Source/JavaScriptCore/runtime/ObjectPrototype.cpp - WebKit - Git at Google

 /*
  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  *  Copyright (C) 2008-2019 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(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(JSGlobalObject*, CallFrame*);
 static EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(JSGlobalObject*, CallFrame*);

 STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(ObjectPrototype);

 const ClassInfo ObjectPrototype::s_info = { "Object", &JSNonFinalObject::s_info, nullptr, nullptr, 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(vm, info()));

     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toString, objectProtoFuncToString, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toLocaleString, objectProtoFuncToLocaleString, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->valueOf, objectProtoFuncValueOf, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
     JSC_NATIVE_INTRINSIC_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->hasOwnProperty, objectProtoFuncHasOwnProperty, static_cast<unsigned>(PropertyAttribute::DontEnum), 1, HasOwnPropertyIntrinsic);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->propertyIsEnumerable, objectProtoFuncPropertyIsEnumerable, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->isPrototypeOf, objectProtoFuncIsPrototypeOf, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineGetter__, objectProtoFuncDefineGetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 2);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineSetter__, objectProtoFuncDefineSetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 2);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupGetter__, objectProtoFuncLookupGetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
     JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupSetter__, objectProtoFuncLookupSetter, static_cast<unsigned>(PropertyAttribute::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(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     JSValue thisValue = callFrame->thisValue().toThis(globalObject, StrictMode);
     JSObject* valueObj = thisValue.toObject(globalObject);
     if (UNLIKELY(!valueObj))
         return encodedJSValue();
     return JSValue::encode(valueObj);
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

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

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

 EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue thisValue = callFrame->thisValue().toThis(globalObject, StrictMode);
     JSObject* thisObj = thisValue.toObject(globalObject);
     EXCEPTION_ASSERT(!!scope.exception() == !thisObj);
     if (UNLIKELY(!thisObj))
         return encodedJSValue();

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

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

 EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

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

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

     bool shouldThrow = true;
     scope.release();
     thisObject->methodTable(vm)->defineOwnProperty(thisObject, globalObject, propertyName, descriptor, shouldThrow);

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

 EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

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

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

     bool shouldThrow = true;
     scope.release();
     thisObject->methodTable(vm)->defineOwnProperty(thisObject, globalObject, propertyName, descriptor, shouldThrow);

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

 EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

     PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
     bool hasProperty = thisObject->getPropertySlot(globalObject, propertyName, slot);
     EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
     if (hasProperty) {
         if (slot.isAccessor()) {
             GetterSetter* getterSetter = slot.getterSetter();
             return getterSetter->isGetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->getter());
         }
         if (slot.attributes() & PropertyAttribute::CustomAccessor) {
             PropertyDescriptor descriptor;
             ASSERT(slot.slotBase());
             if (slot.slotBase()->getOwnPropertyDescriptor(globalObject, propertyName, descriptor))
                 return descriptor.getterPresent() ? JSValue::encode(descriptor.getter()) : JSValue::encode(jsUndefined());
         }
     }

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

 EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

     PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
     bool hasProperty = thisObject->getPropertySlot(globalObject, propertyName, slot);
     EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
     if (hasProperty) {
         if (slot.isAccessor()) {
             GetterSetter* getterSetter = slot.getterSetter();
             return getterSetter->isSetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->setter());
         }
         if (slot.attributes() & PropertyAttribute::CustomAccessor) {
             PropertyDescriptor descriptor;
             ASSERT(slot.slotBase());
             if (slot.slotBase()->getOwnPropertyDescriptor(globalObject, propertyName, descriptor))
                 return descriptor.setterPresent() ? JSValue::encode(descriptor.setter()) : JSValue::encode(jsUndefined());
         }
     }

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

 EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

     scope.release();
     PropertyDescriptor descriptor;
     bool enumerable = thisObject->getOwnPropertyDescriptor(globalObject, propertyName, descriptor) && descriptor.enumerable();
     return JSValue::encode(jsBoolean(enumerable));
 }

 // 15.2.4.3 Object.prototype.toLocaleString()
 EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     // 1. Let V be the this value.
     JSValue thisValue = callFrame->thisValue();

     // 2. Invoke(V, "toString")

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

     // Let toString be the O.[[Get]]("toString", V)
     PropertySlot slot(thisValue, PropertySlot::InternalMethodType::Get);
     bool hasProperty = object->getPropertySlot(globalObject, vm.propertyNames->toString, slot);
     EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
     JSValue toString = hasProperty ? slot.getValue(globalObject, vm.propertyNames->toString) : jsUndefined();
     RETURN_IF_EXCEPTION(scope, encodedJSValue());

     // If IsCallable(toString) is false, throw a TypeError exception.
     CallData callData;
     CallType callType = getCallData(vm, toString, callData);
     if (callType == CallType::None)
         return throwVMTypeError(globalObject, scope);

     // Return the result of calling the [[Call]] internal method of toString passing the this value and no arguments.
     RELEASE_AND_RETURN(scope, JSValue::encode(call(globalObject, toString, callType, callData, thisValue, *vm.emptyList)));
 }

 EncodedJSValue JSC_HOST_CALL objectProtoFuncToString(JSGlobalObject* globalObject, CallFrame* callFrame)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

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

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

     PropertyName toStringTagSymbol = vm.propertyNames->toStringTagSymbol;
     RELEASE_AND_RETURN(scope, JSValue::encode(thisObject->getPropertySlot(globalObject, toStringTagSymbol, [&] (bool found, PropertySlot& toStringTagSlot) -> JSValue {
         if (found) {
             JSValue stringTag = toStringTagSlot.getValue(globalObject, toStringTagSymbol);
             RETURN_IF_EXCEPTION(scope, { });
             if (stringTag.isString()) {
                 JSString* result = jsString(globalObject, vm.smallStrings.objectStringStart(), asString(stringTag), vm.smallStrings.singleCharacterString(']'));
                 RETURN_IF_EXCEPTION(scope, { });
                 thisObject->structure(vm)->setObjectToStringValue(globalObject, vm, result, toStringTagSlot);
                 return result;
             }
         }

         String tag = thisObject->methodTable(vm)->toStringName(thisObject, globalObject);
         RETURN_IF_EXCEPTION(scope, { });
         String newString = tryMakeString("[object ", WTFMove(tag), "]");
         if (!newString)
             return throwOutOfMemoryError(globalObject, scope);

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

 } // namespace JSC
	/*
	* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
	* Copyright (C) 2008-2019 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(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(JSGlobalObject, CallFrame);
	static EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(JSGlobalObject, CallFrame);

	STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(ObjectPrototype);

	const ClassInfo ObjectPrototype::s_info = { "Object", &JSNonFinalObject::s_info, nullptr, nullptr, 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(vm, info()));

	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toString, objectProtoFuncToString, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toLocaleString, objectProtoFuncToLocaleString, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->valueOf, objectProtoFuncValueOf, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
	JSC_NATIVE_INTRINSIC_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->hasOwnProperty, objectProtoFuncHasOwnProperty, static_cast<unsigned>(PropertyAttribute::DontEnum), 1, HasOwnPropertyIntrinsic);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->propertyIsEnumerable, objectProtoFuncPropertyIsEnumerable, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->isPrototypeOf, objectProtoFuncIsPrototypeOf, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineGetter__, objectProtoFuncDefineGetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 2);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineSetter__, objectProtoFuncDefineSetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 2);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupGetter__, objectProtoFuncLookupGetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
	JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupSetter__, objectProtoFuncLookupSetter, static_cast<unsigned>(PropertyAttribute::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(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	JSValue thisValue = callFrame->thisValue().toThis(globalObject, StrictMode);
	JSObject* valueObj = thisValue.toObject(globalObject);
	if (UNLIKELY(!valueObj))
	return encodedJSValue();
	return JSValue::encode(valueObj);
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncHasOwnProperty(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

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

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

	EncodedJSValue JSC_HOST_CALL objectProtoFuncIsPrototypeOf(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue thisValue = callFrame->thisValue().toThis(globalObject, StrictMode);
	JSObject* thisObj = thisValue.toObject(globalObject);
	EXCEPTION_ASSERT(!!scope.exception() == !thisObj);
	if (UNLIKELY(!thisObj))
	return encodedJSValue();

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

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

	EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineGetter(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

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

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

	bool shouldThrow = true;
	scope.release();
	thisObject->methodTable(vm)->defineOwnProperty(thisObject, globalObject, propertyName, descriptor, shouldThrow);

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

	EncodedJSValue JSC_HOST_CALL objectProtoFuncDefineSetter(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

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

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

	bool shouldThrow = true;
	scope.release();
	thisObject->methodTable(vm)->defineOwnProperty(thisObject, globalObject, propertyName, descriptor, shouldThrow);

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

	EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupGetter(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

	PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
	bool hasProperty = thisObject->getPropertySlot(globalObject, propertyName, slot);
	EXCEPTION_ASSERT(!scope.exception() \|\| !hasProperty);
	if (hasProperty) {
	if (slot.isAccessor()) {
	GetterSetter* getterSetter = slot.getterSetter();
	return getterSetter->isGetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->getter());
	}
	if (slot.attributes() & PropertyAttribute::CustomAccessor) {
	PropertyDescriptor descriptor;
	ASSERT(slot.slotBase());
	if (slot.slotBase()->getOwnPropertyDescriptor(globalObject, propertyName, descriptor))
	return descriptor.getterPresent() ? JSValue::encode(descriptor.getter()) : JSValue::encode(jsUndefined());
	}
	}

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

	EncodedJSValue JSC_HOST_CALL objectProtoFuncLookupSetter(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

	PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
	bool hasProperty = thisObject->getPropertySlot(globalObject, propertyName, slot);
	EXCEPTION_ASSERT(!scope.exception() \|\| !hasProperty);
	if (hasProperty) {
	if (slot.isAccessor()) {
	GetterSetter* getterSetter = slot.getterSetter();
	return getterSetter->isSetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->setter());
	}
	if (slot.attributes() & PropertyAttribute::CustomAccessor) {
	PropertyDescriptor descriptor;
	ASSERT(slot.slotBase());
	if (slot.slotBase()->getOwnPropertyDescriptor(globalObject, propertyName, descriptor))
	return descriptor.setterPresent() ? JSValue::encode(descriptor.setter()) : JSValue::encode(jsUndefined());
	}
	}

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

	EncodedJSValue JSC_HOST_CALL objectProtoFuncPropertyIsEnumerable(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

	scope.release();
	PropertyDescriptor descriptor;
	bool enumerable = thisObject->getOwnPropertyDescriptor(globalObject, propertyName, descriptor) && descriptor.enumerable();
	return JSValue::encode(jsBoolean(enumerable));
	}

	// 15.2.4.3 Object.prototype.toLocaleString()
	EncodedJSValue JSC_HOST_CALL objectProtoFuncToLocaleString(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	// 1. Let V be the this value.
	JSValue thisValue = callFrame->thisValue();

	// 2. Invoke(V, "toString")

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

	// Let toString be the O.[[Get]]("toString", V)
	PropertySlot slot(thisValue, PropertySlot::InternalMethodType::Get);
	bool hasProperty = object->getPropertySlot(globalObject, vm.propertyNames->toString, slot);
	EXCEPTION_ASSERT(!scope.exception() \|\| !hasProperty);
	JSValue toString = hasProperty ? slot.getValue(globalObject, vm.propertyNames->toString) : jsUndefined();
	RETURN_IF_EXCEPTION(scope, encodedJSValue());

	// If IsCallable(toString) is false, throw a TypeError exception.
	CallData callData;
	CallType callType = getCallData(vm, toString, callData);
	if (callType == CallType::None)
	return throwVMTypeError(globalObject, scope);

	// Return the result of calling the [[Call]] internal method of toString passing the this value and no arguments.
	RELEASE_AND_RETURN(scope, JSValue::encode(call(globalObject, toString, callType, callData, thisValue, *vm.emptyList)));
	}

	EncodedJSValue JSC_HOST_CALL objectProtoFuncToString(JSGlobalObject* globalObject, CallFrame* callFrame)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

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

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

	PropertyName toStringTagSymbol = vm.propertyNames->toStringTagSymbol;
	RELEASE_AND_RETURN(scope, JSValue::encode(thisObject->getPropertySlot(globalObject, toStringTagSymbol, [&] (bool found, PropertySlot& toStringTagSlot) -> JSValue {
	if (found) {
	JSValue stringTag = toStringTagSlot.getValue(globalObject, toStringTagSymbol);
	RETURN_IF_EXCEPTION(scope, { });
	if (stringTag.isString()) {
	JSString* result = jsString(globalObject, vm.smallStrings.objectStringStart(), asString(stringTag), vm.smallStrings.singleCharacterString(']'));
	RETURN_IF_EXCEPTION(scope, { });
	thisObject->structure(vm)->setObjectToStringValue(globalObject, vm, result, toStringTagSlot);
	return result;
	}
	}

	String tag = thisObject->methodTable(vm)->toStringName(thisObject, globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	String newString = tryMakeString("[object ", WTFMove(tag), "]");
	if (!newString)
	return throwOutOfMemoryError(globalObject, scope);

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

	} // namespace JSC