Make all write operations to Pointer<> types go through a set() method

The new set() method also taked an ExecutionEngine pointer. This makes
it trivial to now add a write barrier for those operations.

Change-Id: I321eccfe6fb279cc240b5c84910e6854f71759f6
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

19 files changed, 63 insertions, 58 deletions

diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 33cda59b72..bc832c3349 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -48,12 +48,13 @@ DEFINE_OBJECT_VTABLE(ArgumentsObject);
 
 void Heap::ArgumentsObject::init(QV4::CallContext *context)
 {
+    ExecutionEngine *v4 = context->d()->engine;
+
     Object::init();
     fullyCreated = false;
-    this->context = context->d();
+    this->context.set(v4, context->d());
     Q_ASSERT(vtable() == QV4::ArgumentsObject::staticVTable());
 
-    ExecutionEngine *v4 = context->d()->engine;
     Scope scope(v4);
     Scoped<QV4::ArgumentsObject> args(scope, this);
 
@@ -89,7 +90,7 @@ void ArgumentsObject::fullyCreate()
     Scope scope(engine());
     Scoped<MemberData> md(scope, d()->mappedArguments);
     if (numAccessors) {
-        d()->mappedArguments = md->allocate(engine(), numAccessors);
+        d()->mappedArguments.set(scope.engine, md->allocate(engine(), numAccessors));
         for (uint i = 0; i < numAccessors; ++i) {
             d()->mappedArguments->values[i] = context()->callData->args[i];
             arraySet(i, context()->engine->argumentsAccessors + i, Attr_Accessor);
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index ec11422c15..3918d25326 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -72,7 +72,7 @@ Heap::CallContext *ExecutionContext::newCallContext(Function *function, CallData
     c->v4Function = function;
 
     c->strictMode = function->isStrict();
-    c->outer = this->d();
+    c->outer.set(d()->engine, this->d());
 
     c->compilationUnit = function->compilationUnit;
     c->lookups = c->compilationUnit->runtimeLookups;
@@ -119,7 +119,7 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
             Heap::SimpleCallContext *c = static_cast<Heap::SimpleCallContext *>(ctx->d());
             if (!activation) {
                 if (!c->activation)
-                    c->activation = scope.engine->newObject();
+                    c->activation.set(scope.engine, scope.engine->newObject());
                 activation = c->activation;
             }
             break;
@@ -153,21 +153,21 @@ void ExecutionContext::createMutableBinding(String *name, bool deletable)
 void Heap::GlobalContext::init(ExecutionEngine *eng)
 {
     Heap::ExecutionContext::init(eng, Heap::ExecutionContext::Type_GlobalContext);
-    global = eng->globalObject->d();
+    global.set(eng, eng->globalObject->d());
 }
 
 void Heap::CatchContext::init(ExecutionContext *outerContext, String *exceptionVarName,
                               const Value &exceptionValue)
 {
     Heap::ExecutionContext::init(outerContext->engine, Heap::ExecutionContext::Type_CatchContext);
-    outer = outerContext;
+    outer.set(engine, outerContext);
     strictMode = outer->strictMode;
     callData = outer->callData;
     lookups = outer->lookups;
     constantTable = outer->constantTable;
     compilationUnit = outer->compilationUnit;
 
-    this->exceptionVarName = exceptionVarName;
+    this->exceptionVarName.set(engine, exceptionVarName);
     this->exceptionValue = exceptionValue;
 }
 
@@ -252,7 +252,7 @@ void ExecutionContext::call(Scope &scope, CallData *callData, Function *function
 
     Scoped<CallContext> ctx(scope, newCallContext(function, callData));
     if (f)
-        ctx->d()->function = f->d();
+        ctx->d()->function.set(scope.engine, f->d());
     scope.engine->pushContext(ctx);
 
     scope.result = Q_V4_PROFILE(scope.engine, function);
@@ -276,7 +276,7 @@ void QV4::ExecutionContext::simpleCall(Scope &scope, CallData *callData, Functio
     ctx->compilationUnit = function->compilationUnit;
     ctx->lookups = function->compilationUnit->runtimeLookups;
     ctx->constantTable = function->compilationUnit->constants;
-    ctx->outer = this->d();
+    ctx->outer.set(scope.engine, this->d());
     for (int i = callData->argc; i < (int)function->nFormals; ++i)
         callData->args[i] = Encode::undefined();
 
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index f544821729..a405da0f57 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -189,13 +189,13 @@ DECLARE_HEAP_OBJECT(WithContext, ExecutionContext) {
     void init(ExecutionContext *outerContext, Object *with)
     {
         Heap::ExecutionContext::init(outerContext->engine, Heap::ExecutionContext::Type_WithContext);
-        outer = outerContext;
+        outer.set(engine, outerContext);
         callData = outer->callData;
         lookups = outer->lookups;
         constantTable = outer->constantTable;
         compilationUnit = outer->compilationUnit;
 
-        withObject = with;
+        withObject.set(engine, with);
     }
 };
 V4_ASSERT_IS_TRIVIAL(WithContext)
diff --git a/src/qml/jsruntime/qv4dataview.cpp b/src/qml/jsruntime/qv4dataview.cpp
index aa7d01d16c..f1405e08ee 100644
--- a/src/qml/jsruntime/qv4dataview.cpp
+++ b/src/qml/jsruntime/qv4dataview.cpp
@@ -73,7 +73,7 @@ void DataViewCtor::construct(const Managed *, Scope &scope, CallData *callData)
     }
 
     Scoped<DataView> a(scope, scope.engine->memoryManager->allocObject<DataView>());
-    a->d()->buffer = buffer->d();
+    a->d()->buffer.set(scope.engine, buffer->d());
     a->d()->byteLength = byteLength;
     a->d()->byteOffset = byteOffset;
     scope.result = a.asReturnedValue();
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index bc618e3e7a..f38580e5f8 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -398,7 +398,7 @@ ExecutionEngine::ExecutionEngine(EvalISelFactory *factory)
     //
     // set up the global object
     //
-    rootContext()->d()->global = globalObject->d();
+    rootContext()->d()->global.set(scope.engine, globalObject->d());
     rootContext()->d()->callData->thisObject = globalObject;
     Q_ASSERT(globalObject->d()->vtable());
 
@@ -605,7 +605,7 @@ Heap::ArrayObject *ExecutionEngine::newArrayObject(const Value *values, int leng
         d->values.alloc = length;
         d->values.size = length;
         memcpy(&d->values.v, values, length*sizeof(Value));
-        a->d()->arrayData = d;
+        a->d()->arrayData.set(this, d);
         a->setArrayLengthUnchecked(length);
     }
     return a->d();
diff --git a/src/qml/jsruntime/qv4errorobject.cpp b/src/qml/jsruntime/qv4errorobject.cpp
index 798a14086d..daa4f2d9a6 100644
--- a/src/qml/jsruntime/qv4errorobject.cpp
+++ b/src/qml/jsruntime/qv4errorobject.cpp
@@ -168,7 +168,7 @@ void ErrorObject::method_get_stack(const BuiltinFunction *, Scope &scope, CallDa
             if (frame.line >= 0)
                 trace += QLatin1Char(':') + QString::number(frame.line);
         }
-        This->d()->stack = scope.engine->newString(trace);
+        This->d()->stack.set(scope.engine, scope.engine->newString(trace));
     }
     scope.result = This->d()->stack;
 }
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index 9afea01141..a2433e7471 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -75,7 +75,7 @@ void Heap::FunctionObject::init(QV4::ExecutionContext *scope, QV4::String *name,
 {
     Object::init();
     function = nullptr;
-    this->scope = scope->d();
+    this->scope.set(scope->engine(), scope->d());
     Scope s(scope->engine());
     ScopedFunctionObject f(s, this);
     f->init(name, createProto);
@@ -86,7 +86,7 @@ void Heap::FunctionObject::init(QV4::ExecutionContext *scope, Function *function
     Object::init();
     this->function = function;
     function->compilationUnit->addref();
-    this->scope = scope->d();
+    this->scope.set(scope->engine(), scope->d());
     Scope s(scope->engine());
     ScopedString name(s, function->name());
     ScopedFunctionObject f(s, this);
@@ -104,7 +104,7 @@ void Heap::FunctionObject::init()
 {
     Object::init();
     function = nullptr;
-    this->scope = internalClass->engine->rootContext()->d();
+    this->scope.set(internalClass->engine, internalClass->engine->rootContext()->d());
     Q_ASSERT(internalClass && internalClass->find(internalClass->engine->id_prototype()) == Index_Prototype);
     *propertyData(Index_Prototype) = Encode::undefined();
 }
@@ -413,7 +413,7 @@ void ScriptFunction::call(const Managed *that, Scope &scope, CallData *callData)
 void Heap::ScriptFunction::init(QV4::ExecutionContext *scope, Function *function)
 {
     FunctionObject::init();
-    this->scope = scope->d();
+    this->scope.set(scope->engine(), scope->d());
 
     this->function = function;
     function->compilationUnit->addref();
@@ -536,12 +536,12 @@ DEFINE_OBJECT_VTABLE(BoundFunction);
 void Heap::BoundFunction::init(QV4::ExecutionContext *scope, QV4::FunctionObject *target,
                                const Value &boundThis, QV4::MemberData *boundArgs)
 {
+    Scope s(scope);
     Heap::FunctionObject::init(scope, QStringLiteral("__bound function__"));
-    this->target = target->d();
-    this->boundArgs = boundArgs ? boundArgs->d() : 0;
+    this->target.set(s.engine, target->d());
+    this->boundArgs.set(s.engine, boundArgs ? boundArgs->d() : 0);
     this->boundThis = boundThis;
 
-    Scope s(scope);
     ScopedObject f(s, this);
 
     ScopedValue l(s, target->get(s.engine->id_length()));
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index cb7ce03c5c..006615e580 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -63,7 +63,7 @@ void Object::setInternalClass(InternalClass *ic)
     d()->internalClass = ic;
     bool hasMD = d()->memberData != nullptr;
     if ((!hasMD && ic->size) || (hasMD && d()->memberData->values.size < ic->size))
-        d()->memberData = MemberData::allocate(ic->engine, ic->size, d()->memberData);
+        d()->memberData.set(engine(), MemberData::allocate(ic->engine, ic->size, d()->memberData));
 }
 
 void Object::getProperty(uint index, Property *p, PropertyAttributes *attrs) const
@@ -89,7 +89,7 @@ bool Object::setPrototype(Object *proto)
             return false;
         pp = pp->prototype;
     }
-    d()->prototype = proto ? proto->d() : 0;
+    d()->prototype.set(engine(), proto ? proto->d() : 0);
     return true;
 }
 
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 63b132c2e6..df987c88f9 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -198,7 +198,7 @@ struct Q_QML_EXPORT Object: Managed {
     Value *propertyData(uint index) { return d()->propertyData(index); }
 
     Heap::ArrayData *arrayData() const { return d()->arrayData; }
-    void setArrayData(ArrayData *a) { d()->arrayData = a->d(); }
+    void setArrayData(ArrayData *a) { d()->arrayData.set(engine(), a->d()); }
 
     void getProperty(uint index, Property *p, PropertyAttributes *attrs) const;
     void setProperty(uint index, const Property *p);
diff --git a/src/qml/jsruntime/qv4qmlcontext.cpp b/src/qml/jsruntime/qv4qmlcontext.cpp
index cdc29c8b9c..56ecc9f682 100644
--- a/src/qml/jsruntime/qv4qmlcontext.cpp
+++ b/src/qml/jsruntime/qv4qmlcontext.cpp
@@ -298,14 +298,14 @@ bool QmlContextWrapper::put(Managed *m, String *name, const Value &value)
 void Heap::QmlContext::init(QV4::ExecutionContext *outerContext, QV4::QmlContextWrapper *qml)
 {
     Heap::ExecutionContext::init(outerContext->engine(), Heap::ExecutionContext::Type_QmlContext);
-    outer = outerContext->d();
+    outer.set(engine, outerContext->d());
     strictMode = false;
     callData = outer->callData;
     lookups = outer->lookups;
     constantTable = outer->constantTable;
     compilationUnit = outer->compilationUnit;
 
-    this->qml = qml->d();
+    this->qml.set(engine, qml->d());
 }
 
 Heap::QmlContext *QmlContext::createWorkerContext(ExecutionContext *parent, const QUrl &source, Value *sendFunction)
diff --git a/src/qml/jsruntime/qv4qobjectwrapper.cpp b/src/qml/jsruntime/qv4qobjectwrapper.cpp
index deea893632..4f6c179026 100644
--- a/src/qml/jsruntime/qv4qobjectwrapper.cpp
+++ b/src/qml/jsruntime/qv4qobjectwrapper.cpp
@@ -1704,7 +1704,7 @@ ReturnedValue QObjectMethod::create(ExecutionContext *scope, const QQmlValueType
     Scoped<QObjectMethod> method(valueScope, valueScope.engine->memoryManager->allocObject<QObjectMethod>(scope));
     method->d()->setPropertyCache(valueType->d()->propertyCache());
     method->d()->index = index;
-    method->d()->valueTypeWrapper = valueType->d();
+    method->d()->valueTypeWrapper.set(valueScope.engine, valueType->d());
     return method.asReturnedValue();
 }
 
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index ca893839ef..3ec24edb5d 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -74,7 +74,7 @@ void Heap::RegExpObject::init()
     Object::init();
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
-    o->d()->value = QV4::RegExp::create(scope.engine, QString(), false, false);
+    o->d()->value.set(scope.engine, QV4::RegExp::create(scope.engine, QString(), false, false));
     o->d()->global = false;
     o->initProperties();
 }
@@ -82,9 +82,9 @@ void Heap::RegExpObject::init()
 void Heap::RegExpObject::init(QV4::RegExp *value, bool global)
 {
     Object::init();
-    this->global = global;
-    this->value = value->d();
     Scope scope(internalClass->engine);
+    this->global = global;
+    this->value.set(scope.engine, value->d());
     Scoped<QV4::RegExpObject> o(scope, this);
     o->initProperties();
 }
@@ -137,7 +137,8 @@ void Heap::RegExpObject::init(const QRegExp &re)
     Scope scope(internalClass->engine);
     Scoped<QV4::RegExpObject> o(scope, this);
 
-    o->d()->value = QV4::RegExp::create(scope.engine, pattern, re.caseSensitivity() == Qt::CaseInsensitive, false);
+    o->d()->value.set(scope.engine,
+                        QV4::RegExp::create(scope.engine, pattern, re.caseSensitivity() == Qt::CaseInsensitive, false));
 
     o->initProperties();
 }
@@ -220,7 +221,7 @@ void Heap::RegExpCtor::init(QV4::ExecutionContext *scope)
 void Heap::RegExpCtor::clearLastMatch()
 {
     lastMatch = Primitive::nullValue();
-    lastInput = internalClass->engine->id_empty()->d();
+    lastInput.set(internalClass->engine, internalClass->engine->id_empty()->d());
     lastMatchStart = 0;
     lastMatchEnd = 0;
 }
@@ -377,7 +378,7 @@ void RegExpPrototype::method_exec(const BuiltinFunction *, Scope &scope, CallDat
 
     RegExpCtor::Data *dd = regExpCtor->d();
     dd->lastMatch = array;
-    dd->lastInput = str->d();
+    dd->lastInput.set(scope.engine, str->d());
     dd->lastMatchStart = matchOffsets[0];
     dd->lastMatchEnd = matchOffsets[1];
 
@@ -414,7 +415,7 @@ void RegExpPrototype::method_compile(const BuiltinFunction *, Scope &scope, Call
     scope.engine->regExpCtor()->as<FunctionObject>()->construct(scope, cData);
     Scoped<RegExpObject> re(scope, scope.result.asReturnedValue());
 
-    r->d()->value = re->value();
+    r->d()->value.set(scope.engine, re->value());
     r->d()->global = re->global();
     RETURN_UNDEFINED();
 }
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index c6cc5a4639..628c220bae 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -77,14 +77,14 @@ void Heap::StringObject::init()
 {
     Object::init();
     Q_ASSERT(vtable() == QV4::StringObject::staticVTable());
-    string = internalClass->engine->id_empty()->d();
+    string.set(internalClass->engine, internalClass->engine->id_empty()->d());
     *propertyData(LengthPropertyIndex) = Primitive::fromInt32(0);
 }
 
 void Heap::StringObject::init(const QV4::String *str)
 {
     Object::init();
-    string = str->d();
+    string.set(internalClass->engine, str->d());
     *propertyData(LengthPropertyIndex) = Primitive::fromInt32(length());
 }
 
diff --git a/src/qml/jsruntime/qv4typedarray.cpp b/src/qml/jsruntime/qv4typedarray.cpp
index e936158ab1..a34a8922e1 100644
--- a/src/qml/jsruntime/qv4typedarray.cpp
+++ b/src/qml/jsruntime/qv4typedarray.cpp
@@ -229,8 +229,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
             return;
         }
 
-        Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-        array->d()->buffer = buffer->d();
+        Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+        array->d()->buffer.set(scope.engine, buffer->d());
         array->d()->byteLength = byteLength;
         array->d()->byteOffset = 0;
 
@@ -252,8 +252,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
             return;
         }
 
-        Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-        array->d()->buffer = newBuffer->d();
+        Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+        array->d()->buffer.set(scope.engine, newBuffer->d());
         array->d()->byteLength = destByteLength;
         array->d()->byteOffset = 0;
 
@@ -311,8 +311,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
             byteLength = (uint)l;
         }
 
-        Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-        array->d()->buffer = buffer->d();
+        Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+        array->d()->buffer.set(scope.engine, buffer->d());
         array->d()->byteLength = byteLength;
         array->d()->byteOffset = byteOffset;
         scope.result = array.asReturnedValue();
@@ -335,8 +335,8 @@ void TypedArrayCtor::construct(const Managed *m, Scope &scope, CallData *callDat
         return;
     }
 
-    Scoped<TypedArray > array(scope, TypedArray::create(scope.engine, that->d()->type));
-    array->d()->buffer = newBuffer->d();
+    Scoped<TypedArray> array(scope, TypedArray::create(scope.engine, that->d()->type));
+    array->d()->buffer.set(scope.engine, newBuffer->d());
     array->d()->byteLength = l * elementSize;
     array->d()->byteOffset = 0;
 
diff --git a/src/qml/memory/qv4heap_p.h b/src/qml/memory/qv4heap_p.h
index b3dfa407f8..2cf3e721f9 100644
--- a/src/qml/memory/qv4heap_p.h
+++ b/src/qml/memory/qv4heap_p.h
@@ -167,15 +167,18 @@ V4_ASSERT_IS_TRIVIAL(Base)
 template <typename T, size_t o>
 struct Pointer {
     static Q_CONSTEXPR size_t offset = o;
-    static Q_CONSTEXPR quint64 markBits = Mark_Pointer << (o >> 2);
     T operator->() const { return ptr; }
     operator T () const { return ptr; }
 
-    Pointer &operator =(T t) { ptr = t; return *this; }
+    void set(ExecutionEngine *e, T newVal) {
+        Q_UNUSED(e);
+        ptr = newVal;
+    }
 
     template <typename Type>
     Type *cast() { return static_cast<Type *>(ptr); }
 
+private:
     T ptr;
 };
 typedef Pointer<char *, 0> V4PointerCheck;
diff --git a/src/qml/memory/qv4mm.cpp b/src/qml/memory/qv4mm.cpp
index edd26cf982..39272850b4 100644
--- a/src/qml/memory/qv4mm.cpp
+++ b/src/qml/memory/qv4mm.cpp
@@ -731,7 +731,7 @@ Heap::Object *MemoryManager::allocObjectWithMemberData(std::size_t size, uint nM
         else
             m = *blockAllocator.allocate(memberSize, true);
         memset(m, 0, memberSize);
-        o->memberData = static_cast<Heap::MemberData *>(m);
+        o->memberData.set(engine, static_cast<Heap::MemberData *>(m));
         o->memberData->setVtable(MemberData::staticVTable());
         o->memberData->values.alloc = static_cast<uint>((memberSize - sizeof(Heap::MemberData) + sizeof(Value))/sizeof(Value));
         o->memberData->values.size = o->memberData->values.alloc;
diff --git a/src/qml/memory/qv4mm_p.h b/src/qml/memory/qv4mm_p.h
index 0bd9229792..6e9303acb6 100644
--- a/src/qml/memory/qv4mm_p.h
+++ b/src/qml/memory/qv4mm_p.h
@@ -245,7 +245,7 @@ public:
         o->setVtable(ObjectType::staticVTable());
         Object *prototype = ObjectType::defaultPrototype(engine);
         o->internalClass = ic;
-        o->prototype = prototype->d();
+        o->prototype.set(engine, prototype->d());
         return static_cast<typename ObjectType::Data *>(o);
     }
 
@@ -272,7 +272,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init();
         return t->d();
     }
@@ -282,7 +282,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1);
         return t->d();
     }
@@ -292,7 +292,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1, arg2);
         return t->d();
     }
@@ -302,7 +302,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1, arg2, arg3);
         return t->d();
     }
@@ -312,7 +312,7 @@ public:
     {
         Scope scope(engine);
         Scoped<ObjectType> t(scope, allocateObject<ObjectType>(ic));
-        t->d_unchecked()->prototype = prototype->d();
+        t->d_unchecked()->prototype.set(engine, prototype->d());
         t->d_unchecked()->init(arg1, arg2, arg3, arg4);
         return t->d();
     }
diff --git a/src/qml/qml/qqmlcomponent.cpp b/src/qml/qml/qqmlcomponent.cpp
index c1a0637d00..993ad10639 100644
--- a/src/qml/qml/qqmlcomponent.cpp
+++ b/src/qml/qml/qqmlcomponent.cpp
@@ -1377,7 +1377,7 @@ void QQmlComponent::incubateObject(QQmlV4Function *args)
 
     if (!valuemap->isUndefined())
         r->d()->valuemap = valuemap;
-    r->d()->qmlContext = v4->qmlContext();
+    r->d()->qmlContext.set(scope.engine, v4->qmlContext());
     r->d()->parent = parent;
 
     QQmlIncubator *incubator = r->d()->incubator;
@@ -1476,7 +1476,7 @@ void QV4::Heap::QmlIncubatorObject::init(QQmlIncubator::IncubationMode m)
     valuemap = QV4::Primitive::undefinedValue();
     statusChanged = QV4::Primitive::undefinedValue();
     parent.init();
-    qmlContext = nullptr;
+    qmlContext.set(internalClass->engine, nullptr);
     incubator = new QQmlComponentIncubator(this, m);
 }
 
diff --git a/src/qml/qml/qqmlxmlhttprequest.cpp b/src/qml/qml/qqmlxmlhttprequest.cpp
index 502a693d5c..b18904fc73 100644
--- a/src/qml/qml/qqmlxmlhttprequest.cpp
+++ b/src/qml/qml/qqmlxmlhttprequest.cpp
@@ -1683,7 +1683,7 @@ void QQmlXMLHttpRequestCtor::setupProto()
     ExecutionEngine *v4 = engine();
     Scope scope(v4);
     ScopedObject p(scope, v4->newObject());
-    d()->proto = p->d();
+    d()->proto.set(scope.engine, p->d());
 
     // Methods
     p->defineDefaultProperty(QStringLiteral("open"), method_open);