JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / runtime / JSNotAnObject.h

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#ifndef JSNotAnObject_h
#define JSNotAnObject_h

#include "JSObject.h"

namespace JSC {

// This unholy class is used to allow us to avoid multiple exception checks
// in certain SquirrelFish bytecodes -- effectively it just silently consumes
// any operations performed on the result of a failed toObject call.
class JSNotAnObject final : public JSNonFinalObject {
private:
    explicit JSNotAnObject(VM& vm)
        : JSNonFinalObject(vm, vm.notAnObjectStructure.get())
    {
    }

public:
    typedef JSNonFinalObject Base;
    static const unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal | OverridesGetOwnPropertySlot | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | OverridesGetPropertyNames;

    static JSNotAnObject* create(VM& vm)
    {
        JSNotAnObject* object = new (NotNull, allocateCell<JSNotAnObject>(vm.heap)) JSNotAnObject(vm);
        object->finishCreation(vm);
        return object;
    }

    static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
    {
        return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
    }

    DECLARE_INFO;

private:
    // JSValue methods
    static JSValue defaultValue(const JSObject*, ExecState*, PreferredPrimitiveType);

    // JSObject methods
    static bool getOwnPropertySlot(JSObject*, ExecState*, PropertyName, PropertySlot&);
    static bool getOwnPropertySlotByIndex(JSObject*, ExecState*, unsigned propertyName, PropertySlot&);

    static void put(JSCell*, ExecState*, PropertyName, JSValue, PutPropertySlot&);
    static void putByIndex(JSCell*, ExecState*, unsigned propertyName, JSValue, bool shouldThrow);

    static bool deleteProperty(JSCell*, ExecState*, PropertyName);
    static bool deletePropertyByIndex(JSCell*, ExecState*, unsigned propertyName);

    static void getOwnPropertyNames(JSObject*, ExecState*, PropertyNameArray&, EnumerationMode);
};

} // namespace JSC

#endif // JSNotAnObject_h