Convert some methods to use Returned<>

Change-Id: I631606cb5ab3b35b72104e70092a5200dd235fbc
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

16 files changed, 135 insertions, 71 deletions

diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 1a1efc0b4c..56701457e4 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -363,6 +363,7 @@ void ExecutionContext::mark()
 
 void ExecutionContext::setProperty(String *name, const Value& value)
 {
+    Scope scope(this);
     for (ExecutionContext *ctx = this; ctx; ctx = ctx->outer) {
         if (ctx->type == Type_WithContext) {
             Object *w = static_cast<WithContext *>(ctx)->withObject;
@@ -398,8 +399,10 @@ void ExecutionContext::setProperty(String *name, const Value& value)
             }
         }
     }
-    if (strictMode || name->isEqualTo(engine->id_this))
-        throwReferenceError(Value::fromString(name));
+    if (strictMode || name->isEqualTo(engine->id_this)) {
+        Scoped<String> n(scope, name);
+        throwReferenceError(n);
+    }
     engine->globalObject->put(name, value);
 }
 
@@ -463,7 +466,8 @@ ReturnedValue ExecutionContext::getProperty(String *name)
                 return v.asReturnedValue();
         }
     }
-    throwReferenceError(Value::fromString(name));
+    Scoped<String> n(scope, name);
+    throwReferenceError(n);
     return Value::undefinedValue().asReturnedValue();
 }
 
@@ -595,75 +599,92 @@ ReturnedValue ExecutionContext::getPropertyAndBase(String *name, Object **base)
                 return v.asReturnedValue();
         }
     }
-    throwReferenceError(Value::fromString(name));
+    Scoped<String> n(scope, name);
+    throwReferenceError(n);
     return Value::undefinedValue().asReturnedValue();
 }
 
 
-void ExecutionContext::throwError(const Value &value)
+void ExecutionContext::throwError(const ValueRef value)
 {
-    Scope scope(this);
-    ScopedValue v(scope, value);
-    __qmljs_throw(this, v);
+    __qmljs_throw(this, value);
 }
 
 void ExecutionContext::throwError(const QString &message)
 {
-    Value v = Value::fromString(this, message);
-    throwError(Value::fromObject(engine->newErrorObject(v)));
+    Scope scope(this);
+    ScopedValue v(scope, Value::fromString(this, message));
+    v = engine->newErrorObject(v);
+    throwError(v);
 }
 
 void ExecutionContext::throwSyntaxError(const QString &message, const QString &fileName, int line, int column)
 {
-    Object *error = engine->newSyntaxErrorObject(message, fileName, line, column);
-    throwError(Value::fromObject(error));
+    Scope scope(this);
+    Scoped<Object> error(scope, engine->newSyntaxErrorObject(message, fileName, line, column));
+    throwError(error);
 }
 
 void ExecutionContext::throwSyntaxError(const QString &message)
 {
-    Object *error = engine->newSyntaxErrorObject(message);
-    throwError(Value::fromObject(error));
+    Scope scope(this);
+    Scoped<Object> error(scope, engine->newSyntaxErrorObject(message));
+    throwError(error);
 }
 
 void ExecutionContext::throwTypeError()
 {
-    throwError(Value::fromObject(engine->newTypeErrorObject(QStringLiteral("Type error"))));
+    Scope scope(this);
+    Scoped<Object> error(scope, engine->newTypeErrorObject(QStringLiteral("Type error")));
+    throwError(error);
 }
 
 void ExecutionContext::throwTypeError(const QString &message)
 {
-    throwError(Value::fromObject(engine->newTypeErrorObject(message)));
+    Scope scope(this);
+    Scoped<Object> error(scope, engine->newTypeErrorObject(message));
+    throwError(error);
 }
 
 void ExecutionContext::throwUnimplemented(const QString &message)
 {
-    Value v = Value::fromString(this, QStringLiteral("Unimplemented ") + message);
-    throwError(Value::fromObject(engine->newErrorObject(v)));
+    Scope scope(this);
+    ScopedValue v(scope, Value::fromString(this, QStringLiteral("Unimplemented ") + message));
+    v = engine->newErrorObject(v);
+    throwError(v);
 }
 
-void ExecutionContext::throwReferenceError(Value value)
+void ExecutionContext::throwReferenceError(const ValueRef value)
 {
-    String *s = value.toString(this);
+    Scope scope(this);
+    Scoped<String> s(scope, value->toString(this));
     QString msg = s->toQString() + QStringLiteral(" is not defined");
-    throwError(Value::fromObject(engine->newReferenceErrorObject(msg)));
+    Scoped<Object> error(scope, engine->newReferenceErrorObject(msg));
+    throwError(error);
 }
 
 void ExecutionContext::throwReferenceError(const QString &message, const QString &fileName, int line, int column)
 {
+    Scope scope(this);
     QString msg = message + QStringLiteral(" is not defined");
-    throwError(Value::fromObject(engine->newReferenceErrorObject(msg, fileName, line, column)));
+    Scoped<Object> error(scope, engine->newReferenceErrorObject(msg, fileName, line, column));
+    throwError(error);
 }
 
 void ExecutionContext::throwRangeError(Value value)
 {
-    String *s = value.toString(this);
+    Scope scope(this);
+    Scoped<String> s(scope, value.toString(this));
     QString msg = s->toQString() + QStringLiteral(" out of range");
-    throwError(Value::fromObject(engine->newRangeErrorObject(msg)));
+    Scoped<Object> error(scope, engine->newRangeErrorObject(msg));
+    throwError(error);
 }
 
 void ExecutionContext::throwURIError(Value msg)
 {
-    throwError(Value::fromObject(engine->newURIErrorObject(msg)));
+    Scope scope(this);
+    Scoped<Object> error(scope, engine->newURIErrorObject(msg));
+    throwError(error);
 }
 
 void SimpleCallContext::initSimpleCallContext(ExecutionEngine *engine)
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index 8ebffea981..0c3b189401 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -54,6 +54,7 @@ struct ExecutionEngine;
 struct DeclarativeEnvironment;
 struct Lookup;
 struct Function;
+struct ValueRef;
 
 namespace CompiledData {
 struct CompilationUnit;
@@ -129,13 +130,13 @@ struct Q_QML_EXPORT ExecutionContext
 
     void createMutableBinding(String *name, bool deletable);
 
-    void Q_NORETURN throwError(const Value &value);
+    void Q_NORETURN throwError(const QV4::ValueRef value);
     void Q_NORETURN throwError(const QString &message);
     void Q_NORETURN throwSyntaxError(const QString &message);
     void Q_NORETURN throwSyntaxError(const QString &message, const QString &fileName, int line, int column);
     void Q_NORETURN throwTypeError();
     void Q_NORETURN throwTypeError(const QString &message);
-    void Q_NORETURN throwReferenceError(Value value);
+    void Q_NORETURN throwReferenceError(const ValueRef value);
     void Q_NORETURN throwReferenceError(const QString &value, const QString &fileName, int line, int column);
     void Q_NORETURN throwRangeError(Value value);
     void Q_NORETURN throwURIError(Value msg);
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 875ab84cf5..0187099f62 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -375,10 +375,10 @@ String *ExecutionEngine::newIdentifier(const QString &text)
     return identifierTable->insertString(text);
 }
 
-Object *ExecutionEngine::newStringObject(const Value &value)
+Returned<Object> *ExecutionEngine::newStringObject(const Value &value)
 {
     StringObject *object = new (memoryManager) StringObject(this, value);
-    return object;
+    return object->asReturned<Object>();
 }
 
 Returned<Object> *ExecutionEngine::newNumberObject(const Value &value)
@@ -455,20 +455,22 @@ Returned<RegExpObject> *ExecutionEngine::newRegExpObject(const QRegExp &re)
     return object->asReturned<RegExpObject>();
 }
 
-Object *ExecutionEngine::newErrorObject(const Value &value)
+Returned<Object> *ExecutionEngine::newErrorObject(const Value &value)
 {
     ErrorObject *object = new (memoryManager) ErrorObject(errorClass, value);
-    return object;
+    return object->asReturned<Object>();
 }
 
-Object *ExecutionEngine::newSyntaxErrorObject(const QString &message)
+Returned<Object> *ExecutionEngine::newSyntaxErrorObject(const QString &message)
 {
-    return new (memoryManager) SyntaxErrorObject(this, Value::fromString(this, message));
+    Object *error = new (memoryManager) SyntaxErrorObject(this, Value::fromString(this, message));
+    return error->asReturned<Object>();
 }
 
-Object *ExecutionEngine::newSyntaxErrorObject(const QString &message, const QString &fileName, int line, int column)
+Returned<Object> *ExecutionEngine::newSyntaxErrorObject(const QString &message, const QString &fileName, int line, int column)
 {
-    return new (memoryManager) SyntaxErrorObject(this, message, fileName, line, column);
+    Object *error = new (memoryManager) SyntaxErrorObject(this, message, fileName, line, column);
+    return error->asReturned<Object>();
 }
 
 
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index a59a837499..5ef7d08a4a 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -270,7 +270,7 @@ struct Q_QML_EXPORT ExecutionEngine
     String *newString(const QString &s);
     String *newIdentifier(const QString &text);
 
-    Object *newStringObject(const Value &value);
+    Returned<Object> *newStringObject(const Value &value);
     Returned<Object> *newNumberObject(const Value &value);
     Returned<Object> *newBooleanObject(const Value &value);
 
@@ -285,9 +285,9 @@ struct Q_QML_EXPORT ExecutionEngine
     Returned<RegExpObject> *newRegExpObject(RegExp* re, bool global);
     Returned<RegExpObject> *newRegExpObject(const QRegExp &re);
 
-    Object *newErrorObject(const Value &value);
-    Object *newSyntaxErrorObject(const QString &message, const QString &fileName, int line, int column);
-    Object *newSyntaxErrorObject(const QString &message);
+    Returned<Object> *newErrorObject(const Value &value);
+    Returned<Object> *newSyntaxErrorObject(const QString &message, const QString &fileName, int line, int column);
+    Returned<Object> *newSyntaxErrorObject(const QString &message);
     Object *newReferenceErrorObject(const QString &message);
     Object *newReferenceErrorObject(const QString &message, const QString &fileName, int lineNumber, int columnNumber);
     Object *newTypeErrorObject(const QString &message);
diff --git a/src/qml/jsruntime/qv4errorobject.cpp b/src/qml/jsruntime/qv4errorobject.cpp
index 7c75d1162a..987d5083fa 100644
--- a/src/qml/jsruntime/qv4errorobject.cpp
+++ b/src/qml/jsruntime/qv4errorobject.cpp
@@ -242,7 +242,7 @@ ErrorCtor::ErrorCtor(ExecutionContext *scope, String *name)
 
 ReturnedValue ErrorCtor::construct(Managed *m, CallData *callData)
 {
-    return Value::fromObject(m->engine()->newErrorObject(callData->argc ? callData->args[0] : Value::undefinedValue())).asReturnedValue();
+    return Encode(m->engine()->newErrorObject(callData->argc ? callData->args[0] : Value::undefinedValue()));
 }
 
 ReturnedValue ErrorCtor::call(Managed *that, CallData *callData)
diff --git a/src/qml/jsruntime/qv4lookup.cpp b/src/qml/jsruntime/qv4lookup.cpp
index a4116b049e..a844a25008 100644
--- a/src/qml/jsruntime/qv4lookup.cpp
+++ b/src/qml/jsruntime/qv4lookup.cpp
@@ -334,7 +334,9 @@ ReturnedValue Lookup::globalGetterGeneric(Lookup *l, ExecutionContext *ctx)
             return o->getValue(p, attrs);
         }
     }
-    ctx->throwReferenceError(Value::fromString(l->name));
+    Scope scope(ctx);
+    Scoped<String> n(scope, l->name);
+    ctx->throwReferenceError(n);
 }
 
 ReturnedValue Lookup::globalGetter0(Lookup *l, ExecutionContext *ctx)
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 7af8b21cc5..d98087b6a4 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -607,7 +607,7 @@ Returned<Object> *__qmljs_convert_to_object(ExecutionContext *ctx, const ValueRe
     case Value::Boolean_Type:
         return ctx->engine->newBooleanObject(*value);
     case Value::String_Type:
-        return ctx->engine->newStringObject(*value)->asReturned<Object>();
+        return ctx->engine->newStringObject(*value);
         break;
     case Value::Object_Type:
         Q_UNREACHABLE();
diff --git a/src/qml/jsruntime/qv4scopedvalue_p.h b/src/qml/jsruntime/qv4scopedvalue_p.h
index eed49bfe1f..4bbd3303ee 100644
--- a/src/qml/jsruntime/qv4scopedvalue_p.h
+++ b/src/qml/jsruntime/qv4scopedvalue_p.h
@@ -142,7 +142,7 @@ struct ScopedValue
     ScopedValue(const Scope &scope, Returned<T> *t)
     {
         ptr = scope.engine->jsStackTop++;
-        ptr->val = T::toValue(t->getPointer());
+        *ptr = T::toValue(t->getPointer());
 #ifndef QT_NO_DEBUG
         ++scope.size;
 #endif
@@ -159,8 +159,8 @@ struct ScopedValue
     }
 
     template<typename T>
-    ScopedValue &operator=(const Returned<T> *t) {
-        ptr->val = T::toValue(t->getPointer());
+    ScopedValue &operator=(Returned<T> *t) {
+        *ptr = T::toValue(t->getPointer());
         return *this;
     }
 
@@ -331,6 +331,9 @@ struct ScopedCallData {
 struct ValueRef {
     ValueRef(const ScopedValue &v)
         : ptr(v.ptr) {}
+    template <typename T>
+    ValueRef(const Scoped<T> &v)
+        : ptr(v.ptr) {}
     ValueRef(const PersistentValue &v)
         : ptr(&v.d->value) {}
     ValueRef(PersistentValuePrivate *p)
diff --git a/src/qml/jsruntime/qv4script.cpp b/src/qml/jsruntime/qv4script.cpp
index e3c9505ab7..1834e28be6 100644
--- a/src/qml/jsruntime/qv4script.cpp
+++ b/src/qml/jsruntime/qv4script.cpp
@@ -153,6 +153,7 @@ void Script::parse()
     parsed = true;
 
     ExecutionEngine *v4 = scope->engine;
+    Scope valueScope(v4);
 
     MemoryManager::GCBlocker gcBlocker(v4->memoryManager);
 
@@ -199,9 +200,11 @@ void Script::parse()
         compilationUnitHolder = Value::fromObject(new (v4->memoryManager) CompilationUnitHolder(v4, compilationUnit));
     }
 
-    if (!vmFunction)
+    if (!vmFunction) {
         // ### FIX file/line number
-        v4->current->throwError(QV4::Value::fromObject(v4->newSyntaxErrorObject("Syntax error")));
+        Scoped<Object> error(valueScope, v4->newSyntaxErrorObject("Syntax error"));
+        v4->current->throwError(error);
+    }
 }
 
 ReturnedValue Script::run()
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index 2b2eda7c8c..d0f3a196b7 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -173,15 +173,17 @@ ReturnedValue String::getIndexed(Managed *m, uint index, bool *hasProperty)
 
 void String::put(Managed *m, String *name, const Value &value)
 {
+    Scope scope(m->engine());
     String *that = static_cast<String *>(m);
-    Object *o = that->engine()->newStringObject(Value::fromString(that));
+    Scoped<Object> o(scope, that->engine()->newStringObject(Value::fromString(that)));
     o->put(name, value);
 }
 
 void String::putIndexed(Managed *m, uint index, const Value &value)
 {
+    Scope scope(m->engine());
     String *that = static_cast<String *>(m);
-    Object *o = m->engine()->newStringObject(Value::fromString(that));
+    Scoped<Object> o(scope, that->engine()->newStringObject(Value::fromString(that)));
     o->putIndexed(index, value);
 }
 
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index dfdb639d1e..2223432ec9 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -167,7 +167,7 @@ ReturnedValue StringCtor::construct(Managed *m, CallData *callData)
         value = Value::fromString(callData->args[0].toString(m->engine()->current));
     else
         value = Value::fromString(m->engine()->current, QString());
-    return Value::fromObject(m->engine()->newStringObject(value)).asReturnedValue();
+    return Encode(m->engine()->newStringObject(value));
 }
 
 ReturnedValue StringCtor::call(Managed *m, CallData *callData)
diff --git a/src/qml/qml/qqmlcontextwrapper.cpp b/src/qml/qml/qqmlcontextwrapper.cpp
index 50d1f32c10..153743aa58 100644
--- a/src/qml/qml/qqmlcontextwrapper.cpp
+++ b/src/qml/qml/qqmlcontextwrapper.cpp
@@ -274,8 +274,9 @@ ReturnedValue QmlContextWrapper::get(Managed *m, String *name, bool *hasProperty
 
 void QmlContextWrapper::put(Managed *m, String *name, const Value &value)
 {
-    QmlContextWrapper *wrapper = m->as<QmlContextWrapper>();
     ExecutionEngine *v4 = m->engine();
+    QV4::Scope scope(v4);
+    QV4::Scoped<QmlContextWrapper> wrapper(scope, m->as<QmlContextWrapper>());
     if (!wrapper)
         v4->current->throwTypeError();
 
@@ -283,7 +284,8 @@ void QmlContextWrapper::put(Managed *m, String *name, const Value &value)
         if (wrapper && wrapper->readOnly) {
             QString error = QLatin1String("Invalid write to global property \"") + name->toQString() +
                             QLatin1Char('"');
-            v4->current->throwError(Value::fromString(v4->current->engine->newString(error)));
+            Scoped<String> e(scope, v4->current->engine->newString(error));
+            v4->current->throwError(e);
         }
 
         Object::put(m, name, value);
diff --git a/src/qml/qml/qqmlvaluetypewrapper.cpp b/src/qml/qml/qqmlvaluetypewrapper.cpp
index 88704d58b3..f89ce15a57 100644
--- a/src/qml/qml/qqmlvaluetypewrapper.cpp
+++ b/src/qml/qml/qqmlvaluetypewrapper.cpp
@@ -327,14 +327,15 @@ ReturnedValue QmlValueTypeWrapper::get(Managed *m, String *name, bool *hasProper
 
 void QmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
 {
-    QmlValueTypeWrapper *r = m->as<QmlValueTypeWrapper>();
     ExecutionEngine *v4 = m->engine();
+    Scope scope(v4);
+    Scoped<QmlValueTypeWrapper> r(scope, m->as<QmlValueTypeWrapper>());
     if (!r)
         v4->current->throwTypeError();
 
     QByteArray propName = name->toQString().toUtf8();
     if (r->objectType == QmlValueTypeWrapper::Reference) {
-        QmlValueTypeReference *reference = static_cast<QmlValueTypeReference *>(r);
+        QmlValueTypeReference *reference = static_cast<QmlValueTypeReference *>(r.getPointer());
         QMetaProperty writebackProperty = reference->object->metaObject()->property(reference->property);
 
         if (!reference->object || !writebackProperty.isWritable() || !readReferenceValue(reference))
@@ -353,7 +354,8 @@ void QmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
             if (!f->bindingKeyFlag) {
                 // assigning a JS function to a non-var-property is not allowed.
                 QString error = QLatin1String("Cannot assign JavaScript function to value-type property");
-                v4->current->throwError(r->v8->toString(error));
+                Scoped<String> e(scope, r->v8->toString(error));
+                v4->current->throwError(e);
             }
 
             QQmlContextData *context = r->v8->callingContext();
@@ -400,7 +402,7 @@ void QmlValueTypeWrapper::put(Managed *m, String *name, const Value &value)
     } else {
         Q_ASSERT(r->objectType == QmlValueTypeWrapper::Copy);
 
-        QmlValueTypeCopy *copy = static_cast<QmlValueTypeCopy *>(r);
+        QmlValueTypeCopy *copy = static_cast<QmlValueTypeCopy *>(r.getPointer());
 
         int index = r->type->metaObject()->indexOfProperty(propName.constData());
         if (index == -1)
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index b7447aee07..dc98bd176e 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -70,8 +70,10 @@ using namespace QV4;
 
 #ifndef QT_NO_XMLSTREAMREADER
 
-#define V4THROW_REFERENCE(string) \
-    ctx->throwError(Value::fromObject(ctx->engine->newReferenceErrorObject(QStringLiteral(string))))
+#define V4THROW_REFERENCE(string) { \
+        Scoped<Object> error(scope, ctx->engine->newReferenceErrorObject(QStringLiteral(string))); \
+        ctx->throwError(error); \
+    }
 
 QT_BEGIN_NAMESPACE
 
@@ -1658,6 +1660,7 @@ void QQmlXMLHttpRequestCtor::setupProto()
 // XMLHttpRequest methods
 ReturnedValue QQmlXMLHttpRequestCtor::method_open(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1706,6 +1709,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_open(SimpleCallContext *ctx)
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_setRequestHeader(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1752,6 +1757,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_setRequestHeader(SimpleCallContext
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_send(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1772,6 +1779,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_send(SimpleCallContext *ctx)
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_abort(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1782,6 +1791,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_abort(SimpleCallContext *ctx)
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_getResponseHeader(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1802,6 +1813,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_getResponseHeader(SimpleCallContext
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_getAllResponseHeaders(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1823,6 +1836,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_getAllResponseHeaders(SimpleCallCon
 // XMLHttpRequest properties
 ReturnedValue QQmlXMLHttpRequestCtor::method_get_readyState(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1833,6 +1848,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_get_readyState(SimpleCallContext *c
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_get_status(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1850,6 +1867,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_get_status(SimpleCallContext *ctx)
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_get_statusText(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1869,6 +1888,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_get_statusText(SimpleCallContext *c
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_get_responseText(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
@@ -1885,6 +1906,8 @@ ReturnedValue QQmlXMLHttpRequestCtor::method_get_responseText(SimpleCallContext
 
 ReturnedValue QQmlXMLHttpRequestCtor::method_get_responseXML(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
+
     QQmlXMLHttpRequestWrapper *w = ctx->thisObject.as<QQmlXMLHttpRequestWrapper>();
     if (!w)
         V4THROW_REFERENCE("Not an XMLHttpRequest object");
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index 2a75bf9834..6389ad2715 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -949,29 +949,30 @@ See \l {Dynamic QML Object Creation from JavaScript} for more information on usi
 */
 ReturnedValue QtObject::method_createQmlObject(SimpleCallContext *ctx)
 {
+    Scope scope(ctx);
     if (ctx->argumentCount < 2 || ctx->argumentCount > 3)
         V4THROW_ERROR("Qt.createQmlObject(): Invalid arguments");
 
     struct Error {
-        static Value create(QV8Engine *engine, const QList<QQmlError> &errors) {
+        static ReturnedValue create(QV4::ExecutionEngine *v4, const QList<QQmlError> &errors) {
+            Scope scope(v4);
             QString errorstr = QLatin1String("Qt.createQmlObject(): failed to create object: ");
 
-            QV4::ExecutionEngine *v4 = QV8Engine::getV4(engine);
-            QV4::ArrayObject *qmlerrors = v4->newArrayObject();
+            QV4::Scoped<ArrayObject> qmlerrors(scope, v4->newArrayObject());
             for (int ii = 0; ii < errors.count(); ++ii) {
                 const QQmlError &error = errors.at(ii);
                 errorstr += QLatin1String("\n    ") + error.toString();
                 QV4::Object *qmlerror = v4->newObject();
                 qmlerror->put(v4->newString("lineNumber"), QV4::Value::fromInt32(error.line()));
                 qmlerror->put(v4->newString("columnNumber"), QV4::Value::fromInt32(error.column()));
-                qmlerror->put(v4->newString("fileName"), engine->toString(error.url().toString()));
-                qmlerror->put(v4->newString("message"), engine->toString(error.description()));
+                qmlerror->put(v4->newString("fileName"), Value::fromString(v4->newString(error.url().toString())));
+                qmlerror->put(v4->newString("message"), Value::fromString(v4->newString(error.description())));
                 qmlerrors->putIndexed(ii, QV4::Value::fromObject(qmlerror));
             }
 
-            QV4::Object *errorObject = v4->newErrorObject(engine->toString(errorstr));
-            errorObject->put(v4->newString("qmlErrors"), Value::fromObject(qmlerrors));
-            return Value::fromObject(errorObject);
+            Scoped<Object> errorObject(scope, v4->newErrorObject(Value::fromString(v4->newString(errorstr))));
+            errorObject->put(v4->newString("qmlErrors"), qmlerrors.asValue());
+            return errorObject.asReturnedValue();
         }
     };
 
@@ -1009,7 +1010,8 @@ ReturnedValue QtObject::method_createQmlObject(SimpleCallContext *ctx)
     component.setData(qml.toUtf8(), url);
 
     if (component.isError()) {
-        ctx->throwError(Error::create(v8engine, component.errors()));
+        ScopedValue v(scope, Error::create(ctx->engine, component.errors()));
+        ctx->throwError(v);
         return QV4::Encode::undefined();
     }
 
@@ -1033,7 +1035,8 @@ ReturnedValue QtObject::method_createQmlObject(SimpleCallContext *ctx)
     component.completeCreate();
 
     if (component.isError()) {
-        ctx->throwError(Error::create(v8engine, component.errors()));
+        ScopedValue v(scope, Error::create(ctx->engine, component.errors()));
+        ctx->throwError(v);
         return QV4::Encode::undefined();
     }
 
diff --git a/src/qml/qml/v8/qv4domerrors_p.h b/src/qml/qml/v8/qv4domerrors_p.h
index ed38886e15..ce6fb9edea 100644
--- a/src/qml/qml/v8/qv4domerrors_p.h
+++ b/src/qml/qml/v8/qv4domerrors_p.h
@@ -77,10 +77,10 @@ QT_BEGIN_NAMESPACE
 #define DOMEXCEPTION_TYPE_MISMATCH_ERR 17
 
 #define V4THROW_DOM(error, string) { \
-    QV4::Value v = QV4::Value::fromString(ctx, QStringLiteral(string)); \
-    QV4::Object *ex = ctx->engine->newErrorObject(v); \
+    QV4::ScopedValue v(scope, QV4::Value::fromString(ctx, QStringLiteral(string))); \
+    QV4::Scoped<Object> ex(scope, ctx->engine->newErrorObject(v)); \
     ex->put(ctx->engine->newIdentifier(QStringLiteral("code")), QV4::Value::fromInt32(error)); \
-    ctx->throwError(QV4::Value::fromObject(ex)); \
+    ctx->throwError(ex); \
 }
 
 namespace QV4 {