Extend the ReturnedValue mechanism to pointers to Managed objects

Add a Returned<T> that we can return instead of raw pointers
to Managed objects.

Start using the Returned<T> for a few methods.

Also clean up all our classes to use the Q_MANAGED macro instead
of manually defining their vtable.

Change-Id: I0a2962e47f3de955cd2cd8474f8f3fcc9e36d084
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

src/qml/jsruntime/qv4argumentsobject_p.h

@@ -50,32 +50,29 @@ namespace QV4 {
 
 struct ArgumentsGetterFunction: FunctionObject
 {
+    Q_MANAGED
     uint index;
 
     ArgumentsGetterFunction(ExecutionContext *scope, uint index)
         : FunctionObject(scope), index(index) { vtbl = &static_vtbl; }
 
     static ReturnedValue call(Managed *that, CallData *d);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct ArgumentsSetterFunction: FunctionObject
 {
+    Q_MANAGED
     uint index;
 
     ArgumentsSetterFunction(ExecutionContext *scope, uint index)
         : FunctionObject(scope), index(index) { vtbl = &static_vtbl; }
 
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 
 struct ArgumentsObject: Object {
+    Q_MANAGED
     CallContext *context;
     QVector<Value> mappedArguments;
     ArgumentsObject(CallContext *context);
@@ -90,7 +87,6 @@ struct ArgumentsObject: Object {
 
     static void markObjects(Managed *that);
 protected:
-    static const ManagedVTable static_vtbl;
     static void destroy(Managed *);
 };
 

src/qml/jsruntime/qv4arrayobject_p.h

@@ -51,13 +51,11 @@ namespace QV4 {
 
 struct ArrayCtor: FunctionObject
 {
+    Q_MANAGED
     ArrayCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct ArrayPrototype: ArrayObject

src/qml/jsruntime/qv4booleanobject.cpp

@@ -54,13 +54,13 @@ BooleanCtor::BooleanCtor(ExecutionContext *scope)
 ReturnedValue BooleanCtor::construct(Managed *m, CallData *callData)
 {
     bool n = callData->argc ? callData->args[0].toBoolean() : false;
-    return Value::fromObject(m->engine()->newBooleanObject(Value::fromBoolean(n))).asReturnedValue();
+    return Encode(m->engine()->newBooleanObject(Value::fromBoolean(n)));
 }
 
 ReturnedValue BooleanCtor::call(Managed *, CallData *callData)
 {
     bool value = callData->argc ? callData->args[0].toBoolean() : 0;
-    return Value::fromBoolean(value).asReturnedValue();
+    return Encode(value);
 }
 
 void BooleanPrototype::init(ExecutionContext *ctx, const Value &ctor)

src/qml/jsruntime/qv4booleanobject_p.h

@@ -51,13 +51,11 @@ namespace QV4 {
 
 struct BooleanCtor: FunctionObject
 {
+    Q_MANAGED
     BooleanCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct BooleanPrototype: BooleanObject

src/qml/jsruntime/qv4dateobject_p.h

@@ -64,13 +64,11 @@ protected:
 
 struct DateCtor: FunctionObject
 {
+    Q_MANAGED
     DateCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct DatePrototype: DateObject

src/qml/jsruntime/qv4engine.cpp

@@ -381,16 +381,16 @@ Object *ExecutionEngine::newStringObject(const Value &value)
     return object;
 }
 
-Object *ExecutionEngine::newNumberObject(const Value &value)
+Returned<Object> *ExecutionEngine::newNumberObject(const Value &value)
 {
     NumberObject *object = new (memoryManager) NumberObject(this, value);
-    return object;
+    return object->asReturned<Object>();
 }
 
-Object *ExecutionEngine::newBooleanObject(const Value &value)
+Returned<Object> *ExecutionEngine::newBooleanObject(const Value &value)
 {
     Object *object = new (memoryManager) BooleanObject(this, value);
-    return object;
+    return object->asReturned<Object>();
 }
 
 ArrayObject *ExecutionEngine::newArrayObject(int count)

src/qml/jsruntime/qv4engine_p.h

@@ -271,8 +271,8 @@ struct Q_QML_EXPORT ExecutionEngine
     String *newIdentifier(const QString &text);
 
     Object *newStringObject(const Value &value);
-    Object *newNumberObject(const Value &value);
-    Object *newBooleanObject(const Value &value);
+    Returned<Object> *newNumberObject(const Value &value);
+    Returned<Object> *newBooleanObject(const Value &value);
 
     ArrayObject *newArrayObject(int count = 0);
     ArrayObject *newArrayObject(const QStringList &list);

src/qml/jsruntime/qv4errorobject_p.h

@@ -93,11 +93,9 @@ struct ReferenceErrorObject: ErrorObject {
 };
 
 struct SyntaxErrorObject: ErrorObject {
+    Q_MANAGED
     SyntaxErrorObject(ExecutionEngine *engine, const Value &msg);
     SyntaxErrorObject(ExecutionEngine *engine, const QString &msg, const QString &fileName, int lineNumber, int columnNumber);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct TypeErrorObject: ErrorObject {
@@ -111,74 +109,60 @@ struct URIErrorObject: ErrorObject {
 
 struct ErrorCtor: FunctionObject
 {
+    Q_MANAGED
     ErrorCtor(ExecutionContext *scope);
     ErrorCtor(ExecutionContext *scope, String *name);
 
     static ReturnedValue construct(Managed *, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct EvalErrorCtor: ErrorCtor
 {
+    Q_MANAGED
     EvalErrorCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct RangeErrorCtor: ErrorCtor
 {
+    Q_MANAGED
     RangeErrorCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct ReferenceErrorCtor: ErrorCtor
 {
+    Q_MANAGED
     ReferenceErrorCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct SyntaxErrorCtor: ErrorCtor
 {
+    Q_MANAGED
     SyntaxErrorCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct TypeErrorCtor: ErrorCtor
 {
+    Q_MANAGED
     TypeErrorCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct URIErrorCtor: ErrorCtor
 {
+    Q_MANAGED
     URIErrorCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 

src/qml/jsruntime/qv4functionobject_p.h

@@ -93,6 +93,7 @@ struct InternalClass;
 struct Lookup;
 
 struct Q_QML_EXPORT FunctionObject: Object {
+    Q_MANAGED
     // Used with Managed::subType
     enum FunctionType {
         RegularFunction = 0,
@@ -135,7 +136,6 @@ struct Q_QML_EXPORT FunctionObject: Object {
 protected:
     FunctionObject(InternalClass *ic);
 
-    static const ManagedVTable static_vtbl;
     static void markObjects(Managed *that);
     static bool hasInstance(Managed *that, const Value &value);
     static void destroy(Managed *that)
@@ -144,13 +144,11 @@ protected:
 
 struct FunctionCtor: FunctionObject
 {
+    Q_MANAGED
     FunctionCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *that, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct FunctionPrototype: FunctionObject
@@ -165,15 +163,13 @@ struct FunctionPrototype: FunctionObject
 };
 
 struct BuiltinFunction: FunctionObject {
+    Q_MANAGED
     ReturnedValue (*code)(SimpleCallContext *);
 
     BuiltinFunction(ExecutionContext *scope, String *name, ReturnedValue (*code)(SimpleCallContext *));
 
     static ReturnedValue construct(Managed *, CallData *);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct IndexedBuiltinFunction: FunctionObject
@@ -203,26 +199,23 @@ struct IndexedBuiltinFunction: FunctionObject
 
 
 struct ScriptFunction: FunctionObject {
+    Q_MANAGED
     ScriptFunction(ExecutionContext *scope, Function *function);
 
     static ReturnedValue construct(Managed *, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct SimpleScriptFunction: FunctionObject {
+    Q_MANAGED
     SimpleScriptFunction(ExecutionContext *scope, Function *function);
 
     static ReturnedValue construct(Managed *, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct BoundFunction: FunctionObject {
+    Q_MANAGED
     FunctionObject *target;
     Value boundThis;
     QVector<Value> boundArgs;
@@ -234,7 +227,6 @@ struct BoundFunction: FunctionObject {
     static ReturnedValue construct(Managed *, CallData *d);
     static ReturnedValue call(Managed *that, CallData *dd);
 
-    static const ManagedVTable static_vtbl;
     static void destroy(Managed *);
     static void markObjects(Managed *that);
     static bool hasInstance(Managed *that, const Value &value);

src/qml/jsruntime/qv4globalobject_p.h

@@ -50,15 +50,13 @@ namespace QV4 {
 
 struct Q_QML_EXPORT EvalFunction : FunctionObject
 {
+    Q_MANAGED
     EvalFunction(ExecutionContext *scope);
 
     ReturnedValue evalCall(Value thisObject, Value *args, int argc, bool directCall);
 
     using Managed::construct;
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct GlobalFunctions

src/qml/jsruntime/qv4lookup.cpp

@@ -436,7 +436,7 @@ void Lookup::setterGeneric(Lookup *l, const Value &object, const Value &value)
 {
     Object *o = object.asObject();
     if (!o) {
-        o = __qmljs_convert_to_object(l->name->engine()->current, ValueRef::fromRawValue(&object));
+        o = __qmljs_convert_to_object(l->name->engine()->current, ValueRef::fromRawValue(&object))->getPointer();
         o->put(l->name, value);
         return;
     }

src/qml/jsruntime/qv4managed_p.h

@@ -61,10 +61,22 @@ inline int qYouForgotTheQ_MANAGED_Macro(T, T) { return 0; }
 template <typename T1, typename T2>
 inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
 
+template <typename T>
+struct Returned : private T
+{
+    static Returned<T> *create(T *t) { return static_cast<Returned<T> *>(t); }
+    T *getPointer() { return this; }
+    template<typename X>
+    static T *getPointer(Returned<X> *x) { return x->getPointer(); }
+};
+
 #define Q_MANAGED \
     public: \
         Q_MANAGED_CHECK \
-        static const QV4::ManagedVTable static_vtbl;
+        static const QV4::ManagedVTable static_vtbl; \
+        template <typename T> \
+        QV4::Returned<T> *asReturned() { return QV4::Returned<T>::create(this); } \
+
 
 struct GCDeletable
 {
@@ -162,6 +174,7 @@ const QV4::ManagedVTable classname::static_vtbl =    \
 
 struct Q_QML_EXPORT Managed
 {
+    Q_MANAGED
 private:
     void *operator new(size_t);
     Managed(const Managed &other);
@@ -319,9 +332,6 @@ public:
     };
 
 protected:
-
-    static const ManagedVTable static_vtbl;
-
     const ManagedVTable *vtbl;
 public:
     InternalClass *internalClass;

src/qml/jsruntime/qv4numberobject.cpp

@@ -59,7 +59,7 @@ NumberCtor::NumberCtor(ExecutionContext *scope)
 ReturnedValue NumberCtor::construct(Managed *m, CallData *callData)
 {
     double dbl = callData->argc ? callData->args[0].toNumber() : 0.;
-    return Value::fromObject(m->engine()->newNumberObject(Value::fromDouble(dbl))).asReturnedValue();
+    return Encode(m->engine()->newNumberObject(Value::fromDouble(dbl)));
 }
 
 ReturnedValue NumberCtor::call(Managed *, CallData *callData)

src/qml/jsruntime/qv4numberobject_p.h

@@ -51,13 +51,11 @@ namespace QV4 {
 
 struct NumberCtor: FunctionObject
 {
+    Q_MANAGED
     NumberCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *that, CallData *callData);
     static ReturnedValue call(Managed *, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct NumberPrototype: NumberObject

src/qml/jsruntime/qv4object_p.h

@@ -105,6 +105,7 @@ typedef Value (*PropertyEnumeratorFunction)(Object *object);
 typedef PropertyAttributes (*PropertyQueryFunction)(const Object *object, String *name);
 
 struct Q_QML_EXPORT Object: Managed {
+    Q_MANAGED
     uint memberDataAlloc;
     Property *memberData;
 
@@ -182,6 +183,9 @@ struct Q_QML_EXPORT Object: Managed {
     static Object *cast(const Value &v) {
         return v.asObject();
     }
+    static Value toValue(Object *o) {
+        return Value::fromObject(o);
+    }
 
     // Array handling
 
@@ -283,7 +287,8 @@ public:
     void ensureArrayAttributes();
 
     inline bool protoHasArray() {
-        Object *p = this;
+        Scope scope(engine());
+        Scoped<Object> p(scope, this);
 
         while ((p = p->prototype()))
             if (p->arrayDataLen)
@@ -313,7 +318,6 @@ public:
     using Managed::setLookup;
     using Managed::advanceIterator;
 protected:
-    static const ManagedVTable static_vtbl;
     static void destroy(Managed *that);
     static void markObjects(Managed *that);
     static ReturnedValue get(Managed *m, String *name, bool *hasProperty);

src/qml/jsruntime/qv4objectproto_p.h

@@ -51,13 +51,11 @@ namespace QV4 {
 
 struct ObjectCtor: FunctionObject
 {
+    Q_MANAGED
     ObjectCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *that, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct ObjectPrototype: Object

src/qml/jsruntime/qv4qobjectwrapper.cpp

@@ -559,7 +559,7 @@ ReturnedValue QObjectWrapper::wrap(ExecutionEngine *engine, QObject *object)
     } else {
         // If this object is tainted, we have to check to see if it is in our
         // tainted object list
-        Scoped<Object> alternateWrapper(scope, 0);
+        Scoped<Object> alternateWrapper(scope, (Object *)0);
         if (engine->m_multiplyWrappedQObjects && ddata->hasTaintedV8Object)
             alternateWrapper = Value::fromObject(engine->m_multiplyWrappedQObjects->value(object));
 

src/qml/jsruntime/qv4regexpobject_p.h

@@ -103,13 +103,11 @@ protected:
 
 struct RegExpCtor: FunctionObject
 {
+    Q_MANAGED
     RegExpCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct RegExpPrototype: RegExpObject

src/qml/jsruntime/qv4runtime.cpp

@@ -598,7 +598,7 @@ Bool __qmljs_to_boolean(const ValueRef value)
 }
 
 
-Object *__qmljs_convert_to_object(ExecutionContext *ctx, const ValueRef value)
+Returned<Object> *__qmljs_convert_to_object(ExecutionContext *ctx, const ValueRef value)
 {
     assert(!value->isObject());
     switch (value->type()) {
@@ -608,7 +608,7 @@ Object *__qmljs_convert_to_object(ExecutionContext *ctx, const ValueRef value)
     case Value::Boolean_Type:
         return ctx->engine->newBooleanObject(*value);
     case Value::String_Type:
-        return ctx->engine->newStringObject(*value);
+        return ctx->engine->newStringObject(*value)->asReturned<Object>();
         break;
     case Value::Object_Type:
         Q_UNREACHABLE();
@@ -658,9 +658,10 @@ void __qmljs_set_property(ExecutionContext *ctx, const ValueRef object, String *
 
 ReturnedValue __qmljs_get_element(ExecutionContext *ctx, const ValueRef object, const ValueRef index)
 {
+    Scope scope(ctx);
     uint idx = index->asArrayIndex();
 
-    Object *o = object->asObject();
+    Scoped<Object> o(scope, object);
     if (!o) {
         if (idx < UINT_MAX) {
             if (String *str = object->asString()) {
@@ -766,18 +767,19 @@ void __qmljs_set_activation_property(ExecutionContext *ctx, String *name, const
 
 ReturnedValue __qmljs_get_property(ExecutionContext *ctx, const ValueRef object, String *name)
 {
-    Value res;
-    Managed *m = object->asManaged();
-    if (m)
-        return m->get(name);
+    Scope scope(ctx);
+
+    Scoped<Object> o(scope, object);
+    if (o)
+        return o->get(name);
 
     if (object->isNullOrUndefined()) {
         QString message = QStringLiteral("Cannot read property '%1' of %2").arg(name->toQString()).arg(object->toQStringNoThrow());
         ctx->throwTypeError(message);
     }
 
-    m = __qmljs_convert_to_object(ctx, object);
-    return m->get(name);
+    o = __qmljs_convert_to_object(ctx, object);
+    return o->get(name);
 }
 
 ReturnedValue __qmljs_get_activation_property(ExecutionContext *ctx, String *name)
@@ -974,7 +976,7 @@ ReturnedValue __qmljs_call_activation_property(ExecutionContext *context, String
 ReturnedValue __qmljs_call_property(ExecutionContext *context, String *name, CallDataRef callData)
 {
     Scope scope(context);
-    Managed *baseObject = callData->thisObject.asManaged();
+    Scoped<Object> baseObject(scope, callData->thisObject);
     if (!baseObject) {
         if (callData->thisObject.isNullOrUndefined()) {
             QString message = QStringLiteral("Cannot call method '%1' of %2").arg(name->toQString()).arg(callData->thisObject.toQStringNoThrow());
@@ -982,7 +984,7 @@ ReturnedValue __qmljs_call_property(ExecutionContext *context, String *name, Cal
         }
 
         baseObject = __qmljs_convert_to_object(context, ValueRef(&callData->thisObject));
-        callData->thisObject = Value::fromObject(static_cast<Object *>(baseObject));
+        callData->thisObject = baseObject.asValue();
     }
 
     Scoped<FunctionObject> o(scope, baseObject->get(name));
@@ -1251,6 +1253,20 @@ QV4::ReturnedValue __qmljs_decrement(const QV4::ValueRef value)
     }
 }
 
+QV4::ReturnedValue __qmljs_to_string(const QV4::ValueRef value, QV4::ExecutionContext *ctx)
+{
+    if (value->isString())
+        return value.asReturnedValue();
+    return __qmljs_convert_to_string(ctx, value)->asReturnedValue();
+}
+
+QV4::ReturnedValue __qmljs_to_object(QV4::ExecutionContext *ctx, const QV4::ValueRef value)
+{
+    if (value->isObject())
+        return value.asReturnedValue();
+    return Encode(__qmljs_convert_to_object(ctx, value));
+}
+
 void __qmljs_value_to_double(double *result, const ValueRef value)
 {
     *result = value->toNumber();

src/qml/jsruntime/qv4runtime_p.h

@@ -172,7 +172,7 @@ QV4::ReturnedValue __qmljs_to_string(const ValueRef value, QV4::ExecutionContext
 Q_QML_EXPORT QV4::String *__qmljs_convert_to_string(QV4::ExecutionContext *ctx, const ValueRef value);
 void __qmljs_numberToString(QString *result, double num, int radix = 10);
 ReturnedValue __qmljs_to_object(QV4::ExecutionContext *ctx, const ValueRef value);
-QV4::Object *__qmljs_convert_to_object(QV4::ExecutionContext *ctx, const ValueRef value);
+Returned<Object> *__qmljs_convert_to_object(QV4::ExecutionContext *ctx, const ValueRef value);
 
 QV4::Bool __qmljs_equal_helper(const ValueRef x, const ValueRef y);
 Q_QML_EXPORT QV4::Bool __qmljs_strict_equal(const ValueRef x, const ValueRef y);
@@ -294,21 +294,6 @@ inline double __qmljs_to_number(const ValueRef value)
     return value->toNumber();
 }
 
-inline QV4::ReturnedValue __qmljs_to_string(const QV4::ValueRef value, QV4::ExecutionContext *ctx)
-{
-    if (value->isString())
-        return value.asReturnedValue();
-    return __qmljs_convert_to_string(ctx, value)->asReturnedValue();
-}
-
-inline QV4::ReturnedValue __qmljs_to_object(QV4::ExecutionContext *ctx, const QV4::ValueRef value)
-{
-    if (value->isObject())
-        return value.asReturnedValue();
-    return Value::fromObject(__qmljs_convert_to_object(ctx, value)).asReturnedValue();
-}
-
-
 inline QV4::ReturnedValue __qmljs_uplus(const QV4::ValueRef value)
 {
     TRACE1(value);

src/qml/jsruntime/qv4scopedvalue_p.h

@@ -138,6 +138,16 @@ struct ScopedValue
 #endif
     }
 
+    template<typename T>
+    ScopedValue(const Scope &scope, Returned<T> *t)
+    {
+        ptr = scope.engine->jsStackTop++;
+        ptr->val = T::toValue(t->getPointer());
+#ifndef QT_NO_DEBUG
+        ++scope.size;
+#endif
+    }
+
     ScopedValue &operator=(const Value &v) {
         *ptr = v;
         return *this;
@@ -148,6 +158,12 @@ struct ScopedValue
         return *this;
     }
 
+    template<typename T>
+    ScopedValue &operator=(const Returned<T> *t) {
+        ptr->val = T::toValue(t->getPointer());
+        return *this;
+    }
+
     ScopedValue &operator=(const ScopedValue &other) {
         *ptr = *other.ptr;
         return *this;
@@ -193,6 +209,27 @@ struct Scoped
 #endif
     }
 
+    Scoped(const Scope &scope, const ValueRef &v);
+
+    Scoped(const Scope &scope, T *t)
+    {
+        ptr = scope.engine->jsStackTop++;
+        *ptr = T::toValue(t);
+#ifndef QT_NO_DEBUG
+        ++scope.size;
+#endif
+    }
+    template<typename X>
+    Scoped(const Scope &scope, Returned<X> *x)
+    {
+        ptr = scope.engine->jsStackTop++;
+        T *t = Returned<T>::getPointer(x);
+        *ptr = T::toValue(t);
+#ifndef QT_NO_DEBUG
+        ++scope.size;
+#endif
+    }
+
     Scoped(const Scope &scope, const ReturnedValue &v)
     {
         ptr = scope.engine->jsStackTop++;
@@ -213,6 +250,8 @@ struct Scoped
         return *this;
     }
 
+    Scoped<T> &operator=(const ValueRef &v);
+
     Scoped<T> &operator=(const ReturnedValue &v) {
         if (T::cast(QV4::Value::fromReturnedValue(v)))
             ptr->val = v;
@@ -226,17 +265,32 @@ struct Scoped
         return *this;
     }
 
+    Scoped<T> &operator=(T *t) {
+        *ptr = T::toValue(t);
+        return *this;
+    }
+
+    template<typename X>
+    Scoped<T> &operator=(Returned<X> *x) {
+        *ptr = T::toValue(Returned<T>::getPointer(x));
+        return *this;
+    }
+
+
     T *operator->() {
         return static_cast<T *>(ptr->managed());
     }
 
-//    const Value *operator->() const {
-//        return T::cast(*ptr);
-//    }
+    const Value *operator->() const {
+        return T::cast(*ptr);
+    }
 
     bool operator!() const {
         return !ptr->managed();
     }
+    operator bool() const {
+        return ptr->managed();
+    }
 
     T *getPointer() {
         return static_cast<T *>(ptr->managed());
@@ -325,6 +379,29 @@ private:
     Value *ptr;
 };
 
+template<typename T>
+Scoped<T>::Scoped(const Scope &scope, const ValueRef &v)
+{
+    ptr = scope.engine->jsStackTop++;
+    if (T::cast(*v.operator ->()))
+        *ptr = *v.operator ->();
+    else
+        *ptr = QV4::Value::undefinedValue();
+#ifndef QT_NO_DEBUG
+    ++scope.size;
+#endif
+}
+
+template<typename T>
+Scoped<T> &Scoped<T>::operator=(const ValueRef &v)
+{
+    if (T::cast(*v.operator ->()))
+        *ptr = *v.operator ->();
+    else
+        *ptr = QV4::Value::undefinedValue();
+    return *this;
+}
+
 
 struct CallDataRef {
     CallDataRef(const ScopedCallData &c)
@@ -384,6 +461,14 @@ struct Encode : private Value {
             dbl = i;
         }
     }
+    Encode(ReturnedValue v) {
+        val = v;
+    }
+
+    template<typename T>
+    Encode(Returned<T> *t) {
+        val = T::toValue(t->getPointer()).val;
+    }
 
     operator ReturnedValue() const {
         return val;

src/qml/jsruntime/qv4string_p.h

@@ -52,6 +52,7 @@ struct ExecutionEngine;
 struct Identifier;
 
 struct Q_QML_EXPORT String : public Managed {
+    Q_MANAGED
     enum StringType {
         StringType_Unknown,
         StringType_Regular,
@@ -122,6 +123,9 @@ struct Q_QML_EXPORT String : public Managed {
     static String *cast(const Value &v) {
         return v.asString();
     }
+    static Value toValue(String *s) {
+        return Value::fromString(s);
+    }
 
     ReturnedValue asReturnedValue() { return Value::fromString(this).asReturnedValue(); }
 
@@ -141,8 +145,6 @@ protected:
     static bool deleteProperty(Managed *, String *);
     static bool deleteIndexedProperty(Managed *m, uint index);
     static bool isEqualTo(Managed *that, Managed *o);
-
-    static const ManagedVTable static_vtbl;
 };
 
 }

src/qml/jsruntime/qv4stringobject_p.h

@@ -68,13 +68,11 @@ protected:
 
 struct StringCtor: FunctionObject
 {
+    Q_MANAGED
     StringCtor(ExecutionContext *scope);
 
     static ReturnedValue construct(Managed *m, CallData *callData);
     static ReturnedValue call(Managed *that, CallData *callData);
-
-protected:
-    static const ManagedVTable static_vtbl;
 };
 
 struct StringPrototype: StringObject

src/qml/jsruntime/qv4value.cpp

@@ -312,7 +312,7 @@ Object *Value::toObject(ExecutionContext *ctx) const
 {
     if (isObject())
         return objectValue();
-    return __qmljs_convert_to_object(ctx, ValueRef::fromRawValue(this));
+    return __qmljs_convert_to_object(ctx, ValueRef::fromRawValue(this))->getPointer();
 }
 
 

src/qml/jsruntime/qv4value_p.h

@@ -59,8 +59,6 @@ QT_BEGIN_NAMESPACE
 
 namespace QV4 {
 
-QV4::Object *__qmljs_convert_to_object(QV4::ExecutionContext *ctx, const QV4::Value &value);
-
 inline Managed *Value::asManaged() const
 {
     if (isManaged())