Fix Persistent/WeakValue API

Don't use unprotected Values in the API anymore.

Change-Id: I8851628227fca374de24701bc8ee0908b5ae3923
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

22 files changed, 144 insertions, 109 deletions

diff --git a/src/qml/qml/qqmlbinding.cpp b/src/qml/qml/qqmlbinding.cpp
index a5e281dc56..a388178952 100644
--- a/src/qml/qml/qqmlbinding.cpp
+++ b/src/qml/qml/qqmlbinding.cpp
@@ -178,7 +178,7 @@ QQmlBinding::QQmlBinding(const QString &str, QObject *obj,
     v4function = qmlBinding(ctxt, obj, str, url, m_lineNumber);
 }
 
-QQmlBinding::QQmlBinding(const QV4::Value &functionPtr, QObject *obj, QQmlContextData *ctxt,
+QQmlBinding::QQmlBinding(const QV4::ValueRef functionPtr, QObject *obj, QQmlContextData *ctxt,
                          const QString &url, quint16 lineNumber, quint16 columnNumber)
 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
   m_url(url), m_lineNumber(lineNumber), m_columnNumber(columnNumber)
@@ -250,7 +250,8 @@ void QQmlBinding::update(QQmlPropertyPrivate::WriteFlags flags)
 
             bool isUndefined = false;
 
-            QV4::ScopedValue result(scope, QQmlJavaScriptExpression::evaluate(context(), v4function.value(), &isUndefined));
+            QV4::ScopedValue f(scope, v4function.value());
+            QV4::ScopedValue result(scope, QQmlJavaScriptExpression::evaluate(context(), f, &isUndefined));
 
             trace.event("writing binding result");
 
@@ -291,7 +292,8 @@ QVariant QQmlBinding::evaluate()
 
     bool isUndefined = false;
 
-    QV4::ScopedValue result(scope, QQmlJavaScriptExpression::evaluate(context(), v4function.value(), &isUndefined));
+    QV4::ScopedValue f(scope, v4function.value());
+    QV4::ScopedValue result(scope, QQmlJavaScriptExpression::evaluate(context(), f, &isUndefined));
 
     ep->dereferenceScarceResources();
 
diff --git a/src/qml/qml/qqmlbinding_p.h b/src/qml/qml/qqmlbinding_p.h
index ea703e8d38..e872482373 100644
--- a/src/qml/qml/qqmlbinding_p.h
+++ b/src/qml/qml/qqmlbinding_p.h
@@ -84,7 +84,7 @@ public:
     QQmlBinding(const QString &, QObject *, QQmlContextData *);
     QQmlBinding(const QString &, QObject *, QQmlContextData *,
                 const QString &url, quint16 lineNumber, quint16 columnNumber);
-    QQmlBinding(const QV4::Value &, QObject *, QQmlContextData *,
+    QQmlBinding(const QV4::ValueRef, QObject *, QQmlContextData *,
                 const QString &url, quint16 lineNumber, quint16 columnNumber);
 
     void setTarget(const QQmlProperty &);
diff --git a/src/qml/qml/qqmlboundsignal.cpp b/src/qml/qml/qqmlboundsignal.cpp
index 3a0d58d87c..cc2edb7b19 100644
--- a/src/qml/qml/qqmlboundsignal.cpp
+++ b/src/qml/qml/qqmlboundsignal.cpp
@@ -86,7 +86,7 @@ QQmlBoundSignalExpression::QQmlBoundSignalExpression(QObject *target, int index,
     m_expression = expression;
 }
 
-QQmlBoundSignalExpression::QQmlBoundSignalExpression(QObject *target, int index, QQmlContextData *ctxt, QObject *scope, const QV4::PersistentValue &function)
+QQmlBoundSignalExpression::QQmlBoundSignalExpression(QObject *target, int index, QQmlContextData *ctxt, QObject *scope, const QV4::ValueRef &function)
     : QQmlJavaScriptExpression(&QQmlBoundSignalExpression_jsvtable),
       m_v8function(function),
       m_line(-1),
@@ -128,7 +128,9 @@ QString QQmlBoundSignalExpression::expression() const
 {
     if (m_expressionFunctionValid) {
         Q_ASSERT (context() && engine());
-        return m_v8function.value().toQStringNoThrow();
+        QV4::Scope scope(QQmlEnginePrivate::get(engine())->v4engine());
+        QV4::ScopedValue v(scope, m_v8function.value());
+        return v->toQStringNoThrow();
     } else {
         return m_expression;
     }
@@ -144,6 +146,7 @@ void QQmlBoundSignalExpression::evaluate(void **a)
         return;
 
     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine());
+    QV4::Scope scope(ep->v4engine());
 
     ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
     {
@@ -181,7 +184,7 @@ void QQmlBoundSignalExpression::evaluate(void **a)
             m_v8function = evalFunction(context(), scopeObject(), expression,
                                         m_fileName, m_line, &m_v8qmlscope);
 
-            if (m_v8function.isUndefined() || m_v8function.value().isNull()) {
+            if (m_v8function.isNullOrUndefined()) {
                 ep->dereferenceScarceResources();
                 return; // could not evaluate function.  Not valid.
             }
@@ -223,7 +226,8 @@ void QQmlBoundSignalExpression::evaluate(void **a)
             }
         }
 
-        QQmlJavaScriptExpression::evaluate(context(), m_v8function.value(), argCount, args, 0);
+        QV4::ScopedValue f(scope, m_v8function.value());
+        QQmlJavaScriptExpression::evaluate(context(), f, argCount, args, 0);
     }
     ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
 }
diff --git a/src/qml/qml/qqmlboundsignal_p.h b/src/qml/qml/qqmlboundsignal_p.h
index 86e3dc20ea..feb79d5484 100644
--- a/src/qml/qml/qqmlboundsignal_p.h
+++ b/src/qml/qml/qqmlboundsignal_p.h
@@ -76,7 +76,7 @@ public:
                               const QString &parameterString = QString());
 
     QQmlBoundSignalExpression(QObject *target, int index,
-                              QQmlContextData *ctxt, QObject *scope, const QV4::PersistentValue &function);
+                              QQmlContextData *ctxt, QObject *scope, const QV4::ValueRef &function);
 
 
     // "inherited" from QQmlJavaScriptExpression.
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index cf3493a590..cfda595438 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -1123,7 +1123,7 @@ public:
     QV8Engine *v8;
     QPointer<QObject> parent;
     QV4::Value valuemap;
-    QV4::Value qmlGlobal;
+    QV4::SafeValue qmlGlobal;
     QV4::Value m_statusChanged;
 protected:
     virtual void statusChanged(Status);
@@ -1244,7 +1244,8 @@ void QQmlComponent::createObject(QQmlV4Function *args)
 
     if (!valuemap.isUndefined()) {
         QQmlComponentExtension *e = componentExtension(v8engine);
-        QV4::ScopedValue f(scope, QV4::Script::evaluate(v4engine, QString::fromLatin1(INITIALPROPERTIES_SOURCE), args->qmlGlobal().asObject()));
+        QV4::ScopedObject qmlglobal(scope, args->qmlGlobal());
+        QV4::ScopedValue f(scope, QV4::Script::evaluate(v4engine, QString::fromLatin1(INITIALPROPERTIES_SOURCE), qmlglobal));
         Q_ASSERT(f->asFunctionObject());
         QV4::ScopedCallData callData(scope, 2);
         callData->thisObject = QV4::Value::fromObject(v4engine->globalObject);
@@ -1329,9 +1330,11 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
     Q_ASSERT(d->engine);
     Q_UNUSED(d);
     Q_ASSERT(args);
+    QV4::ExecutionEngine *v4 = QV8Engine::getV4(args->engine());
+    QV4::Scope scope(v4);
 
     QObject *parent = 0;
-    QV4::Value valuemap = QV4::Value::undefinedValue();
+    QV4::ScopedValue valuemap(scope, QV4::Value::undefinedValue());
     QQmlIncubator::IncubationMode mode = QQmlIncubator::Asynchronous;
 
     if (args->length() >= 1) {
@@ -1340,9 +1343,9 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
     }
 
     if (args->length() >= 2) {
-        QV4::Value v = (*args)[1];
-        if (v.isNull()) {
-        } else if (!v.asObject() || v.asArrayObject()) {
+        QV4::ScopedValue v(scope, (*args)[1]);
+        if (v->isNull()) {
+        } else if (!v->asObject() || v->asArrayObject()) {
             qmlInfo(this) << tr("createObject: value is not an object");
             args->setReturnValue(QV4::Value::nullValue());
             return;
@@ -1361,27 +1364,27 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
 
     QQmlComponentExtension *e = componentExtension(args->engine());
 
-    QV4::ExecutionEngine *v4 = QV8Engine::getV4(args->engine());
-    QmlIncubatorObject *r = new (v4->memoryManager) QmlIncubatorObject(args->engine(), mode);
-    r->setPrototype(e->incubationProto.value().asObject());
+    QV4::Scoped<QmlIncubatorObject> r(scope, new (v4->memoryManager) QmlIncubatorObject(args->engine(), mode));
+    QV4::ScopedObject p(scope, e->incubationProto.value());
+    r->setPrototype(p.getPointer());
 
-    if (!valuemap.isUndefined()) {
+    if (!valuemap->isUndefined()) {
         r->valuemap = valuemap;
         r->qmlGlobal = args->qmlGlobal();
     }
     r->parent = parent;
 
-    create(*r, creationContext());
+    create(*r.getPointer(), creationContext());
 
     if (r->status() == QQmlIncubator::Null) {
         args->setReturnValue(QV4::Value::nullValue());
     } else {
-        args->setReturnValue(QV4::Value::fromObject(r));
+        args->setReturnValue(r.asValue());
     }
 }
 
 // XXX used by QSGLoader
-void QQmlComponentPrivate::initializeObjectWithInitialProperties(const QV4::Value &qmlGlobal, const QV4::Value &valuemap, QObject *toCreate)
+void QQmlComponentPrivate::initializeObjectWithInitialProperties(const QV4::ValueRef qmlGlobal, const QV4::Value &valuemap, QObject *toCreate)
 {
     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
     QV8Engine *v8engine = ep->v8engine();
@@ -1393,8 +1396,9 @@ void QQmlComponentPrivate::initializeObjectWithInitialProperties(const QV4::Valu
 
     if (!valuemap.isUndefined()) {
         QQmlComponentExtension *e = componentExtension(v8engine);
+        QV4::ScopedObject qmlGlobalObj(scope, qmlGlobal);
         QV4::Scoped<QV4::FunctionObject>  f(scope, QV4::Script::evaluate(QV8Engine::getV4(v8engine),
-                                                                    QString::fromLatin1(INITIALPROPERTIES_SOURCE), qmlGlobal.asObject()));
+                                                                    QString::fromLatin1(INITIALPROPERTIES_SOURCE), qmlGlobalObj));
         QV4::ScopedCallData callData(scope, 2);
         callData->thisObject = QV4::Value::fromObject(v4engine->globalObject);
         callData->args[0] = object;
@@ -1490,7 +1494,7 @@ void QmlIncubatorObject::setInitialState(QObject *o)
         QV4::ExecutionEngine *v4 = QV8Engine::getV4(v8);
         QV4::Scope scope(v4);
 
-        QV4::Scoped<QV4::FunctionObject> f(scope, QV4::Script::evaluate(v4, QString::fromLatin1(INITIALPROPERTIES_SOURCE), qmlGlobal.asObject()));
+        QV4::Scoped<QV4::FunctionObject> f(scope, QV4::Script::evaluate(v4, QString::fromLatin1(INITIALPROPERTIES_SOURCE), qmlGlobal));
         QV4::ScopedCallData callData(scope, 2);
         callData->thisObject = QV4::Value::fromObject(v4->globalObject);
         callData->args[0] = QV4::Value::fromReturnedValue(QV4::QObjectWrapper::wrap(v4, o));
diff --git a/src/qml/qml/qqmlcomponent_p.h b/src/qml/qml/qqmlcomponent_p.h
index 08e4dcea7d..f2f81c8ab2 100644
--- a/src/qml/qml/qqmlcomponent_p.h
+++ b/src/qml/qml/qqmlcomponent_p.h
@@ -91,7 +91,7 @@ public:
 
     QObject *beginCreate(QQmlContextData *);
     void completeCreate();
-    void initializeObjectWithInitialProperties(const QV4::Value &qmlGlobal, const QV4::Value &valuemap, QObject *toCreate);
+    void initializeObjectWithInitialProperties(const QV4::ValueRef qmlGlobal, const QV4::Value &valuemap, QObject *toCreate);
 
     QQmlTypeData *typeData;
     virtual void typeDataReady(QQmlTypeData *);
diff --git a/src/qml/qml/qqmlcontextwrapper.cpp b/src/qml/qml/qqmlcontextwrapper.cpp
index 425c19a090..46ff821fff 100644
--- a/src/qml/qml/qqmlcontextwrapper.cpp
+++ b/src/qml/qml/qqmlcontextwrapper.cpp
@@ -188,7 +188,7 @@ ReturnedValue QmlContextWrapper::get(Managed *m, const StringRef name, bool *has
             if (r.scriptIndex != -1) {
                 int index = r.scriptIndex;
                 if (index < context->importedScripts.count())
-                    return context->importedScripts.at(index).value().asReturnedValue();
+                    return context->importedScripts.at(index).value();
                 else
                     return QV4::Value::undefinedValue().asReturnedValue();
             } else if (r.type) {
@@ -318,13 +318,13 @@ void QmlContextWrapper::put(Managed *m, const StringRef name, const ValueRef val
 
         // Search scope object
         if (scopeObject &&
-            QV4::QObjectWrapper::setQmlProperty(v4->current, context, scopeObject, name.getPointer(), QV4::QObjectWrapper::CheckRevision, *value))
+            QV4::QObjectWrapper::setQmlProperty(v4->current, context, scopeObject, name.getPointer(), QV4::QObjectWrapper::CheckRevision, value))
             return;
         scopeObject = 0;
 
         // Search context object
         if (context->contextObject &&
-            QV4::QObjectWrapper::setQmlProperty(v4->current, context, context->contextObject, name.getPointer(), QV4::QObjectWrapper::CheckRevision, *value))
+            QV4::QObjectWrapper::setQmlProperty(v4->current, context, context->contextObject, name.getPointer(), QV4::QObjectWrapper::CheckRevision, value))
             return;
 
         context = context->parent;
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 2e77d8257b..2f873936e3 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -1654,7 +1654,7 @@ void QQmlData::destroyed(QObject *object)
         delete extendedData;
 
     // Dispose the handle.
-    jsWrapper = QV4::Value::undefinedValue();
+    jsWrapper.clear();
 
     if (ownMemory)
         delete this;
diff --git a/src/qml/qml/qqmlexpression.cpp b/src/qml/qml/qqmlexpression.cpp
index 76214c17a4..cdb5813221 100644
--- a/src/qml/qml/qqmlexpression.cpp
+++ b/src/qml/qml/qqmlexpression.cpp
@@ -262,12 +262,17 @@ void QQmlExpression::setExpression(const QString &expression)
 // Must be called with a valid handle scope
 QV4::ReturnedValue QQmlExpressionPrivate::v4value(bool *isUndefined)
 {
+    Q_Q(QQmlExpression);
+
     if (!expressionFunctionValid) {
         function = qmlBinding(context(), scopeObject(), expression, url, line, &qmlscope);
         expressionFunctionValid = true;
     }
 
-    return evaluate(context(), function.value(), isUndefined);
+    QV4::ExecutionEngine *v4 = QQmlEnginePrivate::get(q->engine())->v4engine();
+    QV4::Scope scope(v4);
+    QV4::ScopedValue f(scope, function.value());
+    return evaluate(context(), f, isUndefined);
 }
 
 QVariant QQmlExpressionPrivate::value(bool *isUndefined)
diff --git a/src/qml/qml/qqmljavascriptexpression.cpp b/src/qml/qml/qqmljavascriptexpression.cpp
index b1184729d0..e08e8eebb7 100644
--- a/src/qml/qml/qqmljavascriptexpression.cpp
+++ b/src/qml/qml/qqmljavascriptexpression.cpp
@@ -321,7 +321,7 @@ void QQmlJavaScriptExpression::exceptionToError(const QV4::Exception &e, QQmlErr
     }
 }
 
-QV4::PersistentValue
+QV4::ReturnedValue
 QQmlJavaScriptExpression::evalFunction(QQmlContextData *ctxt, QObject *scopeObject,
                                        const QString &code, const QString &filename, quint16 line,
                                        QV4::PersistentValue *qmlscope)
@@ -333,8 +333,8 @@ QQmlJavaScriptExpression::evalFunction(QQmlContextData *ctxt, QObject *scopeObje
     QV4::ExecutionContext *ctx = v4->current;
     QV4::Scope scope(v4);
 
-    QV4::Scoped<QV4::Object> qmlScopeObject(scope, QV4::QmlContextWrapper::qmlScope(ep->v8engine(), ctxt, scopeObject));
-    QV4::Script script(v4, qmlScopeObject.getPointer(), code, filename, line);
+    QV4::ScopedObject qmlScopeObject(scope, QV4::QmlContextWrapper::qmlScope(ep->v8engine(), ctxt, scopeObject));
+    QV4::Script script(v4, qmlScopeObject, code, filename, line);
     QV4::ScopedValue result(scope);
     try {
         script.parse();
@@ -351,14 +351,14 @@ QQmlJavaScriptExpression::evalFunction(QQmlContextData *ctxt, QObject *scopeObje
             error.setUrl(QUrl::fromLocalFile(filename));
         error.setObject(scopeObject);
         ep->warning(error);
-        return QV4::PersistentValue();
+        return QV4::Encode::undefined();
     }
     if (qmlscope)
-        *qmlscope = qmlScopeObject.asValue();
+        *qmlscope = qmlScopeObject;
     return result.asReturnedValue();
 }
 
-QV4::PersistentValue QQmlJavaScriptExpression::qmlBinding(QQmlContextData *ctxt, QObject *qmlScope,
+QV4::ReturnedValue QQmlJavaScriptExpression::qmlBinding(QQmlContextData *ctxt, QObject *qmlScope,
                                                        const QString &code, const QString &filename, quint16 line,
                                                        QV4::PersistentValue *qmlscope)
 {
@@ -369,8 +369,8 @@ QV4::PersistentValue QQmlJavaScriptExpression::qmlBinding(QQmlContextData *ctxt,
     QV4::ExecutionContext *ctx = v4->current;
     QV4::Scope scope(v4);
 
-    QV4::ScopedValue qmlScopeObject(scope, QV4::QmlContextWrapper::qmlScope(ep->v8engine(), ctxt, qmlScope));
-    QV4::Script script(v4, qmlScopeObject->asObject(), code, filename, line);
+    QV4::ScopedObject qmlScopeObject(scope, QV4::QmlContextWrapper::qmlScope(ep->v8engine(), ctxt, qmlScope));
+    QV4::Script script(v4, qmlScopeObject, code, filename, line);
     QV4::ScopedValue result(scope);
     try {
         script.parse();
@@ -387,7 +387,7 @@ QV4::PersistentValue QQmlJavaScriptExpression::qmlBinding(QQmlContextData *ctxt,
             error.setUrl(QUrl::fromLocalFile(filename));
         error.setObject(qmlScope);
         ep->warning(error);
-        return QV4::PersistentValue();
+        return QV4::Encode::undefined();
     }
     if (qmlscope)
         *qmlscope = qmlScopeObject;
diff --git a/src/qml/qml/qqmljavascriptexpression_p.h b/src/qml/qml/qqmljavascriptexpression_p.h
index f08b3af6cf..c13e191216 100644
--- a/src/qml/qml/qqmljavascriptexpression_p.h
+++ b/src/qml/qml/qqmljavascriptexpression_p.h
@@ -146,12 +146,12 @@ public:
     QQmlDelayedError *delayedError();
 
     static void exceptionToError(const QV4::Exception &e, QQmlError &);
-    static QV4::PersistentValue evalFunction(QQmlContextData *ctxt, QObject *scope,
+    static QV4::ReturnedValue evalFunction(QQmlContextData *ctxt, QObject *scope,
                                                      const QString &code, const QString &filename,
                                                      quint16 line,
                                                      QV4::PersistentValue *qmlscope = 0);
     // doesn't require rewriting the expression
-    static QV4::PersistentValue qmlBinding(QQmlContextData *ctxt, QObject *scope,
+    static QV4::ReturnedValue qmlBinding(QQmlContextData *ctxt, QObject *scope,
                                         const QString &code,
                                         const QString &filename, quint16 line,
                                         QV4::PersistentValue *qmlscope = 0);
diff --git a/src/qml/qml/qqmllocale.cpp b/src/qml/qml/qqmllocale.cpp
index c3c7d0282d..db949467d1 100644
--- a/src/qml/qml/qqmllocale.cpp
+++ b/src/qml/qml/qqmllocale.cpp
@@ -835,11 +835,13 @@ QV4::ReturnedValue QQmlLocale::locale(QV8Engine *v8engine, const QString &locale
 {
     QV8LocaleDataDeletable *d = localeV8Data(v8engine);
     QV4::ExecutionEngine *engine = QV8Engine::getV4(v8engine);
-    QQmlLocaleData *wrapper = new (engine->memoryManager) QQmlLocaleData(engine);
+    QV4::Scope scope(engine);
+    QV4::Scoped<QQmlLocaleData> wrapper(scope, new (engine->memoryManager) QQmlLocaleData(engine));
     if (!locale.isEmpty())
         wrapper->locale = QLocale(locale);
-    wrapper->setPrototype(d->prototype.value().asObject());
-    return QV4::Value::fromObject(wrapper).asReturnedValue();
+    QV4::ScopedObject p(scope, d->prototype.value());
+    wrapper->setPrototype(p.getPointer());
+    return wrapper.asReturnedValue();
 }
 
 void QQmlLocale::registerStringLocaleCompare(QV4::ExecutionEngine *engine)
diff --git a/src/qml/qml/qqmlobjectcreator.cpp b/src/qml/qml/qqmlobjectcreator.cpp
index 601f4dbba0..2f4e782069 100644
--- a/src/qml/qml/qqmlobjectcreator.cpp
+++ b/src/qml/qml/qqmlobjectcreator.cpp
@@ -1080,7 +1080,9 @@ bool QmlObjectCreator::setPropertyValue(QQmlPropertyData *property, int bindingI
 
     if (binding->type == QV4::CompiledData::Binding::Type_Script) {
         QV4::Function *runtimeFunction = jsUnit->runtimeFunctions[binding->value.compiledScriptIndex];
-        QV4::Value function = QV4::Value::fromObject(QV4::FunctionObject::creatScriptFunction(_qmlContext, runtimeFunction));
+
+        QV4::Scope scope(_qmlContext);
+        QV4::ScopedFunctionObject function(scope, QV4::FunctionObject::creatScriptFunction(_qmlContext, runtimeFunction));
 
         if (binding->flags & QV4::CompiledData::Binding::IsSignalHandlerExpression) {
             int signalIndex = _propertyCache->methodIndexToSignalIndex(property->coreIndex);
@@ -1194,6 +1196,8 @@ bool QmlObjectCreator::setPropertyValue(QQmlPropertyData *property, int bindingI
 
 void QmlObjectCreator::setupFunctions()
 {
+    QV4::Scope scope(_qmlContext);
+    QV4::ScopedValue function(scope);
     QQmlVMEMetaObject *vme = QQmlVMEMetaObject::get(_qobject);
 
     const quint32 *functionIdx = _compiledObject->functionOffsetTable();
@@ -1205,8 +1209,8 @@ void QmlObjectCreator::setupFunctions()
         if (!property->isVMEFunction())
             continue;
 
-        QV4::FunctionObject *function = QV4::FunctionObject::creatScriptFunction(_qmlContext, runtimeFunction);
-        vme->setVmeMethod(property->coreIndex, QV4::Value::fromObject(function));
+        function = QV4::FunctionObject::creatScriptFunction(_qmlContext, runtimeFunction);
+        vme->setVmeMethod(property->coreIndex, function);
     }
 }
 
diff --git a/src/qml/qml/qqmlproperty.cpp b/src/qml/qml/qqmlproperty.cpp
index f821687f63..bcecda9c57 100644
--- a/src/qml/qml/qqmlproperty.cpp
+++ b/src/qml/qml/qqmlproperty.cpp
@@ -1460,7 +1460,7 @@ bool QQmlPropertyPrivate::writeBinding(QObject *object,
                                                const QQmlPropertyData &core,
                                                QQmlContextData *context,
                                                QQmlJavaScriptExpression *expression,
-                                               const QV4::Value &result, bool isUndefined,
+                                               const QV4::ValueRef result, bool isUndefined,
                                                WriteFlags flags)
 {
     Q_ASSERT(object);
@@ -1482,22 +1482,22 @@ bool QQmlPropertyPrivate::writeBinding(QObject *object,
     if (!isUndefined && !core.isValueTypeVirtual()) {
         switch (core.propType) {
         case QMetaType::Int:
-            if (result.isInteger())
-                QUICK_STORE(int, result.integerValue())
-            else if (result.isNumber())
-                QUICK_STORE(int, qRound(result.doubleValue()))
+            if (result->isInteger())
+                QUICK_STORE(int, result->integerValue())
+            else if (result->isNumber())
+                QUICK_STORE(int, qRound(result->doubleValue()))
             break;
         case QMetaType::Double:
-            if (result.isNumber())
-                QUICK_STORE(double, result.asDouble())
+            if (result->isNumber())
+                QUICK_STORE(double, result->asDouble())
             break;
         case QMetaType::Float:
-            if (result.isNumber())
-                QUICK_STORE(float, result.asDouble())
+            if (result->isNumber())
+                QUICK_STORE(float, result->asDouble())
             break;
         case QMetaType::QString:
-            if (result.isString())
-                QUICK_STORE(QString, result.toQStringNoThrow())
+            if (result->isString())
+                QUICK_STORE(QString, result->toQStringNoThrow())
             break;
         default:
             break;
@@ -1514,19 +1514,19 @@ bool QQmlPropertyPrivate::writeBinding(QObject *object,
 
     if (isUndefined) {
     } else if (core.isQList()) {
-        value = v8engine->toVariant(result, qMetaTypeId<QList<QObject *> >());
-    } else if (result.isNull() && core.isQObject()) {
+        value = v8engine->toVariant(*result, qMetaTypeId<QList<QObject *> >());
+    } else if (result->isNull() && core.isQObject()) {
         value = QVariant::fromValue((QObject *)0);
     } else if (core.propType == qMetaTypeId<QList<QUrl> >()) {
-        value = resolvedUrlSequence(v8engine->toVariant(result, qMetaTypeId<QList<QUrl> >()), context);
+        value = resolvedUrlSequence(v8engine->toVariant(*result, qMetaTypeId<QList<QUrl> >()), context);
     } else if (!isVarProperty && type != qMetaTypeId<QJSValue>()) {
-        value = v8engine->toVariant(result, type);
+        value = v8engine->toVariant(*result, type);
     }
 
     if (expression->hasError()) {
         return false;
     } else if (isVarProperty) {
-        QV4::FunctionObject *f = result.asFunctionObject();
+        QV4::FunctionObject *f = result->asFunctionObject();
         if (f && f->bindingKeyFlag) {
             // we explicitly disallow this case to avoid confusion.  Users can still store one
             // in an array in a var property if they need to, but the common case is user error.
@@ -1537,14 +1537,14 @@ bool QQmlPropertyPrivate::writeBinding(QObject *object,
 
         QQmlVMEMetaObject *vmemo = QQmlVMEMetaObject::get(object);
         Q_ASSERT(vmemo);
-        vmemo->setVMEProperty(core.coreIndex, result);
+        vmemo->setVMEProperty(core.coreIndex, *result);
     } else if (isUndefined && core.isResettable()) {
         void *args[] = { 0 };
         QMetaObject::metacall(object, QMetaObject::ResetProperty, core.coreIndex, args);
     } else if (isUndefined && type == qMetaTypeId<QVariant>()) {
         writeValueProperty(object, core, QVariant(), context, flags);
     } else if (type == qMetaTypeId<QJSValue>()) {
-        QV4::FunctionObject *f = result.asFunctionObject();
+        QV4::FunctionObject *f = result->asFunctionObject();
         if (f && f->bindingKeyFlag) {
             expression->delayedError()->setErrorDescription(QLatin1String("Invalid use of Qt.binding() in a binding declaration."));
             expression->delayedError()->setErrorObject(object);
@@ -1562,7 +1562,7 @@ bool QQmlPropertyPrivate::writeBinding(QObject *object,
         expression->delayedError()->setErrorDescription(errorStr);
         expression->delayedError()->setErrorObject(object);
         return false;
-    } else if (QV4::FunctionObject *f = result.asFunctionObject()) {
+    } else if (QV4::FunctionObject *f = result->asFunctionObject()) {
         if (f->bindingKeyFlag)
             expression->delayedError()->setErrorDescription(QLatin1String("Invalid use of Qt.binding() in a binding declaration."));
         else
diff --git a/src/qml/qml/qqmlproperty_p.h b/src/qml/qml/qqmlproperty_p.h
index 9af091ad46..ce15061ba0 100644
--- a/src/qml/qml/qqmlproperty_p.h
+++ b/src/qml/qml/qqmlproperty_p.h
@@ -148,7 +148,7 @@ public:
     static bool writeBinding(QObject *, const QQmlPropertyData &,
                              QQmlContextData *context,
                              QQmlJavaScriptExpression *expression,
-                             const QV4::Value &result, bool isUndefined,
+                             const QV4::ValueRef result, bool isUndefined,
                              WriteFlags flags);
     static int valueTypeCoreIndex(const QQmlProperty &that);
     static int bindingIndex(const QQmlProperty &that);
diff --git a/src/qml/qml/qqmltypewrapper.cpp b/src/qml/qml/qqmltypewrapper.cpp
index d5c0ed058c..13dad049c8 100644
--- a/src/qml/qml/qqmltypewrapper.cpp
+++ b/src/qml/qml/qqmltypewrapper.cpp
@@ -160,9 +160,8 @@ ReturnedValue QmlTypeWrapper::get(Managed *m, const StringRef name, bool *hasPro
                 // check for property.
                 return QV4::QObjectWrapper::getQmlProperty(v4->current, context, qobjectSingleton, name.getPointer(), QV4::QObjectWrapper::IgnoreRevision, hasProperty);
             } else if (!siinfo->scriptApi(e).isUndefined()) {
-                QV4::ExecutionEngine *engine = QV8Engine::getV4(v8engine);
                 // NOTE: if used in a binding, changes will not trigger re-evaluation since non-NOTIFYable.
-                QV4::Scoped<Object> o(scope, QJSValuePrivate::get(siinfo->scriptApi(e))->getValue(engine));
+                QV4::ScopedObject o(scope, QJSValuePrivate::get(siinfo->scriptApi(e))->getValue(v4));
                 if (!!o)
                     return o->get(name);
             }
@@ -203,7 +202,7 @@ ReturnedValue QmlTypeWrapper::get(Managed *m, const StringRef name, bool *hasPro
             } else if (r.scriptIndex != -1) {
                 int index = r.scriptIndex;
                 if (index < context->importedScripts.count())
-                    return context->importedScripts.at(index).value().asReturnedValue();
+                    return context->importedScripts.at(index).value();
             } else if (r.importNamespace) {
                 return create(w->v8, object, context->imports, r.importNamespace);
             }
@@ -231,6 +230,7 @@ void QmlTypeWrapper::put(Managed *m, const StringRef name, const ValueRef value)
     if (!w)
         v4->current->throwTypeError();
 
+    QV4::Scope scope(v4);
     QV8Engine *v8engine = v4->v8Engine;
     QQmlContextData *context = v8engine->callingContext();
 
@@ -239,7 +239,7 @@ void QmlTypeWrapper::put(Managed *m, const StringRef name, const ValueRef value)
         QObject *object = w->object;
         QObject *ao = qmlAttachedPropertiesObjectById(type->attachedPropertiesId(), object);
         if (ao) 
-            QV4::QObjectWrapper::setQmlProperty(v4->current, context, ao, name.getPointer(), QV4::QObjectWrapper::IgnoreRevision, *value);
+            QV4::QObjectWrapper::setQmlProperty(v4->current, context, ao, name.getPointer(), QV4::QObjectWrapper::IgnoreRevision, value);
     } else if (type && type->isSingleton()) {
         QQmlEngine *e = v8engine->engine();
         QQmlType::SingletonInstanceInfo *siinfo = type->singletonInstanceInfo();
@@ -247,9 +247,9 @@ void QmlTypeWrapper::put(Managed *m, const StringRef name, const ValueRef value)
 
         QObject *qobjectSingleton = siinfo->qobjectApi(e);
         if (qobjectSingleton) {
-            QV4::QObjectWrapper::setQmlProperty(v4->current, context, qobjectSingleton, name.getPointer(), QV4::QObjectWrapper::IgnoreRevision, *value);
+            QV4::QObjectWrapper::setQmlProperty(v4->current, context, qobjectSingleton, name.getPointer(), QV4::QObjectWrapper::IgnoreRevision, value);
         } else if (!siinfo->scriptApi(e).isUndefined()) {
-            QV4::Object *apiprivate = QJSValuePrivate::get(siinfo->scriptApi(e))->value.asObject();
+            QV4::ScopedObject apiprivate(scope, QJSValuePrivate::get(siinfo->scriptApi(e))->value);
             if (!apiprivate) {
                 QString error = QLatin1String("Cannot assign to read-only property \"") + name->toQString() + QLatin1Char('\"');
                 v4->current->throwError(error);
diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index b27d99793f..f1d2f3a85c 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -372,7 +372,7 @@ void QmlValueTypeWrapper::put(Managed *m, const StringRef name, const ValueRef v
 
             QV4::ExecutionEngine::StackFrame frame = v4->currentStackFrame();
 
-            newBinding = new QQmlBinding(*value, reference->object, context,
+            newBinding = new QQmlBinding(value, reference->object, context,
                                          frame.source, qmlSourceCoordinate(frame.line), qmlSourceCoordinate(frame.column));
             newBinding->setTarget(reference->object, cacheData, context);
             newBinding->setEvaluateFlags(newBinding->evaluateFlags() |
diff --git a/src/qml/qml/qqmlvme.cpp b/src/qml/qml/qqmlvme.cpp
index 1a6577d7ad..3b88e148c7 100644
--- a/src/qml/qml/qqmlvme.cpp
+++ b/src/qml/qml/qqmlvme.cpp
@@ -1087,7 +1087,7 @@ void QQmlScriptData::initialize(QQmlEngine *engine)
 
     // If compilation throws an error, a surrounding catch will record it.
     // pass 0 as the QML object, we set it later before calling run()
-    QV4::Script *program = new QV4::Script(v4, 0, m_programSource, urlString, 1);
+    QV4::Script *program = new QV4::Script(v4, QV4::ObjectRef::null(), m_programSource, urlString, 1);
     try {
         program->parse();
     } catch (QV4::Exception &) {
diff --git a/src/qml/qml/qqmlvmemetaobject.cpp b/src/qml/qml/qqmlvmemetaobject.cpp
index d70df5175b..18f3dff39d 100644
--- a/src/qml/qml/qqmlvmemetaobject.cpp
+++ b/src/qml/qml/qqmlvmemetaobject.cpp
@@ -76,7 +76,7 @@ void QQmlVMEVariantQObjectPtr::objectDestroyed(QObject *)
             QV4::ExecutionEngine *v4 = m_target->varProperties.engine();
             if (v4) {
                 QV4::Scope scope(v4);
-                QV4::ScopedArrayObject a(scope, m_target->varProperties.value().asArrayObject());
+                QV4::ScopedArrayObject a(scope, m_target->varProperties.value());
                 if (a)
                     a->putIndexed(m_index - m_target->firstVarPropertyIndex, QV4::ScopedValue(scope, QV4::Value::nullValue()));
             }
@@ -989,24 +989,30 @@ QV4::ReturnedValue QQmlVMEMetaObject::method(int index)
                                                                ctxt->urlString, data->lineNumber);
     }
 
-    return v8methods[index].value().asReturnedValue();
+    return v8methods[index].value();
 }
 
 QV4::ReturnedValue QQmlVMEMetaObject::readVarProperty(int id)
 {
     Q_ASSERT(id >= firstVarPropertyIndex);
 
-    if (ensureVarPropertiesAllocated())
-        return varProperties.value().asObject()->getIndexed(id - firstVarPropertyIndex);
+    if (ensureVarPropertiesAllocated()) {
+        QV4::Scope scope(QQmlEnginePrivate::get(ctxt->engine)->v4engine());
+        QV4::ScopedObject o(scope, varProperties.value());
+        return o->getIndexed(id - firstVarPropertyIndex);
+    }
     return QV4::Value::undefinedValue().asReturnedValue();
 }
 
 QVariant QQmlVMEMetaObject::readPropertyAsVariant(int id)
 {
     if (id >= firstVarPropertyIndex) {
-        if (ensureVarPropertiesAllocated())
+        if (ensureVarPropertiesAllocated()) {
+            QV4::Scope scope(QQmlEnginePrivate::get(ctxt->engine)->v4engine());
+            QV4::ScopedObject o(scope, varProperties.value());
             return QQmlEnginePrivate::get(ctxt->engine)->v8engine()->toVariant(
-                        QV4::Value::fromReturnedValue(varProperties.value().asObject()->getIndexed(id - firstVarPropertyIndex)), -1);
+                        QV4::Value::fromReturnedValue(o->getIndexed(id - firstVarPropertyIndex)), -1);
+        }
         return QVariant();
     } else {
         if (data[id].dataType() == QMetaType::QObjectStar) {
@@ -1026,7 +1032,8 @@ void QQmlVMEMetaObject::writeVarProperty(int id, const QV4::Value &value)
     QV4::Scope scope(varProperties.engine());
     // Importantly, if the current value is a scarce resource, we need to ensure that it
     // gets automatically released by the engine if no other references to it exist.
-    QV4::Scoped<QV4::VariantObject> oldv(scope, varProperties.value().asObject()->getIndexed(id - firstVarPropertyIndex));
+    QV4::ScopedObject vp(scope, varProperties.value());
+    QV4::Scoped<QV4::VariantObject> oldv(scope, vp->getIndexed(id - firstVarPropertyIndex));
     if (!!oldv)
         oldv->removeVmePropertyReference();
 
@@ -1057,7 +1064,7 @@ void QQmlVMEMetaObject::writeVarProperty(int id, const QV4::Value &value)
     }
 
     // Write the value and emit change signal as appropriate.
-    varProperties.value().asObject()->putIndexed(id - firstVarPropertyIndex, v);
+    vp->putIndexed(id - firstVarPropertyIndex, v);
     activate(object, methodOffset() + id, 0);
 }
 
@@ -1071,7 +1078,8 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
 
         // Importantly, if the current value is a scarce resource, we need to ensure that it
         // gets automatically released by the engine if no other references to it exist.
-        QV4::Scoped<QV4::VariantObject> oldv(scope, varProperties.value().asObject()->getIndexed(id - firstVarPropertyIndex));
+        QV4::ScopedObject vp(scope, varProperties.value());
+        QV4::Scoped<QV4::VariantObject> oldv(scope, vp->getIndexed(id - firstVarPropertyIndex));
         if (!!oldv)
             oldv->removeVmePropertyReference();
 
@@ -1083,7 +1091,7 @@ void QQmlVMEMetaObject::writeProperty(int id, const QVariant &value)
 
         // Write the value and emit change signal as appropriate.
         QVariant currentValue = readPropertyAsVariant(id);
-        varProperties.value().asObject()->putIndexed(id - firstVarPropertyIndex, newv);
+        vp->putIndexed(id - firstVarPropertyIndex, newv);
         if ((currentValue.userType() != value.userType() || currentValue != value))
             activate(object, methodOffset() + id, 0);
     } else {
@@ -1169,7 +1177,7 @@ QV4::ReturnedValue QQmlVMEMetaObject::vmeMethod(int index)
 }
 
 // Used by debugger
-void QQmlVMEMetaObject::setVmeMethod(int index, QV4::PersistentValue function)
+void QQmlVMEMetaObject::setVmeMethod(int index, QV4::ValueRef function)
 {
     if (index < methodOffset()) {
         Q_ASSERT(parentVMEMetaObject());
diff --git a/src/qml/qml/qqmlvmemetaobject_p.h b/src/qml/qml/qqmlvmemetaobject_p.h
index 35592c4906..c9babc0492 100644
--- a/src/qml/qml/qqmlvmemetaobject_p.h
+++ b/src/qml/qml/qqmlvmemetaobject_p.h
@@ -166,7 +166,7 @@ public:
     void registerInterceptor(int index, int valueIndex, QQmlPropertyValueInterceptor *interceptor);
     QV4::ReturnedValue vmeMethod(int index);
     quint16 vmeMethodLineNumber(int index);
-    void setVmeMethod(int index, QV4::PersistentValue function);
+    void setVmeMethod(int index, QV4::ValueRef function);
     QV4::ReturnedValue vmeProperty(int index);
     void setVMEProperty(int index, const QV4::Value &v);
 
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 48072f53c8..10d407a48d 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -579,13 +579,14 @@ ReturnedValue NodePrototype::method_get_attributes(SimpleCallContext *ctx)
 
 Value NodePrototype::getProto(ExecutionEngine *v4)
 {
+    Scope scope(v4);
     QQmlXMLHttpRequestData *d = xhrdata(v4->v8Engine);
     if (d->nodePrototype.isUndefined()) {
-        Object *p = new (v4->memoryManager) NodePrototype(v4);
-        d->nodePrototype = Value::fromObject(p);
-        v4->v8Engine->freezeObject(d->nodePrototype.value());
+        ScopedObject p(scope, new (v4->memoryManager) NodePrototype(v4));
+        d->nodePrototype = p;
+        v4->v8Engine->freezeObject(p.asValue());
     }
-    return d->nodePrototype.value();
+    return Value::fromReturnedValue(d->nodePrototype.value());
 }
 
 Value Node::create(QV8Engine *engine, NodeImpl *data)
@@ -631,9 +632,9 @@ Value Element::prototype(ExecutionEngine *engine)
         p->setPrototype(NodePrototype::getProto(engine).asObject());
         p->defineAccessorProperty(QStringLiteral("tagName"), NodePrototype::method_get_nodeName, 0);
         d->elementPrototype = p;
-        engine->v8Engine->freezeObject(d->elementPrototype.value());
+        engine->v8Engine->freezeObject(p.asValue());
     }
-    return d->elementPrototype.value();
+    return Value::fromReturnedValue(d->elementPrototype.value());
 }
 
 Value Attr::prototype(ExecutionEngine *engine)
@@ -647,9 +648,9 @@ Value Attr::prototype(ExecutionEngine *engine)
         p->defineAccessorProperty(QStringLiteral("value"), method_value, 0);
         p->defineAccessorProperty(QStringLiteral("ownerElement"), method_ownerElement, 0);
         d->attrPrototype = p;
-        engine->v8Engine->freezeObject(d->attrPrototype.value());
+        engine->v8Engine->freezeObject(p.asValue());
     }
-    return d->attrPrototype.value();
+    return Value::fromReturnedValue(d->attrPrototype.value());
 }
 
 ReturnedValue Attr::method_name(SimpleCallContext *ctx)
@@ -702,9 +703,9 @@ Value CharacterData::prototype(ExecutionEngine *v4)
         p->defineAccessorProperty(QStringLiteral("data"), NodePrototype::method_get_nodeValue, 0);
         p->defineAccessorProperty(QStringLiteral("length"), method_length, 0);
         d->characterDataPrototype = p;
-        v4->v8Engine->freezeObject(d->characterDataPrototype);
+        v4->v8Engine->freezeObject(p.asValue());
     }
-    return d->characterDataPrototype.value();
+    return Value::fromReturnedValue(d->characterDataPrototype.value());
 }
 
 ReturnedValue Text::method_isElementContentWhitespace(SimpleCallContext *ctx)
@@ -735,9 +736,9 @@ Value Text::prototype(ExecutionEngine *v4)
         p->defineAccessorProperty(QStringLiteral("isElementContentWhitespace"), method_isElementContentWhitespace, 0);
         p->defineAccessorProperty(QStringLiteral("wholeText"), method_wholeText, 0);
         d->textPrototype = p;
-        v4->v8Engine->freezeObject(d->textPrototype);
+        v4->v8Engine->freezeObject(p.asValue());
     }
-    return d->textPrototype.value();
+    return Value::fromReturnedValue(d->textPrototype.value());
 }
 
 Value CDATA::prototype(ExecutionEngine *v4)
@@ -749,9 +750,9 @@ Value CDATA::prototype(ExecutionEngine *v4)
         Scoped<Object> p(scope, v4->newObject());
         p->setPrototype(Text::prototype(v4).asObject());
         d->cdataPrototype = p;
-        v4->v8Engine->freezeObject(d->cdataPrototype);
+        v4->v8Engine->freezeObject(p.asValue());
     }
-    return d->cdataPrototype.value();
+    return Value::fromReturnedValue(d->cdataPrototype.value());
 }
 
 Value Document::prototype(ExecutionEngine *v4)
@@ -766,9 +767,9 @@ Value Document::prototype(ExecutionEngine *v4)
         p->defineAccessorProperty(QStringLiteral("xmlStandalone"), method_xmlStandalone, 0);
         p->defineAccessorProperty(QStringLiteral("documentElement"), method_documentElement, 0);
         d->documentPrototype = p;
-        v4->v8Engine->freezeObject(d->documentPrototype);
+        v4->v8Engine->freezeObject(p.asValue());
     }
-    return d->documentPrototype.value();
+    return Value::fromReturnedValue(d->documentPrototype.value());
 }
 
 ReturnedValue Document::load(QV8Engine *engine, const QByteArray &data)
@@ -1284,7 +1285,7 @@ ReturnedValue QQmlXMLHttpRequest::abort(const ValueRef me)
 
 ReturnedValue QQmlXMLHttpRequest::getMe() const
 {
-    return m_me.value().asReturnedValue();
+    return m_me.value();
 }
 
 void QQmlXMLHttpRequest::setMe(const ValueRef me)
diff --git a/src/qml/qml/v8/qv8engine.cpp b/src/qml/qml/v8/qv8engine.cpp
index b62e2150af..e8c84eee35 100644
--- a/src/qml/qml/v8/qv8engine.cpp
+++ b/src/qml/qml/v8/qv8engine.cpp
@@ -120,6 +120,8 @@ QV8Engine::~QV8Engine()
 QVariant QV8Engine::toVariant(const QV4::Value &value, int typeHint)
 {
     Q_ASSERT (!value.isEmpty());
+    QV4::Scope scope(m_v4Engine);
+    QV4::ScopedValue v(scope, value);
 
     if (QV4::VariantObject *v = value.as<QV4::VariantObject>())
         return v->data;
@@ -131,7 +133,7 @@ QVariant QV8Engine::toVariant(const QV4::Value &value, int typeHint)
         return QVariant::fromValue(QV4::JsonObject::toJsonValue(value));
 
     if (typeHint == qMetaTypeId<QJSValue>())
-        return QVariant::fromValue(QJSValue(new QJSValuePrivate(m_v4Engine, value)));
+        return QVariant::fromValue(QJSValue(new QJSValuePrivate(m_v4Engine, v)));
 
     if (QV4::Object *object = value.asObject()) {
         if (typeHint == QMetaType::QJsonObject
@@ -450,9 +452,9 @@ void QV8Engine::initializeGlobal()
                       "    }"\
                       "})"
 
-        QV4::Scoped<QV4::FunctionObject> result(scope, QV4::Script::evaluate(m_v4Engine, QString::fromUtf8(FREEZE_SOURCE), 0));
+        QV4::Scoped<QV4::FunctionObject> result(scope, QV4::Script::evaluate(m_v4Engine, QString::fromUtf8(FREEZE_SOURCE), QV4::ObjectRef::null()));
         Q_ASSERT(!!result);
-        m_freezeObject = result.asValue();
+        m_freezeObject = result;
 #undef FREEZE_SOURCE
     }
 }
@@ -460,10 +462,11 @@ void QV8Engine::initializeGlobal()
 void QV8Engine::freezeObject(const QV4::Value &value)
 {
     QV4::Scope scope(m_v4Engine);
+    QV4::ScopedFunctionObject f(scope, m_freezeObject.value());
     QV4::ScopedCallData callData(scope, 1);
     callData->args[0] = value;
     callData->thisObject = QV4::Value::fromObject(m_v4Engine->globalObject);
-    m_freezeObject.value().asFunctionObject()->call(callData);
+    f->call(callData);
 }
 
 void QV8Engine::gc()
@@ -709,6 +712,8 @@ QV4::ReturnedValue QV8Engine::metaTypeToJS(int type, const void *data)
 // data must point to a place that can store a value of the given type.
 // Returns true if conversion succeeded, false otherwise.
 bool QV8Engine::metaTypeFromJS(const QV4::Value &value, int type, void *data) {
+    QV4::Scope scope(QV8Engine::getV4(this));
+
     // check if it's one of the types we know
     switch (QMetaType::Type(type)) {
     case QMetaType::Bool:
@@ -871,7 +876,7 @@ bool QV8Engine::metaTypeFromJS(const QV4::Value &value, int type, void *data) {
         *reinterpret_cast<void* *>(data) = 0;
         return true;
     } else if (type == qMetaTypeId<QJSValue>()) {
-        *reinterpret_cast<QJSValue*>(data) = QJSValuePrivate::get(new QJSValuePrivate(m_v4Engine, value));
+        *reinterpret_cast<QJSValue*>(data) = QJSValuePrivate::get(new QJSValuePrivate(m_v4Engine, QV4::ScopedValue(scope, value)));
         return true;
     }