webkit/src/JavaScriptCore/runtime/ObjectConstructor.cpp - toolchain/benchmark - Git at Google

 /*
  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
  *  Copyright (C) 2008 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 "ObjectConstructor.h"

 #include "Error.h"
 #include "JSFunction.h"
 #include "JSArray.h"
 #include "JSGlobalObject.h"
 #include "ObjectPrototype.h"
 #include "PropertyDescriptor.h"
 #include "PropertyNameArray.h"
 #include "PrototypeFunction.h"

 namespace JSC {

 ASSERT_CLASS_FITS_IN_CELL(ObjectConstructor);

 static JSValue JSC_HOST_CALL objectConstructorGetPrototypeOf(ExecState*, JSObject*, JSValue, const ArgList&);
 static JSValue JSC_HOST_CALL objectConstructorGetOwnPropertyDescriptor(ExecState*, JSObject*, JSValue, const ArgList&);
 static JSValue JSC_HOST_CALL objectConstructorKeys(ExecState*, JSObject*, JSValue, const ArgList&);
 static JSValue JSC_HOST_CALL objectConstructorDefineProperty(ExecState*, JSObject*, JSValue, const ArgList&);
 static JSValue JSC_HOST_CALL objectConstructorDefineProperties(ExecState*, JSObject*, JSValue, const ArgList&);
 static JSValue JSC_HOST_CALL objectConstructorCreate(ExecState*, JSObject*, JSValue, const ArgList&);

 ObjectConstructor::ObjectConstructor(ExecState* exec, NonNullPassRefPtr<Structure> structure, ObjectPrototype* objectPrototype, Structure* prototypeFunctionStructure)
 : InternalFunction(&exec->globalData(), structure, Identifier(exec, "Object"))
 {
     // ECMA 15.2.3.1
     putDirectWithoutTransition(exec->propertyNames().prototype, objectPrototype, DontEnum | DontDelete | ReadOnly);

     // no. of arguments for constructor
     putDirectWithoutTransition(exec->propertyNames().length, jsNumber(exec, 1), ReadOnly | DontEnum | DontDelete);

     putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 1, exec->propertyNames().getPrototypeOf, objectConstructorGetPrototypeOf), DontEnum);
     putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 2, exec->propertyNames().getOwnPropertyDescriptor, objectConstructorGetOwnPropertyDescriptor), DontEnum);
     putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 1, exec->propertyNames().keys, objectConstructorKeys), DontEnum);
     putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 3, exec->propertyNames().defineProperty, objectConstructorDefineProperty), DontEnum);
     putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 2, exec->propertyNames().defineProperties, objectConstructorDefineProperties), DontEnum);
     putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 2, exec->propertyNames().create, objectConstructorCreate), DontEnum);
 }

 // ECMA 15.2.2
 static ALWAYS_INLINE JSObject* constructObject(ExecState* exec, const ArgList& args)
 {
     JSValue arg = args.at(0);
     if (arg.isUndefinedOrNull())
         return new (exec) JSObject(exec->lexicalGlobalObject()->emptyObjectStructure());
     return arg.toObject(exec);
 }

 static JSObject* constructWithObjectConstructor(ExecState* exec, JSObject*, const ArgList& args)
 {
     return constructObject(exec, args);
 }

 ConstructType ObjectConstructor::getConstructData(ConstructData& constructData)
 {
     constructData.native.function = constructWithObjectConstructor;
     return ConstructTypeHost;
 }

 static JSValue JSC_HOST_CALL callObjectConstructor(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     return constructObject(exec, args);
 }

 CallType ObjectConstructor::getCallData(CallData& callData)
 {
     callData.native.function = callObjectConstructor;
     return CallTypeHost;
 }

 JSValue JSC_HOST_CALL objectConstructorGetPrototypeOf(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     if (!args.at(0).isObject())
         return throwError(exec, TypeError, "Requested prototype of a value that is not an object.");
     return asObject(args.at(0))->prototype();
 }

 JSValue JSC_HOST_CALL objectConstructorGetOwnPropertyDescriptor(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     if (!args.at(0).isObject())
         return throwError(exec, TypeError, "Requested property descriptor of a value that is not an object.");
     UString propertyName = args.at(1).toString(exec);
     if (exec->hadException())
         return jsNull();
     JSObject* object = asObject(args.at(0));
     PropertyDescriptor descriptor;
     if (!object->getOwnPropertyDescriptor(exec, Identifier(exec, propertyName), descriptor))
         return jsUndefined();
     if (exec->hadException())
         return jsUndefined();

     JSObject* description = constructEmptyObject(exec);
     if (!descriptor.isAccessorDescriptor()) {
         description->putDirect(exec->propertyNames().value, descriptor.value() ? descriptor.value() : jsUndefined(), 0);
         description->putDirect(exec->propertyNames().writable, jsBoolean(descriptor.writable()), 0);
     } else {
         description->putDirect(exec->propertyNames().get, descriptor.getter() ? descriptor.getter() : jsUndefined(), 0);
         description->putDirect(exec->propertyNames().set, descriptor.setter() ? descriptor.setter() : jsUndefined(), 0);
     }

     description->putDirect(exec->propertyNames().enumerable, jsBoolean(descriptor.enumerable()), 0);
     description->putDirect(exec->propertyNames().configurable, jsBoolean(descriptor.configurable()), 0);

     return description;
 }

 // FIXME: Use the enumeration cache.
 JSValue JSC_HOST_CALL objectConstructorKeys(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     if (!args.at(0).isObject())
         return throwError(exec, TypeError, "Requested keys of a value that is not an object.");
     PropertyNameArray properties(exec);
     asObject(args.at(0))->getOwnPropertyNames(exec, properties);
     JSArray* keys = constructEmptyArray(exec);
     size_t numProperties = properties.size();
     for (size_t i = 0; i < numProperties; i++)
         keys->push(exec, jsOwnedString(exec, properties[i].ustring()));
     return keys;
 }

 // ES5 8.10.5 ToPropertyDescriptor
 static bool toPropertyDescriptor(ExecState* exec, JSValue in, PropertyDescriptor& desc)
 {
     if (!in.isObject()) {
         throwError(exec, TypeError, "Property description must be an object.");
         return false;
     }
     JSObject* description = asObject(in);

     PropertySlot enumerableSlot;
     if (description->getPropertySlot(exec, exec->propertyNames().enumerable, enumerableSlot)) {
         desc.setEnumerable(enumerableSlot.getValue(exec, exec->propertyNames().enumerable).toBoolean(exec));
         if (exec->hadException())
             return false;
     }

     PropertySlot configurableSlot;
     if (description->getPropertySlot(exec, exec->propertyNames().configurable, configurableSlot)) {
         desc.setConfigurable(configurableSlot.getValue(exec, exec->propertyNames().configurable).toBoolean(exec));
         if (exec->hadException())
             return false;
     }

     JSValue value;
     PropertySlot valueSlot;
     if (description->getPropertySlot(exec, exec->propertyNames().value, valueSlot)) {
         desc.setValue(valueSlot.getValue(exec, exec->propertyNames().value));
         if (exec->hadException())
             return false;
     }

     PropertySlot writableSlot;
     if (description->getPropertySlot(exec, exec->propertyNames().writable, writableSlot)) {
         desc.setWritable(writableSlot.getValue(exec, exec->propertyNames().writable).toBoolean(exec));
         if (exec->hadException())
             return false;
     }

     PropertySlot getSlot;
     if (description->getPropertySlot(exec, exec->propertyNames().get, getSlot)) {
         JSValue get = getSlot.getValue(exec, exec->propertyNames().get);
         if (exec->hadException())
             return false;
         if (!get.isUndefined()) {
             CallData callData;
             if (get.getCallData(callData) == CallTypeNone) {
                 throwError(exec, TypeError, "Getter must be a function.");
                 return false;
             }
         } else
             get = JSValue();
         desc.setGetter(get);
     }

     PropertySlot setSlot;
     if (description->getPropertySlot(exec, exec->propertyNames().set, setSlot)) {
         JSValue set = setSlot.getValue(exec, exec->propertyNames().set);
         if (exec->hadException())
             return false;
         if (!set.isUndefined()) {
             CallData callData;
             if (set.getCallData(callData) == CallTypeNone) {
                 throwError(exec, TypeError, "Setter must be a function.");
                 return false;
             }
         } else
             set = JSValue();

         desc.setSetter(set);
     }

     if (!desc.isAccessorDescriptor())
         return true;

     if (desc.value()) {
         throwError(exec, TypeError, "Invalid property.  'value' present on property with getter or setter.");
         return false;
     }

     if (desc.writablePresent()) {
         throwError(exec, TypeError, "Invalid property.  'writable' present on property with getter or setter.");
         return false;
     }
     return true;
 }

 JSValue JSC_HOST_CALL objectConstructorDefineProperty(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     if (!args.at(0).isObject())
         return throwError(exec, TypeError, "Properties can only be defined on Objects.");
     JSObject* O = asObject(args.at(0));
     UString propertyName = args.at(1).toString(exec);
     if (exec->hadException())
         return jsNull();
     PropertyDescriptor descriptor;
     if (!toPropertyDescriptor(exec, args.at(2), descriptor))
         return jsNull();
     ASSERT((descriptor.attributes() & (Getter | Setter)) || (!descriptor.isAccessorDescriptor()));
     ASSERT(!exec->hadException());
     O->defineOwnProperty(exec, Identifier(exec, propertyName), descriptor, true);
     return O;
 }

 static JSValue defineProperties(ExecState* exec, JSObject* object, JSObject* properties)
 {
     PropertyNameArray propertyNames(exec);
     asObject(properties)->getOwnPropertyNames(exec, propertyNames);
     size_t numProperties = propertyNames.size();
     Vector<PropertyDescriptor> descriptors;
     MarkedArgumentBuffer markBuffer;
     for (size_t i = 0; i < numProperties; i++) {
         PropertySlot slot;
         JSValue prop = properties->get(exec, propertyNames[i]);
         if (exec->hadException())
             return jsNull();
         PropertyDescriptor descriptor;
         if (!toPropertyDescriptor(exec, prop, descriptor))
             return jsNull();
         descriptors.append(descriptor);
         // Ensure we mark all the values that we're accumulating
         if (descriptor.isDataDescriptor() && descriptor.value())
             markBuffer.append(descriptor.value());
         if (descriptor.isAccessorDescriptor()) {
             if (descriptor.getter())
                 markBuffer.append(descriptor.getter());
             if (descriptor.setter())
                 markBuffer.append(descriptor.setter());
         }
     }
     for (size_t i = 0; i < numProperties; i++) {
         object->defineOwnProperty(exec, propertyNames[i], descriptors[i], true);
         if (exec->hadException())
             return jsNull();
     }
     return object;
 }

 JSValue JSC_HOST_CALL objectConstructorDefineProperties(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     if (!args.at(0).isObject())
         return throwError(exec, TypeError, "Properties can only be defined on Objects.");
     if (!args.at(1).isObject())
         return throwError(exec, TypeError, "Property descriptor list must be an Object.");
     return defineProperties(exec, asObject(args.at(0)), asObject(args.at(1)));
 }

 JSValue JSC_HOST_CALL objectConstructorCreate(ExecState* exec, JSObject*, JSValue, const ArgList& args)
 {
     if (!args.at(0).isObject() && !args.at(0).isNull())
         return throwError(exec, TypeError, "Object prototype may only be an Object or null.");
     JSObject* newObject = constructEmptyObject(exec);
     newObject->setPrototype(args.at(0));
     if (args.at(1).isUndefined())
         return newObject;
     if (!args.at(1).isObject())
         return throwError(exec, TypeError, "Property descriptor list must be an Object.");
     return defineProperties(exec, newObject, asObject(args.at(1)));
 }

 } // namespace JSC
	/*
	* Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
	* Copyright (C) 2008 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 "ObjectConstructor.h"

	#include "Error.h"
	#include "JSFunction.h"
	#include "JSArray.h"
	#include "JSGlobalObject.h"
	#include "ObjectPrototype.h"
	#include "PropertyDescriptor.h"
	#include "PropertyNameArray.h"
	#include "PrototypeFunction.h"

	namespace JSC {

	ASSERT_CLASS_FITS_IN_CELL(ObjectConstructor);

	static JSValue JSC_HOST_CALL objectConstructorGetPrototypeOf(ExecState, JSObject, JSValue, const ArgList&);
	static JSValue JSC_HOST_CALL objectConstructorGetOwnPropertyDescriptor(ExecState, JSObject, JSValue, const ArgList&);
	static JSValue JSC_HOST_CALL objectConstructorKeys(ExecState, JSObject, JSValue, const ArgList&);
	static JSValue JSC_HOST_CALL objectConstructorDefineProperty(ExecState, JSObject, JSValue, const ArgList&);
	static JSValue JSC_HOST_CALL objectConstructorDefineProperties(ExecState, JSObject, JSValue, const ArgList&);
	static JSValue JSC_HOST_CALL objectConstructorCreate(ExecState, JSObject, JSValue, const ArgList&);

	ObjectConstructor::ObjectConstructor(ExecState* exec, NonNullPassRefPtr<Structure> structure, ObjectPrototype* objectPrototype, Structure* prototypeFunctionStructure)
	: InternalFunction(&exec->globalData(), structure, Identifier(exec, "Object"))
	{
	// ECMA 15.2.3.1
	putDirectWithoutTransition(exec->propertyNames().prototype, objectPrototype, DontEnum \| DontDelete \| ReadOnly);

	// no. of arguments for constructor
	putDirectWithoutTransition(exec->propertyNames().length, jsNumber(exec, 1), ReadOnly \| DontEnum \| DontDelete);

	putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 1, exec->propertyNames().getPrototypeOf, objectConstructorGetPrototypeOf), DontEnum);
	putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 2, exec->propertyNames().getOwnPropertyDescriptor, objectConstructorGetOwnPropertyDescriptor), DontEnum);
	putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 1, exec->propertyNames().keys, objectConstructorKeys), DontEnum);
	putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 3, exec->propertyNames().defineProperty, objectConstructorDefineProperty), DontEnum);
	putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 2, exec->propertyNames().defineProperties, objectConstructorDefineProperties), DontEnum);
	putDirectFunctionWithoutTransition(exec, new (exec) NativeFunctionWrapper(exec, prototypeFunctionStructure, 2, exec->propertyNames().create, objectConstructorCreate), DontEnum);
	}

	// ECMA 15.2.2
	static ALWAYS_INLINE JSObject* constructObject(ExecState* exec, const ArgList& args)
	{
	JSValue arg = args.at(0);
	if (arg.isUndefinedOrNull())
	return new (exec) JSObject(exec->lexicalGlobalObject()->emptyObjectStructure());
	return arg.toObject(exec);
	}

	static JSObject* constructWithObjectConstructor(ExecState* exec, JSObject*, const ArgList& args)
	{
	return constructObject(exec, args);
	}

	ConstructType ObjectConstructor::getConstructData(ConstructData& constructData)
	{
	constructData.native.function = constructWithObjectConstructor;
	return ConstructTypeHost;
	}

	static JSValue JSC_HOST_CALL callObjectConstructor(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	return constructObject(exec, args);
	}

	CallType ObjectConstructor::getCallData(CallData& callData)
	{
	callData.native.function = callObjectConstructor;
	return CallTypeHost;
	}

	JSValue JSC_HOST_CALL objectConstructorGetPrototypeOf(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	if (!args.at(0).isObject())
	return throwError(exec, TypeError, "Requested prototype of a value that is not an object.");
	return asObject(args.at(0))->prototype();
	}

	JSValue JSC_HOST_CALL objectConstructorGetOwnPropertyDescriptor(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	if (!args.at(0).isObject())
	return throwError(exec, TypeError, "Requested property descriptor of a value that is not an object.");
	UString propertyName = args.at(1).toString(exec);
	if (exec->hadException())
	return jsNull();
	JSObject* object = asObject(args.at(0));
	PropertyDescriptor descriptor;
	if (!object->getOwnPropertyDescriptor(exec, Identifier(exec, propertyName), descriptor))
	return jsUndefined();
	if (exec->hadException())
	return jsUndefined();

	JSObject* description = constructEmptyObject(exec);
	if (!descriptor.isAccessorDescriptor()) {
	description->putDirect(exec->propertyNames().value, descriptor.value() ? descriptor.value() : jsUndefined(), 0);
	description->putDirect(exec->propertyNames().writable, jsBoolean(descriptor.writable()), 0);
	} else {
	description->putDirect(exec->propertyNames().get, descriptor.getter() ? descriptor.getter() : jsUndefined(), 0);
	description->putDirect(exec->propertyNames().set, descriptor.setter() ? descriptor.setter() : jsUndefined(), 0);
	}

	description->putDirect(exec->propertyNames().enumerable, jsBoolean(descriptor.enumerable()), 0);
	description->putDirect(exec->propertyNames().configurable, jsBoolean(descriptor.configurable()), 0);

	return description;
	}

	// FIXME: Use the enumeration cache.
	JSValue JSC_HOST_CALL objectConstructorKeys(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	if (!args.at(0).isObject())
	return throwError(exec, TypeError, "Requested keys of a value that is not an object.");
	PropertyNameArray properties(exec);
	asObject(args.at(0))->getOwnPropertyNames(exec, properties);
	JSArray* keys = constructEmptyArray(exec);
	size_t numProperties = properties.size();
	for (size_t i = 0; i < numProperties; i++)
	keys->push(exec, jsOwnedString(exec, properties[i].ustring()));
	return keys;
	}

	// ES5 8.10.5 ToPropertyDescriptor
	static bool toPropertyDescriptor(ExecState* exec, JSValue in, PropertyDescriptor& desc)
	{
	if (!in.isObject()) {
	throwError(exec, TypeError, "Property description must be an object.");
	return false;
	}
	JSObject* description = asObject(in);

	PropertySlot enumerableSlot;
	if (description->getPropertySlot(exec, exec->propertyNames().enumerable, enumerableSlot)) {
	desc.setEnumerable(enumerableSlot.getValue(exec, exec->propertyNames().enumerable).toBoolean(exec));
	if (exec->hadException())
	return false;
	}

	PropertySlot configurableSlot;
	if (description->getPropertySlot(exec, exec->propertyNames().configurable, configurableSlot)) {
	desc.setConfigurable(configurableSlot.getValue(exec, exec->propertyNames().configurable).toBoolean(exec));
	if (exec->hadException())
	return false;
	}

	JSValue value;
	PropertySlot valueSlot;
	if (description->getPropertySlot(exec, exec->propertyNames().value, valueSlot)) {
	desc.setValue(valueSlot.getValue(exec, exec->propertyNames().value));
	if (exec->hadException())
	return false;
	}

	PropertySlot writableSlot;
	if (description->getPropertySlot(exec, exec->propertyNames().writable, writableSlot)) {
	desc.setWritable(writableSlot.getValue(exec, exec->propertyNames().writable).toBoolean(exec));
	if (exec->hadException())
	return false;
	}

	PropertySlot getSlot;
	if (description->getPropertySlot(exec, exec->propertyNames().get, getSlot)) {
	JSValue get = getSlot.getValue(exec, exec->propertyNames().get);
	if (exec->hadException())
	return false;
	if (!get.isUndefined()) {
	CallData callData;
	if (get.getCallData(callData) == CallTypeNone) {
	throwError(exec, TypeError, "Getter must be a function.");
	return false;
	}
	} else
	get = JSValue();
	desc.setGetter(get);
	}

	PropertySlot setSlot;
	if (description->getPropertySlot(exec, exec->propertyNames().set, setSlot)) {
	JSValue set = setSlot.getValue(exec, exec->propertyNames().set);
	if (exec->hadException())
	return false;
	if (!set.isUndefined()) {
	CallData callData;
	if (set.getCallData(callData) == CallTypeNone) {
	throwError(exec, TypeError, "Setter must be a function.");
	return false;
	}
	} else
	set = JSValue();

	desc.setSetter(set);
	}

	if (!desc.isAccessorDescriptor())
	return true;

	if (desc.value()) {
	throwError(exec, TypeError, "Invalid property. 'value' present on property with getter or setter.");
	return false;
	}

	if (desc.writablePresent()) {
	throwError(exec, TypeError, "Invalid property. 'writable' present on property with getter or setter.");
	return false;
	}
	return true;
	}

	JSValue JSC_HOST_CALL objectConstructorDefineProperty(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	if (!args.at(0).isObject())
	return throwError(exec, TypeError, "Properties can only be defined on Objects.");
	JSObject* O = asObject(args.at(0));
	UString propertyName = args.at(1).toString(exec);
	if (exec->hadException())
	return jsNull();
	PropertyDescriptor descriptor;
	if (!toPropertyDescriptor(exec, args.at(2), descriptor))
	return jsNull();
	ASSERT((descriptor.attributes() & (Getter \| Setter)) \|\| (!descriptor.isAccessorDescriptor()));
	ASSERT(!exec->hadException());
	O->defineOwnProperty(exec, Identifier(exec, propertyName), descriptor, true);
	return O;
	}

	static JSValue defineProperties(ExecState* exec, JSObject* object, JSObject* properties)
	{
	PropertyNameArray propertyNames(exec);
	asObject(properties)->getOwnPropertyNames(exec, propertyNames);
	size_t numProperties = propertyNames.size();
	Vector<PropertyDescriptor> descriptors;
	MarkedArgumentBuffer markBuffer;
	for (size_t i = 0; i < numProperties; i++) {
	PropertySlot slot;
	JSValue prop = properties->get(exec, propertyNames[i]);
	if (exec->hadException())
	return jsNull();
	PropertyDescriptor descriptor;
	if (!toPropertyDescriptor(exec, prop, descriptor))
	return jsNull();
	descriptors.append(descriptor);
	// Ensure we mark all the values that we're accumulating
	if (descriptor.isDataDescriptor() && descriptor.value())
	markBuffer.append(descriptor.value());
	if (descriptor.isAccessorDescriptor()) {
	if (descriptor.getter())
	markBuffer.append(descriptor.getter());
	if (descriptor.setter())
	markBuffer.append(descriptor.setter());
	}
	}
	for (size_t i = 0; i < numProperties; i++) {
	object->defineOwnProperty(exec, propertyNames[i], descriptors[i], true);
	if (exec->hadException())
	return jsNull();
	}
	return object;
	}

	JSValue JSC_HOST_CALL objectConstructorDefineProperties(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	if (!args.at(0).isObject())
	return throwError(exec, TypeError, "Properties can only be defined on Objects.");
	if (!args.at(1).isObject())
	return throwError(exec, TypeError, "Property descriptor list must be an Object.");
	return defineProperties(exec, asObject(args.at(0)), asObject(args.at(1)));
	}

	JSValue JSC_HOST_CALL objectConstructorCreate(ExecState* exec, JSObject*, JSValue, const ArgList& args)
	{
	if (!args.at(0).isObject() && !args.at(0).isNull())
	return throwError(exec, TypeError, "Object prototype may only be an Object or null.");
	JSObject* newObject = constructEmptyObject(exec);
	newObject->setPrototype(args.at(0));
	if (args.at(1).isUndefined())
	return newObject;
	if (!args.at(1).isObject())
	return throwError(exec, TypeError, "Property descriptor list must be an Object.");
	return defineProperties(exec, newObject, asObject(args.at(1)));
	}

	} // namespace JSC