Source/JavaScriptCore/runtime/ObjectPrototype.cpp - third_party/webkit - Git at Google

 /*
  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  *  Copyright (C) 2008, 2011, 2016 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
  *
  *  You should have received a copy of the GNU Lesser General Public
  *  License along with this library; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */

 #include "config.h"
 #include "ObjectPrototype.h"

 #include "Error.h"
 #include "GetterSetter.h"
 #include "HasOwnPropertyCache.h"
 #include "JSFunction.h"
 #include "JSString.h"
 #include "JSCInlines.h"
 #include "PropertySlot.h"
 #include "StructureInlines.h"
 #include "StructureRareDataInlines.h"

 namespace JSC {

 static EncodedJSValue JSC_HOST_CALL objectProtoFuncValueOf(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(ExecState*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(ExecState*);

 STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(ObjectPrototype);

 const ClassInfo ObjectPrototype::s_info = { "Object", &JSNonFinalObject::s_info, 0, CREATE_METHOD_TABLE(ObjectPrototype) };

 ObjectPrototype::ObjectPrototype(VM& vm, Structure* stucture)
     : JSNonFinalObject(vm, stucture)
 {
 }

 void ObjectPrototype::finishCreation(VM& vm, JSGlobalObject* globalObject)
 {
     Base::finishCreation(vm);
     ASSERT(inherits(info()));
     vm.prototypeMap.addPrototype(this);

     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toString, objectProtoFuncToString, DontEnum, 0);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toLocaleString, objectProtoFuncToLocaleString, DontEnum, 0);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->valueOf, objectProtoFuncValueOf, DontEnum, 0);
     JSC_NATIVE_INTRINSIC_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->hasOwnProperty, objectProtoFuncHasOwnProperty, DontEnum, 1, HasOwnPropertyIntrinsic);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->propertyIsEnumerable, objectProtoFuncPropertyIsEnumerable, DontEnum, 1);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->isPrototypeOf, objectProtoFuncIsPrototypeOf, DontEnum, 1);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineGetter__, objectProtoFuncDefineGetter, DontEnum, 2);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineSetter__, objectProtoFuncDefineSetter, DontEnum, 2);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupGetter__, objectProtoFuncLookupGetter, DontEnum, 1);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupSetter__, objectProtoFuncLookupSetter, DontEnum, 1);
 }

 ObjectPrototype* ObjectPrototype::create(VM& vm, JSGlobalObject* globalObject, Structure* structure)
 {
     ObjectPrototype* prototype = new (NotNull, allocateCell<ObjectPrototype>(vm.heap)) ObjectPrototype(vm, structure);
     prototype->finishCreation(vm, globalObject);
     return prototype;
 }

 // ------------------------------ Functions --------------------------------

 EncodedJSValue JSC_HOST_CALL objectProtoFuncValueOf(ExecState* exec)
 {
     JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
     JSObject* valueObj = thisValue.toObject(exec);
     if (!valueObj)
         return JSValue::encode(JSValue());
     return JSValue::encode(valueObj);
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
     auto propertyName = exec->argument(0).toPropertyKey(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());
     JSObject* thisObject = thisValue.toObject(exec);
     if (UNLIKELY(!thisObject))
         return JSValue::encode(JSValue());

     Structure* structure = thisObject->structure(vm);
     HasOwnPropertyCache* hasOwnPropertyCache = vm.ensureHasOwnPropertyCache();
     if (Optional<bool> result = hasOwnPropertyCache->get(structure, propertyName)) {
         ASSERT(*result == thisObject->hasOwnProperty(exec, propertyName));
         ASSERT(!scope.exception());
         return JSValue::encode(jsBoolean(*result));
     }

     PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
     bool result = thisObject->hasOwnProperty(exec, propertyName, slot);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     hasOwnPropertyCache->tryAdd(vm, slot, thisObject, propertyName, result);
     return JSValue::encode(jsBoolean(result));
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
     JSObject* thisObj = thisValue.toObject(exec);
     if (!thisObj)
         return JSValue::encode(JSValue());

     if (!exec->argument(0).isObject())
         return JSValue::encode(jsBoolean(false));

     JSValue v = asObject(exec->argument(0))->getPrototype(vm, exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     while (true) {
         if (!v.isObject())
             return JSValue::encode(jsBoolean(false));
         if (v == thisObj)
             return JSValue::encode(jsBoolean(true));
         v = asObject(v)->getPrototype(vm, exec);
         RETURN_IF_EXCEPTION(scope, encodedJSValue());
     }
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     JSValue get = exec->argument(1);
     CallData callData;
     if (getCallData(get, callData) == CallType::None)
         return throwVMTypeError(exec, scope, ASCIILiteral("invalid getter usage"));

     auto propertyName = exec->argument(0).toPropertyKey(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     PropertyDescriptor descriptor;
     descriptor.setGetter(get);
     descriptor.setEnumerable(true);
     descriptor.setConfigurable(true);

     bool shouldThrow = true;
     thisObject->methodTable(vm)->defineOwnProperty(thisObject, exec, propertyName, descriptor, shouldThrow);

     return JSValue::encode(jsUndefined());
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     JSValue set = exec->argument(1);
     CallData callData;
     if (getCallData(set, callData) == CallType::None)
         return throwVMTypeError(exec, scope, ASCIILiteral("invalid setter usage"));

     auto propertyName = exec->argument(0).toPropertyKey(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     PropertyDescriptor descriptor;
     descriptor.setSetter(set);
     descriptor.setEnumerable(true);
     descriptor.setConfigurable(true);

     bool shouldThrow = true;
     thisObject->methodTable(vm)->defineOwnProperty(thisObject, exec, propertyName, descriptor, shouldThrow);

     return JSValue::encode(jsUndefined());
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     auto propertyName = exec->argument(0).toPropertyKey(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
     if (thisObject->getPropertySlot(exec, propertyName, slot)) {
         if (slot.isAccessor()) {
             GetterSetter* getterSetter = slot.getterSetter();
             return getterSetter->isGetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->getter());
         }
         if (slot.attributes() & CustomAccessor) {
             PropertyDescriptor descriptor;
             ASSERT(slot.slotBase());
             if (slot.slotBase()->getOwnPropertyDescriptor(exec, propertyName, descriptor))
                 return descriptor.getterPresent() ? JSValue::encode(descriptor.getter()) : JSValue::encode(jsUndefined());
         }
     }

     return JSValue::encode(jsUndefined());
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     auto propertyName = exec->argument(0).toPropertyKey(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
     if (thisObject->getPropertySlot(exec, propertyName, slot)) {
         if (slot.isAccessor()) {
             GetterSetter* getterSetter = slot.getterSetter();
             return getterSetter->isSetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->setter());
         }
         if (slot.attributes() & CustomAccessor) {
             PropertyDescriptor descriptor;
             ASSERT(slot.slotBase());
             if (slot.slotBase()->getOwnPropertyDescriptor(exec, propertyName, descriptor))
                 return descriptor.setterPresent() ? JSValue::encode(descriptor.setter()) : JSValue::encode(jsUndefined());
         }
     }

     return JSValue::encode(jsUndefined());
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     auto propertyName = exec->argument(0).toPropertyKey(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());
     PropertyDescriptor descriptor;
     bool enumerable = thisObject->getOwnPropertyDescriptor(exec, propertyName, descriptor) && descriptor.enumerable();
     return JSValue::encode(jsBoolean(enumerable));
 }

 // 15.2.4.3 Object.prototype.toLocaleString()
 EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     // 1. Let O be the result of calling ToObject passing the this value as the argument.
     JSObject* object = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     // 2. Let toString be the result of calling the [[Get]] internal method of O passing "toString" as the argument.
     JSValue toString = object->get(exec, exec->propertyNames().toString);

     // 3. If IsCallable(toString) is false, throw a TypeError exception.
     CallData callData;
     CallType callType = getCallData(toString, callData);
     if (callType == CallType::None)
         return JSValue::encode(jsUndefined());

     // 4. Return the result of calling the [[Call]] internal method of toString passing O as the this value and no arguments.
     return JSValue::encode(call(exec, toString, callType, callData, object, exec->emptyList()));
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncToString(ExecState* exec)
 {
     VM& vm = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
     if (thisValue.isUndefinedOrNull())
         return JSValue::encode(thisValue.isUndefined() ? vm.smallStrings.undefinedObjectString() : vm.smallStrings.nullObjectString());
     JSObject* thisObject = thisValue.toObject(exec);
     if (!thisObject)
         return JSValue::encode(jsUndefined());

     auto result = thisObject->structure(vm)->objectToStringValue();
     if (result)
         return JSValue::encode(result);

     PropertyName toStringTagSymbol = exec->propertyNames().toStringTagSymbol;
     return JSValue::encode(thisObject->getPropertySlot(exec, toStringTagSymbol, [&] (bool found, PropertySlot& toStringTagSlot) -> JSValue {
         if (found) {
             JSValue stringTag = toStringTagSlot.getValue(exec, toStringTagSymbol);
             RETURN_IF_EXCEPTION(scope, JSValue());
             if (stringTag.isString()) {
                 JSRopeString::RopeBuilder ropeBuilder(vm);
                 ropeBuilder.append(vm.smallStrings.objectStringStart());
                 ropeBuilder.append(jsCast<JSString*>(stringTag));
                 ropeBuilder.append(vm.smallStrings.singleCharacterString(']'));
                 JSString* result = ropeBuilder.release();

                 thisObject->structure(vm)->setObjectToStringValue(exec, vm, result, toStringTagSlot);
                 return result;
             }
         }

         String tag = thisObject->methodTable(exec->vm())->toStringName(thisObject, exec);
         RETURN_IF_EXCEPTION(scope, JSValue());
         String newString = WTF::tryMakeString("[object ", WTFMove(tag), "]");
         if (!newString)
             return throwOutOfMemoryError(exec, scope);

         auto result = jsNontrivialString(&vm, newString);
         thisObject->structure(vm)->setObjectToStringValue(exec, vm, result, toStringTagSlot);
         return result;
     }));
 }

 } // namespace JSC
	/*
	* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
	* Copyright (C) 2008, 2011, 2016 Apple Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*
	*/

	#include "config.h"
	#include "ObjectPrototype.h"

	#include "Error.h"
	#include "GetterSetter.h"
	#include "HasOwnPropertyCache.h"
	#include "JSFunction.h"
	#include "JSString.h"
	#include "JSCInlines.h"
	#include "PropertySlot.h"
	#include "StructureInlines.h"
	#include "StructureRareDataInlines.h"

	namespace JSC {

	static EncodedJSValue JSC_HOST_CALL objectProtoFuncValueOf(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(ExecState*);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(ExecState*);

	STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(ObjectPrototype);

	const ClassInfo ObjectPrototype::s_info = { "Object", &JSNonFinalObject::s_info, 0, CREATE_METHOD_TABLE(ObjectPrototype) };

	ObjectPrototype::ObjectPrototype(VM& vm, Structure* stucture)
	: JSNonFinalObject(vm, stucture)
	{
	}

	void ObjectPrototype::finishCreation(VM& vm, JSGlobalObject* globalObject)
	{
	Base::finishCreation(vm);
	ASSERT(inherits(info()));
	vm.prototypeMap.addPrototype(this);

	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toString, objectProtoFuncToString, DontEnum, 0);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toLocaleString, objectProtoFuncToLocaleString, DontEnum, 0);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->valueOf, objectProtoFuncValueOf, DontEnum, 0);
	JSC_NATIVE_INTRINSIC_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->hasOwnProperty, objectProtoFuncHasOwnProperty, DontEnum, 1, HasOwnPropertyIntrinsic);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->propertyIsEnumerable, objectProtoFuncPropertyIsEnumerable, DontEnum, 1);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->isPrototypeOf, objectProtoFuncIsPrototypeOf, DontEnum, 1);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineGetter__, objectProtoFuncDefineGetter, DontEnum, 2);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineSetter__, objectProtoFuncDefineSetter, DontEnum, 2);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupGetter__, objectProtoFuncLookupGetter, DontEnum, 1);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupSetter__, objectProtoFuncLookupSetter, DontEnum, 1);
	}

	ObjectPrototype* ObjectPrototype::create(VM& vm, JSGlobalObject* globalObject, Structure* structure)
	{
	ObjectPrototype* prototype = new (NotNull, allocateCell<ObjectPrototype>(vm.heap)) ObjectPrototype(vm, structure);
	prototype->finishCreation(vm, globalObject);
	return prototype;
	}

	// ------------------------------ Functions --------------------------------

	EncodedJSValue JSC_HOST_CALL objectProtoFuncValueOf(ExecState* exec)
	{
	JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
	JSObject* valueObj = thisValue.toObject(exec);
	if (!valueObj)
	return JSValue::encode(JSValue());
	return JSValue::encode(valueObj);
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
	auto propertyName = exec->argument(0).toPropertyKey(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());
	JSObject* thisObject = thisValue.toObject(exec);
	if (UNLIKELY(!thisObject))
	return JSValue::encode(JSValue());

	Structure* structure = thisObject->structure(vm);
	HasOwnPropertyCache* hasOwnPropertyCache = vm.ensureHasOwnPropertyCache();
	if (Optional<bool> result = hasOwnPropertyCache->get(structure, propertyName)) {
	ASSERT(*result == thisObject->hasOwnProperty(exec, propertyName));
	ASSERT(!scope.exception());
	return JSValue::encode(jsBoolean(*result));
	}

	PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
	bool result = thisObject->hasOwnProperty(exec, propertyName, slot);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	hasOwnPropertyCache->tryAdd(vm, slot, thisObject, propertyName, result);
	return JSValue::encode(jsBoolean(result));
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
	JSObject* thisObj = thisValue.toObject(exec);
	if (!thisObj)
	return JSValue::encode(JSValue());

	if (!exec->argument(0).isObject())
	return JSValue::encode(jsBoolean(false));

	JSValue v = asObject(exec->argument(0))->getPrototype(vm, exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	while (true) {
	if (!v.isObject())
	return JSValue::encode(jsBoolean(false));
	if (v == thisObj)
	return JSValue::encode(jsBoolean(true));
	v = asObject(v)->getPrototype(vm, exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());
	}
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	JSValue get = exec->argument(1);
	CallData callData;
	if (getCallData(get, callData) == CallType::None)
	return throwVMTypeError(exec, scope, ASCIILiteral("invalid getter usage"));

	auto propertyName = exec->argument(0).toPropertyKey(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	PropertyDescriptor descriptor;
	descriptor.setGetter(get);
	descriptor.setEnumerable(true);
	descriptor.setConfigurable(true);

	bool shouldThrow = true;
	thisObject->methodTable(vm)->defineOwnProperty(thisObject, exec, propertyName, descriptor, shouldThrow);

	return JSValue::encode(jsUndefined());
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	JSValue set = exec->argument(1);
	CallData callData;
	if (getCallData(set, callData) == CallType::None)
	return throwVMTypeError(exec, scope, ASCIILiteral("invalid setter usage"));

	auto propertyName = exec->argument(0).toPropertyKey(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	PropertyDescriptor descriptor;
	descriptor.setSetter(set);
	descriptor.setEnumerable(true);
	descriptor.setConfigurable(true);

	bool shouldThrow = true;
	thisObject->methodTable(vm)->defineOwnProperty(thisObject, exec, propertyName, descriptor, shouldThrow);

	return JSValue::encode(jsUndefined());
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	auto propertyName = exec->argument(0).toPropertyKey(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
	if (thisObject->getPropertySlot(exec, propertyName, slot)) {
	if (slot.isAccessor()) {
	GetterSetter* getterSetter = slot.getterSetter();
	return getterSetter->isGetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->getter());
	}
	if (slot.attributes() & CustomAccessor) {
	PropertyDescriptor descriptor;
	ASSERT(slot.slotBase());
	if (slot.slotBase()->getOwnPropertyDescriptor(exec, propertyName, descriptor))
	return descriptor.getterPresent() ? JSValue::encode(descriptor.getter()) : JSValue::encode(jsUndefined());
	}
	}

	return JSValue::encode(jsUndefined());
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	auto propertyName = exec->argument(0).toPropertyKey(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
	if (thisObject->getPropertySlot(exec, propertyName, slot)) {
	if (slot.isAccessor()) {
	GetterSetter* getterSetter = slot.getterSetter();
	return getterSetter->isSetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->setter());
	}
	if (slot.attributes() & CustomAccessor) {
	PropertyDescriptor descriptor;
	ASSERT(slot.slotBase());
	if (slot.slotBase()->getOwnPropertyDescriptor(exec, propertyName, descriptor))
	return descriptor.setterPresent() ? JSValue::encode(descriptor.setter()) : JSValue::encode(jsUndefined());
	}
	}

	return JSValue::encode(jsUndefined());
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	auto propertyName = exec->argument(0).toPropertyKey(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	JSObject* thisObject = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());
	PropertyDescriptor descriptor;
	bool enumerable = thisObject->getOwnPropertyDescriptor(exec, propertyName, descriptor) && descriptor.enumerable();
	return JSValue::encode(jsBoolean(enumerable));
	}

	// 15.2.4.3 Object.prototype.toLocaleString()
	EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	// 1. Let O be the result of calling ToObject passing the this value as the argument.
	JSObject* object = exec->thisValue().toThis(exec, StrictMode).toObject(exec);
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	// 2. Let toString be the result of calling the [[Get]] internal method of O passing "toString" as the argument.
	JSValue toString = object->get(exec, exec->propertyNames().toString);

	// 3. If IsCallable(toString) is false, throw a TypeError exception.
	CallData callData;
	CallType callType = getCallData(toString, callData);
	if (callType == CallType::None)
	return JSValue::encode(jsUndefined());

	// 4. Return the result of calling the [[Call]] internal method of toString passing O as the this value and no arguments.
	return JSValue::encode(call(exec, toString, callType, callData, object, exec->emptyList()));
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncToString(ExecState* exec)
	{
	VM& vm = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue thisValue = exec->thisValue().toThis(exec, StrictMode);
	if (thisValue.isUndefinedOrNull())
	return JSValue::encode(thisValue.isUndefined() ? vm.smallStrings.undefinedObjectString() : vm.smallStrings.nullObjectString());
	JSObject* thisObject = thisValue.toObject(exec);
	if (!thisObject)
	return JSValue::encode(jsUndefined());

	auto result = thisObject->structure(vm)->objectToStringValue();
	if (result)
	return JSValue::encode(result);

	PropertyName toStringTagSymbol = exec->propertyNames().toStringTagSymbol;
	return JSValue::encode(thisObject->getPropertySlot(exec, toStringTagSymbol, [&] (bool found, PropertySlot& toStringTagSlot) -> JSValue {
	if (found) {
	JSValue stringTag = toStringTagSlot.getValue(exec, toStringTagSymbol);
	RETURN_IF_EXCEPTION(scope, JSValue());
	if (stringTag.isString()) {
	JSRopeString::RopeBuilder ropeBuilder(vm);
	ropeBuilder.append(vm.smallStrings.objectStringStart());
	ropeBuilder.append(jsCast<JSString*>(stringTag));
	ropeBuilder.append(vm.smallStrings.singleCharacterString(']'));
	JSString* result = ropeBuilder.release();

	thisObject->structure(vm)->setObjectToStringValue(exec, vm, result, toStringTagSlot);
	return result;
	}
	}

	String tag = thisObject->methodTable(exec->vm())->toStringName(thisObject, exec);
	RETURN_IF_EXCEPTION(scope, JSValue());
	String newString = WTF::tryMakeString("[object ", WTFMove(tag), "]");
	if (!newString)
	return throwOutOfMemoryError(exec, scope);

	auto result = jsNontrivialString(&vm, newString);
	thisObject->structure(vm)->setObjectToStringValue(exec, vm, result, toStringTagSlot);
	return result;
	}));
	}

	} // namespace JSC