Move Managed::type and some flags into the vtable

Move the type flag into the vtable to free up these
bits in the Managed class, and not have to set them
at object construction time.

As we often need to know whether a Managed object is a
Object, FunctionObject or String, add some bitflags to test
for these to the vtable.

Change-Id: I7d08ca044544debb307b55f124f34cb086ad9e84
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

32 files changed, 175 insertions, 82 deletions

diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 629c255b48..df08b5a89e 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -51,7 +51,6 @@ ArgumentsObject::ArgumentsObject(CallContext *context)
     , context(context)
     , fullyCreated(false)
 {
-    type = Type_ArgumentsObject;
     flags &= ~SimpleArray;
 
     ExecutionEngine *v4 = context->engine;
diff --git a/src/qml/jsruntime/qv4argumentsobject_p.h b/src/qml/jsruntime/qv4argumentsobject_p.h
index d306fae92b..b300dcf805 100644
--- a/src/qml/jsruntime/qv4argumentsobject_p.h
+++ b/src/qml/jsruntime/qv4argumentsobject_p.h
@@ -77,6 +77,7 @@ struct ArgumentsSetterFunction: FunctionObject
 
 struct ArgumentsObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(ArgumentsObject)
     CallContext *context;
     bool fullyCreated;
     QVector<SafeValue> mappedArguments;
diff --git a/src/qml/jsruntime/qv4context.cpp b/src/qml/jsruntime/qv4context.cpp
index 05a0e66e09..f5d8106f06 100644
--- a/src/qml/jsruntime/qv4context.cpp
+++ b/src/qml/jsruntime/qv4context.cpp
@@ -53,6 +53,13 @@ using namespace QV4;
 
 const ManagedVTable ExecutionContext::static_vtbl =
 {
+    ExecutionContext::IsExecutionContext,
+    ExecutionContext::IsString,
+    ExecutionContext::IsObject,
+    ExecutionContext::IsFunctionObject,
+    ExecutionContext::IsErrorObject,
+    0,
+    ExecutionContext::MyType,
     call,
     construct,
     markObjects,
diff --git a/src/qml/jsruntime/qv4context_p.h b/src/qml/jsruntime/qv4context_p.h
index 4eb89ad905..851f024a60 100644
--- a/src/qml/jsruntime/qv4context_p.h
+++ b/src/qml/jsruntime/qv4context_p.h
@@ -70,6 +70,10 @@ struct WithContext;
 struct Q_QML_EXPORT ExecutionContext : public Managed
 {
     Q_MANAGED
+    Q_MANAGED_TYPE(ExecutionContext)
+    enum {
+        IsExecutionContext = true
+    };
 
     enum ContextType {
         Type_GlobalContext = 0x1,
diff --git a/src/qml/jsruntime/qv4dateobject.cpp b/src/qml/jsruntime/qv4dateobject.cpp
index 5d0c8ccf8e..2b6aa21ac2 100644
--- a/src/qml/jsruntime/qv4dateobject.cpp
+++ b/src/qml/jsruntime/qv4dateobject.cpp
@@ -647,7 +647,6 @@ DateObject::DateObject(ExecutionEngine *engine, const QDateTime &date)
     : Object(engine->dateClass)
 {
     setVTable(&static_vtbl);
-    type = Type_DateObject;
     value.setDouble(date.isValid() ? date.toMSecsSinceEpoch() : qSNaN());
 }
 
diff --git a/src/qml/jsruntime/qv4dateobject_p.h b/src/qml/jsruntime/qv4dateobject_p.h
index 9c451dd251..244553b1d4 100644
--- a/src/qml/jsruntime/qv4dateobject_p.h
+++ b/src/qml/jsruntime/qv4dateobject_p.h
@@ -53,9 +53,9 @@ namespace QV4 {
 
 struct DateObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(DateObject)
     SafeValue value;
     DateObject(ExecutionEngine *engine, const ValueRef date): Object(engine->dateClass) {
-        type = Type_DateObject;
         value = date;
     }
     DateObject(ExecutionEngine *engine, const QDateTime &value);
@@ -64,8 +64,7 @@ struct DateObject: Object {
 
 protected:
     DateObject(InternalClass *ic): Object(ic) {
-        setVTable(&static_vtbl);
-        type = Type_DateObject;
+        Q_ASSERT(internalClass->vtable == &static_vtbl);
         value = Primitive::fromDouble(qSNaN());
     }
 };
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index f55b47c7e0..384254f896 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -249,16 +249,16 @@ ExecutionEngine::ExecutionEngine(QQmlJS::EvalISelFactory *factory)
 
     initRootContext();
 
-    StringPrototype *stringPrototype = new (memoryManager) StringPrototype(objectClass);
+    StringPrototype *stringPrototype = new (memoryManager) StringPrototype(InternalClass::create(this, &StringPrototype::static_vtbl, objectPrototype));
     stringObjectClass = InternalClass::create(this, &String::static_vtbl, stringPrototype);
 
-    NumberPrototype *numberPrototype = new (memoryManager) NumberPrototype(objectClass);
+    NumberPrototype *numberPrototype = new (memoryManager) NumberPrototype(InternalClass::create(this, &NumberPrototype::static_vtbl, objectPrototype));
     numberClass = InternalClass::create(this, &NumberObject::static_vtbl, numberPrototype);
 
-    BooleanPrototype *booleanPrototype = new (memoryManager) BooleanPrototype(objectClass);
+    BooleanPrototype *booleanPrototype = new (memoryManager) BooleanPrototype(InternalClass::create(this, &BooleanPrototype::static_vtbl, objectPrototype));
     booleanClass = InternalClass::create(this, &BooleanObject::static_vtbl, booleanPrototype);
 
-    DatePrototype *datePrototype = new (memoryManager) DatePrototype(objectClass);
+    DatePrototype *datePrototype = new (memoryManager) DatePrototype(InternalClass::create(this, &DatePrototype::static_vtbl, objectPrototype));
     dateClass = InternalClass::create(this, &DateObject::static_vtbl, datePrototype);
 
     FunctionPrototype *functionPrototype = new (memoryManager) FunctionPrototype(InternalClass::create(this, &FunctionPrototype::static_vtbl, objectPrototype));
@@ -269,14 +269,14 @@ ExecutionEngine::ExecutionEngine(QQmlJS::EvalISelFactory *factory)
     protoClass = objectClass->addMember(id_constructor, Attr_NotEnumerable, &index);
     Q_ASSERT(index == FunctionObject::Index_ProtoConstructor);
 
-    RegExpPrototype *regExpPrototype = new (memoryManager) RegExpPrototype(objectClass);
+    RegExpPrototype *regExpPrototype = new (memoryManager) RegExpPrototype(InternalClass::create(this, &RegExpPrototype::static_vtbl, objectPrototype));
     regExpClass = InternalClass::create(this, &RegExpObject::static_vtbl, regExpPrototype);
     regExpExecArrayClass = arrayClass->addMember(id_index, Attr_Data, &index);
     Q_ASSERT(index == RegExpObject::Index_ArrayIndex);
     regExpExecArrayClass = regExpExecArrayClass->addMember(id_input, Attr_Data, &index);
     Q_ASSERT(index == RegExpObject::Index_ArrayInput);
 
-    ErrorPrototype *errorPrototype = new (memoryManager) ErrorPrototype(objectClass);
+    ErrorPrototype *errorPrototype = new (memoryManager) ErrorPrototype(InternalClass::create(this, &ErrorObject::static_vtbl, objectPrototype));
     errorClass = InternalClass::create(this, &ErrorObject::static_vtbl, errorPrototype);
     EvalErrorPrototype *evalErrorPrototype = new (memoryManager) EvalErrorPrototype(errorClass);
     evalErrorClass = InternalClass::create(this, &EvalErrorObject::static_vtbl, evalErrorPrototype);
@@ -357,8 +357,8 @@ ExecutionEngine::ExecutionEngine(QQmlJS::EvalISelFactory *factory)
     globalObject->defineDefaultProperty(QStringLiteral("TypeError"), typeErrorCtor);
     globalObject->defineDefaultProperty(QStringLiteral("URIError"), uRIErrorCtor);
     ScopedObject o(scope);
-    globalObject->defineDefaultProperty(QStringLiteral("Math"), (o = new (memoryManager) MathObject(this)));
-    globalObject->defineDefaultProperty(QStringLiteral("JSON"), (o = new (memoryManager) JsonObject(this)));
+    globalObject->defineDefaultProperty(QStringLiteral("Math"), (o = new (memoryManager) MathObject(QV4::InternalClass::create(this, &MathObject::static_vtbl, objectPrototype))));
+    globalObject->defineDefaultProperty(QStringLiteral("JSON"), (o = new (memoryManager) JsonObject(QV4::InternalClass::create(this, &JsonObject::static_vtbl, objectPrototype))));
 
     globalObject->defineReadonlyProperty(QStringLiteral("undefined"), Primitive::undefinedValue());
     globalObject->defineReadonlyProperty(QStringLiteral("NaN"), Primitive::fromDouble(std::numeric_limits<double>::quiet_NaN()));
diff --git a/src/qml/jsruntime/qv4errorobject.cpp b/src/qml/jsruntime/qv4errorobject.cpp
index cf5c06dd41..f5d21b2f30 100644
--- a/src/qml/jsruntime/qv4errorobject.cpp
+++ b/src/qml/jsruntime/qv4errorobject.cpp
@@ -76,8 +76,6 @@ ErrorObject::ErrorObject(InternalClass *ic)
     : Object(ic)
     , stack(0)
 {
-    type = Type_ErrorObject;
-
     Scope scope(engine());
     ScopedValue protectThis(scope, this);
 
@@ -89,7 +87,6 @@ ErrorObject::ErrorObject(InternalClass *ic, const ValueRef message, ErrorType t)
     : Object(ic)
     , stack(0)
 {
-    type = Type_ErrorObject;
     subtype = t;
 
     Scope scope(engine());
@@ -113,7 +110,6 @@ ErrorObject::ErrorObject(InternalClass *ic, const QString &message, ErrorObject:
     : Object(ic)
     , stack(0)
 {
-    type = Type_ErrorObject;
     subtype = t;
 
     Scope scope(engine());
@@ -137,7 +133,6 @@ ErrorObject::ErrorObject(InternalClass *ic, const QString &message, const QStrin
     : Object(ic)
     , stack(0)
 {
-    type = Type_ErrorObject;
     subtype = t;
 
     Scope scope(engine());
diff --git a/src/qml/jsruntime/qv4errorobject_p.h b/src/qml/jsruntime/qv4errorobject_p.h
index def776d3b6..560b003062 100644
--- a/src/qml/jsruntime/qv4errorobject_p.h
+++ b/src/qml/jsruntime/qv4errorobject_p.h
@@ -52,6 +52,10 @@ struct SyntaxErrorObject;
 
 struct ErrorObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(ErrorObject)
+    enum {
+        IsErrorObject = true
+    };
 
     enum ErrorType {
         Error,
diff --git a/src/qml/jsruntime/qv4functionobject.cpp b/src/qml/jsruntime/qv4functionobject.cpp
index 6e5c137e0b..dc6f310b75 100644
--- a/src/qml/jsruntime/qv4functionobject.cpp
+++ b/src/qml/jsruntime/qv4functionobject.cpp
@@ -112,7 +112,6 @@ FunctionObject::FunctionObject(InternalClass *ic)
 {
     name = ic->engine->id_undefined;
 
-    type = Type_FunctionObject;
     needsActivation = false;
     strictMode = false;
 }
@@ -130,7 +129,6 @@ void FunctionObject::init(const StringRef n, bool createProto)
     Scope s(internalClass->engine);
     ScopedValue protectThis(s, this);
 
-    type = Type_FunctionObject;
     needsActivation = true;
     strictMode = false;
 #ifndef QT_NO_DEBUG
diff --git a/src/qml/jsruntime/qv4functionobject_p.h b/src/qml/jsruntime/qv4functionobject_p.h
index 96534cb68c..0168e13a6f 100644
--- a/src/qml/jsruntime/qv4functionobject_p.h
+++ b/src/qml/jsruntime/qv4functionobject_p.h
@@ -94,6 +94,10 @@ struct Lookup;
 
 struct Q_QML_EXPORT FunctionObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(FunctionObject)
+    enum {
+        IsFunctionObject = true
+    };
     // Used with Managed::subType
     enum FunctionType {
         RegularFunction = 0,
diff --git a/src/qml/jsruntime/qv4jsonobject.cpp b/src/qml/jsruntime/qv4jsonobject.cpp
index 6633435668..ecdb50be92 100644
--- a/src/qml/jsruntime/qv4jsonobject.cpp
+++ b/src/qml/jsruntime/qv4jsonobject.cpp
@@ -66,6 +66,8 @@ static int indent = 0;
 #endif
 
 
+DEFINE_MANAGED_VTABLE(JsonObject);
+
 class JsonParser
 {
 public:
@@ -884,12 +886,10 @@ QString Stringify::JA(ArrayObjectRef a)
 }
 
 
-JsonObject::JsonObject(ExecutionEngine *engine)
-    : Object(engine)
+JsonObject::JsonObject(InternalClass *ic)
+    : Object(ic)
 {
-    type = Type_JSONObject;
-
-    Scope scope(engine);
+    Scope scope(ic->engine);
     ScopedObject protectThis(scope, this);
 
     defineDefaultProperty(QStringLiteral("parse"), method_parse, 2);
diff --git a/src/qml/jsruntime/qv4jsonobject_p.h b/src/qml/jsruntime/qv4jsonobject_p.h
index 3bcbdeadbf..b37b28b078 100644
--- a/src/qml/jsruntime/qv4jsonobject_p.h
+++ b/src/qml/jsruntime/qv4jsonobject_p.h
@@ -51,10 +51,12 @@ QT_BEGIN_NAMESPACE
 namespace QV4 {
 
 struct JsonObject : Object {
+    Q_MANAGED_TYPE(JsonObject)
+    Q_MANAGED
 private:
     typedef QSet<QV4::Object *> V4ObjectSet;
 public:
-    JsonObject(ExecutionEngine *engine);
+    JsonObject(InternalClass *ic);
 
     static ReturnedValue method_parse(CallContext *ctx);
     static ReturnedValue method_stringify(CallContext *ctx);
diff --git a/src/qml/jsruntime/qv4managed.cpp b/src/qml/jsruntime/qv4managed.cpp
index fef7489110..47f9195322 100644
--- a/src/qml/jsruntime/qv4managed.cpp
+++ b/src/qml/jsruntime/qv4managed.cpp
@@ -47,6 +47,13 @@ using namespace QV4;
 
 const ManagedVTable Managed::static_vtbl =
 {
+    Managed::IsExecutionContext,
+    Managed::IsString,
+    Managed::IsObject,
+    Managed::IsFunctionObject,
+    Managed::IsErrorObject,
+    0,
+    Managed::MyType,
     call,
     construct,
     0 /*markObjects*/,
@@ -101,7 +108,7 @@ ExecutionEngine *Managed::engine() const
 QString Managed::className() const
 {
     const char *s = 0;
-    switch (Type(type)) {
+    switch (Type(internalClass->vtable->type)) {
     case Type_Invalid:
     case Type_String:
         return QString();
@@ -157,18 +164,23 @@ QString Managed::className() const
     case Type_ArgumentsObject:
         s = "Arguments";
         break;
-    case Type_JSONObject:
+    case Type_JsonObject:
         s = "JSON";
         break;
     case Type_MathObject:
         s = "Math";
         break;
+
+    case Type_ExecutionContext:
+        s = "__ExecutionContext";
+        break;
     case Type_ForeachIteratorObject:
         s = "__ForeachIterator";
         break;
     case Type_RegExp:
-        s = "RegExp";
+        s = "__RegExp";
         break;
+
     case Type_QmlSequence:
         s = "QmlSequence";
         break;
diff --git a/src/qml/jsruntime/qv4managed_p.h b/src/qml/jsruntime/qv4managed_p.h
index 63972688a7..afb6bb56d7 100644
--- a/src/qml/jsruntime/qv4managed_p.h
+++ b/src/qml/jsruntime/qv4managed_p.h
@@ -69,6 +69,9 @@ inline void qYouForgotTheQ_MANAGED_Macro(T1, T2) {}
         template <typename T> \
         QV4::Returned<T> *asReturned() { return QV4::Returned<T>::create(this); } \
 
+#define Q_MANAGED_TYPE(type) \
+    public: \
+        enum { MyType = Type_##type };
 
 struct GCDeletable
 {
@@ -80,6 +83,13 @@ struct GCDeletable
 
 struct ManagedVTable
 {
+    uint isExecutionContext : 1;
+    uint isString : 1;
+    uint isObject : 1;
+    uint isFunctionObject : 1;
+    uint isErrorObject : 1;
+    uint unused : 19;
+    uint type : 8;
     ReturnedValue (*call)(Managed *, CallData *data);
     ReturnedValue (*construct)(Managed *, CallData *data);
     void (*markObjects)(Managed *, ExecutionEngine *e);
@@ -103,6 +113,13 @@ struct ManagedVTable
 #define DEFINE_MANAGED_VTABLE(classname) \
 const QV4::ManagedVTable classname::static_vtbl =    \
 {                                               \
+    classname::IsExecutionContext,   \
+    classname::IsString,   \
+    classname::IsObject,   \
+    classname::IsFunctionObject,   \
+    classname::IsErrorObject,   \
+    0,                                          \
+    classname::MyType,                          \
     call,                                       \
     construct,                                  \
     markObjects,                                \
@@ -123,9 +140,46 @@ const QV4::ManagedVTable classname::static_vtbl =    \
     #classname                                  \
 }
 
+#define DEFINE_MANAGED_VTABLE_WITH_NAME(classname, name) \
+const QV4::ManagedVTable classname::static_vtbl =    \
+{                                               \
+    classname::IsExecutionContext,   \
+    classname::IsString,   \
+    classname::IsObject,   \
+    classname::IsFunctionObject,   \
+    classname::IsErrorObject,   \
+    0,                                          \
+    classname::MyType,                          \
+    call,                                       \
+    construct,                                  \
+    markObjects,                                \
+    destroy,                                    \
+    0,                                          \
+    get,                                        \
+    getIndexed,                                 \
+    put,                                        \
+    putIndexed,                                 \
+    query,                                      \
+    queryIndexed,                               \
+    deleteProperty,                             \
+    deleteIndexedProperty,                      \
+    getLookup,                                  \
+    setLookup,                                  \
+    isEqualTo,                                  \
+    advanceIterator,                            \
+    #name                                       \
+}
+
 #define DEFINE_MANAGED_VTABLE_WITH_DELETABLES(classname) \
 const QV4::ManagedVTable classname::static_vtbl =    \
 {                                               \
+    classname::IsExecutionContext,   \
+    classname::IsString,   \
+    classname::IsObject,   \
+    classname::IsFunctionObject,   \
+    classname::IsErrorObject,   \
+    0,                                          \
+    classname::MyType,                          \
     call,                                       \
     construct,                                  \
     markObjects,                                \
@@ -149,6 +203,13 @@ const QV4::ManagedVTable classname::static_vtbl =    \
 struct Q_QML_EXPORT Managed
 {
     Q_MANAGED
+    enum {
+        IsExecutionContext = false,
+        IsString = false,
+        IsObject = false,
+        IsFunctionObject = false,
+        IsErrorObject = false
+    };
 private:
     void *operator new(size_t);
     Managed(const Managed &other);
@@ -183,13 +244,16 @@ public:
         Type_RegExpObject,
         Type_ErrorObject,
         Type_ArgumentsObject,
-        Type_JSONObject,
+        Type_JsonObject,
         Type_MathObject,
+
+        Type_ExecutionContext,
         Type_ForeachIteratorObject,
         Type_RegExp,
 
         Type_QmlSequence
     };
+    Q_MANAGED_TYPE(Invalid)
 
     ExecutionEngine *engine() const;
 
@@ -214,21 +278,21 @@ public:
         return internalClass->vtable == &T::static_vtbl ? static_cast<const T *>(this) : 0;
     }
 
-    String *asString() { return type == Type_String ? reinterpret_cast<String *>(this) : 0; }
-    Object *asObject() { return type != Type_String ? reinterpret_cast<Object *>(this) : 0; }
-    ArrayObject *asArrayObject() { return type == Type_ArrayObject ? reinterpret_cast<ArrayObject *>(this) : 0; }
-    FunctionObject *asFunctionObject() { return type == Type_FunctionObject ? reinterpret_cast<FunctionObject *>(this) : 0; }
-    BooleanObject *asBooleanObject() { return type == Type_BooleanObject ? reinterpret_cast<BooleanObject *>(this) : 0; }
-    NumberObject *asNumberObject() { return type == Type_NumberObject ? reinterpret_cast<NumberObject *>(this) : 0; }
-    StringObject *asStringObject() { return type == Type_StringObject ? reinterpret_cast<StringObject *>(this) : 0; }
-    DateObject *asDateObject() { return type == Type_DateObject ? reinterpret_cast<DateObject *>(this) : 0; }
-    ErrorObject *asErrorObject() { return type == Type_ErrorObject ? reinterpret_cast<ErrorObject *>(this) : 0; }
-    ArgumentsObject *asArgumentsObject() { return type == Type_ArgumentsObject ? reinterpret_cast<ArgumentsObject *>(this) : 0; }
+    String *asString() { return internalClass->vtable->type == Type_String ? reinterpret_cast<String *>(this) : 0; }
+    Object *asObject() { return internalClass->vtable->type != Type_String ? reinterpret_cast<Object *>(this) : 0; }
+    ArrayObject *asArrayObject() { return internalClass->vtable->type == Type_ArrayObject ? reinterpret_cast<ArrayObject *>(this) : 0; }
+    FunctionObject *asFunctionObject() { return internalClass->vtable->type == Type_FunctionObject ? reinterpret_cast<FunctionObject *>(this) : 0; }
+    BooleanObject *asBooleanObject() { return internalClass->vtable->type == Type_BooleanObject ? reinterpret_cast<BooleanObject *>(this) : 0; }
+    NumberObject *asNumberObject() { return internalClass->vtable->type == Type_NumberObject ? reinterpret_cast<NumberObject *>(this) : 0; }
+    StringObject *asStringObject() { return internalClass->vtable->type == Type_StringObject ? reinterpret_cast<StringObject *>(this) : 0; }
+    DateObject *asDateObject() { return internalClass->vtable->type == Type_DateObject ? reinterpret_cast<DateObject *>(this) : 0; }
+    ErrorObject *asErrorObject() { return internalClass->vtable->type == Type_ErrorObject ? reinterpret_cast<ErrorObject *>(this) : 0; }
+    ArgumentsObject *asArgumentsObject() { return internalClass->vtable->type == Type_ArgumentsObject ? reinterpret_cast<ArgumentsObject *>(this) : 0; }
 
-    bool isListType() const { return type == Type_QmlSequence; }
+    bool isListType() const { return internalClass->vtable->type == Type_QmlSequence; }
 
-    bool isArrayObject() const { return type == Type_ArrayObject; }
-    bool isStringObject() const { return type == Type_StringObject; }
+    bool isArrayObject() const { return internalClass->vtable->type == Type_ArrayObject; }
+    bool isStringObject() const { return internalClass->vtable->type == Type_StringObject; }
 
     QString className() const;
 
@@ -272,10 +336,6 @@ public:
     static void setLookup(Managed *m, Lookup *l, const ValueRef v);
     static bool isEqualTo(Managed *m, Managed *other);
 
-    uint internalType() const {
-        return type;
-    }
-
     ReturnedValue asReturnedValue() { return Value::fromManaged(this).asReturnedValue(); }
 
 
@@ -296,7 +356,7 @@ public:
             uchar strictMode : 1; // used by FunctionObject
             uchar bindingKeyFlag : 1;
             uchar hasAccessorProperty : 1;
-            uchar type;
+            uchar _type;
             mutable uchar subtype;
             uchar flags;
         };
diff --git a/src/qml/jsruntime/qv4mathobject.cpp b/src/qml/jsruntime/qv4mathobject.cpp
index 5a7af1f041..6225d6b4ae 100644
--- a/src/qml/jsruntime/qv4mathobject.cpp
+++ b/src/qml/jsruntime/qv4mathobject.cpp
@@ -51,14 +51,14 @@
 
 using namespace QV4;
 
+DEFINE_MANAGED_VTABLE(MathObject);
+
 static const double qt_PI = 2.0 * ::asin(1.0);
 
-MathObject::MathObject(ExecutionEngine *engine)
-    : Object(engine)
+MathObject::MathObject(InternalClass *ic)
+    : Object(ic)
 {
-    type = Type_MathObject;
-
-    Scope scope(engine);
+    Scope scope(ic->engine);
     ScopedObject protectThis(scope, this);
 
     defineReadonlyProperty(QStringLiteral("E"), Primitive::fromDouble(::exp(1.0)));
diff --git a/src/qml/jsruntime/qv4mathobject_p.h b/src/qml/jsruntime/qv4mathobject_p.h
index 6fe3db3950..45f8e7cd2e 100644
--- a/src/qml/jsruntime/qv4mathobject_p.h
+++ b/src/qml/jsruntime/qv4mathobject_p.h
@@ -49,7 +49,9 @@ namespace QV4 {
 
 struct MathObject: Object
 {
-    MathObject(ExecutionEngine *engine);
+    Q_MANAGED
+    Q_MANAGED_TYPE(MathObject)
+    MathObject(InternalClass *ic);
 
     static ReturnedValue method_abs(CallContext *context);
     static ReturnedValue method_acos(CallContext *context);
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp
index 115473604c..559792d898 100644
--- a/src/qml/jsruntime/qv4object.cpp
+++ b/src/qml/jsruntime/qv4object.cpp
@@ -73,7 +73,6 @@ Object::Object(ExecutionEngine *engine)
     : Managed(engine->objectClass)
     , memberDataAlloc(InlinePropertySize), memberData(inlineProperties)
 {
-    type = Type_Object;
     flags = SimpleArray;
 }
 
@@ -82,7 +81,6 @@ Object::Object(InternalClass *ic)
     , memberDataAlloc(InlinePropertySize), memberData(inlineProperties)
 {
     Q_ASSERT(internalClass->vtable && internalClass->vtable != &Managed::static_vtbl);
-    type = Type_Object;
     flags = SimpleArray;
 
     if (internalClass->size >= memberDataAlloc) {
@@ -1438,7 +1436,6 @@ void ArrayObject::init(ExecutionEngine *engine)
 {
     Q_UNUSED(engine);
 
-    type = Type_ArrayObject;
     memberData[LengthPropertyIndex].value = Primitive::fromInt32(0);
 }
 
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 23f2f682fd..5c03b1f840 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -102,6 +102,10 @@ struct URIErrorPrototype;
 
 struct Q_QML_EXPORT Object: Managed {
     Q_MANAGED
+    Q_MANAGED_TYPE(Object)
+    enum {
+        IsObject = true
+    };
     uint memberDataAlloc;
     Property *memberData;
 
@@ -328,40 +332,39 @@ private:
 
 struct BooleanObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(BooleanObject)
     SafeValue value;
     BooleanObject(ExecutionEngine *engine, const ValueRef val)
         : Object(engine->booleanClass) {
-        type = Type_BooleanObject;
         value = val;
     }
 protected:
     BooleanObject(InternalClass *ic)
         : Object(ic) {
-        setVTable(&static_vtbl);
-        type = Type_BooleanObject;
+        Q_ASSERT(internalClass->vtable == &static_vtbl);
         value = Encode(false);
     }
 };
 
 struct NumberObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(NumberObject)
     SafeValue value;
     NumberObject(ExecutionEngine *engine, const ValueRef val)
         : Object(engine->numberClass) {
-        type = Type_NumberObject;
         value = val;
     }
 protected:
     NumberObject(InternalClass *ic)
         : Object(ic) {
-        setVTable(&static_vtbl);
-        type = Type_NumberObject;
+        Q_ASSERT(internalClass->vtable == &static_vtbl);
         value = Encode((int)0);
     }
 };
 
 struct ArrayObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(ArrayObject)
     enum {
         LengthPropertyIndex = 0
     };
diff --git a/src/qml/jsruntime/qv4objectiterator_p.h b/src/qml/jsruntime/qv4objectiterator_p.h
index 6c333b328c..33228cefaa 100644
--- a/src/qml/jsruntime/qv4objectiterator_p.h
+++ b/src/qml/jsruntime/qv4objectiterator_p.h
@@ -86,11 +86,11 @@ struct Q_QML_EXPORT ObjectIterator
 
 struct ForEachIteratorObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(ForeachIteratorObject)
     ObjectIterator it;
     ForEachIteratorObject(ExecutionContext *ctx, const ObjectRef o)
         : Object(ctx->engine), it(workArea, workArea + 1, o, ObjectIterator::EnumerableOnly|ObjectIterator::WithProtoChain) {
         setVTable(&static_vtbl);
-        type = Type_ForeachIteratorObject;
     }
 
     ReturnedValue nextPropertyName() { return it.nextPropertyNameAsString(); }
diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index 7ca790b970..a8e78b44c2 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -105,9 +105,9 @@ ReturnedValue ObjectCtor::call(Managed *m, CallData *callData)
 void ObjectPrototype::init(ExecutionEngine *v4, ObjectRef ctor)
 {
     Scope scope(v4);
-    ScopedObject o(scope);
+    ScopedObject o(scope, this);
 
-    ctor->defineReadonlyProperty(v4->id_prototype, (o = this));
+    ctor->defineReadonlyProperty(v4->id_prototype, o);
     ctor->defineReadonlyProperty(v4->id_length, Primitive::fromInt32(1));
     ctor->defineDefaultProperty(QStringLiteral("getPrototypeOf"), method_getPrototypeOf, 1);
     ctor->defineDefaultProperty(QStringLiteral("getOwnPropertyDescriptor"), method_getOwnPropertyDescriptor, 2);
diff --git a/src/qml/jsruntime/qv4regexp.cpp b/src/qml/jsruntime/qv4regexp.cpp
index 41ff9f9741..8544970347 100644
--- a/src/qml/jsruntime/qv4regexp.cpp
+++ b/src/qml/jsruntime/qv4regexp.cpp
@@ -99,8 +99,6 @@ RegExp::RegExp(ExecutionEngine* engine, const QString &pattern, bool ignoreCase,
     , m_ignoreCase(ignoreCase)
     , m_multiLine(multiline)
 {
-    type = Type_RegExpObject;
-
     if (!engine)
         return;
     const char* error = 0;
diff --git a/src/qml/jsruntime/qv4regexp_p.h b/src/qml/jsruntime/qv4regexp_p.h
index 9041ff2ef4..d8e9930876 100644
--- a/src/qml/jsruntime/qv4regexp_p.h
+++ b/src/qml/jsruntime/qv4regexp_p.h
@@ -94,6 +94,7 @@ public:
 class RegExp : public Managed
 {
     Q_MANAGED
+    Q_MANAGED_TYPE(RegExp)
 public:
     static RegExp* create(ExecutionEngine* engine, const QString& pattern, bool ignoreCase = false, bool multiline = false);
     ~RegExp();
diff --git a/src/qml/jsruntime/qv4regexpobject.cpp b/src/qml/jsruntime/qv4regexpobject.cpp
index 468fb34d76..425fb8a21d 100644
--- a/src/qml/jsruntime/qv4regexpobject.cpp
+++ b/src/qml/jsruntime/qv4regexpobject.cpp
@@ -76,6 +76,7 @@ RegExpObject::RegExpObject(InternalClass *ic)
     , value(RegExp::create(ic->engine, QString(), false, false))
     , global(false)
 {
+    Q_ASSERT(internalClass->vtable == &static_vtbl);
     init(ic->engine);
 }
 
@@ -143,7 +144,6 @@ RegExpObject::RegExpObject(ExecutionEngine *engine, const QRegExp &re)
 void RegExpObject::init(ExecutionEngine *engine)
 {
     setVTable(&static_vtbl);
-    type = Type_RegExpObject;
 
     Scope scope(engine);
     ScopedObject protectThis(scope, this);
diff --git a/src/qml/jsruntime/qv4regexpobject_p.h b/src/qml/jsruntime/qv4regexpobject_p.h
index 0129f8d396..bd91e8f693 100644
--- a/src/qml/jsruntime/qv4regexpobject_p.h
+++ b/src/qml/jsruntime/qv4regexpobject_p.h
@@ -67,6 +67,7 @@ class RegExp;
 
 struct RegExpObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(RegExpObject)
     // needs to be compatible with the flags in qv4jsir_p.h
     enum Flags {
         RegExp_Global     = 0x01,
diff --git a/src/qml/jsruntime/qv4sequenceobject.cpp b/src/qml/jsruntime/qv4sequenceobject.cpp
index 8b0e31cb71..988762c842 100644
--- a/src/qml/jsruntime/qv4sequenceobject.cpp
+++ b/src/qml/jsruntime/qv4sequenceobject.cpp
@@ -166,6 +166,7 @@ template <typename Container>
 class QQmlSequence : public QV4::Object
 {
     Q_MANAGED
+    Q_MANAGED_TYPE(QmlSequence)
 public:
     QQmlSequence(QV4::ExecutionEngine *engine, const Container &container)
         : QV4::Object(InternalClass::create(engine, &static_vtbl, engine->sequencePrototype.asObject()))
@@ -174,7 +175,6 @@ public:
         , m_propertyIndex(-1)
         , m_isReference(false)
     {
-        type = Type_QmlSequence;
         flags &= ~SimpleArray;
         QV4::Scope scope(engine);
         QV4::ScopedObject protectThis(scope, this);
@@ -188,7 +188,6 @@ public:
         , m_propertyIndex(propertyIndex)
         , m_isReference(true)
     {
-        type = Type_QmlSequence;
         flags &= ~SimpleArray;
         QV4::Scope scope(engine);
         QV4::ScopedObject protectThis(scope, this);
diff --git a/src/qml/jsruntime/qv4string.cpp b/src/qml/jsruntime/qv4string.cpp
index e5633eb06f..0b38b5c08b 100644
--- a/src/qml/jsruntime/qv4string.cpp
+++ b/src/qml/jsruntime/qv4string.cpp
@@ -103,6 +103,13 @@ static uint toArrayIndex(const char *ch, const char *end, bool *ok)
 
 const ManagedVTable String::static_vtbl =
 {
+    String::IsExecutionContext,
+    String::IsString,
+    String::IsObject,
+    String::IsFunctionObject,
+    String::IsErrorObject,
+    0,
+    String::MyType,
     call,
     construct,
     markObjects,
@@ -233,10 +240,10 @@ bool String::isEqualTo(Managed *t, Managed *o)
     if (t == o)
         return true;
 
-    if (o->type != Type_String)
+    if (o->internalClass->vtable->type != Type_String)
         return false;
 
-    Q_ASSERT(t->type == Type_String);
+    Q_ASSERT(t->internalClass->vtable->type == Type_String);
     String *that = static_cast<String *>(t);
     String *other = static_cast<String *>(o);
     if (that->hashValue() != other->hashValue())
@@ -257,7 +264,6 @@ String::String(ExecutionEngine *engine, const QString &text)
 {
     _text->ref.ref();
     len = _text->size;
-    type = Type_String;
     subtype = StringType_Unknown;
 }
 
@@ -267,7 +273,6 @@ String::String(ExecutionEngine *engine, String *l, String *r)
     , stringHash(UINT_MAX), largestSubLength(qMax(l->largestSubLength, r->largestSubLength))
     , len(l->len + r->len)
 {
-    type = Type_String;
     subtype = StringType_Unknown;
 
     if (!l->largestSubLength && l->len > largestSubLength)
diff --git a/src/qml/jsruntime/qv4string_p.h b/src/qml/jsruntime/qv4string_p.h
index 64e15b04c2..7e2824d8a0 100644
--- a/src/qml/jsruntime/qv4string_p.h
+++ b/src/qml/jsruntime/qv4string_p.h
@@ -53,6 +53,11 @@ struct Identifier;
 
 struct Q_QML_EXPORT String : public Managed {
     Q_MANAGED
+    Q_MANAGED_TYPE(String)
+    enum {
+        IsString = true
+    };
+
     enum StringType {
         StringType_Unknown,
         StringType_Regular,
@@ -63,7 +68,7 @@ struct Q_QML_EXPORT String : public Managed {
     String()
         : Managed(0), _text(QStringData::sharedNull()), identifier(0)
         , stringHash(UINT_MAX), largestSubLength(0), len(0)
-    { type = Type_String; subtype = StringType_Unknown; }
+    { subtype = StringType_Unknown; }
     String(ExecutionEngine *engine, const QString &text);
     String(ExecutionEngine *engine, String *l, String *n);
     ~String() {
diff --git a/src/qml/jsruntime/qv4stringobject.cpp b/src/qml/jsruntime/qv4stringobject.cpp
index d468fb6b83..39667f00a4 100644
--- a/src/qml/jsruntime/qv4stringobject.cpp
+++ b/src/qml/jsruntime/qv4stringobject.cpp
@@ -80,8 +80,7 @@ DEFINE_MANAGED_VTABLE(StringObject);
 StringObject::StringObject(InternalClass *ic)
     : Object(ic)
 {
-    setVTable(&static_vtbl);
-    type = Type_StringObject;
+    Q_ASSERT(internalClass->vtable == &static_vtbl);
 
     Scope scope(engine());
     ScopedObject protectThis(scope, this);
@@ -97,7 +96,6 @@ StringObject::StringObject(ExecutionEngine *engine, const ValueRef val)
     : Object(engine->stringObjectClass)
 {
     setVTable(&static_vtbl);
-    type = Type_StringObject;
 
     Scope scope(engine);
     ScopedObject protectThis(scope, this);
diff --git a/src/qml/jsruntime/qv4stringobject_p.h b/src/qml/jsruntime/qv4stringobject_p.h
index e8e46b85e7..b91cc48e36 100644
--- a/src/qml/jsruntime/qv4stringobject_p.h
+++ b/src/qml/jsruntime/qv4stringobject_p.h
@@ -51,6 +51,7 @@ namespace QV4 {
 
 struct StringObject: Object {
     Q_MANAGED
+    Q_MANAGED_TYPE(StringObject)
 
     SafeValue value;
     mutable Property tmpProperty;
diff --git a/src/qml/jsruntime/qv4value_p.h b/src/qml/jsruntime/qv4value_p.h
index 680c7465ca..b93fcbe4bd 100644
--- a/src/qml/jsruntime/qv4value_p.h
+++ b/src/qml/jsruntime/qv4value_p.h
@@ -64,13 +64,13 @@ inline bool Value::isString() const
 {
     if (!isManaged())
         return false;
-    return managed() && managed()->type == Managed::Type_String;
+    return managed() && managed()->internalClass->vtable->isString;
 }
 inline bool Value::isObject() const
 {
     if (!isManaged())
         return false;
-    return managed() && managed()->type != Managed::Type_String;
+    return managed() && managed()->internalClass->vtable->isObject;
 }
 
 inline bool Value::isPrimitive() const
diff --git a/src/qml/qml/qqmllocale.cpp b/src/qml/qml/qqmllocale.cpp
index 36e0da5b60..c814298286 100644
--- a/src/qml/qml/qqmllocale.cpp
+++ b/src/qml/qml/qqmllocale.cpp
@@ -62,7 +62,6 @@ public:
         : QV4::Object(engine)
     {
         setVTable(&static_vtbl);
-        type = Type_Object;
     }
 
     QLocale locale;