Clean up ArgumentsObject handling

Introduce a proper strict arguments object.

Change-Id: Ie4e7f904b3a0e03893b18b3c6709f4f25dbc1030
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

6 files changed, 55 insertions, 32 deletions

diff --git a/src/qml/jsruntime/qv4argumentsobject.cpp b/src/qml/jsruntime/qv4argumentsobject.cpp
index 4d34099c73..075e7afd8a 100644
--- a/src/qml/jsruntime/qv4argumentsobject.cpp
+++ b/src/qml/jsruntime/qv4argumentsobject.cpp
@@ -46,38 +46,48 @@
 using namespace QV4;
 
 DEFINE_OBJECT_VTABLE(ArgumentsObject);
+DEFINE_OBJECT_VTABLE(StrictArgumentsObject);
 
-void Heap::ArgumentsObject::init(QV4::CallContext *context, int nFormals, bool strict)
+void Heap::ArgumentsObject::init(QV4::CppStackFrame *frame)
 {
     ExecutionEngine *v4 = internalClass->engine;
 
+    int nFormals = frame->v4Function->nFormals;
+    QV4::CallContext *context = static_cast<QV4::CallContext *>(frame->context());
+
     Object::init();
     fullyCreated = false;
-    isStrict = strict;
     this->nFormals = nFormals;
     this->context.set(v4, context->d());
     Q_ASSERT(vtable() == QV4::ArgumentsObject::staticVTable());
 
+    Q_ASSERT(CalleePropertyIndex == internalClass->find(v4->id_callee()));
+    setProperty(v4, CalleePropertyIndex, context->d()->function);
+    Q_ASSERT(LengthPropertyIndex == internalClass->find(v4->id_length()));
+    setProperty(v4, LengthPropertyIndex, Primitive::fromInt32(context->argc()));
+}
+
+void Heap::StrictArgumentsObject::init(QV4::CppStackFrame *frame)
+{
+    Q_ASSERT(vtable() == QV4::StrictArgumentsObject::staticVTable());
+    ExecutionEngine *v4 = internalClass->engine;
+
+    Object::init();
+
+    Q_ASSERT(CalleePropertyIndex == internalClass->find(v4->id_callee()));
+    Q_ASSERT(CallerPropertyIndex == internalClass->find(v4->id_caller()));
+    setProperty(v4, CalleePropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
+    setProperty(v4, CalleePropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
+    setProperty(v4, CallerPropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
+    setProperty(v4, CallerPropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
+
     Scope scope(v4);
-    Scoped<QV4::ArgumentsObject> args(scope, this);
-
-    if (isStrict) {
-        Q_ASSERT(CalleePropertyIndex == args->internalClass()->find(v4->id_callee()));
-        Q_ASSERT(CallerPropertyIndex == args->internalClass()->find(v4->id_caller()));
-        args->setProperty(CalleePropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
-        args->setProperty(CalleePropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
-        args->setProperty(CallerPropertyIndex + QV4::Object::GetterOffset, *v4->thrower());
-        args->setProperty(CallerPropertyIndex + QV4::Object::SetterOffset, *v4->thrower());
-
-        args->arrayReserve(context->argc());
-        args->arrayPut(0, context->args(), context->argc());
-        args->d()->fullyCreated = true;
-    } else {
-        Q_ASSERT(CalleePropertyIndex == args->internalClass()->find(v4->id_callee()));
-        args->setProperty(CalleePropertyIndex, context->d()->function);
-    }
+    Scoped<QV4::StrictArgumentsObject> args(scope, this);
+    args->arrayReserve(frame->originalArgumentsCount);
+    args->arrayPut(0, frame->originalArguments, frame->originalArgumentsCount);
+
     Q_ASSERT(LengthPropertyIndex == args->internalClass()->find(v4->id_length()));
-    args->setProperty(LengthPropertyIndex, Primitive::fromInt32(context->argc()));
+    setProperty(v4, LengthPropertyIndex, Primitive::fromInt32(frame->originalArgumentsCount));
 }
 
 void ArgumentsObject::fullyCreate()
@@ -132,8 +142,6 @@ bool ArgumentsObject::defineOwnProperty(ExecutionEngine *engine, uint index, con
 
     bool result = Object::defineOwnProperty2(scope.engine, index, desc, attrs);
     if (!result) {
-        if (d()->isStrict)
-            return engine->throwTypeError();
         return false;
     }
 
diff --git a/src/qml/jsruntime/qv4argumentsobject_p.h b/src/qml/jsruntime/qv4argumentsobject_p.h
index cc7eada4b9..ac281f555a 100644
--- a/src/qml/jsruntime/qv4argumentsobject_p.h
+++ b/src/qml/jsruntime/qv4argumentsobject_p.h
@@ -79,17 +79,26 @@ DECLARE_HEAP_OBJECT(ArgumentsSetterFunction, FunctionObject) {
     Member(class, Pointer, CallContext *, context) \
     Member(class, Pointer, MemberData *, mappedArguments) \
     Member(class, NoMark, bool, fullyCreated) \
-    Member(class, NoMark, bool, isStrict) \
     Member(class, NoMark, int, nFormals)
 
 DECLARE_HEAP_OBJECT(ArgumentsObject, Object) {
     DECLARE_MARKOBJECTS(ArgumentsObject);
     enum {
         LengthPropertyIndex = 0,
+        CalleePropertyIndex = 1
+    };
+    void init(CppStackFrame *frame);
+};
+
+#define StrictArgumentsObjectMembers(class, Member)
+
+DECLARE_HEAP_OBJECT(StrictArgumentsObject, Object) {
+    enum {
+        LengthPropertyIndex = 0,
         CalleePropertyIndex = 1,
         CallerPropertyIndex = 3
     };
-    void init(QV4::CallContext *context, int nFormals, bool strict);
+    void init(CppStackFrame *frame);
 };
 
 }
@@ -133,8 +142,7 @@ struct ArgumentsObject: Object {
     bool fullyCreated() const { return d()->fullyCreated; }
 
     static bool isNonStrictArgumentsObject(Managed *m) {
-        return m->d()->vtable()->type == Type_ArgumentsObject &&
-                !static_cast<ArgumentsObject *>(m)->d()->isStrict;
+        return m->d()->vtable() == staticVTable();
     }
 
     bool defineOwnProperty(ExecutionEngine *engine, uint index, const Property *desc, PropertyAttributes attrs);
@@ -148,6 +156,11 @@ struct ArgumentsObject: Object {
 
 };
 
+struct StrictArgumentsObject : Object {
+    V4_OBJECT2(StrictArgumentsObject, Object)
+    Q_MANAGED_TYPE(ArgumentsObject)
+};
+
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4engine.cpp b/src/qml/jsruntime/qv4engine.cpp
index 78c10eacc7..b92bd3992d 100644
--- a/src/qml/jsruntime/qv4engine.cpp
+++ b/src/qml/jsruntime/qv4engine.cpp
@@ -242,6 +242,8 @@ ExecutionEngine::ExecutionEngine()
     InternalClass *argsClass = newInternalClass(ArgumentsObject::staticVTable(), objectPrototype());
     argsClass = argsClass->addMember(id_length(), Attr_NotEnumerable);
     internalClasses[EngineBase::Class_ArgumentsObject] = argsClass->addMember(id_callee(), Attr_Data|Attr_NotEnumerable);
+    argsClass = newInternalClass(StrictArgumentsObject::staticVTable(), objectPrototype());
+    argsClass = argsClass->addMember(id_length(), Attr_NotEnumerable);
     argsClass = argsClass->addMember(id_callee(), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
     internalClasses[EngineBase::Class_StrictArgumentsObject] = argsClass->addMember(id_caller(), Attr_Accessor|Attr_NotConfigurable|Attr_NotEnumerable);
 
diff --git a/src/qml/jsruntime/qv4engine_p.h b/src/qml/jsruntime/qv4engine_p.h
index aaf69f6555..d165294a87 100644
--- a/src/qml/jsruntime/qv4engine_p.h
+++ b/src/qml/jsruntime/qv4engine_p.h
@@ -92,6 +92,8 @@ struct Q_QML_EXPORT CppStackFrame {
     CppStackFrame *parent;
     Function *v4Function;
     CallData *jsFrame;
+    const Value *originalArguments;
+    int originalArgumentsCount;
     const uchar *instructionPointer;
 
     QString source() const;
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index 9728f5454c..8bbc021738 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -1220,19 +1220,15 @@ ReturnedValue Runtime::method_objectLiteral(ExecutionEngine *engine, const QV4::
 QV4::ReturnedValue Runtime::method_createMappedArgumentsObject(ExecutionEngine *engine)
 {
     Q_ASSERT(engine->currentContext()->d()->type == Heap::ExecutionContext::Type_CallContext);
-    QV4::CallContext *c = static_cast<QV4::CallContext *>(&engine->currentStackFrame->jsFrame->context);
     QV4::InternalClass *ic = engine->internalClasses[EngineBase::Class_ArgumentsObject];
-    int nFormals = engine->currentStackFrame->v4Function->nFormals;
-    return engine->memoryManager->allocObject<ArgumentsObject>(ic, engine->objectPrototype(), c, nFormals, false)->asReturnedValue();
+    return engine->memoryManager->allocObject<ArgumentsObject>(ic, engine->objectPrototype(), engine->currentStackFrame)->asReturnedValue();
 }
 
 QV4::ReturnedValue Runtime::method_createUnmappedArgumentsObject(ExecutionEngine *engine)
 {
     Q_ASSERT(engine->currentContext()->d()->type == Heap::ExecutionContext::Type_CallContext);
-    QV4::CallContext *c = static_cast<QV4::CallContext *>(&engine->currentStackFrame->jsFrame->context);
     QV4::InternalClass *ic = engine->internalClasses[EngineBase::Class_StrictArgumentsObject];
-    int nFormals = engine->currentStackFrame->v4Function->nFormals;
-    return engine->memoryManager->allocObject<ArgumentsObject>(ic, engine->objectPrototype(), c, nFormals, true)->asReturnedValue();
+    return engine->memoryManager->allocObject<StrictArgumentsObject>(ic, engine->objectPrototype(), engine->currentStackFrame)->asReturnedValue();
 }
 
 ReturnedValue Runtime::method_loadQmlContext(NoThrowEngine *engine)
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 42c0abf3cb..a6cfa7cff1 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -503,6 +503,8 @@ QV4::ReturnedValue VME::exec(const FunctionObject *fo, const Value *thisObject,
     ExecutionEngine *engine;
     Value *stack;
     CppStackFrame frame;
+    frame.originalArguments = argv;
+    frame.originalArgumentsCount = argc;
     Function *function;
 
     {