
+    bool isSignalHandler() const { return _flags.isSignalHandler; }
+    bool isOverload() const { return _flags.isOverload; }
+    void setOverload(bool onoff) { _flags.isOverload = onoff; }
+    bool isCloned() const { return _flags.isCloned; }
+    bool isConstructor() const { return _flags.isConstructor; }
+
+    bool hasOverride() const { return overrideIndex() >= 0; }
+    bool hasRevision() const { return revision() != 0; }
+
+    bool isFullyResolved() const { return !_flags.notFullyResolved; }
+
+    int propType() const { Q_ASSERT(isFullyResolved()); return _propType; }
+    void setPropType(int pt)
+    {
+        Q_ASSERT(pt >= 0);
+        Q_ASSERT(pt <= std::numeric_limits<qint16>::max());
+        _propType = quint16(pt);
+    }
+
+    int notifyIndex() const { return _notifyIndex; }
+    void setNotifyIndex(int idx)
+    {
+        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
+        _notifyIndex = qint16(idx);
+    }
+
+    bool overrideIndexIsProperty() const { return _flags.overrideIndexIsProperty; }
+    void setOverrideIndexIsProperty(bool onoff) { _flags.overrideIndexIsProperty = onoff; }
+
+    int overrideIndex() const { return _overrideIndex; }
+    void setOverrideIndex(int idx)
+    {
+        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
+        _overrideIndex = qint16(idx);
+    }
+
+    int coreIndex() const { return _coreIndex; }
+    void setCoreIndex(int idx)
+    {
+        Q_ASSERT(idx >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(idx <= std::numeric_limits<qint16>::max());
+        _coreIndex = qint16(idx);
+    }
+
+    quint8 revision() const { return _revision; }
+    void setRevision(quint8 rev)
+    {
+        Q_ASSERT(rev <= std::numeric_limits<quint8>::max());
+        _revision = quint8(rev);
+    }
+
+    /* If a property is a C++ type, then we store the minor
+     * version of this type.
+     * This is required to resolve property or signal revisions
+     * if this property is used as a grouped property.
+     *
+     * Test.qml
+     * property TextEdit someTextEdit: TextEdit {}
+     *
+     * Test {
+     *   someTextEdit.preeditText: "test" //revision 7
+     *   someTextEdit.onEditingFinished: console.log("test") //revision 6
+     * }
+     *
+     * To determine if these properties with revisions are available we need
+     * the minor version of TextEdit as imported in Test.qml.
+     *
+     */
+
+    quint8 typeMinorVersion() const { return _typeMinorVersion; }
+    void setTypeMinorVersion(quint8 rev)
+    {
+        Q_ASSERT(rev <= std::numeric_limits<quint8>::max());
+        _typeMinorVersion = quint8(rev);
+    }
+
+    QQmlPropertyCacheMethodArguments *arguments() const { return _arguments; }
+    void setArguments(QQmlPropertyCacheMethodArguments *args) { _arguments = args; }
+
+    int metaObjectOffset() const { return _metaObjectOffset; }
+    void setMetaObjectOffset(int off)
+    {
+        Q_ASSERT(off >= std::numeric_limits<qint16>::min());
+        Q_ASSERT(off <= std::numeric_limits<qint16>::max());
+        _metaObjectOffset = qint16(off);
+    }
+
+    StaticMetaCallFunction staticMetaCallFunction() const { return _staticMetaCallFunction; }
+    void trySetStaticMetaCallFunction(StaticMetaCallFunction f, unsigned relativePropertyIndex)
+    {
+        if (relativePropertyIndex < (1 << Flags::BitsLeftInFlags) - 1) {
+            _flags._otherBits = relativePropertyIndex;
+            _staticMetaCallFunction = f;
+        }
+    }
+    quint16 relativePropertyIndex() const { Q_ASSERT(hasStaticMetaCallFunction()); return _flags._otherBits; }
+
+private:
+    Flags _flags;
+    qint16 _coreIndex = 0;
+    quint16 _propType = 0;
+
+    // The notify index is in the range returned by QObjectPrivate::signalIndex().
+    // This is different from QMetaMethod::methodIndex().
+    qint16 _notifyIndex = 0;
+    qint16 _overrideIndex = 0;
+
+    quint8 _revision = 0;
+    quint8 _typeMinorVersion = 0;
+    qint16 _metaObjectOffset = 0;
+
+    QQmlPropertyCacheMethodArguments *_arguments = nullptr;
+    StaticMetaCallFunction _staticMetaCallFunction = nullptr;
+
+    friend class QQmlPropertyData;
+    friend class QQmlPropertyCache;
+};
+
+#if QT_POINTER_SIZE == 4
+    Q_STATIC_ASSERT(sizeof(QQmlPropertyRawData) == 24);
+#else // QT_POINTER_SIZE == 8
+    Q_STATIC_ASSERT(sizeof(QQmlPropertyRawData) == 32);
+#endif
+
+QQmlPropertyRawData::Flags::Flags()
+    : _otherBits(0)
+    , isConstant(false)
+    , isWritable(false)
+    , isResettable(false)
+    , isAlias(false)
+    , isFinal(false)
+    , isOverridden(false)
+    , isDirect(false)
+    , type(OtherType)
+    , isVMEFunction(false)
+    , hasArguments(false)
+    , isSignal(false)
+    , isVMESignal(false)
+    , isV4Function(false)
+    , isSignalHandler(false)
+    , isOverload(false)
+    , isCloned(false)
+    , isConstructor(false)
+    , notFullyResolved(false)
+    , overrideIndexIsProperty(false)
+{}
+
+bool QQmlPropertyRawData::Flags::operator==(const QQmlPropertyRawData::Flags &other) const
+{
+    return isConstant == other.isConstant &&
+            isWritable == other.isWritable &&
+            isResettable == other.isResettable &&
+            isAlias == other.isAlias &&
+            isFinal == other.isFinal &&
+            isOverridden == other.isOverridden &&
+            type == other.type &&
+            isVMEFunction == other.isVMEFunction &&
+            hasArguments == other.hasArguments &&
+            isSignal == other.isSignal &&
+            isVMESignal == other.isVMESignal &&
+            isV4Function == other.isV4Function &&
+            isSignalHandler == other.isSignalHandler &&
+            isOverload == other.isOverload &&
+            isCloned == other.isCloned &&
+            isConstructor == other.isConstructor &&
+            notFullyResolved == other.notFullyResolved &&
+            overrideIndexIsProperty == other.overrideIndexIsProperty;
+}
+
+void QQmlPropertyRawData::Flags::copyPropertyTypeFlags(QQmlPropertyRawData::Flags from)
+{
+    switch (from.type) {
+    case QObjectDerivedType:
+    case EnumType:
+    case QListType:
+    case QmlBindingType:
+    case QJSValueType:
+    case V4HandleType:
+    case QVariantType:
+        type = from.type;
+    }
+}
+
+QT_END_NAMESPACE
+
+#endif // QQMLPROPERTYRAWDATA_P_H
diff --git a/src/qml/qml/qqmlpropertyvalueinterceptor.cpp b/src/qml/qml/qqmlpropertyvalueinterceptor.cpp
index 52c003ab59..603245f29d 100644
--- a/src/qml/qml/qqmlpropertyvalueinterceptor.cpp
+++ b/src/qml/qml/qqmlpropertyvalueinterceptor.cpp
@@ -55,7 +55,7 @@ QT_BEGIN_NAMESPACE
 /*!
     Constructs a QQmlPropertyValueInterceptor.
 */
-QQmlPropertyValueInterceptor::QQmlPropertyValueInterceptor() : m_next(0)
+QQmlPropertyValueInterceptor::QQmlPropertyValueInterceptor() : m_next(nullptr)
 {
 }
 
diff --git a/src/qml/qml/qqmlproxymetaobject.cpp b/src/qml/qml/qqmlproxymetaobject.cpp
index 27e3c13ff8..e1500f70fb 100644
--- a/src/qml/qml/qqmlproxymetaobject.cpp
+++ b/src/qml/qml/qqmlproxymetaobject.cpp
@@ -43,7 +43,7 @@
 QT_BEGIN_NAMESPACE
 
 QQmlProxyMetaObject::QQmlProxyMetaObject(QObject *obj, QList<ProxyData> *mList)
-: metaObjects(mList), proxies(0), parent(0), object(obj)
+: metaObjects(mList), proxies(nullptr), parent(nullptr), object(obj)
 {
     *static_cast<QMetaObject *>(this) = *metaObjects->constFirst().metaObject;
 
@@ -58,11 +58,11 @@ QQmlProxyMetaObject::~QQmlProxyMetaObject()
 {
     if (parent)
         delete parent;
-    parent = 0;
+    parent = nullptr;
 
     if (proxies)
         delete [] proxies;
-    proxies = 0;
+    proxies = nullptr;
 }
 
 int QQmlProxyMetaObject::metaCall(QObject *o, QMetaObject::Call c, int id, void **a)
diff --git a/src/qml/qml/qqmlscriptstring_p.h b/src/qml/qml/qqmlscriptstring_p.h
index 2dfb817186..fd8ccd5d53 100644
--- a/src/qml/qml/qqmlscriptstring_p.h
+++ b/src/qml/qml/qqmlscriptstring_p.h
@@ -59,7 +59,7 @@ QT_BEGIN_NAMESPACE
 class Q_AUTOTEST_EXPORT QQmlScriptStringPrivate : public QSharedData
 {
 public:
-    QQmlScriptStringPrivate() : context(0), scope(0), bindingId(-1), lineNumber(0), columnNumber(0),
+    QQmlScriptStringPrivate() : context(nullptr), scope(nullptr), bindingId(-1), lineNumber(0), columnNumber(0),
         numberValue(0), isStringLiteral(false), isNumberLiteral(false) {}
 
     //for testing
diff --git a/src/qml/qml/qqmlstaticmetaobject.cpp b/src/qml/qml/qqmlstaticmetaobject.cpp
new file mode 100644
index 0000000000..218d0134fd
--- /dev/null
+++ b/src/qml/qml/qqmlstaticmetaobject.cpp
@@ -0,0 +1,51 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlstaticmetaobject_p.h"
+
+QT_BEGIN_NAMESPACE
+
+int *QQmlStaticMetaObject::constructorParameterTypes(int index, ArgTypeStorage *dummy,
+                                                     QByteArray *unknownTypeError) const
+{
+    QMetaMethod m = _m.asT2()->constructor(index);
+    return methodParameterTypes(m, dummy, unknownTypeError);
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlstaticmetaobject_p.h b/src/qml/qml/qqmlstaticmetaobject_p.h
new file mode 100644
index 0000000000..e1ca496080
--- /dev/null
+++ b/src/qml/qml/qqmlstaticmetaobject_p.h
@@ -0,0 +1,68 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLSTATICMETAOBJECT_P_H
+#define QQMLSTATICMETAOBJECT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmlobjectorgadget_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlStaticMetaObject : public QQmlObjectOrGadget {
+public:
+    QQmlStaticMetaObject(const QMetaObject* metaObject)
+        : QQmlObjectOrGadget(metaObject)
+    {}
+    int *constructorParameterTypes(int index, ArgTypeStorage *dummy, QByteArray *unknownTypeError) const;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLSTATICMETAOBJECT_P_H
diff --git a/src/qml/qml/qqmlstringconverters_p.h b/src/qml/qml/qqmlstringconverters_p.h
index af344e3344..215f0c0aaf 100644
--- a/src/qml/qml/qqmlstringconverters_p.h
+++ b/src/qml/qml/qqmlstringconverters_p.h
@@ -67,19 +67,19 @@ class QByteArray;
 namespace QQmlStringConverters
 {
     Q_QML_PRIVATE_EXPORT QVariant variantFromString(const QString &);
-    Q_QML_PRIVATE_EXPORT QVariant variantFromString(const QString &, int preferredType, bool *ok = 0);
+    Q_QML_PRIVATE_EXPORT QVariant variantFromString(const QString &, int preferredType, bool *ok = nullptr);
 
-    Q_QML_PRIVATE_EXPORT QVariant colorFromString(const QString &, bool *ok = 0);
-    Q_QML_PRIVATE_EXPORT unsigned rgbaFromString(const QString &, bool *ok = 0);
+    Q_QML_PRIVATE_EXPORT QVariant colorFromString(const QString &, bool *ok = nullptr);
+    Q_QML_PRIVATE_EXPORT unsigned rgbaFromString(const QString &, bool *ok = nullptr);
 
 #if QT_CONFIG(datestring)
-    Q_QML_PRIVATE_EXPORT QDate dateFromString(const QString &, bool *ok = 0);
-    Q_QML_PRIVATE_EXPORT QTime timeFromString(const QString &, bool *ok = 0);
-    Q_QML_PRIVATE_EXPORT QDateTime dateTimeFromString(const QString &, bool *ok = 0);
+    Q_QML_PRIVATE_EXPORT QDate dateFromString(const QString &, bool *ok = nullptr);
+    Q_QML_PRIVATE_EXPORT QTime timeFromString(const QString &, bool *ok = nullptr);
+    Q_QML_PRIVATE_EXPORT QDateTime dateTimeFromString(const QString &, bool *ok = nullptr);
 #endif
-    Q_QML_PRIVATE_EXPORT QPointF pointFFromString(const QString &, bool *ok = 0);
-    Q_QML_PRIVATE_EXPORT QSizeF sizeFFromString(const QString &, bool *ok = 0);
-    Q_QML_PRIVATE_EXPORT QRectF rectFFromString(const QString &, bool *ok = 0);
+    Q_QML_PRIVATE_EXPORT QPointF pointFFromString(const QString &, bool *ok = nullptr);
+    Q_QML_PRIVATE_EXPORT QSizeF sizeFFromString(const QString &, bool *ok = nullptr);
+    Q_QML_PRIVATE_EXPORT QRectF rectFFromString(const QString &, bool *ok = nullptr);
 
     Q_QML_PRIVATE_EXPORT bool createFromString(int, const QString &, void *, size_t);
 }
diff --git a/src/qml/qml/qqmltype.cpp b/src/qml/qml/qqmltype.cpp
new file mode 100644
index 0000000000..efe190cbcf
--- /dev/null
+++ b/src/qml/qml/qqmltype.cpp
@@ -0,0 +1,977 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmltype_p_p.h"
+
+#include <QtQml/qjsvalue.h>
+#include <QtQml/qqmlengine.h>
+#include <QtQml/qqmlcontext.h>
+#include <QtQml/qqmlcomponent.h>
+
+#include <private/qqmlcustomparser_p.h>
+#include <private/qqmldata_p.h>
+#include <private/qqmlmetatypedata_p.h>
+#include <private/qqmlpropertycache_p.h>
+
+QT_BEGIN_NAMESPACE
+
+void QQmlType::SingletonInstanceInfo::init(QQmlEngine *e)
+{
+    if (scriptCallback && scriptApi(e).isUndefined()) {
+        QJSValue value = scriptCallback(e, e);
+        if (value.isQObject()) {
+            QObject *o = value.toQObject();
+            // even though the object is defined in C++, qmlContext(obj) and qmlEngine(obj)
+            // should behave identically to QML singleton types.
+            e->setContextForObject(o, new QQmlContext(e->rootContext(), e));
+        }
+        setScriptApi(e, value);
+    } else if (qobjectCallback && !qobjectApi(e)) {
+        QObject *o = qobjectCallback(e, e);
+        setQObjectApi(e, o);
+        if (!o) {
+            qFatal("qmlRegisterSingletonType(): \"%s\" is not available because the callback function returns a null pointer.", qPrintable(typeName));
+        }
+        // if this object can use a property cache, create it now
+        QQmlData::ensurePropertyCache(e, o);
+        // even though the object is defined in C++, qmlContext(obj) and qmlEngine(obj)
+        // should behave identically to QML singleton types.
+        e->setContextForObject(o, new QQmlContext(e->rootContext(), e));
+    } else if (!url.isEmpty() && !qobjectApi(e)) {
+        QQmlComponent component(e, url, QQmlComponent::PreferSynchronous);
+        QObject *o = component.beginCreate(e->rootContext());
+        setQObjectApi(e, o);
+        if (o)
+            component.completeCreate();
+    }
+}
+
+void QQmlType::SingletonInstanceInfo::destroy(QQmlEngine *e)
+{
+    // cleans up the engine-specific singleton instances if they exist.
+    scriptApis.remove(e);
+    QObject *o = qobjectApis.take(e);
+    if (o) {
+        QQmlData *ddata = QQmlData::get(o, false);
+        if (url.isEmpty() && ddata && ddata->indestructible && ddata->explicitIndestructibleSet)
+            return;
+        delete o;
+    }
+}
+
+void QQmlType::SingletonInstanceInfo::setQObjectApi(QQmlEngine *e, QObject *o)
+{
+    qobjectApis.insert(e, o);
+}
+
+QObject *QQmlType::SingletonInstanceInfo::qobjectApi(QQmlEngine *e) const
+{
+    return qobjectApis.value(e);
+}
+
+void QQmlType::SingletonInstanceInfo::setScriptApi(QQmlEngine *e, const QJSValue &v)
+{
+    scriptApis.insert(e, v);
+}
+
+QJSValue QQmlType::SingletonInstanceInfo::scriptApi(QQmlEngine *e) const
+{
+    return scriptApis.value(e);
+}
+
+QQmlTypePrivate::QQmlTypePrivate(QQmlType::RegistrationType type)
+    : regType(type), iid(nullptr), typeId(0), listId(0), revision(0),
+    containsRevisionedAttributes(false), baseMetaObject(nullptr),
+    index(-1), isSetup(false), isEnumSetup(false), haveSuperType(false)
+{
+    switch (type) {
+    case QQmlType::CppType:
+        extraData.cd = new QQmlCppTypeData;
+        extraData.cd->allocationSize = 0;
+        extraData.cd->newFunc = nullptr;
+        extraData.cd->parserStatusCast = -1;
+        extraData.cd->extFunc = nullptr;
+        extraData.cd->extMetaObject = nullptr;
+        extraData.cd->customParser = nullptr;
+        extraData.cd->attachedPropertiesFunc = nullptr;
+        extraData.cd->attachedPropertiesType = nullptr;
+        extraData.cd->propertyValueSourceCast = -1;
+        extraData.cd->propertyValueInterceptorCast = -1;
+        extraData.cd->registerEnumClassesUnscoped = true;
+        break;
+    case QQmlType::SingletonType:
+    case QQmlType::CompositeSingletonType:
+        extraData.sd = new QQmlSingletonTypeData;
+        extraData.sd->singletonInstanceInfo = nullptr;
+        break;
+    case QQmlType::InterfaceType:
+        extraData.cd = nullptr;
+        break;
+    case QQmlType::CompositeType:
+        extraData.fd = new QQmlCompositeTypeData;
+        break;
+    default: qFatal("QQmlTypePrivate Internal Error.");
+    }
+}
+
+QQmlTypePrivate::~QQmlTypePrivate()
+{
+    qDeleteAll(scopedEnums);
+    switch (regType) {
+    case QQmlType::CppType:
+        // If attached properties were successfully registered, deregister them.
+        // (They may not have been registered if some other type used the same baseMetaObject)
+        if (extraData.cd->attachedPropertiesType)
+            QQmlMetaType::unregisterAttachedPropertyId(baseMetaObject, index);
+        delete extraData.cd->customParser;
+        delete extraData.cd;
+        break;
+    case QQmlType::SingletonType:
+    case QQmlType::CompositeSingletonType:
+        delete extraData.sd->singletonInstanceInfo;
+        delete extraData.sd;
+        break;
+    case QQmlType::CompositeType:
+        delete extraData.fd;
+        break;
+    default: //Also InterfaceType, because it has no extra data
+        break;
+    }
+}
+
+QQmlType::QQmlType() = default;
+QQmlType::QQmlType(const QQmlType &other) = default;
+QQmlType::QQmlType(QQmlType &&other) = default;
+QQmlType &QQmlType::operator =(const QQmlType &other) = default;
+QQmlType &QQmlType::operator =(QQmlType &&other) = default;
+QQmlType::QQmlType(const QQmlTypePrivate *priv) : d(priv) {}
+QQmlType::~QQmlType() = default;
+
+QHashedString QQmlType::module() const
+{
+    if (!d)
+        return QHashedString();
+    return d->module;
+}
+
+int QQmlType::majorVersion() const
+{
+    if (!d)
+        return -1;
+    return d->version_maj;
+}
+
+int QQmlType::minorVersion() const
+{
+    if (!d)
+        return -1;
+    return d->version_min;
+}
+
+bool QQmlType::availableInVersion(int vmajor, int vminor) const
+{
+    Q_ASSERT(vmajor >= 0 && vminor >= 0);
+    if (!d)
+        return false;
+    return vmajor == d->version_maj && vminor >= d->version_min;
+}
+
+bool QQmlType::availableInVersion(const QHashedStringRef &module, int vmajor, int vminor) const
+{
+    Q_ASSERT(vmajor >= 0 && vminor >= 0);
+    if (!d)
+        return false;
+    return module == d->module && vmajor == d->version_maj && vminor >= d->version_min;
+}
+
+// returns the nearest _registered_ super class
+QQmlType QQmlType::superType() const
+{
+    if (!d)
+        return QQmlType();
+    if (!d->haveSuperType && d->baseMetaObject) {
+        const QMetaObject *mo = d->baseMetaObject->superClass();
+        while (mo && !d->superType.isValid()) {
+            d->superType = QQmlMetaType::qmlType(mo, d->module, d->version_maj, d->version_min);
+            mo = mo->superClass();
+        }
+        d->haveSuperType = true;
+    }
+
+    return d->superType;
+}
+
+QQmlType QQmlType::resolveCompositeBaseType(QQmlEnginePrivate *engine) const
+{
+    Q_ASSERT(isComposite());
+    if (!engine || !d)
+        return QQmlType();
+    QQmlRefPointer<QQmlTypeData> td(engine->typeLoader.getType(sourceUrl()));
+    if (td.isNull() || !td->isComplete())
+        return QQmlType();
+    QV4::CompiledData::CompilationUnit *compilationUnit = td->compilationUnit();
+    const QMetaObject *mo = compilationUnit->rootPropertyCache()->firstCppMetaObject();
+    return QQmlMetaType::qmlType(mo);
+}
+
+QQmlPropertyCache *QQmlType::compositePropertyCache(QQmlEnginePrivate *engine) const
+{
+    // similar logic to resolveCompositeBaseType
+    Q_ASSERT(isComposite());
+    if (!engine)
+        return nullptr;
+    QQmlRefPointer<QQmlTypeData> td(engine->typeLoader.getType(sourceUrl()));
+    if (td.isNull() || !td->isComplete())
+        return nullptr;
+    QV4::CompiledData::CompilationUnit *compilationUnit = td->compilationUnit();
+    return compilationUnit->rootPropertyCache().data();
+}
+
+static bool isPropertyRevisioned(const QMetaObject *mo, int index)
+{
+    int i = index;
+    i -= mo->propertyOffset();
+    if (i < 0 && mo->d.superdata)
+        return isPropertyRevisioned(mo->d.superdata, index);
+
+    const QMetaObjectPrivate *mop = reinterpret_cast<const QMetaObjectPrivate*>(mo->d.data);
+    if (i >= 0 && i < mop->propertyCount) {
+        int handle = mop->propertyData + 3*i;
+        int flags = mo->d.data[handle + 2];
+
+        return (flags & Revisioned);
+    }
+
+    return false;
+}
+
+void QQmlTypePrivate::init() const
+{
+    if (isSetup)
+        return;
+
+    QMutexLocker lock(QQmlMetaType::typeRegistrationLock());
+    if (isSetup)
+        return;
+
+    const QMetaObject *mo = baseMetaObject;
+    if (!mo) {
+        // version 0 singleton type without metaobject information
+        return;
+    }
+
+    if (regType == QQmlType::CppType) {
+        // Setup extended meta object
+        // XXX - very inefficient
+        if (extraData.cd->extFunc) {
+            QMetaObjectBuilder builder;
+            QQmlMetaType::clone(builder, extraData.cd->extMetaObject, extraData.cd->extMetaObject,
+                                extraData.cd->extMetaObject);
+            builder.setFlags(QMetaObjectBuilder::DynamicMetaObject);
+            QMetaObject *mmo = builder.toMetaObject();
+            mmo->d.superdata = mo;
+            QQmlProxyMetaObject::ProxyData data = { mmo, extraData.cd->extFunc, 0, 0 };
+            metaObjects << data;
+        }
+    }
+
+    metaObjects.append(QQmlMetaType::proxyData(
+            mo, baseMetaObject, metaObjects.isEmpty() ? nullptr
+                                                      : metaObjects.constLast().metaObject));
+
+    for (int ii = 0; ii < metaObjects.count(); ++ii) {
+        metaObjects[ii].propertyOffset =
+                metaObjects.at(ii).metaObject->propertyOffset();
+        metaObjects[ii].methodOffset =
+                metaObjects.at(ii).metaObject->methodOffset();
+    }
+
+    // Check for revisioned details
+    {
+        const QMetaObject *mo = nullptr;
+        if (metaObjects.isEmpty())
+            mo = baseMetaObject;
+        else
+            mo = metaObjects.constFirst().metaObject;
+
+        for (int ii = 0; !containsRevisionedAttributes && ii < mo->propertyCount(); ++ii) {
+            if (isPropertyRevisioned(mo, ii))
+                containsRevisionedAttributes = true;
+        }
+
+        for (int ii = 0; !containsRevisionedAttributes && ii < mo->methodCount(); ++ii) {
+            if (mo->method(ii).revision() != 0)
+                containsRevisionedAttributes = true;
+        }
+    }
+
+    isSetup = true;
+    lock.unlock();
+}
+
+void QQmlTypePrivate::initEnums(const QQmlPropertyCache *cache) const
+{
+    if (isEnumSetup) return;
+
+    init();
+
+    QMutexLocker lock(QQmlMetaType::typeRegistrationLock());
+    if (isEnumSetup) return;
+
+    if (cache)
+        insertEnumsFromPropertyCache(cache);
+    if (baseMetaObject) // could be singleton type without metaobject
+        insertEnums(baseMetaObject);
+
+    isEnumSetup = true;
+}
+
+void QQmlTypePrivate::insertEnums(const QMetaObject *metaObject) const
+{
+    // Add any enum values defined by 'related' classes
+    if (metaObject->d.relatedMetaObjects) {
+        const auto *related = metaObject->d.relatedMetaObjects;
+        if (related) {
+            while (*related)
+                insertEnums(*related++);
+        }
+    }
+
+    QSet<QString> localEnums;
+    const QMetaObject *localMetaObject = nullptr;
+
+    // Add any enum values defined by this class, overwriting any inherited values
+    for (int ii = 0; ii < metaObject->enumeratorCount(); ++ii) {
+        QMetaEnum e = metaObject->enumerator(ii);
+        const bool isScoped = e.isScoped();
+        QStringHash<int> *scoped = isScoped ? new QStringHash<int>() : nullptr;
+
+    // We allow enums in sub-classes to overwrite enums from base-classes, such as
+    // ListView.Center (from enum PositionMode) overwriting Item.Center (from enum TransformOrigin).
+    // This is acceptable because the _use_ of the enum from the QML side requires qualification
+    // anyway, i.e. ListView.Center vs. Item.Center.
+        // However if a class defines two enums with the same value, then that must produce a warning
+        // because it represents a valid conflict.
+        if (e.enclosingMetaObject() != localMetaObject) {
+            localEnums.clear();
+            localMetaObject = e.enclosingMetaObject();
+        }
+
+        for (int jj = 0; jj < e.keyCount(); ++jj) {
+            const QString key = QString::fromUtf8(e.key(jj));
+            const int value = e.value(jj);
+            if (!isScoped || (regType == QQmlType::CppType && extraData.cd->registerEnumClassesUnscoped)) {
+                if (localEnums.contains(key)) {
+                    auto existingEntry = enums.find(key);
+                    if (existingEntry != enums.end() && existingEntry.value() != value) {
+                        qWarning("Previously registered enum will be overwritten due to name clash: %s.%s", metaObject->className(), key.toUtf8().constData());
+                        createEnumConflictReport(metaObject, key);
+                    }
+                } else {
+                    localEnums.insert(key);
+                }
+                enums.insert(key, value);
+            }
+            if (isScoped)
+                scoped->insert(key, value);
+        }
+
+        if (isScoped) {
+            scopedEnums << scoped;
+            scopedEnumIndex.insert(QString::fromUtf8(e.name()), scopedEnums.count()-1);
+        }
+    }
+}
+
+void QQmlTypePrivate::createListOfPossibleConflictingItems(const QMetaObject *metaObject, QList<EnumInfo> &enumInfoList, QStringList path) const
+{
+    path.append(QString::fromUtf8(metaObject->className()));
+
+    if (metaObject->d.relatedMetaObjects) {
+        const auto *related = metaObject->d.relatedMetaObjects;
+        if (related) {
+            while (*related)
+                createListOfPossibleConflictingItems(*related++, enumInfoList, path);
+        }
+    }
+
+    for (int ii = 0; ii < metaObject->enumeratorCount(); ++ii) {
+        const auto e = metaObject->enumerator(ii);
+
+        for (int jj = 0; jj < e.keyCount(); ++jj) {
+            const QString key = QString::fromUtf8(e.key(jj));
+
+            EnumInfo enumInfo;
+            enumInfo.metaObjectName = QString::fromUtf8(metaObject->className());
+            enumInfo.enumName = QString::fromUtf8(e.name());
+            enumInfo.enumKey = key;
+            enumInfo.scoped = e.isScoped();
+            enumInfo.path = path;
+            enumInfo.metaEnumScope = QString::fromUtf8(e.scope());
+            enumInfoList.append(enumInfo);
+        }
+    }
+}
+
+void QQmlTypePrivate::createEnumConflictReport(const QMetaObject *metaObject, const QString &conflictingKey) const
+{
+    QList<EnumInfo> enumInfoList;
+
+    if (baseMetaObject) // prefer baseMetaObject if available
+        metaObject = baseMetaObject;
+
+    if (!metaObject) { // If there is no metaObject at all return early
+        qWarning() << "No meta object information available. Skipping conflict analysis.";
+        return;
+    }
+
+    createListOfPossibleConflictingItems(metaObject, enumInfoList, QStringList());
+
+    qWarning().noquote() << QLatin1String("Possible conflicting items:");
+    // find items with conflicting key
+    for (const auto i : enumInfoList) {
+        if (i.enumKey == conflictingKey)
+        qWarning().noquote().nospace() << "    " << i.metaObjectName << "." << i.enumName << "." << i.enumKey << " from scope "
+                                           << i.metaEnumScope << " injected by " << i.path.join(QLatin1String("->"));
+    }
+}
+
+void QQmlTypePrivate::insertEnumsFromPropertyCache(const QQmlPropertyCache *cache) const
+{
+    const QMetaObject *cppMetaObject = cache->firstCppMetaObject();
+
+    while (cache && cache->metaObject() != cppMetaObject) {
+
+        int count = cache->qmlEnumCount();
+        for (int ii = 0; ii < count; ++ii) {
+            QStringHash<int> *scoped = new QStringHash<int>();
+            QQmlEnumData *enumData = cache->qmlEnum(ii);
+
+            for (int jj = 0; jj < enumData->values.count(); ++jj) {
+                const QQmlEnumValue &value = enumData->values.at(jj);
+                enums.insert(value.namedValue, value.value);
+                scoped->insert(value.namedValue, value.value);
+            }
+            scopedEnums << scoped;
+            scopedEnumIndex.insert(enumData->name, scopedEnums.count()-1);
+        }
+        cache = cache->parent();
+    }
+    insertEnums(cppMetaObject);
+}
+
+void QQmlTypePrivate::setName(const QString &uri, const QString &element)
+{
+    module = uri;
+    elementName = element;
+    name = uri.isEmpty() ? element : (uri + QLatin1Char('/') + element);
+}
+
+QQmlPropertyCache *QQmlTypePrivate::propertyCacheForMinorVersion(int minorVersion) const
+{
+    for (int i = 0; i < propertyCaches.count(); ++i)
+        if (propertyCaches.at(i).minorVersion == minorVersion)
+            return propertyCaches.at(i).cache.data();
+    return nullptr;
+}
+
+void QQmlTypePrivate::setPropertyCacheForMinorVersion(int minorVersion, QQmlPropertyCache *cache)
+{
+    for (int i = 0; i < propertyCaches.count(); ++i) {
+        if (propertyCaches.at(i).minorVersion == minorVersion) {
+            propertyCaches[i].cache = cache;
+            return;
+        }
+    }
+    propertyCaches.append(PropertyCacheByMinorVersion(cache, minorVersion));
+}
+
+QByteArray QQmlType::typeName() const
+{
+    if (d) {
+        if (d->regType == SingletonType || d->regType == CompositeSingletonType)
+            return d->extraData.sd->singletonInstanceInfo->typeName.toUtf8();
+        else if (d->baseMetaObject)
+            return d->baseMetaObject->className();
+    }
+    return QByteArray();
+}
+
+QString QQmlType::elementName() const
+{
+    if (!d)
+        return QString();
+    return d->elementName;
+}
+
+QString QQmlType::qmlTypeName() const
+{
+    if (!d)
+        return QString();
+    return d->name;
+}
+
+QObject *QQmlType::create() const
+{
+    if (!d || !isCreatable())
+        return nullptr;
+
+    d->init();
+
+    QObject *rv = (QObject *)operator new(d->extraData.cd->allocationSize);
+    d->extraData.cd->newFunc(rv);
+
+    if (rv && !d->metaObjects.isEmpty())
+        (void)new QQmlProxyMetaObject(rv, &d->metaObjects);
+
+    return rv;
+}
+
+void QQmlType::create(QObject **out, void **memory, size_t additionalMemory) const
+{
+    if (!d || !isCreatable())
+        return;
+
+    d->init();
+
+    QObject *rv = (QObject *)operator new(d->extraData.cd->allocationSize + additionalMemory);
+    d->extraData.cd->newFunc(rv);
+
+    if (rv && !d->metaObjects.isEmpty())
+        (void)new QQmlProxyMetaObject(rv, &d->metaObjects);
+
+    *out = rv;
+    *memory = ((char *)rv) + d->extraData.cd->allocationSize;
+}
+
+QQmlType::SingletonInstanceInfo *QQmlType::singletonInstanceInfo() const
+{
+    if (!d)
+        return nullptr;
+    if (d->regType != SingletonType && d->regType != CompositeSingletonType)
+        return nullptr;
+    return d->extraData.sd->singletonInstanceInfo;
+}
+
+QQmlCustomParser *QQmlType::customParser() const
+{
+    if (!d)
+        return nullptr;
+    if (d->regType != CppType)
+        return nullptr;
+    return d->extraData.cd->customParser;
+}
+
+QQmlType::CreateFunc QQmlType::createFunction() const
+{
+    if (!d || d->regType != CppType)
+        return nullptr;
+    return d->extraData.cd->newFunc;
+}
+
+QString QQmlType::noCreationReason() const
+{
+    if (!d || d->regType != CppType)
+        return QString();
+    return d->extraData.cd->noCreationReason;
+}
+
+bool QQmlType::isCreatable() const
+{
+    return d && d->regType == CppType && d->extraData.cd->newFunc;
+}
+
+QQmlType::ExtensionFunc QQmlType::extensionFunction() const
+{
+    if (!d || d->regType != CppType)
+        return nullptr;
+    return d->extraData.cd->extFunc;
+}
+
+bool QQmlType::isExtendedType() const
+{
+    if (!d)
+        return false;
+    d->init();
+
+    return !d->metaObjects.isEmpty();
+}
+
+bool QQmlType::isSingleton() const
+{
+    return d && (d->regType == SingletonType || d->regType == CompositeSingletonType);
+}
+
+bool QQmlType::isInterface() const
+{
+    return d && d->regType == InterfaceType;
+}
+
+bool QQmlType::isComposite() const
+{
+    return d && (d->regType == CompositeType || d->regType == CompositeSingletonType);
+}
+
+bool QQmlType::isCompositeSingleton() const
+{
+    return d && d->regType == CompositeSingletonType;
+}
+
+int QQmlType::typeId() const
+{
+    return d ? d->typeId : -1;
+}
+
+int QQmlType::qListTypeId() const
+{
+    return d ? d->listId : -1;
+}
+
+const QMetaObject *QQmlType::metaObject() const
+{
+    if (!d)
+        return nullptr;
+    d->init();
+
+    if (d->metaObjects.isEmpty())
+        return d->baseMetaObject;
+    else
+        return d->metaObjects.constFirst().metaObject;
+
+}
+
+const QMetaObject *QQmlType::baseMetaObject() const
+{
+    return d ? d->baseMetaObject : nullptr;
+}
+
+bool QQmlType::containsRevisionedAttributes() const
+{
+    if (!d)
+        return false;
+    d->init();
+
+    return d->containsRevisionedAttributes;
+}
+
+int QQmlType::metaObjectRevision() const
+{
+    return d ? d->revision : -1;
+}
+
+QQmlAttachedPropertiesFunc QQmlType::attachedPropertiesFunction(QQmlEnginePrivate *engine) const
+{
+    if (!d)
+        return nullptr;
+    if (d->regType == CppType)
+        return d->extraData.cd->attachedPropertiesFunc;
+
+    QQmlType base;
+    if (d->regType == CompositeType)
+        base = resolveCompositeBaseType(engine);
+    return base.attachedPropertiesFunction(engine);
+}
+
+const QMetaObject *QQmlType::attachedPropertiesType(QQmlEnginePrivate *engine) const
+{
+    if (!d)
+        return nullptr;
+    if (d->regType == CppType)
+        return d->extraData.cd->attachedPropertiesType;
+
+    QQmlType base;
+    if (d->regType == CompositeType)
+        base = resolveCompositeBaseType(engine);
+    return base.attachedPropertiesType(engine);
+}
+
+/*
+This is the id passed to qmlAttachedPropertiesById().  This is different from the index
+for the case that a single class is registered under two or more names (eg. Item in
+Qt 4.7 and QtQuick 1.0).
+*/
+int QQmlType::attachedPropertiesId(QQmlEnginePrivate *engine) const
+{
+    if (!d)
+        return -1;
+    if (d->regType == CppType)
+        return d->extraData.cd->attachedPropertiesId;
+
+    QQmlType base;
+    if (d->regType == CompositeType)
+        base = resolveCompositeBaseType(engine);
+    return base.attachedPropertiesId(engine);
+}
+
+int QQmlType::parserStatusCast() const
+{
+    if (!d || d->regType != CppType)
+        return -1;
+    return d->extraData.cd->parserStatusCast;
+}
+
+int QQmlType::propertyValueSourceCast() const
+{
+    if (!d || d->regType != CppType)
+        return -1;
+    return d->extraData.cd->propertyValueSourceCast;
+}
+
+int QQmlType::propertyValueInterceptorCast() const
+{
+    if (!d || d->regType != CppType)
+        return -1;
+    return d->extraData.cd->propertyValueInterceptorCast;
+}
+
+const char *QQmlType::interfaceIId() const
+{
+    if (!d || d->regType != InterfaceType)
+        return nullptr;
+    return d->iid;
+}
+
+int QQmlType::index() const
+{
+    return d ? d->index : -1;
+}
+
+QUrl QQmlType::sourceUrl() const
+{
+    if (d) {
+        if (d->regType == CompositeType)
+            return d->extraData.fd->url;
+        else if (d->regType == CompositeSingletonType)
+            return d->extraData.sd->singletonInstanceInfo->url;
+    }
+    return QUrl();
+}
+
+int QQmlType::enumValue(QQmlEnginePrivate *engine, const QHashedStringRef &name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->enums.value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::enumValue(QQmlEnginePrivate *engine, const QHashedCStringRef &name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->enums.value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::enumValue(QQmlEnginePrivate *engine, const QV4::String *name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->enums.value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::scopedEnumIndex(QQmlEnginePrivate *engine, const QV4::String *name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->scopedEnumIndex.value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::scopedEnumIndex(QQmlEnginePrivate *engine, const QString &name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->scopedEnumIndex.value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, int index, const QV4::String *name, bool *ok) const
+{
+    Q_UNUSED(engine)
+    Q_ASSERT(ok);
+    *ok = true;
+
+    if (d) {
+        Q_ASSERT(index > -1 && index < d->scopedEnums.count());
+        int *rv = d->scopedEnums.at(index)->value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &name, bool *ok) const
+{
+    Q_UNUSED(engine)
+    Q_ASSERT(ok);
+    *ok = true;
+
+    if (d) {
+        Q_ASSERT(index > -1 && index < d->scopedEnums.count());
+        int *rv = d->scopedEnums.at(index)->value(name);
+        if (rv)
+            return *rv;
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &scopedEnumName, const QByteArray &name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->scopedEnumIndex.value(QHashedCStringRef(scopedEnumName.constData(), scopedEnumName.length()));
+        if (rv) {
+            int index = *rv;
+            Q_ASSERT(index > -1 && index < d->scopedEnums.count());
+            rv = d->scopedEnums.at(index)->value(QHashedCStringRef(name.constData(), name.length()));
+            if (rv)
+                return *rv;
+        }
+    }
+
+    *ok = false;
+    return -1;
+}
+
+int QQmlType::scopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &scopedEnumName, const QStringRef &name, bool *ok) const
+{
+    Q_ASSERT(ok);
+    if (d) {
+        const QQmlPropertyCache *cache = isComposite() ? compositePropertyCache(engine) : nullptr;
+        *ok = true;
+
+        d->initEnums(cache);
+
+        int *rv = d->scopedEnumIndex.value(QHashedStringRef(scopedEnumName));
+        if (rv) {
+            int index = *rv;
+            Q_ASSERT(index > -1 && index < d->scopedEnums.count());
+            rv = d->scopedEnums.at(index)->value(QHashedStringRef(name));
+            if (rv)
+                return *rv;
+        }
+    }
+
+    *ok = false;
+    return -1;
+}
+
+void QQmlType::refHandle(const QQmlTypePrivate *priv)
+{
+    if (priv)
+        priv->addref();
+}
+
+void QQmlType::derefHandle(const QQmlTypePrivate *priv)
+{
+    if (priv)
+        priv->release();
+}
+
+int QQmlType::refCount(const QQmlTypePrivate *priv)
+{
+    if (priv)
+        return priv->count();
+    return -1;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltype_p.h b/src/qml/qml/qqmltype_p.h
new file mode 100644
index 0000000000..1d1345a0cb
--- /dev/null
+++ b/src/qml/qml/qqmltype_p.h
@@ -0,0 +1,211 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTYPE_P_H
+#define QQMLTYPE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qtqmlglobal_p.h>
+#include <private/qqmlrefcount_p.h>
+
+#include <QtQml/qqmlprivate.h>
+#include <QtQml/qjsvalue.h>
+
+#include <QtCore/qobject.h>
+
+QT_BEGIN_NAMESPACE
+
+class QHashedCStringRef;
+class QQmlTypePrivate;
+class QHashedString;
+class QHashedStringRef;
+class QQmlCustomParser;
+class QQmlEnginePrivate;
+class QQmlPropertyCache;
+
+namespace QV4 {
+struct String;
+}
+
+class Q_QML_PRIVATE_EXPORT QQmlType
+{
+public:
+    QQmlType();
+    QQmlType(const QQmlType &other);
+    QQmlType(QQmlType &&other);
+    QQmlType &operator =(const QQmlType &other);
+    QQmlType &operator =(QQmlType &&other);
+    explicit QQmlType(const QQmlTypePrivate *priv);
+    ~QQmlType();
+
+    bool operator ==(const QQmlType &other) const {
+        return d.data() == other.d.data();
+    }
+
+    bool isValid() const { return !d.isNull(); }
+    const QQmlTypePrivate *key() const { return d.data(); }
+
+    QByteArray typeName() const;
+    QString qmlTypeName() const;
+    QString elementName() const;
+
+    QHashedString module() const;
+    int majorVersion() const;
+    int minorVersion() const;
+
+    bool availableInVersion(int vmajor, int vminor) const;
+    bool availableInVersion(const QHashedStringRef &module, int vmajor, int vminor) const;
+
+    QObject *create() const;
+    void create(QObject **, void **, size_t) const;
+
+    typedef void (*CreateFunc)(void *);
+    CreateFunc createFunction() const;
+    QQmlCustomParser *customParser() const;
+
+    bool isCreatable() const;
+    typedef QObject *(*ExtensionFunc)(QObject *);
+    ExtensionFunc extensionFunction() const;
+    bool isExtendedType() const;
+    QString noCreationReason() const;
+
+    bool isSingleton() const;
+    bool isInterface() const;
+    bool isComposite() const;
+    bool isCompositeSingleton() const;
+
+    int typeId() const;
+    int qListTypeId() const;
+
+    const QMetaObject *metaObject() const;
+    const QMetaObject *baseMetaObject() const;
+    int metaObjectRevision() const;
+    bool containsRevisionedAttributes() const;
+
+    QQmlAttachedPropertiesFunc attachedPropertiesFunction(QQmlEnginePrivate *engine) const;
+    const QMetaObject *attachedPropertiesType(QQmlEnginePrivate *engine) const;
+    int attachedPropertiesId(QQmlEnginePrivate *engine) const;
+
+    int parserStatusCast() const;
+    const char *interfaceIId() const;
+    int propertyValueSourceCast() const;
+    int propertyValueInterceptorCast() const;
+
+    int index() const;
+
+    class Q_QML_PRIVATE_EXPORT SingletonInstanceInfo
+    {
+    public:
+        SingletonInstanceInfo()
+            : scriptCallback(nullptr), qobjectCallback(nullptr), instanceMetaObject(nullptr) {}
+
+        QJSValue (*scriptCallback)(QQmlEngine *, QJSEngine *);
+        QObject *(*qobjectCallback)(QQmlEngine *, QJSEngine *);
+        const QMetaObject *instanceMetaObject;
+        QString typeName;
+        QUrl url; // used by composite singletons
+
+        void setQObjectApi(QQmlEngine *, QObject *);
+        QObject *qobjectApi(QQmlEngine *) const;
+        void setScriptApi(QQmlEngine *, const QJSValue &);
+        QJSValue scriptApi(QQmlEngine *) const;
+
+        void init(QQmlEngine *);
+        void destroy(QQmlEngine *);
+
+        QHash<QQmlEngine *, QJSValue> scriptApis;
+        QHash<QQmlEngine *, QObject *> qobjectApis;
+    };
+    SingletonInstanceInfo *singletonInstanceInfo() const;
+
+    QUrl sourceUrl() const;
+
+    int enumValue(QQmlEnginePrivate *engine, const QHashedStringRef &, bool *ok) const;
+    int enumValue(QQmlEnginePrivate *engine, const QHashedCStringRef &, bool *ok) const;
+    int enumValue(QQmlEnginePrivate *engine, const QV4::String *, bool *ok) const;
+
+    int scopedEnumIndex(QQmlEnginePrivate *engine, const QV4::String *, bool *ok) const;
+    int scopedEnumIndex(QQmlEnginePrivate *engine, const QString &, bool *ok) const;
+    int scopedEnumValue(QQmlEnginePrivate *engine, int index, const QV4::String *, bool *ok) const;
+    int scopedEnumValue(QQmlEnginePrivate *engine, int index, const QString &, bool *ok) const;
+    int scopedEnumValue(QQmlEnginePrivate *engine, const QByteArray &, const QByteArray &, bool *ok) const;
+    int scopedEnumValue(QQmlEnginePrivate *engine, const QStringRef &, const QStringRef &, bool *ok) const;
+
+    const QQmlTypePrivate *priv() const { return d.data(); }
+    static void refHandle(const QQmlTypePrivate *priv);
+    static void derefHandle(const QQmlTypePrivate *priv);
+    static int refCount(const QQmlTypePrivate *priv);
+
+    enum RegistrationType {
+        CppType = 0,
+        SingletonType = 1,
+        InterfaceType = 2,
+        CompositeType = 3,
+        CompositeSingletonType = 4,
+        AnyRegistrationType = 255
+    };
+
+private:
+    QQmlType superType() const;
+    QQmlType resolveCompositeBaseType(QQmlEnginePrivate *engine) const;
+    int resolveCompositeEnumValue(QQmlEnginePrivate *engine, const QString &name, bool *ok) const;
+    QQmlPropertyCache *compositePropertyCache(QQmlEnginePrivate *engine) const;
+    friend uint qHash(const QQmlType &t, uint seed);
+
+    QQmlRefPointer<const QQmlTypePrivate> d;
+};
+
+inline uint qHash(const QQmlType &t, uint seed = 0)
+{
+    return qHash(reinterpret_cast<quintptr>(t.d.data()), seed);
+}
+
+QT_END_NAMESPACE
+
+#endif // QQMLTYPE_P_H
diff --git a/src/qml/qml/qqmltype_p_p.h b/src/qml/qml/qqmltype_p_p.h
new file mode 100644
index 0000000000..380139f385
--- /dev/null
+++ b/src/qml/qml/qqmltype_p_p.h
@@ -0,0 +1,161 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTYPE_P_P_H
+#define QQMLTYPE_P_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmltype_p.h>
+#include <private/qstringhash_p.h>
+#include <private/qqmlproxymetaobject_p.h>
+#include <private/qqmlrefcount_p.h>
+#include <private/qqmlpropertycache_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlTypePrivate : public QQmlRefCount
+{
+    Q_DISABLE_COPY_MOVE(QQmlTypePrivate)
+public:
+    QQmlTypePrivate(QQmlType::RegistrationType type);
+
+    void init() const;
+    void initEnums(const QQmlPropertyCache *cache = nullptr) const;
+    void insertEnums(const QMetaObject *metaObject) const;
+    void insertEnumsFromPropertyCache(const QQmlPropertyCache *cache) const;
+
+    QQmlType::RegistrationType regType;
+
+    struct QQmlCppTypeData
+    {
+        int allocationSize;
+        void (*newFunc)(void *);
+        QString noCreationReason;
+        int parserStatusCast;
+        QObject *(*extFunc)(QObject *);
+        const QMetaObject *extMetaObject;
+        QQmlCustomParser *customParser;
+        QQmlAttachedPropertiesFunc attachedPropertiesFunc;
+        const QMetaObject *attachedPropertiesType;
+        int attachedPropertiesId;
+        int propertyValueSourceCast;
+        int propertyValueInterceptorCast;
+        bool registerEnumClassesUnscoped;
+    };
+
+    struct QQmlSingletonTypeData
+    {
+        QQmlType::SingletonInstanceInfo *singletonInstanceInfo;
+    };
+
+    struct QQmlCompositeTypeData
+    {
+        QUrl url;
+    };
+
+    union extraData {
+        QQmlCppTypeData* cd;
+        QQmlSingletonTypeData* sd;
+        QQmlCompositeTypeData* fd;
+    } extraData;
+
+    const char *iid;
+    QHashedString module;
+    QString name;
+    QString elementName;
+    int version_maj;
+    int version_min;
+    int typeId;
+    int listId;
+    int revision;
+    mutable bool containsRevisionedAttributes;
+    mutable QQmlType superType;
+    const QMetaObject *baseMetaObject;
+
+    int index;
+    mutable volatile bool isSetup:1;
+    mutable volatile bool isEnumSetup:1;
+    mutable bool haveSuperType:1;
+    mutable QList<QQmlProxyMetaObject::ProxyData> metaObjects;
+    mutable QStringHash<int> enums;
+    mutable QStringHash<int> scopedEnumIndex; // maps from enum name to index in scopedEnums
+    mutable QList<QStringHash<int>*> scopedEnums;
+
+    struct PropertyCacheByMinorVersion
+    {
+        PropertyCacheByMinorVersion() : cache(nullptr), minorVersion(-1) {}
+        explicit PropertyCacheByMinorVersion(QQmlPropertyCache *pc, int ver) : cache(pc), minorVersion(ver) {}
+        QQmlPropertyCachePtr cache;
+        int minorVersion;
+    };
+    QVector<PropertyCacheByMinorVersion> propertyCaches;
+    QQmlPropertyCache *propertyCacheForMinorVersion(int minorVersion) const;
+    void setPropertyCacheForMinorVersion(int minorVersion, QQmlPropertyCache *cache);
+
+    void setName(const QString &uri, const QString &element);
+
+private:
+    ~QQmlTypePrivate() override;
+
+    struct EnumInfo {
+        QStringList path;
+        QString metaObjectName;
+        QString enumName;
+        QString enumKey;
+        QString metaEnumScope;
+        bool scoped;
+    };
+
+    void createListOfPossibleConflictingItems(const QMetaObject *metaObject, QList<EnumInfo> &enumInfoList, QStringList path) const;
+    void createEnumConflictReport(const QMetaObject *metaObject, const QString &conflictingKey) const;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLTYPE_P_P_H
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index e4293596d8..457558fb56 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -44,13 +44,14 @@
 #include <private/qqmlengine_p.h>
 #include <private/qqmlglobal_p.h>
 #include <private/qqmlthread_p.h>
+#include <private/qv4codegen_p.h>
 #include <private/qqmlcomponent_p.h>
 #include <private/qqmlprofiler_p.h>
 #include <private/qqmlmemoryprofiler_p.h>
 #include <private/qqmltypecompiler_p.h>
 #include <private/qqmlpropertyvalidator_p.h>
 #include <private/qqmlpropertycachecreator_p.h>
-#include <private/qdeferredcleanup_p.h>
+#include <private/qv4module_p.h>
 
 #include <QtCore/qdir.h>
 #include <QtCore/qfile.h>
@@ -65,6 +66,7 @@
 #include <QtCore/qloggingcategory.h>
 #include <QtQml/qqmlextensioninterface.h>
 #include <QtCore/qcryptographichash.h>
+#include <QtCore/qscopeguard.h>
 
 #include <functional>
 
@@ -155,8 +157,8 @@ public:
     void loadAsync(QQmlDataBlob *b);
     void loadWithStaticData(QQmlDataBlob *b, const QByteArray &);
     void loadWithStaticDataAsync(QQmlDataBlob *b, const QByteArray &);
-    void loadWithCachedUnit(QQmlDataBlob *b, const QQmlPrivate::CachedQmlUnit *unit);
-    void loadWithCachedUnitAsync(QQmlDataBlob *b, const QQmlPrivate::CachedQmlUnit *unit);
+    void loadWithCachedUnit(QQmlDataBlob *b, const QV4::CompiledData::Unit *unit);
+    void loadWithCachedUnitAsync(QQmlDataBlob *b, const QV4::CompiledData::Unit *unit);
     void callCompleted(QQmlDataBlob *b);
     void callDownloadProgressChanged(QQmlDataBlob *b, qreal p);
     void initializeEngine(QQmlExtensionInterface *, const char *);
@@ -167,7 +169,7 @@ protected:
 private:
     void loadThread(QQmlDataBlob *b);
     void loadWithStaticDataThread(QQmlDataBlob *b, const QByteArray &);
-    void loadWithCachedUnitThread(QQmlDataBlob *b, const QQmlPrivate::CachedQmlUnit *unit);
+    void loadWithCachedUnitThread(QQmlDataBlob *b, const QV4::CompiledData::Unit *unit);
     void callCompletedMain(QQmlDataBlob *b);
     void callDownloadProgressChangedMain(QQmlDataBlob *b, qreal p);
     void initializeEngineMain(QQmlExtensionInterface *iface, const char *uri);
@@ -316,7 +318,8 @@ Returns true if the status is WaitingForDependencies.
 */
 bool QQmlDataBlob::isWaiting() const
 {
-    return status() == WaitingForDependencies;
+    return status() == WaitingForDependencies ||
+            status() == ResolvingDependencies;
 }
 
 /*!
@@ -355,8 +358,9 @@ qreal QQmlDataBlob::progress() const
 }
 
 /*!
-Returns the blob url passed to the constructor.  If a network redirect
-happens while fetching the data, this url remains the same.
+Returns the physical url of the data.  Initially this is the same as
+finalUrl(), but if a URL interceptor is set, it will work on this URL
+and leave finalUrl() alone.
 
 \sa finalUrl()
 */
@@ -365,16 +369,29 @@ QUrl QQmlDataBlob::url() const
     return m_url;
 }
 
+QString QQmlDataBlob::urlString() const
+{
+    if (m_urlString.isEmpty())
+        m_urlString = m_url.toString();
+
+    return m_urlString;
+}
+
 /*!
-Returns the final url of the data.  Initially this is the same as
-url(), but if a network redirect happens while fetching the data, this url
-is updated to reflect the new location.
+Returns the logical URL to be used for resolving further URLs referred to in
+the code.
 
-May only be called from the load thread, or after the blob isCompleteOrError().
+This is the blob url passed to the constructor. If a URL interceptor rewrites
+the URL, this one stays the same. If a network redirect happens while fetching
+the data, this url is updated to reflect the new location. Therefore, if both
+an interception and a redirection happen, the final url will indirectly
+incorporate the result of the interception, potentially breaking further
+lookups.
+
+\sa url()
 */
 QUrl QQmlDataBlob::finalUrl() const
 {
-    Q_ASSERT(isCompleteOrError() || (m_typeLoader && m_typeLoader->m_thread->isThisThread()));
     return m_finalUrl;
 }
 
@@ -383,7 +400,6 @@ Returns the finalUrl() as a string.
 */
 QString QQmlDataBlob::finalUrlString() const
 {
-    Q_ASSERT(isCompleteOrError() || (m_typeLoader && m_typeLoader->m_thread->isThisThread()));
     if (m_finalUrlString.isEmpty())
         m_finalUrlString = m_finalUrl.toString();
 
@@ -432,7 +448,7 @@ void QQmlDataBlob::setError(const QList<QQmlError> &errors)
     m_data.setStatus(Error);
 
     if (dumpErrors()) {
-        qWarning().nospace() << "Errors for " << m_finalUrl.toString();
+        qWarning().nospace() << "Errors for " << urlString();
         for (int ii = 0; ii < errors.count(); ++ii)
             qWarning().nospace() << "    " << qPrintable(errors.at(ii).toString());
     }
@@ -471,7 +487,7 @@ void QQmlDataBlob::setError(const QString &description)
 {
     QQmlError e;
     e.setDescription(description);
-    e.setUrl(finalUrl());
+    e.setUrl(url());
     setError(e);
 }
 
@@ -489,11 +505,12 @@ void QQmlDataBlob::addDependency(QQmlDataBlob *blob)
 
     if (!blob ||
         blob->status() == Error || blob->status() == Complete ||
-        status() == Error || status() == Complete || m_isDone ||
-        m_waitingFor.contains(blob))
+        status() == Error || status() == Complete || m_isDone)
         return;
 
-    blob->addref();
+    for (auto existingDep: qAsConst(m_waitingFor))
+        if (existingDep.data() == blob)
+            return;
 
     m_data.setStatus(WaitingForDependencies);
 
@@ -536,9 +553,9 @@ void QQmlDataBlob::networkError(QNetworkReply::NetworkError networkError)
     Q_UNUSED(networkError);
 
     QQmlError error;
-    error.setUrl(m_finalUrl);
+    error.setUrl(m_url);
 
-    const char *errorString = 0;
+    const char *errorString = nullptr;
     switch (networkError) {
         default:
             errorString = "Network error";
@@ -608,6 +625,7 @@ The default implementation does nothing.
 */
 void QQmlDataBlob::allDependenciesDone()
 {
+    m_data.setStatus(QQmlDataBlob::ResolvingDependencies);
 }
 
 /*!
@@ -652,7 +670,7 @@ void QQmlDataBlob::tryDone()
         addref();
 
 #ifdef DATABLOB_DEBUG
-        qWarning("QQmlDataBlob::done() %s", qPrintable(url().toString()));
+        qWarning("QQmlDataBlob::done() %s", qPrintable(urlString()));
 #endif
         done();
 
@@ -675,13 +693,11 @@ void QQmlDataBlob::tryDone()
 void QQmlDataBlob::cancelAllWaitingFor()
 {
     while (m_waitingFor.count()) {
-        QQmlDataBlob *blob = m_waitingFor.takeLast();
+        QQmlRefPointer<QQmlDataBlob> blob = m_waitingFor.takeLast();
 
         Q_ASSERT(blob->m_waitingOnMe.contains(this));
 
         blob->m_waitingOnMe.removeOne(this);
-
-        blob->release();
     }
 }
 
@@ -690,7 +706,8 @@ void QQmlDataBlob::notifyAllWaitingOnMe()
     while (m_waitingOnMe.count()) {
         QQmlDataBlob *blob = m_waitingOnMe.takeLast();
 
-        Q_ASSERT(blob->m_waitingFor.contains(this));
+        Q_ASSERT(std::any_of(blob->m_waitingFor.constBegin(), blob->m_waitingFor.constEnd(),
+                             [this](const QQmlRefPointer<QQmlDataBlob> &waiting) { return waiting.data() == this; }));
 
         blob->notifyComplete(this);
     }
@@ -698,14 +715,19 @@ void QQmlDataBlob::notifyAllWaitingOnMe()
 
 void QQmlDataBlob::notifyComplete(QQmlDataBlob *blob)
 {
-    Q_ASSERT(m_waitingFor.contains(blob));
     Q_ASSERT(blob->status() == Error || blob->status() == Complete);
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(typeLoader()->engine())->profiler,
-                               blob);
+    QQmlCompilingProfiler prof(typeLoader()->profiler(), blob);
 
     m_inCallback = true;
 
-    m_waitingFor.removeOne(blob);
+    QQmlRefPointer<QQmlDataBlob> blobRef;
+    for (int i = 0; i < m_waitingFor.count(); ++i) {
+        if (m_waitingFor.at(i).data() == blob) {
+            blobRef = m_waitingFor.takeAt(i);
+            break;
+        }
+    }
+    Q_ASSERT(blobRef);
 
     if (blob->status() == Error) {
         dependencyError(blob);
@@ -713,8 +735,6 @@ void QQmlDataBlob::notifyComplete(QQmlDataBlob *blob)
         dependencyComplete(blob);
     }
 
-    blob->release();
-
     if (!isError() && m_waitingFor.isEmpty())
         allDependenciesDone();
 
@@ -779,7 +799,7 @@ void QQmlDataBlob::ThreadData::setProgress(quint8 v)
 QQmlTypeLoaderThread::QQmlTypeLoaderThread(QQmlTypeLoader *loader)
 : m_loader(loader)
 #if QT_CONFIG(qml_network)
-, m_networkAccessManager(0), m_networkReplyProxy(0)
+, m_networkAccessManager(nullptr), m_networkReplyProxy(nullptr)
 #endif // qml_network
 {
     // Do that after initializing all the members.
@@ -791,7 +811,7 @@ QNetworkAccessManager *QQmlTypeLoaderThread::networkAccessManager() const
 {
     Q_ASSERT(isThisThread());
     if (!m_networkAccessManager) {
-        m_networkAccessManager = QQmlEnginePrivate::get(m_loader->engine())->createNetworkAccessManager(0);
+        m_networkAccessManager = QQmlEnginePrivate::get(m_loader->engine())->createNetworkAccessManager(nullptr);
         m_networkReplyProxy = new QQmlTypeLoaderNetworkReplyProxy(m_loader);
     }
 
@@ -830,13 +850,13 @@ void QQmlTypeLoaderThread::loadWithStaticDataAsync(QQmlDataBlob *b, const QByteA
     postMethodToThread(&This::loadWithStaticDataThread, b, d);
 }
 
-void QQmlTypeLoaderThread::loadWithCachedUnit(QQmlDataBlob *b, const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlTypeLoaderThread::loadWithCachedUnit(QQmlDataBlob *b, const QV4::CompiledData::Unit *unit)
 {
     b->addref();
     callMethodInThread(&This::loadWithCachedUnitThread, b, unit);
 }
 
-void QQmlTypeLoaderThread::loadWithCachedUnitAsync(QQmlDataBlob *b, const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlTypeLoaderThread::loadWithCachedUnitAsync(QQmlDataBlob *b, const QV4::CompiledData::Unit *unit)
 {
     b->addref();
     postMethodToThread(&This::loadWithCachedUnitThread, b, unit);
@@ -845,13 +865,23 @@ void QQmlTypeLoaderThread::loadWithCachedUnitAsync(QQmlDataBlob *b, const QQmlPr
 void QQmlTypeLoaderThread::callCompleted(QQmlDataBlob *b)
 {
     b->addref();
+#if !QT_CONFIG(thread)
+    if (!isThisThread())
+        postMethodToThread(&This::callCompletedMain, b);
+#else
     postMethodToMain(&This::callCompletedMain, b);
+#endif
 }
 
 void QQmlTypeLoaderThread::callDownloadProgressChanged(QQmlDataBlob *b, qreal p)
 {
     b->addref();
+#if !QT_CONFIG(thread)
+    if (!isThisThread())
+        postMethodToThread(&This::callDownloadProgressChangedMain, b, p);
+#else
     postMethodToMain(&This::callDownloadProgressChangedMain, b, p);
+#endif
 }
 
 void QQmlTypeLoaderThread::initializeEngine(QQmlExtensionInterface *iface,
@@ -864,9 +894,9 @@ void QQmlTypeLoaderThread::shutdownThread()
 {
 #if QT_CONFIG(qml_network)
     delete m_networkAccessManager;
-    m_networkAccessManager = 0;
+    m_networkAccessManager = nullptr;
     delete m_networkReplyProxy;
-    m_networkReplyProxy = 0;
+    m_networkReplyProxy = nullptr;
 #endif // qml_network
 }
 
@@ -882,7 +912,7 @@ void QQmlTypeLoaderThread::loadWithStaticDataThread(QQmlDataBlob *b, const QByte
     b->release();
 }
 
-void QQmlTypeLoaderThread::loadWithCachedUnitThread(QQmlDataBlob *b, const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlTypeLoaderThread::loadWithCachedUnitThread(QQmlDataBlob *b, const QV4::CompiledData::Unit *unit)
 {
     m_loader->loadWithCachedUnitThread(b, unit);
     b->release();
@@ -892,7 +922,7 @@ void QQmlTypeLoaderThread::callCompletedMain(QQmlDataBlob *b)
 {
     QML_MEMORY_SCOPE_URL(b->url());
 #ifdef DATABLOB_DEBUG
-    qWarning("QQmlTypeLoaderThread: %s completed() callback", qPrintable(b->url().toString()));
+    qWarning("QQmlTypeLoaderThread: %s completed() callback", qPrintable(b->urlString()));
 #endif
     b->completed();
     b->release();
@@ -902,7 +932,7 @@ void QQmlTypeLoaderThread::callDownloadProgressChangedMain(QQmlDataBlob *b, qrea
 {
 #ifdef DATABLOB_DEBUG
     qWarning("QQmlTypeLoaderThread: %s downloadProgressChanged(%f) callback",
-             qPrintable(b->url().toString()), p);
+             qPrintable(b->urlString()), p);
 #endif
     b->downloadProgressChanged(p);
     b->release();
@@ -950,7 +980,7 @@ void QQmlTypeLoader::invalidate()
     if (m_thread) {
         shutdownThread();
         delete m_thread;
-        m_thread = 0;
+        m_thread = nullptr;
     }
 
 #if QT_CONFIG(qml_network)
@@ -963,15 +993,13 @@ void QQmlTypeLoader::invalidate()
 #endif // qml_network
 }
 
-void QQmlTypeLoader::lock()
-{
-    m_thread->lock();
-}
-
-void QQmlTypeLoader::unlock()
+#if QT_CONFIG(qml_debug)
+void QQmlTypeLoader::setProfiler(QQmlProfiler *profiler)
 {
-    m_thread->unlock();
+    Q_ASSERT(!m_profiler);
+    m_profiler.reset(profiler);
 }
+#endif
 
 struct PlainLoader {
     void loadThread(QQmlTypeLoader *loader, QQmlDataBlob *blob) const
@@ -1007,8 +1035,8 @@ struct StaticLoader {
 };
 
 struct CachedLoader {
-    const QQmlPrivate::CachedQmlUnit *unit;
-    CachedLoader(const QQmlPrivate::CachedQmlUnit *unit) :  unit(unit) {}
+    const QV4::CompiledData::Unit *unit;
+    CachedLoader(const QV4::CompiledData::Unit *unit) :  unit(unit) {}
 
     void loadThread(QQmlTypeLoader *loader, QQmlDataBlob *blob) const
     {
@@ -1028,7 +1056,7 @@ template<typename Loader>
 void QQmlTypeLoader::doLoad(const Loader &loader, QQmlDataBlob *blob, Mode mode)
 {
 #ifdef DATABLOB_DEBUG
-    qWarning("QQmlTypeLoader::doLoad(%s): %s thread", qPrintable(blob->m_url.toString()),
+    qWarning("QQmlTypeLoader::doLoad(%s): %s thread", qPrintable(blob->urlString()),
              m_thread->isThisThread()?"Compile":"Engine");
 #endif
     blob->startLoading();
@@ -1080,7 +1108,7 @@ void QQmlTypeLoader::loadWithStaticData(QQmlDataBlob *blob, const QByteArray &da
     doLoad(StaticLoader(data), blob, mode);
 }
 
-void QQmlTypeLoader::loadWithCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit, Mode mode)
+void QQmlTypeLoader::loadWithCachedUnit(QQmlDataBlob *blob, const QV4::CompiledData::Unit *unit, Mode mode)
 {
     doLoad(CachedLoader(unit), blob, mode);
 }
@@ -1092,7 +1120,7 @@ void QQmlTypeLoader::loadWithStaticDataThread(QQmlDataBlob *blob, const QByteArr
     setData(blob, data);
 }
 
-void QQmlTypeLoader::loadWithCachedUnitThread(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlTypeLoader::loadWithCachedUnitThread(QQmlDataBlob *blob, const QV4::CompiledData::Unit *unit)
 {
     ASSERT_LOADTHREAD();
 
@@ -1150,14 +1178,17 @@ void QQmlTypeLoader::loadThread(QQmlDataBlob *blob)
         }
 
 #ifdef DATABLOB_DEBUG
-        qWarning("QQmlDataBlob: requested %s", qPrintable(blob->url().toString()));
+        qWarning("QQmlDataBlob: requested %s", qPrintable(blob->urlString()));
 #endif // DATABLOB_DEBUG
 #endif // qml_network
     }
 }
 
 #define DATALOADER_MAXIMUM_REDIRECT_RECURSION 16
+
+#ifndef TYPELOADER_MINIMUM_TRIM_THRESHOLD
 #define TYPELOADER_MINIMUM_TRIM_THRESHOLD 64
+#endif
 
 #if QT_CONFIG(qml_network)
 void QQmlTypeLoader::networkReplyFinished(QNetworkReply *reply)
@@ -1177,13 +1208,14 @@ void QQmlTypeLoader::networkReplyFinished(QNetworkReply *reply)
         if (redirect.isValid()) {
             QUrl url = reply->url().resolved(redirect.toUrl());
             blob->m_finalUrl = url;
+            blob->m_finalUrlString.clear();
 
             QNetworkReply *reply = m_thread->networkAccessManager()->get(QNetworkRequest(url));
             QObject *nrp = m_thread->networkReplyProxy();
             QObject::connect(reply, SIGNAL(finished()), nrp, SLOT(finished()));
             m_networkReplies.insert(reply, blob);
 #ifdef DATABLOB_DEBUG
-            qWarning("QQmlDataBlob: redirected to %s", qPrintable(blob->m_finalUrl.toString()));
+            qWarning("QQmlDataBlob: redirected to %s", qPrintable(blob->finalUrlString()));
 #endif
             return;
         }
@@ -1248,6 +1280,7 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QByteArray &data)
     QML_MEMORY_SCOPE_URL(blob->url());
     QQmlDataBlob::SourceCodeData d;
     d.inlineSourceCode = QString::fromUtf8(data);
+    d.hasInlineSourceCode = true;
     setData(blob, d);
 }
 
@@ -1262,7 +1295,7 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QString &fileName)
 void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeData &d)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
+    QQmlCompilingProfiler prof(profiler(), blob);
 
     blob->m_inCallback = true;
 
@@ -1279,10 +1312,10 @@ void QQmlTypeLoader::setData(QQmlDataBlob *blob, const QQmlDataBlob::SourceCodeD
     blob->tryDone();
 }
 
-void QQmlTypeLoader::setCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlTypeLoader::setCachedUnit(QQmlDataBlob *blob, const QV4::CompiledData::Unit *unit)
 {
     QML_MEMORY_SCOPE_URL(blob->url());
-    QQmlCompilingProfiler prof(QQmlEnginePrivate::get(engine())->profiler, blob);
+    QQmlCompilingProfiler prof(profiler(), blob);
 
     blob->m_inCallback = true;
 
@@ -1312,20 +1345,17 @@ QQmlTypeLoader::Blob::Blob(const QUrl &url, QQmlDataBlob::Type type, QQmlTypeLoa
 
 QQmlTypeLoader::Blob::~Blob()
 {
-    for (int ii = 0; ii < m_qmldirs.count(); ++ii)
-        m_qmldirs.at(ii)->release();
 }
 
 bool QQmlTypeLoader::Blob::fetchQmldir(const QUrl &url, const QV4::CompiledData::Import *import, int priority, QList<QQmlError> *errors)
 {
-    QQmlQmldirData *data = typeLoader()->getQmldir(url);
+    QQmlRefPointer<QQmlQmldirData> data = typeLoader()->getQmldir(url);
 
     data->setImport(this, import);
     data->setPriority(this, priority);
 
     if (data->status() == Error) {
         // This qmldir must not exist - which is not an error
-        data->release();
         return true;
     } else if (data->status() == Complete) {
         // This data is already available
@@ -1333,13 +1363,13 @@ bool QQmlTypeLoader::Blob::fetchQmldir(const QUrl &url, const QV4::CompiledData:
     }
 
     // Wait for this data to become available
-    addDependency(data);
+    addDependency(data.data());
     return true;
 }
 
-bool QQmlTypeLoader::Blob::updateQmldir(QQmlQmldirData *data, const QV4::CompiledData::Import *import, QList<QQmlError> *errors)
+bool QQmlTypeLoader::Blob::updateQmldir(const QQmlRefPointer<QQmlQmldirData> &data, const QV4::CompiledData::Import *import, QList<QQmlError> *errors)
 {
-    QString qmldirIdentifier = data->url().toString();
+    QString qmldirIdentifier = data->urlString();
     QString qmldirUrl = qmldirIdentifier.left(qmldirIdentifier.lastIndexOf(QLatin1Char('/')) + 1);
 
     typeLoader()->setQmldirContent(qmldirIdentifier, data->content());
@@ -1359,12 +1389,12 @@ bool QQmlTypeLoader::Blob::updateQmldir(QQmlQmldirData *data, const QV4::Compile
     if (!importQualifier.isEmpty()) {
         // Does this library contain any qualified scripts?
         QUrl libraryUrl(qmldirUrl);
-        const QQmlTypeLoaderQmldirContent *qmldir = typeLoader()->qmldirContent(qmldirIdentifier);
-        const auto qmldirScripts = qmldir->scripts();
+        const QQmlTypeLoaderQmldirContent qmldir = typeLoader()->qmldirContent(qmldirIdentifier);
+        const auto qmldirScripts = qmldir.scripts();
         for (const QQmlDirParser::Script &script : qmldirScripts) {
             QUrl scriptUrl = libraryUrl.resolved(QUrl(script.fileName));
-            QQmlScriptBlob *blob = typeLoader()->getScript(scriptUrl);
-            addDependency(blob);
+            QQmlRefPointer<QQmlScriptBlob> blob = typeLoader()->getScript(scriptUrl);
+            addDependency(blob.data());
 
             scriptImported(blob, import->location, script.nameSpace, importQualifier);
         }
@@ -1383,8 +1413,8 @@ bool QQmlTypeLoader::Blob::addImport(const QV4::CompiledData::Import *import, QL
     const QString &importQualifier = stringAt(import->qualifierIndex);
     if (import->type == QV4::CompiledData::Import::ImportScript) {
         QUrl scriptUrl = finalUrl().resolved(QUrl(importUri));
-        QQmlScriptBlob *blob = typeLoader()->getScript(scriptUrl);
-        addDependency(blob);
+        QQmlRefPointer<QQmlScriptBlob> blob = typeLoader()->getScript(scriptUrl);
+        addDependency(blob.data());
 
         scriptImported(blob, import->location, importQualifier, QString());
     } else if (import->type == QV4::CompiledData::Import::ImportLibrary) {
@@ -1407,12 +1437,12 @@ bool QQmlTypeLoader::Blob::addImport(const QV4::CompiledData::Import *import, QL
             if (!importQualifier.isEmpty()) {
                 // Does this library contain any qualified scripts?
                 QUrl libraryUrl(qmldirUrl);
-                const QQmlTypeLoaderQmldirContent *qmldir = typeLoader()->qmldirContent(qmldirFilePath);
-                const auto qmldirScripts = qmldir->scripts();
+                const QQmlTypeLoaderQmldirContent qmldir = typeLoader()->qmldirContent(qmldirFilePath);
+                const auto qmldirScripts = qmldir.scripts();
                 for (const QQmlDirParser::Script &script : qmldirScripts) {
                     QUrl scriptUrl = libraryUrl.resolved(QUrl(script.fileName));
-                    QQmlScriptBlob *blob = typeLoader()->getScript(scriptUrl);
-                    addDependency(blob);
+                    QQmlRefPointer<QQmlScriptBlob> blob = typeLoader()->getScript(scriptUrl);
+                    addDependency(blob.data());
 
                     scriptImported(blob, import->location, script.nameSpace, importQualifier);
                 }
@@ -1427,8 +1457,13 @@ bool QQmlTypeLoader::Blob::addImport(const QV4::CompiledData::Import *import, QL
                 // We haven't yet resolved this import
                 m_unresolvedImports.insert(import, 0);
 
-                // Query any network import paths for this library
-                QStringList remotePathList = importDatabase->importPathList(QQmlImportDatabase::Remote);
+                QQmlAbstractUrlInterceptor *interceptor = typeLoader()->engine()->urlInterceptor();
+
+                // Query any network import paths for this library.
+                // Interceptor might redirect local paths.
+                QStringList remotePathList = importDatabase->importPathList(
+                            interceptor ? QQmlImportDatabase::LocalOrRemote
+                                        : QQmlImportDatabase::Remote);
                 if (!remotePathList.isEmpty()) {
                     // Add this library and request the possible locations for it
                     if (!m_importCache.addLibraryImport(importDatabase, importUri, importQualifier, import->majorVersion,
@@ -1439,8 +1474,18 @@ bool QQmlTypeLoader::Blob::addImport(const QV4::CompiledData::Import *import, QL
                     int priority = 0;
                     const QStringList qmlDirPaths = QQmlImports::completeQmldirPaths(importUri, remotePathList, import->majorVersion, import->minorVersion);
                     for (const QString &qmldirPath : qmlDirPaths) {
-                        if (!fetchQmldir(QUrl(qmldirPath), import, ++priority, errors))
+                        if (interceptor) {
+                            QUrl url = interceptor->intercept(
+                                        QQmlImports::urlFromLocalFileOrQrcOrUrl(qmldirPath),
+                                        QQmlAbstractUrlInterceptor::QmldirFile);
+                            if (!QQmlFile::isLocalFile(url)
+                                    && !fetchQmldir(url, import, ++priority, errors)) {
+                                return false;
+                            }
+                        } else if (!fetchQmldir(QUrl(qmldirPath), import, ++priority, errors)) {
                             return false;
+                        }
+
                     }
                 }
             }
@@ -1469,14 +1514,6 @@ bool QQmlTypeLoader::Blob::addImport(const QV4::CompiledData::Import *import, QL
     return true;
 }
 
-void QQmlTypeLoader::Blob::dependencyError(QQmlDataBlob *blob)
-{
-    if (blob->type() == QQmlDataBlob::QmldirFile) {
-        QQmlQmldirData *data = static_cast<QQmlQmldirData *>(blob);
-        data->release();
-    }
-}
-
 void QQmlTypeLoader::Blob::dependencyComplete(QQmlDataBlob *blob)
 {
     if (blob->type() == QQmlDataBlob::QmldirFile) {
@@ -1499,15 +1536,15 @@ void QQmlTypeLoader::Blob::dependencyComplete(QQmlDataBlob *blob)
 
 bool QQmlTypeLoader::Blob::isDebugging() const
 {
-    return QV8Engine::getV4(typeLoader()->engine())->debugger() != 0;
+    return typeLoader()->engine()->handle()->debugger() != nullptr;
 }
 
-bool QQmlTypeLoader::Blob::qmldirDataAvailable(QQmlQmldirData *data, QList<QQmlError> *errors)
+bool QQmlTypeLoader::Blob::qmldirDataAvailable(const QQmlRefPointer<QQmlQmldirData> &data, QList<QQmlError> *errors)
 {
     bool resolve = true;
 
     const QV4::CompiledData::Import *import = data->import(this);
-    data->setImport(this, 0);
+    data->setImport(this, nullptr);
 
     int priority = data->priority(this);
     data->setPriority(this, 0);
@@ -1522,7 +1559,6 @@ bool QQmlTypeLoader::Blob::qmldirDataAvailable(QQmlQmldirData *data, QList<QQmlE
         if (resolve) {
             // This is the (current) best resolution for this import
             if (!updateQmldir(data, import, errors)) {
-                data->release();
                 return false;
             }
 
@@ -1532,7 +1568,6 @@ bool QQmlTypeLoader::Blob::qmldirDataAvailable(QQmlQmldirData *data, QList<QQmlE
         }
     }
 
-    data->release();
     return true;
 }
 
@@ -1558,6 +1593,7 @@ QString QQmlTypeLoaderQmldirContent::typeNamespace() const
 
 void QQmlTypeLoaderQmldirContent::setContent(const QString &location, const QString &content)
 {
+    m_hasContent = true;
     m_location = location;
     m_parser.parse(content);
 }
@@ -1596,8 +1632,10 @@ bool QQmlTypeLoaderQmldirContent::designerSupported() const
 Constructs a new type loader that uses the given \a engine.
 */
 QQmlTypeLoader::QQmlTypeLoader(QQmlEngine *engine)
-    : m_engine(engine), m_thread(new QQmlTypeLoaderThread(this)),
-      m_typeCacheTrimThreshold(TYPELOADER_MINIMUM_TRIM_THRESHOLD)
+    : m_engine(engine)
+    , m_thread(new QQmlTypeLoaderThread(this))
+    , m_mutex(m_thread->mutex())
+    , m_typeCacheTrimThreshold(TYPELOADER_MINIMUM_TRIM_THRESHOLD)
 {
 }
 
@@ -1620,14 +1658,24 @@ QQmlImportDatabase *QQmlTypeLoader::importDatabase() const
     return &QQmlEnginePrivate::get(engine())->importDatabase;
 }
 
+QUrl QQmlTypeLoader::normalize(const QUrl &unNormalizedUrl)
+{
+    QUrl normalized(unNormalizedUrl);
+    if (normalized.scheme() == QLatin1String("qrc"))
+        normalized.setHost(QString()); // map qrc:///a.qml to qrc:/a.qml
+    return normalized;
+}
+
 /*!
 Returns a QQmlTypeData for the specified \a url.  The QQmlTypeData may be cached.
 */
-QQmlTypeData *QQmlTypeLoader::getType(const QUrl &url, Mode mode)
+QQmlRefPointer<QQmlTypeData> QQmlTypeLoader::getType(const QUrl &unNormalizedUrl, Mode mode)
 {
-    Q_ASSERT(!url.isRelative() &&
-            (QQmlFile::urlToLocalFileOrQrc(url).isEmpty() ||
-             !QDir::isRelativePath(QQmlFile::urlToLocalFileOrQrc(url))));
+    Q_ASSERT(!unNormalizedUrl.isRelative() &&
+            (QQmlFile::urlToLocalFileOrQrc(unNormalizedUrl).isEmpty() ||
+             !QDir::isRelativePath(QQmlFile::urlToLocalFileOrQrc(unNormalizedUrl))));
+
+    const QUrl url = normalize(unNormalizedUrl);
 
     LockHolder<QQmlTypeLoader> holder(this);
 
@@ -1641,9 +1689,11 @@ QQmlTypeData *QQmlTypeLoader::getType(const QUrl &url, Mode mode)
         typeData = new QQmlTypeData(url, this);
         // TODO: if (compiledData == 0), is it safe to omit this insertion?
         m_typeCache.insert(url, typeData);
-        if (const QQmlPrivate::CachedQmlUnit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(typeData->url())) {
+        QQmlMetaType::CachedUnitLookupError error = QQmlMetaType::CachedUnitLookupError::NoError;
+        if (const QV4::CompiledData::Unit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(typeData->url(), &error)) {
             QQmlTypeLoader::loadWithCachedUnit(typeData, cachedUnit, mode);
         } else {
+            typeData->setCachedUnitStatus(error);
             QQmlTypeLoader::load(typeData, mode);
         }
     } else if ((mode == PreferSynchronous || mode == Synchronous) && QQmlFile::isSynchronous(url)) {
@@ -1662,8 +1712,6 @@ QQmlTypeData *QQmlTypeLoader::getType(const QUrl &url, Mode mode)
         }
     }
 
-    typeData->addref();
-
     return typeData;
 }
 
@@ -1671,24 +1719,26 @@ QQmlTypeData *QQmlTypeLoader::getType(const QUrl &url, Mode mode)
 Returns a QQmlTypeData for the given \a data with the provided base \a url.  The
 QQmlTypeData will not be cached.
 */
-QQmlTypeData *QQmlTypeLoader::getType(const QByteArray &data, const QUrl &url, Mode mode)
+QQmlRefPointer<QQmlTypeData> QQmlTypeLoader::getType(const QByteArray &data, const QUrl &url, Mode mode)
 {
     LockHolder<QQmlTypeLoader> holder(this);
 
     QQmlTypeData *typeData = new QQmlTypeData(url, this);
     QQmlTypeLoader::loadWithStaticData(typeData, data, mode);
 
-    return typeData;
+    return QQmlRefPointer<QQmlTypeData>(typeData, QQmlRefPointer<QQmlTypeData>::Adopt);
 }
 
 /*!
 Return a QQmlScriptBlob for \a url.  The QQmlScriptData may be cached.
 */
-QQmlScriptBlob *QQmlTypeLoader::getScript(const QUrl &url)
+QQmlRefPointer<QQmlScriptBlob> QQmlTypeLoader::getScript(const QUrl &unNormalizedUrl)
 {
-    Q_ASSERT(!url.isRelative() &&
-            (QQmlFile::urlToLocalFileOrQrc(url).isEmpty() ||
-             !QDir::isRelativePath(QQmlFile::urlToLocalFileOrQrc(url))));
+    Q_ASSERT(!unNormalizedUrl.isRelative() &&
+            (QQmlFile::urlToLocalFileOrQrc(unNormalizedUrl).isEmpty() ||
+             !QDir::isRelativePath(QQmlFile::urlToLocalFileOrQrc(unNormalizedUrl))));
+
+    const QUrl url = normalize(unNormalizedUrl);
 
     LockHolder<QQmlTypeLoader> holder(this);
 
@@ -1698,27 +1748,26 @@ QQmlScriptBlob *QQmlTypeLoader::getScript(const QUrl &url)
         scriptBlob = new QQmlScriptBlob(url, this);
         m_scriptCache.insert(url, scriptBlob);
 
-        if (const QQmlPrivate::CachedQmlUnit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(scriptBlob->url())) {
+        QQmlMetaType::CachedUnitLookupError error;
+        if (const QV4::CompiledData::Unit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(scriptBlob->url(), &error)) {
             QQmlTypeLoader::loadWithCachedUnit(scriptBlob, cachedUnit);
         } else {
+            scriptBlob->setCachedUnitStatus(error);
             QQmlTypeLoader::load(scriptBlob);
         }
     }
 
-    scriptBlob->addref();
-
     return scriptBlob;
 }
 
 /*!
 Returns a QQmlQmldirData for \a url.  The QQmlQmldirData may be cached.
 */
-QQmlQmldirData *QQmlTypeLoader::getQmldir(const QUrl &url)
+QQmlRefPointer<QQmlQmldirData> QQmlTypeLoader::getQmldir(const QUrl &url)
 {
     Q_ASSERT(!url.isRelative() &&
             (QQmlFile::urlToLocalFileOrQrc(url).isEmpty() ||
              !QDir::isRelativePath(QQmlFile::urlToLocalFileOrQrc(url))));
-
     LockHolder<QQmlTypeLoader> holder(this);
 
     QQmlQmldirData *qmldirData = m_qmldirCache.value(url);
@@ -1729,8 +1778,6 @@ QQmlQmldirData *QQmlTypeLoader::getQmldir(const QUrl &url)
         QQmlTypeLoader::load(qmldirData);
     }
 
-    qmldirData->addref();
-
     return qmldirData;
 }
 
@@ -1774,41 +1821,37 @@ QString QQmlTypeLoader::absoluteFilePath(const QString &path)
         // assets resource url
         QFileInfo fileInfo(QQmlFile::urlToLocalFileOrQrc(path));
         return fileInfo.isFile() ? fileInfo.absoluteFilePath() : QString();
+    } else if (path.count() > 8 && path.at(7) == QLatin1Char(':') && path.at(8) == QLatin1Char('/') &&
+           path.startsWith(QLatin1String("content"), Qt::CaseInsensitive)) {
+        // content url
+        QFileInfo fileInfo(QQmlFile::urlToLocalFileOrQrc(path));
+        return fileInfo.isFile() ? fileInfo.absoluteFilePath() : QString();
     }
 #endif
 
     int lastSlash = path.lastIndexOf(QLatin1Char('/'));
-    QStringRef dirPath(&path, 0, lastSlash);
+    QString dirPath(path.left(lastSlash));
 
-    StringSet **fileSet = m_importDirCache.value(QHashedStringRef(dirPath.constData(), dirPath.length()));
-    if (!fileSet) {
-        QHashedString dirPathString(dirPath.toString());
-        bool exists = QDir(dirPathString).exists();
-        QStringHash<bool> *files = exists ? new QStringHash<bool> : 0;
-        m_importDirCache.insert(dirPathString, files);
-        fileSet = m_importDirCache.value(dirPathString);
+    LockHolder<QQmlTypeLoader> holder(this);
+    if (!m_importDirCache.contains(dirPath)) {
+        bool exists = QDir(dirPath).exists();
+        QCache<QString, bool> *entry = exists ? new QCache<QString, bool> : nullptr;
+        m_importDirCache.insert(dirPath, entry);
     }
-    if (!(*fileSet))
+    QCache<QString, bool> *fileSet = m_importDirCache.object(dirPath);
+    if (!fileSet)
         return QString();
 
     QString absoluteFilePath;
-    QHashedStringRef fileName(path.constData()+lastSlash+1, path.length()-lastSlash-1);
+    QString fileName(path.mid(lastSlash+1, path.length()-lastSlash-1));
 
-    bool *value = (*fileSet)->value(fileName);
+    bool *value = fileSet->object(fileName);
     if (value) {
         if (*value)
             absoluteFilePath = path;
     } else {
-        bool exists = false;
-#ifdef Q_OS_UNIX
-        struct stat statBuf;
-        // XXX Avoid encoding entire path. Should store encoded dirpath in cache
-        if (::stat(QFile::encodeName(path).constData(), &statBuf) == 0)
-            exists = S_ISREG(statBuf.st_mode);
-#else
-        exists = QFile::exists(path);
-#endif
-        (*fileSet)->insert(fileName.toString(), exists);
+        bool exists = QFile::exists(path);
+        fileSet->insert(fileName, new bool(exists));
         if (exists)
             absoluteFilePath = path;
     }
@@ -1819,6 +1862,55 @@ QString QQmlTypeLoader::absoluteFilePath(const QString &path)
     return absoluteFilePath;
 }
 
+bool QQmlTypeLoader::fileExists(const QString &path, const QString &file)
+{
+    if (path.isEmpty())
+        return false;
+    Q_ASSERT(path.endsWith(QLatin1Char('/')));
+    if (path.at(0) == QLatin1Char(':')) {
+        // qrc resource
+        QFileInfo fileInfo(path + file);
+        return fileInfo.isFile();
+    } else if (path.count() > 3 && path.at(3) == QLatin1Char(':') &&
+               path.startsWith(QLatin1String("qrc"), Qt::CaseInsensitive)) {
+        // qrc resource url
+        QFileInfo fileInfo(QQmlFile::urlToLocalFileOrQrc(path + file));
+        return fileInfo.isFile();
+    }
+#if defined(Q_OS_ANDROID)
+    else if (path.count() > 7 && path.at(6) == QLatin1Char(':') && path.at(7) == QLatin1Char('/') &&
+           path.startsWith(QLatin1String("assets"), Qt::CaseInsensitive)) {
+        // assets resource url
+        QFileInfo fileInfo(QQmlFile::urlToLocalFileOrQrc(path + file));
+        return fileInfo.isFile();
+    } else if (path.count() > 8 && path.at(7) == QLatin1Char(':') && path.at(8) == QLatin1Char('/') &&
+           path.startsWith(QLatin1String("content"), Qt::CaseInsensitive)) {
+        // content url
+        QFileInfo fileInfo(QQmlFile::urlToLocalFileOrQrc(path + file));
+        return fileInfo.isFile();
+    }
+#endif
+
+    LockHolder<QQmlTypeLoader> holder(this);
+    if (!m_importDirCache.contains(path)) {
+        bool exists = QDir(path).exists();
+        QCache<QString, bool> *entry = exists ? new QCache<QString, bool> : nullptr;
+        m_importDirCache.insert(path, entry);
+    }
+    QCache<QString, bool> *fileSet = m_importDirCache.object(path);
+    if (!fileSet)
+        return false;
+
+    bool *value = fileSet->object(file);
+    if (value) {
+        return *value;
+    } else {
+        bool exists = QFile::exists(path + file);
+        fileSet->insert(file, new bool(exists));
+        return exists;
+    }
+}
+
 
 /*!
 Returns true if the path is a directory via a directory cache.  Cache is
@@ -1831,7 +1923,7 @@ bool QQmlTypeLoader::directoryExists(const QString &path)
 
     bool isResource = path.at(0) == QLatin1Char(':');
 #if defined(Q_OS_ANDROID)
-    isResource = isResource || path.startsWith(QLatin1String("assets:/"));
+    isResource = isResource || path.startsWith(QLatin1String("assets:/")) || path.startsWith(QLatin1String("content:/"));
 #endif
 
     if (isResource) {
@@ -1843,18 +1935,17 @@ bool QQmlTypeLoader::directoryExists(const QString &path)
     int length = path.length();
     if (path.endsWith(QLatin1Char('/')))
         --length;
-    QStringRef dirPath(&path, 0, length);
+    QString dirPath(path.left(length));
 
-    StringSet **fileSet = m_importDirCache.value(QHashedStringRef(dirPath.constData(), dirPath.length()));
-    if (!fileSet) {
-        QHashedString dirPathString(dirPath.toString());
-        bool exists = QDir(dirPathString).exists();
-        QStringHash<bool> *files = exists ? new QStringHash<bool> : 0;
-        m_importDirCache.insert(dirPathString, files);
-        fileSet = m_importDirCache.value(dirPathString);
+    LockHolder<QQmlTypeLoader> holder(this);
+    if (!m_importDirCache.contains(dirPath)) {
+        bool exists = QDir(dirPath).exists();
+        QCache<QString, bool> *files = exists ? new QCache<QString, bool> : nullptr;
+        m_importDirCache.insert(dirPath, files);
     }
 
-    return (*fileSet);
+    QCache<QString, bool> *fileSet = m_importDirCache.object(dirPath);
+    return fileSet != nullptr;
 }
 
 
@@ -1865,51 +1956,56 @@ Return a QQmlTypeLoaderQmldirContent for absoluteFilePath.  The QQmlTypeLoaderQm
 
 It can also be a remote path for a remote directory import, but it will have been cached by now in this case.
 */
-const QQmlTypeLoaderQmldirContent *QQmlTypeLoader::qmldirContent(const QString &filePathIn)
+const QQmlTypeLoaderQmldirContent QQmlTypeLoader::qmldirContent(const QString &filePathIn)
 {
-    QUrl url(filePathIn); //May already contain http scheme
-    if (url.scheme() == QLatin1String("http") || url.scheme() == QLatin1String("https"))
-        return *(m_importQmlDirCache.value(filePathIn)); //Can't load the remote here, but should be cached
-    else
-        url = QUrl::fromLocalFile(filePathIn);
-    if (engine() && engine()->urlInterceptor())
-        url = engine()->urlInterceptor()->intercept(url, QQmlAbstractUrlInterceptor::QmldirFile);
-    Q_ASSERT(url.scheme() == QLatin1String("file"));
+    LockHolder<QQmlTypeLoader> holder(this);
+
     QString filePath;
-    if (url.scheme() == QLatin1String("file"))
-        filePath = url.toLocalFile();
-    else
-        filePath = url.path();
 
-    QQmlTypeLoaderQmldirContent *qmldir;
+    // Try to guess if filePathIn is already a URL. This is necessarily fragile, because
+    // - paths can contain ':', which might make them appear as URLs with schemes.
+    // - windows drive letters appear as schemes (thus "< 2" below).
+    // - a "file:" URL is equivalent to the respective file, but will be treated differently.
+    // Yet, this heuristic is the best we can do until we pass more structured information here,
+    // for example a QUrl also for local files.
+    QUrl url(filePathIn);
+    if (url.scheme().length() < 2) {
+        filePath = filePathIn;
+    } else {
+        filePath = QQmlFile::urlToLocalFileOrQrc(url);
+        if (filePath.isEmpty()) { // Can't load the remote here, but should be cached
+            if (auto entry = m_importQmlDirCache.value(filePathIn))
+                return **entry;
+            else
+                return QQmlTypeLoaderQmldirContent();
+        }
+    }
+
     QQmlTypeLoaderQmldirContent **val = m_importQmlDirCache.value(filePath);
-    if (!val) {
-        qmldir = new QQmlTypeLoaderQmldirContent;
+    if (val)
+        return **val;
+    QQmlTypeLoaderQmldirContent *qmldir = new QQmlTypeLoaderQmldirContent;
 
 #define ERROR(description) { QQmlError e; e.setDescription(description); qmldir->setError(e); }
 #define NOT_READABLE_ERROR QString(QLatin1String("module \"$$URI$$\" definition \"%1\" not readable"))
 #define CASE_MISMATCH_ERROR QString(QLatin1String("cannot load module \"$$URI$$\": File name case mismatch for \"%1\""))
 
-        QFile file(filePath);
-        if (!QQml_isFileCaseCorrect(filePath)) {
-            ERROR(CASE_MISMATCH_ERROR.arg(filePath));
-        } else if (file.open(QFile::ReadOnly)) {
-            QByteArray data = file.readAll();
-            qmldir->setContent(filePath, QString::fromUtf8(data));
-        } else {
-            ERROR(NOT_READABLE_ERROR.arg(filePath));
-        }
+    QFile file(filePath);
+    if (!QQml_isFileCaseCorrect(filePath)) {
+        ERROR(CASE_MISMATCH_ERROR.arg(filePath));
+    } else if (file.open(QFile::ReadOnly)) {
+        QByteArray data = file.readAll();
+        qmldir->setContent(filePath, QString::fromUtf8(data));
+    } else {
+        ERROR(NOT_READABLE_ERROR.arg(filePath));
+    }
 
 #undef ERROR
 #undef NOT_READABLE_ERROR
 #undef CASE_MISMATCH_ERROR
 
-        m_importQmlDirCache.insert(filePath, qmldir);
-    } else {
-        qmldir = *val;
-    }
-
-    return qmldir;
+    m_importQmlDirCache.insert(filePath, qmldir);
+    return *qmldir;
 }
 
 void QQmlTypeLoader::setQmldirContent(const QString &url, const QString &content)
@@ -1938,7 +2034,7 @@ void QQmlTypeLoader::clearCache()
         (*iter)->release();
     for (QmldirCache::Iterator iter = m_qmldirCache.begin(), end = m_qmldirCache.end(); iter != end; ++iter)
         (*iter)->release();
-    qDeleteAll(m_importDirCache);
+
     qDeleteAll(m_importQmlDirCache);
 
     m_typeCache.clear();
@@ -1947,6 +2043,7 @@ void QQmlTypeLoader::clearCache()
     m_qmldirCache.clear();
     m_importDirCache.clear();
     m_importQmlDirCache.clear();
+    QQmlMetaType::freeUnusedTypesAndCaches();
 }
 
 void QQmlTypeLoader::updateTypeCacheTrimThreshold()
@@ -1988,6 +2085,8 @@ void QQmlTypeLoader::trimCache()
 
     updateTypeCacheTrimThreshold();
 
+    QQmlMetaType::freeUnusedTypesAndCaches();
+
     // TODO: release any scripts which are no longer referenced by any types
 }
 
@@ -2013,7 +2112,7 @@ QString QQmlTypeData::TypeReference::qualifiedName() const
     if (!prefix.isEmpty()) {
         result = prefix + QLatin1Char('.');
     }
-    result.append(type->qmlTypeName());
+    result.append(type.qmlTypeName());
     return result;
 }
 
@@ -2026,17 +2125,9 @@ QQmlTypeData::QQmlTypeData(const QUrl &url, QQmlTypeLoader *manager)
 
 QQmlTypeData::~QQmlTypeData()
 {
-    for (int ii = 0; ii < m_scripts.count(); ++ii)
-        m_scripts.at(ii).script->release();
-    for (int ii = 0; ii < m_compositeSingletons.count(); ++ii) {
-        if (QQmlTypeData *tdata = m_compositeSingletons.at(ii).typeData)
-            tdata->release();
-    }
-    for (auto it = m_resolvedTypes.constBegin(), end = m_resolvedTypes.constEnd();
-         it != end; ++it) {
-        if (QQmlTypeData *tdata = it->typeData)
-            tdata->release();
-    }
+    m_scripts.clear();
+    m_compositeSingletons.clear();
+    m_resolvedTypes.clear();
 }
 
 const QList<QQmlTypeData::ScriptReference> &QQmlTypeData::resolvedScripts() const
@@ -2070,20 +2161,20 @@ bool QQmlTypeData::tryLoadFromDiskCache()
     if (isDebugging())
         return false;
 
-    QV4::ExecutionEngine *v4 = QQmlEnginePrivate::getV4Engine(typeLoader()->engine());
+    QV4::ExecutionEngine *v4 = typeLoader()->engine()->handle();
     if (!v4)
         return false;
 
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = v4->iselFactory->createUnitForLoading();
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = QV4::Compiler::Codegen::createUnitForLoading();
     {
         QString error;
-        if (!unit->loadFromDisk(url(), m_backupSourceCode.sourceTimeStamp(), v4->iselFactory.data(), &error)) {
-            qCDebug(DBG_DISK_CACHE) << "Error loading" << url().toString() << "from disk cache:" << error;
+        if (!unit->loadFromDisk(url(), m_backupSourceCode.sourceTimeStamp(), &error)) {
+            qCDebug(DBG_DISK_CACHE) << "Error loading" << urlString() << "from disk cache:" << error;
             return false;
         }
     }
 
-    if (unit->data->flags & QV4::CompiledData::Unit::PendingTypeCompilation) {
+    if (unit->unitData()->flags & QV4::CompiledData::Unit::PendingTypeCompilation) {
         restoreIR(unit);
         return true;
     }
@@ -2105,8 +2196,8 @@ bool QQmlTypeData::tryLoadFromDiskCache()
                 return false;
 
             // find the implicit import
-            for (quint32 i = 0; i < m_compiledData->data->nImports; ++i) {
-                const QV4::CompiledData::Import *import = m_compiledData->data->importAt(i);
+            for (quint32 i = 0, count = m_compiledData->importCount(); i < count; ++i) {
+                const QV4::CompiledData::Import *import = m_compiledData->importAt(i);
                 if (m_compiledData->stringAt(import->uriIndex) == QLatin1String(".")
                     && import->qualifierIndex == 0
                     && import->majorVersion == -1
@@ -2122,8 +2213,8 @@ bool QQmlTypeData::tryLoadFromDiskCache()
         }
     }
 
-    for (int i = 0, count = m_compiledData->data->nImports; i < count; ++i) {
-        const QV4::CompiledData::Import *import = m_compiledData->data->importAt(i);
+    for (int i = 0, count = m_compiledData->importCount(); i < count; ++i) {
+        const QV4::CompiledData::Import *import = m_compiledData->importAt(i);
         QList<QQmlError> errors;
         if (!addImport(import, &errors)) {
             Q_ASSERT(errors.size());
@@ -2149,8 +2240,12 @@ void QQmlTypeData::createTypeAndPropertyCaches(const QQmlRefPointer<QQmlTypeName
 
     QQmlEnginePrivate * const engine = QQmlEnginePrivate::get(typeLoader()->engine());
 
+    QQmlPendingGroupPropertyBindings pendingGroupPropertyBindings;
+
     {
-        QQmlPropertyCacheCreator<QV4::CompiledData::CompilationUnit> propertyCacheCreator(&m_compiledData->propertyCaches, engine, m_compiledData, &m_importCache);
+        QQmlPropertyCacheCreator<QV4::CompiledData::CompilationUnit> propertyCacheCreator(&m_compiledData->propertyCaches,
+                                                                                          &pendingGroupPropertyBindings,
+                                                                                          engine, m_compiledData.data(), &m_importCache);
         QQmlCompileError error = propertyCacheCreator.buildMetaObjects();
         if (error.isSet()) {
             setError(error);
@@ -2158,18 +2253,20 @@ void QQmlTypeData::createTypeAndPropertyCaches(const QQmlRefPointer<QQmlTypeName
         }
     }
 
-    QQmlPropertyCacheAliasCreator<QV4::CompiledData::CompilationUnit> aliasCreator(&m_compiledData->propertyCaches, m_compiledData);
+    QQmlPropertyCacheAliasCreator<QV4::CompiledData::CompilationUnit> aliasCreator(&m_compiledData->propertyCaches, m_compiledData.data());
     aliasCreator.appendAliasPropertiesToMetaObjects();
+
+    pendingGroupPropertyBindings.resolveMissingPropertyCaches(engine, &m_compiledData->propertyCaches);
 }
 
 static bool addTypeReferenceChecksumsToHash(const QList<QQmlTypeData::TypeReference> &typeRefs, QCryptographicHash *hash, QQmlEngine *engine)
 {
     for (const auto &typeRef: typeRefs) {
         if (typeRef.typeData) {
-            const auto unit = typeRef.typeData->compilationUnit();
-            hash->addData(unit->data->md5Checksum, sizeof(unit->data->md5Checksum));
-        } else if (typeRef.type) {
-            const auto propertyCache = QQmlEnginePrivate::get(engine)->cache(typeRef.type->metaObject());
+            const auto unit = typeRef.typeData->compilationUnit()->unitData();
+            hash->addData(unit->md5Checksum, sizeof(unit->md5Checksum));
+        } else if (typeRef.type.isValid()) {
+            const auto propertyCache = QQmlEnginePrivate::get(engine)->cache(typeRef.type.metaObject());
             bool ok = false;
             hash->addData(propertyCache->checksum(&ok));
             if (!ok)
@@ -2181,7 +2278,7 @@ static bool addTypeReferenceChecksumsToHash(const QList<QQmlTypeData::TypeRefere
 
 void QQmlTypeData::done()
 {
-    QDeferredCleanup cleanup([this]{
+    auto cleanup = qScopeGuard([this]{
         m_document.reset();
         m_typeReferences.clear();
         if (isError())
@@ -2198,10 +2295,10 @@ void QQmlTypeData::done()
         if (script.script->isError()) {
             QList<QQmlError> errors = script.script->errors();
             QQmlError error;
-            error.setUrl(finalUrl());
+            error.setUrl(url());
             error.setLine(script.location.line);
             error.setColumn(script.location.column);
-            error.setDescription(QQmlTypeLoader::tr("Script %1 unavailable").arg(script.script->url().toString()));
+            error.setDescription(QQmlTypeLoader::tr("Script %1 unavailable").arg(script.script->urlString()));
             errors.prepend(error);
             setError(errors);
             return;
@@ -2218,7 +2315,7 @@ void QQmlTypeData::done()
 
             QList<QQmlError> errors = type.typeData->errors();
             QQmlError error;
-            error.setUrl(finalUrl());
+            error.setUrl(url());
             error.setLine(type.location.line);
             error.setColumn(type.location.column);
             error.setDescription(QQmlTypeLoader::tr("Type %1 unavailable").arg(typeName));
@@ -2233,11 +2330,11 @@ void QQmlTypeData::done()
         const TypeReference &type = m_compositeSingletons.at(ii);
         Q_ASSERT(!type.typeData || type.typeData->isCompleteOrError());
         if (type.typeData && type.typeData->isError()) {
-            QString typeName = type.type->qmlTypeName();
+            QString typeName = type.type.qmlTypeName();
 
             QList<QQmlError> errors = type.typeData->errors();
             QQmlError error;
-            error.setUrl(finalUrl());
+            error.setUrl(url());
             error.setLine(type.location.line);
             error.setColumn(type.location.column);
             error.setDescription(QQmlTypeLoader::tr("Type %1 unavailable").arg(typeName));
@@ -2259,7 +2356,7 @@ void QQmlTypeData::done()
 
     QQmlEngine *const engine = typeLoader()->engine();
 
-    const auto dependencyHasher = [engine, resolvedTypeCache, this](QCryptographicHash *hash) {
+    const auto dependencyHasher = [engine, &resolvedTypeCache, this](QCryptographicHash *hash) {
         if (!resolvedTypeCache.addToHash(hash, engine))
             return false;
         return ::addTypeReferenceChecksumsToHash(m_compositeSingletons, hash, engine);
@@ -2267,7 +2364,7 @@ void QQmlTypeData::done()
 
     // verify if any dependencies changed if we're using a cache
     if (m_document.isNull() && !m_compiledData->verifyChecksum(dependencyHasher)) {
-        qCDebug(DBG_DISK_CACHE) << "Checksum mismatch for cached version of" << m_compiledData->url().toString();
+        qCDebug(DBG_DISK_CACHE) << "Checksum mismatch for cached version of" << m_compiledData->fileName();
         if (!loadFromSource())
             return;
         m_backupSourceCode = SourceCodeData();
@@ -2276,7 +2373,7 @@ void QQmlTypeData::done()
 
     if (!m_document.isNull()) {
         // Compile component
-        compile(typeNameCache, resolvedTypeCache, dependencyHasher);
+        compile(typeNameCache, &resolvedTypeCache, dependencyHasher);
     } else {
         createTypeAndPropertyCaches(typeNameCache, resolvedTypeCache);
     }
@@ -2296,28 +2393,28 @@ void QQmlTypeData::done()
             }
         }
 
-        m_compiledData->finalize(enginePrivate);
+        m_compiledData->finalizeCompositeType(enginePrivate);
     }
 
     {
-        QQmlType *type = QQmlMetaType::qmlType(finalUrl(), true);
-        if (m_compiledData && m_compiledData->data->flags & QV4::CompiledData::Unit::IsSingleton) {
-            if (!type) {
+        QQmlType type = QQmlMetaType::qmlType(finalUrl(), true);
+        if (m_compiledData && m_compiledData->unitData()->flags & QV4::CompiledData::Unit::IsSingleton) {
+            if (!type.isValid()) {
                 QQmlError error;
                 error.setDescription(QQmlTypeLoader::tr("No matching type found, pragma Singleton files cannot be used by QQmlComponent."));
                 setError(error);
                 return;
-            } else if (!type->isCompositeSingleton()) {
+            } else if (!type.isCompositeSingleton()) {
                 QQmlError error;
-                error.setDescription(QQmlTypeLoader::tr("pragma Singleton used with a non composite singleton type %1").arg(type->qmlTypeName()));
+                error.setDescription(QQmlTypeLoader::tr("pragma Singleton used with a non composite singleton type %1").arg(type.qmlTypeName()));
                 setError(error);
                 return;
             }
         } else {
             // If the type is CompositeSingleton but there was no pragma Singleton in the
             // QML file, lets report an error.
-            if (type && type->isCompositeSingleton()) {
-                QString typeName = type->qmlTypeName();
+            if (type.isValid() && type.isCompositeSingleton()) {
+                QString typeName = type.qmlTypeName();
                 setError(QQmlTypeLoader::tr("qmldir defines type as singleton, but no pragma Singleton found in type %1.").arg(typeName));
                 return;
             }
@@ -2340,8 +2437,7 @@ void QQmlTypeData::done()
             }
 
             m_compiledData->typeNameCache->add(qualifier.toString(), scriptIndex, enclosingNamespace);
-            QQmlScriptData *scriptData = script.script->scriptData();
-            scriptData->addref();
+            QQmlRefPointer<QQmlScriptData> scriptData = script.script->scriptData();
             m_compiledData->dependentScripts << scriptData;
         }
     }
@@ -2387,8 +2483,13 @@ void QQmlTypeData::dataReceived(const SourceCodeData &data)
     if (isError())
         return;
 
-    if (!m_backupSourceCode.exists()) {
-        setError(QQmlTypeLoader::tr("No such file or directory"));
+    if (!m_backupSourceCode.exists() || m_backupSourceCode.isEmpty()) {
+        if (m_cachedUnitStatus == QQmlMetaType::CachedUnitLookupError::VersionMismatch)
+            setError(QQmlTypeLoader::tr("File was compiled ahead of time with an incompatible version of Qt and the original file cannot be found. Please recompile"));
+        else if (!m_backupSourceCode.exists())
+            setError(QQmlTypeLoader::tr("No such file or directory"));
+        else
+            setError(QQmlTypeLoader::tr("File is empty"));
         return;
     }
 
@@ -2398,10 +2499,14 @@ void QQmlTypeData::dataReceived(const SourceCodeData &data)
     continueLoadFromIR();
 }
 
-void QQmlTypeData::initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlTypeData::initializeFromCachedUnit(const QV4::CompiledData::Unit *unit)
 {
     m_document.reset(new QmlIR::Document(isDebugging()));
-    unit->loadIR(m_document.data(), unit);
+    QmlIR::IRLoader loader(unit, m_document.data());
+    loader.load();
+    m_document->jsModule.fileName = urlString();
+    m_document->jsModule.finalUrl = finalUrlString();
+    m_document->javaScriptCompilationUnit.adopt(new QV4::CompiledData::CompilationUnit(unit));
     continueLoadFromIR();
 }
 
@@ -2410,7 +2515,7 @@ bool QQmlTypeData::loadFromSource()
     m_document.reset(new QmlIR::Document(isDebugging()));
     m_document->jsModule.sourceTimeStamp = m_backupSourceCode.sourceTimeStamp();
     QQmlEngine *qmlEngine = typeLoader()->engine();
-    QmlIR::IRBuilder compiler(QV8Engine::get(qmlEngine)->illegalNames());
+    QmlIR::IRBuilder compiler(qmlEngine->handle()->v8Engine->illegalNames());
 
     QString sourceError;
     const QString source = m_backupSourceCode.readAll(&sourceError);
@@ -2424,7 +2529,7 @@ bool QQmlTypeData::loadFromSource()
         errors.reserve(compiler.errors.count());
         for (const QQmlJS::DiagnosticMessage &msg : qAsConst(compiler.errors)) {
             QQmlError e;
-            e.setUrl(finalUrl());
+            e.setUrl(url());
             e.setLine(msg.loc.startLine);
             e.setColumn(msg.loc.startColumn);
             e.setDescription(msg.message);
@@ -2439,9 +2544,10 @@ bool QQmlTypeData::loadFromSource()
 void QQmlTypeData::restoreIR(QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit)
 {
     m_document.reset(new QmlIR::Document(isDebugging()));
-    QmlIR::IRLoader loader(unit->data, m_document.data());
+    QmlIR::IRLoader loader(unit->unitData(), m_document.data());
     loader.load();
-    m_document->jsModule.setFileName(finalUrlString());
+    m_document->jsModule.fileName = urlString();
+    m_document->jsModule.finalUrl = finalUrlString();
     m_document->javaScriptCompilationUnit = unit;
     continueLoadFromIR();
 }
@@ -2493,6 +2599,8 @@ void QQmlTypeData::continueLoadFromIR()
 
 void QQmlTypeData::allDependenciesDone()
 {
+    QQmlTypeLoader::Blob::allDependenciesDone();
+
     if (!m_typesResolved) {
         // Check that all imports were resolved
         QList<QQmlError> errors;
@@ -2538,12 +2646,13 @@ QString QQmlTypeData::stringAt(int index) const
     return m_document->jsGenerator.stringTable.stringForIndex(index);
 }
 
-void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache, const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache,
+void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
+                           QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache,
                            const QV4::CompiledData::DependentTypesHasher &dependencyHasher)
 {
     Q_ASSERT(m_compiledData.isNull());
 
-    const bool typeRecompilation = m_document && m_document->javaScriptCompilationUnit && m_document->javaScriptCompilationUnit->data->flags & QV4::CompiledData::Unit::PendingTypeCompilation;
+    const bool typeRecompilation = m_document && m_document->javaScriptCompilationUnit && m_document->javaScriptCompilationUnit->unitData()->flags & QV4::CompiledData::Unit::PendingTypeCompilation;
 
     QQmlEnginePrivate * const enginePrivate = QQmlEnginePrivate::get(typeLoader()->engine());
     QQmlTypeCompiler compiler(enginePrivate, this, m_document.data(), typeNameCache, resolvedTypeCache, dependencyHasher);
@@ -2558,11 +2667,11 @@ void QQmlTypeData::compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCach
         QString errorString;
         if (m_compiledData->saveToDisk(url(), &errorString)) {
             QString error;
-            if (!m_compiledData->loadFromDisk(url(), m_backupSourceCode.sourceTimeStamp(), enginePrivate->v4engine()->iselFactory.data(), &error)) {
+            if (!m_compiledData->loadFromDisk(url(), m_backupSourceCode.sourceTimeStamp(), &error)) {
                 // ignore error, keep using the in-memory compilation unit.
             }
         } else {
-            qCDebug(DBG_DISK_CACHE) << "Error saving cached version of" << m_compiledData->url().toString() << "to disk:" << errorString;
+            qCDebug(DBG_DISK_CACHE) << "Error saving cached version of" << m_compiledData->fileName() << "to disk:" << errorString;
         }
     }
 }
@@ -2572,8 +2681,8 @@ void QQmlTypeData::resolveTypes()
     // Add any imported scripts to our resolved set
     const auto resolvedScripts = m_importCache.resolvedScripts();
     for (const QQmlImports::ScriptReference &script : resolvedScripts) {
-        QQmlScriptBlob *blob = typeLoader()->getScript(script.location);
-        addDependency(blob);
+        QQmlRefPointer<QQmlScriptBlob> blob = typeLoader()->getScript(script.location);
+        addDependency(blob.data());
 
         ScriptReference ref;
         //ref.location = ...
@@ -2606,22 +2715,23 @@ void QQmlTypeData::resolveTypes()
         int majorVersion = csRef.majorVersion > -1 ? csRef.majorVersion : -1;
         int minorVersion = csRef.minorVersion > -1 ? csRef.minorVersion : -1;
 
-        if (!resolveType(typeName, majorVersion, minorVersion, ref))
+        if (!resolveType(typeName, majorVersion, minorVersion, ref, -1, -1, true,
+                         QQmlType::CompositeSingletonType))
             return;
 
-        if (ref.type->isCompositeSingleton()) {
-            ref.typeData = typeLoader()->getType(ref.type->sourceUrl());
-            addDependency(ref.typeData);
+        if (ref.type.isCompositeSingleton()) {
+            ref.typeData = typeLoader()->getType(ref.type.sourceUrl());
+            if (ref.typeData->status() == QQmlDataBlob::ResolvingDependencies) {
+                // TODO: give an error message? If so, we should record and show the path of the cycle.
+                continue;
+            }
+            addDependency(ref.typeData.data());
             ref.prefix = csRef.prefix;
 
             m_compositeSingletons << ref;
         }
     }
 
-    std::stable_sort(m_compositeSingletons.begin(), m_compositeSingletons.end(), [](const TypeReference &lhs, const TypeReference &rhs){
-        return lhs.qualifiedName() < rhs.qualifiedName();
-    });
-
     for (QV4::CompiledData::TypeReferenceMap::ConstIterator unresolvedRef = m_typeReferences.constBegin(), end = m_typeReferences.constEnd();
          unresolvedRef != end; ++unresolvedRef) {
 
@@ -2634,12 +2744,14 @@ void QQmlTypeData::resolveTypes()
 
         const QString name = stringAt(unresolvedRef.key());
 
-        if (!resolveType(name, majorVersion, minorVersion, ref, unresolvedRef->location.line, unresolvedRef->location.column, reportErrors) && reportErrors)
+        if (!resolveType(name, majorVersion, minorVersion, ref, unresolvedRef->location.line,
+                         unresolvedRef->location.column, reportErrors,
+                         QQmlType::AnyRegistrationType) && reportErrors)
             return;
 
-        if (ref.type && ref.type->isComposite()) {
-            ref.typeData = typeLoader()->getType(ref.type->sourceUrl());
-            addDependency(ref.typeData);
+        if (ref.type.isComposite()) {
+            ref.typeData = typeLoader()->getType(ref.type.sourceUrl());
+            addDependency(ref.typeData.data());
         }
         ref.majorVersion = majorVersion;
         ref.minorVersion = minorVersion;
@@ -2651,6 +2763,10 @@ void QQmlTypeData::resolveTypes()
 
         m_resolvedTypes.insert(unresolvedRef.key(), ref);
     }
+
+    // ### this allows enums to work without explicit import or instantiation of the type
+    if (!m_implicitImportLoaded)
+        loadImplicitImport();
 }
 
 QQmlCompileError QQmlTypeData::buildTypeResolutionCaches(
@@ -2665,32 +2781,32 @@ QQmlCompileError QQmlTypeData::buildTypeResolutionCaches(
 
     // Add any Composite Singletons that were used to the import cache
     for (const QQmlTypeData::TypeReference &singleton: m_compositeSingletons)
-        (*typeNameCache)->add(singleton.type->qmlTypeName(), singleton.type->sourceUrl(), singleton.prefix);
+        (*typeNameCache)->add(singleton.type.qmlTypeName(), singleton.type.sourceUrl(), singleton.prefix);
 
-    m_importCache.populateCache(*typeNameCache);
+    m_importCache.populateCache(typeNameCache->data());
 
     QQmlEnginePrivate * const engine = QQmlEnginePrivate::get(typeLoader()->engine());
 
     for (auto resolvedType = m_resolvedTypes.constBegin(), end = m_resolvedTypes.constEnd(); resolvedType != end; ++resolvedType) {
         QScopedPointer<QV4::CompiledData::ResolvedTypeReference> ref(new QV4::CompiledData::ResolvedTypeReference);
-        QQmlType *qmlType = resolvedType->type;
+        QQmlType qmlType = resolvedType->type;
         if (resolvedType->typeData) {
-            if (resolvedType->needsCreation && qmlType->isCompositeSingleton()) {
-                return QQmlCompileError(resolvedType->location, tr("Composite Singleton Type %1 is not creatable.").arg(qmlType->qmlTypeName()));
+            if (resolvedType->needsCreation && qmlType.isCompositeSingleton()) {
+                return QQmlCompileError(resolvedType->location, tr("Composite Singleton Type %1 is not creatable.").arg(qmlType.qmlTypeName()));
             }
             ref->compilationUnit = resolvedType->typeData->compilationUnit();
-        } else if (qmlType) {
+        } else if (qmlType.isValid()) {
             ref->type = qmlType;
-            Q_ASSERT(ref->type);
+            Q_ASSERT(ref->type.isValid());
 
-            if (resolvedType->needsCreation && !ref->type->isCreatable()) {
-                QString reason = ref->type->noCreationReason();
+            if (resolvedType->needsCreation && !ref->type.isCreatable()) {
+                QString reason = ref->type.noCreationReason();
                 if (reason.isEmpty())
                     reason = tr("Element is not creatable.");
                 return QQmlCompileError(resolvedType->location, reason);
             }
 
-            if (ref->type->containsRevisionedAttributes()) {
+            if (ref->type.containsRevisionedAttributes()) {
                 ref->typePropertyCache = engine->cache(ref->type,
                                                        resolvedType->minorVersion);
             }
@@ -2704,20 +2820,22 @@ QQmlCompileError QQmlTypeData::buildTypeResolutionCaches(
     return noError;
 }
 
-bool QQmlTypeData::resolveType(const QString &typeName, int &majorVersion, int &minorVersion, TypeReference &ref, int lineNumber, int columnNumber, bool reportErrors)
+bool QQmlTypeData::resolveType(const QString &typeName, int &majorVersion, int &minorVersion,
+                               TypeReference &ref, int lineNumber, int columnNumber,
+                               bool reportErrors, QQmlType::RegistrationType registrationType)
 {
-    QQmlImportNamespace *typeNamespace = 0;
+    QQmlImportNamespace *typeNamespace = nullptr;
     QList<QQmlError> errors;
 
-    bool typeFound = m_importCache.resolveType(typeName, &ref.type,
-                                          &majorVersion, &minorVersion, &typeNamespace, &errors);
+    bool typeFound = m_importCache.resolveType(typeName, &ref.type, &majorVersion, &minorVersion,
+                                               &typeNamespace, &errors, registrationType);
     if (!typeNamespace && !typeFound && !m_implicitImportLoaded) {
         // Lazy loading of implicit import
         if (loadImplicitImport()) {
             // Try again to find the type
             errors.clear();
-            typeFound = m_importCache.resolveType(typeName, &ref.type,
-                                              &majorVersion, &minorVersion, &typeNamespace, &errors);
+            typeFound = m_importCache.resolveType(typeName, &ref.type, &majorVersion, &minorVersion,
+                                                  &typeNamespace, &errors, registrationType);
         } else {
             return false; //loadImplicitImport() hit an error, and called setError already
         }
@@ -2755,7 +2873,7 @@ bool QQmlTypeData::resolveType(const QString &typeName, int &majorVersion, int &
     return true;
 }
 
-void QQmlTypeData::scriptImported(QQmlScriptBlob *blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &/*nameSpace*/)
+void QQmlTypeData::scriptImported(const QQmlRefPointer<QQmlScriptBlob> &blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &/*nameSpace*/)
 {
     ScriptReference ref;
     ref.script = blob;
@@ -2766,126 +2884,117 @@ void QQmlTypeData::scriptImported(QQmlScriptBlob *blob, const QV4::CompiledData:
 }
 
 QQmlScriptData::QQmlScriptData()
-    : typeNameCache(0)
+    : typeNameCache(nullptr)
     , m_loaded(false)
-    , m_program(0)
 {
 }
 
-QQmlScriptData::~QQmlScriptData()
+QQmlContextData *QQmlScriptData::qmlContextDataForContext(QQmlContextData *parentQmlContextData)
 {
-    delete m_program;
-}
-
-void QQmlScriptData::initialize(QQmlEngine *engine)
-{
-    Q_ASSERT(!m_program);
-    Q_ASSERT(engine);
-    Q_ASSERT(!hasEngine());
-
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
-    QV8Engine *v8engine = ep->v8engine();
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(v8engine);
-
-    m_program = new QV4::Script(v4, 0, m_precompiledScript);
-
-    addToEngine(engine);
-
-    addref();
-}
-
-QV4::ReturnedValue QQmlScriptData::scriptValueForContext(QQmlContextData *parentCtxt)
-{
-    if (m_loaded)
-        return m_value.value();
-
-    Q_ASSERT(parentCtxt && parentCtxt->engine);
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(parentCtxt->engine);
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(parentCtxt->engine);
-    QV4::Scope scope(v4);
+    Q_ASSERT(parentQmlContextData && parentQmlContextData->engine);
 
-    bool shared = m_precompiledScript->data->flags & QV4::CompiledData::Unit::IsSharedLibrary;
+    if (m_precompiledScript->isESModule())
+        return nullptr;
 
-    QQmlContextData *effectiveCtxt = parentCtxt;
-    if (shared)
-        effectiveCtxt = 0;
+    auto qmlContextData = new QQmlContextData();
 
-    // Create the script context if required
-    QQmlContextData *ctxt = new QQmlContextData;
-    ctxt->isInternal = true;
-    ctxt->isJSContext = true;
-    if (shared)
-        ctxt->isPragmaLibraryContext = true;
+    qmlContextData->isInternal = true;
+    qmlContextData->isJSContext = true;
+    if (m_precompiledScript->isSharedLibrary())
+        qmlContextData->isPragmaLibraryContext = true;
     else
-        ctxt->isPragmaLibraryContext = parentCtxt->isPragmaLibraryContext;
-    ctxt->baseUrl = url;
-    ctxt->baseUrlString = urlString;
+        qmlContextData->isPragmaLibraryContext = parentQmlContextData->isPragmaLibraryContext;
+    qmlContextData->baseUrl = url;
+    qmlContextData->baseUrlString = urlString;
 
     // For backward compatibility, if there are no imports, we need to use the
     // imports from the parent context.  See QTBUG-17518.
     if (!typeNameCache->isEmpty()) {
-        ctxt->imports = typeNameCache;
-    } else if (effectiveCtxt) {
-        ctxt->imports = effectiveCtxt->imports;
-        ctxt->importedScripts = effectiveCtxt->importedScripts;
+        qmlContextData->imports = typeNameCache;
+    } else if (!m_precompiledScript->isSharedLibrary()) {
+        qmlContextData->imports = parentQmlContextData->imports;
+        qmlContextData->importedScripts = parentQmlContextData->importedScripts;
     }
 
-    if (effectiveCtxt) {
-        ctxt->setParent(effectiveCtxt, true);
+    if (!m_precompiledScript->isSharedLibrary()) {
+        qmlContextData->setParent(parentQmlContextData);
     } else {
-        ctxt->engine = parentCtxt->engine; // Fix for QTBUG-21620
+        qmlContextData->engine = parentQmlContextData->engine; // Fix for QTBUG-21620
     }
 
+    QV4::ExecutionEngine *v4 = parentQmlContextData->engine->handle();
+    QV4::Scope scope(v4);
     QV4::ScopedObject scriptsArray(scope);
-    if (ctxt->importedScripts.isNullOrUndefined()) {
+    if (qmlContextData->importedScripts.isNullOrUndefined()) {
         scriptsArray = v4->newArrayObject(scripts.count());
-        ctxt->importedScripts.set(v4, scriptsArray);
+        qmlContextData->importedScripts.set(v4, scriptsArray);
     } else {
-        scriptsArray = ctxt->importedScripts.valueRef();
+        scriptsArray = qmlContextData->importedScripts.valueRef();
     }
     QV4::ScopedValue v(scope);
     for (int ii = 0; ii < scripts.count(); ++ii)
-        scriptsArray->putIndexed(ii, (v = scripts.at(ii)->scriptData()->scriptValueForContext(ctxt)));
+        scriptsArray->put(ii, (v = scripts.at(ii)->scriptData()->scriptValueForContext(qmlContextData)));
+
+    return qmlContextData;
+}
 
-    if (!hasEngine())
-        initialize(parentCtxt->engine);
+QV4::ReturnedValue QQmlScriptData::scriptValueForContext(QQmlContextData *parentQmlContextData)
+{
+    if (m_loaded)
+        return m_value.value();
 
-    if (!m_program) {
-        if (shared)
-            m_loaded = true;
-        ctxt->destroy();
-        return QV4::Encode::undefined();
+    Q_ASSERT(parentQmlContextData && parentQmlContextData->engine);
+    QV4::ExecutionEngine *v4 = parentQmlContextData->engine->handle();
+    QV4::Scope scope(v4);
+
+    if (!hasEngine()) {
+        addToEngine(parentQmlContextData->engine);
+        addref();
     }
 
-    QV4::Scoped<QV4::QmlContext> qmlContext(scope, QV4::QmlContext::create(v4->rootContext(), ctxt, 0));
-    qmlContext->takeContextOwnership();
+    QQmlContextDataRef qmlContextData = qmlContextDataForContext(parentQmlContextData);
+    QV4::Scoped<QV4::QmlContext> qmlExecutionContext(scope);
+    if (qmlContextData)
+        qmlExecutionContext =
+            QV4::QmlContext::create(v4->rootContext(), qmlContextData, /* scopeObject: */ nullptr);
 
-    m_program->qmlContext.set(scope.engine, qmlContext);
-    m_program->run();
-    if (scope.engine->hasException) {
-        QQmlError error = scope.engine->catchExceptionAsQmlError();
+    QV4::Scoped<QV4::Module> module(scope, m_precompiledScript->instantiate(v4));
+    if (module) {
+        if (qmlContextData) {
+            module->d()->scope->outer.set(v4, qmlExecutionContext->d());
+            qmlExecutionContext->d()->qml()->module.set(v4, module->d());
+        }
+
+        module->evaluate();
+    }
+
+    if (v4->hasException) {
+        QQmlError error = v4->catchExceptionAsQmlError();
         if (error.isValid())
-            ep->warning(error);
+            QQmlEnginePrivate::get(v4)->warning(error);
     }
 
-    QV4::ScopedValue retval(scope, qmlContext->d()->qml);
-    if (shared) {
-        m_value.set(scope.engine, retval);
+    QV4::ScopedValue value(scope);
+    if (qmlContextData)
+        value = qmlExecutionContext->d()->qml();
+    else if (module)
+        value = module->d();
+
+    if (m_precompiledScript->isSharedLibrary() || m_precompiledScript->isESModule()) {
         m_loaded = true;
+        m_value.set(v4, value);
     }
 
-    return retval->asReturnedValue();
+    return value->asReturnedValue();
 }
 
 void QQmlScriptData::clear()
 {
     if (typeNameCache) {
         typeNameCache->release();
-        typeNameCache = 0;
+        typeNameCache = nullptr;
     }
 
-    for (int ii = 0; ii < scripts.count(); ++ii)
-        scripts.at(ii)->release();
     scripts.clear();
 
     // An addref() was made when the QQmlCleanup was added to the engine.
@@ -2893,47 +3002,41 @@ void QQmlScriptData::clear()
 }
 
 QQmlScriptBlob::QQmlScriptBlob(const QUrl &url, QQmlTypeLoader *loader)
-: QQmlTypeLoader::Blob(url, JavaScriptFile, loader), m_scriptData(0)
+    : QQmlTypeLoader::Blob(url, JavaScriptFile, loader)
+    , m_isModule(url.path().endsWith(QLatin1String(".mjs")))
 {
 }
 
 QQmlScriptBlob::~QQmlScriptBlob()
 {
-    if (m_scriptData) {
-        m_scriptData->release();
-        m_scriptData = 0;
-    }
 }
 
-QQmlScriptData *QQmlScriptBlob::scriptData() const
+QQmlRefPointer<QQmlScriptData> QQmlScriptBlob::scriptData() const
 {
     return m_scriptData;
 }
 
-struct EmptyCompilationUnit : public QV4::CompiledData::CompilationUnit
-{
-    void linkBackendToEngine(QV4::ExecutionEngine *) override {}
-};
-
 void QQmlScriptBlob::dataReceived(const SourceCodeData &data)
 {
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(m_typeLoader->engine());
-
     if (!disableDiskCache() || forceDiskCache()) {
-        QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = v4->iselFactory->createUnitForLoading();
+        QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = QV4::Compiler::Codegen::createUnitForLoading();
         QString error;
-        if (unit->loadFromDisk(url(), data.sourceTimeStamp(), v4->iselFactory.data(), &error)) {
+        if (unit->loadFromDisk(url(), data.sourceTimeStamp(), &error)) {
             initializeFromCompilationUnit(unit);
             return;
         } else {
-            qCDebug(DBG_DISK_CACHE()) << "Error loading" << url().toString() << "from disk cache:" << error;
+            qCDebug(DBG_DISK_CACHE()) << "Error loading" << urlString() << "from disk cache:" << error;
         }
     }
 
+    if (!data.exists()) {
+        if (m_cachedUnitStatus == QQmlMetaType::CachedUnitLookupError::VersionMismatch)
+            setError(QQmlTypeLoader::tr("File was compiled ahead of time with an incompatible version of Qt and the original file cannot be found. Please recompile"));
+        else
+            setError(QQmlTypeLoader::tr("No such file or directory"));
+        return;
+    }
 
-    QmlIR::Document irUnit(isDebugging());
-
-    irUnit.jsModule.sourceTimeStamp = data.sourceTimeStamp();
     QString error;
     QString source = data.readAll(&error);
     if (!error.isEmpty()) {
@@ -2941,43 +3044,63 @@ void QQmlScriptBlob::dataReceived(const SourceCodeData &data)
         return;
     }
 
-    QmlIR::ScriptDirectivesCollector collector(&irUnit.jsParserEngine, &irUnit.jsGenerator);
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit;
 
-    QList<QQmlError> errors;
-    QQmlRefPointer<QV4::CompiledData::CompilationUnit> unit = QV4::Script::precompile(&irUnit.jsModule, &irUnit.jsGenerator, v4, finalUrl(), source, &errors, &collector);
-    // No need to addref on unit, it's initial refcount is 1
-    source.clear();
-    if (!errors.isEmpty()) {
-        setError(errors);
-        return;
-    }
-    if (!unit) {
-        unit.adopt(new EmptyCompilationUnit);
-    }
-    irUnit.javaScriptCompilationUnit = unit;
-    irUnit.imports = collector.imports;
-    if (collector.hasPragmaLibrary)
-        irUnit.jsModule.unitFlags |= QV4::CompiledData::Unit::IsSharedLibrary;
+    if (m_isModule) {
+        QList<QQmlJS::DiagnosticMessage> diagnostics;
+        unit = QV4::ExecutionEngine::compileModule(isDebugging(), urlString(), source, data.sourceTimeStamp(), &diagnostics);
+        QList<QQmlError> errors = QQmlEnginePrivate::qmlErrorFromDiagnostics(urlString(), diagnostics);
+        if (!errors.isEmpty()) {
+            setError(errors);
+            return;
+        }
+    } else {
+        QmlIR::Document irUnit(isDebugging());
 
-    QmlIR::QmlUnitGenerator qmlGenerator;
-    QV4::CompiledData::Unit *unitData = qmlGenerator.generate(irUnit);
-    Q_ASSERT(!unit->data);
-    // The js unit owns the data and will free the qml unit.
-    unit->data = unitData;
+        irUnit.jsModule.sourceTimeStamp = data.sourceTimeStamp();
 
-    if (!disableDiskCache() || forceDiskCache()) {
+        QmlIR::ScriptDirectivesCollector collector(&irUnit);
+        irUnit.jsParserEngine.setDirectives(&collector);
+
+        QList<QQmlError> errors;
+        unit = QV4::Script::precompile(
+                    &irUnit.jsModule, &irUnit.jsParserEngine, &irUnit.jsGenerator, urlString(), finalUrlString(),
+                    source, &errors, QV4::Compiler::ContextType::ScriptImportedByQML);
+        // No need to addref on unit, it's initial refcount is 1
+        source.clear();
+        if (!errors.isEmpty()) {
+            setError(errors);
+            return;
+        }
+        if (!unit) {
+            unit.adopt(new QV4::CompiledData::CompilationUnit);
+        }
+        irUnit.javaScriptCompilationUnit = unit;
+
+        QmlIR::QmlUnitGenerator qmlGenerator;
+        qmlGenerator.generate(irUnit);
+    }
+
+    if ((!disableDiskCache() || forceDiskCache()) && !isDebugging()) {
         QString errorString;
-        if (!unit->saveToDisk(url(), &errorString)) {
-            qCDebug(DBG_DISK_CACHE()) << "Error saving cached version of" << unit->url().toString() << "to disk:" << errorString;
+        if (unit->saveToDisk(url(), &errorString)) {
+            QString error;
+            if (!unit->loadFromDisk(url(), data.sourceTimeStamp(), &error)) {
+                // ignore error, keep using the in-memory compilation unit.
+            }
+        } else {
+            qCDebug(DBG_DISK_CACHE()) << "Error saving cached version of" << unit->fileName() << "to disk:" << errorString;
         }
     }
 
     initializeFromCompilationUnit(unit);
 }
 
-void QQmlScriptBlob::initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *unit)
+void QQmlScriptBlob::initializeFromCachedUnit(const QV4::CompiledData::Unit *unit)
 {
-    initializeFromCompilationUnit(unit->createCompilationUnit());
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit;
+    compilationUnit.adopt(new QV4::CompiledData::CompilationUnit(unit, urlString(), finalUrlString()));
+    initializeFromCompilationUnit(compilationUnit);
 }
 
 void QQmlScriptBlob::done()
@@ -2992,43 +3115,46 @@ void QQmlScriptBlob::done()
         if (script.script->isError()) {
             QList<QQmlError> errors = script.script->errors();
             QQmlError error;
-            error.setUrl(finalUrl());
+            error.setUrl(url());
             error.setLine(script.location.line);
             error.setColumn(script.location.column);
-            error.setDescription(QQmlTypeLoader::tr("Script %1 unavailable").arg(script.script->url().toString()));
+            error.setDescription(QQmlTypeLoader::tr("Script %1 unavailable").arg(script.script->urlString()));
             errors.prepend(error);
             setError(errors);
             return;
         }
     }
 
-    m_scriptData->typeNameCache = new QQmlTypeNameCache(m_importCache);
+    if (!m_isModule) {
+        m_scriptData->typeNameCache = new QQmlTypeNameCache(m_importCache);
 
-    QSet<QString> ns;
+        QSet<QString> ns;
 
-    for (int scriptIndex = 0; scriptIndex < m_scripts.count(); ++scriptIndex) {
-        const ScriptReference &script = m_scripts.at(scriptIndex);
+        for (int scriptIndex = 0; scriptIndex < m_scripts.count(); ++scriptIndex) {
+            const ScriptReference &script = m_scripts.at(scriptIndex);
 
-        m_scriptData->scripts.append(script.script);
+            m_scriptData->scripts.append(script.script);
 
-        if (!script.nameSpace.isNull()) {
-            if (!ns.contains(script.nameSpace)) {
-                ns.insert(script.nameSpace);
-                m_scriptData->typeNameCache->add(script.nameSpace);
+            if (!script.nameSpace.isNull()) {
+                if (!ns.contains(script.nameSpace)) {
+                    ns.insert(script.nameSpace);
+                    m_scriptData->typeNameCache->add(script.nameSpace);
+                }
             }
+            m_scriptData->typeNameCache->add(script.qualifier, scriptIndex, script.nameSpace);
         }
-        m_scriptData->typeNameCache->add(script.qualifier, scriptIndex, script.nameSpace);
-    }
 
-    m_importCache.populateCache(m_scriptData->typeNameCache);
+        m_importCache.populateCache(m_scriptData->typeNameCache);
+    }
+    m_scripts.clear();
 }
 
 QString QQmlScriptBlob::stringAt(int index) const
 {
-    return m_scriptData->m_precompiledScript->data->stringAt(index);
+    return m_scriptData->m_precompiledScript->stringAt(index);
 }
 
-void QQmlScriptBlob::scriptImported(QQmlScriptBlob *blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace)
+void QQmlScriptBlob::scriptImported(const QQmlRefPointer<QQmlScriptBlob> &blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace)
 {
     ScriptReference ref;
     ref.script = blob;
@@ -3039,33 +3165,48 @@ void QQmlScriptBlob::scriptImported(QQmlScriptBlob *blob, const QV4::CompiledDat
     m_scripts << ref;
 }
 
-void QQmlScriptBlob::initializeFromCompilationUnit(QV4::CompiledData::CompilationUnit *unit)
+void QQmlScriptBlob::initializeFromCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit)
 {
     Q_ASSERT(!m_scriptData);
-    m_scriptData = new QQmlScriptData();
+    m_scriptData.adopt(new QQmlScriptData());
     m_scriptData->url = finalUrl();
     m_scriptData->urlString = finalUrlString();
     m_scriptData->m_precompiledScript = unit;
 
     m_importCache.setBaseUrl(finalUrl(), finalUrlString());
 
-    Q_ASSERT(m_scriptData->m_precompiledScript->data->flags & QV4::CompiledData::Unit::IsQml);
-    const QV4::CompiledData::Unit *qmlUnit = m_scriptData->m_precompiledScript->data;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> script = m_scriptData->m_precompiledScript;
 
-    QList<QQmlError> errors;
-    for (quint32 i = 0; i < qmlUnit->nImports; ++i) {
-        const QV4::CompiledData::Import *import = qmlUnit->importAt(i);
-        if (!addImport(import, &errors)) {
-           Q_ASSERT(errors.size());
-            QQmlError error(errors.takeFirst());
-            error.setUrl(m_importCache.baseUrl());
-            error.setLine(import->location.line);
-            error.setColumn(import->location.column);
-            errors.prepend(error); // put it back on the list after filling out information.
-            setError(errors);
-            return;
+    if (!m_isModule) {
+        QList<QQmlError> errors;
+        for (quint32 i = 0, count = script->importCount(); i < count; ++i) {
+            const QV4::CompiledData::Import *import = script->importAt(i);
+            if (!addImport(import, &errors)) {
+                Q_ASSERT(errors.size());
+                QQmlError error(errors.takeFirst());
+                error.setUrl(m_importCache.baseUrl());
+                error.setLine(import->location.line);
+                error.setColumn(import->location.column);
+                errors.prepend(error); // put it back on the list after filling out information.
+                setError(errors);
+                return;
+            }
         }
     }
+
+    auto *v4 = QQmlEnginePrivate::getV4Engine(typeLoader()->engine());
+
+    v4->injectModule(unit);
+
+    for (const QString &request: unit->moduleRequests()) {
+        if (v4->moduleForUrl(QUrl(request), unit.data()))
+            continue;
+
+        const QUrl absoluteRequest = unit->finalUrl().resolved(QUrl(request));
+        QQmlRefPointer<QQmlScriptBlob> blob = typeLoader()->getScript(absoluteRequest);
+        addDependency(blob.data());
+        scriptImported(blob, /* ### */QV4::CompiledData::Location(), /*qualifier*/QString(), /*namespace*/QString());
+    }
 }
 
 QQmlQmldirData::QQmlQmldirData(const QUrl &url, QQmlTypeLoader *loader)
@@ -3083,7 +3224,7 @@ const QV4::CompiledData::Import *QQmlQmldirData::import(QQmlTypeLoader::Blob *bl
     QHash<QQmlTypeLoader::Blob *, const QV4::CompiledData::Import *>::const_iterator it =
         m_imports.find(blob);
     if (it == m_imports.end())
-        return 0;
+        return nullptr;
     return *it;
 }
 
@@ -3115,7 +3256,7 @@ void QQmlQmldirData::dataReceived(const SourceCodeData &data)
     }
 }
 
-void QQmlQmldirData::initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *)
+void QQmlQmldirData::initializeFromCachedUnit(const QV4::CompiledData::Unit *)
 {
     Q_UNIMPLEMENTED();
 }
@@ -3123,7 +3264,7 @@ void QQmlQmldirData::initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *
 QString QQmlDataBlob::SourceCodeData::readAll(QString *error) const
 {
     error->clear();
-    if (!inlineSourceCode.isEmpty())
+    if (hasInlineSourceCode)
         return inlineSourceCode;
 
     QFile f(fileInfo.absoluteFilePath());
@@ -3150,26 +3291,26 @@ QString QQmlDataBlob::SourceCodeData::readAll(QString *error) const
 
 QDateTime QQmlDataBlob::SourceCodeData::sourceTimeStamp() const
 {
-    if (!inlineSourceCode.isEmpty())
+    if (hasInlineSourceCode)
         return QDateTime();
 
-    QDateTime timeStamp = fileInfo.lastModified();
-    if (timeStamp.isValid())
-        return timeStamp;
-
-    static QDateTime appTimeStamp;
-    if (!appTimeStamp.isValid())
-        appTimeStamp = QFileInfo(QCoreApplication::applicationFilePath()).lastModified();
-    return appTimeStamp;
+    return fileInfo.lastModified();
 }
 
 bool QQmlDataBlob::SourceCodeData::exists() const
 {
-    if (!inlineSourceCode.isEmpty())
+    if (hasInlineSourceCode)
         return true;
     return fileInfo.exists();
 }
 
+bool QQmlDataBlob::SourceCodeData::isEmpty() const
+{
+    if (hasInlineSourceCode)
+        return inlineSourceCode.isEmpty();
+    return fileInfo.size() == 0;
+}
+
 QT_END_NAMESPACE
 
 #include "qqmltypeloader.moc"
diff --git a/src/qml/qml/qqmltypeloader_p.h b/src/qml/qml/qqmltypeloader_p.h
index f367fa6f58..987e47222d 100644
--- a/src/qml/qml/qqmltypeloader_p.h
+++ b/src/qml/qml/qqmltypeloader_p.h
@@ -55,6 +55,7 @@
 #include <QtCore/qobject.h>
 #include <QtCore/qatomic.h>
 #include <QtCore/qfileinfo.h>
+#include <QtCore/qcache.h>
 #if QT_CONFIG(qml_network)
 #include <QtNetwork/qnetworkreply.h>
 #endif
@@ -83,6 +84,7 @@ class QQmlComponentPrivate;
 class QQmlTypeData;
 class QQmlTypeLoader;
 class QQmlExtensionInterface;
+class QQmlProfiler;
 struct QQmlCompileError;
 
 namespace QmlIR {
@@ -96,6 +98,7 @@ public:
         Null,                    // Prior to QQmlTypeLoader::load()
         Loading,                 // Prior to data being received and dataReceived() being called
         WaitingForDependencies,  // While there are outstanding addDependency()s
+        ResolvingDependencies,   // While resolving outstanding dependencies, to detect cycles
         Complete,                // Finished
         Error                    // Error
     };
@@ -107,7 +110,7 @@ public:
     };
 
     QQmlDataBlob(const QUrl &, Type, QQmlTypeLoader* manager);
-    virtual ~QQmlDataBlob();
+    ~QQmlDataBlob() override;
 
     void startLoading();
 
@@ -126,6 +129,7 @@ public:
     qreal progress() const;
 
     QUrl url() const;
+    QString urlString() const;
     QUrl finalUrl() const;
     QString finalUrlString() const;
 
@@ -136,11 +140,13 @@ public:
         QString readAll(QString *error) const;
         QDateTime sourceTimeStamp() const;
         bool exists() const;
+        bool isEmpty() const;
     private:
         friend class QQmlDataBlob;
         friend class QQmlTypeLoader;
         QString inlineSourceCode;
         QFileInfo fileInfo;
+        bool hasInlineSourceCode = false;
     };
 
 protected:
@@ -154,7 +160,7 @@ protected:
 
     // Callbacks made in load thread
     virtual void dataReceived(const SourceCodeData &) = 0;
-    virtual void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit*) = 0;
+    virtual void initializeFromCachedUnit(const QV4::CompiledData::Unit*) = 0;
     virtual void done();
 #if QT_CONFIG(qml_network)
     virtual void networkError(QNetworkReply::NetworkError);
@@ -204,13 +210,14 @@ private:
 
     QUrl m_url;
     QUrl m_finalUrl;
+    mutable QString m_urlString;
     mutable QString m_finalUrlString;
 
     // List of QQmlDataBlob's that are waiting for me to complete.
     QList<QQmlDataBlob *> m_waitingOnMe;
 
     // List of QQmlDataBlob's that I am waiting for to complete.
-    QList<QQmlDataBlob *> m_waitingFor;
+    QVector<QQmlRefPointer<QQmlDataBlob>> m_waitingFor;
 
     int m_redirectCount:30;
     bool m_inCallback:1;
@@ -223,12 +230,16 @@ class QQmlTypeLoaderQmldirContent
 {
 private:
     friend class QQmlTypeLoader;
-    QQmlTypeLoaderQmldirContent();
 
     void setContent(const QString &location, const QString &content);
     void setError(const QQmlError &);
 
 public:
+    QQmlTypeLoaderQmldirContent();
+    QQmlTypeLoaderQmldirContent(const QQmlTypeLoaderQmldirContent &) = default;
+    QQmlTypeLoaderQmldirContent &operator=(const QQmlTypeLoaderQmldirContent &) = default;
+
+    bool hasContent() const { return m_hasContent; }
     bool hasError() const;
     QList<QQmlError> errors(const QString &uri) const;
 
@@ -245,9 +256,10 @@ public:
 private:
     QQmlDirParser m_parser;
     QString m_location;
+    bool m_hasContent = false;
 };
 
-class Q_AUTOTEST_EXPORT QQmlTypeLoader
+class Q_QML_PRIVATE_EXPORT QQmlTypeLoader
 {
     Q_DECLARE_TR_FUNCTIONS(QQmlTypeLoader)
 public:
@@ -257,22 +269,23 @@ public:
     {
     public:
         Blob(const QUrl &url, QQmlDataBlob::Type type, QQmlTypeLoader *loader);
-        ~Blob();
+        ~Blob() override;
 
         const QQmlImports &imports() const { return m_importCache; }
 
+        void setCachedUnitStatus(QQmlMetaType::CachedUnitLookupError status) { m_cachedUnitStatus = status; }
+
     protected:
         bool addImport(const QV4::CompiledData::Import *import, QList<QQmlError> *errors);
 
         bool fetchQmldir(const QUrl &url, const QV4::CompiledData::Import *import, int priority, QList<QQmlError> *errors);
-        bool updateQmldir(QQmlQmldirData *data, const QV4::CompiledData::Import *import, QList<QQmlError> *errors);
+        bool updateQmldir(const QQmlRefPointer<QQmlQmldirData> &data, const QV4::CompiledData::Import *import, QList<QQmlError> *errors);
 
     private:
-        virtual bool qmldirDataAvailable(QQmlQmldirData *, QList<QQmlError> *);
+        virtual bool qmldirDataAvailable(const QQmlRefPointer<QQmlQmldirData> &, QList<QQmlError> *);
 
-        virtual void scriptImported(QQmlScriptBlob *, const QV4::CompiledData::Location &, const QString &, const QString &) {}
+        virtual void scriptImported(const QQmlRefPointer<QQmlScriptBlob> &, const QV4::CompiledData::Location &, const QString &, const QString &) {}
 
-        void dependencyError(QQmlDataBlob *) override;
         void dependencyComplete(QQmlDataBlob *) override;
 
     protected:
@@ -282,7 +295,8 @@ public:
 
         QQmlImports m_importCache;
         QHash<const QV4::CompiledData::Import*, int> m_unresolvedImports;
-        QList<QQmlQmldirData *> m_qmldirs;
+        QVector<QQmlRefPointer<QQmlQmldirData>> m_qmldirs;
+        QQmlMetaType::CachedUnitLookupError m_cachedUnitStatus = QQmlMetaType::CachedUnitLookupError::NoError;
     };
 
     QQmlTypeLoader(QQmlEngine *);
@@ -290,16 +304,19 @@ public:
 
     QQmlImportDatabase *importDatabase() const;
 
-    QQmlTypeData *getType(const QUrl &url, Mode mode = PreferSynchronous);
-    QQmlTypeData *getType(const QByteArray &, const QUrl &url, Mode mode = PreferSynchronous);
+    static QUrl normalize(const QUrl &unNormalizedUrl);
 
-    QQmlScriptBlob *getScript(const QUrl &);
-    QQmlQmldirData *getQmldir(const QUrl &);
+    QQmlRefPointer<QQmlTypeData> getType(const QUrl &unNormalizedUrl, Mode mode = PreferSynchronous);
+    QQmlRefPointer<QQmlTypeData> getType(const QByteArray &, const QUrl &url, Mode mode = PreferSynchronous);
+
+    QQmlRefPointer<QQmlScriptBlob> getScript(const QUrl &unNormalizedUrl);
+    QQmlRefPointer<QQmlQmldirData> getQmldir(const QUrl &);
 
     QString absoluteFilePath(const QString &path);
+    bool fileExists(const QString &path, const QString &file);
     bool directoryExists(const QString &path);
 
-    const QQmlTypeLoaderQmldirContent *qmldirContent(const QString &filePath);
+    const QQmlTypeLoaderQmldirContent qmldirContent(const QString &filePath);
     void setQmldirContent(const QString &filePath, const QString &content);
 
     void clearCache();
@@ -308,17 +325,26 @@ public:
     bool isTypeLoaded(const QUrl &url) const;
     bool isScriptLoaded(const QUrl &url) const;
 
-    void lock();
-    void unlock();
+    void lock() { m_mutex.lock(); }
+    void unlock() { m_mutex.unlock(); }
 
     void load(QQmlDataBlob *, Mode = PreferSynchronous);
     void loadWithStaticData(QQmlDataBlob *, const QByteArray &, Mode = PreferSynchronous);
-    void loadWithCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit, Mode mode = PreferSynchronous);
+    void loadWithCachedUnit(QQmlDataBlob *blob, const QV4::CompiledData::Unit *unit, Mode mode = PreferSynchronous);
 
     QQmlEngine *engine() const;
     void initializeEngine(QQmlExtensionInterface *, const char *);
     void invalidate();
 
+#if !QT_CONFIG(qml_debug)
+    quintptr profiler() const { return 0; }
+    void setProfiler(quintptr) {}
+#else
+    QQmlProfiler *profiler() const { return m_profiler.data(); }
+    void setProfiler(QQmlProfiler *profiler);
+#endif // QT_CONFIG(qml_debug)
+
+
 private:
     friend class QQmlDataBlob;
     friend class QQmlTypeLoaderThread;
@@ -330,7 +356,7 @@ private:
 
     void loadThread(QQmlDataBlob *);
     void loadWithStaticDataThread(QQmlDataBlob *, const QByteArray &);
-    void loadWithCachedUnitThread(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit);
+    void loadWithCachedUnitThread(QQmlDataBlob *blob, const QV4::CompiledData::Unit *unit);
 #if QT_CONFIG(qml_network)
     void networkReplyFinished(QNetworkReply *);
     void networkReplyProgress(QNetworkReply *, qint64, qint64);
@@ -341,7 +367,7 @@ private:
     void setData(QQmlDataBlob *, const QByteArray &);
     void setData(QQmlDataBlob *, const QString &fileName);
     void setData(QQmlDataBlob *, const QQmlDataBlob::SourceCodeData &);
-    void setCachedUnit(QQmlDataBlob *blob, const QQmlPrivate::CachedQmlUnit *unit);
+    void setCachedUnit(QQmlDataBlob *blob, const QV4::CompiledData::Unit *unit);
 
     template<typename T>
     struct TypedCallback
@@ -362,12 +388,17 @@ private:
     typedef QHash<QUrl, QQmlTypeData *> TypeCache;
     typedef QHash<QUrl, QQmlScriptBlob *> ScriptCache;
     typedef QHash<QUrl, QQmlQmldirData *> QmldirCache;
-    typedef QStringHash<bool> StringSet;
-    typedef QStringHash<StringSet*> ImportDirCache;
+    typedef QCache<QString, QCache<QString, bool> > ImportDirCache;
     typedef QStringHash<QQmlTypeLoaderQmldirContent *> ImportQmlDirCache;
 
     QQmlEngine *m_engine;
     QQmlTypeLoaderThread *m_thread;
+    QMutex &m_mutex;
+
+#if QT_CONFIG(qml_debug)
+    QScopedPointer<QQmlProfiler> m_profiler;
+#endif
+
 #if QT_CONFIG(qml_network)
     NetworkReplies m_networkReplies;
 #endif
@@ -393,13 +424,13 @@ class Q_AUTOTEST_EXPORT QQmlTypeData : public QQmlTypeLoader::Blob
 public:
     struct TypeReference
     {
-        TypeReference() : type(0), majorVersion(0), minorVersion(0), typeData(0), needsCreation(true) {}
+        TypeReference() : majorVersion(0), minorVersion(0), needsCreation(true) {}
 
         QV4::CompiledData::Location location;
-        QQmlType *type;
+        QQmlType type;
         int majorVersion;
         int minorVersion;
-        QQmlTypeData *typeData;
+        QQmlRefPointer<QQmlTypeData> typeData;
         QString prefix; // used by CompositeSingleton types
         QString qualifiedName() const;
         bool needsCreation;
@@ -407,11 +438,9 @@ public:
 
     struct ScriptReference
     {
-        ScriptReference() : script(0) {}
-
         QV4::CompiledData::Location location;
         QString qualifier;
-        QQmlScriptBlob *script;
+        QQmlRefPointer<QQmlScriptBlob> script;
     };
 
 private:
@@ -420,7 +449,7 @@ private:
     QQmlTypeData(const QUrl &, QQmlTypeLoader *);
 
 public:
-    ~QQmlTypeData();
+    ~QQmlTypeData() override;
 
     const QList<ScriptReference> &resolvedScripts() const;
 
@@ -439,7 +468,7 @@ protected:
     void done() override;
     void completed() override;
     void dataReceived(const SourceCodeData &) override;
-    void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *unit) override;
+    void initializeFromCachedUnit(const QV4::CompiledData::Unit *unit) override;
     void allDependenciesDone() override;
     void downloadProgressChanged(qreal) override;
 
@@ -456,12 +485,16 @@ private:
             QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache
             ) const;
     void compile(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
-                 const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache, const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
+                 QV4::CompiledData::ResolvedTypeReferenceMap *resolvedTypeCache,
+                 const QV4::CompiledData::DependentTypesHasher &dependencyHasher);
     void createTypeAndPropertyCaches(const QQmlRefPointer<QQmlTypeNameCache> &typeNameCache,
                                       const QV4::CompiledData::ResolvedTypeReferenceMap &resolvedTypeCache);
-    bool resolveType(const QString &typeName, int &majorVersion, int &minorVersion, TypeReference &ref, int lineNumber = -1, int columnNumber = -1, bool reportErrors = true);
+    bool resolveType(const QString &typeName, int &majorVersion, int &minorVersion,
+                     TypeReference &ref, int lineNumber = -1, int columnNumber = -1,
+                     bool reportErrors = true,
+                     QQmlType::RegistrationType registrationType = QQmlType::AnyRegistrationType);
 
-    void scriptImported(QQmlScriptBlob *blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace) override;
+    void scriptImported(const QQmlRefPointer<QQmlScriptBlob> &blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace) override;
 
 
     SourceCodeData m_backupSourceCode; // used when cache verification fails.
@@ -502,15 +535,15 @@ private:
     QQmlScriptData();
 
 public:
-    ~QQmlScriptData();
-
     QUrl url;
     QString urlString;
     QQmlTypeNameCache *typeNameCache;
-    QList<QQmlScriptBlob *> scripts;
+    QVector<QQmlRefPointer<QQmlScriptBlob>> scripts;
 
     QV4::ReturnedValue scriptValueForContext(QQmlContextData *parentCtxt);
 
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> compilationUnit() const { return m_precompiledScript; }
+
 protected:
     void clear() override; // From QQmlCleanup
 
@@ -518,10 +551,10 @@ private:
     friend class QQmlScriptBlob;
 
     void initialize(QQmlEngine *);
+    QQmlContextData *qmlContextDataForContext(QQmlContextData *parentQmlContextData);
 
     bool m_loaded;
     QQmlRefPointer<QV4::CompiledData::CompilationUnit> m_precompiledScript;
-    QV4::Script *m_program;
     QV4::PersistentValue m_value;
 };
 
@@ -533,33 +566,32 @@ private:
     QQmlScriptBlob(const QUrl &, QQmlTypeLoader *);
 
 public:
-    ~QQmlScriptBlob();
+    ~QQmlScriptBlob() override;
 
     struct ScriptReference
     {
-        ScriptReference() : script(0) {}
-
         QV4::CompiledData::Location location;
         QString qualifier;
         QString nameSpace;
-        QQmlScriptBlob *script;
+        QQmlRefPointer<QQmlScriptBlob> script;
     };
 
-    QQmlScriptData *scriptData() const;
+    QQmlRefPointer<QQmlScriptData> scriptData() const;
 
 protected:
     void dataReceived(const SourceCodeData &) override;
-    void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit *unit) override;
+    void initializeFromCachedUnit(const QV4::CompiledData::Unit *unit) override;
     void done() override;
 
     QString stringAt(int index) const override;
 
 private:
-    void scriptImported(QQmlScriptBlob *blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace) override;
-    void initializeFromCompilationUnit(QV4::CompiledData::CompilationUnit *unit);
+    void scriptImported(const QQmlRefPointer<QQmlScriptBlob> &blob, const QV4::CompiledData::Location &location, const QString &qualifier, const QString &nameSpace) override;
+    void initializeFromCompilationUnit(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &unit);
 
     QList<ScriptReference> m_scripts;
-    QQmlScriptData *m_scriptData;
+    QQmlRefPointer<QQmlScriptData> m_scriptData;
+    const bool m_isModule;
 };
 
 class Q_AUTOTEST_EXPORT QQmlQmldirData : public QQmlTypeLoader::Blob
@@ -580,7 +612,7 @@ public:
 
 protected:
     void dataReceived(const SourceCodeData &) override;
-    void initializeFromCachedUnit(const QQmlPrivate::CachedQmlUnit*) override;
+    void initializeFromCachedUnit(const QV4::CompiledData::Unit *) override;
 
 private:
     QString m_content;
diff --git a/src/qml/qml/qqmltypemodule.cpp b/src/qml/qml/qqmltypemodule.cpp
new file mode 100644
index 0000000000..4d7553fbab
--- /dev/null
+++ b/src/qml/qml/qqmltypemodule.cpp
@@ -0,0 +1,174 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmltypemodule_p_p.h"
+
+#include <private/qqmltype_p_p.h>
+
+#include <QtCore/qmutex.h>
+
+QT_BEGIN_NAMESPACE
+
+QQmlTypeModule::QQmlTypeModule(const QString &module, int majorVersion)
+    : d(new QQmlTypeModulePrivate(module, majorVersion))
+{
+}
+
+QQmlTypeModule::~QQmlTypeModule()
+{
+    delete d;
+}
+
+QString QQmlTypeModule::module() const
+{
+    // No need to lock. d->module is const
+    return d->module;
+}
+
+int QQmlTypeModule::majorVersion() const
+{
+    // No need to lock. d->majorVersion is const
+    return d->majorVersion;
+}
+
+int QQmlTypeModule::minimumMinorVersion() const
+{
+    return d->minMinorVersion.load();
+}
+
+int QQmlTypeModule::maximumMinorVersion() const
+{
+    return d->maxMinorVersion.load();
+}
+
+void QQmlTypeModule::addMinorVersion(int version)
+{
+    for (int oldVersion = d->minMinorVersion.load();
+         oldVersion > version && !d->minMinorVersion.testAndSetOrdered(oldVersion, version);
+         oldVersion = d->minMinorVersion.load()) {
+    }
+
+    for (int oldVersion = d->maxMinorVersion.load();
+         oldVersion < version && !d->maxMinorVersion.testAndSetOrdered(oldVersion, version);
+         oldVersion = d->maxMinorVersion.load()) {
+    }
+}
+
+void QQmlTypeModule::add(QQmlTypePrivate *type)
+{
+    QMutexLocker lock(&d->mutex);
+    addMinorVersion(type->version_min);
+
+    QList<QQmlTypePrivate *> &list = d->typeHash[type->elementName];
+    for (int ii = 0; ii < list.count(); ++ii) {
+        Q_ASSERT(list.at(ii));
+        if (list.at(ii)->version_min < type->version_min) {
+            list.insert(ii, type);
+            return;
+        }
+    }
+    list.append(type);
+}
+
+void QQmlTypeModule::remove(const QQmlTypePrivate *type)
+{
+    QMutexLocker lock(&d->mutex);
+    for (auto elementIt = d->typeHash.begin(); elementIt != d->typeHash.end();) {
+        QQmlMetaType::removeQQmlTypePrivate(elementIt.value(), type);
+
+#if 0
+        if (list.isEmpty())
+            elementIt = typeHash.erase(elementIt);
+        else
+            ++elementIt;
+#else
+        ++elementIt;
+#endif
+    }
+}
+
+bool QQmlTypeModule::isLocked() const
+{
+    return d->locked.load() != 0;
+}
+
+void QQmlTypeModule::lock()
+{
+    d->locked.store(1);
+}
+
+QQmlType QQmlTypeModule::type(const QHashedStringRef &name, int minor) const
+{
+    QMutexLocker lock(&d->mutex);
+    QList<QQmlTypePrivate *> *types = d->typeHash.value(name);
+    if (types) {
+        for (int ii = 0; ii < types->count(); ++ii)
+            if (types->at(ii)->version_min <= minor)
+                return QQmlType(types->at(ii));
+    }
+
+    return QQmlType();
+}
+
+QQmlType QQmlTypeModule::type(const QV4::String *name, int minor) const
+{
+    QMutexLocker lock(&d->mutex);
+    QList<QQmlTypePrivate *> *types = d->typeHash.value(name);
+    if (types) {
+        for (int ii = 0; ii < types->count(); ++ii)
+            if (types->at(ii)->version_min <= minor)
+                return QQmlType(types->at(ii));
+    }
+
+    return QQmlType();
+}
+
+void QQmlTypeModule::walkCompositeSingletons(const std::function<void(const QQmlType &)> &callback) const
+{
+    QMutexLocker lock(&d->mutex);
+    for (auto typeCandidates = d->typeHash.begin(), end = d->typeHash.end();
+         typeCandidates != end; ++typeCandidates) {
+        for (auto type: typeCandidates.value()) {
+            if (type->regType == QQmlType::CompositeSingletonType)
+                callback(QQmlType(type));
+        }
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltypemodule_p.h b/src/qml/qml/qqmltypemodule_p.h
new file mode 100644
index 0000000000..b84a91b5db
--- /dev/null
+++ b/src/qml/qml/qqmltypemodule_p.h
@@ -0,0 +1,102 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTYPEMODULE_P_H
+#define QQMLTYPEMODULE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQml/qtqmlglobal.h>
+#include <QtCore/qstring.h>
+
+#include <functional>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlType;
+class QQmlTypePrivate;
+struct QQmlMetaTypeData;
+class QHashedString;
+class QHashedStringRef;
+
+namespace QV4 {
+struct String;
+}
+
+class QQmlTypeModulePrivate;
+class QQmlTypeModule
+{
+public:
+    QQmlTypeModule(const QString &uri = QString(), int majorVersion = 0);
+    ~QQmlTypeModule();
+
+    void add(QQmlTypePrivate *);
+    void remove(const QQmlTypePrivate *type);
+
+    bool isLocked() const;
+    void lock();
+
+    QString module() const;
+    int majorVersion() const;
+
+    void addMinorVersion(int minorVersion);
+    int minimumMinorVersion() const;
+    int maximumMinorVersion() const;
+
+    QQmlType type(const QHashedStringRef &, int) const;
+    QQmlType type(const QV4::String *, int) const;
+
+    void walkCompositeSingletons(const std::function<void(const QQmlType &)> &callback) const;
+
+private:
+    QQmlTypeModulePrivate *d;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLTYPEMODULE_P_H
diff --git a/src/qml/qml/qqmltypemodule_p_p.h b/src/qml/qml/qqmltypemodule_p_p.h
new file mode 100644
index 0000000000..b1dab1c4a0
--- /dev/null
+++ b/src/qml/qml/qqmltypemodule_p_p.h
@@ -0,0 +1,89 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTYPEMODULE_P_P_H
+#define QQMLTYPEMODULE_P_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmltypemodule_p.h>
+#include <private/qstringhash_p.h>
+#include <private/qqmlmetatypedata_p.h>
+
+#include <QtCore/qmutex.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlTypeModulePrivate
+{
+public:
+    QQmlTypeModulePrivate(QString module, int majorVersion) :
+        module(std::move(module)), majorVersion(majorVersion)
+    {}
+
+    const QString module;
+    const int majorVersion = 0;
+
+    // Can only ever decrease
+    QAtomicInt minMinorVersion = std::numeric_limits<int>::max();
+
+    // Can only ever increase
+    QAtomicInt maxMinorVersion = 0;
+
+    // Bool. Can only be set to 1 once.
+    QAtomicInt locked = 0;
+
+    typedef QStringHash<QList<QQmlTypePrivate *> > TypeHash;
+    TypeHash typeHash;
+
+    QMutex mutex;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLTYPEMODULE_P_P_H
diff --git a/src/qml/qml/qqmltypemoduleversion.cpp b/src/qml/qml/qqmltypemoduleversion.cpp
new file mode 100644
index 0000000000..bbbfa1a7b6
--- /dev/null
+++ b/src/qml/qml/qqmltypemoduleversion.cpp
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmltypemoduleversion_p.h"
+
+#include <private/qqmltype_p.h>
+#include <private/qqmltypemodule_p.h>
+
+QT_BEGIN_NAMESPACE
+
+QQmlTypeModuleVersion::QQmlTypeModuleVersion()
+    : m_module(nullptr), m_minor(0)
+{
+}
+
+QQmlTypeModuleVersion::QQmlTypeModuleVersion(QQmlTypeModule *module, int minor)
+    : m_module(module), m_minor(minor)
+{
+    Q_ASSERT(m_module);
+    Q_ASSERT(m_minor >= 0);
+}
+
+QQmlTypeModuleVersion::QQmlTypeModuleVersion(const QQmlTypeModuleVersion &o)
+    : m_module(o.m_module), m_minor(o.m_minor)
+{
+}
+
+QQmlTypeModuleVersion &QQmlTypeModuleVersion::operator=(const QQmlTypeModuleVersion &o)
+{
+    m_module = o.m_module;
+    m_minor = o.m_minor;
+    return *this;
+}
+
+QQmlTypeModule *QQmlTypeModuleVersion::module() const
+{
+    return m_module;
+}
+
+int QQmlTypeModuleVersion::minorVersion() const
+{
+    return m_minor;
+}
+
+QQmlType QQmlTypeModuleVersion::type(const QHashedStringRef &name) const
+{
+    if (!m_module)
+        return QQmlType();
+    return m_module->type(name, m_minor);
+}
+
+QQmlType QQmlTypeModuleVersion::type(const QV4::String *name) const
+{
+    if (!m_module)
+        return QQmlType();
+    return m_module->type(name, m_minor);
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltypemoduleversion_p.h b/src/qml/qml/qqmltypemoduleversion_p.h
new file mode 100644
index 0000000000..20f4709ecb
--- /dev/null
+++ b/src/qml/qml/qqmltypemoduleversion_p.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTYPEMODULEVERSION_P_H
+#define QQMLTYPEMODULEVERSION_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQml/qtqmlglobal.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlTypeModule;
+class QQmlType;
+class QHashedStringRef;
+
+namespace QV4 {
+struct String;
+}
+
+class QQmlTypeModuleVersion
+{
+public:
+    QQmlTypeModuleVersion();
+    QQmlTypeModuleVersion(QQmlTypeModule *, int);
+    QQmlTypeModuleVersion(const QQmlTypeModuleVersion &);
+    QQmlTypeModuleVersion &operator=(const QQmlTypeModuleVersion &);
+
+    QQmlTypeModule *module() const;
+    int minorVersion() const;
+
+    QQmlType type(const QHashedStringRef &) const;
+    QQmlType type(const QV4::String *) const;
+
+private:
+    QQmlTypeModule *m_module;
+    int m_minor;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLTYPEMODULEVERSION_P_H
diff --git a/src/qml/qml/qqmltypenamecache.cpp b/src/qml/qml/qqmltypenamecache.cpp
index c8e2b92c29..8f1a61e6ad 100644
--- a/src/qml/qml/qqmltypenamecache.cpp
+++ b/src/qml/qml/qqmltypenamecache.cpp
@@ -55,8 +55,8 @@ QQmlTypeNameCache::~QQmlTypeNameCache()
 void QQmlTypeNameCache::add(const QHashedString &name, const QUrl &url, const QHashedString &nameSpace)
 {
     if (nameSpace.length() != 0) {
-        Import *i = m_namedImports.value(nameSpace);
-        Q_ASSERT(i != 0);
+        QQmlImportRef *i = m_namedImports.value(nameSpace);
+        Q_ASSERT(i != nullptr);
         i->compositeSingletons.insert(name, url);
         return;
     }
@@ -69,13 +69,13 @@ void QQmlTypeNameCache::add(const QHashedString &name, const QUrl &url, const QH
 
 void QQmlTypeNameCache::add(const QHashedString &name, int importedScriptIndex, const QHashedString &nameSpace)
 {
-    Import import;
+    QQmlImportRef import;
     import.scriptIndex = importedScriptIndex;
     import.m_qualifier = name;
 
     if (nameSpace.length() != 0) {
-        Import *i = m_namedImports.value(nameSpace);
-        Q_ASSERT(i != 0);
+        QQmlImportRef *i = m_namedImports.value(nameSpace);
+        Q_ASSERT(i != nullptr);
         m_namespacedImports[i].insert(name, import);
         return;
     }
@@ -98,10 +98,10 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QHashedStringRef &name)
 
     if (!result.isValid()) {
         // Look up anonymous types from the imports of this document
-        QQmlImportNamespace *typeNamespace = 0;
+        QQmlImportNamespace *typeNamespace = nullptr;
         QList<QQmlError> errors;
-        QQmlType *t = 0;
-        bool typeFound = m_imports.resolveType(name, &t, 0, 0, &typeNamespace, &errors);
+        QQmlType t;
+        bool typeFound = m_imports.resolveType(name, &t, nullptr, nullptr, &typeNamespace, &errors);
         if (typeFound) {
             return Result(t);
         }
@@ -112,26 +112,24 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QHashedStringRef &name)
 }
 
 QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QHashedStringRef &name,
-                                                   const void *importNamespace) const
+                                                   const QQmlImportRef *importNamespace) const
 {
-    Q_ASSERT(importNamespace);
-    const Import *i = static_cast<const Import *>(importNamespace);
-    Q_ASSERT(i->scriptIndex == -1);
+    Q_ASSERT(importNamespace && importNamespace->scriptIndex == -1);
 
-    Result result = typeSearch(i->modules, name);
+    Result result = typeSearch(importNamespace->modules, name);
 
     if (!result.isValid())
-        result = query(i->compositeSingletons, name);
+        result = query(importNamespace->compositeSingletons, name);
 
     if (!result.isValid()) {
         // Look up types from the imports of this document
         // ### it would be nice if QQmlImports allowed us to resolve a namespace
         // first, and then types on it.
-        QString qualifiedTypeName = i->m_qualifier + QLatin1Char('.') + name.toString();
-        QQmlImportNamespace *typeNamespace = 0;
+        QString qualifiedTypeName = importNamespace->m_qualifier + QLatin1Char('.') + name.toString();
+        QQmlImportNamespace *typeNamespace = nullptr;
         QList<QQmlError> errors;
-        QQmlType *t = 0;
-        bool typeFound = m_imports.resolveType(qualifiedTypeName, &t, 0, 0, &typeNamespace, &errors);
+        QQmlType t;
+        bool typeFound = m_imports.resolveType(qualifiedTypeName, &t, nullptr, nullptr, &typeNamespace, &errors);
         if (typeFound) {
             return Result(t);
         }
@@ -140,7 +138,7 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QHashedStringRef &name,
     return result;
 }
 
-QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name) const
+QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name, QQmlImport::RecursionRestriction recursionRestriction) const
 {
     Result result = query(m_namedImports, name);
 
@@ -153,10 +151,11 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name) cons
     if (!result.isValid()) {
         // Look up anonymous types from the imports of this document
         QString typeName = name->toQStringNoThrow();
-        QQmlImportNamespace *typeNamespace = 0;
+        QQmlImportNamespace *typeNamespace = nullptr;
         QList<QQmlError> errors;
-        QQmlType *t = 0;
-        bool typeFound = m_imports.resolveType(typeName, &t, 0, 0, &typeNamespace, &errors);
+        QQmlType t;
+        bool typeFound = m_imports.resolveType(typeName, &t, nullptr, nullptr, &typeNamespace, &errors,
+                                               QQmlType::AnyRegistrationType, recursionRestriction);
         if (typeFound) {
             return Result(t);
         }
@@ -166,33 +165,31 @@ QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name) cons
     return result;
 }
 
-QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name, const void *importNamespace) const
+QQmlTypeNameCache::Result QQmlTypeNameCache::query(const QV4::String *name, const QQmlImportRef *importNamespace) const
 {
-    Q_ASSERT(importNamespace);
-    const Import *i = static_cast<const Import *>(importNamespace);
-    Q_ASSERT(i->scriptIndex == -1);
+    Q_ASSERT(importNamespace && importNamespace->scriptIndex == -1);
 
-    QMap<const Import *, QStringHash<Import> >::const_iterator it = m_namespacedImports.constFind(i);
+    QMap<const QQmlImportRef *, QStringHash<QQmlImportRef> >::const_iterator it = m_namespacedImports.constFind(importNamespace);
     if (it != m_namespacedImports.constEnd()) {
         Result r = query(*it, name);
         if (r.isValid())
             return r;
     }
 
-    Result r = typeSearch(i->modules, name);
+    Result r = typeSearch(importNamespace->modules, name);
 
     if (!r.isValid())
-        r = query(i->compositeSingletons, name);
+        r = query(importNamespace->compositeSingletons, name);
 
     if (!r.isValid()) {
         // Look up types from the imports of this document
         // ### it would be nice if QQmlImports allowed us to resolve a namespace
         // first, and then types on it.
-        QString qualifiedTypeName = i->m_qualifier + QLatin1Char('.') + name->toQStringNoThrow();
-        QQmlImportNamespace *typeNamespace = 0;
+        QString qualifiedTypeName = importNamespace->m_qualifier + QLatin1Char('.') + name->toQStringNoThrow();
+        QQmlImportNamespace *typeNamespace = nullptr;
         QList<QQmlError> errors;
-        QQmlType *t = 0;
-        bool typeFound = m_imports.resolveType(qualifiedTypeName, &t, 0, 0, &typeNamespace, &errors);
+        QQmlType t;
+        bool typeFound = m_imports.resolveType(qualifiedTypeName, &t, nullptr, nullptr, &typeNamespace, &errors);
         if (typeFound) {
             return Result(t);
         }
diff --git a/src/qml/qml/qqmltypenamecache_p.h b/src/qml/qml/qqmltypenamecache_p.h
index 7cdcbe91b6..b98fe77ed5 100644
--- a/src/qml/qml/qqmltypenamecache_p.h
+++ b/src/qml/qml/qqmltypenamecache_p.h
@@ -55,20 +55,38 @@
 #include "qqmlcleanup_p.h"
 #include "qqmlmetatype_p.h"
 
-#include <private/qhashedstring_p.h>
+#include <private/qstringhash_p.h>
 #include <private/qqmlimport_p.h>
+#include <private/qqmltypemoduleversion_p.h>
 
 #include <QtCore/qvector.h>
 
 QT_BEGIN_NAMESPACE
 
+struct QQmlImportRef {
+    inline QQmlImportRef()
+        : scriptIndex(-1)
+    {}
+    // Imported module
+    QVector<QQmlTypeModuleVersion> modules;
+
+    // Or, imported script
+    int scriptIndex;
+
+    // Or, imported compositeSingletons
+    QStringHash<QUrl> compositeSingletons;
+
+    // The qualifier of this import
+    QString m_qualifier;
+};
+
 class QQmlType;
 class QQmlEngine;
-class QQmlTypeNameCache : public QQmlRefCount
+class Q_QML_PRIVATE_EXPORT QQmlTypeNameCache : public QQmlRefCount
 {
 public:
     QQmlTypeNameCache(const QQmlImports &imports);
-    virtual ~QQmlTypeNameCache();
+    ~QQmlTypeNameCache() override;
 
     inline bool isEmpty() const;
 
@@ -77,50 +95,35 @@ public:
 
     struct Result {
         inline Result();
-        inline Result(const void *importNamespace);
-        inline Result(QQmlType *type);
+        inline Result(const QQmlImportRef *importNamespace);
+        inline Result(const QQmlType &type);
         inline Result(int scriptIndex);
         inline Result(const Result &);
 
         inline bool isValid() const;
 
-        QQmlType *type;
-        const void *importNamespace;
+        QQmlType type;
+        const QQmlImportRef *importNamespace;
         int scriptIndex;
     };
     Result query(const QHashedStringRef &) const;
-    Result query(const QHashedStringRef &, const void *importNamespace) const;
-    Result query(const QV4::String *) const;
-    Result query(const QV4::String *, const void *importNamespace) const;
+    Result query(const QHashedStringRef &, const QQmlImportRef *importNamespace) const;
+    Result query(const QV4::String *, QQmlImport::RecursionRestriction recursionRestriction = QQmlImport::PreventRecursion) const;
+    Result query(const QV4::String *, const QQmlImportRef *importNamespace) const;
 
 private:
     friend class QQmlImports;
 
-    struct Import {
-        inline Import();
-        // Imported module
-        QVector<QQmlTypeModuleVersion> modules;
-
-        // Or, imported script
-        int scriptIndex;
-
-        // Or, imported compositeSingletons
-        QStringHash<QUrl> compositeSingletons;
-
-        // The qualifier of this import
-        QString m_qualifier;
-    };
-
     template<typename Key>
-    Result query(const QStringHash<Import> &imports, Key key) const
+    Result query(const QStringHash<QQmlImportRef> &imports, Key key) const
     {
-        Import *i = imports.value(key);
+        QQmlImportRef *i = imports.value(key);
         if (i) {
             Q_ASSERT(!i->m_qualifier.isEmpty());
             if (i->scriptIndex != -1) {
                 return Result(i->scriptIndex);
             } else {
-                return Result(static_cast<const void *>(i));
+                return Result(i);
             }
         }
 
@@ -132,9 +135,8 @@ private:
     {
         QUrl *url = urls.value(key);
         if (url) {
-            QQmlType *type = QQmlMetaType::qmlType(*url);
-            if (type)
-                return Result(type);
+            QQmlType type = QQmlMetaType::qmlType(*url);
+            return Result(type);
         }
 
         return Result();
@@ -145,37 +147,38 @@ private:
     {
         QVector<QQmlTypeModuleVersion>::const_iterator end = modules.constEnd();
         for (QVector<QQmlTypeModuleVersion>::const_iterator it = modules.constBegin(); it != end; ++it) {
-            if (QQmlType *type = it->type(key))
+            QQmlType type = it->type(key);
+            if (type.isValid())
                 return Result(type);
         }
 
         return Result();
     }
 
-    QStringHash<Import> m_namedImports;
-    QMap<const Import *, QStringHash<Import> > m_namespacedImports;
+    QStringHash<QQmlImportRef> m_namedImports;
+    QMap<const QQmlImportRef *, QStringHash<QQmlImportRef> > m_namespacedImports;
     QVector<QQmlTypeModuleVersion> m_anonymousImports;
     QStringHash<QUrl> m_anonymousCompositeSingletons;
     QQmlImports m_imports;
 };
 
 QQmlTypeNameCache::Result::Result()
-: type(0), importNamespace(0), scriptIndex(-1)
+: importNamespace(nullptr), scriptIndex(-1)
 {
 }
 
-QQmlTypeNameCache::Result::Result(const void *importNamespace)
-: type(0), importNamespace(importNamespace), scriptIndex(-1)
+QQmlTypeNameCache::Result::Result(const QQmlImportRef *importNamespace)
+: importNamespace(importNamespace), scriptIndex(-1)
 {
 }
 
-QQmlTypeNameCache::Result::Result(QQmlType *type)
-: type(type), importNamespace(0), scriptIndex(-1)
+QQmlTypeNameCache::Result::Result(const QQmlType &type)
+: type(type), importNamespace(nullptr), scriptIndex(-1)
 {
 }
 
 QQmlTypeNameCache::Result::Result(int scriptIndex)
-: type(0), importNamespace(0), scriptIndex(scriptIndex)
+: importNamespace(nullptr), scriptIndex(scriptIndex)
 {
 }
 
@@ -186,12 +189,7 @@ QQmlTypeNameCache::Result::Result(const Result &o)
 
 bool QQmlTypeNameCache::Result::isValid() const
 {
-    return type || importNamespace || scriptIndex != -1;
-}
-
-QQmlTypeNameCache::Import::Import()
-: scriptIndex(-1)
-{
+    return type.isValid() || importNamespace || scriptIndex != -1;
 }
 
 bool QQmlTypeNameCache::isEmpty() const
diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index 7a06077c11..3ec828ea2d 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -42,6 +42,7 @@
 
 #include <private/qqmlengine_p.h>
 #include <private/qqmlcontext_p.h>
+#include <private/qqmlmetaobject_p.h>
 
 #include <private/qjsvalue_p.h>
 #include <private/qv4functionobject_p.h>
@@ -64,78 +65,86 @@ void Heap::QQmlTypeWrapper::init()
 
 void Heap::QQmlTypeWrapper::destroy()
 {
+    QQmlType::derefHandle(typePrivate);
+    typePrivate = nullptr;
     if (typeNamespace)
         typeNamespace->release();
     object.destroy();
     Object::destroy();
 }
 
+QQmlType Heap::QQmlTypeWrapper::type() const
+{
+    return QQmlType(typePrivate);
+}
+
 bool QQmlTypeWrapper::isSingleton() const
 {
-    return d()->type && d()->type->isSingleton();
+    return d()->type().isSingleton();
 }
 
 QObject* QQmlTypeWrapper::singletonObject() const
 {
     if (!isSingleton())
-        return 0;
+        return nullptr;
 
     QQmlEngine *e = engine()->qmlEngine();
-    QQmlType::SingletonInstanceInfo *siinfo = d()->type->singletonInstanceInfo();
+    QQmlType::SingletonInstanceInfo *siinfo = d()->type().singletonInstanceInfo();
     siinfo->init(e);
     return siinfo->qobjectApi(e);
 }
 
 QVariant QQmlTypeWrapper::toVariant() const
 {
-    if (d()->type && d()->type->isSingleton()) {
-        QQmlEngine *e = engine()->qmlEngine();
-        QQmlType::SingletonInstanceInfo *siinfo = d()->type->singletonInstanceInfo();
-        siinfo->init(e); // note: this will also create QJSValue singleton which isn't strictly required.
-        QObject *qobjectSingleton = siinfo->qobjectApi(e);
-        if (qobjectSingleton) {
-            return QVariant::fromValue<QObject*>(qobjectSingleton);
-        }
-    }
+    // Only Singleton type wrappers can be converted to a variant.
+    if (!isSingleton())
+        return QVariant();
+
+    QQmlEngine *e = engine()->qmlEngine();
+    QQmlType::SingletonInstanceInfo *siinfo = d()->type().singletonInstanceInfo();
+    siinfo->init(e);
+    if (QObject *qobjectSingleton = siinfo->qobjectApi(e))
+        return QVariant::fromValue<QObject*>(qobjectSingleton);
 
-    // only QObject Singleton Type can be converted to a variant.
-    return QVariant();
+    return QVariant::fromValue<QJSValue>(siinfo->scriptApi(e));
 }
 
 
 // Returns a type wrapper for type t on o.  This allows access of enums, and attached properties.
-ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o, QQmlType *t,
+ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o, const QQmlType &t,
                                      Heap::QQmlTypeWrapper::TypeNameMode mode)
 {
-    Q_ASSERT(t);
+    Q_ASSERT(t.isValid());
     Scope scope(engine);
 
-    Scoped<QQmlTypeWrapper> w(scope, engine->memoryManager->allocObject<QQmlTypeWrapper>());
-    w->d()->mode = mode; w->d()->object = o; w->d()->type = t;
+    Scoped<QQmlTypeWrapper> w(scope, engine->memoryManager->allocate<QQmlTypeWrapper>());
+    w->d()->mode = mode; w->d()->object = o;
+    w->d()->typePrivate = t.priv();
+    QQmlType::refHandle(w->d()->typePrivate);
     return w.asReturnedValue();
 }
 
 // Returns a type wrapper for importNamespace (of t) on o.  This allows nested resolution of a type in a
 // namespace.
-ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o, QQmlTypeNameCache *t, const void *importNamespace,
+ReturnedValue QQmlTypeWrapper::create(QV4::ExecutionEngine *engine, QObject *o, const QQmlRefPointer<QQmlTypeNameCache> &t, const QQmlImportRef *importNamespace,
                                      Heap::QQmlTypeWrapper::TypeNameMode mode)
 {
     Q_ASSERT(t);
     Q_ASSERT(importNamespace);
     Scope scope(engine);
 
-    Scoped<QQmlTypeWrapper> w(scope, engine->memoryManager->allocObject<QQmlTypeWrapper>());
-    w->d()->mode = mode; w->d()->object = o; w->d()->typeNamespace = t; w->d()->importNamespace = importNamespace;
+    Scoped<QQmlTypeWrapper> w(scope, engine->memoryManager->allocate<QQmlTypeWrapper>());
+    w->d()->mode = mode; w->d()->object = o; w->d()->typeNamespace = t.data(); w->d()->importNamespace = importNamespace;
     t->addref();
     return w.asReturnedValue();
 }
 
 static int enumForSingleton(QV4::ExecutionEngine *v4, String *name, QObject *qobjectSingleton,
-                            QQmlType *type)
+                            const QQmlType &type, bool *ok)
 {
-    bool ok;
-    int value = type->enumValue(QQmlEnginePrivate::get(v4->qmlEngine()), name, &ok);
-    if (ok)
+    Q_ASSERT(ok != nullptr);
+    int value = type.enumValue(QQmlEnginePrivate::get(v4->qmlEngine()), name, ok);
+    if (*ok)
         return value;
 
     // ### Optimize
@@ -143,27 +152,32 @@ static int enumForSingleton(QV4::ExecutionEngine *v4, String *name, QObject *qob
     const QMetaObject *metaObject = qobjectSingleton->metaObject();
     for (int ii = metaObject->enumeratorCount() - 1; ii >= 0; --ii) {
         QMetaEnum e = metaObject->enumerator(ii);
-        value = e.keyToValue(enumName.constData(), &ok);
-        if (ok)
+        value = e.keyToValue(enumName.constData(), ok);
+        if (*ok)
             return value;
     }
+    *ok = false;
     return -1;
 }
 
-static ReturnedValue throwLowercaseEnumError(QV4::ExecutionEngine *v4, String *name, QQmlType *type)
+static ReturnedValue throwLowercaseEnumError(QV4::ExecutionEngine *v4, String *name, const QQmlType &type)
 {
     const QString message =
             QStringLiteral("Cannot access enum value '%1' of '%2', enum values need to start with an uppercase letter.")
-                .arg(name->toQString()).arg(QLatin1String(type->typeName()));
+                .arg(name->toQString()).arg(QLatin1String(type.typeName()));
     return v4->throwTypeError(message);
 }
 
-ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProperty)
+ReturnedValue QQmlTypeWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<QQmlTypeWrapper>());
 
+    if (!id.isString())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+
     QV4::ExecutionEngine *v4 = static_cast<const QQmlTypeWrapper *>(m)->engine();
     QV4::Scope scope(v4);
+    ScopedString name(scope, id.asStringOrSymbol());
 
     Scoped<QQmlTypeWrapper> w(scope, static_cast<const QQmlTypeWrapper *>(m));
 
@@ -173,14 +187,14 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
     QQmlContextData *context = v4->callingQmlContext();
 
     QObject *object = w->d()->object;
-    QQmlType *type = w->d()->type;
+    QQmlType type = w->d()->type();
 
-    if (type) {
+    if (type.isValid()) {
 
         // singleton types are handled differently to other types.
-        if (type->isSingleton()) {
+        if (type.isSingleton()) {
             QQmlEngine *e = v4->qmlEngine();
-            QQmlType::SingletonInstanceInfo *siinfo = type->singletonInstanceInfo();
+            QQmlType::SingletonInstanceInfo *siinfo = type.singletonInstanceInfo();
             siinfo->init(e);
 
             QObject *qobjectSingleton = siinfo->qobjectApi(e);
@@ -189,9 +203,19 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
                 // check for enum value
                 const bool includeEnums = w->d()->mode == Heap::QQmlTypeWrapper::IncludeEnums;
                 if (includeEnums && name->startsWithUpper()) {
-                    const int value = enumForSingleton(v4, name, qobjectSingleton, type);
-                    if (value != -1)
-                        return QV4::Primitive::fromInt32(value).asReturnedValue();
+                    bool ok = false;
+                    int value = enumForSingleton(v4, name, qobjectSingleton, type, &ok);
+                    if (ok)
+                        return QV4::Value::fromInt32(value).asReturnedValue();
+
+                    value = type.scopedEnumIndex(QQmlEnginePrivate::get(v4->qmlEngine()), name, &ok);
+                    if (ok) {
+                        Scoped<QQmlScopedEnumWrapper> enumWrapper(scope, v4->memoryManager->allocate<QQmlScopedEnumWrapper>());
+                        enumWrapper->d()->typePrivate = type.priv();
+                        QQmlType::refHandle(enumWrapper->d()->typePrivate);
+                        enumWrapper->d()->scopeEnumIndex = value;
+                        return enumWrapper.asReturnedValue();
+                    }
                 }
 
                 // check for property.
@@ -202,8 +226,8 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
 
                 // Warn when attempting to access a lowercased enum value, singleton case
                 if (!ok && includeEnums && !name->startsWithUpper()) {
-                    const int value = enumForSingleton(v4, name, qobjectSingleton, type);
-                    if (value != -1)
+                    enumForSingleton(v4, name, qobjectSingleton, type, &ok);
+                    if (ok)
                         return throwLowercaseEnumError(v4, name, type);
                 }
 
@@ -221,14 +245,15 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
 
             if (name->startsWithUpper()) {
                 bool ok = false;
-                int value = type->enumValue(QQmlEnginePrivate::get(v4->qmlEngine()), name, &ok);
+                int value = type.enumValue(QQmlEnginePrivate::get(v4->qmlEngine()), name, &ok);
                 if (ok)
-                    return QV4::Primitive::fromInt32(value).asReturnedValue();
+                    return QV4::Value::fromInt32(value).asReturnedValue();
 
-                value = type->scopedEnumIndex(QQmlEnginePrivate::get(v4->qmlEngine()), name, &ok);
+                value = type.scopedEnumIndex(QQmlEnginePrivate::get(v4->qmlEngine()), name, &ok);
                 if (ok) {
-                    Scoped<QQmlScopedEnumWrapper> enumWrapper(scope, v4->memoryManager->allocObject<QQmlScopedEnumWrapper>());
-                    enumWrapper->d()->type = type;
+                    Scoped<QQmlScopedEnumWrapper> enumWrapper(scope, v4->memoryManager->allocate<QQmlScopedEnumWrapper>());
+                    enumWrapper->d()->typePrivate = type.priv();
+                    QQmlType::refHandle(enumWrapper->d()->typePrivate);
                     enumWrapper->d()->scopeEnumIndex = value;
                     return enumWrapper.asReturnedValue();
                 }
@@ -236,7 +261,7 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
                 // Fall through to base implementation
 
             } else if (w->d()->object) {
-                QObject *ao = qmlAttachedPropertiesObjectById(type->attachedPropertiesId(QQmlEnginePrivate::get(v4->qmlEngine())), object);
+                QObject *ao = qmlAttachedPropertiesObjectById(type.attachedPropertiesId(QQmlEnginePrivate::get(v4->qmlEngine())), object);
                 if (ao)
                     return QV4::QObjectWrapper::getQmlProperty(v4, context, ao, name, QV4::QObjectWrapper::IgnoreRevision, hasProperty);
 
@@ -253,11 +278,11 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
         QQmlTypeNameCache::Result r = w->d()->typeNamespace->query(name, w->d()->importNamespace);
 
         if (r.isValid()) {
-            if (r.type) {
+            if (r.type.isValid()) {
                 return create(scope.engine, object, r.type, w->d()->mode);
             } else if (r.scriptIndex != -1) {
                 QV4::ScopedObject scripts(scope, context->importedScripts.valueRef());
-                return scripts->getIndexed(r.scriptIndex);
+                return scripts->get(r.scriptIndex);
             } else if (r.importNamespace) {
                 return create(scope.engine, object, context->imports, r.importNamespace);
             }
@@ -273,14 +298,14 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
     }
 
     bool ok = false;
-    const ReturnedValue result = Object::get(m, name, &ok);
+    const ReturnedValue result = Object::virtualGet(m, id, receiver, &ok);
     if (hasProperty)
         *hasProperty = ok;
 
     // Warn when attempting to access a lowercased enum value, non-singleton case
-    if (!ok && type && !type->isSingleton() && !name->startsWithUpper()) {
+    if (!ok && type.isValid() && !type.isSingleton() && !name->startsWithUpper()) {
         bool enumOk = false;
-        type->enumValue(QQmlEnginePrivate::get(v4->qmlEngine()), name, &enumOk);
+        type.enumValue(QQmlEnginePrivate::get(v4->qmlEngine()), name, &enumOk);
         if (enumOk)
             return throwLowercaseEnumError(v4, name, type);
     }
@@ -289,38 +314,42 @@ ReturnedValue QQmlTypeWrapper::get(const Managed *m, String *name, bool *hasProp
 }
 
 
-bool QQmlTypeWrapper::put(Managed *m, String *name, const Value &value)
+bool QQmlTypeWrapper::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
+    if (!id.isString())
+        return Object::virtualPut(m, id, value, receiver);
+
+
     Q_ASSERT(m->as<QQmlTypeWrapper>());
     QQmlTypeWrapper *w = static_cast<QQmlTypeWrapper *>(m);
-    QV4::ExecutionEngine *v4 = w->engine();
-    if (v4->hasException)
+    QV4::Scope scope(w);
+    if (scope.engine->hasException)
         return false;
 
-    QV4::Scope scope(v4);
-    QQmlContextData *context = v4->callingQmlContext();
+    ScopedString name(scope, id.asStringOrSymbol());
+    QQmlContextData *context = scope.engine->callingQmlContext();
 
-    QQmlType *type = w->d()->type;
-    if (type && !type->isSingleton() && w->d()->object) {
+    QQmlType type = w->d()->type();
+    if (type.isValid() && !type.isSingleton() && w->d()->object) {
         QObject *object = w->d()->object;
         QQmlEngine *e = scope.engine->qmlEngine();
-        QObject *ao = qmlAttachedPropertiesObjectById(type->attachedPropertiesId(QQmlEnginePrivate::get(e)), object);
+        QObject *ao = qmlAttachedPropertiesObjectById(type.attachedPropertiesId(QQmlEnginePrivate::get(e)), object);
         if (ao)
-            return QV4::QObjectWrapper::setQmlProperty(v4, context, ao, name, QV4::QObjectWrapper::IgnoreRevision, value);
+            return QV4::QObjectWrapper::setQmlProperty(scope.engine, context, ao, name, QV4::QObjectWrapper::IgnoreRevision, value);
         return false;
-    } else if (type && type->isSingleton()) {
+    } else if (type.isSingleton()) {
         QQmlEngine *e = scope.engine->qmlEngine();
-        QQmlType::SingletonInstanceInfo *siinfo = type->singletonInstanceInfo();
+        QQmlType::SingletonInstanceInfo *siinfo = type.singletonInstanceInfo();
         siinfo->init(e);
 
         QObject *qobjectSingleton = siinfo->qobjectApi(e);
         if (qobjectSingleton) {
-            return QV4::QObjectWrapper::setQmlProperty(v4, context, qobjectSingleton, name, QV4::QObjectWrapper::IgnoreRevision, value);
+            return QV4::QObjectWrapper::setQmlProperty(scope.engine, context, qobjectSingleton, name, QV4::QObjectWrapper::IgnoreRevision, value);
         } else if (!siinfo->scriptApi(e).isUndefined()) {
-            QV4::ScopedObject apiprivate(scope, QJSValuePrivate::convertedToValue(v4, siinfo->scriptApi(e)));
+            QV4::ScopedObject apiprivate(scope, QJSValuePrivate::convertedToValue(scope.engine, siinfo->scriptApi(e)));
             if (!apiprivate) {
                 QString error = QLatin1String("Cannot assign to read-only property \"") + name->toQString() + QLatin1Char('\"');
-                v4->throwError(error);
+                scope.engine->throwError(error);
                 return false;
             } else {
                 return apiprivate->put(name, value);
@@ -331,15 +360,21 @@ bool QQmlTypeWrapper::put(Managed *m, String *name, const Value &value)
     return false;
 }
 
-PropertyAttributes QQmlTypeWrapper::query(const Managed *m, String *name)
+PropertyAttributes QQmlTypeWrapper::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
 {
-    // ### Implement more efficiently.
-    bool hasProperty = false;
-    static_cast<Object *>(const_cast<Managed*>(m))->get(name, &hasProperty);
-    return hasProperty ? Attr_Data : Attr_Invalid;
+    if (id.isString()) {
+        Scope scope(m);
+        ScopedString n(scope, id.asStringOrSymbol());
+        // ### Implement more efficiently.
+        bool hasProperty = false;
+        static_cast<const Object *>(m)->get(n, &hasProperty);
+        return hasProperty ? Attr_Data : Attr_Invalid;
+    }
+
+    return QV4::Object::virtualGetOwnProperty(m, id, p);
 }
 
-bool QQmlTypeWrapper::isEqualTo(Managed *a, Managed *b)
+bool QQmlTypeWrapper::virtualIsEqualTo(Managed *a, Managed *b)
 {
     Q_ASSERT(a->as<QV4::QQmlTypeWrapper>());
     QV4::QQmlTypeWrapper *qmlTypeWrapperA = static_cast<QV4::QQmlTypeWrapper *>(a);
@@ -351,7 +386,7 @@ bool QQmlTypeWrapper::isEqualTo(Managed *a, Managed *b)
     return false;
 }
 
-ReturnedValue QQmlTypeWrapper::instanceOf(const Object *typeObject, const Value &var)
+ReturnedValue QQmlTypeWrapper::virtualInstanceOf(const Object *typeObject, const Value &var)
 {
     Q_ASSERT(typeObject->as<QV4::QQmlTypeWrapper>());
     const QV4::QQmlTypeWrapper *typeWrapper = static_cast<const QV4::QQmlTypeWrapper *>(typeObject);
@@ -368,7 +403,7 @@ ReturnedValue QQmlTypeWrapper::instanceOf(const Object *typeObject, const Value
     if (!wrapperObject)
         return engine->throwTypeError();
 
-    const int myTypeId = typeWrapper->d()->type->typeId();
+    const int myTypeId = typeWrapper->d()->type().typeId();
     QQmlMetaObject myQmlType;
     if (myTypeId == 0) {
         // we're a composite type; a composite type cannot be equal to a
@@ -379,7 +414,7 @@ ReturnedValue QQmlTypeWrapper::instanceOf(const Object *typeObject, const Value
         if (!theirDData->compilationUnit)
             return Encode(false);
 
-        QQmlTypeData *td = qenginepriv->typeLoader.getType(typeWrapper->d()->type->sourceUrl());
+        QQmlRefPointer<QQmlTypeData> td = qenginepriv->typeLoader.getType(typeWrapper->d()->type().sourceUrl());
         CompiledData::CompilationUnit *cu = td->compilationUnit();
         myQmlType = qenginepriv->metaObjectForType(cu->metaTypeId);
     } else {
@@ -391,22 +426,38 @@ ReturnedValue QQmlTypeWrapper::instanceOf(const Object *typeObject, const Value
     return QV4::Encode(QQmlMetaObject::canConvert(theirType, myQmlType));
 }
 
-ReturnedValue QQmlScopedEnumWrapper::get(const Managed *m, String *name, bool *hasProperty)
+void Heap::QQmlScopedEnumWrapper::destroy()
+{
+    QQmlType::derefHandle(typePrivate);
+    typePrivate = nullptr;
+    Object::destroy();
+}
+
+QQmlType Heap::QQmlScopedEnumWrapper::type() const
+{
+    return QQmlType(typePrivate);
+}
+
+ReturnedValue QQmlScopedEnumWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<QQmlScopedEnumWrapper>());
+    if (!id.isString())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+
     const QQmlScopedEnumWrapper *resource = static_cast<const QQmlScopedEnumWrapper *>(m);
     QV4::ExecutionEngine *v4 = resource->engine();
     QV4::Scope scope(v4);
+    ScopedString name(scope, id.asStringOrSymbol());
 
-    QQmlType *type = resource->d()->type;
+    QQmlType type = resource->d()->type();
     int index = resource->d()->scopeEnumIndex;
 
     bool ok = false;
-    int value = type->scopedEnumValue(QQmlEnginePrivate::get(v4->qmlEngine()), index, name, &ok);
+    int value = type.scopedEnumValue(QQmlEnginePrivate::get(v4->qmlEngine()), index, name, &ok);
     if (hasProperty)
         *hasProperty = ok;
     if (ok)
-        return QV4::Primitive::fromInt32(value).asReturnedValue();
+        return QV4::Value::fromInt32(value).asReturnedValue();
 
     return Encode::undefined();
 }
diff --git a/src/qml/qml/qqmltypewrapper_p.h b/src/qml/qml/qqmltypewrapper_p.h
index 730bfd6d12..bc615e0f6c 100644
--- a/src/qml/qml/qqmltypewrapper_p.h
+++ b/src/qml/qml/qqmltypewrapper_p.h
@@ -60,6 +60,9 @@
 QT_BEGIN_NAMESPACE
 
 class QQmlTypeNameCache;
+class QQmlType;
+class QQmlTypePrivate;
+struct QQmlImportRef;
 
 namespace QV4 {
 
@@ -76,16 +79,19 @@ struct QQmlTypeWrapper : Object {
     TypeNameMode mode;
     QQmlQPointer<QObject> object;
 
-    QQmlType *type;
+    QQmlType type() const;
+
+    const QQmlTypePrivate *typePrivate;
     QQmlTypeNameCache *typeNamespace;
-    const void *importNamespace;
+    const QQmlImportRef *importNamespace;
 };
 
 struct QQmlScopedEnumWrapper : Object {
     void init() { Object::init(); }
-    void destroy() { Object::destroy(); }
+    void destroy();
     int scopeEnumIndex;
-    QQmlType *type;
+    const QQmlTypePrivate *typePrivate;
+    QQmlType type() const;
 };
 
 }
@@ -100,17 +106,17 @@ struct Q_QML_EXPORT QQmlTypeWrapper : Object
 
     QVariant toVariant() const;
 
-    static ReturnedValue create(ExecutionEngine *, QObject *, QQmlType *,
+    static ReturnedValue create(ExecutionEngine *, QObject *, const QQmlType &,
                                 Heap::QQmlTypeWrapper::TypeNameMode = Heap::QQmlTypeWrapper::IncludeEnums);
-    static ReturnedValue create(ExecutionEngine *, QObject *, QQmlTypeNameCache *, const void *,
+    static ReturnedValue create(ExecutionEngine *, QObject *, const QQmlRefPointer<QQmlTypeNameCache> &, const QQmlImportRef *,
                                 Heap::QQmlTypeWrapper::TypeNameMode = Heap::QQmlTypeWrapper::IncludeEnums);
 
-
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static bool put(Managed *m, String *name, const Value &value);
-    static PropertyAttributes query(const Managed *, String *name);
-    static bool isEqualTo(Managed *that, Managed *o);
-    static ReturnedValue instanceOf(const Object *typeObject, const Value &var);
+protected:
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static bool virtualIsEqualTo(Managed *that, Managed *o);
+    static ReturnedValue virtualInstanceOf(const Object *typeObject, const Value &var);
 };
 
 struct Q_QML_EXPORT QQmlScopedEnumWrapper : Object
@@ -118,7 +124,7 @@ struct Q_QML_EXPORT QQmlScopedEnumWrapper : Object
     V4_OBJECT2(QQmlScopedEnumWrapper, Object)
     V4_NEEDS_DESTROY
 
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
 };
 
 }
diff --git a/src/qml/qml/qqmlvaluetype.cpp b/src/qml/qml/qqmlvaluetype.cpp
index 520f512b1a..21505754bb 100644
--- a/src/qml/qml/qqmlvaluetype.cpp
+++ b/src/qml/qml/qqmlvaluetype.cpp
@@ -38,7 +38,6 @@
 ****************************************************************************/
 
 #include "qqmlvaluetype_p.h"
-#include "qqmlmetatype_p.h"
 
 #include <private/qqmlglobal_p.h>
 #include <QtCore/qdebug.h>
@@ -67,8 +66,7 @@ struct QQmlValueTypeFactoryImpl
 
 QQmlValueTypeFactoryImpl::QQmlValueTypeFactoryImpl()
 {
-    for (unsigned int ii = 0; ii < QVariant::UserType; ++ii)
-        valueTypes[ii] = 0;
+    std::fill_n(valueTypes, int(QVariant::UserType), nullptr);
 
     // See types wrapped in qqmlmodelindexvaluetype_p.h
     qRegisterMetaType<QItemSelectionRange>();
@@ -83,7 +81,7 @@ QQmlValueTypeFactoryImpl::~QQmlValueTypeFactoryImpl()
 bool QQmlValueTypeFactoryImpl::isValueType(int idx)
 {
     if (idx >= (int)QVariant::UserType) {
-        return (valueType(idx) != 0);
+        return (valueType(idx) != nullptr);
     } else if (idx >= 0
             && idx != QVariant::StringList
             && idx != QMetaType::QObjectStar
@@ -130,7 +128,7 @@ const QMetaObject *QQmlValueTypeFactoryImpl::metaObjectForMetaType(int t)
     QMetaType metaType(t);
     if (metaType.flags() & QMetaType::IsGadget)
         return metaType.metaObject();
-    return 0;
+    return nullptr;
 }
 
 QQmlValueType *QQmlValueTypeFactoryImpl::valueType(int idx)
@@ -141,7 +139,7 @@ QQmlValueType *QQmlValueTypeFactoryImpl::valueType(int idx)
 
         QHash<int, QQmlValueType *>::iterator it = userTypes.find(idx);
         if (it == userTypes.end()) {
-            QQmlValueType *vt = 0;
+            QQmlValueType *vt = nullptr;
             if (const QMetaObject *mo = metaObjectForMetaType(idx))
                 vt = new QQmlValueType(idx, mo);
             it = userTypes.insert(idx, vt);
@@ -192,7 +190,6 @@ void QQmlValueTypeFactory::registerValueTypes(const char *uri, int versionMajor,
 
 QQmlValueType::QQmlValueType(int typeId, const QMetaObject *gadgetMetaObject)
     : gadgetPtr(QMetaType::create(typeId))
-    , typeId(typeId)
     , metaType(typeId)
 {
     QObjectPrivate *op = QObjectPrivate::get(this);
@@ -209,14 +206,14 @@ QQmlValueType::~QQmlValueType()
 {
     QObjectPrivate *op = QObjectPrivate::get(this);
     Q_ASSERT(op->metaObject == this);
-    op->metaObject = 0;
+    op->metaObject = nullptr;
     ::free(const_cast<QMetaObject *>(_metaObject));
     metaType.destroy(gadgetPtr);
 }
 
 void QQmlValueType::read(QObject *obj, int idx)
 {
-    void *a[] = { gadgetPtr, 0 };
+    void *a[] = { gadgetPtr, nullptr };
     QMetaObject::metacall(obj, QMetaObject::ReadProperty, idx, a);
 }
 
@@ -224,19 +221,19 @@ void QQmlValueType::write(QObject *obj, int idx, QQmlPropertyData::WriteFlags fl
 {
     Q_ASSERT(gadgetPtr);
     int status = -1;
-    void *a[] = { gadgetPtr, 0, &status, &flags };
+    void *a[] = { gadgetPtr, nullptr, &status, &flags };
     QMetaObject::metacall(obj, QMetaObject::WriteProperty, idx, a);
 }
 
 QVariant QQmlValueType::value()
 {
     Q_ASSERT(gadgetPtr);
-    return QVariant(typeId, gadgetPtr);
+    return QVariant(metaType.id(), gadgetPtr);
 }
 
 void QQmlValueType::setValue(const QVariant &value)
 {
-    Q_ASSERT(typeId == value.userType());
+    Q_ASSERT(metaType.id() == value.userType());
     metaType.destruct(gadgetPtr);
     metaType.construct(gadgetPtr, value.constData());
 }
@@ -521,38 +518,33 @@ void QQmlEasingValueType::setBezierCurve(const QVariantList &customCurveVariant)
     if (customCurveVariant.isEmpty())
         return;
 
-    QVariantList variantList = customCurveVariant;
-    if ((variantList.count() % 6) == 0) {
-        bool allRealsOk = true;
-        QVector<qreal> reals;
-        const int variantListCount = variantList.count();
-        reals.reserve(variantListCount);
-        for (int i = 0; i < variantListCount; i++) {
-            bool ok;
-            const qreal real = variantList.at(i).toReal(&ok);
-            reals.append(real);
-            if (!ok)
-                allRealsOk = false;
-        }
-        if (allRealsOk) {
-            QEasingCurve newEasingCurve(QEasingCurve::BezierSpline);
-            for (int i = 0; i < reals.count() / 6; i++) {
-                const qreal c1x = reals.at(i * 6);
-                const qreal c1y = reals.at(i * 6 + 1);
-                const qreal c2x = reals.at(i * 6 + 2);
-                const qreal c2y = reals.at(i * 6 + 3);
-                const qreal c3x = reals.at(i * 6 + 4);
-                const qreal c3y = reals.at(i * 6 + 5);
-
-                const QPointF c1(c1x, c1y);
-                const QPointF c2(c2x, c2y);
-                const QPointF c3(c3x, c3y);
-
-                newEasingCurve.addCubicBezierSegment(c1, c2, c3);
-                v = newEasingCurve;
-            }
-        }
+    if ((customCurveVariant.count() % 6) != 0)
+        return;
+
+    auto convert = [](const QVariant &v, qreal &r) {
+        bool ok;
+        r = v.toReal(&ok);
+        return ok;
+    };
+
+    QEasingCurve newEasingCurve(QEasingCurve::BezierSpline);
+    for (int i = 0, ei = customCurveVariant.size(); i < ei; i += 6) {
+        qreal c1x, c1y, c2x, c2y, c3x, c3y;
+        if (!convert(customCurveVariant.at(i    ), c1x)) return;
+        if (!convert(customCurveVariant.at(i + 1), c1y)) return;
+        if (!convert(customCurveVariant.at(i + 2), c2x)) return;
+        if (!convert(customCurveVariant.at(i + 3), c2y)) return;
+        if (!convert(customCurveVariant.at(i + 4), c3x)) return;
+        if (!convert(customCurveVariant.at(i + 5), c3y)) return;
+
+        const QPointF c1(c1x, c1y);
+        const QPointF c2(c2x, c2y);
+        const QPointF c3(c3x, c3y);
+
+        newEasingCurve.addCubicBezierSegment(c1, c2, c3);
     }
+
+    v = newEasingCurve;
 }
 
 QVariantList QQmlEasingValueType::bezierCurve() const
diff --git a/src/qml/qml/qqmlvaluetype_p.h b/src/qml/qml/qqmlvaluetype_p.h
index 0502a5d665..89f1b71d61 100644
--- a/src/qml/qml/qqmlvaluetype_p.h
+++ b/src/qml/qml/qqmlvaluetype_p.h
@@ -67,7 +67,7 @@ class Q_QML_PRIVATE_EXPORT QQmlValueType : public QObject, public QAbstractDynam
 {
 public:
     QQmlValueType(int userType, const QMetaObject *metaObject);
-    ~QQmlValueType();
+    ~QQmlValueType() override;
     void read(QObject *, int);
     void write(QObject *, int, QQmlPropertyData::WriteFlags flags);
     QVariant value();
@@ -84,7 +84,6 @@ private:
     void *gadgetPtr;
 
 public:
-    int typeId;
     QMetaType metaType;
 };
 
@@ -272,19 +271,19 @@ int qmlRegisterValueTypeEnums(const char *uri, int versionMajor, int versionMino
     QQmlPrivate::RegisterType type = {
         0,
 
-        qRegisterNormalizedMetaType<T *>(pointerName.constData()), 0, 0, 0,
+        qRegisterNormalizedMetaType<T *>(pointerName.constData()), 0, 0, nullptr,
 
         QString(),
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
 
-        0, 0,
+        nullptr, nullptr,
 
         0, 0, 0,
 
-        0, 0,
+        nullptr, nullptr,
 
-        0,
+        nullptr,
         0
     };
 
diff --git a/src/qml/qml/qqmlvaluetypeproxybinding.cpp b/src/qml/qml/qqmlvaluetypeproxybinding.cpp
index 4e2e7b06c7..d5cff26444 100644
--- a/src/qml/qml/qqmlvaluetypeproxybinding.cpp
+++ b/src/qml/qml/qqmlvaluetypeproxybinding.cpp
@@ -43,7 +43,7 @@ QT_BEGIN_NAMESPACE
 
 QQmlValueTypeProxyBinding::QQmlValueTypeProxyBinding(QObject *o, QQmlPropertyIndex index)
     : QQmlAbstractBinding(),
-      m_bindings(0)
+      m_bindings(nullptr)
 {
     m_target = o;
     m_targetIndex = index;
@@ -72,6 +72,11 @@ bool QQmlValueTypeProxyBinding::isValueTypeProxy() const
     return true;
 }
 
+QQmlAbstractBinding *QQmlValueTypeProxyBinding::subBindings() const
+{
+    return m_bindings.data();
+}
+
 QQmlAbstractBinding *QQmlValueTypeProxyBinding::binding(QQmlPropertyIndex propertyIndex) const
 {
     QQmlAbstractBinding *binding = m_bindings.data();
@@ -88,7 +93,7 @@ Removes a collection of bindings, corresponding to the set bits in \a mask.
 void QQmlValueTypeProxyBinding::removeBindings(quint32 mask)
 {
     QQmlAbstractBinding *binding = m_bindings.data();
-    QQmlAbstractBinding *lastBinding = 0;
+    QQmlAbstractBinding *lastBinding = nullptr;
 
     while (binding) {
         const int valueTypeIndex = binding->targetPropertyIndex().valueTypeIndex();
@@ -97,7 +102,7 @@ void QQmlValueTypeProxyBinding::removeBindings(quint32 mask)
             remove->setAddedToObject(false);
             binding = remove->nextBinding();
 
-            if (lastBinding == 0)
+            if (lastBinding == nullptr)
                 m_bindings = remove->nextBinding();
             else
                 lastBinding->setNextBinding(remove->nextBinding());
diff --git a/src/qml/qml/qqmlvaluetypeproxybinding_p.h b/src/qml/qml/qqmlvaluetypeproxybinding_p.h
index 92b5470f39..35b54c339b 100644
--- a/src/qml/qml/qqmlvaluetypeproxybinding_p.h
+++ b/src/qml/qml/qqmlvaluetypeproxybinding_p.h
@@ -55,11 +55,12 @@
 
 QT_BEGIN_NAMESPACE
 
-class QQmlValueTypeProxyBinding : public QQmlAbstractBinding
+class Q_AUTOTEST_EXPORT QQmlValueTypeProxyBinding : public QQmlAbstractBinding
 {
 public:
     QQmlValueTypeProxyBinding(QObject *o, QQmlPropertyIndex coreIndex);
 
+    QQmlAbstractBinding *subBindings() const;
     QQmlAbstractBinding *binding(QQmlPropertyIndex targetPropertyIndex) const;
     void removeBindings(quint32 mask);
 
diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index ce47ab9fa9..9ce1c82f09 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -39,7 +39,6 @@
 
 #include "qqmlvaluetypewrapper_p.h"
 #include <private/qv8engine_p.h>
-
 #include <private/qqmlvaluetype_p.h>
 #include <private/qqmlbinding_p.h>
 #include <private/qqmlglobal_p.h>
@@ -49,6 +48,7 @@
 #include <private/qv4functionobject_p.h>
 #include <private/qv4variantobject_p.h>
 #include <private/qv4alloca_p.h>
+#include <private/qv4stackframe_p.h>
 #include <private/qv4objectiterator_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 #include <QtCore/qloggingcategory.h>
@@ -98,12 +98,14 @@ void Heap::QQmlValueTypeWrapper::destroy()
         valueType->metaType.destruct(gadgetPtr);
         ::operator delete(gadgetPtr);
     }
+    if (_propertyCache)
+        _propertyCache->release();
     Object::destroy();
 }
 
 void Heap::QQmlValueTypeWrapper::setValue(const QVariant &value) const
 {
-    Q_ASSERT(valueType->typeId == value.userType());
+    Q_ASSERT(valueType->metaType.id() == value.userType());
     if (gadgetPtr)
         valueType->metaType.destruct(gadgetPtr);
     if (!gadgetPtr)
@@ -114,7 +116,7 @@ void Heap::QQmlValueTypeWrapper::setValue(const QVariant &value) const
 QVariant Heap::QQmlValueTypeWrapper::toVariant() const
 {
     Q_ASSERT(gadgetPtr);
-    return QVariant(valueType->typeId, gadgetPtr);
+    return QVariant(valueType->metaType.id(), gadgetPtr);
 }
 
 
@@ -129,7 +131,7 @@ bool QQmlValueTypeReference::readReferenceValue() const
         // variant-containing-value-type reference
         QVariant variantReferenceValue;
 
-        void *a[] = { &variantReferenceValue, 0 };
+        void *a[] = { &variantReferenceValue, nullptr };
         QMetaObject::metacall(d()->object, QMetaObject::ReadProperty, d()->property, a);
 
         int variantReferenceType = variantReferenceValue.userType();
@@ -139,14 +141,14 @@ bool QQmlValueTypeReference::readReferenceValue() const
             // We need to modify this reference to the updated value type, if
             // possible, or return false if it is not a value type.
             if (QQmlValueTypeFactory::isValueType(variantReferenceType)) {
-                QQmlPropertyCache *cache = 0;
+                QQmlPropertyCache *cache = nullptr;
                 if (const QMetaObject *mo = QQmlValueTypeFactory::metaObjectForMetaType(variantReferenceType))
                     cache = QJSEnginePrivate::get(engine())->cache(mo);
                 if (d()->gadgetPtr) {
                     d()->valueType->metaType.destruct(d()->gadgetPtr);
                     ::operator delete(d()->gadgetPtr);
                 }
-                d()->gadgetPtr =0;
+                d()->gadgetPtr =nullptr;
                 d()->setPropertyCache(cache);
                 d()->valueType = QQmlValueTypeFactory::valueType(variantReferenceType);
                 if (!cache)
@@ -159,10 +161,10 @@ bool QQmlValueTypeReference::readReferenceValue() const
     } else {
         if (!d()->gadgetPtr) {
             d()->gadgetPtr = ::operator new(d()->valueType->metaType.sizeOf());
-            d()->valueType->metaType.construct(d()->gadgetPtr, 0);
+            d()->valueType->metaType.construct(d()->gadgetPtr, nullptr);
         }
         // value-type reference
-        void *args[] = { d()->gadgetPtr, 0 };
+        void *args[] = { d()->gadgetPtr, nullptr };
         QMetaObject::metacall(d()->object, QMetaObject::ReadProperty, d()->property, args);
     }
     return true;
@@ -184,12 +186,12 @@ ReturnedValue QQmlValueTypeWrapper::create(ExecutionEngine *engine, QObject *obj
     Scope scope(engine);
     initProto(engine);
 
-    Scoped<QQmlValueTypeReference> r(scope, engine->memoryManager->allocObject<QQmlValueTypeReference>());
+    Scoped<QQmlValueTypeReference> r(scope, engine->memoryManager->allocate<QQmlValueTypeReference>());
     r->d()->object = object;
     r->d()->property = property;
     r->d()->setPropertyCache(QJSEnginePrivate::get(engine)->cache(metaObject));
     r->d()->valueType = QQmlValueTypeFactory::valueType(typeId);
-    r->d()->gadgetPtr = 0;
+    r->d()->gadgetPtr = nullptr;
     return r->asReturnedValue();
 }
 
@@ -198,10 +200,10 @@ ReturnedValue QQmlValueTypeWrapper::create(ExecutionEngine *engine, const QVaria
     Scope scope(engine);
     initProto(engine);
 
-    Scoped<QQmlValueTypeWrapper> r(scope, engine->memoryManager->allocObject<QQmlValueTypeWrapper>());
+    Scoped<QQmlValueTypeWrapper> r(scope, engine->memoryManager->allocate<QQmlValueTypeWrapper>());
     r->d()->setPropertyCache(QJSEnginePrivate::get(engine)->cache(metaObject));
     r->d()->valueType = QQmlValueTypeFactory::valueType(typeId);
-    r->d()->gadgetPtr = 0;
+    r->d()->gadgetPtr = nullptr;
     r->d()->setValue(value);
     return r->asReturnedValue();
 }
@@ -219,13 +221,13 @@ bool QQmlValueTypeWrapper::toGadget(void *data) const
     if (const QQmlValueTypeReference *ref = as<const QQmlValueTypeReference>())
         if (!ref->readReferenceValue())
             return false;
-    const int typeId = d()->valueType->typeId;
+    const int typeId = d()->valueType->metaType.id();
     QMetaType::destruct(typeId, data);
     QMetaType::construct(typeId, data, d()->gadgetPtr);
     return true;
 }
 
-bool QQmlValueTypeWrapper::isEqualTo(Managed *m, Managed *other)
+bool QQmlValueTypeWrapper::virtualIsEqualTo(Managed *m, Managed *other)
 {
     Q_ASSERT(m && m->as<QQmlValueTypeWrapper>() && other);
     QV4::QQmlValueTypeWrapper *lv = static_cast<QQmlValueTypeWrapper *>(m);
@@ -239,41 +241,58 @@ bool QQmlValueTypeWrapper::isEqualTo(Managed *m, Managed *other)
     return false;
 }
 
-PropertyAttributes QQmlValueTypeWrapper::query(const Managed *m, String *name)
+PropertyAttributes QQmlValueTypeWrapper::virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p)
 {
-    Q_ASSERT(m->as<const QQmlValueTypeWrapper>());
-    const QQmlValueTypeWrapper *r = static_cast<const QQmlValueTypeWrapper *>(m);
+    if (id.isString()) {
+        Scope scope(m);
+        ScopedString n(scope, id.asStringOrSymbol());
+        const QQmlValueTypeWrapper *r = static_cast<const QQmlValueTypeWrapper *>(m);
+        QQmlPropertyData *result = r->d()->propertyCache()->property(n.getPointer(), nullptr, nullptr);
+        return result ? Attr_Data : Attr_Invalid;
+    }
 
-    QQmlPropertyData *result = r->d()->propertyCache()->property(name, 0, 0);
-    return result ? Attr_Data : Attr_Invalid;
+    return QV4::Object::virtualGetOwnProperty(m, id, p);
 }
 
-void QQmlValueTypeWrapper::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes)
+struct QQmlValueTypeWrapperOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
 {
-    name->setM(0);
-    *index = UINT_MAX;
+    int propertyIndex = 0;
+    ~QQmlValueTypeWrapperOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
 
-    QQmlValueTypeWrapper *that = static_cast<QQmlValueTypeWrapper*>(m);
+PropertyKey QQmlValueTypeWrapperOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs) {
+    const QQmlValueTypeWrapper *that = static_cast<const QQmlValueTypeWrapper *>(o);
 
-    if (QQmlValueTypeReference *ref = that->as<QQmlValueTypeReference>()) {
+    if (const QQmlValueTypeReference *ref = that->as<QQmlValueTypeReference>()) {
         if (!ref->readReferenceValue())
-            return;
+            return PropertyKey::invalid();
     }
 
     if (that->d()->propertyCache()) {
         const QMetaObject *mo = that->d()->propertyCache()->createMetaObject();
         const int propertyCount = mo->propertyCount();
-        if (it->arrayIndex < static_cast<uint>(propertyCount)) {
+        if (propertyIndex < propertyCount) {
             Scope scope(that->engine());
-            ScopedString propName(scope, that->engine()->newString(QString::fromUtf8(mo->property(it->arrayIndex).name())));
-            name->setM(propName->d());
-            ++it->arrayIndex;
-            *attributes = QV4::Attr_Data;
-            p->value = that->QV4::Object::get(propName);
-            return;
+            ScopedString propName(scope, that->engine()->newString(QString::fromUtf8(mo->property(propertyIndex).name())));
+            ++propertyIndex;
+            if (attrs)
+                *attrs = QV4::Attr_Data;
+            if (pd)
+                pd->value = that->QV4::Object::get(propName);
+            return propName->toPropertyKey();
         }
     }
-    QV4::Object::advanceIterator(m, it, name, index, p, attributes);
+
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+
+OwnPropertyKeyIterator *QQmlValueTypeWrapper::virtualOwnPropertyKeys(const Object *m, Value *target)
+{
+    *target = *m;
+    return new QQmlValueTypeWrapperOwnPropertyKeyIterator;
 }
 
 bool QQmlValueTypeWrapper::isEqual(const QVariant& value) const
@@ -286,7 +305,7 @@ bool QQmlValueTypeWrapper::isEqual(const QVariant& value) const
 
 int QQmlValueTypeWrapper::typeId() const
 {
-    return d()->valueType->typeId;
+    return d()->valueType->metaType.id();
 }
 
 bool QQmlValueTypeWrapper::write(QObject *target, int propertyIndex) const
@@ -297,7 +316,7 @@ bool QQmlValueTypeWrapper::write(QObject *target, int propertyIndex) const
         if (!d()->gadgetPtr) {
             Q_ALLOCA_ASSIGN(void, gadget, d()->valueType->metaType.sizeOf());
             d()->gadgetPtr = gadget;
-            d()->valueType->metaType.construct(d()->gadgetPtr, 0);
+            d()->valueType->metaType.construct(d()->gadgetPtr, nullptr);
             destructGadgetOnExit = true;
         }
         if (!ref->readReferenceValue())
@@ -306,26 +325,26 @@ bool QQmlValueTypeWrapper::write(QObject *target, int propertyIndex) const
 
     int flags = 0;
     int status = -1;
-    void *a[] = { d()->gadgetPtr, 0, &status, &flags };
+    void *a[] = { d()->gadgetPtr, nullptr, &status, &flags };
     QMetaObject::metacall(target, QMetaObject::WriteProperty, propertyIndex, a);
 
     if (destructGadgetOnExit) {
         d()->valueType->metaType.destruct(d()->gadgetPtr);
-        d()->gadgetPtr = 0;
+        d()->gadgetPtr = nullptr;
     }
     return true;
 }
 
-void QQmlValueTypeWrapper::method_toString(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QQmlValueTypeWrapper::method_toString(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Object *o = callData->thisObject.as<Object>();
+    const Object *o = thisObject->as<Object>();
     if (!o)
-        THROW_TYPE_ERROR();
-    QQmlValueTypeWrapper *w = o->as<QQmlValueTypeWrapper>();
+        return b->engine()->throwTypeError();
+    const QQmlValueTypeWrapper *w = o->as<QQmlValueTypeWrapper>();
     if (!w)
-        THROW_TYPE_ERROR();
+        return b->engine()->throwTypeError();
 
-    if (QQmlValueTypeReference *ref = w->as<QQmlValueTypeReference>())
+    if (const QQmlValueTypeReference *ref = w->as<QQmlValueTypeReference>())
         if (!ref->readReferenceValue())
             RETURN_UNDEFINED();
 
@@ -333,10 +352,10 @@ void QQmlValueTypeWrapper::method_toString(const BuiltinFunction *, Scope &scope
     // Prepare a buffer to pass to QMetaType::convert()
     QString convertResult;
     convertResult.~QString();
-    if (QMetaType::convert(w->d()->gadgetPtr, w->d()->valueType->typeId, &convertResult, QMetaType::QString)) {
+    if (QMetaType::convert(w->d()->gadgetPtr, w->d()->valueType->metaType.id(), &convertResult, QMetaType::QString)) {
         result = convertResult;
     } else {
-        result += QString::fromUtf8(QMetaType::typeName(w->d()->valueType->typeId))
+        result += QString::fromUtf8(QMetaType::typeName(w->d()->valueType->metaType.id()))
                 + QLatin1Char('(');
         const QMetaObject *mo = w->d()->propertyCache()->metaObject();
         const int propCount = mo->propertyCount();
@@ -350,24 +369,30 @@ void QQmlValueTypeWrapper::method_toString(const BuiltinFunction *, Scope &scope
         }
         result += QLatin1Char(')');
     }
-    scope.result = scope.engine->newString(result);
+    return Encode(b->engine()->newString(result));
 }
 
-ReturnedValue QQmlValueTypeWrapper::get(const Managed *m, String *name, bool *hasProperty)
+ReturnedValue QQmlValueTypeWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<QQmlValueTypeWrapper>());
+
+    if (!id.isString())
+        return Object::virtualGet(m, id, receiver, hasProperty);
+
     const QQmlValueTypeWrapper *r = static_cast<const QQmlValueTypeWrapper *>(m);
     QV4::ExecutionEngine *v4 = r->engine();
+    Scope scope(v4);
+    ScopedString name(scope, id.asStringOrSymbol());
 
     // Note: readReferenceValue() can change the reference->type.
     if (const QQmlValueTypeReference *reference = r->as<QQmlValueTypeReference>()) {
         if (!reference->readReferenceValue())
-            return Primitive::undefinedValue().asReturnedValue();
+            return Value::undefinedValue().asReturnedValue();
     }
 
-    QQmlPropertyData *result = r->d()->propertyCache()->property(name, 0, 0);
+    QQmlPropertyData *result = r->d()->propertyCache()->property(name.getPointer(), nullptr, nullptr);
     if (!result)
-        return Object::get(m, name, hasProperty);
+        return Object::virtualGet(m, id, receiver, hasProperty);
 
     if (hasProperty)
         *hasProperty = true;
@@ -399,11 +424,11 @@ ReturnedValue QQmlValueTypeWrapper::get(const Managed *m, String *name, bool *ha
     VALUE_TYPE_LOAD(QMetaType::Bool, bool, bool);
 
     QVariant v;
-    void *args[] = { Q_NULLPTR, Q_NULLPTR };
+    void *args[] = { nullptr, nullptr };
     if (result->propType() == QMetaType::QVariant) {
         args[0] = &v;
     } else {
-        v = QVariant(result->propType(), static_cast<void *>(Q_NULLPTR));
+        v = QVariant(result->propType(), static_cast<void *>(nullptr));
         args[0] = v.data();
     }
     metaObject->d.static_metacall(reinterpret_cast<QObject*>(gadget), QMetaObject::ReadProperty, index, args);
@@ -411,8 +436,11 @@ ReturnedValue QQmlValueTypeWrapper::get(const Managed *m, String *name, bool *ha
 #undef VALUE_TYPE_ACCESSOR
 }
 
-bool QQmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
+bool QQmlValueTypeWrapper::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
+    if (!id.isString())
+        return Object::virtualPut(m, id, value, receiver);
+
     Q_ASSERT(m->as<QQmlValueTypeWrapper>());
     ExecutionEngine *v4 = static_cast<QQmlValueTypeWrapper *>(m)->engine();
     Scope scope(v4);
@@ -433,8 +461,10 @@ bool QQmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
         writeBackPropertyType = writebackProperty.userType();
     }
 
+    ScopedString name(scope, id.asStringOrSymbol());
+
     const QMetaObject *metaObject = r->d()->propertyCache()->metaObject();
-    const QQmlPropertyData *pd = r->d()->propertyCache()->property(name, 0, 0);
+    const QQmlPropertyData *pd = r->d()->propertyCache()->property(name.getPointer(), nullptr, nullptr);
     if (!pd)
         return false;
 
@@ -461,8 +491,12 @@ bool QQmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
 
             QV4::Scoped<QQmlBindingFunction> bindingFunction(scope, (const Value &)f);
 
-            QV4::ScopedContext ctx(scope, bindingFunction->scope());
-            QQmlBinding *newBinding = QQmlBinding::create(&cacheData, bindingFunction->function(), referenceObject, context, ctx);
+            QV4::ScopedFunctionObject f(scope, bindingFunction->bindingFunction());
+            QV4::ScopedContext ctx(scope, f->scope());
+            QQmlBinding *newBinding = QQmlBinding::create(&cacheData, f->function(), referenceObject, context, ctx);
+            newBinding->setSourceLocation(bindingFunction->currentLocation());
+            if (f->isBoundFunction())
+                newBinding->setBoundFunction(static_cast<QV4::BoundFunction *>(f.getPointer()));
             newBinding->setSourceLocation(bindingFunction->currentLocation());
             newBinding->setTarget(referenceObject, cacheData, pd);
             QQmlPropertyPrivate::setBinding(newBinding);
@@ -472,13 +506,13 @@ bool QQmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
                 if (auto binding = QQmlPropertyPrivate::binding(referenceObject, QQmlPropertyIndex(referencePropertyIndex, pd->coreIndex()))) {
                     Q_ASSERT(!binding->isValueTypeProxy());
                     const auto qmlBinding = static_cast<const QQmlBinding*>(binding);
-                    const auto stackFrame = v4->currentStackFrame();
+                    const auto stackFrame = v4->currentStackFrame;
                     qCInfo(lcBindingRemoval,
                            "Overwriting binding on %s::%s which was initially bound at %s by setting \"%s\" at %s:%d",
                            referenceObject->metaObject()->className(), referenceObject->metaObject()->property(referencePropertyIndex).name(),
                            qPrintable(qmlBinding->expressionIdentifier()),
                            metaObject->property(pd->coreIndex()).name(),
-                           qPrintable(stackFrame.source), stackFrame.line);
+                           qPrintable(stackFrame->source()), stackFrame->lineNumber());
                 }
             }
             QQmlPropertyPrivate::removeBinding(referenceObject, QQmlPropertyIndex(referencePropertyIndex, pd->coreIndex()));
@@ -503,13 +537,13 @@ bool QQmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
 
             int flags = 0;
             int status = -1;
-            void *a[] = { &variantReferenceValue, 0, &status, &flags };
+            void *a[] = { &variantReferenceValue, nullptr, &status, &flags };
             QMetaObject::metacall(reference->d()->object, QMetaObject::WriteProperty, reference->d()->property, a);
 
         } else {
             int flags = 0;
             int status = -1;
-            void *a[] = { r->d()->gadgetPtr, 0, &status, &flags };
+            void *a[] = { r->d()->gadgetPtr, nullptr, &status, &flags };
             QMetaObject::metacall(reference->d()->object, QMetaObject::WriteProperty, reference->d()->property, a);
         }
     }
diff --git a/src/qml/qml/qqmlvaluetypewrapper_p.h b/src/qml/qml/qqmlvaluetypewrapper_p.h
index c8aac719ab..8db9474132 100644
--- a/src/qml/qml/qqmlvaluetypewrapper_p.h
+++ b/src/qml/qml/qqmlvaluetypewrapper_p.h
@@ -56,6 +56,7 @@
 
 #include <private/qv4value_p.h>
 #include <private/qv4object_p.h>
+#include <private/qqmlpropertycache_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -105,13 +106,12 @@ public:
     int typeId() const;
     bool write(QObject *target, int propertyIndex) const;
 
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static bool put(Managed *m, String *name, const Value &value);
-    static bool isEqualTo(Managed *m, Managed *other);
-    static PropertyAttributes query(const Managed *, String *name);
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-
-    static void method_toString(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static bool virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver);
+    static bool virtualIsEqualTo(Managed *m, Managed *other);
+    static PropertyAttributes virtualGetOwnProperty(const Managed *m, PropertyKey id, Property *p);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
+    static ReturnedValue method_toString(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
     static void initProto(ExecutionEngine *v4);
 };
diff --git a/src/qml/qml/qqmlvme.cpp b/src/qml/qml/qqmlvme.cpp
index c60f4edc80..018769948d 100644
--- a/src/qml/qml/qqmlvme.cpp
+++ b/src/qml/qml/qqmlvme.cpp
@@ -96,7 +96,7 @@ bool QQmlVME::componentCompleteEnabled()
 }
 
 QQmlVMEGuard::QQmlVMEGuard()
-: m_objectCount(0), m_objects(0), m_contextCount(0), m_contexts(0)
+: m_objectCount(0), m_objects(nullptr), m_contextCount(0), m_contexts(nullptr)
 {
 }
 
@@ -120,27 +120,15 @@ void QQmlVMEGuard::guard(QQmlObjectCreator *creator)
     m_contexts[0] = creator->parentContextData();
 }
 
-void QQmlVMEGuard::unguard(QObject *object)
-{
-    for (int ii = 0; ii < m_objectCount; ++ii) {
-        if (m_objects[ii] == object) {
-            if (ii < m_objectCount - 1)
-                ::memmove((void *) m_objects[ii], (void *) m_objects[ii + 1], sizeof(QPointer<QObject> *));
-            delete m_objects[--m_objectCount];
-            break;
-        }
-    }
-}
-
 void QQmlVMEGuard::clear()
 {
     delete [] m_objects;
     delete [] m_contexts;
 
     m_objectCount = 0;
-    m_objects = 0;
+    m_objects = nullptr;
     m_contextCount = 0;
-    m_contexts = 0;
+    m_contexts = nullptr;
 }
 
 bool QQmlVMEGuard::isOK() const
diff --git a/src/qml/qml/qqmlvme_p.h b/src/qml/qml/qqmlvme_p.h
index 9585b5b6df..13c5524d96 100644
--- a/src/qml/qml/qqmlvme_p.h
+++ b/src/qml/qml/qqmlvme_p.h
@@ -83,7 +83,7 @@ namespace QQmlVMETypes {
     struct State {
         enum Flag { Deferred = 0x00000001 };
 
-        State() : flags(0), context(0), instructionStream(0) {}
+        State() : flags(0), context(nullptr), instructionStream(nullptr) {}
         quint32 flags;
         QQmlContextData *context;
         const char *instructionStream;
@@ -124,6 +124,10 @@ private:
 // Used to check that a QQmlVME that is interrupted mid-execution
 // is still valid.  Checks all the objects and contexts have not been
 // deleted.
+//
+// VME stands for Virtual Machine Execution. QML files used to
+// be compiled to a byte code data structure that a virtual machine executed
+// (for constructing the tree of QObjects and setting properties).
 class QQmlVMEGuard
 {
 public:
@@ -131,7 +135,6 @@ public:
     ~QQmlVMEGuard();
 
     void guard(QQmlObjectCreator *);
-    void unguard(QObject *);
     void clear();
 
     bool isOK() const;
@@ -144,7 +147,7 @@ private:
 };
 
 QQmlInstantiationInterrupt::QQmlInstantiationInterrupt()
-    : mode(None), nsecs(0), runWhile(0)
+    : mode(None), nsecs(0), runWhile(nullptr)
 {
 }
 
@@ -154,7 +157,7 @@ QQmlInstantiationInterrupt::QQmlInstantiationInterrupt(volatile bool *runWhile,
 }
 
 QQmlInstantiationInterrupt::QQmlInstantiationInterrupt(int nsecs)
-    : mode(Time), nsecs(nsecs), runWhile(0)
+    : mode(Time), nsecs(nsecs), runWhile(nullptr)
 {
 }
 
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index a2ab9bdfed..6bc469c836 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -55,6 +55,7 @@
 #include <private/qv4variantobject_p.h>
 #include <private/qv4functionobject_p.h>
 #include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 #include <private/qv4qobjectwrapper_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -63,7 +64,7 @@ static void list_append(QQmlListProperty<QObject> *prop, QObject *o)
 {
     QList<QObject *> *list = static_cast<QList<QObject *> *>(prop->data);
     list->append(o);
-    static_cast<QQmlVMEMetaObject *>(prop->dummy1)->activate(prop->object, reinterpret_cast<quintptr>(prop->dummy2), 0);
+    static_cast<QQmlVMEMetaObject *>(prop->dummy1)->activate(prop->object, reinterpret_cast<quintptr>(prop->dummy2), nullptr);
 }
 
 static int list_count(QQmlListProperty<QObject> *prop)
@@ -82,11 +83,11 @@ static void list_clear(QQmlListProperty<QObject> *prop)
 {
     QList<QObject *> *list = static_cast<QList<QObject *> *>(prop->data);
     list->clear();
-    static_cast<QQmlVMEMetaObject *>(prop->dummy1)->activate(prop->object, reinterpret_cast<quintptr>(prop->dummy2), 0);
+    static_cast<QQmlVMEMetaObject *>(prop->dummy1)->activate(prop->object, reinterpret_cast<quintptr>(prop->dummy2), nullptr);
 }
 
 QQmlVMEVariantQObjectPtr::QQmlVMEVariantQObjectPtr()
-    : QQmlGuard<QObject>(0), m_target(0), m_index(-1)
+    : QQmlGuard<QObject>(nullptr), m_target(nullptr), m_index(-1)
 {
 }
 
@@ -105,12 +106,12 @@ void QQmlVMEVariantQObjectPtr::objectDestroyed(QObject *)
             QV4::Scope scope(v4);
             QV4::Scoped<QV4::MemberData> sp(scope, m_target->propertyAndMethodStorage.value());
             if (sp) {
-                QV4::MemberData::Index index{ sp->d(), sp->d()->values.values + m_index };
-                index.set(v4, QV4::Primitive::nullValue());
+                QV4::PropertyIndex index{ sp->d(), sp->d()->values.values + m_index };
+                index.set(v4, QV4::Value::nullValue());
             }
         }
 
-        m_target->activate(m_target->object, m_target->methodOffset() + m_index, 0);
+        m_target->activate(m_target->object, m_target->methodOffset() + m_index, nullptr);
     }
 }
 
@@ -149,7 +150,7 @@ void QQmlVMEMetaObjectEndpoint::tryConnect()
     if (metaObject.flag()) {
         // This is actually notify
         int sigIdx = metaObject->methodOffset() + aliasId + metaObject->compiledObject->nProperties;
-        metaObject->activate(metaObject->object, sigIdx, 0);
+        metaObject->activate(metaObject->object, sigIdx, nullptr);
     } else {
         const QV4::CompiledData::Alias *aliasData = &metaObject->compiledObject->aliasTable()[aliasId];
         if (!aliasData->isObjectAlias()) {
@@ -175,10 +176,10 @@ void QQmlVMEMetaObjectEndpoint::tryConnect()
 }
 
 
-QQmlInterceptorMetaObject::QQmlInterceptorMetaObject(QObject *obj, QQmlPropertyCache *cache)
+QQmlInterceptorMetaObject::QQmlInterceptorMetaObject(QObject *obj, const QQmlRefPointer<QQmlPropertyCache> &cache)
     : object(obj),
       cache(cache),
-      interceptors(0),
+      interceptors(nullptr),
       hasAssignedMetaObjectData(false)
 {
     QObjectPrivate *op = QObjectPrivate::get(obj);
@@ -313,24 +314,25 @@ QAbstractDynamicMetaObject *QQmlInterceptorMetaObject::toDynamicMetaObject(QObje
     return this;
 }
 
-QQmlVMEMetaObject::QQmlVMEMetaObject(QObject *obj,
-                                     QQmlPropertyCache *cache, QV4::CompiledData::CompilationUnit *qmlCompilationUnit, int qmlObjectId)
+QQmlVMEMetaObject::QQmlVMEMetaObject(QV4::ExecutionEngine *engine,
+                                     QObject *obj,
+                                     const QQmlRefPointer<QQmlPropertyCache> &cache, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &qmlCompilationUnit, int qmlObjectId)
     : QQmlInterceptorMetaObject(obj, cache),
+      engine(engine),
       ctxt(QQmlData::get(obj, true)->outerContext),
-      aliasEndpoints(0), compilationUnit(qmlCompilationUnit), compiledObject(0)
+      aliasEndpoints(nullptr), compilationUnit(qmlCompilationUnit), compiledObject(nullptr)
 {
+    Q_ASSERT(engine);
     QQmlData::get(obj)->hasVMEMetaObject = true;
 
     if (compilationUnit && qmlObjectId >= 0) {
-        compiledObject = compilationUnit->data->objectAt(qmlObjectId);
+        compiledObject = compilationUnit->objectAt(qmlObjectId);
 
         if (compiledObject->nProperties || compiledObject->nFunctions) {
-            Q_ASSERT(cache && cache->engine);
-            QV4::ExecutionEngine *v4 = cache->engine;
             uint size = compiledObject->nProperties + compiledObject->nFunctions;
             if (size) {
-                QV4::Heap::MemberData *data = QV4::MemberData::allocate(v4, size);
-                propertyAndMethodStorage.set(v4, data);
+                QV4::Heap::MemberData *data = QV4::MemberData::allocate(engine, size);
+                propertyAndMethodStorage.set(engine, data);
                 std::fill(data->values.values, data->values.values + data->values.size, QV4::Encode::undefined());
             }
 
@@ -356,7 +358,7 @@ QV4::MemberData *QQmlVMEMetaObject::propertyAndMethodStorageAsMemberData() const
             // such as the varProperties array) will have been cleaned up, but the
             // QObject ptr will not yet have been deleted (eg, waiting on deleteLater).
             // In this situation, return 0.
-            return 0;
+            return nullptr;
     }
 
     return static_cast<QV4::MemberData*>(propertyAndMethodStorage.asManaged());
@@ -366,77 +368,77 @@ void QQmlVMEMetaObject::writeProperty(int id, int v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, QV4::Primitive::fromInt32(v));
+        md->set(engine, id, QV4::Value::fromInt32(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, bool v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, QV4::Primitive::fromBoolean(v));
+        md->set(engine, id, QV4::Value::fromBoolean(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, double v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, QV4::Primitive::fromDouble(v));
+        md->set(engine, id, QV4::Value::fromDouble(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QString& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newString(v));
+        md->set(engine, id, engine->newString(v));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QUrl& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
+        md->set(engine, id, engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QDate& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
+        md->set(engine, id, engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QDateTime& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
+        md->set(engine, id, engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QPointF& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
+        md->set(engine, id, engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QSizeF& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
+        md->set(engine, id, engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QRectF& v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, cache->engine->newVariantObject(QVariant::fromValue(v)));
+        md->set(engine, id, engine->newVariantObject(QVariant::fromValue(v)));
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, QObject* v)
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
-        md->set(cache->engine, id, QV4::Value::fromReturnedValue(QV4::QObjectWrapper::wrap(cache->engine, v)));
+        md->set(engine, id, QV4::Value::fromReturnedValue(QV4::QObjectWrapper::wrap(engine, v)));
 
     QQmlVMEVariantQObjectPtr *guard = getQObjectGuardForProperty(id);
     if (v && !guard) {
@@ -453,7 +455,7 @@ int QQmlVMEMetaObject::readPropertyAsInt(int id) const
     if (!md)
         return 0;
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     if (!sv->isInt32())
         return 0;
@@ -466,7 +468,7 @@ bool QQmlVMEMetaObject::readPropertyAsBool(int id) const
     if (!md)
         return false;
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     if (!sv->isBoolean())
         return false;
@@ -479,7 +481,7 @@ double QQmlVMEMetaObject::readPropertyAsDouble(int id) const
     if (!md)
         return 0.0;
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     if (!sv->isDouble())
         return 0.0;
@@ -492,7 +494,7 @@ QString QQmlVMEMetaObject::readPropertyAsString(int id) const
     if (!md)
         return QString();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     if (QV4::String *s = sv->stringValue())
         return s->toQString();
@@ -505,7 +507,7 @@ QUrl QQmlVMEMetaObject::readPropertyAsUrl(int id) const
     if (!md)
         return QUrl();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
     if (!v || v->d()->data().type() != QVariant::Url)
@@ -519,7 +521,7 @@ QDate QQmlVMEMetaObject::readPropertyAsDate(int id) const
     if (!md)
         return QDate();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
     if (!v || v->d()->data().type() != QVariant::Date)
@@ -533,7 +535,7 @@ QDateTime QQmlVMEMetaObject::readPropertyAsDateTime(int id)
     if (!md)
         return QDateTime();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
     if (!v || v->d()->data().type() != QVariant::DateTime)
@@ -547,7 +549,7 @@ QSizeF QQmlVMEMetaObject::readPropertyAsSizeF(int id) const
     if (!md)
         return QSizeF();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
     if (!v || v->d()->data().type() != QVariant::SizeF)
@@ -561,7 +563,7 @@ QPointF QQmlVMEMetaObject::readPropertyAsPointF(int id) const
     if (!md)
         return QPointF();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
     if (!v || v->d()->data().type() != QVariant::PointF)
@@ -573,13 +575,13 @@ QObject* QQmlVMEMetaObject::readPropertyAsQObject(int id) const
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (!md)
-        return 0;
+        return nullptr;
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::QObjectWrapper *wrapper = sv->as<QV4::QObjectWrapper>();
     if (!wrapper)
-        return 0;
+        return nullptr;
     return wrapper->object();
 }
 
@@ -587,14 +589,14 @@ QList<QObject *> *QQmlVMEMetaObject::readPropertyAsList(int id) const
 {
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (!md)
-        return 0;
+        return nullptr;
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::Scoped<QV4::VariantObject> v(scope, *(md->data() + id));
     if (!v || (int)v->d()->data().userType() != qMetaTypeId<QList<QObject *> >()) {
         QVariant variant(qVariantFromValue(QList<QObject*>()));
-        v = cache->engine->newVariantObject(variant);
-        md->set(cache->engine, id, v);
+        v = engine->newVariantObject(variant);
+        md->set(engine, id, v);
     }
     return static_cast<QList<QObject *> *>(v->d()->data().data());
 }
@@ -605,7 +607,7 @@ QRectF QQmlVMEMetaObject::readPropertyAsRectF(int id) const
     if (!md)
         return QRectF();
 
-    QV4::Scope scope(cache->engine);
+    QV4::Scope scope(engine);
     QV4::ScopedValue sv(scope, *(md->data() + id));
     const QV4::VariantObject *v = sv->as<QV4::VariantObject>();
     if (!v || v->d()->data().type() != QVariant::RectF)
@@ -641,9 +643,8 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
 
                 if (t == QV4::CompiledData::Property::Var) {
                     // the context can be null if accessing var properties from cpp after re-parenting an item.
-                    QQmlEnginePrivate *ep = (ctxt == 0 || ctxt->engine == 0) ? 0 : QQmlEnginePrivate::get(ctxt->engine);
-                    QV8Engine *v8e = (ep == 0) ? 0 : ep->v8engine();
-                    if (v8e) {
+                    QQmlEnginePrivate *ep = (ctxt == nullptr || ctxt->engine == nullptr) ? nullptr : QQmlEnginePrivate::get(ctxt->engine);
+                    if (ep) {
                         if (c == QMetaObject::ReadProperty) {
                             *reinterpret_cast<QVariant *>(a[0]) = readPropertyAsVariant(id);
                         } else if (c == QMetaObject::WriteProperty) {
@@ -819,7 +820,7 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                             if (QV4::MemberData *md = propertyAndMethodStorageAsMemberData()) {
                                 const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
                                 if (!v) {
-                                    md->set(cache->engine, id, cache->engine->newVariantObject(QVariant()));
+                                    md->set(engine, id, engine->newVariantObject(QVariant()));
                                     v = (md->data() + id)->as<QV4::VariantObject>();
                                     QQml_valueTypeProvider()->initValueType(fallbackMetaType, v->d()->data());
                                 }
@@ -835,7 +836,7 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                 }
 
                 if (c == QMetaObject::WriteProperty && needActivate) {
-                    activate(object, methodOffset() + id, 0);
+                    activate(object, methodOffset() + id, nullptr);
                 }
 
                 return -1;
@@ -847,7 +848,7 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                 const QV4::CompiledData::Alias *aliasData = &compiledObject->aliasTable()[id];
 
                 if ((aliasData->flags & QV4::CompiledData::Alias::AliasPointsToPointerObject) && c == QMetaObject::ReadProperty)
-                        *reinterpret_cast<void **>(a[0]) = 0;
+                        *reinterpret_cast<void **>(a[0]) = nullptr;
 
                 if (!ctxt) return -1;
 
@@ -898,7 +899,7 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                     int rv = QMetaObject::metacall(valueType, c, valueTypePropertyIndex, a);
 
                     if (c == QMetaObject::WriteProperty)
-                        valueType->write(target, coreIndex, 0x00);
+                        valueType->write(target, coreIndex, nullptr);
 
                     return rv;
 
@@ -925,12 +926,14 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
             id -= plainSignals;
 
             if (id < methodCount) {
-                if (!ctxt->engine)
+                QQmlEngine *engine = ctxt->engine;
+                if (!engine)
                     return -1; // We can't run the method
 
-                QQmlEnginePrivate *ep = QQmlEnginePrivate::get(ctxt->engine);
+                QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
+                QV4::ExecutionEngine *v4 = engine->handle();
                 ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
-                QV4::Scope scope(ep->v4engine());
+                QV4::Scope scope(v4);
 
 
                 QV4::ScopedFunctionObject function(scope, method(id));
@@ -949,20 +952,20 @@ int QQmlVMEMetaObject::metaCall(QObject *o, QMetaObject::Call c, int _id, void *
                 }
 
                 const unsigned int parameterCount = function->formalParameterCount();
-                QV4::ScopedCallData callData(scope, parameterCount);
-                callData->thisObject = ep->v8engine()->global();
+                QV4::JSCallData jsCallData(scope, parameterCount);
+                *jsCallData->thisObject = v4->global();
 
                 for (uint ii = 0; ii < parameterCount; ++ii)
-                    callData->args[ii] = scope.engine->fromVariant(*(QVariant *)a[ii + 1]);
+                    jsCallData->args[ii] = scope.engine->fromVariant(*(QVariant *)a[ii + 1]);
 
-                function->call(scope, callData);
+                QV4::ScopedValue result(scope, function->call(jsCallData));
                 if (scope.hasException()) {
                     QQmlError error = scope.engine->catchExceptionAsQmlError();
                     if (error.isValid())
                         ep->warning(error);
                     if (a[0]) *(QVariant *)a[0] = QVariant();
                 } else {
-                    if (a[0]) *(QVariant *)a[0] = scope.engine->toVariant(scope.result, 0);
+                    if (a[0]) *(QVariant *)a[0] = scope.engine->toVariant(result, 0);
                 }
 
                 ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
@@ -1002,7 +1005,7 @@ QV4::ReturnedValue QQmlVMEMetaObject::readVarProperty(int id) const
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (md)
         return (md->data() + id)->asReturnedValue();
-    return QV4::Primitive::undefinedValue().asReturnedValue();
+    return QV4::Value::undefinedValue().asReturnedValue();
 }
 
 QVariant QQmlVMEMetaObject::readPropertyAsVariant(int id) const
@@ -1015,7 +1018,7 @@ QVariant QQmlVMEMetaObject::readPropertyAsVariant(int id) const
         const QV4::VariantObject *v = (md->data() + id)->as<QV4::VariantObject>();
         if (v)
             return v->d()->data();
-        return cache->engine->toVariant(*(md->data() + id), -1);
+        return engine->toVariant(*(md->data() + id), -1);
     }
     return QVariant();
 }
@@ -1034,7 +1037,7 @@ void QQmlVMEMetaObject::writeVarProperty(int id, const QV4::Value &value)
     if (oldVariant)
         oldVariant->removeVmePropertyReference();
 
-    QObject *valueObject = 0;
+    QObject *valueObject = nullptr;
     QQmlVMEVariantQObjectPtr *guard = getQObjectGuardForProperty(id);
 
     // And, if the new value is a scarce resource, we need to ensure that it does not get
@@ -1056,8 +1059,8 @@ void QQmlVMEMetaObject::writeVarProperty(int id, const QV4::Value &value)
         guard->setGuardedValue(valueObject, this, id);
 
     // Write the value and emit change signal as appropriate.
-    md->set(cache->engine, id, value);
-    activate(object, methodOffset() + id, 0);
+    md->set(engine, id, value);
+    activate(object, methodOffset() + id, nullptr);
 }
 
 void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
@@ -1075,17 +1078,17 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
 
         // And, if the new value is a scarce resource, we need to ensure that it does not get
         // automatically released by the engine until no other references to it exist.
-        QV4::Scope scope(cache->engine);
-        QV4::ScopedValue newv(scope, cache->engine->fromVariant(value));
+        QV4::Scope scope(engine);
+        QV4::ScopedValue newv(scope, engine->fromVariant(value));
         QV4::Scoped<QV4::VariantObject> v(scope, newv);
         if (!!v)
             v->addVmePropertyReference();
 
         // Write the value and emit change signal as appropriate.
         QVariant currentValue = readPropertyAsVariant(id);
-        md->set(cache->engine, id, newv);
+        md->set(engine, id, newv);
         if ((currentValue.userType() != value.userType() || currentValue != value))
-            activate(object, methodOffset() + id, 0);
+            activate(object, methodOffset() + id, nullptr);
     } else {
         bool needActivate = false;
         if (value.userType() == QMetaType::QObjectStar) {
@@ -1101,14 +1104,14 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
                                  v->d()->data() != value);
                 if (v)
                     v->removeVmePropertyReference();
-                md->set(cache->engine, id, cache->engine->newVariantObject(value));
+                md->set(engine, id, engine->newVariantObject(value));
                 v = static_cast<const QV4::VariantObject *>(md->data() + id);
                 v->addVmePropertyReference();
             }
         }
 
         if (needActivate)
-            activate(object, methodOffset() + id, 0);
+            activate(object, methodOffset() + id, nullptr);
     }
 }
 
@@ -1119,7 +1122,7 @@ QV4::ReturnedValue QQmlVMEMetaObject::vmeMethod(int index) const
         return parentVMEMetaObject()->vmeMethod(index);
     }
     if (!compiledObject)
-        return QV4::Primitive::undefinedValue().asReturnedValue();
+        return QV4::Value::undefinedValue().asReturnedValue();
     const int plainSignals = compiledObject->nSignals + compiledObject->nProperties + compiledObject->nAliases;
     Q_ASSERT(index >= (methodOffset() + plainSignals) && index < (methodOffset() + plainSignals + int(compiledObject->nFunctions)));
     return method(index - methodOffset() - plainSignals);
@@ -1141,7 +1144,7 @@ void QQmlVMEMetaObject::setVmeMethod(int index, const QV4::Value &function)
     QV4::MemberData *md = propertyAndMethodStorageAsMemberData();
     if (!md)
         return;
-    md->set(cache->engine, methodIndex + compiledObject->nProperties, function);
+    md->set(engine, methodIndex + compiledObject->nProperties, function);
 }
 
 QV4::ReturnedValue QQmlVMEMetaObject::vmeProperty(int index) const
@@ -1165,15 +1168,13 @@ void QQmlVMEMetaObject::setVMEProperty(int index, const QV4::Value &v)
 
 void QQmlVMEMetaObject::ensureQObjectWrapper()
 {
-    Q_ASSERT(cache && cache->engine);
-    QV4::ExecutionEngine *v4 = cache->engine;
-    QV4::QObjectWrapper::wrap(v4, object);
+    Q_ASSERT(cache);
+    QV4::QObjectWrapper::wrap(engine, object);
 }
 
 void QQmlVMEMetaObject::mark(QV4::MarkStack *markStack)
 {
-    QV4::ExecutionEngine *v4 = cache ? cache->engine : 0;
-    if (v4 != markStack->engine)
+    if (engine != markStack->engine)
         return;
 
     propertyAndMethodStorage.markOnce(markStack);
@@ -1186,7 +1187,7 @@ bool QQmlVMEMetaObject::aliasTarget(int index, QObject **target, int *coreIndex,
 {
     Q_ASSERT(compiledObject && (index >= propOffset() + int(compiledObject->nProperties)));
 
-    *target = 0;
+    *target = nullptr;
     *coreIndex = -1;
     *valueTypeIndex = -1;
 
@@ -1288,7 +1289,7 @@ QQmlVMEVariantQObjectPtr *QQmlVMEMetaObject::getQObjectGuardForProperty(int inde
         }
     }
 
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlvmemetaobject_p.h b/src/qml/qml/qqmlvmemetaobject_p.h
index 031a9a9ddd..87dc9fb0b2 100644
--- a/src/qml/qml/qqmlvmemetaobject_p.h
+++ b/src/qml/qml/qqmlvmemetaobject_p.h
@@ -65,7 +65,6 @@
 
 #include "qqmlguard_p.h"
 #include "qqmlcontext_p.h"
-#include "qqmlpropertycache_p.h"
 
 #include <private/qv8engine_p.h>
 #include <private/qflagpointer_p.h>
@@ -81,7 +80,7 @@ class QQmlVMEVariantQObjectPtr : public QQmlGuard<QObject>
 {
 public:
     inline QQmlVMEVariantQObjectPtr();
-    inline ~QQmlVMEVariantQObjectPtr();
+    inline ~QQmlVMEVariantQObjectPtr() override;
 
     inline void objectDestroyed(QObject *) override;
     inline void setGuardedValue(QObject *obj, QQmlVMEMetaObject *target, int index);
@@ -94,17 +93,17 @@ public:
 class Q_QML_PRIVATE_EXPORT QQmlInterceptorMetaObject : public QAbstractDynamicMetaObject
 {
 public:
-    QQmlInterceptorMetaObject(QObject *obj, QQmlPropertyCache *cache);
-    ~QQmlInterceptorMetaObject();
+    QQmlInterceptorMetaObject(QObject *obj, const QQmlRefPointer<QQmlPropertyCache> &cache);
+    ~QQmlInterceptorMetaObject() override;
 
     void registerInterceptor(QQmlPropertyIndex index, QQmlPropertyValueInterceptor *interceptor);
 
     static QQmlInterceptorMetaObject *get(QObject *obj);
 
-    QAbstractDynamicMetaObject *toDynamicMetaObject(QObject *o) Q_DECL_OVERRIDE;
+    QAbstractDynamicMetaObject *toDynamicMetaObject(QObject *o) override;
 
     // Used by auto-tests for inspection
-    QQmlPropertyCache *propertyCache() const { return cache; }
+    QQmlPropertyCache *propertyCache() const { return cache.data(); }
 
     bool intercepts(QQmlPropertyIndex propertyIndex) const
     {
@@ -112,11 +111,13 @@ public:
             if (it->m_propertyIndex == propertyIndex)
                 return true;
         }
+        if (auto parentInterceptor = ((parent.isT1() && parent.flag()) ? static_cast<QQmlInterceptorMetaObject *>(parent.asT1()) : nullptr))
+            return parentInterceptor->intercepts(propertyIndex);
         return false;
     }
 
 protected:
-    int metaCall(QObject *o, QMetaObject::Call c, int id, void **a) Q_DECL_OVERRIDE;
+    int metaCall(QObject *o, QMetaObject::Call c, int id, void **a) override;
     bool intercept(QMetaObject::Call c, int id, void **a);
 
 public:
@@ -137,15 +138,15 @@ inline QQmlInterceptorMetaObject *QQmlInterceptorMetaObject::get(QObject *obj)
         }
     }
 
-    return 0;
+    return nullptr;
 }
 
 class QQmlVMEMetaObjectEndpoint;
 class Q_QML_PRIVATE_EXPORT QQmlVMEMetaObject : public QQmlInterceptorMetaObject
 {
 public:
-    QQmlVMEMetaObject(QObject *obj, QQmlPropertyCache *cache, QV4::CompiledData::CompilationUnit *qmlCompilationUnit, int qmlObjectId);
-    ~QQmlVMEMetaObject();
+    QQmlVMEMetaObject(QV4::ExecutionEngine *engine, QObject *obj, const QQmlRefPointer<QQmlPropertyCache> &cache, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &qmlCompilationUnit, int qmlObjectId);
+    ~QQmlVMEMetaObject() override;
 
     bool aliasTarget(int index, QObject **target, int *coreIndex, int *valueTypeIndex) const;
     QV4::ReturnedValue vmeMethod(int index) const;
@@ -161,9 +162,10 @@ public:
     static QQmlVMEMetaObject *getForSignal(QObject *o, int coreIndex);
 
 protected:
-    int metaCall(QObject *o, QMetaObject::Call _c, int _id, void **_a) Q_DECL_OVERRIDE;
+    int metaCall(QObject *o, QMetaObject::Call _c, int _id, void **_a) override;
 
 public:
+    QV4::ExecutionEngine *engine;
     QQmlGuardedContextData ctxt;
 
     inline int propOffset() const;
@@ -238,7 +240,7 @@ QQmlVMEMetaObject *QQmlVMEMetaObject::get(QObject *obj)
         }
     }
 
-    return 0;
+    return nullptr;
 }
 
 int QQmlVMEMetaObject::propOffset() const
@@ -266,7 +268,7 @@ QQmlVMEMetaObject *QQmlVMEMetaObject::parentVMEMetaObject() const
     if (parent.isT1() && parent.flag())
         return static_cast<QQmlVMEMetaObject *>(parent.asT1());
 
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 9e8735cbc6..9f629f974d 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -51,6 +51,7 @@
 #include <private/qv4engine_p.h>
 #include <private/qv4functionobject_p.h>
 #include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 
 #include <QtCore/qobject.h>
 #include <QtQml/qjsvalue.h>
@@ -74,8 +75,7 @@ using namespace QV4;
 #define V4THROW_REFERENCE(string) \
     do { \
         ScopedObject error(scope, scope.engine->newReferenceErrorObject(QStringLiteral(string))); \
-        scope.result = scope.engine->throwError(error); \
-        return; \
+        return scope.engine->throwError(error); \
     } while (false)
 
 QT_BEGIN_NAMESPACE
@@ -116,7 +116,7 @@ class DocumentImpl;
 class NodeImpl
 {
 public:
-    NodeImpl() : type(Element), document(0), parent(0) {}
+    NodeImpl() : type(Element), document(nullptr), parent(nullptr) {}
     virtual ~NodeImpl() {
         qDeleteAll(children);
         qDeleteAll(attributes);
@@ -157,7 +157,7 @@ public:
 class DocumentImpl : public QQmlRefCount, public NodeImpl
 {
 public:
-    DocumentImpl() : root(0) { type = Document; }
+    DocumentImpl() : root(nullptr) { type = Document; }
     virtual ~DocumentImpl() {
         delete root;
     }
@@ -228,8 +228,7 @@ public:
     static ReturnedValue create(ExecutionEngine *, NodeImpl *, const QList<NodeImpl *> &);
 
     // JS API
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
 };
 
 void Heap::NamedNodeMap::init(NodeImpl *data, const QList<NodeImpl *> &list)
@@ -250,8 +249,7 @@ public:
     V4_NEEDS_DESTROY
 
     // JS API
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static ReturnedValue getIndexed(const Managed *m, uint index, bool *hasProperty);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
 
     // C++ API
     static ReturnedValue create(ExecutionEngine *, NodeImpl *);
@@ -276,25 +274,25 @@ public:
     static void initClass(ExecutionEngine *engine);
 
     // JS API
-    static void method_get_nodeName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_nodeValue(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_nodeType(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_namespaceUri(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-
-    static void method_get_parentNode(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_childNodes(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_firstChild(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_lastChild(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_previousSibling(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_nextSibling(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_attributes(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-
-    //static void ownerDocument(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    //static void namespaceURI(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    //static void prefix(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    //static void localName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    //static void baseURI(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    //static void textContent(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_get_nodeName(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_nodeValue(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_nodeType(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_namespaceUri(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_get_parentNode(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_childNodes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_firstChild(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_lastChild(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_previousSibling(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_nextSibling(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_attributes(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    //static ReturnedValue ownerDocument(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    //static ReturnedValue namespaceURI(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    //static ReturnedValue prefix(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    //static ReturnedValue localName(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    //static ReturnedValue baseURI(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    //static ReturnedValue textContent(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
     static ReturnedValue getProto(ExecutionEngine *v4);
 
@@ -306,18 +304,18 @@ void Heap::NodePrototype::init()
     Scope scope(internalClass->engine);
     ScopedObject o(scope, this);
 
-    o->defineAccessorProperty(QStringLiteral("nodeName"), QV4::NodePrototype::method_get_nodeName, 0);
-    o->defineAccessorProperty(QStringLiteral("nodeValue"), QV4::NodePrototype::method_get_nodeValue, 0);
-    o->defineAccessorProperty(QStringLiteral("nodeType"), QV4::NodePrototype::method_get_nodeType, 0);
-    o->defineAccessorProperty(QStringLiteral("namespaceUri"), QV4::NodePrototype::method_get_namespaceUri, 0);
+    o->defineAccessorProperty(QStringLiteral("nodeName"), QV4::NodePrototype::method_get_nodeName, nullptr);
+    o->defineAccessorProperty(QStringLiteral("nodeValue"), QV4::NodePrototype::method_get_nodeValue, nullptr);
+    o->defineAccessorProperty(QStringLiteral("nodeType"), QV4::NodePrototype::method_get_nodeType, nullptr);
+    o->defineAccessorProperty(QStringLiteral("namespaceUri"), QV4::NodePrototype::method_get_namespaceUri, nullptr);
 
-    o->defineAccessorProperty(QStringLiteral("parentNode"), QV4::NodePrototype::method_get_parentNode, 0);
-    o->defineAccessorProperty(QStringLiteral("childNodes"), QV4::NodePrototype::method_get_childNodes, 0);
-    o->defineAccessorProperty(QStringLiteral("firstChild"), QV4::NodePrototype::method_get_firstChild, 0);
-    o->defineAccessorProperty(QStringLiteral("lastChild"), QV4::NodePrototype::method_get_lastChild, 0);
-    o->defineAccessorProperty(QStringLiteral("previousSibling"), QV4::NodePrototype::method_get_previousSibling, 0);
-    o->defineAccessorProperty(QStringLiteral("nextSibling"), QV4::NodePrototype::method_get_nextSibling, 0);
-    o->defineAccessorProperty(QStringLiteral("attributes"), QV4::NodePrototype::method_get_attributes, 0);
+    o->defineAccessorProperty(QStringLiteral("parentNode"), QV4::NodePrototype::method_get_parentNode, nullptr);
+    o->defineAccessorProperty(QStringLiteral("childNodes"), QV4::NodePrototype::method_get_childNodes, nullptr);
+    o->defineAccessorProperty(QStringLiteral("firstChild"), QV4::NodePrototype::method_get_firstChild, nullptr);
+    o->defineAccessorProperty(QStringLiteral("lastChild"), QV4::NodePrototype::method_get_lastChild, nullptr);
+    o->defineAccessorProperty(QStringLiteral("previousSibling"), QV4::NodePrototype::method_get_previousSibling, nullptr);
+    o->defineAccessorProperty(QStringLiteral("nextSibling"), QV4::NodePrototype::method_get_nextSibling, nullptr);
+    o->defineAccessorProperty(QStringLiteral("attributes"), QV4::NodePrototype::method_get_attributes, nullptr);
 }
 
 
@@ -355,10 +353,10 @@ class Attr : public Node
 {
 public:
     // JS API
-    static void method_name(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_name(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 //    static void specified(CallContext *);
-    static void method_value(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_ownerElement(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_value(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_ownerElement(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 //    static void schemaTypeInfo(CallContext *);
 //    static void isId(CallContext *c);
 
@@ -370,7 +368,7 @@ class CharacterData : public Node
 {
 public:
     // JS API
-    static void method_length(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_length(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
     // C++ API
     static ReturnedValue prototype(ExecutionEngine *v4);
@@ -380,8 +378,8 @@ class Text : public CharacterData
 {
 public:
     // JS API
-    static void method_isElementContentWhitespace(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_wholeText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_isElementContentWhitespace(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_wholeText(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
     // C++ API
     static ReturnedValue prototype(ExecutionEngine *);
@@ -398,10 +396,10 @@ class Document : public Node
 {
 public:
     // JS API
-    static void method_xmlVersion(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_xmlEncoding(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_xmlStandalone(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_documentElement(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_xmlVersion(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_xmlEncoding(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_xmlStandalone(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_documentElement(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
     // C++ API
     static ReturnedValue prototype(ExecutionEngine *);
@@ -420,9 +418,10 @@ void NodeImpl::release()
     document->release();
 }
 
-void NodePrototype::method_get_nodeName(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_nodeName(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
@@ -441,12 +440,13 @@ void NodePrototype::method_get_nodeName(const QV4::BuiltinFunction *, QV4::Scope
         name = r->d()->d->name;
         break;
     }
-    scope.result = Encode(scope.engine->newString(name));
+    return Encode(scope.engine->newString(name));
 }
 
-void NodePrototype::method_get_nodeValue(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_nodeValue(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
@@ -459,75 +459,82 @@ void NodePrototype::method_get_nodeValue(const QV4::BuiltinFunction *, QV4::Scop
         r->d()->d->type == NodeImpl::Notation)
         RETURN_RESULT(Encode::null());
 
-    scope.result = Encode(scope.engine->newString(r->d()->d->data));
+    return Encode(scope.engine->newString(r->d()->d->data));
 }
 
-void NodePrototype::method_get_nodeType(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_nodeType(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
-    scope.result = Encode(r->d()->d->type);
+    return Encode(r->d()->d->type);
 }
 
-void NodePrototype::method_get_namespaceUri(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_namespaceUri(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
-    scope.result = Encode(scope.engine->newString(r->d()->d->namespaceUri));
+    return Encode(scope.engine->newString(r->d()->d->namespaceUri));
 }
 
-void NodePrototype::method_get_parentNode(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_parentNode(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
     if (r->d()->d->parent)
-        scope.result = Node::create(scope.engine, r->d()->d->parent);
+        return Node::create(scope.engine, r->d()->d->parent);
     else
-        scope.result = Encode::null();
+        return Encode::null();
 }
 
-void NodePrototype::method_get_childNodes(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_childNodes(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
-    scope.result = NodeList::create(scope.engine, r->d()->d);
+    return NodeList::create(scope.engine, r->d()->d);
 }
 
-void NodePrototype::method_get_firstChild(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_firstChild(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
     if (r->d()->d->children.isEmpty())
-        scope.result = Encode::null();
+        return Encode::null();
     else
-        scope.result = Node::create(scope.engine, r->d()->d->children.constFirst());
+        return Node::create(scope.engine, r->d()->d->children.constFirst());
 }
 
-void NodePrototype::method_get_lastChild(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_lastChild(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
     if (r->d()->d->children.isEmpty())
-        scope.result = Encode::null();
+        return Encode::null();
     else
-        scope.result = Node::create(scope.engine, r->d()->d->children.constLast());
+        return Node::create(scope.engine, r->d()->d->children.constLast());
 }
 
-void NodePrototype::method_get_previousSibling(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_previousSibling(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
@@ -537,19 +544,19 @@ void NodePrototype::method_get_previousSibling(const QV4::BuiltinFunction *, QV4
     for (int ii = 0; ii < r->d()->d->parent->children.count(); ++ii) {
         if (r->d()->d->parent->children.at(ii) == r->d()->d) {
             if (ii == 0)
-                scope.result = Encode::null();
+                return Encode::null();
             else
-                scope.result = Node::create(scope.engine, r->d()->d->parent->children.at(ii - 1));
-            return;
+                return Node::create(scope.engine, r->d()->d->parent->children.at(ii - 1));
         }
     }
 
-    scope.result = Encode::null();
+    return Encode::null();
 }
 
-void NodePrototype::method_get_nextSibling(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_nextSibling(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
@@ -559,26 +566,26 @@ void NodePrototype::method_get_nextSibling(const QV4::BuiltinFunction *, QV4::Sc
     for (int ii = 0; ii < r->d()->d->parent->children.count(); ++ii) {
         if (r->d()->d->parent->children.at(ii) == r->d()->d) {
             if ((ii + 1) == r->d()->d->parent->children.count())
-                scope.result = Encode::null();
+                return Encode::null();
             else
-                scope.result = Node::create(scope.engine, r->d()->d->parent->children.at(ii + 1));
-            return;
+                return Node::create(scope.engine, r->d()->d->parent->children.at(ii + 1));
         }
     }
 
-    scope.result = Encode::null();
+    return Encode::null();
 }
 
-void NodePrototype::method_get_attributes(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue NodePrototype::method_get_attributes(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         THROW_TYPE_ERROR();
 
     if (r->d()->d->type != NodeImpl::Element)
-        scope.result = Encode::null();
+        return Encode::null();
     else
-        scope.result = NamedNodeMap::create(scope.engine, r->d()->d, r->d()->d->attributes);
+        return NamedNodeMap::create(scope.engine, r->d()->d, r->d()->d->attributes);
 }
 
 ReturnedValue NodePrototype::getProto(ExecutionEngine *v4)
@@ -586,7 +593,7 @@ ReturnedValue NodePrototype::getProto(ExecutionEngine *v4)
     Scope scope(v4);
     QQmlXMLHttpRequestData *d = xhrdata(v4);
     if (d->nodePrototype.isUndefined()) {
-        ScopedObject p(scope, v4->memoryManager->allocObject<NodePrototype>());
+        ScopedObject p(scope, v4->memoryManager->allocate<NodePrototype>());
         d->nodePrototype.set(v4, p);
         v4->v8Engine->freezeObject(p);
     }
@@ -597,12 +604,12 @@ ReturnedValue Node::create(ExecutionEngine *v4, NodeImpl *data)
 {
     Scope scope(v4);
 
-    Scoped<Node> instance(scope, v4->memoryManager->allocObject<Node>(data));
+    Scoped<Node> instance(scope, v4->memoryManager->allocate<Node>(data));
     ScopedObject p(scope);
 
     switch (data->type) {
     case NodeImpl::Attr:
-        instance->setPrototype((p = Attr::prototype(v4)));
+        instance->setPrototypeUnchecked((p = Attr::prototype(v4)));
         break;
     case NodeImpl::Comment:
     case NodeImpl::Document:
@@ -614,13 +621,13 @@ ReturnedValue Node::create(ExecutionEngine *v4, NodeImpl *data)
     case NodeImpl::ProcessingInstruction:
         return Encode::undefined();
     case NodeImpl::CDATA:
-        instance->setPrototype((p = CDATA::prototype(v4)));
+        instance->setPrototypeUnchecked((p = CDATA::prototype(v4)));
         break;
     case NodeImpl::Text:
-        instance->setPrototype((p = Text::prototype(v4)));
+        instance->setPrototypeUnchecked((p = Text::prototype(v4)));
         break;
     case NodeImpl::Element:
-        instance->setPrototype((p = Element::prototype(v4)));
+        instance->setPrototypeUnchecked((p = Element::prototype(v4)));
         break;
     }
 
@@ -634,8 +641,8 @@ ReturnedValue Element::prototype(ExecutionEngine *engine)
         Scope scope(engine);
         ScopedObject p(scope, engine->newObject());
         ScopedObject pp(scope);
-        p->setPrototype((pp = NodePrototype::getProto(engine)));
-        p->defineAccessorProperty(QStringLiteral("tagName"), NodePrototype::method_get_nodeName, 0);
+        p->setPrototypeUnchecked((pp = NodePrototype::getProto(engine)));
+        p->defineAccessorProperty(QStringLiteral("tagName"), NodePrototype::method_get_nodeName, nullptr);
         d->elementPrototype.set(engine, p);
         engine->v8Engine->freezeObject(p);
     }
@@ -649,50 +656,54 @@ ReturnedValue Attr::prototype(ExecutionEngine *engine)
         Scope scope(engine);
         ScopedObject p(scope, engine->newObject());
         ScopedObject pp(scope);
-        p->setPrototype((pp = NodePrototype::getProto(engine)));
-        p->defineAccessorProperty(QStringLiteral("name"), method_name, 0);
-        p->defineAccessorProperty(QStringLiteral("value"), method_value, 0);
-        p->defineAccessorProperty(QStringLiteral("ownerElement"), method_ownerElement, 0);
+        p->setPrototypeUnchecked((pp = NodePrototype::getProto(engine)));
+        p->defineAccessorProperty(QStringLiteral("name"), method_name, nullptr);
+        p->defineAccessorProperty(QStringLiteral("value"), method_value, nullptr);
+        p->defineAccessorProperty(QStringLiteral("ownerElement"), method_ownerElement, nullptr);
         d->attrPrototype.set(engine, p);
         engine->v8Engine->freezeObject(p);
     }
     return d->attrPrototype.value();
 }
 
-void Attr::method_name(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Attr::method_name(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         RETURN_UNDEFINED();
 
-    scope.result = scope.engine->newString(r->d()->d->name);
+    return Encode(scope.engine->newString(r->d()->d->name));
 }
 
-void Attr::method_value(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Attr::method_value(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         RETURN_UNDEFINED();
 
-    scope.result = scope.engine->newString(r->d()->d->data);
+    return Encode(scope.engine->newString(r->d()->d->data));
 }
 
-void Attr::method_ownerElement(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Attr::method_ownerElement(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         RETURN_UNDEFINED();
 
-    scope.result = Node::create(scope.engine, r->d()->d->parent);
+    return Node::create(scope.engine, r->d()->d->parent);
 }
 
-void CharacterData::method_length(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue CharacterData::method_length(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         RETURN_UNDEFINED();
 
-    scope.result = Encode(r->d()->d->data.length());
+    return Encode(r->d()->d->data.length());
 }
 
 ReturnedValue CharacterData::prototype(ExecutionEngine *v4)
@@ -702,31 +713,33 @@ ReturnedValue CharacterData::prototype(ExecutionEngine *v4)
         Scope scope(v4);
         ScopedObject p(scope, v4->newObject());
         ScopedObject pp(scope);
-        p->setPrototype((pp = NodePrototype::getProto(v4)));
-        p->defineAccessorProperty(QStringLiteral("data"), NodePrototype::method_get_nodeValue, 0);
-        p->defineAccessorProperty(QStringLiteral("length"), method_length, 0);
+        p->setPrototypeUnchecked((pp = NodePrototype::getProto(v4)));
+        p->defineAccessorProperty(QStringLiteral("data"), NodePrototype::method_get_nodeValue, nullptr);
+        p->defineAccessorProperty(QStringLiteral("length"), method_length, nullptr);
         d->characterDataPrototype.set(v4, p);
         v4->v8Engine->freezeObject(p);
     }
     return d->characterDataPrototype.value();
 }
 
-void Text::method_isElementContentWhitespace(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Text::method_isElementContentWhitespace(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         RETURN_UNDEFINED();
 
-    scope.result = Encode(QStringRef(&r->d()->d->data).trimmed().isEmpty());
+    return Encode(QStringRef(&r->d()->d->data).trimmed().isEmpty());
 }
 
-void Text::method_wholeText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Text::method_wholeText(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    QV4::Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r)
         RETURN_UNDEFINED();
 
-    scope.result = scope.engine->newString(r->d()->d->data);
+    return Encode(scope.engine->newString(r->d()->d->data));
 }
 
 ReturnedValue Text::prototype(ExecutionEngine *v4)
@@ -736,9 +749,9 @@ ReturnedValue Text::prototype(ExecutionEngine *v4)
         Scope scope(v4);
         ScopedObject p(scope, v4->newObject());
         ScopedObject pp(scope);
-        p->setPrototype((pp = CharacterData::prototype(v4)));
-        p->defineAccessorProperty(QStringLiteral("isElementContentWhitespace"), method_isElementContentWhitespace, 0);
-        p->defineAccessorProperty(QStringLiteral("wholeText"), method_wholeText, 0);
+        p->setPrototypeUnchecked((pp = CharacterData::prototype(v4)));
+        p->defineAccessorProperty(QStringLiteral("isElementContentWhitespace"), method_isElementContentWhitespace, nullptr);
+        p->defineAccessorProperty(QStringLiteral("wholeText"), method_wholeText, nullptr);
         d->textPrototype.set(v4, p);
         v4->v8Engine->freezeObject(p);
     }
@@ -753,7 +766,7 @@ ReturnedValue CDATA::prototype(ExecutionEngine *v4)
         Scope scope(v4);
         ScopedObject p(scope, v4->newObject());
         ScopedObject pp(scope);
-        p->setPrototype((pp = Text::prototype(v4)));
+        p->setPrototypeUnchecked((pp = Text::prototype(v4)));
         d->cdataPrototype.set(v4, p);
         v4->v8Engine->freezeObject(p);
     }
@@ -767,11 +780,11 @@ ReturnedValue Document::prototype(ExecutionEngine *v4)
         Scope scope(v4);
         ScopedObject p(scope, v4->newObject());
         ScopedObject pp(scope);
-        p->setPrototype((pp = NodePrototype::getProto(v4)));
-        p->defineAccessorProperty(QStringLiteral("xmlVersion"), method_xmlVersion, 0);
-        p->defineAccessorProperty(QStringLiteral("xmlEncoding"), method_xmlEncoding, 0);
-        p->defineAccessorProperty(QStringLiteral("xmlStandalone"), method_xmlStandalone, 0);
-        p->defineAccessorProperty(QStringLiteral("documentElement"), method_documentElement, 0);
+        p->setPrototypeUnchecked((pp = NodePrototype::getProto(v4)));
+        p->defineAccessorProperty(QStringLiteral("xmlVersion"), method_xmlVersion, nullptr);
+        p->defineAccessorProperty(QStringLiteral("xmlEncoding"), method_xmlEncoding, nullptr);
+        p->defineAccessorProperty(QStringLiteral("xmlStandalone"), method_xmlStandalone, nullptr);
+        p->defineAccessorProperty(QStringLiteral("documentElement"), method_documentElement, nullptr);
         d->documentPrototype.set(v4, p);
         v4->v8Engine->freezeObject(p);
     }
@@ -782,7 +795,7 @@ ReturnedValue Document::load(ExecutionEngine *v4, const QByteArray &data)
 {
     Scope scope(v4);
 
-    DocumentImpl *document = 0;
+    DocumentImpl *document = nullptr;
     QStack<NodeImpl *> nodeStack;
 
     QXmlStreamReader reader(data);
@@ -861,45 +874,45 @@ ReturnedValue Document::load(ExecutionEngine *v4, const QByteArray &data)
         return Encode::null();
     }
 
-    ScopedObject instance(scope, v4->memoryManager->allocObject<Node>(document));
+    ScopedObject instance(scope, v4->memoryManager->allocate<Node>(document));
     document->release(); // the GC should own the NodeImpl via Node now
     ScopedObject p(scope);
-    instance->setPrototype((p = Document::prototype(v4)));
+    instance->setPrototypeUnchecked((p = Document::prototype(v4)));
     return instance.asReturnedValue();
 }
 
 bool Node::isNull() const
 {
-    return d()->d == 0;
+    return d()->d == nullptr;
 }
 
-ReturnedValue NamedNodeMap::getIndexed(const Managed *m, uint index, bool *hasProperty)
+ReturnedValue NamedNodeMap::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<NamedNodeMap>());
+
     const NamedNodeMap *r = static_cast<const NamedNodeMap *>(m);
     QV4::ExecutionEngine *v4 = r->engine();
 
-    if ((int)index < r->d()->list().count()) {
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+
+        if ((int)index < r->d()->list().count()) {
+            if (hasProperty)
+                *hasProperty = true;
+            return Node::create(v4, r->d()->list().at(index));
+        }
         if (hasProperty)
-            *hasProperty = true;
-        return Node::create(v4, r->d()->list().at(index));
+            *hasProperty = false;
+        return Encode::undefined();
     }
-    if (hasProperty)
-        *hasProperty = false;
-    return Encode::undefined();
-}
 
-ReturnedValue NamedNodeMap::get(const Managed *m, String *name, bool *hasProperty)
-{
-    Q_ASSERT(m->as<NamedNodeMap>());
-    const NamedNodeMap *r = static_cast<const NamedNodeMap *>(m);
-    QV4::ExecutionEngine *v4 = r->engine();
+    if (id.isSymbol())
+        return Object::virtualGet(m, id, receiver, hasProperty);
 
-    name->makeIdentifier();
-    if (name->equals(v4->id_length()))
-        return Primitive::fromInt32(r->d()->list().count()).asReturnedValue();
+    if (id == v4->id_length()->propertyKey())
+        return Value::fromInt32(r->d()->list().count()).asReturnedValue();
 
-    QString str = name->toQString();
+    QString str = id.toQString();
     for (int ii = 0; ii < r->d()->list().count(); ++ii) {
         if (r->d()->list().at(ii)->name == str) {
             if (hasProperty)
@@ -915,77 +928,75 @@ ReturnedValue NamedNodeMap::get(const Managed *m, String *name, bool *hasPropert
 
 ReturnedValue NamedNodeMap::create(ExecutionEngine *v4, NodeImpl *data, const QList<NodeImpl *> &list)
 {
-    return (v4->memoryManager->allocObject<NamedNodeMap>(data, list))->asReturnedValue();
+    return (v4->memoryManager->allocate<NamedNodeMap>(data, list))->asReturnedValue();
 }
 
-ReturnedValue NodeList::getIndexed(const Managed *m, uint index, bool *hasProperty)
+ReturnedValue NodeList::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     Q_ASSERT(m->as<NodeList>());
     const NodeList *r = static_cast<const NodeList *>(m);
     QV4::ExecutionEngine *v4 = r->engine();
 
-    if ((int)index < r->d()->d->children.count()) {
+    if (id.isArrayIndex()) {
+        uint index = id.asArrayIndex();
+        if ((int)index < r->d()->d->children.count()) {
+            if (hasProperty)
+                *hasProperty = true;
+            return Node::create(v4, r->d()->d->children.at(index));
+        }
         if (hasProperty)
-            *hasProperty = true;
-        return Node::create(v4, r->d()->d->children.at(index));
+            *hasProperty = false;
+        return Encode::undefined();
     }
-    if (hasProperty)
-        *hasProperty = false;
-    return Encode::undefined();
-}
 
-ReturnedValue NodeList::get(const Managed *m, String *name, bool *hasProperty)
-{
-    Q_ASSERT(m->as<NodeList>());
-    const NodeList *r = static_cast<const NodeList *>(m);
-    QV4::ExecutionEngine *v4 = r->engine();
-
-    name->makeIdentifier();
-
-    if (name->equals(v4->id_length()))
-        return Primitive::fromInt32(r->d()->d->children.count()).asReturnedValue();
-    return Object::get(m, name, hasProperty);
+    if (id == v4->id_length()->propertyKey())
+        return Value::fromInt32(r->d()->d->children.count()).asReturnedValue();
+    return Object::virtualGet(m, id, receiver, hasProperty);
 }
 
 ReturnedValue NodeList::create(ExecutionEngine *v4, NodeImpl *data)
 {
-    return (v4->memoryManager->allocObject<NodeList>(data))->asReturnedValue();
+    return (v4->memoryManager->allocate<NodeList>(data))->asReturnedValue();
 }
 
-void Document::method_documentElement(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Document::method_documentElement(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r || r->d()->d->type != NodeImpl::Document)
         RETURN_UNDEFINED();
 
-    scope.result = Node::create(scope.engine, static_cast<DocumentImpl *>(r->d()->d)->root);
+    return Node::create(scope.engine, static_cast<DocumentImpl *>(r->d()->d)->root);
 }
 
-void Document::method_xmlStandalone(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Document::method_xmlStandalone(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r || r->d()->d->type != NodeImpl::Document)
         RETURN_UNDEFINED();
 
-    scope.result = Encode(static_cast<DocumentImpl *>(r->d()->d)->isStandalone);
+    return Encode(static_cast<DocumentImpl *>(r->d()->d)->isStandalone);
 }
 
-void Document::method_xmlVersion(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Document::method_xmlVersion(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r || r->d()->d->type != NodeImpl::Document)
         RETURN_UNDEFINED();
 
-    scope.result = scope.engine->newString(static_cast<DocumentImpl *>(r->d()->d)->version);
+    return Encode(scope.engine->newString(static_cast<DocumentImpl *>(r->d()->d)->version));
 }
 
-void Document::method_xmlEncoding(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue Document::method_xmlEncoding(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<Node> r(scope, callData->thisObject.as<Node>());
+    Scope scope(b);
+    Scoped<Node> r(scope, thisObject->as<Node>());
     if (!r || r->d()->d->type != NodeImpl::Document)
         RETURN_UNDEFINED();
 
-    scope.result = scope.engine->newString(static_cast<DocumentImpl *>(r->d()->d)->encoding);
+    return Encode(scope.engine->newString(static_cast<DocumentImpl *>(r->d()->d)->encoding));
 }
 
 class QQmlXMLHttpRequest : public QObject
@@ -1000,7 +1011,7 @@ public:
                  Opened = 1, HeadersReceived = 2,
                  Loading = 3, Done = 4 };
 
-    QQmlXMLHttpRequest(QNetworkAccessManager *manager);
+    QQmlXMLHttpRequest(QNetworkAccessManager *manager, QV4::ExecutionEngine *v4);
     virtual ~QQmlXMLHttpRequest();
 
     bool sendFlag() const;
@@ -1009,9 +1020,9 @@ public:
     int replyStatus() const;
     QString replyStatusText() const;
 
-    ReturnedValue open(Object *thisObject, QQmlContextData *context, const QString &, const QUrl &, LoadType);
+    ReturnedValue open(Object *thisObject, const QString &, const QUrl &, LoadType);
     ReturnedValue send(Object *thisObject, QQmlContextData *context, const QByteArray &);
-    ReturnedValue abort(Object *thisObject, QQmlContextData *context);
+    ReturnedValue abort(Object *thisObject);
 
     void addHeader(const QString &, const QString &);
     QString header(const QString &name) const;
@@ -1058,10 +1069,12 @@ private:
     void readEncoding();
 
     PersistentValue m_thisObject;
-    QQmlGuardedContextData m_qmlContext;
+    QQmlContextDataRef m_qmlContext;
+    bool m_wasConstructedWithQmlContext = true;
 
-    static void dispatchCallback(Object *thisObj, QQmlContextData *context);
-    void dispatchCallback();
+    void dispatchCallbackNow(Object *thisObj);
+    static void dispatchCallbackNow(Object *thisObj, bool done, bool error);
+    void dispatchCallbackSafely();
 
     int m_status;
     QString m_statusText;
@@ -1077,12 +1090,13 @@ private:
     QV4::PersistentValue m_parsedDocument;
 };
 
-QQmlXMLHttpRequest::QQmlXMLHttpRequest(QNetworkAccessManager *manager)
+QQmlXMLHttpRequest::QQmlXMLHttpRequest(QNetworkAccessManager *manager, QV4::ExecutionEngine *v4)
     : m_state(Unsent), m_errorFlag(false), m_sendFlag(false)
-    , m_redirectCount(0), m_gotXml(false), m_textCodec(0), m_network(0), m_nam(manager)
+    , m_redirectCount(0), m_gotXml(false), m_textCodec(nullptr), m_network(nullptr), m_nam(manager)
     , m_responseType()
     , m_parsedDocument()
 {
+    m_wasConstructedWithQmlContext = v4->callingQmlContext() != nullptr;
 }
 
 QQmlXMLHttpRequest::~QQmlXMLHttpRequest()
@@ -1115,7 +1129,7 @@ QString QQmlXMLHttpRequest::replyStatusText() const
     return m_statusText;
 }
 
-ReturnedValue QQmlXMLHttpRequest::open(Object *thisObject, QQmlContextData *context, const QString &method, const QUrl &url, LoadType loadType)
+ReturnedValue QQmlXMLHttpRequest::open(Object *thisObject, const QString &method, const QUrl &url, LoadType loadType)
 {
     destroyNetwork();
     m_sendFlag = false;
@@ -1126,7 +1140,7 @@ ReturnedValue QQmlXMLHttpRequest::open(Object *thisObject, QQmlContextData *cont
     m_request.setAttribute(QNetworkRequest::SynchronousRequestAttribute, loadType == SynchronousLoad);
     m_state = Opened;
     m_addedHeaders.clear();
-    dispatchCallback(thisObject, context);
+    dispatchCallbackNow(thisObject);
     return Encode::undefined();
 }
 
@@ -1278,7 +1292,7 @@ ReturnedValue QQmlXMLHttpRequest::send(Object *thisObject, QQmlContextData *cont
     return Encode::undefined();
 }
 
-ReturnedValue QQmlXMLHttpRequest::abort(Object *thisObject, QQmlContextData *context)
+ReturnedValue QQmlXMLHttpRequest::abort(Object *thisObject)
 {
     destroyNetwork();
     m_responseEntityBody = QByteArray();
@@ -1291,7 +1305,7 @@ ReturnedValue QQmlXMLHttpRequest::abort(Object *thisObject, QQmlContextData *con
 
         m_state = Done;
         m_sendFlag = false;
-        dispatchCallback(thisObject, context);
+        dispatchCallbackNow(thisObject);
     }
 
     m_state = Unsent;
@@ -1310,7 +1324,7 @@ void QQmlXMLHttpRequest::readyRead()
     if (m_state < HeadersReceived) {
         m_state = HeadersReceived;
         fillHeadersList ();
-        dispatchCallback();
+        dispatchCallbackSafely();
     }
 
     bool wasEmpty = m_responseEntityBody.isEmpty();
@@ -1318,7 +1332,7 @@ void QQmlXMLHttpRequest::readyRead()
     if (wasEmpty && !m_responseEntityBody.isEmpty())
         m_state = Loading;
 
-    dispatchCallback();
+    dispatchCallbackSafely();
 }
 
 static const char *errorToString(QNetworkReply::NetworkError error)
@@ -1361,14 +1375,14 @@ void QQmlXMLHttpRequest::error(QNetworkReply::NetworkError error)
         error == QNetworkReply::ServiceUnavailableError ||
         error == QNetworkReply::UnknownServerError) {
         m_state = Loading;
-        dispatchCallback();
+        dispatchCallbackSafely();
     } else {
         m_errorFlag = true;
         m_responseEntityBody = QByteArray();
     }
 
     m_state = Done;
-    dispatchCallback();
+    dispatchCallbackSafely();
 }
 
 #define XMLHTTPREQUEST_MAXIMUM_REDIRECT_RECURSION 15
@@ -1400,7 +1414,7 @@ void QQmlXMLHttpRequest::finished()
     if (m_state < HeadersReceived) {
         m_state = HeadersReceived;
         fillHeadersList ();
-        dispatchCallback();
+        dispatchCallbackSafely();
     }
     m_responseEntityBody.append(m_network->readAll());
     readEncoding();
@@ -1417,14 +1431,14 @@ void QQmlXMLHttpRequest::finished()
     destroyNetwork();
     if (m_state < Loading) {
         m_state = Loading;
-        dispatchCallback();
+        dispatchCallbackSafely();
     }
     m_state = Done;
 
-    dispatchCallback();
+    dispatchCallbackSafely();
 
     m_thisObject.clear();
-    m_qmlContext.setContextData(0);
+    m_qmlContext.setContextData(nullptr);
 }
 
 
@@ -1497,7 +1511,7 @@ QV4::ReturnedValue QQmlXMLHttpRequest::xmlResponseBody(QV4::ExecutionEngine* eng
 #if QT_CONFIG(textcodec)
 QTextCodec* QQmlXMLHttpRequest::findTextCodec() const
 {
-    QTextCodec *codec = 0;
+    QTextCodec *codec = nullptr;
 
     if (!m_charset.isEmpty())
         codec = QTextCodec::codecForName(m_charset);
@@ -1509,10 +1523,10 @@ QTextCodec* QQmlXMLHttpRequest::findTextCodec() const
     }
 
     if (!codec && m_mime == "text/html")
-        codec = QTextCodec::codecForHtml(m_responseEntityBody, 0);
+        codec = QTextCodec::codecForHtml(m_responseEntityBody, nullptr);
 
     if (!codec)
-        codec = QTextCodec::codecForUtfText(m_responseEntityBody, 0);
+        codec = QTextCodec::codecForUtfText(m_responseEntityBody, nullptr);
 
     if (!codec)
         codec = QTextCodec::codecForName("UTF-8");
@@ -1538,38 +1552,52 @@ const QByteArray &QQmlXMLHttpRequest::rawResponseBody() const
     return m_responseEntityBody;
 }
 
-void QQmlXMLHttpRequest::dispatchCallback(Object *thisObj, QQmlContextData *context)
+void QQmlXMLHttpRequest::dispatchCallbackNow(Object *thisObj)
+{
+    dispatchCallbackNow(thisObj, m_state == Done, m_errorFlag);
+}
+
+void QQmlXMLHttpRequest::dispatchCallbackNow(Object *thisObj, bool done, bool error)
 {
     Q_ASSERT(thisObj);
 
-    if (!context)
-        // if the calling context object is no longer valid, then it has been
-        // deleted explicitly (e.g., by a Loader deleting the itemContext when
-        // the source is changed).  We do nothing in this case, as the evaluation
-        // cannot succeed.
-        return;
+    const auto dispatch = [thisObj](const QString &eventName) {
+        QV4::Scope scope(thisObj->engine());
+        ScopedString s(scope, scope.engine->newString(eventName));
+        ScopedFunctionObject callback(scope, thisObj->get(s));
+        // not an error, but no event handler to call.
+        if (!callback)
+            return;
 
-    QV4::Scope scope(thisObj->engine());
-    ScopedString s(scope, scope.engine->newString(QStringLiteral("onreadystatechange")));
-    ScopedFunctionObject callback(scope, thisObj->get(s));
-    if (!callback) {
-        // not an error, but no onreadystatechange function to call.
-        return;
-    }
+        QV4::JSCallData jsCallData(scope);
+        callback->call(jsCallData);
 
-    QV4::ScopedCallData callData(scope);
-    callData->thisObject = Encode::undefined();
-    callback->call(scope, callData);
+        if (scope.engine->hasException) {
+            QQmlError error = scope.engine->catchExceptionAsQmlError();
+            QQmlEnginePrivate::warning(QQmlEnginePrivate::get(scope.engine->qmlEngine()), error);
+        }
+    };
 
-    if (scope.engine->hasException) {
-        QQmlError error = scope.engine->catchExceptionAsQmlError();
-        QQmlEnginePrivate::warning(QQmlEnginePrivate::get(scope.engine->qmlEngine()), error);
+    dispatch(QStringLiteral("onreadystatechange"));
+    if (done) {
+        if (error)
+            dispatch(QStringLiteral("onerror"));
+        else
+            dispatch(QStringLiteral("onload"));
+        dispatch(QStringLiteral("onloadend"));
     }
 }
 
-void QQmlXMLHttpRequest::dispatchCallback()
+void QQmlXMLHttpRequest::dispatchCallbackSafely()
 {
-    dispatchCallback(m_thisObject.as<Object>(), m_qmlContext.contextData());
+    if (m_wasConstructedWithQmlContext && !m_qmlContext.contextData())
+        // if the calling context object is no longer valid, then it has been
+        // deleted explicitly (e.g., by a Loader deleting the itemContext when
+        // the source is changed).  We do nothing in this case, as the evaluation
+        // cannot succeed.
+        return;
+
+    dispatchCallbackNow(m_thisObject.as<Object>());
 }
 
 void QQmlXMLHttpRequest::destroyNetwork()
@@ -1577,7 +1605,7 @@ void QQmlXMLHttpRequest::destroyNetwork()
     if (m_network) {
         m_network->disconnect();
         m_network->deleteLater();
-        m_network = 0;
+        m_network = nullptr;
     }
 }
 
@@ -1601,7 +1629,7 @@ struct QQmlXMLHttpRequestWrapper : Object {
     Member(class, Pointer, Object *, proto)
 
 DECLARE_HEAP_OBJECT(QQmlXMLHttpRequestCtor, FunctionObject) {
-    DECLARE_MARK_TABLE(QQmlXMLHttpRequestCtor);
+    DECLARE_MARKOBJECTS(QQmlXMLHttpRequestCtor);
     void init(ExecutionEngine *engine);
 };
 
@@ -1617,42 +1645,39 @@ struct QQmlXMLHttpRequestCtor : public FunctionObject
 {
     V4_OBJECT2(QQmlXMLHttpRequestCtor, FunctionObject)
 
-    static void construct(const Managed *that, Scope &scope, QV4::CallData *)
+    static ReturnedValue virtualCallAsConstructor(const FunctionObject *f, const Value *, int, const Value *)
     {
-        Scoped<QQmlXMLHttpRequestCtor> ctor(scope, that->as<QQmlXMLHttpRequestCtor>());
-        if (!ctor) {
-            scope.result = scope.engine->throwTypeError();
-            return;
-        }
+        Scope scope(f->engine());
+        const QQmlXMLHttpRequestCtor *ctor = static_cast<const QQmlXMLHttpRequestCtor *>(f);
 
-        QQmlXMLHttpRequest *r = new QQmlXMLHttpRequest(scope.engine->v8Engine->networkAccessManager());
-        Scoped<QQmlXMLHttpRequestWrapper> w(scope, scope.engine->memoryManager->allocObject<QQmlXMLHttpRequestWrapper>(r));
+        QQmlXMLHttpRequest *r = new QQmlXMLHttpRequest(scope.engine->v8Engine->networkAccessManager(), scope.engine);
+        Scoped<QQmlXMLHttpRequestWrapper> w(scope, scope.engine->memoryManager->allocate<QQmlXMLHttpRequestWrapper>(r));
         ScopedObject proto(scope, ctor->d()->proto);
-        w->setPrototype(proto);
-        scope.result = w.asReturnedValue();
+        w->setPrototypeUnchecked(proto);
+        return w.asReturnedValue();
     }
 
-    static void call(const Managed *, Scope &scope, QV4::CallData *) {
-        scope.result = Primitive::undefinedValue();
+    static ReturnedValue virtualCall(const FunctionObject *, const Value *, const Value *, int) {
+        return Encode::undefined();
     }
 
     void setupProto();
 
-    static void method_open(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_setRequestHeader(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_send(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_abort(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_getResponseHeader(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_getAllResponseHeaders(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-
-    static void method_get_readyState(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_status(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_statusText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_responseText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_responseXML(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_response(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_get_responseType(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void method_set_responseType(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static ReturnedValue method_open(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_setRequestHeader(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_send(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_abort(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getResponseHeader(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_getAllResponseHeaders(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_get_readyState(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_status(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_statusText(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_responseText(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_responseXML(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_response(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_responseType(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_set_responseType(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 };
 
 }
@@ -1665,11 +1690,11 @@ void Heap::QQmlXMLHttpRequestCtor::init(ExecutionEngine *engine)
     Scope scope(engine);
     Scoped<QV4::QQmlXMLHttpRequestCtor> ctor(scope, this);
 
-    ctor->defineReadonlyProperty(QStringLiteral("UNSENT"), Primitive::fromInt32(0));
-    ctor->defineReadonlyProperty(QStringLiteral("OPENED"), Primitive::fromInt32(1));
-    ctor->defineReadonlyProperty(QStringLiteral("HEADERS_RECEIVED"), Primitive::fromInt32(2));
-    ctor->defineReadonlyProperty(QStringLiteral("LOADING"), Primitive::fromInt32(3));
-    ctor->defineReadonlyProperty(QStringLiteral("DONE"), Primitive::fromInt32(4));
+    ctor->defineReadonlyProperty(QStringLiteral("UNSENT"), Value::fromInt32(0));
+    ctor->defineReadonlyProperty(QStringLiteral("OPENED"), Value::fromInt32(1));
+    ctor->defineReadonlyProperty(QStringLiteral("HEADERS_RECEIVED"), Value::fromInt32(2));
+    ctor->defineReadonlyProperty(QStringLiteral("LOADING"), Value::fromInt32(3));
+    ctor->defineReadonlyProperty(QStringLiteral("DONE"), Value::fromInt32(4));
     if (!ctor->d()->proto)
         ctor->setupProto();
     ScopedString s(scope, engine->id_prototype());
@@ -1694,38 +1719,39 @@ void QQmlXMLHttpRequestCtor::setupProto()
     p->defineDefaultProperty(QStringLiteral("getAllResponseHeaders"), method_getAllResponseHeaders);
 
     // Read-only properties
-    p->defineAccessorProperty(QStringLiteral("readyState"), method_get_readyState, 0);
-    p->defineAccessorProperty(QStringLiteral("status"),method_get_status, 0);
-    p->defineAccessorProperty(QStringLiteral("statusText"),method_get_statusText, 0);
-    p->defineAccessorProperty(QStringLiteral("responseText"),method_get_responseText, 0);
-    p->defineAccessorProperty(QStringLiteral("responseXML"),method_get_responseXML, 0);
-    p->defineAccessorProperty(QStringLiteral("response"),method_get_response, 0);
+    p->defineAccessorProperty(QStringLiteral("readyState"), method_get_readyState, nullptr);
+    p->defineAccessorProperty(QStringLiteral("status"),method_get_status, nullptr);
+    p->defineAccessorProperty(QStringLiteral("statusText"),method_get_statusText, nullptr);
+    p->defineAccessorProperty(QStringLiteral("responseText"),method_get_responseText, nullptr);
+    p->defineAccessorProperty(QStringLiteral("responseXML"),method_get_responseXML, nullptr);
+    p->defineAccessorProperty(QStringLiteral("response"),method_get_response, nullptr);
 
     // Read-write properties
     p->defineAccessorProperty(QStringLiteral("responseType"), method_get_responseType, method_set_responseType);
 
     // State values
-    p->defineReadonlyProperty(QStringLiteral("UNSENT"), Primitive::fromInt32(0));
-    p->defineReadonlyProperty(QStringLiteral("OPENED"), Primitive::fromInt32(1));
-    p->defineReadonlyProperty(QStringLiteral("HEADERS_RECEIVED"), Primitive::fromInt32(2));
-    p->defineReadonlyProperty(QStringLiteral("LOADING"), Primitive::fromInt32(3));
-    p->defineReadonlyProperty(QStringLiteral("DONE"), Primitive::fromInt32(4));
+    p->defineReadonlyProperty(QStringLiteral("UNSENT"), Value::fromInt32(0));
+    p->defineReadonlyProperty(QStringLiteral("OPENED"), Value::fromInt32(1));
+    p->defineReadonlyProperty(QStringLiteral("HEADERS_RECEIVED"), Value::fromInt32(2));
+    p->defineReadonlyProperty(QStringLiteral("LOADING"), Value::fromInt32(3));
+    p->defineReadonlyProperty(QStringLiteral("DONE"), Value::fromInt32(4));
 }
 
 
 // XMLHttpRequest methods
-void QQmlXMLHttpRequestCtor::method_open(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_open(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    if (callData->argc < 2 || callData->argc > 5)
+    if (argc < 2 || argc > 5)
         THROW_DOM(DOMEXCEPTION_SYNTAX_ERR, "Incorrect argument count");
 
     // Argument 0 - Method
-    QString method = callData->args[0].toQStringNoThrow().toUpper();
+    QString method = argv[0].toQStringNoThrow().toUpper();
     if (method != QLatin1String("GET") &&
         method != QLatin1String("PUT") &&
         method != QLatin1String("HEAD") &&
@@ -1737,23 +1763,23 @@ void QQmlXMLHttpRequestCtor::method_open(const QV4::BuiltinFunction *, QV4::Scop
         THROW_DOM(DOMEXCEPTION_SYNTAX_ERR, "Unsupported HTTP method type");
 
     // Argument 1 - URL
-    QUrl url = QUrl(callData->args[1].toQStringNoThrow());
+    QUrl url = QUrl(argv[1].toQStringNoThrow());
 
     if (url.isRelative())
         url = scope.engine->callingQmlContext()->resolvedUrl(url);
 
     bool async = true;
     // Argument 2 - async (optional)
-    if (callData->argc > 2) {
-        async = callData->args[2].booleanValue();
+    if (argc > 2) {
+        async = argv[2].booleanValue();
     }
 
     // Argument 3/4 - user/pass (optional)
     QString username, password;
-    if (callData->argc > 3)
-        username = callData->args[3].toQStringNoThrow();
-    if (callData->argc > 4)
-        password = callData->args[4].toQStringNoThrow();
+    if (argc > 3)
+        username = argv[3].toQStringNoThrow();
+    if (argc > 4)
+        password = argv[4].toQStringNoThrow();
 
     // Clear the fragment (if any)
     url.setFragment(QString());
@@ -1762,24 +1788,25 @@ void QQmlXMLHttpRequestCtor::method_open(const QV4::BuiltinFunction *, QV4::Scop
     if (!username.isNull()) url.setUserName(username);
     if (!password.isNull()) url.setPassword(password);
 
-    scope.result = r->open(w, scope.engine->callingQmlContext(), method, url, async ? QQmlXMLHttpRequest::AsynchronousLoad : QQmlXMLHttpRequest::SynchronousLoad);
+    return r->open(w, method, url, async ? QQmlXMLHttpRequest::AsynchronousLoad : QQmlXMLHttpRequest::SynchronousLoad);
 }
 
-void QQmlXMLHttpRequestCtor::method_setRequestHeader(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_setRequestHeader(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    if (callData->argc != 2)
+    if (argc != 2)
         THROW_DOM(DOMEXCEPTION_SYNTAX_ERR, "Incorrect argument count");
 
     if (r->readyState() != QQmlXMLHttpRequest::Opened || r->sendFlag())
         THROW_DOM(DOMEXCEPTION_INVALID_STATE_ERR, "Invalid state");
 
-    QString name = callData->args[0].toQStringNoThrow();
-    QString value = callData->args[1].toQStringNoThrow();
+    QString name = argv[0].toQStringNoThrow();
+    QString value = argv[1].toQStringNoThrow();
 
     // ### Check that name and value are well formed
 
@@ -1811,9 +1838,10 @@ void QQmlXMLHttpRequestCtor::method_setRequestHeader(const QV4::BuiltinFunction
     RETURN_UNDEFINED();
 }
 
-void QQmlXMLHttpRequestCtor::method_send(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_send(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
@@ -1823,30 +1851,37 @@ void QQmlXMLHttpRequestCtor::method_send(const QV4::BuiltinFunction *, QV4::Scop
         THROW_DOM(DOMEXCEPTION_INVALID_STATE_ERR, "Invalid state");
 
     QByteArray data;
-    if (callData->argc > 0)
-        data = callData->args[0].toQStringNoThrow().toUtf8();
+    if (argc > 0) {
+        if (const ArrayBuffer *buffer = argv[0].as<ArrayBuffer>()) {
+            data = buffer->asByteArray();
+        } else {
+            data = argv[0].toQStringNoThrow().toUtf8();
+        }
+    }
 
-    scope.result = r->send(w, scope.engine->callingQmlContext(), data);
+    return r->send(w, scope.engine->callingQmlContext(), data);
 }
 
-void QQmlXMLHttpRequestCtor::method_abort(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_abort(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    scope.result = r->abort(w, scope.engine->callingQmlContext());
+    return r->abort(w);
 }
 
-void QQmlXMLHttpRequestCtor::method_getResponseHeader(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_getResponseHeader(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    if (callData->argc != 1)
+    if (argc != 1)
         THROW_DOM(DOMEXCEPTION_SYNTAX_ERR, "Incorrect argument count");
 
     if (r->readyState() != QQmlXMLHttpRequest::Loading &&
@@ -1854,17 +1889,18 @@ void QQmlXMLHttpRequestCtor::method_getResponseHeader(const QV4::BuiltinFunction
         r->readyState() != QQmlXMLHttpRequest::HeadersReceived)
         THROW_DOM(DOMEXCEPTION_INVALID_STATE_ERR, "Invalid state");
 
-    scope.result = scope.engine->newString(r->header(callData->args[0].toQStringNoThrow()));
+    return Encode(scope.engine->newString(r->header(argv[0].toQStringNoThrow())));
 }
 
-void QQmlXMLHttpRequestCtor::method_getAllResponseHeaders(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_getAllResponseHeaders(const FunctionObject *b, const Value *thisObject, const Value *, int argc)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    if (callData->argc != 0)
+    if (argc != 0)
         THROW_DOM(DOMEXCEPTION_SYNTAX_ERR, "Incorrect argument count");
 
     if (r->readyState() != QQmlXMLHttpRequest::Loading &&
@@ -1872,23 +1908,25 @@ void QQmlXMLHttpRequestCtor::method_getAllResponseHeaders(const QV4::BuiltinFunc
         r->readyState() != QQmlXMLHttpRequest::HeadersReceived)
         THROW_DOM(DOMEXCEPTION_INVALID_STATE_ERR, "Invalid state");
 
-    scope.result = scope.engine->newString(r->headers());
+    return Encode(scope.engine->newString(r->headers()));
 }
 
 // XMLHttpRequest properties
-void QQmlXMLHttpRequestCtor::method_get_readyState(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_readyState(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    scope.result = Encode(r->readyState());
+    return Encode(r->readyState());
 }
 
-void QQmlXMLHttpRequestCtor::method_get_status(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_status(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
@@ -1898,14 +1936,15 @@ void QQmlXMLHttpRequestCtor::method_get_status(const QV4::BuiltinFunction *, QV4
         THROW_DOM(DOMEXCEPTION_INVALID_STATE_ERR, "Invalid state");
 
     if (r->errorFlag())
-        scope.result = Encode(0);
+        return Encode(0);
     else
-        scope.result = Encode(r->replyStatus());
+        return Encode(r->replyStatus());
 }
 
-void QQmlXMLHttpRequestCtor::method_get_statusText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_statusText(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
@@ -1915,28 +1954,30 @@ void QQmlXMLHttpRequestCtor::method_get_statusText(const QV4::BuiltinFunction *,
         THROW_DOM(DOMEXCEPTION_INVALID_STATE_ERR, "Invalid state");
 
     if (r->errorFlag())
-        scope.result = scope.engine->newString(QString());
+        return Encode(scope.engine->newString(QString()));
     else
-        scope.result = scope.engine->newString(r->replyStatusText());
+        return Encode(scope.engine->newString(r->replyStatusText()));
 }
 
-void QQmlXMLHttpRequestCtor::method_get_responseText(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_responseText(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
     if (r->readyState() != QQmlXMLHttpRequest::Loading &&
         r->readyState() != QQmlXMLHttpRequest::Done)
-        scope.result = scope.engine->newString(QString());
+        return Encode(scope.engine->newString(QString()));
     else
-        scope.result = scope.engine->newString(r->responseBody());
+        return Encode(scope.engine->newString(r->responseBody()));
 }
 
-void QQmlXMLHttpRequestCtor::method_get_responseXML(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_responseXML(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
@@ -1944,17 +1985,18 @@ void QQmlXMLHttpRequestCtor::method_get_responseXML(const QV4::BuiltinFunction *
     if (!r->receivedXml() ||
         (r->readyState() != QQmlXMLHttpRequest::Loading &&
          r->readyState() != QQmlXMLHttpRequest::Done)) {
-        scope.result = Encode::null();
+        return Encode::null();
     } else {
         if (r->responseType().isEmpty())
             r->setResponseType(QLatin1String("document"));
-        scope.result = r->xmlResponseBody(scope.engine);
+        return r->xmlResponseBody(scope.engine);
     }
 }
 
-void QQmlXMLHttpRequestCtor::method_get_response(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_response(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
@@ -1978,29 +2020,31 @@ void QQmlXMLHttpRequestCtor::method_get_response(const QV4::BuiltinFunction *, Q
 }
 
 
-void QQmlXMLHttpRequestCtor::method_get_responseType(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_get_responseType(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
-    scope.result = scope.engine->newString(r->responseType());
+    return Encode(scope.engine->newString(r->responseType()));
 }
 
-void QQmlXMLHttpRequestCtor::method_set_responseType(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+ReturnedValue QQmlXMLHttpRequestCtor::method_set_responseType(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    Scoped<QQmlXMLHttpRequestWrapper> w(scope, callData->thisObject.as<QQmlXMLHttpRequestWrapper>());
+    Scope scope(b);
+    Scoped<QQmlXMLHttpRequestWrapper> w(scope, thisObject->as<QQmlXMLHttpRequestWrapper>());
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
     QQmlXMLHttpRequest *r = w->d()->request;
 
-    if (callData->argc < 1)
+    if (argc < 1)
         THROW_DOM(DOMEXCEPTION_SYNTAX_ERR, "Incorrect argument count");
 
     // Argument 0 - response type
-    r->setResponseType(callData->args[0].toQStringNoThrow());
+    r->setResponseType(argv[0].toQStringNoThrow());
 
-    scope.result = Encode::undefined();
+    return Encode::undefined();
 }
 
 void qt_rem_qmlxmlhttprequest(ExecutionEngine * /* engine */, void *d)
@@ -2013,7 +2057,7 @@ void *qt_add_qmlxmlhttprequest(ExecutionEngine *v4)
 {
     Scope scope(v4);
 
-    Scoped<QQmlXMLHttpRequestCtor> ctor(scope, v4->memoryManager->allocObject<QQmlXMLHttpRequestCtor>(v4));
+    Scoped<QQmlXMLHttpRequestCtor> ctor(scope, v4->memoryManager->allocate<QQmlXMLHttpRequestCtor>(v4));
     ScopedString s(scope, v4->newString(QStringLiteral("XMLHttpRequest")));
     v4->globalObject->defineReadonlyProperty(s, ctor);
 
diff --git a/src/qml/qml/qqmlxmlhttprequest_p.h b/src/qml/qml/qqmlxmlhttprequest_p.h
index f2836d8301..7515ef8dcc 100644
--- a/src/qml/qml/qqmlxmlhttprequest_p.h
+++ b/src/qml/qml/qqmlxmlhttprequest_p.h
@@ -55,7 +55,7 @@
 #include <QtCore/qglobal.h>
 #include <private/qqmlglobal_p.h>
 
-#if QT_CONFIG(xmlstreamreader) && QT_CONFIG(qml_network)
+QT_REQUIRE_CONFIG(qml_xml_http_request);
 
 QT_BEGIN_NAMESPACE
 
@@ -64,7 +64,5 @@ void qt_rem_qmlxmlhttprequest(QV4::ExecutionEngine *engine, void *);
 
 QT_END_NAMESPACE
 
-#endif // xmlstreamreader && qml_network
-
 #endif // QQMLXMLHTTPREQUEST_P_H
 
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index 8cc0b32168..64dc581a56 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -44,7 +44,9 @@
 #include <private/qqmlcomponent_p.h>
 #include <private/qqmlloggingcategory_p.h>
 #include <private/qqmlstringconverters_p.h>
+#if QT_CONFIG(qml_locale)
 #include <private/qqmllocale_p.h>
+#endif
 #include <private/qv8engine_p.h>
 #include <private/qqmldelayedcallqueue_p.h>
 #include <QFileInfo>
@@ -65,6 +67,7 @@
 #include <private/qv4jsonobject_p.h>
 #include <private/qv4objectproto_p.h>
 #include <private/qv4qobjectwrapper_p.h>
+#include <private/qv4stackframe_p.h>
 
 #include <QtCore/qstring.h>
 #include <QtCore/qdatetime.h>
@@ -87,8 +90,7 @@ DEFINE_OBJECT_VTABLE(QtObject);
 
 #define THROW_TYPE_ERROR_WITH_MESSAGE(msg) \
     do { \
-        scope.result = scope.engine->throwTypeError(QString::fromUtf8(msg)); \
-        return; \
+        return scope.engine->throwTypeError(QString::fromUtf8(msg)); \
     } while (false)
 
 struct StaticQtMetaObject : public QObject
@@ -108,8 +110,8 @@ void Heap::QtObject::init(QQmlEngine *qmlEngine)
     {
         ScopedString str(scope);
         ScopedValue v(scope);
-        o->put((str = scope.engine->newString(QStringLiteral("Asynchronous"))), (v = QV4::Primitive::fromInt32(0)));
-        o->put((str = scope.engine->newString(QStringLiteral("Synchronous"))), (v = QV4::Primitive::fromInt32(1)));
+        o->put((str = scope.engine->newString(QStringLiteral("Asynchronous"))), (v = QV4::Value::fromInt32(0)));
+        o->put((str = scope.engine->newString(QStringLiteral("Synchronous"))), (v = QV4::Value::fromInt32(1)));
     }
 
     o->defineDefaultProperty(QStringLiteral("include"), QV4Include::method_include);
@@ -139,7 +141,9 @@ void Heap::QtObject::init(QQmlEngine *qmlEngine)
     o->defineDefaultProperty(QStringLiteral("btoa"), QV4::QtObject::method_btoa);
     o->defineDefaultProperty(QStringLiteral("atob"), QV4::QtObject::method_atob);
     o->defineDefaultProperty(QStringLiteral("resolvedUrl"), QV4::QtObject::method_resolvedUrl);
+#if QT_CONFIG(qml_locale)
     o->defineDefaultProperty(QStringLiteral("locale"), QV4::QtObject::method_locale);
+#endif
     o->defineDefaultProperty(QStringLiteral("binding"), QV4::QtObject::method_binding);
 
     if (qmlEngine) {
@@ -152,10 +156,10 @@ void Heap::QtObject::init(QQmlEngine *qmlEngine)
         o->defineDefaultProperty(QStringLiteral("createComponent"), QV4::QtObject::method_createComponent);
     }
 
-    o->defineAccessorProperty(QStringLiteral("platform"), QV4::QtObject::method_get_platform, 0);
-    o->defineAccessorProperty(QStringLiteral("application"), QV4::QtObject::method_get_application, 0);
-    o->defineAccessorProperty(QStringLiteral("inputMethod"), QV4::QtObject::method_get_inputMethod, 0);
-    o->defineAccessorProperty(QStringLiteral("styleHints"), QV4::QtObject::method_get_styleHints, 0);
+    o->defineAccessorProperty(QStringLiteral("platform"), QV4::QtObject::method_get_platform, nullptr);
+    o->defineAccessorProperty(QStringLiteral("application"), QV4::QtObject::method_get_application, nullptr);
+    o->defineAccessorProperty(QStringLiteral("inputMethod"), QV4::QtObject::method_get_inputMethod, nullptr);
+    o->defineAccessorProperty(QStringLiteral("styleHints"), QV4::QtObject::method_get_styleHints, nullptr);
 
     o->defineDefaultProperty(QStringLiteral("callLater"), QV4::QtObject::method_callLater);
 }
@@ -179,7 +183,7 @@ ReturnedValue QtObject::findAndAdd(const QString *name, bool &foundProperty) con
         QMetaEnum enumerator = qtMetaObject->enumerator(d()->enumeratorIterator);
         for (int keyCount = enumerator.keyCount(); d()->keyIterator < keyCount; ++d()->keyIterator) {
             key = scope.engine->newString(QString::fromUtf8(enumerator.key(d()->keyIterator)));
-            value = QV4::Primitive::fromInt32(enumerator.value(d()->keyIterator));
+            value = QV4::Value::fromInt32(enumerator.value(d()->keyIterator));
             o->put(key, value);
             if (name && key->toQString() == *name) {
                 ++d()->keyIterator;
@@ -194,47 +198,46 @@ ReturnedValue QtObject::findAndAdd(const QString *name, bool &foundProperty) con
     return Encode::undefined();
 }
 
-ReturnedValue QtObject::get(const Managed *m, String *name, bool *hasProperty)
+ReturnedValue QtObject::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
     bool hasProp = false;
     if (hasProperty == nullptr) {
         hasProperty = &hasProp;
     }
 
-    ReturnedValue ret = QV4::Object::get(m, name, hasProperty);
+    ReturnedValue ret = QV4::Object::virtualGet(m, id, receiver, hasProperty);
     if (*hasProperty) {
         return ret;
     }
 
     auto that = static_cast<const QtObject*>(m);
     if (!that->d()->isComplete()) {
-        const QString key = name->toQString();
+        const QString key = id.toQString();
         ret = that->findAndAdd(&key, *hasProperty);
     }
 
     return ret;
 }
 
-void QtObject::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes)
+OwnPropertyKeyIterator *QtObject::virtualOwnPropertyKeys(const Object *m, Value *target)
 {
-    auto that = static_cast<QtObject*>(m);
-    if (!that->d()->isComplete()) {
-        that->addAll();
-    }
+    auto that = static_cast<const QtObject*>(m);
+    if (!that->d()->isComplete())
+        const_cast<QtObject *>(that)->addAll();
 
-    QV4::Object::advanceIterator(m, it, name, index, p, attributes);
+    return Object::virtualOwnPropertyKeys(m, target);
 }
 
 /*!
 \qmlmethod bool Qt::isQtObject(object)
 Returns true if \c object is a valid reference to a Qt or QML object, otherwise false.
 */
-void QtObject::method_isQtObject(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_isQtObject(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    if (argc == 0)
         RETURN_RESULT(QV4::Encode(false));
 
-    scope.result = QV4::Encode(callData->args[0].as<QV4::QObjectWrapper>() != 0);
+    return QV4::Encode(argv[0].as<QV4::QObjectWrapper>() != nullptr);
 }
 
 /*!
@@ -243,16 +246,16 @@ void QtObject::method_isQtObject(const BuiltinFunction *, Scope &scope, CallData
 Returns a color with the specified \c red, \c green, \c blue and \c alpha components.
 All components should be in the range 0-1 inclusive.
 */
-void QtObject::method_rgba(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_rgba(const FunctionObject *f, const Value *, const Value *argv, int argc)
 {
-    int argCount = callData->argc;
-    if (argCount < 3 || argCount > 4)
+    QV4::Scope scope(f);
+    if (argc < 3 || argc > 4)
         THROW_GENERIC_ERROR("Qt.rgba(): Invalid arguments");
 
-    double r = callData->args[0].toNumber();
-    double g = callData->args[1].toNumber();
-    double b = callData->args[2].toNumber();
-    double a = (argCount == 4) ? callData->args[3].toNumber() : 1;
+    double r = argv[0].toNumber();
+    double g = argv[1].toNumber();
+    double b = argv[2].toNumber();
+    double a = (argc == 4) ? argv[3].toNumber() : 1;
 
     if (r < 0.0) r=0.0;
     if (r > 1.0) r=1.0;
@@ -263,7 +266,7 @@ void QtObject::method_rgba(const BuiltinFunction *, Scope &scope, CallData *call
     if (a < 0.0) a=0.0;
     if (a > 1.0) a=1.0;
 
-    scope.result = scope.engine->fromVariant(QQml_colorProvider()->fromRgbF(r, g, b, a));
+    return scope.engine->fromVariant(QQml_colorProvider()->fromRgbF(r, g, b, a));
 }
 
 /*!
@@ -272,16 +275,17 @@ void QtObject::method_rgba(const BuiltinFunction *, Scope &scope, CallData *call
 Returns a color with the specified \c hue, \c saturation, \c lightness and \c alpha components.
 All components should be in the range 0-1 inclusive.
 */
-void QtObject::method_hsla(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_hsla(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    int argCount = callData->argc;
+    QV4::Scope scope(b);
+    int argCount = argc;
     if (argCount < 3 || argCount > 4)
         THROW_GENERIC_ERROR("Qt.hsla(): Invalid arguments");
 
-    double h = callData->args[0].toNumber();
-    double s = callData->args[1].toNumber();
-    double l = callData->args[2].toNumber();
-    double a = (argCount == 4) ? callData->args[3].toNumber() : 1;
+    double h = argv[0].toNumber();
+    double s = argv[1].toNumber();
+    double l = argv[2].toNumber();
+    double a = (argCount == 4) ? argv[3].toNumber() : 1;
 
     if (h < 0.0) h=0.0;
     if (h > 1.0) h=1.0;
@@ -292,7 +296,7 @@ void QtObject::method_hsla(const BuiltinFunction *, Scope &scope, CallData *call
     if (a < 0.0) a=0.0;
     if (a > 1.0) a=1.0;
 
-    scope.result = scope.engine->fromVariant(QQml_colorProvider()->fromHslF(h, s, l, a));
+    return scope.engine->fromVariant(QQml_colorProvider()->fromHslF(h, s, l, a));
 }
 
 /*!
@@ -303,23 +307,24 @@ All components should be in the range 0-1 inclusive.
 
 \since 5.5
 */
-void QtObject::method_hsva(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_hsva(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    int argCount = callData->argc;
+    QV4::Scope scope(b);
+    int argCount = argc;
     if (argCount < 3 || argCount > 4)
         THROW_GENERIC_ERROR("Qt.hsva(): Invalid arguments");
 
-    double h = callData->args[0].toNumber();
-    double s = callData->args[1].toNumber();
-    double v = callData->args[2].toNumber();
-    double a = (argCount == 4) ? callData->args[3].toNumber() : 1;
+    double h = argv[0].toNumber();
+    double s = argv[1].toNumber();
+    double v = argv[2].toNumber();
+    double a = (argCount == 4) ? argv[3].toNumber() : 1;
 
     h = qBound(0.0, h, 1.0);
     s = qBound(0.0, s, 1.0);
     v = qBound(0.0, v, 1.0);
     a = qBound(0.0, a, 1.0);
 
-    scope.result = scope.engine->fromVariant(QQml_colorProvider()->fromHsvF(h, s, v, a));
+    return scope.engine->fromVariant(QQml_colorProvider()->fromHsvF(h, s, v, a));
 }
 
 /*!
@@ -330,14 +335,15 @@ may be either color values or string values.  If a string value is supplied it
 must be convertible to a color, as described for the \l{colorbasictypedocs}{color}
 basic type.
 */
-void QtObject::method_colorEqual(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_colorEqual(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 2)
         THROW_GENERIC_ERROR("Qt.colorEqual(): Invalid arguments");
 
     bool ok = false;
 
-    QVariant lhs = scope.engine->toVariant(callData->args[0], -1);
+    QVariant lhs = scope.engine->toVariant(argv[0], -1);
     if (lhs.userType() == QVariant::String) {
         lhs = QQmlStringConverters::colorFromString(lhs.toString(), &ok);
         if (!ok) {
@@ -347,7 +353,7 @@ void QtObject::method_colorEqual(const BuiltinFunction *, Scope &scope, CallData
         THROW_GENERIC_ERROR("Qt.colorEqual(): Invalid arguments");
     }
 
-    QVariant rhs = scope.engine->toVariant(callData->args[1], -1);
+    QVariant rhs = scope.engine->toVariant(argv[1], -1);
     if (rhs.userType() == QVariant::String) {
         rhs = QQmlStringConverters::colorFromString(rhs.toString(), &ok);
         if (!ok) {
@@ -358,7 +364,7 @@ void QtObject::method_colorEqual(const BuiltinFunction *, Scope &scope, CallData
     }
 
     bool equal = (lhs == rhs);
-    scope.result = QV4::Encode(equal);
+    return QV4::Encode(equal);
 }
 
 /*!
@@ -368,47 +374,50 @@ Returns a \c rect with the top-left corner at \c x, \c y and the specified \c wi
 
 The returned object has \c x, \c y, \c width and \c height attributes with the given values.
 */
-void QtObject::method_rect(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_rect(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 4)
+    QV4::Scope scope(b);
+    if (argc != 4)
         THROW_GENERIC_ERROR("Qt.rect(): Invalid arguments");
 
-    double x = callData->args[0].toNumber();
-    double y = callData->args[1].toNumber();
-    double w = callData->args[2].toNumber();
-    double h = callData->args[3].toNumber();
+    double x = argv[0].toNumber();
+    double y = argv[1].toNumber();
+    double w = argv[2].toNumber();
+    double h = argv[3].toNumber();
 
-    scope.result = scope.engine->fromVariant(QVariant::fromValue(QRectF(x, y, w, h)));
+    return scope.engine->fromVariant(QVariant::fromValue(QRectF(x, y, w, h)));
 }
 
 /*!
 \qmlmethod point Qt::point(int x, int y)
 Returns a Point with the specified \c x and \c y coordinates.
 */
-void QtObject::method_point(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_point(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 2)
         THROW_GENERIC_ERROR("Qt.point(): Invalid arguments");
 
-    double x = callData->args[0].toNumber();
-    double y = callData->args[1].toNumber();
+    double x = argv[0].toNumber();
+    double y = argv[1].toNumber();
 
-    scope.result = scope.engine->fromVariant(QVariant::fromValue(QPointF(x, y)));
+    return scope.engine->fromVariant(QVariant::fromValue(QPointF(x, y)));
 }
 
 /*!
 \qmlmethod Qt::size(int width, int height)
 Returns a Size with the specified \c width and \c height.
 */
-void QtObject::method_size(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_size(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 2)
         THROW_GENERIC_ERROR("Qt.size(): Invalid arguments");
 
-    double w = callData->args[0].toNumber();
-    double h = callData->args[1].toNumber();
+    double w = argv[0].toNumber();
+    double h = argv[1].toNumber();
 
-    scope.result = scope.engine->fromVariant(QVariant::fromValue(QSizeF(w, h)));
+    return scope.engine->fromVariant(QVariant::fromValue(QSizeF(w, h)));
 }
 
 /*!
@@ -419,17 +428,18 @@ key-value pairs where valid keys are the \l{fontbasictypedocs}{font} type's
 subproperty names, and the values are valid values for each subproperty.
 Invalid keys will be ignored.
 */
-void QtObject::method_font(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_font(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1 || !callData->args[0].isObject())
+    QV4::Scope scope(b);
+    if (argc != 1 || !argv[0].isObject())
         THROW_GENERIC_ERROR("Qt.font(): Invalid arguments");
 
     QV4::ExecutionEngine *v4 = scope.engine;
     bool ok = false;
-    QVariant v = QQml_valueTypeProvider()->createVariantFromJsObject(QMetaType::QFont, QQmlV4Handle(callData->args[0]), v4, &ok);
+    QVariant v = QQml_valueTypeProvider()->createVariantFromJsObject(QMetaType::QFont, QQmlV4Handle(argv[0]), v4, &ok);
     if (!ok)
         THROW_GENERIC_ERROR("Qt.font(): Invalid argument: no valid font subproperties specified");
-    scope.result = scope.engine->fromVariant(v);
+    return scope.engine->fromVariant(v);
 }
 
 
@@ -438,73 +448,77 @@ void QtObject::method_font(const BuiltinFunction *, Scope &scope, CallData *call
 \qmlmethod Qt::vector2d(real x, real y)
 Returns a Vector2D with the specified \c x and \c y.
 */
-void QtObject::method_vector2d(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_vector2d(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 2)
         THROW_GENERIC_ERROR("Qt.vector2d(): Invalid arguments");
 
     float xy[3]; // qvector2d uses float internally
-    xy[0] = callData->args[0].toNumber();
-    xy[1] = callData->args[1].toNumber();
+    xy[0] = argv[0].toNumber();
+    xy[1] = argv[1].toNumber();
 
     const void *params[] = { xy };
-    scope.result = scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QVector2D, 1, params));
+    return scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QVector2D, 1, params));
 }
 
 /*!
 \qmlmethod Qt::vector3d(real x, real y, real z)
 Returns a Vector3D with the specified \c x, \c y and \c z.
 */
-void QtObject::method_vector3d(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_vector3d(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 3)
+    QV4::Scope scope(b);
+    if (argc != 3)
         THROW_GENERIC_ERROR("Qt.vector3d(): Invalid arguments");
 
     float xyz[3]; // qvector3d uses float internally
-    xyz[0] = callData->args[0].toNumber();
-    xyz[1] = callData->args[1].toNumber();
-    xyz[2] = callData->args[2].toNumber();
+    xyz[0] = argv[0].toNumber();
+    xyz[1] = argv[1].toNumber();
+    xyz[2] = argv[2].toNumber();
 
     const void *params[] = { xyz };
-    scope.result = scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QVector3D, 1, params));
+    return scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QVector3D, 1, params));
 }
 
 /*!
 \qmlmethod Qt::vector4d(real x, real y, real z, real w)
 Returns a Vector4D with the specified \c x, \c y, \c z and \c w.
 */
-void QtObject::method_vector4d(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_vector4d(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 4)
+    QV4::Scope scope(b);
+    if (argc != 4)
         THROW_GENERIC_ERROR("Qt.vector4d(): Invalid arguments");
 
     float xyzw[4]; // qvector4d uses float internally
-    xyzw[0] = callData->args[0].toNumber();
-    xyzw[1] = callData->args[1].toNumber();
-    xyzw[2] = callData->args[2].toNumber();
-    xyzw[3] = callData->args[3].toNumber();
+    xyzw[0] = argv[0].toNumber();
+    xyzw[1] = argv[1].toNumber();
+    xyzw[2] = argv[2].toNumber();
+    xyzw[3] = argv[3].toNumber();
 
     const void *params[] = { xyzw };
-    scope.result = scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QVector4D, 1, params));
+    return scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QVector4D, 1, params));
 }
 
 /*!
 \qmlmethod Qt::quaternion(real scalar, real x, real y, real z)
 Returns a Quaternion with the specified \c scalar, \c x, \c y, and \c z.
 */
-void QtObject::method_quaternion(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_quaternion(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 4)
+    QV4::Scope scope(b);
+    if (argc != 4)
         THROW_GENERIC_ERROR("Qt.quaternion(): Invalid arguments");
 
     qreal sxyz[4]; // qquaternion uses qreal internally
-    sxyz[0] = callData->args[0].toNumber();
-    sxyz[1] = callData->args[1].toNumber();
-    sxyz[2] = callData->args[2].toNumber();
-    sxyz[3] = callData->args[3].toNumber();
+    sxyz[0] = argv[0].toNumber();
+    sxyz[1] = argv[1].toNumber();
+    sxyz[2] = argv[2].toNumber();
+    sxyz[3] = argv[3].toNumber();
 
     const void *params[] = { sxyz };
-    scope.result = scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QQuaternion, 1, params));
+    return scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QQuaternion, 1, params));
 }
 
 /*!
@@ -516,47 +530,45 @@ matrix values.
 Finally, the function may be called with no arguments and the resulting
 matrix will be the identity matrix.
 */
-void QtObject::method_matrix4x4(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_matrix4x4(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    QV4::ExecutionEngine *v4 = scope.engine;
+    QV4::Scope scope(b);
 
-    if (callData->argc == 0) {
-        scope.result = scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QMatrix4x4, 0, Q_NULLPTR));
-        return;
+    if (argc == 0) {
+        return scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QMatrix4x4, 0, nullptr));
     }
 
-    if (callData->argc == 1 && callData->args[0].isObject()) {
+    if (argc == 1 && argv[0].isObject()) {
         bool ok = false;
-        QVariant v = QQml_valueTypeProvider()->createVariantFromJsObject(QMetaType::QMatrix4x4, QQmlV4Handle(callData->args[0]), v4, &ok);
+        QVariant v = QQml_valueTypeProvider()->createVariantFromJsObject(QMetaType::QMatrix4x4, QQmlV4Handle(argv[0]), scope.engine, &ok);
         if (!ok)
             THROW_GENERIC_ERROR("Qt.matrix4x4(): Invalid argument: not a valid matrix4x4 values array");
-        scope.result = scope.engine->fromVariant(v);
-        return;
+        return scope.engine->fromVariant(v);
     }
 
-    if (callData->argc != 16)
+    if (argc != 16)
         THROW_GENERIC_ERROR("Qt.matrix4x4(): Invalid arguments");
 
     qreal vals[16]; // qmatrix4x4 uses qreal internally
-    vals[0] = callData->args[0].toNumber();
-    vals[1] = callData->args[1].toNumber();
-    vals[2] = callData->args[2].toNumber();
-    vals[3] = callData->args[3].toNumber();
-    vals[4] = callData->args[4].toNumber();
-    vals[5] = callData->args[5].toNumber();
-    vals[6] = callData->args[6].toNumber();
-    vals[7] = callData->args[7].toNumber();
-    vals[8] = callData->args[8].toNumber();
-    vals[9] = callData->args[9].toNumber();
-    vals[10] = callData->args[10].toNumber();
-    vals[11] = callData->args[11].toNumber();
-    vals[12] = callData->args[12].toNumber();
-    vals[13] = callData->args[13].toNumber();
-    vals[14] = callData->args[14].toNumber();
-    vals[15] = callData->args[15].toNumber();
+    vals[0] = argv[0].toNumber();
+    vals[1] = argv[1].toNumber();
+    vals[2] = argv[2].toNumber();
+    vals[3] = argv[3].toNumber();
+    vals[4] = argv[4].toNumber();
+    vals[5] = argv[5].toNumber();
+    vals[6] = argv[6].toNumber();
+    vals[7] = argv[7].toNumber();
+    vals[8] = argv[8].toNumber();
+    vals[9] = argv[9].toNumber();
+    vals[10] = argv[10].toNumber();
+    vals[11] = argv[11].toNumber();
+    vals[12] = argv[12].toNumber();
+    vals[13] = argv[13].toNumber();
+    vals[14] = argv[14].toNumber();
+    vals[15] = argv[15].toNumber();
 
     const void *params[] = { vals };
-    scope.result = scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QMatrix4x4, 1, params));
+    return scope.engine->fromVariant(QQml_valueTypeProvider()->createValueType(QMetaType::QMatrix4x4, 1, params));
 }
 
 /*!
@@ -573,29 +585,28 @@ by factor and converts the color back to RGB.
 
 If \c factor is not supplied, returns a color 50% lighter than \c baseColor (factor 1.5).
 */
-void QtObject::method_lighter(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_lighter(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1 && callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 1 && argc != 2)
         THROW_GENERIC_ERROR("Qt.lighter(): Invalid arguments");
 
-    QVariant v = scope.engine->toVariant(callData->args[0], -1);
+    QVariant v = scope.engine->toVariant(argv[0], -1);
     if (v.userType() == QVariant::String) {
         bool ok = false;
         v = QQmlStringConverters::colorFromString(v.toString(), &ok);
         if (!ok) {
-            scope.result = QV4::Encode::null();
-            return;
+            return QV4::Encode::null();
         }
     } else if (v.userType() != QVariant::Color) {
-        scope.result = QV4::Encode::null();
-        return;
+        return QV4::Encode::null();
     }
 
     qreal factor = 1.5;
-    if (callData->argc == 2)
-        factor = callData->args[1].toNumber();
+    if (argc == 2)
+        factor = argv[1].toNumber();
 
-    scope.result = scope.engine->fromVariant(QQml_colorProvider()->lighter(v, factor));
+    return scope.engine->fromVariant(QQml_colorProvider()->lighter(v, factor));
 }
 
 /*!
@@ -613,29 +624,28 @@ by factor and converts the color back to RGB.
 
 If \c factor is not supplied, returns a color 50% darker than \c baseColor (factor 2.0).
 */
-void QtObject::method_darker(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_darker(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1 && callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 1 && argc != 2)
         THROW_GENERIC_ERROR("Qt.darker(): Invalid arguments");
 
-    QVariant v = scope.engine->toVariant(callData->args[0], -1);
+    QVariant v = scope.engine->toVariant(argv[0], -1);
     if (v.userType() == QVariant::String) {
         bool ok = false;
         v = QQmlStringConverters::colorFromString(v.toString(), &ok);
         if (!ok) {
-            scope.result = QV4::Encode::null();
-            return;
+            return QV4::Encode::null();
         }
     } else if (v.userType() != QVariant::Color) {
-        scope.result = QV4::Encode::null();
-        return;
+        return QV4::Encode::null();
     }
 
     qreal factor = 2.0;
-    if (callData->argc == 2)
-        factor = callData->args[1].toNumber();
+    if (argc == 2)
+        factor = argv[1].toNumber();
 
-    scope.result = scope.engine->fromVariant(QQml_colorProvider()->darker(v, factor));
+    return scope.engine->fromVariant(QQml_colorProvider()->darker(v, factor));
 }
 
 /*!
@@ -662,40 +672,37 @@ void QtObject::method_darker(const BuiltinFunction *, Scope &scope, CallData *ca
 
     Tint is most useful when a subtle change is intended to be conveyed due to some event; you can then use tinting to more effectively tune the visible color.
 */
-void QtObject::method_tint(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_tint(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 2)
+    QV4::Scope scope(b);
+    if (argc != 2)
         THROW_GENERIC_ERROR("Qt.tint(): Invalid arguments");
 
     // base color
-    QVariant v1 = scope.engine->toVariant(callData->args[0], -1);
+    QVariant v1 = scope.engine->toVariant(argv[0], -1);
     if (v1.userType() == QVariant::String) {
         bool ok = false;
         v1 = QQmlStringConverters::colorFromString(v1.toString(), &ok);
         if (!ok) {
-            scope.result = QV4::Encode::null();
-            return;
+            return QV4::Encode::null();
         }
     } else if (v1.userType() != QVariant::Color) {
-        scope.result = QV4::Encode::null();
-        return;
+        return QV4::Encode::null();
     }
 
     // tint color
-    QVariant v2 = scope.engine->toVariant(callData->args[1], -1);
+    QVariant v2 = scope.engine->toVariant(argv[1], -1);
     if (v2.userType() == QVariant::String) {
         bool ok = false;
         v2 = QQmlStringConverters::colorFromString(v2.toString(), &ok);
         if (!ok) {
-            scope.result = QV4::Encode::null();
-            return;
+            return QV4::Encode::null();
         }
     } else if (v2.userType() != QVariant::Color) {
-        scope.result = QV4::Encode::null();
-        return;
+        return QV4::Encode::null();
     }
 
-    scope.result = scope.engine->fromVariant(QQml_colorProvider()->tint(v1, v2));
+    return scope.engine->fromVariant(QQml_colorProvider()->tint(v1, v2));
 }
 
 /*!
@@ -714,21 +721,22 @@ If \a format is not specified, \a date is formatted using
 
 \sa Locale
 */
-void QtObject::method_formatDate(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_formatDate(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1 || callData->argc > 2)
+    QV4::Scope scope(b);
+    if (argc < 1 || argc > 2)
         THROW_GENERIC_ERROR("Qt.formatDate(): Invalid arguments");
 
     Qt::DateFormat enumFormat = Qt::DefaultLocaleShortDate;
-    QDate date = scope.engine->toVariant(callData->args[0], -1).toDateTime().date();
+    QDate date = scope.engine->toVariant(argv[0], -1).toDateTime().date();
     QString formattedDate;
-    if (callData->argc == 2) {
-        QV4::ScopedString s(scope, callData->args[1]);
+    if (argc == 2) {
+        QV4::ScopedString s(scope, argv[1]);
         if (s) {
             QString format = s->toQString();
             formattedDate = date.toString(format);
-        } else if (callData->args[1].isNumber()) {
-            quint32 intFormat = callData->args[1].asDouble();
+        } else if (argv[1].isNumber()) {
+            quint32 intFormat = argv[1].asDouble();
             Qt::DateFormat format = Qt::DateFormat(intFormat);
             formattedDate = date.toString(format);
         } else {
@@ -738,7 +746,7 @@ void QtObject::method_formatDate(const BuiltinFunction *, Scope &scope, CallData
          formattedDate = date.toString(enumFormat);
     }
 
-    scope.result = scope.engine->newString(formattedDate);
+    return Encode(scope.engine->newString(formattedDate));
 }
 
 /*!
@@ -756,27 +764,28 @@ If \a format is not specified, \a time is formatted using
 
 \sa Locale
 */
-void QtObject::method_formatTime(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_formatTime(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1 || callData->argc > 2)
+    QV4::Scope scope(b);
+    if (argc < 1 || argc > 2)
         THROW_GENERIC_ERROR("Qt.formatTime(): Invalid arguments");
 
-    QVariant argVariant = scope.engine->toVariant(callData->args[0], -1);
+    QVariant argVariant = scope.engine->toVariant(argv[0], -1);
     QTime time;
-    if (callData->args[0].as<DateObject>() || (argVariant.type() == QVariant::String))
+    if (argv[0].as<DateObject>() || (argVariant.type() == QVariant::String))
         time = argVariant.toDateTime().time();
     else // if (argVariant.type() == QVariant::Time), or invalid.
         time = argVariant.toTime();
 
     Qt::DateFormat enumFormat = Qt::DefaultLocaleShortDate;
     QString formattedTime;
-    if (callData->argc == 2) {
-        QV4::ScopedString s(scope, callData->args[1]);
+    if (argc == 2) {
+        QV4::ScopedString s(scope, argv[1]);
         if (s) {
             QString format = s->toQString();
             formattedTime = time.toString(format);
-        } else if (callData->args[1].isNumber()) {
-            quint32 intFormat = callData->args[1].asDouble();
+        } else if (argv[1].isNumber()) {
+            quint32 intFormat = argv[1].asDouble();
             Qt::DateFormat format = Qt::DateFormat(intFormat);
             formattedTime = time.toString(format);
         } else {
@@ -786,7 +795,7 @@ void QtObject::method_formatTime(const BuiltinFunction *, Scope &scope, CallData
          formattedTime = time.toString(enumFormat);
     }
 
-    scope.result = scope.engine->newString(formattedTime);
+    return Encode(scope.engine->newString(formattedTime));
 }
 
 /*!
@@ -851,6 +860,8 @@ In addition the following expressions can be used to specify the time:
             \li use AM/PM display. \e AP will be replaced by either "AM" or "PM".
     \row \li ap
             \li use am/pm display. \e ap will be replaced by either "am" or "pm".
+    \row \li t
+            \li include a time-zone indicator.
     \endtable
 
     All other input characters will be ignored. Any sequence of characters that
@@ -879,21 +890,22 @@ with the \a format values below to produce the following results:
 
     \sa Locale
 */
-void QtObject::method_formatDateTime(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_formatDateTime(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1 || callData->argc > 2)
+    QV4::Scope scope(b);
+    if (argc < 1 || argc > 2)
         THROW_GENERIC_ERROR("Qt.formatDateTime(): Invalid arguments");
 
     Qt::DateFormat enumFormat = Qt::DefaultLocaleShortDate;
-    QDateTime dt = scope.engine->toVariant(callData->args[0], -1).toDateTime();
+    QDateTime dt = scope.engine->toVariant(argv[0], -1).toDateTime();
     QString formattedDt;
-    if (callData->argc == 2) {
-        QV4::ScopedString s(scope, callData->args[1]);
+    if (argc == 2) {
+        QV4::ScopedString s(scope, argv[1]);
         if (s) {
             QString format = s->toQString();
             formattedDt = dt.toString(format);
-        } else if (callData->args[1].isNumber()) {
-            quint32 intFormat = callData->args[1].asDouble();
+        } else if (argv[1].isNumber()) {
+            quint32 intFormat = argv[1].asDouble();
             Qt::DateFormat format = Qt::DateFormat(intFormat);
             formattedDt = dt.toString(format);
         } else {
@@ -903,7 +915,7 @@ void QtObject::method_formatDateTime(const BuiltinFunction *, Scope &scope, Call
          formattedDt = dt.toString(enumFormat);
     }
 
-    scope.result = scope.engine->newString(formattedDt);
+    return Encode(scope.engine->newString(formattedDt));
 }
 
 /*!
@@ -917,94 +929,98 @@ void QtObject::method_formatDateTime(const BuiltinFunction *, Scope &scope, Call
     still fail to launch or fail to open the requested URL. This result will not be reported back
     to the application.
 */
-void QtObject::method_openUrlExternally(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_openUrlExternally(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc != 1) {
-        scope.result = QV4::Encode(false);
-        return;
-    }
+    QV4::Scope scope(b);
+    if (argc != 1)
+        return QV4::Encode(false);
 
-    method_resolvedUrl(b, scope, callData);
-    QUrl url(scope.result.toQStringNoThrow());
-    scope.result = scope.engine->fromVariant(QQml_guiProvider()->openUrlExternally(url));
+    ScopedValue result(scope, method_resolvedUrl(b, thisObject, argv, argc));
+    QUrl url(result->toQStringNoThrow());
+    return scope.engine->fromVariant(QQml_guiProvider()->openUrlExternally(url));
 }
 
 /*!
   \qmlmethod url Qt::resolvedUrl(url url)
   Returns \a url resolved relative to the URL of the caller.
 */
-void QtObject::method_resolvedUrl(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_resolvedUrl(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    ExecutionEngine *v4 = scope.engine;
+    QV4::Scope scope(b);
+    if (argc != 1)
+        return Encode::undefined();
 
-    QUrl url = v4->toVariant(callData->args[0], -1).toUrl();
-    QQmlEngine *e = v4->qmlEngine();
-    QQmlEnginePrivate *p = 0;
+    QUrl url = scope.engine->toVariant(argv[0], -1).toUrl();
+    QQmlEngine *e = scope.engine->qmlEngine();
+    QQmlEnginePrivate *p = nullptr;
     if (e) p = QQmlEnginePrivate::get(e);
     if (p) {
-        QQmlContextData *ctxt = v4->callingQmlContext();
+        QQmlContextData *ctxt = scope.engine->callingQmlContext();
         if (ctxt)
-            scope.result = v4->newString(ctxt->resolvedUrl(url).toString());
+            return Encode(scope.engine->newString(ctxt->resolvedUrl(url).toString()));
         else
-            scope.result = v4->newString(url.toString());
-        return;
+            return Encode(scope.engine->newString(url.toString()));
     }
 
-    scope.result = v4->newString(e->baseUrl().resolved(url).toString());
+    return Encode(scope.engine->newString(e->baseUrl().resolved(url).toString()));
 }
 
 /*!
 \qmlmethod list<string> Qt::fontFamilies()
 Returns a list of the font families available to the application.
 */
-void QtObject::method_fontFamilies(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_fontFamilies(const FunctionObject *b, const Value *, const Value *, int argc)
 {
-    if (callData->argc != 0)
+    QV4::Scope scope(b);
+    if (argc != 0)
         THROW_GENERIC_ERROR("Qt.fontFamilies(): Invalid arguments");
 
-    scope.result = scope.engine->fromVariant(QVariant(QQml_guiProvider()->fontFamilies()));
+    return scope.engine->fromVariant(QVariant(QQml_guiProvider()->fontFamilies()));
 }
 
 /*!
 \qmlmethod string Qt::md5(data)
 Returns a hex string of the md5 hash of \c data.
 */
-void QtObject::method_md5(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_md5(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("Qt.md5(): Invalid arguments");
 
-    QByteArray data = callData->args[0].toQStringNoThrow().toUtf8();
+    QByteArray data = argv[0].toQStringNoThrow().toUtf8();
     QByteArray result = QCryptographicHash::hash(data, QCryptographicHash::Md5);
-    scope.result = scope.engine->newString(QLatin1String(result.toHex()));
+    return Encode(scope.engine->newString(QLatin1String(result.toHex())));
 }
 
 /*!
 \qmlmethod string Qt::btoa(data)
 Binary to ASCII - this function returns a base64 encoding of \c data.
 */
-void QtObject::method_btoa(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_btoa(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("Qt.btoa(): Invalid arguments");
 
-    QByteArray data = callData->args[0].toQStringNoThrow().toUtf8();
+    QByteArray data = argv[0].toQStringNoThrow().toUtf8();
 
-    scope.result = scope.engine->newString(QLatin1String(data.toBase64()));
+    return Encode(scope.engine->newString(QLatin1String(data.toBase64())));
 }
 
 /*!
 \qmlmethod string Qt::atob(data)
 ASCII to binary - this function decodes the base64 encoded \a data string and returns it.
 */
-void QtObject::method_atob(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_atob(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("Qt.atob(): Invalid arguments");
 
-    QByteArray data = callData->args[0].toQStringNoThrow().toLatin1();
+    QByteArray data = argv[0].toQStringNoThrow().toLatin1();
 
-    scope.result = scope.engine->newString(QString::fromUtf8(QByteArray::fromBase64(data)));
+    return Encode(scope.engine->newString(QString::fromUtf8(QByteArray::fromBase64(data))));
 }
 
 /*!
@@ -1016,10 +1032,10 @@ QQmlEngine::quit() signal to the QCoreApplication::quit() slot.
 
 \sa exit()
 */
-void QtObject::method_quit(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue QtObject::method_quit(const FunctionObject *b, const Value *, const Value *, int)
 {
-    QQmlEnginePrivate::get(scope.engine->qmlEngine())->sendQuit();
-    scope.result = Encode::undefined();
+    QQmlEnginePrivate::get(b->engine()->qmlEngine())->sendQuit();
+    return Encode::undefined();
 }
 
 /*!
@@ -1033,15 +1049,16 @@ void QtObject::method_quit(const BuiltinFunction *, Scope &scope, CallData *)
 
     \sa quit()
 */
-void QtObject::method_exit(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_exit(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("Qt.exit(): Invalid arguments");
 
-    int retCode = callData->args[0].toNumber();
+    int retCode = argv[0].toNumber();
 
     QQmlEnginePrivate::get(scope.engine->qmlEngine())->sendExit(retCode);
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
 /*!
@@ -1068,9 +1085,10 @@ If this is the case, consider using \l{QtQml::Qt::createComponent()}{Qt.createCo
 
 See \l {Dynamic QML Object Creation from JavaScript} for more information on using this function.
 */
-void QtObject::method_createQmlObject(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_createQmlObject(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 2 || callData->argc > 3)
+    QV4::Scope scope(b);
+    if (argc < 2 || argc > 3)
         THROW_GENERIC_ERROR("Qt.createQmlObject(): Invalid arguments");
 
     struct Error {
@@ -1088,11 +1106,11 @@ void QtObject::method_createQmlObject(const BuiltinFunction *, Scope &scope, Cal
                 const QQmlError &error = errors.at(ii);
                 errorstr += QLatin1String("\n    ") + error.toString();
                 qmlerror = v4->newObject();
-                qmlerror->put((s = v4->newString(QStringLiteral("lineNumber"))), (v = QV4::Primitive::fromInt32(error.line())));
-                qmlerror->put((s = v4->newString(QStringLiteral("columnNumber"))), (v = QV4::Primitive::fromInt32(error.column())));
+                qmlerror->put((s = v4->newString(QStringLiteral("lineNumber"))), (v = QV4::Value::fromInt32(error.line())));
+                qmlerror->put((s = v4->newString(QStringLiteral("columnNumber"))), (v = QV4::Value::fromInt32(error.column())));
                 qmlerror->put((s = v4->newString(QStringLiteral("fileName"))), (v = v4->newString(error.url().toString())));
                 qmlerror->put((s = v4->newString(QStringLiteral("message"))), (v = v4->newString(error.description())));
-                qmlerrors->putIndexed(ii, qmlerror);
+                qmlerrors->put(ii, qmlerror);
             }
 
             v = v4->newString(errorstr);
@@ -1102,39 +1120,43 @@ void QtObject::method_createQmlObject(const BuiltinFunction *, Scope &scope, Cal
         }
     };
 
-    QV8Engine *v8engine = scope.engine->v8Engine;
-    QQmlEngine *engine = v8engine->engine();
+    QQmlEngine *engine = scope.engine->qmlEngine();
 
     QQmlContextData *context = scope.engine->callingQmlContext();
+    if (!context) {
+        QQmlEngine *qmlEngine = scope.engine->qmlEngine();
+        if (qmlEngine)
+            context = QQmlContextData::get(QQmlEnginePrivate::get(qmlEngine)->rootContext);
+    }
     Q_ASSERT(context);
-    QQmlContext *effectiveContext = 0;
+    QQmlContext *effectiveContext = nullptr;
     if (context->isPragmaLibraryContext)
         effectiveContext = engine->rootContext();
     else
         effectiveContext = context->asQQmlContext();
     Q_ASSERT(effectiveContext);
 
-    QString qml = callData->args[0].toQStringNoThrow();
+    QString qml = argv[0].toQStringNoThrow();
     if (qml.isEmpty())
         RETURN_RESULT(Encode::null());
 
     QUrl url;
-    if (callData->argc > 2)
-        url = QUrl(callData->args[2].toQStringNoThrow());
+    if (argc > 2)
+        url = QUrl(argv[2].toQStringNoThrow());
     else
         url = QUrl(QLatin1String("inline"));
 
     if (url.isValid() && url.isRelative())
         url = context->resolvedUrl(url);
 
-    QObject *parentArg = 0;
-    QV4::Scoped<QV4::QObjectWrapper> qobjectWrapper(scope, callData->args[1]);
+    QObject *parentArg = nullptr;
+    QV4::Scoped<QV4::QObjectWrapper> qobjectWrapper(scope, argv[1]);
     if (!!qobjectWrapper)
         parentArg = qobjectWrapper->object();
     if (!parentArg)
         THROW_GENERIC_ERROR("Qt.createQmlObject(): Missing parent object");
 
-    QQmlTypeData *typeData = QQmlEnginePrivate::get(engine)->typeLoader.getType(
+    QQmlRefPointer<QQmlTypeData> typeData = QQmlEnginePrivate::get(engine)->typeLoader.getType(
                 qml.toUtf8(), url, QQmlTypeLoader::Synchronous);
     Q_ASSERT(typeData->isCompleteOrError());
     QQmlComponent component(engine);
@@ -1150,6 +1172,10 @@ void QtObject::method_createQmlObject(const BuiltinFunction *, Scope &scope, Cal
     if (!component.isReady())
         THROW_GENERIC_ERROR("Qt.createQmlObject(): Component is not ready");
 
+    if (!effectiveContext->isValid()) {
+        THROW_GENERIC_ERROR("Qt.createQmlObject(): Cannot create a component in an invalid context");
+    }
+
     QObject *obj = component.beginCreate(effectiveContext);
     if (obj) {
         QQmlData::get(obj, true)->explicitIndestructibleSet = false;
@@ -1168,13 +1194,12 @@ void QtObject::method_createQmlObject(const BuiltinFunction *, Scope &scope, Cal
 
     if (component.isError()) {
         ScopedValue v(scope, Error::create(scope.engine, component.errors()));
-        scope.result = scope.engine->throwError(v);
-        return;
+        return scope.engine->throwError(v);
     }
 
     Q_ASSERT(obj);
 
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, obj);
+    return QV4::QObjectWrapper::wrap(scope.engine, obj);
 }
 
 /*!
@@ -1221,45 +1246,50 @@ See \l {Dynamic QML Object Creation from JavaScript} for more information on usi
 To create a QML object from an arbitrary string of QML (instead of a file),
 use \l{QtQml::Qt::createQmlObject()}{Qt.createQmlObject()}.
 */
-void QtObject::method_createComponent(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_createComponent(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1 || callData->argc > 3)
+    QV4::Scope scope(b);
+    if (argc < 1 || argc > 3)
         THROW_GENERIC_ERROR("Qt.createComponent(): Invalid arguments");
 
-    QV8Engine *v8engine = scope.engine->v8Engine;
-    QQmlEngine *engine = v8engine->engine();
+    QQmlEngine *engine = scope.engine->qmlEngine();
 
     QQmlContextData *context = scope.engine->callingQmlContext();
+    if (!context) {
+        QQmlEngine *qmlEngine = scope.engine->qmlEngine();
+        if (qmlEngine)
+            context = QQmlContextData::get(QQmlEnginePrivate::get(qmlEngine)->rootContext);
+    }
     Q_ASSERT(context);
     QQmlContextData *effectiveContext = context;
     if (context->isPragmaLibraryContext)
-        effectiveContext = 0;
+        effectiveContext = nullptr;
 
-    QString arg = callData->args[0].toQStringNoThrow();
+    QString arg = argv[0].toQStringNoThrow();
     if (arg.isEmpty())
         RETURN_RESULT(QV4::Encode::null());
 
     QQmlComponent::CompilationMode compileMode = QQmlComponent::PreferSynchronous;
-    QObject *parentArg = 0;
+    QObject *parentArg = nullptr;
 
     int consumedCount = 1;
-    if (callData->argc > 1) {
-        ScopedValue lastArg(scope, callData->args[callData->argc-1]);
+    if (argc > 1) {
+        ScopedValue lastArg(scope, argv[argc-1]);
 
         // The second argument could be the mode enum
-        if (callData->args[1].isInteger()) {
-            int mode = callData->args[1].integerValue();
+        if (argv[1].isInteger()) {
+            int mode = argv[1].integerValue();
             if (mode != int(QQmlComponent::PreferSynchronous) && mode != int(QQmlComponent::Asynchronous))
                 THROW_GENERIC_ERROR("Qt.createComponent(): Invalid arguments");
             compileMode = QQmlComponent::CompilationMode(mode);
             consumedCount += 1;
         } else {
             // The second argument could be the parent only if there are exactly two args
-            if ((callData->argc != 2) || !(lastArg->isObject() || lastArg->isNull()))
+            if ((argc != 2) || !(lastArg->isObject() || lastArg->isNull()))
                 THROW_GENERIC_ERROR("Qt.createComponent(): Invalid arguments");
         }
 
-        if (consumedCount < callData->argc) {
+        if (consumedCount < argc) {
             if (lastArg->isObject()) {
                 Scoped<QObjectWrapper> qobjectWrapper(scope, lastArg);
                 if (qobjectWrapper)
@@ -1267,7 +1297,7 @@ void QtObject::method_createComponent(const BuiltinFunction *, Scope &scope, Cal
                 if (!parentArg)
                     THROW_GENERIC_ERROR("Qt.createComponent(): Invalid parent object");
             } else if (lastArg->isNull()) {
-                parentArg = 0;
+                parentArg = nullptr;
             } else {
                 THROW_GENERIC_ERROR("Qt.createComponent(): Invalid parent object");
             }
@@ -1280,9 +1310,10 @@ void QtObject::method_createComponent(const BuiltinFunction *, Scope &scope, Cal
     QQmlData::get(c, true)->explicitIndestructibleSet = false;
     QQmlData::get(c)->indestructible = false;
 
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, c);
+    return QV4::QObjectWrapper::wrap(scope.engine, c);
 }
 
+#if QT_CONFIG(qml_locale)
 /*!
     \qmlmethod Qt::locale(name)
 
@@ -1303,31 +1334,37 @@ void QtObject::method_createComponent(const BuiltinFunction *, Scope &scope, Cal
 
     \sa Locale
 */
-void QtObject::method_locale(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_locale(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
+    QV4::Scope scope(b);
     QString code;
-    if (callData->argc > 1)
+    if (argc > 1)
         THROW_GENERIC_ERROR("locale() requires 0 or 1 argument");
-    if (callData->argc == 1 && !callData->args[0].isString())
+    if (argc == 1 && !argv[0].isString())
         THROW_TYPE_ERROR_WITH_MESSAGE("locale(): argument (locale code) must be a string");
 
-    if (callData->argc == 1)
-        code = callData->args[0].toQStringNoThrow();
+    if (argc == 1)
+        code = argv[0].toQStringNoThrow();
 
-    scope.result = QQmlLocale::locale(scope.engine, code);
+    return QQmlLocale::locale(scope.engine, code);
 }
+#endif
 
-void Heap::QQmlBindingFunction::init(const QV4::FunctionObject *originalFunction)
+void Heap::QQmlBindingFunction::init(const QV4::FunctionObject *bindingFunction)
 {
-    Scope scope(originalFunction->engine());
-    ScopedContext context(scope, originalFunction->scope());
-    FunctionObject::init(context, originalFunction->function());
+    Scope scope(bindingFunction->engine());
+    ScopedContext context(scope, bindingFunction->scope());
+    FunctionObject::init(context, bindingFunction->function());
+    this->bindingFunction.set(internalClass->engine, bindingFunction->d());
 }
 
 QQmlSourceLocation QQmlBindingFunction::currentLocation() const
 {
-    QV4::StackFrame frame = engine()->currentStackFrame();
-    return QQmlSourceLocation(frame.source, frame.line, 0);
+    QV4::CppStackFrame *frame = engine()->currentStackFrame;
+    if (frame->v4Function) // synchronous loading:
+        return QQmlSourceLocation(frame->source(), frame->lineNumber(), 0);
+    else // async loading:
+        return bindingFunction()->function->sourceLocation();
 }
 
 DEFINE_OBJECT_VTABLE(QQmlBindingFunction);
@@ -1370,31 +1407,29 @@ DEFINE_OBJECT_VTABLE(QQmlBindingFunction);
 
     \snippet qml/qtBinding.4.qml 0
 
-    \note In \l {Qt Quick 1}, all function assignments were treated as
-    binding assignments. The Qt.binding() function is new to
-    \l {Qt Quick}{Qt Quick 2}.
-
     \since 5.0
 */
-void QtObject::method_binding(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_binding(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("binding() requires 1 argument");
-    const QV4::FunctionObject *f = callData->args[0].as<FunctionObject>();
+    const QV4::FunctionObject *f = argv[0].as<FunctionObject>();
     if (!f)
         THROW_TYPE_ERROR_WITH_MESSAGE("binding(): argument (binding expression) must be a function");
 
-    scope.result = scope.engine->memoryManager->allocObject<QQmlBindingFunction>(f);
+    return Encode(scope.engine->memoryManager->allocate<QQmlBindingFunction>(f));
 }
 
 
-void QtObject::method_get_platform(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_get_platform(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
+    QV4::Scope scope(b);
     // ### inefficient. Should be just a value based getter
-    Object *o = callData->thisObject.as<Object>();
+    const Object *o = thisObject->as<Object>();
     if (!o)
         THROW_TYPE_ERROR();
-    QtObject *qt = o->as<QtObject>();
+    const QtObject *qt = o->as<QtObject>();
     if (!qt)
         THROW_TYPE_ERROR();
 
@@ -1402,16 +1437,17 @@ void QtObject::method_get_platform(const BuiltinFunction *, Scope &scope, CallDa
         // Only allocate a platform object once
         qt->d()->platform = new QQmlPlatform(scope.engine->jsEngine());
 
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, qt->d()->platform);
+    return QV4::QObjectWrapper::wrap(scope.engine, qt->d()->platform);
 }
 
-void QtObject::method_get_application(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_get_application(const FunctionObject *b, const Value *thisObject, const Value *, int)
 {
+    QV4::Scope scope(b);
     // ### inefficient. Should be just a value based getter
-    Object *o = callData->thisObject.as<Object>();
+    const Object *o = thisObject->as<Object>();
     if (!o)
         THROW_TYPE_ERROR();
-    QtObject *qt = o->as<QtObject>();
+    const QtObject *qt = o->as<QtObject>();
     if (!qt)
         THROW_TYPE_ERROR();
 
@@ -1419,19 +1455,19 @@ void QtObject::method_get_application(const BuiltinFunction *, Scope &scope, Cal
         // Only allocate an application object once
         qt->d()->application = QQml_guiProvider()->application(scope.engine->jsEngine());
 
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, qt->d()->application);
+    return QV4::QObjectWrapper::wrap(scope.engine, qt->d()->application);
 }
 
-void QtObject::method_get_inputMethod(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue QtObject::method_get_inputMethod(const FunctionObject *b, const Value *, const Value *, int)
 {
     QObject *o = QQml_guiProvider()->inputMethod();
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, o);
+    return QV4::QObjectWrapper::wrap(b->engine(), o);
 }
 
-void QtObject::method_get_styleHints(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue QtObject::method_get_styleHints(const FunctionObject *b, const Value *, const Value *, int)
 {
     QObject *o = QQml_guiProvider()->styleHints();
-    scope.result = QV4::QObjectWrapper::wrap(scope.engine, o);
+    return QV4::QObjectWrapper::wrap(b->engine(), o);
 }
 
 
@@ -1491,16 +1527,38 @@ static QString jsStack(QV4::ExecutionEngine *engine) {
     return stack;
 }
 
-static void writeToConsole(const BuiltinFunction *, Scope &scope, CallData *callData,
-                                         ConsoleLogTypes logType, bool printStack = false)
+static QString serializeArray(Object *array, ExecutionEngine *v4) {
+    Scope scope(v4);
+    ScopedValue val(scope);
+    QString result;
+
+    result += QLatin1Char('[');
+    const uint length = array->getLength();
+    for (uint i = 0; i < length; ++i) {
+        if (i != 0)
+            result += QLatin1Char(',');
+        val = array->get(i);
+        if (val->isManaged() && val->managed()->isArrayLike())
+            result += serializeArray(val->objectValue(), v4);
+        else
+            result += val->toQStringNoThrow();
+    }
+    result += QLatin1Char(']');
+
+    return result;
+};
+
+static ReturnedValue writeToConsole(const FunctionObject *b, const Value *, const Value *argv, int argc,
+                                    ConsoleLogTypes logType, bool printStack = false)
 {
-    QLoggingCategory *loggingCategory = 0;
+    QLoggingCategory *loggingCategory = nullptr;
     QString result;
+    QV4::Scope scope(b);
     QV4::ExecutionEngine *v4 = scope.engine;
 
     int start = 0;
-    if (callData->argc > 0) {
-        if (const QObjectWrapper* wrapper = callData->args[0].as<QObjectWrapper>()) {
+    if (argc > 0) {
+        if (const QObjectWrapper* wrapper = argv[0].as<QObjectWrapper>()) {
             if (QQmlLoggingCategory* category = qobject_cast<QQmlLoggingCategory*>(wrapper->object())) {
                 if (category->category())
                     loggingCategory = category->category();
@@ -1512,14 +1570,14 @@ static void writeToConsole(const BuiltinFunction *, Scope &scope, CallData *call
     }
 
 
-    for (int i = start; i < callData->argc; ++i) {
+    for (int i = start, ei = argc; i < ei; ++i) {
         if (i != start)
             result.append(QLatin1Char(' '));
 
-        if (callData->args[i].as<ArrayObject>())
-            result += QLatin1Char('[') + callData->args[i].toQStringNoThrow() + QLatin1Char(']');
+        if (argv[i].isManaged() && argv[i].managed()->isArrayLike())
+            result.append(serializeArray(argv[i].objectValue(), v4));
         else
-            result.append(callData->args[i].toQStringNoThrow());
+            result.append(argv[i].toQStringNoThrow());
     }
 
     if (printStack)
@@ -1530,10 +1588,10 @@ static void writeToConsole(const BuiltinFunction *, Scope &scope, CallData *call
 
     if (!loggingCategory)
         loggingCategory = v4->qmlEngine() ? &qmlLoggingCategory : &jsLoggingCategory;
-    QV4::StackFrame frame = v4->currentStackFrame();
-    const QByteArray baSource = frame.source.toUtf8();
-    const QByteArray baFunction = frame.function.toUtf8();
-    QMessageLogger logger(baSource.constData(), frame.line, baFunction.constData(), loggingCategory->categoryName());
+    QV4::CppStackFrame *frame = v4->currentStackFrame;
+    const QByteArray baSource = frame->source().toUtf8();
+    const QByteArray baFunction = frame->function().toUtf8();
+    QMessageLogger logger(baSource.constData(), frame->lineNumber(), baFunction.constData(), loggingCategory->categoryName());
 
     switch (logType) {
     case Log:
@@ -1556,37 +1614,38 @@ static void writeToConsole(const BuiltinFunction *, Scope &scope, CallData *call
         break;
     }
 
-    scope.result = QV4::Encode::undefined();
+    return Encode::undefined();
 }
 
 DEFINE_OBJECT_VTABLE(ConsoleObject);
 
-void ConsoleObject::method_error(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_error(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    writeToConsole(b, scope, callData, Error);
+    return writeToConsole(b, thisObject, argv, argc, Error);
 }
 
-void ConsoleObject::method_log(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_log(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
     //console.log
     //console.debug
     //print
-    writeToConsole(b, scope, callData, Log);
+    return writeToConsole(b, thisObject, argv, argc, Log);
 }
 
-void ConsoleObject::method_info(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_info(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    writeToConsole(b, scope, callData, Info);
+    return writeToConsole(b, thisObject, argv, argc, Info);
 }
 
-void ConsoleObject::method_profile(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue ConsoleObject::method_profile(const FunctionObject *b, const Value *, const Value *, int)
 {
+    QV4::Scope scope(b);
     QV4::ExecutionEngine *v4 = scope.engine;
 
-    QV4::StackFrame frame = v4->currentStackFrame();
-    const QByteArray baSource = frame.source.toUtf8();
-    const QByteArray baFunction = frame.function.toUtf8();
-    QMessageLogger logger(baSource.constData(), frame.line, baFunction.constData());
+    QV4::CppStackFrame *frame = v4->currentStackFrame;
+    const QByteArray baSource = frame->source().toUtf8();
+    const QByteArray baFunction = frame->function().toUtf8();
+    QMessageLogger logger(baSource.constData(), frame->lineNumber(), baFunction.constData());
     QQmlProfilerService *service = QQmlDebugConnector::service<QQmlProfilerService>();
     if (!service) {
         logger.warning("Cannot start profiling because debug service is disabled. Start with -qmljsdebugger=port:XXXXX.");
@@ -1595,17 +1654,18 @@ void ConsoleObject::method_profile(const BuiltinFunction *, Scope &scope, CallDa
         logger.debug("Profiling started.");
     }
 
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_profileEnd(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue ConsoleObject::method_profileEnd(const FunctionObject *b, const Value *, const Value *, int)
 {
+    QV4::Scope scope(b);
     QV4::ExecutionEngine *v4 = scope.engine;
 
-    QV4::StackFrame frame = v4->currentStackFrame();
-    const QByteArray baSource = frame.source.toUtf8();
-    const QByteArray baFunction = frame.function.toUtf8();
-    QMessageLogger logger(baSource.constData(), frame.line, baFunction.constData());
+    QV4::CppStackFrame *frame = v4->currentStackFrame;
+    const QByteArray baSource = frame->source().toUtf8();
+    const QByteArray baFunction = frame->function().toUtf8();
+    QMessageLogger logger(baSource.constData(), frame->lineNumber(), baFunction.constData());
 
     QQmlProfilerService *service = QQmlDebugConnector::service<QQmlProfilerService>();
     if (!service) {
@@ -1615,118 +1675,122 @@ void ConsoleObject::method_profileEnd(const BuiltinFunction *, Scope &scope, Cal
         logger.debug("Profiling ended.");
     }
 
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_time(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_time(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("console.time(): Invalid arguments");
 
     QV8Engine *v8engine = scope.engine->v8Engine;
 
-    QString name = callData->args[0].toQStringNoThrow();
+    QString name = argv[0].toQStringNoThrow();
     v8engine->startTimer(name);
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_timeEnd(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_timeEnd(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("console.timeEnd(): Invalid arguments");
 
     QV8Engine *v8engine = scope.engine->v8Engine;
 
-    QString name = callData->args[0].toQStringNoThrow();
+    QString name = argv[0].toQStringNoThrow();
     bool wasRunning;
     qint64 elapsed = v8engine->stopTimer(name, &wasRunning);
     if (wasRunning) {
         qDebug("%s: %llims", qPrintable(name), elapsed);
     }
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_count(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_count(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
     // first argument: name to print. Ignore any additional arguments
     QString name;
-    if (callData->argc > 0)
-        name = callData->args[0].toQStringNoThrow();
+    if (argc > 0)
+        name = argv[0].toQStringNoThrow();
 
+    Scope scope(b);
     QV4::ExecutionEngine *v4 = scope.engine;
     QV8Engine *v8engine = scope.engine->v8Engine;
 
-    QV4::StackFrame frame = v4->currentStackFrame();
+    QV4::CppStackFrame *frame = v4->currentStackFrame;
 
-    QString scriptName = frame.source;
+    QString scriptName = frame->source();
 
-    int value = v8engine->consoleCountHelper(scriptName, frame.line, frame.column);
+    int value = v8engine->consoleCountHelper(scriptName, frame->lineNumber(), 0);
     QString message = name + QLatin1String(": ") + QString::number(value);
 
-    QMessageLogger(qPrintable(scriptName), frame.line,
-                   qPrintable(frame.function))
+    QMessageLogger(qPrintable(scriptName), frame->lineNumber(),
+                   qPrintable(frame->function()))
         .debug("%s", qPrintable(message));
 
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_trace(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_trace(const FunctionObject *b, const Value *, const Value *, int argc)
 {
-    if (callData->argc != 0)
+    QV4::Scope scope(b);
+    if (argc != 0)
         THROW_GENERIC_ERROR("console.trace(): Invalid arguments");
 
     QV4::ExecutionEngine *v4 = scope.engine;
 
     QString stack = jsStack(v4);
 
-    QV4::StackFrame frame = v4->currentStackFrame();
-    QMessageLogger(frame.source.toUtf8().constData(), frame.line,
-                   frame.function.toUtf8().constData())
+    QV4::CppStackFrame *frame = v4->currentStackFrame;
+    QMessageLogger(frame->source().toUtf8().constData(), frame->lineNumber(),
+                   frame->function().toUtf8().constData())
         .debug("%s", qPrintable(stack));
 
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_warn(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_warn(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    return writeToConsole(b, scope, callData, Warn);
+    return writeToConsole(b, thisObject, argv, argc, Warn);
 }
 
-void ConsoleObject::method_assert(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_assert(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    QV4::Scope scope(b);
+    if (argc == 0)
         THROW_GENERIC_ERROR("console.assert(): Missing argument");
 
     QV4::ExecutionEngine *v4 = scope.engine;
 
-    if (!callData->args[0].toBoolean()) {
+    if (!argv[0].toBoolean()) {
         QString message;
-        for (int i = 1; i < callData->argc; ++i) {
+        for (int i = 1, ei = argc; i < ei; ++i) {
             if (i != 1)
                 message.append(QLatin1Char(' '));
 
-            message.append(callData->args[i].toQStringNoThrow());
+            message.append(argv[i].toQStringNoThrow());
         }
 
         QString stack = jsStack(v4);
 
-        QV4::StackFrame frame = v4->currentStackFrame();
-        QMessageLogger(frame.source.toUtf8().constData(), frame.line,
-                       frame.function.toUtf8().constData())
+        QV4::CppStackFrame *frame = v4->currentStackFrame;
+        QMessageLogger(frame->source().toUtf8().constData(), frame->lineNumber(),
+                       frame->function().toUtf8().constData())
             .critical("%s\n%s",qPrintable(message), qPrintable(stack));
 
     }
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
-void ConsoleObject::method_exception(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue ConsoleObject::method_exception(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc == 0)
+    QV4::Scope scope(b);
+    if (argc == 0)
         THROW_GENERIC_ERROR("console.exception(): Missing argument");
 
-    writeToConsole(b, scope, callData, Error, true);
-
-    scope.result = QV4::Encode::undefined();
+    return writeToConsole(b, thisObject, argv, argc, Error, true);
 }
 
 
@@ -1754,7 +1818,7 @@ void QV4::GlobalExtensions::init(Object *globalObject, QJSEngine::Extensions ext
         globalObject->defineDefaultProperty(QStringLiteral("print"), QV4::ConsoleObject::method_log);
 
 
-        QV4::ScopedObject console(scope, globalObject->engine()->memoryManager->allocObject<QV4::ConsoleObject>());
+        QV4::ScopedObject console(scope, globalObject->engine()->memoryManager->allocate<QV4::ConsoleObject>());
         globalObject->defineDefaultProperty(QStringLiteral("console"), console);
     }
 
@@ -1782,38 +1846,43 @@ void QV4::GlobalExtensions::init(Object *globalObject, QJSEngine::Extensions ext
 
     \sa {Internationalization and Localization with Qt Quick}
 */
-void GlobalExtensions::method_qsTranslate(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_qsTranslate(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 2)
+    QV4::Scope scope(b);
+    if (argc < 2)
         THROW_GENERIC_ERROR("qsTranslate() requires at least two arguments");
-    if (!callData->args[0].isString())
+    if (!argv[0].isString())
         THROW_GENERIC_ERROR("qsTranslate(): first argument (context) must be a string");
-    if (!callData->args[1].isString())
+    if (!argv[1].isString())
         THROW_GENERIC_ERROR("qsTranslate(): second argument (sourceText) must be a string");
-    if ((callData->argc > 2) && !callData->args[2].isString())
+    if ((argc > 2) && !argv[2].isString())
         THROW_GENERIC_ERROR("qsTranslate(): third argument (disambiguation) must be a string");
 
-    QString context = callData->args[0].toQStringNoThrow();
-    QString text = callData->args[1].toQStringNoThrow();
+    QString context = argv[0].toQStringNoThrow();
+    QString text = argv[1].toQStringNoThrow();
     QString comment;
-    if (callData->argc > 2) comment = callData->args[2].toQStringNoThrow();
+    if (argc > 2) comment = argv[2].toQStringNoThrow();
 
     int i = 3;
-    if (callData->argc > i && callData->args[i].isString()) {
+    if (argc > i && argv[i].isString()) {
         qWarning("qsTranslate(): specifying the encoding as fourth argument is deprecated");
         ++i;
     }
 
     int n = -1;
-    if (callData->argc > i)
-        n = callData->args[i].toInt32();
+    if (argc > i)
+        n = argv[i].toInt32();
+
+    if (QQmlEnginePrivate *ep = (scope.engine->qmlEngine() ? QQmlEnginePrivate::get(scope.engine->qmlEngine()) : nullptr))
+        if (ep->propertyCapture)
+            ep->propertyCapture->captureTranslation();
 
     QString result = QCoreApplication::translate(context.toUtf8().constData(),
                                                  text.toUtf8().constData(),
                                                  comment.toUtf8().constData(),
                                                  n);
 
-    scope.result = scope.engine->newString(result);
+    return Encode(scope.engine->newString(result));
 }
 
 /*!
@@ -1838,12 +1907,13 @@ void GlobalExtensions::method_qsTranslate(const BuiltinFunction *, Scope &scope,
 
     \sa {Internationalization and Localization with Qt Quick}
 */
-void GlobalExtensions::method_qsTranslateNoOp(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_qsTranslateNoOp(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 2)
-        scope.result = QV4::Encode::undefined();
+    QV4::Scope scope(b);
+    if (argc < 2)
+        return QV4::Encode::undefined();
     else
-        scope.result = callData->args[1];
+        return argv[1].asReturnedValue();
 }
 
 /*!
@@ -1863,15 +1933,16 @@ void GlobalExtensions::method_qsTranslateNoOp(const BuiltinFunction *, Scope &sc
 
     \sa {Internationalization and Localization with Qt Quick}
 */
-void GlobalExtensions::method_qsTr(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_qsTr(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1)
+    QV4::Scope scope(b);
+    if (argc < 1)
         THROW_GENERIC_ERROR("qsTr() requires at least one argument");
-    if (!callData->args[0].isString())
+    if (!argv[0].isString())
         THROW_GENERIC_ERROR("qsTr(): first argument (sourceText) must be a string");
-    if ((callData->argc > 1) && !callData->args[1].isString())
+    if ((argc > 1) && !argv[1].isString())
         THROW_GENERIC_ERROR("qsTr(): second argument (disambiguation) must be a string");
-    if ((callData->argc > 2) && !callData->args[2].isNumber())
+    if ((argc > 2) && !argv[2].isNumber())
         THROW_GENERIC_ERROR("qsTr(): third argument (n) must be a number");
 
     QString context;
@@ -1882,10 +1953,10 @@ void GlobalExtensions::method_qsTr(const BuiltinFunction *, Scope &scope, CallDa
         int length = lastDot - (lastSlash + 1);
         context = (lastSlash > -1) ? path.mid(lastSlash + 1, (length > -1) ? length : -1) : QString();
     } else {
-        ExecutionContext *parentCtx = scope.engine->currentContext;
+        CppStackFrame *frame = scope.engine->currentStackFrame;
         // The first non-empty source URL in the call stack determines the translation context.
-        while (!!parentCtx && context.isEmpty()) {
-            if (CompiledData::CompilationUnit *unit = static_cast<CompiledData::CompilationUnit*>(parentCtx->d()->compilationUnit)) {
+        while (frame && context.isEmpty()) {
+            if (CompiledData::CompilationUnit *unit = frame->v4Function->compilationUnit) {
                 QString fileName = unit->fileName();
                 QUrl url(unit->fileName());
                 if (url.isValid() && url.isRelative()) {
@@ -1897,22 +1968,26 @@ void GlobalExtensions::method_qsTr(const BuiltinFunction *, Scope &scope, CallDa
                 }
                 context = QFileInfo(context).baseName();
             }
-            parentCtx = scope.engine->parentContext(parentCtx);
+            frame = frame->parent;
         }
     }
 
-    QString text = callData->args[0].toQStringNoThrow();
+    QString text = argv[0].toQStringNoThrow();
     QString comment;
-    if (callData->argc > 1)
-        comment = callData->args[1].toQStringNoThrow();
+    if (argc > 1)
+        comment = argv[1].toQStringNoThrow();
     int n = -1;
-    if (callData->argc > 2)
-        n = callData->args[2].toInt32();
+    if (argc > 2)
+        n = argv[2].toInt32();
+
+    if (QQmlEnginePrivate *ep = (scope.engine->qmlEngine() ? QQmlEnginePrivate::get(scope.engine->qmlEngine()) : nullptr))
+        if (ep->propertyCapture)
+            ep->propertyCapture->captureTranslation();
 
     QString result = QCoreApplication::translate(context.toUtf8().constData(), text.toUtf8().constData(),
                                                  comment.toUtf8().constData(), n);
 
-    scope.result = scope.engine->newString(result);
+    return Encode(scope.engine->newString(result));
 }
 
 /*!
@@ -1937,12 +2012,12 @@ void GlobalExtensions::method_qsTr(const BuiltinFunction *, Scope &scope, CallDa
 
     \sa {Internationalization and Localization with Qt Quick}
 */
-void GlobalExtensions::method_qsTrNoOp(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_qsTrNoOp(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1)
-        scope.result = QV4::Encode::undefined();
+    if (argc < 1)
+        return QV4::Encode::undefined();
     else
-        scope.result = callData->args[0];
+        return argv[0].asReturnedValue();
 }
 
 /*!
@@ -1975,20 +2050,25 @@ void GlobalExtensions::method_qsTrNoOp(const BuiltinFunction *, Scope &scope, Ca
 
     \sa QT_TRID_NOOP(), {Internationalization and Localization with Qt Quick}
 */
-void GlobalExtensions::method_qsTrId(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_qsTrId(const FunctionObject *b, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1)
+    QV4::Scope scope(b);
+    if (argc < 1)
         THROW_GENERIC_ERROR("qsTrId() requires at least one argument");
-    if (!callData->args[0].isString())
+    if (!argv[0].isString())
         THROW_TYPE_ERROR_WITH_MESSAGE("qsTrId(): first argument (id) must be a string");
-    if (callData->argc > 1 && !callData->args[1].isNumber())
+    if (argc > 1 && !argv[1].isNumber())
         THROW_TYPE_ERROR_WITH_MESSAGE("qsTrId(): second argument (n) must be a number");
 
     int n = -1;
-    if (callData->argc > 1)
-        n = callData->args[1].toInt32();
+    if (argc > 1)
+        n = argv[1].toInt32();
+
+    if (QQmlEnginePrivate *ep = (scope.engine->qmlEngine() ? QQmlEnginePrivate::get(scope.engine->qmlEngine()) : nullptr))
+        if (ep->propertyCapture)
+            ep->propertyCapture->captureTranslation();
 
-    scope.result = scope.engine->newString(qtTrId(callData->args[0].toQStringNoThrow().toUtf8().constData(), n));
+    return Encode(scope.engine->newString(qtTrId(argv[0].toQStringNoThrow().toUtf8().constData(), n)));
 }
 
 /*!
@@ -2007,33 +2087,34 @@ void GlobalExtensions::method_qsTrId(const BuiltinFunction *, Scope &scope, Call
 
     \sa qsTrId(), {Internationalization and Localization with Qt Quick}
 */
-void GlobalExtensions::method_qsTrIdNoOp(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_qsTrIdNoOp(const FunctionObject *, const Value *, const Value *argv, int argc)
 {
-    if (callData->argc < 1)
-        scope.result = QV4::Encode::undefined();
+    if (argc < 1)
+        return QV4::Encode::undefined();
     else
-        scope.result = callData->args[0];
+        return argv[0].asReturnedValue();
 }
 #endif // translation
 
 
-void GlobalExtensions::method_gc(const BuiltinFunction *, Scope &scope, CallData *)
+ReturnedValue GlobalExtensions::method_gc(const FunctionObject *b, const Value *, const Value *, int)
 {
-    scope.engine->memoryManager->runGC();
+    b->engine()->memoryManager->runGC();
 
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
 
 
-void GlobalExtensions::method_string_arg(const BuiltinFunction *, Scope &scope, CallData *callData)
+ReturnedValue GlobalExtensions::method_string_arg(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    if (callData->argc != 1)
+    QV4::Scope scope(b);
+    if (argc != 1)
         THROW_GENERIC_ERROR("String.arg(): Invalid arguments");
 
-    QString value = callData->thisObject.toQString();
+    QString value = thisObject->toQString();
 
-    QV4::ScopedValue arg(scope, callData->args[0]);
+    QV4::ScopedValue arg(scope, argv[0]);
     if (arg->isInteger())
         RETURN_RESULT(scope.engine->newString(value.arg(arg->integerValue())));
     else if (arg->isDouble())
@@ -2064,10 +2145,10 @@ be passed on to the function invoked. Note that if redundant calls
 are eliminated, then only the last set of arguments will be passed to the
 function.
 */
-void QtObject::method_callLater(const BuiltinFunction *b, Scope &scope, CallData *callData)
+ReturnedValue QtObject::method_callLater(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
-    QV8Engine *v8engine = scope.engine->v8Engine;
-    v8engine->delayedCallQueue()->addUniquelyAndExecuteLater(b, scope, callData);
+    QV8Engine *v8engine = b->engine()->v8Engine;
+    return v8engine->delayedCallQueue()->addUniquelyAndExecuteLater(b, thisObject, argv, argc);
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions_p.h b/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
index 21613b7c10..d87b83ba10 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
@@ -80,8 +80,11 @@ struct ConsoleObject : Object {
     void init();
 };
 
-struct QQmlBindingFunction : FunctionObject {
-    void init(const QV4::FunctionObject *originalFunction);
+#define QQmlBindingFunctionMembers(class, Member) \
+    Member(class, Pointer, FunctionObject *, bindingFunction)
+DECLARE_HEAP_OBJECT(QQmlBindingFunction, FunctionObject) {
+    DECLARE_MARKOBJECTS(QQmlBindingFunction)
+    void init(const QV4::FunctionObject *bindingFunction);
 };
 
 }
@@ -90,48 +93,50 @@ struct QtObject : Object
 {
     V4_OBJECT2(QtObject, Object)
 
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-
-    static void method_isQtObject(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_rgba(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_hsla(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_hsva(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_colorEqual(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_font(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_rect(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_point(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_size(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_vector2d(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_vector3d(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_vector4d(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_quaternion(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_matrix4x4(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_lighter(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_darker(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_tint(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_formatDate(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_formatTime(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_formatDateTime(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_openUrlExternally(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_fontFamilies(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_md5(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_btoa(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_atob(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_quit(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_exit(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_resolvedUrl(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_createQmlObject(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_createComponent(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_locale(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_binding(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_get_platform(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_application(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_inputMethod(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_get_styleHints(const BuiltinFunction *, Scope &scope, CallData *callData);
-
-    static void method_callLater(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
+
+    static ReturnedValue method_isQtObject(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_rgba(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_hsla(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_hsva(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_colorEqual(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_font(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_rect(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_point(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_size(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_vector2d(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_vector3d(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_vector4d(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_quaternion(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_matrix4x4(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_lighter(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_darker(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_tint(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_formatDate(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_formatTime(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_formatDateTime(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_openUrlExternally(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_fontFamilies(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_md5(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_btoa(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_atob(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_quit(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_exit(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_resolvedUrl(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_createQmlObject(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_createComponent(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+#if QT_CONFIG(qml_locale)
+    static ReturnedValue method_locale(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+#endif
+    static ReturnedValue method_binding(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_get_platform(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_application(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_inputMethod(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_get_styleHints(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+
+    static ReturnedValue method_callLater(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
 
 private:
     void addAll();
@@ -142,18 +147,18 @@ struct ConsoleObject : Object
 {
     V4_OBJECT2(ConsoleObject, Object)
 
-    static void method_error(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_log(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_info(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_profile(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_profileEnd(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_time(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_timeEnd(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_count(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_trace(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_warn(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_assert(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_exception(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_error(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_log(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_info(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_profile(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_profileEnd(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_time(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_timeEnd(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_count(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_trace(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_warn(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_assert(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_exception(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
 };
 
@@ -161,17 +166,17 @@ struct Q_QML_PRIVATE_EXPORT GlobalExtensions {
     static void init(Object *globalObject, QJSEngine::Extensions extensions);
 
 #if QT_CONFIG(translation)
-    static void method_qsTranslate(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_qsTranslateNoOp(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_qsTr(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_qsTrNoOp(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_qsTrId(const BuiltinFunction *, Scope &scope, CallData *callData);
-    static void method_qsTrIdNoOp(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_qsTranslate(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_qsTranslateNoOp(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_qsTr(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_qsTrNoOp(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_qsTrId(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_qsTrIdNoOp(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 #endif
-    static void method_gc(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_gc(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
     // on String:prototype
-    static void method_string_arg(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static ReturnedValue method_string_arg(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc);
 
 };
 
@@ -179,9 +184,15 @@ struct QQmlBindingFunction : public QV4::FunctionObject
 {
     V4_OBJECT2(QQmlBindingFunction, FunctionObject)
 
+    Heap::FunctionObject *bindingFunction() const { return d()->bindingFunction; }
     QQmlSourceLocation currentLocation() const; // from caller stack trace
 };
 
+inline bool FunctionObject::isBinding() const
+{
+    return d()->vtable() == QQmlBindingFunction::staticVTable();
+}
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/v8/qv4domerrors.cpp b/src/qml/qml/v8/qv4domerrors.cpp
index b680aa07da..7ad37d098f 100644
--- a/src/qml/qml/v8/qv4domerrors.cpp
+++ b/src/qml/qml/v8/qv4domerrors.cpp
@@ -48,23 +48,23 @@ void qt_add_domexceptions(ExecutionEngine *e)
 {
     Scope scope(e);
     ScopedObject domexception(scope, e->newObject());
-    domexception->defineReadonlyProperty(QStringLiteral("INDEX_SIZE_ERR"), Primitive::fromInt32(DOMEXCEPTION_INDEX_SIZE_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("DOMSTRING_SIZE_ERR"), Primitive::fromInt32(DOMEXCEPTION_DOMSTRING_SIZE_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("HIERARCHY_REQUEST_ERR"), Primitive::fromInt32(DOMEXCEPTION_HIERARCHY_REQUEST_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("WRONG_DOCUMENT_ERR"), Primitive::fromInt32(DOMEXCEPTION_WRONG_DOCUMENT_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("INVALID_CHARACTER_ERR"), Primitive::fromInt32(DOMEXCEPTION_INVALID_CHARACTER_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("NO_DATA_ALLOWED_ERR"), Primitive::fromInt32(DOMEXCEPTION_NO_DATA_ALLOWED_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("NO_MODIFICATION_ALLOWED_ERR"), Primitive::fromInt32(DOMEXCEPTION_NO_MODIFICATION_ALLOWED_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("NOT_FOUND_ERR"), Primitive::fromInt32(DOMEXCEPTION_NOT_FOUND_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("NOT_SUPPORTED_ERR"), Primitive::fromInt32(DOMEXCEPTION_NOT_SUPPORTED_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("INUSE_ATTRIBUTE_ERR"), Primitive::fromInt32(DOMEXCEPTION_INUSE_ATTRIBUTE_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("INVALID_STATE_ERR"), Primitive::fromInt32(DOMEXCEPTION_INVALID_STATE_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("SYNTAX_ERR"), Primitive::fromInt32(DOMEXCEPTION_SYNTAX_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("INVALID_MODIFICATION_ERR"), Primitive::fromInt32(DOMEXCEPTION_INVALID_MODIFICATION_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("NAMESPACE_ERR"), Primitive::fromInt32(DOMEXCEPTION_NAMESPACE_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("INVALID_ACCESS_ERR"), Primitive::fromInt32(DOMEXCEPTION_INVALID_ACCESS_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("VALIDATION_ERR"), Primitive::fromInt32(DOMEXCEPTION_VALIDATION_ERR));
-    domexception->defineReadonlyProperty(QStringLiteral("TYPE_MISMATCH_ERR"), Primitive::fromInt32(DOMEXCEPTION_TYPE_MISMATCH_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("INDEX_SIZE_ERR"), Value::fromInt32(DOMEXCEPTION_INDEX_SIZE_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("DOMSTRING_SIZE_ERR"), Value::fromInt32(DOMEXCEPTION_DOMSTRING_SIZE_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("HIERARCHY_REQUEST_ERR"), Value::fromInt32(DOMEXCEPTION_HIERARCHY_REQUEST_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("WRONG_DOCUMENT_ERR"), Value::fromInt32(DOMEXCEPTION_WRONG_DOCUMENT_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("INVALID_CHARACTER_ERR"), Value::fromInt32(DOMEXCEPTION_INVALID_CHARACTER_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("NO_DATA_ALLOWED_ERR"), Value::fromInt32(DOMEXCEPTION_NO_DATA_ALLOWED_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("NO_MODIFICATION_ALLOWED_ERR"), Value::fromInt32(DOMEXCEPTION_NO_MODIFICATION_ALLOWED_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("NOT_FOUND_ERR"), Value::fromInt32(DOMEXCEPTION_NOT_FOUND_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("NOT_SUPPORTED_ERR"), Value::fromInt32(DOMEXCEPTION_NOT_SUPPORTED_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("INUSE_ATTRIBUTE_ERR"), Value::fromInt32(DOMEXCEPTION_INUSE_ATTRIBUTE_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("INVALID_STATE_ERR"), Value::fromInt32(DOMEXCEPTION_INVALID_STATE_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("SYNTAX_ERR"), Value::fromInt32(DOMEXCEPTION_SYNTAX_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("INVALID_MODIFICATION_ERR"), Value::fromInt32(DOMEXCEPTION_INVALID_MODIFICATION_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("NAMESPACE_ERR"), Value::fromInt32(DOMEXCEPTION_NAMESPACE_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("INVALID_ACCESS_ERR"), Value::fromInt32(DOMEXCEPTION_INVALID_ACCESS_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("VALIDATION_ERR"), Value::fromInt32(DOMEXCEPTION_VALIDATION_ERR));
+    domexception->defineReadonlyProperty(QStringLiteral("TYPE_MISMATCH_ERR"), Value::fromInt32(DOMEXCEPTION_TYPE_MISMATCH_ERR));
     e->globalObject->defineDefaultProperty(QStringLiteral("DOMException"), domexception);
 }
 
diff --git a/src/qml/qml/v8/qv4domerrors_p.h b/src/qml/qml/v8/qv4domerrors_p.h
index a9bdbe01ae..1842e46a9c 100644
--- a/src/qml/qml/v8/qv4domerrors_p.h
+++ b/src/qml/qml/v8/qv4domerrors_p.h
@@ -77,9 +77,8 @@ QT_BEGIN_NAMESPACE
 #define THROW_DOM(error, string) { \
     QV4::ScopedValue v(scope, scope.engine->newString(QStringLiteral(string))); \
     QV4::ScopedObject ex(scope, scope.engine->newErrorObject(v)); \
-    ex->put(QV4::ScopedString(scope, scope.engine->newIdentifier(QStringLiteral("code"))), QV4::ScopedValue(scope, QV4::Primitive::fromInt32(error))); \
-    scope.result = scope.engine->throwError(ex); \
-    return; \
+    ex->put(QV4::ScopedString(scope, scope.engine->newIdentifier(QStringLiteral("code"))), QV4::ScopedValue(scope, QV4::Value::fromInt32(error))); \
+    return scope.engine->throwError(ex); \
 }
 
 namespace QV4 {
diff --git a/src/qml/qml/v8/qv4sqlerrors.cpp b/src/qml/qml/v8/qv4sqlerrors.cpp
index db8d130cef..3f1744a687 100644
--- a/src/qml/qml/v8/qv4sqlerrors.cpp
+++ b/src/qml/qml/v8/qv4sqlerrors.cpp
@@ -49,14 +49,14 @@ void qt_add_sqlexceptions(QV4::ExecutionEngine *engine)
 {
     Scope scope(engine);
     ScopedObject sqlexception(scope, engine->newObject());
-    sqlexception->defineReadonlyProperty(QStringLiteral("UNKNOWN_ERR"), Primitive::fromInt32(SQLEXCEPTION_UNKNOWN_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("DATABASE_ERR"), Primitive::fromInt32(SQLEXCEPTION_DATABASE_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("VERSION_ERR"), Primitive::fromInt32(SQLEXCEPTION_VERSION_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("TOO_LARGE_ERR"), Primitive::fromInt32(SQLEXCEPTION_TOO_LARGE_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("QUOTA_ERR"), Primitive::fromInt32(SQLEXCEPTION_QUOTA_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("SYNTAX_ERR"), Primitive::fromInt32(SQLEXCEPTION_SYNTAX_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("CONSTRAINT_ERR"), Primitive::fromInt32(SQLEXCEPTION_CONSTRAINT_ERR));
-    sqlexception->defineReadonlyProperty(QStringLiteral("TIMEOUT_ERR"), Primitive::fromInt32(SQLEXCEPTION_TIMEOUT_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("UNKNOWN_ERR"), Value::fromInt32(SQLEXCEPTION_UNKNOWN_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("DATABASE_ERR"), Value::fromInt32(SQLEXCEPTION_DATABASE_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("VERSION_ERR"), Value::fromInt32(SQLEXCEPTION_VERSION_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("TOO_LARGE_ERR"), Value::fromInt32(SQLEXCEPTION_TOO_LARGE_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("QUOTA_ERR"), Value::fromInt32(SQLEXCEPTION_QUOTA_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("SYNTAX_ERR"), Value::fromInt32(SQLEXCEPTION_SYNTAX_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("CONSTRAINT_ERR"), Value::fromInt32(SQLEXCEPTION_CONSTRAINT_ERR));
+    sqlexception->defineReadonlyProperty(QStringLiteral("TIMEOUT_ERR"), Value::fromInt32(SQLEXCEPTION_TIMEOUT_ERR));
     engine->globalObject->defineDefaultProperty(QStringLiteral("SQLException"), sqlexception);
 }
 
diff --git a/src/qml/qml/v8/qv8engine.cpp b/src/qml/qml/v8/qv8engine.cpp
index dadff819cf..d76344b613 100644
--- a/src/qml/qml/v8/qv8engine.cpp
+++ b/src/qml/qml/v8/qv8engine.cpp
@@ -39,14 +39,21 @@
 
 #include "qv8engine_p.h"
 
+#if QT_CONFIG(qml_sequence_object)
 #include "qv4sequenceobject_p.h"
+#endif
+
 #include "private/qjsengine_p.h"
 
 #include <private/qqmlbuiltinfunctions_p.h>
 #include <private/qqmllist_p.h>
 #include <private/qqmlengine_p.h>
+#if QT_CONFIG(qml_xml_http_request)
 #include <private/qqmlxmlhttprequest_p.h>
+#endif
+#if QT_CONFIG(qml_locale)
 #include <private/qqmllocale_p.h>
+#endif
 #include <private/qqmlglobal_p.h>
 #include <private/qqmlmemoryprofiler_p.h>
 #include <private/qqmlplatform_p.h>
@@ -78,6 +85,7 @@
 #include <private/qv4script_p.h>
 #include <private/qv4include_p.h>
 #include <private/qv4jsonobject_p.h>
+#include <private/qv4identifiertable_p.h>
 
 Q_DECLARE_METATYPE(QList<int>)
 
@@ -123,17 +131,20 @@ static void restoreJSValue(QDataStream &stream, void *data)
     }
 }
 
-QV8Engine::QV8Engine(QJSEngine* qq)
-    : q(qq)
-    , m_engine(0)
-    , m_xmlHttpRequestData(0)
-    , m_listModelData(0)
+QV8Engine::QV8Engine(QV4::ExecutionEngine *v4)
+    : m_engine(nullptr)
+    , m_v4Engine(v4)
+#if QT_CONFIG(qml_xml_http_request)
+    , m_xmlHttpRequestData(nullptr)
+#endif
 {
+#ifndef Q_OS_WASM // wasm does not have working simd QTBUG-63924
 #ifdef Q_PROCESSOR_X86_32
     if (!qCpuHasFeature(SSE2)) {
         qFatal("This program requires an X86 processor that supports SSE2 extension, at least a Pentium 4 or newer");
     }
 #endif
+#endif
 
     QML_MEMORY_SCOPE_STRING("QV8Engine::QV8Engine");
     qMetaTypeId<QJSValue>();
@@ -147,8 +158,6 @@ QV8Engine::QV8Engine(QJSEngine* qq)
         QMetaType::registerConverter<QJSValue, QStringList>(convertJSValueToVariantType<QStringList>);
     QMetaType::registerStreamOperators(qMetaTypeId<QJSValue>(), saveJSValue, restoreJSValue);
 
-    m_v4Engine = new QV4::ExecutionEngine;
-    m_v4Engine->v8Engine = this;
     m_delayedCallQueue.init(m_v4Engine);
 
     QV4::QObjectWrapper::initializeBindings(m_v4Engine);
@@ -159,15 +168,10 @@ QV8Engine::~QV8Engine()
     qDeleteAll(m_extensionData);
     m_extensionData.clear();
 
-#if QT_CONFIG(xmlstreamreader) && QT_CONFIG(qml_network)
+#if QT_CONFIG(qml_xml_http_request)
     qt_rem_qmlxmlhttprequest(m_v4Engine, m_xmlHttpRequestData);
-    m_xmlHttpRequestData = 0;
+    m_xmlHttpRequestData = nullptr;
 #endif
-
-    delete m_listModelData;
-    m_listModelData = 0;
-
-    delete m_v4Engine;
 }
 
 #if QT_CONFIG(qml_network)
@@ -187,14 +191,16 @@ void QV8Engine::initializeGlobal()
     QV4::Scope scope(m_v4Engine);
     QV4::GlobalExtensions::init(m_v4Engine->globalObject, QJSEngine::AllExtensions);
 
-    QV4::ScopedObject qt(scope, m_v4Engine->memoryManager->allocObject<QV4::QtObject>(m_engine));
+    QV4::ScopedObject qt(scope, m_v4Engine->memoryManager->allocate<QV4::QtObject>(m_engine));
     m_v4Engine->globalObject->defineDefaultProperty(QStringLiteral("Qt"), qt);
 
+#if QT_CONFIG(qml_locale)
     QQmlLocale::registerStringLocaleCompare(m_v4Engine);
     QQmlDateExtension::registerExtension(m_v4Engine);
     QQmlNumberExtension::registerExtension(m_v4Engine);
+#endif
 
-#if QT_CONFIG(xmlstreamreader) && QT_CONFIG(qml_network)
+#if QT_CONFIG(qml_xml_http_request)
     qt_add_domexceptions(m_v4Engine);
     m_xmlHttpRequestData = qt_add_qmlxmlhttprequest(m_v4Engine);
 #endif
@@ -203,8 +209,10 @@ void QV8Engine::initializeGlobal()
 
     {
         for (uint i = 0; i < m_v4Engine->globalObject->internalClass()->size; ++i) {
-            if (m_v4Engine->globalObject->internalClass()->nameMap.at(i))
-                m_illegalNames.insert(m_v4Engine->globalObject->internalClass()->nameMap.at(i)->string);
+            if (m_v4Engine->globalObject->internalClass()->nameMap.at(i).isString()) {
+                QV4::PropertyKey id = m_v4Engine->globalObject->internalClass()->nameMap.at(i);
+                m_illegalNames.insert(id.toQString());
+            }
         }
     }
 }
@@ -217,25 +225,25 @@ static void freeze_recursive(QV4::ExecutionEngine *v4, QV4::Object *object)
     QV4::Scope scope(v4);
 
     bool instanceOfObject = false;
-    QV4::ScopedObject p(scope, object->prototype());
+    QV4::ScopedObject p(scope, object->getPrototypeOf());
     while (p) {
         if (p->d() == v4->objectPrototype()->d()) {
             instanceOfObject = true;
             break;
         }
-        p = p->prototype();
+        p = p->getPrototypeOf();
     }
     if (!instanceOfObject)
         return;
 
-    QV4::InternalClass *frozen = object->internalClass()->propertiesFrozen();
+    QV4::Heap::InternalClass *frozen = object->internalClass()->propertiesFrozen();
     if (object->internalClass() == frozen)
         return;
     object->setInternalClass(frozen);
 
     QV4::ScopedObject o(scope);
     for (uint i = 0; i < frozen->size; ++i) {
-        if (!frozen->nameMap.at(i))
+        if (!frozen->nameMap.at(i).isStringOrSymbol())
             continue;
         o = *object->propertyData(i);
         if (o)
@@ -292,11 +300,6 @@ void QV8Engine::setEngine(QQmlEngine *engine)
     initQmlGlobalObject();
 }
 
-QV4::ReturnedValue QV8Engine::global()
-{
-    return m_v4Engine->globalObject->asReturnedValue();
-}
-
 void QV8Engine::startTimer(const QString &timerName)
 {
     if (!m_time.isValid())
diff --git a/src/qml/qml/v8/qv8engine_p.h b/src/qml/qml/v8/qv8engine_p.h
index 3bd3517968..23559618ef 100644
--- a/src/qml/qml/v8/qv8engine_p.h
+++ b/src/qml/qml/v8/qv8engine_p.h
@@ -67,6 +67,7 @@
 #include <private/qv4value_p.h>
 #include <private/qv4identifier_p.h>
 #include <private/qv4context_p.h>
+#include <private/qv4stackframe_p.h>
 #include <private/qqmldelayedcallqueue_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -77,12 +78,6 @@ namespace QV4 {
     struct QObjectMethod;
 }
 
-#define V4THROW_ERROR(string) \
-    return ctx->engine()->throwError(QString::fromUtf8(string));
-
-#define V4THROW_TYPE(string) \
-    return ctx->engine()->throwTypeError(QStringLiteral(string));
-
 #define V4_DEFINE_EXTENSION(dataclass, datafunction) \
     static inline dataclass *datafunction(QV4::ExecutionEngine *engine) \
     { \
@@ -116,8 +111,8 @@ namespace QV4 {
 class QQmlV4Function
 {
 public:
-    int length() const { return callData->argc; }
-    QV4::ReturnedValue operator[](int idx) const { return (idx < callData->argc ? callData->args[idx].asReturnedValue() : QV4::Encode::undefined()); }
+    int length() const { return callData->argc(); }
+    QV4::ReturnedValue operator[](int idx) const { return (idx < callData->argc() ? callData->args[idx].asReturnedValue() : QV4::Encode::undefined()); }
     void setReturnValue(QV4::ReturnedValue rv) { *retVal = rv; }
     QV4::ExecutionEngine *v4engine() const { return e; }
 private:
@@ -159,12 +154,10 @@ class Q_QML_PRIVATE_EXPORT QV8Engine
 {
     friend class QJSEngine;
 public:
-    static QV8Engine* get(QJSEngine* q) { Q_ASSERT(q); return q->handle(); }
 //    static QJSEngine* get(QV8Engine* d) { Q_ASSERT(d); return d->q; }
-    static QV4::ExecutionEngine *getV4(QJSEngine *q) { return q->handle()->m_v4Engine; }
     static QV4::ExecutionEngine *getV4(QV8Engine *d) { return d->m_v4Engine; }
 
-    QV8Engine(QJSEngine* qq);
+    QV8Engine(QV4::ExecutionEngine *v4);
     virtual ~QV8Engine();
 
     // This enum should be in sync with QQmlEngine::ObjectOwnership
@@ -177,14 +170,11 @@ public:
     void initQmlGlobalObject();
     void setEngine(QQmlEngine *engine);
     QQmlEngine *engine() { return m_engine; }
-    QJSEngine *publicEngine() { return q; }
-    QV4::ReturnedValue global();
     QQmlDelayedCallQueue *delayedCallQueue() { return &m_delayedCallQueue; }
 
+#if QT_CONFIG(qml_xml_http_request)
     void *xmlHttpRequestData() const { return m_xmlHttpRequestData; }
-
-    Deletable *listModelData() const { return m_listModelData; }
-    void setListModelData(Deletable *d) { if (m_listModelData) delete m_listModelData; m_listModelData = d; }
+#endif
 
     void freezeObject(const QV4::Value &value);
 
@@ -213,16 +203,16 @@ public:
     int consoleCountHelper(const QString &file, quint16 line, quint16 column);
 
 protected:
-    QJSEngine* q;
     QQmlEngine *m_engine;
     QQmlDelayedCallQueue m_delayedCallQueue;
 
     QV4::ExecutionEngine *m_v4Engine;
 
+#if QT_CONFIG(qml_xml_http_request)
     void *m_xmlHttpRequestData;
+#endif
 
     QVector<Deletable *> m_extensionData;
-    Deletable *m_listModelData;
 
     QSet<QString> m_illegalNames;
 
@@ -242,7 +232,7 @@ inline QV8Engine::Deletable *QV8Engine::extensionData(int index) const
     if (index < m_extensionData.count())
         return m_extensionData[index];
     else
-        return 0;
+        return nullptr;
 }
 
 
diff --git a/src/qml/qmldirparser/qmldirparser.pri b/src/qml/qmldirparser/qmldirparser.pri
new file mode 100644
index 0000000000..660e7b395a
--- /dev/null
+++ b/src/qml/qmldirparser/qmldirparser.pri
@@ -0,0 +1,11 @@
+INCLUDEPATH += $$PWD
+INCLUDEPATH += $$OUT_PWD
+
+HEADERS += \
+    $$PWD/qqmldirparser_p.h \
+    $$PWD/qqmlerror.h \
+    $$PWD/qqmlsourcecoordinate_p.h
+
+SOURCES += \
+    $$PWD/qqmldirparser.cpp \
+    $$PWD/qqmlerror.cpp
diff --git a/src/qml/qml/qqmldirparser.cpp b/src/qml/qmldirparser/qqmldirparser.cpp
index 4cca8a4d58..e944b52e47 100644
--- a/src/qml/qml/qqmldirparser.cpp
+++ b/src/qml/qmldirparser/qqmldirparser.cpp
@@ -107,6 +107,7 @@ bool QQmlDirParser::parse(const QString &source)
     _components.clear();
     _scripts.clear();
     _designerSupported = false;
+    _className.clear();
 
     quint16 lineNumber = 0;
     bool firstLine = true;
@@ -196,7 +197,8 @@ bool QQmlDirParser::parse(const QString &source)
                 continue;
             }
 
-            // Ignore these. qmlimportscanner uses them.
+            _className = sections[1];
+
         } else if (sections[0] == QLatin1String("internal")) {
             if (sectionCount != 3) {
                 reportError(lineNumber, 0,
@@ -270,7 +272,7 @@ bool QQmlDirParser::parse(const QString &source)
             if (parseVersion(sections[1], &major, &minor)) {
                 const QString &fileName = sections[2];
 
-                if (fileName.endsWith(QLatin1String(".js"))) {
+                if (fileName.endsWith(QLatin1String(".js")) || fileName.endsWith(QLatin1String(".mjs"))) {
                     // A 'js' extension indicates a namespaced script import
                     const Script entry(sections[0], fileName, major, minor);
                     _scripts.append(entry);
@@ -365,18 +367,21 @@ QList<QQmlDirParser::Script> QQmlDirParser::scripts() const
     return _scripts;
 }
 
-#ifdef QT_CREATOR
 QList<QQmlDirParser::TypeInfo> QQmlDirParser::typeInfos() const
 {
     return _typeInfos;
 }
-#endif
 
 bool QQmlDirParser::designerSupported() const
 {
     return _designerSupported;
 }
 
+QString QQmlDirParser::className() const
+{
+    return _className;
+}
+
 QDebug &operator<< (QDebug &debug, const QQmlDirParser::Component &component)
 {
     const QString output = QStringLiteral("{%1 %2.%3}").
diff --git a/src/qml/qml/qqmldirparser_p.h b/src/qml/qmldirparser/qqmldirparser_p.h
index 1530b7a6cf..cff9cb11a4 100644
--- a/src/qml/qml/qqmldirparser_p.h
+++ b/src/qml/qmldirparser/qqmldirparser_p.h
@@ -63,8 +63,6 @@ class QQmlError;
 class QQmlEngine;
 class Q_QML_PRIVATE_EXPORT QQmlDirParser
 {
-    Q_DISABLE_COPY(QQmlDirParser)
-
 public:
     QQmlDirParser();
     ~QQmlDirParser();
@@ -91,8 +89,7 @@ public:
 
     struct Component
     {
-        Component()
-            : majorVersion(0), minorVersion(0), internal(false), singleton(false) {}
+        Component() {}
 
         Component(const QString &typeName, const QString &fileName, int majorVersion, int minorVersion)
             : typeName(typeName), fileName(fileName), majorVersion(majorVersion), minorVersion(minorVersion),
@@ -100,24 +97,23 @@ public:
 
         QString typeName;
         QString fileName;
-        int majorVersion;
-        int minorVersion;
-        bool internal;
-        bool singleton;
+        int majorVersion = 0;
+        int minorVersion = 0;
+        bool internal = false;
+        bool singleton = false;
     };
 
     struct Script
     {
-        Script()
-            : majorVersion(0), minorVersion(0) {}
+        Script() {}
 
         Script(const QString &nameSpace, const QString &fileName, int majorVersion, int minorVersion)
             : nameSpace(nameSpace), fileName(fileName), majorVersion(majorVersion), minorVersion(minorVersion) {}
 
         QString nameSpace;
         QString fileName;
-        int majorVersion;
-        int minorVersion;
+        int majorVersion = 0;
+        int minorVersion = 0;
     };
 
     QHash<QString,Component> components() const;
@@ -126,7 +122,6 @@ public:
     QList<Plugin> plugins() const;
     bool designerSupported() const;
 
-#ifdef QT_CREATOR
     struct TypeInfo
     {
         TypeInfo() {}
@@ -137,7 +132,8 @@ public:
     };
 
     QList<TypeInfo> typeInfos() const;
-#endif
+
+    QString className() const;
 
 private:
     bool maybeAddComponent(const QString &typeName, const QString &fileName, const QString &version, QHash<QString,Component> &hash, int lineNumber = -1, bool multi = true);
@@ -151,9 +147,8 @@ private:
     QList<Script> _scripts;
     QList<Plugin> _plugins;
     bool _designerSupported;
-#ifdef QT_CREATOR
     QList<TypeInfo> _typeInfos;
-#endif
+    QString _className;
 };
 
 typedef QHash<QString,QQmlDirParser::Component> QQmlDirComponents;
diff --git a/src/qml/qml/qqmlerror.cpp b/src/qml/qmldirparser/qqmlerror.cpp
index 64f008cd32..5e181f7e27 100644
--- a/src/qml/qml/qqmlerror.cpp
+++ b/src/qml/qmldirparser/qqmlerror.cpp
@@ -38,15 +38,17 @@
 ****************************************************************************/
 
 #include "qqmlerror.h"
-#include "qqmlglobal_p.h"
+#include "qqmlsourcecoordinate_p.h"
 
 #include <QtCore/qdebug.h>
 #include <QtCore/qfile.h>
 #include <QtCore/qstringlist.h>
 #include <QtCore/qvector.h>
-#include <QtCore/qpointer.h>
 
-#include <private/qv4errorobject_p.h>
+#ifndef QT_NO_QOBJECT
+#include <QtCore/qobject.h>
+#include <QtCore/qpointer.h>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -73,8 +75,6 @@ QT_BEGIN_NAMESPACE
                ^
     \endcode
 
-    Note that the \l {Qt Quick 1} version is named QDeclarativeError
-
     \sa QQuickView::errors(), QQmlComponent::errors()
 */
 class QQmlErrorPrivate
@@ -87,11 +87,13 @@ public:
     quint16 line;
     quint16 column;
     QtMsgType messageType;
+#ifndef QT_NO_QOBJECT
     QPointer<QObject> object;
+#endif
 };
 
 QQmlErrorPrivate::QQmlErrorPrivate()
-: line(0), column(0), messageType(QtMsgType::QtWarningMsg), object()
+: line(0), column(0), messageType(QtMsgType::QtWarningMsg)
 {
 }
 
@@ -99,7 +101,7 @@ QQmlErrorPrivate::QQmlErrorPrivate()
     Creates an empty error object.
 */
 QQmlError::QQmlError()
-: d(0)
+: d(nullptr)
 {
 }
 
@@ -107,7 +109,7 @@ QQmlError::QQmlError()
     Creates a copy of \a other.
 */
 QQmlError::QQmlError(const QQmlError &other)
-: d(0)
+: d(nullptr)
 {
     *this = other;
 }
@@ -119,7 +121,7 @@ QQmlError &QQmlError::operator=(const QQmlError &other)
 {
     if (!other.d) {
         delete d;
-        d = 0;
+        d = nullptr;
     } else {
         if (!d)
             d = new QQmlErrorPrivate;
@@ -127,7 +129,9 @@ QQmlError &QQmlError::operator=(const QQmlError &other)
         d->description = other.d->description;
         d->line = other.d->line;
         d->column = other.d->column;
+#ifndef QT_NO_QOBJECT
         d->object = other.d->object;
+#endif
         d->messageType = other.d->messageType;
     }
     return *this;
@@ -138,7 +142,7 @@ QQmlError &QQmlError::operator=(const QQmlError &other)
 */
 QQmlError::~QQmlError()
 {
-    delete d; d = 0;
+    delete d; d = nullptr;
 }
 
 /*!
@@ -146,7 +150,7 @@ QQmlError::~QQmlError()
 */
 bool QQmlError::isValid() const
 {
-    return d != 0;
+    return d != nullptr;
 }
 
 /*!
@@ -229,6 +233,7 @@ void QQmlError::setColumn(int column)
     d->column = qmlSourceCoordinate(column);
 }
 
+#ifndef QT_NO_QOBJECT
 /*!
     Returns the nearest object where this error occurred.
     Exceptions in bound property expressions set this to the object
@@ -239,7 +244,7 @@ QObject *QQmlError::object() const
 {
     if (d)
         return d->object;
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -251,6 +256,7 @@ void QQmlError::setObject(QObject *object)
         d = new QQmlErrorPrivate;
     d->object = object;
 }
+#endif // QT_NO_QOBJECT
 
 /*!
     \since 5.9
@@ -268,7 +274,7 @@ QtMsgType QQmlError::messageType() const
     \since 5.9
 
     Sets the \a messageType for this message. The message type determines which
-    QDebug handlers are responsible for recieving the message.
+    QDebug handlers are responsible for receiving the message.
  */
 void QQmlError::setMessageType(QtMsgType messageType)
 {
diff --git a/src/qml/qml/qqmlerror.h b/src/qml/qmldirparser/qqmlerror.h
index ef529e3828..f4221358e9 100644
--- a/src/qml/qml/qqmlerror.h
+++ b/src/qml/qmldirparser/qqmlerror.h
@@ -68,8 +68,12 @@ public:
     void setLine(int);
     int column() const;
     void setColumn(int);
+
+#ifndef QT_NO_QOBJECT
     QObject *object() const;
     void setObject(QObject *);
+#endif
+
     QtMsgType messageType() const;
     void setMessageType(QtMsgType messageType);
 
diff --git a/src/qml/qmldirparser/qqmlsourcecoordinate_p.h b/src/qml/qmldirparser/qqmlsourcecoordinate_p.h
new file mode 100644
index 0000000000..76ac741ae8
--- /dev/null
+++ b/src/qml/qmldirparser/qqmlsourcecoordinate_p.h
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLSOURCECOORDINATE_P_H
+#define QQMLSOURCECOORDINATE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+
+#include <climits>
+
+QT_BEGIN_NAMESPACE
+
+inline quint16 qmlSourceCoordinate(int n)
+{
+    return (n > 0 && n <= static_cast<int>(USHRT_MAX)) ? static_cast<quint16>(n) : 0;
+}
+
+inline int qmlSourceCoordinate(quint16 n)
+{
+    return (n == 0) ? -1 : static_cast<int>(n);
+}
+
+QT_END_NAMESPACE
+
+#endif // QQMLSOURCECOORDINATE_P_H
diff --git a/src/qml/qtqmlglobal.h b/src/qml/qtqmlglobal.h
index 387c28a945..090b830b3c 100644
--- a/src/qml/qtqmlglobal.h
+++ b/src/qml/qtqmlglobal.h
@@ -50,6 +50,10 @@
 #  if QT_CONFIG(qml_network)
 #    include <QtNetwork/qtnetworkglobal.h>
 #  endif
+#else
+#  define QT_FEATURE_qml_debug -1
+#  define QT_FEATURE_qml_sequence_object 1
+#  define QT_FEATURE_qml_tracing -1
 #endif
 
 QT_BEGIN_NAMESPACE
diff --git a/src/qml/qtqmlglobal_p.h b/src/qml/qtqmlglobal_p.h
index 4c0ba338d8..60988d12e6 100644
--- a/src/qml/qtqmlglobal_p.h
+++ b/src/qml/qtqmlglobal_p.h
@@ -57,6 +57,8 @@
 #  include <QtQml/private/qtqml-config_p.h>
 #endif
 
+#define Q_QML_PRIVATE_API_VERSION 3
+
 #define Q_QML_PRIVATE_EXPORT Q_QML_EXPORT
 
 #if !defined(QT_QMLDEVTOOLS_LIB) && !defined(QT_BUILD_QMLDEVTOOLS_LIB)
diff --git a/src/qml/types/qqmlbind.cpp b/src/qml/types/qqmlbind.cpp
index da644becc2..513f7f2997 100644
--- a/src/qml/types/qqmlbind.cpp
+++ b/src/qml/types/qqmlbind.cpp
@@ -60,7 +60,7 @@ QT_BEGIN_NAMESPACE
 class QQmlBindPrivate : public QObjectPrivate
 {
 public:
-    QQmlBindPrivate() : obj(0), componentComplete(true), delayed(false), pendingEval(false) {}
+    QQmlBindPrivate() : obj(nullptr), componentComplete(true), delayed(false), pendingEval(false) {}
     ~QQmlBindPrivate() { }
 
     QQmlNullableValue<bool> when;
@@ -102,7 +102,7 @@ void QQmlBindPrivate::validate(QObject *binding) const
     In QML, property bindings result in a dependency between the properties of
     different objects.
 
-    \section1 Binding to an inaccessible property
+    \section1 Binding to an Inaccessible Property
 
     Sometimes it is necessary to bind an object's property to
     that of another object that isn't directly instantiated by QML, such as a
@@ -120,7 +120,7 @@ void QQmlBindPrivate::validate(QObject *binding) const
     When \c{text} changes, the C++ property \c{enteredText} will update
     automatically.
 
-    \section1 Conditional bindings
+    \section1 Conditional Bindings
 
     In some cases you may want to modify the value of a property when a certain
     condition is met but leave it unmodified otherwise. Often, it's not possible
@@ -370,7 +370,7 @@ void QQmlBind::eval()
             //restore any previous binding
             if (d->prevBind) {
                 QQmlAbstractBinding::Ptr p = d->prevBind;
-                d->prevBind = 0;
+                d->prevBind = nullptr;
                 QQmlPropertyPrivate::setBinding(p.data());
             }
             return;
diff --git a/src/qml/types/qqmlbind_p.h b/src/qml/types/qqmlbind_p.h
index c9dd14b58a..5bf9ef85c6 100644
--- a/src/qml/types/qqmlbind_p.h
+++ b/src/qml/types/qqmlbind_p.h
@@ -71,7 +71,7 @@ class Q_AUTOTEST_EXPORT QQmlBind : public QObject, public QQmlPropertyValueSourc
     Q_PROPERTY(bool delayed READ delayed WRITE setDelayed REVISION 8)
 
 public:
-    QQmlBind(QObject *parent=0);
+    QQmlBind(QObject *parent=nullptr);
     ~QQmlBind();
 
     bool when() const;
diff --git a/src/qml/types/qqmlconnections.cpp b/src/qml/types/qqmlconnections.cpp
index e218cdcfe4..f601087690 100644
--- a/src/qml/types/qqmlconnections.cpp
+++ b/src/qml/types/qqmlconnections.cpp
@@ -56,7 +56,7 @@ QT_BEGIN_NAMESPACE
 class QQmlConnectionsPrivate : public QObjectPrivate
 {
 public:
-    QQmlConnectionsPrivate() : target(0), enabled(true), targetSet(false), ignoreUnknownSignals(false), componentcomplete(true) {}
+    QQmlConnectionsPrivate() : target(nullptr), enabled(true), targetSet(false), ignoreUnknownSignals(false), componentcomplete(true) {}
 
     QList<QQmlBoundSignal*> boundsignals;
     QObject *target;
@@ -75,7 +75,7 @@ public:
     \instantiates QQmlConnections
     \inqmlmodule QtQml
     \ingroup qtquick-interceptors
-    \brief Describes generalized connections to signals
+    \brief Describes generalized connections to signals.
 
     A Connections object creates a connection to a QML signal.
 
@@ -231,11 +231,11 @@ void QQmlConnections::setIgnoreUnknownSignals(bool ignore)
     d->ignoreUnknownSignals = ignore;
 }
 
-void QQmlConnectionsParser::verifyBindings(const QV4::CompiledData::Unit *qmlUnit, const QList<const QV4::CompiledData::Binding *> &props)
+void QQmlConnectionsParser::verifyBindings(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &props)
 {
     for (int ii = 0; ii < props.count(); ++ii) {
         const QV4::CompiledData::Binding *binding = props.at(ii);
-        const QString &propName = qmlUnit->stringAt(binding->propertyNameIndex);
+        const QString &propName = compilationUnit->stringAt(binding->propertyNameIndex);
 
         if (!propName.startsWith(QLatin1String("on")) || (propName.length() < 3 || !propName.at(2).isUpper())) {
             error(props.at(ii), QQmlConnections::tr("Cannot assign to non-existent property \"%1\"").arg(propName));
@@ -243,8 +243,8 @@ void QQmlConnectionsParser::verifyBindings(const QV4::CompiledData::Unit *qmlUni
         }
 
         if (binding->type >= QV4::CompiledData::Binding::Type_Object) {
-            const QV4::CompiledData::Object *target = qmlUnit->objectAt(binding->value.objectIndex);
-            if (!qmlUnit->stringAt(target->inheritedTypeNameIndex).isEmpty())
+            const QV4::CompiledData::Object *target = compilationUnit->objectAt(binding->value.objectIndex);
+            if (!compilationUnit->stringAt(target->inheritedTypeNameIndex).isEmpty())
                 error(binding, QQmlConnections::tr("Connections: nested objects not allowed"));
             else
                 error(binding, QQmlConnections::tr("Connections: syntax error"));
@@ -256,7 +256,7 @@ void QQmlConnectionsParser::verifyBindings(const QV4::CompiledData::Unit *qmlUni
     }
 }
 
-void QQmlConnectionsParser::applyBindings(QObject *object, QV4::CompiledData::CompilationUnit *compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
+void QQmlConnectionsParser::applyBindings(QObject *object, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
 {
     QQmlConnectionsPrivate *p =
         static_cast<QQmlConnectionsPrivate *>(QObjectPrivate::get(object));
@@ -274,12 +274,11 @@ void QQmlConnections::connectSignals()
         return;
     QObject *target = this->target();
     QQmlData *ddata = QQmlData::get(this);
-    QQmlContextData *ctxtdata = ddata ? ddata->outerContext : 0;
+    QQmlContextData *ctxtdata = ddata ? ddata->outerContext : nullptr;
 
-    const QV4::CompiledData::Unit *qmlUnit = d->compilationUnit->data;
     for (const QV4::CompiledData::Binding *binding : qAsConst(d->bindings)) {
         Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Script);
-        QString propName = qmlUnit->stringAt(binding->propertyNameIndex);
+        QString propName = d->compilationUnit->stringAt(binding->propertyNameIndex);
 
         QQmlProperty prop(target, propName);
         if (prop.isValid() && (prop.type() & QQmlProperty::SignalProperty)) {
@@ -288,9 +287,10 @@ void QQmlConnections::connectSignals()
                 new QQmlBoundSignal(target, signalIndex, this, qmlEngine(this));
             signal->setEnabled(d->enabled);
 
-            QQmlBoundSignalExpression *expression = ctxtdata ?
-                new QQmlBoundSignalExpression(target, signalIndex,
-                                              ctxtdata, this, d->compilationUnit->runtimeFunctions[binding->value.compiledScriptIndex]) : 0;
+            auto f = d->compilationUnit->runtimeFunctions[binding->value.compiledScriptIndex];
+            QQmlBoundSignalExpression *expression =
+                    ctxtdata ? new QQmlBoundSignalExpression(target, signalIndex, ctxtdata, this, f)
+                             : nullptr;
             signal->takeExpression(expression);
             d->boundsignals += signal;
         } else {
diff --git a/src/qml/types/qqmlconnections_p.h b/src/qml/types/qqmlconnections_p.h
index 580b6522de..bd03d7e152 100644
--- a/src/qml/types/qqmlconnections_p.h
+++ b/src/qml/types/qqmlconnections_p.h
@@ -69,11 +69,11 @@ class Q_AUTOTEST_EXPORT QQmlConnections : public QObject, public QQmlParserStatu
 
     Q_INTERFACES(QQmlParserStatus)
     Q_PROPERTY(QObject *target READ target WRITE setTarget NOTIFY targetChanged)
-    Q_REVISION(1) Q_PROPERTY(bool enabled READ isEnabled WRITE setEnabled NOTIFY enabledChanged)
+    Q_PROPERTY(bool enabled READ isEnabled WRITE setEnabled NOTIFY enabledChanged REVISION 1)
     Q_PROPERTY(bool ignoreUnknownSignals READ ignoreUnknownSignals WRITE setIgnoreUnknownSignals)
 
 public:
-    QQmlConnections(QObject *parent=0);
+    QQmlConnections(QObject *parent=nullptr);
     ~QQmlConnections();
 
     QObject *target() const;
@@ -98,8 +98,8 @@ private:
 class QQmlConnectionsParser : public QQmlCustomParser
 {
 public:
-    void verifyBindings(const QV4::CompiledData::Unit *qmlUnit, const QList<const QV4::CompiledData::Binding *> &props) override;
-    void applyBindings(QObject *object, QV4::CompiledData::CompilationUnit *compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings) override;
+    void verifyBindings(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &props) override;
+    void applyBindings(QObject *object, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings) override;
 };
 
 
diff --git a/src/qml/types/qqmldelegatecomponent.cpp b/src/qml/types/qqmldelegatecomponent.cpp
new file mode 100644
index 0000000000..470f6cab6a
--- /dev/null
+++ b/src/qml/types/qqmldelegatecomponent.cpp
@@ -0,0 +1,300 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmldelegatecomponent_p.h"
+#include <QtQml/private/qqmladaptormodel_p.h>
+
+QT_BEGIN_NAMESPACE
+
+QQmlAbstractDelegateComponent::QQmlAbstractDelegateComponent(QObject *parent)
+    : QQmlComponent(parent)
+{
+}
+
+QQmlAbstractDelegateComponent::~QQmlAbstractDelegateComponent()
+{
+}
+
+QVariant QQmlAbstractDelegateComponent::value(QQmlAdaptorModel *adaptorModel, int row, int column, const QString &role) const
+{
+    if (!adaptorModel)
+        return QVariant();
+    return adaptorModel->value(adaptorModel->indexAt(row, column), role);
+}
+
+/*!
+    \qmlmodule Qt.labs.qmlmodels 1.0
+    \title Qt Labs QML Models - QML Types
+    \ingroup qmlmodules
+    \brief The Qt Labs QML Models module provides various model-related types for use with views.
+
+    To use this module, import the module with the following line:
+
+    \qml
+    import Qt.labs.qmlmodels 1.0
+    \endqml
+*/
+
+/*!
+    \qmltype DelegateChoice
+    \instantiates QQmlDelegateChoice
+    \inqmlmodule Qt.labs.qmlmodels
+    \brief Encapsulates a delegate and when to use it.
+
+    The DelegateChoice type wraps a delegate and defines the circumstances
+    in which it should be chosen.
+
+    DelegateChoices can be nested inside a DelegateChooser.
+
+    \sa DelegateChooser
+*/
+
+/*!
+    \qmlproperty string QtQml.Models::DelegateChoice::roleValue
+    This property holds the value used to match the role data for the role provided by \l DelegateChooser::role.
+*/
+QVariant QQmlDelegateChoice::roleValue() const
+{
+    return m_value;
+}
+
+void QQmlDelegateChoice::setRoleValue(const QVariant &value)
+{
+    if (m_value == value)
+        return;
+    m_value = value;
+    emit roleValueChanged();
+    emit changed();
+}
+
+/*!
+    \qmlproperty index QtQml.Models::DelegateChoice::row
+    This property holds the value used to match the row value of model elements.
+    With models that have only the index property (and thus only one column), this property
+    should be intended as an index, and set to the desired index value.
+
+    \note Setting both row and index has undefined behavior. The two are equivalent and only
+    one should be used.
+
+    \sa index
+*/
+
+/*!
+    \qmlproperty index QtQml.Models::DelegateChoice::index
+    This property holds the value used to match the index value of model elements.
+    This is effectively an alias for \l row.
+
+    \sa row
+*/
+int QQmlDelegateChoice::row() const
+{
+    return m_row;
+}
+
+void QQmlDelegateChoice::setRow(int r)
+{
+    if (m_row == r)
+        return;
+    m_row = r;
+    emit rowChanged();
+    emit indexChanged();
+    emit changed();
+}
+
+/*!
+    \qmlproperty index QtQml.Models::DelegateChoice::column
+    This property holds the value used to match the column value of model elements.
+*/
+int QQmlDelegateChoice::column() const
+{
+    return m_column;
+}
+
+void QQmlDelegateChoice::setColumn(int c)
+{
+    if (m_column == c)
+        return;
+    m_column = c;
+    emit columnChanged();
+    emit changed();
+}
+
+QQmlComponent *QQmlDelegateChoice::delegate() const
+{
+    return m_delegate;
+}
+
+/*!
+    \qmlproperty Component QtQml.Models::DelegateChoice::delegate
+    This property holds the delegate to use if this choice matches the model item.
+*/
+void QQmlDelegateChoice::setDelegate(QQmlComponent *delegate)
+{
+    if (m_delegate == delegate)
+        return;
+    QQmlAbstractDelegateComponent *adc = static_cast<QQmlAbstractDelegateComponent *>(m_delegate);
+    if (adc)
+        disconnect(adc, &QQmlAbstractDelegateComponent::delegateChanged, this, &QQmlDelegateChoice::delegateChanged);
+    m_delegate = delegate;
+    adc = static_cast<QQmlAbstractDelegateComponent *>(delegate);
+    if (adc)
+        connect(adc, &QQmlAbstractDelegateComponent::delegateChanged, this, &QQmlDelegateChoice::delegateChanged);
+    emit delegateChanged();
+    emit changed();
+}
+
+bool QQmlDelegateChoice::match(int row, int column, const QVariant &value) const
+{
+    if (!m_value.isValid() && m_row < 0 && m_column < 0)
+        return true;
+
+    const bool roleMatched = (m_value.isValid()) ? value == m_value : true;
+    const bool rowMatched = (m_row < 0 ) ? true : m_row == row;
+    const bool columnMatched = (m_column < 0 ) ? true : m_column == column;
+    return roleMatched && rowMatched && columnMatched;
+}
+
+/*!
+    \qmltype DelegateChooser
+    \instantiates QQmlDelegateChooser
+    \inqmlmodule Qt.labs.qmlmodels
+    \brief Allows a view to use different delegates for different types of items in the model.
+
+    The DelegateChooser is a special \l Component type intended for those scenarios where a Component is required
+    by a view and used as a delegate.
+    DelegateChooser encapsulates a set of \l {DelegateChoice}s.
+    These choices are used determine the delegate that will be instantiated for each
+    item in the model.
+    The selection of the choice is performed based on the value that a model item has for \l role,
+    and also based on index.
+
+    \note This type is intended to transparently work only with TableView and any DelegateModel-based view.
+    Views (including user-defined views) that aren't internally based on a DelegateModel need to explicitly support
+    this type of component to make it function as described.
+
+    \sa DelegateChoice
+*/
+
+/*!
+    \qmlproperty string QtQml.Models::DelegateChooser::role
+    This property holds the role used to determine the delegate for a given model item.
+
+    \sa DelegateChoice
+*/
+void QQmlDelegateChooser::setRole(const QString &role)
+{
+    if (m_role == role)
+        return;
+    m_role = role;
+    emit roleChanged();
+}
+
+/*!
+    \qmlproperty list<DelegateChoice> QtQml.Models::DelegateChooser::choices
+    \default
+
+    The list of DelegateChoices for the chooser.
+
+    The list is treated as an ordered list, where the first DelegateChoice to match
+    will be used be a view.
+
+    It should not generally be necessary to refer to the \c choices property,
+    as it is the default property for DelegateChooser and thus all child items are
+    automatically assigned to this property.
+*/
+
+QQmlListProperty<QQmlDelegateChoice> QQmlDelegateChooser::choices()
+{
+    return QQmlListProperty<QQmlDelegateChoice>(this, nullptr,
+                                                QQmlDelegateChooser::choices_append,
+                                                QQmlDelegateChooser::choices_count,
+                                                QQmlDelegateChooser::choices_at,
+                                                QQmlDelegateChooser::choices_clear);
+}
+
+void QQmlDelegateChooser::choices_append(QQmlListProperty<QQmlDelegateChoice> *prop, QQmlDelegateChoice *choice)
+{
+    QQmlDelegateChooser *q = static_cast<QQmlDelegateChooser *>(prop->object);
+    q->m_choices.append(choice);
+    connect(choice, &QQmlDelegateChoice::changed, q, &QQmlAbstractDelegateComponent::delegateChanged);
+    q->delegateChanged();
+}
+
+int QQmlDelegateChooser::choices_count(QQmlListProperty<QQmlDelegateChoice> *prop)
+{
+    QQmlDelegateChooser *q = static_cast<QQmlDelegateChooser*>(prop->object);
+    return q->m_choices.count();
+}
+
+QQmlDelegateChoice *QQmlDelegateChooser::choices_at(QQmlListProperty<QQmlDelegateChoice> *prop, int index)
+{
+    QQmlDelegateChooser *q = static_cast<QQmlDelegateChooser*>(prop->object);
+    return q->m_choices.at(index);
+}
+
+void QQmlDelegateChooser::choices_clear(QQmlListProperty<QQmlDelegateChoice> *prop)
+{
+    QQmlDelegateChooser *q = static_cast<QQmlDelegateChooser *>(prop->object);
+    for (QQmlDelegateChoice *choice : q->m_choices)
+        disconnect(choice, &QQmlDelegateChoice::changed, q, &QQmlAbstractDelegateComponent::delegateChanged);
+    q->m_choices.clear();
+    q->delegateChanged();
+}
+
+QQmlComponent *QQmlDelegateChooser::delegate(QQmlAdaptorModel *adaptorModel, int row, int column) const
+{
+    QVariant v;
+    if (!m_role.isNull())
+        v = value(adaptorModel, row, column, m_role);
+    if (!v.isValid()) { // check if the row only has modelData, for example if the row is a QVariantMap
+        v = value(adaptorModel, row, column, QStringLiteral("modelData"));
+        if (v.isValid())
+            v = v.toMap().value(m_role);
+    }
+    // loop through choices, finding first one that fits
+    for (int i = 0; i < m_choices.count(); ++i) {
+        const QQmlDelegateChoice *choice = m_choices.at(i);
+        if (choice->match(row, column, v))
+            return choice->delegate();
+    }
+
+    return nullptr;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/types/qqmldelegatecomponent_p.h b/src/qml/types/qqmldelegatecomponent_p.h
new file mode 100644
index 0000000000..c925ed9a60
--- /dev/null
+++ b/src/qml/types/qqmldelegatecomponent_p.h
@@ -0,0 +1,155 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLDELEGATECOMPONENT_P_H
+#define QQMLDELEGATECOMPONENT_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qtqmlglobal_p.h>
+#include <qqmlcomponent.h>
+
+QT_REQUIRE_CONFIG(qml_delegate_model);
+
+QT_BEGIN_NAMESPACE
+
+// TODO: consider making QQmlAbstractDelegateComponent public API
+class QQmlAbstractDelegateComponentPrivate;
+class QQmlAdaptorModel;
+class Q_QML_PRIVATE_EXPORT QQmlAbstractDelegateComponent : public QQmlComponent
+{
+    Q_OBJECT
+public:
+    QQmlAbstractDelegateComponent(QObject *parent = nullptr);
+    ~QQmlAbstractDelegateComponent() override;
+
+    virtual QQmlComponent *delegate(QQmlAdaptorModel *adaptorModel, int row, int column = 0) const = 0;
+
+signals:
+    void delegateChanged();
+
+protected:
+    QVariant value(QQmlAdaptorModel *adaptorModel,int row, int column, const QString &role) const;
+
+private:
+    Q_DECLARE_PRIVATE(QQmlAbstractDelegateComponent)
+    Q_DISABLE_COPY(QQmlAbstractDelegateComponent)
+};
+
+class Q_QML_PRIVATE_EXPORT QQmlDelegateChoice : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QVariant roleValue READ roleValue WRITE setRoleValue NOTIFY roleValueChanged)
+    Q_PROPERTY(int row READ row WRITE setRow NOTIFY rowChanged)
+    Q_PROPERTY(int index READ row WRITE setRow NOTIFY indexChanged)
+    Q_PROPERTY(int column READ column WRITE setColumn NOTIFY columnChanged)
+    Q_PROPERTY(QQmlComponent* delegate READ delegate WRITE setDelegate NOTIFY delegateChanged)
+    Q_CLASSINFO("DefaultProperty", "delegate")
+public:
+    QVariant roleValue() const;
+    void setRoleValue(const QVariant &roleValue);
+
+    int row() const;
+    void setRow(int r);
+
+    int column() const;
+    void setColumn(int c);
+
+    QQmlComponent *delegate() const;
+    void setDelegate(QQmlComponent *delegate);
+
+    virtual bool match(int row, int column, const QVariant &value) const;
+
+signals:
+    void roleValueChanged();
+    void rowChanged();
+    void indexChanged();
+    void columnChanged();
+    void delegateChanged();
+    void changed();
+
+private:
+    QVariant m_value;
+    int m_row = -1;
+    int m_column = -1;
+    QQmlComponent *m_delegate = nullptr;
+};
+
+class Q_QML_PRIVATE_EXPORT QQmlDelegateChooser : public QQmlAbstractDelegateComponent
+{
+    Q_OBJECT
+    Q_PROPERTY(QString role READ role WRITE setRole NOTIFY roleChanged)
+    Q_PROPERTY(QQmlListProperty<QQmlDelegateChoice> choices READ choices CONSTANT)
+    Q_CLASSINFO("DefaultProperty", "choices")
+
+public:
+    QString role() const { return m_role; }
+    void setRole(const QString &role);
+
+    virtual QQmlListProperty<QQmlDelegateChoice> choices();
+    static void choices_append(QQmlListProperty<QQmlDelegateChoice> *, QQmlDelegateChoice *);
+    static int choices_count(QQmlListProperty<QQmlDelegateChoice> *);
+    static QQmlDelegateChoice *choices_at(QQmlListProperty<QQmlDelegateChoice> *, int);
+    static void choices_clear(QQmlListProperty<QQmlDelegateChoice> *);
+
+    QQmlComponent *delegate(QQmlAdaptorModel *adaptorModel, int row, int column = -1) const override;
+
+signals:
+    void roleChanged();
+
+private:
+    QString m_role;
+    QList<QQmlDelegateChoice *> m_choices;
+};
+
+QT_END_NAMESPACE
+
+QML_DECLARE_TYPE(QQmlDelegateChoice)
+QML_DECLARE_TYPE(QQmlDelegateChooser)
+
+#endif // QQMLDELEGATECOMPONENT_P_H
diff --git a/src/qml/types/qqmldelegatemodel.cpp b/src/qml/types/qqmldelegatemodel.cpp
index 9620df6af9..572f58339f 100644
--- a/src/qml/types/qqmldelegatemodel.cpp
+++ b/src/qml/types/qqmldelegatemodel.cpp
@@ -38,6 +38,7 @@
 ****************************************************************************/
 
 #include "qqmldelegatemodel_p_p.h"
+#include "qqmldelegatecomponent_p.h"
 
 #include <QtQml/qqmlinfo.h>
 
@@ -93,20 +94,19 @@ struct DelegateModelGroupFunction : QV4::FunctionObject
 
     static Heap::DelegateModelGroupFunction *create(QV4::ExecutionContext *scope, uint flag, QV4::ReturnedValue (*code)(QQmlDelegateModelItem *item, uint flag, const QV4::Value &arg))
     {
-        return scope->engine()->memoryManager->allocObject<DelegateModelGroupFunction>(scope, flag, code);
+        return scope->engine()->memoryManager->allocate<DelegateModelGroupFunction>(scope, flag, code);
     }
 
-    static void call(const QV4::Managed *that, QV4::Scope &scope, QV4::CallData *callData)
+    static ReturnedValue virtualCall(const QV4::FunctionObject *that, const Value *thisObject, const Value *argv, int argc)
     {
+        QV4::Scope scope(that->engine());
         QV4::Scoped<DelegateModelGroupFunction> f(scope, static_cast<const DelegateModelGroupFunction *>(that));
-        QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject);
-        if (!o) {
-            scope.result = scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object"));
-            return;
-        }
+        QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject);
+        if (!o)
+            return scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
 
-        QV4::ScopedValue v(scope, callData->argument(0));
-        scope.result = f->d()->code(o->d()->item, f->d()->flag, v);
+        QV4::ScopedValue v(scope, argc ? argv[0] : Value::undefinedValue());
+        return f->d()->code(o->d()->item, f->d()->flag, v);
     }
 };
 
@@ -129,7 +129,8 @@ public:
     QQmlDelegateModelEngineData(QV4::ExecutionEngine *v4);
     ~QQmlDelegateModelEngineData();
 
-    QV4::ReturnedValue array(QV8Engine *engine, const QVector<QQmlChangeSet::Change> &changes);
+    QV4::ReturnedValue array(QV4::ExecutionEngine *engine,
+                             const QVector<QQmlChangeSet::Change> &changes);
 
     QV4::PersistentValue changeProto;
 };
@@ -160,26 +161,10 @@ QQmlDelegateModelParts::QQmlDelegateModelParts(QQmlDelegateModel *parent)
 //---------------------------------------------------------------------------
 
 /*!
-    \qmltype VisualDataModel
-    \instantiates QQmlDelegateModel
-    \inqmlmodule QtQuick
-    \ingroup qtquick-models
-    \brief Encapsulates a model and delegate
-
-    The VisualDataModel type encapsulates a model and the delegate that will
-    be instantiated for items in a model.
-
-    This type is provided by the \l{Qt QML} module due to compatibility reasons.
-    The same implementation is now primarily available as DelegateModel in the
-    \l{Qt QML Models QML Types}{Qt QML Models} module.
-
-    \sa {QtQml.Models::DelegateModel}
-*/
-/*!
     \qmltype DelegateModel
     \instantiates QQmlDelegateModel
     \inqmlmodule QtQml.Models
-    \brief Encapsulates a model and delegate
+    \brief Encapsulates a model and delegate.
 
     The DelegateModel type encapsulates a model and the delegate that will
     be instantiated for items in the model.
@@ -193,17 +178,14 @@ QQmlDelegateModelParts::QQmlDelegateModelParts(QQmlDelegateModel *parent)
 
     The example below illustrates using a DelegateModel with a ListView.
 
-    \snippet delegatemodel/visualdatamodel.qml 0
-
-    \note This type is also available as \l VisualDataModel in the \l{Qt QML}
-    module due to compatibility reasons.
+    \snippet delegatemodel/delegatemodel.qml 0
 */
 
 QQmlDelegateModelPrivate::QQmlDelegateModelPrivate(QQmlContext *ctxt)
-    : m_delegate(0)
-    , m_cacheMetaType(0)
+    : m_delegateChooser(nullptr)
+    , m_cacheMetaType(nullptr)
     , m_context(ctxt)
-    , m_parts(0)
+    , m_parts(nullptr)
     , m_filterGroup(QStringLiteral("items"))
     , m_count(0)
     , m_groupCount(Compositor::MinimumGroupCount)
@@ -214,9 +196,9 @@ QQmlDelegateModelPrivate::QQmlDelegateModelPrivate(QQmlContext *ctxt)
     , m_transaction(false)
     , m_incubatorCleanupScheduled(false)
     , m_waitingToFetchMore(false)
-    , m_cacheItems(0)
-    , m_items(0)
-    , m_persistedItems(0)
+    , m_cacheItems(nullptr)
+    , m_items(nullptr)
+    , m_persistedItems(nullptr)
 {
 }
 
@@ -228,6 +210,14 @@ QQmlDelegateModelPrivate::~QQmlDelegateModelPrivate()
         m_cacheMetaType->release();
 }
 
+int QQmlDelegateModelPrivate::adaptorModelCount() const
+{
+    // QQmlDelegateModel currently only support list models.
+    // So even if a model is a table model, only the first
+    // column will be used.
+    return m_adaptorModel.rowCount();
+}
+
 void QQmlDelegateModelPrivate::requestMoreIfNecessary()
 {
     Q_Q(QQmlDelegateModel);
@@ -263,14 +253,17 @@ QQmlDelegateModel::QQmlDelegateModel(QQmlContext *ctxt, QObject *parent)
 QQmlDelegateModel::~QQmlDelegateModel()
 {
     Q_D(QQmlDelegateModel);
+    d->disconnectFromAbstractItemModel();
+    d->m_adaptorModel.setObject(nullptr, this);
 
     for (QQmlDelegateModelItem *cacheItem : qAsConst(d->m_cache)) {
         if (cacheItem->object) {
             delete cacheItem->object;
 
-            cacheItem->object = 0;
-            cacheItem->contextData->destroy();
-            cacheItem->contextData = 0;
+            cacheItem->object = nullptr;
+            cacheItem->contextData->invalidate();
+            Q_ASSERT(cacheItem->contextData->refCount == 1);
+            cacheItem->contextData = nullptr;
             cacheItem->scriptRef -= 1;
         }
         cacheItem->groups &= ~Compositor::UnresolvedFlag;
@@ -278,7 +271,7 @@ QQmlDelegateModel::~QQmlDelegateModel()
         if (!cacheItem->isReferenced())
             delete cacheItem;
         else if (cacheItem->incubationTask)
-            cacheItem->incubationTask->vdm = 0;
+            cacheItem->incubationTask->vdm = nullptr;
     }
 }
 
@@ -325,7 +318,7 @@ void QQmlDelegateModel::componentComplete()
     }
 
     d->m_cacheMetaType = new QQmlDelegateModelItemMetaType(
-            QQmlEnginePrivate::getV8Engine(d->m_context->engine()), this, groupNames);
+                d->m_context->engine()->handle(), this, groupNames);
 
     d->m_compositor.setGroupCount(d->m_groupCount);
     d->m_compositor.setDefaultGroups(defaultGroups);
@@ -335,7 +328,7 @@ void QQmlDelegateModel::componentComplete()
         static_cast<QQmlPartsModel *>(d->m_pendingParts.first())->updateFilterGroup();
 
     QVector<Compositor::Insert> inserts;
-    d->m_count = d->m_adaptorModel.count();
+    d->m_count = d->adaptorModelCount();
     d->m_compositor.append(
             &d->m_adaptorModel,
             0,
@@ -357,9 +350,10 @@ void QQmlDelegateModel::componentComplete()
     {QAbstractItemModel} subclass or a simple list.
 
     Models can also be created directly in QML, using a \l{ListModel} or
-    \l{XmlListModel}.
+    \l{QtQuick.XmlListModel::XmlListModel}{XmlListModel}.
 
     \sa {qml-data-models}{Data Models}
+    \keyword dm-model-property
 */
 QVariant QQmlDelegateModel::model() const
 {
@@ -367,6 +361,54 @@ QVariant QQmlDelegateModel::model() const
     return d->m_adaptorModel.model();
 }
 
+void QQmlDelegateModelPrivate::connectToAbstractItemModel()
+{
+    Q_Q(QQmlDelegateModel);
+    if (!m_adaptorModel.adaptsAim())
+        return;
+
+    auto aim = m_adaptorModel.aim();
+
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(rowsInserted(QModelIndex,int,int)),
+                      q, QQmlDelegateModel, SLOT(_q_rowsInserted(QModelIndex,int,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(rowsRemoved(QModelIndex,int,int)),
+                      q,  QQmlDelegateModel, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
+                      q,  QQmlDelegateModel, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
+                      q, QQmlDelegateModel, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
+                      q, QQmlDelegateModel, SLOT(_q_rowsMoved(QModelIndex,int,int,QModelIndex,int)));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(modelReset()),
+                      q, QQmlDelegateModel, SLOT(_q_modelReset()));
+    qmlobject_connect(aim, QAbstractItemModel, SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
+                      q, QQmlDelegateModel, SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)));
+}
+
+void QQmlDelegateModelPrivate::disconnectFromAbstractItemModel()
+{
+    Q_Q(QQmlDelegateModel);
+    if (!m_adaptorModel.adaptsAim())
+        return;
+
+    auto aim = m_adaptorModel.aim();
+
+    QObject::disconnect(aim, SIGNAL(rowsInserted(QModelIndex,int,int)),
+                        q, SLOT(_q_rowsInserted(QModelIndex,int,int)));
+    QObject::disconnect(aim, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
+                        q, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
+    QObject::disconnect(aim, SIGNAL(rowsRemoved(QModelIndex,int,int)),
+                        q, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
+    QObject::disconnect(aim, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
+                        q, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
+    QObject::disconnect(aim, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
+                        q, SLOT(_q_rowsMoved(QModelIndex,int,int,QModelIndex,int)));
+    QObject::disconnect(aim, SIGNAL(modelReset()),
+                        q, SLOT(_q_modelReset()));
+    QObject::disconnect(aim, SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
+                        q, SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)));
+}
+
 void QQmlDelegateModel::setModel(const QVariant &model)
 {
     Q_D(QQmlDelegateModel);
@@ -374,7 +416,10 @@ void QQmlDelegateModel::setModel(const QVariant &model)
     if (d->m_complete)
         _q_itemsRemoved(0, d->m_count);
 
+    d->disconnectFromAbstractItemModel();
     d->m_adaptorModel.setModel(model, this, d->m_context->engine());
+    d->connectToAbstractItemModel();
+
     d->m_adaptorModel.replaceWatchedRoles(QList<QByteArray>(), d->m_watchedRoles);
     for (int i = 0; d->m_parts && i < d->m_parts->models.count(); ++i) {
         d->m_adaptorModel.replaceWatchedRoles(
@@ -382,7 +427,7 @@ void QQmlDelegateModel::setModel(const QVariant &model)
     }
 
     if (d->m_complete) {
-        _q_itemsInserted(0, d->m_adaptorModel.count());
+        _q_itemsInserted(0, d->adaptorModelCount());
         d->requestMoreIfNecessary();
     }
 }
@@ -407,22 +452,25 @@ void QQmlDelegateModel::setDelegate(QQmlComponent *delegate)
         qmlWarning(this) << tr("The delegate of a DelegateModel cannot be changed within onUpdated.");
         return;
     }
-    bool wasValid = d->m_delegate != 0;
-    d->m_delegate = delegate;
+    if (d->m_delegate == delegate)
+        return;
+    bool wasValid = d->m_delegate != nullptr;
+    d->m_delegate.setObject(delegate, this);
     d->m_delegateValidated = false;
-    if (wasValid && d->m_complete) {
-        for (int i = 1; i < d->m_groupCount; ++i) {
-            QQmlDelegateModelGroupPrivate::get(d->m_groups[i])->changeSet.remove(
-                    0, d->m_compositor.count(Compositor::Group(i)));
-        }
-    }
-    if (d->m_complete && d->m_delegate) {
-        for (int i = 1; i < d->m_groupCount; ++i) {
-            QQmlDelegateModelGroupPrivate::get(d->m_groups[i])->changeSet.insert(
-                    0, d->m_compositor.count(Compositor::Group(i)));
+    if (d->m_delegateChooser)
+        QObject::disconnect(d->m_delegateChooserChanged);
+
+    d->m_delegateChooser = nullptr;
+    if (delegate) {
+        QQmlAbstractDelegateComponent *adc =
+                qobject_cast<QQmlAbstractDelegateComponent *>(delegate);
+        if (adc) {
+            d->m_delegateChooser = adc;
+            d->m_delegateChooserChanged = connect(adc, &QQmlAbstractDelegateComponent::delegateChanged,
+                                               [d](){ d->delegateChanged(); });
         }
     }
-    d->emitChanges();
+    d->delegateChanged(d->m_delegate, wasValid);
 }
 
 /*!
@@ -441,16 +489,15 @@ void QQmlDelegateModel::setDelegate(QQmlComponent *delegate)
     the new directory's contents.
 
     \c main.cpp:
-    \snippet delegatemodel/visualdatamodel_rootindex/main.cpp 0
+    \snippet delegatemodel/delegatemodel_rootindex/main.cpp 0
 
     \c view.qml:
-    \snippet delegatemodel/visualdatamodel_rootindex/view.qml 0
-
-    If the \l model is a QAbstractItemModel subclass, the delegate can also
-    reference a \c hasModelChildren property (optionally qualified by a
-    \e model. prefix) that indicates whether the delegate's model item has
-    any child nodes.
+    \snippet delegatemodel/delegatemodel_rootindex/view.qml 0
 
+    If the \l {dm-model-property}{model} is a QAbstractItemModel subclass,
+    the delegate can also reference a \c hasModelChildren property (optionally
+    qualified by a \e model. prefix) that indicates whether the delegate's
+    model item has any child nodes.
 
     \sa modelIndex(), parentModelIndex()
 */
@@ -469,12 +516,16 @@ void QQmlDelegateModel::setRootIndex(const QVariant &root)
     if (changed || !d->m_adaptorModel.isValid()) {
         const int oldCount = d->m_count;
         d->m_adaptorModel.rootIndex = modelIndex;
-        if (!d->m_adaptorModel.isValid() && d->m_adaptorModel.aim())  // The previous root index was invalidated, so we need to reconnect the model.
+        if (!d->m_adaptorModel.isValid() && d->m_adaptorModel.aim()) {
+            // The previous root index was invalidated, so we need to reconnect the model.
+            d->disconnectFromAbstractItemModel();
             d->m_adaptorModel.setModel(d->m_adaptorModel.list.list(), this, d->m_context->engine());
+            d->connectToAbstractItemModel();
+        }
         if (d->m_adaptorModel.canFetchMore())
             d->m_adaptorModel.fetchMore();
         if (d->m_complete) {
-            const int newCount = d->m_adaptorModel.count();
+            const int newCount = d->adaptorModelCount();
             if (oldCount)
                 _q_itemsRemoved(0, oldCount);
             if (newCount)
@@ -535,25 +586,24 @@ int QQmlDelegateModel::count() const
 
 QQmlDelegateModel::ReleaseFlags QQmlDelegateModelPrivate::release(QObject *object)
 {
-    QQmlDelegateModel::ReleaseFlags stat = 0;
     if (!object)
-        return stat;
-
-    if (QQmlDelegateModelItem *cacheItem = QQmlDelegateModelItem::dataForObject(object)) {
-        if (cacheItem->releaseObject()) {
-            cacheItem->destroyObject();
-            emitDestroyingItem(object);
-            if (cacheItem->incubationTask) {
-                releaseIncubator(cacheItem->incubationTask);
-                cacheItem->incubationTask = 0;
-            }
-            cacheItem->Dispose();
-            stat |= QQmlInstanceModel::Destroyed;
-        } else {
-            stat |= QQmlDelegateModel::Referenced;
-        }
+        return QQmlDelegateModel::ReleaseFlags(0);
+
+    QQmlDelegateModelItem *cacheItem = QQmlDelegateModelItem::dataForObject(object);
+    if (!cacheItem)
+        return QQmlDelegateModel::ReleaseFlags(0);
+
+    if (!cacheItem->releaseObject())
+        return QQmlDelegateModel::Referenced;
+
+    cacheItem->destroyObject();
+    emitDestroyingItem(object);
+    if (cacheItem->incubationTask) {
+        releaseIncubator(cacheItem->incubationTask);
+        cacheItem->incubationTask = nullptr;
     }
-    return stat;
+    cacheItem->Dispose();
+    return QQmlInstanceModel::Destroyed;
 }
 
 /*
@@ -581,7 +631,7 @@ void QQmlDelegateModel::cancel(int index)
     if (cacheItem) {
         if (cacheItem->incubationTask && !cacheItem->isObjectReferenced()) {
             d->releaseIncubator(cacheItem->incubationTask);
-            cacheItem->incubationTask = 0;
+            cacheItem->incubationTask = nullptr;
 
             if (cacheItem->object) {
                 QObject *object = cacheItem->object;
@@ -630,7 +680,7 @@ QQmlDelegateModelGroup *QQmlDelegateModelPrivate::group_at(
     QQmlDelegateModelPrivate *d = static_cast<QQmlDelegateModelPrivate *>(property->data);
     return index >= 0 && index < d->m_groupCount - 1
             ? d->m_groups[index + 1]
-            : 0;
+            : nullptr;
 }
 
 /*!
@@ -648,7 +698,8 @@ QQmlDelegateModelGroup *QQmlDelegateModelPrivate::group_at(
 
     The following example illustrates using groups to select items in a model.
 
-    \snippet delegatemodel/visualdatagroup.qml 0
+    \snippet delegatemodel/delegatemodelgroup.qml 0
+    \keyword dm-groups-property
 */
 
 QQmlListProperty<QQmlDelegateModelGroup> QQmlDelegateModel::groups()
@@ -660,13 +711,13 @@ QQmlListProperty<QQmlDelegateModelGroup> QQmlDelegateModel::groups()
             QQmlDelegateModelPrivate::group_append,
             QQmlDelegateModelPrivate::group_count,
             QQmlDelegateModelPrivate::group_at,
-            0);
+            nullptr);
 }
 
 /*!
     \qmlproperty DelegateModelGroup QtQml.Models::DelegateModel::items
 
-    This property holds visual data model's default group to which all new items are added.
+    This property holds default group to which all new items are added.
 */
 
 QQmlDelegateModelGroup *QQmlDelegateModel::items()
@@ -678,7 +729,7 @@ QQmlDelegateModelGroup *QQmlDelegateModel::items()
 /*!
     \qmlproperty DelegateModelGroup QtQml.Models::DelegateModel::persistedItems
 
-    This property holds visual data model's persisted items group.
+    This property holds delegate model's persisted items group.
 
     Items in this group are not destroyed when released by a view, instead they are persisted
     until removed from the group.
@@ -701,9 +752,9 @@ QQmlDelegateModelGroup *QQmlDelegateModel::persistedItems()
 /*!
     \qmlproperty string QtQml.Models::DelegateModel::filterOnGroup
 
-    This property holds the name of the group used to filter the visual data model.
+    This property holds name of the group that is used to filter the delegate model.
 
-    Only items which belong to this group are visible to a view.
+    Only items that belong to this group are visible to a view.
 
     By default this is the \l items group.
 */
@@ -807,6 +858,12 @@ QObject *QQmlDelegateModel::parts()
     return d->m_parts;
 }
 
+const QAbstractItemModel *QQmlDelegateModel::abstractItemModel() const
+{
+    Q_D(const QQmlDelegateModel);
+    return d->m_adaptorModel.adaptsAim() ? d->m_adaptorModel.aim() : nullptr;
+}
+
 void QQmlDelegateModelPrivate::emitCreatedPackage(QQDMIncubationTask *incubationTask, QQuickPackage *package)
 {
     for (int i = 1; i < m_groupCount; ++i)
@@ -838,10 +895,11 @@ void QQDMIncubationTask::statusChanged(Status status)
         Q_ASSERT(incubating);
         // The model was deleted from under our feet, cleanup ourselves
         delete incubating->object;
-        incubating->object = 0;
+        incubating->object = nullptr;
         if (incubating->contextData) {
-            incubating->contextData->destroy();
-            incubating->contextData = 0;
+            incubating->contextData->invalidate();
+            Q_ASSERT(incubating->contextData->refCount == 1);
+            incubating->contextData = nullptr;
         }
         incubating->scriptRef = 0;
         incubating->deleteLater();
@@ -860,9 +918,16 @@ void QQmlDelegateModelPrivate::releaseIncubator(QQDMIncubationTask *incubationTa
     }
 }
 
+void QQmlDelegateModelPrivate::addCacheItem(QQmlDelegateModelItem *item, Compositor::iterator it)
+{
+    m_cache.insert(it.cacheIndex, item);
+    m_compositor.setFlags(it, 1, Compositor::CacheFlag);
+    Q_ASSERT(m_cache.count() == m_compositor.count(Compositor::Cache));
+}
+
 void QQmlDelegateModelPrivate::removeCacheItem(QQmlDelegateModelItem *cacheItem)
 {
-    int cidx = m_cache.indexOf(cacheItem);
+    int cidx = m_cache.lastIndexOf(cacheItem);
     if (cidx >= 0) {
         m_compositor.clearFlags(Compositor::Cache, cidx, 1, Compositor::CacheFlag);
         m_cache.removeAt(cidx);
@@ -872,13 +937,14 @@ void QQmlDelegateModelPrivate::removeCacheItem(QQmlDelegateModelItem *cacheItem)
 
 void QQmlDelegateModelPrivate::incubatorStatusChanged(QQDMIncubationTask *incubationTask, QQmlIncubator::Status status)
 {
-    Q_Q(QQmlDelegateModel);
     if (!isDoneIncubating(status))
         return;
 
+    const QList<QQmlError> incubationTaskErrors = incubationTask->errors();
+
     QQmlDelegateModelItem *cacheItem = incubationTask->incubating;
-    cacheItem->incubationTask = 0;
-    incubationTask->incubating = 0;
+    cacheItem->incubationTask = nullptr;
+    incubationTask->incubating = nullptr;
     releaseIncubator(incubationTask);
 
     if (status == QQmlIncubator::Ready) {
@@ -889,7 +955,7 @@ void QQmlDelegateModelPrivate::incubatorStatusChanged(QQDMIncubationTask *incuba
             emitCreatedItem(incubationTask, cacheItem->object);
         cacheItem->releaseObject();
     } else if (status == QQmlIncubator::Error) {
-        qmlWarning(q, m_delegate->errors()) << "Error creating delegate";
+        qmlInfo(m_delegate, incubationTaskErrors + m_delegate->errors()) << "Cannot create delegate";
     }
 
     if (!cacheItem->isObjectReferenced()) {
@@ -898,11 +964,13 @@ void QQmlDelegateModelPrivate::incubatorStatusChanged(QQDMIncubationTask *incuba
         else
             emitDestroyingItem(cacheItem->object);
         delete cacheItem->object;
-        cacheItem->object = 0;
+        cacheItem->object = nullptr;
         cacheItem->scriptRef -= 1;
-        if (cacheItem->contextData)
-            cacheItem->contextData->destroy();
-        cacheItem->contextData = 0;
+        if (cacheItem->contextData) {
+            cacheItem->contextData->invalidate();
+            Q_ASSERT(cacheItem->contextData->refCount == 1);
+        }
+        cacheItem->contextData = nullptr;
 
         if (!cacheItem->isReferenced()) {
             removeCacheItem(cacheItem);
@@ -927,13 +995,13 @@ void QQmlDelegateModelPrivate::setInitialState(QQDMIncubationTask *incubationTas
         emitInitItem(incubationTask, cacheItem->object);
 }
 
-QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, bool asynchronous)
+QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, QQmlIncubator::IncubationMode incubationMode)
 {
     if (!m_delegate || index < 0 || index >= m_compositor.count(group)) {
         qWarning() << "DelegateModel::item: index out range" << index << m_compositor.count(group);
-        return 0;
+        return nullptr;
     } else if (!m_context || !m_context->isValid()) {
-        return 0;
+        return nullptr;
     }
 
     Compositor::iterator it = m_compositor.find(group, index);
@@ -941,15 +1009,12 @@ QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, bo
     QQmlDelegateModelItem *cacheItem = it->inCache() ? m_cache.at(it.cacheIndex) : 0;
 
     if (!cacheItem) {
-        cacheItem = m_adaptorModel.createItem(m_cacheMetaType, m_context->engine(), it.modelIndex());
+        cacheItem = m_adaptorModel.createItem(m_cacheMetaType, it.modelIndex());
         if (!cacheItem)
-            return 0;
+            return nullptr;
 
         cacheItem->groups = it->flags;
-
-        m_cache.insert(it.cacheIndex, cacheItem);
-        m_compositor.setFlags(it, 1, Compositor::CacheFlag);
-        Q_ASSERT(m_cache.count() == m_compositor.count(Compositor::Cache));
+        addCacheItem(cacheItem, it);
     }
 
     // Bump the reference counts temporarily so neither the content data or the delegate object
@@ -958,16 +1023,28 @@ QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, bo
     cacheItem->referenceObject();
 
     if (cacheItem->incubationTask) {
-        if (!asynchronous && cacheItem->incubationTask->incubationMode() == QQmlIncubator::Asynchronous) {
+        bool sync = (incubationMode == QQmlIncubator::Synchronous || incubationMode == QQmlIncubator::AsynchronousIfNested);
+        if (sync && cacheItem->incubationTask->incubationMode() == QQmlIncubator::Asynchronous) {
             // previously requested async - now needed immediately
             cacheItem->incubationTask->forceCompletion();
         }
     } else if (!cacheItem->object) {
-        QQmlContext *creationContext = m_delegate->creationContext();
+        QQmlComponent *delegate = m_delegate;
+        if (m_delegateChooser) {
+            QQmlAbstractDelegateComponent *chooser = m_delegateChooser;
+            do {
+                delegate = chooser->delegate(&m_adaptorModel, index);
+                chooser = qobject_cast<QQmlAbstractDelegateComponent *>(delegate);
+            } while (chooser);
+            if (!delegate)
+                return nullptr;
+        }
+
+        QQmlContext *creationContext = delegate->creationContext();
 
         cacheItem->scriptRef += 1;
 
-        cacheItem->incubationTask = new QQDMIncubationTask(this, asynchronous ? QQmlIncubator::Asynchronous : QQmlIncubator::AsynchronousIfNested);
+        cacheItem->incubationTask = new QQDMIncubationTask(this, incubationMode);
         cacheItem->incubationTask->incubating = cacheItem;
         cacheItem->incubationTask->clear();
 
@@ -983,15 +1060,19 @@ QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, bo
             if (QQmlAdaptorModelProxyInterface *proxy
                     = qobject_cast<QQmlAdaptorModelProxyInterface *>(cacheItem)) {
                 ctxt = new QQmlContextData;
-                ctxt->setParent(cacheItem->contextData, true);
-                ctxt->contextObject = proxy->proxiedObject();
+                ctxt->setParent(cacheItem->contextData, /*stronglyReferencedByParent*/true);
+                QObject *proxied = proxy->proxiedObject();
+                ctxt->contextObject = proxied;
+                // We don't own the proxied object. We need to clear it if it goes away.
+                QObject::connect(proxied, &QObject::destroyed,
+                                 cacheItem, &QQmlDelegateModelItem::childContextObjectDestroyed);
             }
         }
 
-        QQmlComponentPrivate *cp = QQmlComponentPrivate::get(m_delegate);
+        QQmlComponentPrivate *cp = QQmlComponentPrivate::get(delegate);
         cp->incubateObject(
                     cacheItem->incubationTask,
-                    m_delegate,
+                    delegate,
                     m_context->engine(),
                     ctxt,
                     QQmlContextData::get(m_context));
@@ -1011,30 +1092,39 @@ QObject *QQmlDelegateModelPrivate::object(Compositor::Group group, int index, bo
         delete cacheItem;
     }
 
-    return 0;
+    return nullptr;
 }
 
 /*
   If asynchronous is true or the component is being loaded asynchronously due
-  to an ancestor being loaded asynchronously, item() may return 0.  In this
-  case createdItem() will be emitted when the item is available.  The item
-  at this stage does not have any references, so item() must be called again
-  to ensure a reference is held.  Any call to item() which returns a valid item
-  must be matched by a call to release() in order to destroy the item.
+  to an ancestor being loaded asynchronously, object() may return 0.  In this
+  case createdItem() will be emitted when the object is available.  The object
+  at this stage does not have any references, so object() must be called again
+  to ensure a reference is held.  Any call to object() which returns a valid object
+  must be matched by a call to release() in order to destroy the object.
 */
-QObject *QQmlDelegateModel::object(int index, bool asynchronous)
+QObject *QQmlDelegateModel::object(int index, QQmlIncubator::IncubationMode incubationMode)
 {
     Q_D(QQmlDelegateModel);
     if (!d->m_delegate || index < 0 || index >= d->m_compositor.count(d->m_compositorGroup)) {
         qWarning() << "DelegateModel::item: index out range" << index << d->m_compositor.count(d->m_compositorGroup);
-        return 0;
+        return nullptr;
     }
 
-    QObject *object = d->object(d->m_compositorGroup, index, asynchronous);
-    if (!object)
-        return 0;
+    return d->object(d->m_compositorGroup, index, incubationMode);
+}
+
+QQmlIncubator::Status QQmlDelegateModel::incubationStatus(int index)
+{
+    Q_D(QQmlDelegateModel);
+    Compositor::iterator it = d->m_compositor.find(d->m_compositorGroup, index);
+    if (!it->inCache())
+        return QQmlIncubator::Null;
+
+    if (auto incubationTask = d->m_cache.at(it.cacheIndex)->incubationTask)
+        return incubationTask->status();
 
-    return object;
+    return QQmlIncubator::Ready;
 }
 
 QString QQmlDelegateModelPrivate::stringValue(Compositor::Group group, int index, const QString &name)
@@ -1254,8 +1344,12 @@ void QQmlDelegateModel::_q_itemsInserted(int index, int count)
     const QList<QQmlDelegateModelItem *> cache = d->m_cache;
     for (int i = 0, c = cache.count();  i < c; ++i) {
         QQmlDelegateModelItem *item = cache.at(i);
-        if (item->modelIndex() >= index)
-            item->setModelIndex(item->modelIndex() + count);
+        if (item->modelIndex() >= index) {
+            const int newIndex = item->modelIndex() + count;
+            const int row = newIndex;
+            const int column = 0;
+            item->setModelIndex(newIndex, row, column);
+        }
     }
 
     QVector<Compositor::Insert> inserts;
@@ -1264,6 +1358,13 @@ void QQmlDelegateModel::_q_itemsInserted(int index, int count)
     d->emitChanges();
 }
 
+//### This method should be split in two. It will remove delegates, and it will re-render the list.
+// When e.g. QQmlListModel::remove is called, the removal of the delegates should be done on
+// QAbstractItemModel::rowsAboutToBeRemoved, and the re-rendering on
+// QAbstractItemModel::rowsRemoved. Currently both are done on the latter signal. The problem is
+// that the destruction of an item will emit a changed signal that ends up at the delegate, which
+// in turn will try to load the data from the model (which should have already freed it), resulting
+// in a use-after-free. See QTBUG-59256.
 void QQmlDelegateModelPrivate::itemsRemoved(
         const QVector<Compositor::Remove> &removes,
         QVarLengthArray<QVector<QQmlChangeSet::Change>, Compositor::MaximumGroupCount> *translatedRemoves,
@@ -1329,7 +1430,7 @@ void QQmlDelegateModelPrivate::itemsRemoved(
                     if (QQDMIncubationTask *incubationTask = cacheItem->incubationTask) {
                         if (!cacheItem->isObjectReferenced()) {
                             releaseIncubator(cacheItem->incubationTask);
-                            cacheItem->incubationTask = 0;
+                            cacheItem->incubationTask = nullptr;
                             if (cacheItem->object) {
                                 QObject *object = cacheItem->object;
                                 cacheItem->destroyObject();
@@ -1389,10 +1490,14 @@ void QQmlDelegateModel::_q_itemsRemoved(int index, int count)
         if (!d->m_cache.contains(item))
             continue;
 
-        if (item->modelIndex() >= index + count)
-            item->setModelIndex(item->modelIndex() - count);
-        else  if (item->modelIndex() >= index)
-            item->setModelIndex(-1);
+        if (item->modelIndex() >= index + count) {
+            const int newIndex = item->modelIndex() - count;
+            const int row = newIndex;
+            const int column = 0;
+            item->setModelIndex(newIndex, row, column);
+        } else if (item->modelIndex() >= index) {
+            item->setModelIndex(-1, -1, -1);
+        }
     }
 
     QVector<Compositor::Remove> removes;
@@ -1437,10 +1542,17 @@ void QQmlDelegateModel::_q_itemsMoved(int from, int to, int count)
     const QList<QQmlDelegateModelItem *> cache = d->m_cache;
     for (int i = 0, c = cache.count();  i < c; ++i) {
         QQmlDelegateModelItem *item = cache.at(i);
-        if (item->modelIndex() >= from && item->modelIndex() < from + count)
-            item->setModelIndex(item->modelIndex() - from + to);
-        else if (item->modelIndex() >= minimum && item->modelIndex() < maximum)
-            item->setModelIndex(item->modelIndex() + difference);
+        if (item->modelIndex() >= from && item->modelIndex() < from + count) {
+            const int newIndex = item->modelIndex() - from + to;
+            const int row = newIndex;
+            const int column = 0;
+            item->setModelIndex(newIndex, row, column);
+        } else if (item->modelIndex() >= minimum && item->modelIndex() < maximum) {
+            const int newIndex = item->modelIndex() + difference;
+            const int row = newIndex;
+            const int column = 0;
+            item->setModelIndex(newIndex, row, column);
+        }
     }
 
     QVector<Compositor::Remove> removes;
@@ -1458,13 +1570,39 @@ void QQmlDelegateModelPrivate::emitModelUpdated(const QQmlChangeSet &changeSet,
         emit q->countChanged();
 }
 
+void QQmlDelegateModelPrivate::delegateChanged(bool add, bool remove)
+{
+    Q_Q(QQmlDelegateModel);
+    if (!m_complete)
+        return;
+
+    if (m_transaction) {
+        qmlWarning(q) << QQmlDelegateModel::tr("The delegates of a DelegateModel cannot be changed within onUpdated.");
+        return;
+    }
+
+    if (remove) {
+        for (int i = 1; i < m_groupCount; ++i) {
+            QQmlDelegateModelGroupPrivate::get(m_groups[i])->changeSet.remove(
+                    0, m_compositor.count(Compositor::Group(i)));
+        }
+    }
+    if (add) {
+        for (int i = 1; i < m_groupCount; ++i) {
+            QQmlDelegateModelGroupPrivate::get(m_groups[i])->changeSet.insert(
+                    0, m_compositor.count(Compositor::Group(i)));
+        }
+    }
+    emitChanges();
+}
+
 void QQmlDelegateModelPrivate::emitChanges()
 {
     if (m_transaction || !m_complete || !m_context || !m_context->isValid())
         return;
 
     m_transaction = true;
-    QV8Engine *engine = QQmlEnginePrivate::getV8Engine(m_context->engine());
+    QV4::ExecutionEngine *engine = m_context->engine()->handle();
     for (int i = 1; i < m_groupCount; ++i)
         QQmlDelegateModelGroupPrivate::get(m_groups[i])->emitChanges(engine);
     m_transaction = false;
@@ -1491,13 +1629,13 @@ void QQmlDelegateModel::_q_modelReset()
     d->m_adaptorModel.rootIndex = QModelIndex();
 
     if (d->m_complete) {
-        d->m_count = d->m_adaptorModel.count();
+        d->m_count = d->adaptorModelCount();
 
         const QList<QQmlDelegateModelItem *> cache = d->m_cache;
         for (int i = 0, c = cache.count();  i < c; ++i) {
             QQmlDelegateModelItem *item = cache.at(i);
             if (item->modelIndex() != -1)
-                item->setModelIndex(-1);
+                item->setModelIndex(-1, -1, -1);
         }
 
         QVector<Compositor::Remove> removes;
@@ -1533,7 +1671,8 @@ void QQmlDelegateModel::_q_rowsAboutToBeRemoved(const QModelIndex &parent, int b
     if (index.parent() == parent && index.row() >= begin && index.row() <= end) {
         const int oldCount = d->m_count;
         d->m_count = 0;
-        d->m_adaptorModel.invalidateModel(this);
+        d->disconnectFromAbstractItemModel();
+        d->m_adaptorModel.invalidateModel();
 
         if (d->m_complete && oldCount > 0) {
             QVector<Compositor::Remove> removes;
@@ -1623,7 +1762,7 @@ bool QQmlDelegateModelPrivate::insert(Compositor::insert_iterator &before, const
     if (!m_context || !m_context->isValid())
         return false;
 
-    QQmlDelegateModelItem *cacheItem = m_adaptorModel.createItem(m_cacheMetaType, m_context->engine(), -1);
+    QQmlDelegateModelItem *cacheItem = m_adaptorModel.createItem(m_cacheMetaType, -1);
     if (!cacheItem)
         return false;
     if (!object.isObject())
@@ -1635,7 +1774,7 @@ bool QQmlDelegateModelPrivate::insert(Compositor::insert_iterator &before, const
     if (!o)
         return false;
 
-    QV4::ObjectIterator it(scope, o, QV4::ObjectIterator::EnumerableOnly|QV4::ObjectIterator::WithProtoChain);
+    QV4::ObjectIterator it(scope, o, QV4::ObjectIterator::EnumerableOnly);
     QV4::ScopedValue propertyName(scope);
     QV4::ScopedValue v(scope);
     while (1) {
@@ -1650,7 +1789,7 @@ bool QQmlDelegateModelPrivate::insert(Compositor::insert_iterator &before, const
     // Must be before the new object is inserted into the cache or its indexes will be adjusted too.
     itemsInserted(QVector<Compositor::Insert>(1, Compositor::Insert(before, 1, cacheItem->groups & ~Compositor::CacheFlag)));
 
-    before = m_compositor.insert(before, 0, 0, 1, cacheItem->groups);
+    before = m_compositor.insert(before, nullptr, 0, 1, cacheItem->groups);
     m_cache.insert(before.cacheIndex, cacheItem);
 
     return true;
@@ -1659,11 +1798,11 @@ bool QQmlDelegateModelPrivate::insert(Compositor::insert_iterator &before, const
 //============================================================================
 
 QQmlDelegateModelItemMetaType::QQmlDelegateModelItemMetaType(
-        QV8Engine *engine, QQmlDelegateModel *model, const QStringList &groupNames)
+        QV4::ExecutionEngine *engine, QQmlDelegateModel *model, const QStringList &groupNames)
     : model(model)
     , groupCount(groupNames.count() + 1)
-    , v8Engine(engine)
-    , metaObject(0)
+    , v4Engine(engine)
+    , metaObject(nullptr)
     , groupNames(groupNames)
 {
 }
@@ -1703,57 +1842,56 @@ void QQmlDelegateModelItemMetaType::initializeMetaObject()
 
 void QQmlDelegateModelItemMetaType::initializePrototype()
 {
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(v8Engine);
-    QV4::Scope scope(v4);
+    QV4::Scope scope(v4Engine);
 
-    QV4::ScopedObject proto(scope, v4->newObject());
-    proto->defineAccessorProperty(QStringLiteral("model"), QQmlDelegateModelItem::get_model, 0);
+    QV4::ScopedObject proto(scope, v4Engine->newObject());
+    proto->defineAccessorProperty(QStringLiteral("model"), QQmlDelegateModelItem::get_model, nullptr);
     proto->defineAccessorProperty(QStringLiteral("groups"), QQmlDelegateModelItem::get_groups, QQmlDelegateModelItem::set_groups);
     QV4::ScopedString s(scope);
     QV4::ScopedProperty p(scope);
 
-    s = v4->newString(QStringLiteral("isUnresolved"));
+    s = v4Engine->newString(QStringLiteral("isUnresolved"));
     QV4::ScopedFunctionObject f(scope);
     QV4::ExecutionContext *global = scope.engine->rootContext();
     p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, 30, QQmlDelegateModelItem::get_member)));
-    p->setSetter(0);
+    p->setSetter(nullptr);
     proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
 
-    s = v4->newString(QStringLiteral("inItems"));
+    s = v4Engine->newString(QStringLiteral("inItems"));
     p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, QQmlListCompositor::Default, QQmlDelegateModelItem::get_member)));
     p->setSetter((f = QV4::DelegateModelGroupFunction::create(global, QQmlListCompositor::Default, QQmlDelegateModelItem::set_member)));
     proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
 
-    s = v4->newString(QStringLiteral("inPersistedItems"));
+    s = v4Engine->newString(QStringLiteral("inPersistedItems"));
     p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, QQmlListCompositor::Persisted, QQmlDelegateModelItem::get_member)));
     p->setSetter((f = QV4::DelegateModelGroupFunction::create(global, QQmlListCompositor::Persisted, QQmlDelegateModelItem::set_member)));
     proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
 
-    s = v4->newString(QStringLiteral("itemsIndex"));
+    s = v4Engine->newString(QStringLiteral("itemsIndex"));
     p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, QQmlListCompositor::Default, QQmlDelegateModelItem::get_index)));
     proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
 
-    s = v4->newString(QStringLiteral("persistedItemsIndex"));
+    s = v4Engine->newString(QStringLiteral("persistedItemsIndex"));
     p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, QQmlListCompositor::Persisted, QQmlDelegateModelItem::get_index)));
-    p->setSetter(0);
+    p->setSetter(nullptr);
     proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
 
     for (int i = 2; i < groupNames.count(); ++i) {
         QString propertyName = QLatin1String("in") + groupNames.at(i);
         propertyName.replace(2, 1, propertyName.at(2).toUpper());
-        s = v4->newString(propertyName);
+        s = v4Engine->newString(propertyName);
         p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, i + 1, QQmlDelegateModelItem::get_member)));
         p->setSetter((f = QV4::DelegateModelGroupFunction::create(global, i + 1, QQmlDelegateModelItem::set_member)));
         proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
     }
     for (int i = 2; i < groupNames.count(); ++i) {
         const QString propertyName = groupNames.at(i) + QLatin1String("Index");
-        s = v4->newString(propertyName);
+        s = v4Engine->newString(propertyName);
         p->setGetter((f = QV4::DelegateModelGroupFunction::create(global, i + 1, QQmlDelegateModelItem::get_index)));
-        p->setSetter(0);
+        p->setSetter(nullptr);
         proto->insertMember(s, p, QV4::Attr_Accessor|QV4::Attr_NotConfigurable|QV4::Attr_NotEnumerable);
     }
-    modelItemProto.set(v4, proto);
+    modelItemProto.set(v4Engine, proto);
 }
 
 int QQmlDelegateModelItemMetaType::parseGroups(const QStringList &groups) const
@@ -1770,7 +1908,7 @@ int QQmlDelegateModelItemMetaType::parseGroups(const QStringList &groups) const
 int QQmlDelegateModelItemMetaType::parseGroups(const QV4::Value &groups) const
 {
     int groupFlags = 0;
-    QV4::Scope scope(QV8Engine::getV4(v8Engine));
+    QV4::Scope scope(v4Engine);
 
     QV4::ScopedString s(scope, groups);
     if (s) {
@@ -1786,7 +1924,7 @@ int QQmlDelegateModelItemMetaType::parseGroups(const QV4::Value &groups) const
         QV4::ScopedValue v(scope);
         uint arrayLength = array->getLength();
         for (uint i = 0; i < arrayLength; ++i) {
-            v = array->getIndexed(i);
+            v = array->get(i);
             const QString groupName = v->toQString();
             int index = groupNames.indexOf(groupName);
             if (index != -1)
@@ -1796,26 +1934,24 @@ int QQmlDelegateModelItemMetaType::parseGroups(const QV4::Value &groups) const
     return groupFlags;
 }
 
-void QQmlDelegateModelItem::get_model(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+QV4::ReturnedValue QQmlDelegateModelItem::get_model(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
-    if (!o) {
-        scope.result = scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object"));
-        return;
-    }
+    QV4::Scope scope(b);
+    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
+    if (!o)
+        return b->engine()->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
     if (!o->d()->item->metaType->model)
         RETURN_UNDEFINED();
 
-    scope.result = o->d()->item->get();
+    return o->d()->item->get();
 }
 
-void QQmlDelegateModelItem::get_groups(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+QV4::ReturnedValue QQmlDelegateModelItem::get_groups(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
-    if (!o) {
-        scope.result = scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object"));
-        return;
-    }
+    QV4::Scope scope(b);
+    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
+    if (!o)
+        return scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
 
     QStringList groups;
     for (int i = 1; i < o->d()->item->metaType->groupCount; ++i) {
@@ -1823,29 +1959,28 @@ void QQmlDelegateModelItem::get_groups(const QV4::BuiltinFunction *, QV4::Scope
             groups.append(o->d()->item->metaType->groupNames.at(i - 1));
     }
 
-    scope.result = scope.engine->fromVariant(groups);
+    return scope.engine->fromVariant(groups);
 }
 
-void QQmlDelegateModelItem::set_groups(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+QV4::ReturnedValue QQmlDelegateModelItem::set_groups(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
-    if (!o) {
-        scope.result = scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object"));
-        return;
-    }
+    QV4::Scope scope(b);
+    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
+    if (!o)
+        return scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
 
-    if (!callData->argc)
+    if (!argc)
         THROW_TYPE_ERROR();
 
     if (!o->d()->item->metaType->model)
         RETURN_UNDEFINED();
     QQmlDelegateModelPrivate *model = QQmlDelegateModelPrivate::get(o->d()->item->metaType->model);
 
-    const int groupFlags = model->m_cacheMetaType->parseGroups(callData->args[0]);
+    const int groupFlags = model->m_cacheMetaType->parseGroups(argv[0]);
     const int cacheIndex = model->m_cache.indexOf(o->d()->item);
     Compositor::iterator it = model->m_compositor.find(Compositor::Cache, cacheIndex);
     model->setGroups(it, 1, Compositor::Cache, groupFlags);
-    scope.result = QV4::Encode::undefined();
+    return QV4::Encode::undefined();
 }
 
 QV4::ReturnedValue QQmlDelegateModelItem::get_member(QQmlDelegateModelItem *thisItem, uint flag, const QV4::Value &)
@@ -1879,6 +2014,17 @@ QV4::ReturnedValue QQmlDelegateModelItem::get_index(QQmlDelegateModelItem *thisI
     return QV4::Encode((int)thisItem->groupIndex(Compositor::Group(flag)));
 }
 
+void QQmlDelegateModelItem::childContextObjectDestroyed(QObject *childContextObject)
+{
+    if (!contextData)
+        return;
+
+    for (QQmlContextData *ctxt = contextData->childContexts; ctxt; ctxt = ctxt->nextChild) {
+        if (ctxt->contextObject == childContextObject)
+            ctxt->contextObject = nullptr;
+    }
+}
+
 
 //---------------------------------------------------------------------------
 
@@ -1891,20 +2037,40 @@ void QV4::Heap::QQmlDelegateModelItemObject::destroy()
 }
 
 
-QQmlDelegateModelItem::QQmlDelegateModelItem(
-        QQmlDelegateModelItemMetaType *metaType, int modelIndex)
-    : v4(QV8Engine::getV4(metaType->v8Engine))
+QQmlDelegateModelItem::QQmlDelegateModelItem(QQmlDelegateModelItemMetaType *metaType,
+                                             QQmlAdaptorModel::Accessors *accessor,
+                                             int modelIndex, int row, int column)
+    : v4(metaType->v4Engine)
     , metaType(metaType)
-    , contextData(0)
-    , object(0)
-    , attached(0)
-    , incubationTask(0)
+    , contextData(nullptr)
+    , object(nullptr)
+    , attached(nullptr)
+    , incubationTask(nullptr)
+    , delegate(nullptr)
+    , poolTime(0)
     , objectRef(0)
     , scriptRef(0)
     , groups(0)
     , index(modelIndex)
+    , row(row)
+    , column(column)
 {
     metaType->addref();
+
+    if (accessor->propertyCache) {
+        // The property cache in the accessor is common for all the model
+        // items in the model it wraps. It describes available model roles,
+        // together with revisioned properties like row, column and index, all
+        // which should be available in the delegate. We assign this cache to the
+        // model item so that the QML engine can use the revision information
+        // when resolving the properties (rather than falling back to just
+        // inspecting the QObject in the model item directly).
+        QQmlData *qmldata = QQmlData::get(this, true);
+        if (qmldata->propertyCache)
+            qmldata->propertyCache->release();
+        qmldata->propertyCache = accessor->propertyCache.data();
+        qmldata->propertyCache->addref();
+    }
 }
 
 QQmlDelegateModelItem::~QQmlDelegateModelItem()
@@ -1937,6 +2103,24 @@ void QQmlDelegateModelItem::Dispose()
     delete this;
 }
 
+void QQmlDelegateModelItem::setModelIndex(int idx, int newRow, int newColumn)
+{
+    const int prevIndex = index;
+    const int prevRow = row;
+    const int prevColumn = column;
+
+    index = idx;
+    row = newRow;
+    column = newColumn;
+
+    if (idx != prevIndex)
+        emit modelIndexChanged();
+    if (row != prevRow)
+        emit rowChanged();
+    if (column != prevColumn)
+        emit columnChanged();
+}
+
 void QQmlDelegateModelItem::destroyObject()
 {
     Q_ASSERT(object);
@@ -1944,38 +2128,43 @@ void QQmlDelegateModelItem::destroyObject()
 
     QQmlData *data = QQmlData::get(object);
     Q_ASSERT(data);
-    if (data->ownContext && data->context)
-        data->context->clearContext();
+    if (data->ownContext) {
+        data->ownContext->clearContext();
+        if (data->ownContext->contextObject == object)
+            data->ownContext->contextObject = nullptr;
+        data->ownContext = nullptr;
+        data->context = nullptr;
+    }
     object->deleteLater();
 
     if (attached) {
-        attached->m_cacheItem = 0;
-        attached = 0;
+        attached->m_cacheItem = nullptr;
+        attached = nullptr;
     }
 
-    contextData->destroy();
-    contextData = 0;
-    object = 0;
+    contextData->invalidate();
+    contextData = nullptr;
+    object = nullptr;
 }
 
 QQmlDelegateModelItem *QQmlDelegateModelItem::dataForObject(QObject *object)
 {
     QQmlData *d = QQmlData::get(object);
-    QQmlContextData *context = d ? d->context : 0;
-    for (context = context ? context->parent : 0; context; context = context->parent) {
+    QQmlContextData *context = d ? d->context : nullptr;
+    for (context = context ? context->parent : nullptr; context; context = context->parent) {
         if (QQmlDelegateModelItem *cacheItem = qobject_cast<QQmlDelegateModelItem *>(
                 context->contextObject)) {
             return cacheItem;
         }
     }
-    return 0;
+    return nullptr;
 }
 
 int QQmlDelegateModelItem::groupIndex(Compositor::Group group)
 {
     if (QQmlDelegateModelPrivate * const model = metaType->model
             ? QQmlDelegateModelPrivate::get(metaType->model)
-            : 0) {
+            : nullptr) {
         return model->m_compositor.find(Compositor::Cache, model->m_cache.indexOf(this)).index[group];
     }
     return -1;
@@ -2048,7 +2237,7 @@ int QQmlDelegateModelAttachedMetaObject::metaCall(QObject *object, QMetaObject::
 }
 
 QQmlDelegateModelAttached::QQmlDelegateModelAttached(QObject *parent)
-    : m_cacheItem(0)
+    : m_cacheItem(nullptr)
     , m_previousGroups(0)
 {
     QQml_setParent_noEvent(this, parent);
@@ -2060,35 +2249,42 @@ QQmlDelegateModelAttached::QQmlDelegateModelAttached(
     , m_previousGroups(cacheItem->groups)
 {
     QQml_setParent_noEvent(this, parent);
+    resetCurrentIndex();
+    // Let m_previousIndex be equal to m_currentIndex
+    std::copy(std::begin(m_currentIndex), std::end(m_currentIndex), std::begin(m_previousIndex));
+
+    if (!cacheItem->metaType->metaObject)
+        cacheItem->metaType->initializeMetaObject();
+
+    QObjectPrivate::get(this)->metaObject = cacheItem->metaType->metaObject;
+    cacheItem->metaType->metaObject->addref();
+}
+
+void QQmlDelegateModelAttached::resetCurrentIndex()
+{
     if (QQDMIncubationTask *incubationTask = m_cacheItem->incubationTask) {
         for (int i = 1; i < qMin<int>(m_cacheItem->metaType->groupCount, Compositor::MaximumGroupCount); ++i)
-            m_currentIndex[i] = m_previousIndex[i] = incubationTask->index[i];
+            m_currentIndex[i] = incubationTask->index[i];
     } else {
         QQmlDelegateModelPrivate * const model = QQmlDelegateModelPrivate::get(m_cacheItem->metaType->model);
         Compositor::iterator it = model->m_compositor.find(
                 Compositor::Cache, model->m_cache.indexOf(m_cacheItem));
         for (int i = 1; i < m_cacheItem->metaType->groupCount; ++i)
-            m_currentIndex[i] = m_previousIndex[i] = it.index[i];
+            m_currentIndex[i] = it.index[i];
     }
-
-    if (!cacheItem->metaType->metaObject)
-        cacheItem->metaType->initializeMetaObject();
-
-    QObjectPrivate::get(this)->metaObject = cacheItem->metaType->metaObject;
-    cacheItem->metaType->metaObject->addref();
 }
 
 /*!
-    \qmlattachedproperty int QtQml.Models::DelegateModel::model
+    \qmlattachedproperty model QtQml.Models::DelegateModel::model
 
-    This attached property holds the visual data model this delegate instance belongs to.
+    This attached property holds the data model this delegate instance belongs to.
 
     It is attached to each instance of the delegate.
 */
 
 QQmlDelegateModel *QQmlDelegateModelAttached::model() const
 {
-    return m_cacheItem ? m_cacheItem->metaType->model : 0;
+    return m_cacheItem ? m_cacheItem->metaType->model : nullptr;
 }
 
 /*!
@@ -2128,7 +2324,7 @@ void QQmlDelegateModelAttached::setGroups(const QStringList &groups)
 /*!
     \qmlattachedproperty bool QtQml.Models::DelegateModel::isUnresolved
 
-    This attached property holds whether the visual item is bound to a data model index.
+    This attached property indicates whether the visual item is bound to a data model index.
     Returns true if the item is not bound to the model, and false if it is.
 
     An unresolved item can be bound to the data model using the DelegateModelGroup::resolve()
@@ -2200,11 +2396,11 @@ void QQmlDelegateModelAttached::emitChanges()
     const QMetaObject *meta = metaObject();
     for (int i = 1; i < m_cacheItem->metaType->groupCount; ++i, ++notifierId) {
         if (groupChanges & (1 << i))
-            QMetaObject::activate(this, meta, notifierId, 0);
+            QMetaObject::activate(this, meta, notifierId, nullptr);
     }
     for (int i = 1; i < m_cacheItem->metaType->groupCount; ++i, ++notifierId) {
         if (indexChanges & (1 << i))
-            QMetaObject::activate(this, meta, notifierId, 0);
+            QMetaObject::activate(this, meta, notifierId, nullptr);
     }
 
     if (groupChanges)
@@ -2226,13 +2422,13 @@ bool QQmlDelegateModelGroupPrivate::isChangedConnected()
     IS_SIGNAL_CONNECTED(q, QQmlDelegateModelGroup, changed, (const QQmlV4Handle &,const QQmlV4Handle &));
 }
 
-void QQmlDelegateModelGroupPrivate::emitChanges(QV8Engine *engine)
+void QQmlDelegateModelGroupPrivate::emitChanges(QV4::ExecutionEngine *v4)
 {
     Q_Q(QQmlDelegateModelGroup);
     if (isChangedConnected() && !changeSet.isEmpty()) {
-        QV4::Scope scope(QV8Engine::getV4(engine));
-        QV4::ScopedValue removed(scope, engineData(scope.engine)->array(engine, changeSet.removes()));
-        QV4::ScopedValue inserted(scope, engineData(scope.engine)->array(engine, changeSet.inserts()));
+        QV4::Scope scope(v4);
+        QV4::ScopedValue removed(scope, engineData(scope.engine)->array(v4, changeSet.removes()));
+        QV4::ScopedValue inserted(scope, engineData(scope.engine)->array(v4, changeSet.inserts()));
         emit q->changed(QQmlV4Handle(removed), QQmlV4Handle(inserted));
     }
     if (changeSet.difference() != 0)
@@ -2267,27 +2463,11 @@ void QQmlDelegateModelGroupPrivate::destroyingPackage(QQuickPackage *package)
 }
 
 /*!
-    \qmltype VisualDataGroup
-    \instantiates QQmlDelegateModelGroup
-    \inqmlmodule QtQuick
-    \ingroup qtquick-models
-    \brief Encapsulates a filtered set of visual data items
-
-    The VisualDataGroup type provides a means to address the model data of a
-    model's delegate items, as well as sort and filter these delegate items.
-
-    This type is provided by the \l{Qt QML} module due to compatibility reasons.
-    The same implementation is now primarily available as \l DelegateModelGroup
-    in the \l{Qt QML Models QML Types}{Qt QML Models} module.
-
-    \sa {QtQml.Models::DelegateModelGroup}
-*/
-/*!
     \qmltype DelegateModelGroup
     \instantiates QQmlDelegateModelGroup
     \inqmlmodule QtQml.Models
     \ingroup qtquick-models
-    \brief Encapsulates a filtered set of visual data items
+    \brief Encapsulates a filtered set of visual data items.
 
     The DelegateModelGroup type provides a means to address the model data of a
     DelegateModel's delegate items, as well as sort and filter these delegate
@@ -2303,7 +2483,8 @@ void QQmlDelegateModelGroupPrivate::destroyingPackage(QQuickPackage *package)
     information about group membership and indexes as well as model data.  In combination
     with the move() function this can be used to implement view sorting, with remove() to filter
     items out of a view, or with setGroups() and \l Package delegates to categorize items into
-    different views.
+    different views. Different groups can only be sorted independently if they are disjunct. Moving
+    an item in one group will also move it in all other groups it is a part of.
 
     Data from models can be supplemented by inserting data directly into a DelegateModelGroup
     with the insert() function.  This can be used to introduce mock items into a view, or
@@ -2315,9 +2496,6 @@ void QQmlDelegateModelGroupPrivate::destroyingPackage(QQuickPackage *package)
     type or to cherry-pick specific items that should be instantiated irregardless of whether
     they're currently within a view's visible area.
 
-    \note This type is also available as \l VisualDataGroup in the \l{Qt QML}
-    module due to compatibility reasons.
-
     \sa {QML Dynamic View Ordering Tutorial}
 */
 QQmlDelegateModelGroup::QQmlDelegateModelGroup(QObject *parent)
@@ -2450,7 +2628,7 @@ QQmlV4Handle QQmlDelegateModelGroup::get(int index)
 
     if (!cacheItem) {
         cacheItem = model->m_adaptorModel.createItem(
-                model->m_cacheMetaType, model->m_context->engine(), it.modelIndex());
+                model->m_cacheMetaType, it.modelIndex());
         if (!cacheItem)
             return QQmlV4Handle(QV4::Encode::undefined());
         cacheItem->groups = it->flags;
@@ -2461,12 +2639,11 @@ QQmlV4Handle QQmlDelegateModelGroup::get(int index)
 
     if (model->m_cacheMetaType->modelItemProto.isUndefined())
         model->m_cacheMetaType->initializePrototype();
-    QV8Engine *v8 = model->m_cacheMetaType->v8Engine;
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(v8);
+    QV4::ExecutionEngine *v4 = model->m_cacheMetaType->v4Engine;
     QV4::Scope scope(v4);
-    QV4::ScopedObject o(scope, v4->memoryManager->allocObject<QQmlDelegateModelItemObject>(cacheItem));
+    QV4::ScopedObject o(scope, v4->memoryManager->allocate<QQmlDelegateModelItemObject>(cacheItem));
     QV4::ScopedObject p(scope, model->m_cacheMetaType->modelItemProto.value());
-    o->setPrototype(p);
+    o->setPrototypeOf(p);
     ++cacheItem->scriptRef;
 
     return QQmlV4Handle(o);
@@ -2490,7 +2667,7 @@ bool QQmlDelegateModelGroupPrivate::parseIndex(const QV4::Value &value, int *ind
         QQmlDelegateModelItem * const cacheItem = object->d()->item;
         if (QQmlDelegateModelPrivate *model = cacheItem->metaType->model
                 ? QQmlDelegateModelPrivate::get(cacheItem->metaType->model)
-                : 0) {
+                : nullptr) {
             *index = model->m_cache.indexOf(cacheItem);
             *group = Compositor::Cache;
             return true;
@@ -2621,7 +2798,7 @@ void QQmlDelegateModelGroup::create(QQmlV4Function *args)
         return;
     }
 
-    QObject *object = model->object(group, index, false);
+    QObject *object = model->object(group, index, QQmlIncubator::AsynchronousIfNested);
     if (object) {
         QVector<Compositor::Insert> inserts;
         Compositor::iterator it = model->m_compositor.find(group, index);
@@ -2919,6 +3096,11 @@ void QQmlDelegateModelGroup::setGroups(QQmlV4Function *args)
     \qmlmethod QtQml.Models::DelegateModelGroup::move(var from, var to, int count)
 
     Moves \a count at \a from in a group \a to a new position.
+
+    \note The DelegateModel acts as a proxy model: it holds the delegates in a
+    different order than the \l{dm-model-property}{underlying model} has them.
+    Any subsequent changes to the underlying model will not undo whatever
+    reordering you have done via this function.
 */
 
 void QQmlDelegateModelGroup::move(QQmlV4Function *args)
@@ -3109,21 +3291,21 @@ bool QQmlPartsModel::isValid() const
     return m_model->isValid();
 }
 
-QObject *QQmlPartsModel::object(int index, bool asynchronous)
+QObject *QQmlPartsModel::object(int index, QQmlIncubator::IncubationMode incubationMode)
 {
     QQmlDelegateModelPrivate *model = QQmlDelegateModelPrivate::get(m_model);
 
     if (!model->m_delegate || index < 0 || index >= model->m_compositor.count(m_compositorGroup)) {
         qWarning() << "DelegateModel::item: index out range" << index << model->m_compositor.count(m_compositorGroup);
-        return 0;
+        return nullptr;
     }
 
-    QObject *object = model->object(m_compositorGroup, index, asynchronous);
+    QObject *object = model->object(m_compositorGroup, index, incubationMode);
 
     if (QQuickPackage *package = qmlobject_cast<QQuickPackage *>(object)) {
         QObject *part = package->part(m_part);
         if (!part)
-            return 0;
+            return nullptr;
         m_packaged.insertMulti(part, package);
         return part;
     }
@@ -3135,12 +3317,12 @@ QObject *QQmlPartsModel::object(int index, bool asynchronous)
         model->m_delegateValidated = true;
     }
 
-    return 0;
+    return nullptr;
 }
 
 QQmlInstanceModel::ReleaseFlags QQmlPartsModel::release(QObject *item)
 {
-    QQmlInstanceModel::ReleaseFlags flags = 0;
+    QQmlInstanceModel::ReleaseFlags flags = nullptr;
 
     QHash<QObject *, QQuickPackage *>::iterator it = m_packaged.find(item);
     if (it != m_packaged.end()) {
@@ -3168,6 +3350,19 @@ void QQmlPartsModel::setWatchedRoles(const QList<QByteArray> &roles)
     m_watchedRoles = roles;
 }
 
+QQmlIncubator::Status QQmlPartsModel::incubationStatus(int index)
+{
+    QQmlDelegateModelPrivate *model = QQmlDelegateModelPrivate::get(m_model);
+    Compositor::iterator it = model->m_compositor.find(model->m_compositorGroup, index);
+    if (!it->inCache())
+        return QQmlIncubator::Null;
+
+    if (auto incubationTask = model->m_cache.at(it.cacheIndex)->incubationTask)
+        return incubationTask->status();
+
+    return QQmlIncubator::Ready;
+}
+
 int QQmlPartsModel::indexOf(QObject *item, QObject *) const
 {
     QHash<QObject *, QQuickPackage *>::const_iterator it = m_packaged.find(item);
@@ -3185,7 +3380,10 @@ void QQmlPartsModel::createdPackage(int index, QQuickPackage *package)
 
 void QQmlPartsModel::initPackage(int index, QQuickPackage *package)
 {
-    emit initItem(index, package->part(m_part));
+    if (m_modelUpdatePending)
+        m_pendingPackageInitializations << index;
+    else
+        emit initItem(index, package->part(m_part));
 }
 
 void QQmlPartsModel::destroyingPackage(QQuickPackage *package)
@@ -3197,9 +3395,22 @@ void QQmlPartsModel::destroyingPackage(QQuickPackage *package)
 
 void QQmlPartsModel::emitModelUpdated(const QQmlChangeSet &changeSet, bool reset)
 {
+    m_modelUpdatePending = false;
     emit modelUpdated(changeSet, reset);
     if (changeSet.difference() != 0)
         emit countChanged();
+
+    QQmlDelegateModelPrivate *model = QQmlDelegateModelPrivate::get(m_model);
+    QVector<int> pendingPackageInitializations;
+    qSwap(pendingPackageInitializations, m_pendingPackageInitializations);
+    for (int index : pendingPackageInitializations) {
+        if (!model->m_delegate || index < 0 || index >= model->m_compositor.count(m_compositorGroup))
+            continue;
+        QObject *object = model->object(m_compositorGroup, index, QQmlIncubator::Asynchronous);
+        if (QQuickPackage *package = qmlobject_cast<QQuickPackage *>(object))
+            emit initItem(index, package->part(m_part));
+        model->release(object);
+    }
 }
 
 //============================================================================
@@ -3209,28 +3420,31 @@ struct QQmlDelegateModelGroupChange : QV4::Object
     V4_OBJECT2(QQmlDelegateModelGroupChange, QV4::Object)
 
     static QV4::Heap::QQmlDelegateModelGroupChange *create(QV4::ExecutionEngine *e) {
-        return e->memoryManager->allocObject<QQmlDelegateModelGroupChange>();
+        return e->memoryManager->allocate<QQmlDelegateModelGroupChange>();
     }
 
-    static void method_get_index(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData) {
-        QV4::Scoped<QQmlDelegateModelGroupChange> that(scope, callData->thisObject.as<QQmlDelegateModelGroupChange>());
+    static QV4::ReturnedValue method_get_index(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int) {
+        QV4::Scope scope(b);
+        QV4::Scoped<QQmlDelegateModelGroupChange> that(scope, thisObject->as<QQmlDelegateModelGroupChange>());
         if (!that)
             THROW_TYPE_ERROR();
-        scope.result = QV4::Encode(that->d()->change.index);
+        return QV4::Encode(that->d()->change.index);
     }
-    static void method_get_count(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData) {
-        QV4::Scoped<QQmlDelegateModelGroupChange> that(scope, callData->thisObject.as<QQmlDelegateModelGroupChange>());
+    static QV4::ReturnedValue method_get_count(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int) {
+        QV4::Scope scope(b);
+        QV4::Scoped<QQmlDelegateModelGroupChange> that(scope, thisObject->as<QQmlDelegateModelGroupChange>());
         if (!that)
             THROW_TYPE_ERROR();
-        scope.result = QV4::Encode(that->d()->change.count);
+        return QV4::Encode(that->d()->change.count);
     }
-    static void method_get_moveId(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData) {
-        QV4::Scoped<QQmlDelegateModelGroupChange> that(scope, callData->thisObject.as<QQmlDelegateModelGroupChange>());
+    static QV4::ReturnedValue method_get_moveId(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int) {
+        QV4::Scope scope(b);
+        QV4::Scoped<QQmlDelegateModelGroupChange> that(scope, thisObject->as<QQmlDelegateModelGroupChange>());
         if (!that)
             THROW_TYPE_ERROR();
         if (that->d()->change.moveId < 0)
             RETURN_UNDEFINED();
-        scope.result = QV4::Encode(that->d()->change.moveId);
+        return QV4::Encode(that->d()->change.moveId);
     }
 };
 
@@ -3243,49 +3457,49 @@ struct QQmlDelegateModelGroupChangeArray : public QV4::Object
 public:
     static QV4::Heap::QQmlDelegateModelGroupChangeArray *create(QV4::ExecutionEngine *engine, const QVector<QQmlChangeSet::Change> &changes)
     {
-        return engine->memoryManager->allocObject<QQmlDelegateModelGroupChangeArray>(changes);
+        return engine->memoryManager->allocate<QQmlDelegateModelGroupChangeArray>(changes);
     }
 
     quint32 count() const { return d()->changes->count(); }
     const QQmlChangeSet::Change &at(int index) const { return d()->changes->at(index); }
 
-    static QV4::ReturnedValue getIndexed(const QV4::Managed *m, uint index, bool *hasProperty)
+    static QV4::ReturnedValue virtualGet(const QV4::Managed *m, QV4::PropertyKey id, const QV4::Value *receiver, bool *hasProperty)
     {
-        Q_ASSERT(m->as<QQmlDelegateModelGroupChangeArray>());
-        QV4::ExecutionEngine *v4 = static_cast<const QQmlDelegateModelGroupChangeArray *>(m)->engine();
-        QV4::Scope scope(v4);
-        QV4::Scoped<QQmlDelegateModelGroupChangeArray> array(scope, static_cast<const QQmlDelegateModelGroupChangeArray *>(m));
-
-        if (index >= array->count()) {
-            if (hasProperty)
-                *hasProperty = false;
-            return QV4::Primitive::undefinedValue().asReturnedValue();
-        }
+        if (id.isArrayIndex()) {
+            uint index = id.asArrayIndex();
+            Q_ASSERT(m->as<QQmlDelegateModelGroupChangeArray>());
+            QV4::ExecutionEngine *v4 = static_cast<const QQmlDelegateModelGroupChangeArray *>(m)->engine();
+            QV4::Scope scope(v4);
+            QV4::Scoped<QQmlDelegateModelGroupChangeArray> array(scope, static_cast<const QQmlDelegateModelGroupChangeArray *>(m));
+
+            if (index >= array->count()) {
+                if (hasProperty)
+                    *hasProperty = false;
+                return QV4::Value::undefinedValue().asReturnedValue();
+            }
 
-        const QQmlChangeSet::Change &change = array->at(index);
+            const QQmlChangeSet::Change &change = array->at(index);
 
-        QV4::ScopedObject changeProto(scope, engineData(v4)->changeProto.value());
-        QV4::Scoped<QQmlDelegateModelGroupChange> object(scope, QQmlDelegateModelGroupChange::create(v4));
-        object->setPrototype(changeProto);
-        object->d()->change = change;
+            QV4::ScopedObject changeProto(scope, engineData(v4)->changeProto.value());
+            QV4::Scoped<QQmlDelegateModelGroupChange> object(scope, QQmlDelegateModelGroupChange::create(v4));
+            object->setPrototypeOf(changeProto);
+            object->d()->change = change;
 
-        if (hasProperty)
-            *hasProperty = true;
-        return object.asReturnedValue();
-    }
+            if (hasProperty)
+                *hasProperty = true;
+            return object.asReturnedValue();
+        }
 
-    static QV4::ReturnedValue get(const QV4::Managed *m, QV4::String *name, bool *hasProperty)
-    {
         Q_ASSERT(m->as<QQmlDelegateModelGroupChangeArray>());
         const QQmlDelegateModelGroupChangeArray *array = static_cast<const QQmlDelegateModelGroupChangeArray *>(m);
 
-        if (name->equals(array->engine()->id_length())) {
+        if (id == array->engine()->id_length()->propertyKey()) {
             if (hasProperty)
                 *hasProperty = true;
             return QV4::Encode(array->count());
         }
 
-        return Object::get(m, name, hasProperty);
+        return Object::virtualGet(m, id, receiver, hasProperty);
     }
 };
 
@@ -3305,9 +3519,9 @@ QQmlDelegateModelEngineData::QQmlDelegateModelEngineData(QV4::ExecutionEngine *v
     QV4::Scope scope(v4);
 
     QV4::ScopedObject proto(scope, v4->newObject());
-    proto->defineAccessorProperty(QStringLiteral("index"), QQmlDelegateModelGroupChange::method_get_index, 0);
-    proto->defineAccessorProperty(QStringLiteral("count"), QQmlDelegateModelGroupChange::method_get_count, 0);
-    proto->defineAccessorProperty(QStringLiteral("moveId"), QQmlDelegateModelGroupChange::method_get_moveId, 0);
+    proto->defineAccessorProperty(QStringLiteral("index"), QQmlDelegateModelGroupChange::method_get_index, nullptr);
+    proto->defineAccessorProperty(QStringLiteral("count"), QQmlDelegateModelGroupChange::method_get_count, nullptr);
+    proto->defineAccessorProperty(QStringLiteral("moveId"), QQmlDelegateModelGroupChange::method_get_moveId, nullptr);
     changeProto.set(v4, proto);
 }
 
@@ -3315,9 +3529,9 @@ QQmlDelegateModelEngineData::~QQmlDelegateModelEngineData()
 {
 }
 
-QV4::ReturnedValue QQmlDelegateModelEngineData::array(QV8Engine *engine, const QVector<QQmlChangeSet::Change> &changes)
+QV4::ReturnedValue QQmlDelegateModelEngineData::array(QV4::ExecutionEngine *v4,
+                                                      const QVector<QQmlChangeSet::Change> &changes)
 {
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
     QV4::Scope scope(v4);
     QV4::ScopedObject o(scope, QQmlDelegateModelGroupChangeArray::create(v4, changes));
     return o.asReturnedValue();
diff --git a/src/qml/types/qqmldelegatemodel_p.h b/src/qml/types/qqmldelegatemodel_p.h
index 186144d107..0ad8939732 100644
--- a/src/qml/types/qqmldelegatemodel_p.h
+++ b/src/qml/types/qqmldelegatemodel_p.h
@@ -54,6 +54,7 @@
 #include <private/qtqmlglobal_p.h>
 #include <private/qqmllistcompositor_p.h>
 #include <private/qqmlobjectmodel_p.h>
+#include <private/qqmlincubator_p.h>
 
 #include <QtCore/qabstractitemmodel.h>
 #include <QtCore/qstringlist.h>
@@ -61,10 +62,11 @@
 #include <private/qv8engine_p.h>
 #include <private/qqmlglobal_p.h>
 
+QT_REQUIRE_CONFIG(qml_delegate_model);
+
 QT_BEGIN_NAMESPACE
 
 class QQmlChangeSet;
-class QQmlComponent;
 class QQuickPackage;
 class QQmlV4Function;
 class QQmlDelegateModelGroup;
@@ -89,7 +91,7 @@ class Q_QML_PRIVATE_EXPORT QQmlDelegateModel : public QQmlInstanceModel, public
     Q_INTERFACES(QQmlParserStatus)
 public:
     QQmlDelegateModel();
-    QQmlDelegateModel(QQmlContext *, QObject *parent=0);
+    QQmlDelegateModel(QQmlContext *, QObject *parent=nullptr);
     ~QQmlDelegateModel();
 
     void classBegin() override;
@@ -108,12 +110,13 @@ public:
     Q_INVOKABLE QVariant parentModelIndex() const;
 
     int count() const override;
-    bool isValid() const override { return delegate() != 0; }
-    QObject *object(int index, bool asynchronous = false) override;
+    bool isValid() const override { return delegate() != nullptr; }
+    QObject *object(int index, QQmlIncubator::IncubationMode incubationMode = QQmlIncubator::AsynchronousIfNested) override;
     ReleaseFlags release(QObject *object) override;
     void cancel(int index) override;
     QString stringValue(int index, const QString &role) override;
     void setWatchedRoles(const QList<QByteArray> &roles) override;
+    QQmlIncubator::Status incubationStatus(int index) override;
 
     int indexOf(QObject *object, QObject *objectContext) const override;
 
@@ -126,6 +129,8 @@ public:
     QQmlListProperty<QQmlDelegateModelGroup> groups();
     QObject *parts();
 
+    const QAbstractItemModel *abstractItemModel() const override;
+
     bool event(QEvent *) override;
 
     static QQmlDelegateModelAttached *qmlAttachedProperties(QObject *obj);
@@ -162,8 +167,8 @@ class Q_QML_PRIVATE_EXPORT QQmlDelegateModelGroup : public QObject
     Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
     Q_PROPERTY(bool includeByDefault READ defaultInclude WRITE setDefaultInclude NOTIFY defaultIncludeChanged)
 public:
-    QQmlDelegateModelGroup(QObject *parent = 0);
-    QQmlDelegateModelGroup(const QString &name, QQmlDelegateModel *model, int compositorType, QObject *parent = 0);
+    QQmlDelegateModelGroup(QObject *parent = nullptr);
+    QQmlDelegateModelGroup(const QString &name, QQmlDelegateModel *model, int compositorType, QObject *parent = nullptr);
     ~QQmlDelegateModelGroup();
 
     QString name() const;
@@ -208,6 +213,7 @@ public:
     QQmlDelegateModelAttached(QQmlDelegateModelItem *cacheItem, QObject *parent);
     ~QQmlDelegateModelAttached() {}
 
+    void resetCurrentIndex();
     void setCacheItem(QQmlDelegateModelItem *item);
 
     QQmlDelegateModel *model() const;
diff --git a/src/qml/types/qqmldelegatemodel_p_p.h b/src/qml/types/qqmldelegatemodel_p_p.h
index 4ebfd9b938..0028849828 100644
--- a/src/qml/types/qqmldelegatemodel_p_p.h
+++ b/src/qml/types/qqmldelegatemodel_p_p.h
@@ -60,16 +60,19 @@
 // We mean it.
 //
 
+QT_REQUIRE_CONFIG(qml_delegate_model);
+
 QT_BEGIN_NAMESPACE
 
 typedef QQmlListCompositor Compositor;
 
 class QQmlDelegateModelAttachedMetaObject;
+class QQmlAbstractDelegateComponent;
 
-class QQmlDelegateModelItemMetaType : public QQmlRefCount
+class Q_QML_PRIVATE_EXPORT QQmlDelegateModelItemMetaType : public QQmlRefCount
 {
 public:
-    QQmlDelegateModelItemMetaType(QV8Engine *engine, QQmlDelegateModel *model, const QStringList &groupNames);
+    QQmlDelegateModelItemMetaType(QV4::ExecutionEngine *engine, QQmlDelegateModel *model, const QStringList &groupNames);
     ~QQmlDelegateModelItemMetaType();
 
     void initializeMetaObject();
@@ -80,7 +83,7 @@ public:
 
     QPointer<QQmlDelegateModel> model;
     const int groupCount;
-    QV8Engine * const v8Engine;
+    QV4::ExecutionEngine * const v4Engine;
     QQmlDelegateModelAttachedMetaObject *metaObject;
     const QStringList groupNames;
     QV4::PersistentValue modelItemProto;
@@ -93,14 +96,19 @@ class QQmlDelegateModelItem : public QObject
 {
     Q_OBJECT
     Q_PROPERTY(int index READ modelIndex NOTIFY modelIndexChanged)
+    Q_PROPERTY(int row READ modelRow NOTIFY rowChanged REVISION 12)
+    Q_PROPERTY(int column READ modelColumn NOTIFY columnChanged REVISION 12)
     Q_PROPERTY(QObject *model READ modelObject CONSTANT)
 public:
-    QQmlDelegateModelItem(QQmlDelegateModelItemMetaType *metaType, int modelIndex);
+    QQmlDelegateModelItem(QQmlDelegateModelItemMetaType *metaType,
+                          QQmlAdaptorModel::Accessors *accessor, int modelIndex,
+                          int row, int column);
     ~QQmlDelegateModelItem();
 
     void referenceObject() { ++objectRef; }
     bool releaseObject() { return --objectRef == 0 && !(groups & Compositor::PersistedFlag); }
     bool isObjectReferenced() const { return objectRef != 0 || (groups & Compositor::PersistedFlag); }
+    void childContextObjectDestroyed(QObject *childContextObject);
 
     bool isReferenced() const {
         return scriptRef
@@ -118,27 +126,31 @@ public:
 
     int groupIndex(Compositor::Group group);
 
+    int modelRow() const { return row; }
+    int modelColumn() const { return column; }
     int modelIndex() const { return index; }
-    void setModelIndex(int idx) { index = idx; Q_EMIT modelIndexChanged(); }
+    virtual void setModelIndex(int idx, int newRow, int newColumn);
 
     virtual QV4::ReturnedValue get() { return QV4::QObjectWrapper::wrap(v4, this); }
 
     virtual void setValue(const QString &role, const QVariant &value) { Q_UNUSED(role); Q_UNUSED(value); }
     virtual bool resolveIndex(const QQmlAdaptorModel &, int) { return false; }
 
-    static void get_model(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void get_groups(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
-    static void set_groups(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue get_model(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue get_groups(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue set_groups(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
     static QV4::ReturnedValue get_member(QQmlDelegateModelItem *thisItem, uint flag, const QV4::Value &);
     static QV4::ReturnedValue set_member(QQmlDelegateModelItem *thisItem, uint flag, const QV4::Value &arg);
     static QV4::ReturnedValue get_index(QQmlDelegateModelItem *thisItem, uint flag, const QV4::Value &arg);
 
     QV4::ExecutionEngine *v4;
     QQmlDelegateModelItemMetaType * const metaType;
-    QQmlContextData *contextData;
+    QQmlContextDataRef contextData;
     QPointer<QObject> object;
     QPointer<QQmlDelegateModelAttached> attached;
     QQDMIncubationTask *incubationTask;
+    QQmlComponent *delegate;
+    int poolTime;
     int objectRef;
     int scriptRef;
     int groups;
@@ -146,9 +158,13 @@ public:
 
 Q_SIGNALS:
     void modelIndexChanged();
+    Q_REVISION(12) void rowChanged();
+    Q_REVISION(12) void columnChanged();
 
 protected:
     void objectDestroyed(QObject *);
+    int row;
+    int column;
 };
 
 namespace QV4 {
@@ -182,14 +198,14 @@ class QQDMIncubationTask : public QQmlIncubator
 public:
     QQDMIncubationTask(QQmlDelegateModelPrivate *l, IncubationMode mode)
         : QQmlIncubator(mode)
-        , incubating(0)
+        , incubating(nullptr)
         , vdm(l) {}
 
     void statusChanged(Status) override;
     void setInitialState(QObject *) override;
 
-    QQmlDelegateModelItem *incubating;
-    QQmlDelegateModelPrivate *vdm;
+    QQmlDelegateModelItem *incubating = nullptr;
+    QQmlDelegateModelPrivate *vdm = nullptr;
     int index[QQmlListCompositor::MaximumGroupCount];
 };
 
@@ -220,7 +236,7 @@ public:
 
     void setModel(QQmlDelegateModel *model, Compositor::Group group);
     bool isChangedConnected();
-    void emitChanges(QV8Engine *engine);
+    void emitChanges(QV4::ExecutionEngine *engine);
     void emitModelUpdated(bool reset);
 
     void createdPackage(int index, QQuickPackage *package);
@@ -254,9 +270,11 @@ public:
 
     void init();
     void connectModel(QQmlAdaptorModel *model);
+    void connectToAbstractItemModel();
+    void disconnectFromAbstractItemModel();
 
     void requestMoreIfNecessary();
-    QObject *object(Compositor::Group group, int index, bool asynchronous);
+    QObject *object(Compositor::Group group, int index, QQmlIncubator::IncubationMode incubationMode);
     QQmlDelegateModel::ReleaseFlags release(QObject *object);
     QString stringValue(Compositor::Group group, int index, const QString &name);
     void emitCreatedPackage(QQDMIncubationTask *incubationTask, QQuickPackage *package);
@@ -267,6 +285,7 @@ public:
         Q_EMIT q_func()->initItem(incubationTask->index[m_compositorGroup], item); }
     void emitDestroyingPackage(QQuickPackage *package);
     void emitDestroyingItem(QObject *item) { Q_EMIT q_func()->destroyingItem(item); }
+    void addCacheItem(QQmlDelegateModelItem *item, Compositor::iterator it);
     void removeCacheItem(QQmlDelegateModelItem *cacheItem);
 
     void updateFilterGroup();
@@ -278,21 +297,24 @@ public:
     void itemsInserted(
             const QVector<Compositor::Insert> &inserts,
             QVarLengthArray<QVector<QQmlChangeSet::Change>, Compositor::MaximumGroupCount> *translatedInserts,
-            QHash<int, QList<QQmlDelegateModelItem *> > *movedItems = 0);
+            QHash<int, QList<QQmlDelegateModelItem *> > *movedItems = nullptr);
     void itemsInserted(const QVector<Compositor::Insert> &inserts);
     void itemsRemoved(
             const QVector<Compositor::Remove> &removes,
             QVarLengthArray<QVector<QQmlChangeSet::Change>, Compositor::MaximumGroupCount> *translatedRemoves,
-            QHash<int, QList<QQmlDelegateModelItem *> > *movedItems = 0);
+            QHash<int, QList<QQmlDelegateModelItem *> > *movedItems = nullptr);
     void itemsRemoved(const QVector<Compositor::Remove> &removes);
     void itemsMoved(
             const QVector<Compositor::Remove> &removes, const QVector<Compositor::Insert> &inserts);
     void itemsChanged(const QVector<Compositor::Change> &changes);
     void emitChanges();
     void emitModelUpdated(const QQmlChangeSet &changeSet, bool reset) override;
+    void delegateChanged(bool add = true, bool remove = true);
 
     bool insert(Compositor::insert_iterator &before, const QV4::Value &object, int groups);
 
+    int adaptorModelCount() const;
+
     static void group_append(QQmlListProperty<QQmlDelegateModelGroup> *property, QQmlDelegateModelGroup *group);
     static int group_count(QQmlListProperty<QQmlDelegateModelGroup> *property);
     static QQmlDelegateModelGroup *group_at(QQmlListProperty<QQmlDelegateModelGroup> *property, int index);
@@ -303,7 +325,9 @@ public:
 
     QQmlAdaptorModel m_adaptorModel;
     QQmlListCompositor m_compositor;
-    QQmlComponent *m_delegate;
+    QQmlStrongJSQObjectReference<QQmlComponent> m_delegate;
+    QQmlAbstractDelegateComponent *m_delegateChooser;
+    QMetaObject::Connection m_delegateChooserChanged;
     QQmlDelegateModelItemMetaType *m_cacheMetaType;
     QPointer<QQmlContext> m_context;
     QQmlDelegateModelParts *m_parts;
@@ -341,7 +365,7 @@ class QQmlPartsModel : public QQmlInstanceModel, public QQmlDelegateModelGroupEm
     Q_OBJECT
     Q_PROPERTY(QString filterOnGroup READ filterGroup WRITE setFilterGroup NOTIFY filterGroupChanged RESET resetFilterGroup)
 public:
-    QQmlPartsModel(QQmlDelegateModel *model, const QString &part, QObject *parent = 0);
+    QQmlPartsModel(QQmlDelegateModel *model, const QString &part, QObject *parent = nullptr);
     ~QQmlPartsModel();
 
     QString filterGroup() const;
@@ -352,11 +376,12 @@ public:
 
     int count() const override;
     bool isValid() const override;
-    QObject *object(int index, bool asynchronous = false) override;
+    QObject *object(int index, QQmlIncubator::IncubationMode incubationMode = QQmlIncubator::AsynchronousIfNested) override;
     ReleaseFlags release(QObject *item) override;
     QString stringValue(int index, const QString &role) override;
     QList<QByteArray> watchedRoles() const { return m_watchedRoles; }
     void setWatchedRoles(const QList<QByteArray> &roles) override;
+    QQmlIncubator::Status incubationStatus(int index) override;
 
     int indexOf(QObject *item, QObject *objectContext) const override;
 
@@ -375,8 +400,10 @@ private:
     QString m_part;
     QString m_filterGroup;
     QList<QByteArray> m_watchedRoles;
+    QVector<int> m_pendingPackageInitializations; // vector holds model indices
     Compositor::Group m_compositorGroup;
     bool m_inheritGroup;
+    bool m_modelUpdatePending = true;
 };
 
 class QMetaPropertyBuilder;
diff --git a/src/qml/types/qqmlinstantiator.cpp b/src/qml/types/qqmlinstantiator.cpp
index 2de5875deb..a23ec0f2b4 100644
--- a/src/qml/types/qqmlinstantiator.cpp
+++ b/src/qml/types/qqmlinstantiator.cpp
@@ -44,7 +44,9 @@
 #include <QtQml/QQmlInfo>
 #include <QtQml/QQmlError>
 #include <QtQml/private/qqmlobjectmodel_p.h>
+#if QT_CONFIG(qml_delegate_model)
 #include <QtQml/private/qqmldelegatemodel_p.h>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -53,11 +55,13 @@ QQmlInstantiatorPrivate::QQmlInstantiatorPrivate()
     , effectiveReset(false)
     , active(true)
     , async(false)
+#if QT_CONFIG(qml_delegate_model)
     , ownModel(false)
+#endif
     , requestedIndex(-1)
     , model(QVariant(1))
-    , instanceModel(0)
-    , delegate(0)
+    , instanceModel(nullptr)
+    , delegate(nullptr)
 {
 }
 
@@ -85,7 +89,7 @@ void QQmlInstantiatorPrivate::clear()
 QObject *QQmlInstantiatorPrivate::modelObject(int index, bool async)
 {
     requestedIndex = index;
-    QObject *o = instanceModel->object(index, async);
+    QObject *o = instanceModel->object(index, async ? QQmlIncubator::Asynchronous : QQmlIncubator::AsynchronousIfNested);
     requestedIndex = -1;
     return o;
 }
@@ -123,7 +127,7 @@ void QQmlInstantiatorPrivate::_q_createdItem(int idx, QObject* item)
     if (objects.contains(item)) //Case when it was created synchronously in regenerate
         return;
     if (requestedIndex != idx) // Asynchronous creation, reference the object
-        (void)instanceModel->object(idx, false);
+        (void)instanceModel->object(idx);
     item->setParent(q);
     if (objects.size() < idx + 1) {
         int modelCount = instanceModel->count();
@@ -183,7 +187,7 @@ void QQmlInstantiatorPrivate::_q_modelUpdated(const QQmlChangeSet &changeSet, bo
             objects = objects.mid(0, index) + movedObjects + objects.mid(index);
         } else {
             if (insert.index <= objects.size())
-                objects.insert(insert.index, insert.count, 0);
+                objects.insert(insert.index, insert.count, nullptr);
             for (int i = 0; i < insert.count; ++i) {
                 int modelIndex = index + i;
                 QObject* obj = modelObject(modelIndex, async);
@@ -198,6 +202,7 @@ void QQmlInstantiatorPrivate::_q_modelUpdated(const QQmlChangeSet &changeSet, bo
         q->countChanged();
 }
 
+#if QT_CONFIG(qml_delegate_model)
 void QQmlInstantiatorPrivate::makeModel()
 {
     Q_Q(QQmlInstantiator);
@@ -209,13 +214,14 @@ void QQmlInstantiatorPrivate::makeModel()
     if (componentComplete)
         delegateModel->componentComplete();
 }
+#endif
 
 
 /*!
     \qmltype Instantiator
     \instantiates QQmlInstantiator
     \inqmlmodule QtQml
-    \brief Dynamically creates objects
+    \brief Dynamically creates objects.
 
     A Instantiator can be used to control the dynamic creation of objects, or to dynamically
     create multiple objects from a template.
@@ -349,6 +355,7 @@ void QQmlInstantiator::setDelegate(QQmlComponent* c)
     d->delegate = c;
     emit delegateChanged();
 
+#if QT_CONFIG(qml_delegate_model)
     if (!d->ownModel)
         return;
 
@@ -356,6 +363,7 @@ void QQmlInstantiator::setDelegate(QQmlComponent* c)
         dModel->setDelegate(c);
     if (d->componentComplete)
         d->regenerate();
+#endif
 }
 
 /*!
@@ -396,14 +404,17 @@ void QQmlInstantiator::setModel(const QVariant &v)
 
     QQmlInstanceModel *prevModel = d->instanceModel;
     QObject *object = qvariant_cast<QObject*>(v);
-    QQmlInstanceModel *vim = 0;
+    QQmlInstanceModel *vim = nullptr;
     if (object && (vim = qobject_cast<QQmlInstanceModel *>(object))) {
+#if QT_CONFIG(qml_delegate_model)
         if (d->ownModel) {
             delete d->instanceModel;
-            prevModel = 0;
+            prevModel = nullptr;
             d->ownModel = false;
         }
+#endif
         d->instanceModel = vim;
+#if QT_CONFIG(qml_delegate_model)
     } else if (v != QVariant(0)){
         if (!d->ownModel)
             d->makeModel();
@@ -413,6 +424,7 @@ void QQmlInstantiator::setModel(const QVariant &v)
             dataModel->setModel(v);
             d->effectiveReset = false;
         }
+#endif
     }
 
     if (d->instanceModel != prevModel) {
@@ -423,10 +435,12 @@ void QQmlInstantiator::setModel(const QVariant &v)
             //disconnect(prevModel, SIGNAL(initItem(int,QObject*)), this, SLOT(initItem(int,QObject*)));
         }
 
-        connect(d->instanceModel, SIGNAL(modelUpdated(QQmlChangeSet,bool)),
-                this, SLOT(_q_modelUpdated(QQmlChangeSet,bool)));
-        connect(d->instanceModel, SIGNAL(createdItem(int,QObject*)), this, SLOT(_q_createdItem(int,QObject*)));
-        //connect(d->instanceModel, SIGNAL(initItem(int,QObject*)), this, SLOT(initItem(int,QObject*)));
+        if (d->instanceModel) {
+            connect(d->instanceModel, SIGNAL(modelUpdated(QQmlChangeSet,bool)),
+                    this, SLOT(_q_modelUpdated(QQmlChangeSet,bool)));
+            connect(d->instanceModel, SIGNAL(createdItem(int,QObject*)), this, SLOT(_q_createdItem(int,QObject*)));
+            //connect(d->instanceModel, SIGNAL(initItem(int,QObject*)), this, SLOT(initItem(int,QObject*)));
+        }
     }
 
     d->regenerate();
@@ -444,7 +458,7 @@ QObject *QQmlInstantiator::object() const
     Q_D(const QQmlInstantiator);
     if (d->objects.count())
         return d->objects[0];
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -457,7 +471,7 @@ QObject *QQmlInstantiator::objectAt(int index) const
     Q_D(const QQmlInstantiator);
     if (index >= 0 && index < d->objects.count())
         return d->objects[index];
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -476,10 +490,13 @@ void QQmlInstantiator::componentComplete()
 {
     Q_D(QQmlInstantiator);
     d->componentComplete = true;
+#if QT_CONFIG(qml_delegate_model)
     if (d->ownModel) {
         static_cast<QQmlDelegateModel*>(d->instanceModel)->componentComplete();
         d->regenerate();
-    } else {
+    } else
+#endif
+    {
         QVariant realModel = d->model;
         d->model = QVariant(0);
         setModel(realModel); //If realModel == d->model this won't do anything, but that's fine since the model's 0
diff --git a/src/qml/types/qqmlinstantiator_p.h b/src/qml/types/qqmlinstantiator_p.h
index ee18daa48c..ca371adc23 100644
--- a/src/qml/types/qqmlinstantiator_p.h
+++ b/src/qml/types/qqmlinstantiator_p.h
@@ -53,11 +53,12 @@
 
 #include <QtQml/qqmlcomponent.h>
 #include <QtQml/qqmlparserstatus.h>
+#include <QtQml/private/qtqmlglobal_p.h>
 
 QT_BEGIN_NAMESPACE
 
 class QQmlInstantiatorPrivate;
-class Q_AUTOTEST_EXPORT QQmlInstantiator : public QObject, public QQmlParserStatus
+class Q_QML_PRIVATE_EXPORT QQmlInstantiator : public QObject, public QQmlParserStatus
 {
     Q_OBJECT
     Q_INTERFACES(QQmlParserStatus)
@@ -71,7 +72,7 @@ class Q_AUTOTEST_EXPORT QQmlInstantiator : public QObject, public QQmlParserStat
     Q_CLASSINFO("DefaultProperty", "delegate")
 
 public:
-    QQmlInstantiator(QObject *parent = 0);
+    QQmlInstantiator(QObject *parent = nullptr);
     ~QQmlInstantiator();
 
     bool isActive() const;
diff --git a/src/qml/types/qqmlinstantiator_p_p.h b/src/qml/types/qqmlinstantiator_p_p.h
index 9edaecf7a8..4c76d5c689 100644
--- a/src/qml/types/qqmlinstantiator_p_p.h
+++ b/src/qml/types/qqmlinstantiator_p_p.h
@@ -59,7 +59,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QQmlInstantiatorPrivate : public QObjectPrivate
+class Q_QML_PRIVATE_EXPORT QQmlInstantiatorPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QQmlInstantiator)
 
@@ -69,16 +69,23 @@ public:
 
     void clear();
     void regenerate();
+#if QT_CONFIG(qml_delegate_model)
     void makeModel();
+#endif
     void _q_createdItem(int, QObject *);
     void _q_modelUpdated(const QQmlChangeSet &, bool);
     QObject *modelObject(int index, bool async);
 
+    static QQmlInstantiatorPrivate *get(QQmlInstantiator *instantiator) { return instantiator->d_func(); }
+    static const QQmlInstantiatorPrivate *get(const QQmlInstantiator *instantiator) { return instantiator->d_func(); }
+
     bool componentComplete:1;
     bool effectiveReset:1;
     bool active:1;
     bool async:1;
+#if QT_CONFIG(qml_delegate_model)
     bool ownModel:1;
+#endif
     int requestedIndex;
     QVariant model;
     QQmlInstanceModel *instanceModel;
diff --git a/src/qml/types/qqmlitemmodels.qdoc b/src/qml/types/qqmlitemmodels.qdoc
index 6733330209..f6e1b0b1b9 100644
--- a/src/qml/types/qqmlitemmodels.qdoc
+++ b/src/qml/types/qqmlitemmodels.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
diff --git a/src/qml/types/qqmlitemselectionmodel.qdoc b/src/qml/types/qqmlitemselectionmodel.qdoc
index c223ef614e..43da4f7a55 100644
--- a/src/qml/types/qqmlitemselectionmodel.qdoc
+++ b/src/qml/types/qqmlitemselectionmodel.qdoc
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
@@ -11,8 +11,8 @@
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Free Documentation License Usage
 ** Alternatively, this file may be used under the terms of the GNU Free
@@ -20,7 +20,7 @@
 ** Foundation and appearing in the file included in the packaging of
 ** this file. Please review the following information to ensure
 ** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -35,9 +35,6 @@
     \brief Instantiates a QItemSelectionModel to be used in conjunction
     with a QAbstractItemModel and any view supporting it.
 
-    This page only enumerates the properties, methods, and signals available in QML.
-    See \l QItemSelectionModel for the actual documentation of this class.
-
     \sa QItemSelectionModel, {Models and Views in Qt Quick}
 */
 
@@ -55,7 +52,7 @@
     It will trigger property binding updates every time \l selectionChanged()
     is emitted, even though its value hasn't changed.
 
-    \sa selection(), selectedIndexes, select(), selectionChanged()
+    \sa selection, selectedIndexes, select(), selectionChanged()
 */
 
 /*!
@@ -76,68 +73,167 @@
 
 /*!
     \qmlmethod bool ItemSelectionModel::isSelected(QModelIndex index)
+
+    Returns \c true if the given model item \a index is selected.
 */
 
 /*!
     \qmlmethod bool ItemSelectionModel::isRowSelected(int row, QModelIndex parent)
+
+    Returns \c true if all items are selected in the \a row with the given
+    \a parent.
+
+    Note that this function is usually faster than calling isSelected()
+    on all items in the same row, and that unselectable items are ignored.
 */
 
 /*!
     \qmlmethod bool ItemSelectionModel::isColumnSelected(int column, QModelIndex parent)
+
+    Returns \c true if all items are selected in the \a column with the given
+    \a parent.
+
+    Note that this function is usually faster than calling isSelected()
+    on all items in the same column, and that unselectable items are ignored.
 */
 
 /*!
     \qmlmethod bool ItemSelectionModel::rowIntersectsSelection(int row, QModelIndex parent)
+
+    Returns \c true if there are any items selected in the \a row with the
+    given \a parent.
 */
 
 /*!
     \qmlmethod bool ItemSelectionModel::columnIntersectsSelection(int column, QModelIndex parent)
+
+    Returns \c true if there are any items selected in the \a column with the
+    given \a parent.
 */
 
 /*!
     \qmlmethod QModelIndexList ItemSelectionModel::selectedRows(int column)
+
+    Returns the indexes in the given \a column for the rows where all columns
+    are selected.
+
+    \sa selectedColumns()
 */
 
 /*!
     \qmlmethod QModelIndexList ItemSelectionModel::selectedColumns(int row)
+
+    Returns the indexes in the given \a row for columns where all rows are
+    selected.
+
+    \sa selectedRows()
 */
 
 /*!
-    \qmlmethod QItemSelection ItemSelectionModel::selection()
+    \qmlproperty object ItemSelectionModel::selection
+    \readonly
+
+    Holds the selection ranges stored in the selection model.
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::setCurrentIndex(QModelIndex index, SelectionFlags command)
+
+    Sets the model item \a index to be the current item, and emits
+    currentChanged(). The current item is used for keyboard navigation and
+    focus indication; it is independent of any selected items, although a
+    selected item can also be the current item.
+
+    Depending on the specified \a command, the \a index can also become part
+    of the current selection.
+
+    Valid \a command values are described in \l {itemselectionmodelselectindex}
+    {select(\e index, \e command)}.
+
+    \sa select()
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::select(QModelIndex index, SelectionFlags command)
+    \keyword itemselectionmodelselectindex
+
+    Selects the model item \a index using the specified \a command, and emits
+    selectionChanged().
+
+    Valid values for the \a command parameter, are:
+
+    \value NoUpdate       No selection will be made.
+    \value Clear          The complete selection will be cleared.
+    \value Select         All specified indexes will be selected.
+    \value Deselect       All specified indexes will be deselected.
+    \value Toggle         All specified indexes will be selected or
+                          deselected depending on their current state.
+    \value Current        The current selection will be updated.
+    \value Rows           All indexes will be expanded to span rows.
+    \value Columns        All indexes will be expanded to span columns.
+    \value SelectCurrent  A combination of Select and Current, provided for
+                          convenience.
+    \value ToggleCurrent  A combination of Toggle and Current, provided for
+                          convenience.
+    \value ClearAndSelect A combination of Clear and Select, provided for
+                          convenience.
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::select(QItemSelection selection, SelectionFlags command)
+
+    Selects the item \a selection using the specified \a command, and emits
+    selectionChanged().
+
+    Valid \a command values are described in \l {itemselectionmodelselectindex}
+    {select(\e index, \e command)}.
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::clear()
+
+    Clears the selection model. Emits selectionChanged() and currentChanged().
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::reset()
+
+    Clears the selection model. Does not emit any signals.
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::clearSelection()
+
+    Clears the selection in the selection model. Emits selectionChanged().
 */
 
 /*!
     \qmlmethod void ItemSelectionModel::clearCurrentIndex()
+
+    Clears the current index. Emits currentChanged().
 */
 
 /*!
     \qmlsignal ItemSelectionModel::selectionChanged(QItemSelection selected, QItemSelection deselected)
+
+    This signal is emitted whenever the selection changes. The change in the
+    selection is represented as an item selection of \a deselected items and
+    an item selection of \a selected items.
+
+    Note the that the current index changes independently from the selection.
+    Also note that this signal will not be emitted when the item model is reset.
+
+    \sa select(), currentChanged()
 */
 
 /*!
     \qmlsignal ItemSelectionModel::currentChanged(QModelIndex current, QModelIndex previous)
+
+    This signal is emitted whenever the current item changes. The \a previous
+    model item index is replaced by the \a current index as the selection's
+    current item.
+
+    Note that this signal will not be emitted when the item model is reset.
+
+    \sa currentIndex, setCurrentIndex(), selectionChanged()
 */
diff --git a/src/qml/types/qqmllistmodel.cpp b/src/qml/types/qqmllistmodel.cpp
index 517411fa47..27171b9bd4 100644
--- a/src/qml/types/qqmllistmodel.cpp
+++ b/src/qml/types/qqmllistmodel.cpp
@@ -42,6 +42,7 @@
 #include <private/qqmlopenmetaobject_p.h>
 #include <private/qqmljsast_p.h>
 #include <private/qqmljsengine_p.h>
+#include <private/qjsvalue_p.h>
 
 #include <private/qqmlcustomparser_p.h>
 #include <private/qqmlengine_p.h>
@@ -61,6 +62,8 @@
 #include <QtCore/qdatetime.h>
 #include <QScopedValueRollback>
 
+Q_DECLARE_METATYPE(const QV4::CompiledData::Binding*);
+
 QT_BEGIN_NAMESPACE
 
 // Set to 1024 as a debugging aid - easier to distinguish uids from indices of elements/models.
@@ -84,7 +87,7 @@ static QString roleTypeName(ListLayout::Role::DataType t)
     static const QString roleTypeNames[] = {
         QStringLiteral("String"), QStringLiteral("Number"), QStringLiteral("Bool"),
         QStringLiteral("List"), QStringLiteral("QObject"), QStringLiteral("VariantMap"),
-        QStringLiteral("DateTime")
+        QStringLiteral("DateTime"), QStringLiteral("Function")
     };
 
     if (t > ListLayout::Role::Invalid && t < ListLayout::Role::MaxDataType)
@@ -99,7 +102,7 @@ const ListLayout::Role &ListLayout::getRoleOrCreate(const QString &key, Role::Da
     if (node) {
         const Role &r = *node->value;
         if (type != r.type)
-            qmlWarning(0) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(r.name).arg(roleTypeName(type)).arg(roleTypeName(r.type));
+            qmlWarning(nullptr) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(r.name).arg(roleTypeName(type)).arg(roleTypeName(r.type));
         return r;
     }
 
@@ -112,7 +115,7 @@ const ListLayout::Role &ListLayout::getRoleOrCreate(QV4::String *key, Role::Data
     if (node) {
         const Role &r = *node->value;
         if (type != r.type)
-            qmlWarning(0) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(r.name).arg(roleTypeName(type)).arg(roleTypeName(r.type));
+            qmlWarning(nullptr) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(r.name).arg(roleTypeName(type)).arg(roleTypeName(r.type));
         return r;
     }
 
@@ -123,8 +126,8 @@ const ListLayout::Role &ListLayout::getRoleOrCreate(QV4::String *key, Role::Data
 
 const ListLayout::Role &ListLayout::createRole(const QString &key, ListLayout::Role::DataType type)
 {
-    const int dataSizes[] = { sizeof(QString), sizeof(double), sizeof(bool), sizeof(ListModel *), sizeof(QPointer<QObject>), sizeof(QVariantMap), sizeof(QDateTime) };
-    const int dataAlignments[] = { sizeof(QString), sizeof(double), sizeof(bool), sizeof(ListModel *), sizeof(QObject *), sizeof(QVariantMap), sizeof(QDateTime) };
+    const int dataSizes[] = { sizeof(StringOrTranslation), sizeof(double), sizeof(bool), sizeof(ListModel *), sizeof(QPointer<QObject>), sizeof(QVariantMap), sizeof(QDateTime), sizeof(QJSValue) };
+    const int dataAlignments[] = { sizeof(StringOrTranslation), sizeof(double), sizeof(bool), sizeof(ListModel *), sizeof(QObject *), sizeof(QVariantMap), sizeof(QDateTime), sizeof(QJSValue) };
 
     Role *r = new Role;
     r->name = key;
@@ -133,7 +136,7 @@ const ListLayout::Role &ListLayout::createRole(const QString &key, ListLayout::R
     if (type == Role::List) {
         r->subLayout = new ListLayout;
     } else {
-        r->subLayout = 0;
+        r->subLayout = nullptr;
     }
 
     int dataSize = dataSizes[type];
@@ -202,7 +205,7 @@ ListLayout::Role::Role(const Role *other)
     if (other->subLayout)
         subLayout = new ListLayout(other->subLayout);
     else
-        subLayout = 0;
+        subLayout = nullptr;
 }
 
 ListLayout::Role::~Role()
@@ -217,17 +220,30 @@ const ListLayout::Role *ListLayout::getRoleOrCreate(const QString &key, const QV
     switch (data.type()) {
         case QVariant::Double:      type = Role::Number;      break;
         case QVariant::Int:         type = Role::Number;      break;
-        case QVariant::UserType:    type = Role::List;        break;
         case QVariant::Bool:        type = Role::Bool;        break;
         case QVariant::String:      type = Role::String;      break;
         case QVariant::Map:         type = Role::VariantMap;  break;
         case QVariant::DateTime:    type = Role::DateTime;    break;
+        case QVariant::UserType:    {
+            if (data.userType() == qMetaTypeId<QJSValue>() &&
+                data.value<QJSValue>().isCallable()) {
+                type = Role::Function;
+                break;
+            } else if (data.userType() == qMetaTypeId<const QV4::CompiledData::Binding*>()
+                       && data.value<const QV4::CompiledData::Binding*>()->isTranslationBinding()) {
+                type = Role::String;
+                break;
+            } else {
+                type = Role::List;
+                break;
+            }
+        }
         default:                    type = Role::Invalid;     break;
     }
 
     if (type == Role::Invalid) {
-        qmlWarning(0) << "Can't create role for unsupported data type";
-        return 0;
+        qmlWarning(nullptr) << "Can't create role for unsupported data type";
+        return nullptr;
     }
 
     return &getRoleOrCreate(key, type);
@@ -235,7 +251,7 @@ const ListLayout::Role *ListLayout::getRoleOrCreate(const QString &key, const QV
 
 const ListLayout::Role *ListLayout::getExistingRole(const QString &key) const
 {
-    Role *r = 0;
+    Role *r = nullptr;
     QStringHash<Role *>::Node *node = roleHash.findNode(key);
     if (node)
         r = node->value;
@@ -244,40 +260,114 @@ const ListLayout::Role *ListLayout::getExistingRole(const QString &key) const
 
 const ListLayout::Role *ListLayout::getExistingRole(QV4::String *key) const
 {
-    Role *r = 0;
+    Role *r = nullptr;
     QStringHash<Role *>::Node *node = roleHash.findNode(key);
     if (node)
         r = node->value;
     return r;
 }
 
+StringOrTranslation::StringOrTranslation(const QString &s)
+{
+    d.setFlag();
+    setString(s);
+}
+
+StringOrTranslation::StringOrTranslation(const QV4::CompiledData::Binding *binding)
+{
+    d.setFlag();
+    clear();
+    d = binding;
+}
+
+StringOrTranslation::~StringOrTranslation()
+{
+    clear();
+}
+
+void StringOrTranslation::setString(const QString &s)
+{
+    d.setFlag();
+    clear();
+    QStringData *stringData = const_cast<QString &>(s).data_ptr();
+    d = stringData;
+    if (stringData)
+        stringData->ref.ref();
+}
+
+void StringOrTranslation::setTranslation(const QV4::CompiledData::Binding *binding)
+{
+    d.setFlag();
+    clear();
+    d = binding;
+}
+
+QString StringOrTranslation::toString(const QQmlListModel *owner) const
+{
+    if (d.isNull())
+        return QString();
+    if (d.isT1()) {
+        QStringDataPtr holder = { d.asT1() };
+        holder.ptr->ref.ref();
+        return QString(holder);
+    }
+    if (!owner)
+        return QString();
+    return d.asT2()->valueAsString(owner->m_compilationUnit.data());
+}
+
+QString StringOrTranslation::asString() const
+{
+    if (d.isNull())
+        return QString();
+    if (!d.isT1())
+        return QString();
+    QStringDataPtr holder = { d.asT1() };
+    holder.ptr->ref.ref();
+    return QString(holder);
+}
+
+void StringOrTranslation::clear()
+{
+    if (QStringData *strData = d.isT1() ? d.asT1() : nullptr) {
+        if (!strData->ref.deref())
+            QStringData::deallocate(strData);
+    }
+    d = static_cast<QStringData *>(nullptr);
+}
+
 QObject *ListModel::getOrCreateModelObject(QQmlListModel *model, int elementIndex)
 {
     ListElement *e = elements[elementIndex];
-    if (e->m_objectCache == 0) {
-        e->m_objectCache = new QObject;
+    if (e->m_objectCache == nullptr) {
+        void *memory = operator new(sizeof(QObject) + sizeof(QQmlData));
+        void *ddataMemory = ((char *)memory) + sizeof(QObject);
+        e->m_objectCache = new (memory) QObject;
+        QQmlData *ddata = new (ddataMemory) QQmlData;
+        ddata->ownMemory = false;
+        QObjectPrivate::get(e->m_objectCache)->declarativeData = ddata;
         (void)new ModelNodeMetaObject(e->m_objectCache, model, elementIndex);
     }
     return e->m_objectCache;
 }
 
-void ListModel::sync(ListModel *src, ListModel *target, QHash<int, ListModel *> *targetModelHash)
+bool ListModel::sync(ListModel *src, ListModel *target)
 {
     // Sanity check
-    target->m_uid = src->m_uid;
-    if (targetModelHash)
-        targetModelHash->insert(target->m_uid, target);
+
+    bool hasChanges = false;
 
     // Build hash of elements <-> uid for each of the lists
     QHash<int, ElementSync> elementHash;
-    for (int i=0 ; i < target->elements.count() ; ++i) {
+    for (int i = 0; i < target->elements.count(); ++i) {
         ListElement *e = target->elements.at(i);
         int uid = e->getUid();
         ElementSync sync;
         sync.target = e;
+        sync.targetIndex = i;
         elementHash.insert(uid, sync);
     }
-    for (int i=0 ; i < src->elements.count() ; ++i) {
+    for (int i = 0; i < src->elements.count(); ++i) {
         ListElement *e = src->elements.at(i);
         int uid = e->getUid();
 
@@ -285,24 +375,39 @@ void ListModel::sync(ListModel *src, ListModel *target, QHash<int, ListModel *>
         if (it == elementHash.end()) {
             ElementSync sync;
             sync.src = e;
+            sync.srcIndex = i;
             elementHash.insert(uid, sync);
         } else {
             ElementSync &sync = it.value();
             sync.src = e;
+            sync.srcIndex = i;
         }
     }
 
+    QQmlListModel *targetModel = target->m_modelCache;
+
     // Get list of elements that are in the target but no longer in the source. These get deleted first.
-    QHash<int, ElementSync>::iterator it = elementHash.begin();
-    QHash<int, ElementSync>::iterator end = elementHash.end();
-    while (it != end) {
-        const ElementSync &s = it.value();
-        if (s.src == 0) {
+    int rowsRemoved = 0;
+    for (int i = 0 ; i < target->elements.count() ; ++i) {
+        ListElement *element = target->elements.at(i);
+        ElementSync &s = elementHash.find(element->getUid()).value();
+        Q_ASSERT(s.targetIndex >= 0);
+        // need to update the targetIndex, to keep it correct after removals
+        s.targetIndex -= rowsRemoved;
+        if (s.src == nullptr) {
+            Q_ASSERT(s.targetIndex == i);
+            hasChanges = true;
+            if (targetModel)
+                targetModel->beginRemoveRows(QModelIndex(), i, i);
             s.target->destroy(target->m_layout);
             target->elements.removeOne(s.target);
             delete s.target;
+            if (targetModel)
+                targetModel->endRemoveRows();
+            ++rowsRemoved;
+            --i;
+            continue;
         }
-        ++it;
     }
 
     // Sync the layouts
@@ -310,15 +415,15 @@ void ListModel::sync(ListModel *src, ListModel *target, QHash<int, ListModel *>
 
     // Clear the target list, and append in correct order from the source
     target->elements.clear();
-    for (int i=0 ; i < src->elements.count() ; ++i) {
+    for (int i = 0; i < src->elements.count(); ++i) {
         ListElement *srcElement = src->elements.at(i);
-        it = elementHash.find(srcElement->getUid());
-        const ElementSync &s = it.value();
+        ElementSync &s = elementHash.find(srcElement->getUid()).value();
+        Q_ASSERT(s.srcIndex >= 0);
         ListElement *targetElement = s.target;
-        if (targetElement == 0) {
+        if (targetElement == nullptr) {
             targetElement = new ListElement(srcElement->getUid());
         }
-        ListElement::sync(srcElement, src->m_layout, targetElement, target->m_layout, targetModelHash);
+        s.changedRoles = ListElement::sync(srcElement, src->m_layout, targetElement, target->m_layout);
         target->elements.append(targetElement);
     }
 
@@ -330,23 +435,54 @@ void ListModel::sync(ListModel *src, ListModel *target, QHash<int, ListModel *>
         if (ModelNodeMetaObject *mo = e->objectCache())
             mo->updateValues();
     }
+
+    // now emit the change notifications required. This can be safely done, as we're only emitting changes, moves and inserts,
+    // so the model indices can't be out of bounds
+    //
+    // to ensure things are kept in the correct order, emit inserts and moves first. This shouls ensure all persistent
+    // model indices are updated correctly
+    int rowsInserted = 0;
+    for (int i = 0 ; i < target->elements.count() ; ++i) {
+        ListElement *element = target->elements.at(i);
+        ElementSync &s = elementHash.find(element->getUid()).value();
+        Q_ASSERT(s.srcIndex >= 0);
+        s.srcIndex += rowsInserted;
+        if (s.srcIndex != s.targetIndex) {
+            if (targetModel) {
+                if (s.targetIndex == -1) {
+                    targetModel->beginInsertRows(QModelIndex(), i, i);
+                    targetModel->endInsertRows();
+                } else {
+                    targetModel->beginMoveRows(QModelIndex(), i, i, QModelIndex(), s.srcIndex);
+                    targetModel->endMoveRows();
+                }
+            }
+            hasChanges = true;
+            ++rowsInserted;
+        }
+        if (s.targetIndex != -1 && !s.changedRoles.isEmpty()) {
+            QModelIndex idx = targetModel->createIndex(i, 0);
+            if (targetModel)
+                targetModel->dataChanged(idx, idx, s.changedRoles);
+            hasChanges = true;
+        }
+    }
+    return hasChanges;
 }
 
-ListModel::ListModel(ListLayout *layout, QQmlListModel *modelCache, int uid) : m_layout(layout), m_modelCache(modelCache)
+ListModel::ListModel(ListLayout *layout, QQmlListModel *modelCache) : m_layout(layout), m_modelCache(modelCache)
 {
-    if (uid == -1)
-        uid = uidCounter.fetchAndAddOrdered(1);
-    m_uid = uid;
 }
 
 void ListModel::destroy()
 {
-    clear();
-    m_uid = -1;
-    m_layout = 0;
+    for (const auto &destroyer : remove(0, elements.count()))
+        destroyer();
+
+    m_layout = nullptr;
     if (m_modelCache && m_modelCache->m_primary == false)
         delete m_modelCache;
-    m_modelCache = 0;
+    m_modelCache = nullptr;
 }
 
 int ListModel::appendElement()
@@ -427,7 +563,7 @@ void ListModel::set(int elementIndex, QV4::Object *object, QVector<int> *roles)
     QV4::Scope scope(v4);
     QV4::ScopedObject o(scope);
 
-    QV4::ObjectIterator it(scope, object, QV4::ObjectIterator::WithProtoChain|QV4::ObjectIterator::EnumerableOnly);
+    QV4::ObjectIterator it(scope, object, QV4::ObjectIterator::EnumerableOnly);
     QV4::ScopedString propertyName(scope);
     QV4::ScopedValue propertyValue(scope);
     while (1) {
@@ -447,11 +583,11 @@ void ListModel::set(int elementIndex, QV4::Object *object, QVector<int> *roles)
             roleIndex = e->setDoubleProperty(r, propertyValue->asDouble());
         } else if (QV4::ArrayObject *a = propertyValue->as<QV4::ArrayObject>()) {
             const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::List);
-            ListModel *subModel = new ListModel(r.subLayout, 0, -1);
+            ListModel *subModel = new ListModel(r.subLayout, nullptr);
 
             int arrayLength = a->getLength();
             for (int j=0 ; j < arrayLength ; ++j) {
-                o = a->getIndexed(j);
+                o = a->get(j);
                 subModel->append(o);
             }
 
@@ -463,6 +599,12 @@ void ListModel::set(int elementIndex, QV4::Object *object, QVector<int> *roles)
             const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::DateTime);
             QDateTime dt = dd->toQDateTime();
             roleIndex = e->setDateTimeProperty(r, dt);
+        } else if (QV4::FunctionObject *f = propertyValue->as<QV4::FunctionObject>()) {
+            const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::Function);
+            QV4::ScopedFunctionObject func(scope, f);
+            QJSValue jsv;
+            QJSValuePrivate::setValue(&jsv, v4, func);
+            roleIndex = e->setFunctionProperty(r, jsv);
         } else if (QV4::Object *o = propertyValue->as<QV4::Object>()) {
             if (QV4::QObjectWrapper *wrapper = o->as<QV4::QObjectWrapper>()) {
                 QObject *o = wrapper->object();
@@ -500,7 +642,7 @@ void ListModel::set(int elementIndex, QV4::Object *object)
     QV4::ExecutionEngine *v4 = object->engine();
     QV4::Scope scope(v4);
 
-    QV4::ObjectIterator it(scope, object, QV4::ObjectIterator::WithProtoChain|QV4::ObjectIterator::EnumerableOnly);
+    QV4::ObjectIterator it(scope, object, QV4::ObjectIterator::EnumerableOnly);
     QV4::ScopedString propertyName(scope);
     QV4::ScopedValue propertyValue(scope);
     QV4::ScopedObject o(scope);
@@ -522,11 +664,11 @@ void ListModel::set(int elementIndex, QV4::Object *object)
         } else if (QV4::ArrayObject *a = propertyValue->as<QV4::ArrayObject>()) {
             const ListLayout::Role &r = m_layout->getRoleOrCreate(propertyName, ListLayout::Role::List);
             if (r.type == ListLayout::Role::List) {
-                ListModel *subModel = new ListModel(r.subLayout, 0, -1);
+                ListModel *subModel = new ListModel(r.subLayout, nullptr);
 
                 int arrayLength = a->getLength();
                 for (int j=0 ; j < arrayLength ; ++j) {
-                    o = a->getIndexed(j);
+                    o = a->get(j);
                     subModel->append(o);
                 }
 
@@ -562,24 +704,20 @@ void ListModel::set(int elementIndex, QV4::Object *object)
     }
 }
 
-void ListModel::clear()
-{
-    int elementCount = elements.count();
-    for (int i=0 ; i < elementCount ; ++i) {
-        elements[i]->destroy(m_layout);
-        delete elements[i];
-    }
-    elements.clear();
-}
-
-void ListModel::remove(int index, int count)
+QVector<std::function<void()>> ListModel::remove(int index, int count)
 {
+    QVector<std::function<void()>> toDestroy;
+    auto layout = m_layout;
     for (int i=0 ; i < count ; ++i) {
-        elements[index+i]->destroy(m_layout);
-        delete elements[index+i];
+        auto element = elements[index+i];
+        toDestroy.append([element, layout](){
+            element->destroy(layout);
+            delete element;
+        });
     }
     elements.remove(index, count);
     updateCacheIndices(index);
+    return toDestroy;
 }
 
 void ListModel::insert(int elementIndex, QV4::Object *object)
@@ -635,7 +773,7 @@ inline char *ListElement::getPropertyMemory(const ListLayout::Role &role)
     ListElement *e = this;
     int blockIndex = 0;
     while (blockIndex < role.blockIndex) {
-        if (e->next == 0) {
+        if (e->next == nullptr) {
             e->next = new ListElement;
             e->next->uid = uid;
         }
@@ -650,15 +788,15 @@ inline char *ListElement::getPropertyMemory(const ListLayout::Role &role)
 ModelNodeMetaObject *ListElement::objectCache()
 {
     if (!m_objectCache)
-        return 0;
+        return nullptr;
     return ModelNodeMetaObject::get(m_objectCache);
 }
 
-QString *ListElement::getStringProperty(const ListLayout::Role &role)
+StringOrTranslation *ListElement::getStringProperty(const ListLayout::Role &role)
 {
     char *mem = getPropertyMemory(role);
-    QString *s = reinterpret_cast<QString *>(mem);
-    return s->data_ptr() ? s : 0;
+    StringOrTranslation *s = reinterpret_cast<StringOrTranslation *>(mem);
+    return s;
 }
 
 QObject *ListElement::getQObjectProperty(const ListLayout::Role &role)
@@ -670,7 +808,7 @@ QObject *ListElement::getQObjectProperty(const ListLayout::Role &role)
 
 QVariantMap *ListElement::getVariantMapProperty(const ListLayout::Role &role)
 {
-    QVariantMap *map = 0;
+    QVariantMap *map = nullptr;
 
     char *mem = getPropertyMemory(role);
     if (isMemoryUsed<QVariantMap>(mem))
@@ -681,7 +819,7 @@ QVariantMap *ListElement::getVariantMapProperty(const ListLayout::Role &role)
 
 QDateTime *ListElement::getDateTimeProperty(const ListLayout::Role &role)
 {
-    QDateTime *dt = 0;
+    QDateTime *dt = nullptr;
 
     char *mem = getPropertyMemory(role);
     if (isMemoryUsed<QDateTime>(mem))
@@ -690,6 +828,17 @@ QDateTime *ListElement::getDateTimeProperty(const ListLayout::Role &role)
     return dt;
 }
 
+QJSValue *ListElement::getFunctionProperty(const ListLayout::Role &role)
+{
+    QJSValue *f = nullptr;
+
+    char *mem = getPropertyMemory(role);
+    if (isMemoryUsed<QJSValue>(mem))
+        f = reinterpret_cast<QJSValue *>(mem);
+
+    return f;
+}
+
 QPointer<QObject> *ListElement::getGuardProperty(const ListLayout::Role &role)
 {
     char *mem = getPropertyMemory(role);
@@ -702,7 +851,7 @@ QPointer<QObject> *ListElement::getGuardProperty(const ListLayout::Role &role)
         }
     }
 
-    QPointer<QObject> *o = 0;
+    QPointer<QObject> *o = nullptr;
 
     if (existingGuard)
         o = reinterpret_cast<QPointer<QObject> *>(mem);
@@ -732,9 +881,9 @@ QVariant ListElement::getProperty(const ListLayout::Role &role, const QQmlListMo
             break;
         case ListLayout::Role::String:
             {
-                QString *value = reinterpret_cast<QString *>(mem);
-                if (value->data_ptr() != 0)
-                    data = *value;
+                StringOrTranslation *value = reinterpret_cast<StringOrTranslation *>(mem);
+                if (value->isSet())
+                    data = value->toString(owner);
             }
             break;
         case ListLayout::Role::Bool:
@@ -749,7 +898,7 @@ QVariant ListElement::getProperty(const ListLayout::Role &role, const QQmlListMo
                 ListModel *model = *value;
 
                 if (model) {
-                    if (model->m_modelCache == 0) {
+                    if (model->m_modelCache == nullptr) {
                         model->m_modelCache = new QQmlListModel(owner, model, eng);
                         QQmlEngine::setContextForObject(model->m_modelCache, QQmlEngine::contextForObject(owner));
                     }
@@ -783,6 +932,14 @@ QVariant ListElement::getProperty(const ListLayout::Role &role, const QQmlListMo
                 }
             }
             break;
+        case ListLayout::Role::Function:
+            {
+                if (isMemoryUsed<QJSValue>(mem)) {
+                    QJSValue *func = reinterpret_cast<QJSValue *>(mem);
+                    data = QVariant::fromValue(*func);
+                }
+            }
+            break;
         default:
             break;
     }
@@ -796,15 +953,13 @@ int ListElement::setStringProperty(const ListLayout::Role &role, const QString &
 
     if (role.type == ListLayout::Role::String) {
         char *mem = getPropertyMemory(role);
-        QString *c = reinterpret_cast<QString *>(mem);
+        StringOrTranslation *c = reinterpret_cast<StringOrTranslation *>(mem);
         bool changed;
-        if (c->data_ptr() == 0) {
-            new (mem) QString(s);
+        if (!c->isSet() || c->isTranslation())
             changed = true;
-        } else {
-            changed = c->compare(s) != 0;
-            *c = s;
-        }
+        else
+            changed = c->asString().compare(s) != 0;
+        c->setString(s);
         if (changed)
             roleIndex = role.index;
     }
@@ -916,7 +1071,11 @@ int ListElement::setVariantMapProperty(const ListLayout::Role &role, QVariantMap
         char *mem = getPropertyMemory(role);
         if (isMemoryUsed<QVariantMap>(mem)) {
             QVariantMap *map = reinterpret_cast<QVariantMap *>(mem);
+            if (m && map->isSharedWith(*m))
+                return roleIndex;
             map->~QMap();
+        } else if (!m) {
+            return roleIndex;
         }
         if (m)
             new (mem) QVariantMap(*m);
@@ -945,10 +1104,42 @@ int ListElement::setDateTimeProperty(const ListLayout::Role &role, const QDateTi
     return roleIndex;
 }
 
+int ListElement::setFunctionProperty(const ListLayout::Role &role, const QJSValue &f)
+{
+    int roleIndex = -1;
+
+    if (role.type == ListLayout::Role::Function) {
+        char *mem = getPropertyMemory(role);
+        if (isMemoryUsed<QJSValue>(mem)) {
+            QJSValue *f = reinterpret_cast<QJSValue *>(mem);
+            f->~QJSValue();
+        }
+        new (mem) QJSValue(f);
+        roleIndex = role.index;
+    }
+
+    return roleIndex;
+}
+
+int ListElement::setTranslationProperty(const ListLayout::Role &role, const QV4::CompiledData::Binding *b)
+{
+    int roleIndex = -1;
+
+    if (role.type == ListLayout::Role::String) {
+        char *mem = getPropertyMemory(role);
+        StringOrTranslation *s = reinterpret_cast<StringOrTranslation *>(mem);
+        s->setTranslation(b);
+        roleIndex = role.index;
+    }
+
+    return roleIndex;
+}
+
+
 void ListElement::setStringPropertyFast(const ListLayout::Role &role, const QString &s)
 {
     char *mem = getPropertyMemory(role);
-    new (mem) QString(s);
+    new (mem) StringOrTranslation(s);
 }
 
 void ListElement::setDoublePropertyFast(const ListLayout::Role &role, double d)
@@ -991,6 +1182,12 @@ void ListElement::setDateTimePropertyFast(const ListLayout::Role &role, const QD
     new (mem) QDateTime(dt);
 }
 
+void ListElement::setFunctionPropertyFast(const ListLayout::Role &role, const QJSValue &f)
+{
+    char *mem = getPropertyMemory(role);
+    new (mem) QJSValue(f);
+}
+
 void ListElement::clearProperty(const ListLayout::Role &role)
 {
     switch (role.type) {
@@ -1004,16 +1201,19 @@ void ListElement::clearProperty(const ListLayout::Role &role)
         setBoolProperty(role, false);
         break;
     case ListLayout::Role::List:
-        setListProperty(role, 0);
+        setListProperty(role, nullptr);
         break;
     case ListLayout::Role::QObject:
-        setQObjectProperty(role, 0);
+        setQObjectProperty(role, nullptr);
         break;
     case ListLayout::Role::DateTime:
         setDateTimeProperty(role, QDateTime());
         break;
     case ListLayout::Role::VariantMap:
-        setVariantMapProperty(role, (QVariantMap *)0);
+        setVariantMapProperty(role, (QVariantMap *)nullptr);
+        break;
+    case ListLayout::Role::Function:
+        setFunctionProperty(role, QJSValue());
         break;
     default:
         break;
@@ -1022,17 +1222,17 @@ void ListElement::clearProperty(const ListLayout::Role &role)
 
 ListElement::ListElement()
 {
-    m_objectCache = 0;
+    m_objectCache = nullptr;
     uid = uidCounter.fetchAndAddOrdered(1);
-    next = 0;
+    next = nullptr;
     memset(data, 0, sizeof(data));
 }
 
 ListElement::ListElement(int existingUid)
 {
-    m_objectCache = 0;
+    m_objectCache = nullptr;
     uid = existingUid;
-    next = 0;
+    next = nullptr;
     memset(data, 0, sizeof(data));
 }
 
@@ -1041,12 +1241,14 @@ ListElement::~ListElement()
     delete next;
 }
 
-void ListElement::sync(ListElement *src, ListLayout *srcLayout, ListElement *target, ListLayout *targetLayout, QHash<int, ListModel *> *targetModelHash)
+QVector<int> ListElement::sync(ListElement *src, ListLayout *srcLayout, ListElement *target, ListLayout *targetLayout)
 {
+    QVector<int> changedRoles;
     for (int i=0 ; i < srcLayout->roleCount() ; ++i) {
         const ListLayout::Role &srcRole = srcLayout->getExistingRole(i);
         const ListLayout::Role &targetRole = targetLayout->getExistingRole(i);
 
+        int roleIndex = -1;
         switch (srcRole.type) {
             case ListLayout::Role::List:
                 {
@@ -1054,40 +1256,45 @@ void ListElement::sync(ListElement *src, ListLayout *srcLayout, ListElement *tar
                     ListModel *targetSubModel = target->getListProperty(targetRole);
 
                     if (srcSubModel) {
-                        if (targetSubModel == 0) {
-                            targetSubModel = new ListModel(targetRole.subLayout, 0, srcSubModel->getUid());
+                        if (targetSubModel == nullptr) {
+                            targetSubModel = new ListModel(targetRole.subLayout, nullptr);
                             target->setListPropertyFast(targetRole, targetSubModel);
                         }
-                        ListModel::sync(srcSubModel, targetSubModel, targetModelHash);
+                        if (ListModel::sync(srcSubModel, targetSubModel))
+                            roleIndex = targetRole.index;
                     }
                 }
                 break;
             case ListLayout::Role::QObject:
                 {
                     QObject *object = src->getQObjectProperty(srcRole);
-                    target->setQObjectProperty(targetRole, object);
+                    roleIndex = target->setQObjectProperty(targetRole, object);
                 }
                 break;
             case ListLayout::Role::String:
             case ListLayout::Role::Number:
             case ListLayout::Role::Bool:
             case ListLayout::Role::DateTime:
+            case ListLayout::Role::Function:
                 {
-                    QVariant v = src->getProperty(srcRole, 0, 0);
-                    target->setVariantProperty(targetRole, v);
+                    QVariant v = src->getProperty(srcRole, nullptr, nullptr);
+                    roleIndex = target->setVariantProperty(targetRole, v);
                 }
                 break;
             case ListLayout::Role::VariantMap:
                 {
                     QVariantMap *map = src->getVariantMapProperty(srcRole);
-                    target->setVariantMapProperty(targetRole, map);
+                    roleIndex = target->setVariantMapProperty(targetRole, map);
                 }
                 break;
             default:
                 break;
         }
+        if (roleIndex >= 0)
+            changedRoles << roleIndex;
     }
 
+    return changedRoles;
 }
 
 void ListElement::destroy(ListLayout *layout)
@@ -1099,9 +1306,9 @@ void ListElement::destroy(ListLayout *layout)
             switch (r.type) {
                 case ListLayout::Role::String:
                     {
-                        QString *string = getStringProperty(r);
+                        StringOrTranslation *string = getStringProperty(r);
                         if (string)
-                            string->~QString();
+                            string->~StringOrTranslation();
                     }
                     break;
                 case ListLayout::Role::List:
@@ -1134,17 +1341,27 @@ void ListElement::destroy(ListLayout *layout)
                             dt->~QDateTime();
                     }
                     break;
+                case ListLayout::Role::Function:
+                    {
+                        QJSValue *f = getFunctionProperty(r);
+                        if (f)
+                            f->~QJSValue();
+                    }
+                    break;
                 default:
                     // other types don't need explicit cleanup.
                     break;
             }
         }
 
-        delete m_objectCache;
+        if (m_objectCache) {
+            m_objectCache->~QObject();
+            operator delete(m_objectCache);
+        }
     }
 
     if (next)
-        next->destroy(0);
+        next->destroy(nullptr);
     uid = -1;
 }
 
@@ -1157,7 +1374,10 @@ int ListElement::setVariantProperty(const ListLayout::Role &role, const QVariant
             roleIndex = setDoubleProperty(role, d.toDouble());
             break;
         case ListLayout::Role::String:
-            roleIndex = setStringProperty(role, d.toString());
+            if (d.userType() == qMetaTypeId<const QV4::CompiledData::Binding *>())
+                roleIndex = setTranslationProperty(role, d.value<const QV4::CompiledData::Binding*>());
+            else
+                roleIndex = setStringProperty(role, d.toString());
             break;
         case ListLayout::Role::Bool:
             roleIndex = setBoolProperty(role, d.toBool());
@@ -1173,6 +1393,9 @@ int ListElement::setVariantProperty(const ListLayout::Role &role, const QVariant
         case ListLayout::Role::DateTime:
             roleIndex = setDateTimeProperty(role, d.toDateTime());
             break;
+        case ListLayout::Role::Function:
+            roleIndex = setFunctionProperty(role, d.value<QJSValue>());
+            break;
         default:
             break;
     }
@@ -1199,15 +1422,15 @@ int ListElement::setJsProperty(const ListLayout::Role &role, const QV4::Value &d
             QV4::Scope scope(a->engine());
             QV4::ScopedObject o(scope);
 
-            ListModel *subModel = new ListModel(role.subLayout, 0, -1);
+            ListModel *subModel = new ListModel(role.subLayout, nullptr);
             int arrayLength = a->getLength();
             for (int j=0 ; j < arrayLength ; ++j) {
-                o = a->getIndexed(j);
+                o = a->get(j);
                 subModel->append(o);
             }
             roleIndex = setListProperty(role, subModel);
         } else {
-            qmlWarning(0) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(role.name).arg(roleTypeName(role.type)).arg(roleTypeName(ListLayout::Role::List));
+            qmlWarning(nullptr) << QStringLiteral("Can't assign to existing role '%1' of different type [%2 -> %3]").arg(role.name).arg(roleTypeName(role.type)).arg(roleTypeName(ListLayout::Role::List));
         }
     } else if (d.isBoolean()) {
         roleIndex = setBoolProperty(role, d.booleanValue());
@@ -1215,6 +1438,11 @@ int ListElement::setJsProperty(const ListLayout::Role &role, const QV4::Value &d
         QV4::Scoped<QV4::DateObject> dd(scope, d);
         QDateTime dt = dd->toQDateTime();
         roleIndex = setDateTimeProperty(role, dt);
+    } else if (d.as<QV4::FunctionObject>()) {
+        QV4::ScopedFunctionObject f(scope, d);
+        QJSValue jsv;
+        QJSValuePrivate::setValue(&jsv, eng, f);
+        roleIndex = setFunctionProperty(role, jsv);
     } else if (d.isObject()) {
         QV4::ScopedObject o(scope, d);
         QV4::QObjectWrapper *wrapper = o->as<QV4::QObjectWrapper>();
@@ -1311,7 +1539,7 @@ void ModelNodeMetaObject::propertyWritten(int index)
         return;
 
     QString propName = QString::fromUtf8(name(index));
-    QVariant value = operator[](index);
+    const QVariant value = this->value(index);
 
     QV4::Scope scope(m_model->engine());
     QV4::ScopedValue v(scope, scope.engine->fromVariant(value));
@@ -1328,8 +1556,8 @@ void ModelNodeMetaObject::emitDirectNotifies(const int *changedRoles, int roleCo
     QQmlData *ddata = QQmlData::get(object(), /*create*/false);
     if (!ddata)
         return;
-    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(qmlEngine(m_model));
-    if (!ep)
+    // There's nothing to emit if we're a list model in a worker thread.
+    if (!qmlEngine(m_model))
         return;
     for (int i = 0; i < roleCount; ++i) {
         const int changedRole = changedRoles[i];
@@ -1339,66 +1567,89 @@ void ModelNodeMetaObject::emitDirectNotifies(const int *changedRoles, int roleCo
 
 namespace QV4 {
 
-bool ModelObject::put(Managed *m, String *name, const Value &value)
+bool ModelObject::virtualPut(Managed *m, PropertyKey id, const Value &value, Value *receiver)
 {
+    if (!id.isString())
+        return Object::virtualPut(m, id, value, receiver);
+    QString propName = id.toQString();
+
     ModelObject *that = static_cast<ModelObject*>(m);
 
     ExecutionEngine *eng = that->engine();
-    const int elementIndex = that->d()->m_elementIndex;
-    const QString propName = name->toQString();
+    const int elementIndex = that->d()->elementIndex();
     int roleIndex = that->d()->m_model->m_listModel->setExistingProperty(elementIndex, propName, value, eng);
     if (roleIndex != -1)
         that->d()->m_model->emitItemsChanged(elementIndex, 1, QVector<int>(1, roleIndex));
 
     ModelNodeMetaObject *mo = ModelNodeMetaObject::get(that->object());
     if (mo->initialized())
-        mo->emitPropertyNotification(name->toQString().toUtf8());
+        mo->emitPropertyNotification(propName.toUtf8());
     return true;
 }
 
-ReturnedValue ModelObject::get(const Managed *m, String *name, bool *hasProperty)
+ReturnedValue ModelObject::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty)
 {
+    if (!id.isString())
+        return QObjectWrapper::virtualGet(m, id, receiver, hasProperty);
+
     const ModelObject *that = static_cast<const ModelObject*>(m);
+    Scope scope(that);
+    ScopedString name(scope, id.asStringOrSymbol());
     const ListLayout::Role *role = that->d()->m_model->m_listModel->getExistingRole(name);
     if (!role)
-        return QObjectWrapper::get(m, name, hasProperty);
+        return QObjectWrapper::virtualGet(m, id, receiver, hasProperty);
     if (hasProperty)
         *hasProperty = true;
 
     if (QQmlEngine *qmlEngine = that->engine()->qmlEngine()) {
         QQmlEnginePrivate *ep = QQmlEnginePrivate::get(qmlEngine);
-        if (ep && ep->propertyCapture) {
-            QObjectPrivate *op = QObjectPrivate::get(that->object());
-            // Temporarily hide the dynamic meta-object, to prevent it from being created when the capture
-            // triggers a QObject::connectNotify() by calling obj->metaObject().
-            QScopedValueRollback<QDynamicMetaObjectData*> metaObjectBlocker(op->metaObject, 0);
-            ep->propertyCapture->captureProperty(that->object(), -1, role->index);
-        }
+        if (ep && ep->propertyCapture)
+            ep->propertyCapture->captureProperty(that->object(), -1, role->index,
+                                                 QQmlPropertyCapture::OnlyOnce, false);
     }
 
-    const int elementIndex = that->d()->m_elementIndex;
+    const int elementIndex = that->d()->elementIndex();
     QVariant value = that->d()->m_model->data(elementIndex, role->index);
     return that->engine()->fromVariant(value);
 }
 
-void ModelObject::advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes)
+struct ModelObjectOwnPropertyKeyIterator : ObjectOwnPropertyKeyIterator
 {
-    ModelObject *that = static_cast<ModelObject*>(m);
+    int roleNameIndex = 0;
+    ~ModelObjectOwnPropertyKeyIterator() override = default;
+    PropertyKey next(const Object *o, Property *pd = nullptr, PropertyAttributes *attrs = nullptr) override;
+
+};
+
+PropertyKey ModelObjectOwnPropertyKeyIterator::next(const Object *o, Property *pd, PropertyAttributes *attrs)
+{
+    const ModelObject *that = static_cast<const ModelObject *>(o);
+
     ExecutionEngine *v4 = that->engine();
-    name->setM(0);
-    *index = UINT_MAX;
-    if (it->arrayIndex < uint(that->d()->m_model->m_listModel->roleCount())) {
+    if (roleNameIndex < that->listModel()->roleCount()) {
         Scope scope(that->engine());
-        const ListLayout::Role &role = that->d()->m_model->m_listModel->getExistingRole(it->arrayIndex);
-        ++it->arrayIndex;
+        const ListLayout::Role &role = that->listModel()->getExistingRole(roleNameIndex);
+        ++roleNameIndex;
         ScopedString roleName(scope, v4->newString(role.name));
-        name->setM(roleName->d());
-        *attributes = QV4::Attr_Data;
-        QVariant value = that->d()->m_model->data(that->d()->m_elementIndex, role.index);
-        p->value = v4->fromVariant(value);
-        return;
+        if (attrs)
+            *attrs = QV4::Attr_Data;
+        if (pd) {
+            QVariant value = that->d()->m_model->data(that->d()->elementIndex(), role.index);
+            pd->value = v4->fromVariant(value);
+        }
+        return roleName->toPropertyKey();
     }
-    QV4::QObjectWrapper::advanceIterator(m, it, name, index, p, attributes);
+
+    // Fall back to QV4::Object as opposed to QV4::QObjectWrapper otherwise it will add
+    // unnecessary entries that relate to the roles used. These just create extra work
+    // later on as they will just be ignored.
+    return ObjectOwnPropertyKeyIterator::next(o, pd, attrs);
+}
+
+OwnPropertyKeyIterator *ModelObject::virtualOwnPropertyKeys(const Object *m, Value *target)
+{
+    *target = *m;
+    return new ModelObjectOwnPropertyKeyIterator;
 }
 
 DEFINE_OBJECT_VTABLE(ModelObject);
@@ -1418,20 +1669,22 @@ DynamicRoleModelNode *DynamicRoleModelNode::create(const QVariantMap &obj, QQmlL
     return object;
 }
 
-void DynamicRoleModelNode::sync(DynamicRoleModelNode *src, DynamicRoleModelNode *target, QHash<int, QQmlListModel *> *targetModelHash)
+QVector<int> DynamicRoleModelNode::sync(DynamicRoleModelNode *src, DynamicRoleModelNode *target)
 {
-    for (int i=0 ; i < src->m_meta->count() ; ++i) {
+    QVector<int> changedRoles;
+    for (int i = 0; i < src->m_meta->count(); ++i) {
         const QByteArray &name = src->m_meta->name(i);
         QVariant value = src->m_meta->value(i);
 
         QQmlListModel *srcModel = qobject_cast<QQmlListModel *>(value.value<QObject *>());
         QQmlListModel *targetModel = qobject_cast<QQmlListModel *>(target->m_meta->value(i).value<QObject *>());
 
+        bool modelHasChanges = false;
         if (srcModel) {
-            if (targetModel == 0)
+            if (targetModel == nullptr)
                 targetModel = QQmlListModel::createWithOwner(target->m_owner);
 
-            QQmlListModel::sync(srcModel, targetModel, targetModelHash);
+            modelHasChanges = QQmlListModel::sync(srcModel, targetModel);
 
             QObject *targetModelObject = targetModel;
             value = QVariant::fromValue(targetModelObject);
@@ -1439,8 +1692,10 @@ void DynamicRoleModelNode::sync(DynamicRoleModelNode *src, DynamicRoleModelNode
             delete targetModel;
         }
 
-        target->setValue(name, value);
+        if (target->setValue(name, value) || modelHasChanges)
+            changedRoles << target->m_owner->m_roles.indexOf(QString::fromUtf8(name));
     }
+    return changedRoles;
 }
 
 void DynamicRoleModelNode::updateValues(const QVariantMap &object, QVector<int> &roles)
@@ -1555,7 +1810,7 @@ void DynamicRoleModelNodeMetaObject::propertyWritten(int index)
     \instantiates QQmlListModel
     \inqmlmodule QtQml.Models
     \ingroup qtquick-models
-    \brief Defines a free-form list data source
+    \brief Defines a free-form list data source.
 
     The ListModel is a simple container of ListElement definitions, each
     containing data roles. The contents can be defined dynamically, or
@@ -1628,13 +1883,13 @@ void DynamicRoleModelNodeMetaObject::propertyWritten(int index)
 
     \snippet ../quick/threading/threadedlistmodel/timedisplay.qml 0
 
-    The included file, \tt dataloader.js, looks like this:
+    The included file, \tt dataloader.mjs, looks like this:
 
-    \snippet ../quick/threading/threadedlistmodel/dataloader.js 0
+    \snippet ../quick/threading/threadedlistmodel/dataloader.mjs 0
 
     The timer in the main example sends messages to the worker script by calling
     \l WorkerScript::sendMessage(). When this message is received,
-    \c WorkerScript.onMessage() is invoked in \c dataloader.js,
+    \c WorkerScript.onMessage() is invoked in \c dataloader.mjs,
     which appends the current time to the list model.
 
     Note the call to sync() from the external thread.
@@ -1649,14 +1904,13 @@ QQmlListModel::QQmlListModel(QObject *parent)
 {
     m_mainThread = true;
     m_primary = true;
-    m_agent = 0;
-    m_uid = uidCounter.fetchAndAddOrdered(1);
+    m_agent = nullptr;
     m_dynamicRoles = false;
 
     m_layout = new ListLayout;
-    m_listModel = new ListModel(m_layout, this, -1);
+    m_listModel = new ListModel(m_layout, this);
 
-    m_engine = 0;
+    m_engine = nullptr;
 }
 
 QQmlListModel::QQmlListModel(const QQmlListModel *owner, ListModel *data, QV4::ExecutionEngine *engine, QObject *parent)
@@ -1668,10 +1922,11 @@ QQmlListModel::QQmlListModel(const QQmlListModel *owner, ListModel *data, QV4::E
 
     Q_ASSERT(owner->m_dynamicRoles == false);
     m_dynamicRoles = false;
-    m_layout = 0;
+    m_layout = nullptr;
     m_listModel = data;
 
     m_engine = engine;
+    m_compilationUnit = owner->m_compilationUnit;
 }
 
 QQmlListModel::QQmlListModel(QQmlListModel *orig, QQmlListModelWorkerAgent *agent)
@@ -1683,14 +1938,15 @@ QQmlListModel::QQmlListModel(QQmlListModel *orig, QQmlListModelWorkerAgent *agen
     m_dynamicRoles = orig->m_dynamicRoles;
 
     m_layout = new ListLayout(orig->m_layout);
-    m_listModel = new ListModel(m_layout, this, orig->m_listModel->getUid());
+    m_listModel = new ListModel(m_layout, this);
 
     if (m_dynamicRoles)
-        sync(orig, this, 0);
+        sync(orig, this);
     else
-        ListModel::sync(orig->m_listModel, m_listModel, 0);
+        ListModel::sync(orig->m_listModel, m_listModel);
 
-    m_engine = 0;
+    m_engine = nullptr;
+    m_compilationUnit = orig->m_compilationUnit;
 }
 
 QQmlListModel::~QQmlListModel()
@@ -1707,10 +1963,10 @@ QQmlListModel::~QQmlListModel()
         }
     }
 
-    m_listModel = 0;
+    m_listModel = nullptr;
 
     delete m_layout;
-    m_layout = 0;
+    m_layout = nullptr;
 }
 
 QQmlListModel *QQmlListModel::createWithOwner(QQmlListModel *newOwner)
@@ -1732,32 +1988,32 @@ QQmlListModel *QQmlListModel::createWithOwner(QQmlListModel *newOwner)
 
 QV4::ExecutionEngine *QQmlListModel::engine() const
 {
-    if (m_engine == 0) {
-        m_engine  = QQmlEnginePrivate::get(qmlEngine(this))->v4engine();
+    if (m_engine == nullptr) {
+        m_engine  = qmlEngine(this)->handle();
     }
 
     return m_engine;
 }
 
-void QQmlListModel::sync(QQmlListModel *src, QQmlListModel *target, QHash<int, QQmlListModel *> *targetModelHash)
+bool QQmlListModel::sync(QQmlListModel *src, QQmlListModel *target)
 {
     Q_ASSERT(src->m_dynamicRoles && target->m_dynamicRoles);
 
-    target->m_uid = src->m_uid;
-    if (targetModelHash)
-        targetModelHash->insert(target->m_uid, target);
+    bool hasChanges = false;
+
     target->m_roles = src->m_roles;
 
     // Build hash of elements <-> uid for each of the lists
     QHash<int, ElementSync> elementHash;
-    for (int i=0 ; i < target->m_modelObjects.count() ; ++i) {
+    for (int i = 0 ; i < target->m_modelObjects.count(); ++i) {
         DynamicRoleModelNode *e = target->m_modelObjects.at(i);
         int uid = e->getUid();
         ElementSync sync;
         sync.target = e;
+        sync.targetIndex = i;
         elementHash.insert(uid, sync);
     }
-    for (int i=0 ; i < src->m_modelObjects.count() ; ++i) {
+    for (int i = 0 ; i < src->m_modelObjects.count(); ++i) {
         DynamicRoleModelNode *e = src->m_modelObjects.at(i);
         int uid = e->getUid();
 
@@ -1765,118 +2021,102 @@ void QQmlListModel::sync(QQmlListModel *src, QQmlListModel *target, QHash<int, Q
         if (it == elementHash.end()) {
             ElementSync sync;
             sync.src = e;
+            sync.srcIndex = i;
             elementHash.insert(uid, sync);
         } else {
             ElementSync &sync = it.value();
             sync.src = e;
+            sync.srcIndex = i;
         }
     }
 
     // Get list of elements that are in the target but no longer in the source. These get deleted first.
-    QHash<int, ElementSync>::iterator it = elementHash.begin();
-    QHash<int, ElementSync>::iterator end = elementHash.end();
-    while (it != end) {
-        const ElementSync &s = it.value();
-        if (s.src == 0) {
-            int targetIndex = target->m_modelObjects.indexOf(s.target);
-            target->m_modelObjects.remove(targetIndex, 1);
+    int rowsRemoved = 0;
+    for (int i = 0 ; i < target->m_modelObjects.count() ; ++i) {
+        DynamicRoleModelNode *element = target->m_modelObjects.at(i);
+        ElementSync &s = elementHash.find(element->getUid()).value();
+        Q_ASSERT(s.targetIndex >= 0);
+        // need to update the targetIndex, to keep it correct after removals
+        s.targetIndex -= rowsRemoved;
+        if (s.src == nullptr) {
+            Q_ASSERT(s.targetIndex == i);
+            hasChanges = true;
+            target->beginRemoveRows(QModelIndex(), i, i);
+            target->m_modelObjects.remove(i, 1);
+            target->endRemoveRows();
             delete s.target;
+            ++rowsRemoved;
+            --i;
+            continue;
         }
-        ++it;
     }
 
     // Clear the target list, and append in correct order from the source
     target->m_modelObjects.clear();
-    for (int i=0 ; i < src->m_modelObjects.count() ; ++i) {
-        DynamicRoleModelNode *srcElement = src->m_modelObjects.at(i);
-        it = elementHash.find(srcElement->getUid());
-        const ElementSync &s = it.value();
+    for (int i = 0 ; i < src->m_modelObjects.count() ; ++i) {
+        DynamicRoleModelNode *element = src->m_modelObjects.at(i);
+        ElementSync &s = elementHash.find(element->getUid()).value();
+        Q_ASSERT(s.srcIndex >= 0);
         DynamicRoleModelNode *targetElement = s.target;
-        if (targetElement == 0) {
-            targetElement = new DynamicRoleModelNode(target, srcElement->getUid());
+        if (targetElement == nullptr) {
+            targetElement = new DynamicRoleModelNode(target, element->getUid());
         }
-        DynamicRoleModelNode::sync(srcElement, targetElement, targetModelHash);
+        s.changedRoles = DynamicRoleModelNode::sync(element, targetElement);
         target->m_modelObjects.append(targetElement);
     }
-}
-
-void QQmlListModel::emitItemsChanged(int index, int count, const QVector<int> &roles)
-{
-    if (count <= 0)
-        return;
 
-    if (m_mainThread) {
-        emit dataChanged(createIndex(index, 0), createIndex(index + count - 1, 0), roles);;
-    } else {
-        int uid = m_dynamicRoles ? getUid() : m_listModel->getUid();
-        m_agent->data.changedChange(uid, index, count, roles);
+    // now emit the change notifications required. This can be safely done, as we're only emitting changes, moves and inserts,
+    // so the model indices can't be out of bounds
+    //
+    // to ensure things are kept in the correct order, emit inserts and moves first. This shouls ensure all persistent
+    // model indices are updated correctly
+    int rowsInserted = 0;
+    for (int i = 0 ; i < target->m_modelObjects.count() ; ++i) {
+        DynamicRoleModelNode *element = target->m_modelObjects.at(i);
+        ElementSync &s = elementHash.find(element->getUid()).value();
+        Q_ASSERT(s.srcIndex >= 0);
+        s.srcIndex += rowsInserted;
+        if (s.srcIndex != s.targetIndex) {
+            if (s.targetIndex == -1) {
+                target->beginInsertRows(QModelIndex(), i, i);
+                target->endInsertRows();
+            } else {
+                target->beginMoveRows(QModelIndex(), i, i, QModelIndex(), s.srcIndex);
+                target->endMoveRows();
+            }
+            hasChanges = true;
+            ++rowsInserted;
+        }
+        if (s.targetIndex != -1 && !s.changedRoles.isEmpty()) {
+            QModelIndex idx = target->createIndex(i, 0);
+            emit target->dataChanged(idx, idx, s.changedRoles);
+            hasChanges = true;
+        }
     }
+    return hasChanges;
 }
 
-void QQmlListModel::emitItemsAboutToBeRemoved(int index, int count)
-{
-    if (count <= 0 || !m_mainThread)
-        return;
-
-    beginRemoveRows(QModelIndex(), index, index + count - 1);
-}
-
-void QQmlListModel::emitItemsRemoved(int index, int count)
+void QQmlListModel::emitItemsChanged(int index, int count, const QVector<int> &roles)
 {
     if (count <= 0)
         return;
 
-    if (m_mainThread) {
-            endRemoveRows();
-            emit countChanged();
-    } else {
-        int uid = m_dynamicRoles ? getUid() : m_listModel->getUid();
-        if (index == 0 && count == this->count())
-            m_agent->data.clearChange(uid);
-        m_agent->data.removeChange(uid, index, count);
-    }
+    if (m_mainThread)
+        emit dataChanged(createIndex(index, 0), createIndex(index + count - 1, 0), roles);;
 }
 
 void QQmlListModel::emitItemsAboutToBeInserted(int index, int count)
 {
-    if (count <= 0 || !m_mainThread)
-        return;
-
-    beginInsertRows(QModelIndex(), index, index + count - 1);
+    Q_ASSERT(index >= 0 && count >= 0);
+    if (m_mainThread)
+        beginInsertRows(QModelIndex(), index, index + count - 1);
 }
 
-void QQmlListModel::emitItemsInserted(int index, int count)
+void QQmlListModel::emitItemsInserted()
 {
-    if (count <= 0)
-        return;
-
     if (m_mainThread) {
         endInsertRows();
         emit countChanged();
-    } else {
-        int uid = m_dynamicRoles ? getUid() : m_listModel->getUid();
-        m_agent->data.insertChange(uid, index, count);
-    }
-}
-
-void QQmlListModel::emitItemsAboutToBeMoved(int from, int to, int n)
-{
-    if (n <= 0 || !m_mainThread)
-        return;
-
-    beginMoveRows(QModelIndex(), from, from + n - 1, QModelIndex(), to > from ? to + n : to);
-}
-
-void QQmlListModel::emitItemsMoved(int from, int to, int n)
-{
-    if (n <= 0)
-        return;
-
-    if (m_mainThread) {
-        endMoveRows();
-    } else {
-        int uid = m_dynamicRoles ? getUid() : m_listModel->getUid();
-        m_agent->data.moveChange(uid, from, n, to);
     }
 }
 
@@ -1990,7 +2230,7 @@ QHash<int, QByteArray> QQmlListModel::roleNames() const
 */
 void QQmlListModel::setDynamicRoles(bool enableDynamicRoles)
 {
-    if (m_mainThread && m_agent == 0) {
+    if (m_mainThread && m_agent == nullptr) {
         if (enableDynamicRoles) {
             if (m_layout->roleCount())
                 qmlWarning(this) << tr("unable to enable dynamic roles as this model is not empty");
@@ -2026,18 +2266,7 @@ int QQmlListModel::count() const
 */
 void QQmlListModel::clear()
 {
-    const int cleared = count();
-
-    emitItemsAboutToBeRemoved(0, cleared);
-
-    if (m_dynamicRoles) {
-        qDeleteAll(m_modelObjects);
-        m_modelObjects.clear();
-    } else {
-        m_listModel->clear();
-    }
-
-    emitItemsRemoved(0, cleared);
+    removeElements(0, count());
 }
 
 /*!
@@ -2061,20 +2290,41 @@ void QQmlListModel::remove(QQmlV4Function *args)
             return;
         }
 
-        emitItemsAboutToBeRemoved(index, removeCount);
+        removeElements(index, removeCount);
+    } else {
+        qmlWarning(this) << tr("remove: incorrect number of arguments");
+    }
+}
+
+void QQmlListModel::removeElements(int index, int removeCount)
+{
+    Q_ASSERT(index >= 0 && removeCount >= 0);
 
-        if (m_dynamicRoles) {
-            for (int i=0 ; i < removeCount ; ++i)
-                delete m_modelObjects[index+i];
-            m_modelObjects.remove(index, removeCount);
-        } else {
-            m_listModel->remove(index, removeCount);
-        }
+    if (!removeCount)
+        return;
+
+    if (m_mainThread)
+        beginRemoveRows(QModelIndex(), index, index + removeCount - 1);
 
-        emitItemsRemoved(index, removeCount);
+    QVector<std::function<void()>> toDestroy;
+    if (m_dynamicRoles) {
+        for (int i=0 ; i < removeCount ; ++i) {
+            auto modelObject = m_modelObjects[index+i];
+            toDestroy.append([modelObject](){
+                delete modelObject;
+            });
+        }
+        m_modelObjects.remove(index, removeCount);
     } else {
-        qmlWarning(this) << tr("remove: incorrect number of arguments");
+        toDestroy = m_listModel->remove(index, removeCount);
     }
+
+    if (m_mainThread) {
+        endRemoveRows();
+        emit countChanged();
+    }
+    for (const auto &destroyer : toDestroy)
+        destroyer();
 }
 
 /*!
@@ -2113,7 +2363,7 @@ void QQmlListModel::insert(QQmlV4Function *args)
             int objectArrayLength = objectArray->getLength();
             emitItemsAboutToBeInserted(index, objectArrayLength);
             for (int i=0 ; i < objectArrayLength ; ++i) {
-                argObject = objectArray->getIndexed(i);
+                argObject = objectArray->get(i);
 
                 if (m_dynamicRoles) {
                     m_modelObjects.insert(index+i, DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
@@ -2121,7 +2371,7 @@ void QQmlListModel::insert(QQmlV4Function *args)
                     m_listModel->insert(index+i, argObject);
                 }
             }
-            emitItemsInserted(index, objectArrayLength);
+            emitItemsInserted();
         } else if (argObject) {
             emitItemsAboutToBeInserted(index, 1);
 
@@ -2131,7 +2381,7 @@ void QQmlListModel::insert(QQmlV4Function *args)
                 m_listModel->insert(index, argObject);
             }
 
-            emitItemsInserted(index, 1);
+            emitItemsInserted();
         } else {
             qmlWarning(this) << tr("insert: value is not an object");
         }
@@ -2156,14 +2406,15 @@ void QQmlListModel::insert(QQmlV4Function *args)
 */
 void QQmlListModel::move(int from, int to, int n)
 {
-    if (n==0 || from==to)
+    if (n == 0 || from == to)
         return;
     if (!canMove(from, to, n)) {
         qmlWarning(this) << tr("move: out of range");
         return;
     }
 
-    emitItemsAboutToBeMoved(from, to, n);
+    if (m_mainThread)
+        beginMoveRows(QModelIndex(), from, from + n - 1, QModelIndex(), to > from ? to + n : to);
 
     if (m_dynamicRoles) {
 
@@ -2192,7 +2443,8 @@ void QQmlListModel::move(int from, int to, int n)
         m_listModel->move(from, to, n);
     }
 
-    emitItemsMoved(from, to, n);
+    if (m_mainThread)
+        endMoveRows();
 }
 
 /*!
@@ -2218,21 +2470,22 @@ void QQmlListModel::append(QQmlV4Function *args)
             QV4::ScopedObject argObject(scope);
 
             int objectArrayLength = objectArray->getLength();
+            if (objectArrayLength > 0) {
+                int index = count();
+                emitItemsAboutToBeInserted(index, objectArrayLength);
 
-            int index = count();
-            emitItemsAboutToBeInserted(index, objectArrayLength);
-
-            for (int i=0 ; i < objectArrayLength ; ++i) {
-                argObject = objectArray->getIndexed(i);
+                for (int i=0 ; i < objectArrayLength ; ++i) {
+                    argObject = objectArray->get(i);
 
-                if (m_dynamicRoles) {
-                    m_modelObjects.append(DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
-                } else {
-                    m_listModel->append(argObject);
+                    if (m_dynamicRoles) {
+                        m_modelObjects.append(DynamicRoleModelNode::create(scope.engine->variantMapFromJS(argObject), this));
+                    } else {
+                        m_listModel->append(argObject);
+                    }
                 }
-            }
 
-            emitItemsInserted(index, objectArrayLength);
+                emitItemsInserted();
+            }
         } else if (argObject) {
             int index;
 
@@ -2246,7 +2499,7 @@ void QQmlListModel::append(QQmlV4Function *args)
                 m_listModel->append(argObject);
             }
 
-            emitItemsInserted(index, 1);
+            emitItemsInserted();
         } else {
             qmlWarning(this) << tr("append: value is not an object");
         }
@@ -2289,7 +2542,7 @@ void QQmlListModel::append(QQmlV4Function *args)
 QQmlV4Handle QQmlListModel::get(int index) const
 {
     QV4::Scope scope(engine());
-    QV4::ScopedValue result(scope, QV4::Primitive::undefinedValue());
+    QV4::ScopedValue result(scope, QV4::Value::undefinedValue());
 
     if (index >= 0 && index < count()) {
 
@@ -2298,10 +2551,14 @@ QQmlV4Handle QQmlListModel::get(int index) const
             result = QV4::QObjectWrapper::wrap(scope.engine, object);
         } else {
             QObject *object = m_listModel->getOrCreateModelObject(const_cast<QQmlListModel *>(this), index);
-            result = scope.engine->memoryManager->allocObject<QV4::ModelObject>(object, const_cast<QQmlListModel *>(this), index);
-            // Keep track of the QObjectWrapper in persistent value storage
-            QV4::Value *val = scope.engine->memoryManager->m_weakValues->allocate();
-            *val = result;
+            QQmlData *ddata = QQmlData::get(object);
+            if (ddata->jsWrapper.isNullOrUndefined()) {
+                result = scope.engine->memoryManager->allocate<QV4::ModelObject>(object, const_cast<QQmlListModel *>(this));
+                // Keep track of the QObjectWrapper in persistent value storage
+                ddata->jsWrapper.set(scope.engine, result);
+            } else {
+                result = ddata->jsWrapper.value();
+            }
         }
     }
 
@@ -2348,7 +2605,7 @@ void QQmlListModel::set(int index, const QQmlV4Handle &handle)
             m_listModel->insert(index, object);
         }
 
-        emitItemsInserted(index, 1);
+        emitItemsInserted();
     } else {
 
         QVector<int> roles;
@@ -2413,12 +2670,12 @@ void QQmlListModel::sync()
     qmlWarning(this) << "List sync() can only be called from a WorkerScript";
 }
 
-bool QQmlListModelParser::verifyProperty(const QV4::CompiledData::Unit *qmlUnit, const QV4::CompiledData::Binding *binding)
+bool QQmlListModelParser::verifyProperty(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QV4::CompiledData::Binding *binding)
 {
     if (binding->type >= QV4::CompiledData::Binding::Type_Object) {
         const quint32 targetObjectIndex = binding->value.objectIndex;
-        const QV4::CompiledData::Object *target = qmlUnit->objectAt(targetObjectIndex);
-        QString objName = qmlUnit->stringAt(target->inheritedTypeNameIndex);
+        const QV4::CompiledData::Object *target = compilationUnit->objectAt(targetObjectIndex);
+        QString objName = compilationUnit->stringAt(target->inheritedTypeNameIndex);
         if (objName != listElementTypeName) {
             const QMetaObject *mo = resolveType(objName);
             if (mo != &QQmlListElement::staticMetaObject) {
@@ -2428,24 +2685,24 @@ bool QQmlListModelParser::verifyProperty(const QV4::CompiledData::Unit *qmlUnit,
             listElementTypeName = objName; // cache right name for next time
         }
 
-        if (!qmlUnit->stringAt(target->idNameIndex).isEmpty()) {
+        if (!compilationUnit->stringAt(target->idNameIndex).isEmpty()) {
             error(target->locationOfIdProperty, QQmlListModel::tr("ListElement: cannot use reserved \"id\" property"));
             return false;
         }
 
         const QV4::CompiledData::Binding *binding = target->bindingTable();
         for (quint32 i = 0; i < target->nBindings; ++i, ++binding) {
-            QString propName = qmlUnit->stringAt(binding->propertyNameIndex);
+            QString propName = compilationUnit->stringAt(binding->propertyNameIndex);
             if (propName.isEmpty()) {
                 error(binding, QQmlListModel::tr("ListElement: cannot contain nested elements"));
                 return false;
             }
-            if (!verifyProperty(qmlUnit, binding))
+            if (!verifyProperty(compilationUnit, binding))
                 return false;
         }
     } else if (binding->type == QV4::CompiledData::Binding::Type_Script) {
-        QString scriptStr = binding->valueAsScriptString(qmlUnit);
-        if (!definesEmptyList(scriptStr)) {
+        QString scriptStr = binding->valueAsScriptString(compilationUnit.data());
+        if (!binding->isFunctionExpression() && !definesEmptyList(scriptStr)) {
             QByteArray script = scriptStr.toUtf8();
             bool ok;
             evaluateEnum(script, &ok);
@@ -2459,24 +2716,24 @@ bool QQmlListModelParser::verifyProperty(const QV4::CompiledData::Unit *qmlUnit,
     return true;
 }
 
-bool QQmlListModelParser::applyProperty(const QV4::CompiledData::Unit *qmlUnit, const QV4::CompiledData::Binding *binding, ListModel *model, int outterElementIndex)
+bool QQmlListModelParser::applyProperty(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QV4::CompiledData::Binding *binding, ListModel *model, int outterElementIndex)
 {
-    const QString elementName = qmlUnit->stringAt(binding->propertyNameIndex);
+    const QString elementName = compilationUnit->stringAt(binding->propertyNameIndex);
 
     bool roleSet = false;
     if (binding->type >= QV4::CompiledData::Binding::Type_Object) {
         const quint32 targetObjectIndex = binding->value.objectIndex;
-        const QV4::CompiledData::Object *target = qmlUnit->objectAt(targetObjectIndex);
+        const QV4::CompiledData::Object *target = compilationUnit->objectAt(targetObjectIndex);
 
-        ListModel *subModel = 0;
+        ListModel *subModel = nullptr;
         if (outterElementIndex == -1) {
             subModel = model;
         } else {
             const ListLayout::Role &role = model->getOrCreateListRole(elementName);
             if (role.type == ListLayout::Role::List) {
                 subModel = model->getListProperty(outterElementIndex, role);
-                if (subModel == 0) {
-                    subModel = new ListModel(role.subLayout, 0, -1);
+                if (subModel == nullptr) {
+                    subModel = new ListModel(role.subLayout, nullptr);
                     QVariant vModel = QVariant::fromValue(subModel);
                     model->setOrCreateProperty(outterElementIndex, elementName, vModel);
                 }
@@ -2487,24 +2744,43 @@ bool QQmlListModelParser::applyProperty(const QV4::CompiledData::Unit *qmlUnit,
 
         const QV4::CompiledData::Binding *subBinding = target->bindingTable();
         for (quint32 i = 0; i < target->nBindings; ++i, ++subBinding) {
-            roleSet |= applyProperty(qmlUnit, subBinding, subModel, elementIndex);
+            roleSet |= applyProperty(compilationUnit, subBinding, subModel, elementIndex);
         }
 
     } else {
         QVariant value;
 
-        if (binding->evaluatesToString()) {
-            value = binding->valueAsString(qmlUnit);
+        if (binding->isTranslationBinding()) {
+            value = QVariant::fromValue<const QV4::CompiledData::Binding*>(binding);
+        } else if (binding->evaluatesToString()) {
+            value = binding->valueAsString(compilationUnit.data());
         } else if (binding->type == QV4::CompiledData::Binding::Type_Number) {
-            value = binding->valueAsNumber();
+            value = binding->valueAsNumber(compilationUnit->constants);
         } else if (binding->type == QV4::CompiledData::Binding::Type_Boolean) {
             value = binding->valueAsBoolean();
+        } else if (binding->type == QV4::CompiledData::Binding::Type_Null) {
+            value = QVariant::fromValue(nullptr);
         } else if (binding->type == QV4::CompiledData::Binding::Type_Script) {
-            QString scriptStr = binding->valueAsScriptString(qmlUnit);
+            QString scriptStr = binding->valueAsScriptString(compilationUnit.data());
             if (definesEmptyList(scriptStr)) {
                 const ListLayout::Role &role = model->getOrCreateListRole(elementName);
-                ListModel *emptyModel = new ListModel(role.subLayout, 0, -1);
+                ListModel *emptyModel = new ListModel(role.subLayout, nullptr);
                 value = QVariant::fromValue(emptyModel);
+            } else if (binding->isFunctionExpression()) {
+                QQmlBinding::Identifier id = binding->value.compiledScriptIndex;
+                Q_ASSERT(id != QQmlBinding::Invalid);
+
+                auto v4 = compilationUnit->engine;
+                QV4::Scope scope(v4);
+                // for now we do not provide a context object; data from the ListElement must be passed to the function
+                QV4::ScopedContext context(scope, QV4::QmlContext::create(v4->rootContext(), QQmlContextData::get(qmlContext(model->m_modelCache)), nullptr));
+                QV4::ScopedFunctionObject function(scope, QV4::FunctionObject::createScriptFunction(context, compilationUnit->runtimeFunctions[id]));
+
+                QV4::ReturnedValue result = function->call(v4->globalObject, nullptr, 0);
+
+                QJSValue v;
+                QJSValuePrivate::setValue(&v, v4, result);
+                value.setValue<QJSValue>(v);
             } else {
                 QByteArray script = scriptStr.toUtf8();
                 bool ok;
@@ -2520,35 +2796,34 @@ bool QQmlListModelParser::applyProperty(const QV4::CompiledData::Unit *qmlUnit,
     return roleSet;
 }
 
-void QQmlListModelParser::verifyBindings(const QV4::CompiledData::Unit *qmlUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
+void QQmlListModelParser::verifyBindings(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
 {
     listElementTypeName = QString(); // unknown
 
     for (const QV4::CompiledData::Binding *binding : bindings) {
-        QString propName = qmlUnit->stringAt(binding->propertyNameIndex);
+        QString propName = compilationUnit->stringAt(binding->propertyNameIndex);
         if (!propName.isEmpty()) { // isn't default property
             error(binding, QQmlListModel::tr("ListModel: undefined property '%1'").arg(propName));
             return;
         }
-        if (!verifyProperty(qmlUnit, binding))
+        if (!verifyProperty(compilationUnit, binding))
             return;
     }
 }
 
-void QQmlListModelParser::applyBindings(QObject *obj, QV4::CompiledData::CompilationUnit *compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
+void QQmlListModelParser::applyBindings(QObject *obj, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings)
 {
     QQmlListModel *rv = static_cast<QQmlListModel *>(obj);
 
-    rv->m_engine = QV8Engine::getV4(qmlEngine(rv));
-
-    const QV4::CompiledData::Unit *qmlUnit = compilationUnit->data;
+    rv->m_engine = qmlEngine(rv)->handle();
+    rv->m_compilationUnit = compilationUnit;
 
     bool setRoles = false;
 
     for (const QV4::CompiledData::Binding *binding : bindings) {
         if (binding->type != QV4::CompiledData::Binding::Type_Object)
             continue;
-        setRoles |= applyProperty(qmlUnit, binding, rv->m_listModel, /*outter element index*/-1);
+        setRoles |= applyProperty(compilationUnit, binding, rv->m_listModel, /*outter element index*/-1);
     }
 
     if (setRoles == false)
@@ -2572,7 +2847,7 @@ bool QQmlListModelParser::definesEmptyList(const QString &s)
     \qmltype ListElement
     \instantiates QQmlListElement
     \inqmlmodule QtQml.Models
-    \brief Defines a data item in a ListModel
+    \brief Defines a data item in a ListModel.
     \ingroup qtquick-models
 
     List elements are defined inside ListModel definitions, and represent items in a
@@ -2588,6 +2863,9 @@ bool QQmlListModelParser::definesEmptyList(const QString &s)
     strings (quoted and optionally within a call to QT_TR_NOOP), boolean values
     (true, false), numbers, or enumeration values (such as AlignText.AlignHCenter).
 
+    Beginning with Qt 5.11 ListElement also allows assigning a function declaration to
+    a role. This allows the definition of ListElements with callable actions.
+
     \section1 Referencing Roles
 
     The role names are used by delegates to obtain data from list elements.
diff --git a/src/qml/types/qqmllistmodel_p.h b/src/qml/types/qqmllistmodel_p.h
index b750d30676..95b797c898 100644
--- a/src/qml/types/qqmllistmodel_p.h
+++ b/src/qml/types/qqmllistmodel_p.h
@@ -64,6 +64,8 @@
 #include <private/qv4engine_p.h>
 #include <private/qpodvector_p.h>
 
+QT_REQUIRE_CONFIG(qml_list_model);
+
 QT_BEGIN_NAMESPACE
 
 
@@ -82,7 +84,7 @@ class Q_QML_PRIVATE_EXPORT QQmlListModel : public QAbstractListModel
     Q_PROPERTY(bool dynamicRoles READ dynamicRoles WRITE setDynamicRoles)
 
 public:
-    QQmlListModel(QObject *parent=0);
+    QQmlListModel(QObject *parent=nullptr);
     ~QQmlListModel();
 
     QModelIndex index(int row, int column, const QModelIndex &parent) const override;
@@ -122,10 +124,11 @@ private:
     friend class ListElement;
     friend class DynamicRoleModelNode;
     friend class DynamicRoleModelNodeMetaObject;
+    friend struct StringOrTranslation;
 
     // Constructs a flat list model for a worker agent
     QQmlListModel(QQmlListModel *orig, QQmlListModelWorkerAgent *agent);
-    QQmlListModel(const QQmlListModel *owner, ListModel *data, QV4::ExecutionEngine *engine, QObject *parent=0);
+    QQmlListModel(const QQmlListModel *owner, ListModel *data, QV4::ExecutionEngine *engine, QObject *parent=nullptr);
 
     QV4::ExecutionEngine *engine() const;
 
@@ -133,6 +136,7 @@ private:
 
     QQmlListModelWorkerAgent *m_agent;
     mutable QV4::ExecutionEngine *m_engine;
+    QQmlRefPointer<QV4::CompiledData::CompilationUnit> m_compilationUnit;
     bool m_mainThread;
     bool m_primary;
 
@@ -143,28 +147,24 @@ private:
 
     QVector<class DynamicRoleModelNode *> m_modelObjects;
     QVector<QString> m_roles;
-    int m_uid;
 
     struct ElementSync
     {
-        ElementSync() : src(0), target(0) {}
-
-        DynamicRoleModelNode *src;
-        DynamicRoleModelNode *target;
+        DynamicRoleModelNode *src = nullptr;
+        DynamicRoleModelNode *target = nullptr;
+        int srcIndex = -1;
+        int targetIndex = -1;
+        QVector<int> changedRoles;
     };
 
-    int getUid() const { return m_uid; }
-
-    static void sync(QQmlListModel *src, QQmlListModel *target, QHash<int, QQmlListModel *> *targetModelHash);
+    static bool sync(QQmlListModel *src, QQmlListModel *target);
     static QQmlListModel *createWithOwner(QQmlListModel *newOwner);
 
     void emitItemsChanged(int index, int count, const QVector<int> &roles);
-    void emitItemsAboutToBeRemoved(int index, int count);
-    void emitItemsRemoved(int index, int count);
     void emitItemsAboutToBeInserted(int index, int count);
-    void emitItemsInserted(int index, int count);
-    void emitItemsAboutToBeMoved(int from, int to, int n);
-    void emitItemsMoved(int from, int to, int n);
+    void emitItemsInserted();
+
+    void removeElements(int index, int removeCount);
 };
 
 // ### FIXME
@@ -187,13 +187,13 @@ public:
 
     QQmlListModelParser() : QQmlCustomParser(QQmlCustomParser::AcceptsSignalHandlers) {}
 
-    void verifyBindings(const QV4::CompiledData::Unit *qmlUnit, const QList<const QV4::CompiledData::Binding *> &bindings) Q_DECL_OVERRIDE;
-    void applyBindings(QObject *obj, QV4::CompiledData::CompilationUnit *compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings) Q_DECL_OVERRIDE;
+    void verifyBindings(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings) override;
+    void applyBindings(QObject *obj, const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QList<const QV4::CompiledData::Binding *> &bindings) override;
 
 private:
-    bool verifyProperty(const QV4::CompiledData::Unit *qmlUnit, const QV4::CompiledData::Binding *binding);
+    bool verifyProperty(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QV4::CompiledData::Binding *binding);
     // returns true if a role was set
-    bool applyProperty(const QV4::CompiledData::Unit *qmlUnit, const QV4::CompiledData::Binding *binding, ListModel *model, int outterElementIndex);
+    bool applyProperty(const QQmlRefPointer<QV4::CompiledData::CompilationUnit> &compilationUnit, const QV4::CompiledData::Binding *binding, ListModel *model, int outterElementIndex);
 
     static bool definesEmptyList(const QString &);
 
diff --git a/src/qml/types/qqmllistmodel_p_p.h b/src/qml/types/qqmllistmodel_p_p.h
index e2653c220d..ff52ee049f 100644
--- a/src/qml/types/qqmllistmodel_p_p.h
+++ b/src/qml/types/qqmllistmodel_p_p.h
@@ -57,6 +57,8 @@
 #include <private/qv4qobjectwrapper_p.h>
 #include <qqml.h>
 
+QT_REQUIRE_CONFIG(qml_list_model);
+
 QT_BEGIN_NAMESPACE
 
 
@@ -108,7 +110,7 @@ public:
         return m_uid;
     }
 
-    static void sync(DynamicRoleModelNode *src, DynamicRoleModelNode *target, QHash<int, QQmlListModel *> *targetModelHash);
+    static QVector<int> sync(DynamicRoleModelNode *src, DynamicRoleModelNode *target);
 
 private:
     QQmlListModel *m_owner;
@@ -142,16 +144,6 @@ protected:
 
 private:
     using QQmlOpenMetaObject::setValue;
-    void setValue(const QByteArray &name, const QVariant &val, bool force)
-    {
-        if (force) {
-            QVariant existingValue = value(name);
-            if (existingValue.isValid()) {
-                (*this)[name] = QVariant();
-            }
-        }
-        setValue(name, val);
-    }
 
     void emitDirectNotifies(const int *changedRoles, int roleCount);
 
@@ -164,27 +156,32 @@ namespace QV4 {
 namespace Heap {
 
 struct ModelObject : public QObjectWrapper {
-    void init(QObject *object, QQmlListModel *model, int elementIndex)
+    void init(QObject *object, QQmlListModel *model)
     {
         QObjectWrapper::init(object);
         m_model = model;
-        m_elementIndex = elementIndex;
+        QObjectPrivate *op = QObjectPrivate::get(object);
+        m_nodeModelMetaObject = static_cast<ModelNodeMetaObject *>(op->metaObject);
     }
     void destroy() { QObjectWrapper::destroy(); }
+    int elementIndex() const { return m_nodeModelMetaObject->m_elementIndex; }
     QQmlListModel *m_model;
-    int m_elementIndex;
+    ModelNodeMetaObject *m_nodeModelMetaObject;
 };
 
 }
 
 struct ModelObject : public QObjectWrapper
 {
-    static bool put(Managed *m, String *name, const Value& value);
-    static ReturnedValue get(const Managed *m, String *name, bool *hasProperty);
-    static void advanceIterator(Managed *m, ObjectIterator *it, Value *name, uint *index, Property *p, PropertyAttributes *attributes);
-
     V4_OBJECT2(ModelObject, QObjectWrapper)
     V4_NEEDS_DESTROY
+
+    ListModel *listModel() const { return d()->m_model->m_listModel; }
+
+protected:
+    static bool virtualPut(Managed *m, PropertyKey id, const Value& value, Value *receiver);
+    static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty);
+    static OwnPropertyKeyIterator *virtualOwnPropertyKeys(const Object *m, Value *target);
 };
 
 } // namespace QV4
@@ -216,6 +213,7 @@ public:
             QObject,
             VariantMap,
             DateTime,
+            Function,
 
             MaxDataType
         };
@@ -249,6 +247,22 @@ private:
     QStringHash<Role *> roleHash;
 };
 
+struct StringOrTranslation
+{
+    explicit StringOrTranslation(const QString &s);
+    explicit StringOrTranslation(const QV4::CompiledData::Binding *binding);
+    ~StringOrTranslation();
+    bool isSet() const { return d.flag(); }
+    bool isTranslation() const { return d.isT2(); }
+    void setString(const QString &s);
+    void setTranslation(const QV4::CompiledData::Binding *binding);
+    QString toString(const QQmlListModel *owner) const;
+    QString asString() const;
+private:
+    void clear();
+    QBiPointer<QStringData, const QV4::CompiledData::Binding> d;
+};
+
 /*!
 \internal
 */
@@ -260,7 +274,7 @@ public:
     ListElement(int existingUid);
     ~ListElement();
 
-    static void sync(ListElement *src, ListLayout *srcLayout, ListElement *target, ListLayout *targetLayout, QHash<int, ListModel *> *targetModelHash);
+    static QVector<int> sync(ListElement *src, ListLayout *srcLayout, ListElement *target, ListLayout *targetLayout);
 
     enum
     {
@@ -283,6 +297,8 @@ private:
     int setVariantMapProperty(const ListLayout::Role &role, QV4::Object *o);
     int setVariantMapProperty(const ListLayout::Role &role, QVariantMap *m);
     int setDateTimeProperty(const ListLayout::Role &role, const QDateTime &dt);
+    int setFunctionProperty(const ListLayout::Role &role, const QJSValue &f);
+    int setTranslationProperty(const ListLayout::Role &role, const QV4::CompiledData::Binding *b);
 
     void setStringPropertyFast(const ListLayout::Role &role, const QString &s);
     void setDoublePropertyFast(const ListLayout::Role &role, double n);
@@ -291,16 +307,18 @@ private:
     void setListPropertyFast(const ListLayout::Role &role, ListModel *m);
     void setVariantMapFast(const ListLayout::Role &role, QV4::Object *o);
     void setDateTimePropertyFast(const ListLayout::Role &role, const QDateTime &dt);
+    void setFunctionPropertyFast(const ListLayout::Role &role, const QJSValue &f);
 
     void clearProperty(const ListLayout::Role &role);
 
     QVariant getProperty(const ListLayout::Role &role, const QQmlListModel *owner, QV4::ExecutionEngine *eng);
     ListModel *getListProperty(const ListLayout::Role &role);
-    QString *getStringProperty(const ListLayout::Role &role);
+    StringOrTranslation *getStringProperty(const ListLayout::Role &role);
     QObject *getQObjectProperty(const ListLayout::Role &role);
     QPointer<QObject> *getGuardProperty(const ListLayout::Role &role);
     QVariantMap *getVariantMapProperty(const ListLayout::Role &role);
     QDateTime *getDateTimeProperty(const ListLayout::Role &role);
+    QJSValue *getFunctionProperty(const ListLayout::Role &role);
 
     inline char *getPropertyMemory(const ListLayout::Role &role);
 
@@ -324,7 +342,7 @@ class ListModel
 {
 public:
 
-    ListModel(ListLayout *layout, QQmlListModel *modelCache, int uid);
+    ListModel(ListLayout *layout, QQmlListModel *modelCache);
     ~ListModel() {}
 
     void destroy();
@@ -366,33 +384,30 @@ public:
     int append(QV4::Object *object);
     void insert(int elementIndex, QV4::Object *object);
 
-    void clear();
-    void remove(int index, int count);
+    Q_REQUIRED_RESULT QVector<std::function<void()>> remove(int index, int count);
 
     int appendElement();
     void insertElement(int index);
 
     void move(int from, int to, int n);
 
-    int getUid() const { return m_uid; }
-
-    static void sync(ListModel *src, ListModel *target, QHash<int, ListModel *> *srcModelHash);
+    static bool sync(ListModel *src, ListModel *target);
 
     QObject *getOrCreateModelObject(QQmlListModel *model, int elementIndex);
 
 private:
     QPODVector<ListElement *, 4> elements;
     ListLayout *m_layout;
-    int m_uid;
 
     QQmlListModel *m_modelCache;
 
     struct ElementSync
     {
-        ElementSync() : src(0), target(0) {}
-
-        ListElement *src;
-        ListElement *target;
+        ListElement *src = nullptr;
+        ListElement *target = nullptr;
+        int srcIndex = -1;
+        int targetIndex = -1;
+        QVector<int> changedRoles;
     };
 
     void newElement(int index);
@@ -401,6 +416,7 @@ private:
 
     friend class ListElement;
     friend class QQmlListModelWorkerAgent;
+    friend class QQmlListModelParser;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/types/qqmllistmodelworkeragent.cpp b/src/qml/types/qqmllistmodelworkeragent.cpp
index 0a5adbf292..fe3eaa3198 100644
--- a/src/qml/types/qqmllistmodelworkeragent.cpp
+++ b/src/qml/types/qqmllistmodelworkeragent.cpp
@@ -50,39 +50,8 @@
 
 QT_BEGIN_NAMESPACE
 
-
-void QQmlListModelWorkerAgent::Data::clearChange(int uid)
-{
-    for (int i=0 ; i < changes.count() ; ++i) {
-        if (changes[i].modelUid == uid) {
-            changes.removeAt(i);
-            --i;
-        }
-    }
-}
-
-void QQmlListModelWorkerAgent::Data::insertChange(int uid, int index, int count)
+QQmlListModelWorkerAgent::Sync::~Sync()
 {
-    Change c = { uid, Change::Inserted, index, count, 0, QVector<int>() };
-    changes << c;
-}
-
-void QQmlListModelWorkerAgent::Data::removeChange(int uid, int index, int count)
-{
-    Change c = { uid, Change::Removed, index, count, 0, QVector<int>() };
-    changes << c;
-}
-
-void QQmlListModelWorkerAgent::Data::moveChange(int uid, int index, int count, int to)
-{
-    Change c = { uid, Change::Moved, index, count, to, QVector<int>() };
-    changes << c;
-}
-
-void QQmlListModelWorkerAgent::Data::changedChange(int uid, int index, int count, const QVector<int> &roles)
-{
-    Change c = { uid, Change::Changed, index, count, 0, roles };
-    changes << c;
 }
 
 QQmlListModelWorkerAgent::QQmlListModelWorkerAgent(QQmlListModel *model)
@@ -117,7 +86,7 @@ void QQmlListModelWorkerAgent::release()
 
 void QQmlListModelWorkerAgent::modelDestroyed()
 {
-    m_orig = 0;
+    m_orig = nullptr;
 }
 
 int QQmlListModelWorkerAgent::count() const
@@ -167,8 +136,7 @@ void QQmlListModelWorkerAgent::move(int from, int to, int count)
 
 void QQmlListModelWorkerAgent::sync()
 {
-    Sync *s = new Sync(data, m_copy);
-    data.changes.clear();
+    Sync *s = new Sync(m_copy);
 
     mutex.lock();
     QCoreApplication::postEvent(this, s);
@@ -183,61 +151,14 @@ bool QQmlListModelWorkerAgent::event(QEvent *e)
         QMutexLocker locker(&mutex);
         if (m_orig) {
             Sync *s = static_cast<Sync *>(e);
-            const QList<Change> &changes = s->data.changes;
 
-            cc = m_orig->count() != s->list->count();
-
-            QHash<int, QQmlListModel *> targetModelDynamicHash;
-            QHash<int, ListModel *> targetModelStaticHash;
+            cc = (m_orig->count() != s->list->count());
 
             Q_ASSERT(m_orig->m_dynamicRoles == s->list->m_dynamicRoles);
             if (m_orig->m_dynamicRoles)
-                QQmlListModel::sync(s->list, m_orig, &targetModelDynamicHash);
+                QQmlListModel::sync(s->list, m_orig);
             else
-                ListModel::sync(s->list->m_listModel, m_orig->m_listModel, &targetModelStaticHash);
-
-            for (int ii = 0; ii < changes.count(); ++ii) {
-                const Change &change = changes.at(ii);
-
-                QQmlListModel *model = 0;
-                if (m_orig->m_dynamicRoles) {
-                    model = targetModelDynamicHash.value(change.modelUid);
-                } else {
-                    ListModel *lm = targetModelStaticHash.value(change.modelUid);
-                    if (lm)
-                        model = lm->m_modelCache;
-                }
-
-                if (model) {
-                    switch (change.type) {
-                    case Change::Inserted:
-                        model->beginInsertRows(
-                                    QModelIndex(), change.index, change.index + change.count - 1);
-                        model->endInsertRows();
-                        break;
-                    case Change::Removed:
-                        model->beginRemoveRows(
-                                    QModelIndex(), change.index, change.index + change.count - 1);
-                        model->endRemoveRows();
-                        break;
-                    case Change::Moved:
-                        model->beginMoveRows(
-                                    QModelIndex(),
-                                    change.index,
-                                    change.index + change.count - 1,
-                                    QModelIndex(),
-                                    change.to > change.index ? change.to + change.count : change.to);
-                        model->endMoveRows();
-                        break;
-                    case Change::Changed:
-                        emit model->dataChanged(
-                                    model->createIndex(change.index, 0),
-                                    model->createIndex(change.index + change.count - 1, 0),
-                                    change.roles);
-                        break;
-                    }
-                }
-            }
+                ListModel::sync(s->list->m_listModel, m_orig->m_listModel);
         }
 
         syncDone.wakeAll();
diff --git a/src/qml/types/qqmllistmodelworkeragent_p.h b/src/qml/types/qqmllistmodelworkeragent_p.h
index 5a39651bf7..ae2d4b11e0 100644
--- a/src/qml/types/qqmllistmodelworkeragent_p.h
+++ b/src/qml/types/qqmllistmodelworkeragent_p.h
@@ -59,6 +59,8 @@
 
 #include <private/qv8engine_p.h>
 
+QT_REQUIRE_CONFIG(qml_list_model);
+
 QT_BEGIN_NAMESPACE
 
 
@@ -91,7 +93,7 @@ public:
 
     struct VariantRef
     {
-        VariantRef() : a(0) {}
+        VariantRef() : a(nullptr) {}
         VariantRef(const VariantRef &r) : a(r.a) { if (a) a->addref(); }
         VariantRef(QQmlListModelWorkerAgent *_a) : a(_a) { if (a) a->addref(); }
         ~VariantRef() { if (a) a->release(); }
@@ -114,35 +116,12 @@ private:
     friend class QQuickWorkerScriptEnginePrivate;
     friend class QQmlListModel;
 
-    struct Change
-    {
-        int modelUid;
-        enum { Inserted, Removed, Moved, Changed } type;
-        int index; // Inserted/Removed/Moved/Changed
-        int count; // Inserted/Removed/Moved/Changed
-        int to;    // Moved
-        QVector<int> roles;
-    };
-
-    struct Data
-    {
-        QList<Change> changes;
-
-        void clearChange(int uid);
-        void insertChange(int uid, int index, int count);
-        void removeChange(int uid, int index, int count);
-        void moveChange(int uid, int index, int count, int to);
-        void changedChange(int uid, int index, int count, const QVector<int> &roles);
-    };
-    Data data;
-
     struct Sync : public QEvent {
-        Sync(const Data &d, QQmlListModel *l)
+        Sync(QQmlListModel *l)
             : QEvent(QEvent::User)
-            , data(d)
             , list(l)
         {}
-        Data data;
+        ~Sync();
         QQmlListModel *list;
     };
 
diff --git a/src/qml/types/qqmlmodelsmodule.cpp b/src/qml/types/qqmlmodelsmodule.cpp
index c36e26a525..b7b9c9ee1c 100644
--- a/src/qml/types/qqmlmodelsmodule.cpp
+++ b/src/qml/types/qqmlmodelsmodule.cpp
@@ -39,9 +39,15 @@
 
 #include "qqmlmodelsmodule_p.h"
 #include <QtCore/qitemselectionmodel.h>
+#if QT_CONFIG(qml_list_model)
 #include <private/qqmllistmodel_p.h>
+#endif
+#if QT_CONFIG(qml_delegate_model)
 #include <private/qqmldelegatemodel_p.h>
+#include <private/qqmldelegatecomponent_p.h>
+#endif
 #include <private/qqmlobjectmodel_p.h>
+#include <private/qqmltablemodel_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -49,14 +55,28 @@ void QQmlModelsModule::defineModule()
 {
     const char uri[] = "QtQml.Models";
 
+#if QT_CONFIG(qml_list_model)
     qmlRegisterType<QQmlListElement>(uri, 2, 1, "ListElement");
     qmlRegisterCustomType<QQmlListModel>(uri, 2, 1, "ListModel", new QQmlListModelParser);
+#endif
+#if QT_CONFIG(qml_delegate_model)
     qmlRegisterType<QQmlDelegateModel>(uri, 2, 1, "DelegateModel");
     qmlRegisterType<QQmlDelegateModelGroup>(uri, 2, 1, "DelegateModelGroup");
+#endif
     qmlRegisterType<QQmlObjectModel>(uri, 2, 1, "ObjectModel");
     qmlRegisterType<QQmlObjectModel,3>(uri, 2, 3, "ObjectModel");
 
     qmlRegisterType<QItemSelectionModel>(uri, 2, 2, "ItemSelectionModel");
 }
 
+void QQmlModelsModule::defineLabsModule()
+{
+    const char uri[] = "Qt.labs.qmlmodels";
+
+    qmlRegisterUncreatableType<QQmlAbstractDelegateComponent>(uri, 1, 0, "AbstractDelegateComponent", QQmlAbstractDelegateComponent::tr("Cannot create instance of abstract class AbstractDelegateComponent."));
+    qmlRegisterType<QQmlDelegateChooser>(uri, 1, 0, "DelegateChooser");
+    qmlRegisterType<QQmlDelegateChoice>(uri, 1, 0, "DelegateChoice");
+    qmlRegisterType<QQmlTableModel>(uri, 1, 0, "TableModel");
+}
+
 QT_END_NAMESPACE
diff --git a/src/qml/types/qqmlmodelsmodule_p.h b/src/qml/types/qqmlmodelsmodule_p.h
index bac9bea81e..939ecc1500 100644
--- a/src/qml/types/qqmlmodelsmodule_p.h
+++ b/src/qml/types/qqmlmodelsmodule_p.h
@@ -59,6 +59,7 @@ class Q_QML_PRIVATE_EXPORT QQmlModelsModule
 {
 public:
     static void defineModule();
+    static void defineLabsModule();
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/types/qqmlobjectmodel.cpp b/src/qml/types/qqmlobjectmodel.cpp
index 2814b9d38f..2f4d427430 100644
--- a/src/qml/types/qqmlobjectmodel.cpp
+++ b/src/qml/types/qqmlobjectmodel.cpp
@@ -72,7 +72,7 @@ public:
         int ref;
     };
 
-    QQmlObjectModelPrivate() : QObjectPrivate() {}
+    QQmlObjectModelPrivate() : QObjectPrivate(), moveId(0) {}
 
     static void children_append(QQmlListProperty<QObject> *prop, QObject *item) {
         int index = static_cast<QQmlObjectModelPrivate *>(prop->data)->children.count();
@@ -129,7 +129,7 @@ public:
         }
 
         QQmlChangeSet changeSet;
-        changeSet.move(from, to, n, -1);
+        changeSet.move(from, to, n, ++moveId);
         emit q->modelUpdated(changeSet, false);
         emit q->childrenChanged();
     }
@@ -166,7 +166,7 @@ public:
         return -1;
     }
 
-
+    uint moveId;
     QList<Item> children;
 };
 
@@ -176,7 +176,7 @@ public:
     \instantiates QQmlObjectModel
     \inqmlmodule QtQml.Models
     \ingroup qtquick-models
-    \brief Defines a set of items to be used as a model
+    \brief Defines a set of items to be used as a model.
 
     An ObjectModel contains the visual items to be used in a view.
     When an ObjectModel is used in a view, the view does not require
@@ -206,27 +206,10 @@ public:
     }
     \endcode
 
-    \image visualitemmodel.png
+    \image objectmodel.png
 
     \sa {Qt Quick Examples - Views}
 */
-/*!
-    \qmltype VisualItemModel
-    \instantiates QQmlObjectModel
-    \inqmlmodule QtQuick
-    \brief Defines a set of objects to be used as a model
-
-    The VisualItemModel type contains the objects to be used
-    as a model.
-
-    This element is now primarily available as ObjectModel in the QtQml.Models module.
-    VisualItemModel continues to be provided, with the same implementation, in \c QtQuick for
-    compatibility reasons.
-
-    For full details about the type, see the \l ObjectModel documentation.
-
-    \sa {QtQml.Models::ObjectModel}
-*/
 
 QQmlObjectModel::QQmlObjectModel(QObject *parent)
     : QQmlInstanceModel(*(new QQmlObjectModelPrivate), parent)
@@ -267,7 +250,7 @@ bool QQmlObjectModel::isValid() const
     return true;
 }
 
-QObject *QQmlObjectModel::object(int index, bool)
+QObject *QQmlObjectModel::object(int index, QQmlIncubator::IncubationMode)
 {
     Q_D(QQmlObjectModel);
     QQmlObjectModelPrivate::Item &item = d->children[index];
@@ -287,7 +270,7 @@ QQmlInstanceModel::ReleaseFlags QQmlObjectModel::release(QObject *item)
         if (!d->children[idx].deref())
             return QQmlInstanceModel::Referenced;
     }
-    return 0;
+    return nullptr;
 }
 
 QString QQmlObjectModel::stringValue(int index, const QString &name)
@@ -298,6 +281,11 @@ QString QQmlObjectModel::stringValue(int index, const QString &name)
     return QQmlEngine::contextForObject(d->children.at(index).item)->contextProperty(name).toString();
 }
 
+QQmlIncubator::Status QQmlObjectModel::incubationStatus(int)
+{
+    return QQmlIncubator::Ready;
+}
+
 int QQmlObjectModel::indexOf(QObject *item, QObject *) const
 {
     Q_D(const QQmlObjectModel);
@@ -332,7 +320,7 @@ QObject *QQmlObjectModel::get(int index) const
 {
     Q_D(const QQmlObjectModel);
     if (index < 0 || index >= d->children.count())
-        return 0;
+        return nullptr;
     return d->children.at(index).item;
 }
 
diff --git a/src/qml/types/qqmlobjectmodel_p.h b/src/qml/types/qqmlobjectmodel_p.h
index fc4c03874f..4ac4f1c65b 100644
--- a/src/qml/types/qqmlobjectmodel_p.h
+++ b/src/qml/types/qqmlobjectmodel_p.h
@@ -52,6 +52,7 @@
 //
 
 #include <private/qtqmlglobal_p.h>
+#include <private/qqmlincubator_p.h>
 #include <QtQml/qqml.h>
 #include <QtCore/qobject.h>
 
@@ -59,6 +60,7 @@ QT_BEGIN_NAMESPACE
 
 class QObject;
 class QQmlChangeSet;
+class QAbstractItemModel;
 
 class Q_QML_PRIVATE_EXPORT QQmlInstanceModel : public QObject
 {
@@ -74,13 +76,15 @@ public:
 
     virtual int count() const = 0;
     virtual bool isValid() const = 0;
-    virtual QObject *object(int index, bool asynchronous=false) = 0;
+    virtual QObject *object(int index, QQmlIncubator::IncubationMode incubationMode = QQmlIncubator::AsynchronousIfNested) = 0;
     virtual ReleaseFlags release(QObject *object) = 0;
     virtual void cancel(int) {}
     virtual QString stringValue(int, const QString &) = 0;
     virtual void setWatchedRoles(const QList<QByteArray> &roles) = 0;
+    virtual QQmlIncubator::Status incubationStatus(int index) = 0;
 
     virtual int indexOf(QObject *object, QObject *objectContext) const = 0;
+    virtual const QAbstractItemModel *abstractItemModel() const { return nullptr; }
 
 Q_SIGNALS:
     void countChanged();
@@ -90,7 +94,7 @@ Q_SIGNALS:
     void destroyingItem(QObject *object);
 
 protected:
-    QQmlInstanceModel(QObjectPrivate &dd, QObject *parent = 0)
+    QQmlInstanceModel(QObjectPrivate &dd, QObject *parent = nullptr)
         : QObject(dd, parent) {}
 
 private:
@@ -108,15 +112,16 @@ class Q_QML_PRIVATE_EXPORT QQmlObjectModel : public QQmlInstanceModel
     Q_CLASSINFO("DefaultProperty", "children")
 
 public:
-    QQmlObjectModel(QObject *parent=0);
+    QQmlObjectModel(QObject *parent=nullptr);
     ~QQmlObjectModel() {}
 
     int count() const override;
     bool isValid() const override;
-    QObject *object(int index, bool asynchronous = false) override;
+    QObject *object(int index, QQmlIncubator::IncubationMode incubationMode = QQmlIncubator::AsynchronousIfNested) override;
     ReleaseFlags release(QObject *object) override;
     QString stringValue(int index, const QString &role) override;
     void setWatchedRoles(const QList<QByteArray> &) override {}
+    QQmlIncubator::Status incubationStatus(int index) override;
 
     int indexOf(QObject *object, QObject *objectContext) const override;
 
diff --git a/src/qml/types/qqmltableinstancemodel.cpp b/src/qml/types/qqmltableinstancemodel.cpp
new file mode 100644
index 0000000000..2170e2daec
--- /dev/null
+++ b/src/qml/types/qqmltableinstancemodel.cpp
@@ -0,0 +1,547 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmltableinstancemodel_p.h"
+#include "qqmldelegatecomponent_p.h"
+
+#include <QtCore/QTimer>
+
+#include <QtQml/private/qqmlincubator_p.h>
+#include <QtQml/private/qqmlchangeset_p.h>
+#include <QtQml/private/qqmlcomponent_p.h>
+
+QT_BEGIN_NAMESPACE
+
+const char* kModelItemTag = "_tableinstancemodel_modelItem";
+
+bool QQmlTableInstanceModel::isDoneIncubating(QQmlDelegateModelItem *modelItem)
+{
+    if (!modelItem->incubationTask)
+        return true;
+
+    const auto status = modelItem->incubationTask->status();
+    return (status == QQmlIncubator::Ready) || (status == QQmlIncubator::Error);
+}
+
+void QQmlTableInstanceModel::deleteModelItemLater(QQmlDelegateModelItem *modelItem)
+{
+    Q_ASSERT(modelItem);
+
+    delete modelItem->object;
+    modelItem->object = nullptr;
+
+    if (modelItem->contextData) {
+        modelItem->contextData->invalidate();
+        Q_ASSERT(modelItem->contextData->refCount == 1);
+        modelItem->contextData = nullptr;
+    }
+
+    modelItem->deleteLater();
+}
+
+QQmlTableInstanceModel::QQmlTableInstanceModel(QQmlContext *qmlContext, QObject *parent)
+    : QQmlInstanceModel(*(new QObjectPrivate()), parent)
+    , m_qmlContext(qmlContext)
+    , m_metaType(new QQmlDelegateModelItemMetaType(m_qmlContext->engine()->handle(), nullptr, QStringList()))
+{
+}
+
+void QQmlTableInstanceModel::useImportVersion(int minorVersion)
+{
+    m_adaptorModel.useImportVersion(minorVersion);
+}
+
+QQmlTableInstanceModel::~QQmlTableInstanceModel()
+{
+    for (const auto modelItem : m_modelItems) {
+        // No item in m_modelItems should be referenced at this point. The view
+        // should release all its items before it deletes this model. Only model items
+        // that are still being incubated should be left for us to delete.
+        Q_ASSERT(modelItem->objectRef == 0);
+        Q_ASSERT(modelItem->incubationTask);
+        // Check that we are not being deleted while we're
+        // in the process of e.g emitting a created signal.
+        Q_ASSERT(modelItem->scriptRef == 0);
+
+        if (modelItem->object) {
+            delete modelItem->object;
+            modelItem->object = nullptr;
+            modelItem->contextData->invalidate();
+            modelItem->contextData = nullptr;
+        }
+    }
+
+    deleteAllFinishedIncubationTasks();
+    qDeleteAll(m_modelItems);
+    drainReusableItemsPool(0);
+}
+
+QQmlComponent *QQmlTableInstanceModel::resolveDelegate(int index)
+{
+    if (m_delegateChooser) {
+        const int row = m_adaptorModel.rowAt(index);
+        const int column = m_adaptorModel.columnAt(index);
+        QQmlComponent *delegate = nullptr;
+        QQmlAbstractDelegateComponent *chooser = m_delegateChooser;
+        do {
+            delegate = chooser->delegate(&m_adaptorModel, row, column);
+            chooser = qobject_cast<QQmlAbstractDelegateComponent *>(delegate);
+        } while (chooser);
+        return delegate;
+    }
+
+    return m_delegate;
+}
+
+QQmlDelegateModelItem *QQmlTableInstanceModel::resolveModelItem(int index)
+{
+    // Check if an item for the given index is already loaded and ready
+    QQmlDelegateModelItem *modelItem = m_modelItems.value(index, nullptr);
+    if (modelItem)
+        return modelItem;
+
+    QQmlComponent *delegate = resolveDelegate(index);
+    if (!delegate)
+        return nullptr;
+
+    // Check if the pool contains an item that can be reused
+    modelItem = takeFromReusableItemsPool(delegate);
+    if (modelItem) {
+        reuseItem(modelItem, index);
+        m_modelItems.insert(index, modelItem);
+        return modelItem;
+    }
+
+    // Create a new item from scratch
+    modelItem = m_adaptorModel.createItem(m_metaType, index);
+    if (modelItem) {
+        modelItem->delegate = delegate;
+        m_modelItems.insert(index, modelItem);
+        return modelItem;
+    }
+
+    qWarning() << Q_FUNC_INFO << "failed creating a model item for index: " << index;
+    return nullptr;
+}
+
+QObject *QQmlTableInstanceModel::object(int index, QQmlIncubator::IncubationMode incubationMode)
+{
+    Q_ASSERT(m_delegate);
+    Q_ASSERT(index >= 0 && index < m_adaptorModel.count());
+    Q_ASSERT(m_qmlContext && m_qmlContext->isValid());
+
+    QQmlDelegateModelItem *modelItem = resolveModelItem(index);
+    if (!modelItem)
+        return nullptr;
+
+    if (modelItem->object) {
+        // The model item has already been incubated. So
+        // just bump the ref-count and return it.
+        modelItem->referenceObject();
+        return modelItem->object;
+    }
+
+    // The object is not ready, and needs to be incubated
+    incubateModelItem(modelItem, incubationMode);
+    if (!isDoneIncubating(modelItem))
+        return nullptr;
+
+    // Incubation is done, so the task should be removed
+    Q_ASSERT(!modelItem->incubationTask);
+
+    if (!modelItem->object) {
+        // The object was incubated synchronously (otherwise we would return above). But since
+        // we have no object, the incubation must have failed. And when we have no object, there
+        // should be no object references either. And there should also not be any internal script
+        // refs at this point. So we delete the model item.
+        Q_ASSERT(!modelItem->isObjectReferenced());
+        Q_ASSERT(!modelItem->isReferenced());
+        m_modelItems.remove(modelItem->index);
+        delete modelItem;
+        return nullptr;
+    }
+
+    // Incubation was completed sync and successful
+    modelItem->referenceObject();
+    return modelItem->object;
+}
+
+QQmlInstanceModel::ReleaseFlags QQmlTableInstanceModel::release(QObject *object, ReusableFlag reusable)
+{
+    Q_ASSERT(object);
+    auto modelItem = qvariant_cast<QQmlDelegateModelItem *>(object->property(kModelItemTag));
+    Q_ASSERT(modelItem);
+
+    if (!modelItem->releaseObject())
+        return QQmlDelegateModel::Referenced;
+
+    if (modelItem->isReferenced()) {
+        // We still have an internal reference to this object, which means that we are told to release an
+        // object while the createdItem signal for it is still on the stack. This can happen when objects
+        // are e.g delivered async, and the user flicks back and forth quicker than the loading can catch
+        // up with. The view might then find that the object is no longer visible and should be released.
+        // We detect this case in incubatorStatusChanged(), and delete it there instead. But from the callers
+        // point of view, it should consider it destroyed.
+        return QQmlDelegateModel::Destroyed;
+    }
+
+    // The item is not referenced by anyone
+    m_modelItems.remove(modelItem->index);
+
+    if (reusable == Reusable) {
+        insertIntoReusableItemsPool(modelItem);
+        return QQmlInstanceModel::Referenced;
+    }
+
+    // The item is not reused or referenced by anyone, so just delete it
+    modelItem->destroyObject();
+    emit destroyingItem(object);
+
+    delete modelItem;
+    return QQmlInstanceModel::Destroyed;
+}
+
+void QQmlTableInstanceModel::cancel(int index)
+{
+    auto modelItem = m_modelItems.value(index);
+    Q_ASSERT(modelItem);
+
+    // Since the view expects the item to be incubating, there should be
+    // an incubation task. And since the incubation is not done, no-one
+    // should yet have received, and therfore hold a reference to, the object.
+    Q_ASSERT(modelItem->incubationTask);
+    Q_ASSERT(!modelItem->isObjectReferenced());
+
+    m_modelItems.remove(index);
+
+    if (modelItem->object)
+        delete modelItem->object;
+
+    // modelItem->incubationTask will be deleted from the modelItems destructor
+    delete modelItem;
+}
+
+void QQmlTableInstanceModel::insertIntoReusableItemsPool(QQmlDelegateModelItem *modelItem)
+{
+    // Currently, the only way for a view to reuse items is to call QQmlTableInstanceModel::release()
+    // with the second argument explicitly set to QQmlTableInstanceModel::Reusable. If the released
+    // item is no longer referenced, it will be added to the pool. Reusing of items can be specified
+    // per item, in case certain items cannot be recycled.
+    // A QQmlDelegateModelItem knows which delegate its object was created from. So when we are
+    // about to create a new item, we first check if the pool contains an item based on the same
+    // delegate from before. If so, we take it out of the pool (instead of creating a new item), and
+    // update all its context-, and attached properties.
+    // When a view is recycling items, it should call QQmlTableInstanceModel::drainReusableItemsPool()
+    // regularly. As there is currently no logic to 'hibernate' items in the pool, they are only
+    // meant to rest there for a short while, ideally only from the time e.g a row is unloaded
+    // on one side of the view, and until a new row is loaded on the opposite side. In-between
+    // this time, the application will see the item as fully functional and 'alive' (just not
+    // visible on screen). Since this time is supposed to be short, we don't take any action to
+    // notify the application about it, since we don't want to trigger any bindings that can
+    // disturb performance.
+    // A recommended time for calling drainReusableItemsPool() is each time a view has finished
+    // loading e.g a new row or column. If there are more items in the pool after that, it means
+    // that the view most likely doesn't need them anytime soon. Those items should be destroyed to
+    // not consume resources.
+    // Depending on if a view is a list or a table, it can sometimes be performant to keep
+    // items in the pool for a bit longer than one "row out/row in" cycle. E.g for a table, if the
+    // number of visible rows in a view is much larger than the number of visible columns.
+    // In that case, if you flick out a row, and then flick in a column, you would throw away a lot
+    // of items in the pool if completely draining it. The reason is that unloading a row places more
+    // items in the pool than what ends up being recycled when loading a new column. And then, when you
+    // next flick in a new row, you would need to load all those drained items again from scratch. For
+    // that reason, you can specify a maxPoolTime to the drainReusableItemsPool() that allows you to keep
+    // items in the pool for a bit longer, effectively keeping more items in circulation.
+    // A recommended maxPoolTime would be equal to the number of dimenstions in the view, which
+    // means 1 for a list view and 2 for a table view. If you specify 0, all items will be drained.
+    Q_ASSERT(!modelItem->incubationTask);
+    Q_ASSERT(!modelItem->isObjectReferenced());
+    Q_ASSERT(!modelItem->isReferenced());
+    Q_ASSERT(modelItem->object);
+
+    modelItem->poolTime = 0;
+    m_reusableItemsPool.append(modelItem);
+    emit itemPooled(modelItem->index, modelItem->object);
+}
+
+QQmlDelegateModelItem *QQmlTableInstanceModel::takeFromReusableItemsPool(const QQmlComponent *delegate)
+{
+    // Find the oldest item in the pool that was made from the same delegate as
+    // the given argument, remove it from the pool, and return it.
+    if (m_reusableItemsPool.isEmpty())
+        return nullptr;
+
+    for (auto it = m_reusableItemsPool.begin(); it != m_reusableItemsPool.end(); ++it) {
+        if ((*it)->delegate != delegate)
+            continue;
+        auto modelItem = *it;
+        m_reusableItemsPool.erase(it);
+        return modelItem;
+    }
+
+    return nullptr;
+}
+
+void QQmlTableInstanceModel::drainReusableItemsPool(int maxPoolTime)
+{
+    // Rather than releasing all pooled items upon a call to this function, each
+    // item has a poolTime. The poolTime specifies for how many loading cycles an item
+    // has been resting in the pool. And for each invocation of this function, poolTime
+    // will increase. If poolTime is equal to, or exceeds, maxPoolTime, it will be removed
+    // from the pool and released. This way, the view can tweak a bit for how long
+    // items should stay in "circulation", even if they are not recycled right away.
+    for (auto it = m_reusableItemsPool.begin(); it != m_reusableItemsPool.end();) {
+        auto modelItem = *it;
+        modelItem->poolTime++;
+        if (modelItem->poolTime <= maxPoolTime) {
+            ++it;
+        } else {
+            it = m_reusableItemsPool.erase(it);
+            release(modelItem->object, NotReusable);
+        }
+    }
+}
+
+void QQmlTableInstanceModel::reuseItem(QQmlDelegateModelItem *item, int newModelIndex)
+{
+    // Update the context properties index, row and column on
+    // the delegate item, and inform the application about it.
+    const int newRow = m_adaptorModel.rowAt(newModelIndex);
+    const int newColumn = m_adaptorModel.columnAt(newModelIndex);
+    item->setModelIndex(newModelIndex, newRow, newColumn);
+
+    // Notify the application that all 'dynamic'/role-based context data has
+    // changed as well (their getter function will use the updated index).
+    auto const itemAsList = QList<QQmlDelegateModelItem *>() << item;
+    auto const updateAllRoles = QVector<int>();
+    m_adaptorModel.notify(itemAsList, newModelIndex, 1, updateAllRoles);
+
+    // Inform the view that the item is recycled. This will typically result
+    // in the view updating its own attached delegate item properties.
+    emit itemReused(newModelIndex, item->object);
+}
+
+void QQmlTableInstanceModel::incubateModelItem(QQmlDelegateModelItem *modelItem, QQmlIncubator::IncubationMode incubationMode)
+{
+    // Guard the model item temporarily so that it's not deleted from
+    // incubatorStatusChanged(), in case the incubation is done synchronously.
+    modelItem->scriptRef++;
+
+    if (modelItem->incubationTask) {
+        // We're already incubating the model item from a previous request. If the previous call requested
+        // the item async, but the current request needs it sync, we need to force-complete the incubation.
+        const bool sync = (incubationMode == QQmlIncubator::Synchronous || incubationMode == QQmlIncubator::AsynchronousIfNested);
+        if (sync && modelItem->incubationTask->incubationMode() == QQmlIncubator::Asynchronous)
+            modelItem->incubationTask->forceCompletion();
+    } else {
+        modelItem->incubationTask = new QQmlTableInstanceModelIncubationTask(this, modelItem, incubationMode);
+
+        QQmlContextData *ctxt = new QQmlContextData;
+        QQmlContext *creationContext = modelItem->delegate->creationContext();
+        ctxt->setParent(QQmlContextData::get(creationContext  ? creationContext : m_qmlContext.data()));
+        ctxt->contextObject = modelItem;
+        modelItem->contextData = ctxt;
+
+        QQmlComponentPrivate::get(modelItem->delegate)->incubateObject(
+                    modelItem->incubationTask,
+                    modelItem->delegate,
+                    m_qmlContext->engine(),
+                    ctxt,
+                    QQmlContextData::get(m_qmlContext));
+    }
+
+    // Remove the temporary guard
+    modelItem->scriptRef--;
+}
+
+void QQmlTableInstanceModel::incubatorStatusChanged(QQmlTableInstanceModelIncubationTask *incubationTask, QQmlIncubator::Status status)
+{
+    QQmlDelegateModelItem *modelItem = incubationTask->modelItemToIncubate;
+    Q_ASSERT(modelItem->incubationTask);
+
+    modelItem->incubationTask = nullptr;
+    incubationTask->modelItemToIncubate = nullptr;
+
+    if (status == QQmlIncubator::Ready) {
+        // Tag the incubated object with the model item for easy retrieval upon release etc.
+        modelItem->object->setProperty(kModelItemTag, QVariant::fromValue(modelItem));
+
+        // Emit that the item has been created. What normally happens next is that the view
+        // upon receiving the signal asks for the model item once more. And since the item is
+        // now in the map, it will be returned directly.
+        Q_ASSERT(modelItem->object);
+        modelItem->scriptRef++;
+        emit createdItem(modelItem->index, modelItem->object);
+        modelItem->scriptRef--;
+    } else if (status == QQmlIncubator::Error) {
+        qWarning() << "Error incubating delegate:" << incubationTask->errors();
+    }
+
+    if (!modelItem->isReferenced() && !modelItem->isObjectReferenced()) {
+        // We have no internal reference to the model item, and the view has no
+        // reference to the incubated object. So just delete the model item.
+        // Note that being here means that the object was incubated _async_
+        // (otherwise modelItem->isReferenced() would be true).
+        m_modelItems.remove(modelItem->index);
+
+        if (modelItem->object) {
+            modelItem->scriptRef++;
+            emit destroyingItem(modelItem->object);
+            modelItem->scriptRef--;
+            Q_ASSERT(!modelItem->isReferenced());
+        }
+
+        deleteModelItemLater(modelItem);
+    }
+
+    deleteIncubationTaskLater(incubationTask);
+}
+
+QQmlIncubator::Status QQmlTableInstanceModel::incubationStatus(int index) {
+    const auto modelItem = m_modelItems.value(index, nullptr);
+    if (!modelItem)
+        return QQmlIncubator::Null;
+
+    if (modelItem->incubationTask)
+        return modelItem->incubationTask->status();
+
+    // Since we clear the incubation task when we're done
+    // incubating, it means that the status is Ready.
+    return QQmlIncubator::Ready;
+}
+
+void QQmlTableInstanceModel::deleteIncubationTaskLater(QQmlIncubator *incubationTask)
+{
+    // We often need to post-delete incubation tasks, since we cannot
+    // delete them while we're in the middle of an incubation change callback.
+    Q_ASSERT(!m_finishedIncubationTasks.contains(incubationTask));
+    m_finishedIncubationTasks.append(incubationTask);
+    if (m_finishedIncubationTasks.count() == 1)
+        QTimer::singleShot(1, this, &QQmlTableInstanceModel::deleteAllFinishedIncubationTasks);
+}
+
+void QQmlTableInstanceModel::deleteAllFinishedIncubationTasks()
+{
+    qDeleteAll(m_finishedIncubationTasks);
+    m_finishedIncubationTasks.clear();
+}
+
+QVariant QQmlTableInstanceModel::model() const
+{
+    return m_adaptorModel.model();
+}
+
+void QQmlTableInstanceModel::setModel(const QVariant &model)
+{
+    // Pooled items are still accessible/alive for the application, and
+    // needs to stay in sync with the model. So we need to drain the pool
+    // completely when the model changes.
+    drainReusableItemsPool(0);
+    if (auto const aim = abstractItemModel())
+        disconnect(aim, &QAbstractItemModel::dataChanged, this, &QQmlTableInstanceModel::dataChangedCallback);
+    m_adaptorModel.setModel(model, this, m_qmlContext->engine());
+    if (auto const aim = abstractItemModel())
+        connect(aim, &QAbstractItemModel::dataChanged, this, &QQmlTableInstanceModel::dataChangedCallback);
+}
+
+void QQmlTableInstanceModel::dataChangedCallback(const QModelIndex &begin, const QModelIndex &end, const QVector<int> &roles)
+{
+    // This function is called when model data has changed. In that case, we tell the adaptor model
+    // to go through all the items we have created, find the ones that are affected, and notify that
+    // their model data has changed. This will in turn update QML bindings inside the delegate items.
+    int numberOfRowsChanged = end.row() - begin.row() + 1;
+    int numberOfColumnsChanged = end.column() - begin.column() + 1;
+
+    for (int column = 0; column < numberOfColumnsChanged; ++column) {
+        const int columnIndex = begin.column() + column;
+        const int rowIndex = begin.row() + (columnIndex * rows());
+        m_adaptorModel.notify(m_modelItems.values(), rowIndex, numberOfRowsChanged, roles);
+    }
+}
+
+QQmlComponent *QQmlTableInstanceModel::delegate() const
+{
+    return m_delegate;
+}
+
+void QQmlTableInstanceModel::setDelegate(QQmlComponent *delegate)
+{
+    if (m_delegate == delegate)
+        return;
+
+    m_delegateChooser = nullptr;
+    if (delegate) {
+        QQmlAbstractDelegateComponent *adc =
+                qobject_cast<QQmlAbstractDelegateComponent *>(delegate);
+        if (adc)
+            m_delegateChooser = adc;
+    }
+
+    m_delegate = delegate;
+}
+
+const QAbstractItemModel *QQmlTableInstanceModel::abstractItemModel() const
+{
+    return m_adaptorModel.adaptsAim() ? m_adaptorModel.aim() : nullptr;
+}
+
+// --------------------------------------------------------
+
+void QQmlTableInstanceModelIncubationTask::setInitialState(QObject *object)
+{
+    modelItemToIncubate->object = object;
+    emit tableInstanceModel->initItem(modelItemToIncubate->index, object);
+}
+
+void QQmlTableInstanceModelIncubationTask::statusChanged(QQmlIncubator::Status status)
+{
+    if (!QQmlTableInstanceModel::isDoneIncubating(modelItemToIncubate))
+        return;
+
+    // We require the view to cancel any ongoing load
+    // requests before the tableInstanceModel is destructed.
+    Q_ASSERT(tableInstanceModel);
+
+    tableInstanceModel->incubatorStatusChanged(this, status);
+}
+
+#include "moc_qqmltableinstancemodel_p.cpp"
+
+QT_END_NAMESPACE
+
diff --git a/src/qml/types/qqmltableinstancemodel_p.h b/src/qml/types/qqmltableinstancemodel_p.h
new file mode 100644
index 0000000000..3dd5c4e4ce
--- /dev/null
+++ b/src/qml/types/qqmltableinstancemodel_p.h
@@ -0,0 +1,162 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTABLEINSTANCEMODEL_P_H
+#define QQMLTABLEINSTANCEMODEL_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQml/private/qqmldelegatemodel_p.h>
+#include <QtQml/private/qqmldelegatemodel_p_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQmlTableInstanceModel;
+class QQmlAbstractDelegateComponent;
+
+class QQmlTableInstanceModelIncubationTask : public QQDMIncubationTask
+{
+public:
+    QQmlTableInstanceModelIncubationTask(
+            QQmlTableInstanceModel *tableInstanceModel
+            , QQmlDelegateModelItem* modelItemToIncubate
+            , IncubationMode mode)
+        : QQDMIncubationTask(nullptr, mode)
+        , modelItemToIncubate(modelItemToIncubate)
+        , tableInstanceModel(tableInstanceModel) {
+        clear();
+    }
+
+    void statusChanged(Status status) override;
+    void setInitialState(QObject *object) override;
+
+    QQmlDelegateModelItem *modelItemToIncubate = nullptr;
+    QQmlTableInstanceModel *tableInstanceModel = nullptr;
+};
+
+class Q_QML_PRIVATE_EXPORT QQmlTableInstanceModel : public QQmlInstanceModel
+{
+    Q_OBJECT
+
+public:
+
+    enum ReusableFlag {
+        NotReusable,
+        Reusable
+    };
+
+    QQmlTableInstanceModel(QQmlContext *qmlContext, QObject *parent = nullptr);
+    ~QQmlTableInstanceModel() override;
+
+    void useImportVersion(int minorVersion);
+
+    int count() const override { return m_adaptorModel.count(); }
+    int rows() const { return m_adaptorModel.rowCount(); }
+    int columns() const { return m_adaptorModel.columnCount(); }
+
+    bool isValid() const override { return true; }
+
+    QVariant model() const;
+    void setModel(const QVariant &model);
+
+    QQmlComponent *delegate() const;
+    void setDelegate(QQmlComponent *);
+
+    const QAbstractItemModel *abstractItemModel() const override;
+
+    QObject *object(int index, QQmlIncubator::IncubationMode incubationMode = QQmlIncubator::AsynchronousIfNested) override;
+    ReleaseFlags release(QObject *object) override { return release(object, NotReusable); }
+    ReleaseFlags release(QObject *object, ReusableFlag reusable);
+    void cancel(int) override;
+
+    void insertIntoReusableItemsPool(QQmlDelegateModelItem *modelItem);
+    QQmlDelegateModelItem *takeFromReusableItemsPool(const QQmlComponent *delegate);
+    void drainReusableItemsPool(int maxPoolTime);
+    int poolSize() { return m_reusableItemsPool.size(); }
+    void reuseItem(QQmlDelegateModelItem *item, int newModelIndex);
+
+    QQmlIncubator::Status incubationStatus(int index) override;
+
+    QString stringValue(int, const QString &) override { Q_UNREACHABLE(); return QString(); }
+    void setWatchedRoles(const QList<QByteArray> &) override { Q_UNREACHABLE(); }
+    int indexOf(QObject *, QObject *) const override { Q_UNREACHABLE(); return 0; }
+
+Q_SIGNALS:
+    void itemPooled(int index, QObject *object);
+    void itemReused(int index, QObject *object);
+
+private:
+    QQmlComponent *resolveDelegate(int index);
+
+    QQmlAdaptorModel m_adaptorModel;
+    QQmlAbstractDelegateComponent *m_delegateChooser = nullptr;
+    QQmlComponent *m_delegate = nullptr;
+    QPointer<QQmlContext> m_qmlContext;
+    QQmlDelegateModelItemMetaType *m_metaType;
+
+    QHash<int, QQmlDelegateModelItem *> m_modelItems;
+    QList<QQmlDelegateModelItem *> m_reusableItemsPool;
+    QList<QQmlIncubator *> m_finishedIncubationTasks;
+
+    void incubateModelItem(QQmlDelegateModelItem *modelItem, QQmlIncubator::IncubationMode incubationMode);
+    void incubatorStatusChanged(QQmlTableInstanceModelIncubationTask *dmIncubationTask, QQmlIncubator::Status status);
+    void deleteIncubationTaskLater(QQmlIncubator *incubationTask);
+    void deleteAllFinishedIncubationTasks();
+    QQmlDelegateModelItem *resolveModelItem(int index);
+
+    void dataChangedCallback(const QModelIndex &begin, const QModelIndex &end, const QVector<int> &roles);
+
+    static bool isDoneIncubating(QQmlDelegateModelItem *modelItem);
+    static void deleteModelItemLater(QQmlDelegateModelItem *modelItem);
+
+    friend class QQmlTableInstanceModelIncubationTask;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQMLTABLEINSTANCEMODEL_P_H
diff --git a/src/qml/types/qqmltablemodel.cpp b/src/qml/types/qqmltablemodel.cpp
new file mode 100644
index 0000000000..6068155f5a
--- /dev/null
+++ b/src/qml/types/qqmltablemodel.cpp
@@ -0,0 +1,950 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmltablemodel_p.h"
+
+#include <QtCore/qloggingcategory.h>
+#include <QtQml/qqmlinfo.h>
+#include <QtQml/qqmlengine.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_LOGGING_CATEGORY(lcTableModel, "qt.qml.tablemodel")
+
+static const QString lengthPropertyName = QStringLiteral("length");
+static const QString displayRoleName = QStringLiteral("display");
+
+/*!
+    \qmltype TableModel
+    \instantiates QQmlTableModel
+    \inqmlmodule Qt.labs.qmlmodels
+    \brief Encapsulates a simple table model.
+    \since 5.12
+
+    The TableModel type stores JavaScript objects as data for a table model
+    that can be used with \l TableView.
+
+    The following snippet shows the simplest use case for TableModel:
+
+    \snippet qml/tablemodel/fruit-example-simpledelegate.qml file
+
+    The model's initial data is set with either the \l rows property or by
+    calling \l appendRow(). Once the first row has been added to the table, the
+    columns and roles are established and will be fixed for the lifetime of the
+    model.
+
+    To access a specific row, the \l getRow() function can be used.
+    It's also possible to access the model's JavaScript data
+    directly via the \l rows property, but it is not possible to
+    modify the model data this way.
+
+    To add new rows, use \l appendRow() and \l insertRow(). To modify
+    existing rows, use \l setRow(), \l moveRow(), \l removeRow(), and
+    \l clear().
+
+    It is also possible to modify the model's data via the delegate,
+    as shown in the example above:
+
+    \snippet qml/tablemodel/fruit-example-simpledelegate.qml delegate
+
+    If the type of the data at the modified role does not match the type of the
+    data that is set, it will be automatically converted via
+    \l {QVariant::canConvert()}{QVariant}.
+
+    For convenience, TableModel provides the \c display role if it is not
+    explicitly specified in any column. When a column only has one role
+    declared, that role will be used used as the display role. However, when
+    there is more than one role in a column, which role will be used is
+    undefined. This is because JavaScript does not guarantee that properties
+    within an object can be accessed according to the order in which they were
+    declared. This is why \c checkable may be used as the display role for the
+    first column even though \c checked is declared before it, for example.
+
+    \section1 Using DelegateChooser with TableModel
+
+    For most real world use cases, it is recommended to use DelegateChooser
+    as the delegate of a TableView that uses TableModel. This allows you to
+    use specific roles in the relevant delegates. For example, the snippet
+    above can be rewritten to use DelegateChooser like so:
+
+    \snippet qml/tablemodel/fruit-example-delegatechooser.qml file
+
+    The most specific delegates are declared first: the columns at index \c 0
+    and \c 1 have \c bool and \c integer data types, so they use a
+    \l [QtQuickControls2]{CheckBox} and \l [QtQuickControls2]{SpinBox},
+    respectively. The remaining columns can simply use a
+    \l [QtQuickControls2]{TextField}, and so that delegate is declared
+    last as a fallback.
+
+    \sa QAbstractTableModel, TableView
+*/
+
+QQmlTableModel::QQmlTableModel(QObject *parent)
+    : QAbstractTableModel(parent)
+{
+    mRoleNames = QAbstractTableModel::roleNames();
+}
+
+QQmlTableModel::~QQmlTableModel()
+{
+}
+
+/*!
+    \qmlproperty object TableModel::rows
+
+    This property holds the model data in the form of an array of rows:
+
+    \snippet qml/tablemodel/fruit-example-simpledelegate.qml rows
+
+    \sa getRow(), setRow(), moveRow(), appendRow(), insertRow(), clear(), rowCount, columnCount
+*/
+QVariant QQmlTableModel::rows() const
+{
+    return mRows;
+}
+
+void QQmlTableModel::setRows(const QVariant &rows)
+{
+    if (rows.userType() != qMetaTypeId<QJSValue>()) {
+        qmlWarning(this) << "setRows(): \"rows\" must be an array; actual type is " << rows.typeName();
+        return;
+    }
+
+    const QJSValue rowsAsJSValue = rows.value<QJSValue>();
+    const QVariantList rowsAsVariantList = rowsAsJSValue.toVariant().toList();
+    if (rowsAsVariantList == mRows) {
+        // No change.
+        return;
+    }
+
+    QVariant firstRowAsVariant;
+    QVariantList firstRow;
+    if (!rowsAsVariantList.isEmpty()) {
+        // There are rows to validate. If they're not valid,
+        // we'll return early without changing anything.
+        firstRowAsVariant = rowsAsVariantList.first();
+        firstRow = firstRowAsVariant.toList();
+
+        if (firstRowAsVariant.type() != QVariant::List) {
+            qmlWarning(this) << "setRows(): each row in \"rows\" must be an array of objects";
+            return;
+        }
+
+        if (mColumnCount > 0) {
+            qCDebug(lcTableModel) << "validating" << rowsAsVariantList.size()
+                << "rows against existing metadata";
+
+            // This is not the first time the rows have been set; validate the new columns.
+            for (int i = 0; i < rowsAsVariantList.size(); ++i) {
+                // validateNewRow() expects a QVariant wrapping a QJSValue, so to
+                // simplify the code, just create one here.
+                const QVariant row = QVariant::fromValue(rowsAsJSValue.property(i));
+                if (!validateNewRow("setRows()", row, i))
+                    return;
+            }
+        }
+    }
+
+    const int oldRowCount = mRowCount;
+    const int oldColumnCount = mColumnCount;
+
+    beginResetModel();
+
+    // We don't clear the column or role data, because a TableModel should not be reused in that way.
+    // Once it has valid data, its columns and roles are fixed.
+    mRows = rowsAsVariantList;
+    mRowCount = mRows.size();
+
+    const bool isFirstTimeSet = mColumnCount == 0;
+    if (isFirstTimeSet && mRowCount > 0) {
+        // This is the first time the rows have been set, so establish
+        // the column count and gather column metadata.
+        mColumnCount = firstRow.size();
+        qCDebug(lcTableModel) << "gathering metadata for" << mColumnCount << "columns from first row:";
+
+        // Go through each property of each cell in the first row
+        // and make a role name from it.
+        int userRoleKey = Qt::UserRole;
+        for (int columnIndex = 0; columnIndex < mColumnCount; ++columnIndex) {
+            // We need it as a QVariantMap because we need to get
+            // the name of the property, which we can't do with QJSValue's API.
+            const QVariantMap column = firstRow.at(columnIndex).toMap();
+            const QStringList columnPropertyNames = column.keys();
+            ColumnProperties properties;
+            int propertyInfoIndex = 0;
+
+            qCDebug(lcTableModel).nospace() << "- column " << columnIndex << ":";
+
+            for (const QString &roleName : columnPropertyNames) {
+                // QML/JS supports utf8.
+                const QByteArray roleNameUtf8 = roleName.toUtf8();
+                if (!mRoleNames.values().contains(roleNameUtf8)) {
+                    // We don't already have this role name, so it's a user role.
+                    mRoleNames[userRoleKey] = roleName.toUtf8().constData();
+                    qCDebug(lcTableModel) << "  - added new user role" << roleName << "with key" << userRoleKey;
+                    ++userRoleKey;
+                } else {
+                    qCDebug(lcTableModel) << "  - found existing role" << roleName;
+                }
+
+                if (properties.explicitDisplayRoleIndex == -1 && roleName == displayRoleName) {
+                    // The user explicitly declared a "display" role,
+                    // so now we don't need to make it the first role in the column for them.
+                    properties.explicitDisplayRoleIndex = propertyInfoIndex;
+                }
+
+                // Keep track of the type of property so we can use it to validate new rows later on.
+                const QVariant roleValue = column.value(roleName);
+                const auto propertyInfo = ColumnPropertyInfo(roleName, roleValue.type(),
+                    QString::fromLatin1(roleValue.typeName()));
+                properties.infoForProperties.append(propertyInfo);
+
+                qCDebug(lcTableModel) << "    - column property" << propertyInfo.name
+                    << "has type" << propertyInfo.typeName;
+
+                ++propertyInfoIndex;
+            }
+
+            mColumnProperties.append(properties);
+        }
+    }
+
+    endResetModel();
+
+    emit rowsChanged();
+
+    if (mRowCount != oldRowCount)
+        emit rowCountChanged();
+    if (mColumnCount != oldColumnCount)
+        emit columnCountChanged();
+}
+
+/*!
+    \qmlmethod TableModel::appendRow(object row)
+
+    Adds a new row to the end of the model, with the
+    values (cells) in \a row.
+
+    \code
+        model.appendRow([
+            { checkable: true, checked: false },
+            { amount: 1 },
+            { fruitType: "Pear" },
+            { fruitName: "Williams" },
+            { fruitPrice: 1.50 },
+        ])
+    \endcode
+
+    \sa insertRow(), setRow(), removeRow()
+*/
+void QQmlTableModel::appendRow(const QVariant &row)
+{
+    if (!validateNewRow("appendRow()", row, -1, AppendOperation))
+        return;
+
+    doInsert(mRowCount, row);
+}
+
+/*!
+    \qmlmethod TableModel::clear()
+
+    Removes all rows from the model.
+
+    \sa removeRow()
+*/
+void QQmlTableModel::clear()
+{
+    QQmlEngine *engine = qmlEngine(this);
+    Q_ASSERT(engine);
+    setRows(QVariant::fromValue(engine->newArray()));
+}
+
+/*!
+    \qmlmethod object TableModel::getRow(int rowIndex)
+
+    Returns the row at \a rowIndex in the model.
+
+    Note that this equivalent to accessing the row directly
+    through the \l rows property:
+
+    \code
+    Component.onCompleted: {
+        // These two lines are equivalent.
+        console.log(model.getRow(0).fruitName);
+        console.log(model.rows[0].fruitName);
+    }
+    \endcode
+
+    \note the returned object cannot be used to modify the contents of the
+    model; use setRow() instead.
+
+    \sa setRow(), appendRow(), insertRow(), removeRow(), moveRow()
+*/
+QVariant QQmlTableModel::getRow(int rowIndex)
+{
+    if (!validateRowIndex("getRow()", "rowIndex", rowIndex))
+        return QVariant();
+
+    return mRows.at(rowIndex);
+}
+
+/*!
+    \qmlmethod TableModel::insertRow(int rowIndex, object row)
+
+    Adds a new row to the list model at position \a rowIndex, with the
+    values (cells) in \a row.
+
+    \code
+        model.insertRow(2, [
+            { checkable: true, checked: false },
+            { amount: 1 },
+            { fruitType: "Pear" },
+            { fruitName: "Williams" },
+            { fruitPrice: 1.50 },
+        ])
+    \endcode
+
+    The \a rowIndex must be to an existing item in the list, or one past
+    the end of the list (equivalent to \l appendRow()).
+
+    \sa appendRow(), setRow(), removeRow(), rowCount
+*/
+void QQmlTableModel::insertRow(int rowIndex, const QVariant &row)
+{
+    if (!validateNewRow("insertRow()", row, rowIndex))
+        return;
+
+    doInsert(rowIndex, row);
+}
+
+void QQmlTableModel::doInsert(int rowIndex, const QVariant &row)
+{
+    beginInsertRows(QModelIndex(), rowIndex, rowIndex);
+
+    // Adding rowAsVariant.toList() will add each invidual variant in the list,
+    // which is definitely not what we want.
+    const QVariant rowAsVariant = row.value<QJSValue>().toVariant();
+    mRows.insert(rowIndex, rowAsVariant);
+    ++mRowCount;
+
+    qCDebug(lcTableModel).nospace() << "inserted the following row to the model at index"
+        << rowIndex << ":\n" << rowAsVariant.toList();
+
+    endInsertRows();
+    emit rowCountChanged();
+}
+
+/*!
+    \qmlmethod TableModel::moveRow(int fromRowIndex, int toRowIndex, int rows)
+
+    Moves \a rows from the index at \a fromRowIndex to the index at
+    \a toRowIndex.
+
+    The from and to ranges must exist; for example, to move the first 3 items
+    to the end of the list:
+
+    \code
+        model.moveRow(0, model.rowCount - 3, 3)
+    \endcode
+
+    \sa appendRow(), insertRow(), removeRow(), rowCount
+*/
+void QQmlTableModel::moveRow(int fromRowIndex, int toRowIndex, int rows)
+{
+    if (fromRowIndex == toRowIndex) {
+        qmlWarning(this) << "moveRow(): \"fromRowIndex\" cannot be equal to \"toRowIndex\"";
+        return;
+    }
+
+    if (rows <= 0) {
+        qmlWarning(this) << "moveRow(): \"rows\" is less than or equal to 0";
+        return;
+    }
+
+    if (!validateRowIndex("moveRow()", "fromRowIndex", fromRowIndex))
+        return;
+
+    if (!validateRowIndex("moveRow()", "toRowIndex", toRowIndex))
+        return;
+
+    if (fromRowIndex + rows > mRowCount) {
+        qmlWarning(this) << "moveRow(): \"fromRowIndex\" (" << fromRowIndex
+            << ") + \"rows\" (" << rows << ") = " << (fromRowIndex + rows)
+            << ", which is greater than rowCount() of " << mRowCount;
+        return;
+    }
+
+    if (toRowIndex + rows > mRowCount) {
+        qmlWarning(this) << "moveRow(): \"toRowIndex\" (" << toRowIndex
+            << ") + \"rows\" (" << rows << ") = " << (toRowIndex + rows)
+            << ", which is greater than rowCount() of " << mRowCount;
+        return;
+    }
+
+    qCDebug(lcTableModel).nospace() << "moving " << rows
+        << " row(s) from index " << fromRowIndex
+        << " to index " << toRowIndex;
+
+    // Based on the same call in QQmlListModel::moveRow().
+    beginMoveRows(QModelIndex(), fromRowIndex, fromRowIndex + rows - 1, QModelIndex(),
+        toRowIndex > fromRowIndex ? toRowIndex + rows : toRowIndex);
+
+    // Based on ListModel::moveRow().
+    if (fromRowIndex > toRowIndex) {
+        // Only move forwards - flip if moving backwards.
+        const int from = fromRowIndex;
+        const int to = toRowIndex;
+        fromRowIndex = to;
+        toRowIndex = to + rows;
+        rows = from - to;
+    }
+
+    QVector<QVariant> store;
+    store.reserve(rows);
+    for (int i = 0; i < (toRowIndex - fromRowIndex); ++i)
+        store.append(mRows.at(fromRowIndex + rows + i));
+    for (int i = 0; i < rows; ++i)
+        store.append(mRows.at(fromRowIndex + i));
+    for (int i = 0; i < store.size(); ++i)
+        mRows[fromRowIndex + i] = store[i];
+
+    qCDebug(lcTableModel).nospace() << "after moving, rows are:\n" << mRows;
+
+    endMoveRows();
+}
+
+/*!
+    \qmlmethod TableModel::removeRow(int rowIndex, int rows = 1)
+
+    Removes the row at \a rowIndex from the model.
+
+    \sa clear(), rowCount
+*/
+void QQmlTableModel::removeRow(int rowIndex, int rows)
+{
+    if (!validateRowIndex("removeRow()", "rowIndex", rowIndex))
+        return;
+
+    if (rows <= 0) {
+        qmlWarning(this) << "removeRow(): \"rows\" is less than or equal to zero";
+        return;
+    }
+
+    if (rowIndex + rows - 1 >= mRowCount) {
+        qmlWarning(this) << "removeRow(): \"rows\" " << rows
+            << " exceeds available rowCount() of " << mRowCount
+            << " when removing from \"rowIndex\" " << rowIndex;
+        return;
+    }
+
+    beginRemoveRows(QModelIndex(), rowIndex, rowIndex + rows - 1);
+
+    auto firstIterator = mRows.begin() + rowIndex;
+    // The "last" argument to erase() is exclusive, so we go one past the last item.
+    auto lastIterator = firstIterator + rows;
+    mRows.erase(firstIterator, lastIterator);
+    mRowCount -= rows;
+
+    endRemoveRows();
+    emit rowCountChanged();
+
+    qCDebug(lcTableModel).nospace() << "removed " << rows
+        << " items from the model, starting at index " << rowIndex;
+}
+
+/*!
+    \qmlmethod TableModel::setRow(int rowIndex, object row)
+
+    Changes the row at \a rowIndex in the model with \a row.
+
+    All columns/cells must be present in \c row, and in the correct order.
+
+    \code
+        model.setRow(0, [
+            { checkable: true, checked: false },
+            { amount: 1 },
+            { fruitType: "Pear" },
+            { fruitName: "Williams" },
+            { fruitPrice: 1.50 },
+        ])
+    \endcode
+
+    If \a rowIndex is equal to \c rowCount(), then a new row is appended to the
+    model. Otherwise, \a rowIndex must point to an existing row in the model.
+
+    \sa appendRow(), insertRow(), rowCount
+*/
+void QQmlTableModel::setRow(int rowIndex, const QVariant &row)
+{
+    if (!validateNewRow("setRow()", row, rowIndex))
+        return;
+
+    if (rowIndex != mRowCount) {
+        // Setting an existing row.
+        mRows[rowIndex] = row;
+
+        // For now we just assume the whole row changed, as it's simpler.
+        const QModelIndex topLeftModelIndex(createIndex(rowIndex, 0));
+        const QModelIndex bottomRightModelIndex(createIndex(rowIndex, mColumnCount - 1));
+        emit dataChanged(topLeftModelIndex, bottomRightModelIndex);
+    } else {
+        // Appending a row.
+        doInsert(rowIndex, row);
+    }
+}
+
+/*!
+    \qmlproperty var TableModel::roleDataProvider
+
+    This property can hold a function that will map roles to values.
+
+    When assigned, it will be called each time data() is called, to enable
+    extracting arbitrary values, converting the data in arbitrary ways, or even
+    doing calculations. It takes 3 arguments: \c index (\l QModelIndex),
+    \c role (string), and \c cellData (object), which is the complete data that
+    is stored in the given cell. (If the cell contains a JS object with
+    multiple named values, the entire object will be given in \c cellData.)
+    The function that you define must return the value to be used; for example
+    a typical delegate will display the value returned for the \c display role,
+    so you can check whether that is the role and return data in a form that is
+    suitable for the delegate to show:
+
+    \snippet qml/tablemodel/roleDataProvider.qml 0
+*/
+QJSValue QQmlTableModel::roleDataProvider() const
+{
+    return mRoleDataProvider;
+}
+
+void QQmlTableModel::setRoleDataProvider(QJSValue roleDataProvider)
+{
+    if (roleDataProvider.strictlyEquals(mRoleDataProvider))
+        return;
+
+    mRoleDataProvider = roleDataProvider;
+    emit roleDataProviderChanged();
+}
+
+/*!
+    \qmlmethod QModelIndex TableModel::index(int row, int column)
+
+    Returns a \l QModelIndex object referencing the given \a row and \a column,
+    which can be passed to the data() function to get the data from that cell,
+    or to setData() to edit the contents of that cell.
+
+    \code
+    import QtQml 2.14
+    import Qt.labs.qmlmodels 1.0
+
+    TableModel {
+        id: model
+        rows: [
+            [{ fruitType: "Apple" }, { fruitPrice: 1.50 }],
+            [{ fruitType: "Orange" }, { fruitPrice: 2.50 }]
+        ]
+        Component.onCompleted: {
+            for (var r = 0; r < model.rowCount; ++r) {
+                console.log("An " + model.data(model.index(r, 0)).fruitType +
+                            " costs " + model.data(model.index(r, 1)).fruitPrice.toFixed(2))
+            }
+        }
+    }
+    \endcode
+
+    \sa {QModelIndex and related Classes in QML}, data()
+*/
+// Note: we don't document the parent argument, because you never need it, because
+// cells in a TableModel don't have parents.  But it is there because this function is an override.
+QModelIndex QQmlTableModel::index(int row, int column, const QModelIndex &parent) const
+{
+    return row >= 0 && row < rowCount() && column >= 0 && column < columnCount() && !parent.isValid()
+        ? createIndex(row, column)
+        : QModelIndex();
+}
+
+/*!
+    \qmlproperty int TableModel::rowCount
+    \readonly
+
+    This read-only property holds the number of rows in the model.
+
+    This value changes whenever rows are added or removed from the model.
+*/
+int QQmlTableModel::rowCount(const QModelIndex &parent) const
+{
+    if (parent.isValid())
+        return 0;
+
+    return mRowCount;
+}
+
+/*!
+    \qmlproperty int TableModel::columnCount
+    \readonly
+
+    This read-only property holds the number of columns in the model.
+
+    The number of columns is fixed for the lifetime of the model
+    after the \l rows property is set or \l appendRow() is called for the first
+    time.
+*/
+int QQmlTableModel::columnCount(const QModelIndex &parent) const
+{
+    if (parent.isValid())
+        return 0;
+
+    return mColumnCount;
+}
+
+/*!
+    \qmlmethod variant TableModel::data(QModelIndex index, string role)
+
+    Returns the data from the table cell at the given \a index belonging to the
+    given \a role.
+
+    \sa index()
+*/
+QVariant QQmlTableModel::data(const QModelIndex &index, const QString &role) const
+{
+    const int iRole = mRoleNames.key(role.toUtf8(), -1);
+    if (iRole >= 0)
+        return data(index, iRole);
+    return QVariant();
+}
+
+QVariant QQmlTableModel::data(const QModelIndex &index, int role) const
+{
+    const int row = index.row();
+    if (row < 0 || row >= rowCount())
+        return QVariant();
+
+    const int column = index.column();
+    if (column < 0 || column >= columnCount())
+        return QVariant();
+
+    if (!mRoleNames.contains(role))
+        return QVariant();
+
+    const QVariantList rowData = mRows.at(row).toList();
+
+    if (mRoleDataProvider.isCallable()) {
+        auto engine = qmlEngine(this);
+        const auto args = QJSValueList() <<
+            engine->toScriptValue(index) <<
+            QString::fromUtf8(mRoleNames.value(role)) <<
+            engine->toScriptValue(rowData.at(column));
+        return const_cast<QQmlTableModel*>(this)->mRoleDataProvider.call(args).toVariant();
+    }
+
+    // TODO: should we also allow this code to be executed if roleDataProvider doesn't
+    // handle the role/column, so that it only has to handle the case where there is
+    // more than one role in a column?
+    const QVariantMap columnData = rowData.at(column).toMap();
+    const QString propertyName = columnPropertyNameFromRole(column, role);
+    const QVariant value = columnData.value(propertyName);
+    return value;
+}
+
+/*!
+    \qmlmethod bool TableModel::setData(QModelIndex index, string role, variant value)
+
+    Inserts or updates the data field named by \a role in the table cell at the
+    given \a index with \a value. Returns true if sucessful, false if not.
+
+    \sa index()
+*/
+bool QQmlTableModel::setData(const QModelIndex &index, const QString &role, const QVariant &value)
+{
+    const int iRole = mRoleNames.key(role.toUtf8(), -1);
+    if (iRole >= 0)
+        return setData(index, value, iRole);
+    return false;
+}
+
+bool QQmlTableModel::setData(const QModelIndex &index, const QVariant &value, int role)
+{
+    const int row = index.row();
+    if (row < 0 || row >= rowCount())
+        return false;
+
+    const int column = index.column();
+    if (column < 0 || column >= columnCount())
+        return false;
+
+    if (!mRoleNames.contains(role))
+        return false;
+
+    const QVariantList rowData = mRows.at(row).toList();
+    const QString propertyName = columnPropertyNameFromRole(column, role);
+
+    qCDebug(lcTableModel).nospace() << "setData() called with index "
+        << index << ", value " << value << " and role " << propertyName;
+
+    // Verify that the role exists for this column.
+    const ColumnPropertyInfo propertyInfo = findColumnPropertyInfo(column, propertyName);
+    if (!propertyInfo.isValid()) {
+        QString message;
+        QDebug stream(&message);
+        stream.nospace() << "setData(): no role named " << propertyName
+            << " at column index " << column << ". The available roles for that column are:\n";
+
+        const QVector<ColumnPropertyInfo> availableProperties = mColumnProperties.at(column).infoForProperties;
+        for (auto propertyInfo : availableProperties)
+            stream << "    - " << propertyInfo.name << " (" << qPrintable(propertyInfo.typeName) << ")";
+
+        qmlWarning(this) << message;
+        return false;
+    }
+
+    // Verify that the type of the value is what we expect.
+    // If the value set is not of the expected type, we can try to convert it automatically.
+    QVariant effectiveValue = value;
+    if (value.type() != propertyInfo.type) {
+        if (!value.canConvert(int(propertyInfo.type))) {
+            qmlWarning(this).nospace() << "setData(): the value " << value
+                << " set at row " << row << " column " << column << " with role " << propertyName
+                << " cannot be converted to " << propertyInfo.typeName;
+            return false;
+        }
+
+        if (!effectiveValue.convert(int(propertyInfo.type))) {
+            qmlWarning(this).nospace() << "setData(): failed converting value " << value
+                << " set at row " << row << " column " << column << " with role " << propertyName
+                << " to " << propertyInfo.typeName;
+            return false;
+        }
+    }
+
+    QVariantMap modifiedColumn = rowData.at(column).toMap();
+    modifiedColumn[propertyName] = value;
+
+    QVariantList modifiedRow = rowData;
+    modifiedRow[column] = modifiedColumn;
+    mRows[row] = modifiedRow;
+
+    QVector<int> rolesChanged;
+    rolesChanged.append(role);
+    emit dataChanged(index, index, rolesChanged);
+
+    return true;
+}
+
+QHash<int, QByteArray> QQmlTableModel::roleNames() const
+{
+    return mRoleNames;
+}
+
+QQmlTableModel::ColumnPropertyInfo::ColumnPropertyInfo()
+{
+}
+
+QQmlTableModel::ColumnPropertyInfo::ColumnPropertyInfo(
+    const QString &name, QVariant::Type type, const QString &typeName) :
+    name(name),
+    type(type),
+    typeName(typeName)
+{
+}
+
+bool QQmlTableModel::ColumnPropertyInfo::isValid() const
+{
+    return !name.isEmpty();
+}
+
+bool QQmlTableModel::validateRowType(const char *functionName, const QVariant &row) const
+{
+    if (row.userType() != qMetaTypeId<QJSValue>()) {
+        qmlWarning(this) << functionName << ": expected \"row\" argument to be an array,"
+            << " but got " << row.typeName() << " instead";
+        return false;
+    }
+
+    const QVariant rowAsVariant = row.value<QJSValue>().toVariant();
+    if (rowAsVariant.type() != QVariant::List) {
+        qmlWarning(this) << functionName << ": expected \"row\" argument to be an array,"
+            << " but got " << row.typeName() << " instead";
+        return false;
+    }
+
+    return true;
+}
+
+bool QQmlTableModel::validateNewRow(const char *functionName, const QVariant &row,
+    int rowIndex, NewRowOperationFlag appendFlag) const
+{
+    if (!validateRowType(functionName, row))
+        return false;
+
+    if (appendFlag == OtherOperation) {
+        // Inserting/setting.
+        if (rowIndex < 0) {
+            qmlWarning(this) << functionName << ": \"rowIndex\" cannot be negative";
+            return false;
+        }
+
+        if (rowIndex > mRowCount) {
+            qmlWarning(this) << functionName << ": \"rowIndex\" " << rowIndex
+                << " is greater than rowCount() of " << mRowCount;
+            return false;
+        }
+    }
+
+    const QVariant rowAsVariant = row.value<QJSValue>().toVariant();
+    const QVariantList rowAsList = rowAsVariant.toList();
+
+    const int columnCount = rowAsList.size();
+    if (columnCount != mColumnCount) {
+        qmlWarning(this) << functionName << ": expected " << mColumnCount
+            << " columns, but got " << columnCount;
+        return false;
+    }
+
+    // Verify that the row's columns and their roles match the name and type of existing data.
+    // This iterates across the columns in the row. For example:
+    // [
+    //     { checkable: true, checked: false },   // columnIndex == 0
+    //     { amount: 1 },                         // columnIndex == 1
+    //     { fruitType: "Orange" },               // etc.
+    //     { fruitName: "Navel" },
+    //     { fruitPrice: 2.50 }
+    // ],
+    for (int columnIndex = 0; columnIndex < mColumnCount; ++columnIndex) {
+        const QVariantMap column = rowAsList.at(columnIndex).toMap();
+        if (!validateColumnPropertyTypes(functionName, column, columnIndex))
+            return false;
+    }
+
+    return true;
+}
+
+bool QQmlTableModel::validateRowIndex(const char *functionName, const char *argumentName, int rowIndex) const
+{
+    if (rowIndex < 0) {
+        qmlWarning(this) << functionName << ": \"" << argumentName << "\" cannot be negative";
+        return false;
+    }
+
+    if (rowIndex >= mRowCount) {
+        qmlWarning(this) << functionName << ": \"" << argumentName
+            << "\" " << rowIndex << " is greater than or equal to rowCount() of " << mRowCount;
+        return false;
+    }
+
+    return true;
+}
+
+bool QQmlTableModel::validateColumnPropertyTypes(const char *functionName,
+    const QVariantMap &column, int columnIndex) const
+{
+    // Actual
+    const QVariantList columnProperties = column.values();
+    const QStringList propertyNames = column.keys();
+    // Expected
+    const QVector<ColumnPropertyInfo> properties = mColumnProperties.at(columnIndex).infoForProperties;
+
+    // This iterates across the properties in the column. For example:
+    //   0         1       2
+    // { foo: "A", bar: 1, baz: true },
+    for (int propertyIndex = 0; propertyIndex < properties.size(); ++propertyIndex) {
+        const QString propertyName = propertyNames.at(propertyIndex);
+        const QVariant propertyValue = columnProperties.at(propertyIndex);
+        const ColumnPropertyInfo expectedPropertyFormat = properties.at(propertyIndex);
+
+        if (!validateColumnPropertyType(functionName, propertyName,
+                propertyValue, expectedPropertyFormat, columnIndex)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool QQmlTableModel::validateColumnPropertyType(const char *functionName, const QString &propertyName,
+    const QVariant &propertyValue, const ColumnPropertyInfo &expectedPropertyFormat, int columnIndex) const
+{
+    if (propertyName != expectedPropertyFormat.name) {
+        qmlWarning(this) << functionName
+            << ": expected property named " << expectedPropertyFormat.name
+            << " at column index " << columnIndex
+            << ", but got " << propertyName << " instead";
+        return false;
+    }
+
+    if (propertyValue.type() != expectedPropertyFormat.type) {
+        qmlWarning(this) << functionName
+            << ": expected property with type " << expectedPropertyFormat.typeName
+            << " at column index " << columnIndex
+            << ", but got " << propertyValue.typeName() << " instead";
+        return false;
+    }
+
+    return true;
+}
+
+QQmlTableModel::ColumnPropertyInfo QQmlTableModel::findColumnPropertyInfo(
+    int columnIndex, const QString &columnPropertyName) const
+{
+    // TODO: check if a hash with its string-based lookup is faster,
+    // keeping in mind that we may be doing index-based lookups too.
+    const QVector<ColumnPropertyInfo> properties = mColumnProperties.at(columnIndex).infoForProperties;
+    for (int i = 0; i < properties.size(); ++i) {
+        const ColumnPropertyInfo &info = properties.at(i);
+        if (info.name == columnPropertyName)
+            return info;
+    }
+
+    return ColumnPropertyInfo();
+}
+
+QString QQmlTableModel::columnPropertyNameFromRole(int columnIndex, int role) const
+{
+    QString propertyName;
+    if (role == Qt::DisplayRole && mColumnProperties.at(columnIndex).explicitDisplayRoleIndex == -1) {
+        // The user is getting or setting data for the display role,
+        // but didn't specify any role with the name "display" in this column.
+        // So, we give them the implicit display role, aka the first property we find.
+        propertyName = mColumnProperties.at(columnIndex).infoForProperties.first().name;
+    } else {
+        // QML/JS supports utf8.
+        propertyName = QString::fromUtf8(mRoleNames.value(role));
+    }
+    return propertyName;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/types/qqmltablemodel_p.h b/src/qml/types/qqmltablemodel_p.h
new file mode 100644
index 0000000000..33b2189fcd
--- /dev/null
+++ b/src/qml/types/qqmltablemodel_p.h
@@ -0,0 +1,158 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQMLTABLEMODEL_P_H
+#define QQMLTABLEMODEL_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/QObject>
+#include <QtCore/QAbstractTableModel>
+#include <QtQml/qqml.h>
+#include <QtQml/private/qtqmlglobal_p.h>
+#include <QtQml/QJSValue>
+
+QT_BEGIN_NAMESPACE
+
+class Q_QML_PRIVATE_EXPORT QQmlTableModel : public QAbstractTableModel
+{
+    Q_OBJECT
+    Q_PROPERTY(int columnCount READ columnCount NOTIFY columnCountChanged FINAL)
+    Q_PROPERTY(int rowCount READ rowCount NOTIFY rowCountChanged FINAL)
+    Q_PROPERTY(QVariant rows READ rows WRITE setRows NOTIFY rowsChanged FINAL)
+    Q_PROPERTY(QJSValue roleDataProvider READ roleDataProvider WRITE setRoleDataProvider NOTIFY roleDataProviderChanged)
+
+public:
+    QQmlTableModel(QObject *parent = nullptr);
+    ~QQmlTableModel() override;
+
+    QVariant rows() const;
+    void setRows(const QVariant &rows);
+
+    Q_INVOKABLE void appendRow(const QVariant &row);
+    Q_INVOKABLE void clear();
+    Q_INVOKABLE QVariant getRow(int rowIndex);
+    Q_INVOKABLE void insertRow(int rowIndex, const QVariant &row);
+    Q_INVOKABLE void moveRow(int fromRowIndex, int toRowIndex, int rows = 1);
+    Q_INVOKABLE void removeRow(int rowIndex, int rows = 1);
+    Q_INVOKABLE void setRow(int rowIndex, const QVariant &row);
+
+    QJSValue roleDataProvider() const;
+    void setRoleDataProvider(QJSValue roleDataProvider);
+
+    QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    int columnCount(const QModelIndex &parent = QModelIndex()) const override;
+    Q_INVOKABLE QVariant data(const QModelIndex &index, const QString &role) const;
+    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    Q_INVOKABLE bool setData(const QModelIndex &index, const QString &role, const QVariant &value);
+    bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::DisplayRole) override;
+    QHash<int, QByteArray> roleNames() const override;
+
+Q_SIGNALS:
+    void columnCountChanged();
+    void rowCountChanged();
+    void rowsChanged();
+    void roleDataProviderChanged();
+
+private:
+    class ColumnPropertyInfo
+    {
+    public:
+        ColumnPropertyInfo();
+        ColumnPropertyInfo(const QString &name, QVariant::Type type, const QString &typeName);
+
+        bool isValid() const;
+
+        QString name;
+        QVariant::Type type = QVariant::Invalid;
+        QString typeName;
+    };
+
+    struct ColumnProperties
+    {
+        QVector<ColumnPropertyInfo> infoForProperties;
+        // If there was a display role found in this column, it'll be stored here.
+        // The index is into infoForProperties.
+        int explicitDisplayRoleIndex = -1;
+    };
+
+    enum NewRowOperationFlag {
+        OtherOperation, // insert(), set(), etc.
+        AppendOperation
+    };
+
+    bool validateRowType(const char *functionName, const QVariant &row) const;
+    bool validateNewRow(const char *functionName, const QVariant &row,
+        int rowIndex, NewRowOperationFlag appendFlag = OtherOperation) const;
+    bool validateRowIndex(const char *functionName, const char *argumentName, int rowIndex) const;
+    bool validateColumnPropertyTypes(const char *functionName, const QVariantMap &column, int columnIndex) const;
+    bool validateColumnPropertyType(const char *functionName, const QString &propertyName,
+        const QVariant &propertyValue, const ColumnPropertyInfo &expectedPropertyFormat, int columnIndex) const;
+
+    ColumnPropertyInfo findColumnPropertyInfo(int columnIndex, const QString &columnPropertyNameFromRole) const;
+    QString columnPropertyNameFromRole(int columnIndex, int role) const;
+
+    void doInsert(int rowIndex, const QVariant &row);
+
+    QVariantList mRows;
+    int mRowCount = 0;
+    int mColumnCount = 0;
+    // Each entry contains information about the properties of the column at that index.
+    QVector<ColumnProperties> mColumnProperties;
+    // key = property index (0 to number of properties across all columns)
+    // value = role name
+    QHash<int, QByteArray> mRoleNames;
+    QJSValue mRoleDataProvider;
+};
+
+QT_END_NAMESPACE
+
+QML_DECLARE_TYPE(QQmlTableModel)
+
+#endif // QQMLTABLEMODEL_P_H
diff --git a/src/qml/types/qqmltimer.cpp b/src/qml/types/qqmltimer.cpp
index 2037c4f6cd..af2ff56f2a 100644
--- a/src/qml/types/qqmltimer.cpp
+++ b/src/qml/types/qqmltimer.cpp
@@ -57,7 +57,7 @@ class QQmlTimerPrivate : public QObjectPrivate, public QAnimationJobChangeListen
     Q_DECLARE_PUBLIC(QQmlTimer)
 public:
     QQmlTimerPrivate()
-        : interval(1000), running(false), repeating(false), triggeredOnStart(false)
+        : running(false), repeating(false), triggeredOnStart(false)
         , classBegun(false), componentComplete(false), firstTick(true), awaitingTick(false) {}
 
     void animationFinished(QAbstractAnimationJob *) override;
@@ -71,7 +71,7 @@ public:
         }
     }
 
-    int interval;
+    int interval = 1000;
     QPauseAnimationJob pause;
     bool running : 1;
     bool repeating : 1;
@@ -87,7 +87,7 @@ public:
     \instantiates QQmlTimer
     \inqmlmodule QtQml
     \ingroup qtquick-interceptors
-    \brief Triggers a handler at a specified interval
+    \brief Triggers a handler at a specified interval.
 
     A Timer can be used to trigger an action either once, or repeatedly
     at a given interval.
diff --git a/src/qml/types/qqmltimer_p.h b/src/qml/types/qqmltimer_p.h
index 7739dad2a6..0160e97a2f 100644
--- a/src/qml/types/qqmltimer_p.h
+++ b/src/qml/types/qqmltimer_p.h
@@ -57,6 +57,8 @@
 
 #include <private/qtqmlglobal_p.h>
 
+QT_REQUIRE_CONFIG(qml_animation);
+
 QT_BEGIN_NAMESPACE
 
 class QQmlTimerPrivate;
@@ -72,7 +74,7 @@ class Q_QML_PRIVATE_EXPORT QQmlTimer : public QObject, public QQmlParserStatus
     Q_PROPERTY(QObject *parent READ parent CONSTANT)
 
 public:
-    QQmlTimer(QObject *parent=0);
+    QQmlTimer(QObject *parent=nullptr);
 
     void setInterval(int interval);
     int interval() const;
diff --git a/src/qml/types/qquickpackage.cpp b/src/qml/types/qquickpackage.cpp
index e0d1888f33..03539d8737 100644
--- a/src/qml/types/qquickpackage.cpp
+++ b/src/qml/types/qquickpackage.cpp
@@ -49,7 +49,7 @@ QT_BEGIN_NAMESPACE
     \instantiates QQuickPackage
     \inqmlmodule QtQuick
     \ingroup qtquick-views
-    \brief Specifies a collection of named items
+    \brief Specifies a collection of named items.
 
     The Package type is used in conjunction with
     DelegateModel to enable delegates with a shared context
@@ -183,7 +183,7 @@ QObject *QQuickPackage::part(const QString &name)
     if (name == QLatin1String("default") && !d->dataList.isEmpty())
         return d->dataList.at(0);
 
-    return 0;
+    return nullptr;
 }
 
 QQuickPackageAttached *QQuickPackage::qmlAttachedProperties(QObject *o)
diff --git a/src/qml/types/qquickpackage_p.h b/src/qml/types/qquickpackage_p.h
index ca383bfdcb..122c7fcb30 100644
--- a/src/qml/types/qquickpackage_p.h
+++ b/src/qml/types/qquickpackage_p.h
@@ -66,7 +66,7 @@ class Q_AUTOTEST_EXPORT QQuickPackage : public QObject
     Q_PROPERTY(QQmlListProperty<QObject> data READ data)
 
 public:
-    QQuickPackage(QObject *parent=0);
+    QQuickPackage(QObject *parent=nullptr);
     virtual ~QQuickPackage();
 
     QQmlListProperty<QObject> data();
diff --git a/src/qml/types/qquickworkerscript.cpp b/src/qml/types/qquickworkerscript.cpp
index 6159355afc..edb112276c 100644
--- a/src/qml/types/qquickworkerscript.cpp
+++ b/src/qml/types/qquickworkerscript.cpp
@@ -37,9 +37,12 @@
 **
 ****************************************************************************/
 
+#include "qtqmlglobal_p.h"
 #include "qquickworkerscript_p.h"
+#if QT_CONFIG(qml_list_model)
 #include "qqmllistmodel_p.h"
 #include "qqmllistmodelworkeragent_p.h"
+#endif
 #include <private/qqmlengine_p.h>
 #include <private/qqmlexpression_p.h>
 
@@ -65,6 +68,7 @@
 #include <private/qv4functionobject_p.h>
 #include <private/qv4script_p.h>
 #include <private/qv4scopedvalue_p.h>
+#include <private/qv4jscall_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -135,49 +139,26 @@ public:
 
     QQuickWorkerScriptEnginePrivate(QQmlEngine *eng);
 
-    class WorkerEngine : public QV8Engine
-    {
-    public:
-        WorkerEngine(QQuickWorkerScriptEnginePrivate *parent);
-        ~WorkerEngine();
+    QQmlEngine *qmlengine;
+
+    QMutex m_lock;
+    QWaitCondition m_wait;
 
-        void init();
+    struct WorkerScript : public QV8Engine {
+        WorkerScript(int id, QQuickWorkerScriptEnginePrivate *parent);
+        ~WorkerScript() override;
 
 #if QT_CONFIG(qml_network)
         QNetworkAccessManager *networkAccessManager() override;
 #endif
 
-        QQuickWorkerScriptEnginePrivate *p;
-
-        QV4::ReturnedValue sendFunction(int id);
-
-        QV4::PersistentValue onmessage;
-    private:
-        QV4::PersistentValue createsend;
+        QQuickWorkerScriptEnginePrivate *p = nullptr;
+        QUrl source;
+        QQuickWorkerScript *owner = nullptr;
 #if QT_CONFIG(qml_network)
-        QNetworkAccessManager *accessManager;
+        QScopedPointer<QNetworkAccessManager> accessManager;
 #endif
-    };
-
-    WorkerEngine *workerEngine;
-    static QQuickWorkerScriptEnginePrivate *get(QV8Engine *e) {
-        return static_cast<WorkerEngine *>(e)->p;
-    }
-
-    QQmlEngine *qmlengine;
-
-    QMutex m_lock;
-    QWaitCondition m_wait;
-
-    struct WorkerScript {
-        WorkerScript();
-        ~WorkerScript();
-
-        int id;
-        QUrl source;
-        bool initialized;
-        QQuickWorkerScript *owner;
-        QV4::PersistentValue qmlContext;
+        int id = -1;
     };
 
     QHash<int, WorkerScript *> workers;
@@ -185,7 +166,7 @@ public:
 
     int m_nextId;
 
-    static void method_sendMessage(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData);
+    static QV4::ReturnedValue method_sendMessage(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 
 signals:
     void stopThread();
@@ -199,128 +180,25 @@ private:
     void reportScriptException(WorkerScript *, const QQmlError &error);
 };
 
-QQuickWorkerScriptEnginePrivate::WorkerEngine::WorkerEngine(QQuickWorkerScriptEnginePrivate *parent)
-: QV8Engine(0), p(parent)
-#if QT_CONFIG(qml_network)
-, accessManager(0)
-#endif
-{
-    m_v4Engine->v8Engine = this;
-}
-
-QQuickWorkerScriptEnginePrivate::WorkerEngine::~WorkerEngine()
-{
-#if QT_CONFIG(qml_network)
-    delete accessManager;
-#endif
-}
-
-void QQuickWorkerScriptEnginePrivate::WorkerEngine::init()
-{
-    initQmlGlobalObject();
-#define CALL_ONMESSAGE_SCRIPT \
-    "(function(object, message) { "\
-        "var isfunction = false; "\
-        "try { "\
-            "isfunction = object.WorkerScript.onMessage instanceof Function; "\
-        "} catch (e) {}" \
-        "if (isfunction) "\
-            "object.WorkerScript.onMessage(message); "\
-    "})"
-
-#define SEND_MESSAGE_CREATE_SCRIPT \
-    "(function(method, engine) { "\
-        "return (function(id) { "\
-            "return (function(message) { "\
-                "if (arguments.length) method(engine, id, message); "\
-            "}); "\
-        "}); "\
-    "})"
-
-    QV4::Scope scope(m_v4Engine);
-    QV4::ExecutionContext *globalContext = scope.engine->rootContext();
-    onmessage.set(scope.engine, QV4::Script(globalContext, QString::fromUtf8(CALL_ONMESSAGE_SCRIPT)).run()); // do not use QStringLiteral here, MSVC2012 cannot apply this cleanly to the macro
-    Q_ASSERT(!scope.engine->hasException);
-    QV4::Script createsendscript(globalContext, QString::fromUtf8(SEND_MESSAGE_CREATE_SCRIPT)); // do not use QStringLiteral here, MSVC2012 cannot apply this cleanly to the macro
-    QV4::ScopedFunctionObject createsendconstructor(scope, createsendscript.run());
-    Q_ASSERT(!scope.engine->hasException);
-    QV4::ScopedString name(scope, m_v4Engine->newString(QStringLiteral("sendMessage")));
-    QV4::ScopedValue function(scope, QV4::BuiltinFunction::create(globalContext, name,
-                                                                    QQuickWorkerScriptEnginePrivate::method_sendMessage));
-    QV4::ScopedCallData callData(scope, 1);
-    callData->args[0] = function;
-    callData->thisObject = global();
-    createsendconstructor->call(scope, callData);
-    createsend.set(scope.engine, scope.result.asReturnedValue());
-}
-
-// Requires handle and context scope
-QV4::ReturnedValue QQuickWorkerScriptEnginePrivate::WorkerEngine::sendFunction(int id)
-{
-    QV4::ExecutionEngine *v4 = createsend.engine();
-    if (!v4)
-        return QV4::Encode::undefined();
-
-    QV4::Scope scope(v4);
-    QV4::ScopedFunctionObject f(scope, createsend.value());
-
-    QV4::ScopedCallData callData(scope, 1);
-    callData->args[0] = QV4::Primitive::fromInt32(id);
-    callData->thisObject = global();
-    f->call(scope, callData);
-    if (scope.hasException())
-        scope.result = scope.engine->catchException();
-    return scope.result.asReturnedValue();
-}
-
-#if QT_CONFIG(qml_network)
-QNetworkAccessManager *QQuickWorkerScriptEnginePrivate::WorkerEngine::networkAccessManager()
-{
-    if (!accessManager) {
-        if (p->qmlengine && p->qmlengine->networkAccessManagerFactory()) {
-            accessManager = p->qmlengine->networkAccessManagerFactory()->create(p);
-        } else {
-            accessManager = new QNetworkAccessManager(p);
-        }
-    }
-    return accessManager;
-}
-#endif
-
 QQuickWorkerScriptEnginePrivate::QQuickWorkerScriptEnginePrivate(QQmlEngine *engine)
-: workerEngine(0), qmlengine(engine), m_nextId(0)
+: qmlengine(engine), m_nextId(0)
 {
 }
 
-void QQuickWorkerScriptEnginePrivate::method_sendMessage(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+QV4::ReturnedValue QQuickWorkerScriptEnginePrivate::method_sendMessage(const QV4::FunctionObject *b,
+                                                                       const QV4::Value *, const QV4::Value *argv, int argc)
 {
-    WorkerEngine *engine = (WorkerEngine*)scope.engine->v8Engine;
-
-    int id = callData->argc > 1 ? callData->args[1].toInt32() : 0;
+    QV4::Scope scope(b);
+    WorkerScript *script = static_cast<WorkerScript *>(scope.engine->v8Engine);
 
-    QV4::ScopedValue v(scope, callData->argument(2));
+    QV4::ScopedValue v(scope, argc > 0 ? argv[0] : QV4::Value::undefinedValue());
     QByteArray data = QV4::Serialize::serialize(v, scope.engine);
 
-    QMutexLocker locker(&engine->p->m_lock);
-    WorkerScript *script = engine->p->workers.value(id);
+    QMutexLocker locker(&script->p->m_lock);
     if (script && script->owner)
         QCoreApplication::postEvent(script->owner, new WorkerDataEvent(0, data));
 
-    scope.result = QV4::Encode::undefined();
-}
-
-QV4::ReturnedValue QQuickWorkerScriptEnginePrivate::getWorker(WorkerScript *script)
-{
-    if (!script->initialized) {
-        script->initialized = true;
-
-        QV4::ExecutionEngine *v4 = QV8Engine::getV4(workerEngine);
-        QV4::Scope scope(v4);
-        QV4::ScopedValue v(scope, workerEngine->sendFunction(script->id));
-        script->qmlContext.set(v4, QV4::QmlContext::createWorkerContext(v4->rootContext(), script->source, v));
-    }
-
-    return script->qmlContext.value();
+    return QV4::Encode::undefined();
 }
 
 bool QQuickWorkerScriptEnginePrivate::event(QEvent *event)
@@ -337,6 +215,7 @@ bool QQuickWorkerScriptEnginePrivate::event(QEvent *event)
         emit stopThread();
         return true;
     } else if (event->type() == (QEvent::Type)WorkerRemoveEvent::WorkerRemove) {
+        QMutexLocker locker(&m_lock);
         WorkerRemoveEvent *workerEvent = static_cast<WorkerRemoveEvent *>(event);
         QHash<int, WorkerScript *>::iterator itr = workers.find(workerEvent->workerId());
         if (itr != workers.end()) {
@@ -355,19 +234,23 @@ void QQuickWorkerScriptEnginePrivate::processMessage(int id, const QByteArray &d
     if (!script)
         return;
 
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(workerEngine);
+    QV4::ExecutionEngine *v4 = QV8Engine::getV4(script);
     QV4::Scope scope(v4);
-    QV4::ScopedFunctionObject f(scope, workerEngine->onmessage.value());
+    QV4::ScopedString v(scope);
+    QV4::ScopedObject worker(scope, v4->globalObject->get((v = v4->newString(QStringLiteral("WorkerScript")))));
+    QV4::ScopedFunctionObject onmessage(scope);
+    if (worker)
+        onmessage = worker->get((v = v4->newString(QStringLiteral("onMessage"))));
+
+    if (!onmessage)
+        return;
 
     QV4::ScopedValue value(scope, QV4::Serialize::deserialize(data, v4));
-    QV4::Scoped<QV4::QmlContext> qmlContext(scope, script->qmlContext.value());
-    Q_ASSERT(!!qmlContext);
-
-    QV4::ScopedCallData callData(scope, 2);
-    callData->thisObject = workerEngine->global();
-    callData->args[0] = qmlContext->d()->qml; // ###
-    callData->args[1] = value;
-    f->call(scope, callData);
+
+    QV4::JSCallData jsCallData(scope, 1);
+    *jsCallData->thisObject = v4->global();
+    jsCallData->args[0] = value;
+    onmessage->call(jsCallData);
     if (scope.hasException()) {
         QQmlError error = scope.engine->catchExceptionAsQmlError();
         reportScriptException(script, error);
@@ -381,39 +264,37 @@ void QQuickWorkerScriptEnginePrivate::processLoad(int id, const QUrl &url)
 
     QString fileName = QQmlFile::urlToLocalFileOrQrc(url);
 
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(workerEngine);
-    QV4::Scope scope(v4);
-    QScopedPointer<QV4::Script> program;
-
     WorkerScript *script = workers.value(id);
     if (!script)
         return;
-    script->source = url;
 
-    QV4::Scoped<QV4::QmlContext> qmlContext(scope, getWorker(script));
-    Q_ASSERT(!!qmlContext);
+    QV4::ExecutionEngine *v4 = QV8Engine::getV4(script);
+
+    script->source = url;
 
-    if (const QQmlPrivate::CachedQmlUnit *cachedUnit = QQmlMetaType::findCachedCompilationUnit(url)) {
-        QV4::CompiledData::CompilationUnit *jsUnit = cachedUnit->createCompilationUnit();
-        program.reset(new QV4::Script(v4, qmlContext, jsUnit));
+    if (fileName.endsWith(QLatin1String(".mjs"))) {
+        auto moduleUnit = v4->loadModule(url);
+        if (moduleUnit) {
+            if (moduleUnit->instantiate(v4))
+                moduleUnit->evaluate();
+        } else {
+            v4->throwError(QStringLiteral("Could not load module file"));
+        }
     } else {
-        QFile f(fileName);
-        if (!f.open(QIODevice::ReadOnly)) {
-            qWarning().nospace() << "WorkerScript: Cannot find source file " << url.toString();
+        QString error;
+        QV4::Scope scope(v4);
+        QScopedPointer<QV4::Script> program;
+        program.reset(QV4::Script::createFromFileOrCache(v4, /*qmlContext*/nullptr, fileName, url, &error));
+        if (program.isNull()) {
+            if (!error.isEmpty())
+                qWarning().nospace() << error;
             return;
         }
 
-        QByteArray data = f.readAll();
-        QString sourceCode = QString::fromUtf8(data);
-        QmlIR::Document::removeScriptPragmas(sourceCode);
-
-        program.reset(new QV4::Script(v4, qmlContext, sourceCode, url.toString()));
-        program->parse();
+        if (!v4->hasException)
+            program->run();
     }
 
-    if (!v4->hasException)
-        program->run();
-
     if (v4->hasException) {
         QQmlError error = v4->catchExceptionAsQmlError();
         reportScriptException(script, error);
@@ -423,9 +304,7 @@ void QQuickWorkerScriptEnginePrivate::processLoad(int id, const QUrl &url)
 void QQuickWorkerScriptEnginePrivate::reportScriptException(WorkerScript *script,
                                                                   const QQmlError &error)
 {
-    QQuickWorkerScriptEnginePrivate *p = QQuickWorkerScriptEnginePrivate::get(workerEngine);
-
-    QMutexLocker locker(&p->m_lock);
+    QMutexLocker locker(&script->p->m_lock);
     if (script->owner)
         QCoreApplication::postEvent(script->owner, new WorkerErrorEvent(error));
 }
@@ -514,21 +393,47 @@ QQuickWorkerScriptEngine::~QQuickWorkerScriptEngine()
     d->deleteLater();
 }
 
-QQuickWorkerScriptEnginePrivate::WorkerScript::WorkerScript()
-: id(-1), initialized(false), owner(0)
+QQuickWorkerScriptEnginePrivate::WorkerScript::WorkerScript(int id, QQuickWorkerScriptEnginePrivate *parent)
+    : QV8Engine(new QV4::ExecutionEngine)
+    , p(parent)
+    , id(id)
 {
+    m_v4Engine->v8Engine = this;
+
+    initQmlGlobalObject();
+
+    QV4::Scope scope(m_v4Engine);
+    QV4::ScopedObject api(scope, scope.engine->newObject());
+    QV4::ScopedString name(scope, m_v4Engine->newString(QStringLiteral("sendMessage")));
+    QV4::ScopedValue sendMessage(scope, QV4::FunctionObject::createBuiltinFunction(m_v4Engine, name, method_sendMessage, 1));
+    api->put(QV4::ScopedString(scope, scope.engine->newString(QStringLiteral("sendMessage"))), sendMessage);
+    m_v4Engine->globalObject->put(QV4::ScopedString(scope, scope.engine->newString(QStringLiteral("WorkerScript"))), api);
 }
 
 QQuickWorkerScriptEnginePrivate::WorkerScript::~WorkerScript()
 {
+    delete m_v4Engine;
+}
+
+#if QT_CONFIG(qml_network)
+QNetworkAccessManager *QQuickWorkerScriptEnginePrivate::WorkerScript::networkAccessManager()
+{
+    if (!accessManager) {
+        if (p->qmlengine && p->qmlengine->networkAccessManagerFactory()) {
+            accessManager.reset(p->qmlengine->networkAccessManagerFactory()->create(p));
+        } else {
+            accessManager.reset(new QNetworkAccessManager(p));
+        }
+    }
+    return accessManager.data();
 }
+#endif
 
 int QQuickWorkerScriptEngine::registerWorkerScript(QQuickWorkerScript *owner)
 {
     typedef QQuickWorkerScriptEnginePrivate::WorkerScript WorkerScript;
-    WorkerScript *script = new WorkerScript;
+    WorkerScript *script = new WorkerScript(d->m_nextId++, d);
 
-    script->id = d->m_nextId++;
     script->owner = owner;
 
     d->m_lock.lock();
@@ -542,7 +447,7 @@ void QQuickWorkerScriptEngine::removeWorkerScript(int id)
 {
     QQuickWorkerScriptEnginePrivate::WorkerScript* script = d->workers.value(id);
     if (script) {
-        script->owner = 0;
+        script->owner = nullptr;
         QCoreApplication::postEvent(d, new WorkerRemoveEvent(id));
     }
 }
@@ -561,9 +466,6 @@ void QQuickWorkerScriptEngine::run()
 {
     d->m_lock.lock();
 
-    d->workerEngine = new QQuickWorkerScriptEnginePrivate::WorkerEngine(d);
-    d->workerEngine->init();
-
     d->m_wait.wakeAll();
 
     d->m_lock.unlock();
@@ -572,8 +474,6 @@ void QQuickWorkerScriptEngine::run()
 
     qDeleteAll(d->workers);
     d->workers.clear();
-
-    delete d->workerEngine; d->workerEngine = 0;
 }
 
 
@@ -581,8 +481,8 @@ void QQuickWorkerScriptEngine::run()
     \qmltype WorkerScript
     \instantiates QQuickWorkerScript
     \ingroup qtquick-threading
-    \inqmlmodule QtQuick
-    \brief Enables the use of threads in a Qt Quick application
+    \inqmlmodule QtQml
+    \brief Enables the use of threads in a Qt Quick application.
 
     Use WorkerScript to run operations in a new thread.
     This is useful for running operations in the background so
@@ -595,22 +495,32 @@ void QQuickWorkerScriptEngine::run()
 
     \snippet qml/workerscript/workerscript.qml 0
 
-    The above worker script specifies a JavaScript file, "script.js", that handles
-    the operations to be performed in the new thread. Here is \c script.js:
+    The above worker script specifies a JavaScript file, "script.mjs", that handles
+    the operations to be performed in the new thread. Here is \c script.mjs:
 
-    \quotefile qml/workerscript/script.js
+    \quotefile qml/workerscript/script.mjs
 
     When the user clicks anywhere within the rectangle, \c sendMessage() is
     called, triggering the \tt WorkerScript.onMessage() handler in
-    \tt script.js. This in turn sends a reply message that is then received
+    \tt script.mjs. This in turn sends a reply message that is then received
     by the \tt onMessage() handler of \tt myWorker.
 
+    The example uses a script that is an ECMAScript module, because it has the ".mjs" extension.
+    It can use import statements to access functionality from other modules and it is run in JavaScript
+    strict mode.
+
+    If a worker script has the extension ".js" instead, then it is considered to contain plain JavaScript
+    statements and it is run in non-strict mode.
+
+    \note Each WorkerScript element will instantiate a separate JavaScript engine to ensure perfect
+    isolation and thread-safety. If the impact of that results in a memory consumption that is too
+    high for your environment, then consider sharing a WorkerScript element.
 
     \section3 Restrictions
 
     Since the \c WorkerScript.onMessage() function is run in a separate thread, the
     JavaScript file is evaluated in a context separate from the main QML engine. This means
-    that unlike an ordinary JavaScript file that is imported into QML, the \c script.js
+    that unlike an ordinary JavaScript file that is imported into QML, the \c script.mjs
     in the above example cannot access the properties, methods or other attributes
     of the QML item, nor can it access any context properties set on the QML object
     through QQmlContext.
@@ -618,13 +528,14 @@ void QQuickWorkerScriptEngine::run()
     Additionally, there are restrictions on the types of values that can be passed to and
     from the worker script. See the sendMessage() documentation for details.
 
-    Worker script can not use \l {qtqml-javascript-imports.html}{.import} syntax.
+    Worker scripts that are plain JavaScript sources can not use \l {qtqml-javascript-imports.html}{.import} syntax.
+    Scripts that are ECMAScript modules can freely use import and export statements.
 
     \sa {Qt Quick Examples - Threading},
         {Threaded ListModel Example}
 */
 QQuickWorkerScript::QQuickWorkerScript(QObject *parent)
-: QObject(parent), m_engine(0), m_scriptId(-1), m_componentComplete(true)
+: QObject(parent), m_engine(nullptr), m_scriptId(-1), m_componentComplete(true)
 {
 }
 
@@ -638,6 +549,10 @@ QQuickWorkerScript::~QQuickWorkerScript()
 
     This holds the url of the JavaScript file that implements the
     \tt WorkerScript.onMessage() handler for threaded operations.
+
+    If the file name component of the url ends with ".mjs", then the script
+    is parsed as an ECMAScript module and run in strict mode. Otherwise it is considered to be
+    plain script.
 */
 QUrl QQuickWorkerScript::source() const
 {
@@ -685,7 +600,7 @@ void QQuickWorkerScript::sendMessage(QQmlV4Function *args)
     }
 
     QV4::Scope scope(args->v4engine());
-    QV4::ScopedValue argument(scope, QV4::Primitive::undefinedValue());
+    QV4::ScopedValue argument(scope, QV4::Value::undefinedValue());
     if (args->length() != 0)
         argument = (*args)[0];
 
@@ -704,7 +619,7 @@ QQuickWorkerScriptEngine *QQuickWorkerScript::engine()
         QQmlEngine *engine = qmlEngine(this);
         if (!engine) {
             qWarning("QQuickWorkerScript: engine() called without qmlEngine() set");
-            return 0;
+            return nullptr;
         }
 
         m_engine = QQmlEnginePrivate::get(engine)->getWorkerScriptEngine();
@@ -715,7 +630,7 @@ QQuickWorkerScriptEngine *QQuickWorkerScript::engine()
 
         return m_engine;
     }
-    return 0;
+    return nullptr;
 }
 
 void QQuickWorkerScript::componentComplete()
@@ -739,8 +654,7 @@ bool QQuickWorkerScript::event(QEvent *event)
         QQmlEngine *engine = qmlEngine(this);
         if (engine) {
             WorkerDataEvent *workerEvent = static_cast<WorkerDataEvent *>(event);
-            QV8Engine *v8engine = QQmlEnginePrivate::get(engine)->v8engine();
-            QV4::Scope scope(QV8Engine::getV4(v8engine));
+            QV4::Scope scope(engine->handle());
             QV4::ScopedValue value(scope, QV4::Serialize::deserialize(workerEvent->data(), scope.engine));
             emit message(QQmlV4Handle(value));
         }
diff --git a/src/qml/types/qquickworkerscript_p.h b/src/qml/types/qquickworkerscript_p.h
index dce3acc3e1..1a8d2ab076 100644
--- a/src/qml/types/qquickworkerscript_p.h
+++ b/src/qml/types/qquickworkerscript_p.h
@@ -51,7 +51,7 @@
 // We mean it.
 //
 
-#include "qqml.h"
+#include <qqml.h>
 
 #include <QtQml/qqmlparserstatus.h>
 #include <QtCore/qthread.h>
@@ -67,7 +67,7 @@ class QQuickWorkerScriptEngine : public QThread
 {
 Q_OBJECT
 public:
-    QQuickWorkerScriptEngine(QQmlEngine *parent = 0);
+    QQuickWorkerScriptEngine(QQmlEngine *parent = nullptr);
     ~QQuickWorkerScriptEngine();
 
     int registerWorkerScript(QQuickWorkerScript *);
@@ -91,7 +91,7 @@ class Q_AUTOTEST_EXPORT QQuickWorkerScript : public QObject, public QQmlParserSt
 
     Q_INTERFACES(QQmlParserStatus)
 public:
-    QQuickWorkerScript(QObject *parent = 0);
+    QQuickWorkerScript(QObject *parent = nullptr);
     ~QQuickWorkerScript();
 
     QUrl source() const;
diff --git a/src/qml/types/types.pri b/src/qml/types/types.pri
index e85ab5982b..1765beb09e 100644
--- a/src/qml/types/types.pri
+++ b/src/qml/types/types.pri
@@ -1,33 +1,56 @@
 SOURCES += \
     $$PWD/qqmlbind.cpp \
     $$PWD/qqmlconnections.cpp \
-    $$PWD/qqmldelegatemodel.cpp \
-    $$PWD/qqmllistmodel.cpp \
-    $$PWD/qqmllistmodelworkeragent.cpp \
     $$PWD/qqmlmodelsmodule.cpp \
     $$PWD/qqmlmodelindexvaluetype.cpp \
     $$PWD/qqmlobjectmodel.cpp \
     $$PWD/qquickpackage.cpp \
-    $$PWD/qquickworkerscript.cpp \
-    $$PWD/qqmlinstantiator.cpp
+    $$PWD/qqmlinstantiator.cpp \
+    $$PWD/qqmltableinstancemodel.cpp \
+    $$PWD/qqmltablemodel.cpp
 
 HEADERS += \
     $$PWD/qqmlbind_p.h \
     $$PWD/qqmlconnections_p.h \
-    $$PWD/qqmldelegatemodel_p.h \
-    $$PWD/qqmldelegatemodel_p_p.h \
-    $$PWD/qqmllistmodel_p.h \
-    $$PWD/qqmllistmodel_p_p.h \
-    $$PWD/qqmllistmodelworkeragent_p.h \
     $$PWD/qqmlmodelsmodule_p.h \
     $$PWD/qqmlmodelindexvaluetype_p.h \
     $$PWD/qqmlobjectmodel_p.h \
     $$PWD/qquickpackage_p.h \
-    $$PWD/qquickworkerscript_p.h \
     $$PWD/qqmlinstantiator_p.h \
-    $$PWD/qqmlinstantiator_p_p.h
+    $$PWD/qqmlinstantiator_p_p.h \
+    $$PWD/qqmltableinstancemodel_p.h \
+    $$PWD/qqmltablemodel_p.h
 
-qtConfig(animation) {
+qtConfig(qml-worker-script) {
+    SOURCES += \
+        $$PWD/qquickworkerscript.cpp
+    HEADERS += \
+        $$PWD/qquickworkerscript_p.h
+}
+
+qtConfig(qml-list-model) {
+    SOURCES += \
+        $$PWD/qqmllistmodel.cpp \
+        $$PWD/qqmllistmodelworkeragent.cpp
+
+    HEADERS += \
+        $$PWD/qqmllistmodel_p.h \
+        $$PWD/qqmllistmodel_p_p.h \
+        $$PWD/qqmllistmodelworkeragent_p.h
+}
+
+qtConfig(qml-delegate-model) {
+    SOURCES += \
+        $$PWD/qqmldelegatemodel.cpp \
+        $$PWD/qqmldelegatecomponent.cpp
+
+    HEADERS += \
+        $$PWD/qqmldelegatemodel_p.h \
+        $$PWD/qqmldelegatemodel_p_p.h \
+        $$PWD/qqmldelegatecomponent_p.h
+}
+
+qtConfig(qml-animation) {
     SOURCES += \
         $$PWD/qqmltimer.cpp
 
diff --git a/src/qml/util/qqmladaptormodel.cpp b/src/qml/util/qqmladaptormodel.cpp
index b9f6ea461a..d9cb6506b8 100644
--- a/src/qml/util/qqmladaptormodel.cpp
+++ b/src/qml/util/qqmladaptormodel.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -61,11 +61,12 @@ public:
 
 V4_DEFINE_EXTENSION(QQmlAdaptorModelEngineData, engineData)
 
-static void get_index(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+static QV4::ReturnedValue get_index(const QV4::FunctionObject *f, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
+    QV4::Scope scope(f);
+    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
     if (!o)
-        RETURN_RESULT(scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object")));
+        RETURN_RESULT(scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object")));
 
     RETURN_RESULT(QV4::Encode(o->d()->item->index));
 }
@@ -95,7 +96,7 @@ public:
     QQmlDMCachedModelData(
             QQmlDelegateModelItemMetaType *metaType,
             VDMModelDelegateDataType *dataType,
-            int index);
+            int index, int row, int column);
 
     int metaCall(QMetaObject::Call call, int id, void **arguments);
 
@@ -105,8 +106,8 @@ public:
     void setValue(const QString &role, const QVariant &value) override;
     bool resolveIndex(const QQmlAdaptorModel &model, int idx) override;
 
-    static QV4::ReturnedValue get_property(QV4::CallContext *ctx, uint propertyId);
-    static QV4::ReturnedValue set_property(QV4::CallContext *ctx, uint propertyId);
+    static QV4::ReturnedValue get_property(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
+    static QV4::ReturnedValue set_property(const QV4::FunctionObject *, const QV4::Value *thisObject, const QV4::Value *argv, int argc);
 
     VDMModelDelegateDataType *type;
     QVector<QVariant> cachedData;
@@ -120,21 +121,12 @@ class VDMModelDelegateDataType
 public:
     VDMModelDelegateDataType(QQmlAdaptorModel *model)
         : model(model)
-        , metaObject(0)
-        , propertyCache(0)
         , propertyOffset(0)
         , signalOffset(0)
         , hasModelData(false)
     {
     }
 
-    ~VDMModelDelegateDataType()
-    {
-        if (propertyCache)
-            propertyCache->release();
-        free(metaObject);
-    }
-
     bool notify(
             const QQmlAdaptorModel &,
             const QList<QQmlDelegateModelItem *> &items,
@@ -175,7 +167,7 @@ public:
             const int idx = item->modelIndex();
             if (idx >= index && idx < index + count) {
                 for (int i = 0; i < signalIndexes.count(); ++i)
-                    QMetaObject::activate(item, signalIndexes.at(i), 0);
+                    QMetaObject::activate(item, signalIndexes.at(i), nullptr);
             }
         }
         return changed;
@@ -194,11 +186,12 @@ public:
         dataType->watchedRoles += newRoles;
     }
 
-    static void get_hasModelChildren(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+    static QV4::ReturnedValue get_hasModelChildren(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
     {
-        QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
+        QV4::Scope scope(b);
+        QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
         if (!o)
-            RETURN_RESULT(scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object")));
+            RETURN_RESULT(scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object")));
 
         const QQmlAdaptorModel *const model = static_cast<QQmlDMCachedModelData *>(o->d()->item)->type->model;
         if (o->d()->item->index >= 0 && *model) {
@@ -215,8 +208,8 @@ public:
         QV4::ExecutionEngine *v4 = data->v4;
         QV4::Scope scope(v4);
         QV4::ScopedObject proto(scope, v4->newObject());
-        proto->defineAccessorProperty(QStringLiteral("index"), get_index, 0);
-        proto->defineAccessorProperty(QStringLiteral("hasModelChildren"), get_hasModelChildren, 0);
+        proto->defineAccessorProperty(QStringLiteral("index"), get_index, nullptr);
+        proto->defineAccessorProperty(QStringLiteral("hasModelChildren"), get_hasModelChildren, nullptr);
         QV4::ScopedProperty p(scope);
 
         typedef QHash<QByteArray, int>::const_iterator iterator;
@@ -226,8 +219,8 @@ public:
 
             QV4::ScopedString name(scope, v4->newString(QString::fromUtf8(propertyName)));
             QV4::ExecutionContext *global = v4->rootContext();
-            QV4::ScopedFunctionObject g(scope, v4->memoryManager->allocObject<QV4::IndexedBuiltinFunction>(global, propertyId, QQmlDMCachedModelData::get_property));
-            QV4::ScopedFunctionObject s(scope, v4->memoryManager->allocObject<QV4::IndexedBuiltinFunction>(global, propertyId, QQmlDMCachedModelData::set_property));
+            QV4::ScopedFunctionObject g(scope, v4->memoryManager->allocate<QV4::IndexedBuiltinFunction>(global, propertyId, QQmlDMCachedModelData::get_property));
+            QV4::ScopedFunctionObject s(scope, v4->memoryManager->allocate<QV4::IndexedBuiltinFunction>(global, propertyId, QQmlDMCachedModelData::set_property));
             p->setGetter(g);
             p->setSetter(s);
             proto->insertMember(name, p, QV4::Attr_Accessor|QV4::Attr_NotEnumerable|QV4::Attr_NotConfigurable);
@@ -253,16 +246,13 @@ public:
     QList<QByteArray> watchedRoles;
     QHash<QByteArray, int> roleNames;
     QQmlAdaptorModel *model;
-    QMetaObject *metaObject;
-    QQmlPropertyCache *propertyCache;
     int propertyOffset;
     int signalOffset;
     bool hasModelData;
 };
 
-QQmlDMCachedModelData::QQmlDMCachedModelData(
-        QQmlDelegateModelItemMetaType *metaType, VDMModelDelegateDataType *dataType, int index)
-    : QQmlDelegateModelItem(metaType, index)
+QQmlDMCachedModelData::QQmlDMCachedModelData(QQmlDelegateModelItemMetaType *metaType, VDMModelDelegateDataType *dataType, int index, int row, int column)
+    : QQmlDelegateModelItem(metaType, dataType, index, row, column)
     , type(dataType)
 {
     if (index == -1)
@@ -271,10 +261,6 @@ QQmlDMCachedModelData::QQmlDMCachedModelData(
     QObjectPrivate::get(this)->metaObject = type;
 
     type->addref();
-
-    QQmlData *qmldata = QQmlData::get(this, true);
-    qmldata->propertyCache = dataType->propertyCache;
-    qmldata->propertyCache->addref();
 }
 
 int QQmlDMCachedModelData::metaCall(QMetaObject::Call call, int id, void **arguments)
@@ -296,11 +282,11 @@ int QQmlDMCachedModelData::metaCall(QMetaObject::Call call, int id, void **argum
             const QMetaObject *meta = metaObject();
             if (cachedData.count() > 1) {
                 cachedData[propertyIndex] = *static_cast<QVariant *>(arguments[0]);
-                QMetaObject::activate(this, meta, propertyIndex, 0);
+                QMetaObject::activate(this, meta, propertyIndex, nullptr);
             } else if (cachedData.count() == 1) {
                 cachedData[0] = *static_cast<QVariant *>(arguments[0]);
-                QMetaObject::activate(this, meta, 0, 0);
-                QMetaObject::activate(this, meta, 1, 0);
+                QMetaObject::activate(this, meta, 0, nullptr);
+                QMetaObject::activate(this, meta, 1, nullptr);
             }
         } else if (*type->model) {
             setValue(type->propertyRoles.at(propertyIndex), *static_cast<QVariant *>(arguments[0]));
@@ -324,29 +310,30 @@ void QQmlDMCachedModelData::setValue(const QString &role, const QVariant &value)
     }
 }
 
-bool QQmlDMCachedModelData::resolveIndex(const QQmlAdaptorModel &, int idx)
+bool QQmlDMCachedModelData::resolveIndex(const QQmlAdaptorModel &adaptorModel, int idx)
 {
     if (index == -1) {
         Q_ASSERT(idx >= 0);
-        index = idx;
         cachedData.clear();
-        emit modelIndexChanged();
+        setModelIndex(idx, adaptorModel.rowAt(idx), adaptorModel.columnAt(idx));
         const QMetaObject *meta = metaObject();
         const int propertyCount = type->propertyRoles.count();
         for (int i = 0; i < propertyCount; ++i)
-            QMetaObject::activate(this, meta, i, 0);
+            QMetaObject::activate(this, meta, i, nullptr);
         return true;
     } else {
         return false;
     }
 }
 
-QV4::ReturnedValue QQmlDMCachedModelData::get_property(QV4::CallContext *ctx, uint propertyId)
+QV4::ReturnedValue QQmlDMCachedModelData::get_property(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
 {
-    QV4::Scope scope(ctx);
-    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, ctx->thisObject().as<QQmlDelegateModelItemObject>());
+    QV4::Scope scope(b);
+    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
     if (!o)
-        return ctx->engine()->throwTypeError(QStringLiteral("Not a valid VisualData object"));
+        return scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
+
+    uint propertyId = static_cast<const QV4::IndexedBuiltinFunction *>(b)->d()->index;
 
     QQmlDMCachedModelData *modelData = static_cast<QQmlDMCachedModelData *>(o->d()->item);
     if (o->d()->item->index == -1) {
@@ -361,25 +348,27 @@ QV4::ReturnedValue QQmlDMCachedModelData::get_property(QV4::CallContext *ctx, ui
     return QV4::Encode::undefined();
 }
 
-QV4::ReturnedValue QQmlDMCachedModelData::set_property(QV4::CallContext *ctx, uint propertyId)
+QV4::ReturnedValue QQmlDMCachedModelData::set_property(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
 {
-    QV4::Scope scope(ctx);
-    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, ctx->thisObject().as<QQmlDelegateModelItemObject>());
+    QV4::Scope scope(b);
+    QV4::Scoped<QQmlDelegateModelItemObject> o(scope, thisObject->as<QQmlDelegateModelItemObject>());
     if (!o)
-        return ctx->engine()->throwTypeError(QStringLiteral("Not a valid VisualData object"));
-    if (!ctx->argc())
-        return ctx->engine()->throwTypeError();
+        return scope.engine->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
+    if (!argc)
+        return scope.engine->throwTypeError();
+
+    uint propertyId = static_cast<const QV4::IndexedBuiltinFunction *>(b)->d()->index;
 
     if (o->d()->item->index == -1) {
         QQmlDMCachedModelData *modelData = static_cast<QQmlDMCachedModelData *>(o->d()->item);
         if (!modelData->cachedData.isEmpty()) {
             if (modelData->cachedData.count() > 1) {
-                modelData->cachedData[propertyId] = scope.engine->toVariant(ctx->args()[0], QVariant::Invalid);
-                QMetaObject::activate(o->d()->item, o->d()->item->metaObject(), propertyId, 0);
+                modelData->cachedData[propertyId] = scope.engine->toVariant(argv[0], QVariant::Invalid);
+                QMetaObject::activate(o->d()->item, o->d()->item->metaObject(), propertyId, nullptr);
             } else if (modelData->cachedData.count() == 1) {
-                modelData->cachedData[0] = scope.engine->toVariant(ctx->args()[0], QVariant::Invalid);
-                QMetaObject::activate(o->d()->item, o->d()->item->metaObject(), 0, 0);
-                QMetaObject::activate(o->d()->item, o->d()->item->metaObject(), 1, 0);
+                modelData->cachedData[0] = scope.engine->toVariant(argv[0], QVariant::Invalid);
+                QMetaObject::activate(o->d()->item, o->d()->item->metaObject(), 0, nullptr);
+                QMetaObject::activate(o->d()->item, o->d()->item->metaObject(), 1, nullptr);
             }
         }
     }
@@ -394,12 +383,13 @@ class QQmlDMAbstractItemModelData : public QQmlDMCachedModelData
 {
     Q_OBJECT
     Q_PROPERTY(bool hasModelChildren READ hasModelChildren CONSTANT)
+
 public:
     QQmlDMAbstractItemModelData(
             QQmlDelegateModelItemMetaType *metaType,
             VDMModelDelegateDataType *dataType,
-            int index)
-        : QQmlDMCachedModelData(metaType, dataType, index)
+            int index, int row, int column)
+        : QQmlDMCachedModelData(metaType, dataType, index, row, column)
     {
     }
 
@@ -407,7 +397,7 @@ public:
     {
         if (index >= 0 && *type->model) {
             const QAbstractItemModel * const model = type->model->aim();
-            return model->hasChildren(model->index(index, 0, type->model->rootIndex));
+            return model->hasChildren(model->index(row, column, type->model->rootIndex));
         } else {
             return false;
         }
@@ -415,13 +405,13 @@ public:
 
     QVariant value(int role) const override
     {
-        return type->model->aim()->index(index, 0, type->model->rootIndex).data(role);
+        return type->model->aim()->index(row, column, type->model->rootIndex).data(role);
     }
 
     void setValue(int role, const QVariant &value) override
     {
         type->model->aim()->setData(
-                type->model->aim()->index(index, 0, type->model->rootIndex), value, role);
+                type->model->aim()->index(row, column, type->model->rootIndex), value, role);
     }
 
     QV4::ReturnedValue get() override
@@ -432,8 +422,8 @@ public:
         }
         QV4::Scope scope(v4);
         QV4::ScopedObject proto(scope, type->prototype.value());
-        QV4::ScopedObject o(scope, proto->engine()->memoryManager->allocObject<QQmlDelegateModelItemObject>(this));
-        o->setPrototype(proto);
+        QV4::ScopedObject o(scope, proto->engine()->memoryManager->allocate<QQmlDelegateModelItemObject>(this));
+        o->setPrototypeOf(proto);
         ++scriptRef;
         return o.asReturnedValue();
     }
@@ -447,31 +437,18 @@ public:
     {
     }
 
-    int count(const QQmlAdaptorModel &model) const override
+    int rowCount(const QQmlAdaptorModel &model) const override
     {
         return model.aim()->rowCount(model.rootIndex);
     }
 
-    void cleanup(QQmlAdaptorModel &model, QQmlDelegateModel *vdm) const override
-    {
-        QAbstractItemModel * const aim = model.aim();
-        if (aim && vdm) {
-            QObject::disconnect(aim, SIGNAL(rowsInserted(QModelIndex,int,int)),
-                                vdm, SLOT(_q_rowsInserted(QModelIndex,int,int)));
-            QObject::disconnect(aim, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
-                                vdm, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
-            QObject::disconnect(aim, SIGNAL(rowsRemoved(QModelIndex,int,int)),
-                                vdm, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
-            QObject::disconnect(aim, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
-                                vdm, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
-            QObject::disconnect(aim, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
-                                vdm, SLOT(_q_rowsMoved(QModelIndex,int,int,QModelIndex,int)));
-            QObject::disconnect(aim, SIGNAL(modelReset()),
-                                vdm, SLOT(_q_modelReset()));
-            QObject::disconnect(aim, SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
-                                vdm, SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)));
-        }
+    int columnCount(const QQmlAdaptorModel &model) const override
+    {
+        return model.aim()->columnCount(model.rootIndex);
+    }
 
+    void cleanup(QQmlAdaptorModel &) const override
+    {
         const_cast<VDMAbstractItemModelDataType *>(this)->release();
     }
 
@@ -479,9 +456,9 @@ public:
     {
         QHash<QByteArray, int>::const_iterator it = roleNames.find(role.toUtf8());
         if (it != roleNames.end()) {
-            return model.aim()->index(index, 0, model.rootIndex).data(*it);
+            return model.aim()->index(model.rowAt(index), model.columnAt(index), model.rootIndex).data(*it);
         } else if (role == QLatin1String("hasModelChildren")) {
-            return QVariant(model.aim()->hasChildren(model.aim()->index(index, 0, model.rootIndex)));
+            return QVariant(model.aim()->hasChildren(model.aim()->index(model.rowAt(index), model.columnAt(index), model.rootIndex)));
         } else {
             return QVariant();
         }
@@ -497,7 +474,7 @@ public:
     QVariant modelIndex(const QQmlAdaptorModel &model, int index) const override
     {
         return model
-                ? QVariant::fromValue(model.aim()->index(index, 0, model.rootIndex))
+                ? QVariant::fromValue(model.aim()->index(model.rowAt(index), model.columnAt(index), model.rootIndex))
                 : QVariant();
     }
 
@@ -515,16 +492,15 @@ public:
     QQmlDelegateModelItem *createItem(
             QQmlAdaptorModel &model,
             QQmlDelegateModelItemMetaType *metaType,
-            QQmlEngine *engine,
-            int index) const override
+            int index, int row, int column) const override
     {
         VDMAbstractItemModelDataType *dataType = const_cast<VDMAbstractItemModelDataType *>(this);
         if (!metaObject)
-            dataType->initializeMetaType(model, engine);
-        return new QQmlDMAbstractItemModelData(metaType, dataType, index);
+            dataType->initializeMetaType(model);
+        return new QQmlDMAbstractItemModelData(metaType, dataType, index, row, column);
     }
 
-    void initializeMetaType(QQmlAdaptorModel &model, QQmlEngine *engine)
+    void initializeMetaType(QQmlAdaptorModel &model)
     {
         QMetaObjectBuilder builder;
         setModelDataType<QQmlDMAbstractItemModelData>(&builder, this);
@@ -547,9 +523,9 @@ public:
             addProperty(&builder, 1, propertyName, propertyType);
         }
 
-        metaObject = builder.toMetaObject();
+        metaObject.reset(builder.toMetaObject());
         *static_cast<QMetaObject *>(this) = *metaObject;
-        propertyCache = new QQmlPropertyCache(QV8Engine::getV4(engine), metaObject);
+        propertyCache = new QQmlPropertyCache(metaObject.data(), model.modelItemRevision);
     }
 };
 
@@ -562,8 +538,10 @@ class QQmlDMListAccessorData : public QQmlDelegateModelItem
     Q_OBJECT
     Q_PROPERTY(QVariant modelData READ modelData WRITE setModelData NOTIFY modelDataChanged)
 public:
-    QQmlDMListAccessorData(QQmlDelegateModelItemMetaType *metaType, int index, const QVariant &value)
-        : QQmlDelegateModelItem(metaType, index)
+    QQmlDMListAccessorData(QQmlDelegateModelItemMetaType *metaType,
+                           QQmlAdaptorModel::Accessors *accessor,
+                           int index, int row, int column, const QVariant &value)
+        : QQmlDelegateModelItem(metaType, accessor, index, row, column)
         , cachedData(value)
     {
     }
@@ -575,40 +553,43 @@ public:
 
     void setModelData(const QVariant &data)
     {
-        if (index == -1 && data != cachedData) {
-            cachedData = data;
-            emit modelDataChanged();
-        }
+        if (data == cachedData)
+            return;
+
+        cachedData = data;
+        emit modelDataChanged();
     }
 
-    static void get_modelData(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+    static QV4::ReturnedValue get_modelData(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *, int)
     {
-        QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
+        QV4::ExecutionEngine *v4 = b->engine();
+        const QQmlDelegateModelItemObject *o = thisObject->as<QQmlDelegateModelItemObject>();
         if (!o)
-            RETURN_RESULT(scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object")));
+            return v4->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
 
-        RETURN_RESULT(scope.engine->fromVariant(static_cast<QQmlDMListAccessorData *>(o->d()->item)->cachedData));
+        return v4->fromVariant(static_cast<QQmlDMListAccessorData *>(o->d()->item)->cachedData);
     }
 
-    static void set_modelData(const QV4::BuiltinFunction *, QV4::Scope &scope, QV4::CallData *callData)
+    static QV4::ReturnedValue set_modelData(const QV4::FunctionObject *b, const QV4::Value *thisObject, const QV4::Value *argv, int argc)
     {
-        QV4::Scoped<QQmlDelegateModelItemObject> o(scope, callData->thisObject.as<QQmlDelegateModelItemObject>());
+        QV4::ExecutionEngine *v4 = b->engine();
+        const QQmlDelegateModelItemObject *o = thisObject->as<QQmlDelegateModelItemObject>();
         if (!o)
-            RETURN_RESULT(scope.engine->throwTypeError(QStringLiteral("Not a valid VisualData object")));
-        if (!callData->argc)
-            RETURN_RESULT(scope.engine->throwTypeError());
+            return v4->throwTypeError(QStringLiteral("Not a valid DelegateModel object"));
+        if (!argc)
+            return v4->throwTypeError();
 
-        static_cast<QQmlDMListAccessorData *>(o->d()->item)->setModelData(scope.engine->toVariant(callData->args[0], QVariant::Invalid));
-        RETURN_RESULT(QV4::Encode::undefined());
+        static_cast<QQmlDMListAccessorData *>(o->d()->item)->setModelData(v4->toVariant(argv[0], QVariant::Invalid));
+        return QV4::Encode::undefined();
     }
 
     QV4::ReturnedValue get() override
     {
         QQmlAdaptorModelEngineData *data = engineData(v4);
         QV4::Scope scope(v4);
-        QV4::ScopedObject o(scope, v4->memoryManager->allocObject<QQmlDelegateModelItemObject>(this));
+        QV4::ScopedObject o(scope, v4->memoryManager->allocate<QQmlDelegateModelItemObject>(this));
         QV4::ScopedObject p(scope, data->listItemProto.value());
-        o->setPrototype(p);
+        o->setPrototypeOf(p);
         ++scriptRef;
         return o.asReturnedValue();
     }
@@ -641,16 +622,29 @@ private:
 };
 
 
-class VDMListDelegateDataType : public QQmlAdaptorModel::Accessors
+class VDMListDelegateDataType : public QQmlRefCount, public QQmlAdaptorModel::Accessors
 {
 public:
-    inline VDMListDelegateDataType() {}
+    VDMListDelegateDataType()
+        : QQmlRefCount()
+        , QQmlAdaptorModel::Accessors()
+    {}
+
+    void cleanup(QQmlAdaptorModel &) const override
+    {
+        const_cast<VDMListDelegateDataType *>(this)->release();
+    }
 
-    int count(const QQmlAdaptorModel &model) const override
+    int rowCount(const QQmlAdaptorModel &model) const override
     {
         return model.list.count();
     }
 
+    int columnCount(const QQmlAdaptorModel &) const override
+    {
+        return 1;
+    }
+
     QVariant value(const QQmlAdaptorModel &model, int index, const QString &role) const override
     {
         return role == QLatin1String("modelData")
@@ -661,14 +655,34 @@ public:
     QQmlDelegateModelItem *createItem(
             QQmlAdaptorModel &model,
             QQmlDelegateModelItemMetaType *metaType,
-            QQmlEngine *,
-            int index) const override
+            int index, int row, int column) const override
     {
+        VDMListDelegateDataType *dataType = const_cast<VDMListDelegateDataType *>(this);
+        if (!propertyCache) {
+            dataType->propertyCache = new QQmlPropertyCache(
+                        &QQmlDMListAccessorData::staticMetaObject, model.modelItemRevision);
+        }
+
         return new QQmlDMListAccessorData(
                 metaType,
-                index,
+                dataType,
+                index, row, column,
                 index >= 0 && index < model.list.count() ? model.list.at(index) : QVariant());
     }
+
+    bool notify(const QQmlAdaptorModel &model, const QList<QQmlDelegateModelItem *> &items, int index, int count, const QVector<int> &) const override
+    {
+        for (auto modelItem : items) {
+            const int modelItemIndex = modelItem->index;
+            if (modelItemIndex < index || modelItemIndex >= index + count)
+                continue;
+
+            auto listModelItem = static_cast<QQmlDMListAccessorData *>(modelItem);
+            QVariant updatedModelData = model.list.at(listModelItem->index);
+            listModelItem->setModelData(updatedModelData);
+        }
+        return true;
+    }
 };
 
 //-----------------------------------------------------------------
@@ -679,33 +693,43 @@ class VDMObjectDelegateDataType;
 class QQmlDMObjectData : public QQmlDelegateModelItem, public QQmlAdaptorModelProxyInterface
 {
     Q_OBJECT
-    Q_PROPERTY(QObject *modelData READ modelData CONSTANT)
+    Q_PROPERTY(QObject *modelData READ modelData NOTIFY modelDataChanged)
     Q_INTERFACES(QQmlAdaptorModelProxyInterface)
 public:
     QQmlDMObjectData(
             QQmlDelegateModelItemMetaType *metaType,
             VDMObjectDelegateDataType *dataType,
-            int index,
+            int index, int row, int column,
             QObject *object);
 
+    void setModelData(QObject *modelData)
+    {
+        if (modelData == object)
+            return;
+
+        object = modelData;
+        emit modelDataChanged();
+    }
+
     QObject *modelData() const { return object; }
     QObject *proxiedObject() override { return object; }
 
     QPointer<QObject> object;
+
+Q_SIGNALS:
+    void modelDataChanged();
 };
 
 class VDMObjectDelegateDataType : public QQmlRefCount, public QQmlAdaptorModel::Accessors
 {
 public:
-    QMetaObject *metaObject;
     int propertyOffset;
     int signalOffset;
     bool shared;
     QMetaObjectBuilder builder;
 
     VDMObjectDelegateDataType()
-        : metaObject(0)
-        , propertyOffset(0)
+        : propertyOffset(0)
         , signalOffset(0)
         , shared(true)
     {
@@ -714,11 +738,10 @@ public:
     VDMObjectDelegateDataType(const VDMObjectDelegateDataType &type)
         : QQmlRefCount()
         , QQmlAdaptorModel::Accessors()
-        , metaObject(0)
         , propertyOffset(type.propertyOffset)
         , signalOffset(type.signalOffset)
         , shared(false)
-        , builder(type.metaObject, QMetaObjectBuilder::Properties
+        , builder(type.metaObject.data(), QMetaObjectBuilder::Properties
                 | QMetaObjectBuilder::Signals
                 | QMetaObjectBuilder::SuperClass
                 | QMetaObjectBuilder::ClassName)
@@ -726,14 +749,14 @@ public:
         builder.setFlags(QMetaObjectBuilder::DynamicMetaObject);
     }
 
-    ~VDMObjectDelegateDataType()
+    int rowCount(const QQmlAdaptorModel &model) const override
     {
-        free(metaObject);
+        return model.list.count();
     }
 
-    int count(const QQmlAdaptorModel &model) const override
+    int columnCount(const QQmlAdaptorModel &) const override
     {
-        return model.list.count();
+        return 1;
     }
 
     QVariant value(const QQmlAdaptorModel &model, int index, const QString &role) const override
@@ -746,28 +769,48 @@ public:
     QQmlDelegateModelItem *createItem(
             QQmlAdaptorModel &model,
             QQmlDelegateModelItemMetaType *metaType,
-            QQmlEngine *,
-            int index) const override
+            int index, int row, int column) const override
     {
         VDMObjectDelegateDataType *dataType = const_cast<VDMObjectDelegateDataType *>(this);
         if (!metaObject)
             dataType->initializeMetaType(model);
         return index >= 0 && index < model.list.count()
-                ? new QQmlDMObjectData(metaType, dataType, index, qvariant_cast<QObject *>(model.list.at(index)))
-                : 0;
+                ? new QQmlDMObjectData(metaType, dataType, index, row, column, qvariant_cast<QObject *>(model.list.at(index)))
+                : nullptr;
     }
 
-    void initializeMetaType(QQmlAdaptorModel &)
+    void initializeMetaType(QQmlAdaptorModel &model)
     {
+        Q_UNUSED(model);
         setModelDataType<QQmlDMObjectData>(&builder, this);
 
-        metaObject = builder.toMetaObject();
+        metaObject.reset(builder.toMetaObject());
+        // Note: ATM we cannot create a shared property cache for this class, since each model
+        // object can have different properties. And to make those properties available to the
+        // delegate, QQmlDMObjectData makes use of a QAbstractDynamicMetaObject subclass
+        // (QQmlDMObjectDataMetaObject), which we cannot represent in a QQmlPropertyCache.
+        // By not having a shared property cache, revisioned properties in QQmlDelegateModelItem
+        // will always be available to the delegate, regardless of the import version.
     }
 
-    void cleanup(QQmlAdaptorModel &, QQmlDelegateModel *) const override
+    void cleanup(QQmlAdaptorModel &) const override
     {
         const_cast<VDMObjectDelegateDataType *>(this)->release();
     }
+
+    bool notify(const QQmlAdaptorModel &model, const QList<QQmlDelegateModelItem *> &items, int index, int count, const QVector<int> &) const override
+    {
+        for (auto modelItem : items) {
+            const int modelItemIndex = modelItem->index;
+            if (modelItemIndex < index || modelItemIndex >= index + count)
+                continue;
+
+            auto objectModelItem = static_cast<QQmlDMObjectData *>(modelItem);
+            QObject *updatedModelData = qvariant_cast<QObject *>(model.list.at(objectModelItem->index));
+            objectModelItem->setModelData(updatedModelData);
+        }
+        return true;
+    }
 };
 
 class QQmlDMObjectDataMetaObject : public QAbstractDynamicMetaObject
@@ -802,7 +845,7 @@ public:
                 QMetaObject::metacall(m_data->object, call, id - m_type->propertyOffset + objectPropertyOffset, arguments);
             return -1;
         } else if (id >= m_type->signalOffset && call == QMetaObject::InvokeMetaMethod) {
-            QMetaObject::activate(m_data, this, id - m_type->signalOffset, 0);
+            QMetaObject::activate(m_data, this, id - m_type->signalOffset, nullptr);
             return -1;
         } else {
             return m_data->qt_metacall(call, id, arguments);
@@ -846,9 +889,7 @@ public:
             propertyBuilder.setConstant(property.isConstant());
         }
 
-        if (m_type->metaObject)
-            free(m_type->metaObject);
-        m_type->metaObject = m_type->builder.toMetaObject();
+        m_type->metaObject.reset(m_type->builder.toMetaObject());
         *static_cast<QMetaObject *>(this) = *m_type->metaObject;
 
         notifierId = previousMethodCount;
@@ -867,12 +908,11 @@ public:
     VDMObjectDelegateDataType *m_type;
 };
 
-QQmlDMObjectData::QQmlDMObjectData(
-        QQmlDelegateModelItemMetaType *metaType,
+QQmlDMObjectData::QQmlDMObjectData(QQmlDelegateModelItemMetaType *metaType,
         VDMObjectDelegateDataType *dataType,
-        int index,
+        int index, int row, int column,
         QObject *object)
-    : QQmlDelegateModelItem(metaType, index)
+    : QQmlDelegateModelItem(metaType, dataType, index, row, column)
     , object(object)
 {
     new QQmlDMObjectDataMetaObject(this, dataType);
@@ -883,7 +923,6 @@ QQmlDMObjectData::QQmlDMObjectData(
 //-----------------------------------------------------------------
 
 static const QQmlAdaptorModel::Accessors qt_vdm_null_accessors;
-static const VDMListDelegateDataType qt_vdm_list_accessors;
 
 QQmlAdaptorModel::Accessors::~Accessors()
 {
@@ -899,50 +938,34 @@ QQmlAdaptorModel::~QQmlAdaptorModel()
     accessors->cleanup(*this);
 }
 
-void QQmlAdaptorModel::setModel(const QVariant &variant, QQmlDelegateModel *vdm, QQmlEngine *engine)
+void QQmlAdaptorModel::setModel(const QVariant &variant, QObject *parent, QQmlEngine *engine)
 {
-    accessors->cleanup(*this, vdm);
+    accessors->cleanup(*this);
 
     list.setList(variant, engine);
 
     if (QObject *object = qvariant_cast<QObject *>(list.list())) {
-        setObject(object);
-        if (QAbstractItemModel *model = qobject_cast<QAbstractItemModel *>(object)) {
+        setObject(object, parent);
+        if (qobject_cast<QAbstractItemModel *>(object))
             accessors = new VDMAbstractItemModelDataType(this);
-
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsInserted(QModelIndex,int,int)),
-                              vdm, QQmlDelegateModel, SLOT(_q_rowsInserted(QModelIndex,int,int)));
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsRemoved(QModelIndex,int,int)),
-                              vdm,  QQmlDelegateModel, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
-                              vdm,  QQmlDelegateModel, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
-                              vdm, QQmlDelegateModel, SLOT(_q_dataChanged(QModelIndex,QModelIndex,QVector<int>)));
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
-                              vdm, QQmlDelegateModel, SLOT(_q_rowsMoved(QModelIndex,int,int,QModelIndex,int)));
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(modelReset()),
-                              vdm, QQmlDelegateModel, SLOT(_q_modelReset()));
-            qmlobject_connect(model, QAbstractItemModel, SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
-                              vdm, QQmlDelegateModel, SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)));
-        } else {
+        else
             accessors = new VDMObjectDelegateDataType;
-        }
     } else if (list.type() == QQmlListAccessor::ListProperty) {
-        setObject(static_cast<const QQmlListReference *>(variant.constData())->object());
+        setObject(static_cast<const QQmlListReference *>(variant.constData())->object(), parent);
         accessors = new VDMObjectDelegateDataType;
     } else if (list.type() != QQmlListAccessor::Invalid
             && list.type() != QQmlListAccessor::Instance) { // Null QObject
-        setObject(0);
-        accessors = &qt_vdm_list_accessors;
+        setObject(nullptr, parent);
+        accessors = new VDMListDelegateDataType;
     } else {
-        setObject(0);
+        setObject(nullptr, parent);
         accessors = &qt_vdm_null_accessors;
     }
 }
 
-void QQmlAdaptorModel::invalidateModel(QQmlDelegateModel *vdm)
+void QQmlAdaptorModel::invalidateModel()
 {
-    accessors->cleanup(*this, vdm);
+    accessors->cleanup(*this);
     accessors = &qt_vdm_null_accessors;
     // Don't clear the model object as we still need the guard to clear the list variant if the
     // object is destroyed.
@@ -953,9 +976,46 @@ bool QQmlAdaptorModel::isValid() const
     return accessors != &qt_vdm_null_accessors;
 }
 
+int QQmlAdaptorModel::count() const
+{
+    return rowCount() * columnCount();
+}
+
+int QQmlAdaptorModel::rowCount() const
+{
+    return qMax(0, accessors->rowCount(*this));
+}
+
+int QQmlAdaptorModel::columnCount() const
+{
+    return qMax(0, accessors->columnCount(*this));
+}
+
+int QQmlAdaptorModel::rowAt(int index) const
+{
+    int count = rowCount();
+    return count <= 0 ? -1 : index % count;
+}
+
+int QQmlAdaptorModel::columnAt(int index) const
+{
+    int count = rowCount();
+    return count <= 0 ? -1 : index / count;
+}
+
+int QQmlAdaptorModel::indexAt(int row, int column) const
+{
+    return column * rowCount() + row;
+}
+
+void QQmlAdaptorModel::useImportVersion(int minorVersion)
+{
+    modelItemRevision = minorVersion;
+}
+
 void QQmlAdaptorModel::objectDestroyed(QObject *)
 {
-    setModel(QVariant(), 0, 0);
+    setModel(QVariant(), nullptr, nullptr);
 }
 
 QQmlAdaptorModelEngineData::QQmlAdaptorModelEngineData(QV4::ExecutionEngine *v4)
@@ -963,7 +1023,7 @@ QQmlAdaptorModelEngineData::QQmlAdaptorModelEngineData(QV4::ExecutionEngine *v4)
 {
     QV4::Scope scope(v4);
     QV4::ScopedObject proto(scope, v4->newObject());
-    proto->defineAccessorProperty(QStringLiteral("index"), get_index, 0);
+    proto->defineAccessorProperty(QStringLiteral("index"), get_index, nullptr);
     proto->defineAccessorProperty(QStringLiteral("modelData"),
                                   QQmlDMListAccessorData::get_modelData, QQmlDMListAccessorData::set_modelData);
     listItemProto.set(v4, proto);
diff --git a/src/qml/util/qqmladaptormodel_p.h b/src/qml/util/qqmladaptormodel_p.h
index 78d964236e..8c18466ab5 100644
--- a/src/qml/util/qqmladaptormodel_p.h
+++ b/src/qml/util/qqmladaptormodel_p.h
@@ -54,8 +54,11 @@
 #include <QtCore/qabstractitemmodel.h>
 
 #include "private/qqmllistaccessor_p.h"
-
+#include <private/qqmlglobal_p.h>
 #include <private/qqmlguard_p.h>
+#include <private/qqmlnullablevalue_p.h>
+
+QT_REQUIRE_CONFIG(qml_delegate_model);
 
 QT_BEGIN_NAMESPACE
 
@@ -65,7 +68,7 @@ class QQmlDelegateModel;
 class QQmlDelegateModelItem;
 class QQmlDelegateModelItemMetaType;
 
-class QQmlAdaptorModel : public QQmlGuard<QObject>
+class Q_QML_PRIVATE_EXPORT QQmlAdaptorModel : public QQmlStrongJSQObjectReference<QObject>
 {
 public:
     class Accessors
@@ -73,8 +76,9 @@ public:
     public:
         inline Accessors() {}
         virtual ~Accessors();
-        virtual int count(const QQmlAdaptorModel &) const { return 0; }
-        virtual void cleanup(QQmlAdaptorModel &, QQmlDelegateModel * = 0) const {}
+        virtual int rowCount(const QQmlAdaptorModel &) const { return 0; }
+        virtual int columnCount(const QQmlAdaptorModel &) const { return 0; }
+        virtual void cleanup(QQmlAdaptorModel &) const {}
 
         virtual QVariant value(const QQmlAdaptorModel &, int, const QString &) const {
             return QVariant(); }
@@ -82,8 +86,7 @@ public:
         virtual QQmlDelegateModelItem *createItem(
                 QQmlAdaptorModel &,
                 QQmlDelegateModelItemMetaType *,
-                QQmlEngine *,
-                int) const { return 0; }
+                int, int, int) const { return nullptr; }
 
         virtual bool notify(
                 const QQmlAdaptorModel &,
@@ -101,29 +104,42 @@ public:
             return QVariant(); }
         virtual bool canFetchMore(const QQmlAdaptorModel &) const { return false; }
         virtual void fetchMore(QQmlAdaptorModel &) const {}
+
+        QScopedPointer<QMetaObject, QScopedPointerPodDeleter> metaObject;
+        QQmlRefPointer<QQmlPropertyCache> propertyCache;
     };
 
     const Accessors *accessors;
     QPersistentModelIndex rootIndex;
     QQmlListAccessor list;
 
+    int modelItemRevision = 0;
+
     QQmlAdaptorModel();
     ~QQmlAdaptorModel();
 
     inline QVariant model() const { return list.list(); }
-    void setModel(const QVariant &variant, QQmlDelegateModel *vdm, QQmlEngine *engine);
-    void invalidateModel(QQmlDelegateModel *vdm);
+    void setModel(const QVariant &variant, QObject *parent, QQmlEngine *engine);
+    void invalidateModel();
 
     bool isValid() const;
+    int count() const;
+    int rowCount() const;
+    int columnCount() const;
+    int rowAt(int index) const;
+    int columnAt(int index) const;
+    int indexAt(int row, int column) const;
+
+    void useImportVersion(int minorVersion);
 
+    inline bool adaptsAim() const { return qobject_cast<QAbstractItemModel *>(object()); }
     inline QAbstractItemModel *aim() { return static_cast<QAbstractItemModel *>(object()); }
     inline const QAbstractItemModel *aim() const { return static_cast<const QAbstractItemModel *>(object()); }
 
-    inline int count() const { return qMax(0, accessors->count(*this)); }
     inline QVariant value(int index, const QString &role) const {
         return accessors->value(*this, index, role); }
-    inline QQmlDelegateModelItem *createItem(QQmlDelegateModelItemMetaType *metaType, QQmlEngine *engine, int index) {
-        return accessors->createItem(*this, metaType, engine, index); }
+    inline QQmlDelegateModelItem *createItem(QQmlDelegateModelItemMetaType *metaType, int index) {
+        return accessors->createItem(*this, metaType, index, rowAt(index), columnAt(index)); }
     inline bool hasProxyObject() const {
         return list.type() == QQmlListAccessor::Instance || list.type() == QQmlListAccessor::ListProperty; }
 
diff --git a/src/qml/util/qqmlchangeset.cpp b/src/qml/util/qqmlchangeset.cpp
index 79e3332331..ba876b42e2 100644
--- a/src/qml/util/qqmlchangeset.cpp
+++ b/src/qml/util/qqmlchangeset.cpp
@@ -120,7 +120,7 @@ void QQmlChangeSet::remove(int index, int count)
 {
     QVector<Change> removes;
     removes.append(Change(index, count));
-    remove(&removes, 0);
+    remove(&removes, nullptr);
 }
 
 /*!
diff --git a/src/qml/util/qqmlchangeset_p.h b/src/qml/util/qqmlchangeset_p.h
index 8e1fa3f9f2..8347a3ff19 100644
--- a/src/qml/util/qqmlchangeset_p.h
+++ b/src/qml/util/qqmlchangeset_p.h
@@ -62,10 +62,10 @@ class Q_QML_PRIVATE_EXPORT QQmlChangeSet
 public:
     struct MoveKey
     {
-        MoveKey() : moveId(-1), offset(0) {}
+        MoveKey() {}
         MoveKey(int moveId, int offset) : moveId(moveId), offset(offset) {}
-        int moveId;
-        int offset;
+        int moveId = -1;
+        int offset = 0;
     };
 
     // The storrage for Change (below). This struct is trivial, which it has to be in order to store
@@ -119,7 +119,7 @@ public:
     void change(int index, int count);
 
     void insert(const QVector<Change> &inserts);
-    void remove(const QVector<Change> &removes, QVector<Change> *inserts = 0);
+    void remove(const QVector<Change> &removes, QVector<Change> *inserts = nullptr);
     void move(const QVector<Change> &removes, const QVector<Change> &inserts);
     void change(const QVector<Change> &changes);
     void apply(const QQmlChangeSet &changeSet);
diff --git a/src/qml/util/qqmllistaccessor.cpp b/src/qml/util/qqmllistaccessor.cpp
index 356584abdc..46a11e2bc2 100644
--- a/src/qml/util/qqmllistaccessor.cpp
+++ b/src/qml/util/qqmllistaccessor.cpp
@@ -72,7 +72,7 @@ void QQmlListAccessor::setList(const QVariant &v, QQmlEngine *engine)
     if (d.userType() == qMetaTypeId<QJSValue>())
         d = d.value<QJSValue>().toVariant();
 
-    QQmlEnginePrivate *enginePrivate = engine?QQmlEnginePrivate::get(engine):0;
+    QQmlEnginePrivate *enginePrivate = engine?QQmlEnginePrivate::get(engine):nullptr;
 
     if (!d.isValid()) {
         m_type = Invalid;
@@ -81,7 +81,26 @@ void QQmlListAccessor::setList(const QVariant &v, QQmlEngine *engine)
     } else if (d.userType() == QMetaType::QVariantList) {
         m_type = VariantList;
     } else if (d.canConvert(QVariant::Int)) {
-        m_type = Integer;
+        // Here we have to check for an upper limit, because down the line code might (well, will)
+        // allocate memory depending on the number of elements. The upper limit cannot be INT_MAX:
+        //      QVector<QPointer<QQuickItem>> something;
+        //      something.resize(count());
+        // (See e.g. QQuickRepeater::regenerate())
+        // This will allocate data along the lines of:
+        //      sizeof(QPointer<QQuickItem>) * count() + QVector::headerSize
+        // So, doing an approximate round-down-to-nice-number, we get:
+        const int upperLimit = 100 * 1000 * 1000;
+
+        int i = v.toInt();
+        if (i < 0) {
+            qWarning("Model size of %d is less than 0", i);
+            m_type = Invalid;
+        } else if (i > upperLimit) {
+            qWarning("Model size of %d is bigger than the upper limit %d", i, upperLimit);
+            m_type = Invalid;
+        } else {
+            m_type = Integer;
+        }
     } else if ((!enginePrivate && QQmlMetaType::isQObject(d.userType())) ||
                (enginePrivate && enginePrivate->isQObject(d.userType()))) {
         QObject *data = enginePrivate?enginePrivate->toQObject(d):QQmlMetaType::toQObject(d);
diff --git a/src/qml/util/qqmllistaccessor_p.h b/src/qml/util/qqmllistaccessor_p.h
index bad5a5803c..bcd079adef 100644
--- a/src/qml/util/qqmllistaccessor_p.h
+++ b/src/qml/util/qqmllistaccessor_p.h
@@ -63,7 +63,7 @@ public:
     ~QQmlListAccessor();
 
     QVariant list() const;
-    void setList(const QVariant &, QQmlEngine * = 0);
+    void setList(const QVariant &, QQmlEngine * = nullptr);
 
     bool isValid() const;
 
diff --git a/src/qml/util/qqmllistcompositor.cpp b/src/qml/util/qqmllistcompositor.cpp
index 05a4eaac39..921e86f355 100644
--- a/src/qml/util/qqmllistcompositor.cpp
+++ b/src/qml/util/qqmllistcompositor.cpp
@@ -99,7 +99,7 @@ QT_BEGIN_NAMESPACE
     ranges is often quite small, which helps as well. If there is a need for faster random access
     then a skip list like index may be an appropriate addition.
 
-    \sa VisualDataModel
+    \sa DelegateModel
 */
 
 #ifdef QT_QML_VERIFY_MINIMAL
@@ -1253,7 +1253,7 @@ void QQmlListCompositor::listItemsRemoved(
 
     QVector<QQmlChangeSet::Change> removals;
     removals.append(QQmlChangeSet::Change(index, count));
-    listItemsRemoved(translatedRemovals, list, &removals, 0, 0);
+    listItemsRemoved(translatedRemovals, list, &removals, nullptr, nullptr);
 }
 
 /*!
diff --git a/src/qml/util/qqmllistcompositor_p.h b/src/qml/util/qqmllistcompositor_p.h
index 6ae9c47df3..172040559c 100644
--- a/src/qml/util/qqmllistcompositor_p.h
+++ b/src/qml/util/qqmllistcompositor_p.h
@@ -87,17 +87,17 @@ public:
     class Range
     {
     public:
-        Range() : next(this), previous(this), list(0), index(0), count(0), flags(0) {}
+        Range() : next(this), previous(this) {}
         Range(Range *next, void *list, int index, int count, uint flags)
             : next(next), previous(next->previous), list(list), index(index), count(count), flags(flags) {
             next->previous = this; previous->next = this; }
 
         Range *next;
         Range *previous;
-        void *list;
-        int index;
-        int count;
-        uint flags;
+        void *list = nullptr;
+        int index = 0;
+        int count = 0;
+        uint flags = 0;
 
         inline int start() const { return index; }
         inline int end() const { return index + count; }
@@ -145,11 +145,11 @@ public:
 
         void setGroup(Group g) { group = g; groupFlag = 1 << g; }
 
-        Range *range;
-        int offset;
-        Group group;
+        Range *range = nullptr;
+        int offset = 0;
+        Group group = Default;
         int groupFlag;
-        int groupCount;
+        int groupCount = 0;
         union {
             struct {
                 int cacheIndex;
@@ -222,22 +222,22 @@ public:
 
     const iterator &end() { return m_end; }
 
-    void append(void *list, int index, int count, uint flags, QVector<Insert> *inserts = 0);
-    void insert(Group group, int before, void *list, int index, int count, uint flags, QVector<Insert> *inserts = 0);
-    iterator insert(iterator before, void *list, int index, int count, uint flags, QVector<Insert> *inserts = 0);
+    void append(void *list, int index, int count, uint flags, QVector<Insert> *inserts = nullptr);
+    void insert(Group group, int before, void *list, int index, int count, uint flags, QVector<Insert> *inserts = nullptr);
+    iterator insert(iterator before, void *list, int index, int count, uint flags, QVector<Insert> *inserts = nullptr);
 
-    void setFlags(Group fromGroup, int from, int count, Group group, int flags, QVector<Insert> *inserts = 0);
-    void setFlags(iterator from, int count, Group group, uint flags, QVector<Insert> *inserts = 0);
-    void setFlags(Group fromGroup, int from, int count, uint flags, QVector<Insert> *inserts = 0) {
+    void setFlags(Group fromGroup, int from, int count, Group group, int flags, QVector<Insert> *inserts = nullptr);
+    void setFlags(iterator from, int count, Group group, uint flags, QVector<Insert> *inserts = nullptr);
+    void setFlags(Group fromGroup, int from, int count, uint flags, QVector<Insert> *inserts = nullptr) {
         setFlags(fromGroup, from, count, fromGroup, flags, inserts); }
-    void setFlags(const iterator from, int count, uint flags, QVector<Insert> *inserts = 0) {
+    void setFlags(const iterator from, int count, uint flags, QVector<Insert> *inserts = nullptr) {
         setFlags(from, count, from.group, flags, inserts); }
 
-    void clearFlags(Group fromGroup, int from, int count, Group group, uint flags, QVector<Remove> *removals = 0);
-    void clearFlags(iterator from, int count, Group group, uint flags, QVector<Remove> *removals = 0);
-    void clearFlags(Group fromGroup, int from, int count, uint flags, QVector<Remove> *removals = 0) {
+    void clearFlags(Group fromGroup, int from, int count, Group group, uint flags, QVector<Remove> *removals = nullptr);
+    void clearFlags(iterator from, int count, Group group, uint flags, QVector<Remove> *removals = nullptr);
+    void clearFlags(Group fromGroup, int from, int count, uint flags, QVector<Remove> *removals = nullptr) {
         clearFlags(fromGroup, from, count, fromGroup, flags, removals); }
-    void clearFlags(const iterator &from, int count, uint flags, QVector<Remove> *removals = 0) {
+    void clearFlags(const iterator &from, int count, uint flags, QVector<Remove> *removals = nullptr) {
         clearFlags(from, count, from.group, flags, removals); }
 
     bool verifyMoveTo(Group fromGroup, int from, Group toGroup, int to, int count, Group group) const;
@@ -249,8 +249,8 @@ public:
             int to,
             int count,
             Group group,
-            QVector<Remove> *removals = 0,
-            QVector<Insert> *inserts = 0);
+            QVector<Remove> *removals = nullptr,
+            QVector<Insert> *inserts = nullptr);
     void clear();
 
     void listItemsInserted(void *list, int index, int count, QVector<Insert> *inserts);
@@ -289,13 +289,13 @@ private:
             QVector<Remove> *translatedRemovals,
             void *list,
             QVector<QQmlChangeSet::Change> *removals,
-            QVector<QQmlChangeSet::Change> *insertions = 0,
-            QVector<MovedFlags> *movedFlags = 0);
+            QVector<QQmlChangeSet::Change> *insertions = nullptr,
+            QVector<MovedFlags> *movedFlags = nullptr);
     void listItemsInserted(
             QVector<Insert> *translatedInsertions,
             void *list,
             const QVector<QQmlChangeSet::Change> &insertions,
-            const QVector<MovedFlags> *movedFlags = 0);
+            const QVector<MovedFlags> *movedFlags = nullptr);
     void listItemsChanged(
             QVector<Change> *translatedChanges,
             void *list,
@@ -308,8 +308,7 @@ Q_DECLARE_TYPEINFO(QQmlListCompositor::Change, Q_PRIMITIVE_TYPE);
 Q_DECLARE_TYPEINFO(QQmlListCompositor::Remove, Q_PRIMITIVE_TYPE);
 Q_DECLARE_TYPEINFO(QQmlListCompositor::Insert, Q_PRIMITIVE_TYPE);
 
-inline QQmlListCompositor::iterator::iterator()
-    : range(0), offset(0), group(Default), groupCount(0) {}
+inline QQmlListCompositor::iterator::iterator() {}
 inline QQmlListCompositor::iterator::iterator(const iterator &it)
     : range(it.range)
     , offset(it.offset)
diff --git a/src/qml/util/qqmlpropertymap.cpp b/src/qml/util/qqmlpropertymap.cpp
index 6e6554f2c3..3f78ca6b69 100644
--- a/src/qml/util/qqmlpropertymap.cpp
+++ b/src/qml/util/qqmlpropertymap.cpp
@@ -122,7 +122,7 @@ QVariant QQmlPropertyMapMetaObject::propertyWriteValue(int index, const QVariant
 
 void QQmlPropertyMapMetaObject::propertyWritten(int index)
 {
-    priv->emitChanged(priv->propertyName(index), operator[](index));
+    priv->emitChanged(priv->propertyName(index), value(index));
 }
 
 void QQmlPropertyMapMetaObject::propertyCreated(int, QMetaPropertyBuilder &b)
@@ -186,9 +186,8 @@ int QQmlPropertyMapMetaObject::createProperty(const char *name, const char *valu
     Constructs a bindable map with parent object \a parent.
 */
 QQmlPropertyMap::QQmlPropertyMap(QObject *parent)
-: QObject(*allocatePrivate(), parent)
+: QQmlPropertyMap(&staticMetaObject, parent)
 {
-    init(metaObject());
 }
 
 /*!
@@ -312,7 +311,7 @@ QVariant &QQmlPropertyMap::operator[](const QString &key)
     if (!d->keys.contains(key))
         insert(key, QVariant());//force creation -- needed below
 
-    return (*(d->mo))[utf8key];
+    return d->mo->valueRef(utf8key);
 }
 
 /*!
@@ -339,18 +338,13 @@ QVariant QQmlPropertyMap::updateValue(const QString &key, const QVariant &input)
 }
 
 /*! \internal */
-void QQmlPropertyMap::init(const QMetaObject *staticMetaObject)
+QQmlPropertyMap::QQmlPropertyMap(const QMetaObject *staticMetaObject, QObject *parent)
+    : QObject(*(new QQmlPropertyMapPrivate), parent)
 {
     Q_D(QQmlPropertyMap);
     d->mo = new QQmlPropertyMapMetaObject(this, d, staticMetaObject);
 }
 
-/*! \internal */
-QObjectPrivate *QQmlPropertyMap::allocatePrivate()
-{
-    return new QQmlPropertyMapPrivate;
-}
-
 /*!
     \fn void QQmlPropertyMap::valueChanged(const QString &key, const QVariant &value)
     This signal is emitted whenever one of the values in the map is changed. \a key
@@ -361,7 +355,7 @@ QObjectPrivate *QQmlPropertyMap::allocatePrivate()
 */
 
 /*!
-    \fn QQmlPropertyMap::QQmlPropertyMap(DerivedType *derived, QObject *parent)
+    \fn template<class DerivedType> QQmlPropertyMap::QQmlPropertyMap(DerivedType *derived, QObject *parent)
 
     Constructs a bindable map with parent object \a parent.  Use this constructor
     in classes derived from QQmlPropertyMap.
diff --git a/src/qml/util/qqmlpropertymap.h b/src/qml/util/qqmlpropertymap.h
index 01048f3662..cb7ada3d79 100644
--- a/src/qml/util/qqmlpropertymap.h
+++ b/src/qml/util/qqmlpropertymap.h
@@ -55,8 +55,8 @@ class Q_QML_EXPORT QQmlPropertyMap : public QObject
 {
     Q_OBJECT
 public:
-    explicit QQmlPropertyMap(QObject *parent = Q_NULLPTR);
-    virtual ~QQmlPropertyMap();
+    explicit QQmlPropertyMap(QObject *parent = nullptr);
+    ~QQmlPropertyMap() override;
 
     QVariant value(const QString &key) const;
     void insert(const QString &key, const QVariant &value);
@@ -80,15 +80,13 @@ protected:
 
     template<class DerivedType>
     QQmlPropertyMap(DerivedType *derived, QObject *parentObj)
-        : QObject(*allocatePrivate(), parentObj)
+        : QQmlPropertyMap(&DerivedType::staticMetaObject, parentObj)
     {
         Q_UNUSED(derived)
-        init(&DerivedType::staticMetaObject);
     }
 
 private:
-    void init(const QMetaObject *staticMetaObject);
-    static QObjectPrivate *allocatePrivate();
+    QQmlPropertyMap(const QMetaObject *staticMetaObject, QObject *parent);
 
     Q_DECLARE_PRIVATE(QQmlPropertyMap)
     Q_DISABLE_COPY(QQmlPropertyMap)
diff --git a/src/qml/util/util.pri b/src/qml/util/util.pri
index a9c5ffe9b7..bebb271f1b 100644
--- a/src/qml/util/util.pri
+++ b/src/qml/util/util.pri
@@ -2,12 +2,18 @@ SOURCES += \
     $$PWD/qqmlchangeset.cpp \
     $$PWD/qqmllistaccessor.cpp \
     $$PWD/qqmllistcompositor.cpp \
-    $$PWD/qqmladaptormodel.cpp \
     $$PWD/qqmlpropertymap.cpp
 
 HEADERS += \
     $$PWD/qqmlchangeset_p.h \
     $$PWD/qqmllistaccessor_p.h \
     $$PWD/qqmllistcompositor_p.h \
-    $$PWD/qqmladaptormodel_p.h \
     $$PWD/qqmlpropertymap.h
+
+qtConfig(qml-delegate-model) {
+    SOURCES += \
+        $$PWD/qqmladaptormodel.cpp
+
+    HEADERS += \
+        $$PWD/qqmladaptormodel_p.h
+}