Reduce the size of QDeclarative*Expression

Reduces the size of QDeclarativeAbstractExpression and
QDeclarativeJavaScriptExpression.

Change-Id: I39386e5a45f8bd12bfb2d80b47dfec37f2f05479
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

9 files changed, 225 insertions, 94 deletions

diff --git a/src/declarative/qml/qdeclarativebinding.cpp b/src/declarative/qml/qdeclarativebinding.cpp
index 93d6feaf55..1fa4594ed1 100644
--- a/src/declarative/qml/qdeclarativebinding.cpp
+++ b/src/declarative/qml/qdeclarativebinding.cpp
@@ -347,7 +347,7 @@ void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)
         prof.addDetail(expression());
         d->updating = true;
 
-        QDeleteWatcher watcher(d);
+        QDeclarativeAbstractExpression::DeleteWatcher watcher(d);
 
         if (d->property.propertyType() == qMetaTypeId<QDeclarativeBinding *>()) {
 
@@ -374,8 +374,9 @@ void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)
             trace.event("writing binding result");
 
             bool needsErrorData = false;
-            if (!watcher.wasDeleted() && !d->error.isValid()) 
-                needsErrorData = !QDeclarativePropertyPrivate::writeBinding(d->property, d, result, 
+            if (!watcher.wasDeleted() && !d->hasError())
+                needsErrorData = !QDeclarativePropertyPrivate::writeBinding(d->property, d->context(),
+                                                                            d, result,
                                                                             isUndefined, flags);
 
             if (!watcher.wasDeleted()) {
@@ -385,15 +386,15 @@ void QDeclarativeBinding::update(QDeclarativePropertyPrivate::WriteFlags flags)
                     int line = d->line;
                     if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));
 
-                    d->error.setUrl(url);
-                    d->error.setLine(line);
-                    d->error.setColumn(-1);
+                    d->delayedError()->error.setUrl(url);
+                    d->delayedError()->error.setLine(line);
+                    d->delayedError()->error.setColumn(-1);
                 }
 
-                if (d->error.isValid()) {
-                    if (!d->addError(ep)) ep->warning(this->error());
+                if (d->hasError()) {
+                    if (!d->delayedError()->addError(ep)) ep->warning(this->error());
                 } else {
-                    d->removeError();
+                    d->clearError();
                 }
 
             }
diff --git a/src/declarative/qml/qdeclarativecontext.cpp b/src/declarative/qml/qdeclarativecontext.cpp
index 3f838d5fd1..3e0db16346 100644
--- a/src/declarative/qml/qdeclarativecontext.cpp
+++ b/src/declarative/qml/qdeclarativecontext.cpp
@@ -579,10 +579,11 @@ void QDeclarativeContextData::clearContext()
     while (expression) {
         QDeclarativeAbstractExpression *nextExpression = expression->m_nextExpression;
 
-        expression->m_context = 0;
         expression->m_prevExpression = 0;
         expression->m_nextExpression = 0;
 
+        expression->setContext(0);
+
         expression = nextExpression;
     }
     expressions = 0;
@@ -656,7 +657,7 @@ void QDeclarativeContextData::setParent(QDeclarativeContextData *p, bool parentT
 
 void QDeclarativeContextData::refreshExpressionsRecursive(QDeclarativeAbstractExpression *expression)
 {
-    QDeleteWatcher w(expression);
+    QDeclarativeAbstractExpression::DeleteWatcher w(expression);
 
     if (expression->m_nextExpression)
         refreshExpressionsRecursive(expression->m_nextExpression);
diff --git a/src/declarative/qml/qdeclarativeengine_p.h b/src/declarative/qml/qdeclarativeengine_p.h
index 8b37b0b938..afc7a18161 100644
--- a/src/declarative/qml/qdeclarativeengine_p.h
+++ b/src/declarative/qml/qdeclarativeengine_p.h
@@ -111,7 +111,8 @@ public:
     inline QDeclarativeJavaScriptExpressionGuard(QDeclarativeJavaScriptExpression *);
 
     static inline void endpointCallback(QDeclarativeNotifierEndpoint *);
-    static inline QDeclarativeJavaScriptExpressionGuard *New(QDeclarativeJavaScriptExpression *e);
+    static inline QDeclarativeJavaScriptExpressionGuard *New(QDeclarativeJavaScriptExpression *e,
+                                                             QDeclarativeEngine *engine);
     inline void Delete();
 
     QDeclarativeJavaScriptExpression *expression;
diff --git a/src/declarative/qml/qdeclarativeexpression.cpp b/src/declarative/qml/qdeclarativeexpression.cpp
index 53ed8e7c19..2b85529429 100644
--- a/src/declarative/qml/qdeclarativeexpression.cpp
+++ b/src/declarative/qml/qdeclarativeexpression.cpp
@@ -69,15 +69,14 @@ bool QDeclarativeDelayedError::addError(QDeclarativeEnginePrivate *e)
 }
 
 QDeclarativeJavaScriptExpression::QDeclarativeJavaScriptExpression()
-: m_requiresThisObject(0), m_useSharedContext(0), m_notifyOnValueChanged(0), 
-  m_scopeObject(0), guardCapture(0)
+: m_delayedError(0)
 {
 }
 
 QDeclarativeJavaScriptExpression::~QDeclarativeJavaScriptExpression()
 {
-    if (guardCapture) guardCapture->expression = 0;
     clearGuards();
+    delete m_delayedError;
 }
 
 QDeclarativeExpressionPrivate::QDeclarativeExpressionPrivate()
@@ -512,7 +511,7 @@ void QDeclarativeExpressionPrivate::exceptionToError(v8::Handle<v8::Message> mes
 
 void QDeclarativeJavaScriptExpression::setNotifyOnValueChanged(bool v)
 {
-    m_notifyOnValueChanged = v;
+    activeGuards.setFlagValue(v);
     if (!v) clearGuards();
 }
 
@@ -521,26 +520,28 @@ void QDeclarativeJavaScriptExpression::resetNotifyOnValueChanged()
     clearGuards();
 }
 
-v8::Local<v8::Value> QDeclarativeJavaScriptExpression::evaluate(v8::Handle<v8::Function> function, bool *isUndefined)
+v8::Local<v8::Value>
+QDeclarativeJavaScriptExpression::evaluate(QDeclarativeContextData *context,
+                                           v8::Handle<v8::Function> function, bool *isUndefined)
 {
-    Q_ASSERT(context() && context()->engine);
+    Q_ASSERT(context && context->engine);
 
     if (function.IsEmpty() || function->IsUndefined()) {
         if (isUndefined) *isUndefined = true;
         return v8::Local<v8::Value>();
     }
 
-    QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(context()->engine);
+    QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(context->engine);
 
     Q_ASSERT(notifyOnValueChanged() || activeGuards.isEmpty());
-    GuardCapture capture(this);
+    GuardCapture capture(context->engine, this);
 
     QDeclarativeEnginePrivate::PropertyCapture *lastPropertyCapture = ep->propertyCapture;
     ep->propertyCapture = notifyOnValueChanged()?&capture:0;
 
 
     if (notifyOnValueChanged())
-        capture.guards.copyAndClear(activeGuards);
+        capture.guards.copyAndClearPrepend(activeGuards);
 
     QDeclarativeContextData *lastSharedContext = 0;
     QObject *lastSharedScope = 0;
@@ -549,12 +550,12 @@ v8::Local<v8::Value> QDeclarativeJavaScriptExpression::evaluate(v8::Handle<v8::F
 
     // All code that follows must check with watcher before it accesses data members 
     // incase we have been deleted.
-    QDeleteWatcher watcher(this);
+    DeleteWatcher watcher(this);
 
     if (sharedContext) {
         lastSharedContext = ep->sharedContext;
         lastSharedScope = ep->sharedScope;
-        ep->sharedContext = context();
+        ep->sharedContext = context;
         ep->sharedScope = scopeObject();
     }
 
@@ -577,12 +578,12 @@ v8::Local<v8::Value> QDeclarativeJavaScriptExpression::evaluate(v8::Handle<v8::F
             v8::Context::Scope scope(ep->v8engine()->context());
             v8::Local<v8::Message> message = try_catch.Message();
             if (!message.IsEmpty()) {
-                QDeclarativeExpressionPrivate::exceptionToError(message, error);
+                QDeclarativeExpressionPrivate::exceptionToError(message, delayedError()->error);
             } else {
-                error = QDeclarativeError();
+                if (m_delayedError) m_delayedError->error = QDeclarativeError();
             }
         } else {
-            error = QDeclarativeError();
+            if (m_delayedError) m_delayedError->error = QDeclarativeError();
         }
     }
 
@@ -620,11 +621,11 @@ void QDeclarativeJavaScriptExpression::GuardCapture::captureProperty(QDeclarativ
             g->cancelNotify();
             Q_ASSERT(g->isConnected(n));
         } else {
-            g = Guard::New(expression);
+            g = Guard::New(expression, engine);
             g->connect(n);
         }
 
-        expression->activeGuards.append(g);
+        expression->activeGuards.prepend(g);
     }
 }
 
@@ -660,15 +661,36 @@ void QDeclarativeJavaScriptExpression::GuardCapture::captureProperty(QObject *o,
                 g->cancelNotify();
                 Q_ASSERT(g->isConnected(o, n));
             } else {
-                g = Guard::New(expression);
+                g = Guard::New(expression, engine);
                 g->connect(o, n);
             }
 
-            expression->activeGuards.append(g);
+            expression->activeGuards.prepend(g);
         }
     }
 }
 
+void QDeclarativeJavaScriptExpression::clearError()
+{
+    if (m_delayedError) {
+        m_delayedError->error = QDeclarativeError();
+        m_delayedError->removeError();
+    }
+}
+
+QDeclarativeError QDeclarativeJavaScriptExpression::error() const
+{
+    if (m_delayedError) return m_delayedError->error;
+    else return QDeclarativeError();
+}
+
+QDeclarativeDelayedError *QDeclarativeJavaScriptExpression::delayedError()
+{
+    if (!m_delayedError)
+        m_delayedError = new QDeclarativeDelayedError;
+    return m_delayedError;
+}
+
 void QDeclarativeJavaScriptExpression::clearGuards()
 {
     while (Guard *g = activeGuards.takeFirst())
@@ -700,11 +722,11 @@ v8::Local<v8::Value> QDeclarativeExpressionPrivate::v8value(QObject *secondarySc
         QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(context()->engine);
         QObject *restoreSecondaryScope = 0;
         restoreSecondaryScope = ep->v8engine()->contextWrapper()->setSecondaryScope(v8qmlscope, secondaryScope);
-        result = evaluate(v8function, isUndefined);
+        result = evaluate(context(), v8function, isUndefined);
         ep->v8engine()->contextWrapper()->setSecondaryScope(v8qmlscope, restoreSecondaryScope);
         return result;
     } else {
-        return evaluate(v8function, isUndefined);
+        return evaluate(context(), v8function, isUndefined);
     }
 }
 
@@ -844,7 +866,7 @@ QObject *QDeclarativeExpression::scopeObject() const
 bool QDeclarativeExpression::hasError() const
 {
     Q_D(const QDeclarativeExpression);
-    return d->error.isValid();
+    return d->hasError();
 }
 
 /*!
@@ -856,7 +878,7 @@ bool QDeclarativeExpression::hasError() const
 void QDeclarativeExpression::clearError()
 {
     Q_D(QDeclarativeExpression);
-    d->error = QDeclarativeError();
+    d->clearError();
 }
 
 /*!
@@ -869,7 +891,7 @@ void QDeclarativeExpression::clearError()
 QDeclarativeError QDeclarativeExpression::error() const
 {
     Q_D(const QDeclarativeExpression);
-    return d->error;
+    return d->error();
 }
 
 /*!
@@ -887,7 +909,7 @@ void QDeclarativeExpressionPrivate::expressionChanged()
 }
 
 QDeclarativeAbstractExpression::QDeclarativeAbstractExpression()
-: m_context(0), m_prevExpression(0), m_nextExpression(0)
+: m_prevExpression(0), m_nextExpression(0)
 {
 }
 
@@ -898,11 +920,15 @@ QDeclarativeAbstractExpression::~QDeclarativeAbstractExpression()
         if (m_nextExpression) 
             m_nextExpression->m_prevExpression = m_prevExpression;
     }
+
+    if (m_context.isT2())
+        m_context.asT2()->_s = 0;
 }
 
 QDeclarativeContextData *QDeclarativeAbstractExpression::context() const
 {
-    return m_context;
+    if (m_context.isT1()) return m_context.asT1();
+    else return m_context.asT2()->_c;
 }
 
 void QDeclarativeAbstractExpression::setContext(QDeclarativeContextData *context)
@@ -915,14 +941,15 @@ void QDeclarativeAbstractExpression::setContext(QDeclarativeContextData *context
         m_nextExpression = 0;
     }
 
-    m_context = context;
+    if (m_context.isT1()) m_context = context;
+    else m_context.asT2()->_c = context;
 
-    if (m_context) {
-        m_nextExpression = m_context->expressions;
+    if (context) {
+        m_nextExpression = context->expressions;
         if (m_nextExpression) 
             m_nextExpression->m_prevExpression = &m_nextExpression;
         m_prevExpression = &context->expressions;
-        m_context->expressions = this;
+        context->expressions = this;
     }
 }
 
@@ -932,7 +959,7 @@ void QDeclarativeAbstractExpression::refresh()
 
 bool QDeclarativeAbstractExpression::isValid() const
 {
-    return m_context != 0;
+    return context() != 0;
 }
 
 QT_END_NAMESPACE
diff --git a/src/declarative/qml/qdeclarativeexpression_p.h b/src/declarative/qml/qdeclarativeexpression_p.h
index bbe4b2ded9..3318595901 100644
--- a/src/declarative/qml/qdeclarativeexpression_p.h
+++ b/src/declarative/qml/qdeclarativeexpression_p.h
@@ -57,13 +57,14 @@
 
 #include <private/qv8engine_p.h>
 #include <private/qfieldlist_p.h>
+#include <private/qflagpointer_p.h>
 #include <private/qdeletewatcher_p.h>
 #include <private/qdeclarativeguard_p.h>
 #include <private/qdeclarativeengine_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class QDeclarativeAbstractExpression : public QDeleteWatchable
+class QDeclarativeAbstractExpression
 {
 public:
     QDeclarativeAbstractExpression();
@@ -76,11 +77,24 @@ public:
 
     virtual void refresh();
 
+    class DeleteWatcher {
+    public:
+        inline DeleteWatcher(QDeclarativeAbstractExpression *);
+        inline ~DeleteWatcher();
+        inline bool wasDeleted() const;
+    private:
+        friend class QDeclarativeAbstractExpression;
+        QDeclarativeContextData *_c;
+        QDeclarativeAbstractExpression **_w;
+        QDeclarativeAbstractExpression *_s;
+    };
+
 private:
     friend class QDeclarativeContext;
     friend class QDeclarativeContextData;
     friend class QDeclarativeContextPrivate;
-    QDeclarativeContextData *m_context;
+
+    QBiPointer<QDeclarativeContextData, DeleteWatcher> m_context;
     QDeclarativeAbstractExpression **m_prevExpression;
     QDeclarativeAbstractExpression  *m_nextExpression;
 };
@@ -108,14 +122,14 @@ private:
     QDeclarativeDelayedError **prevError;
 };
 
-class QDeclarativeJavaScriptExpression : public QDeclarativeAbstractExpression, 
-                                         public QDeclarativeDelayedError
+class QDeclarativeJavaScriptExpression // : public QDeclarativeDelayedError
 {
 public:
     QDeclarativeJavaScriptExpression();
     virtual ~QDeclarativeJavaScriptExpression();
 
-    v8::Local<v8::Value> evaluate(v8::Handle<v8::Function>, bool *isUndefined);
+    v8::Local<v8::Value> evaluate(QDeclarativeContextData *, v8::Handle<v8::Function>,
+                                  bool *isUndefined);
 
     inline bool requiresThisObject() const;
     inline void setRequiresThisObject(bool v);
@@ -131,22 +145,33 @@ public:
 
     virtual void expressionChanged() {}
 
+    class DeleteWatcher {
+    public:
+        inline DeleteWatcher(QDeclarativeJavaScriptExpression *);
+        inline ~DeleteWatcher();
+        inline bool wasDeleted() const;
+    private:
+        friend class QDeclarativeJavaScriptExpression;
+        QObject *_c;
+        QDeclarativeJavaScriptExpression **_w;
+        QDeclarativeJavaScriptExpression *_s;
+    };
+
+    inline bool hasError() const;
+    QDeclarativeError error() const;
+    void clearError();
+    QDeclarativeDelayedError *delayedError();
+
 protected:
     inline virtual QString expressionIdentifier();
 
 private:
-    quint32 m_requiresThisObject:1;
-    quint32 m_useSharedContext:1;
-    quint32 m_notifyOnValueChanged:1;
-    quint32 m_dummy:29;
-
-    QObject *m_scopeObject;
-
     typedef QDeclarativeJavaScriptExpressionGuard Guard;
 
     struct GuardCapture : public QDeclarativeEnginePrivate::PropertyCapture {
-        GuardCapture(QDeclarativeJavaScriptExpression *e) : expression(e), errorString(0) {
-        }
+        GuardCapture(QDeclarativeEngine *engine, QDeclarativeJavaScriptExpression *e)
+        : engine(engine), expression(e), errorString(0) { }
+
         ~GuardCapture()  {
             Q_ASSERT(guards.isEmpty());
             Q_ASSERT(errorString == 0);
@@ -155,20 +180,26 @@ private:
         virtual void captureProperty(QDeclarativeNotifier *);
         virtual void captureProperty(QObject *, int, int);
 
+        QDeclarativeEngine *engine;
         QDeclarativeJavaScriptExpression *expression;
         QFieldList<Guard, &Guard::next> guards;
         QStringList *errorString;
     };
 
-    QFieldList<Guard, &Guard::next> activeGuards;
-    GuardCapture *guardCapture;
+    QDeclarativeDelayedError *m_delayedError;
+    // We store some flag bits in the following flag pointers.
+    //    m_scopeObject:flag1 - requiresThisObject
+    //    activeGuards:flag1  - notifyOnValueChanged
+    //    activeGuards:flag2  - useSharedContext
+    QBiPointer<QObject, DeleteWatcher> m_scopeObject;
+    QForwardFieldList<Guard, &Guard::next> activeGuards;
 
     void clearGuards();
 };
 
 class QDeclarativeExpression;
 class QString;
-class Q_DECLARATIVE_PRIVATE_EXPORT QDeclarativeExpressionPrivate : public QObjectPrivate, public QDeclarativeJavaScriptExpression
+class Q_DECLARATIVE_PRIVATE_EXPORT QDeclarativeExpressionPrivate : public QObjectPrivate, public QDeclarativeJavaScriptExpression, public QDeclarativeAbstractExpression
 {
     Q_DECLARE_PUBLIC(QDeclarativeExpression)
 public:
@@ -223,39 +254,96 @@ public:
     QDeclarativeRefCount *dataRef;
 };
 
+QDeclarativeAbstractExpression::DeleteWatcher::DeleteWatcher(QDeclarativeAbstractExpression *e)
+: _c(0), _w(0), _s(e)
+{
+    if (e->m_context.isT1()) {
+        _w = &_s;
+        _c = e->m_context.asT1();
+        e->m_context = this;
+    } else {
+        // Another watcher is already registered
+        _w = &e->m_context.asT2()->_s;
+    }
+}
+
+QDeclarativeAbstractExpression::DeleteWatcher::~DeleteWatcher()
+{
+    Q_ASSERT(*_w == 0 || (*_w == _s && _s->m_context.isT2()));
+    if (*_w && _s->m_context.asT2() == this)
+        _s->m_context = _c;
+}
+
+bool QDeclarativeAbstractExpression::DeleteWatcher::wasDeleted() const
+{
+    return *_w == 0;
+}
+
+QDeclarativeJavaScriptExpression::DeleteWatcher::DeleteWatcher(QDeclarativeJavaScriptExpression *e)
+: _c(0), _w(0), _s(e)
+{
+    if (e->m_scopeObject.isT1()) {
+        _w = &_s;
+        _c = e->m_scopeObject.asT1();
+        e->m_scopeObject = this;
+    } else {
+        // Another watcher is already registered
+        _w = &e->m_scopeObject.asT2()->_s;
+    }
+}
+
+QDeclarativeJavaScriptExpression::DeleteWatcher::~DeleteWatcher()
+{
+    Q_ASSERT(*_w == 0 || (*_w == _s && _s->m_scopeObject.isT2()));
+    if (*_w && _s->m_scopeObject.asT2() == this)
+        _s->m_scopeObject = _c;
+}
+
+bool QDeclarativeJavaScriptExpression::DeleteWatcher::wasDeleted() const
+{
+    return *_w == 0;
+}
+
 bool QDeclarativeJavaScriptExpression::requiresThisObject() const 
 { 
-    return m_requiresThisObject; 
+    return m_scopeObject.flag();
 }
 
 void QDeclarativeJavaScriptExpression::setRequiresThisObject(bool v) 
 { 
-    m_requiresThisObject = v; 
+    m_scopeObject.setFlagValue(v);
 }
 
 bool QDeclarativeJavaScriptExpression::useSharedContext() const 
 { 
-    return m_useSharedContext; 
+    return activeGuards.flag2();
 }
 
 void QDeclarativeJavaScriptExpression::setUseSharedContext(bool v) 
 { 
-    m_useSharedContext = v; 
+    activeGuards.setFlag2Value(v);
 }
 
 bool QDeclarativeJavaScriptExpression::notifyOnValueChanged() const 
 { 
-    return m_notifyOnValueChanged; 
+    return activeGuards.flag();
 }
 
 QObject *QDeclarativeJavaScriptExpression::scopeObject() const 
 { 
-    return m_scopeObject; 
+    if (m_scopeObject.isT1()) return m_scopeObject.asT1();
+    else return m_scopeObject.asT2()->_c;
 }
 
 void QDeclarativeJavaScriptExpression::setScopeObject(QObject *v) 
 { 
-    m_scopeObject = v; 
+    if (m_scopeObject.isT1()) m_scopeObject = v;
+    else m_scopeObject.asT2()->_c = v;
+}
+
+bool QDeclarativeJavaScriptExpression::hasError() const
+{
+    return m_delayedError && m_delayedError->error.isValid();
 }
 
 QString QDeclarativeJavaScriptExpression::expressionIdentifier() 
@@ -290,10 +378,11 @@ void QDeclarativeJavaScriptExpressionGuard::endpointCallback(QDeclarativeNotifie
 }
 
 QDeclarativeJavaScriptExpressionGuard *
-QDeclarativeJavaScriptExpressionGuard::New(QDeclarativeJavaScriptExpression *e)
+QDeclarativeJavaScriptExpressionGuard::New(QDeclarativeJavaScriptExpression *e,
+                                           QDeclarativeEngine *engine)
 {
     Q_ASSERT(e);
-    return QDeclarativeEnginePrivate::get(e->context()->engine)->jsExpressionGuardPool.New(e);
+    return QDeclarativeEnginePrivate::get(engine)->jsExpressionGuardPool.New(e);
 }
 
 void QDeclarativeJavaScriptExpressionGuard::Delete()
diff --git a/src/declarative/qml/qdeclarativeproperty.cpp b/src/declarative/qml/qdeclarativeproperty.cpp
index a679ead8d4..c50c2d7026 100644
--- a/src/declarative/qml/qdeclarativeproperty.cpp
+++ b/src/declarative/qml/qdeclarativeproperty.cpp
@@ -1393,6 +1393,7 @@ bool QDeclarativePropertyPrivate::write(QObject *object,
 // Returns true if successful, false if an error description was set on expression
 bool QDeclarativePropertyPrivate::writeBinding(QObject *object, 
                                                const QDeclarativePropertyData &core,
+                                               QDeclarativeContextData *context,
                                                QDeclarativeJavaScriptExpression *expression, 
                                                v8::Handle<v8::Value> result, bool isUndefined,
                                                WriteFlags flags)
@@ -1400,7 +1401,6 @@ bool QDeclarativePropertyPrivate::writeBinding(QObject *object,
     Q_ASSERT(object);
     Q_ASSERT(core.coreIndex != -1);
 
-    QDeclarativeContextData *context = expression->context();
     QDeclarativeEngine *engine = context->engine;
     QV8Engine *v8engine = QDeclarativeEnginePrivate::getV8Engine(engine);
 
@@ -1442,7 +1442,7 @@ bool QDeclarativePropertyPrivate::writeBinding(QObject *object,
 
     int type = core.isValueTypeVirtual()?core.valueTypePropType:core.propType;
 
-    QDeleteWatcher watcher(expression);
+    QDeclarativeJavaScriptExpression::DeleteWatcher watcher(expression);
 
     QVariant value;
     bool isVmeProperty = core.isVMEProperty();
@@ -1458,7 +1458,7 @@ bool QDeclarativePropertyPrivate::writeBinding(QObject *object,
         value = v8engine->toVariant(result, type);
     }
 
-    if (expression->error.isValid()) {
+    if (expression->hasError()) {
         return false;
     } else if (isUndefined && core.isResettable()) {
         void *args[] = { 0 };
@@ -1466,11 +1466,10 @@ bool QDeclarativePropertyPrivate::writeBinding(QObject *object,
     } else if (isUndefined && type == qMetaTypeId<QVariant>()) {
         writeValueProperty(object, engine, core, QVariant(), context, flags);
     } else if (isUndefined) {
-        expression->error.setDescription(QLatin1String("Unable to assign [undefined] to ") +
-                                         QLatin1String(QMetaType::typeName(type))); 
+        expression->delayedError()->error.setDescription(QLatin1String("Unable to assign [undefined] to ") + QLatin1String(QMetaType::typeName(type)));
         return false;
     } else if (result->IsFunction()) {
-        expression->error.setDescription(QLatin1String("Unable to assign a function to a property."));
+        expression->delayedError()->error.setDescription(QLatin1String("Unable to assign a function to a property."));
         return false;
     } else if (isVmeProperty) {
         typedef QDeclarativeVMEMetaObject VMEMO;
@@ -1485,10 +1484,10 @@ bool QDeclarativePropertyPrivate::writeBinding(QObject *object,
         if (value.userType() == QVariant::Invalid) valueType = "null";
         else valueType = QMetaType::typeName(value.userType());
 
-        expression->error.setDescription(QLatin1String("Unable to assign ") +
-                                         QLatin1String(valueType) +
-                                         QLatin1String(" to ") +
-                                         QLatin1String(QMetaType::typeName(type)));
+        expression->delayedError()->error.setDescription(QLatin1String("Unable to assign ") +
+                                                         QLatin1String(valueType) +
+                                                         QLatin1String(" to ") +
+                                                         QLatin1String(QMetaType::typeName(type)));
         return false;
     }
 
@@ -1496,6 +1495,7 @@ bool QDeclarativePropertyPrivate::writeBinding(QObject *object,
 }
 
 bool QDeclarativePropertyPrivate::writeBinding(const QDeclarativeProperty &that, 
+                                               QDeclarativeContextData *context,
                                                QDeclarativeJavaScriptExpression *expression, 
                                                v8::Handle<v8::Value> result, bool isUndefined,
                                                WriteFlags flags)
@@ -1509,7 +1509,7 @@ bool QDeclarativePropertyPrivate::writeBinding(const QDeclarativeProperty &that,
     if (!object)
         return true;
 
-    return writeBinding(object, pp->core, expression, result, isUndefined, flags);
+    return writeBinding(object, pp->core, context, expression, result, isUndefined, flags);
 }
 
 const QMetaObject *QDeclarativePropertyPrivate::rawMetaObjectForType(QDeclarativeEnginePrivate *engine, int userType)
diff --git a/src/declarative/qml/qdeclarativeproperty_p.h b/src/declarative/qml/qdeclarativeproperty_p.h
index d7d8827a72..f7ada4e354 100644
--- a/src/declarative/qml/qdeclarativeproperty_p.h
+++ b/src/declarative/qml/qdeclarativeproperty_p.h
@@ -143,10 +143,12 @@ public:
                                                        QDeclarativeExpression *) ;
     static bool write(const QDeclarativeProperty &that, const QVariant &, WriteFlags);
     static bool writeBinding(const QDeclarativeProperty &that, 
+                             QDeclarativeContextData *context,
                              QDeclarativeJavaScriptExpression *expression, 
                              v8::Handle<v8::Value> result, bool isUndefined,
                              WriteFlags flags);
     static bool writeBinding(QObject *, const QDeclarativePropertyData &,
+                             QDeclarativeContextData *context,
                              QDeclarativeJavaScriptExpression *expression, 
                              v8::Handle<v8::Value> result, bool isUndefined,
                              WriteFlags flags);
diff --git a/src/declarative/qml/v8/qv8bindings.cpp b/src/declarative/qml/v8/qv8bindings.cpp
index 39203d35af..cd86e6a13f 100644
--- a/src/declarative/qml/v8/qv8bindings.cpp
+++ b/src/declarative/qml/v8/qv8bindings.cpp
@@ -67,6 +67,12 @@ void QV8Bindings::Binding::setEnabled(bool e, QDeclarativePropertyPrivate::Write
     }
 }
 
+void QV8Bindings::refresh()
+{
+    for (int ii = 0; ii < bindingsCount; ++ii)
+        bindings[ii].refresh();
+}
+
 void QV8Bindings::Binding::refresh()
 {
     update();
@@ -84,7 +90,7 @@ void QV8Bindings::Binding::update(QDeclarativePropertyPrivate::WriteFlags flags)
 
     QDeclarativeBindingProfiler prof(parent->url.toString(), line, column);
 
-    QDeclarativeContextData *context = QDeclarativeAbstractExpression::context();
+    QDeclarativeContextData *context = parent->context();
     if (!context || !context->isValid())
         return;
 
@@ -94,19 +100,21 @@ void QV8Bindings::Binding::update(QDeclarativePropertyPrivate::WriteFlags flags)
 
         bool isUndefined = false;
 
-        QDeleteWatcher watcher(this);
+        DeleteWatcher watcher(this);
         ep->referenceScarceResources(); 
 
         v8::HandleScope handle_scope;
         v8::Context::Scope scope(ep->v8engine()->context());
-        v8::Local<v8::Value> result = evaluate(v8::Handle<v8::Function>::Cast(parent->functions->Get(index)), 
-                                               &isUndefined);
+        v8::Local<v8::Value> result =
+            evaluate(context, v8::Handle<v8::Function>::Cast(parent->functions->Get(index)),
+                     &isUndefined);
 
         trace.event("writing V8 result");
         bool needsErrorData = false;
-        if (!watcher.wasDeleted() && !error.isValid()) {
+        if (!watcher.wasDeleted() && !hasError()) {
             typedef QDeclarativePropertyPrivate PP;
-            needsErrorData = !PP::writeBinding(object, property, this, result, isUndefined, flags);
+            needsErrorData = !PP::writeBinding(object, property, context, this, result,
+                                               isUndefined, flags);
         }
 
         if (!watcher.wasDeleted()) {
@@ -115,15 +123,15 @@ void QV8Bindings::Binding::update(QDeclarativePropertyPrivate::WriteFlags flags)
                 QUrl url = QUrl(parent->url);
                 if (url.isEmpty()) url = QUrl(QLatin1String("<Unknown File>"));
 
-                error.setUrl(url);
-                error.setLine(line);
-                error.setColumn(-1);
+                delayedError()->error.setUrl(url);
+                delayedError()->error.setLine(line);
+                delayedError()->error.setColumn(-1);
             }
 
-            if (error.isValid()) {
-                if (!addError(ep)) ep->warning(error);
+            if (hasError()) {
+                if (!delayedError()->addError(ep)) ep->warning(delayedError()->error);
             } else {
-                removeError();
+                clearError();
             }
 
             updating = false;
@@ -152,7 +160,7 @@ void QV8Bindings::Binding::destroy()
     enabled = false;
     removeFromObject();
     clear();
-    removeError();
+    clearError();
     parent->release();
 }
 
@@ -230,7 +238,6 @@ QDeclarativeAbstractBinding *QV8Bindings::configBinding(int index, QObject *targ
     rv->index = index;
     rv->object = target;
     rv->property = p;
-    rv->setContext(context());
     rv->setScopeObject(scope);
     rv->setUseSharedContext(true);
     rv->setNotifyOnValueChanged(true);
diff --git a/src/declarative/qml/v8/qv8bindings_p.h b/src/declarative/qml/v8/qv8bindings_p.h
index 8eaf4ff290..83bbed5b5a 100644
--- a/src/declarative/qml/v8/qv8bindings_p.h
+++ b/src/declarative/qml/v8/qv8bindings_p.h
@@ -77,6 +77,9 @@ public:
                                                const QDeclarativePropertyData &prop,
                                                int line, int column);
 
+    // Inherited from QDeclarativeAbstractExpression
+    virtual void refresh();
+
 private:
     Q_DISABLE_COPY(QV8Bindings)
 
@@ -85,6 +88,7 @@ private:
         Binding();
 
         void update() { QDeclarativeAbstractBinding::update(); }
+        void refresh();
 
         // Inherited from QDeclarativeJavaScriptExpression
         inline virtual QString expressionIdentifier();
@@ -94,7 +98,6 @@ private:
         virtual void setEnabled(bool, QDeclarativePropertyPrivate::WriteFlags flags);
         virtual void update(QDeclarativePropertyPrivate::WriteFlags flags);
         virtual void destroy();
-        virtual void refresh();
 
         int index:30;
         bool enabled:1;